The aim of this study was to characterize the mechanism of the chemical interaction between L-ascorbic acid (ASC) and tetrahydrobiopterin (BH₄) in vitro and to examine its effect on the activity of endothelial nitric oxide synthase (eNOS) in first trimester human placentae. At room temperature, in Tris–HCl buffer (pH 7.4), both ASC and BH₄ were readily oxidized by dissolved O₂ or H₂O₂. BH₄ was more sensitive to auto-oxidation, while ASC was more susceptible to oxidation by H₂O₂. Addition of 36 μmol/l BH₄ to 143 μmol/l ASC increased the initial rate of ASC oxidation 3.2-fold in a catalase-sensitive manner, indicating that enhanced ASC oxidation is partly due to the formation of H₂O₂. In the presence of catalase, BH₄ still stimulated 1.9-fold the initial rate of ASC oxidation, suggesting that another auto-oxidation product of BH₄, most probably quininoid-BH₂ (qBH₂), could also stimulate ASC oxidation while itself being reduced back to BH₄. ASC prevented the auto-oxidation of BH₄ in a concentration-dependent fashion, with 3 mmol/l ASC providing an almost complete stabilization of 25 μmol/l BH₄. Importantly, basal eNOS activity in placental microsomes was stimulated 2.5-fold by 0.5 μmol/l BH₄, and 0.5 mmol/l ASC enhanced the BH₄-stimulation 1.4-fold, with a smaller effect on basal eNOS activity. Taken together, the findings support the notion that the stabilizing action of ASC on BH₄ is related to the ASC-mediated reductive reversal of the auto-oxidation process of BH₄. Moreover, we demonstrated that concentrations of ASC present in the placenta as a common vitamin C supply are sufficient to protect cellular free BH₄ and may contribute to the stimulation of placental eNOS activity.

Background: Endometriosis is a chronic condition affecting 6–10% of women of reproductive age, with endometriosis-related pain and infertility being the leading symptoms. Currently, the gold standard treatment approach to surgery is conventional laparoscopy (CL); however, the increasing availability of robot-assisted surgery is projected as a competitor of CL. This study aimed to compare the perioperative outcomes of robot-assisted laparoscopy (RAL) and CL in endometriosis surgery. Objectives: We aimed to compare the effectiveness and safety of these two procedures. Methods: A systematic search was conducted in three medical databases. Studies investigating different perioperative outcomes of endometriosis-related surgeries were included. Results are presented as odds ratios (OR) or mean differences (MD) with 95% confidence intervals (CI). Results: Our search yielded 2,014 records, of which 13 were eligible for data extraction. No significant differences were detected between the CL and RAL groups in terms of intraoperative complications (OR = 1.07, CI 0.43–2.63), postoperative complications (OR = 1.3, CI 0.73–2.32), number of conversions to open surgery (OR = 1.34, CI 0.76–2.37), length of hospital stays (MD = 0.12, CI 0.33–0.57), blood loss (MD = 16.73, CI 4.18–37.63) or number of rehospitalizations (OR = 0.95, CI 0.13–6.75). In terms of operative times (MD = 28.09 min, CI 11.59–44.59) and operating room times (MD = 51.39 min, CI 15.07–87.72;), the RAL technique remained inferior. Conclusion: RAL does not have statistically demonstrable advantages over CL in terms of perioperative outcomes for endometriosis-related surgery. Graphical

Background/Objectives: Non-invasive prenatal testing (NIPT) has become a widely used method for screening common fetal aneuploidies due to its high sensitivity and specificity compared to traditional screening methods. With various NIPT technologies available, such as whole-genome sequencing (WGS), single nucleotide polymorphisms (SNPs), microarray, and rolling circle amplification (RCA), understanding the accuracy and reliability of each method is critical for clinical decision-making. However, comprehensive evaluations comparing the performance of these NIPT methods, especially in terms of predictive values for trisomy detection, remain limited. A systematic review of the difference in accuracy of the different NIPT methods used for common aneuploidy screening. Methods: A systematic review of former clinical studies using different NIPT methods, such as whole-genome sequencing (WGS), a targeted method of single nucleotide polymorphisms (SNPs), microarray and rolling circle amplification (RCA). We collected data from the PubMed, Embase, Web of Science, Scopus, clinicaltrials.gov, and Cochrane library from the last 20 years, between 2003 January and 2023 October, without any language, search filter or publication type restrictions. Results: Two authors selected twenty articles including twenty-one studies to perform the systematic review. In these studies, altogether 92,164 pregnant women were tested by genomics-based non-invasive prenatal testing (NIPT). We extracted data on true positive, false positive, false negative, and true negative values from each study, and calculated sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) from them. We collected data regarding trisomy 21 (T21), trisomy 18 (T18) and trisomy 13 (T13) detection from all studies. Conclusions: As a conclusion, for the detection of common fetal trisomies, different methods of NIPT perform similarly in terms of clinical sensitivity, specificity and NPV. However, the tests utilizing SNP and RCA had lower PPV values than other NIPT methods. Our research indicates all NIPT methods showed greater sensitivity for the detection of T21, above 97%, than traditional screening tests. For T18 detection, the targeted method with the microarray had a lower sensitivity compared to other tests. The SNP and the microarray-based test had high PPV, whilst the other tests, utilizing WGS, and the test with RCA had quite low PPV. Regarding T13 detection, all of the tests performed similarly in terms of clinical sensitivity, specificity, PPV, and NPV (with one exception—one of the tests using WGS had lower PPV). According to these results, there was no significant difference between the methods of NIPT, such as WGS, SNPs, microarray, and RCA, used to detect common trisomies, but the variation in PPV underlines the importance of invasive tests to derive positive NIPT results. We suggest that NIPT combined with US screening for structural abnormalities could further improve the utility of the non-invasive tests in pregnancy. This is the first independent systematic review into the efficacy of the different NIPT methods.

Throughout the history of medicine, preeclampsia has remained an enigmatic field of obstetrics. In 2023, despite its prevalence and impact, preeclampsia’s exact cause and effective treatment remain elusive; the current options are limited to delivery. The purpose of this review is to summarize the knowledge of the possible novel prophylactic therapies and screening methods for preeclampsia, thereby providing valuable insights for healthcare professionals and researchers. Aspirin and LMWH have already been widely used; meanwhile, calcium, vitamin D, and pravastatin show promise, and endothelin receptor antagonists are being explored. Stress reduction, dietary changes, and lifestyle modifications are also being investigated. Another interesting and fast-growing area is AI- and software-based screening methods. It is also key to find novel biomarkers, which, in some cases, are not only able to predict the development of the disease, but some of them hold promise to be a potential therapeutic target. We conclude that, while a definitive cure for preeclampsia may not be eligible in the near future, it is likely that the assessment and enhancement of preventive methods will lead to the prevention of many cases. However, it is also important to highlight that more additional research is needed in the future to clarify the exact pathophysiology of preeclampsia and to thus identify potential therapeutic targets for more improved treatment methods.