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Previous reports have noted a constant association between the Carpenter syndrome (acrocephalopolysyndactyly, type II) and mental retardation. We report two patients with this condition with normal intelligence. These observations indicate that mental deficiency is not necessarily a component of the Carpenter syndrome ... | US |
The "idiopathic" Fanconi syndrome occurs mostly sporadically, occasionally as an autosomal recessive trait. However, few instances of autosomal dominant inheritance have been reported. We described a father and son with the Fanconi syndrome, ie, with renal glycosuria, generalized aminoaciduria, phosphaturia, metabolic ... | US |
In the KOP translocation, t(X;14)(q13;q32), virtually the entire long arm of the X has been translocated to the end of the long arm of chromosome 14. Meiotic secondary nondisjunction in a female balanced carrier of the translocation has led to a son with two der(14) or 14-X chromosomes. The normal X chromosome is late ... | US |
We report the anatomical variations of the limbs in eight infants with the trisomy-18 syndrome that were dissected and studied in detail. In each case, the upper limbs showed defects which further define the specific influence of this aneuploidy on the development of its preaxial (radial) component, and the tendency to... | US |
Fourteen patients with hypodontia and the ocular features of the Rieger syndrome were examined for the presence of systemic anomalies. A periumbilical defect that consisted of failure of the periumbilical skin to involute was seen in ten of the thirteen evaluated for the defect. Three others had scars over the umbilica... | US |
Eighty normal Caucasians were studied by CBG technique for estimation of size and inversion heteromorphisms of chromosomes 1, 9, and 16. Size heteromorphisms were classified into one of five sizes using 16p as a reference standard: very small, small, intermediate, large, and very large. Inversion heteromorphisms were a... | US |
The transfer and metabolism of cortisol and cortisone and the effect of protein binding on these processes have been investigated in vitro in the perfused human placenta. The clearance of cortisol in buffer, expressed as a fraction of the antipyrine transfer rate (clearance index), was 0.50 +/- 0.05 SEM in either direc... | US |
We have demonstrated that in patients given a single iv injection of T3, rT3, or, to a lesser extent, T4, all labeled with 125I in the outer or phenolic ring, chromatography of serum on columns of Sephadex G-25 superfine revealed the presence of a labeled material, separate from the administered hormone and from both i... | US |
Chromatography of serum on columns of Sephadex G-25 superfine after the iv administration of 125I-labeled T4 consistently yielded labeled iodide, iodoprotein, T3, and a labeled peak that eluted from the column before the T3, termed "pre-T3." Much larger quantities of pre-T3 were generated after the iv administration of... | US |
As part of a study on the physiological role of hCG in the human fetus, the hCG concentrations in homogenates of various fetal tissues were measured using a hCG beta subunit RIA. The mean concentrations (picograms of hCG per mg wet tissue +/- SEM; n greater than 10, unless otherwise indicated) found in human fetuses of... | US |
An investigation into the feasibility of using X-ray computed tomography (CT) to measure disease induced changes in bone mineral content of the human spine is described. A theoretical study of this type of measurement has been made using a mathematical model of osteomalacia. The measured EMI number changes linearly wit... | US |
The effects of intraventricular cycloheximide (CHX) pretreatment were examined on the ability of rats to recall a light position discrimination task. The CHX pretreatment used inhibited brain protein synthesis at the time of training by 71%. Following treatment with CHX the animals demonstrated no retention of the task... | US |
In a shock escape T-maze task, rats were trained to turn right following one drug treatment and left following a second drug treatment. The specific drug and dose conditions were the only discriminative cues available to the animals. The number of training sessions before criterion performance indicated the discriminab... | US |
As time increased between drug administration and the start of experimental sessions, effects of drugs on food-maintained responding in rhesus monkeys increased to a maximum and then decreased. d-Amphetamine, ethanol, and alpha-l-acetylmethadol (LAAM) generally decreased high response rates in one component of a chain ... | US |
