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Biomedical subjects

Y Hamashima

Publications and source records attributed to Y Hamashima.

At least 19 recordsLinked to original sources
PubMed1991

Analysis of IgG immune complexes in sera from patients with membranous nephropathy: role of IgG4 subclass and low-avidity antibodies.

The levels of circulating immune complexes (CIC) were determined using an anti-C3d binding assay in patients with various types of glomerulonephritis (GN). It was found that IgG class CIC were positive in 20% (7/35) of patients with idiopathic membranous nephropathy (MN) and in 80% (8/10) of patients with lupus glomerulonephritis (LN). Of these patients, IgG4 subclass CIC were observed more frequently in 29% of MN and 60% (3/5) of minimum change nephrotic syndrome, and, with less amounts, in 10% (1/10) of membranoproliferative GN (MPGN) and 20% (2/10) of IgA nephropathy. On the other hand, the patients with LN showed a lower positivity (30%) of IgG4-CIC as compared with that of IgG-CIC. In the comparison of mean levels, only MN patients showed significantly higher value than normal individuals (p less than 0.05). In patients with MN, the CIC of the other IgG subclasses (IgG1, IgG2, IgG3) were not significantly elevated and their positivities were low (9-11%). The study on the salt-dependent dissociability of CIC, which is considered to reflect the avidity of antibodies in CIC, showed that the IgG-CIC of 11 of 15 patients with MN were dissociable to various extents even at the physiological concentration. These findings suggested that IgG4 subclass specificity and low avidity may be pathogenic characteristics of IgG-CIC in certain populations of patients with MN.

Antibody Affinity↗
PubMed1990

Allogeneic bone marrow-plus-liver transplantation in the C57BL/KsJ spm/spm mouse, an animal model of Niemann-Pick disease.

The C57BL/KsJ spm/spm mouse, an animal model of Niemann-Pick disease, shows defective sphingomyelinase activity resulting in accumulation of sphingomyelin in various organs. To replace the defective enzyme, allogeneic bone marrow-plus-liver transplantation was performed. Bone marrow transplantation with or without concomitant liver grafting in C57BL/KsJ spm/spm mice at the age of 2-9 weeks led to an amelioration of the hepatosplenomegaly. The treatment, however, neither prevented the development of neurological signs nor increased the life-span. The sphingomyelin and cholesterol contents of the liver decreased, while sphingomyelinase activity in the liver increased after bone marrow transplantation. Foam cells disappeared from the bone marrow, liver, spleen, thymus, and lymph nodes, but depletion of Purkinje cells was not prevented. These results suggest that bone marrow transplantation either alone or with liver transplantation may become a useful strategy for the treatment of Niemann-Pick disease provided the central nervous system is not involved.

Animals↗
PubMed1987

Expression of epithelial markers in sarcomatoid carcinoma: an immunohistochemical study.

Thirty-four cases of sarcomatoid carcinoma with minimal epithelial components (SC) and six cases of sarcomatous tumour without any epithelial component (ST) in various organs were studied by the immunoperoxidase technique for the expression of epithelial markers, cytokeratins and epithelial membrane antigen (EMA). Employing antibodies against both high and low molecular weight cytokeratins, sarcomatoid components in 30 examples of SC were stained positively. Epithelial membrane antigen was demonstrated in 19 out of 34 SC. The positive cells for epithelial markers within sarcomatoid components in some cases of SC, which were regarded as originating from squamous cell carcinoma, tended to be seen less frequently than in the tumours derived from adenocarcinoma or transitional cell carcinoma. In six cases of ST, stain for EMA was negative and stain for cytokeratins was positive in three examples. The immunohistochemical examination of epithelial markers in the tumours of these types may be of value in differentiating these tumours from true sarcomas.

Adenocarcinoma↗
PubMed1986

Clear cell sarcoma of the kidney. An immunohistochemical study.

Three cases of clear cell sarcoma of the kidney (CCSK) and 5 cases of Wilms' tumor were investigated immunohistochemically to examine the expression of tissue-specific intermediate filaments (cytokeratin, vimentin, and desmin) and myoglobin. In CCSK, tumor cells were negative for cytokeratin, except for occasional tubular structures, and vimentin was demonstrated in only one case. In Wilms' tumor, epithelial components were positive for cytokeratin and stromal cells were positive for vimentin, while no staining was found in blastemal cells for either. Both desmin and myoglobin were negative in all tumor cells except for skeletal muscle cells in Wilms' tumor. In the current study, some neoplastic cells in CCSK were revealed to be of mesenchymal nature, but blastemal cells in Wilms' tumor were not.

Antibodies, Monoclonal↗
PubMed1979

Myocardial fascicle and fiber disarray in 25 mu-thick sections.

