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Biomedical subjects

H Osawa

Publications and source records attributed to H Osawa.

At least 91 records · Page 5Linked to original sources
PubMed1998

A clinicopathological aspect of chorionic villous hemorrhage leading to formation of intervillous thrombosis.

Recently it was reported that chorionic villous hemorrhage (CVH) had a significant association with retroplacental hemorrhage (RPH). In this study, to determine whether CVH has a correlation with RPH or intervillous thrombosis (IVT), placentas associated with CVH were clinico-histopathologically investigated and compared to those with IVT. Obstetric complications in 32 cases with CVH were compared with 258 cases with IVT. Placental abruption was significantly higher (18.7%) in the CVH group than in the IVT group (5.03%) and the incidences of intrauterine fetal death (IUFD) as well as intrauterine growth retardation (IUGR) were also significantly higher (18.7% and 9.37%) in the CVH group than in the IVT group (3.10% and 2.32%). Of the pathological characteristics of the placentas with CVH, IVT was found in 46.8%, but marginal or retroplacental hemorrhages were seen in 34.3%, compared to 14.2% of the IVT group. Premature infants with low birth weight (under 2000 g) and before 36 weeks of gestation were born in 53.1% and 34.3% of cases with CVH placentas. CVH was not only located near the basal plate of the placentas and decidual hemorrhages, but was also highly associated with chorangiosis in 75% of cases. Using histological and ultrastructural studies in CVH cases, villous stroma was filled with fetal erythrocytes and leakage of blood cells was observed through a disruption of the trophoblast layer of hemorrhagic villi. In conclusion, it is suggested that CVH may rather be related to formation of the intervillous thrombosis than to RPH.

Chorionic Villi↗
PubMed1998

Studies on blood compatibility of terpolymers composed of methyl methacrylate, methoxypolyethyleneglycol methacrylate, and dimethylsiloxane methacrylate.

Terpolymers composed of methyl methacrylate (MMA), polydimethylsiloxane methacrylate (PDMSMA), and methoxypolyethyleneglycol methacrylate (MPEGMA), having different compositions were synthesized. Platelets were not adsorbed onto terpolymer surfaces composed of 50 wt% MMA, 25 wt% PDMSMA and 25 wt% MPEGMA, while on terpolymers with the other compositions, platelet adsorption and fibrin clot were observed. It was shown that PDMS segment was predominant on these terpolymer surfaces via XPS. Receding contact angles of terpolymers, on which no platelet was observed, showed intermediate values between PDMS- and MPEG-rich surfaces. It was suggested that these terpolymers had blood compatibility.

Adult↗
PubMed1998

The direct visualization of structural array from laminin to dystrophin in sarcolemmal vesicles prepared from rat skeletal muscles.

It has been biochemically shown that dystrophin and alpha- and beta-dystroglycan form an oligomeric complex which links laminin, a component of the basement membrane, to components of the subsarcolemmal cytoskeleton in skeletal muscle fibers. In the present study the dystrophin-glycoprotein complex and its structural relationships to laminin and subsarcolemmal cytoskeleton were ultrastructurally examined in crude surface membranes prepared from rat skeletal muscles. Sarcolemmal vesicles within crude surface membranes were identified and characterized by fine protrusions on their outer surface and electron-dense materials or patches associated with the inner surface. These two components were seen to be in register with each other across the sarcolemma. The fine protrusions were immunolabeled by anti-alpha-dystroglycan and reassociated with exogenous laminin. Immunolabeling in combination with laminin reassociation demonstrated that the electron-dense materials contained dystrophin at laminin-binding domains of the membrane. In addition, they were often associated with very fine filaments. These results provide morphological evidence for the biochemically proposed model of molecular array of dystrophin complex from the basement membrane to the subsarcolemmal cytoskeleton.

Animals↗
PubMed1998

Cytokine expression during orthotopic corneal allograft rejection in mice.

