坚持理论联系实际原则对生物化学教学改革的指导作用

本文分析了生物化学教学中存在的问题,提出必须坚持理论联系实际原则,全面改革生物化学教学.具体措施为:明确生物化学教学目标,合理安排教学内容;密切联系实际,激发学生学习兴趣,提高课堂教学效果;优化实验教学内容,开展创新实践,培养学生实践能力和创新意识;建立多元化考试方式,改革考试内容,注重实际应用能力.最后,对生物化学教学改革的实践效果进行了分析.     

HbA1c 血脂 UMA 对糖尿病肾病的影响分析

目的：探讨糖化血红蛋白（HbA1c）、血脂、尿微量白蛋白（UMA）对糖尿病肾病的影响。方法收集近年我院糖尿病的患者,定义为研究组,根据研究组 HbA1c 值分为低水平组（HbA1c<10%）、高水平组（HbA1c≥10%）。对照组为同期无高血压、冠心病、糖尿病的健康人群。对比研究组和对照组血脂、HbA1c、UMA水平。低水平组和高水平组血脂、HbA1c、UMA 水平。结果研究组和对照组生化指标和 UMA 水平比较有统计学差异（P<0.05）。低水平组和高水平组生化指标和 UMA 水平比较有统计学差异（P<0.05）。结论糖尿病肾病的发生发展与 HbA1c、血脂水平密切相关,UMA 可灵敏反映糖尿病早期肾脏损害。     

Graded changes in enamel component volumes resulted from a short tooth bleaching procedure

AimTo test the hypothesis that changes in enamel component volumes (mineral, organic, and water volumes, and permeability) are graded from outer to inner enamel after a short bleaching procedure.Materials and methodsExtracted unerupted human third molars had half of their crowns bleached (single bleaching session, 3 × 15 min), and tooth shade changes in bleached parts were analyzed with a spectrophotometer. Ground sections were prepared, component volumes and permeability were quantified at histological points located at varying distances from the enamel surface (n = 10 points/location), representing conditions before and after bleaching.ResultsTooth shade changes were significant (p < 0.001; 95% CI = −1/−8; power = 99%), and most of the enamel layer was unaffected after bleaching, except at the outer layers. Multiple analysis of covariances revealed that most of the variance of the change in enamel composition after bleaching was explained by the combination of the set of types of component volume (in decreasing order of relevance: mineral loss, organic gain, water gain, and decrease in permeability) with the set of distances from the enamel surface (graded from the enamel surface inward) (canonical R² = 0.97; p < 0.0001; power > 99%).ConclusionsChanges in enamel composition after a short bleaching procedure followed a gradient within component volumes (mineral loss > organic gain > water gain > decrease in permeability) and decreased from the enamel surface inward.     

No reduction of metabolic rate in food restricted Caenorhabditis elegans

Dietary restriction (DR) is the most consistent means of extending life span throughout the animal kingdom. Multiple mechanisms by which DR may act have been proposed but none are clearly predominant. We asked whether metabolic rate and stress resistance is altered in Caenorhabditis elegans in response to DR. DR was imposed in two complementary ways: by growing wild-type worms in liquid medium supplemented with reduced concentrations of bacteria and by using eat-2 mutants, which have a feeding defect. Metabolic rate was not reduced when we fed wild-type worms reduced food and was up-regulated in the eat-2 mutants in liquid culture, as assessed by oxygen consumption rate and heat production. The specific activity levels of the antioxidant enzymes superoxide dismutase (SOD) and catalase showed small increases when we reduced food in wild-type worms, but restricted worms acquired no elevated protection against paraquat and hydrogen peroxide. eat-2 mutants showed elevated specific activities of SOD and catalase relative to wild type in liquid culture. These results indicate that the effects imparted by DR and the eat-2 mutation are not identical, and they contradict, at least in C. elegans, the widespread belief that CR acts by lowering the rate of metabolism.     

Normalization of urinary oxalate by taurine in glycolate-fed rats

Oral feeding of sodium glycolate (50 mg/d/rat for ten days) caused a significant (P less than 0.001) increase in oxalate and taurine excretion and a decrease in liver protein content (P less than 0.05), glycolic acid oxidase levels (P less than 0.01), and glycolic acid dehydrogenase levels (P less than 0.01) as compared to normal untreated rats. Taurine (100 mg/d/rat), when administered along with glycolate, prevented these effects of glycolate as evident from normal urinary excretion of oxalate, liver protein content, glycolic acid oxidase, and glycolic acid dehydrogenase levels in glycolate- plus taurine-fed animals.     

