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Biomedical subjects

Y Yoshikawa

Publications and source records attributed to Y Yoshikawa.

At least 325 records · Page 18Linked to original sources

Membranoproliferative glomerulonephritis in Takayasu's arteritis.

The occurrence of glomerulonephritis (GN) in patients with Takayasu's arteritis (TA) is rare. We describe a 28-year-old man with TA who presented with mesangial proliferative GN and subsequently developed membranoproliferative GN with nephrotic syndrome and deterioration of the renal function. The former is the most common type of GN complicating TA, while the latter has not been adequately reported in association with this disease. Although the mechanisms for the initiation and progression of these glomerular injuries are not clear, the present case suggests that a wider spectrum of GN can be seen in patients with TA and that cases of TA with urinary abnormalities should be followed carefully.

Adult↗

Anti-rat myoglobin antisera in the immunocytochemical diagnosis of rhabdomyosarcomas of rats.

Anti-rat myoglobin (Mb) was prepared and used in the avidin-biotin-peroxidase complex (ABC) method on paraffin-embedded sections of nine soft tissue tumors (including two rhabdomyosarcomas) of rats. Distribution and nature of the reactive substance to Mb antiserum were compared to those of desmin antiserum. Rat Mb was isolated from the skeletal muscle; monospecificity of the rat antiserum was confirmed by the immunoblotting procedures. The Mb antiserum reacted specifically to normal and neoplastic striated muscle cells. Mb-staining reactions were present diffusely in the cytoplasm, while desmin-staining substances were localized at Z-bands or were diffuse in the cytoplasm as separated aggregates. Reaction to the Mb serum was also detected in cells of thick portions of Henle's loop and distal convoluted tubules.

Animals↗

In vivo effects of deoxyspergualin (NKT-01) on lymphocyte activation in response to alloantigens.

We studied the effects of deoxyspergualin (NKT-01) on the events of lymphocyte activation in vivo by inoculating mice in the footpad with allogeneic spleen cells, and compared the effects with those of cyclosporin A (CyA). The administration of NKT-01 increased the numbers of cells recovered from the popliteal lymph node (PLN) 7 days after inoculation, but inhibited the proliferation of these cells in the presence of exogenous interleukin 2 (IL-2). NKT-01 enhanced IL-2 production, but suppressed the production of macrophage activating factor (MAF) in the mixed lymphocyte reaction between the PLN cells and allogeneic spleen cells treated with mitomycin C. CyA decreased the numbers of PLN cells little, and suppressed the response to exogenous IL-2 and the production of both IL-2 and MAF. Results with tumor cells used as allogeneic cells suggested that there was a close relationship between the suppression of MAF production by NKT-01 and its inhibition of allograft rejection. The findings showed that NKT-01 inhibited both the MAF production by and the response to IL-2 of PLN cells, and that these effects were involved in the suppression of allograft rejection by NKT-01.

Animals↗

Molecular cloning and sequence analysis of the rinderpest virus mRNA encoding the hemagglutinin protein.

We cloned the full-length cDNAs corresponding to the mRNA for the hemagglutinin (H) protein of rinderpest virus (RV) and determined the nucleotide sequence of RV-H. The gene of RV-H was composed of 1952 nucleotides and contained a single large open reading frame, which was capable of encoding a protein of 609 amino acids with a molecular weight of 68,330 Da. The nucleotide sequence and predicted amino acid sequence were compared with those of the measles virus (MV)-H. The 5' end of the message (nucleotides 1 to 485) was largely conserved, with a homology of 75.1% of the nucleotides and 78.0% of the predicted amino acids. In the middle portion (nucleotides 486-1310), where the potential glycosylation sites exist, 56.6% of the nucleotides and 49.5% of the amino acids were identical. In the 3' end of the message (nucleotides 1311-1850), 63.3% of the nucleotides and 58.1% of the amino acids were identical. Four potential glycosylation sites were found in RV-H protein and three of them were the same as those of MV-H protein. The positions of 13 cysteine residues of RV-H were absolutely identical to those of MV-H. The hydropathy profile of RV-H protein resembled that of MV-H. One major hydrophobic region long enough to be an anchor in the membrane was located near the N-terminus.