We compared the histologic picture of myocardial fiber disarray in thin (4 mu) and thick (25 mu) sections of tissues obtained at autopsy from 18 adults and eight infants with clinically normal hearts, from 10 hearts with concentric hypertrophy (hypertensive patients), nine with myocardial infarction and four with hypertrophic cardiomyopathy (HCM). In the thick sections, so-called bizarre myocardial fiber disarray in thin sections was seen as a bizarre fascicle disarray. Therefore, the usual fiber disarray reported in cases of HCM is actually a fascicle disarray with a three-dimensional complex network. There was no marked difference in distribution and frequency of fascicle disarray among normal adult and infant hearts, and diseased hearts with hypertension and myocardial infarction. In the four hearts with HCM, diffuse bizarre fascicle disarray in the thick section was detected in the septum and anterior and posterior walls of the left ventricles in all cases, and in the lateral walls in one case. In the portions without the diffuse fascicle disarray, the distribution of disarray was the same as that in hearts with no HCM. Such fascicle disarray, including that of HCM, is probably congenital.

Adult↗
PubMed1979

Pathology of Kawasaki disease: I. Pathology and morphogenesis of the vascular changes.

Histopathological investigation of the vascular changes in Kawasaki disease was carried out on thirty-seven autopsied Japanese patients. Arterial lesions could be classified into following five stages from the view point of morphogenesis of arteritis; 1) endothelial degeneration and increased vascular permeability, 2) edema and degeneration of the media, 3) necrotizing panarteritis, 4) granulation formation, and 5) scarformation. Aneurysm with thrombus was observed mainly in the coronary artery in most patients. It is considered that the initial changes begins in the endothelial cells with increased vascular permeability. Platelet aggregation in the damaged endothelial cells seems to play an important role in the further development of the arteritic changes. Vascular lesions were observed not only in the arterial system but also in the venous system, therefore Kawasaki disease is a systemic vasculitis rather than a systemic arteritis.

Aneurysm↗
PubMed1979

Pathology of Kawasaki disease: II. Distribution and incidence of the vascular lesions.

Histopathology, distribution and incidence of vascular changes were studied in tissues obtained at autopsy on thirty-seven children. Elastic and musculoelastic arteries showed a high incidence of arteritic changes, however the degree of the lesions was in general mild to moderate with the exception of the iliac artery, which revealed severe changes and a necrotizing panarteritis which was often accompanied with an aneurysm formation. A high incidence of arteritic changes, of which main histological feature was necrotizing panarteritis, was seen in extravisceral middle sized arteries. The coronary artery in particular was involved in each case and most had an accompanying aneurysm, some of which had ruptured. Intravisceral small sized arteries showed a relatively low incidence of arteritic changes and the degree of inflamation was in general mild. Phlebitis was present in over half the number of patients. The degree of lesions was mild in the small veins and mild to moderate in the large veins. Vascular lesions in Kawasaki disease should be termed systemic vasculitis rather than a systemic arteritis. There was a correlation between the caliber of involved vessels and the degree of vascular lesions. According to the histopathology, distribution and incidence of angitis, Kawasaki disease does resemble infantile periarteritis nodosa with the exception of the different manner of the coronary and iliac involvement.

Aorta↗
PubMed1979

Suppression of cellular immune response in chemically sympathectomized mice.

Delayed-type hypersensitivity to methylated bovine serum albumin (MBSA), as induced by 6-hydroxydopamine (6-OHDA) was studied in chemically sympathectomized mice. Footpad reaction at 48 h after challenge injection of MBSA was suppressed with doses ranging from 10--300 mg/kg. 6-OHDA was neither cytotoxic to peritoneal macrophages nor was the function of immunoglobulin mediated phagocytosis suppressed. Thus, the suppression of delayed-type hypersensitivity may be attributed to interference with T-cell function.

Animals↗
PubMed1979

[Intracranial hemorrhage in autopsy cases with occlusion of the circle of Willis (author's transl)].

Seventeen autopsy cases with occlusion of the circle of Willis were examined clinicopathologically. These patients ranged in age from 8 years to 64 years and consisted of 6 males and 11 females. The following results were obtained. 1. Fresh and massive intracerebral hemorrhage was confirmed in 13 of 17 patients and cerebral infarct in 4 of 17 patients. 2. Among these 13 patients, massive hemorrhage was found in basal ganglia, thalamus and hypothalamus of 9 patients, and in thalamus, cerebral peduncle and midbrain of 4 patients. 3. Rupture of the dilated muscular-type arteries was noted in the thalamus and basal ganglia in 2 of 13 patients. Ruptured arteries with organization of the lumen were found in the old hemorrhagic foci in one of them. 4. Overgrown and dilated arteries, branching off from the circle of Willis, were confirmed in 11 patients. These arteries consisted of "perforating" arteries well developed as collateral circulation. 5. No ruture in these arteries of the subarachnoidal spaces was found in 11 patients. In one of them, a small saccular aneurysm was found. These findings strongly suggest that in patients with occlusion of the circle of Willis intracerebral rupture of overgrown "perforating" arteries as collateral circulation may be the main cause of intracranial hemorrhage and intracerebral hemorrhage due to rupture of the arteries may be repeated.

Adolescent↗