title
stringlengths 0
1.13k
| abstract
stringlengths 1
15.7k
| PMID
int64 22
36.5M
|
|---|---|---|
The role of chromosomal proteins in the C-banding of Allium cepa chromosomes.
|
When chromosomes of Allium cepa are subjected to a C-banding procedure (incubation in saturated barium hydroxide followed by phosphate buffer at 60 degrees C for 1 h) and then treated with Giemsa stain, bands appear at the telomeres of all chromosomes. Microspectrophotometric measurements of Feulgen-DNA content, demonstrated that the C-banding procedure extracted DNA from the nuclei. Staining of banded chromosomes with several DNA-specific stains showed that this loss was differential, with the band DNA exhibiting more resistance to extraction than that of the rest of the chromosome. The C-banding procedure did not extract chromosomal proteins, however, and no difference in mass per unit length could be detected by Nomarski optics between band and interband regions. Several experiments demonstrated that chromosomal proteins play a significant role in C-banding. First, treatment of chromosomes with pronase before C-banding resulted in the elimination of differential staining with Giemsa. Furthermore, in preparations where the DNA was completely hydrolysed with hot TCA, the remaining chromosomal proteins were found to exhibit a differential affinity for Giemsa stain. Amido black staining demonstrated that total chromosomal protein was uniformly distributed after the hot TCA digestion, but the proteins localized in the telomeres had a greater affinity for the Giemsa stain than the bulk of the chromosomal proteins. When the TCA-digested chromosomes were subjected to the C-banding procedure before staining, the differential affinity of the telomeres for the Giemsa stain was lost. Thus, C-banding appears to be the result of a complex interaction between protein and DNA in which the greater resistance to extraction of the band DNA is necessary to stabilize and preserve chromatin protein which exhibits a differential affinity for Giemsa stain.
| 89,024
|
Immunochemical studies of beef pancreas tryptophanyl-tRNA synthetase and its fragments. Determination of the number of antigenic determinants and a comparison with tryptophanyl- tRNA synthetases from other sources and with reverse transcriptase from avian myeloblastosis virus.
|
The immunoglobulin G (IgG) fraction of the antiserum from rabbits immunized with homogeneous beef pancreas tryptophanyl-tRNA synthetase inhibits the enzyme activity in the reactions of both tRNATrp aminoacylation and tryptophan activation. Fab fragments of IgG act in a similar way. Common antigenic determinants have been detected in tryptophanyl-tRNA synthetases from beef, pig, chicken and rat livers using pure antibodies against beef pancreas tryptophanyl-tRNA synthetase. This observation indicates the evolutional stability of certain structural features of tryptophanyl-tRNA synthetases. The interaction of antibodies with the fragments of beef tryptophanyl-tRNA synthetase produced by endogenous and tryptic proteolysis of the enzyme has been studied. On third of the antiserum antibodies interacting with the C-terminal fragment of the enzyme (Mr approximately equal to 40000) inhibits its activity whereas the antibodies to the N-terminal fragment (Mr approximately equal to 20000) have no effect on the enzyme activity. The immunochemical identity of the two synthetase fragments differing in their enzymatic activity supports the assumption that the loss of enzymatic activity of the tryptic fragment is caused by lack of a small peptide which is retained in case of endogenous proteolysis; probably the amino acid residues of this peptide participate in formation of active centre of tryptophanyl-tRNA synthetase. A radioimmunochemical method is described for determining the number of antigenic determinants. One molecule of tryptophanyl-tRNA synthetase was found to bind 9 (+/- 1) molecules of Fab fragments. Antibodies against tryptophanyl-tRNA snythetase from beef pancreas do not inhibit noticeably the activity of reverse transcriptase from avian myeloblastosis virus. No antigenic determinants in common have been detected in reverse transcriptase and tryptophanyl-tRNA synthetase by radioimmunochemical assays.
| 89,031
|
[Determination of antigen structures of Pasteurella multocida: the preparation of vaccines].
|
The discovery of the role played by somatic antigens of the Pasteurella multocida A and D capsular types in the immunization of susceptible species makes it necessary to type the somatic antigens of the isolated strains prior to any action to induce active or passive immunity. Only immunoprecipitation in gel was chosen out of the various typing techniques proposed, and a correlation was established between the capsular types (according to Carter), somatic types (according to Namioka) and types determined by immunoprecipitation in gel (according to Heddleston). Parallel to this, the same technique was developed for strains of Pasteurella multocida B and E capsular types, and the immunogenicity of these capsular antigens was proven.
| 89,055
|
Trasylol prevents trypsin-induced shock in dogs.
|
The effect of simultaneous intravenous administration in the dog of bovine trypsin and Trasylol followed by continued infusion of Trasylol was studied. Special attention was paid to the interchange between the dominating plasma protease inhibitors alpha1-antitrypsin and a-macroglobulins and to the disappearance of Trasylol and its trypsin complexes from the circulation. The following results were obtained: 1) Trypsin was preferentially bound by the alpha-macroglobulins, though Trasylol is a strong trypsin inhibitor. 2) On saturation of the alpha-macroglobulins, a considerable amount of trypsin was bound by alpha1-antitrypsin. 3) Trasylol was bound to the trypsin-alpha-macroglobulin complexes and then rapidly eliminated from the circulation. 4) On saturation of the alpha-macroglobulins, Trasylol was identified in a free form but increasing amounts of Trasylol were also bound to trypsin. This could be explained not only by direct complexation of Trasylol and trypsin but also by a transfer of trypsin from unstable trypsin-alpha1-antitrypsin complexes to free Trasylol.
| 89,067
|
No exit: a symbolic interactionist perspective on aging.
|
Most research on socialization for old age, including that of Rosow, Neugarten, and Riley, reflects a normative bias. An alternative perspective on later life is put forth from the symbolic-interactionist tradition in sociology. The concepts of career and status passage reflect an imagery of humans capable of exercising choice and negotiating their way through life. Later life is seen as a unique status passage in that it is inevitable, irreversible, and does not lead to any subsequent status. Controlling the passage therefore assumes great importance.
| 89,097
|
Purification of a human prostate specific antigen.
|
Rabbit antiserum raised against the crude extract of normal human prostatic tissue contained antibodies to a prostatic tissue-specific antigen as shown by immunoprecipitation techniques. Using this antiserum a prostate antigen was detected in normal, benign hypertrophic, and malignant prostatic tissues, but not in other human tissues. The prostate antigen was purified to homogeneity from prostatic tissues and showed a single protein band on analytical polyacrylamide gel electrophoresis and isoelectric focusing. This report thus presents the first demonstration of the purification of a prostate-specific antigen that does not represent prostatic acid phosphatase.
| 89,106
|
Comparison of spontaneous and experimentally induced canine prostatic hyperplasia.
|
Spontaneous prostatic hyperplasia in the beagle appears to progress with age from a glandular to a cystic histological appearance. Prostatic hyperplasia can be induced in young beagles with intact testes by treatment for 4 mo with either dihydrotestosterone or 5 alpha-androstane-3 alpha, 17 beta-diol, alone, or with either of these steroids in combination with 17 beta-estradiol. In contrast, the induction of prostatic hyperplasia in young castrated beagles, in which the gland had been allowed to involute for 1 mo, requires the administration of both 17 beta-estradiol and either 5 alpha-androstane-3 alpha, 17 beta-diol or dihydrotestosterone. Testosterone and 17 beta-estradiol, either singly or in combination, did not produce the hyperplastic condition in intact or castrated beagles. The experimentally induced prostatic hyperplasia is identical in pathology to the glandular hyperplasia that occurs naturally in the aging dog with intact testes. However, cystic hyperplasia was not produced by any of the treatments tested in young animals.
| 89,121
|
Occult progressive renal damage in the elderly male due to benign prostatic hypertrophy.
|
A review of the case histories of 345 patients who underwent protatectomy showed that 1.7 percent (6 patients) had "occult and progessive renal damage" secondary to prostatic hypertrophy. All these men were over the age of 60 and the disturbances in micturition were so mild that the patients were unaware of, or chose to ignore them. The presenting symptoms were nonspecific and included generalized weakness, anorexia, nausea, constipation, and weight loss. Investigation revealed impaired renal function of varying degrees. Prostatectomy was associated with a dramatic improvement in all 6 patients. Physicians should be aware of the clinical entity of occult and progressive renal damage secondary to obstruction of the bladder outlet, especially in the elderly male. Uremia can develop with minimal urinary symptoms. Elderly men often suppress or deny their symptoms because of the fear of operation.
| 89,133
|
Hospitalization of the elderly patient for acute illness.
|
There is a paucity of studies on the characteristics of elderly patients who are admitted for treatment of acute disorders, even though their utilization of hospitals is high. This study involved 828 older persons admitted to a general hospital during a period of six months, for the treatment of acute illness. The typical patient appeared to be a woman in her 70's who entered the medical department because of a cardiovascular or a gastrointestinal disturbance, stayed no longer than 10 days, and returned home to live with her spouse. Though such a person apparently needed minimal assistance in readjusting successfully to the community, there were some exceptions, especially among those who had been living alone or with persons other than a spouse. There was minimal utilization of professional services that might help to assure an optimal post-hospital readjustment.
| 89,134
|
Neurotoxic effects of leptophos (PhosvelR) in chickens and rats following chronic low-level feeding.
|
Leptophos (O-[4-bromo-2,5 dichlorophenyl] O-methyl phenylphosphonothioate) (PhosvelR) was administered orally to chickens and rats in doses of 0.5 and 5.0 mg/kg/day for 26 weeks. Hens fed 5.0 mg/kg, except one, showed ataxia and became paralysed in the legs at varying times from 8 to 19 weeks. A fifth hen showed ataxia early in the experiment but recovered fully for the remainder of the experiment. Rats fed both doses and chickens fed 0.5 mg/kg showed no signs of delayed neurotoxicity. All hens fed 5.0 mg/kg stopped laying by about the third week. Animals of both species fed 5.0 mg/kg either lost weight (chickens) or gained less weight (rats) than the others. Erythrocyte acetylcholinesterase (AChE) of the chickens given both doses was significantly depressed at first, then increased, and later dropped to control levels. AChE of rats fed 0.5 mg/kg was significantly inhibited but soon recovered to within control levels. On the other hand, the AChE of rats fed 5.0 mg/kg was inhibited throughout the experiment. Plasma cholinesterase (ChE) of both species was first inhibited and then recovered erratically for both insecticide concentrations. Histological alterations in the spinal cord of paralysed hens included axon and myelin degeneration in the ventral, lateral and posterior columns. In the paralysed hens, 79% of the neurotoxic esterase in the brain were inhibited, whereas in the non-paralysed hens (including the one non-paralysed hen receiving 5.0 mg/kg/day) and all rats only about half as much was inhibited.
| 89,138
|
A method for specifically detecting internal immunoglobulin by immunofluorescence.
|
The detection of specifically internal immunoglobulin by staining of fixed preparations of lymphoid cells with appropriate fluorescein-conjugated antisera can be hampered by binding of the conjugates to membrane-bound immunoglobulin. Without preventing staining through membrane-bound immunoglobulin, it is impossible to be sure whether lightly stained cells contain only small amounts of immunoglobulin or wehter the staining is entirely due to the membrane-bound material. Surface immunoglobulin can be stripped from tonsil cells prior to making preparation, and this can be achieved without loss of viable cells. As compared with untreated preparations, pronase-stripped smears contain little non-cellular debris and greatly reduced numbers of small lymphocytes faintly stained by polyvalent anti-human immunoglobulin. The remaining stained cells can be said to specifically contain internal immunoglobulin and are easily scored.