Slow potentials were recorded from the anterior cortex of rats during discrimination conditioning and the effects of various doses of d-amphetamine on these responses were examined. In the discrimination paradigm one tone (Sd) was followed at three see after the onset by food reinforcement while another tone (S delta) ... | US |
The advantages and disadvantages of evolutionary fitness (probability that a single mutant line will not become extinct) and genetic fitness (mean fecundity) are compared. For deterministic processes the two are equivalent, but for stochastic branching processes they may be totally unrelated except that an absolute gen... | US |
A new test of goodness of fit for the polygenic threshold model is proposed. This test, when applied to disorders showing different incidence rates in males and females, is designed to account for ascertainment in more detail than previously done by other investigators. This is accomplished by computing the expected di... | US |
Synthetic filaments prepared from column-purified rabbit skeletal myosin by slow dialysis exhibit characteristic bipolar organization and 14-nm axial subunit spacing. Backbone substructure can be discerned in high resolution micrographs in the form of striations of 3--4-nm width and slight angular tilt from the directi... | US |
The effect of 6-mercaptopurine on the development and expression of delayed hypersensitivity was studied in the guinea pig. Results indicated that 6-MP produced its suppressive effects primarily by action on cells of the monocyte-macrophage series. Suppression could occur under conditions of both developing and pre-est... | US |
Multivariate behavioral genetic analyses may employ either genetic and environmental correlations or phenotypically standardized covariances to assess the structure of genetic and environmental influences. Correlations and phenotypically standardized covariances answer different questions--correlations are appropriate ... | US |
Since Galton's time, critics of the twin method have rejected the evidence of genetic differences in human behavior, because the twin method assumes that identical and fraternal pairs have equally similar environments. Twins whose genetic similarity is misperceived by themselves and others provide a critical test of th... | US |
The present study investigated whether maternal aggression has shown a correlated response in a program of artificial selection for isolation-induced interfemale aggression in housemice. Females from the first replicate of lines (H1, C1, L1) and the second replicate of lines (H2, C2, L2) from generation S5 were given d... | US |
Circulating thymic hormone activity and thymic histology were studied in patients undergoing open heart surgery. Plasma thymic hormone activity was measured using a bioassay based upon thymocyte antigen induction on null mouse lymphocytes. Activity was highest at 15-30 yr of age and declined thereafter, being negligibl... | US |
The concentrations of immunoreactive somatomedin-C (Sm-C) in the sera of women with uncomplicated pregnancies were found to be progressively higher as the duration of gestation increased. Between 19 and 42 weeks of gestation, there was a significant correlation between serum Sm-C concentration and duration of gestation... | US |
The placental membrane radioreceptor assay was used to measure the levels of somatomedin (SM) peptides in plasma. Displacement of both [125I]somatomedin A ([125I]SM-A) and [125I]somatomedin C ([125I]SM-C) by normal whole plasma, the peptide fraction of acid-chromatographed plasma, and a partially purified, insulin-free... | US |
Neuroendocrine function in two women with galactorrhea-amenorrhea arising from abnormalities in the PRL reflex arc was compared to that of normal women. Basal gonadotropins were lower than normal, and one patient lacked episodic secretion of LH; however, the serum gonadotropin rise after iv LRH was in the normal range ... | US |
Fat excretion and absorption in 38 healthy S-f-D born infants fed on 4 kinds of diet, differentiated with regard to fat quantity and quality as well as protein quality, were examined by means of three 24 hour fat balances. Higher fat intake, higher fat excretion in feces and lower index of its absorption, typical of th... | US |
The interaction of a class of oxonol dyes with sonicated phospholipid vesicles was followed optically. The spectra of vesicle-associated dyes resemble those found for the dyes in organic solvents, indicating that the oxonols occupy a hydrophobic region of the membrane. At equilibrium the affinity of the oxonols for the... | US |
