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Biomedical subjects

M Young

Publications and source records attributed to M Young.

At least 379 records · Page 21Linked to original sources
PubMed1980

Measured versus estimated creatinine clearance in the elderly as an index of renal function.

Measured endogenous creatinine clearance (requiring 24-hour urine collection) was compared to estimated (calculated) creatinine clearance obtained by 2 formulas and a nomogram (without urine collection), in 26 elderly nursing home residents. All were clinically stable and had adequate intakes of food and fluid. Of the 26 subjects, 23 had a "normal" value for serum creatinine concentration (0.7-1.5 mg/dl) with a mean of 1.1 mg/dl. Measured creatinine clearance (Cer) was reduced in all patients despite a "normal" serum creatinine level. The mean Cer was 47.2 ml/min, with values as low as 21.6 ml/min. Measured Cer findings compared well with estimated (calculated) findings, the correlation coefficients being highly significant in all instances. If it is difficult or impossible to collect a 24-hour urine specimen, a fairly accurate assessment of renal function may be obtained by using a simple formula (or nomogram) for estimating creatinine clearance on the basis of the patient's age, weight (height) and serum creatinine level.

Age Factors↗
PubMed1980

Discriminant analysis of personality and body-image factors of females differing in percent body fat.

The purpose of the study was to determine whether individuals with high percent body fat can be distinguished on the basis of personality and body-image from those possessing lower levels of body fat. 65 female college students were administered the 16 Personality Factor Questionnaire and the Secord and Jourard Body-cathexis Scale. Measurement of height, weight, and skin folds at the triceps and illiac crest were also taken. On the basis of percent body fat two groups of 20 females each (high and low percent body fat) were identified. From discriminant analyses one personality factor and six body-image items were identified which distinguished between groups. Reclassification of the subjects, based upon derived discriminant functions, resulted in 60.0% of the subjects being correctly reclassified from personality data and 100% of the subjects correctly reclassified from body-image data. Body-image appears to be an important factor that can distinguish between individuals possessing high and low levels of body fat.

Body Height↗
PubMed1980

Body image and females' sexual behavior.

82 female college students completed a body-image scale and an inventory on sexual behavior. These female students differing in sexual activity can be distinguished on the basis of body image.

Adult↗
PubMed1980

Effects of unilateral torsion of the spermatic cord on the contralateral testis in human and guinea pig.

The fine structure of the contralateral, so-called unaffected, testis of two of three patients with unilateral testicular torsion revealed varying degrees of abnormalities, apparently related to the time course of the condition. In one patient (H-87) with unilateral torsion of 16 days duration, the contralateral testis revealed various morphological abnormalities. These included abnormal nuclear condensation in spermatids, disappearance of the inner component of the basal lamina, degeneration of the germinal epithelium, and "intermixing" of germinal epithelial cells with peritubular components. In the other patient (H-109) with severe atrophy of one testis as a result of torsion, the contralateral testis revealed abnormalities which included spermatids with degenerating heads and tails within the Sertoli cell cytoplasm near the basal lamina and peritubular thickening accompanied by a greater than usual number of Leydig cells. In guinea pigs with experimentally induced unilateral torsion, abnormal spermatid development was seen in the contralateral testis of those animals in which the affected testis was severely damaged. Moreover, the Sertoli cells exhibited a high degree of phagocytic activity. Fewer abnormal spermatids in the spermatogonial compartment were found in the contralateral testis of the animals which had only moderately altered histology of the affected testis. No fine structural change was noted in the contralateral testis of control or sham operated animals or in those which displayed only minimal damage in the affected testis. This study suggests that unilateral torsion of the spermatic cord resulting in moderate to severe damage to the affected testis may be associated with morphological abnormalities in the contralateral testis.

Adolescent↗
PubMed1979

Proteolytic activity of nerve growth factor: a case of autocatalytic activation.

