The current perspective on genetic and epigenetic factors in sperm maturation in the epididymis

Male infertility affects approximately 30% of infertile couples. As spermatozoa mature in the epididymal lumen, their potential for mobility increases, and their protein, lipid and small RNA (sRNA) content changes, whereas capacitation and fertilisation take place in the female reproductive tract. Both of the latter processes are affected by maturation, because impaired maturation causes premature capacitation and fertilization. The epididymis produces a suitable environment for sperm maturation via ion transport, vesicle secretion and protein matrix formation. The microenvironment for sperm maturation varies in three broad segments: the caput, the corpus and the cauda epididymis. Epididymosomes transfer proteins, lipids and sRNAs from the epididymal epithelium to spermatozoa and genetic alterations of epididymal genes can lead to decreased sperm motility, morphological abnormalities of spermatozoa and subfertility. Genetic factors are involved in all aetiological categories in male infertility. However, studies conducted on the genes involved in epididymal functions are limited. The sRNA content of spermatozoa changes during epididymal migration, and these sRNAs play a role in embryo development and epigenetic inheritance. This review aims to clarify the role of the epididymal epithelium in the maturation of spermatozoa in light of the current molecular genomic knowledge.     

Pain during sexual activity and ejaculation following hernia repair: A retrospective comparison of transabdominal preperitoneal versus Lichtenstein repair

Pain during sexual activity and ejaculation are the unspoken long-term complications of groin hernia repair. Laparoscopic surgical techniques are associated with decreased post-operative pain and earlier return to daily activities, but its effect on these complications is unclear. This study aims to investigate the effect of transabdominal preperitoneal repair (TAPP) on de-novo pain during sexual intercourse and ejaculation and to compare with open repair. For this reason, two groups were determined according to the surgical technique: the Lichtenstein repair and the TAPP groups and a questionnaire was sent to the patients a minimum of 6 months following the surgery. A total of 317 patients included, as 115 in TAPP and 202 in Lichtenstein repair group. No significant difference was observed concerning pre-operative pain during sexual activity and ejaculation in both groups (p = .75, p = .56). Following the surgery, the number of patients experiencing painful sexual activity was significantly higher in the Lichtenstein repair group compared to the TAPP group (19.3% vs. 11.3%, respectively, p = .03). The post-operative painful ejaculation rate was also significantly lower for the TAPP group (p = .04). The lower rates of post-operative dysejaculation and pain during sexual activity can be achieved with the advantage of laparoscopic surgery.     

Tuberculosis in renal transplant recipients

BACKGROUND: Tuberculosis is an important cause of morbidity and mortality in renal transplant recipients, but there are insufficient data regarding the efficacy and complications of therapy and of INH prophylaxis. METHODS: This study is a retrospective review of the records of 880 renal transplant recipients in two centers in Turkey. RESULTS: Tuberculosis developed in 36 patients (4.1%) at posttransplant 3-111 months, of which 28 were successfully treated. Eight patients (22.2%) died of tuberculosis or complications of anti-tuberculosis therapy. Use of rifampin necessitated a mean of 2-fold increase in the cyclosporine dose, but no allograft rejection occurred due to inadequate cyclosporine levels. Hepatotoxicity developed in eight patients during treatment, two of whom died due to hepatic failure. No risk factor, including age, gender, renal dysfunction, hepatitis C, or past hepatitis B infection, was found to be associated with development of hepatic toxicity. A subgroup of 36 patients with a past history of or radiographic findings suggesting inactive tuberculosis, was considered to be at high risk for developing active disease, of whom 23 were given isoniazid (INH) prophylaxis. None versus 1 of 13 (7.7%) of cases with and without INH prophylaxis, respectively, developed active disease (P>0.05). None of the patients receiving INH had hepatic toxicity or needed modification of cyclosporine dose. CONCLUSIONS: These data show that tuberculosis has a high prevalence in transplant recipients, that it can effectively be treated using rifampin-containing antituberculosis drugs with a close follow-up of serum cyclosporine levels, and that INH prophylaxis is safe but more experience is needed to define the target population.     

Somatostatin infusion withdrawal in the diagnosis of childhood growth hormone deficiency

OBJECTIVE: An evaluation of growth hormone (GH) testing for GH deficiency (GHD) in childhood is confounded by the lack of a world-wide consensus on the definition of GHD. Although a single GH test remains the most powerful biochemical tool in the evaluation of a child with growth failure, the test remains far from ideal. Withdrawal of somatostatin (SS) infusion is followed by a rebound rise of GH thought to be mediated by endogenous GH-releasing hormone (GHRH) function. This study was designed to compare the GH response to 90 min SS infusion in children with normal GH secretion versus children with GH deficiency. METHODS: Ten children with GHD and 10 healthy controls (NC) have been evaluated for GH response to somatostatin infusion withdrawal (SSIW) and compared with response of two provocative tests, glucagon plus propranolol test and L-Dopa test. All children received constant infusion of somatostatin for 90 min (3 microg/kg per h, Stilamin, Serono, Aubonne, Switzerland). In order to determine GH, blood samples were obtained 90 min before the SS infusion and 0, 15, 30, 45, 60, 75, and 90 min after the cessation of infusion. RESULTS: Growth hormone peak levels with SSIW were significantly lower in GH deficient children than in healthy children (2.5 +/- 1.2 ng/dL, vs 21.9 +/- 5.3 ng/dL, respectively, P < 0.01). No adverse effects were observed during or after somatostatin infusion. CONCLUSION: In the present study, SSIW elicited a significant GH rise in healthy children but not in children with GH deficiency. Although further controlled studies using more data are necessary to expand these findings, the results suggested that children with GH deficiency can be reliably discriminated from healthy children by SSIW.     

Three Dimensions of Youth Social Capital and Their Impacts on Substance Use

Substance use is a threat to the health and well-being of youths, their families, and society as well. The literature shows that social interactions with peers, parents, and community may have an impact on adolescents’ behavior. Using data from the National Survey on Drug Use and Health of 2007, this study investigated the impact of social capital on youth behavior. The results show that peer influence is the strongest among the three significant predictors of substance use. While peer influence is positively correlated with substance use, family attachment and youth activities have a negative relationship with substance use. Findings demonstrate that there is a relationship between youth substance use and different aspects of social capital. By integrating different perspectives in social capital and substance use, this study successfully demonstrates how social capital can be utilized as a policy and intervention tool.     

Rapid multi‐echo measurement of brain metabolite T2 values at 7 T using a single‐shot spectroscopic Carr–Purcell–Meiboom–Gill sequence and prior information

We present a method for the robust and accurate estimation of brain metabolite transverse relaxation times (T₂) from multiple spin‐echo data acquired with a single‐shot Carr–Purcell–Meiboom–Gill (CPMG) spectroscopic sequence. Each acquired echo consists of a small number of complex time‐domain data points. The amplitudes of the spectral components in each echo are calculated by solving a set of linear equations in which previously estimated frequencies and linewidths serve as prior information. These priors are obtained from a short MRS experiment in which a large number of time‐domain data points are acquired, and are subsequently estimated using linear prediction with singular value decomposition (LPSVD) processing. We show that this process can be used to accurately and rapidly measure the T₂ values for the main singlet resonances in single‐volume MRS measurements in the brain. The proposed method can be generalized to any set of MRS experiments comprising repeated measurements of amplitude changes, e.g. as a function of an experimental parameter, such as TE, inversion time or diffusion weighting. Copyright © 2013 John Wiley & Sons, Ltd.