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Synchronous beating between chick embryonic heart cell aggregates and heart cell layers was used to study the relationship between intercellular adhesion and ionic coupling. Adhesion was measured by counting the proportion of aggregates which were not to be removed from cell layers by gentle washing after a 30 min incu...
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We have examined correlations between morphological and functional evidence of cell coupling between aggregates of beating embryonic heart cells and underlying layers. Synchronously beating aggregate-layer pairs were compared with asynchronous pairs. Intracellular microelectrode studies demonstrated that asynchronously...
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The microtubule nucleating capacity of chromosomes was tested in vitro in lysates of Chinese hamster ovary cells. Colcemid-blocked mitotic cells were lysed with the detergent Triton X-100, incubated with exogenous porcine brain tubulin, attached to electron microscope grids and observed as whole-mounts. Under suitable ...
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The phosphorylation of proteins from murine splenic lymphocytes was studied. When the phosphorylation of proteins in extracts from Concanavalin A (ConA)-treated lymphocytes was compared with that of resting lymphocytes, there was only one detectable difference between them. A protein of 135,000 mol. wt was highly phosp...
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Double minutes of a human breast cancer cell line revealed no centromeres by Cd banding. They cluster at the periphery of metaphase plates, usually encased in a matrix material. They move in anaphase passively with the chromosomes by attaching to the sides or ends of the chromosomes. The two "sister minutes" move to th...
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The mechanisms of CSF formation and absorption have been reviewed. The conditions that alter the rate of CSF formation and absorption may change the concentration of contrast in the cranial cisterns and the rate of passage through the cisterns. The significance of these alterations in relation to the complications of m...
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We used immunofluorescence to examine the developmental relationship of Ia and IgD on B cells. Pre-B cells in fetal liver did not express Ia. Only very few surface IgM-positive (sIgM+) B cells in fetal spleen were found to be Ia+ and were weakly stained for Ia. After birth there was a linear increase in the proportion ...
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The efficiency of 35 nitroaromatic and nitroheterocyclic compounds in radiosensitizing hypoxic Chinese Hamster cells in vitro was determined. The concentration C of the compound required to achieve an enhancement ratio of 1.6 was measured, and the redox and partition properties were quantified as the one-electron reduc...
United Kingdom
This paper describes measurements of the aerobic cytotoxicity of 42 nitroaromatic and nitroheterocyclic compounds towards Chinese Hamster cells in vitro. The results of acute and chronic exposure were quantified, and the concentration C required to achieve a standard response estimated. Fitting the data to an equation ...
United Kingdom
Sera from 203 recipients prior to transplantation were examined against a panel of 30 T and B lymphocytes at 5 degrees C and 37 degrees C. Those patients classified as having B-cold cytotoxins only had higher 1-year transplant survival rates from cadaver donors (82%) than patients with no antibodies (58%) or patients w...
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The objective of the present study was to determine whether or not thymosin and conditioned medium from human thymus epithelial cultures (HTECM) contain similar fractions, capable of inducing T-cell differentiation. Therefore we tested the ability of rabbit antisera to different thymosin fractions (thymosin fractions 5...
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The objective of these experiments was to determine the effects of neonatal thymectomy on the induction of experimental autoimmune orchitis in inbred rats of the Fischer 344 and Lewis strains. It was found that thymectomy alone in Lewis rats, and thymectomy followed by immunization with testicular extract in both Lewis...
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In vitro culture of haematopoietic cells has provided some surprising insights into critical interactions of blood-forming cells. Subpopulations of lymphoid cells have been shown to produce colony-stimulating activity, to interact with macrophages, and to have important effects on the very early stages of erythropoiesi...
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The effects of Corynebacterium parvum on the lymphohemopoietic tissues of mice was investigated by H3-TdR metabolism, organ weights, DNA-polymerase-alpha activity and terminal deoxynucleotidyl transferase (TdT) activity. Marked increase in spleen size occurred. The increase in size was accompanied by increases in DNA-P...
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Previous studies had suggested that methotrexate (MTX) may have actions other than inhibition of dihydrofolic acid reductase. In this study MTX was added to the assay incubation mixture of the enzyme thymidylate synthetase. 5-fluorodeoxyuridine (FUdR) or folinic acid was added separately as controls. The three compound...
