Toxicology of 3-epi-deoxynivalenol,a deoxynivalenol-transformation product by Devosia mutans 17-2-E-8

Microbial detoxification of deoxynivalenol (DON) represents a new approach to treating DON-contaminated grains. A bacterium Devosia mutans 17-2-E-8 was capable of completely transforming DON into a major product 3-epi-DON and a minor product 3-keto-DON. Evaluation of toxicities of these DON-transformation products is an important part of hazard characterization prior to commercialization of the biotransformation application. Cytotoxicities of the products were demonstrated by two assays: a MTT bioassay assessing cell viability and a BrdU assay assessing DNA synthesis. Compared with DON, the IC₅₀ values of 3-epi-DON and 3-keto-DON were respectively 357 and 3.03 times higher in the MTT bioassay, and were respectively 1181 and 4.54 times higher in the BrdU bioassay. Toxicological effects of 14-day oral exposure of the B6C3F₁ mouse to DON and 3-epi-DON were also investigated. Overall, there were no differences between the control (free of toxin) and the 25 mg/kg bw/day or 100 mg/kg bw/day 3-epi-DON treatments in body and organ weights, hematology and organ histopathology. However, in mice exposed to DON (2 mg/kg bw/day), white blood cell numbers and serum immunoglobulin levels were altered relative to controls, and lesions were observed in adrenals, thymus, stomach, spleen and colon. Taken together, in vitro and in vivo studies indicate that 3-epi-DON is substantially less toxic than DON.     

Heat sensitivity of human parvovirus B19

BACKGROUND AND OBJECTIVES: To date there has been no published report on a systematic evaluation of the heat sensitivity of human parvovirus B19 (B19) and the related safety of the plasma-derived fractionated products. In this study, we examined the heat sensitivity of B19 by using the infectivity assay with cultured cells. MATERIALS AND METHODS: The heat sensitivity of B19 was examined by measuring the reduction in viral infectivity titres after heating liquid containing B19 at 60 degrees C. Viral infectivity was assayed by detection of viral antigens or viral mRNA in infected cells. As a control, canine parvovirus (CPV) was also heat-treated. RESULTS: B19 displayed quite different inactivation kinetics to CPV when both were heated in liquid at 60 degrees C. In sharp contrast to the latter, B19 was rapidly inactivated within 1 h when the virus was suspended in 5% or 25% human serum albumin solution, phosphate-buffered saline, or complete medium. However, B19 appeared to be resistant to heat inactivation in liquid containing 60% sucrose. CONCLUSIONS: The heat sensitivity of B19 in liquid was clearly different from that of CPV. Significantly, the efficiency to inactivate B19 and reduce its infectivity following heating in liquid was mainly affected by the composition of the solutions used for virus suspension.     

In vivo metabolism of the designer anabolic steroid hemapolin in the thoroughbred horse

Hemapolin (2α,3α‐epithio‐17α‐methyl‐5α‐androstan‐17β‐ol) is a designer steroid that is an ingredient in several “dietary” and “nutritional” supplements available online. As an unusual chemical modification to the steroid A‐ring could allow this compound to pass through antidoping screens undetected, the metabolism of hemapolin was investigated by an in vivo equine drug administration study coupled with GC‐MS analysis. Following administration of synthetically prepared hemapolin to a thoroughbred horse, madol (17α‐methyl‐5α‐androst‐2‐en‐17β‐ol), reduced and dihydroxylated madol (17α‐methyl‐5α‐androstane‐2β,3α,17β‐triol), and the isomeric enone metabolites 17β‐hydroxy‐17α‐methyl‐5α‐androst‐3‐en‐2‐one and 17β‐hydroxy‐17α‐methyl‐5α‐androst‐2‐en‐4‐one, were detected and confirmed in equine urine extracts by comparison with a library of synthetically derived reference materials. A number of additional madol derivatives derived from hydroxylation, dihydroxylation, and trihydroxylation were also detected but not fully identified by this approach. A yeast cell‐based androgen receptor bioassay of available reference materials showed that hemapolin and many of the metabolites identified by this study were potent activators of the equine androgen receptor. This study reveals the metabolites resulting from the equine administration of the androgen hemapolin that can be incorporated into routine GC‐MS antidoping screening and confirmation protocols to detect the illicit use of this agent in equine sports.     

