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Biomedical subjects

B Cook

Publications and source records attributed to B Cook.

At least 73 records · Page 4Linked to original sources

Alopecia areata treated with topical minoxidil.

A 1% minoxidil topical solution was used to treat 48 patients with alopecia areata, ie, 24 patients with patchy disease and 24 patients with alopecia totalis or alopecia universalis. Twenty-five patients had terminal hair regrowth; in 11 of the 25 patients, it was cosmetically acceptable. No clinical features of the disease seemed to indicate the likelihood of hair regrowth. Hair regrowth began approximately two months after the initiation of treatment and was not uniformly well maintained after the treatment was terminated. One patient had an allergic contact dermatitis reaction to the minoxidil solution; no systemic side effects were seen. No notable systemic absorption was found in 18 adult patients. Effects on cutaneous blood flow or the immune system or some direct effect on hair follicles are possible mechanisms by which minoxidil therapy might stimulate hair growth.

Administration, Topical

Regulation of oviduct function in pigs by local transfer of ovarian steroids and prostaglandins: a mechanism to influence sperm transport.

Blood was collected from a prominent ear vein and from the arterioles supplying the caudal portion of each oviduct in 5 estrous animals. Sampling was arranged at 4 preovulatory intervals, and just after ovulation in the fifth animal. Steroid hormones and prostaglandins were determined by radioimmunoassay of plasma. Whereas the concentration of cortisol did not differ between peripheral and oviduct blood samples, the overall values for progesterone, androstenedione and estradiol were significantly higher in oviduct samples (P less than 0.001) - frequently by 5- to 10-fold or more. The concentration of these three hormones in oviduct blood corresponded, in most instances, with the number of preovulatory follicles or recent ovulations in the adjacent ovary but suitable statistical correlations could not be performed. Prostaglandin F2 alpha was also present in higher concentrations in oviduct compared with peripheral plasma (P less than 0.005), although pulmonary clearance of prostaglandins would have influenced the peripheral values. Differences in the concentration of prostaglandin E2 were not significant. A local transfer of follicular hormones from the ovarian vein to the ovarian and utero-tubal arteries is proposed as a means of regulating oviduct function. Elevated concentrations of steroids and prostaglandins transferred in this way would permit incisive changes in the patency and contractile activity of the isthmus, thereby facilitating the periovulatory phase of sperm transport from the caudal portion of the oviduct to the site of fertilization.

Animals

Serial dexamethasone suppression test results during antidepressant therapy: relationship to diagnosis and clinical change.

Thirty-two outpatients with major depression of mild to moderate severity were given a 1 mg dexamethasone test (DST) after 1 week of placebo. Those who failed to show a response to placebo began a 6-week course of desipramine treatment. Severity ratings and the DST were repeated during biweekly visits. DST results robustly validated Winokur's familial subtyping and the primary/secondary distinction only when multiple results were considered. The use of multiple DSTs doubled the sensitivity of this test to primary depression and to familal pure depressive disorder without affecting specificity. Based on these data, a single abnormal DST result is considerably more meaningful than a single normal one. This finding may have particular importance to outpatients.

Depressive Disorder

The stability of amoxycillin sodium in intravenous infusion fluids.

The stability of amoxycillin sodium has been determined at 25 degrees C in water and in ten intravenous infusion fluids at concentrations of 1, 2 and 5% w/v. Little difference in stability was found between 1% and 2% amoxycillin solutions in the various vehicles, but the antibiotic was significantly less stable at 5%. Stabilities in sodium and potassium chloride solutions were similar to those in water and were markedly superior to those in dextrose or dextran fluids. Solutions in lactate or bicarbonate had intermediate stability. The antibiotic was, for practical purposes, unstable in 30% sorbitol solution. Guidelines are provided for intravenous infusion of amoxycillin in the solutions studied.

Amoxicillin

Morphology, histology and steroid hormones of the gonads in intersex pigs.

Studies of 3 genetically female, intersex pigs revealed that only one showed oestrous cycles and lordosis, the other 2 exhibited various components of male sexual behaviour. Each uterus was a patent bicornuate structure, but 5 of the oviducts were incompletely formed. Two of the animals had bilateral ovotestes, whilst the third had a functional ovary on the right and an ovotestis on the left. The small ovarian portion of each ovotestis contained Graafian follicles which did not respond to a systemic injection of PMSG. The major portion of each ovotestis consisted of extensive interstitial tissue and seminiferous tubules devoid of germ cells. A structure closely resembling an epididymis adjoined the ovotestes. Concentrations of oestradiol and progesterone in plasma corresponded with those expected in the follicular phase of an oestrous cycle, but concentrations of testosterone represented approximately one-tenth of the values found in mature boars.