Experimental toxicology of formaldehyde

Summary Formaldehyde is a reactive chemical which undergoes spontaneous reactions with various cellular constituents. Mutagenicity data may be interpreted on the background of this behavior. Mice are better able to reduce the irritating effect of formaldehyde than rats and to reduce their ventilation rate when formaldehyde acts on the respiratory tract. Subacute exposure of rats to concentrations higher than 2 ppm inhibits mucociliary clearance of the nasal epithelium and leads to progressive histological and ultrastructural lesions at this site. The occurrence of squamous cell carcinomas of the nasal epithelium of rats after 2 years inhalation of 14.3 ppm formaldehyde (CIIT study) is probably the result of chronic and recurrent local toxicity; this is supported by species differences in susceptibility to the tissue damaging and carcinogenic effect of formaldehyde (rat, mouse, hamster). Data on formaldehyde-DNA interaction further support the argument that a direct risk extrapolation from the formaldehyde effects in rats to those expected for man is not possible.Cancer Research and Clinical Oncology will publish in loose succession Editorials and Guest Editorials on topical and controversial problems in experimental and clinical oncology. These contributions will represent the personal opinion of the author. We would like to ask our readers to send their comments directly to the author.     

Increase of Interstitial Collagen in the Mouse Endometrium During Decidualization

Decidualization in the mouse consists of an extensive remodeling of the endometrial extracellular matrix, resulting in a reduction of the extracellular spaces, an increase in the diameter of collagen fibrils, and changes in the relative ratio of different types of glycosaminoglycans. To assess the dynamic changes of the endometrial extracellular matrix during decidualization, collagen was analyzed biochemically and immunochemically in the endometrium of nulliparous and day 5 to day 8 pregnant mice. The amount of collagen per gram dry weight was higher in the endometrium of implantation sites than in interimplantation sites. Collagen types I, III, and V were the main components of the endometrium of nulliparous and pregnant animals. The amount of collagen type V was higher in the endometrium of pregnant animals than in nulliparous ones. A relative unusual homotrimeric form of collagen type V, probably formed by [ &#102 1(V)] 3 , was detected in pregnant endometrium by gel eletrophoresis and immunoblotting.     

Placenta Hominis Protects Osteoporosis in Ovariectomized Rats

In China, Japan, and Korea, placenta hominis extracts (PHEs) are used clinically for the treatment of osteoporosis. The anti-osteoporotic effect of PHEs was studied. The trabecular bone area and thickness in OVX rats decreased by 50% from those in sham-operated rats; these decreases were completely inhibited by administration of PHEs for 7 weeks. Osteoclast numbers and the osteoblast surface were enhanced in OVX rats, but PHEs had no effect on these phenomena. Serum phosphorus and alkaline phosphatase in OVX rats increased compared to those in sham-operated rats, but the increases were not affected by the administration of PHEs. Thyroxine (T₄) level was stimulated in OVX rats. The extracts inhibited the T₄ level in the OVX rats. These results strongly suggest that PHEs be effective in preventing the development of bone loss induced by OVX in rats.     

基于创客教育2.0的护理本科生创伤现场救护混合式教学实践

目的分析基于创客教育2.0的混合式教学在护理本科生创伤现场救护教学中的实践效果。方法纳入2016级72名护理本科生作为研究对象,用随机数字表法分为试验组(n=36)与对照组(n=36),在急危重症护理学课程创伤现场救护4个学时的教学中,试验组采用基于创客教育2.0的混合式教学,对照组采用传统教学,教学后比较两组创伤现场救护理论与技能成绩,比较试验组教学前后创造力倾向评分。结果教学后,试验组创伤现场救护理论成绩高于对照组(90.46±6.76,78.58±7.83,t=6.890,P<0.001),试验组创伤现场救护技能成绩与对照组成绩差异无统计学意义(74.47±3.29,76.21±4.89,t=1.771,P=0.082);试验组教学后创造力倾向评分高于教学前(106.73±12.30,120.70±8.40,t=7.472,P<0.001)。结论基于创客教育2.0的混合式教学有利于提升护理本科生创伤现场救护的教学效果与学生的创新能力。