| 89,170
|
Acid fast staining of oxidized neuromelanin and lipofuscin in the human brain.
|
Acid fast staining of the bleached residuum of substantia nigra neuromelanin and of oxidized inferior olive lipofuscin was demonstrated in paraffin and frozen sections stained with the acetic acid, carbol fuchsin method of Barbeito-Lopez and the aldehyde fuchsin method of Gomori. Acid fast staining occurred when sections were exposed to a prestain oxidation with potassium permanganate in conjunction with a poststain differentiation with dilute hydrochloric acid. The acid fast staining with acetic acid, carbol fuchsin was differentiable and in contrast to the acid fast staining with aldehyde fuchsin which was nondifferentiable. A possible histochemical basis for differentiable and nondifferentiable acid fast staining was discussed. The identify of the bleached residuum of neuromelanin as lipofuscin was also discussed.
| 89,189
|
[State of the heart conduction system in the sick sinus syndrome (according to the recording of the bundle of His potentials and the atrial stimulation test)].
|
It was established that the presence of Samoilov-Wenckebach's periods and prolongation of the H--V interval at low frequency of the imposed rhythm as well as periods of asystolia of more than 1,200 msec are most typical for these patients. An attempt was made to determine the type of cardiac stimulation indicated for such patients from the character of the disorders of rhythm observed in them and the initial frequency of their own cardiac contractions.
| 89,215
|
[Treatment of severe ventricular arrhythmia by means of repeated cardiac stimulation].
|
The overdrive pacing method is widely used now in clinical practice for prevention and treatment of severe ventricular disorders of the cardiac rhythm. The mechanisms of arrhythmia suppression by means of this stimulation is analysed. Indications are determined for the choice of the site of stimulation and optimal impulce frequency in ischemic heart disease, and overdosage with digitalis drugs, as well as in myocardiopathy.
| 89,216
|
[Lymphocyte membrane receptors mediating recognition of antigens (author's transl)].
|
The present article summarizes briefly our knowledge of antigen-specific B- and T-lymphocyte receptors. Antigen-specific receptors on mammalian B-lymphocytes are mainly monomeric IgM and IgD consisting of conventional immunoglobulin heavy and light chains. The nature of the T-lymphocyte receptors which can specifically recognize antigens is not yet fully defined but it seems that conventional light chains do not participate in the build up of this receptor. However, T-lymphocytes express two polypeptide chains which bear variable domains sharing idiotypic determinants with the corresponding B-lymphocytes. These Tau chains can bind the corresponding antigen.
| 89,223
|
Antigen-antibody system associated with non-A, non-B hepatitis detected by indirect immunofluorescence.
|
Ten chimpanzees were infected with non-A, non-B hepatitis by inoculation of patient serum or serum from a chimpanzee previously inoculated with patient serum. Convalescent serum from one of them reacted, in indirect immunofluorescent tests, with some of the hepatocyte nuclei in sections of autologous liver biopsy specimens and specimens from eight of the other chimpanzees. Serum from a convalescent patient reacted in the same way. These positive sera did not react with liver sections from uninfected chimpanzees. No reaction with positive liver sections was given by serum from chimpanzees which were uninfected or had antibodies to hepatitis A or B antigens. These control results suggest that the antigen-antibody system detected has specificity for non-A, non-B hepatitis.
| 89,332
|
Value of new diagnostic aids in relation to the disease process in pancreatic cancer.
|
An assessment was made of the diagnostic value of six tests done on 28 patients who proved to have resectable and 45 patients who had non-resectable pancreatic cancer. Ultrasonography and endoscopic retrograde cholangiopancreatography (ERCP) were the most sensitive tests for the diagnosis of resectable tumours. Ultrasonography was slightly, and cytology definitely, better for the diagnosis of resectable tumours than for the diagnosis of non-resectable tumours. Computerised tomography, angiography, and scintigraphy were not effective means of diagnosing resectable tumours. The differences in diagnostic sensitivities of the tests for resectable and non-resectable disease are probably due to variations in pathological features which influence not only the stage of presentation, but also the detectability of the tumour. As long as investigation is limited to patients with symptoms, a large proportion of tumours will not be diagnosed at a resectable stage. However, the results of this study suggest that the resectability rate may be maximised by the early use of ultrasonography in patients with symptoms suggesting cancer in the region of the head of the pancreas, and in patients with vague, non-specific complaints. A combination of ERCP and direct ductal aspiration for cytology is the best means of diagnosing resectable tumours.
| 89,449
|
[Studies on human immunoglobulin preparations: I. Viral antibody profiles (author's transl)].
|
A study was undertaken to assess the viral antibody spectrum in human immunoglobulin preparations from four different manufacturers for intravenous and/or intramuscular application. Studies of the kind seem to be reasonable for calculating the expected therapeutic effect of the administered immunoglobulin. The investigated 16 gammaglobulin batches showed almost the same variety of viral antibodies and only slightly differring antibody titers. It is interesting to note, that antibodies to vaccinia virus could not be demonstrated. Quantitative determination of viral antibody titers in immunoglobulin preparations for standardization purposes should include the testing of antibodies to viruses against which a therapy with gammaglobulins is reasonable.
| 89,620
|
[Prognostic elements in bronchial carcinoma].
|
In spite of improvements in diagnosis and treatment, the fatal prognosis of lung cancer has persisted over the course of 25 years in a series of nearly 4000 patients. Only 30% (1149 cases) were operable, and on 23% of those resected (i.e. 7% of the total) survived for 5 years. An assessment is made of the relationship between survival and sex, age, tumour size and site, radiological picture, stage of invasiveness, type of surgery and degree of radicality, histological picture, and number of circulating lymphocytes. Age, sex and the type of resection (lobectomy or pneumonectomy) had no relation to prognosis. Palliative surgery was always associated with a fatal prognosis, as were cases with invasion of the chest wall, or, more particularly, with oat cell cancers. The outlook was more favourable in cases where radical treatment was given, in cases of squamous cancer, as opposed to other histological types, in those in stage 1 (Am. Joint Committee classification), and those with greater than 2000/mm3 lymphocytes--especially in adenocarcinomas.
| 89,646
|
[Isotopic indicators in the diagnosis of malignant pleurisies (author's transl)].
|
The tracers that are used in thoracic pathology have an elective tumoural affinity, present such a special reaction towards pleural effusions that we were led to study Bleomycin labelled with Cobalt 57 in 34 cases of pleurisy of various etiologies. The hyperfixation, circumscribed to the effusion in all these cases, presented a double problem : of radiobiological risk and of diagnostic significance. We tried to solve the last problem by means of a precise protocol applied to 16 cases, quantifying comparatively the specific radio-activity of pleural fluid and serum and studying the evolution of the pleural serous gradient, after injection of 2 mCi of labelled Bleomycin in 16 patients with suspected malignant pleurisy. From this limited study, it appeared that the sero-pleural gradient of the tracer, 24 hours after injection, was very high, above 5 and up to 15 in 7 malignant pleurisies out of 8; between 2 and 4 in others. It was sometimes below 5 and less in effusions, non malignant or doubtful. This gradient decreased very rapidly to reach 0 on the fourth day, except in recurring chronic effusions. Pending the confirmation of results, after a prolonged experiment, this protocol appeared valuable for diagnostic and physiopathological reasons.
| 89,672
|
Histamine-releasing effect of a corticotrophin derivative. II. Mechanism of action of histamine release by C 44 680-Ba, compared with that of Cpd. 48/80, dextran and triton.
|
The mechanism of the histamine-liberating action of the synthetic polypeptide C 44 680-Ba, an alkyl-prolyl derivative of beta 1-19 corticotrophin, was investigated and compared with those of Compound 48/80, dextran, Melittin and Triton X-100. It was found that the release of histamine from rat peritoneal cells induced by the polypeptide is dependent on temperature, pH, calcium ions and energy-providing processes. In regard to these criteria, the mode of action of this histamine liberator resembles that of Compound 48/80 but is quite distinct from that of the unspecific substance Triton X-100.
| 89,804
|
A route for direct retinal input to the preoptic hypothalamus: dendritic projections into the optic chiasm.
|
With the use of Golgi, horseradish peroxidase, and electron microscopic techniques, neurons within a broad region of the preoptic hypothalamus of the mouse were shown to have dendrites that projected well into the depths of the optic chiasm. Further experimental and ultrastructural investigation demonstrated synapses between these dendrites and retinal axonal boutons within the chiasm. All synapses located in the chiasm were classified as Gray's type I. The possible function of these dendritic projections is discussed.
| 89,809
|
Esophagomyotomy versus forceful dilation for achalasia of the esophagus: results in 899 patients.
|
Between 1949 and 1976, 899 patients underwent treatment for achalasia of the esophagus at the Mayo Clinic, 431 by forceful hydrostatic or pneumatic dilation and 468 by a standardized transthoracic esophagomyotomy. Esophageal leak and mediastinal sepsis was an uncommon but major complication of both types of therapy, occurring four times more often with dilation (4%) than with myotomy (1%), although no deaths resulted from this in either group. The 30-day mortality was 0.2% after myotomy and 0.5% after forceful dilation. Although there was minimal morbidity and mortality with either modality, the late results were significantly superior after myotomy. Excellent to good results were obtained by 85% of the group treated with myotomy but only by 65% of those treated with hydrostatic dilation. Late poor results were encountered three times more frequently after dilation (19%) than after myotomy (6%). Analysis of poor results after myotomy indicates that late serious complications of gastroesophageal reflux developed in only 3% of patients operated on.
| 89,837
|
Demonstration of cross-reacting material in Tay-Sachs disease.
|
Antibodies against placental hexosaminidase A and kidney alpha-subunits were raised in rabbits after cross-linking the antigens with glutaraldehyde. Anti-(alpha(n)-subunit) antiserum (anti-alpha(n)) precipitated hexosaminidase A but not hexosaminidase B, whereas anti-(hexosaminidase A) antiserum precipitated both hexosaminidases A and B. Specific anti-(hexosaminidase A) antiserum was prepared by absorbing antiserum with hexosaminidase B. Both anti-alpha(n) and anti-(hexosaminidase A) antisera precipitated the CR (cross-reacting) material from eight unrelated patients with Tay-Sachs disease. Immunotitration, immunoelectrophoresis, double-immunodiffusion and radial-immunodiffusion techniques were used to demonstrate the presence of CR material. The CR-material-antibody complex was enzymically inactive. Antiserum raised against kidney or placental hexosaminidase A, without cross-linking with glutaraldehyde, failed to precipitate the CR material, implying that treatment of the protein with glutaraldehyde exposes antigenic determinants that are hidden in the native protein. Since anti-(hexosaminidase B) antiserum did not precipitate the CR material during the immunoelectrophoresis of Tay-Sachs liver extracts, it is suggested that altered alpha-subunits do not combine with beta-subunits. By using immunotitration we have demonstrated the competition between the hexosaminidase B-free Tay-Sachs liver extract and hexosaminidase A for the common binding sites on monospecific anti-(cross-linked hexosaminidase A) antiserum. The amount of CR material in the liver samples from seven cases of Tay-Sachs desease was found to be in the same range as theoretically calculated alpha-subunits in normal liver samples. Similar results were obtained by the radial-immunodiffusion studies. The present studies therefore suggest that Tay-Sachs disease is caused by a structural-gene mutation.
