Biomedical subjects

T Yanai

Publications and source records attributed to T Yanai.

At least 91 records · Page 5Linked to original sources

PubMed1994

Methicillin-resistant Staphylococcus aureus endocarditis following patch closure of a ventricular septal defect: report of a case.

We report herein the case of a 5-month-old infant who, after developing methicillin-resistant Staphylococcus aureus (MRSA) endocarditis following patch closure of a ventricular septal defect (VSD), was successfully treated by replacement of the Dacron patch with an autogenous pericardial patch. Initially, a large perimembranous VSD was repaired with a Dacron patch and after an uneventful recovery of 1 week, he began to spike intermittent fevers from 38 degrees C to 39 degrees C. Two blood cultures grew MRSA and a two-dimensional echocardiogram performed 16 days after surgery showed an irregular mass attached to the right ventricular aspect of the Dacron patch. At reoperation, a large vegetation attached to the Dacron patch was confirmed, but there was no patch dehiscence. Following removal of the patch, the VSD was repaired with an autogenous pericardial patch, soon after which the fever rapidly subsided. Imipenem, 125 mg every 6 h, and fosfomycin, 300 mg every 6 h, were administered for a total of 24 days after reoperation. The child remains well 12 months after his second operation.

Endocarditis, Bacterial↗

PubMed1994

Constitutive production of IL-6 in the anemic mice of W/Wv genotype.

IL-6 was found to be produced by bone marrow cell fraction enriched for hemopoietic stem cells in response to IL-3 stimulation. To confirm the production of IL-6 by hemopoietic stem cells, we studied the response of W/Wv mouse bone marrow cells to IL-3 stimulation in terms of IL-6 production. Genetically anemic mice of W/Wv genotype are known to be depleted of normal hemopoietic stem cells. Bone marrow cells of W/Wv mice produce IL-6 without IL-3 stimulation. But bone marrow cells of the litter mate (+/+) mice studied as controls do not produce IL-6 without stimulation. IL-3 induced the production of IL-6, GM-CSF and G-CSF from the bone marrow cells of +/+ mice. Gene expression of IL-6, GM-CSF, G-CSF and IL-3 in these mice was detected in total bone marrow cells after IL-3 stimulation. In contrast, bone marrow cells of C3H mice did not produce IL-3 even after IL-3 stimulation. Bone marrow cells of C3H mice reportedly produce a diffusible IL-3 inhibitor (NIL-3), but those of C57BL mice do not. Present findings indicate the strain-dependent differences in hemopoietic stimulating factor production. The constitutive IL-6 production in W/Wv mice might be due to a constant and strong demand for blood cell production of the anemic mice.

Anemia↗

PubMed1994

Spontaneous vascular mineralization in the brains of cows.

The frequency of occurrence and the characteristics of vascular mineralization in the brains of cows were studied. Mineralized lesions were found in the pallidal arteries in eight of 13 cows. They appeared as basophilic deposits in the arterial walls, were sheath-like or tubular in shape, and were accompanied by intimal oedema or fibrous thickening. The deposits were positive for periodic acid-Schiff, von Kossa's, alizarin red and Berlin blue stains. Elemental analysis revealed the presence of large amounts of phosphorus, calcium and zinc, as well as small amounts of iron, copper and sodium.

Animals↗

PubMed1994

Spontaneous aortic arteriosclerosis in layer chickens.

Aortas of 21 grower chickens (both sexes) aged 30-130 days and of 51 layer hens aged 500 days were examined histopathologically. Aortic sclerotic lesions were classified histopathologically into six stages. As early as 30 days, the abdominal aortas of growers had cellular-fibrous plaques that became more severe with advancing age. The majority of the abdominal aortas of all the 500-day-old layers had a conspicuous increase of collagen fibres, with atheromatous lesions in 23 (45.1%). These sclerotic changes were most severe in the distal aortas.

Animals↗

PubMed1994

Adenocarcinoma in the rectum of a capped langur (Presbytis pileata).

A rectal adenocarcinoma in a 22-year-old capped langur histologically resembling those in human cases is reported. An ill-defined diffuse tumor with fibrously firm rectal wall showed diffuse infiltrative growth of signet-ring cancer cells. Immunohistochemistry demonstrated positive staining for CEA, lysozyme, EMA, keratin and B72.3.

Animals↗

PubMed1994

Vascular mineralization in the monkey brain.

