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T Masegi

Publications and source records attributed to T Masegi.

At least 73 records · Page 4Linked to original sources
PubMed1993

An ultrastructural study of cutaneous hemangioma in two chickens.

Cutaneous hemangioma in two laying hens was examined by light and electron microscopy. In close association with capillary and cavernous hemangioma there was a solid cell mass. Ultrastructurally, the cell mass consisted of undifferentiated mesenchymal cells and had an alveolar structure. There were transitional cell types from the alveolar structure to the capillary and cavernous hemangiomas. Hemangiomatous structure may develop from the undifferentiated mesenchymal cells in the solid cell mass.

Animals↗
PubMed1993

Tyzzer's disease complicated with distemper in a puppy.

A Pomeranian puppy which died from diarrhea and nasal discharge showed catarrhal pneumonia, acute enteritis and focal liver necrosis. Slender bacilli were detected within ileal enterocytes and hepatocytes. A double infection with a distemper virus and Tyzzer's organism at a cellular level was seen within the ileal enterocytes.

Animals↗
PubMed1993

Spontaneous coronary arteriolosclerosis in broiler chickens.

Arteriolosclerotic changes were found in 202 out of 203 randomly collected heart specimens of broiler chickens. These chickens were reared in a poultry farm and killed at a poultry meat processing plant at 60 days of age with healthy appearance. Cellular intimal thickening due to a proliferation of smooth muscle cells of small arteries or arterioles were found mostly in the innermost layer of the left ventricle. Severity of the thickening varied from slight to severe. In 2 cases, myocardial necrotic changes were found in the proximity of severely affected small arteries and arterioles.

Animals↗
PubMed1992

Conformational rigidity of specific pyrimidine residues in tRNA arises from posttranscriptional modifications that enhance steric interaction between the base and the 2'-hydroxyl group.

In order to elucidate roles of the 2'-O-methylation of pyrimidine nucleotide residues of tRNAs, conformations of 2'-O-methyluridylyl(3'----5')uridine (UmpU), 2'-O-methyluridine 3'-monophosphate (Ump), and 2'-O-methyluridine (Um) in 2H2O solution were analyzed by one- and two-dimensional proton NMR spectroscopy and compared with those of related nucleotides and nucleoside. As for UpU and UmpU, the 2'-O-methylation was found to stabilize the C3'-endo form of the 3'-nucleotidyl unit (Up-/Ump-moiety). This stabilization of the C3'-endo form is primarily due to an intraresidue effect, since the conformation of the 5'-nucleotidyl unit (-pU moiety) was only slightly affected by the 2'-O-methylation of the 3'-nucleotide unit. In fact even for Up and Ump, the 2'-O-methylation significantly stabilizes the C3'-endo form by 0.8 kcal/.mol-1. By contrast, for nucleosides (U and Um), the C3'-endo form is slightly stabilized by 0.1 kcal/.mol-1. Accordingly, the stabilization of the C3'-endo form by the 2'-O-methylation is primarily due to the steric repulsion among the 2-carbonyl group, the 2'-O-methyl group and the 3'-phosphate group in the C2'-endo form. For some tRNA species, 2-thiolation of pyrimidine residues is found in positions where the 2'-O-methylation is found for other tRNA species.(ABSTRACT TRUNCATED AT 250 WORDS)

Dinucleoside Phosphates↗
PubMed1991

A novel recombinant tumor necrosis factor-alpha mutant with increased anti-tumor activity and lower toxicity.

We prepared a novel recombinant tumor necrosis factor-alpha (TNF) mutant (mutant 471), in which 7 N-terminal amino-acids were deleted and Pro8Ser9Asp10 was replaced by ArgLysArg, and compared its biological activity with that of wild-type recombinant TNF. Mutant 471 had a 7-fold higher anti-tumor activity against murine L-M cells in vitro, and a higher binding activity to TNF receptors on L-M cells, than wild-type TNF. Furthermore, mutant 471 showed a higher anti-tumor effect on murine Meth A-HM tumors transplanted into BALB/c mice, with complete regression of the tumors being observed in the animals. The possible cachectin activity of mutant 471 was almost the same as that of wild-type TNF. The acute lethal toxicity of mutant 471 in beta-D-galactosamine-sensitized C3H/HeJ mice was 18 times lower than that of wild-type TNF. These results suggest that mutant 471 might be a more promising anti-cancer agent than wild-type TNF.

Amino Acid Sequence↗
PubMed1991

S-100 immunoreactive cells in the spleen and bursa of Fabricius of broiler chickens.

The distribution of S-100 protein in spleens and bursae of Fabricius of broiler chickens with various diseases was investigated by an immunohistochemical method with antiserum to bovine S-100 protein. S-100 protein-positive cells were found in six cases of 34 chickens. In spleens, S-100 protein was detected in reticular cells in the ellipsoids of the sheathed arteries and eosinophilic granulocytes. Follicular dendritic cells in germinal centres were also S-100 protein-positive. In the bursa, reticular cells of the follicles and eosinophilic granulocytes in the follicular cortex and surface epithelium were positive for S-100 protein. The evidence suggests that S-100 protein may be involved in diseases of chickens.

