The acute effect of 30 min of moderate exercise on high density lipoprotein cholesterol in untrained middle-aged men

Fifteen middle-aged, untrained (defined as no regular exercise) men (mean age 49.9 years, range 42-67) cycled on a cycle ergometer at 50 rpm for 30 min at an intensity producing 60% predicted maximum heart rate [(fc,max), where fc,max = 220 - age]. Total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and triglyceride (Tg) concentrations were measured from fasting fingertip capillary blood samples collected at rest, after 15 and 30 min of exercise, and at 15 min post-exercise. The mean HDL-C level increased significantly from the resting level of 0.85 mmol.l-1 to 0.97 mmol.l-1 (P < 0.05) after 15 min of exercise, increased further to 1.08 mmol.l-1 (P < 0.01) after 30 min of exercise and remained elevated at 1.07 mmol.l-1 (P < 0.01) at 15 min post-exercise. These increases represented changes above the mean resting level of 14.1%, 27.1% and 25.9% respectively. The HDL-C/LDL-C ratio increased significantly from a resting ratio of 0.20 to 0.26 after 30 min of exercise (P < 0.01) and to 0.24 at 15 min post-exercise (P < 0.05). The mean Tg level increased significantly from a resting level of 0.88 mmol.l-1 to 1.05 mmol.l-1 after 15 min, and to 1.06 mmol.l-1 after 30 min of exercise (P < 0.05 at each time). The TC/HDL-C ratio decreased significantly (P = 0.05) after 30 min of exercise and at 15 min post-exercise by 18.8% and 14%, respectively. No significant changes were observed in the levels of TC or LDL-C over time.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pregnancy induced hypertension: a role for peroxidation in microvillus plasma membranes

It has been recently hypothesized that in PIH a placental oxidant-antioxidant imbalance might cause the release of lipoperoxidation products into the circulation, with subsequent damage of endothelial cell membranes. In this hypothesis the endothelial cell and further increase in circulating lipoperoxide levels, which are by themselves able to induce smooth muscle constriction and increased pressor responsiveness to angiotensin II. In order to investigate this issue, we studied the basal content of lipid peroxides in terms of malondialdehyde (MDA) in the syncytiotrophoblast plasma membranes (SPM) from PIH women. Moreover, we investigated the susceptibility to peroxidation of SPM using anin vitro oxidative stress as a tool to verify the predisposition to thein vivo development of peroxidation products. The fatty acid composition of the membranes was also analyzed. Microvillus membrane lipoperoxide concentrations were significantly increased in PIH women (62.8±7.6 ng MDA/mg prot) compared with healthy pregnant subjects (37.6±4.8 ng MDA/mg prot; p<0.01).The formation of TBARS under the action of phenylhydrazine was significantly greater in PIH women (90.3±7.4 mmol MDA/mol cholesterol) than in normal pregnant subjects (68.6±6.4 mmol MDA/mol cholesterol; p<0.01). In PIH microvillus membrane we also observed a significant increase of the content of polyunsaturated arachidonic acid.The increased susceptibility to oxidative stress of SPMs from PIH women might be due either to reduced antioxidant systems or to an abnormality of the lipid composition of the membrane. The present work also demonstrated in PIH a reduction in the SPM content of saturated fatty acids with an increase in polyunsaturated fatty acids, which are the major substrate for peroxidation. On the other hand, the higher lipoperoxidation may be due to the observed increased susceptibility to peroxidative stress, to a primary reduction in placental perfusion with tissue hypoxia or to both factors, which can potentiate each other.     

Narratives of success among Irish and African Caribbean migrants

This paper compares the narratives of two men in midlife who migrated to the UK from Ireland and from the Caribbean as children, in the middle of the last century. We examine how success is narrated over the life course to show how migrants’ positioning of themselves differs from the ways in which they are positioned by outsiders, including in policy and public discourse. We conclude that while outsider narratives often polarise success and failure, insider understandings of success are dynamic and culturally and historically situated.     