PURPOSE: The acquisition of cell-mediated immunity against donor antigens has been shown to be associated with rejection of orthotopic corneal allografts, but the mechanisms that cause corneal allograft destruction in grafted tissue remain obscure. To determine which T-cell subsets infiltrate graft tissue and cause graft rejection, cytokine expression was examined in corneal tissue after orthotopic corneal allograft. METHODS: BALB/c mice received orthotopic corneal allografts from either syngeneic BALB/c or allogeneic C57BL/6 donors. At 1 or 4 weeks after grafting, the mice were euthanatized, and their corneas were removed. Corneal tissue was frozen, homogenized, and placed in phosphate-buffered saline (PBS). Each sample consisted of five corneas in 500 ml PBS. After centrifugation, the supernatant was collected, and the concentration of the following cytokines was measured by enzyme-linked immunosorbent assay: interleukin (IL)-1alpha, IL-2, IL-4, IL-10, interferon (IFN)-gamma, and tumor necrosis factor (TNF)-alpha. RESULTS: Significantly increased amounts of proinflammatory cytokines (IL-1alpha and TNF-alpha) were detected in supernatants from all grafted corneas (both syngeneic and allogeneic) at 1 week after grafting. At 4 weeks after grafting, supernatants from normal corneas, corneas with syngeneic grafts, and corneas with accepted corneal allografts contained undetectable amounts of IL-2 and IFN-gamma, whereas supernatants from corneas with rejected corneal allografts contained significant amounts of IL-2 and IFN-gamma. There were no significant differences in the amounts of IL-4 or IL-10 among all samples. Histologic examination confirmed the expression of IL-2 and IFN-gamma in rejected corneal allografts. CONCLUSIONS: Because IL-2 and IFN-gamma are secreted primarily by T-helper type 1 (Th 1) cells, whereas IL-4 and IL-10 are secreted by T-helper type 2 (Th 2) cells, these results indicate that Th 1-type cytokines, rather than Th 2-type cytokines, contribute to the rejection of orthotopic corneal allografts in graft tissue.

Animals↗
PubMed1997

A case of Sjögren's syndrome associated with Sweet's syndrome.

We report a case of Sjögren's syndrome whose clinical course had been indolent until the patient presented with Sweet's syndrome (acute febrile neutrophilic dermatosis). This patient showed renal failure and renal tubular acidosis. Sweet's syndrome resolved within 3 weeks without corticosteroid therapy. Renal biopsy findings were consistent with interstitial nephritis. His renal manifestations responded to corticosteroid therapy and the renal function remained stable during 6 years follow-up without recurrence of Sweet's syndrome. Although close association of both syndromes is already known, in our case Sjögren's syndrome may have been exacerbated by occurrence of Sweet's syndrome.

Acute Kidney Injury↗
PubMed1997

Expression of gelatinase A, tissue inhibitor of metalloproteinases-2, matrilysin, and trypsin(ogen) in lung neoplasms: an immunohistochemical study.

Lung cancer is a heterogeneous tumor in terms of clinical and biological behavior, and its aggressiveness depends on its invasive and metastatic properties. Matrix metalloproteinases and serine proteinases are believed to play a crucial role in invasion and metastasis of malignant tumor cells. In the present study, the authors evaluated immunohistochemically the expression of gelatinase A; tissue inhibitor of metalloproteinases-2 (TIMP-2), an inhibitor of gelatinase A; matrilysin; and trypsin(ogen) in 67 lung tumors from a variety of histological types including 17 squamous cell carcinomas, 16 adenocarcinomas, 15 small cell carcinomas, and 12 carcinoids. Interestingly, normal bronchial, bronchiolar, and alveolar epithelial cells expressed gelatinase A, TIMP-2, matrilysin, and trypsin(ogen) at varying frequencies and intensities. Bronchial smooth muscle cells and cartilage cells expressed gelatinase A alone, whereas endothelial cells, fibroblasts, and macrophages expressed gelatinase A and TIMP-2. Gelatinase A was expressed at high levels in most lung tumors examined (47% to 80%). TIMP-2 was also expressed at high levels except in the small cell carcinomas, which showed TIMP-2 expression at a lower frequency (60%) compared with other types of lung tumors (80% to 100%). Although matrilysin was expressed by tumor cells of all the histological types at various frequencies (13% to 63%), its expression was most common in adenocarcinomas. Expression of trypsin(ogen) was observed almost exclusively in adenocarcinomas (56%); other types of lung tumors expressed trypsin(ogen) far less frequently (0% to 12%). The present results, taken together with those of previous studies, suggest that gelatinase A is associated with malignant behavior of all the types of lung tumors, whereas its activity may be controlled by the endogenous inhibitor TIMP-2. The aggressive clinical behavior of small cell carcinoma may be attributable, at least in part, to a loss of the inhibitory effect of TIMP-2, as a significant proportion of these tumors showed negative or low levels of TIMP-2 expression. Matrilysin and trypsin(ogen) expressions are unlikely to be correlated with the aggressiveness of lung tumors. The expression of trypsin (ogen) may rather reflect the differentiation of adenocarcinoma cells toward normal airway epithelial cells.

