Simultaneous multiwavelength spectrophotometric quantitation of active components in analgesic formulations. Comparative study of three calculation methods

This work deals with the UV spectrophotometric quantitation of a mixture of compounds with overlapped spectra. The mixture spectrum is resolved by use of three computational programs based on different algorithms, namely Multicomponent Analysis (commercial software available from Hewlett-Packard), MULTIC (relying on multiple regression analysis) and SIMPLEX. The results obtained for mixtures of acetylsalicylic acid, acetaminophen and caffeine in commercial analgesic formulations, are compared.     

Cotinine determination by immunoassays may be influenced by other nicotine metabolites

Polyclonal rabbit anticotinine antiserum, which can be used for biomonitoring nicotine uptake by the determination of cotinine in body fluids, was checked by a competitive ELISA for its cross-reactivity with nine nicotine metabolites. The highest percentage of relative crossreactivity (about 30%) was observed with trans-3-hydroxycotinine, a metabolite which is known to be excreted in 3-fold higher amounts than cotinine in the urine of human smokers. Therefore, it is possible that cotinine determinations performed by immunochemical methods — especially in urine — may yield overestimated cotinine concentrations.     

Deacetylation and further metabolism of the mercapturic acid of hexachloro-1,3-butadiene by rat kidney cytosol in vitro

Hexachloro-1,3-butadiene (HCBD) is more nephrotoxic to female than male rats. Metabolism of HCBD involves conjugation with glutathione followed by formation of the cysteine conjugate S-(pentachloro-1,3-butadienyl) cysteine (PCBD-CYS) and then the mercapturic acid N-acetyl-S-pentachloro-1,3-butadienyl-cysteine (PCBD-NAC). PCBD-NAC is also more nephrotoxic to female rats than male rats. The deacetylation of [¹⁴C]-PCBD-NAC to PCBD-CYS and the binding of radiolabelled metabolites to protein has been studied using renal cytosol preparations from male and female rats in vitro, since a sex-related difference in these reactions could explain the difference in nephrotoxicity found in vivo. PCBD-NAC was rapidly metabolised by renal cytosol. The rate of metabolism was similar with either male or female renal cytosol, and the major metabolite identified was PCBD-CYS. N-Acetylation of PCBD-CYS to PCBD-NAC was not detected in the presence of either male or female renal cytosol. Covalent binding of radioactivity from [¹⁴C]-PCBD-NAC to cytosolic protein could be detected after 5 min incubation, and although the extent of binding was similar for both male and female cytosol at early time periods, after 60 min incubation more binding was found in the presence of male cytosol. Covalent binding was largely prevented by aminooxyacetic acid, an inhibitor of cysteine conjugate -lyase, suggesting a role for this enzyme in the activation of HCBD. These results indicate that the sex differences in the nephrotoxicity of HCBD and PCBD-NAC in the rat are not attributable to differences in the rate of deacetylation of PCBD-NAC to give the proximate nephrotoxin PCBD-CYS.This work was supported by a fellowship from the European Science Foundation granted to I. S. P.     

Induction of light hydrocarbon nephropathy by p-dichlorobenzene

In order to clarify the etiology of a dose-related increase in the incidence of tubular cell adenocarcinomas of the kidney in male rats, the nephrotoxicity of p-dichlorobenzene (p-DCB) was investigated in a subchronic study. Groups of ten male and ten female Fischer 344 rats were dosed by gavage with 0 (controls), 75, 150, 300 or 600 mg p-DCB/kg/day in corn oil. Half of the animals were sacrificed after 4 weeks and the remainder after 13 weeks. Increased urinary LDH and epithelial cell excretion and exacerbation of hyaline droplet accumulation in the cytoplasm of renal cortical cells were observed in male rats over the entire dose range investigated. Tubular single cell necrosis, dilated tubules with granular cast formation in the outer zone of the medulla, were evident in male rats after 4 and 13 weeks of treatment with doses of 150–600 mg/kg/day. In female rats there was no indication of a nephrotoxic action of p-DCB. The effects on the kidney, both in their morphological characteristics and the fact that they occur exclusively in male animals, correspond to the light hydrocarbon nephropathy observed as a result of short-term treatment with a number of aliphatic and cyclic hydrocarbons. The development of cortical renal tumors seems to be associated with this kind of kidney damage which is unique to male rats. The literature on this subject generally regards these renal effects as not predictive for man.     