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Lymph node cells from normal guinea pigs, when stimulated with the non-specific mitogen PHA, were transformed to activated killer cells, capable of lysing 51Cr labeled mouse fibroblasts. Similarly, these lymphoid cells effected lysis of antibody coated chicken red cells in an antibody-dependent cellular cytotoxicity as...
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TAF (T-cell activating factor), produced by peritoneal macrophages and assayed by its ability to potentiate DNA synthesis in macrophage-depleted lymph node cells stimulated with Phytochemagglutinin-concanavalin A, was shown to contain catheptic carboxypeptidase B (CPB) which accounted almost quantitatively for its pote...
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The apposition between type I hair cells and the calyceal terminals of vestibular ganglion cell peripheral processes was studied in the vestibular epithelium of the guinea-pig, using thin-sectioned and freeze-fractured specimens. Chemical synaptic junctions were exceedingly rare in thin-sectioned specimens, and were no...
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Peripheral blood T and non-T lymphoid cells were examined in 31 patients with a variety of primary immmunodeficiencies for their locomotor activity toward casein and endotoxin-activated serum. T cells from 1 and non-T cells from 2 of 7 patients with Bruton type agammaglobulinemia had poor locomotor activity in this sys...
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New techniques have permitted serial assessments of visual acuity in infants. Acuity measurements in infants with astigmatism did not reveal meridional amblyopia during the first year of life. Measurements in infants with esotropia showed marked differences in acuity of the two eyes as early as the first 6 months of li...
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Male frogs (Rana pipiens) were injected intraperitoneally with triethylenemelamine (TEM). The injected males were held for seven days to permit TEM interaction with sperm. The TEM-treated males were then spermiated with human chorionic gonadotropin (HCG) and the ova of normal females were inseminated with the sperm. Di...
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The hypoxic radiosensitizer misonidazole decreases survival in dense cultures of HeLa cells irradiated with gamma rays in a non-dose modifying fashion. Survival curves of treated hypoxic cells display a much larger extrapolation number than untreated cells. In oxygenated randomly dividing cells, drug treatment has an e...
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Purified L-cell colony stimulating factor (CSF) and rabbit anti-CSF serum were used to devise a radioimmunoassay for this factor. The CSF was radiolabelled with the aid of lactoperoxidase and precipitated by a double antibody technique. Addition of unlabelled CSF caused a dose-related displacement of the labelled trace...
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Corneal degenerations are among the most commonly observed clinical disorders in ophthalmology. They may be classified as (1) aging changes, (2) depositions, and (3) marginal degenerations. Aging changes are often incidental findings and do not usually interfere with vision. Depositions can occur secondary to previous ...
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The viscoelastic properties of reconstituted canine tracheal mucus were correlated with the ciliary transport rate measured on the bullfrog palate. A maximum in mucociliary transport rate was found at an optimal concentration of nondialyzable solids of 1.5 to 2 per cent. At concentrations less than this value, the mucu...
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An iterative Fourier method is applied to solving and refining the electron density profile projected into the line perpendicular to a membrane surface. Solutions to the continuous X-ray scattering pattern derived from swelling of multilayer systems or from membrane dispersions can be obtained by this technique. The me...
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An in vitro preparation of hair cells from the bullfrog sacculus produces a transepithelial microphonic potential in response to well-defined mechanical stimuli. If corrected for the electrical time constant of the epithelium, the response follows a fast stimulus with a 40-microsecond delay at 22 degree C. The short la...
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Spleen cell populations from mice treated with Adriamycin or daunorubicin were found to develop a greater PHA-stimulated clonal response than spleen cells from untreated or cyclophosphamide-treated animals. Daunorubicin, in addition, stimulated an unusual monocytic macrophage-like colony. The results are consistent wit...
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The influence of stretch and radial compression on the width of mechanically skinned fibers from the semitendinosus muscle of the frog (R. pipiens) was examined in relaxing solutions with high-power light microscopy. Fibers were skinned under mineral oil. We find that, after correcting for water uptake in the oil, fibe...
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Preoperative and serial postoperative clinical, cardiovascular, physiologic, and metabolic studies were carried out on 86 patients undergoing coronary artery bypass surgery (CABG); and 48 patients undergoing abdominal general surgical procedures (GSEL). Multivariable statistical analysis of these data showed the patien...