| 89,845
|
Effects of hexachlorocyclohexane isomers on concanavalin A 'capping' in bovine lymphocytes.
|
The effects of alpha, beta, gamma, and delta isomers of hexachlorocyclohexane on concanavalin A 'capping' in bovine lymphocytes were evaluated, gamma and delta hexochlorocyclohexane inhibited 'capping' whereas the alpha and beta isomers were without effect. In addition, gamma-hexachlorocyclohexane has been shown to antagonize the maintenance of preformed 'caps' and cause the rapid dispersal of the concanavalin A-receptor complexes over the surface of cells by a temperature-dependent mechanism. The possible role of a gamma-hexachlorocyclohexane-sensitive process in the organization of microflow patterns in the lectin-activated lymphocyte membrane is discussed.
| 89,870
|
Cytological changes due to urinary calculi: a consideration of the relationship between calculi and the development of urothelial carcinoma.
|
Urinary calculi can induce urothelial cellular abnormalities comparable with those of malignancy; this was found in 11 out of 62 lithiasis cases. Severe cellular changes, comparable with those of carcinoma in situ, may be seen in the epithelium adjacent to a calculus. Squamous metaplasia was frequently observed in cases with staghorn stones in the renal pelvis. The abrasive effect of the calculus may result in many multinucleated cells in the sediment. When the calculi are removed the cytological atypia and the observed multinucleation disappeared, and none of these 62 patients developed urothelial carcinoma. A possible relationship was found between a long-term clinical history of lithiasis and the development of cancer of the upper urinary tract in a study of 92 cases of carcinoma of the ureter and renal pelvis.
| 89,882
|
Influence of cysteamine on differential staining of BUdR-substituted human chromosomes.
|
In 5-bromodeoxyuridine (BUdR)-substituted human chromsomes stained with 4'-6-diamidino-2-phenylindole (DAPI) differential staining is suppressed totally by the H+-donor cysteamine (concentration 0.08 M). We propose that differential staining appears because the double BUdR-substituted chromatid will be disintegrated via a photosensitive dye-visible light system. It is suggested that cysteamine prevents the production of strand breaks in DNA and, consequently, differential staining in BUdR-substituted chromosomes. Furthermore it is shown that differential staining with DAPI causes irreversible changes in the double BUdR-substituted chromatid. This finding can be explained with the above mentioned mechanism.
| 89,890
|
Modulation of cellular interactions between C3H/10T1/2 cells and their transformed counterparts by phosphodiesterase inhibitors.
|
It has been demonstrated previously that nontransformed C3H/10T1/2CL8 mouse embryo fibroblasts (10T1/2) can induce a state of reversible growth inhibition in cocultured malignantly transformed mouse fibroblasts and that this inhibition is modulated by serum concentration. The present study suggests that cyclic nucleotides may be implicated in this intercellular communication. The phosphodiesterase inhibitors theophylline, caffeine, and 3-isobutyl-1-methylxanthine (IBX) at concentrations of 10(-3) M, maintained continuously, were all found to inhibit the expression of 3-methylcholanthrene-induced malignant transformation when added 7 days after removal of carcinogen. IBX was the most potent, causing 100% inhibition at 10(-4) M and 70% inhibition at 10(-5) M. This inhibition was partially reversible in the former case and completely reversible in the latter case by removal of drug. Complete inhibition by 10(-4) M IBX was still observed when treatment was delayed 21 days postcarcinogen. In reconstruction experiments, utilizing confluent monolayers of 10T1/2 cells overlaid with transformed cells, IBX caused a dose-dependent inhibition of colony size of the transformed cells. Adenosine cyclic 2':3'-monophosphoric acid (cAMP) and N6,O2'-dibutyryladenosine cyclic 3':5'-monophophoric acid potentiated this response. The presence of non-transformed 10T1/2 cells was required for this effect, since a concentration of IBX (10(-4) M) inhibitory for the growth of transformed cells in mixed cultures was without effect on the growth rate, plating efficiency, or saturation density of pure cultures of 10T1/2 cells or of their transformed counterparts. Conditioned medium removed from IBX-treated 10T1/2 cells was not growth inhibitory for transformed cells, indicating a requirement for cell-cell contact. IBX caused a dose-dependent increase in intracellular cAMP in confluent 10T1/2 cells and a more pronounced increase in cAMP concentration in the culture medium of these cells. The dose-response effects of IBX on growth inhibition of malignant cells in mixed cultures appear to correlate well with its ability to elevate cAMP levels. Thus, IBX increased the capacity of 10T1/2 cells to cause reversible growth arrest of transformed cells and appears to act in a manner analogous to the previously reported effects of serum.
| 89,899
|
Additive effects of bleomycin and neocarzinostatin on degradation of DNA, inhibition of DNA polymerase beta, and cell growth.
|
The interactions of the two antitumor protein antibiotics, neocarzinostatin (NCS) and bleomycin (BLM), were studied on subcellular and cellular levels. BLM and NCS were found to remove thymine from double-stranded DNA. Combination experiments using BLM and NCS together in an assay with isolated DNA revealed an additive effect in splitting. Under limiting concentration conditions, BLM and NCS induce alkali-labile sites in DNA without a subsequent cleavage of the chain. After transfer of BLM- or NCS-treated DNA into an alkaline solution, strand scissions occur. Combination of BLM and NCS results in an additive DNA-cleaving effect, which indicates that the splitting reactions initiated by BLM or NCS are not influenced if the two antibiotics are applied in combination. The DNA polymerase beta is inhibited by BLM (at higher concentrations) and by NCS in a competitive way with respect to DNA. The inhibition constant of BLM and NCS in a combination experiment was found to be the result of the sum of the inhibition constants of BLM and NCS. Using L5178Y mouse lymphoma cells, it was found that cells incubated with both BLM and NCS show "unbalanced growth." The dose-response curves from BLM and NCS have identical slopes; they are characteristic for compounds which selectively inhibit DNA synthesis. By use of isobolograms, it could also be clearly shown that BLM and NCS interact additively.
| 89,904
|
Relations between fibrillar centres and nucleolus-associated chromatin in Ehrlich tumour cells.
|
By means of diaminobenzidine staining method, the relations between fibrillar centres and nucleolus-associated chromatin are analyzed in Ehrlich tumour cell nucleoli. There is a continuity between fibrillar centres and condensed intra-nucleolar chromatin. The meaning of these connections is discussed.
| 89,913
|
[Identification of actin microfilaments in the neurosecretory axons of rat neural lobe].
|
Incubation of rat neural lobes with heavy meromyosin (HMM) after prolonged glycerination, induced characteristic arrowhead decoration of a number of microfilaments at different levels of the neurosecretory axons. In non terminal sections of axons the labelled microfilaments showed preferential relationships with microtubules in addition to occasional contacts with the axolemma and various axonal organelles. In axonal endings, they were mainly associated to microvesicles and appeared to be anchored on the axolemma facing the perivascular space at the level of membranous densifications.
| 89,915
|
Bone marrow culture in vitro. A technique for analysis and permanent recording of cellular composition.
|
The in vitro cloning of haematopoietic progenitor cells derived from blood or bone marrow is now an established technique for the study of normal and abnormal blood formation. In semi-solid agar the results are conventionally recorded as the number of clusters or colonies that grow on the plate under controlled culture conditions. However, the demonstration of detailed morphology within these cellular aggregates remains unsatisfactory. Aspiration techniques are cumbersome and invariably disturb cellular relationships within the supporting matrix while supravital staining is limited by variable uptake of dye by the agar. We describe a method in which the entire cell-containing layer is removed from the Petri dish, fixed, and after mounting on a glass-slide, is air-dried. This preparation stains well with a wide variety of biological dyes, is minimally influenced by background colouration of the culture medium and excellent demonstration of morphologic detail is possible. A permanent record of the cellular composition of the culture is easily obtained by mounting the stained agar disc.
| 89,962
|
Recovery course in mouse spleen and bone marrow after continuous irradiation.
|
The paper deals with the recovery process of some parameters in the spleen and bone marrow till day 60 after continuous irradiation with a daily dose of 476.5 mGy (50 R), 957 mGy (100 R) and 4785 mGy (500 R) up to the total accumulated dose of 9570 mGy (1000 R). The recovery process in the spleen and bone marrow are relatively significant and completed till day 28 or 60 respectively after irradiation.
| 89,985
|
[Relationship between the capacity to be stimulated of lymphocyte subpopulations and the RAI staging in patients with chronic lymphocytic leukemia].
|
By means of the incorporation rate of 3H thymidine into the lymphocytes of patients with chronic lymphatic leukaemia the possibility of stimulating them by using different mitogens was checked and compared with normal persons. The examination covered 11 patients treated with extracorporeal irradiation of the blood (ECIB), 5 patients treated with a chlorambucil therapy, and 10 untreated patients who were classified according to the staging system proposed by RAI. The lymphocytes of the peripheral blood were stimulated as mixed and isolated T and B-lymphocytes in the microculture by using the mitogens PHA, PWM, ConA, and LPS. In all CLL patients there was a diminished stimulation rate of a mixed lymphocyte population. A relation existed between the seriousness of the stage and the diminution of the incorporation rate of 3H thymidine. A corresponding correlation could not be identified in untreated CLL patients. Isolated T-lymphocytes revealed better results of stimulation than the total population. As to their function B-lymphocytes showed a dependance on the kind of therapy. In the mixed lymphocyte culture of normal persons the best findings could be observed after stimulation with PHA, that is also valid for CLL patients. PHA, PWA, ConA, and LPS were suitable as substances stimulating B-lymphocytes with different efficacy in normal persons and CLL patients. Both collectives showed the best results in the T-lymphocyte culture after stimulation with LPS.
| 89,987
|
The role of religious institutions in evangelization.
|
Religious institutions are called to make an exodus out of their own holy land into the true holy land of humankind. By reflecting on the Beatitudes and Jesus' humanity, Catholic-sponsored health care institutions can better understand the meaning of evangelization.
| 90,002
|
Symbolism in the dreams of the blind.
|
The present study compared a group of visually handicapped adults and normally-sighted college students with respect to extent of symbolic content in nocturnal dreams. The visually handicapped group comprised individuals who were partially sighted, congenitally blind and adventitiously blind. Each subject was required to keep a dream-diary for a period of two or four months. These diaries were then content-analyzed for frequency of symbolic instances, with symbols being identified in line with the criteria suggested by Hall (1966) and Hall and Nordby (1972). Although individual differences were marked and some visually handicapped subjects reported highly symbolic dreams, this group, on the whole, revealed less symbolism in dreams than did the normally sighted subjects. There was also a tendency for individuals blinded later in life (after age seven) to manifest more symbolic content in dreams than subjects blinded earlier (before age five). However, for the partially sighted subjects in the study, there emerged no clear relationship between age of onset of visual impairment and amount of symbolism in dreams. In general, the present findings were congruent with those of Blank (1958).
| 90,024
|
Ocular findings in systemic cutaneous basophil hypersensitivity.
|
SCBH was induced by immunizing guinea pigs with a protein antigen and challenging 1 week later with a large intraperitoneal dose of the same antigen. Animals developed a delayed-onset, erythematous skin rash and dermal infiltration by basophils and eosinophils. The uveal tracts of these animals were infiltrated by eosinophils, as were several other internal organs. The eye is affected in SCBH, and as in other forms of ocular cell-mediated hypersensitivity, the eosinophil is a prominent cellular component of these reactions.
| 90,029
|
Scleroderma: increased biosynthesis of triple-helical type I and type III procollagens associated with unaltered expression of collagenase by skin fibroblasts in culture.
