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T Masegi

Publications and source records attributed to T Masegi.

98 records · Page 6Linked to original sources
PubMedDate not supplied

Expression of cyclin kinase inhibitor p27(Kip1) in skin tumours of dogs.

Skin tumours (n=148) of epidermal or hair follicle origin were examined immunohistochemically to determine the expression of p27(Kip1)(p27), a cyclin-dependent kinase inhibitor (CDKI), and of Ki-67. In normal skin, a large number of basal cells of the epidermis and hair follicles were positive for Ki-67 and many suprabasal epithelial cells were positive for p27. Most of the hair matrix cells were positive for Ki-67 but negative for p27. Hair papillae were strongly positive for p27. Squamous cell carcinomas had a p27 positive index (PI) significantly lower than that of trichoepitheliomas (P<0.005), basal cell tumours (P<0.05) and intracutaneous cornifying epitheliomas (P<0.001). In contrast, Ki-67 PIs of squamous cell carcinomas and pilomatrixomas were significantly higher than those of trichoepitheliomas, basal cell tumours and intracutaneous cornifying epitheliomas (P<0.01 to P<0.001). No significant difference was observed between the Ki-67 PI values of squamous cell carcinomas and pilomatrixomas. The results suggested that p27 is capable of suppressing cell proliferation in the differentiation of normal canine skin. In spite of being a benign neoplasm, pilomatrixomas had a low p27 expression; this may be a reflection of the proliferative potential of the hair matrix. The expression of p27 may be a useful marker for the analysis of cell kinetics.

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Experimental infection with equine herpesvirus 9 (EHV-9) in cats.

The pathogenicity for cats of EHV-9, a new neurotropic equine herpesvirus, was assessed by intranasal inoculation with 10(6) plaque-forming units. Four cats killed 4, 5, 6 or 10 days after inoculation showed neurological signs consisting of hyper-excitability and aggressiveness, followed by tremors, occasional convulsions, and depression. Histologically, the cats showed severe encephalitis characterized by neuronal degeneration and loss, intranuclear inclusions, perivascular cuffing and gliosis in the cerebrum. A positive immunohistochemical reaction for EHV-9 antigen was seen in degenerating neuronal cells. The lesions extended from the olfactory bulb to the rhinencephalon and hippocampus. All cats had rhinitis, with or without intranuclear inclusion bodies in the nasal mucosa, and interstitial pneumonia. These findings indicate that the cat, like certain other species such as the goat, is susceptible to experimental infection with EHV-9, and may be at risk from natural infection.

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PubMedDate not supplied

Proprioceptive innervation of the masticatory muscles in Pinché.

This study of the masticatory muscles of the primate showed that the temporal muscle contained 107 muscle spindles, 45 in the horizontal portion and 62 in the vertical portion; the masseter muscle contained 70, 58 in the profundus portion and 12 in the superficial portion; the medial pterygoid muscle contained 15; the lateral pterygoid muscle contained 6; and the zygomaticomandibular muscle contained 9. The muscle spindles were located around the coronoid process and mandibular ramus.

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PubMedDate not supplied

Effect of phenobarbital on hepatic gap junctional intercellular communication in rats.

The effects of in vivo exposure to phenobarbital (PB) on hepatic gap junctional intercellular communication (GJIC) and connexin protein expression in Sprague-Dawley rats were examined by in vivolin vitro dye-transfer assay, immunohistochemical staining, and by Western blot analysis. PB (50 mg/kg) was administered orally once a day for up to 6 wk. The average size of the dye spread after injection of Lucifer Yellow decreased at week 1 and remained at the same level until week 6. The area and number of connexin 32 (Cx32) spots per hepatocyte in the central zone of liver lobules decreased from week 1 to week 6, but no change of Cx32 spots in the peripheral zone was observed. The average area and number of connexin 26 (Cx26) spots per hepatocytes showed no clear change through the experimental periods. The decreased level of Cx32 protein in plasma membranes was observed in the PB group. These results suggest that PB, a liver tumor-promoting agent, inhibits hepatic GJIC in vivo in rats and that aberrant Cx32 protein expression and/or localization may be responsible for this effect.

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PubMedDate not supplied

The effect of intralesional bleomycin on canine acanthomatous epulis.

Four dogs with recurrent acanthomatous epulis (AE) were injected with bleomycin (5 mg) intralesionally once a week. In three cases, tumors were clinically indistinguishable within three-to-eight weeks. In the fourth case, the tumor disappeared after 10 weekly injections. Through the administration period of bleomycin, no adverse reactions were recognized in any case. Electron microscopic examination together with a decrease in the percentage of mitotic cells implied that bleomycin might inhibit deoxyribonucleic acid (DNA) synthesis of tumor cells.

Ameloblastoma↗
PubMedDate not supplied

In vitro attenuation of highly virulent infectious bursal disease virus: some characteristics of attenuated strains.

Some strains of highly virulent infectious bursal disease virus (HV-IBDV) were adapted through serial passage in embryonated eggs. The embryonated egg-adapted HV-IBDV was successfully adapted to grow in chicken embryo fibroblast (CEF) cell cultures showing a cytopathic effect by preparing the CEF cells from the virus-infected embryos. The embryonated egg- and cell culture-adapted strains significantly reduced their pathogenicity to, and did not kill any, young chickens in experimental infection. The bursal lesions of the adapted strain-infected chickens were similar to those observed in classical strain-infected chickens. Cross-virus neutralization analysis showed antigenic diversity between the cell culture-adapted HV-IBDV strains and classical strains. In immunization tests, the adapted strain-immunized chickens showed good protection against the fatal infection of HV-IBDV. Especially, in case of challenge at 3 days postimmunization, the adapted strains showed effective immunogenicity. The adapted strains appear to provide a new and effective live vaccine against HV-IBDV infection.

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