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91.
Bacillus thuringiensis is indistinguishable from Bacillus cereus except for the production of insecticidal crystal proteins (ICPs). B. thuringiensis strains may show enterotoxin profiles and toxin levels similar to those of B. cereus strains isolated from food-poisoning cases. It is important for the food industry and farmers to consider that with the application of B. thuringiensis strains to crops, their spores may be introduced into the human food chain. In this study, 59 B. thuringiensis strains were assayed for their hemolysin BL (HBL) using a BCET-RPLA kit and their cytotoxicity to Chinese hamster ovary (CHO) cells. The enterotoxin titer was as high as that of B. cereus diarrheal-type strain ATCC 49064. In an attempt to obtain a food safety strain for bioinsecticide use, in this study, a 3.5-kb cry1Ac DNA fragment was amplified with PCR from the total DNA of B. thuringiensis subsp. kurstaki CCRC 11502 and cloned into the Bacillus expression vector pHY300PLK. The alpha-amylase promoter, amyE, was then introduced into the promoter region and, afterward, the recombinant plasmid pHYe1Ac35 was introduced into a non-enterotoxigenic and non-cytotoxic B. thuringiensis subsp. kurstaki Tt14 strain. The transformant, without any detectable enterotoxigenicity or cytotoxicity, produced Cry1Ac toxin properly, and its insecticidal activity against Trichoplusia ni larvae was found to be satisfactory. 相似文献
92.
To verify the role of porcine reproductive and respiratory syndrome virus (PRRSV) infection on pulmonary defense mechanisms, alterations in the viability, morphology, and various functions of porcine alveolar macrophages (AMs) were evaluated in vitro for 2-72 h after exposure to a Taiwan isolate, tw91, at a multiplicity of infection (MOI) of 0.1. A low but constant rate of infection, around 5%, was seen in AMs from the PRRSV-infected group throughout the study. When compared with a mock-infected group, AMs from the PRRSV-infected group had a significantly lower viability at 18-72 h post-infection (HPI) as determined by trypan blue dye exclusion. Also during this time period, the cells showed morphological changes, including rounding, bleb formation, and rupture. The phagocytic and microbicidal capacity of AMs against Candida albicans was significantly inhibited after 6 HPI. Although the total amount of superoxide anion (O2-) and hydrogen peroxide (H2O2) produced by the AMs was reduced after 18 and 12 HPI, respectively, the amount of production was enhanced in both reactive oxygen species on a per viable cell basis after 12 HPI. In contrast, the level of bioactive tumor necrosis factor alpha (TNF-alpha) secretion, either total or on a per viable cell basis, was markedly reduced soon after PRRSV infection, up to 36 HPI, followed by a rebound thereafter. Prostaglandin E2 (PGE2) production was enhanced, both in total and on a per viable cell basis, in the first 6 h of infection, especially at 2 HPI. However, it became lower than that of the control after 36 HPI. The results indicated that PRRSV infection could cause, directly and/or indirectly, not only death of AMs but also adverse alterations in their morphology and function, although some of the effects seemed to be reversible. Because AMs are crucial to the host against airborne pathogens, PRRSV infection may potentially predispose pigs to secondary pulmonary infections. 相似文献
93.