Nerve growth factor is a highly specific protease that can convert plasminogen to plasmin and that can hydrolyze certain synthetic N-substituted arginine esters (e.g., Nalpha=p-toluenesulfonyl-L-arginine methyl ester (TAME); N.S. Orenstein et al. (1978) Proc. Natl. Acad. Sci. U.S.A. 75, 5497). Hydrolysis of TAME is characterized by a lag phase of lower velocity which precedes development of the steady-state maximal velcity. Kinetic analyses indicate that this behavior stems from autocatalytic activation of a nerve growth factor (NGF)-zymogen by NGF. As isolated from the mouse submandibular gland at high concentration, NGF is largely enzymically inactive. Upon high dilution, the protein undergoes autocatalytic activation with concomitant generation of full enzymic activity. The biologic significance of this unusual property of NGF is not clear, but it may serve to prevent expression of enzymic activity until the protein reaches its target cell(s) or until it recognizes its physiological substrate.

Catalysis↗
PubMed1979

Extrapyramidal side effects and increased serum prolactin following fluoxetine, a new antidepressant.

Fluoxetine (Lilly 110140) is a potent, specific serotonin (5-HT) uptake blocker which is being tested in man for antidepressant activity. One of 9 depressed patients receiving this drug developed a dystonic reaction, parkinsonian rigidity, and increased serum prolactin levels, all signs of decreased dopaminergic activity. Homovanillic acid levels also decreased in the cerebrospinal fluid of this subject. We postulate that fluoxetine, via the increase in 5-HT activity resulting from 5-HT uptake blockade, inhibited both the nigro-striatal and tubero-infundibular dopaminergic neurons. These results provide additional evidence for a linkage between serotonergic and dopaminergic neurons in man.

Adult↗
PubMed1979

Effect of clozapine on human serum prolactin levels.

The authors determined serum prolactin levels in 13 patients receiving clozapine, an antipsychotic drug that does not produce extrapyramidal side effects. Morning serum prolactin levels, 11 hours after the last dose, were not elevated during chronic treatment with clozapine in any subject despite its therapeutic effects. Serum prolactin levels were moderately increased between 90 minutes and 4 hours after administration of very high doses of oral clozapine in 4 patients but were smaller than those produced by chlorpromazine in other subjects. The authors suggest that clozapine in other subjects. The authors suggest that clozapine may achieve its antipsychotic effect differently than do classical neuroleptics and that sustained prolactin increases are not essential for antipsychotic action.

Animals↗
PubMed1979

Diethylstilbestrol and estradiol binding to serum albumin and pregnancy plasma of rat and human.

The equilibrium binding of diethylstilbestrol (DES) and 17 beta-estradiol (E2) to plasma proteins has been characterized. DES exhibits a 10- to 20-fold greater binding affinity index for bovine serum albumin and rat plasma than E2. As expected, E2 gave high values for binding to plasma from pregnant mice or rats, reflecting the presence of alpha-fetoprotein. DES bound to these samples as it did to bovine albumin and rat plasma. These results suggested that DES ineracts weakly with alpha-fetoprotein. This was verified by Scatchard plots of DES and E2 binding to rat and human pregnancy plasma. High affinity, low capacity binding was demonstrated with E2 but not with DES. The significantly lower binding of DES suggests that increased delivery of DES to the fetus may be at least partially responsible for the transplacental toxicity and carcinogenicity of DES.

Animals↗
PubMed1979

Intranuclear inclusion bodies in epithelial cells of human vas deferens.

Four different types of inclusion bodies were seen within the nucleus of the principal cells in segments of vas deferens from 40 fertile males: (1) electron-dense homogeneous bodies of various sizes (0.1--1.8 microns) and shapes, (2) granular bodies approximately 0.06--0.12 microns, (3) lipid inclusion bodies, and (4) less electron-dense, filamentous bodies. They were either membrane-bound or free within the nucleoplasm. Some membranous material was scattered within the nucleoplasm. The internal structure of nuclei containing these bodies differed from cell to cell. The nucleoplasm was composed either of dense granular elements or fine filamentous components. The aggregation and density of the ground nuclear material increased with increasing numbers of inclusion bodies. Very dense nuclei were in cells with typical features of degeneration. Frequently, extruded parts of cells or entire cells were seen within the lumen of the vas deferens.

Adult↗
PubMed1979

Behavioral epidemiology of food additives.

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. Many such issues arose in a study of behavioral responses to artificial food colors in children. Difficulties in employing Applied Behavioral Analysis in such a context run the gamut from selection of retrospective criteria to appropriate statistical models.

Child↗