We have found that herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) has the ability to increase the rate of transport of positive ions of several kinds, and to inhibit transport of negatively charged tetraphenylborate ions in lipid bilayer membranes. It has been found that only the neutral form of 2,4-D is transport ac... | US |
The orientation of an amphipathic, long acyl chain fluorescent carbocyanine dye [diI-C18-(3)] in a biological membrane is examined by steady-state fluorescence polarization microscopy on portions of single erythrocyte ghosts. The thermodynamically plausible orientation model most consistent with the experimental data i... | US |
The alignment of dilauryl-, dimyristoyl-, and dipalmitoylphosphatidylcholine at various water concentrations into large oriented monodomain multilayers by annealing at elevated temperatures (Powers and Clark, 1975, Proc. Natl. Acad. Sci. U.S.A. 72:840; Powers and Pershan. 1977. Biophys. J. 20:137) is accompanied by the... | US |
In the absence of C-protein, synthetic filaments prepared from column-purified myosin exhibit the following features: individual filament diameters are uniform over a long length, but a wide distribution of diameters is apparent over the population; approximately 25% of the filaments have a frayed appearance and take u... | US |
The effect of the small anesthetic molecule, benzyl alcohol, on the structure of various bilayer system has been studied by optical, electrical, and x-ray diffraction techniques. We find that the modifications in bilayer thickness caused by benzyl alcohol differ dramatically for planar (or black lipid) bilayers contain... | US |
An order parameter-based interpretation is applied to the temperature dependence of the deuterium magnetic resonance splittings and the anisotropic contribution to the chemical shift for 31P from the head groups of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC). It is shown that the rotational motion of the molecul... | US |
The synthesis of very high specific activity 25-OH-vitamin D3 (78 Ci/mmol) has made possible the study of the metabolism and plasma disappearance of 3H after a single dose of 3H-1,25-(OH)2-D3 in quantities that are only 10-20% of the endogenous plasma pool. We studied seven healthy adults who were given doses of 1,25-(... | US |
A simple, reproducible, and highly specific RIA has been developed for measurement of 3',5'-diiodothyronine ((3',5'-T2) in unextracted serum. Interference in binding of radioactive 3',5'-T2 to anti-3',5'-T2 by serum proteins was minimized by using 0.4 M phosphate buffer (pH 6.2) and merthiolate. The detection threshol... | US |
This report describes the effect of administration of repeated doses of ipodate (Oragrafin; 3 g orally every third day for five doses) in six hyperthyroid patients. Baseline serum concentrations of immunoassayable T3, rT3, and T4, were 926 +/- 206 ng/100 ml, 165 +/- 31 ng/100 ml and 21 +/- 2.7 micrograms/100 ml (mean +... | US |
Fetal rat bones in organ culture constitute a sensitive system for assay of the vitamin D metabolite, 1 alpha,25-dihydroxyvitamin D3. Significant bone resorption is obtained with as little as 2 pg 1,25-dihydroxyvitamin D3 after 48 h of culture and with 1 pg after 64 h of culture. In the current study, organ cultures of... | US |
To evaluate the interactions of the renal prostaglandin and kallikrein-kinin systems during mineralocorticoid escape, we administered desoxycorticosterone acetate (DOCA; 20 mg im daily for 10 days) to five normal men and then repeated the study 2-16 weeks later with simultaneous indomethacin (200 mg/day) or ibuprofen (... | US |
This report presents the results of interviews with 16 Mexican-American folk healers (curanderos and curanderas) in San Antonio, Tex. Curanderismo was found to be alive and well in San Antonio, though its practitioners tend to be older and its future unclear. Several salient characteristics of the practitioners were cl... | US |
This report describes a study of subject refusal as a source of bias limiting the generality of psychiatric research results. Fifty psychiatric patients who refused to participate in a battery of research interviews and psychological tests were compared with 50 participant patients. Between-group comparisons were made ... | US |
We compare the effects of chlordiazepoxide, oxazepam, and placebo on hostility, as both an inner motivational or potential state and verbal interpersonal behavior. This article reports the findings relevant to the latter dimension of hostility and integrates them with those findings, presented in an initial report, rel... | US |