Mineralization of various degrees was found in the brains of 79 (59%) of 134 cynomolgus monkeys (Macaca fascicularis). There was no age dependency in the incidence or severity, nor were there any abnormalities in growth, weight gain, or neurologic signs, although a slight sex difference was observed. The lesions, which were basophilic and intensely positive for periodic acid-Schiff or von Kossa stain, occurred in the vascular walls of the globus pallidus in two types: globoid bodies with prominent concentric lamellar structures in and around the arteriolar and venular wall (type A) and fine granules in the media of small or medium-sized arteries (type B). Electron microscopic examination revealed dense deposits in the degenerated media of small or medium-sized arteries or the thickened walls of the arterioles. X-ray microanalysis demonstrated the presence of calcium, phosphorus, iron, zinc, magnesium, and aluminum.

Animals↗

PubMed1994

Ameloblastic fibro-odontoma in the mandibular incisor of a cow.

Odontogenic neoplasm was found in the mandibular incisor area of a 3-year-old Japanese black ox. Macroscopically, the cut surface was white and firm with streaks of hard tissue. Histologically, the tumor was composed of enamel organ structures with odontogenic hard tissue in fibromatous areas. It was diagnosed as ameloblastic fibro-odontoma. The absence of the 4th permanent incisor confirmed by radiography and microscopic examination strongly suggests that this tumor has been originated from the tooth germ tissues of the permanent left 4th incisor.

Animals↗

PubMed1994

The reduction of humeral fracture in pigeons with intramedullary poly (methyl methacrylate) and neutralization plate fixation.

The reduction of experimental humeral fracture in pigeons was performed with intramedullary bone cement (poly (methyl methacrylate): PMMA) and neutralization plate fixation to investigate the effect on bone fracture healing and the recovery of flying ability. As a result, neither plate nor bone cement fixation held for more than 2 weeks, but not refracture was observed in any cases with both plate and bone cement. In the latter group, it was confirmed by flight tests that almost normal flying ability was recovered in 6 weeks. In pathological findings, blood supply to the fractured ends recovered within 2 weeks and no cortical bone necrosis was observed at the time except for a disturbance of endosteal callus formation. The process of fracture healing on the plate side took place slightly later than that on the non-plate side, and when much PMMA remained between the fractured ends of the cortical bone the bone formation became spongioid. In view of the quick recovery of flying ability, however, plate and bone cement fixation is considered appropriate to prevent the displacement of a humeral fracture in the pigeon.

Animals↗

PubMed1994

Induction of granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF) expression in bone marrow and fractionated marrow cell populations by interleukin 3 (IL-3): IL-3-mediated positive feedback mechanisms of granulopoiesis.

Interleukin 3 (IL-3) induces proliferation and differentiation of mast cell progenitors in vitro, whereas it induces granulocytosis in vivo. In this paper, a positive feedback mechanism of granulopoiesis was studied in order to elucidate the granulocytosis induced by IL-3 in mouse. IL-3 induced expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF) in total bone marrow cells and a marrow adherent cell population. In fractionated marrow cell populations, a different expression pattern of induction of IL-3 stimulation was observed; GM-CSF was expressed in macrophages and fraction 1 (P < 1.061) and 2(1.061 < P 1.074) of bone marrow cells fractionated by equilibrium density centrifugation, G-CSF was expressed in macrophages and fraction 2 and 3 (1.074 < P < 1.097), and interleukin 6 (IL-6) in macrophages and fraction 1 to 3. These results indicate a hierarchical regulation of cytokine production and the existence of a positive feedback mechanism in granulopoiesis. IL-6, induced by IL-3, stimulates stem cells into cycle and induces stem cells to respond to IL-3. The stem cells differentiate to granulocyte-macrophage colony-forming cells by the combined effect of IL-3 and IL-6. IL-3 also induces GM- and G-CSF expression which in turn makes granulocyte-macrophage colony-forming cells differentiate to granulocytes. These factors organize a cytokine network in granulopoiesis.

Animals↗

PubMed1994

Gastric adenocarcinoma in a cougar (Felis concolor).

Diffusely invasive tumors occurred in the stomach of a 9-year-old female cougar (Felis concolor) from a zoo in Japan. The tumors consisted of tubular adenocarcinoma cells, and had infiltrative growth to the submucosa and muscularis propria. Tumor cells were positive for carcinoembryonic antigen (CEA), lysozyme, epithelial membrane antigen (EMA), gastrin, alpha-1-fetoprotein (AFP), keratin, and B72.3. Mucin-like materials occurred within cytoplasmic vacuoles.

Adenocarcinoma↗

PubMed1994

Hypertrophic pulmonary osteoarthropathy in a raccoon dog (Nyctereutes procyonoides) with chronic pulmonary inflammatory lesions.