D. Pang BVSc J. Hethey N. A. Caulkett DVM MVetSc DACVA T. Duke BVetMed DVA DACVA DECVA 《Journal of Veterinary Emergency and Critical Care》2007,17(2):143-148
Objective: To demonstrate correlation and clinical usefulness of the partial pressure of end‐tidal CO2 (ETCO2) measurement by nasal catheter placement in sedated dogs with and without concurrent nasal oxygen administration as a substitute for partial pressure of arterial CO2 (PaCO2). Design: Prospective, cross‐over trial. Setting: University of Saskatchewan veterinary research laboratory. Animals: Six cross‐breed dogs with a mean (±SD) weight of 29.1±4.03 kg. Interventions: All dogs were sedated with 5 μg/kg medetomidine intravenously (IV) and an arterial catheter was placed in a dorsal pedal artery for removal of blood for gas analysis. A nasal catheter was placed in the ventral meatus and connected to a capnometer for ETCO2 measurements in all dogs. Dogs receiving supplemental nasal oxygen had a second nasal catheter placed in the contralateral naris. Measurements and main results: In the group without nasal oxygen supplementation, the ETCO2 measurement underestimated (negative bias) the PaCO2 by ?2.20 mmHg with limits of agreement (95% confidence interval) of ?5.79, 1.39 mmHg. In the group receiving oxygen supplementation, ETCO2 measurement underestimated (negative bias) the PaCO2 by ?2.46 mmHg with limits of agreement (95% confidence interval) of ?8.42, 3.50 mmHg. Conclusions: The results of this study demonstrate that ETCO2 monitoring via a nasal catheter provides a clinically acceptable substitute to arterial blood gas analysis as a means of monitoring ventilation in healthy, sedated dogs. The limits of agreement were within acceptable limits with and without concurrent insufflation of oxygen. 相似文献
94.
2007年7月14日下午17时许,河南省淮阳县冯塘乡罗庄村村民宋某之女在本村附近失踪,其家人及亲戚在多方寻找无果的情况下,于当晚20时报案.
接到报警后,冯塘派出所民警连夜赶往失踪者家中进行调查了解情况.并协助其家人在暴雨中积极寻找失踪者,但一夜无果.7月15日上午8时许,失踪女宋某的尸体在该村西北角树林西边的水沟内被发现,派出所民警随即将这一情况向淮阳县公安局领导及刑警大队报告.局长段业林当即指令全局启动命案侦破预案,同时调动警犬到现场协助破案.…… 相似文献
95.
魔芋葡甘聚糖在环保、医药及食品中的应用 总被引:7,自引:0,他引:7
对魔芋葡甘聚糖的特性及在环保、医药、食品及其他领域中的广阔应用进行了综述,讨论了魔芋葡甘聚糖的环保性能、药理作用、食品加工等方面的应用前景. 相似文献
96.
97.
杆状病毒非必需基因的结构与功能 总被引:1,自引:0,他引:1
本文主要以苜蓿丫纹夜蛾核型多角体病毒(AcMNPV)为例,概述了迄今展报道的杆状病毒非必需基因的结构与功能,为杆状病毒的基因工程研究提供参考。 相似文献
98.
M. Nagai M. Sato H. Nagano H. Pang X. Kong T. Murakami T. Ozawa H. Akashi 《Veterinary microbiology》1998,60(2-4):271-276
Cytopathogenic and non-cytopathogenic bovine viral diarrhea viruses (BVDVs) were isolated from cattle with mucosal disease or persistent infection in Japan. These isolates were compared for antigenic properties by cross-neutralization tests with Japanese reference strains of BVDV belonging to classical type 1. Significantly low cross-reactivity to reference strains was noted, indicating the viruses to possibly represent a new serotype in Japan. Thus, to determine the genotype of the isolates, nucleotide sequences of the 5′ untranslated region were determined and compared with those of previously reported BVDV 1 and 2. The isolates were clearly shown to belong to BVDV 2, not to BVDV 1. 相似文献
99.
从5000余只杂种兔中,按公母比例1∶8选择300余只体重大、产毛量高的个体进行横交固定,经过4个世代的选育,兔只(11月龄)平均体重达5386克,年产毛量1424克,粗毛率11.74%,结块率2.24%,胎产活仔7.26只,料毛比43∶1。种兔外貌特征一致,遗传性能稳定。现有核心群种兔1200只,繁殖群7200只,生产群2.5万余只,向省内外推广繁育28万只,各项生产指标均达到或超过预定标准及全国家兔育种委员会制定的“德系长毛兔种兔鉴定标准”和“粗毛型长毛兔的选育指标”。 相似文献
100.
痣鳞鳃金龟二年发生一代 ,此虫在砂质土壤的林地密度大 ,为害严重。造林时在每株根际施 5g 3 %呋喃丹颗粒剂 ,可有效地控制此虫的危害并兼治其它地下害虫和造林初期的食叶害虫。 相似文献