Development of a nonchiral HPLC method with circular dichroism detection for chiral analysis of molybdenum-catalyzed enantioselective synthesis products

The combination of a circular dichroism detector and nonchiral liquid chromatography was used for the chiral analysis of unresolved enantiomers to determine the enantioselectivity of a molybdenum-catalyzed asymmetric allylic alkylation reaction. The CD/UV peak area ratio of the unresolved enantiomers was calculated and compared with that of a reference standard to determine the enantiomeric purity. The limit of quantitation (LOQ) is 20 ng for the chiral ligand and 1 microg for the branched chiral product. The viability of the system depends on the limit of quantitation of the CD response and the linearity range of the CD and UV response.     

Effect of Carotid Artery Stenting on Cognitive Function in Patients with Internal Carotid Artery Stenosis and Cerebral Lacunar Infarction: A 3-Year Follow-Up Study in China

Background and Objectives

Carotid artery stenting (CAS) is an important therapeutic strategy for patients with carotid artery stenosis. However, the potential influence of CAS on cognitive function in patients with carotid artery stenosis and cerebral lacunar infarction has not been determined. This study investigated changes in cognitive function associated with CAS and the factors related to these changes.

Methods

This prospective cohort study comprised 579 Chinese patients with cerebral lacunar infarction and carotid artery stenosis for whom CAS was indicated, and a matched control group of 552 healthy individuals. Cognitive function before CAS and at scheduled intervals from 6 months to 3 years was assessed with instruments that included the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) scale. Potential factors that might affect cognitive function were analyzed via logistic regression.

Results

The MMSE and MoCA scores of the patients before CAS were significantly lower than that of the control subjects. These scores were significantly higher 6 months after CAS and sustained or increased throughout the 3-year follow-up. Also significantly improved after CAS from baseline were scores for an alternating trail test, cube copying, clock-drawing, attention, and delayed recall in an auditory-verbal learning test. Logistic regression analyses showed that age greater than 65 y, little education, diabetes, and hypertension were independent risk factors for deteriorated MoCA scores 3 years after CAS.

Conclusion

CAS was associated with significantly improved cognitive function in cerebral lacunar infarction patients with severe stenosis.     

Construction and Analysis of High-Ethanol-Producing Fusants with Co-Fermentation Ability through Protoplast Fusion and Double Labeling Technology

Double labeling of resistance markers and report genes can be used to breed engineered Saccharomyces cerevisiae strains that can assimilate xylose and glucose as a mixed carbon source for ethanol fermentation and increased ethanol production. In this study Saccharomyces cerevisiae W5 and Candida shehatae 20335 were used as parent strains to conduct protoplast fusion and the resulting fusants were screened by double labeling. High performance liquid chromatography (HPLC) was used to assess the ethanol yield following the fermentation of xylose and glucose, as both single and mixed carbon sources, by the fusants. Interestingly, one fusant (ZLYRHZ7) was demonstrated to have an excellent fermentation performance, with an ethanol yield using the mixed carbon source of 0.424 g g⁻¹, which compares with 0.240 g g⁻¹ (W5) and 0.353 g g⁻¹ (20335) for the parent strains. This indicates an improvement in the ethanol yield of 43.4% and 16.7%, respectively.     

Differences in the Induction of Defence Responses in Resistant and Susceptible Muskmelon Plants Infected with Colletotrichum lagenarium

Defence reactions occurring in resistant (cv. Gankezaomi) and susceptible (cv. Ganmibao) muskmelon leaves were investigated after inoculating with Colletotrichum lagenarium. Lesion restriction in resistant cultivars was associated with the accumulation of hydrogen peroxide (H₂O₂). The activity of antioxidants catalase (CAT) and peroxidase (POD) significantly increased in both cultivars after inoculation, while levels of both CAT and POD activity were significantly higher in the resistant cultivar. Ascorbate peroxidase (APX) increased in both cultivars after inoculation, and level of APX activity was significantly higher in the resistant cultivar. Glutathione reductase (GR) activity significantly increased in both cultivars following inoculation, but was higher in the resistant cultivar, resulting in higher levels of ascorbic acid (AsA) and reduced glutathione (GSH). Phenylalanine ammonia lyase (PAL) significantly increased in inoculated leaves of both cultivars, resulting in higher levels of total phenolic compounds and flavonoids. The pathogenesis‐related proteins chitinase (CHT) and β‐1, 3‐glucanase (GLU) significantly increased following inoculation with higher activity in the resistant cultivar. These findings show that resistance of muskmelon plants against C. lagenarium is associated with the rapid accumulation of H₂O₂, resulting in altered cellular redox status, accumulation of pathogenesis‐related proteins, activation of phenylpropanoid pathway to accumulation of phenolic compounds and flavonoids.     

