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Effect of clomipramine on monoamine metabolites in the cerebrospinal fluid of behaviorally normal dogs
2000
Hewson, C. J. | Luescher, U. A. | Parent, J. M. | Ball, R. O.
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.
Show more [+] Less [-]Intestinal parasites of raccoons (Procyon lotor) from southwest British Columbia
2000
Ching, H. L. | Leighton, B. J. | Stephen, C.
This is the first extensive survey of metazoan parasites (particularly of the roundworm Baylisascaris procyonis) from the intestines of raccoons in British Columbia. The sample collected in 1997-1998 consisted of 82 raccoons that had been sick or had been killed accidentally by automobiles. Fifteen parasite taxa were found: 3 nematodes, 9 digenetic trematodes, 2 acanthocephalans and 1 cestode. Ten of these parasites constitute new host records for raccoons, including 4 digenetic trematodes that have been reported in marine birds and mammals on the Pacific Coast of North America. Baylisascaris procyonis infected 61% of the raccoons with a mean intensity of 27. The high rate of infection indicates a large potential for environmental contamination and, thus, human and animal exposure to infectious eggs. Prevention of larva migrans is discussed, particularly for people in contact with raccoons in wildlife rehabilitation centers.
Show more [+] Less [-]Isolation of Pseudomonas aeruginosa from Ushubetsu River water in Hokkaido, Japan
2000
Aoi, Y. (Hokkaido Univ. of Education, Asahikawa (Japan). Asahikawa Branch) | Nakata, H. | Kida, H.
Immunohistochemistry for parathyroid hormone-related protein (PTHrP) in benign and malignant mammary mixed tumors of dogs with and without hypercalcemia
2000
Konno, A. (Hokkaido Univ., Sapporo (Japan)) | Sukegawa, A. | Kusano, M. | Kariya, K. | Ishida, T. | Okada, H.
We evaluated the expression of parathyroid hormone-related protein (PTHrP) by immunohistochemistry in eight benign and malignant mammary mixed tumors of dogs with (n = 4) and without (n = 4) hypercalcemia. Positive immunoreactive staining for PTHrP was observed in all four tumors from hypercalcemic dogs. The mammary tumors from 2 of the 4 normocalcemic dogs stained positively for PTHrP, but the numbers of immunoreactive cells and intensity of the immunoreaction were less than in the hypercalcemic dogs. In the other 2 tumors without hypercalcemia, the tissue samples were negative for PTHrP
Show more [+] Less [-]Accumulation of diacylglycerol induced by CCl4-derived radicals in rat liver membrane and its inhibition with radical trapping reagent: FT-IR spectroscopic and HPLC chromatographic observations
2000
Yoon, S. (Hokkaido Univ., Sapporo (Japan)) | Maruyama, Y. | Kazusaka, A. | Fujita, S.
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
Show more [+] Less [-]Experimental reproduction of itai-itai disease, a chronic cadmium poisoning of humans, in rats and monkeys
2000
Umemura, T. (Hokkaido Univ., Sapporo (Japan))
Indices for nutritional condition and thresholds for winter survival in sika deer in Hokkaido, Japan
2000
Yokoyama, M. (Hokkaido Univ., Sapporo (Japan)) | Uno, H. | Suzuki, M. | Kaji, K. | Ohtaishi, N.
An analysis of the growth based on the size and age distributions of the hawksbill sea turtle inhabiting Cuban waters
2000
Kobayashi, M. (Hokkaido Univ., Sapporo (Japan))
Parasitic forms of a myxosporean in the kidney of the arctic lamprey, Lampetra japonica: An ultrastructural study
2000
Mori, K. (Hokkaido Univ., Sapporo (Japan)) | Takahashi Iwanaga, H. | Iwanaga, T.
Application of FT-IR and ESR spectroscopic techniques to the study of CCl4-induced peroxidation in rat liver microsomes
2000
Yoon, S. (Hokkaido Univ., Sapporo (Japan)) | Maruyama, Y. | Kazusaka, A. | Fujita, S.
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
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