Commitment and paradox in sociological research: School integration in Israel*

Panethnicity ‐ the development of bridging organizations and the generalization of solidarity among ethnic subgroups ‐ is important theoretically because it focuses attention on ethnic change, and allows one to assess the relative importance of structural and cultural factors. In this article we present a framework for the study of panethnicity, generate research questions from this framework, and then test these questions by examining panethnicity within four broad racial/ethnic groupings: Asian Americans, Native Americans, Indo Americans and Latinos in the United States. A review of these four cases demonstrates that those groups with the greatest cross‐subgroup structural similarity (Asian Americans and Indo Americans) also display the greatest panethnic development and potential, despite their considerable cultural diversity. This suggests that structural factors are more important for understanding the development of panethnicity and, by extension, for understanding ethnic change generally.     

Challenging the racialization of child sexual exploitation: Muslim men,racism and belonging in Rotherham

This paper presents findings from original research exploring the impact on Muslim men of a child sexual exploitation scandal that attracted significant attention to the northern English town where they live and contributed to a sustained detrimental effect on local community relations. It foregrounds men’s accounts to reveal their agency and resilience in responding to racism that they identified as resulting from the scandal. It reveals how their accounts disrupt dominant discourses foregrounding Muslim self-segregation and lack of integration, demonstrating positive attachments and claims to localized space, and commitment to belonging. In doing so, it shows how men’s responses to racism challenge racialized forms of knowledge about Muslims. The paper draws attention to the significance of localized forms of belonging in facilitating the inclusion of Muslim minorities. It also highlights the importance of centring Muslim men as historically speaking subjects in accounts of issues involving them.     

Partner notification methods for African American men being treated for trichomoniasis: a consideration of main men, Second Hitters, and Third Players

This pilot study sought information on African American men's preferences for partner notification methods for a common sexually transmitted infection called trichomoniasis. Two focus groups of African American men were convened at a public STI clinic where they were being treated for trichomoniasis. The groups identified a sexual hierarchy in men's preferences for methods of partner notification. The hierarchy consisted of main men (Cake Daddies), second men (Second Hitters), and third or fourth men (Third Players), with placement depending on age, income, and social status. Health department employees affirmed the existence of a sexual hierarchy in a separate focus group. Sexual and economic bartering formed the basis of the hierarchy, and the secrecy involved in such arrangements presented a considerable challenge for STI control. Disease intervention specialists who were responsible for contact tracing spoke of cat-and-mouse methods in contacting the men without understanding fully exactly how the hierarchy influenced men's responses to partner notification. The findings suggest that STI control efforts must take the sexual hierarchy and its privacy implications into account if partner notification methods are to be acceptable to African American men.     

Growth Hormone Secretion after Testosterone Administration to Men with Visceral Obesity

Visceral obese men were characterized by a decreased total GH secretion and diminished peak amplitude, size, and number. T-substitution was followed by elevation of IGF-I levels. The IGF-I increase correlated with the elevation of T-concentration, and was most pronounced in men with the lowest concentrations of free T from the outset. There were no detectable changes in total quantity, amplitude, size or number of peaks of GH secretion. Glucose, cholesterol and triglycerides as well as diastolic blood pressure decreased. There were no changes in thyroid or hematology variables. Visceral obesity in men has been reported to be characterized by low testosterone (T) and insulin-like growth factor I (IGF-I) concentrations, the latter suggesting a relative growth hormone (GH) deficiency. Since T and GH-secretions are interrelated, men with visceral obesity were substituted with T for 14 days, and diurnal secretion pattern of GH as well as IGF-I concentrations, and metabolic variables were followed. T-substitution of visceral obese men is followed by an elevation of IGF-I concentrations. It is suggested that this might be due either to minor, non-detectable increases in GH secretion, or to direct effects of T on IGF-I concentrations. The regulatory mechanisms by which T-administration are leading to metabolic and anthropometric improvements, might be direct effects of T, with or without mediation via GH secretion.     

