Biomedical subjects

R Yamaguchi

Publications and source records attributed to R Yamaguchi.

At least 127 records · Page 7Linked to original sources

PubMed1995

Secretion of MPB64 antigen by a recombinant clone of Mycobacterium smegmatis: characterization and application for the diagnosis of tuberculosis.

MPB64, a specific antigen to Mycobacterium tuberculosis complex (TB complex), was produced and secreted by a clone of M. smegmatis-MPB64 where the structural gene of MPB64 was inserted using a new mycobacteria, E. coli shuttle plasmid pNIS vector. Antibodies against the recombinant MPB64 (rMPB64) were used for the reverse particle latex agglutination (RPLA) test to detect the MPB64 antigen rapidly. RPLA tests were applied to the shock cultures and the clinical isolates of mycobacteria to identify TB complex. RPLA with anti-MPB64 antibody-coated latex beads completely distinguished TB complex from other mycobacteria. Thus, it is suggested that RPLA with anti-MPB64 antibody would be a new, easy and inexpensive method for the rapid diagnosis of tuberculosis.

Antigens, Bacterial↗

PubMed1995

Giant cell glioblastoma in the frontal cortex of a dog.

A dark gray mass 3 cm in diameter replacing the right frontal cortex was found in the brain of a 5-year-old male Doberman Pinscher dog at necropsy. Microscopic studies revealed that the mass consisted of a proliferation of pleomorphic tumor cells: large bizarre or plump eosinophilic cells, multinucleated giant cells, and small lymphocytic cells. These neoplastic cells at the margin of the necrotic area had a psuedopalisade arrangement and tended to proliferate around blood vessels. Immunohistochemically, the tumor cells reacted intensely with the antibody for vimentin and moderately with those for S-100 and glial fibrillary acidic protein. This canine tumor is placed in the category of glioblastoma or undifferentiated astrocytoma, which is analogous to human giant cell glioblastoma.

Animals↗

PubMed1995

Senile plaques and other senile changes in the brain of an aged American black bear.

A female American black bear (Euarctos ursus americanus) over 20 years old had shown epileptiform neurologic signs starting in March 1992 and was found dead unexpectedly 8 months later. At necropsy, pulmonary and intrabronchial hemorrhage was noted. In the brain, the leptomeninges exhibited slight thickening, and petechiae were evident in the hippocampus. Histopathologic examination of the brain revealed several senile changes: numerous senile plaques, amyloid deposition in cerebromeningeal arterioles, mineral deposition in the pallidum, and numerous corpora amylacea in the cerebellum.

Aging↗

PubMed1995

Granulomatous epididymitis related to Rhodotorula glutinis infection in a dog.

A 4-year-old, male Great Dane dog developed severe swelling of the scrotum on 9 December 1991, and the testes and epididymides were removed surgically on 12 December 1992. The cut surface of the epididymides consisted of hard connective tissue and several small abcesses with slight hemorrhage. Histopathologically, the seminiferous tubules in the testes had only a few spermatogenic cells, but Sertoli cells were well preserved. Both epididymides consisted entirely of a proliferation of fibrous connective tissue, and only a few ducts deferens containing cell debris, neutrophils, and macrophages in the lumina were present. In all lesions of the epididymides, the macrophages contained periodic acid-Schiff- and Grocott's silver-positive round granules, 5-8 microns in diameter. Microbiologically, smooth salmon-pink colonies consisting of ovoidal yeast, about 10 microns in diameter, were isolated from the samples of epididymides but not from those of the testes. The isolated yeast had microbiological characteristics of Rhodotorula glutinis. From these observations, we diagnosed the present case as granulomatous epididymitis due to Rhodotorula infection.

Animals↗

PubMed1995

Congenital lymphedema in a calf with lymph node dysplasia or aplasia.

A 9-month-old male Japanese Black calf with subcutaneous edema in mainly both limbs was investigated. Necropsy revealed about 20 l of ascites and severe edema in the large omentum, abomasal folds, conjunctiva and rectum. Only small internal iliac and hepatic lymph nodes were found. Histopathology revealed lymph node dysplasia showing excess trabecular formation, reticular cell proliferation, and obvious dilation of both afferent and efferent lymphatics. These findings suggest that disturbance of lymphatic flow with congenital lymph nodes dyspalsia or aplasia resulted in lymphedema in this calf.

Animals↗

PubMed1995

Antiproliferation and colony-forming inhibition activities of recombinant feline interferon (rFeIFN) on various cells in vitro.

