Biomedical subjects
J Beach
Publications and source records attributed to J Beach.
Preoperative anxiety and myocardial ischaemia: is there a relationship?
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Hypogonadotropic hypogonadism in nephrotic rats: increased sensitivity to negative feedback effects of testosterone.
Pituitary-testicular function was examined in adult male rats with aminonucleoside-induced nephrotic syndrome as a model for similar disease in humans. Nephrotic rats developed androgen deficiency, as manifested by decreased prostate and seminal vesicle weights, lower serum total and free testosterone levels, and reduced testosterone release from testes incubated in vitro. Despite hypoandrogenism, the weight and histologic appearance of the testes (light microscopy) were not affected in nephrotic rats. This androgen deficiency seemed to be a consequence of decreased gonadotropin output rather than primary testicular failure, since both pituitary gonadotropin content and serum gonadotropin levels (basally and after luteinizing hormone releasing factor; LHRH) were reduced in nephrotic rats. In addition, the percentage increase in testosterone release by testes incubated in vitro after addition of exogenous gonadotropin was similar in nephrotic and control groups. However, gonadotropin output in nephrotic rats was not impaired in the absence of testis, since no reduction was seen in either post-castration serum gonadotropin levels in vivo or gonadotropin release from pituitaries incubated in vitro. This presumed inhibitory effect of the testis on gonadotropin output in nephrotic rats was confirmed directly by demonstrating an increased sensitivity to testosterone-mediated suppression of gonadotropins in castrate animals in vivo. The presence or absence of albumin also seemed to modulate the suppressive effect of testosterone on gonadotropin output from normal pituitaries incubated in vitro. We conclude that nephrotic male rats develop hypogonadotropic hypogonadism secondary to an increase in sensitivity of the pituitary to the negative feedback effects of testosterone.
CT and MR for brain tumor implant therapy using CF-252 neutrons.
Magnetic resonance (MR) imaging of the brain allows very effective localization of tumor in brain, visualization of brain reaction to tumor, peritumoral edema, as well as destruction of normal anatomy and spread of tumor. MR readily imaged the brain in multiple views allowing three dimensional (3D) evaluation and more precise localization of tumor in the depths of the brain. It also assessed the extent of tumor infiltration away from the primary site. In an ongoing study of Cf-252 neutron brachytherapy of hemispheric malignant gliomas of the brain, we have found that the extent of tumor and the planning of the placement of multiple applicators in the brain for implant therapy was facilitated by both CT and MR scanning, but MR allowed better 3D localization, assessment of response and follow-up of tumor response. MR gave additional and different types of information about the tumor than CT scanning based upon proton distribution which greatly aided planning of tumor implant therapy and understanding of patterns of tumor response and recurrence after therapy.
A method for quantifying electromyograms.
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A double-blind randomized trial of low-dose oral urea to prevent sickle cell crises.
Seventy-nine homozygous SS patients were randomly assigned to control or oral prophylactic urea treatment in a double-blind trial designed to determine whether prophylactic oral urea, in low doses, prevents sickle cell crises. The average follow-up time for these patients was 13.7 months and 33 patients were diagnosed as having one or more crises during the study. No statistically significant treatment differences were found in weight changes, bilirubin changes, or hemoglobin changes over the course of the study or in the distribution of time to first crises or time to second crisis. This study gives no evidence in favor of the hypothesis that prophylactic oral urea, in low doses, prolongs time to crisis.
Bone marrow transplantation in children.
Bone marrow transplantation is a new concept in the treatment of leukemia and aplastic anemia. The problems seen in the transplanted patient are abundant and often life-threatening. Caring for these patients offers one of the most exciting challenges of nursing. The nurse not only acquires skill in caring for a patient with leukemia and aplastic anemia, but also becomes knowledgeable in infectious diseases, immunology, fluid and electrolyte balance, and cardiac, respiratory, and renal diseases. The complexity of these patients allows the nurse more direct, comsistent contact with them. As she becomes involved, she is given excellent opportunities for supporting the patient and family through this stressful time. Althoug bone marrow transplantation is an experimental procedure with problems still to be solved, results indicate its value in the treatment of refractory leukemia and aplastic anemia.
Suggested guide for doing a cost study.
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