Spermatogenesis is contingent upon hormones and growth factors acting through endocrine and paracrine pathways either in vivo or in vitro. Sertoli cells (SCs) furnish essential factors for the successful advancement of spermatogenesis and spermiogenesis. Moreover, receptors for follicle stimulating hormone (FSH) and testosterone, which are the main hormonal regulators of spermatogenesis, are identified on SCs. Testosterone, FSH and luteinizing hormone are known to determine the destiny of germ cells and in their absence germ cells undergo apoptosis. Bcl-2 family proteins determine one signaling pathway which seems to be crucial for the homeostasis of male gametes. In addition to paracrine signals, germ cell development also relies on signals generated by SCs via direct membrane contact. The regulatory peptide somatostatin has an important role in the regulation of the proliferation of the male germ cells. Activin A, follistatin and FSH control germ cell development. In vitro culture systems have provided initial evidence supporting the achievement of the completion of the first and second male meiotic division in vitro. This review article provides an overview of the literature regarding the hormonal pathways governing spermatogenesis and spermiogenesis.
Physicians should be cautious about uncommon presentations of the viral infection and consider EBV as a causative agent when they encounter similar clinical pictures.
In humans, microbial colonisation of the intestine begins just after birth. However, development of the normal flora is a gradual process, which is initially determined by factors such as genetic aspects, the maternal-foetal interaction, place and mode of delivery, early feedings strategies, and the use of antibiotics. Current knowledge on the significance and impact of the gut microflora on the development of the gut immune system indicates that a close relationship between allergic sensitisation and the development of the intestinal microflora may occur in infancy. Intestinal micro-organisms could downregulate the allergic inflammation by counterbalancing type 2 T-helper cell responses and by enhancing allergen exclusion through an immunological response.
This report highlights the fact that in case of simultaneous presentation of polyendocrinopathies and renal disease early in childhood, KSS should be considered.
Background/Aim: The adipocytokines leptin and adiponectin represent a critical link between metabolism, immunity and chronic inflammation. A chronic vascular inflammatory state plays an important role in the pathophysiology of thalassaemia. We aimed to analyze the levels of these adipocytokines and determine any possible correlations with disease severity or vascular inflammation markers in beta-thalassaemia. Methods: Serum leptin, adiponectin, high-sensitivity C-reactive protein, endothelins, vascular adhesion molecule-1, intracellular adhesion molecule-1 and L- and E-selectin were measured in 28 beta-thalassaemia patients and compared with levels in healthy controls. Results: Leptin was significantly lower in patients compared to controls (2.23 ± 1.8 vs. 10.24 ± 5.78 µg/l; p = 0.0018), whereas adiponectin was elevated (11.75 ± 5.67 vs. 6.83 ± 2.75 µg/l; p = 0.009). For both adipocytokines, no correlations were found with characteristics such as age, gender, type of chelation, body mass index z score or haemoglobin. Leptin, but not adiponectin, was negatively correlated with ferritin (p = 0.032, r = –0.61). No correlations were found between leptin and the inflammation markers. However, adiponectin was positively correlated with endothelin-1 (p = 0.022, r = 0.63). Conclusions: Serum leptin is low in beta-thalassaemia, perhaps due to the toxic effect of iron overload on adipose tissue. Paradoxically, adiponectin levels are high and positively correlated with endothelin-1, raising questions about the pro- or anti-inflammatory role of this adipocytokine in beta-thalassaemia.
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