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Fetal and maternal compartments differ in factors shown to regulate 24.25 dihydroxyvitamin D [24,25(OH)2D] metabolism [calcium, phosphorus, and parathyroid hormone (PTH)] such that one might predict that maternal serum 24,25(OH)2D levels are decreased and fetal 24,25(OH)2D concentrations are increased. To evaluate this...
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In a cross-sectional study, the serum levels of pregnancy-specific beta 1-glycoprotein (PSBG), hCG, human LH, and progesterone were measured by RIAs during 94 mid or late luteal phases of 69 women using oral contraceptives. Subsequent spontaneous menstruation took place in every cycle. None of the women using oral cont...
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Epidermal growth factor (EGF), a polypeptide hormone originally discovered in the mouse submaxillary gland, stimulates growth in a variety of tissues in several species. This hormone has recently been identified in human urine. A homologous RIA for human EGF (RIA-hEGF) has been developed. In general, levels were simila...
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beta-Lactamase encoded by a small, nontransferring R-plasmid, NTP1, conferring ampicillin resistance to its host bacteria, was purified. NTP1 plasmid-coded beta-lactamase was found to be periplasmically located in the host Escherichia coli cell, to have a molecular weight of about 25,000, and to show a relatively low a...
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Receptor cells in the ear are excited through the bending of sensory hairs which project in a bundle from their surface. The individual stereocilia of a bundle contain filaments about 5 nm in diameter. The identity of these filaments has been investigated in the crista ampullaris of the frog and guinea pig by a techniq...
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Membrane turnover in outer segments of Rana pipiens red rods (ROS) was studied in tadpoles maintained under cyclic lighting (12L:12D) at 23 degrees, 28 degrees, and 33 degrees C. Large fragments (greater than 2 microns in diameter or length) were shed from the ROS tips shortly after the onset of light. These were phago...
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Chronic unit activity and gross movement were recorded from rats during two discrimination reversals in a classical appetitive conditioning situation. The anticipatory movement decreased in response to the former CS+ tone and increased to the previous CS- tone after each reversal. Hippocampus and motor cortex were diff...
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Three types of synapses occur in the anteroventral thalamic nucleus (AVN). Type 1 consists of small (0.5-0.8 microns) axonal endings densely packed with spherical synaptic vesicles. They form markedly asymmetrical synaptic contacts with distal portions of dendrites. Degenerative changes in these axons following destruc...
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In order to clarify which midbrain areas project to the caudate nucleus (Cd), horseradish peroxidase (HRP) was deposited in the Cd of 13 cats. Midbrain sections were reacted with diaminobenzidine and sometimes with cobaltous chloride to intensify the reaction, and then examined for retrograde labelling. Afferents to th...
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Morphine administered intracerebrally (IC) (10 micrograms as the base on each side) into the MRF produced a significant dose dependent elevation of nociceptive threshold (i.e., analgesia) on the tail flick test and hemostat pinch test. However, morphine IC at lower doses had no analgesic effect. After morphine was inje...
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All the opiate-like peptides we tested (Met-enkephalin, (D-Ala2)-Met-enkephalin-NH2, beta-endorphin, (D-Ala2)-beta-endorphin, (D-Ala2)-alpha-endorphin, (D-Ala2)-gamma-endorphin) were capable of reducing distress vocalizations (DV's) in socially-isolated chicks when injected into the vicinity of the fourth ventricle in ...
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Prior studies of developmentally protein malnourished rats have reported substantial changes in brain and peripheral utilization of 14C-leucine, 14C-phenylalanine, and 14C-tryptophan. In the present study rats born to dams fed a low protein diet (8% casein) compared to the offspring of control rats fed a normal diet (2...
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Procedures and instrumentation are described for making micro-injections into early avian embryos. Tools for implementing injection include support probes and micro-cannula adapters, both of which greatly reduce embryonic insult. Using these instruments, viability following certain early embryonic injections has been s...
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In view of the demonstrated role of light and of the suprachiasmatic nucleus (SCN) in the maintenance of circadian rhythms related to endocrine functions and as the mediobasal hypothalamus (MBH) controls neuroendocrine activity, the effects of light and MBH stimulation on the electrical activity of SCN neurons were stu...
