Two agar gel immunodiffusion (AGID) kits for the serodiagnosis of bovine leukemia virus (BLV) were imported from Europe and were compared with North American kits. The BLV AGID kits from North America and from Europe differed significantly. The punches were different, as were the pattern distribution in the agar of the reference and the test sera, resulting in differences in the reading of the immunoprecipitation lines. Based on the testing of 1200 serum samples from cattle, the European kits gave a good correlation with the American kits, as indicated by their respective kappa values. However, the European kits were found to be less sensitive when evaluated against weakly positive samples from field specimens or following a dilution trial. Only 65% and 50% of the weakly positive samples detected by the American kit #1 were detected by the European kits #2 and #3, respectively. The American kit was also capable of detecting BLV antibodies in 45% of strongly positive samples diluted 1/50 in negative sera, while antibodies were detected in only 15% of the samples with the European kit #2 and in none of the samples with the European kit #3. False negatives were also detected with the European kits. Among the false negatives, the degree of expected reactions was weak (European kit #2) or of varying degrees of positivity (European kit #3). Besides the differences in format and performance, the BLV-AGID kits in Europe are evaluated with the National Standard Serum E4 while a proficiency panel composed of a quadruplicate set of 10 reference sera is used in Canada to monitor the kits. Based on the overall observations, we noted a lack of standardization between the BLV-AGID kits used in North America and in Europe.

Four calves were exposed via aerosol to 1 of 2 strains of foot-and-mouth disease virus. Two animals received virus derived from an infectious clone virus (A12-IC) and 2 received virus derived from the same clone but which lacked the leader coding region (A12-LLV2) that codes for a protein responsible for turning off host protein synthesis. Animals were euthanized at 24 and 72 h post exposure. Cattle receiving A12-IC had a rapid course of disease with more virus in tissues while A12-LLV2-infected cattle did not develop clinical signs of disease. Formalin-fixed, paraffin-embedded tissue sections were probed with digoxigenin-labeled riboprobes corresponding to the coding sequence for bovine interferon (IFN) alpha and IFNbeta. Staining for IFNalpha mRNA was noted in mononuclear cells of the lungs of all animals and in respiratory lymph nodes of cattle receiving A12-IC. Staining for IFNbeta mRNA was confined to bronchiolar epithelium and present only in the animals infected with A12-IC. Inability of the A12-LLV2 virus to achieve levels of spread seen with A12-IC may be related to translation of IFNalpha in A12-LLV2-infected cells, which renders adjacent cells less susceptible to productive infection.

Blood glycated hemoglobin concentration reflects long-term serum glucose levels in dogs. In this study, the effects of several diseases on blood glycated hemoglobin levels have been evaluated. For this study, blood samples were drawn from 93 unhealthy dogs. The animals were distributed into 10 groups according to pathological process (group 1, digestive problems; group 2, leishmaniasis; group 3, anemia; group 4, dermatological disorders; group 5, urinary problems; group 6, cardiorespiratory problems; group 7, diabetes mellitus; group 8, insulinoma; group 9, general diseases; group 10, control group). Blood glucose and glycated hemoglobin concentrations and hemoglobin and hematocrit values were analyzed in all the animals. In diabetic dogs, a strong increase in blood glycated hemoglobin was observed when compared with the other groups (P < 0.01). In contrast, dogs with insulinoma showed a decrease in blood glycated hemoglobin, though significant differences were not reported in all cases. No change in blood glycated hemoglobin concentrations were reported in dogs affected by other diseases. So, we can suppose that only the chronic alterations in glucose metabolism (chronic hyper- or hypoglycemia) can induce significant changes on the blood glycated hemoglobin concentrations in dogs.

To provide information on the role of Rho, a GTP-binding protein, in postnatal development of the brain cells, the change in the levels of Rho protein and Rho-related proteins was examined in the brain of mice for two weeks after birth, in parallel with the changes in the activity of marker enzymes for neuronal and glial cells. The activities of acetylcholine esterase and choline acetyltransferase of whole brain homogenate, both of which are neuronal marker enzymes, were progressively increased in an age-dependent manner. The activity of 2',3'-cyclic nucleotide 3'-phosphohydrolase, a glial marker enzyme, increased markedly between one and two weeks after birth. In contrast, the levels of RhoA and RhoB in the membrane fraction were decreased during the postnatal period. The amount of Rho GDP dissociation inhibitor, a regulatory protein for Rho, was unchanged, while those of Rho target proteins, Rock-2 and citron, were gradually increased. Since the inactivation of Rho is known to induce neurite extension and neuronal and glial differentiation in vitro, our results suggest that the Rho signalling pathway plays a regulatory role in the postnatal differentiation of neuronal and glial cells in vivo

We have investigated the accumulation of diacylglycerol (DAG) induced by carbon tetrachloride (CCl4)-derived radicals in the liver of female Sprague-Dawley (SD) rats after intraperitoneally injecting CCl4. DAG is an intracellular activator of protein kinase C (PKC) which regulates cell proliferation and differentiation. The electron spin resonance (ESR) study gave the signal of the PBN-CCl3 adduct in the liver of the rats which were pretreated with PBN, confirming that CCl4 was metabolized into CCl3-radicals with cytochrome P450 enzyme and indicating that PBN could trap them. The blood biochemical assay supported the trapping of the CCl3-radicals; the pretreatment of rats with PBN inhibited the increase in the GOT and GPT values upon exposure to CCl4. The Fourier transform-infrared (FT-IR) study indicated in comparison with the model compounds that the CCl4-injected rats accumulated DAG in addition to phosphatidylcholine, phosphatidylethanolamine and triglyceride (TG) in the lipid membrane fraction of the liver homogenate. DAG was found to be ca. 10-15% of the membrane phospholipids by weight. However, DAG was not found in the lipid of the liver microsomes, suggesting that it is formed only in the cell membrane of liver. Also, neither DAG nor TG was found in the lipid membrane of the rats that were pretreated with PBN followed by an injection of CCl4. The formation of DAG was confirmed by an HPLC study. The activation of PKC was observed in liver homogenate in the rats that were injected with CCl4. On the basis of the above findings, it was concluded that the CCl4-derived radicals stimulate PKC through the accumulation of DAG in the liver membrane of the rats. Furthermore, it was shown that PBN has a protective and therapeutic effect against CCl4-induced damage

FT-IR and ESR were used for on the investigation of the CCl4-induced peroxidation of rat liver microsomes in combination with biochemical methods. Lipid peroxidation was assayed by TBA reagent in the presence of CCl4 and NADPH. The CCl3 - radical was detected by ESR spectroscopy with a spin trapping reagent of PBN. The FT-IR spectroscopy revealed that absorption band of -C-H in -C=C-H decreased in intensity at 3012 cm(-1), but the absorption bands of the phosphate head and choline in the phospholipids did not significantly change between 1300 and 900 cm(-1). These findings were interpreted to be due to the removal of H- from -C=C-H by radicals as the first step of lipid peroxidation, and to the absence of dephosphorylation of phospholipids in the microsomal membrane. This is the first IR spectroscopic evidence indicating the nature of damage to a microsomal membrane caused by CCl4 treatment. The spectroscopies used here demonstrated that they are useful tools to observe the damage