Quantifying Acidity in Heterogeneous Systems: Biphasic pKa Values.

Acidities of lipophilic compounds, such as various ligands or catalysts, in systems consisting of an aqueous phase at equilibrium with a water-immiscible phase (lipid bilayers, phase transfer catalysis, sensor membranes, to name just few) are typically approximated by the aqueous pKa values. Our research shows that such approximations can lead to seriously biased estimations of the acidities as the bulk of solvated H+ ions reside in the aqueous phase, while the lipophilic species─both neutral acid and anion─predominantly reside in the organic phase. Therefore, the use of aqueous pKa in such situations is not justified. In this work, we provide a more accurate description of the acidities of acids in such systems by applying the biphasic pKa concept. Biphasic pKa values (pKaow values) of 35 acids of various structures and chemical properties were determined in a 1-octanol:water system. We provide detailed descriptions of the UV-vis and NMR measurement methods. The directly obtained (apparent) pKaow values depend on concentration. Concentration-independent values were obtained by extrapolating the apparent values to zero concentration using a Debye-Hückel model.

Outcomes of robotic surgery in morbidly obese patients with endometrial cancer: a retrospective study.

With advances in minimal invasive surgery, robotic surgery has become the widespread approach for surgical staging of endometrial cancer in the obese population. This study aimed to evaluate safety and surgical outcomes of robotic surgery in the morbidly obese and extremely morbidly obese patients with endometrial cancer. Retrospective cohort study. A total of 391 obese women undergoing robotic-assisted surgical staging were identified and included in the study. Surgical outcomes for obese patients (BMI > 30 kg/m2) who underwent surgical staging between 2011 and 2019 were retrospectively collected. Preoperative characteristics, perioperative outcomes and postoperative complications were analyzed among the categories of obesity (BMI ≥ 30-34.9 kg/m2, ≥ 35-39.9 kg/m2, ≥ 40-49.9 kg/m2) including the extremely morbid obese (BMI > 50 kg/m2). Comparative analysis revealed a higher percentage of postoperative complications with increasing BMI, although the results were not statistically significant. Postoperative complications are observed at higher rates among women with increasing BMI.

Management of Refractory Menstrual Bleeding in an Adolescent with Glanzmann Thrombasthenia: A Case Report and Review.

Glanzmann Thrombasthenia is a rare bleeding disorder causing life-threatening bleeding at menarche in the adolescent female. Bleeding often necessitates admission and multiple blood transfusions. Due to the rarity of the disease, management of acute bleeding in new-onset menarche poses a particular challenge. A 12-year-old menarchial female had persistent vaginal bleeding despite multiple treatment modalities including aminocaproic acid, recombinant factor VIIa, intravenous estrogen, and gonadotropin receptor hormone agonists. Although the standard treatment of bleeding in patients with GT is primarily rFVIIa, new-onset menstrual bleeding in conjunction with an immature hypothalamic-pituitary-ovarian axis often requires expanding treatment to include multiple drug modalities. In our case, a two-step approach was necessary. The first is targeting the cessation of the first menses. The second is optimizing ongoing management of long-term control of heavy menstrual bleeding to achieve amenorrhea, prevent further hospital admissions, and avoid recurrent transfusions.

Maternal risk factors associated with persistent placenta previa.

INTRODUCTION: Maternal risk factors associated with placenta previa are well documented in the literature. However, there are limited studies identifying maternal characteristics associated with the persistence of placenta previa. The objective of the study was to determine maternal characteristics associated with the persistent placenta previa. METHODS: A retrospective cohort study was conducted in which 705 pregnant women diagnosed with low-lying placenta or placenta previa between 17 and 24 weeks gestation were identified from a single institution between 2003 and 2017. The primary outcome included persistent placenta previa (i.e., persistent placental tissue within 2 cm of the internal os) at or after 36 weeks 0 days. Those with abnormal placentation (e.g., vasa previa, placenta accreta) or delivery prior to 36 weeks 0 days were excluded. Multivariable logistic regression modeling was utilized to determine significant maternal characteristics associated with persistent placenta previa among women diagnosed with either placenta previa or low-lying placenta. RESULTS: Women with a prior cesarean delivery were seven times more likely to have persistent placenta previa (odds ratio, 7.0, 95% confidence interval, 3.7-13.1). A history of intrauterine curettage or evacuation in the setting of placenta previa increases the likelihood of persistent placenta previa almost 3-fold (odds ratio, 2.5, 95% confidence interval, 1.3-5.0). DISCUSSION: To date, our study is the largest, retrospective cohort study assessing maternal risk factors associated with persistent placenta previa; and is the first to detect a statistically significant correlation between a history of intrauterine surgeries and persistent placenta previa.

Occupational and environmental exposures to heavy metals: risk factors for male infertility in Lebanon?

A case-control study was conducted to examine whether occupational or environmental exposures, particularly to heavy metals, are associated with male infertility in Lebanon, a war-torn country with a history of environmental degradation. Seventy-four infertile cases and 76 fertile controls were selected from 2 major fertility clinics in Beirut. Data collection involved risk-factor interviews, semen analysis, and blood collection for heavy metal analysis. Multiple regression analysis showed that men with reported occupational exposures were twice as likely to be infertile as unexposed men. However, none of the subcategories of infertile men (based on semen analysis results) had significantly higher whole blood concentrations of heavy metals when compared to fertile controls. Blood concentrations were well within the range for referent populations of healthy individuals. Thus, despite Lebanon's poor record of occupational and environmental stewardship, exposure to metal pollutants does not appear to represent an important risk factor for male infertility.

Malignant Brenner tumor: Two case reports.

Malignant Brenner tumor (MBT) is a rare ovarian tumor that, given the infrequency of the disease, has not been well documented in the literature. Diagnosing MBT both radiographically and histologically remains a challenge. We report two cases of ovarian MBT, detailing the clinical presentation, radiographic characteristics, and histologic findings with supplementary imaging. Our cases demonstrate the pathologic challenge of histologically diagnosing MBT versus other Brenner tumors and transitional cell carcinoma (TCC) of the ovary.