Fifty preterm children who had experienced a range of biological hazards were divided into two competence groups on the basis of their receptive language development at 24 months. The groups were then compared in terms of the kinds of caregiver-child interactions the children and their primary caregivers engaged in thr... | US |
Rhabdomyosarcoma of the head and neck often presents with vague symptoms which mimic other disease conditions. These factors lead to undue delay in the establishment of the correct diagnosis and the delivery of acceptable therapy, including surgery, radiation therapy, and chemotherapy. There is, however, evidence of im... | US |
The experience of three institutions in the management of atrial flutter in infants under 2 years of age without associated heart disease is reviewed. Five babies with neonatal onset were treated with digoxin and had uncomplicated resolution of their arrhythmia, although one continued to have episodes of paroxysmal sup... | US |
To assess the possibility that non-aminoglycoside antibiotics may adversely affect the nephrotoxicity of the new semisynthetic aminoglycoside netilmicin, we gave ampicillin, carbenicillin, methicillin, cefamandole, and clindamycin, either singly or in combination with netilmicin, at two dose concentrations in rats. Res... | US |
The vehicle of miconazole inhibited adherence and leukotaxis, but did not affect nitroblue tetrazolium reduction and trypan blue exclusion by granulocytes at 0.33% concentration and above. | US |
By in vitro methods, five aminoglycoside antibiotics (amikacin, kanamycin, gentamicin, tobramycin, and netilmicin) were shown to produce modest changes in granulocyte adherence (increase) and migration (decrease) and no change in phagocytosis or nitroblue tetrazolium reduction. | US |
Fifteen children with scleroderma have been presented. All had characteristic cutaneous abnormalities at onset and during the course of disease. All were girls. All had visceral involvement, primarily of the gastrointestinal tract, heart, and lungs. The presence of visceral disease might have been missed without specif... | US |
Seven girls and 3 boys with MCTD have been described. As a group their clinical characteristics and serological findings are similar to those reported in adults, with several important differences. Children with MCTD may have marked thrombocytopenia and more frequently they have RF. Significant cardiac and renal involv... | US |
A synthetic polycarbonate (PC) membrane supplied by C.R. Bard Inc. was assessed as to its clinical usefulness and suitability to regular use with artificial kidney. The permeability of the PC membrane to 11 solutes of increasing molecular volumes (Na+, Ca++, K+, Cl-, HPO4-, urea, creatinine, uric acid, glucose, BSP, cy... | US |
Let me summarize. I distinguish between two major different relationships between transference and resistance. One is resistance to awareness of the transference and the other is resistance to resolution of the transference. I argue that the bulk of the analytic work should take place in the transference in the here an... | US |
A specially designed silicone balloon, expanded in vivo with normal saline, was tested for possible use as a retinal tamponade in desperate cases of rhegmatogenous retinal detachment. In six pigmented rabbits there were extensive postoperative complications, but in eight owl monkeys results were noticeably better. When... | US |
The osteoplastic flap technique for treating frontal sinus mucoceles is described. This procedure has the advantages of: being a direct approach, which allows exposure of the entire sinus, provides complete obliteration of the sinus to prevent recurrence of the sinus disease, and prevents blind curettage of any exposed... | US |
Some aspects of the surgical, radiotherapeutic, chemotherapeutic, cryosurgical, and immunological aspects of eyelid and adnexal malignancy have been discussed. Possibilities for future developments have been mentioned and even rationalized. Oncology is a constantly changing field. It is important for the oculoplastic s... | US |
Experimental evaluation of Wikler's interoceptive conditioning hypothesis of relapse to opioid use in ex-addicts requires a preliminary study of the degree of physical dependence produced by two methods of drug administration. Wistar rats were made physically dependent on morphine by single daily intravenous injections... | US |
Sequential dependencies were examined as a function of learning, masking, and subject factors in a two-stage differential eyelid conditioning experiment. In Stage 1, all subjects were differentially conditioned to two Vanderplas and Garvin (1959) forms. In Stage 2, the conditional stimuli (CSs) were one of eight words,... | US |