The antiproliferative and colony inhibiting activities of recombinant feline interferon (rFeIFN Type I) against various cells in vitro were examined. Feline and canine cells were both sensitive to rFeIFN. To inhibit the growth of feline cells by 50% approximately 5 x 10(2) to 1 x 10(3) U/mL rFeIFN was required and maximum activity was achieved at a concentration of 1 x 10(5) U/mL. Approximately 5 x 10(3) to 5 x 10(4) U/mL rFeIFN was necessary to inhibit the growth of canine cells by 50%. The antiproliferative and colony inhibiting activities of rFeIFN on canine cells appeared to be cell-specific and dose-dependent. However, human, monkey and hamster cells were resistant to rFeIFN. We suggest that rFeIFN might be useful for treatment of feline and some canine neoplastic conditions.

Animals↗

PubMed1995

[Long-term changes in body mass index in rural inhabitants: Takasu study].

Based on community health examination data (1975-1992) of Takasu, a rural town in Hokkaido Prefecture, long-term changes in body mass index (BMI) were studied and contour maps were developed. The results were as follows: 1) A high median BMI, 23 or more, appeared in female age groups from 50's to 70's during the observation period, whereas the high median BMI appeared in male age groups 30's and 40's after 1981. 2) Median BMI in age groups 30's and 40's at the time of the initial observation increased gradually with age in both sexes.

Adult↗

PubMed1994

Unphosphorylated and tyrosine-phosphorylated forms of a focal adhesion protein, paxillin, are substrates for calpain II in vitro: implications for the possible involvement of calpain II in mitosis-specific degradation of paxillin.

Cell-to-substratum adhesion becomes weakened during mitosis of the cell cycle in fibroblasts. The level of one focal adhesion protein, paxillin, is greatly reduced in mitotic-arrested cells. We show here the possible involvement of calpain II, known to be localized in focal adhesion plaques, in the degradation of paxillin. Paxillin is tyrosine-phosphorylated during interphase of the cell cycle by protein tyrosine kinases (PTK) such as c-Src and Csk, and becomes dephosphorylated during mitosis. Our data, however, indicate that tyrosine phosphorylation of paxillin does not affect the rate of paxillin degradation by calpain in vitro.

3T3 Cells↗

PubMed1994

The distribution of amyloid beta precursor protein in canine brain.

The distribution of amyloid beta precursor protein (APP) in canine brain was investigated. By immunoblot analysis, APP-positive bands corresponding to proteins of 105-120 kilodalton were recognized in all canine brains regardless of the individual age of the dogs. Bands of similar molecular mass were also detected in the meninges, cerebrospinal fluid, and several visceral organs. Immunohistochemical studies were performed using cryostat and paraffin-embedded sections pretreated with formic acid or by the hydrated autoclave method. In the normal canine brain, APP was found to be distributed in the neurons and vascular system. In the brains with SP, obvious accumulation of APP was observed in swollen neurites within amyloid plaques, although the relationship between APP and diffuse plaques was unclear. APP accumulation in swollen axons was also seen around necrotic foci in the brain of one dog with necrotizing purulent encephalitis. These studies revealed that distribution of APP in canine tissues, especially in the brain, and the accumulation of APP in swollen neurites or axons.

Amyloid beta-Protein Precursor↗

PubMed1994

Sinusoidal variation of wall shear stress in daughter tube through 45 deg branch model in laminar flow.

The present paper describes the experimental implemented work on the flow situation through a branch model having a daughter tube bifurcated from a parent tube at 45 deg. Experiments have been conducted utilizing an electrochemical method. The results show that, even in steady flow, the wall shear stress along the proximal wall in the daughter tube varies significantly with position in the form of a damped sine wave. For pulsating flow at the nondimensional pulsating frequency of alpha = 6.6, the above mentioned tendency appears to be severe, and the distribution of its amplitude in pulsating flow is similar to that of wall shear stress in steady flow.

Aorta, Abdominal↗

PubMed1994

Mammary fibroadenoma in a young Holstein cow.

A mammary mass approximately 60 cm in diameter, which developed in the left udder of a 17-month-old Holstein cow, was removed surgically. The mass was well demarcated from the surrounding tissues and its cut surface was lobular in appearance. Microscopically, the mass consisted of a proliferation of well differentiated ducts and mucinous connective tissue. Immunohistochemically, the proliferative stroma contained two distinct cell types; vimentin-positive fibroblasts and spindle cells positive for vimentin and actin at the periphery of the ducts. The biological features of the present mammary tumor are thought to be generally compatible with those of mammary fibroadenoma reported in humans and dogs.

Animals↗

PubMed1994

Human c-yes-1-related proto-oncogene in clinically normal dogs.

