Association between angiotensin-converting enzyme gene insertion/deletion polymorphism and susceptibility to preterm birth: A case-control study and meta-analysis.

BACKGROUND: Preterm birth is the largest contributor to newborn mortality, morbidity, and hospitalization in the first year of life worldwide. Previous studies have suggested the importance of genetic variation in the angiotensin-converting enzyme gene, including the angiotensin-converting enzyme gene insertion/deletion polymorphism, in association with preterm birth. The angiotensin-converting enzyme is a key component of the renin-angiotensin system that is involved in blood pressure homeostasis during pregnancy and also affects risk factors of preterm birth, including the regulation of fibrinolytic system, uteroplacental circulation, vascularization of the placenta, and inflammation. OBJECTIVE: The results of previous studies investigating the association between the insertion/deletion polymorphism and susceptibility to preterm birth have been inconsistent, therefore, we have performed a case-control study and conducted a meta-analysis of related studies to clarify this association. STUDY DESIGN: In a case-control genetic association study, performed on 217 women with a history of preterm birth and 158 women who experienced full-term pregnancy, the significances of associations between allelic and genotype frequencies and preterm birth were determined using Chi-square tests. Following the case-control study, PubMed, Scopus, Google Scholar, and HugeNavigator databases were systematically searched to identify relevant studies. Altogether, four eligible studies involving 369 cases and 559 controls were included in the meta-analysis. The strength of the association between the angiotensin-converting enzyme gene insertion/deletion polymorphism for preterm birth was estimated by odds ratios (ORs) and corresponding 95% confidence intervals (95% CIs), using a fixed-effects model (Mantel-Haenszel method). RESULTS: In our case-control study we did not detect a significant association of angiotensin-converting enzyme insertion/deletion alleles and genotypes with preterm birth. The results of the meta-analysis showed a significant association between the angiotensin-converting enzyme gene insertion/deletion and the risk of preterm birth under allelic, dominant, and recessive comparison genetic models (D vs. I: OR = 1.35, 95% CI = 1.11-1.65, p = 0.0033; DD + ID vs. II: OR = 1.52, 95% CI = 1.08-2.15, p = 0.0161; DD vs. ID + II: OR = 1.48, 95% CI = 1.07-2.04, p = 0.0184). CONCLUSIONS: The present meta-analysis suggests that the insertion/deletion polymorphism of the angiotensin-converting enzyme gene in mothers might be associated with preterm birth, however, further well-designed large replication studies involving various ethnicities are needed to confirm this association.

Melatonin: a "Higgs boson" in human reproduction.

As the Higgs boson could be a key to unlocking mysteries regarding our Universe, melatonin, a somewhat mysterious substance secreted by the pineal gland primarily at night, might be a crucial factor in regulating numerous processes in human reproduction. Melatonin is a powerful antioxidant which has an essential role in controlling several physiological reactions, as well as biological rhythms throughout human reproductive life. Melatonin, which is referred to as a hormone, but also as an autocoid, a chronobiotic, a hypnotic, an immunomodulator and a biological modifier, plays a crucial part in establishing homeostatic, neurohumoral balance and circadian rhythm in the body through synergic actions with other hormones and neuropeptides. This paper aims to analyze the effects of melatonin on the reproductive function, as well as to shed light on immunological and oncostatic properties of one of the most powerful hormones.

The influence of probiotics on the cervical malignancy diagnostics quality.

BACKGROUND/AIM: Probiotics help to provide an optimum balance in the intestines. Probiotics species competitive block toxic substances and growth of unwanted bacteria and yeast species while they compete for the space and food. Lactogyn is the first oral probiotics on Serbian market dedicated to maintaining a normal vaginal flora. Lactogyn contains two well studied probiotics strains - Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14. Both of them are considered as probiotic agents with therapeutic properties increase the population of beneficial lactobacillus organisms within the vagina. The aim of this study was to exam an influence of Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 on results of cervical smear cytological testing including detection of atypical cells, detection of false positive and false negative findings as well as on vaginal microflora content in patients with vaginal infection signs and symptoms. METHODS: Totally 250 women with signs of vaginal infection were selected to participate in the study. The study group comprised 125 patients taking studied probiotic strains along with specific anti-infective therapy. The control group comprised, also, 125 patients taking anti-infective agents, only. Probiotic preparation (Lactogyn capsules) was administered orally (one capsule daily) during 4 weeks. Before and six weeks after beginning of the therapy a cervical smear cytological test (the Papanicolaou test), as well as microbiological examination of the vaginal smear were performed. RESULTS: Number of cases of inflammation and atypical squamous cells of undeterminated significance (ASCUS) in the study group were significantly higher before administration of the probiotic preparation. The number of lactobacilli was significantly higher, and the number of pathogenic microorganisms lower in the group treated with this preparation. CONCLUSION: The application of probiotic strains Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 concomitantly with specific anti-infective agents provides more reliable cytological diagnostics, reduces the number of false positive and false negative findings on cervical malignancy and normalizes vaginal microflora in higher percentage of patients with vaginal infections comapred with therapy including antiinfective agents only.