A rapid MTT colorimetric assay to assess the proliferative index of two Indian strains of Theileria annulata

A study was undertaken to compare the proliferative index of macroschizont-infected lymphoblastoid cells of two Indian strains [Izatnagar (IZT) and Parbhani (PBN)] of Theileria annulata by an in vitro MTT [3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide], colorimetric assay. Culture conditions were standardized to define the optimal cell concentration in 96-well microculture plates to yield nearly 100% living cells for measurement of the metabolized formazan activity. A cell concentration of 1.5x10(5) cells/ml was found to be optimal for effective discrimination of the parasite strains. On the basis of conversion of MTT by the actively proliferating lymphoblastoid cells, the PBN strain of T. annulata stimulated a 2.5-fold increase in formazan activity in comparison to the IZT strain. The in vitro MTT assay was found to be a simple and convenient method for assessing the cell activation rate and growth, obviating the need for radioactive material for the assay. The results of the proliferation assay are discussed in relation to previously documented information on the biological characteristics of this important pathogen of cattle.     

检测南方水稻黑条矮缩病毒胶体金免疫试纸条的建立

由白背飞虱Sogatella furcifera(Horváth)传播的南方水稻黑条矮缩病毒(Southern rice blackstreaked dwarf virus,SRBSDV)是目前我国南方水稻上危害最严重的病毒,为开发简便、快速、准确的SRBSDV病毒检测技术和检测试剂,以感染SRBSDV的植物粗提液为免疫原,利用杂交瘤技术制备了2株抗SRBSDV的单抗(14A8和15G6),并利用制备的单抗建立了可快速、特异、灵敏地检测SRBSDV的胶体金免疫试纸条。结果表明,2株制备单抗的抗体类型及亚类均为Ig G1、kappa链,单抗腹水的间接ELISA效价均达到10~(-7);Western blot分析表明,2株单抗均与SRBSDV的外壳蛋白亚基有特异反应,而不与水稻黑条矮缩病毒(Rice black-streaked dwarf virus,RBSDV)反应。以制备14A8和15G6单抗分别为捕获抗体和胶体金标记抗体,开发成能在5 min内准确、特异地检测水稻植物和白背飞虱传毒介体体内SRBSDV的胶体金免疫试纸条;灵敏度分析表明,该检测试纸条的检测水稻病叶的灵敏度达到1∶6 400倍(g/m L),检测单头携毒白背飞虱的灵敏度达到1∶51 200倍(单头/μL)。田间样品检测结果表明,该试纸条的检测结果与RT-PCR的符合率达到100%。建立的SRBSDV胶体金免疫试纸条可对南方水稻黑条矮缩病毒进行快速、特异、灵敏的诊断和检测。     

Potentiation of warfarin toxicity to roof rats (Rattus rattus) by L-histidine and by vitamin K adsorbers

The efficacy of warfarin alone or with various additives was tested against roof rats (Rattus rattus). Warfarin alone at 50 mg kg^?1 of bait killed 37% of the roof rats where-as the additives, L -histidine (40 mg kg^?1 of bait), activated-clay, charcoal and carbon (10 g kg^?1 of bait), tested individually, produced no mortality. However, when warfarin wascombined with each of these additives in turn, only the L -histidine combination resulted in 100% mortality while the other combinations killed 88, 75 and 63% of the test rats respectively. Further trials of paired comparison tests were carried out in order to evaluate the efficacy of the warfarin/L -histidine combination under different environmental conditions. All the rats succumbed to this combination in both cage and rattery conditions when there was no alternative food. Mortality decreased to 60% in cage and 70% in rattery when alternative food was provided alongside the poison bait. Rats tended to die more quickly with the L -histidine combination than with warfarin alone. Field trials also confirmed that this combination was effective in reducing roof rat infestations as shown by the yield of corpses, the post-poison bait intake and post-operational surveillance.     

Responses of buffaloes to heavy working load under tropical conditions

Four male buffaloes of 3 to $\text{3}\text{1}\text{2}$ years were subjected to heavy loads during hot dry conditions for 3 h continuously. Rectal temperature, respiration rate and heart rate increased significantly. The blood pH, P_O2, increased significantly and P_CO2 declined. During work, buffaloes were not able to eliminate heat produced and exhibited such distress symptoms as profuse salivation, frothing, lack of leg co-ordination, excitement and tongue protrusion. The muzzle secretion of buffaloes increased greatly. Even 3 h after discontinuation of work, the physiological reactions had not fully disappeared.     

Interaction between Eimeria uzura infection and aflatoxicosis in Japanese quail (Coturnix coturnix japonica)

The clinical signs and gross lesions caused by Eimeria uzura (10(5) oocysts) in Japanese quail (Coturnix coturnix japonica) exhibited little or no influence in the face of intercurrent dietary aflatoxicosis (1 p.p.m. of aflatoxin B1 from Day 0 to 55). Similarly, no significant differences in the mucosal morphology of the intestine were evident histologically between the two groups of Japanese quail. The nervous signs of ataxia, leg weakness, incoordination of movement, torticollis and terminal opisthotonos were toxin-induced manifestations. In the aflatoxic quail, hypoplastic changes and selective depletion of lymphocytes were more prominent in the bursa of fabricius. Increased relative mean weights of liver, kidney, spleen, crop, proventriculus and gizzard were observed in birds due to aflatoxin sensitivity. The combination of E. uzura infection and aflatoxicosis in Japanese quail may cause significant weight loss, and increased oocyst production and reproductive potential.     

An Electrothermochromic Fabric Prepared by Electrodeposition of Polypyrrole on Single Side

An electrothermochromic fabric triggered by electric voltages was prepared by combining the electric heating feature of conductive polypyrrole (PPy) and the temperature-response color-changing feature of thermochromic inks. PPy was deposited selectively on the carbon-coated side of the sailcloth fabric via electrochemical polymerization. Thermochromic inks were painted on the reverse side with white color. The obtained fabric could be heated to about 48 °C and change its color significantly under an applied voltage of 3 V.