Human c-yes-1-related canine proto-oncogene in genomic DNAs from 21 clinically normal dogs was analyzed by Southern blot hybridization. The present study indicated that this proto-oncogene was well conserved in clinically normal dogs, however, there were structural changes in some dogs. These changes were different in each individuals and detected in low frequency.

Animals↗

PubMed1994

Tumors in domestic animals examined during a ten-year period (1980 to 1989) at Miyazaki University.

During the ten years from 1980 to 1989 inclusive, a total of 468 (16.1%) tumors were found in 2,907 pathological samples from domestic animals, collected from Southern Kyushu, around Miyazaki City. In this study, canine tumors were collected most commonly (340/468 cases, 73%). In small animals, the skin and mammary gland were associated particularly with tumorigenetic hazards. In cattle, high incidence of leukemia and mesothelioma was found. These tendencies were almost the same as those we reported for the preceding ten-year period, although the number of cases of tumor was higher in this study.

Animals↗

PubMed1994

Canine splenic hemangiosarcoma with abdominal dissemination.

Disseminated hemangiosarcoma was encountered in a 12-year-old female Maltese dog. Tumor tissues were dispersed on the serosal surface of the liver, kidney, digestive tract, omentum and diaphragm. Metastatic lesions were not observed in the parenchyma of the lung and heart. The spleen was enlarged with rupture at the anterior region of the hilus. The disseminated protruding tumor masses could be easily peeled off from the organ surfaces. The tumor cells were round or spindle in shape, with hyperchromatic nuclei containing prominent nucleoli. Various-sized vascular spaces containing erythrocytes and serum could be identified in this tumor. This case was diagnosed as hemangiosarcoma originating from the spleen with abdominal dissemination.

Abdominal Neoplasms↗

PubMed1994

Amplification of a c-yes-1-related oncogene in canine lymphoid leukemia.

Genomic DNAs from 4 canine spontaneous lymphoid neoplasms were examined by Southern blot hybridization using 7 kinds of oncogene probes. Analysis using a human c-yes-1 cDNA probe revealed amplification of the proto-oncogene in a DNA sample from a dog with lymphoid leukemia. Its degree was about 4- to 8-fold in comparison with a control DNA sample from a healthy dog. The genomic abnormality of canine c-yes-1-related oncogene may have a role in the tumorigenesis of this neoplasm, although the significance of the structural change in this oncogene remains unclear.

Animals↗

PubMed1993

Cloning and sequencing of the gene for alpha antigen from Mycobacterium avium and mapping of B-cell epitopes.

The complete nucleotide sequence of alpha antigen secreted from Mycobacterium avium (A-alpha) was determined. The gene encodes 330 amino acids, including 40 amino acids for the signal peptide, followed by 290 amino acids for the mature protein with a molecular mass of 30,811 Da. This is the first sequence of A-alpha. Comparisons between A-alpha and alpha antigens of Mycobacterium leprae, Mycobacterium bovis BCG, and Mycobacterium kansasii showed highly homologous regions which suggested a conserved functional domain and two less-homologous regions. Serological analysis of recombinant A-alpha, expressed by a series of deletion constructs, indicated the possibility that A-alpha carries at least six B-cell epitopes. The three antigenic determinants were common to Mycobacterium tuberculosis, M. kansasii, and M. avium. The results also suggested the possibility that there are three species-specific epitopes.

Amino Acid Sequence↗

PubMed1993

Eosinophilic meningitis in two cows.

A neurological disorder was noted in 5 cows on a farm. Histopathological examination in 2 of these 5 animals revealed an infiltration of eosinophils with some macrophages in the meninges and around arterioles of the cerebral cortex. The endothelial cells of the reactive blood vessels were swollen. From these observations, the brain lesions were diagnosed as "eosinophilic meningitis". In one case, pulmonary arterioles were also infiltrated with eosinophils and macrophages in a granulomatous tissue. No bacteria, fungi, protozoa, or parasitic worms were detected in the present cases.

Animals↗

PubMed1993

Proto-oncogene of genomic DNA, related to the human epidermal growth factor receptor (EGFR) gene, from clinically normal domestic animals.

Genomic DNAs of cattle, horses, pigs, dogs, cats and chickens were surveyed using Southern blot hybridization analysis, with a human EGFR cDNA fragment. Several bands with different numbers and molecular weights were observed under the condition of low stringency in the individual animal species. The bands showing DNA polymorphism were observed among bovine genomic PstI-digested DNAs from 4 individuals and EcoRI-digested genomic DNAs from 4 chickens. These results may provide basic data which are useful for analysis of tumorigenetic mechanisms in domestic animals.

Animals↗