Animals↗
PubMed1991

Interactions between novel tumor necrosis factor-alpha mutants and receptors on tumor and normal cells.

We prepared several TNF mutants by protein engineering techniques and compared their biological properties with those of the wild-type TNF. The mutant that lacked 7 N-terminal amino acids had higher cytotoxicity and higher binding activity to receptors on tumor cells. In contrast, the mutagenesis of Arg32 or Ala84, in combination with the deletion of 7 N-terminal amino acids, eliminated the cytotoxicity and the receptor binding. These mutants also lacked acute lethal toxicity in normal mice. Therefore, we concluded that the N-terminus, Arg32 and Ala84 of TNF might be concerned with binding to the TNF receptor. It was also suggested that the receptor molecules on tumor cells bound to the same or neighboring sites on TNF molecules as normal cell receptors.

Animals↗
PubMed1990

Improvement in pulmonary arterial lesions after heartworm removal using flexible alligator forceps.

Improvement of pulmonary arterial lesions after heartworm removal using flexible alligator forceps was investigated by measuring pulmonary arterial pressure (PAP), and by angiographic and histopathological examinations in 11 dogs. PAP obtained immediately after worm removal corresponded well with angiographic abnormalities. In 2 dogs, high PAP immediately after worm removal fell gradually by 12 weeks, and obstructions on angiogram were resolved at 4 to 12 weeks. In 4 dogs, slightly high PAP fell to the normal range at 4 weeks, and angiographic abnormalities were considerably reduced at 4 to 12 weeks. In 5 dogs, PAP returned to normal range immediately after worm removal, and angiographic changes almost disappeared at 4 to 8 weeks. On biopsy immediately after worm removal, samples of the main pulmonary arteries showed severe intimal proliferations with villous or papillary protrusion into the lumen. Autopsy at 12 to 20 weeks indicated that the intimal protrusions were remarkably reduced as compared with the biopsy samples in all cases. However, villous intimal protrusions were seen in the caudal lobar arteries in cases with remaining alive worms. New vessels seemed to develop into thromboemboli with time. From these findings, it is clear that the pulmonary arterial lesions improved after heartworm removal, and the clinical signs disappeared following the improvement in hemodynamics. Aspirin therapy (5 mg/kg/day) for 4 weeks after worm removal in 5 dogs did not improve the intimal lesions as compared to 3 control dogs.

Animals↗
PubMed1990

Extracellular production of human tumor necrosis factor-alpha by Escherichia coli using a chemically-synthesized gene.

A DNA fragment of approximately 490 base pairs encoding human TNF was chemically synthesized and expressed within Escherichia coli cells. Furthermore, extracellular production of human TNF and several N-terminal deletion mutants of TNF was attempted using the excretion vector pEAP8. The TNF mutant with two N-terminal amino acids deleted (N delta 2-TNF) was efficiently excreted into the culture medium by E. coli carrying the plasmid pEXTNF3. In this clone, the signal peptide was correctly processed during the excretion. The E. coli-excreted N delta 2-TNF had higher antitumor activity than wild-type TNF or N delta 2-TNF produced intracellularly by E. coli.

Amino Acid Sequence↗
PubMed1982

Humoral immunity following double freezing of the prostate of patients with prostatic cancer.

In these studies, double freezing of the prostate was applied to 10 patients with a confirmed histologic diagnosis of stage C and D carcinoma. The clinical courses in the first group (five patients) were favorable. In the second group (two patients), death by cachexia occurred due to the cancer. In the third group (three patients), death 4 weeks after the second cryosurgery suggests the effects of Cryoshock. In the first and second groups, the results of immunologic examinations after the second freezing did not attain the predicted levels. Comparing the results of the third group with those of the first and second groups, the primary difference was that the percentages of gamma globulins and IgE were higher in the third group preoperatively. These findings suggest that in patients with high gamma globulin percentages and high IgE levels cryosurgery of the prostate is contraindicated.

Acid Phosphatase↗
PubMed1980

Muscle spindle supply to the bovine jaw muscles.

The jaw-closing muscles of two bovine fetuses average 1,177 muscle spindles on one side of the face: 549 in the masseter, 433 in the temporalis, 192 in the medial pterygoid, and three in the lateral pterygoid. The jaw-opening muscles have no spindles.

Animals↗
PubMed1979

Muscle spindle supply to the masticatory muscles in the Japane ermine (Carnivora).

Histological examination of the jaw muscles of the Japanese ermine showed that 4 jaw-closing muscles have 13 muscle spindles on one side of the face. The temporal muscle has 99 muscle spindles, 68 being in the anterior vertical and 31 in the posterior horizontal belly. The masseter muscle has 33 muscle spindles, 23 being in the profound and 10 in the superficial belly. The medial pterygoid muscle has 7 muscle spindles and the zygomaticomandibular muscle contains 4 muscle spindles. The lateral pterygoid and the jaw-opening muscles have no spindles.

Animals↗