|
To assess potential abnormalities in collagen metabolism in systemic scleroderma, skin fibroblast lines from patients with this disease were established and compared to control cell lines derived from healthy subjects. For studies on the biosynthesis of procollagen, the cells were incubated with [(14)C]proline in a medium supplemented with ascorbic acid and beta-aminopropionitrile, and the synthesis of nondialyzable [(14)C]hydroxyproline, in relation to DNA or cell protein, was taken as an index of procollagen formation. Five of eight scleroderma fibroblast cell lines demonstrated procollagen biosynthesis rates significantly higher than the controls, and the mean rate of procollagen synthesis by scleroderma fibroblasts was about twice that of the control cells. Control experiments demonstrated that the specific activity of the intracellular free proline was not different in scleroderma and control fibroblasts, and the mean population doubling times of the scleroderma and the control fibroblast cell lines were the same. The relative synthesis of the genetically distinct procollagens was examined by isolating type I and type III procollagens from the cell culture medium using DEAE-cellulose chromatography. The ratios of type I/III procollagens in scleroderma cell lines did not differ from the controls. The helical stability of the collagenous portion of type I and type III procollagens, estimated by the resistance of (14)C-collagen to limited proteolytic digestion with pepsin under nondenaturing conditions, was the same in both scleroderma and control cultures. The capacity of the cells to synthesize enzymatically active and immunologically reacting collagenase was also studied; no marked differences in these parameters could be observed. The results suggest that cultured skin fibroblasts from patients with scleroderma demonstrate a metabolic abnormality expressed as increased synthesis of type I and type III procollagens in a normal ratio. This abnormality may play a role in the excessive accumulation of collagen in the skin and other organs affected in scleroderma.
| 90,059
|
The histochemical distribution of protein bound sulfhydryl groups in human epidermis by the new staining method.
|
Recently, we synthesized a new fluorescent thiol reagent, N-(7-dimethylamino-4-methylcoumarinyl)-maleimide (DACM) which is nonfluorescent by itself but will react readily with -SH groups to form highly fluorescent addition products. By the use of this reagent, we studied the localization and concentration of -SH groups and S--S linkages in the human epidermis. The distribution of -SH groups in living layers was abundant in cytoplasm but not in nuclei. The fluorescence was concentrated on the cell membrane or intercellular spaces (MIC parts) and was increased at the spino-granular junction. In the horny layer, the fluorescence of the MIC parts appeared brilliantly in the lower layers and decreased gradually. On the other hand, the fluorescence of cytoplasm in keratinized cells in the stratum corneum was faint. The localization of S--S linkages was not a characteristic of the living layers, but appeared abruptly at the junction of living and horny layers. The fluorescence was localized to the MIC parts and disappeared gradually. The distribution of S--S linkages appeared to be very low in the cytoplasm of keratinized cells. No substantial fluorescence was localized on keratohyalin granules even after reduction.
| 90,070
|
Development of a new primary fixative for electron microscopic immunocytochemical localization of intracellular antigens in cultured cells.
|
We have developed a new primary fixative that permits the localization of intracellular antigens with well preserved ultrastructural morphology. This primary fixation method employs a mixture of a water soluble carbodiimide with glutaraldehyde, and preserves morphology, yet produces a permeable cytosol matrix so that antibodies can gain access to fixed proteins. Cultured cells were primarily fixed, treated with detergent to permeabilize their membranes, reacted with peroxidase labeled antibodies, secondarily fixed, and embedded in situ. The variations in morphology and accessibility of intracellular antigens were evaluated for a variety of fixatives. Concanavalin A and alpha 2 macroglobulin were chosen as examples of intracellular protein antigens to evaluate these fixation methods. Both of the proteins were localized in intracellular vesicles.
| 90,071
|
Study of a new strain of paramyxoviruses isolated from wild ducks: antigenic and biological properties.
|
Among the different strains of avian paramyxoviruses isolated from migrating feral ducks, two were identified as Newcastle disease viruses (NDV) and the five others would correspond to a new serotype for which we suggest the name of Duck/Mississippi/75 virus. The characteristics of this new serotype are as follows: (1) Duck/Mississippi/75 virus is able to grow as well in allantoic as in amniotic cavities of embryonated hen's eggs; (2) the haemagglutinin and haemolytic activities can be detected with hen red blood cells; (3) the neuraminidase hydrolyses the alpha 2 leads to 3 bonds of the fetuin substrate and its pH activity could be species specific. Antigenically, this serotype is different from all human and animal paramyxoviruses, in spite of an antigenic relationship with NDV.
| 90,111
|
Cytostatic treatment of meningeal blastoses.
|
Intrathecal treatment with MTX was attempted in patients with diffuse meningeal blastoses. As a rule, symptoms and clinical findings improved rapidly. As objective parameters, the differential cell pictures of the CSF showed dissimilar results during therapy (25 mg MTX weekly i.t.). In leukoses (n = 10) and malignant lymphomas (n = 12), the CSF could be cleared with three exceptions which concerned differentiated tumors. The success was similarly good with meningeal dissemination of a seminoma. Meningeal carcinoses with mammary carcinoma (n = 7) and melanoma (n = 2) showed dissimilar results. No alteration of the cytograms of four bronchial carcinomas and one colon carcinoma was demonstrable. Besides the growth form, the degree of differentiation appears to be decisive for the success of therapy. The labeling index appears to be a useful indicator. Since symptoms and clinical findings often markedly improve even when a success cannot be objectively detected cytologically, an attempt at therapy is always to be recommended.
| 90,137
|
The evaluation of cell nuclei staining parameters regarding the reproducibility of fluorescence measurements.
|
The present methodological study is an attempt to optimize the staining parameters for a quantitative DNA determination of fluorescent cells. The application of pure dyes and a precise control of the staining procedure are preliminary conditions which have to be fulfilled, because the reproducibility of measurements is in this connection the most important criterion for a quantitative DNA related analysis of cell population. Chicken erythrocytes and isolated nuclei were applied as biological test objects. The staining procedure with acridine derivatives (acriflavine, proflavine, rivanol) was performed in accordance with the fluorescence-Feulgen reaction. The influence of staining parameters, such as (1) pH and (2) dye concentration of the staining solution, were evaluated regarding the spectral behaviour, the total fluorescence intensity, and the reproducibility of results.
| 90,149
|
Intracavitary uses of colloids.
|
Pleural and peritoneal effusion secondary to primary malignancy is a significant problem in the management of the cancer patient. Respiratory embarrassment and discomfort associated with the formation and collection of fluid in the chest and abdomen are among the most distressing symptoms encountered as a result of malignant disease. The guidelines for treatment should be based on respiratory symptoms, and with the understanding that the procedure is palliative. Both surgical and medical forms of treatment have been used. These include thoracostomy-tube drainage alone or with the instillation of antimicrobial agents. Pleurectomy is effective but should be reserved for situations in which conservative approaches have failed. Antitumor agents, such as nitrogen mustard, are effective but toxic. The mode of action of antineoplastic agents is related to their ability to cause pleural sclerosis and obliterate the pleural space. Systemic chemotherapy and external beam radiation are rarely effective. The intracavitary application of radioactive colloids has been used since 1945. Colloidal radioactive gold Au 198 has been replaced by the pure beta emitter, colloidal chromic phosphate P 32. Instillation of a colloidal suspension of radioactive phosphorus represents a significant and effective palliative therapeutic modality for malignant effusion.
| 90,386
|
Results of systemic-to-pulmonary artery anastomosis for tricuspid atresia with reduced pulmonary blood flow.
|
Fifty-six patients with tricuspid atresia and decreased pulmonary blood flow received a systemic-to-pulmonary artery anastomosis as a preliminary operation. Thirty-five had a Waterston shunt, 12 a Blalock-Taussig anastomosis, and nine various other procedures. The age at operation ranged from 2 days to 10 years (median 4.5 months). Pulmonary atresia was present in eight newborn infants. Four patients (7%), all less than 3 months old, died in hospital from persistent servere hypoxia despite the palliative procedure. By actuarial methods, 93% of the survivors were alive at and after one year (longest follow-up:9.8 years), while 83% had not required further palliation at and after four years from the first operation. None of the patients subsequently restudied had raised pulmonary pressure or resistances, and in most of them the pulmonary arterial tree was deemed adequate for the Fontan operation.
| 90,392
|
The development of Onchocerca ochengi (nematoda: filariodea) to the infective stage in Simulium damnosum s.l. with a note on the histochemical staining of the parasite.
|
Onchocerca ochengi, an intradermal filarial parasite of cattle in Africa, was shown to develop normally to the infective stage in a member of the Simulium damnosum complex, almost certainly S. sanctipauli. The development of the parasite in the thoracic musculature and head of the fly was completed in 6 days at an ambient temperature of 25-30 degrees C. The larvae were very similar in rates of development, morphology and distribution to those of the human parasite O. volvulus in the same vector. No histochemical differences were found in the enzyme staining of O. ochengi distinct from the pattern described earlier for O. volvulus.
| 90,413
|
[Use of 5-bromodeoxyuridine for determining the duration of cell cycle phases].
|
The method of differential staining of sister chromatids by means of 5-bromdesoxyuridine (BDU) was used to determine duration of the cellular cycle and its phases in a cell culture of Chinese hamster. The mitotic cycle lasted for 16 hrs, G1 for 5 hrs, S for 8 hrs and G2 for 3 hrs. These values do not differ from those obtained by the autoradiography. The given method permits quicker determination of the cellular cycle phases duration as compared with the autoradiography method.
| 90,414
|
The extrinsic innervation of the abdominal organs in the female rat.
|
The extrinsic innervation of the abdominal organs in neonatal and adult female rats is described. Mainly an in toto acetylcholinesterase method was used; moreover, formaldehyde-induced fluorescence and acetylcholinesterase were demonstrated in sections. The major splanchnic nerve has its origin in the ninth and tenth thoracic sympathetic trunc ganglia. In the major splanchnic nerve a suprarenal ganglion is present. Sometimes the minor splanchnic nerve, arising from the tenth thoracic ganglion, joins the distal part of the suprarenal ganglion. The left and right major splanchnic nerves join the left and right celiac ganglia in the plexus. The left celiac ganglion is always bigger than the right one. The celiac plexus and the celiac inferior mesenteric plexus are joined by the intermesenteric plexus. Para-aortic nerves, originating in the caudal part of the thoracic sympathetic truncs, also join the abdominal prevertebral plexuses. The lumbar splanchnic nerves, not symmetrical in their origin, join the prevertebral plexuses and give off branches to the abdominal organs. The suprarenal glands receive bundles of nerve fibers, sometimes ganglionated, from the suprarenal ganglion. The kidneys are innervated from the celiac plexus, the upper lumbar splanchnic nerves and the intermesenteric plexus. The ovarian nerves are derived from the celiac plexus, the intermesenteric plexus and the upper lumbar splanchnic nerves. Bundles of nerve fibers run from the suprarenal ganglion in the celiac plexus in the direction of the suspensory ligament of the ovary. In many respects this description is at variance with existing literature on the autonomic innervation in the rat. These differences with the standard literature are relevant to those workers engaged in experiments on the sympathetic innervation of abdominal viscera.
| 90,440
|
[Chemotherapy of skin tumors of the head and neck].
