鞣酸蛋白酵母散对幼年大鼠腹泻的治疗作用及其机制研究

目的 研究鞣酸蛋白酵母散的治疗作用及其与保护肠黏膜、促进其修复的关系。方法 将48只21 d SD大鼠随机分为6组：对照组、模型组、蒙脱石散（阳性药,0.8 g/kg）组和鞣酸蛋白酵母散低、中、高剂量（0.1、0.3、0.9 g/kg）组。除对照组外,所有动物用4 g/kg番泻叶水煎剂连续ig 2周后,ig给药,对照组和模型组给予等体积的蒸馏水,每天2次,给药5 d。记录各组大鼠稀便率和腹泻指数。经治疗后,取各组大鼠空肠做苏木精-伊红染色和免疫组化,分别观察肠黏膜组织结构的改变和肠黏膜增殖细胞核抗原（PCNA）表达的变化。同时,刮取大鼠空肠黏膜分别测定DNA、总蛋白和IL-6的表达水平。结果 与模型组比较,经高剂量的鞣酸蛋白酵母散治疗后,大鼠稀便率和腹泻指数显著降低（P<0.001）,空肠绒毛结构基本恢复正常,空肠黏膜DNA含量显著增加（P<0.05）,PCNA表达显著增加（P<0.001）,IL-6表达减少。中剂量的鞣酸蛋白酵母散可改善大鼠腹泻,但对其他指标没有显著影响。而低剂量的鞣酸蛋白酵母散则无作用。结论 鞣酸蛋白酵母散对幼年大鼠腹泻有治疗作用,并可促进肠黏膜修复。     

Synthesis and characterization of high‐purity N,N‐dimethyltryptamine hemifumarate for human clinical trials

Since 2006, there has been a resurgent interest in the pharmacology and therapeutics of psychedelic drugs. Psilocybin, the 4‐phosphoryl ester of N,N‐dimethyltryptamine (DMT), has been studied most often, but DMT itself is also appealing because of its brief but profound psychological effects and its presence as an endogenous substance in mammalian brain. Although there have been a few studies of ayahuasca, a DMT‐containing water infusion, only one human study with pure DMT has been reported since the early 2000s. Newly planned clinical trials to assess the safety and efficacy of DMT in humans with major depressive disorders require high‐purity water‐soluble DMT for intravenous administration. Accordingly, we synthesized and characterized DMT hemifumarate for these upcoming studies. The synthetic approach of Speeter and Anthony was slightly modified to gain some efficiency in time. In particular, this is the first known report to use aluminum hydride, generated in situ from lithium aluminum hydride, to reduce the intermediate 2‐(1H‐indol‐3‐yl)‐N,N‐dimethyl‐2‐oxoacetamide to DMT. A quench protocol was developed to produce a good yield of exceptionally pure free base DMT upon workup, which was then converted to the hemifumarate salt. Analysis of the final product included differential scanning calorimetry, thermogravimetric analysis, gas chromatography–mass spectrometry (GC–MS), ¹H and ¹³C nuclear magnetic resonance spectroscopy, high‐performance liquid chromatography, residual solvent analysis by GC headspace sampling, X‐ray powder diffraction analysis, and residual lithium analysis by inductively coupled plasma‐mass spectrometry. The DMT hemifumarate was minimally 99.9% pure, with no significant impurities or residual solvents, thus meeting regulatory standards for administration to humans.     

Three dimensionally printed pearl powder/poly-caprolactone composite scaffolds for bone regeneration**

Abstract

Pearl has great potential as a natural biomaterial for bone tissue engineering, but it suffers from low porosity, difficulty in molding, and poor anti-buckling property. In this study, we used the 3-D printing technique to fabricate original pearl powder and PCL composite scaffolds with different concentrations of pearl powder. The four groups of scaffolds were termed PCL, 30% Pearl/PCL, 50% Pearl/PCL and 80% Pearl/PCL scaffolds according to the proportion of pearl powder. The samples were systematically investigated by scanning electron microscopy (SEM), wide-angle XRD, liquid substitution, Zwick static materials testing, and energy dispersive X-ray analysis. Biological characterization included SEM, fluorescent staining using calcein-AM, cell counting kit-8 assay, alkaline phosphatase and qRT-PCR analysis. The results show that the pore size and the pore morphology of the scaffolds are closely controlled via 3-D printing. This is very beneficial for tissue growth and nutrition transmission. The regular and uniform square macropore structure ensured that the pearl powder/PCL scaffolds had favorable mechanical strength. As the concentration of pearl powder in the scaffolds increase, the compressive strength and apatite formation increase as well as cell adhesion, proliferation, and osteogenic differentiation. These results show that pearl powder/PCL scaffolds fit the requirements of bone tissue engineering. The structures as well as physicochemical and biological properties of pearl powder/PCL composite scaffolds are positively associated with pearl powder concentrations.     