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The possible involvement of basal telencephalic structures in visually conditioned heart rate change (established by pairing light and foot-shock) was studied in 156 pigeons by evaluating conditioning performance following lesions of the septum or lobus parolfactorius. Extensive destruction of the septal complex had no...
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In Golgi-prepared material, opossum basilar pontine intrinsic neurons measured less than 22 microns and gave origin to only two or three primary dendrites which gradually tapered in diameter, branched infrequently and exhibited few spines or protrusions. Characteristically, such neurons gave rise to several axon-like p...
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The paraventricular nucleus (PVN) has been identified as the most responsive site in the brain for eliciting feeding and preprandial drinking responses with local injection of norepinephrine (NE) in satiated rats. The present study examined these phenomena as a function of dose and time of injection in the light-dark c...
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To study the question of whether or not cell death contributes significantly to normal or stressed postnatal brain development in a way which is biochemically quantifiable, we carried out an experiment to assess the amount of cell death in developing cerebellum. By measuring the loss of DNA content and the loss of 14C ...
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Single, intravenously administered doses of cefoxitin and cefamandole did not penetrate into cerebrospinal fluid of normal humans. Multiple-dose administration with or without probenecid facilitated penetration of both antibiotics into the cerebrospinal fluid. Preliminary data showed that cefoxitin penetrated into cere...
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A clinical trial was designed for evaluation of the efficacy, safety, and patient tolerance of cefoxitin. Of 26 patients who could be evaluated clinically, 21 had respiratory tract infections; all but one patient responded satisfactorily to therapy with cefoxitin. There were no adverse systemic reactions, nor was any r...
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1. Hymenolepis diminuta incorporated label from 14C-galactose into glycogen, but the sugar would not support net glycogen synthesis. Glucose stimulated the incorporation of label from 14C-galactose into glycogen, while glycerol did not. 2. During incubations in galactose, large internal pools of galactose and galactose...
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1. Many organs of the skate Raja erinacea have been found to contain scyllo-inositol levels that are much higher than myo-inositol, the opposite to that found in mammals. 2. Both inositols were found in all skate organs studied. 3. myo-Inosose-2 was found to accompany the inositols in many of these organs.
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1. Myosin from the thin-filament regulated flexor muscle of lobster contains 2 moles of each of 2 light chains. 2. The Lb 1 light chain of 19,000 daltons which can be removed by DTNB is heavier than the DTNB light chain of chicken. The Lb 2 light chain of 17,000 daltons can be removed with urea. 3. On electrophoresis i...
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1. The main bilirubin conjugate in bile of spiny dogfish (Squalus Acanthias) and small skate (Raja Erinacea) is bilirubin monoglucuronide. 2. Microsomal preparations from dogfish and small skate liver have similar bilirubin UDPglucuronyltransferase (UDPGT) activity and catalyze the conjugation of bilirubin with glucose...
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1. Chicken IgA purified from biliary fluids was chemically and immunologically characterized. 2. Chicken IgA was determined to be the only immunoglobulin class present in bile. Gel filtration studies reveal polymeric IgA e.g. 17-19S. 3. Antigenically, chicken IgA is distinct from chicken IgG, and IgM. 4. Chicken IgA do...
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1. Plasma levels of lactate dehydrogenase (LD) were estimated in Hereford cattle of 1 month to 12 yr of age kept under range conditions. 2. Plasma levels of LD were estimated in a group of confined cows and their calves fed a constant diet and kept in individual pens in the same geographic area as the range Herefords. ...
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1. Muscle and brain from developing chick embryos, as well as from day-old chicks, rats, and ducks were analyzed for the histidine-containing dipeptides, anserine and carnosine. 2. Anserine was found in the brain of all species studied, whereas in muscle, anserine was found only in chicks. 3. At 15 days, the muscle of ...
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1. Various parameters of glucose metabolism--glucose replacement rate, percent recycling, mean transit time, and glucose mass were examined using various double labeled glucose tracers--2T-, U-14C; 3T-, U-14C; 4T-, U-14C; 5T-, U14C; and 6T-, U-14C. 2. Estimates of replacement rate were greatest for 2T-glucose (21.4 mg/...
