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Biomedical subjects

D White

Publications and source records attributed to D White.

At least 415 records · Page 23Linked to original sources
PubMed1977

Plasma prostaglandins across the tumor bed of patients with gynecologic malignancy.

Prostaglandin E produced by tumors has recently been implicated as a mechanism by which tumors may subvert the immune system and grow despite their antigenicity. Arterial and venous determinations of prostaglandin E were performed in eleven patients with gynecologic malignancy. No significant difference was found when arterial and venous levels were compared and there was no difference in venous PGE levels when subjects with cancer were compared to patients with benign gynecologic disease.

Adenocarcinoma↗
PubMed1977

Luteinizing hormone and testosterone during nocturnal sleep: relation to penile tumescent cycles.

Variations of plasma LH and testosterone in relation to sleep-related penile tumescence were assessed. Plasma LH and testosterone were measured at 10-20 min intervals in five normal adult men during 2 nights of sleep. Blood samples were obtained by means of an indwelling venous catheter while sleep was monitored polygraphically and penile tumescence recorded with a penile mercury strain gauge. Tumescent episodes were recorded in all subjects during 9 of the 10 nights of the study, and the percentage of time during sleep, which was associated with tumescence, ranged from 13% to 34%. Simultaneous REM and tumescence comprised 57.7% of total tumescent time. Abrupt elevations of plasma LH and testosterone were observed during the night without a significant relationship to stages of sleep. The mean of all hormonal determinations for the five subjects did not show significant differences in plasma LH and testosterone between fully and partially tumescent episodes and nontumescent periods. Mean testosterone during REM sleep with tumescence, a state of autonomic activation involving sexual function, was consistently higher for the five subjects than during periods free from REM and tumescence.

Adult↗
PubMed1977

Myxospore coat synthesis in Myxococcus xanthus: in vivo incorporation of acetate and glycine.

Myxospore coat synthesis in Myxococcus xanthus was studied by incorporation of [(14)C]acetate into intermediates in the biosynthesis of coat polysaccharide and into acid-insoluble material during vegetative growth and after glycerol induction of myxospores. During short labeling periods at 27 degrees C, the radioactivity was shown to be located primarily in N-acetyl groups rather than sugar moieties. Two hours after glycerol induction, the pools of N-acetylglucosamine 6-phosphate and uridine 5'-diphosphate-N-acetylgalactosamine (UDPGalNAc) plus uridine 5'-diphosphate-N-glucosamine increased about twofold and were labeled at twice the rate measured for vegetative cells. The increased rate of synthesis of UDPGalNAc and its precursors could be correlated with increased enzyme activities measured in vitro. Controlled acid hydrolysis revealed that the galactosamine portion of the myxospore coat was N-acetylated. After glycerol induction, the incorporation of acetate into acid-insoluble material increased threefold. This enhanced incorporation was sensitive to neither penicillin nor d-cycloserine. In contrast, bacitracin inhibited the incorporation of [(14)C]acetate into acid-insoluble material more effectively 2 h after myxospore induction than during vegetative growth. Chloramphenicol added to cells 90 min after induction blocked further increase in the rate of [(14)C]acetate incorporation. Since the myxospore coat contains glycine, polymer synthesis was also measured by chloramphenicol-insensitive [(14)C]glycine incorporation into acid-insoluble material. Although protein synthesis decreased after glycerol induction, glycine incorporation increased. Two hours after induction, glycine incorporation was only 75% inhibited by chloramphenicol and rifampin. The chloramphenicol-insensitive rate of incorporation of [(14)C]glycine increased during the first hour after myxospore induction and reached a peak rate after 2 to 3 h. The chloramphenicol-resistant incorporation of [(14)C]glycine was resistant to penicillin but sensitive to bacitracin.

Acetates↗
PubMed1976

Cardiopulmonary effects of long-term bronchodilator administration.