Amino Acid Sequence↗

OF4949, new inhibitors of aminopeptidase B. IV. Effects of OF4949 and its derivatives on enzyme systems.

OF4949-I and II inhibited aminopeptidase B from Ehrlich ascites carcinoma in a competitive way and the Ki value for both against L-arginine-beta-naphthylamide was 8 X 10(-9) M. Inhibition by I and II of various exopeptidases and endopeptidases was examined. OF4949-I and II both strongly inhibited leucine aminopeptidase and enkephalin-degrading aminopeptidase; I also inhibited enkephalinase B. The inhibitory effects of various derivatives of I and II on aminopeptidase B activity, showed that the terminal amino and carboxamide groups are essential for activity.

Aminopeptidases↗

OF4949, new inhibitors of aminopeptidase B. V. Effect on the murine immune system.

OF4949-I inhibited the growth of the solid form of IMC carcinoma and protected against pulmonary metastases of Lewis lung carcinoma. It also augmented the cytostatic activity of mouse peritoneal macrophages, the natural killer activity, and the antibody-dependent cell-mediated cytotoxicity of mouse spleen cells. This substance was not cytotoxic to cultured tumor or normal cells even at high concentrations. These results suggest that a cell-mediated immune response stimulated by this compound might account for its antitumor activity.

Aminopeptidases↗

Effects of coenzyme Q10 on recovery of hypoxia-induced changes in ATP and creatine phosphate contents of sinoatrial nodal cells of the rabbit's heart after reoxygenation.

We have studied the effects of reoxygenation on hypoxia-induced changes in contents of high energy phosphate compounds in pacemaker cells of nodal tissues excised from the rabbit heart, and effects of coenzyme Q10 on the electrical activity and metabolite contents in the tissue exposed to hypoxia and then reoxygenated. The contents of ATP and creatine phosphate (CP) in the sinoatrial node tissue were markedly reduced within 15-30 min after exposure to hypoxic Tyrode's solution. Reoxygenation produced almost complete recovery of the tissue ATP, but not of CP. After 60-120 min of hypoxia, the tissue ATP and CP decreased to about 60-30% of the initial value, but were not recovered by reoxygenation. Coenzyme Q10 (CoQ) at concentrations of 10(-6)-10(-5) g/ml did not produce changes in action potential parameters in the normal Tyrode's solution. CoQ (10(-5) g/ml) did not prevent the decreases in tissular ATP and CP in the initial period of hypoxia (30-60 min), but the ATP content at 120 min of hypoxia in the presence of CoQ was higher than the control. CoQ promoted recovery of tissular ATP after reoxygenation. Our results provide direct evidence that generation of action potentials in the sinoatrial nodal cells can be maintained by a small amount of ATP produced by the anaerobic glycolytic pathway. The present results suggest that exogenous CoQ would facilitate resynthesis of ATP in the functionally impaired mitochondria.

Action Potentials↗

Pulmonary lesions in Wegener's granulomatosis: a clinicopathologic study of 22 autopsy cases.

Pulmonary lesions in 22 autopsy cases of Wegener's granulomatosis (WG) were studied clinicopathologically, with special emphasis on the relation of the lesions to systemic vasculitis, glomerular changes, and clinical manifestations. The pulmonary lesions were divided, on the basis of morphologic characteristics, into four types: 1) the fulminant type, which was characterized by diffusely distributed acute exudative and proliferative alveolitis with prominent small vessel vasculitis (three cases); 2) the granulomatous type, the classic granulomatous lesion (seven cases); 3) the fibrous scar type (five cases); and 4) the mixed type, which had features of both acute exudative and scar-type lesions (seven cases). Clinically, lesions of the fulminant type had rapidly deteriorating courses, terminating in respiratory failure immediately following the onset of the pulmonary manifestations, whereas those of the fibrous scar type had protracted courses. The systemic vasculitis and glomerular lesions in the cases of the fulminant type were almost exclusively fresh lesions. In contrast, the systemic lesions in the cases of the fibrous scar type were nearly always cicatricial. Thus, the morphologic features of the systemic lesions and the clinical profile in each case were well correlated with the pathologic classification of the pulmonary lesions. This correlation may support the assumption that the respiratory tract lesion plays an important role in the progression of systemic involvement in the disease. A comparative study of vascular lesions in various organs revealed some histologic differences between vasculitis in the lungs and that observed outside the respiratory tract; pathogenetic heterogeneity was thus suggested between lesions in the two locations.