Development of ELISA for melamine detection in milk powder

A sensitive ELISA method was developed based on a monoclonal antibody to detect melamine in milk powder. Two haptens were prepared using the melamine structural analogue, 2-chloro-4, 6-diamino-1, 3, 5-triazine. The obtained antibody belonged to the IgG1κ family and had high affinity for melamine (affinity constant was 3.09×10⁹). The antibody could also recognise cyromazine (cross-reactivity was 131%) and had low cross-reactivity toward the haptens. The effects of pH, ionic strength and organic solvents on ELISA performance were evaluated. The lowest IC₅₀ value (6.0±0.55 ng/mL) and the limit of detection in milk powder, 50 ng/g, were achieved under optimised conditions. Milk powder spiked at two levels of melamine (100 ng/g and 500 ng/g) was analysed with this ELISA method. Good recovery was obtained (76.2±7.3% at the 100 ng/g spiked level and 91.4±5.0% at 500 ng/g).     

冻干驴乳粉中的矿物元素含量测定分析

按国标法对冻干驴乳粉中11种矿物元素含量进行测定,结果表明:驴乳粉含人体必需的常量和微量矿物元素,其中钙819 mg/100g、磷604 mg/100g、钾672 mg/100g、钠183 mg/100g、镁86 mg/100g、氯547 mg/100 g,钙磷比值1.36,钠钾比值0.27,同时还含有铁、锌、锰、铜、硒等。     

注射用华蟾素对大鼠心率及心电图的影响

目的观察注射用华蟾素对大鼠心率及心电图的影响,为该药在临床应用时监控心脏的不良反应提供实验依据。 方法大鼠经颈外静脉插管后恒速蠕动泵给药,标准肢体Ⅱ导联监测大鼠的心率及心电图;比较给药前后心率及心电图的变化。 结果静脉注射华蟾素注射液与注射用华蟾素中、大剂量30 min后均可使大鼠心率加快,分别为:(469±40),(466±29) 和(484±40)次·min-1,与空白对照组[(411±17)次·min-1]比较,差异有统计学意义(P＜0.05),但随后恢复正常。少数大鼠可偶致心律失常(期前收缩、传导阻滞等),且相比于空白对照组[P-R间期:(46.90±3.90) ms,Q-T间期:(61.29±9.46) ms],给药后能明显缩短心电图的P-R间期[华蟾素注射液组(39.70±2.54) ms,注射用华蟾素中剂量组(37.70±3.77) ms,注射用华蟾素大剂量组(39.30±7.12) ms]和Q-T间期[注射用华蟾素中剂量组(55.13±4.67) ms,注射用华蟾素大剂量组(51.75±11.53) ms](P＜0.05),而对QRS与S-T段无明显改变。 结论注射用华蟾素对大鼠心脏有一定的毒副作用,可引起心率加快,偶发心律失常。     

双歧三联活菌联合蒙脱石散治疗小儿急性腹泻疗效观察

目的：探讨双歧三联活菌联合蒙脱石散治疗急性腹泻对患儿排便次数及症状改善的影响。方法选择2012年8月至2013年8月在我院接受治疗的急性腹泻患儿132例作为研究对象。根据随机数表法将患儿分成观察组和对照组各66例。对照组患儿给予蒙脱石散治疗,观察组在此基础上采用双歧三联活菌进行治疗。比较两组患儿治疗前后的腹泻排便次数、疗效以及症状改善情况。结果观察组患儿治疗后5d的腹泻排便次数明显少于对照组,差异有统计学意义(P<0.05);观察组患儿的显效率和总有效率分别为65.15%,98.48%,均明显高于对照组的45.45%,86.36%,差异均有统计学意义(P<0.05);观察组患儿的腹痛消失时间、呕吐消失时间、退热时间及大便常规的正常时间均少于对照组,差异均有显著统计学意义(P<0.01)。结论双歧三联活菌与蒙脱石散联合治疗小儿急性腹泻可明显减少患儿排便次数,改善其临床症状,疗效明显,值得临床上推广应用。     

Fundamental Improvement of Creep Resistance of New-Generation Nano-Oxide Strengthened Alloys via Hot Rotary Swaging Consolidation

New-generation oxide dispersion-strengthened (ODS) alloys with a high volume fraction of nano-oxides of 5% are intended to become the leading creep- and oxidation-resistant alloys for applications at 1100–1300 °C. Hot consolidation of mechanically alloyed powders by intensive plastic deformation followed by heat treatment of the alloys are the key aspects for achieving top creep properties, typically ensured by a coarse-grained microstructure strengthened with homogeneously dispersed, very stable yttrium nano-oxides. The rotary swaging method proves to be favourable for hot consolidation of the new-generation ODS alloy presented. Compared to specimens consolidated by hot rolling, consolidation by hot rotary swaging predetermines the formation of coarse grains with a very high aspect ratio during subsequent secondary recrystallization. Such a grain morphology increases the creep strength of the new-generation ODS alloy considerably.