A Comparison of Seitz and Millipore Membrane Filters for the Enumeration of Fecal Coliforms

In a comparison of two commonly used membrane filters for enumerating fecal coliform bacteria it was demonstrated that Seitz type M filters recovered statistically more colonies of bacteria than did Millipore HAWG 047S1 filters from pure cultures of Escherichia coli incubated at 44 °C. The membranes were grown on 0.4 % Teepol agar. On incubation at 37°C no significant discrepancy was found. As a reference method was used pour plating in plate count agar (Difco). It was demonstrated that incubation at 44°C did not per se inhibit propagation of fecal coliforms. Both types of filters examined were sterilized by the manufacturers with ethylene oxide. The discrepancy found can therefore not be due to sterilization procedures.     

Fat globule membrane of sow milk as a target for adhesion of K88-positive Escherichia coli

Membrane adhesion of K88-positive Escherichia coli was studied on intestinal brush-border membranes on 237 Finnish Landrace pigs. Forty-one per cent of the brush-border membrane preparations aggregated E. coli (positive adhesion). Similar dualism of adherence/nonadherence was observed on sow milk fat globule membranes. Washed milk fat globules (washed cream) can be used as a convenient source of material for adhesion studies. Bacterial adherence on to milk fat globules is evident as agglutination of the globules (dark-field microscopy). By this procedure the sows can be typed according to their receptor phenotype. This simple principle of fat globule agglutination due to receptors for K88-positive E. coli might be complicated by SigA-mediated bacterial adherence. Fat globule membranes were shown to contain SigA, which may act as a mediator of bacterial adherence onto fat globules. The significance of this adhesive property of milk fat globule might be to provide alternative receptors for E. coli thus preventing bacterial adhesion on to gastro-intestinal epithelium of the offspring. Sow milk fat globules can be used for typing E. coli for membrane adhesiveness. The adhesiveness of the strains showed a good correlation with the presence of the K88 antigen, as well as the hydrophobicity of the bacterial strain as determined by an association on Phenyl-Sepharose beads.     

猪胆囊壁组织用于兔体内组织修复和粘贴止血的实验观察

以猪胆囊壁组织作为生物膜,用ZT胶粘合的方法,修补兔食管壁人造缺损创10例,对兔肝、脾人工致伤断面进行粘贴止血15个样本。结果,前者成功7例,食管壁缺损创得到修复,愈合良好,且无食管狭窄现象;后者15个样本的止血效果都很确实,并对创面起到了保护作用,有利于创面的愈合。     

小梁切除术联合羊膜植入和干扰素α-2b治疗难治性青光眼

目的 :观察小梁切除术联合同种异体羊膜植入和术眼球结膜下注射干扰素 α- 2 b治疗顽固性青光眼的疗效。方法 :对 1 3例 (1 3只眼 )顽固性青光眼行小梁切除术联合羊膜移植于巩膜床 ,分别于术时、术后 1 d、3 d、7d、1 4 d术眼球结膜下注射干扰素α- 2 b 50万单位。术后随访 6～ 1 5个月 ,平均 1 0 .5个月。观察术后阻止瘢痕性滤过泡形成的效果、降眼压作用、手术成功率及视力变化。结果 :1 3只眼中 ,形成功能性滤过泡 1 1只眼 ,无功能滤过泡 2只眼 ,术后 3个月眼压从术前的 (36.42± 5.64) mm Hg降低到 (1 5.73± 2 .99) mm Hg(t=1 1 .465 ,P<0 .0 1 )。术后1 2个月末 ,手术的成功率为 79.8% (寿命表法 )。结论 :小梁切除术联合羊膜植入与干扰素α- 2 b注射能提高成功率 ,且安全、可靠。     

感染柔嫩艾美尔球虫的雏鸡血清蛋白醋膜电泳分析

用E .tenella卵囊感染雏鸡 ,通过醋酸纤维薄膜电泳检测 5种血清蛋白百分含量的变化。分别在感染后 3d和 7d进行采血检测。结果如下 :试验组的白蛋白 (% )在感染后 7d显著低于对照组 (P <0 0 5 ) ;试验组的α1 球蛋白 (% )在感染后 7d比在3d显著下降 (P <0 0 1) ;试验组的γ球蛋白 (% )在感染后 7d极显著高于 3d和对照组 (P <0 0 1)。α2 球蛋白 (% )和β球蛋白(% )在组间和组内无明显差异     

钴离子抑制种子引发对绿豆抗旱性的诱导过程

以陕西农家品种绿豆为材料，研究了钴对种子萌发，种子引发及幼苗生长的影响，结果表：在０．２－１．０ｍｍｏｌｅＬ＾－１浓度范围内，钴离子能够延迟缓豆种子萌发，抑制幼苗生长，这种效应随钴浓度的增加而加大，种子引发能够加快种子萌发，促进幼苗生长，提高细胞膜稳定性，植物对渗透胁迫的适应，在引发过程中，加入２ｍｍｏｌｅＬ＾－１ＣｏＣｌ２能够抑制种子引发对植物抗旱性的诱导作用，但不影响种了萌发，进一步实验表明，     

大豆地膜覆盖——大豆稀、少、覆栽培法研究

我所于1985—1986年在所内外开展了大豆地膜覆盖试验——大豆稀、少、覆栽培法的研究工作。试验分为地膜覆盖和露地直播(对照,参考对照)密植栽培三个处理,供试品种为密枝1号和嫩丰11,三次重复,随机排列。研究结果表明,覆盖栽培,由于提高地温,(0—25cm平均地温比直播增温1.56—3.04℃)提前成熟9—14天。覆膜保墒节水,提高水的利用率,生育期水分生产效率比对照增加53.1—75.0％,对抗御干旱起到了卓有成效的作用。覆膜使土壤微生物数量增加,有利于养分分解,苗期的碱解氮、速效磷分别比直播增加50.0％和14.9％。为大豆生长发育提供了充足的养分。协调大豆生长发育环境中的热量、水分、养分、气体的组合,这些综合因素作用,使大豆生长发育沿着最佳的生物轨道运转。经济产量每公顷达到2630.8—4317.0kg,比露地直播增产62.4—72.7％。     

Cell Membrane Stability in Relation to Drought Tolerance in Wheat Genotypes

Genotyptc differences in wheat were observed in cell membrane with respect to injury caused by osmotic shock created with 40 per cent polyethylene glycol-6000. In general, genotypes with high cell membrane injury also registered much reduction in leaf water potential and osmotic potential. Cell membrane injury measured at 25 days after germination was found to be related with genotypic performance under drought conditions in field. Cell membrane stability measurements of normal plants, even at a very early stage of growth, is reported as criteria for selecting drought tolerant wheat genotypes.