ACE inhibitor use was associated with lower serum dehydroepiandrosterone concentrations in older men

ContextAngiotensin converting enzyme (ACE) activity may influence the production of adrenal androgen precursors and testosterone. Use of ACE inhibitors may therefore have an influence on serum sex hormone concentrations in older men.Design and Methods1486 out of 2,000 community-dwelling Chinese men aged 65 years who participated in a cohort study were randomly selected to have archived fasting morning serum analyzed for androgen precursors and sex hormones. DNA was extracted from whole blood and analyzed for ACE gene I/D polymorphism.ResultsSubjects with the ACE gene D allele (higher ACE activity) had higher serum dehydroepiandrosterone (DHEA) sulphate and DHEA than those with I/I genotype (P = 0.014 and 0.018 respectively, Mann Whitney test). These differences were not significant after Bonferroni correction. Among those with history of hypertension, but without diabetes mellitus or cardiac failure, users of ACE inhibitors had significantly lower serum DHEA (median 1.78 versus 1.49 ng/ml in non-users, P = 0.0074, Mann Whitney test) and also tended to have lower serum androstenedione and androst-5-ene-3β,17β-diol (0.68 versus 0.72 ng/ml in non-users; 552.4 versus 624.1 pg/ml respectively, both P values < 0.05). Serum testosterone and estradiol were not significantly changed.ConclusionsACE inhibitor use was associated with lower serum DHEA in older men.     

Morphology of human T lymphocyte clones

Six human T lymphocyte clones, characterized as to cytolytic activities and several surface markers, were investigated for possible morphologic correlates of function. Cytotoxic T lymphocyte clones and natural killer-like clones had basically similar morphology, but cytotoxic T lymphocytes tended to cluster in groups and had many more lipid bodies, whereas natural killer-like cells had fewer intercellular contacts and had more and larger electron-dense bodies. Dense bodies were also quite prominent in noncytotoxic clones. The latter were distinctive in having a minority of very large cells (10 to 16 microns) with many microvilli, scattered among the majority of 5- to 8-microns diameter cells.     

Nicotine activation of neuronal nitric oxide synthase and guanylyl cyclase in the medulla increases blood flow of the common carotid artery in cats

Individual activation of nicotinic acetylcholine receptor (nAChR) or nitric oxide (NO) synthase in the dorsal facial area (DFA) increases blood flow of common carotid artery (CCA) supplying intra- and extra-cranial tissues. We investigated whether the activation of nAChR initiated the activation of NO synthase and guanylyl cyclase to increase CCA blood flow in anesthetized cats. Microinjections of nicotine (a non-selective nAChR agonist), or choline (a selective α7-nAChR agonist) in the DFA produced increases in CCA blood flow ipsilaterally. These increases were significantly reduced by pretreatment with NG-nitro-arginine methyl ester (l-NAME, a non-specific NO synthase inhibitor), 7-nitroindazole (7-NI, a relatively selective neuronal NO synthase inhibitor) or methylene blue (MB, a guanylyl cyclase inhibitor) but not by that with N5-(1-iminoethyl)-l-ornithine (l-NIO, a potent endothelial NO synthase inhibitor). Control microinjection with d-NAME (an isomer of l-NAME), artificial cerebrospinal fluid or DMSO (a solvent for 7-NI) did not affect resting CCA blood flow, nor did they affect nicotine- or choline-induced response. In conclusion, activation of nAChR, at least α7-nAChR, led to the activation of neuronal NO synthase and guanylyl cyclase in the DFA, which induced an increase in CCA blood flow.     

Sleep apnoea syndrome--a study of 5 cases

Sleep apnoea syndrome (SAS) is common in the West but its prevalence is uncertain in Southeast Asia. Five Chinese patients seen in a Sleep Assessment Unit in Hong Kong are presented to illustrate the spectrum of clinical features and treatment methods involved in obstructive and central sleep apnoea. The first patient is a 45-year old woman with severe obstructive SAS and cardiopulmonary complications who improved significantly after tracheostomy. The second patient is a 43-year old man who improved with weight reduction and protriptyline. The third is a 42-year old man whose SAS did not improve with uvulopalatopharyngoplasty but with continuous positive airway pressure (CPAP). The fourth is a 12-year old girl with obstructive SAS who improved significantly after tonsillectomy. The last patient is a 52-year old man with central SAS who improved with CPAP.