A female raccoon dog (Nyctereutes procyonoides) captured September 1992 in Nara prefecture, Japan, suffering from swollen joints of all four limbs was necropsied. Radiographically, there was a shadow in the right pulmonary caudal lobe and periosteal bone formation around several joints. Microscopically, there was extensive edema, along with one large and many small pyogranulomatous nodules and purulent bronchitis in the right lobe and left caudal lobe of the lungs. There were intermingled branching filamentous bacteria in the lesion, which stained positively with Warthin-Starry, Grocott, and Gram stains, and partially with periodic acid Schiff and Ziehl-Neelsen stains. Extensive exostosis with coralloid trabeculation had developed bilaterally at the carpal, stifle and hock joints in the surrounding well vascularized loose connective tissue. Degeneration of articular cartilage and villous proliferation of synovial membranes were apparent. This is the first report of hypertrophic pulmonary osteoarthropathy in the raccoon dog.

Animals↗

PubMed1993

A rice homeotic gene, OSH1, causes unusual phenotypes in transgenic tobacco.

A rice gene, OSH1, which shares homology with animal homeobox genes, has been isolated. We have introduced the OSH1 cDNA into tobacco in order to examine its function. Expression of the OSH1 cDNA in tobacco induced morphological abnormalities in the leaves, petals and stems of the transformants suggesting that OSH1 functions as a morphological regulator. OSH1 cDNA expression was analyzed under the control of three different promoters. This work revealed that not only the level of OSH1 expression but also the site and timing of the expression affect the morphology of the plant.

Gene Expression Regulation↗

PubMed1993

Colony promoting activity (CPA) is a novel factor distinct from IL-6.

The supernatant (CM) of long-term bone marrow culture (LTBMC) contains colony promoting activity (CPA) which does not have granulocyte-macrophage (GM) colony-stimulating activity but which enhances GM-colony formation in the presence of CSF. CPA is different from IL-1, IL-3 and GM, G-, and M-CSF. Since CPA-containing LTBMC-CM always contains a substantial level of IL-6, CPA was thought to be similar to IL-6. In the present study, we found that LTBMC with a particular batch of horse serum produced IL-6 without a corresponding production of CPA. Addition of IL-6 to GM-colony assay system in the presence of GM-CSF did not enhance the colony formation. LTBMC-CM did not stimulate proliferation nor differentiation of mast cell progenitors. Anti-IL-6 antibodies suppressed IL-6 activity, but not CPA. These results indicate that CPA is a novel factor distinct from IL-1, IL-3, G-, M-, GM-CSF, IL-6 and SCF (c-kit ligand).

Animals↗

PubMed1993

Spontaneous globoid mineralization in the cerebellum of rats.

Cerebellar globoid mineralization in two rats was examined by light and electron microscopy, and by X-ray microanalysis. The mineralization was round to oval in shape; it varied in size and was positive for the periodic acid-Schiff and von Kossa reactions. Ultrastructurally, a concentric lamellar structure was prominent in moderately electron-dense depositions. Elemental analysis revealed the presence of large amounts of calcium and phosphorus, and small amounts of zinc, potassium and aluminum.

Animals↗

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↗

PubMed1993

Two cases of Goodpasture's syndrome--clinicopathological studies and relapse.

The requirements for a diagnosis of Goodpasture's syndrome (GPS) include: (1) the presence of glomerulonephritis, (2) alveolar bleeding, and (3) the presence of anti-glomerular basement membrane (anti-GBM antibody). Among Japanese case, the 2 patients reported here were rare in that they satisfied all of these requirements. In case 1 (a 40-year-old male), the disease developed with initial signs of proteinuria and hematuria. The patient developed hemoptysis after hospitalization. The interval from onset to hospitalization was 38 days. The serum creatinine (CRN) level was 3.6 mg/dl on admission. The pathological findings were rated as full-circumferential, cellular crescentic nephritis, and the patient did not display oliguria. The renal and pulmonary impairments in this case were markedly improved by glucocorticoid (prednisolone PSL, 60 mg/day), cyclophosphamide therapy (50 mg/day) and plasma exchange (PE 10 times). In case 2 (a 58-year-old male), the initial signs developed as proteinuria and hematuria, followed by rapidly progressive renal functional deterioration and hemoptysis occurred. Compared to Case 1, the interval from onset to hospitalization was longer in Case 2 (125 days) and the CRN level was also higher (10.7 mg/dl). Case 2 was rated as full-circumferential, fibrous crescentic nephritis, and the patient was oliguric. Although the pulmonary impairment was reduced by pulse therapy and 10 PEs, recovery of renal function has not been achieved, still necessitating maintenance hemodialysis at present. In case 1, the disease relapsed at 4.5 years after remission, presenting with aggravated renal function and hemoptysis. In this case, low-dose PSL therapy had been discontinued at 3 months before the relapse.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