Thiol Reduction of 3′-Azidothymidine to 3′-Aminothymidine: Kinetics and Biomedical Implications

The ability of thiols to reduce 3-azidothymidine (AZT) to 3-aminothymidine has been investigated. Incubation with glutathione, dithiothreitol (DTT), or mercaptoethanol at pH 7.2 and 37°C leads to quantitative reduction of the azido moiety to an amine. The reaction is first order in AZT and first order in reducing agent (mono- or dithiol). The second-order rate constants are 2.77 × 10^–3, 6.55 × 10^–5, and 6.35 × 10^–6 M ^–l sec^–1 for the dithiothreitol, glutathione, and mercaptoethanol reductions, respectively. The thiol reduction of alkyl azide to amine under mild conditions is a synthetic method particularly suitable for water-soluble azido compounds that are sensitive to catalytic hydrogenation. The potential for the mono- or dithiol-mediated reduction of alkyl azides under biological conditions must be considered when conducting studies of azido drugs.     

职业卫生与职业医学开放性实验教学效果评价研究

目的 在预防医学专业本科学生中开展开放性实验,探索实验教学改革方法,提升学生的专业素养和科研能力。方法 针对预防医学专业大四学生,以职业卫生与职业医学实验课程为抓手,进行开放实验教学,然后用问卷调查评估实验效果。2016级预防医学专业学生147人为对照组,开展常规验证性实验;2017级预防医学专业学生176人为试验组,开展开放性实验。从综合考评成绩、教师自评、学生满意度调查3个方面进行评价。采用SPSS 22.0软件进行独立样本t检验、卡方检验。结果 试验组和对照组学生的职业卫生与职业医学期末考试理论成绩是[（84.37±10.45）分 vs. （81.44±9.22）分]（t=2.68,P=0.008）,实验技能成绩是[（93.66±3.89）分 vs. （88.41±5.67）分]（t=9.51,P<0.001）,两组相比,试验组高于对照组,差异有统计学意义。问卷调查显示,试验组学生对于学时安排（χ²=8.31,P=0.004）、小组协作（χ²=21.10,P<0.001）、考核形式（χ²=7.92,P=0.005）、提升科研论文撰写能力（χ²=17.56,P<0.001）、提高实践技能（χ²=11.70,P=0.001）、逻辑思维和语言组织表达能力（χ²=10.33,P=0.001）的满意度更高。学生认为开放实验有助于培养学生创新思维和能力,但是对于就业优势的培养作用有限。学生认为开设专业课的开放性实验具有充分必要性。结论 在预防医学专业学生中开展开放性实验对于学生提升专业素养、增强实践和科研能力是有益的。     

广州地区高校医学生自主学习差异性研究

目的 了解广州地区医学生自主学习情况,分析影响广州地区医学生自主学习的要素,探讨提高医学生自主学习能力的策略。方法 采用自编的《医学生自主学习问卷》对广州市6所高等院校的2 480名医学生进行分层抽样调查。采用SPSS 22.0统计软件对资料进行统计学分析。结果 医学生专业与自主学习频率（χ²=21.33,P<0.001）、性别与自主学习有效性（χ²=4.86,P=0.027）、学年制与自主学习必要性认知（χ²=4.65,P=0.031）、家庭指导与自主学习方法选择能力适宜性的差异有统计学意义（χ²=32.43,P<0.001）。结论 学校、个人和家庭共同影响医学生的自主学习,三方应该相互协作,提高医学生自主学习能力,培育具备终身学习能力的高素质医学人才。     

