Sarah R. Aldhaheri

Galactose and its Metabolites Deteriorate Metaphase II Mouse Oocyte Quality and Subsequent Embryo Development by Disrupting the Spindle Structure

Premature ovarian insufficiency (POI) is a frequent long-term complication of classic galactosemia. The majority of women with this disorder develop POI, however rare spontaneous pregnancies have been reported. Here, we evaluate the effect of D-galactose and its metabolites, galactitol and galactose 1-phosphate, on oocyte quality as well as embryo development to elucidate the mechanism through which these compounds mediate oocyte deterioration. Metaphase II mouse oocytes (n = 240), with and without cumulus cells (CCs), were exposed for 4 hours to D-galactose (2 μM), galactitol (11 μM) and galactose 1-phosphate (0.1 mM), (corresponding to plasma concentrations in patients on galactose-restricted diet) and compared to controls. The treated oocytes showed decreased quality as a function of significant enhancement in production of reactive oxygen species (ROS) when compared to controls. The presence of CCs offered no protection, as elevated ROS was accompanied by increased apoptosis of CCs. Our results suggested that D-galactose and its metabolites disturbed the spindle structure and chromosomal alignment, which was associated with significant decline in oocyte cleavage and blastocyst development after in-vitro fertilization. The results provide insight into prevention and treatment strategies that may be used to extend the window of fertility in these patients.

Cyclophosphamide and Acrolein induced oxidative stress leading to deterioration of metaphase II mouse oocyte quality

Abstract Cyclophosphamide (CTX) is a chemotherapeutic agent widely used to treat ovarian, breast, and hematological cancers as well as autoimmune disorders. Such chemotherapy is associated with reproductive failure and premature ovarian insufficiency. The mechanism by which CTX and/or its main metabolite, acrolein, affect female fertility remains unclear, but it is thought to be caused by an overproduction of reactive oxygen species (ROS). Here, we investigated the effect of CTX on metaphase II mouse oocytes obtained from treated animals (120 mg/kg, 24 h of single treatment), and oocytes directly exposed to increasing concentrations of CTX and acrolein (n=480; 0, 5, 10, 25, 50, and 100 &mgr;M) with and without cumulus cells (CCs) for 45 min which correlates to the time of maximum peak plasma concentrations after administration. Oocytes were fixed and subjected to indirect immunofluorescence and were scored based on microtubule spindle structure (MT) and chromosomal alignment (CH). Generation of ROS was evaluated using the Cellular Reactive Oxygen Species Detection Assay Kit. Deterioration of oocyte quality was noted when oocytes were obtained from CTX treated mice along with CTX and acrolein treated oocytes in a dose‐dependent manner as shown by an increase in poor scores. Acrolein had an impact at a significantly lower level as compared to CTX, plateau at 10 &mgr;M versus 50 &mgr;M, respectively. These variation is are associated with the higher amount of ROS generated with acrolein exposure as compared to CTX (p<0.05). Utilization of antioxidant therapy and acrolein scavengers may mitigate the damaging effects of these compounds and help women undergoing such treatment. Graphical abstract Figure. No caption available. HighlightsCyclophosphamide and acrolein treatment deteriorate oocyte quality.The deterioration in oocyte quality progresses in a concentration dependent manner.Oocytes obtained from mice treated with cyclophosphamide displayed similar effect.Cyclophosphamide and acrolein deteriorate oocytes through ROS overproduction.

Uterine tachysystole in spontaneous labor at term

Abstract Objectives: The objective of this study is to determine the incidence of uterine tachysystole and its association with spontaneous labor at term. Methods: A retrospective cohort study of 8008 women in spontaneous labor (without prostaglandins or oxytocin). Fetal heart tracings and uterine activity were recorded every 15 min. Primary outcome: occurrence of tachysystole (> 5 uterine contractions /10 min over 30 min periods). Secondary outcomes: non-reassuring fetal heart tracings (NRFHT), NICU admissions, and cesarean deliveries. Results: About 890 patients (11.1 %) had at least one episode of tachysystole. Non-whites have higher incidence of uterine tachysystole; adjusted odds ratio (aOR) was 1.66 for Hispanics (95% CI 1.28–2.05), 1.58 for African Americans (95% CI 1.05–2.38), and 1.51 for Asians (95% CI = 1.13–2.0). The use of epidural analgesia was higher in the tachysystole group (62.2% versus 40.9%, aOR 1.89, CI 1.58–2.26; p < 0.001). Tachysystole was more frequent among nulliparous women and in women carrying higher weight fetuses. Oligohydramnios (aOR 1.62, CI 0.70–3.72; p < 0.004), and NRFHT were more common in the tachysystole group (4.2% versus 2.5%, p = 0.002). Newborns in the tachysystole group were two times more likely to be admitted to NICU (30 /890 [3.4%] versus 122 /7118 [1.7%], OR = 2, p=0.001). There was no difference in the frequency of meconium-stained amniotic fluid or Apgar scores <7 at 5 min. Conclusion: Uterine tachysystole occurs in more than 10% of spontaneous labors and is associated with NRFHR, increased rate of caesarean deliveries and NICU admissions. It is not associated with low Apgar scores or meconium-stained amniotic fluid.

