Associations of sex hormone levels with body mass index (BMI) in men: a cross-sectional study using quantile regression analysis / 亚洲男科学杂志(英文版)

Body mass index (BMI) has been increasing globally in recent decades. Previous studies reported that BMI was associated with sex hormone levels, but the results were generated via linear regression or logistic regression, which would lose part of information. Quantile regression analysis can maximize the use of variable information. Our study compared the associations among different regression models. The participants were recruited from the Center of Reproductive Medicine, The First Hospital of Jilin University (Changchun, China) between June 2018 and June 2019. We used linear, logistic, and quantile regression models to calculate the associations between sex hormone levels and BMI. In total, 448 men were included in this study. The average BMI was 25.7 (standard deviation [s.d.]: 3.7) kg m-2; 29.7% (n = 133) of the participants were normal weight, 45.3% (n = 203) of the participants were overweight, and 23.4% (n = 105) of the participants were obese. The levels of testosterone and estradiol significantly differed among BMI groups (all P < 0.05). In linear regression and logistic regression, BMI was associated with testosterone and estradiol levels (both P < 0.05). In quantile regression, BMI was negatively associated with testosterone levels in all quantiles after adjustment for age (all P < 0.05). BMI was positively associated with estradiol levels in most quantiles (≤80th) after adjustment for age (all P < 0.05). Our study suggested that BMI was one of the influencing factors of testosterone and estradiol. Of note, the quantile regression showed that BMI was associated with estradiol only up to the 80th percentile of estradiol.

Dihydrolipoamide Acetyltransferase Promotes Nucleic Acid Synthesis by Controlling Phosphogluconate Dehydrogenase Acetylation / 中国生物化学与分子生物学报

Mitochondrial pyruvate dehydrogenase complex (PDC) is crucial for glucose homeostasis in mammalian cells‚ decarboxylation of glycolytic intermediate pyruvate to acetyl coenzyme A (acetyl-CoA) in mitochondria. Dihydrolipoyl acetyltransferase (DLAT) is a subunit of the pyruvate dehydrogenase complex. Here‚ we reported that DLAT was commonly increased in lung cancer and its expression was associated with worse clinical outcomes. We found that suppression of DLAT in lung cancer cells resulted in reduced nucleic acid biosynthesis and attenuated cancer cell proliferation through controlling acetylation level of 6-phosphogluconate dehydrogenase (6PGD) ‚ the third enzyme in the oxidative pentose phosphate pathway (PPP) ‚ in which ribulose-5-phosphate (Ru-5-P) is produced for nucleic acid biosynthesis. Together‚ our study contributes to recent interest and discussion cross talk in cancer metabolism‚ which contributes to tumor growth. Future mechanistic studies should lead to the elucidation of the mode of action of DLAT in human lung cancer and establish DLAT as a viable drug target.

Decline of semen quality and increase of leukocytes with cigarette smoking in infertile men

Previous researches about the effect of smoking on semen quality are contradictory, and the mechanism behind the harmful effect of smoking on semen quality still remains unclear until today. The objectives of this study are evaluation of the relationship between smoking and fertility, investigation of the effects of cigarette smoking on sperm parameters and detection of presence of leukocytes within the semen of idiopathic infertile men from Northeastern China. A retrospective study of 1512 infertile patients who visited affiliated hospitals of Jilin University from 2007-2010 were enrolled in this study. Patients were assigned into one non-smoking and one smoking group which was divided into mild, moderate and heavy subgroups. Sperm parameters [including leukocytes] and sperm morphology analysis were performed using standard techniques. Compared with non-smokers, smokers had a significant decrease in semen volumes [p=0.006], rapid progressive motility [p=0.002] and sperm viability [p=0.019]; moreover, smokers had a significant increase in the levels of immotile sperms [p=0.005] and semen leukocytes [p=0.002]; pH and sperm concentration were not statistically significant [p=0.789 and p=0.297 respectively]. Sperm motion parameters were all lower in the smokers except for beat-cross frequency [Hz] [BCF]. Further, the percentage of normal morphology sperm was decreased significantly in smokers [p=0.003], the sperm morphology was worse with increasing degree of smoking. These findings suggest that smoking leads to a significant decline in semen quality and higher levels of leukocytes, thus smoking may affects the fertilization efficiency