|
The authors report on the therapeutic results performed in the 126 skin tumors with three different chemotherapic schedules: a) Endovenous Bleomycin (BLM); b) Combined schedule with BLM, Methotrexate (MTX), Cyclophosphamide and Corticoid; c) Local BLM infiltration. There were 42,8 % of complete remission and 87,2 % of responsiveness (effectiveness). The best response rates were achieved in not advanced tumors. Local BLM infiltration has shown the best response rates 63,9 % being this schedule performed mainly in not advanced tumors. Overdosage of local infiltration may produce tissue necrose. Response rates for squamouscell carcinoma and basal cell carcinoma were alike. BMEM therapy presents the best results in the squamous cell carcinoma and the BLM infiltration in the basal cell carcinoma. There were 24 % of recurrence from the complete remissions.
| 90,474
|
Palliation of esophageal carcinoma with intraluminal tubes: experience with 30 patients.
|
Between 1968 and 1978, 26 patients with carcinomas of the thoracic esophagus and 4 with adenocarcinomas involving the esophagogastric junction were treated by the insertion of indwelling intraluminal (endoesophageal) tubes. Four different types of tube were inserted by the pull-through technique. Thirteen of the 30 patients died in the hospital within 30 days. However, among the 20 patients who did not have neoplasms of the upper third of the thoracic esophagus or who had not had a prior resection, only 5 died. The principal cause of death was aspiration pneumonia. Survival averaged 2.5 months. Four patients survived 5 to 7 months. Deglutition was adequate in most patients but was not as satisfactory as after esophagogastrectomy. Our best results were obtained in patients with carcinoma of the middle or lower third of the esophagus, with or without an esophagorespiratory fistula, who had not had a previous resection.
| 90,489
|
Rapid staining technique for Trichomonas vaginalis. Preliminary report.
|
A simple, rapid, staining method for the identification of Trichomonas vaginalis has been tested on cultured trichomonads and specimens of vaginal discharge. Fifty-eight stained slides of vaginal discharge were examined and trichomonads were correctly identified in the 31 specimens from patients with confirmed vaginal trichomoniasis. No false-positive results were obtained. This staining procedure could prove a useful addition to wet-film and cultural methods.
| 90,513
|
[Counterimmunoelectrophoresis in the diagnosis of visceral leishmaniasis].
|
Technique of counter current immunoelectrophoresis (C.I.E.P.) was employed for the diagnosis of V.L. using an antigen grossly extracted (by means of repeated freezing and thawing) from culture of Leishmania. 6 lots of antigen were prepared - in various time - at the same way. Positive results are obtained in V.L. from 83.3 to 94% (according to various lots of antigens). Few false positivity (from 1.4 to 8.8%) are obtained in sera from patients with other diseases (especially) cirrhosis and blood disorders. No positivity in controls (blood donors). The reproducibility of results appear satisfactory. Our results suggested that C.I.E.P., rapid and less sophisticated test, can be applied for the diagnosis of V.L. But false positivity and false negativity limit the value of these test.
| 90,514
|
Enzymic O-glycosylation of synthetic peptides from sequences in basic myelin protein.
|
Nine synthetic peptides containing sequences in the region of a threonine residue at position 98 of bovine basic myelin protein were prepared by the Merrifield solid-phase method and tested for their ability to be glycosylated with [14C]uridinediphospho-N-acetylgalactosamine and a crude detergent-solubilized preparation of uridinediphospho-N-acetylgalactosamine:mucin polypeptide N-acetylgalactosaminyltransferase obtained from porcine submaxillary glands. The tetrapeptide Thr-Pro-Pro-Pro and all larger peptides containing this sequence were glycosylated. The glycosylation was greater for peptides containing residues N-terminal to the Thr-Pro-Pro-Pro. Under the conditions used, the peptide Val-Thr-Pro-Arg-Thr-Pro-Pro-Pro was glycoslyated twice as much as bovine basic myelin protein. Thr-Pro and Thr-Pro-Pro, as well as 10 other synthetic peptides which did not contain the Thr-Pro-Pro-Pro sequence, were not glycosylated. Treatment of the glycopeptide of Phe-Lys-Asn-Leu-Val-Thr-Pro-Arg-Thr-Pro-Pro-Pro-Ser with an alpha-N-acetylgalactosaminidase released N-acetylgalactosamine from the peptide, indicating that the hexosamine was covalently bonded to the peptide in an alpha linkage.
| 90,521
|
Cells of origin of the spinocerebellar tract in the rat, studied with the method of retrograde transport of horseradish peroxidase.
|
Following injections of horseradish peroxidase into the cerebellum, the distribution of labeled neurons was studied in the whole length of the spinal cord of the rat. To find the ascending side of the axons, injections were made following hemisections at C1 or between C1 and C2. Labeled spinocerebellar tract neurons were classified into two groups according to the axonal course in the spinal cord; one is composed of neurons with uncrossed ascending axons and the other, neurons with crossed ascending axons. Neurons of origin of the uncrossed tracts were located in the medial part of lamina VI of C2 to C8, the central part of lamina VII of C4 to C8, lamina V of C7 to L3 and Clarke's column. Neurons of origin of the crossed tracts were found in the central cervical nucleus of C1 to C3, the intermediate zone and the ventral horn of the lower thoracic and the lumbar segments (T11 to L3), and in the dorsal horn, the medial part of lamina VII and the ventrolateral part of the ventral horn of the sacral and caudal spinal cord. In comparison with our previous results in the cat, it was suggested that the spinocerebellar system in the rat is organized in the same fashion as in the cat, in terms of the location and the intraspinal axonal course of the cells of origin.
| 90,539
|
Axonal transport in early experimental diabetes.
|
In the present study fast axonal transport was examined in streptozotocin rats with 4 weeks duration in diabetes. Tritiated leucine and 14C-labelled glucosamine were injected into the fifth lumbar ganglion and TCA-soluble as well as insoluble activity were measured in segments of the sciatic nerve at various time intervals. (1) Time from injection until start of fast axonal transport was prolonged in diabetic rats whereas anterograde transport velocity was unchanged. (2) Incorporation of labelled leucine was reduced by 40%, whereas labelled glucosamine incorporation was unchanged. (3) Alterations observed in accumulations of labelled glycoconjugates proximal and distal to a collection crush might represent a decreased amount of retrograde transported material. The changes found in protein and glycoconjugate synthesis and transport could be related to the early reduction in axon calibre and conduction velocity in peripheral nerve of streptozotocin-diabetic rat.
| 90,540
|
Ultrastructural identification of non-adrenergic, non-cholinergic nerves in the rat anococcygeus muscle.
|
The innervation of the rat anococcygeus muscle has been investigated ultrastructurally following fixation with a modified chromaffin reaction for the demonstration of biogenic amines (Tranzer and Richards, 1976). Three types of nerve profiles were revealed: (1) 60-70% of the profiles are adrenergic; (2) less than 5% of the profiles appear to be cholinergic; (3) up to 40% of the profiles are distinguished by the presence of a characteristically high proportion of electron-opaque, chromaffin-negative vesicles, 85-110 nm in diameter. This third type of profile was not affected by 6-OHDA, and is considered to represent the non-adrenergic, non-cholinergic inhibitory innervation of this tissue. Because of the morphological similarity of this nerve type, apart from the smaller vesicle size, to classical peptidergic nerve endings, they have been termed "small p-type" (sp-type). These results are discussed in relation to a previous report describing only two types of nerve profiles in this tissue (Gillespie and Lüllmann-Rauch, 1974).
| 90,550
|
Neural inputs to the prefrontal agranular insular cortex in the rat: horseradish peroxidase study.
|
The prefrontal cortex, dorsal to the rhinal sulcus of the rat (hereinafter termed the agranular insular cortex) has been examined with the use of the retrograde transport of horseradish peroxidase. Labelled perikarya were seen in the region of the ipsilateral medial forebrain bundle, consistently rostral to the caudal edge of the posterior mammillary nucleus. These cells were interpreted as being the rostral members of the A10 dopaminergic cell group. Labelled cells were also seen in the dorsal raphe nucleus, the ipsilateral pyriform cortex, the contralateral agranular insular cortex, the ipsilateral basolateral amygdaloid nucleus, the ipsilateral locus coeruleus, and the medio-dorsal, ventromedial, and parafascicular thalamic nuclei. Detailed examination of the thalamic input confirmed a differential innervation of the dorsal and ventral regions of the agranular insular cortex. Possible functional correlates of these prefrontal afferents are discussed.
| 90,546
|
The use of fluorescein conjugated antisera to identify proteins on stained and dried electrophoresis strips.
|
Paraprotein bands discovered on routine electrophoresis may be identified immunologically without repeating the electrophoretic separation. It is only necessary to heat the stained and dried strip in a hot air oven to reactivate the antigenic sites and insolubilise the protein. The strip may then be stained using specific antisera conjugated with fluorescein. The absence of prozone phenomena greatly helps in typing of free light chains.
| 90,563
|
Acute mouse and chronic dog toxicity studies of danthron, dioctyl sodium sulfosuccinate, poloxalkol and combinations.
|
Because of an apparent typographic error in a US patent, there has been some confusion as to the acute oral toxicity of danthron and danthron in combination with dioctyl sodium sulfosuccinate (DSS). Acute oral toxicity studies in mice revealed LD50 values of greater than 7 gm/kg for danthron, 2.64 gm/kg for DSS and 3.42 gm/kg for danthron/DSS mixture (1:2 ratio). These results indicate that the lethality of these compounds is in the gm/kg range and not in the mg/kg range. A one year chronic toxicity study of danthron, dioctyl sodium sulfosuccinate, poloxalkol and combinations in dogs failed to reveal any toxic effects. In particular, there was no evidence of hepatotoxicity or of any changes in the myenteric plexuses in the chronically treated dogs.
| 90,594
|
Human slow auditory evoked potentials during natural and drug-induced sleep.
|
The alterations of human slow auditory evoked potential (SAEP) were studied during the sleep-waking cycle. Simultaneous recording of the mean square and standard error curves proved helpful in obtaining more information on the EEG samples used for averaging. In both natural and drug-induced sleep the earlier SAEP components decreased or disappeared, while the later components increased. A significant lengthening of all SAEP peak latencies was found in all sleep stages during tone-burst stimulation. With click stimulation the peak latencies of most SAEP components remained constant. Due to the variability of individual SAEPs, the interpretation of averaged SAEPs was commonly more difficult in sleep as compared with wakefulness. The alterations of SAEPs during sleep are considered from the point of view of their exrralemniscal origin. The hypothesis is put forward that the activating (desynchronizing) and depressing (synchronizing) systems participate in the generation of the earlier and later SAEP components, respectively.
| 90,599
|
Stimulus induced and seizure related changes in extracellular potassium concentration in cat thalamus (VPL).
|
Extracellular potassium activity (ak) and field potentials (fp) were measured in the nucleus ventro-postero-lateralis (VPL) thalami in order to assess the extent of thalamic participation in cortical seizure activity. Small increases (up to 0.7 mmole/l) or decreases (up to 0.2 mmole/l) in ak were induced by electrical stimulation of the contralateral forepaw. These changes in ak were spatially more limited than the simultaneously recorded fp. Similar observations were made during weak electrical stimulation of the somatosensory cortex and during interictal spikes in a cortical penicillin focus. Large and widespread increases in ak to levels of 11.6 mmoles/l and slow negative fps of 8 mV accompanied seizure generation either in a cortical penicillin focus or during intense repetitive electrical stimulation of the cortical surface. Subsequent to such increases ak fell to subnormal levels. The amplitudes and durations of such undershoots were correlated with the amplitudes of the preceding increases in ak. Sometimes thalamic seizures ceases before cortical epileptic episodes. This resulted in a decrease of cortical EEG amplitudes. After ablation of the sensorimotor cortex seizures in forepaw-VPL could be induced by stimulation of the somatosensory cortex. These results further support the conclusion that specific thalamic nuclei participate in seizure generation and may serve as a subcortical route of seizure spread.