老年男性教师骨密度的调查

目的 为了解老年性骨质疏松情况,用超声骨密度仪对150例老年男性教师做跟骨超振幅衰减值的测试研究。方法：用DMS公怀UBIS5000型骨密度超声仪检查跟骨,研究受检者的年龄、体重、身高和巳患病咎与测得超声振幅衰减值（BUA）,声速（SOS）,骨硬度（STI）和相对骨折危险性（RRF）等参数之间的关系。结果：本仪器输出3种结果供医师参考：1.一幅灰阶图,2.一幅彩色图和曲线图,3.感兴趣区所测得的参数,受检者的平均BUA为63.87dB/MHz,SOS为1485.21m/s,本文数据经Statpal软件处理,得出回归公式：体重=189.1417 0.2062BUA-0.0224SOS,R=0.0466,P值有显著意义。结论：BUA值为主要参数,SOS为补充参数,作为评估老年男性教师的骨密度情况,假如BUA值突然下降则提示近期可能发生骨质疏松。     

Physiological and biomechanical differences between wheelchair-dependent and able-bodied subjects during wheelchair ergometry

The purpose of this study was to compare the physiological and biomechanical responses of wheelchair-dependent persons (WCD) to able-bodied persons (AB) during manual wheelchair ergometry. Five WCD and five AB performed a discontinuous wheelchair ergometer test starting at 12.8 W at 30 rev.min-1 (57 m.min-1) with increments of 7.0 W at 6-min intervals. Biomechanical data were collected 3.5 min into each stage followed by the collection of physiological data. After the fifth stage, peak oxygen consumption was determined by having the subject work against a resistance of 14.7-19.6 N at 30 rev.min-1. The WCD had significantly higher net mechanical efficiency at 26.7, 33.6 and 40.6 W in comparison to the AB. The WCD had significantly greater shoulder extension at the point of initial wheel contact as measured by the shoulder angle, while the AB had significantly greater shoulder range of motion at all work rates in comparison to the WCD. The results demonstrate that a significant physiological difference exists in the manner by which WCD and AB accomplish wheelchair ergometry. The biomechanical differences between AB and WCD were found to be a prominent factor contributing to the higher mechanical efficiency of WCD over AB. It was concluded that basic physiological and biomechanical differences exist between WCD and AB in manual wheelchair locomotion and that these differences are important considerations to the interpretation of data in wheelchair ergometry studies.     

Running economy deteriorates following 60?min of exercise at 80% V˙O2max

Fifteen young adult Singaporean male physical education students maximum oxygen consumption [(V˙O_2max) = 56 (4.7) ml · kg⁻¹ · min⁻¹] performed three prolonged runs in a counterbalanced design. The running bouts varied in time (40 vs 60 min) and intensity (70% vs 80% V˙O_{2 max} ). Each prolonged run was separated by 7 days. The running economy (RE) at 10.8 km · h⁻¹ during 10-min running bouts was measured before (RE1) and after (RE2) each prolonged run. A control study involved monitoring RE at 10.8 km · h⁻¹ before and after 60 min rest. There were no differences between RE1 and RE2 values during the control run. However, there were differences between RE1 and RE2 values when separated by a prolonged run. For example, the mean (SD) changes in oxygen consumption (ml · kg⁻¹ · min⁻¹) values were 38.2 (2.5) versus 40.1 (2.6) (40 min at 80% V˙O_{2 max} ), 38.9 (2.8) versus 41.5 (2.6) (60 min at 70% V˙O_{2 max} ), and 39.0 (3.1) versus 42.7 (2.9) (60 min at 80% V˙O_{2 max} ; P < 0.01). The results of this investigation support the hypothesis that RE deteriorates during prolonged running, and that the magnitude of the deterioration in RE increases with both increasing exercise intensity and duration. Accepted: 14 July 1997