Dimercapto-1-propanesulfonic acid (DMPS) induces metaphase II mouse oocyte deterioration

In light of the recent lead contamination of the water in Flint, Michigan and its potential adverse outcomes, much research and media attention has turned towards the safety profile of commonly used chelators. Dimercapto-1-propanesulfonic acid (DMPS) typically used in the treatment of lead, mercury and arsenic poisoning also displays a high affinity towards transition metals such as zinc and copper, essential for biological functioning. It is given in series of dosages (0.2-0.4g/day) over a long period, and has the ability to enter cells. In this work, we investigated the mechanism through which increasing concentrations of DMPS alter oocyte quality as judged by changes in microtubule morphology (MT) and chromosomal alignment (CH) of metaphase II mice oocyte. The oocytes were directly exposed to increasing concentration of DMPS (10, 25, 50, 100 and 300μM) for four hours (time of peak plasma concentration after administration) and reactive oxygen species (mainly hydroxyl radical and superoxide) and zinc content were measured. This data showed DMPS plays an important role in deterioration of oocyte quality through a mechanism involving zinc deficiency and enhancement of reactive oxygen species a major contributor to oocyte damage. Our current work, for the first time, demonstrates the possibility of DMPS to negatively impact fertility. This finding can not only help in counseling reproductive age patients undergoing such treatment but also in the development of potential therapies to alleviate oxidative damage and preserve fertility in people receiving heavy metal chelators.

Sonographic Measurement of Cervical Volume in Pregnant Women at High Risk of Preterm Birth Using a Geometric Formula for a Frustum Versus 3-Dimensional Automated Virtual Organ Computer-Aided Analysis

To compare cervical volume measurements by 3‐dimensional (3D) sonography using Virtual Organ computer‐aided analysis (VOCAL; GE Healthcare, Milwaukee, WI) versus a manual method using a geometric formula for a frustum.

Mesna (2-mercaptoethane sodium sulfonate) functions as a regulator of myeloperoxidase

Abstract Myeloperoxidase (MPO), an abundant protein in neutrophils, monocytes, and macrophages, is thought to play a critical role in the pathogenesis of various disorders ranging from cardiovascular diseases to cancer. We show that mesna (2‐mercaptoethanesulfonic acid sodium salt), a detoxifying agent, which inhibits side effects of oxazaphosphorine chemotherapy, functions as a potent inhibitor of MPO; modulating its catalytic activity and function. Using rapid kinetic methods, we examined the interactions of mesna with MPO compounds I and II and ferric forms in the presence and absence of chloride (Cl‐), the preferred substrate of MPO. Our results suggest that low mesna concentrations dramatically influenced the build‐up, duration, and decay of steady‐state levels of Compound I and Compound II, which is the rate‐limiting intermediate in the classic peroxidase cycle. Whereas, higher mesna concentrations facilitate the porphyrin‐to‐adjacent amino acid electron transfer allowing the formation of an unstable transient intermediate, Compound I*, that displays a characteristic spectrum similar to Compound I. In the absence of plasma level of chloride, mesna not only accelerated the formation and decay of Compound II but also reduced its stability in a dose depend manner. Mesna competes with Cl‐, inhibiting MPOs chlorinating activity with an IC50 of 5 &mgr;M, and switches the reaction from a 2e‐ to a 1e‐ pathway allowing the enzyme to function only with catalase‐like activity. A kinetic model which shows the dual regulation through which mesna interacts with MPO and regulates its downstream inflammatory pathways is presented further validating the repurposing of mesna as an anti‐inflammatory drug. Graphical abstract Figure. No caption available. HighlightsMesna inhibits MPO by the formation of Compound I* where the e‐ in the protein moiety.Mesna regulates MPO chlorinating activity and inhibits its inflammatory pathways.Therefore, suggesting repurposing mesna to serve as a potent anti‐inflammatory drug.