Molecular epidemiological characteristics of Streptococcus pyogenes strains involved in an outbreak of scarlet fever in China, 2011 / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate molecular characterization of streptococcus pyogenes isolates involved in an outbreak of scarlet fever in China in 2011.</p><p><b>METHODS</b>Seventy-four Streptococcal pyogenes involved in an outbreak of scarlet fever were isolated from pediatric patients in the areas with high incidence in China from May to August of 2011. Emm genotyping, pulsed-field gel electrophoresis (PFGE), superantigen (SAg) genes and antimicrobial susceptibility profiling were analyzed for these isolates.</p><p><b>RESULTS</b>A total of 4 different emm types were identified. Emm12 was the most prevalent type which contained four predominating PFGE patterns corresponding to four different virulence and superantigen profiles. Emm12 (79.7%) and emm1 (14.9%) accounted for approximately 94% of all the isolates. The speA gene was all negative in emm12 isolates and positive in emm1 isolates. All strains were resistant to erythromycin, and 89.4% of them were resistant to erythromycin, tracycline, and clindamycin simultaneously.</p><p><b>CONCLUSION</b>Several highly diversified clones with a high macrolide resistance rate comprise a predominant proportion of circulating strains, though no new emm type was found in this outbreak. The data provide a baseline for further surveillance of scarlet fever, which may contribute to the explanation of the outbreak and development of a GAS vaccine in China.</p>

Clinical and cytogenetic analysis of 45,X/46,XY individuals / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze main clinical manifestations and cytogenetic characteristics of patients with a 45,X/46,XY karyotype.</p><p><b>METHODS</b>G-banding karyotype analysis was carried out. PCR was performed to detect azoospermia factor (AZF) microdeletion in adult male patients and sex-determining region on Y chromosome (SRY) gene in all patients. Clinical phenotype and genetic characteristics were summarized.</p><p><b>RESULTS</b>Among the 9 individuals with 45,X/46,XY, there have been 7 males and 2 females. Six out of the 7 males have manifested primary infertility, which included 5 with azoospermia, 1 with oligospermia, and 1 with hypospadia. Three of the 6 infertile patients were found to have AZF microdeletions. Two females showed typical Turner syndrome. All of the 9 cases were SRY-positive.</p><p><b>CONCLUSION</b>The 45,X/46,XY karyotype may result in a range of phenotypes. No correlation has been found between clinical manifestations and proportion of mosaicism cells for their peripheral blood karyotypes. As phenotypically normal male patients may produce sperm, infertile patients should undergo further examination at the molecular level.</p>

Y chromosome microdeletions in severe oligospermia men with varicocele / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate Y chromosome microdeletions in severe oligospermia men with varicocele.</p><p><b>METHODS</b>We randomly selected 100 cases of severe oligospermia with left varicocele (sperm concentration <5 x 10(6)/ml, group 1), 100 cases of mild oligospermia with left varicocele (sperm concentration 10 -20 x 10(6)/ml, group 2), 100 cases of idiopathic infertility with severe oligospermia (group 3), 100 cases of idiopathic infertility with moderate oligospermia (group 4) and 30 normal fertile men as controls (group 5). We used polymerase chain reaction (PCR) technology to screen 9 sequence tagged sites (STS) of the AZF a, b and c regions and detect Y chromosome microdeletions.</p><p><b>RESULTS</b>AZF microdeletions were found in 19 patients in group 1 (19%) and 11 in group 3 (11%), with a higher rate in the former than in the latter, but not in the other three groups.</p><p><b>CONCLUSION</b>Screening of Y chromosome microdeletions should be performed before the treatment of severe spermatogenesis with varicocele.</p>