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1. A hemoglobin elution-staining procedure has been developed for distinguishing embryonic chick red blood cells from adult chicken red blood cells. 2. Adult hemoglobin is eluted from red blood cells with 1.9 M potassium phosphate buffer, pH 7.2; whereas, embryonic hemoglobin is retained within the cells and gives posi...
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1. The technique of microacrylamide slab gel electrophoresis was used to repeatedly monitor the qualitative isozyme composition in the tube feet of the sea urchin, Arbacia punctulata exposed to different temperature regimes. 2. Four enzyme systems were assayed. Three (MDH, HK, and ACPH) were monomorphic for each animal...
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1. Female gouramis incorporated pulse-fed [U-14C]oleic, linoleic and linolenic acids more readily into roe than body lipids. Labeling was highest in eggs spawned 20-30 days after feeding. 2. In the fry, linoleic and linolenic were catabolized more slowly than oleic acid, indicating conservation of the polyunsaturated a...
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Cholesterol, triglyceride, and non-esterified fatty acid (NEFA) levels and lipoprotein electrophoretic patterns in blood plasma of ten species of wild rodents are compared with those of the laboratory mouse and man under standard conditions. 1. Average plasma lipid levels for the mouse and man appear in the middle of t...
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1. Adenylosuccinate synthetase has been partially purified from rat liver, fetal rat liver, Novikoff ascites cells, Walker carcinoma 256 solid tumors, chicken liver and muscle, rabbit muscle and pig brain. 2. Considerable differences exist in Michaelis constants among the various species and the changes possibly reflec...
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1. Sera from different embryonic stages of development and adult chickens were examined for embryonic-adult differences. 2. An antisera prepared in rabbits to 14 day embryonic chick sera revealed an antigen present in the early stages of embryonic development. The antigen reached a peak on day 14 and was not detectable...
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1. Superoxide dismutase activities in five tissues of the relatively anaerobic freshwater turtle were compared with SOD activities in the same tissues of two mammalian species (mouse and rabbit) with a more usual pattern of dependence on O2 availability. 2. SOD activities in brain, lung and skeletal muscle, but not liv...
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1. Three low molecular weight (12,000, 10,000 and 7,000) metal binding proteins have been isolated from the livers of normal and chondrodysplastic Alaskan Malamutes. 2. Comparison studies between kennel (mixed breed) dogs and both adult and immature Alaskan Malamutes suggested that the disturbance in trace mineral meta...
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1. Commercially available preparations of venoms of three subspecies of copperhead snake (Agkistrodon contortrix) were compared as to toxicity, enzymatic activities, effect on a nerve-muscle preparation and capacity to induce clotting of a fibrinogen solution or plasma. 2. Northern copperhead venom contained apparent n...
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1. Characterization of fetal, winter-hibernating, winter-active, summer-active and summer-induced hibernating hemoglobins of 13-lined ground squirrels (Citellus tridecemlineatus) by isoelectric focusing (IEF) pH 7.0-9.0 indicated that this molecule is extremely responsive to the various activity states of this hibernat...
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1. Studies have been made of products obtained by treating several reptilian fossil bones with dilute formic acid. 2. Their amounts and compositions have been compared with those of similarly treated fresh and Pleistocene bones. 3. Fewer and small peptides are obtained from the older fossils but in only one instance wa...
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1. Aortae and other tissues from numerous animals were examined for the presence of the rubbery protein elastin by (a) chemical purification and amino acid analysis, (b) presence of the cross-linking amino acids desmosine and isodesmosine and (c) histological staining. 2. Elastin was found in all vertebrates examined (...
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1. Phospholipid analysis of kidney lipids from active and hibernating ground squirrels (Citellus lateralis) indicate that molar quantities of phosphatidyl choline increase, while sphingomyelin decreases in hibernating animals. 2. Both of these changes are in such a direction as to enhance membrane fluidity and possibly...
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1. The biosynthesis of 18-19S thyroglobulin has been studied in a larval and adult freshwater lamprey (Lampetra planeri Bl.). 2. In vivo and in vitro experiments have been performed by injecting into the coelomic cavity or by incubating branchial region labeled constituents of Tg of higher vertebrates (125I, [3H]leucin...