Because of reports of drug tolerance occurring with chronic use of adrenergic agents in asthma, we investigated cardiopulmonary responsiveness to ephedrine and to the beta-2 agent, tebutaline, following chronic drug administration for periods up to one year. With chronic drug administration baseline (prior to daily medication) FEV increased 19% in the terbutaline group and 3.5% in the ephedrine group. An additional increase of FEV above baseline of 23% for terbutaline and 12% for ephedrine was noted after daily medication. Terbutaline also had a longer duration of effect; peak response after ephedrine occurred at 2 hr while terbutaline effect was maximal at 3 to 4 hr. There was no evidence for reduced responsiveness to the bronchodilator actions of either drug at any time. Despite prolonged use, both drugs continue to increase heart rate and pulse pressure moderately following ingestion, with a peak effect occurring at 3 hr; however, pulse pressure widened after terbutaline because of a diastolic fall, while the major effect of ephedrine was to increase systolic pressure. Baseline blood pressure, particularly diastolic, declined progressively with continued drug use. No evidence of cardiac, ehpatic, renal, or ophthalmologic toxicity or change in need for other bronchodilator agents was noted during the study with either drug.

Asthma↗
PubMed1976

Androgens and male sexual function: a review of human studies.

The scope of this article will be a review and brief discussion of recently gathered information on androgens and sexual behavior in men. It will include experimental observations on the covariance between androgens, mainly testosterone, and sexual functioning in normal heterosexual men and studies on sexual dysfunction and homo-sexual behavior. The effects of castration, hypogonadal conditions, hormonal replacement, and endogenous testosterone variations on sexual behavior are examined. Further psychoendocrine studies, are necessary to evaluate the role of gonadal hormone production in impotency. Current pharmacological research does not furnish specific evidence, that the administration of androgens or preparations that stimulate the secretion of endogenous androgens have beneficial effects on functional impotence. After reviewing the studies on male homosexuality and androgen levels, the article concludes that it has not been established that homosexual men are characterized by abnormalities in plasma testosterone.

Adolescent↗
PubMed1976

Decreased prevalence of immediate hypersensitivity (atopy) in a cancer population.

It has been suggested that the atopic population has decreased risk of cancer. This investigation examined the cumulative prevalence of atopy in a population with neoplastic disease and compared this with the prevalence of atopy in an age-matched control group and with published estimates of atopy in the general peopulation. Seventy-four patients with neoplastic disease and 86 patients without cancer were evaluated. The subjects were given a standard allergic questionnaire which evaluated them with regard to a history of allergic symptoms, hives, eczema, frequent colds, frequent unexplained rashes, hay fever, and asthma. All were skin tested with a representative group of regionally significant allergens. There was a 15-fold decrease in prevalence of atopy in the cancer population, compared with the control group and compared with published estimates of atopy in the general population.

Adult↗
PubMed1975

Early predictors of incomplete recovery in children with Guillain-Barr'e polyneuritis.

Case histories of 47 children with strict criteria for Landry-Guillain-Barré-Strohl polyneuritis admitted to a rehabilitation facility from late 1959 through 1972 were analyzed retrospectively. The children were followed to full recovery (good to normal strength in all muscle groups) or for three years without full recovery. The data were then compared statistically for possible predictive indicators of recovery or lack of recovery within three years. The most significant early predictor of incomplete recovery was the time interval between the greatest weakness and beginning improvement; a period longer than 18 days of plateau before gains are evident is indicative of incomplete recovery within limits of 99% confidence.

Cerebrospinal Fluid Proteins↗
PubMed1975

Coats from Myxococcus xanthus: characterization and synthesis during myxospore differentiation.

An extracellular coat from glycerol-induced myxospores of Myxococcus xanthus has been isolated and characterized. Coats were examined chemically and by using both transmission and scanning electron microscopy. On a dry weight basis, approximately 75% of the coat is polysaccharide composed entirely of galactosamine and glucose. The remainder of the coat is protein (14%), glycine (8%), and organic phosphorus (less than 1%). Coats remained morphologically intact despite boiling in 10 M urea, sodium lauryl sulfate plus beta-mercaptoethanol, or extraction with warm phenol. Coats also resisted digestion with a variety of proteolytic and polysaccharide degrading enzymes. Synthesis of myxospore coat begins approximately 1 h after the addition of glycerol to a culture. One portion of the coat is complete by 5 to 6 h but additional material consisting primarily of glucose is added after 8 h.

Bacterial Proteins↗