Antiphospholipid antibody‐activated NETs exacerbate trophoblast and endothelial cell injury in obstetric antiphospholipid syndrome

Despite the widespread use of antiplatelets and anticoagulants, women with antiphospholipid syndrome (APS) may face pregnancy complications associated with placental dysplasia. Neutrophil extracellular traps (NETs) are involved in the pathogenesis of many autoimmune diseases, including vascular APS; however, their role in obstetric APS is unclear. Herein, we investigated the role of NETs by quantifying cell‐free DNA and NET marker levels. Live‐cell imaging was used to visualize NET formation, and MAPK signalling pathway proteins were analysed. Cell migration, invasion and tube formation assays were performed to observe the effects of NETs on trophoblasts and human umbilical vein endothelial cells (HUVECs). The concentrations of cell‐free DNA and NETs in sera of pregnant patients with APS were elevated compared with that of healthy controls (HCs) matched to gestational week. APS neutrophils were predisposed to spontaneous NET release and IgG purified from the patients (APS‐IgG) induced neutrophils from HCs to release NETs. Additionally, APS‐IgG NET induction was abolished with inhibitors of reactive oxygen species, AKT, p38 MAPK and ERK1/2. Moreover, NETs were detrimental to trophoblasts and HUVECs. In summary, APS‐IgG‐induced NET formation deserves further investigation as a potential novel therapeutic target in obstetrical APS.     

Regulation of myostatin expression is associated with growth and muscle development in commercial broiler and DMC muscle

Myostatin is a negative regulator of skeletal muscle growth. Muscle tissue is the largest tissue in the body and influences body growth. Commercial Avian broiler chickens are selected for high growth rate and muscularity. Daweishan mini chickens are a slow growing small-sized chicken breed. We investigated the relations between muscle (breast and leg) myostatin mRNA expression and body and muscle growth. Twenty chickens per breed were slaughtered at 0, 30, 60, 90, 120, and 150 days of age. Body and muscle weights were higher at all times in Avian chickens. Breast muscle myostatin expression was higher in Avian chickens than in Daweishan mini chickens at day 30. Myostatin expression peaked at day 60 in Daweishan mini chickens and expression remained higher in breast muscle. Daweishan mini chickens myostatin expression correlated positively with carcass weight, breast and leg muscle weight from day 0 to 60, and correlated negatively with body weight from day 90 to 150, while myostatin expression in Avian chickens was negatively correlated with carcass and muscle weight from day 90 to 150. The results suggest that myostatin expression is related to regulation of body growth and muscle development, with two different regulatory mechanisms that switch between days 30 and 60.     

Heat-inactivated C. pneumoniae organisms are not atherogenic

We have previously shown that infection with Chlamydia pneumoniae can significantly exacerbate atherosclerotic lesions in LDLR-/- mice concurrently fed a high cholesterol diet in 6 or 9 months. We now report that a period of 4 month was sufficient for demonstrating the C. pneumoniae atherogenicity. However, heat inactivation of C. pneumoniae organisms completely abolished the ability of C. pneumoniae to exacerbate the atherosclerotic lesions, suggesting that viable organism infection may be required for the C. pneumoniae atherogenicity.     

Hepatoprotective effect of Herpetospermum caudigerum Wall. on carbon tetrachloride‐induced hepatic fibrosis in rats

Tibetan medicine Herpetospermum caudigerum Wall. (HCW) has long been employed to treat hepatitis, inflammatory diseases and jaundice according to the records of “The Four Medical Tantras” in China. This study was investigated to explore the protective effects of HCW on hepatic fibrosis and the possible mechanism in a rat model. Hepatic fibrosis was established by intragastric administration of 3 ml/kg carbon tetrachloride (CCl₄) twice a week for 6 weeks. CCl₄‐treated rats were received HCW (1 and 3 g/kg/d) and silymarin (0.1 g/kg/d) from 3 to 6 weeks. The results showed that HCW could significantly decrease the levels of AST, ALT, HA, LN, PCIII, Col IV, TNF‐α, IL‐1β and IL‐6. Moreover, HCW could effectively inhibit collagen deposition and reduce the pathological damage. Analysis experiments finally exhibited that HCW was able to markedly inhibit hepatic fibrosis by modulating the expressions of NF‐κB p65, IκBα, Samd3 and TGF‐β1 proteins. Therefore, our results suggest that HCW has hepatoprotective activity against CCl₄‐induced hepatic fibrosis in rats by regulating the inflammatory responses.