Late-onset hypogonadism (LOH) : an emerging pathophysiological entity requiring the physician's attention

Late-onset hypogonadism (LOH) is an emerging pathophysiological entity. Not everybody is familiar with LOH or even recognizes its existence. Since the 19th century women's life expectancy has become progressively greater than that of men and therefore their ailments associated with aging from the climacteric onwards attracted medical attention much earlier than male aging health problems. In addition, male aging problems start at a later age than the climacteric occurs in women. However, men's life expectancy is also continuously increasing: in Europe a newborn male now has a life expectancy of about 75 years, and a 60-year-old man has a statistical possibility of reaching 80 years of age. The increasing number of aging men forces physicians to focus on their health problems.peer-reviewe

Paternal age and reproduction

BACKGROUND Due to various sociological factors, couples in developed countries are increasingly delaying childbearing. Besides ethical, economical and sociological issues, this trend presents us with several complex problems in reproduction. Although it is well-known that maternal age has a negative effect on fertility and increases the risk of adverse outcome during pregnancy and in offspring, the paternal influence on these outcomes is less well researched and not well-known. METHODS We performed a systematic search of PubMed, and retrieved original articles and review articles to update our previous survey in this journal. RESULTS This review highlights the link between male age and genetic abnormalities in the germ line and summarizes the knowledge about the effects of paternal age on reproductive function and outcome. Increasing paternal age can be associated with decreasing androgen levels, decreased sexual activity, alterations of testicular morphology and a deterioration of semen quality (volume, motility, morphology). Increased paternal age has an influence on DNA integrity of sperm, increases telomere length in spermatozoa and is suggested to have epigenetic effects. These changes may, at least in part, be responsible for the association of paternal age over 40 years with reduced fertility, an increase in pregnancy-associated complications and adverse outcome in the offspring. CONCLUSION Although higher maternal age can be an indication for intensive prenatal diagnosis, including invasive diagnostics, consideration of the available evidence suggests that paternal age itself, however, provides no rationale for invasive procedure

Grounding line migration as response to cycles of sliding pertubations and initial geometries in the MISMIP3D experiment

The benchmark experiment MISMIP3D (Pattyn et al., 2013) investigated the response of a artificial ice stream-ice shelf system to a sliding perturbation. We continued this experiment by applying cycles of pertubations at different time scales in order to see the long term response of the grounding line positions to changes in basal sliding. For this purpose we applied the finite-difference full-Stokes model TIM-FD3 on 2.5km and 1.25km using three different initial geometries. We found that our steady-state geometry shows a strong dependency of the grounding line position on the horizontal grid size and the chosen initial geometry. Not all experiments show a neutral equilibrium in subsequent basal sliding perturbation simulations

Numerical design of rotationally molded composite tie rods

Rotational molding constitutes a promising manufacturing technology for rotationally symmetric components made of thermoset matrix with continuous fiber reinforcement. The present study deals with the numerical analysis of a rotationally molded composite tie rod with metallic load introduction elements. For this purpose, the adhesive joint between carbon fiber reinforced plastic and metallic load introduction element was investigated in more detail. Different geometries of a spew fillet were evaluated to reduce the stress peaks occurring at the ends of the overlap. A design of experiments was used to determine the influence of the different parameters. An optimized geometry was derived and compared with a reference in terms of stress distribution. Subsequently, test specimens were rotationally molded and mechanically tested. The results of the study show that the maximum stresses within the adhesive layer can be reduced with an optimized spew fillet, and thus a higher mechanical tensile load of the composite tie rod can be achieved

Modelling of the temperature distribution of spot-weldable composite/metal joints

Resistance spot welding is the most economical joining method for the production of automotive steel bodies. In modern car body construction, however, its future applicability is limited due to the growing mix of materials in multi-material design. In response to increasing weight reduction requirements to protect the environment and natural resources, lightweight materials, and fibre-reinforced plastics (FRP) in particular, are more and more used in modern vehicle bodies. To facilitate the future joining of FRP/steel structures with resistance spot welding, spot-weldable force-introduction elements may be embedded in the laminate as a joining interface. When welding the so-called inserts, thermal damage to the surrounding polymer should be avoided, as this is the only way to calculate the strength of the joint correctly. For this purpose, the paper presents a numerical model that allows the prediction of the temperature propagation during spot welding of FRP/steel joints with embedded inserts. The simulative approach is subsequently validated by comparison with experimentally determined temperature curves and in doing so, an excellent model prediction can be noted

Eine neue Trennmethode für Radioimmunoassays von Proteohormonen: enzymatische Proteolyse des freien Hormons durch Pronase

Peer Reviewe

The aging male: investigation, treatment and monitoring of late-onset hypogonadism in males

Androgen deficiency in the aging male has become a topic of increasing interest and debate throughout the world. The demographics clearly demonstrate the increasing percentage of the population that is in the older age groups. The data also support the concept that testosterone falls progressively with age and that a significant percentage of men over the age of 60 years have serum testosterone levels that are below the lower limits of young adults (age 20-30 years) men. The principal questions raised by these observations are whether older hypogonadal men will benefit from testosterone treatment and what will be the risks associated with such intervention. The past decade has brought evidence of benefit of androgen treatment on multiple target organs of hypogonadal men and recent studies show short-term beneficial effects of testosterone in older men that are similar to those in younger men. Long-term data on the effects of testosterone treatment in the older population are limited and specific risk data on the prostate and cardiovascular systems are needed. Answers to key questions of functional benefits that may retard frailty of the elderly are not yet available. The recommendations described below were prepared for the International Society of Andrology (ISA) and the International Society for the Study of the Aging Male (ISSAM) following a panel discussion with active participation from the audience sponsored by the ISA on the topic at the 4th ISSAM Congress in Prague in February 2004.peer-reviewe

Epidermal growth factor receptor pathway substrate 8 (Eps8) expression in maturing testis.

AIM: Although epidermal growth factor receptors are expressed in the testes, whether they signal through epidermal growth factor receptor pathway substrate 8 (Eps8) is unknown. Here we evaluated the expression pattern of Eps8 in the maturing testis. METHODS: The expression of Eps8 was analysed by Northern blotting, immunocytochemistry and Western blotting in primary Sertoli cell cultures and in testicular tissue of rodents. RESULTS: Eps8 is specifically expressed in gonocytes, Leydig and Sertoli cells of the neonatal rats and in Leydig and Sertoli cells of the adult rats and mice. Although gonocytes express Eps8, no signal was found in prepubertal or mature spermatogonia and the expression level of Eps8 in Sertoli cells increases with age. No regulation of Eps8 expression in primary immature rat Sertoli cells by Follicle stimulating hormone (FSH) was detected by Western blotting. CONCLUSION: Eps8 seems to be involved in the growth factor-controlled regulation of cell proliferation and differentiation in the seminiferous epithelium. Eps8 is a possible marker for gonocytes and in Sertoli cells it could be involved in crosstalk with other growth factor pathways