Glucose regulates cyclin D2 expression in quiescent and replicating pancreatic β-cells through glycolysis and calcium channels

Understanding the molecular triggers of pancreatic β-cell proliferation may facilitate the development of regenerative therapies for diabetes. Genetic studies have demonstrated an important role for cyclin D2 in β-cell proliferation and mass homeostasis, but its specific function in β-cell division and mechanism of regulation remain unclear. Here, we report that cyclin D2 is present at high levels in the nucleus of quiescent β-cells in vivo. The major regulator of cyclin D2 expression is glucose, acting via glycolysis and calcium channels in the β-cell to control cyclin D2 mRNA levels. Furthermore, cyclin D2 mRNA is down-regulated during S-G(2)-M phases of each β-cell division, via a mechanism that is also affected by glucose metabolism. Thus, glucose metabolism maintains high levels of nuclear cyclin D2 in quiescent β-cells and modulates the down-regulation of cyclin D2 in replicating β-cells. These data challenge the standard model for regulation of cyclin D2 during the cell division cycle and suggest cyclin D2 as a molecular link between glucose levels and β-cell replication.     

Humoral serological response to the BNT162b2 vaccine is abrogated in lymphoma patients within the first 12 months following treatment with anti-CD2O antibodies

Patients with lymphoma, especially those treated with anti-CD20 monoclonal antibodies, suffer high COVID-19-associated morbidity and mortality. The goal of this study was to assess the ability of lymphoma patients to generate a sufficient humoral response after two injections of BNT162b2 Pfizer vaccine and to identify factors influencing the response. Antibody titers were measured with the SARS-CoV-2 IgG II Quant (Abbott^©) assay in blood samples drawn from lymphoma patients 4±2 weeks after the second dose of vaccine. The cutoff for a positive response was set at 50 AU/mL. Positive serological responses were observed in 51% of the 162 patients enrolled in this cross-sectional study. In a multivariate analysis, an interval of <12 months between the last anti-CD20 monoclonal antibody dose and the second vaccine dose (odds ratio=31.3 [95% confidence interval: 8.4-116.9], P<0.001) and presence of active lymphoma (odds ratio=4.2 (95% confidence interval: 2.1-8.2), P=0.006) were identified as negative response predictors. The rate of seropositivity increased from 3% in patients vaccinated within 45 days after the last monoclonal antibody administration to 80% in patients vaccinated >1 year after this therapy. The latter percentage was equal to that of patients never exposed to monoclonal antibodies. In conclusion, lymphoma patients, especially those recently treated with anti- CD20 monoclonal antibodies, fail to develop sufficient humoral response to BNT162b2 vaccine. While a serological response is not the only predictor of immunity, its low level could make this population more vulnerable to COVID-19, which implies the need for a different vaccination schedule for such patients.     

Uteroplacental circulation, preeclampsia, and maternal abdominal aortic stiffness in normal and compromised pregnancies

A study of 82 normal and 60 compromised pregnant women who were identified by uterine artery Doppler flow waveform systolic/diastolic ratio >95th percentile (increased peripheral resistance) was carried out to examine the elastic properties of the maternal abdominal aorta (AA). An aortic stiffness index (SI) was measured between 18 and 40 weeks at four-weekly intervals with a phase-locked loop ultrasound technique to estimate the aortic systolic and diastolic diameters and their correlation with blood pressure. In the normal group, the aortic systolic and diastolic diameters, as well as the SI, increased with the maternal age. In the compromised group, aortic diameter and blood pressure were normal, but the SI during the early second trimester was increased. Twenty-two women from the compromised group with an SI above the 95th percentile for their age had a significantly higher prevalence of preeclampsia in comparison with women with a normal SI (P<0.001). The aortic SI was significantly higher in severe than in mild preeclampsia. This study demonstrates that stiffness of the AA is increased in pregnant women with preeclampsia and that a progressive increase of the SI in serial studies is associated with severity of the disease. Aberrant hemodynamic adaptation in preeclampsia seems to include increased stiffness of the larger artery besides high resistance in small peripheral arteries.     

Outcome of breastfed infants following post-partum methylergonovine treatment

Objective: To evaluate maternal and breastfed infant’s outcome following post-partum maternal use of methylergonovine.

Methods: A prospective, controlled observational study design was used. Mothers who contacted Beilinson Teratology Information Service (BELTIS) were followed by phone interview. Data on lactation, neonatal symptoms and outcomes at the age of 1–3 years were obtained. Mothers’ breastfeeding while treated with methylergonovine and their infants were compared to a matched control group of breastfeeding mothers using a drug known to be safe during lactation (amoxicillin).

Results: Follow-up was obtained for 38 of 42 women (90.5%). Of whom, six stopped breastfeeding because of concerns regarding drug treatment and three refused to participate. The remaining 29 women and infant pairs were compared to a control group of 58 women and their infants. Comparison showed no effect of methylergonovine on lactation and similarly showed no difference in rate of neonatal complications (p?=?1). At time of follow-up there were no differences in growth or in adverse neurodevelopment outcomes (p?=?0.26).

Conclusions: No increase in adverse long-term outcomes was found in infants exposed to methylergonovine through breastfeeding. Our data in conjunction with previous estimates of very low drug exposure support continuation of breastfeeding in women requiring treatment with methylergonovine.     

Syncytial variant of nodular sclerosing Hodgkin lymphoma in children: A prognostic factor?

Nodular sclerosing Hodgkin lymphoma (HL) has an excellent prognosis in children. The syncytial variant (SV) of HL in adults represents a clinic pathologic entity with a worse outcome. We report the clinical features and the course of the disease of three children with refractory HL. The three patients with SV were analyzed in a retrospective multi-institutional study conducted in Israel in 51 children diagnosed with refractory or recurrent HL between 1997 and 2014. All the three children developed multiple recurrences soon after diagnosis. All three received at least three different chemotherapy combinations with autologous bone marrow transplantation for two patients, allogenic bone marrow transplantation in one, and immunotherapy in one. One patient died of disease, one is in complete response of the disease but developed a second metastatic malignancy, and one is alive without disease. This retrospective study shows that SV histology may be a prognostic factor for poor outcome in children diagnosed with HL.