The basic findings of these two studies are as follows: a failure of orientating and conditioning of viscero-autonomic responses, but essentially normal orienting and conditioning of a temporal muscle response in amygdalectomized animals. Small procedural differences exist between the two studies,and a possible order e... | US |
Experiments were carried out on cats fitted with a gastric fistula. In one group of 6 cats basal gastric secretion, and in another group of 7 cats pentagastrin induced gastric secretion was collected two or three times a week during a 2 hr session. The sessions were conducted either in a "harness" situation where the c... | US |
An epidemiologic investigation of the mental needs and services of 1645 respondents, aged 17 to 92 years and living in a representative southeastern county in Florida, revealed that 7.8% of the sample lived in crowded conditions. The crowded respondents scored significantly higher than did the uncrowded on both a depre... | US |
A retrospective review of 500 patients with primary hyperparathyroidism seen from 1951 to 1975 was conducted; the effect of routine screening of calcium and phosphate levels (initiated in 1968) on the incidence and spectrum of the disease was analyzed. The majority of the patients (77%) were diagnosed in the eight-year... | US |
Eleven of 12 patients treated for invasive melanomas of the conjunctiva at the UCLA Hospitals from 1955 to 1976 revealed data sufficient for evaluation. Of these 11 cases, 4 died from 3 to 13 years after treatment as a result of the disease. The plan presented for surgical management of melanosis is based on histologic... | US |
Here we describe the change in thick filament length in striated muscle of Limulus, the horseshoe crab. Long thick filaments (4.0 microns) are isolated from living, unstimulated Limulus striated muscle while those isolated from either electrically or K+-stimulated fibers are significantly shorter (3.1 microns) (P less ... | US |
The vitelline layers (VLs) of unfertilized sea urchin eggs were isolated by homogenization in a hypotonic medium containing Triton X-100 and EDTA. The surface topography of the VL is not changed by isolation. The thickness of the isolated VLs (300-400 A) is greater than that reported for VLs on intact eggs (100-200 A).... | US |
Histogenesis of thyroid follicles in the chick embryo begins with a penetration by cells of the mesenchymal capsule into a solid epithelial primordium. Before penetration occurs, slits containing fibrillar material form between the epithelial cells. The fibrillar material is an epithelial cell product as shown by its f... | US |
The rate of disk addition to rod outer segments (ROS) varies widely in Xenopus laevis tadpoles kept in cyclic light (12L:12D). When measured as radioactive band (3H-band) displacement during the 2nd day after injection of [3H]leucine, 75% of the daily increment of displacement occurred during the first 8 h of light. Du... | US |
Pigment migration in cultured erythrophores of the squirrel fish Holocentrus ascensionis, after manipulation with K+, epinephrine, 3',5'-dibutyryl cyclic adenosine monophosphate, theophylline, and caffeine, is essentially identical to that observed in this chromatophore in situ. For such observations, the erythrophores... | US |
To determine whether microtubules are linked to intracellular transport in absorptive cells of the proximal intestine, quantitative ultrastructural studies were carried out in which microtubule distribution and content were determined in cells from fasting and fed animals. Rats were given a 1-h meal of standard chow, a... | US |
Renal corpuscles from the juxtamedullary and subcapsular regions of the renal cortex were morphometrically analyzed in young rats and in adult rats that had been unilaterally nephrectomized or sham-operated at an early age. Mean corpuscular volumes increased 4.5-fold during normal development, and 7.7-fold as a result ... | US |
An examination was made of the services received by Chicano and Native American clients in 17 community mental health facilities. Although these minority clients differed from Anglos in demographic variables, there was no evidence that they were rendered inferior or discriminatory services. However, failure to return f... | US |
One hundred and eleven cases of syncope or loss of consciousness are analyzed. Most are of obscure nature while some illustrate features of syncope that deserve further scrutiny. The cases are divided into six groups: Resembling cardiac syncope (30 cases); vasovagal syncope (22 cases); features of both cardiac and vaso... | US |