Adult↗
PubMed1997

Thrombin stimulates production of transforming growth factor-beta by cultured human mesangial cells.

Fibrin formation within the glomeruli occurs in various forms of human and experimental glomerulonephritis and it may play an important role in progressive glomerular injury. Transforming growth factor-beta (TGF-beta) has been shown to participate in the glomerular accumulation of extracellular matrix in glomerulonephritis. We investigated whether thrombin, an important coagulation factor, could modulate the production of TGF-beta by cultured human mesangial cells (HMC). TGF-beta levels in the culture supernatants were measured by ELISA using a specific antibody. The TGF-beta concentration was significantly increased by incubation of HMC with thrombin in a time-dependent manner. The stimulating effect of thrombin on TGF-beta was inhibited by addition of hirudin (a natural thrombin inhibitor) and argatroban (a synthetic thrombin inhibitor). In addition DFP-inactivated thrombin, which has no enzymatic activity, did not stimulate TGF-beta production. A protein kinase C inhibitor (H7) and a tyrosine kinase inhibitor (herbimycin A) also inhibited thrombin induced TGF-beta production. These findings suggested that thrombin may modulate the synthesis of TGF-beta via protein kinase C- and tyrosine kinase-dependent mechanisms in cultured HMC. Thus thrombin may participate in the accumulation of extracellular matrix in glomeruli through the augmentation of TGF-beta production.

Cells, Cultured↗
PubMed1997

Immunohistochemical study of sulfatide expression in gastric carcinoma: alteration of sulfatide expression.

Immunohistochemical staining using a specific monoclonal antibody against sulfatide was performed to examine cellular localization of sulfatides in normal human gastric mucosa and in various types of gastric carcinoma. In normal gastric mucosa without Helicobacter pylori infection, both epithelial and glandular cells were densely stained with anti-sulfatide antibody. Sulfatide staining was more abundant in the apical area of normal epithelium compared with cytosol or basolateral areas. This tendency was stronger in the antrum than the gastric body and was more intensified in glandular cells of the pyloric glands. The levels of sulfatide expression were decreased in papillary and well-differentiated adenocarcinomas compared with normal mucosa, were markedly attenuated in moderately differentiated adenocarcinomas, and were very low in poorly differentiated adenocarcinomas. The polarity of the stains was preserved in gastric cancers that exhibited differentiated tissue organization. The levels of sulfatide expression were highly variable in signet ring carcinoma cells. The cancer cells that expressed sulfatides did not show any polarity of staining.

Adenocarcinoma↗
PubMed1997

Reversible limbic encephalitis caused by ovarian teratoma.

A 19-year-old woman developed memory loss followed by psychosis, coma, convulsion, and central hypoventilation requiring mechanical ventilation. MRI of the brain showed minimal changes, and SPECT imaging revealed a small region of increased uptake in the cortex. Intravenous acyclovir and high-dose corticosteroids were administered without any effect. An extensive work-up revealed an elevated serum alpha-fetoprotein (AFP) concentration and the presence of an ovarian tumor. Following resection of the tumor, an immature teratoma by pathology, the patient had significant recovery of her cognitive function with some psychotic sequela. Serum anti-neuronal antibody (anti-Hu) was negative both by immunohistochemistry and by Western blot analysis. A rare combination of paraneoplastic limbic encephalitis and brainstem encephalitis was the suspected diagnosis. Because the tumor contained a neuronal component, we propose an immunologic cross-reaction as the pathomechanism, but the lack of a specific antibody may suggest cell-mediated rather than globulin-mediated immunity.

Adult↗
PubMed1997

[Study of diarrhea-inducing strains of Escherichia coli mainly isolated in Kanto area between June and September 1996].

