The relationship between patterns of insulin secretion and risks of gestational diabetes mellitus.

OBJECTIVE: To evaluate patterns of insulin secretion in pregnancy and analyze the association between insulin patterns and risks of gestational diabetes mellitus (GDM). METHODS: A prospective study was conducted to collect and analyze pregnant women's materials from January 2015 to December 2018. Pregnant women were grouped according to results of 75-g oral glucose tolerance test at 24-28 weeks of pregnancy: normal glucose tolerance (NGT) and GDM. Insulin secretion patterns were based on the time of peak(s) and shape of insulin secretion curve. The relationship between insulin secretion patterns and pregnant outcomes was analyzed. RESULTS: A total of 2432 pregnant women met the inclusion criteria during the study period. Among them, 737 (30.3%) women were grouped as GDM and 1695 (69.7%) as NGT. Type I insulin secretion represented the early phase of insulin secretion (peak time at 30 or 60 minutes), while type II represented the delayed peak of insulin secretion (peak time at 120 or 180 minutes). Logistic regression analysis showed that type II insulin secretion was a risk factor of pre-eclampsia, large-for-gestational-age, and neonatal hypoglycemia. CONCLUSION: The delayed insulin peak is a useful marker for risk of GDM and adverse pregnant outcomes in women with GDM.

Yeast Surface Display of Antheraea pernyi Lysozyme Revealed α-Helical Antibacterial Peptides in Its N-Terminal Domain.

The present study investigated a novel lysozyme ApLyz from the Chinese oak silkmoth, Antheraea pernyi, for its active expression with N- or C-terminus fused to the yeast cell surface, and the antimicrobial activities of the corresponding expressed lysozymes were evaluated. The bactericidal activity of C-terminal fusion of ApLyz surpassed that of the N-terminal fusion, which revealed the implication of an N-terminal stretch of ApLyz in the bactericidal function based on the structural mobility of this region. Two N-terminal peptides of ApLyz (residues 1-15 and 1-32), which primarily consist of amphiphilic α-helices, exerted similar bactericidal efficacy and had a strong preference for the Gram-negative strains. Further investigation revealed that the N-terminal peptides are membrane-targeting peptides causing cell permeabilization and also possess nonmembrane disturbing bactericidal mechanism. Overall, in addition to the key findings of novel bactericidal peptides from silkmoth lysozyme, this work laid the foundation for future improvement of ApLyz by protein engineering.

Association between glycemic control and birthweight with glycated albumin in Chinese women with gestational diabetes mellitus.

AIMS/INTRODUCTION: To assess glycated albumin (GA) as a potential glycemic index in managing gestational diabetes mellitus (GDM). MATERIALS AND METHODS: Eligible pregnant women were divided into the GDM group with abnormal result on a 75-g oral glucose tolerance test (OGTT) and the control (normal) group. GA measurements, Pearson's correlation analysis, multiple logistic regression and receiver operating characteristic curve analysis were obtained at the follow-up examination of participants in the two groups. RESULTS: A total of 2,118 women were assigned to the GDM group (n = 639) and control group (n = 1,479). The mean level of serum GA in GDM group was significantly greater than that in the control group at both 24-28 and 36-38 weeks of gestation (P < 0.05). The area under the receiver operating characteristic curve for GA defining good glycemic control in GDM was 0.874 (95% confidence interval 0.811-0.938). The cut-off point for the GA levels derived from the receiver operating characteristic curve was 11.60%, which had sensitivity and specificity for detecting a poor glycemic status of 75.93% and 86.36%, respectively. The risk of birthweight ≥3,500 g and macrosomia increased significantly with GA levels ≥13.00% at 24-28 weeks and ≥12.00% at 36-38 weeks of gestation. CONCLUSIONS: GA might be an appropriate and conveniently measured index that can detect poor glycemic control and predict birthweights in GDM women.

Engineered constitutive pathway in Klebsiella pneumoniae for 3-hydroxypropionic acid production and implications for decoupling glycerol dissimilation pathways.

3-Hydroxypropionic acid (3-HP) is a commercially important platform chemical from which a panel of chemicals can be generated. Klebsiella pneumoniae has been regarded as a promising host strain in glycerol-based 3-HP production for its exceptional ability to metabolize glycerol. Since the glycerol dissimilation mechanism governs the carbon flux distribution from glycerol, inducible strong promoters were usually employed to enhance the glycerol consumption and 3-HP production. Here, we report an alternative strategy that the native promoter of dhaB gene was applied to enhance 3-HP production in K. pneumoniae. The key enzyme genes (ald4 and dhaB) for 3-HP biosynthesis were co-expressed under this promoter. Metabolic analysis revealed that the 3-HP formation was partially coupled with cell metabolism. To optimize the production of 3-HP, the effects of glucose as energy source assistant were investigated based on the analysis of fermentation process kinetics. The highest 3-HP yield (3.77 g/L in flask) was observed upon optimized conditions. Since there were no additional inducers needed, the strategy of employing native promoter seems more feasible to industrial application. More importantly, the employment of constitutive promoter demonstrated an effective approach for decoupling the natural correlation between respiratory metabolism and glycerol dissimilation in K. pneumoniae.