Metformin may produce antidepressant effects through improvement of cognitive function among depressed patients with diabetes mellitus

Diabetes mellitus and depressive disorders are both common chronic diseases that increase functional disability and social burden. Cognitive impairment is a potentially debilitating feature of depression. Previous evidence indicates that the antidiabetic drug metformin could be suitable for diabetic patients with cognitive impairment. However, there is no direct evidence from clinical studies that metformin treatment improves cognitive function in diabetic patients suffering from depression. In the present study, 58 participants diagnosed with depression and type 2 diabetes mellitus (T2DM) were recruited and divided into two groups, one treated with metformin and the other treated with placebo for 24 weeks. Cognitive function, depressive behaviour and diabetes improvement were evaluated. Chronic treatment with metformin for 24 weeks improved cognitive performance, as assessed by the Wechsler Memory Scale–Revised, in depressed patients with T2DM. In addition, metformin significantly improved depressive performance and changed the glucose metabolism in depressed patients with diabetes. Depressive symptoms were negatively correlated with cognitive performance in metformin‐treated participants. Furthermore, associations were observed between the parameters of blood glucose metabolism and the depression phenotype. These findings suggest that chronic treatment with metformin has antidepressant behavioural effects and that improved cognitive function is involved in the therapeutic outcome of metformin. The results of the present study also raise the possibility that supplementary administration of antidiabetic medications may enhance the recovery of depression, comorbid with T2DM, through improvements in cognitive performance.     

Toll‐like receptor‐4 signalling in the progression of non‐alcoholic fatty liver disease induced by high‐fat and high‐fructose diet in mice

The aim of the present study was to investigate Toll‐like receptor‐4 (TLR4) signalling at different stages of non‐alcoholic fatty liver disease (NAFLD) induced by a high‐fat, high‐fructose (HFHFr) diet in mice. Both TLR4 wild‐type (WT) and mutant (TLR4^mut) mice were fed either standard chow (SC) or the HFHFr diet for different periods of time from 4 to 16 weeks. Pathological characteristics and function of the liver were assessed. Simple steatosis, steatohepatitis and hepatic fibrosis occurred sequentially in Week 4, 8 and 16 in WT mice fed with the HFHFr. Expression of TLR4, myeloid differentiation factor 88 (MyD88), interferon regulatory factor (IRF) 3 and IRF7 started to increase at Week 4, peaked at Week 8 and then declined to basal levels at Week 16. This pattern was consistent with changes in inflammation in the liver revealed by haematoxylin and eosin staining. However, lipid accumulation, inflammation and fibrosis in livers of TLR4^mut mice fed the HFHFr diet were significantly alleviated. In addition, the expression of activin A in WT mice fed the HFHFr diet increased at Week 16. The data suggest that TLR4 signalling mediates non‐alcoholic steatohepatitis before fibrosis and that activin A is subsequently involved in NAFLD.     

KCNJ11 E23K variant is associated with the therapeutic effect of sulphonylureas in Chinese type 2 diabetic patients

The aim of the present study was to investigate the effect of the E23K variant of the potassium inwardly rectifying channel, subfamily J, member 11 (KCNJ11) gene on gliclazide modified release (MR) treatment in newly diagnosed patients with type 2 diabetes mellitus (T2DM). A total of 108 diabetic patients with no history of antidiabetic medication was treated with gliclazide MR for 16 weeks and underwent follow up at Weeks 2, 4, 8, 12 and 16. All patients were genotyped for KCNJ11 E23K (rs5219). At baseline, patients with the KK genotype had higher blood glucose and lower serum insulin levels after oral glucose administration than patients with the EE and EK genotypes (P < 0.05 for all). During treatment, individuals with the KK genotype had lower fasting glucose levels and were more likely to attain the target fasting glucose level (P_{log rank} = 0.028) than E allele carriers. Patients with the KK genotype had larger augmentations in changes (Δ) in acute insulin response (P = 0.049) and Δ body mass index (P = 0.003). Moreover, patients with the EK genotype had a lower variance in changes in fasting insulin levels (P = 0.049) and homeostasis model assessment of β‐cell function (P = 0.021) than those with the KK genotype. The findings of the present study suggest that the KCNJ11 E23K variant is associated with a greater effect of sulphonylurea treatment in newly diagnosed Chinese patients with T2DM.     

The protective effect of autophagy on mouse spermatocyte derived cells exposure to 1800 MHz radiofrequency electromagnetic radiation

The increasing exposure to radiofrequency (RF) radiation emitted from mobile phone use has raised public concern regarding the biological effects of RF exposure on the male reproductive system. Autophagy contributes to maintaining intracellular homeostasis under environmental stress. To clarify whether RF exposure could induce autophagy in the spermatocyte, mouse spermatocyte-derived cells (GC-2) were exposed to 1800 MHz Global System for Mobile Communication (GSM) signals in GSM-Talk mode at specific absorption rate (SAR) values of 1 w/kg, 2 w/kg or 4 w/kg for 24 h, respectively. The results indicated that the expression of LC3-II increased in a dose- and time-dependent manner with RF exposure, and showed a significant change at the SAR value of 4 w/kg. The autophagosome formation and the occurrence of autophagy were further confirmed by GFP-LC3 transient transfection assay and transmission electron microscopy (TEM) analysis. Furthermore, the conversion of LC3-I to LC3-II was enhanced by co-treatment with Chloroquine (CQ), indicating autophagic flux could be enhanced by RF exposure. Intracellular ROS levels significantly increased in a dose- and time-dependent manner after cells were exposed to RF. Pretreatment with anti-oxidative NAC obviously decreased the conversion of LC3-I to LC3-II and attenuated the degradation of p62 induced by RF exposure. Meanwhile, phosphorylated extracellular-signal-regulated kinase (ERK) significantly increased after RF exposure at the SAR value of 2 w/kg and 4 w/kg. Moreover, we observed that RF exposure did not increase the percentage of apoptotic cells, but inhibition of autophagy could increase the percentage of apoptotic cells. These findings suggested that autophagy flux could be enhanced by 1800 MHz GSM exposure (4 w/kg), which is mediated by ROS generation. Autophagy may play an important role in preventing cells from apoptotic cell death under RF exposure stress.     

