The possibility exists that rabbit hemorrhagic disease virus (RHDV) can be transmitted to swine, through lapinized hog cholera virus (HCV) vaccine. To investigate the infectivity of RHDV in swine, 16 four- to six-week-old piglets were inoculated subcutaneously with RHDV, and samples of liver, lung, spleen, kidney, bile, adrenal gland, tonsil, mesenteric lymph node, thymus, urine, buffy coat, and feces were collected from each of 2 animals on Days 0, 1, 2, 3, 5, 7, 14, and 28 post infection. Using reverse transcription-polymerase chain reaction, viral RNA was detected in most tissues by Day 3 and was absent after Day 5, except in lung and liver tissues, in which viral RNA was detected up to Day 14. Viral RNA was not detected in kidney, urine, feces or bile. Antibody responses, as detected by hemagglutination inhibition, were of low titer and short duration, and were similar in animals inoculated with viable RHD and in those given formalin-inactivated RHDV (n = 2). Neither viral RNA nor antibody were detected in the negative control or in the uninfected, in-contact animals.

The tricyclic antidepressant, clomipramine, is an effective treatment for canine compulsive disorder (canine CD). This disorder is a clinical syndrome of abnormal conflict behaviors and its pathophysiology is unknown. However, because clomipramine is an effective treatment, information about the drug's neurochemical effect could enhance the understanding of canine CD. The following experiment used 6 behaviorally normal dogs to assess the effect of clomipramine (3 mg/kg, q24h, PO) on the central turnover of 3 monoamines (serotonin, dopamine, and norepinephrine) as measured by the concentrations of their respective metabolites in cerebrospinal fluid (CSF). In a randomized, placebo-controlled, AB-BA crossover experiment, cisternal CSF was taken after 1, 2, 4, and 6 wk on each treatment. No effect of clomipramine was detected. This contrasts with human studies that have suggested that clomipramine affects the concentrations of monoamine metabolites in lumbar CSF. However, those papers do not address methodological assumptions, such as (i) metabolites in CSF originate only from the brain, and (ii) concentrations of metabolites in cisternal/lumbar CSF reflect the concentrations in local areas of the brain. Notwithstanding the small sample size, our results suggest that more localized sampling techniques (e.g. microdialysis) are needed when examining the effect of drugs on central monoamine metabolites. Clomipramine's efficacy for canine CD indicates the need for neurobiological research and, to our knowledge, our study is the first of its kind in dogs. The resulting data are preliminary but they can inform optimal neurobiological studies of canine CD.

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

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