Gut microbiome in Schizophrenia: Altered functional pathways related to immune modulation and atherosclerotic risk

Emerging evidence has linked the gut microbiome changes to schizophrenia. However, there has been limited research into the functional pathways by which the gut microbiota contributes to the phenotype of persons with chronic schizophrenia. We characterized the composition and functional potential of the gut microbiota in 48 individuals with chronic schizophrenia and 48 matched (sequencing plate, age, sex, BMI, and antibiotic use) non-psychiatric comparison subjects (NCs) using 16S rRNA sequencing. Patients with schizophrenia demonstrated significant beta-diversity differences in microbial composition and predicted genetic functional potential compared to NCs. Alpha-diversity of taxa and functional pathways were not different between groups. Random forests analyses revealed that the microbiome predicts differentiation of patients with schizophrenia from NCs using taxa (75% accuracy) and functional profiles (67% accuracy for KEGG orthologs, 70% for MetaCyc pathways). We utilized a new compositionally-aware method incorporating reference frames to identify differentially abundant microbes and pathways, which revealed that Lachnospiraceae is associated with schizophrenia. Functional pathways related to trimethylamine-N-oxide reductase and Kdo₂-lipid A biosynthesis were altered in schizophrenia. These metabolic pathways were associated with inflammatory cytokines and risk for coronary heart disease in schizophrenia. Findings suggest potential mechanisms by which the microbiota may impact the pathophysiology of the disease through modulation of functional pathways related to immune signaling/response and lipid and glucose regulation to be further investigated in future studies.     

胰岛素生物检定的快速测定方法的建立

目的:建立胰岛素生物测定的快速检测方法。方法:血糖试纸上的葡萄糖脱氢酶将血液中的葡萄糖转化为葡萄糖酸内脂。这种作用会产生直流电,血糖仪以此判读血糖值。使用血糖仪快速测定小鼠血糖。结果:血糖仪能够快速测定小鼠血糖值,与全自动生化分析仪测定结果高度相关,效价偏差率<5%,结果无显著性差异(P>0.05)。结论:经方法学验证,本法可用于胰岛素生物活性的快速测定。     

不同包装和贮藏条件下酸枣仁的质量比较

目的:确定酸枣仁适合的贮藏条件、包装材料和包装方式,为保障酸枣仁质量提供参考。方法:选用同一批酸枣仁样品,分别采取塑料编织袋包装、塑料袋包装、塑料袋真空包装、铝塑复合袋包装、铝塑复合袋真空包装和牛皮淋膜纸袋包装,贮藏在阴凉库(温度≤20℃、相对湿度为45%~75%)和药品稳定性试验箱[温度为(40±2)℃、相对湿度为(75±5)%]中,以性状及水分、黄曲霉毒素、酸枣仁皂苷A、斯皮诺素含量为考察指标,开展为期6个月的阴凉长期稳定性试验和加速稳定性试验研究。结果:6个月阴凉长期稳定性试验结果显示,不同包装条件下酸枣仁样品的性状以及水分、黄曲霉毒素、酸枣仁皂苷A含量均符合2015年版《中国药典》(一部)(后文简称"药典")酸枣仁项下规定;斯皮诺素含量均不符合药典的规定(不低于0.080%),但其中铝塑复合袋真空包装样品中斯皮诺素含量(0.079%)与药典要求接近。6个月加速稳定性试验结果显示,牛皮淋膜纸袋包装、塑料编织袋包装样品发霉严重,塑料袋包装、塑料袋真空包装样品表面颜色变暗,铝塑复合袋包装样品颜色稍变暗,但铝塑复合袋真空包装样品外观基本无变化;塑料编织袋包装、牛皮淋膜纸袋包装样品中水分含量超过了药典要求最高值(9.0%);仅在贮藏2个月时,编织塑料袋包装样品被检出黄曲霉毒素B1含量为8.64μg/kg,超出药典规定;各包装样品中酸枣仁皂苷A含量虽有下降,但均满足药典要求;仅塑料袋真空包装样品中斯皮诺素含量(0.084%)满足药典要求,其次属铝塑复合袋真空包装样品中含量(0.071%)相对较高。结论:酸枣仁以铝塑复合袋真空包装后置于阴凉干燥处为宜。     

加速康复外科护理在减重代谢手术患者中的效果观察

目的分析在减重代谢手术患者中应用加速康复外科护理理念的临床效果。 方法选择从2015年1月至2018年1月在中山市小榄人民医院减重代谢外科接受手术的91例患者,随机分组研究,42例纳入对照组,采取常规护理,49例纳入观察组,基于快速康复外科护理理念护理,对照分析两组临床效果。 结果从术后观察指标来看,观察组术后肛门排气时间比对照组早,术后下床活动时间比对照组早,进食时间比对照组早,住院时间比对照组短,住院费用比对照组少,P<0.05;从护理满意度来看,观察组高于对照组,P<0.05;从术后并发症发生率来看,观察组低于对照组,P<0.05。 结论加速康复外科护理的应用可以促进减重代谢手术患者术后恢复,减少并发症发生,增加患者对临床护理服务的满意度。     