The Development of Drug-Free Therapy for Prevention of Dental Caries

Purpose

The purpose of this study was to develop a novel, drug-free therapy that can reduce the over-accumulation of cariogenic bacteria on dental surfaces.

Methods

We designed and synthesized a polyethylene glycol (PEG)-based hydrophilic copolymer functionalized with a pyrophosphate (PPi) tooth-binding anchor using “click” chemistry. The polymer was then evaluated for hydroxyapatite (HA) binding kinetics and capability of reducing bacteria adhesion to artificial tooth surface.

Results

The PPi-PEG copolymer can effectively inhibit salivary protein adsorption after rapid binding to an artificial tooth surface. As a result, the in vitro S. mutans adhesion study showed that the PPi-PEG copolymer can inhibit saliva protein-promoted S. mutans adhesion through the creation of a neutral, hydrophilic layer on the artificial tooth surface.

Conclusions

The results suggested the potential application of a PPi-PEG copolymer as a drug-free alternative to current antimicrobial therapy for caries prevention.     

循证护理对小儿腹股沟嵌顿疝术后并发症的预防研究

目的探讨循证护理预防小儿腹股沟嵌顿疝术后并发症的临床效果。方法选取2013年4月至2014年3月在我院行手术治疗的的腹股沟嵌顿疝患儿76例作为研究对象,并随机分为两组各38例。对照组患儿实施常规护理,实验组患儿进行循证护理,比较两组患儿的疼痛程度及其他并发症情况。结果 1两组轻度疼痛和重度疼痛发生率比较,实验组显著优于对照组,差异具有统计学意义(P<0.05)。2实验组术后切口感染发生率显著低于对照组(P<0.05),但组间阴囊水肿和切口渗血的发生率差异无统计学意义(P>0.05)。结论循证护理可有效预防小儿腹股沟嵌顿疝的术后并发症,值得在临床上推广。     

左氧氟沙星对铜绿假单胞菌密度感应系统及毒力因子的调控

目的：评价铜绿假单胞菌在亚抑制浓度（ SIC）的左氧氟沙星作用下毒力因子表型及基因表达的变化并探索其可能的调控途径。方法用临床标准菌株PAO1及其密度感应系统（ QS）的基因突变株,测定不同浓度下菌株生长曲线,以不影响细菌生长的最高抗菌素浓度为亚抑制浓度。分别测定各菌株在SIC的抗菌素作用下生物膜形成、绿脓菌素和鼠李糖脂的变化。用实时定量聚合酶链式反应（ RT－PCR）测定菌株毒力蛋白编码基因以及QS基因在SIC的左氧氟沙星作用下表达的变化。用生物发光法测定QS信号分子在SIC的抗菌素作用下的变化。结果在SIC的左氧氟沙星作用下,PAO1的毒力因子编码基因和QS调控基因（lasR、rhlR）表达均显著增加,PAO1野生株的毒力因子也增加,但lasR、rhlR突变株无此变化,同时QS信号分子水平也无显著变化。结论亚抑制浓度的左氧氟沙星促进铜绿假单胞菌毒力因子的产生,这一效应是通过lasR和rhlR调节实现的,但这一调控作用可能并不是直接通过AHL信号分子完成。     

产黄青霉简单高效遗传转化法——电激转化法

目的 研究产黄青霉(P.chrysogenum)电激转化方法,建立产黄青霉快速、高效的遗传转化方法.方法 应用美国Bio-Rad电转仪,将外源DNA转化入产黄青霉菌丝中,研究了菌丝培养时间、电场强度、DNA类型等对遗传转化的影响.结果菌丝培养24h,处于旺盛生长阶段,电场强度为6000V/cm,电阻200Ω,电容20μF,环状质粒DNA较线状能获得转化效率稍高,1μg DNA获得的克隆数可达500个.结论 应用电激转化方法对产黄青霉进行遗传转化属首次报道,特别是可直接将目的片段与T-DNA相融合,转化入产黄青霉中,该方法操作简单,快速高效.     

建立医疗器械产品分类界定工作新模式的探索与实践

目的使医疗器械企业和监管部门更全面地了解分类界定工作程序和相关要求,做好分类界定工作。方法分析以往分类界定工作中的主要问题,解析新的分类界定工作流程、申报材料要求以及申请途径,并重点介绍《医疗器械分类规则》修订等基础性工作的研究进展。结果与结论建立完善科学的分类界定工作模式,将有效提高分类界定工作的效率和质量。