Changes in the male voice at puberty

The changes in the male voice in relation to the biological characteristics of puberty were assessed longitudinally in 26 boys. Speaking and singing fundamental frequencies were analysed in relation to the Tanner staging of puberty, saliva testosterone levels, and the Cooksey classification of voice analysis. There were abrupt changes in voice characteristics between Tanner stages G3 and G4 and more gradually from stages C3 to C5 of Cooksey. Although testosterone concentrations were not predictive of the changes, there was a correlation with testis volume. Voice fundamental frequencies were seen to change abruptly in late puberty, in contrast with previous studies. There is a good correlation between the Tanner and Cooksey methods of classification during male puberty.     

Endothelial nitric oxide synthase in placental villous tissue from normal, pre-eclamptic and intrauterine growth restricted pregnancies

Nitric oxide (NO) regulates blood flow in the human placenta. As increased resistance to blood flow is seen in the fetal-placental vasculature in pregnancies complicated by pre-eclampsia and/or intrauterine growth restriction (IUGR), we examined expression of endothelial nitric oxide synthase (eNOS) in these placentas. Placental villous tissue sections were obtained from normotensive control (n = 5), IUGR alone (n = 5) or pre-eclamptic (with or without IUGR (n = 9) patients, immunostained for eNOS and scored for localization, type (punctate or diffuse) and intensity of eNOS staining in syncytiotrophoblast and placental vessels. The significance of differences was calculated using the Mann-Whitney U-test. No differences in intensity or type of immunostaining in syncytiotrophoblast were seen. Placentas from patients with pre- eclampsia with or without IUGR had a significantly more basal distribution of eNOS in syncytiotrophoblast. eNOS immunostaining was absent in terminal villous capillary and faint in stem villous vessel endothelium of normal placentas, but was intense in the endothelium of both of these types of vessels in the IUGR and pre-eclampsia groups, with significantly greater staining seen in stem vessels of patients with IUGR alone. This increased eNOS expression and hence increased NO production in the fetal-placental vasculature may be an adaptive response to the increased resistance and poor perfusion in these pathological pregnancies.      

稀有放线菌产生的抗生素

由于从链霉菌中发现新抗生素的几率越来越小，从稀有放线菌中寻找新抗生素成为研究的重点。稀有放线菌是新生物活性物质的重要产生菌，其产生的抗生素具有结构多样及活性独特的特点。本文概述近年来稀有放线菌中的小单孢菌属、诺卡菌属、马杜拉放线菌属、游动放线菌属、拟无枝菌酸菌属、小双孢菌属及糖多孢菌属等产生的抗生素种类及其活性。     

Surgical Treatment of Annuloaortic Ectasia with Composite Grafts Including Homologous Dura Mater Valves

We describe 3 patients in whom a composite dura mater valve-Dacron tube graft was used for replacement of the entire ascending aorta and aortic valve. Two patients had Marfan's syndrome and 1, a chronic aortic dissection, type II. All had severe aortic regurgitation. There were no early or late deaths in a follow-up period of 2, 7, and 12 months, respectively. All 3 patients were asymptomatic when last seen. Two underwent postoperative aortography that disclosed well-functioning valves and good filling of the coronary arteries.It is concluded that annuloaortic ectasia is best treated by the technique of total replacement of the ascending aorta and aortic valve by a composite valve-tube graft, and that the homologous dura mater valve, for its characteristics of central flow, lack of need for anticoagulants, and durability, represents a reasonable alternative for use in this situation.     

P16和视网膜母细胞瘤蛋白在高砷煤引起的砷中毒患者皮损中的表达

目的 研究P16和视网膜母细胞瘤蛋白(Rb)在高砷煤引起的砷中毒患者皮损中的表达.方法 采用免疫组化SP法检测46例高砷煤引起的砷中毒患者皮损中P16和Rb蛋白的表达.结果 高砷煤引起的砷中毒患者皮损中P16蛋白的表达缺损率为59.7%,其表达随病损的加剧而减低,并与临床分级和病理分型明显相关(P<0.01).Rb蛋白的阳性表达率为60.9%,与临床分级相关(P<0.05).P16蛋白的阳性表达与Rb蛋白呈负相关(P<0.01).结论 P16蛋白表达降低和P16-Rb通路的失活可能与高砷煤引起的砷中毒患者皮损的发生密切相关.