Animals

Three radioligands compared for determining cytoplasmic estrogen-receptor content of human breast carcinomas.

We compared three radioligands for use in a cytoplasmic estrogen-receptor assay, using pooled cytosol from human breast adenocarcinomas. The estrogen receptor content was determined in vitro by a dextran-coated charcoal method involving a 4-h incubation with and without diethylstilbestrol. Tritiated moxestrol failed to come to equilibrium in 4 h, thereby preventing the use of conventional one-component Scatchard analysis. The use of 125I-labeled estradiol resulted in a higher estimate of estrogen-receptor concentration than that obtained with use of tritiated estradiol. This overestimation was not corrected by Scatchard, double-reciprocal, or Woolf plots, or by two different methods of data analysis: least squared and "robust." An underestimation of the specific activity of iodoestradiol with respect to that of tritiated estradiol and an unrecognized second component of nonreceptor binding could explain this disparity.

Breast Neoplasms

Effect of exercise on amino acid incorporation into myocardial contractile proteins.

Amino acid incorporation into myocardial protein was studied in rats after an acute bout of exhaustive swimming. Hearts were removed at exhaustion, 1, 2, or 4 h of recovery and amino acid incorporation measured using [3H] phenylalanine in an isolated perfused heart preparation. Amino acid incorporation into total tissue protein was reduced 30% at exhaustion but returned to normal by 1 h of recovery and showed no further change 4 h post exercise. In the myofibrillar fraction amino acid incorporation decreased slightly after exhaustive exercise but was stimulated by 57% following 2 h recovery. Myosin, electrophoretically fractionated showed an 84% stimulation in phenylalanine incorporation at exhaustion and 112% increase 2 h post exercise. Amino acid incorporation into myosin light chains (LC1 and LC2) accounted for most of the increased rate of synthesis. These data suggest that there was a preferential increase in myocardial protein synthesis following exercise which was associated with the myosin light chain components of the contractile proteins.

Amino Acids

Critique of the Danish-American studies of the adopted-away offspring of schizophrenic parents.

Studies of the adopted-away children of schizophrenic parents that have claimed to have shown a strong genetic factor in the etiology of schizophrenia have had a great impact on psychiatry, including effects on the direction and support of research. An examination of these studies, however, controverts these conclusions. The authors demonstrate that without the inclusion of parents with manic-depressive and indefinite diagnoses in the index group, there is no statistically significant difference between the number of offspring with schizophrenic spectrum diagnoses in the index and control groups.

Adoption

Transformation of human embryo cells with the use of cell-free extracts of a human rhabdomyosarcoma cell line (HUS-2): brief communication.

Cell-free extracts of the human rhabdomyosarcoma cell line HUS-2 caused the transformation of human embryo fibroblasts. This transformation included morphologic alteration, karyotypic change, and an increase in culture longevity. With the use of sex markers, multiple karyotypes confirmed that the human embryo fibroblasts were transformed, and the use of cell-free material further suggested the presence of a transforming virus. RNA-dependent DNA polymerase activity in a particle with a specific gravity of 1.16 g/cm3 indicated the presence of an RNA type C virus. Evidence also suggested that the known mammalian type C viruses, routine cytopathic effect-inducing viruses, or mycoplasma were not the agents responsible for the transformation. That both the donor (HUS-2) and converted (HUE-T) cell lines cross-reacted with antisera prepared against HUE-T indicated a common antigen arising in the process of conversion of HUS-2 cells to HUE-T cells.

Animals

Steroid-binding proteins in follicular fluid and peripheral plasma from pigs, cows and sheep.

No unusual steroid-binding proteins that might react with the oocyte or its investments could be detected in follicular fluid. Corticosteroid-binding globulin occurred in follicular fluid from pigs, sheep and cows, and sex hormone-binding globulin occurred in follicular fluid from sheep and cows. The bulk of the steroid in follicular fluid is bound to albumin with low affinity, indicating that steroid molecules can readily be released, and oestrogen can react with the oocyte and granulosa cells in a manner analogous to that demonstrated for target cells bathed with interstitial fluid. Pigs lack a sex-hormone binding globulin in blood plasma and, hence, in follicular fluid. Because no proteins exist in follicular fluid that would compete with antibodies to bind steroids, direct radioimmunoassay of follicular steroids appears to be a valid technique.

Animals