Low-dose lactulose produces a tonic contraction in the human colon

Lactulose (10-20 g day(-1)) is used to treat constipation. At this therapeutic dose, its effects on colonic motility remain unknown. Twenty-two healthy subjects swallowed a probe with an infusion catheter, six perfused catheters and a balloon connected to a barostat. Colonic phasic and tonic motor activity was recorded in fasting state. In group 1, four volunteers ingested 15 g lactulose and motility was recorded for 5 h after entry of lactulose into the caecum; in group 2, motility was recorded during (3 h) and 2 h after intracolonic infusion of isoosmotic and isovolumetric solutions containing sodium chloride alone (n = 9) or with 15 g lactulose (n = 9). In a last group of volunteers, isotopic colonic transit after ingestion of lactulose (10 g,n = 9) was assessed and compared with a control group (n = 17). Ingestion or intracolonic infusion of 15 g lactulose significantly decreased barostat bag volume (maximal decrease: 45 +/- 12% and 35 +/- 9% of basal value respectively). Phasic contractions remained unchanged. Tonic and phasic motility was unchanged by the isotonic and isovolumetric infusion of saline. Ingestion of lactulose significantly accelerated isotopic colonic transit time compared with the control group. We conclude that in healthy humans, 10-15 g ingestion or intracaecal infusion of lactulose produces a prolonged tonic contraction that may be involved in the laxative effect of lactulose.     

油页岩及其矿渣的致突变研究

采用Ames试验、E Coli大肠杆菌突变试验和动物骨髓细胞微核试验对油页岩及其矿渣提取物进行了致突变性鉴定。结果表明油页岩及其矿渣提取物在微核试验中呈阳性反应,而在细菌回变试验中呈阴性反应。     

采用生活垃圾研制烧结砖

该文介绍了用好氧发酵工艺对新鲜生活垃圾进行预处理,用做制砖的原料。制砖工艺采用对辊,双轴搅拌,真空挤出,轮窑烧成等工序,垃圾掺加量为30％～50％,可完全取代内掺材料,节省90％以上的煤炭。     

Polymeric genes MEL8, MEL9 and MEL10 — new members of α-galactosidase gene family in Saccharomyces cerevisiae

Summary We used a combination of genetic hybridization analysis and electrokaryotyping with radioactively labelled MEL1 gene probe hybridization to isolate and identify seven polymeric genes for the fermentation of melibiose in strain CBS 5378 of Saccharomyces cerevisiae (syn. norbensis). Four of the MEL genes, i.e. MEL3, MEL4, MEL6 and MEL7, were allelic to those found in S. cerevisiae strain CBS 4411 (syn. S. oleaginosus) whereas three genes, i.e. MEL8, MEL9 and MEL10 occupied new loci. Electrokaryotyping showed that all seven MEL genes in CBS 5378 were located on different chromosomes. The new MEL8, MEL9 and MEL10 genes were found on chromosomes XV, X/XIV and XII, respectively.     

骨形成蛋白(BMP)复合材料的实验研究

作者利用异种、同种、半脱钙骨基质明胶和羟基磷灰石四种材料植入20只大鼠肌肉内,通过光学显微镜观察比较了各种材料的吸收速度、抗原性和成骨情况。结果表明,异种骨基质明胶在植骨早期有轻度的排斥反应。羟基磷灰石不易被吸收,无诱导成骨作用。同种骨基质明胶适合作为较小骨缺损的骨形成蛋白复合材料,修复较大骨缺损,半脱钙骨基质明胶是较佳的复合材料。     

论网络化时代电视教材的重要性

针对教学实践中重视计算机辅助教学忽视电视教材的倾向，本文通过对网络时代中电视教材的作用和地位的分析，阐述了加强计算机辅助教学的必要性和加强电视教材制作及应用的重要性以及二者间的关系。     

Evaluation of Mechanical Properties of ZY-1 Maxillofacial Prosthetic Materials

Objective Maxillofacial prosthetic materials are used to replace facial parts lost through disease or trauma. Silicone rubbers are the materials of choice. The silicone elastomer A-2186 is a widely used maxillofacial prosthetic material. It is a pourable two-component silicone rubber cured by a platinum catalyst. Used as a prosthetic material, A-2186 has short working time and good mechanical properties. The purpose of this study is to evaluate the physical properties of new prosthetic materials based on addition-type silicone elastomer （ZY-1）, and compared the mechanical properties with those of A-2186, Methods Hardness, tensile strength, ultimate elongation, tear strength and adhesive bonding strength of ZY-1 and A-2186 were compared. Statistical analyses were done using a two-way analysis of variance （ANOVA）. Results The hardness and ultimate elongation of ZY-1 is similar to A-2186. However, tensile strength, tear strength of ZY-1 were higher than those of A-2186. Conclusion ZY-1 addition-type silicone elastomer processed good mechanical properties for use as a maxillofacial prosthetic material.     

中西结合治疗椎动脉型颈椎病62例临床观察

1 临床资料 本组62例中,男38例,女24例;年龄最大67岁,最小21岁,平均36岁;病程最长8 a,最短2个月,平均15个月.全部病例均有眩晕症状,常在颈部旋转或屈伸时出现或加重,伴颈枕部不适或疼痛,颈肌僵硬.伴耳鸣32例,伴恶心或呕吐23例,伴上肢麻木感15例.