| 90,603
|
Identification and characterisation of the major antiproteases in equine serum and an investigation of their role in the onset of chronic obstructive pulmonary disease (COPD).
|
Three major antiprotease components in equine serum were identified and characterised. These were the acidic prealbumin Pr, the homologue of human alpha-1 antitrypsin and 2 protease binding proteins, the acidic prealbumin Xc and alpha-2 macroglobulin, both capable of inhibiting the proteolytic activity of trypsin, but with only limited inhibitory effect on its esterolytic activity. The possible role of these serum antiproteases in the onset of chronic obstructive pulmonary disease (COPD), analogous to the hereditary dysproteinaemia of alpha-1 antitrypsin in man, was investigated. There was no evidence of a genetically determined variation in the protease binding proteins but an increased frequency of the electrophoretically slower Pr antitrypsin alleles was present in horses affected with COPD. However, because of both the mixed breeding of the animals investigated and the lack of correlation with low serum trypsin inhibitory capacity, measured by inhibition of DL-BAPA hydrolysis, the significance of this observation could not be critically assessed.
| 90,612
|
The indirect rat mast cell degranulation test reconsidered.
|
The indirect rat mast cell degranulation test for the detection of human reaginic antibodies was reinvestigated. When the mast cells were incubated with human reaginic serum at concentrations exceeding approximately 3%, a massive, non-specific histamine release occurred, irrespective of the presence or absence of allergen. At tolerated serum concentrations (below 3%), the allergen concentration did not influence the release process. We conclude that the indirect rat mast cell test is not applicable as an alternative test system for the study of immediate hypersensitivity in humans.
| 90,655
|
Analysis of the expression of H-2 and H-2-linked antigens on mammary tumor cells.
|
The products of the recently discovered H-2L locus were expressed on BALB/c mammary tumor cells and behaved as histocompatibility antigens, in contrast to the products of H-2 linked loci (Qa-loci) that did not influence the acceptance or rejection of tumor transplants.
| 90,659
|
Regional topography within noradrenergic locus coeruleus as revealed by retrograde transport of horseradish peroxidase.
|
A hitherto unsuspected degree of regional topographic organization in the noradrenergic nucleus, locus coeruleus, was revealed by the use of retrograde transport of horseradish peroxidase (HRP) from terminal areas receiving noradrenergic innervation. HRP was injected into hippocampus, hypothalamus, thalamus, caudate-putamen, septum, amygdala-piriform cortex, cerebellum and cortex. Successful transport was obtained from all areas, including the caudate-putamen and cerebral cortex. The pattern of HRP positive cells in the ipsilateral locus coeruleus was markedly different depending on the location of the HRP injection. Thus, hippocampal injections labeled cells in the dorsal locus coeruleus but not at all in the ventral tip. Injections of HRP into caudate-putamen or cerebellum labeled the ventral tip along with the rest of the dorsal portion. HRP injections into the septum labeled cells only in the dorsal half of the dorsal locus coeruleus. There thus exists a three tier division of locus coeruleus into the ventral one third, dorsal one third and intermediate one third. A further division was seen in the anterior-posterior plane with HRP injections into the thalamus labeling the posterior pole of locus very intensely but with little transport to more anterior levels; conversely HRP injection into the hypothalamus resulted in intense labeling only in the anterior pole of locus coeruleus. Amygdala-piriform cortex HRP injections revealed a further pattern with very intensely reactive cells scattered sparsely throughout the nucleus. Cortical HRP injections yielded weaker labeling also in occasional, scattered cells. All HRP transport to locus coeruleus was shown to be noradrenergic by degeneration with 6-hydroxydopamine and due to terminal, rather than fiber of passage, uptake by control injection into the dorsal NA bundle. It is concluded that the locus coeruleus is not an homogenous nucleus with respect to the origin of the noradrenergic projections to sundry forebrain, spinal and cerebellar areas but is comprised of distinct subdivisions of noradrenergic neurons.
| 90,684
|
Batrachotoxin inhibits axonal transport without affecting membrane potential in single neurons of Aplysia californica.
|
Intrasomatic injection of 0.25 ng of batrachotoxin (BTX) caused no depolarization of giant cerebral neurons (GCN) of Aplysia californica within 4 hr at 23 degrees C. The amplitude of action potential and the input resistance were slightly and reversibly decreased. The same dose of BTX caused a 68% inhibition of fast axonal transport.
| 90,717
|
On the kinetics and maximal capacity of the system for rapid axonal transport in mammalian neurones.
|
1. Rabbit peroneal nerves were incubated in vitro in two-compartment chambers. Step-gradients of temperature were established so that the proximal part of each nerve was slightly warmer than the distal part. After incubation, the distribution of dopamine-beta-hydroxylase (DBH) activity along the nerves was examined as an indication of the behaviour of rapid transport in adrenergic axons. 2. With temperature gradients of 5 and 8 degrees C, transport velocity in the proximal regions was expected from previous work to be, respectively, 1.5 and 2 times faster than in the distal regions. Exposing nerves to these gradients induced a significant increment in the concentration of DBH activity, beginning at the boundary between regions. This increment was up to 50% of the normal activity and it propagated distally at the velocity expected for transport at the local temperature. 3. A temperature gradient of 13 degrees C was expected to produce a threefold difference in transport velocity between proximal and distal regions. This gradient produced a slightly larger increment of DBH activity propagating distally, again at the expected velocity. However there was also a disproportionate accumulation of enzyme activity at the boundary between regions. Further increases in the temperature gradient did not enhance the size of the propagating increment but only the rate at which enzyme accumulated at the temperature boundary. 4. It was concluded that adrenergic nerves can transport between two and three times as much material per unit time as they normally do. The ability to increase the flux of material appeared to depend on increases in the concentration of material in motion. There was no indication that such increases led to significant changes in the velocity of transport.
| 90,719
|
The nature of remission in acute myeloblastic leukaemia.
|
15 patients with acute myeloblastic leukaemia (AML) in remission were given immunotherapy and 17 similar patients were given immunotherapy plus chemotherapy with the drugs used to induce remission. Median remission length was 245 days for both groups and median survival was 465 days for patients given chemoimmunotherapy and 476 days for patients given only immunotherapy. The failure of remission chemotherapy in AML cannot be attributed to induced resistance because the same drugs induced a second remission in 60% of the patients. From laboratory studies with human AML cells it is suggested that in AML the residual leukaemic cells mature after induction chemotherapy and are then refractory to further drug treatment. Relapse occurs when the leukaemic population proliferates and the environment permits dedifferentiation into frank blast cells.
| 90,762
|
Lysozyme-induced T-suppressor cells and antibodies have a predominant idiotype.
|
The existence of shared idiotypic determinants on the surfaces of T and B cells is now firmly established, suggesting that on both these cell types immunoglobulin variable regions are expressed which presumably function as antigen receptors. In most systems this has been inferred through the use of anti-idiotypic antibody instead of antigen to induce either helper or suppressor T cells. Recent evidence demonstrates that antigen-specific suppressor or helper factors can also bear idiotypic determinants. It is possible that these factors represent released receptors or portions of receptors. We show here the direct elimination of an antigen-induced T-suppressor population by an anti-idiotypic serum and complement. These suppressor T cells as well as the idiotypic population used to generate the antiserum are each specific for the same limited portion of the multi-determinant antigen, lysozyme. Apparently, these suppressor cells are restricted in specificity as well as share idiotypy with antibodies of the same specificity.
| 91,111
|
Oxytalan fibers in peripheral odontogenic fibromas. A histochemical study of eighteen cases.
|
Oxytalan fibers, identified by histochemical methods alone, were found embedded. Since oxytalan fibers have been found embedded in bone in the periodontal ligament, the finding of these fibers in the calcified material of peripheral odontogenic fibromas adds considerable weight to the assumption that these lesions are of periodontal ligament origin.
| 91,150
|
Non-H-2 antigens on fibroblasts and an embryocarcinoma cell line react with xenoantisera against H-2 antigens.
|
The murine embryocarcinoma cell line F9 lacks the classical transplantation antigens. However, rabbit anti-H-2 antigen sera, recognizing "backbone structures" of H-2 K and D antigens, react with three types of molecules manufactured by F9 cells. A 49,000- and a 25,000-dalton chain are glycoproteins located on the cell surface. The third component with an apparent molecular weight of 15,000, and the 25,000-dalton chain seem to be unrelated to the 49,000-dalton glycoprotein. The 25,000- and 15,000-dalton components are not manufactured by splenocytes, thymocytes, hepatocytes, or various lymphoma, mastocytoma, and plasmacytoma cell lines. However, fibroblasts derived from both embryos and adult animals synthesize 25,000- and 15,000-dalton molecules reactive with the rabbit anti-H-2 antigen sera. The 49,000-, 25,000-, and 15,000-dalton molecules are not recognized by a syngeneic anti-F9 cell serum.
| 91,173
|
[Study of simultaneous dosage of carcino-embryonic antigen (C.E.A.) and beta 2-microglobulin in serum and pleural liquid (author's transl)].
|
Simultaneous dosage of carcino-embryonic antigen and beta 2-microglobulin was studied in serum and pleural liquid. Among the 20 patients with non-neoplasic infections, the carcino-embryonic antigen was not increased in the serum and only once at a border-line level in the pleura. The level of beta 2-microglobulin seems to be related to the number of lymphocytes in the pleural liquid (increase in 45% of the cases compared to 20% in the serum). Among the 31 cancer patients, carcino-embryonic antigen is increased in the serum of 36% of the cases and in the pleura of 48%. In 5 observations, the pleural levels were considerably increased compared with serum levels, suggesting the existence of a pleural metastasis. The beta 2-microglobulin is elevated in only 26% of the cases in the pleural liquid and in 13% in the serum. At the present state of knowledge, it therefore seems unnecessary to continue investigations concerning the beta 2-microglobulin. On the contrary, the pleural dosage of carcinoembryonic antigen could contribute to the diagnosis.
| 91,184
|
Increased frequency of HLA--DRw2 and DRw3 in multiple sclerosis.
|
Previous studies of multiple sclerosis patients showed the existence of a positive association between multiple sclerosis and HLA--A3 and --B7, as well as a negative association with B12. These observations have been confirmed. In addition, a more marked association has been observed with two recently identified B-cell antigens, DRw2 and DRw3, closely related to the HLA--D locus. The presence of cold lymphocytotoxic antibodies was found to bear no relationship with those two specificities. These results suggest that two genes of the HLA--DR region may play a role in the pathogenesis of multiple sclerosis.
| 91,212
|
On the heterogeneity of B40.
|
Evidence is presented for the heterogeneity of HLA-B40. At least two sub-groups can be recognized: Bw40.1 which is Cw3 associated and Bw40.2 which is Cw2 associated in Caucasians, but not in other populations. The recognition of Bw41 (Sabell), Bw47 (407*), and Bw48 (KSO) with both local Bw40 antisera and sera from the 7th Histocompatibility Workshop is discussed.
| 91,218
|
Detection of the H and I blood group antigens in normal plasma. A comparison with A and i antigens.