The toxic action of misonidazole towards hypoxic mammalian cells has been shown to be a function of serum concentration, with higher serum concentrations enhancing the toxic effect. Added thiols protect cells against misonidazole toxicity. In addition, the action of misonidazole on hypoxic cells labelled with 5-BUdR ha... | United Kingdom |
The clinical use of misonidazole as a hypoxic cell radiosensitizer is at present limited by its neurotoxicity at high doses (Urtasun et al., 1977; Dische et al., 1977). An in vivo neurological end point, viz. measurement of nerve conduction velocity, has been developed to examine sensitizer action. Conduction velocity ... | United Kingdom |
The structure of the staphylococcal nuclease (EC 3.1.4.7)-thymidine 3',5'-bisphosphate-Ca(2+) (enzyme-inhibitor) complex has been extended to 1.5-A resolution by using much additional data and a phase refinement scheme based on an electron-density map modification procedure. By correlating this structure with the known... | US |
Twenty-five patients with symptoms of myofascial pain and abnormal jaw function were treated with use of a full arch maxillary occlusal splint. The level of nocturnal activity of the masseter muscle was monitored as were symptoms before, during, and after occlusal splint therapy. A decreased nocturnal EMG level during ... | US |
We used a combined behavioral and electrophysiological technique to test the hypothesis that storage of information is impaired in childhood autism. Endogenous event-related potentials associated with the random deletion of stimuli within a regular train of auditory or visual stimuli were examined in three autistic and... | US |
Beta-endorphin, morphine, and saline were given intravenously to a single schizophrenic subject on separate occasions in a double-blind design. EEG spectral analyses performed on data collected before and after drug injection demonstrated that beta-endorphin and morphine produced similar increases in alpha power within... | US |
Interindividual differences in endorphin levels may relate to widespread changes in adaptive processes, and endorphin levels may thus be related to personality traits. In 40 patients with chronic pain syndromes of both psychogenic and organic origin, endorphin levels in cerebrospinal fluid (CSF) were determined, and th... | US |
A systematic programme of research on the development of spatial vision (acuity and contrast-sensitivity functions or CSFs) in human and macaque monkey infants (Macaca nemestrina) is described. A forced-choice preferential looking technique has been used to follow the development of acuity in both species. Acuity devel... | US |
A hand-held stimulator-ophthalmoscope was used to elicit foveal cone electroretinograms (ERGs) from fifteen patients with strabismic amblyopia. The ERGs were in response to a 4 degrees stimulus visualized on the fundus and centred on the fovea throughout testing. Foveal cone ERGs from amblyopic eyes were normal in ampl... | US |
The geniculocortical pathways of many mammals, including primates, are largely comprised of two neuron types. These are known as X and Y cells. Their functional significance in unclear, but the following highly speculative hypothesis is suggested. Y cells, because of their broad sensitivity to the crucial lower spatial... | US |
We have studied the relative importance of visual and nonvisual signals to striate neurons in causing the loss of cortical binocularity that occurs when young kittens are subjected to brief episodes of stabismus. In kittens kept in a normally illuminated colony, the reduction in binocularity was the same whether the st... | US |
Studies of the striate cortex of the kitten are reviewed with reference to the effects of very brief periods of uniocular occlusion. It is shown that changes occur in binocular connections within 4 hours after the vision of an eye is blocked. Effects are also found if the occlusion is instituted while an animal is anae... | US |
Uniocular occlusion (dark patching) of adults for a period of days produces marked reduction in the directional sensitivity of the eye (Stiles-Crawford effect). The effect reaches a maximum 3 to 5 days after the onset of patching. Recovery occurs in a comparable period. The second eye is not affected, and a simple ligh... | US |
A sensitive period exists in humans and experimental animals during which certain visual functions are modifiable by decreased or abnormal visual stimulation. Experiments in monkeys have shown that, at the beginning of this sensitive period, the manifestations of the visual deprivation syndrome develop more rapidly at ... | US |
The significance of the distinctive morphological difference between mammalian and non-mammalian vertebrate erythrocytes (disc versus ellipse) is discussed in the light of mammalian erythrocyte rheology. | US |