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1. When ATP is added to Limulus myosin B and the mixture is centrifuged at 50,000 rev/min for 3 hr to dissociate it into a supernatant of myosin and a pellet of actin, the results are contrary to expectation. The pellet does contain actin but no more than one obtains if the ATP is omitted. The supernatant also contains...
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1. mRNA isolated from larval Taenia crassiceps directs efficiently the synthesis of proteins in cell-free heterologous systems. 2. Part of the newly synthesized proteins in a reticulocyte system are precipitable by a rabbit antiserum against T. crassiceps proteins. 3. Analysis of the antiserum-protein dissociated compl...
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1. The hemoglobin of the sting-ray, Dasyatis sabina, is both polymorphic and heterogeneous; three components predominate. 2. One major component has two kinds of polypeptide chain, of which one, presumably an alpha-chain, has a blocked NH2-terminus and an arginyl COOH-terminus, whereas carboxypeptidases A and B release...
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1. Increasing the Mg2+ concentration results in a depression of succinoxidase-linked state 3 respiration of liver mitochondria from both control and cold-acclimated rats and hamsters. 2. It appears that in the cold-acclimated hamster, liver mitochondrial respiration is more sensitive to changes in Mg2+ levels than that...
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1. Like the malate dehydrogenases of eucaryotic cells, the Propionibacterium shermanii enzyme is a dimer consisting of two 35,000 molecular weight subunits. 2. In electrophoretic behavior, resistance to substrate inhibition and stability to heating and dilution the P. shermanii MDH is more similar to the s-MDH than to ...
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1. Ion exchange column chromatography of red cell extracts from the smooth dogfish (Mustelus canis) reveals a phosphate pool which includes inorganic phosphate, AMP, ADP and ATP. 2. GTP and an iron complex of this nucleotide (Fe-GTP) account for approximately 40% of the principal organic phosphates. 3. ATP accounts for...
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1. Polyacrylamide gel electrophoresis (PAGE) in 4% gels of Blatta orientalis larval hemolymph revealed 4 major proteins. 2. Maximum incorporation of [14C]-leucine into total hemolymph protein occurs within 24 hr and is followed by negligible turnover in the next 24 hr. 3. Quantitative PAGE was used to monitor concentra...
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1. Analysis of the enolase isozymic distribution has been performed in tissues of the Coho salmon, using electrophoretic separation on cellulose acetate strips followed by localization of enzymatic activity. 2. A total of six electrophoretically distinct forms are seen in Coho salmon in patterns that differ both qualit...
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1. Salivary secretions of the stumptail monkey (Macaca arctoides) were compared biochemically and immunologically with human salivas. 2. Similarities in biochemical composition and antigenic profiles as seen by immunoelectrophoresis indicate that monkey salivas can provide an excellent model system to study the role of...
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1. The degree of immunological identity of the hemopexin of 64 mammals and non-mammals is determined by double diffusion in agar and two radioimmunoassays, employing antisera produced with the human or the rabbit protein. 2. Antigenic determinants are shared by the Eutherian mammals but not by the non-Eutherian mammals...
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1. In a homologous radioimmunoassay for canine ventricular myosin light chains, the following percentages of cross-reactivities were obtained using the dog as a reference: human, 28%; sheep, 21%; cat, 8%; guinea-pig, 7%; rabbit, 5%; and rat, 4%. 2. In a homologous double diffusion immunoassay using specific gamma G to ...
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1. Trimethyl amine oxide, dimethyl amine and choline chloride have been isolated from the marine hydroid Tubularia larynx and identified using physical constants and spectral data. 2. The presence of two guanidine molecules has been demonstrated.
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1. Mitochondria isolated from the ventricles of Cavia porcellus, Mesocricetus auratus, Rattus rattus and Mus musculus accumulate calcium in an energy-linked process. 2. Measurements of the initial velocity of accumulation by dual-wavelength spectrophotometry show species-dependent variation, with Cavia demonstrating th...
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1. Soy-peptone has been fractionated to yield a series of increasingly purified components which sharply increase the populations of Caenorhabditis briggsae and Caenorhabditis elegans when added to the basal medium. The nutritionally active material appears to be a small polypeptide. 2. C. briggsae and C. elegans routi...
