Abnormal accumulation of the presynaptic protein alpha-synuclein has recently been implicated in the pathogenesis of Alzheimer's and Parkinson's diseases. Because neurodegeneration in these conditions might be associated with mitochondrial dysfunction and oxidative stress, the effects of alpha-synuclein were investigated in a hypothalamic neuronal cell line (GT1-7). alpha-Synuclein overexpression in these cells resulted in formation of alpha-synuclein-immunopositive inclusion-like structures and mitochondrial alterations accompanied by increased levels of free radicals and decreased secretion of gonadotropin-releasing hormone. These alterations were ameliorated by pretreatment with anti-oxidants such as vitamin E. Taken together these results suggest that abnormal accumulation of alpha-synuclein could lead to mitochondrial alterations that may result in oxidative stress and, eventually, cell death.
This systematic review and meta-analysis compares adverse neonatal outcomes among mothers exposed to marijuana during pregnancy vs mothers not exposed to marijuana during pregnancy in 16 cohort studies.
Objectives COVID-19 is a rapidly changing and developing emergency that requires constant re-evaluation of available data. We report a systematic review and meta analysis based on all published high quality data up to and including June 3rd 2021 on the maternal and neonatal outcomes in pregnant women infected with the Coronavirus Disease 2019 (COVID-19). Data Sources PubMed, SCOPUS, MEDLINE, ClinicalTrials.gov, and Web of Science databases were queried from inception up to June 3rd 2021. Study Eligibility Criteria We included all clinical studies (prospective and retrospective cohort studies, case-control studies, case series, and rapid communications) that reported data on any maternal and neonatal outcomes of pregnant women with COVID-19. Study Appraisal and Synthesis Methods Data were analyzed as pooled proportions or odds ratios (OR) and 95% confidence intervals (95% CI) in meta-analysis models. Results We included 111 studies enrolling 42754 COVID-19-positive pregnant women. From COVID-19-positive pregnant women, the incidence rate of cesarean section was 53.2% (95% CI: 48%–58.4%), 41.5% (95% CI: 36.3%–46.8%) for spontaneous vaginal delivery and 6.4% (95% CI: 4.5%–9.2%) for operative delivery. The rate of some adverse neonatal events was relatively high in mothers infected with COVID-19 including premature delivery (16.7%, 95% CI: 12.8%–21.5%), and low birthweight (16.7%, 95% CI: 12.8%–21.5%). Vertical transmission (3.5%, 95% CI: 2.7%–4.7%), neonatal death (3%, 95% CI: 2%–4%), stillbirth (1.9%, 95% CI: 1.5–2.4%) and maternal mortality (0.012% 95% CI: 0.010-0.014%) were rare adverse events. Mean birth weight was 3069.7g, 95% CI: 3009.7g–3129.8g). In the comparative analysis, COVID-19 significantly increased the risk of premature delivery (OR= 1. 48, [95% CI; 1 .22, 1.8]), preeclampsia (OR= 1. 6, [95% CI; 1.2, 2.1]), stillbirth (OR= 2.36, [95% CI 1.24, 4.462]), neonatal mortality (OR= 3.35, [95% CI; 1.07, 10.5]), and maternal mortality (OR= 3.08, [95% CI; 1.5, 6.3]). Pooled analyses were homogenous, with mild heterogeneity in premature delivery and preeclampsia outcomes. Conclusion Data must be interpreted with caution as limited data is available and no complete assessment of bias is possible at this time. Our data suggests that pregnant women who test positive for COVID-19 seem to be at higher risk for lower birth weights and premature delivery. There is no evidence at this time of the sharply increased maternal mortality that was seen with both the previous 2002 Middle East Respiratory Syndrome (MERS) and 2003 Severe Acute Respiratory Syndrome (SARS) pandemics.
The ovarian follicle luteinizing hormone (LH) signaling molecules that regulate oocyte meiotic maturation have recently been identified. The LH signal reduces preovulatory follicle cyclic nucleotide levels which releases oocytes from the first meiotic arrest. In the ovarian follicle, the LH signal reduces cyclic nucleotide levels via the CNP/NPR2 system, the EGF/EGF receptor network, and follicle/oocyte gap junctions. In the oocyte, reduced cyclic nucleotide levels activate the maturation promoting factor (MPF). The activated MPF induces chromosome segregation and completion of the first and second meiotic divisions. The purpose of this paper is to present an overview of the current understanding of human LH signaling regulation of oocyte meiotic maturation by identifying and integrating the human studies on this topic. We found 89 human studies in the literature that identified 24 LH follicle/oocyte signaling proteins. These studies show that human oocyte meiotic maturation is regulated by the same proteins that regulate animal oocyte meiotic maturation. We also found that these LH signaling pathway molecules regulate human oocyte quality and subsequent embryo quality. Remarkably, in vitro maturation (IVM) prematuration culture (PMC) protocols that manipulate the LH signaling pathway improve human oocyte quality of cultured human oocytes. This knowledge has improved clinical human IVM efficiency which may become a routine alternative ART for some infertile patients.
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