|
The levels of A, H, I and i antigens were measured in the plasma of 185 normal subjects by the agglutination-inhibition method. The presence of H in the plasma was only detectable with immune anti-H. The level of H in the plasma was directly correlated with the amount on the red cells, and was affected by the donor secretor status. The plasma of group O secretors contained more H than the plasma of donors of other phenotypes. On the other hand, I and i plasma antigens were not related to the other systems studied. Unlike the Ii antigens on the red cell membrane, there was no relationship between the levels of I and i in plasma.
| 91,265
|
[Immunologic study of the cellular components of bacillus pyocyaneus. V. Antigenic analysis of slime and its fractions].
|
Various slime fractions were obtained from newly isolated mucoid strains of P. aeruginosa by the method of ultrafiltration or differential centrifugation with subsequent gel chromatography. Purified slime was found to react with a broader spectrum of typing O sera than the corresponding cell wall lipopolysaccharides. Erythrocytic diagnostic preparations produced on the basis of slime antigens allowed to reveale the presence of circulating antibodies against P. aeruginosa. The slime components with molecular weight of 30,000--100,000 daltons and greater contained common antigenic determinants, and the slime components with molecular weight of 10,000--30,000 daltons contained both specific antigenic determinants and those also common to the high molecular components.
| 91,285
|
Effect of sensitization on spontaneous and phosphatidylserine-induced histamine release and on cyclic AMP and GMP levels in isolated rat mast cells.
|
Sprague Dawley rats were sensitized with 20 microgram or 100 mg egg albumin (using pertussis vaccine as adjuvant). Mast cells isolated from the former group of animals showed a higher degree of histamine release upon challenge in vitro with egg albumin than those from the latter group. Using the lower amount of antigen for immunization mast cells from Hooded Lister rats showed an even higher degree of histamine release induced by antigen. An increased antigen-induced histamine release was associated with an increased spontaneous and phosphatidylserine-induced histamine release. Histamine release induced by phosphatidylserine was found to be specific in so far as it was calcium dependent and theophylline-inhibited. The basal level of cyclic AMP in mast cells was significantly depressed by sensitization. There was a relationship between the cyclic AMP/cyclic GMP ratio and the degree of spontaneous, phosphatidylserine-induced and anaphylactic histamine release. The results suggest that sensitization induces an increased release of histamine not only to the specific antigenic stimulus but also to more unspecific stimuli. Concomitantly there is a fall in the cyclic AMP/cyclic GMP ratio. The relationship between these two phenomena is discussed.
| 91,306
|
Sulphate-ion/sodium-ion co-transport by brush-border membrane vesicles isolated from rat kidney cortex.
|
Uptake of SO(4) (2-) into brush-border membrane vesicles isolated from rat kindey cortex by a Ca(2+)-precipitation method was investigated by using a rapid-filtration technique. Uptake of SO(4) (2-) by the vesicles was osmotically sensitive and represented transport into an intra-vesicular space. Transport of SO(4) (2-) by brush-border membranes was stimulated in the presence of Na(+), compared with the presence of K(+) or other univalent cations. A typical ;overshoot' phenomenon was observed in the presence of an NaCl gradient (100mm-Na(+) outside/zero mm-Na(+) inside). Radioactive-SO(4) (2-) exchange was faster in the presence of Na(+) than in the presence of K(+). Addition of gramicidin-D, an ionophore for univalent cations, decreased the Na(+)-gradient-driven SO(4) (2-) uptake. SO(4) (2-) uptake was only saturable in the presence of Na(+). Counter-transport of Na(+)-dependent SO(4) (2-) transport was shown with MoO(4) (2-) and S(2)O(3) (2-), but not with PO(4) (2-). Changing the electrical potential difference across the vesicle membrane by establishing different diffusion potentials (anion replacement; K(+) gradient+/-valinomycin) was not able to alter Na(+)-dependent SO(4) (2-) uptake. The experiments indicate the presence of an electroneutral Na(+)/SO(4) (2-)-co-transport system in brush-border membrane vesicles isolated from rat kidney cortex.
| 91,368
|
Galactosyltransferase from commerical preparations of fetuin.
|
A galactosyltransferase that transfers galactose from UDPgalactose to asialoagalacto fetuin or N-acetylglucosamine was partly purified from two commerical preparations of fetuin and its kinetic properties were characterized. Several other preparations of fetuin were also found to contain galactosyltransferase activity.
| 91,386
|
Non-immunological release of slow-reacting substance from guinea-pig lungs.
|
1 During incubation with calcium ionophore A23187, sensitized and unsensitized guinea-pig chopped lung released a slow-reacting substance (SRS) and histamine. 2 SRS possessed many characteristics of slow-reacting substance of anaphylaxis (SRS-A). It was inactivated by arylsulphatase, antagonized by FPL55712 (1 microgram/ml) and more stable in alkali than acid. Furthermore, it behaved like SRS-A by stimulating archidonic acid metabolism in guinea-pig isolated perfused lungs. 3 Maximal ionophore generation of SRS in sensitized lung was greater than maximal anaphylactic generation of SRS-A but the release of histamine was not significantly different. Simultaneous challenge with antigen and ionophore produced more SRS-like or SRS-A-like activity than either stimulus alone. 4 These results have shown a non-immunological release from guinea-pig lung of SRS which was similar (or possibly identical) to SRS-A. It is suggested that in addition to mast cells, other cell types may be involved.
| 91,403
|
Primary leiomyosarcoma of the bone and its comparison with fibrosarcoma.
|
Two cases of primary leiomyosarcoma of the bone are recorded, one in the distal fibula of a 66-year-old man, the other in the proximal tibia of a 61-year-old woman. The cytological, histological, and ultrastructural features of leiomyosarcoma of bone are described and compared with those of fibrosarcoma. These features are sufficiently characteristic to enable a confident diagnostic distinction between leiomyosarcoma and fibrosarcoma. Nevertheless, certain basic similarities exist between these two tumors, manifested at the ultrastructural level by the presence of myofilaments in fibrosarcoma; it would seem that the observed differences relate to the degree of development of the myofilamentous structures. It is postulated that primary leiomyosarcoma of the bone need not necessarily always arise from the media of blood vessels; it might also conceivably develop through advanced myogenic metaplasia of a sarcoma originating from fibroblastic tissue.
| 91,423
|
Mutagenicity and cytotoxicity of nineteen heterocyclic mustards (ICR compounds) in cultured mammalian cells.
|
The mutagenicity and cytotoxicity of 19 ICR compounds, including 6 reported previously, have been determined in the Chinese hamster ovary/hypoxanthine-guanine phosphoribosyltransferase system. As with other physical and chemical agents, ICR 170 and 191 exhibit a phenotypic expression time of 7 to 9 days, independent of concentrations tested. Thirteen of these compounds are mutagenic. At equimolar concentrations, the compounds with the tertiary amine-type side chain (ICR 217, 340, 355, 368, 170, and 292) are more mutagenic than the compounds with the secondary amine-type side chain (ICR 449, 371, 191, and 372). All secondary amine types show a "plateau" in their concentration-dependent mutagenesis curves at 3 to 4 microM. Shortening of the side chain by one carbon (ICR 171) results in a reduced mutagenicity. Substitution of a sulfur atom for a nitrogen in the side chain (ICR 342) increases both mutagenicity and cytotoxicity. The presence of two 2-chloroethyl groups on the side chain (ICR 220) also results in greatly increased cytotoxicity and mutagenicity. When the 2-chloroethyl group of ICR 340, 372, 292, 191, or 170 is replaced by a 2-hydroxyethyl group (ICR 340-OH, 372-OH, 292-OH, 191-OH, or 170-OH), a mutagenically inactive compound results which remains toxic. Replacement of the amine linkage with an ether linkage (ICR 283) also yields a mutagenically inactive compound.
| 91,429
|
Treatment of metastatic nonseminomatous testicular cancer: a preliminary report of induction chemotherapy followed by maintenance chemotherapy or radiotherapy.
|
Patients with metastatic nonseminomatous testicular cancer received an induction regimen consisting of bleomycin in 24-hour infusions and bolus iv doses of vinblastine followed by an Adriamycin and cis-dichlorodiammineplatinum(II) combination. Patients achieving complete remission after one or two cycles of this induction chemotherapy were then randomized to receive either radiotherapy (RT) to the previously involved tumor areas or maintenance chemotherapy (MCT) with CCNU, methotrexate, and vinblastine for 2 years. Among 62 evaluable patients, induction chemotherapy achieved 15 (24%) partial remissions and 35 (56%) complete remissions. Two patients with partial remission and single pulmonary metastases were rendered disease-free by surgical resection of residual tumor. Twenty patients received MCT and 15 received RT. To date, median survival is 10,8+ months in the MCT group with five relapses and 12.5 months in the RT group with two relapses. Toxicity in the induction phase was moderately severe with two drug-related deaths.
| 91,436
|
ZIO staining in synaptic vesicles of the rat pineal nerves after inhibition of serotonin and noradrenaline synthesizing enzymes.
|
Two compartments have been defined in monoaminergic synaptic vesicles: the core or central compartment, storage site for monoamines, and the matrix or outer compartment, of unknown function. The outer compartment reacts with the mixture of zinc iodide-osmium tetroxide (ZIO). This reaction is temperature and time dependent and may be abolished by -SH reagents. The effect of drugs inhibiting the synthesis of serotonin and noradrenaline (stored in the core) on the ZIO reaction in the matrix was studied in synaptic vesicles of rat pineal nerves. The inhibitors of monoamine synthesis abolish or decrease the ZIO reaction directly or in combination with the administration of tyramine. This effect is temperature dependent suggesting that the drugs act on different components of the matrix that react with ZIO at different temperatures. A comparison of the present results with those obtained with -SH reagents seems to indicate that the drugs assayed act, at least in part, by changing the accessibility of -SH groups in vesicle proteins. (An abstract of this paper was presented at the 7th International Congress of Pharmacology, Paris, 1978.)
| 91,445
|
Differential staining and segregation of parental chromosomes in mouse-rabbit hybridomas.
|
Hoechst 33258 fluorescent staining can be coupled with G-banding to identify the chromosomal contribution of each parent in mouse-rabbit hybridomas. A fast and essentially complete segregation of rabbit chromosomes is obtained in these cells. The rabbit X chromosome is preferentially maintained in media imposing HGPRT activity for cell growth. Mouse-rabbit hybridomas, some of which secrete rabbit immunoglobulin chains, should be a convenient material for the identification of chromosomes governing rabbit Ig chain synthesis.
| 91,448
|
Selective production of human antigen specific helper factor from normal volunteers: implications for human Ir genes.
|
Based on previous systems for generating helper cells and factors from mouse spleen cell cultures, an in vitro system for the production and detection of human helper factors to the synthetic polypeptide antigens (T,G)-A--L and GAT10 was developed. The factors are made by human peripheral blood leucocytes and are antigen-specific, as judged both by functional criteria and specific binding and elution from antigen columns. Out of the first six volunteers studied two were high responders to (T,G)-A--L, but non-responders to GAT, two responders to GAT but not (T,G)-A--L. One subject made factors to both antigens and the sixth reacted to neither. The antigens chosen are known to be under MHC-linked immune response (Ir) gene control in all animal species tested, with some strains being responders while others are not. The selective responsiveness, different between individuals, thus suggests that the response to these antigens in man is under Ir gene control. Because of the small size of the sample initially studied and HLA typed, it was not surprising that there was no clear-cut association of response with any particular histocompatibility type at the HLA-A, B, C or D locus.
