Serum inhibin B as a marker of spermatogenesis

Inhibin B is produced by Sertoli cells, provides negative feedback on FSH secretion, and may prove to be an important marker for the functioning of seminiferous tubules. The purpose of the present study was to examine the relationship between the spermatogenic function of the testis of subfertile men and the plasma concentrations of inhibin B and FSH. These parameters were estimated in a group of 218 subfertile men. Serum inhibin B levels were closely correlated with the serum FSH levels (r = -0.78, P < 0.001), confirming the role of inhibin B as feedback signal for FSH production. The spermatogenic function of the testis was evaluated by determining testicular volume and total sperm count. Inhibin B levels were significantly correlated with the total sperm count and testicular volume (r = 0.54 and r = 0.63, respectively; P < 0.001). Testicular biopsies were obtained in 22 of these men. Inhibin B was significantly correlated with the biopsy score (r = 0.76, P < 0.001). Receiver operating characteristic analysis revealed a diagnostic accuracy of 95% for differentiating competent from impaired spermatogenesis for inhibin B, whereas for FSH, a value of 80% was found. We conclude that inhibin B is the best available endocrine marker of spermatogenesis in subfertile men

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Considerable concern has been raised in recent publications that oestrogen-lihe compounds in either food or the environment cause adverse effects on reproductive health. There is clear evidence that reproductive disruption in wildlife may be caused by environmental pollutants and more specifÌcally by endocrine-disrupting compounds. The increase in the incidence of disorders of the male reproductive tract (e.g. testicular cancer, cryptorchidisn, hypospadias) and the possible decline o[ sperm quality led to the hypothesis in 1993 that the reported increases stem from fetal or neonatal exposure of the developing male to oestrogens. Cryptorchidism, hypospadias, testicular cancer and poor semen quality have also been proposed to be symptoms of one underlying cause, the testicular dysgenesis syndrome, which may deveÌop during fetal life under the influence of environmental factors. However, there is only circumstantial evidence in humans that exposure to endocrine disrupters, especially diethylstilbestrol, during pregnancy causes problems of reproductive health. Oestrogenlike effects have been reported for a variety of naturalÌy occurring oestrogens (so-called phytoestrogens) and for numerous synthetic compounds. The critical issue is whether there are suflìciently high levels of endocrine disrupters in the ambient environment to exert adverse health effects on the general populatio

The role of high-intensity physical exercise in the prevention of disability among community-dwelling older people

Background: Moderate to vigorous physical activity (MVPA) is considered important to prevent disability among community-dwelling older people. To develop MVPA programs aimed at reducing or preventing disability more insight is needed in the contributions of exercise duration and intensity and the interplay between the two. Methods: Longitudinal data of 276 Dutch community-dwelling persons aged 65 years and older participating in the Elderly And their Neighbourhood (ELANE) study were used. MVPA exercise (yes/no), duration (hours per two weeks), intensit

How many walking and cycling trips made by elderly are beyond commonly used buffer sizes: Results from a GPS study

In choosing appropriate buffer sizes to study environmental influences on physical activity, studies are hampered by insufficient insight into the distance elderly travel actively. This study aims at getting insight into the number of trips walked and cycled within various buffer sizes using GPS measures. Data were obtained from the Elderly And their Neighborhood study (Spijkenisse, the Netherlands (2011-2012)). Trip length and mode of transport were derived from the GPS data (N=120; total number of trips=337). Distance decay functions were fitted to estimate the percentage of trips to grocery stores within commonly used buffer sizes. Fifty percent of the trips walked had a distance of at least 729. m; for trips cycled this was 1665. m. Elderly aged under 75 years and those with functional limitations walked and cycled shorter distances than those over 75 years and those without functional limitations. Males cycled shorter distances than females. Distance decay functions may aid the selection of appropriate buffer sizes, which may be tailored to individual characteristics

Characteristics of residential areas and transportational walking among frail and non-frail Dutch elderly: Does the size of the area matter?

Background: A residential area supportive for walking may facilitate elderly to live longer independently. However, current evidence on area characteristics potentially important for walking among older persons is mixed. This study hypothesized that the importance of area characteristics for transportational walking depends on the size of the area characteristics measured, and older person's frailty level.Methods: The study population consisted of 408 Dutch community-dwelling persons aged 65 years and older participating in the Elderly And their Neighborhood (ELANE) study in 2011-2012. Characteristics (aesthetics, functional features, safety, and destinations) of areas surrounding participants' residences ranging from a buffer of 400 meters up to 1600 meters (based on walking path networks) were linked with self-reported transportational walking using linear regression analyses. In addition, interaction effects between frailty level and area characteristics were tested.Results:

Physical activity in non-frail and frail older adults

Introduction: Physical activity (PA) is important for healthy ageing. Better insight into objectively measured PA levels in older adults is needed, since most previous studies employed self-report measures for PA assessment, which are associated with overestimation of PA. Aim: This study aimed to provide insight in objectively measured indoor and outdoor PA of older adults, and in PA differences by frailty levels. Methods: Data were collected among non-frail (N = 74) and frail (N = 10) subjects, aged 65 to 89 years. PA, measured for seven days with accelerometers and GPS-devices, was categorized into three levels of intensity (sedentary, light, and moderate-to-vigorous PA). Results: Older adults spent most time in sedentary and light PA. Subjects spent 84.7%, 15.1% and 0.2% per day in sedentary, light and moderate-to-vigorous PA respectively. On average, older adults spent 9.8 (SD 23.7) minutes per week in moderate-to-vigorous activity, and 747.0 (SD 389.6) minutes per week in light activity. None of the subjects met the WHO recommendations of 150 weekly minutes of moderate-to-vigorous PA. Age-, sex- and health status-adjusted results revealed no differences in PA between non-frail and frail older adults. Subjects spent significantly more sedentary time at home, than not at home. Non-frail subjects spent significantly more time not at home during moderate-to-vigorous activities, than at home. Conclusions: Objective assessment of PA in older adults revealed that most PA was of light intensity, and time spent in moderate-to-vigorous PA was very low. None of the older adults met the World Health Organization recommendations for PA. These levels of MVPA are much lower than generally reported based on self-reported PA. Future studies should employ objective methods, and age specific thresholds for healthy PA levels in older adults are needed. These results emphasize the need for effective strategies for healthy PA levels for the growing proportion of older adults

Comparative potency of different UV sources in reducing the density and antigen-presenting capacity of Langerhans cells in C3H mice

Although broadband UV.B irradiation has been shown to induce selective immunosuppression in a variety of experimental systems, the wavelength dependence of the immunornodulation and the initial events in the skin remain unclear. In the present study three UV lamps werc used at suberythermal doses on C3H mice: a conventional broadband UV-B sourcc (270-350 nm), a narrowbnnd UV-B source (3 ll-3 l2 nm) and a UV-A source (320-400nm). Their cffects on thc photoisomerization olthe naturally occurring trans-isomer of urocanic acid (UCA) to cis- UCA, on the density of Langerhans cetls and on the ability of epidermal cells to stimulate allogeneic lymphocytes in the mixed skin lymphocyte reaction (MSLR) were ascertained. Broadband UV-B irradiation was more efficient than narrowband UV-B at rcducing the density and lunction oftangerhans cells, while UV-A inadiation was least effective. These changes were most pronounced immediately following irradiation, were dose dependent and were only detecled in UV-exposed areas of skin. There was a close correlation betveen the Uv-induced reduction in Langerhans cell density and the formation of cis-UCA in the epidermis, This conelation was not detected between the reduction in the MSLR response following UV irradiation in vivo and cis-UCA formatio