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Biomedical subjects

C R Shaw

Publications and source records attributed to C R Shaw.

At least 19 recordsLinked to original sources

Concept maps: a strategy to teach and evaluate critical thinking.

The purpose of this article is to describe a study that implemented concept maps as a methodology to teach and evaluate critical thinking. Students in six senior clinical groups were taught to use concept maps. Students created three concept maps over the course of the semester. Data analysis demonstrated a group mean score of 40.38 on the first concept map and 135.55 on the final concept map, for a difference of 98.16. The paired t value comparing the first concept map to the final concept map was -5.69. The data indicated a statistically significant difference between the first and final maps. This difference is indicative of the students' increase in conceptual and critical thinking.

Achievement↗

The perimenopausal hot flash: epidemiology, physiology, and treatment.

The "hot flash" (HF), or vasomotor instability, is experienced by 75% of perimenopausal and menopausal women in the United States. The experience for some women is a minor annoyance but for others, the HF is an intensely unpleasant sensation that is disruptive to their lives. The HF is thought to be triggered by a number of external and internal stimuli such as anxiety, stress, ambient high temperatures, caffeine, and alcohol. The thinner woman tends to experience more severe and frequent HFs than the woman with more adipose tissue, probably because of the ability of adipose tissue to transform androstenedione to estrone and estradiol. Smoking history also tends to be associated with the experience of HFs at an earlier age. The etiology of HFs in the decreasing estrogen state is related to the downward resetting of the hypothalamic thermoregulating mechanism, probably by the action of norepinephrine, which is usually modulated by estrogen. The body attempts to dissipate unwanted body heat by vasodilation, thus causing the sensation of the HF. The most successful treatment modalities have been hormone replacement therapy with estrogen and progesterone. Alpha 2-adrenergic blockers have also shown some limited effectiveness. Many alternative therapies such as vitamin E, primrose oil, dong quai, and black cohash have anecdotal support but have not been thoroughly studied. Relaxation, exercise, avoidance of triggering factors, and control of external environment have all been utilized with some success by women.

Adaptation, Psychological↗

Information needs prior to breast biopsy.

Biopsy is the definitive diagnostic procedure for breast cancer. The fear of cancer may make the breast biopsy itself a distressing experience for women and their significant others. Information seeking is believed to be a primary mode of coping with distressful events. The purpose of this study was to describe the information needs of women and their significant others prior to a breast biopsy and to explore the influence of information on the breast biopsy experience. Semi-structured, audiotape-recorded interviews with 11 women and 8 significant others were conducted prior to breast biopsy, and categories arising from the data were developed. The primary information need identified by the participants was to know "Is it cancer?" Participants' uncertainty regarding the outcome of the biopsy led to feelings of distress. The major strategy used to reduce distress was information management, in which the amount and type of incoming information was controlled. Nursing interventions based on the study findings are presented.

Adult↗

The effect of Ca deprivation and of Ca-blocking drugs on oxytocin-induced contractions of the male mouse anococcygeus.

Oxytocin (4 nM)-induced contractions of the male mouse anococcygeus were rapidly and completely lost in EGTA (2 mM)-containing, Ca-free Krebs solution. Contractions were also lost, although more slowly, in Ca-free Krebs solution without EGTA; under such conditions, readdition of Ca did not by itself cause contraction, but readdition of Ca (0.1-2.5 mM) in the presence of 4 nM oxytocin resulted in a rapid contractile response. These Ca-induced responses, in the presence of oxytocin, and those to oxytocin in normal Ca-containing Krebs solution, were unaffected by nitrendipine (0.01-1 microM). Contractions to oxytocin were completely blocked by the calmodulin antagonists trifluoperazine (50 microM) and W-7 (75 microM). It is concluded that oxytocin-induced contraction of the mouse anococcygeus does not require opening of nitrendipine-sensitive Ca channels, and there is no Ca-independent component of the contractile response; the cellular mechanisms linked to the oxytocin receptor in the anococcygeus are therefore different from those in the uterus.

Animals↗

Genetic effects of hydralazine.

Hydralazine and its acetone condensation product (ACP) were found to induce base-pair substitution mutations in the Salmonella/microsomal activation test system and to display genetic toxicity in the PolA+/A- test system. Incubation with a rat-liver microsomal fraction did not affect the genetic toxicity of either compound. Other derivatives of hydralazine, including the major metabolite, 3-hydroxy-methyl-s-triazolo-[3,4a]phthalazine, did not yield any evidence of genetic toxicity nor were they metabolically convertible to a toxic product. Therefore, individuals who convert hydralazine to MTP slowly, the "slow acetylators", would be expected to be at risk.

Drug Evaluation, Preclinical↗

N'-hydroxy-2-aminofluorene: the principal mutagen produced from N-hydroxy-2-acetylaminofluorene by a mammalian supernatant enzyme preparation.

A Salmonella typhimurium TA 1538 culture system wasused to monitor the production of mutagen from N-hydroxy-2-acetylaminofluorene by soluble liver enzymes. When benzene was used to extract the mutagen, no mutagenic activity remained in the liver enzyme preparation. The benzene extract contained approximately two-thirds of the total mutagenic activity produced by the liver enzyme preparation. Using thin layer and column chromatography to analyze the benzene extract, we deduced that N-hydroxy-2-aminofluorene accounted for the mutagenic activity which resulted from the incubation of N-hydroxy-2-acetylaminofluorene with soluble liver enzymes.

2-Acetylaminofluorene↗

Altered proteins with triosephosphate isomerase activity in suppressor-containing strains of Bacillus subtilis.

Suppressor mutations in Bacillus subtilis cause the synthesis of a new protein with the enzymatic activity of l-leucine dehydrogenase and two groups of new proteins with the activity of triosephosphate isomerase. The new isoenzymes of triosephosphate isomerase are separable by zone electrophoresis and differ among themselves in elution behavior upon gel permeation chromatography. One group has an apparent average molecular weight of 120,000 to 135,000, which is more than twice that of the wild-type enzyme. Another group appears to be even higher in molecular weight. These data are consistent with the working hypothesis that the new isoenzymes are produced by extension of growing polypeptide chains through one or more chain-terminating triplets, although other mechanisms resulting in alteration of shapes, charges, or associations of the enzymes are not excluded.

Alleles↗

Aryl hydrocarbon hydroxylase induction in human leukocytes.

A method for determining aryl hydrocarbon hydroxylase induction in human leukocytes is described. Leukocytes from healthy volunteers were cultured in the presence of phytohemagglutinin, a mitogen. Addition of 3-methylcholanthrene to 72-hour cultures induced a fourfold increase in aryl hydroxylase activity. In the absence of a mitogenic agent, 3-methylcholanthrene stimulation of increased enzymatic activity did not occur.

Cells, Cultured↗