Microvascular transposition of the arterial supply to the testis of the boar.

The origin of the arterial supply to a testis was changed in 7 boars with a microsurgical technique. A. testicularis was connected, end to side, to a branch of the femoral artery. The capillary blood flow was unchanged, indicating viable transplants. The temperature difference between testis and body disappeared after the surgery, indicating an interruption of the heat transfer in the pampiniform plexus. The lower values of the histological score and the possibly lower peripheral plasma concentration of testosterone after the arterial by-pass may indicate a physiological importance of the counter current exchange.     

Negative regulators of growth.

The proliferation of cells is regulated by countervailing positively- and negatively-acting signaling networks. The anti-proliferative signals, the study of which has been much neglected until recently, are often conveyed by growth-inhibitory peptides. Elements that mediate the cellular response to growth inhibitors are encoded by tumor suppressor genes that if lost may lead to the runaway growth of the cancer cell.     

Decision to treat mild hypertension after assessment by ambulatory monitoring and World Health Organisation recommendations.

OBJECTIVE--To determine if one ambulatory blood pressure recording over 12 hours could detect those patients with mild hypertension who needed treatment according to the World Health Organisation-International Society of Hypertension (ISH) guidelines based on the causal measurement of diastolic blood pressure at successive visits to a clinic. DESIGN--Comparison of decision to treat based on one ambulatory measurement over 12 hours and standard blood pressure measurements over six months in the same patients. SETTING--Outpatient hypertension clinic. SUBJECTS--130 men and women with diastolic blood pressure of 90-104 mm Hg at second visit to clinic. MAIN OUTCOME MEASURES--Blood pressure measurements over six months. Measurement from ambulatory monitoring. Decision to treat. RESULTS--Of the 130 patients included, 108 were followed up over the six months. Treatment was started according to WHO-ISH criteria in 44 (13 at the third visit, 13 at the fourth, 18 at the fifth). According to the selected criteria for ambulatory blood pressure monitoring 41 patients would have been treated. Both methods agreed that the same 27 patients required treatment and the same 50 did not, but they did not agree in 31 patients. When calculated at the optimal diastolic blood pressure threshold determined by a receiver operating characteristic curve, the sensitivity, specificity, and positive predictive value of ambulatory blood pressure monitoring were 71% (95% confidence interval 57% to 84%), 82% (72% to 92%), and 66% (51% to 81%), respectively. CONCLUSION--If the WHO-ISH criteria are accepted as the standard for deciding to treat patients with mild hypertension the predictive value of one ambulatory blood pressure recording over 12 hours is too low to detect with confidence those patients who need treatment when managed according to these criteria.     

Studies on anabolic steroids--12. Epimerization and degradation of anabolic 17 beta-sulfate-17 alpha-methyl steroids in human: qualitative and quantitative GC/MS analysis.

The epimerization and dehydration reactions of the 17 beta-hydroxy group of anabolic 17 beta-hydroxy-17 alpha-methyl steroids have been investigated using the pyridinium salts of 17 beta-sulfate derivatives of methandienone 1, methyltestosterone 4, oxandrolone 7, mestanolone 10 and stanozolol 11 as model compounds. Rearrangement of the sulfate conjugates in buffered urine (pH 5.2) afforded the corresponding 17-epimers and 18-nor-17,17-dimethyl-13(14)-enes in a ratio of 0.8:1. These data indicated that both epimerization and dehydration of the 17 beta-sulfate derivatives were not dependent upon the respective chemical features of the steroids studied, but were instead inherent to the chemistry of the tertiary 17 beta-hydroxy group of these steroids. Interestingly, in vivo studies carried out with human male volunteers showed that only methandienone 1, methyltestosterone 4 and oxandrolone 7 yielded the corresponding 17-epimers 2, 5 and 8 and the 18-nor-17,17-dimethyl-13(14)-enes 3, 6 and 9 in ratios of 0.5:1, 2:1 and 2.7:1, respectively. No trace of the corresponding 17-epimers and 18-nor-17,17-dimethyl-13(14)-enes derivatives of mestanolone 10 and stanozolol 11 was detected in urine samples collected after administration of these steroids. These data suggested that the in vivo formation of the 17-epimers and 18-nor-17,17-dimethyl-13(14)-enes derivatives of 17 beta-hydroxy-17 alpha-methyl steroids is also dependent upon phase I and phase II metabolic reactions other than sulfation of the tertiary 17 beta-hydroxyl group, which are probably modulated by the respective chemical features of the steroidal substrates. The data reported in this study demonstrate that the 17-epimers and 18-nor-17,17-dimethyl-13(14)-enes are not artifacts resulting from the acidic or microbial degradation of the parent steroids in the gut as previously suggested by other authors, but arise from the rearrangement of their 17 beta-sulfate derivatives. Unchanged oxandrolone 7 was solely detected in the unconjugated steroid fraction whereas unchanged steroids 1, 4 and 11 were recovered from the glucuronide fraction. These data are indirect evidences suggesting that the glucuronide conjugates of compounds 1 and 4 are probably enol glucuronides and that of compound 11 is excreted in urine as a N-glucuronide involving its pyrazole moiety. The urinary excretion profiles of the epimeric and 18-nor-17,17-dimethyl-13(14)-ene steroids are presented and discussed on the basis of their structural features.     

Biotransformation of 2-acetylthiophene by micromycetes

Summary The biotransformation of 2-acetylthiophene by 800 strains of micromycetes has been investigated. Among them, 460 strains have been selected on solid media and cultivated in a liquid synthetic medium. Of these, 106 strains were able to completely deplete 2-acetylthiophene with or without production of intermediary metabolites. 2-Thienylglyoxylic acid was not detected but 72 strains produced 2-thiophenecarboxylic acid. Among them, eight strains have been selected for further optimization of this bioconversion.