Dynamic aspects of whole body protein (nitrogen) metabolism were explored in healthy young adults and elderly men and women. Measurements were made of the rate of whole body protein breakdown, with the aid of 15N-glycine, and the rate of muscle protein breakdown, as estimated from urinary N tau-methylhistidine excretio... | US |
The time required to name four groups of pictures was measured in 83 community dwelling males (18-70 years of age). One group consisted of objects used 50 to 70 years ago (unique dated exemplars), and another consisted of objects unique to contemporary times (unique contemporary exemplars). For comparison, other pictur... | US |
Two experiments were carried out to measure age-related differences in speed of error-free recall by normal adults. The major results were that: (a) the time taken to read a word aloud (retrieval from lexical memory) does not increase appreciably until subjects reach their 60s; (b) the time taken to recall a verbal ite... | US |
In a simulation of the "cocktail party" problem, subjects listened to recordings of a target voice, obscured by four background voices from adjacent locations in space. Listening conditions were either dichotic (with interaural directional cues preserved) or diotic (same input to both ears, directional cues removed). E... | US |
This study described several brief behavioral measures which, with further validation, could be useful in predicting the deaths of older adults within a five-year period following testing. Such tests can be used in routine biomedical examinations, alerting the physician to possible problems in the future. The study was... | US |
In the present state of science no morphological or chemical changes may be detectable at a time when behavior is profoundly disturbed, as in schizophrenia. Until we are reassured to the contrary, we must assume that exogenetic intoxication can produce changes detectable only as behavioral changes. Therefore behavioral... | US |
Two sets of observations are reported as illustrations of problems encountered in behavioral toxicology. First, in an attempt to determine the contribution of methylmercury-induced ataxia to behavioral changes observed on the fixed-consecutive-number schedule, some ancillary control experiments were undertaken. Neither... | US |
Behavioral toxicology in the natural environment can be considered a special branch of epidemiology. Behavioral epidemiology, because it typically relies on complex functional criteria, faces all of the problems of behavior measurement posed by uncontrollable variation, and amplified even further by chemical exposure. ... | US |
The analysis of visual toxicity is complicated by the heterogeneity of visual capacities in different regions of the visual field. Since various toxicants may impair different functions allied to localized portions of the visual field, it is important to explore the relationship of field defects to residual visual abil... | US |
Neonatal rats were exposed to lead (Pb) from parturition to weaning via the milk of dams which consumed 0 (tap water), 0.02% or 0.2% PbAc2 solutions. To determine if this regimen altered physiological and neurobehavioral development, responses to a battery of sensory-motor tests were evaluated during maturation and as ... | US |
Pregnant Sprague-Dawley rats received 25 mg/kg of prochlorperazine, 20 mg/kg of fenfluramine, 75 mg/kg of propoxyphene or 200 mg/kg of diazepam daily between the 7th and 20th days of gestation. Vehicle control groups and a positive control group (vitamin A 40,000 IU/kg/day) were similarly prepared. Observations of repr... | US |
Broad agreement on specific approaches or standardized test batteries for assessing behavioral toxicity is unlikely to emerge in the foreseeable future. EPA should reject test standardization in any case, however; standardization stifles progress and, in addition, may bypass unique properties of new types of substances... | US |
Behavioral conditioning together with conventional sensory testing methods may be used in the evaluation of toxic effects on sensory systems in experimental animal models. Such procedures yield precise quantitative estimates of impairment in absolute and differential acuity and in sensory perception. Additionally, thes... | US |
Laboratory procedures have been developed for the experimental analysis of risk-taking and psychophysical functions in dog-faced baboons (Papio anubis). In a procedure analogous to the traffic light situation, animals are rewarded with food pellets for completing a fixed ratio of 100 responses in the presence of a gree... | US |
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