Larvicidal activity of Persea americana Mill. against Aedes aegypti

ObjectiveTo evaluate the toxicity of the ethanol and hexane extracts of the different parts of Persea americana Mill. (P. americana) toward third and fourth instars larvae of Aedes aegypti (Ae. aegypti) and to characterize the ethanol extract by qualitative phytochemical analysis.MethodsThe seeds, peels and pulp of P. americana were processed for crude extraction using 95% ethanol and n-hexane. Crude extracts were bio-assayed for larvicidal activity against Ae. aegypti following the World Health Organization standard bioassay method. The mortality was observed at 24 h and 48 h after treatment and data were subjected to probit analysis to determine lethal concentrations (LC₅₀ and LC₉₀). The ethanol extract was characterized by phytochemical analysis.ResultsBoth the hexane and ethanol extracts from the different parts of P. americana exhibited evidence of larvicidal toxicity. The hexane extract from the seeds exhibited the highest toxicity with LC₅₀ and LC₉₀ values of 9.82 mg/L and 22.19 mg/L, respectively, while the ethanol seed extract exhibited LC₅₀ of 16.48 mg/L and LC₉₀ 45.77 mg/L, respectively. This was closely followed by the ethanol extract of the peels with an LC₅₀ of 10.35 mg/L and LC₉₀ of 26.29 mg/L. The pulp extracted with ethanol also yielded great larvicidal toxicity with LC₅₀ of 21.32 mg/L and LC₉₀ of 59.45 mg/L. Results of the phytochemical analysis of the ethanol seed extract indicated presence of alkaloids, tannins, saponins, unsaturated steroids and triterpenoids, flavonoids (leucoanthocyanins), fats and oils.ConclusionsBoth the hexane and ethanol extracts of P. americana showed promising potential as an alternative source of a more sustainable, non-toxic and environmentally friendly solution for the control of dengue vector, Ae. aegypti.     

Cyclic fatigue testing of denture teeth for bulk fracture

Objectives

Clinical experience with implant-supported dentures indicates that fracture and chipping of teeth are becoming an issue. Tooth fracture and chipping rates of approximately 2.5% per year are being experienced at one university. There has been no standardized test developed for bulk fracture or chipping of denture teeth. Such a test would aid in the development of improved teeth and in their evaluation.

Methods

Central incisor teeth were embedded in acrylic and loaded on incisal edges at 90° to their long axes. Teeth tested included ones commercially available and two sets made from improved materials designed to increase toughness. Cyclic loading was done at 5 Hz from 20 N to 135 N, 150 N, 175 N and 200 N. Data was analyzed using lifetime analysis software fit at each of the accelerated loads and then extrapolated to clinical use loads (Alta 7, Reliasoft Corp.) Clinical use loads were derived from extrapolation of probability of failure (Pf) data to 2.5% Pf.

Results

When carefully embedded, teeth could be reproducibly loaded to failure by bulk fracture involving a failure mode similar to that seen clinically. Clinical use loads were calculated to be in the range of 70 N. Results from accelerated loading could be fit to similar probability of failure distributions allowing extrapolation to clinical use loads.

Significance

This work was able to develop a clinically valid bulk fracture test for the fatigue failure of incisor denture teeth. It appears that teeth fabricated with improved materials will be expected to perform better clinically. Thus both the null hypotheses were rejected.     

川芎及其中成药抗凝血作用测定方法的研究

目的以延长活化部分凝血活酶时间(APTT)为指标,建立定量测定川芎抗凝血作用的方法,评价川芎及其中成药的质量。方法川芎先后用乙醇和水定量提取,以总提取物为供试品,体外测定延长APTT值。家兔心脏取血,制备血浆,加入APTT试剂后,测定凝结时间。以APTT延长率为抗凝血活性的评价指标,用阿魏酸钠标定川芎的延长APTT活性。根据量反应平行线法(2.2)计算川芎的抗凝血活性。并测定了9份川芎药材、饮片及中成药的抗凝血活性。结果阿魏酸钠和川芎总提取物均具有显著的抗凝血活性,且可靠性检验结果成立。阿魏酸钠的给药质量浓度(1~5 mg/m L)与其APTT延长率呈良好的线性关系(r=0.995 5)。供试品重复测定抗凝血活性的RSD为9.34%(n=6),可信限率为15.98%(n=6)。不同川芎样品的抗凝血活性不同,5份川芎药材的抗凝血效价分别为5.431~7.620 U/g,川芎饮片及川芎酒炙饮片分别为5.910、3.017 U/g,通脉颗粒和血府逐瘀丸分别为14.516、29.035 U/g。结论建立的方法能准确测定川芎药材、饮片及其中成药的抗凝血活性并评价其质量。