民族药香青兰化学成分及药理作用研究进展

摘要：目的：对民族药香青兰进行化学成分及药理活性的研究,对该药材的综合应用和深入研究奠定基础。方法：通过查阅1995-2022年知网、PubMed中的中英文文献与相关文献对香青兰进行综述。结果：经过系统的研究,发现香青兰的组成主要包含总黄酮和黄酮苷类、挥发油、三萜类和蛋白质等。这些成分有着多种药理作用,如抗缺氧、抗血栓和降血压。结论：香青兰对于治疗高血压,心脏病等有一定疗效。香青兰在蒙医临床中应用广泛。研究表明,香青兰的化学成分和药理作用已经取得了一定的进展,其作用范围广泛,对心血管疾病有显著的疗效。     

呼吸道真菌感染核酸胶体金试纸条快速检测方法的建立和评价

目的 采用聚合酶链式反应（PCR）技术和胶体金技术建立一种呼吸道真菌感染核酸胶体金试纸条检测方法,并对其检测效果进行评价。 方法 根据GenBank数据库选择真菌内转录间隔区（ITS）基因片段作为靶基因,应用DNAMAN软件对真菌ITS基因片段进行分析,并分别在真菌通用引物5'端用生物素（Biotin）和异硫氰酸荧光素（FITC）进行修饰标记;建立PCR体系,进行体系的最佳条件优化;确定胶体金免疫层析试纸条标记链霉亲和素的最佳标记量和质控线及检测线最佳包被物浓度,组装核酸胶体金试纸条,对试纸条的特异度、灵敏度、重复性和稳定性进行验证。 结果 水煮法提取白假丝酵母菌、新生隐球菌和毛霉菌DNA,浓度为180 μg·L^－1以上,纯度为1.60~2.10;在pH 7.0条件下,每100 μL胶体金溶液中制备胶体金标记链霉亲和素最佳标记量为 3.3 μg,质控线包被Biotin化牛血清白蛋白（BSA-Biotin）浓度为2.00 g·L^－1,检测线包被抗FITC抗体浓度为1.00 g·L^－1。核酸试纸条的特异度与电泳结果一致,仅白假丝酵母菌、新生隐球菌和毛霉菌出现阳性结果,与金黄色葡萄球菌、肺炎链球菌、乙型溶血性链球菌、铜绿假单胞菌、肺炎克雷伯菌、鲍曼不动杆菌和大肠埃希菌等常见呼吸道感染细菌无交叉反应。灵敏度检测,白假丝酵母菌、新生隐球菌和毛霉菌的DNA浓度分别为10^－4、10^－2和10^－3 mg·L^－1时核酸试纸条仍可准确检出,而普通PCR电泳结果显示白假丝酵母菌、新生隐球菌和毛霉菌最低检测浓度分别为0.01、1.00和0.10 mg·L^－1;重复性检测,在不同实验室不同操作人员对核酸试纸条进行验证,结果一致,重复性良好;稳定性检测,核酸试纸条在第6、9和12个月进行检测,结果符合预期,稳定性良好。 结论 本研究建立的呼吸道真菌感染核酸胶体金试纸条可以检测白假丝酵母菌、新生隐球菌和毛霉菌等真菌,特异度和灵敏度均较高,操作简便且快速。     

术前右美托咪定滴鼻对扁桃体腺样体切除术患儿围术期的影响

探讨术前应用右美托咪定滴鼻对扁桃体腺样体切除术患儿围术期呼吸系统不良事件的影响。方法 选取2020年10月—2021年6月徐州医科大学附属医院收治的择期扁桃体腺样体切除术的患儿120例,采用随机数字表法将患儿分为右美托咪定组（D组）和生理盐水组（N组）,每组60例。D组在术前30 min经鼻给予右美托咪定2.0 μg/kg（容量配置1 mL）,N组术前30 min经鼻给予1 mL生理盐水。比较两组围术期呼吸系统不良事件发生率,镇静水平,术后疼痛评分,术后躁动谵妄水平,恶心、呕吐等其他不良事件。结果D组围术期呼吸系统不良事件发生率明显低于N组（P＜0.05）,且镇静水平高于N组（P＜0.05）,D组术后需求补救镇静的人数低于N组（P＜0.05）,D组苏醒期躁动发生率低于N组（P＜0.05）。结论 右美托咪定术前滴鼻可能与降低呼吸系统不良事件的发生率相关,并可取得较为满意的镇静效果,能减轻术后疼痛,降低苏醒期躁动的发生率