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1. The relationship between Km and assay temperature was examined in three tropical and two temperate Drosophila species, and in the cosmopolitan species, D. melanogaster, for isocitrate dehydrogenase and acetylcholinesterase. 2. For both enzymes Km patterns were similar among species from the same habitat, and differe...
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1. The brain and ocular fluid of skipjack tuna (Katsuwonus pelamis) contained high levels of N-acetylhistidine deacetylase. 2. This enzyme had a molecular weight of about 120,000 and was activated by zinc or cobaltous ions. 3. Cod (Gadus callarias) brain, ocular fluid and muscle contained a similar metal-activated thio...
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1. The enzyme arginase in chicken kidney is associated with mitochondria and the mitochondrial membranes must be disrupted to obtain maximum activity. 2. When the membranes were disrupted by sonication, approximately 30% higher 2. When the membranes were disrupted by sonication, approximately 30% higher arginase activi...
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1. Microsomal fractions isolated from various housefly strains have been characterized with respect to multiple forms of cytochrome P-450 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. 2. Susceptible NAIDM houseflies were pretreated with known inducers of cytochrome P-450, and their microsomal electropho...
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1. AMP-deaminase activity in erythrocytes increases gradually during chick (Gallus domesticus) maturation, reaching the adult level of enzymatic activity at about 16 weeks after hatching. 2. Adenosine deaminase activity increases approximately two-fold during this period. 3. Substrate specificity and immunoinhibition s...
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1. Starch gel electrophoresis of adult brine shrimps from 15 populations revealed little intrapopulation polymorphism in NAD-dependent malate dehydrogenase (MDH) isozymes or in the two fastest esterases (demonstrated with alpha-naphthyl propionate as substrate). 2. Interpopulation differences could be summarized as thr...
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1. Urease from a sea urchin Lytechinus variegatus, was purified 300-fold, using heat precipitation, ethanol precipitation and gel filtration. 2. The pH optimum is 8.0. 3. The apparent Michaelis constant for urea is 0.13 mM at pH 8.0. 4. The inhibitory effects of seven reagents on urease were evaluated. The pattern of i...
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1. Glycoproteins of bovine (Bos taurus) and human (Homo sapiens) milk lipid globule membranes were characterized by ability to bind lectins after electrophoretic separation. 2. Seven lectin receptor glycoproteins were detected in bovine and five in human milk lipid globule membranes. Bovine and human globule membrane g...
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1. Exposure of cells to ultraviolet light induces molecular changes in DNA which may lead to cellular death. 2. One product, pyrimidine dimers, is reversed during subsequent exposure to visible light by photoreactivating enzyme. 3. Photoreactivating enzyme has been recorded in different organisms, but inconsistencies i...
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1. Hemolysates of newt (Triturus cristatus) red cells contain four distinct hemoglobin species which have been observed consistently both in individual animals and pooled samples. 2. Hemoglobin heterogeneity in the species arises from existence of multiple hemoglobulins, with no indication of genetic polymorphism. 3. W...
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1. Gluconeogenesis was studied in isolated avian hepatocytes. The highest rate of glucose production obtained was from lactate, followed by dihydroxyacetone, glyceraldehyde, and fructose. Alanine was converted to glucose at only about 4% the rate of lactate. 2. Addition of 10 mM sorbitol, xylitol, or ethanol to the hep...
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1. The effect of sustained (48 hr) oxygen depletion on tissue (brain, heart, skeletal muscle) pyruvate kinase (PyKi) activities was examined in the pond turtle (Pseudemys scripta elegans). 2. PyKi activities in skeletal muscle are significantly increased (from 322 +/- 84 to 450 +/- 95) following 48 hr of tissue hypoxia...
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1. Hemolymph from the giant African snail Archachatina marginata has been analyzed for its content of certain lysosomal hydrolases and shown to contain substantial quantities of acid phosphatase (285 units/ml) hexosaminidase (512 units per ml) and beta-glucuronidase (28 units/ml). 2. Hemolymph acid phosphatase can be f...
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1. Age-related alterations in the distribution of water-soluble, high molecular weight (colloidal), and water-insoluble proteins of the lens of smooth dogfish (Mustelus canis) were measured. 2. The ages of these animals ranged approx from 2 to 50 yr, during which time the lenses grew from 100 to 1500 mg (wet wt). The l...
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