A total of 21,609 faecal specimens obtained from patients with diarrhea mainly in Kanto area between June and September 1996 were investigated to identify the causative pathogens for diarrhea. One-hundred fifty-seven strains of Escherichia coli of 29 different O-serotypes were isolated as the causative pathogens, which were previously recognized to induce severe abdominal cramps and diarrhea. Of these, 114 strains, in which the possibility of enterohemorrhagic E. coli due to their O-serotypes was predicted, were examined for the producibility of Vero toxins. Twenty-six (76.5%) of the 34 strains of E. coli O157 produced the Vero toxins, and other 8 strains were the non-producers. Twenty of the 26 producers produced both VT1 and VT2, whereas the other 6 strains produced VT2 only. Furthermore, 4 strains of E. coli O26, and 1 strain each of E. coli O125 and O126 produced Vero toxins. Thirty-two of the 114 strains, isolated from the patients with diarrhea and selected as the enterohemorrhagic E. coli according to the specific O-serotypes, were actually confirmed produce Vero toxins. Thirty-four strains of E. coli O157 tested were susceptible to all antibiotics such as ampicillin, doxycylin, levofloxacin, fosfomycin, chloramphenicol and polymyxin B, and no strains resistant to levofloxacin, polymyxin B and fosfomycin were found.

Bacterial Toxins↗
PubMed1997

Systemic lupus erythematosus associated with transverse myelitis and parkinsonian symptoms.

A 31-year old woman developed transverse myelitis after 10 years remission since she was first diagnosed as systemic lupus erythematosus. Although pulse methyl prednisolone resolved her myelitis, Parkinson-like symptoms developed subsequently after reduction of steroid. Treatments including apheresis did not improve her Parkinson-like symptoms such as rigidity, akinesia, impairment of speech and mask-like facial expression. Levodopa was effective as a symptomatic therapy. Orally administered cyclophosphamide eventually led her to remission and withdrawal from levodopa. Her clinical course and the absence of other possible causes prompted us to conclude that Parkinsonian symptoms as well as transverse myelitis may have developed as manifestations of central nervous system lupus.

Adult↗
PubMed1997

[Renal lesions of rats induced by antibodies to cultured rat glomerular epithelial cells and mesangial cells].

Renal lesions of rats induced by antibodies to cultured rat glomerular epithelial cells (GEC) and mesangial cells (GMC) were studied. Antibodies to cultured rat GEC and GMC were produced by immunization of rabbits with GEC and GMC respectively. The rats injected with anti-GEC antibody showed a small amount of urinary protein, glomerular deposition of rabbit IgG and subepithelial dense deposits observed by electron microscopy. Proteinuria was suppressed in the rats in which complement was depleted with cobra venom factor. Western blot analysis demonstrated a band of 200 KD in GEC lysates reacted with anti-GEC antibody. The rats injected with anti-GMC antibody showed little urinary protein, glomerular deposition of rabbit IgG and mesangial dense deposits. Western blot analysis demonstrated two bands of 43 and 14 KD in GMC lysates reacted with anti-GMC antibody. These data showed that the injection of anti-GEC antibody or anti-GMC antibody induced similar lesions to passive Heymann nephritis and anti Thy 1.1 nephritis. This study suggested that antigenicity of structural glomerular cells is important as the antigens of glomerulonephritis.

Animals↗
PubMed1997

[Peripheral carcinoid tumor of the lung presenting as a solitary mass shadow on a chest roentgenogram and diagnosed by CT-guided percutaneous needle biopsy].

A 59-year-old woman was referred to our clinic because a solitary mass shadow (2.5 cm in diameter was seen in the left lower lung field on a chest roentgenogram. Transbronchial biopsy via a fiberoptic bronchoscope did not yield a definitive diagnosis. Examination of a specimen obtained by CT-guided percutaneous needle biopsy revealed that the tumor consisted of small cells proliferating in a solid, tubular, pseudoglandular, and follicular pattern, which suggested the diagnosis of carcinoid. A left lower lobectomy was performed, and several hilar and mediastinal lymph nodes were also removed. The tumor cells did not show pleomorphism of nuclei, mitotic activity, or necrosis. Grimelius and immunohistochemical stains for chromogranin. A, neuron-specific-enorase, synaptophysin, and serotonin were positive. These findings confirmed the diagnosis of carcinoid CT-guided percutaneous needle biopsy can be useful for the diagnosis of peripheral carcinoid and other peripheral lung tumors.

Biopsy, Needle↗