| 91,463
|
Antigen-specific detection of HBsAG-containing immune complexes in the course of hepatitis B virus infection.
|
In recent studies extrahepatic manifestations of viral hepatitis have been recognized as immune complex diseases. Hepatitis B surface antigen (HBsAg) has been successfully identified in immune complexes, but the pathogenic role of HBsAg-containing immune complexes (IC) remains questionable. The subject of the present study was the antigen-specific determination of IC in the course of hepatitis B virus infection using a new HBsAg-specific IC test (Pernice & Sedlacek, 1978). This test is based on the following principle: rabbit anti-HBs-coated polystyrole test tubes are incubated with the IC-containing test sample. The HBsAg-containing IC bind to the solid phase by their free antigenic determinants. There they can be quantified using a peroxidase-labelled anti-human IgG antibody. A good correlation was found between the level of HBsAg-containing immune complexes and the clinical state of six patients in a follow-up study. IC could be detected simultaneously with HBsAg and either decreased or disappeared before the occurrence of free anti-HBs. In the sera of an additional twenty-eight patient suffering from chronic active hepatitis, HBsAg-containing immune complexes were detected in 85% of cases. One patient suffering from polyarteritis nodosa was also positive. Occasionally, extremely high levels of IC were found in the course of these diseases.
| 91,465
|
Transport of vitamin D metabolites.
|
Vitamin D and its metabolites are bound to an alpha globulin (DBP) in human serum. This carrier protein binds 25-OHD and 24,25(OH)2D with higher affinity than vitamin D or 1,25(OH)2D, but the binding is highly specific for the vitamin D structure. The carrier mechanism appears to be unique in that it is a high affinity and high capacity system, capable of binding as much as 120,000 IU of biological activity per liter of plasma. DBP is apparently identical to group-specific component, and a DBP-deficient state has not been identified among approximately 75,000 human sera examined thus far. The liver appears to be the site for synthesis of DBP, and serum DBP levels are increased during pregnancy and during estrogen-progesterone therapy. However, in a variety of disorders of mineral homeostasis, serum DBP levels are normal. Two tissue binding proteins for vitamin D metabolites have been identified. One protein, sedimenting at 5-6S, has been found in all nucleated tissues, and exhibits a ligand preference similar to DBP. This tissue binding protein appears to be a complex of serum DBP with a tissue protein which is heat-labile, and which shows no capacity for binding vitamin D sterols. The physiologic role, if any, for this complex of serum DBP and tissue protein is not presently understood. The other tissue binding component is a 3-4S protein found only in recognized target tissues, and which shows a high binding affinity and specificity for 1,25(OH)2 D. It appears to be the receptor in the receptor-1,25(OH)2D migration to the nucleus, leading to the biosynthesis of mRNA which codes for products which affect calcium and phosphorus transport in target tissues.
| 91,467
|
Short latency mechanically evoked somatosensory potentials in humans.
|
Somatosensory potentials evoked by mechanical stimulation were recorded by surface electrodes over (1) the digital nerves in the index finger, (2) the median nerve at the wrist, (3) the median nerve near the axilla, (4) the brachial plexus, (5) the cervical cord at CII, (6) the scalp overlying the somatosensory cortex. Nerve conduction velocities varied inversely with age and ranged from 43 to 68 m/sec. Mechanically evoked potentials recorded from the electrodes overlying the digital nerves were an artifact of the finger movement. All other electrode configurations recorded potentials comparable to those evoked by electrical stimulation of nerves. These mechanically evoked potentials could prove useful in the assessment of clinical disorders of somatosensory function from receptor to cortex in man.
| 91,479
|
L-tryptophan and sleep in healthy man.
|
The effect of L-tryptophan on night-time and day-time sleep (from 14.00 h) sleep was studied in six healthy males aged between 20 and 30 years. The doses used in the night-time studies were 2, 4 and 6 g, and in the day-time studies 1, 2 and 4 g. It was not possible to establish an effect of L-tryptophan compared with placebo on night-time sleep, but analysis of the sleep measures with 4 g compared with placebo and the other doses of L-tryptophan considered together suggested reduced awakenings, increased stage 3 and an increased percentage of REM sleep. With 4 g L-tryptophan there was an increase in the duration of stage 3 of day-time sleep compared with placebo. The studies provide marginal evidence that REM sleep may be modified by L-tryptophan in man, though the evidence is somewhat stronger that SWS may be increased. The effect on REM sleep may involve circadian mechanisms. The hypnotic activity of L-tryptophan per se is limited and uncertain.
| 91,481
|
A portable pulse-interval modulation telemetry/multiplexing EEG recording system for use in the home.
|
A portable 6-channel recording system employing time-division multiplexing with cable or radio-telemetry has been developed. The system is very compact and has proved to be reliable when used in a domestic environment. The use of multiplexing, in general, permits an expansion in the number of available channels and a reduction in equipment and tape costs, while the use of pulse interval modulation, in particular, overcomes tape recording limitations which may be encountered with the more common amplitude modulation techniques.
| 91,491
|
[Immunological concentration determinations of the streptokinase preparation Awelysin dissolved in various infusion solutions for its stability evaluation].
|
By means of the electro-immuno-assay according to Laurell the decrease of concentration was determined for the streptokinase preparation Awelysin dissolved in various infusion media at 20 degrees C. The stability behaviour of a streptokinase solution of 1.000 IE/ml showed a significant decrease of concentration after 24 hours (alpha less than 5%) as compared with the initial concentration. However, in comparison no significant differences as to the streptokinase stability could be found by using different infusion solutions. At 20 degrees C the decrease of streptokinase concentration may be neglected up to 24 hours in an infusion solution of streptokinase previously prepared.
| 91,562
|
Amplification of plaque-forming cells in the spleen after intracloacal antigen stimulation in neonatal chicken.
|
Neonatal chickens were primed by multiple or a single injection with sheep red blood cells (SRBC) into the cloacal lumen and then were challenged by intravenous injection with the same antigen. Direct plaque-forming cells (PFC) in the spleen were markedly increased shortly after intracloacal priming. This enhancing effect was antigen specific and was abolished by surgical bursectomy 24 h after intracloacal priming. A similar effect was also found in mature adult chickens, although the degree of enhancement was far less than that found in neonatal chickens. These results suggest that a certain stage of B-cell differentiation in the bursa of Fabricius (BF) is regulated by antigenic stimulation.
| 91,577
|
Fragility of attenuated Rauscher leukemia virus.
|
Some biochemical properties of virulent (RRL+) and attenuated (RCL-) Rauscher leukemia virus were compared. It was shown that the reverse transcriptase (RT) activity of 'aged' as well as 'fresh' RCL- virions was 25--30% of that found for RRL+. The thermal sensitivity of the RT was the same for both viruses. A 60--70S RNA could be extracted from 'aged' RRL+, while no high molecular weight RNA was obtained from 'aged' RCL-. After centrifuging in sucrose gradient, most of the RT activity and 3H-labeled RNA of 'aged' RRL+ was recovered at 1.14--1.16 g/cm3, while for 'aged' RCL- no labeled RNA, and at most 10% of the original RT activity were found in the same zone. The fragility seemed to increase in the course of aging, since 'fresh' RCL- banded at 1.14--1.16 g/cm3 as did 'fresh' RRL+. Also, 3H-labeled viral RNA was found in the viral bands, from which 60--70S RNA could be extracted. Molecular hybridizations showed that 20% of the nucleic acid sequences related to Rauscher leukemia virus found in the RNA of RRL+-infected cells were missing in the RNA of RCL--infected cells.
| 91,588
|
Picrosirius staining plus polarization microscopy, a specific method for collagen detection in tissue sections.
|
Sirius Red, a strong anionic dye, stains collagen by reacting, via its sulphonic acid groups, with basic groups present in the collagen molecule. The elongated dye molecules are attached to the collagen fibre in such a way that their long axes are parallel. This parallel relationship between dye and collagen results in an enhanced birefringency. Examination of tissue sections from 15 species of vertebrates suggests that staining with Sirius Red, when combined with enhancement of birefringency, may be considered specific for collagen. An improved and modified method of staining with Sirius Red is presented.
| 91,593
|
The significance of a differential distribution of phosphomonoesterases on bone surfaces after prolonged demineralization.
|
An observed differential distribution of alkaline and acid phosphatase on the surfaces of growing bones may serve to describe transformative processes of bone growth. This conclusion has been reached by comparing the distribution of the two enzymes on the surfaces of fibulae from young rats with the patterns of apposition and resorption on the periosteal surfaces of this bone, revealed by in vivo staining with alizarin red S. Presence of reaction to acid phosphatase is, as shown before, an indication of resorptive surfaces, while the presence of reaction to alkaline phosphatase is an indication of depository surfaces.
| 91,597
|
Multi-media graphics: a transparency system.
|
Persons responsible for teaching in the health sciences are justifiably concerned about the cost of their visual presentations. These graphics can be used as slides and in publications and illustrators need to know how the transparency system can convert publication material into effective color visuals as 35mm slides, video tapes or television graphics at a moderate cost.
| 91,604
|
Some properties of polyethylene glycol:phenylalanine ammonia-lyase adducts.
|
Methoxypolyethylene glycol of 5000 daltons (PEG) was attached covalently to phenylalanine ammonia-lyase from Rhodotorula glutinis. Attachment of sufficient quantities of PEG to phenylalanine ammonia-lyase substantially reduces immunological recognition and clearance of the conjugated enzyme in mice. The modified enzyme demonstrates altered catalytic properties such as shifts in the pH and temperature optima, an increase in the Michaelis-Menten constant, and a lowered Vmax in comparison with the native enzyme. PEG-phenylalanine ammonia-lyase has increased resistance to proteolytic digestion, particularly when in the presence of cinnamate, a competitive inhibitor, while the native enzyme is rapidly inactivated. In the ultracentrifuge PEG-phenylalanine ammonia-lyase exhibits a lower sedimentation rate than the unmodified enzyme, despite the fact that it is much larger. The electrophoretic mobility of PEG-phenylalanine ammonia-lyase is greatly decreased in comparison to the unmodified enzyme. PEG-phenylalanine ammonia-lyase had a much longer blood-circulating life in mice, both initially and after a number of injections, than did the native enzyme. PEG-phenylalanine ammonia-lyase was a good immunogen but a poor antigen in mice and rabbits, that is, it readily induced antibody formation, but reacted poorly in vitro with the antibodies that were formed against it.
| 91,612
|
Effect of various histological fixatives on fluorescent antibody detection of Legionnaires disease bacteria.
|
Human lung tissue containing the Legionnaires disease bacterium was fixed in seven different histological fixatives, processed, and embedded in paraffin. Deparaffined sections from each were stained by fluorescent antibody and by Dieterle silver impregnation. With the fluorescent antibody stain, the Legionnaires disease bacterium could be detected in tissues prepared with any of the fixatures, but the Dieterle silver impregnation was not satisfactory on Zenker-fixed tissues.
| 91,621
|
Immunochemical evidence for multiple serotypes of Bacteroides fragilis.
|
An immunochemical comparison of outer membrane antigens obtained from five select and biochemically defined strains indicated that there are several serotypes of Bacteroides fragilis. Each strain was serologically defined by individual or by combinations of determinant groups composed of carbohydrates in the form of polysaccharides or glycoproteins. The carbohydrate constituents were tentatively identified as glucose, galactose, fucose, rhamnose, glucosamine, galactosamine, and traces of mannose. Strains were observed to have minor qualitative and major quantitative variations in carbohydrate composition.
| 91,622
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.