Maternal-infant transfer of SARS-CoV-2 antibodies following vaccination in pregnancy: A prospective cohort study.

OBJECTIVES: To measure and evaluate the impact of receiving severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines in pregnancy on immunoglobulin G (IgG) and immunoglobulin A (IgA) titres in maternal and infant samples. DESIGN: Prospective cohort study. SETTING: Tertiary obstetric centre. POPULATION OR SAMPLE: 52 pregnant women who received one or more SARS-CoV-2 vaccine doses during pregnancy and their neonates. METHODS: IgG and IgA concentrations against SARS-CoV-2 antigens were measured from samples collected at delivery and 4-6 weeks postpartum and compared using Spearman correlations. MAIN OUTCOME MEASURES: Maternal and infant IgG and IgA titres in response to vaccination and infection in pregnancy. RESULTS: In maternal serum collected at delivery, participants without evidence of prior infection who received 3 + doses of a SARS-CoV-2 vaccine had higher Anti-Spike (S) IgG geometric mean concentrations (log10 AU/mL)(GMC) than those who received 2 doses (3 + Doses = 5.00, 2 Doses = 4.60, p = 0.08). The differences in IgG Anti-S GMC were statistically significant in cord serum, and in postpartum samples of maternal serum, infant serum and breast milk (Cord GMCs: 3 + Doses = 5.32, 2 Doses = 4.98, p < 0.05; Postpartum maternal serum GMCs: 3 + Doses = 5.25, 2 Doses = 4.57, p < 0.001; Postpartum infant serum GMCs: 3 + Doses = 5.10, 2 Doses = 4.72, p = 0.03; Postpartum breast milk GMCs: 3 + Doses = 2.61, 2 Doses = 1.94, p < 0.0001). Among participants with 3 + Doses, those with evidence of SARS-CoV-2 infection had statistically significant higher anti-S IgG GMCs than those without prior infection (Maternal serum at delivery: SARS-CoV-2+=5.65, SARS-CoV-2-=5.00, p = 0.004; Cord: SARS-CoV-2+=5.68, SARS-CoV-2-=5.32, p = 0.02; Postpartum maternal serum: SARS-CoV-2+=5.66, SARS-CoV-2-=5.25, p < 0.001; postpartum infant serum: SARS-CoV-2+=5.50, SARS-CoV-2-=5.10, p = 0.003; Postpartum breast milk: SARS-COV-2+=3.25, SARS-COV-2-=2.61, p = 0.009). Significant positive correlations were found for anti-S IgG titres between paired maternal and infant samples at delivery and postpartum (Delivery: R = 0.91, p < 0.001; postpartum: R = 0.86, p < 0.001). CONCLUSIONS: Receipt of a SARS-CoV-2 vaccine and SARS-CoV-2 infection elicit strong IgG and IgA antibody responses in pregnant women with evidence of transplacental transfer to the fetus.

Simple approximation of sample size for precise estimates of SARS-CoV-2 infection from point-seroprevalence studies.

OBJECTIVE: This study aimed to model the precision of SARS-CoV-2 seroprevalence estimates. METHODS: Sample size and precision estimates were calculated using the normal approximation to the binomial distribution. The relationship between sample size and precision was visualized across a range of assumed SARS-CoV-2 seroprevalence from 2% to 75%. RESULTS: The calculation found that 2% precision was attainable by taking moderately sized sample sets when the expected seroprevalence of SARS-CoV-2 infection exceeds 2%. In populations with a low incidence of SARS-CoV-2 infection and an expected seroprevalence of less than 2%, larger samples are required for precise estimates. CONCLUSIONS: Taking a sample of 177-1000 participants can provide precise prevalence estimates of SARS-CoV-2 infection in vaccinated and unvaccinated populations. Larger sample sizes are only necessary in low prevalence settings.

Chronic thromboxane synthase inhibition prevents fructose-induced hypertension.

To investigate the role of thromboxane A(2) in the development of hypertension in the fructose-fed rat, we treated male fructose-fed rats with dazmegrel (a thromboxane synthase inhibitor) and monitored blood pressure, fasting plasma parameters, and insulin sensitivity for 7 weeks. Systolic blood pressure was measured each week using tail plethysmography, and an oral glucose tolerance test was performed at the end of the study to assess insulin sensitivity. Treatment with a 60% fructose diet and dazmegrel (100 mg. kg(-1). d(-1) via oral gavage) was initiated on the same day. Plasma triglyceride levels increased 2-fold in both fructose- and fructose/dazmegrel-treated groups, and plasma insulin levels tended to be higher in these groups, although not significantly. Systolic blood pressure increased significantly throughout the study in the fructose-fed group only (132+/-3 versus 112+/-4 mm Hg in control rats, 118+/-2 mm Hg in control-treated rats, 116+/-2 mm Hg in fructose-treated rats). Both fructose groups demonstrated a higher peak insulin response to oral glucose challenge and had 40% to 60% lower insulin sensitivity index values. The results of this study show that treatment with a thromboxane synthase inhibitor, dazmegrel, can prevent the development of hypertension but does not improve insulin sensitivity or other fructose-induced metabolic impairments. Based on these data, we conclude that the potent vasoconstrictor thromboxane is involved in the link between hyperinsulinemia/insulin resistance and hypertension.

[New method of encapsulating isolated nuclei into a lipid membrane]. / Novyi metod zakliucheniia izolirovannykh iader v lipidnuiu obolochku.

A new method of the coating of isolated cell nuclei with additional phosphatidylcholine membranes is described. The additional membrane was visualized under the electron microscope using ferritin as a label. The coating diminished leakage of the content of the nuclei and restricted permeability of the nuclei for exterior macromolecules.