Adolescent↗

Characterization of messenger RNAs of measles virus.

Ten different RNA species associated with measles virus were detected in virus-infected cells. The largest RNA (no. 1) was considered to be genomic RNA and the other nine RNAs were found to have a methylated cap as well as a poly(A) tail. Northern blot hybridization indicated that RNAs no. 2 and 7 to 10 correspond to mRNAs encoding structural proteins, and that RNAs no. 3 to 6 are intermediate-sized (IS)RNAs. The possibility that the ISRNAs represent defective interfering RNA or a precursor form of the mRNA seems to be unlikely since the amounts of IS RNAs did not increase after undiluted passages or decrease in a pulse-chase experiment. These results indicate that IS RNAs are readthrough transcripts of neighbouring cistrons.

Genes, Viral↗

Adaptation of the lapinized rinderpest virus to in vitro growth and attenuation of its virulence in rabbits.

A lapinized rinderpest virus, the L strain, which is virulent in rabbits and had been grown only in rabbits, was adapted to grow in Vero cells by the fusion of Vero cells with virus-infected rabbit spleen cells in the presence of polyethylene glycol, and subsequently passaged in Vero cells by co-culture technique. After several passages, free virus was produced at high titre. The Vero cell-adapted virus acquired the ability to infect several cell lines which were non-permissive to the unadapted virus. Analysis of virus proteins by immunofluorescence using monoclonal antibodies revealed that marked changes occurred in F, P, NP and M proteins by passage in Vero cells. In parallel to the adaptation to cell culture in vitro, the virulence of the virus measured in terms of clinical signs and histological lesions in the lymphoid tissues decreased in its severity whereas its immunosuppressive capacity was maintained unaltered. Thus, rinderpest virus with different degrees of virulence is now available for study in vitro.

Acclimatization↗

Neurovirulence in mice of neural cell-adapted canine distemper virus.

Neurovirulence of the Onderstepoort strain of canine distemper virus (CDV) adapted to human neural cell lines was determined by the intracerebral inoculation of DDD mice at 3 and 5 weeks of age. Intensity of neurovirulence was estimated by histopathological changes in the central nervous system and clinical symptoms. The original virus propagated in Vero cells induced leptomeningoencephalitis, whereas neuroblastoma-adapted virus induced nerve cell degeneration and mild encephalitis with relatively low morbidity and fatality. In contrast, the viruses adapted to glioblastoma and oligodendroglioma caused high morbidity and fatality. The latter two viruses induced necrotizing encephalopathy including edema and hyperemia. In addition, the glioblastoma-adapted virus induced formation of giant cells. The oligodendroglioma-adapted virus caused demyelination and spongy state associated with degeneration of glial cells and axons. These observations are discussed in regard to a possible correlation between the neurovirulence of CDV in mice and its tropism for neural cells in vitro.

Aging↗

Hemodiafiltration treatment of deep hepatic coma by protein passing membrane: case report.

Based on the assumption that middle molecules that induce hepatic coma occur in the plasma of patients with fulminant hepatic failure (FHF), the authors have developed a hemodiafiltration (HDF) method using a large-pore poly(methylmethacrylate) (PMMA) membrane that allows proteins to pass through. PMMA HDF resulted in complete recovery of deep coma and long-term survival in a patient with severe FHF. Although a large-scale controlled trial is needed, PMMA HDF is believed to be promising as a future artificial liver support.

Adult↗