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Biomedical subjects

T Suga

Publications and source records attributed to T Suga.

At least 271 records · Page 15Linked to original sources
PubMed1985

Specific binding of circulating IgA antibodies in patients with IgA nephropathy.

Detection of circulating IgA antibodies which are specific in patients with IgA nephropathy is described. Freeze and thawed extracts of pharyngeal cells obtained from patients with IgA nephropathy, other glomerular diseases, and healthy adults were cultured with fibroblasts such as Vero or Hel cells at 37 degrees C for 2 weeks. Serum samples were obtained from these patients and healthy adults. The cultured fibroblasts were fixed on slide glasses, and then incubated with the serum samples from the same or other patients with IgA nephropathy. The cells were stained with FITC-labeled heavy-chain specific anti-human IgA antiserum and then examined with a fluorescent microscope. It was demonstrated that the IgA antibodies in sera obtained from patients with IgA nephropathy or HSP nephritis were bound with the nuclear regions of such fibroblasts. It was suggested that IgA antibodies in sera could be bound with some antigenic substances which were transferred from pharyngeal cells of patients with IgA nephropathy to fibroblasts in vitro.

Antibodies, Anti-Idiotypic↗
PubMed1985

The regulation of peroxisomal enzyme systems of Tetrahymena pyriformis by fatty acid composition, glucose and oxygen in the medium.

The effect of the chain length of fatty acids on peroxisomal enzyme activities of Tetrahymena pyriformis was investigated. The growth of cells and the activities of peroxisomal enzymes were inhibited markedly by the addition of medium-chain fatty acids (C6-C12) to the culture medium, whereas the addition of longer-chain fatty acids (C14-C18) resulted in a slight increase of growth and in the marked stimulation of enzyme activities concerned with fatty acid beta-oxidation and the glyoxylate cycle in peroxisomes. Peroxisomal beta-oxidation (fatty acyl-CoA oxidase) was more potent towards longer-chain fatty acids than the mitochondrial activity (fatty acyl-CoA dehydrogenase). The induction of the peroxisomal beta-oxidation system by palmitate was repressed both by the addition of glucose and the aeration of the culture medium, whereas that of the peroxisomal glyoxylate cycle was repressed only by the addition of glucose to the medium. These results indicate that peroxisomal enzyme systems related to the beta-oxidation of fatty acids and the glyoxylate cycle are regulated by the compositions of fatty acids, glucose, and oxygen in the medium.

Acyl-CoA Dehydrogenases↗
PubMed1985

The presence of peroxisomal carnitine palmitoyltransferase in chick embryo liver.

Hepatic peroxisomes and mitochondria from 20-day-old chick embryo were separated by sucrose density gradient centrifugation and the characteristics of carnitine acyltransferases in these organelles were studied. The carnitine acyltransferase activities in peroxisomes were increased markedly by the treatment of chick embryo with clofibrate, while those in mitochondria did not change. In the liver of clofibrate-treated chick embryo, approximately 50% of total liver carnitine palmitoyltransferase (CPT) activity was present in the peroxisomal fraction. Peroxisomal CPT activity was easily solubilized, in contrast with mitochondrial CPT. The solubilized protein solutions from isolated peroxisomes and mitochondria were separately chromatographed on a column of Blue Sepharose CL-6B after the gel filtration on Sephadex G-25. Peroxisomal CPT was completely bound to a Blue Sepharose CL-6B column and was eluted below 0.25 M KCl, whereas mitochondrial CPT was not retained on the column. The substrate specificity profile of peroxisomal CPT with long-chain acyl-CoAs (C8 to C18) was similar to that of mitochondrial CPT, and the apparent Km value of peroxisomal CPT for palmitoyl-CoA was 5.2 microM, being similar to that of mitochondrial CPT. It is concluded that carnitine long-chain acyltransferase, which is different from mitochondrial CPT and is induced by clofibrate treatment, is present in peroxisomes of chick embryo liver.

Acyltransferases↗
PubMed1985

Discrepancy of serum IgA levels determined by single radial immunodiffusion and laser nephelometry in patients with IgA nephropathy.

The levels of IgA in sera were quantitated by single radial immunodiffusion (SRID) and laser nephelometer (LN) to evaluate a precise amount of serum IgA in patients with IgA nephropathy, other glomerular diseases and healthy adults. Thirty patients with IgA nephropathy, twenty patients with other glomerular diseases and eighteen healthy adults were examined. It was shown that the levels of IgA in sera measured by LN were significantly higher than those in sera measured by SRID in patients with IgA nephropathy associated with increased levels of serum IgA. This suggests that the levels of serum IgA measured by SRID in patients with IgA nephropathy were affected by the physicochemical characteristics of circulating IgA in patients with IgA nephropathy. It is postulated that an increase of serum IgA in patients with IgA nephropathy may be mainly due to an increase of polymers rather than a monomer of IgA.

Adult↗
PubMed1985

Evaluation of the staining findings of immunofluorescence in unfixed or fixed renal biopsy specimens from patients with IgA nephropathy and membranous nephropathy.

A study on the evaluation of staining findings of immunofluorescence in unfixed or fixed renal biopsy specimens is described. Renal biopsy specimens obtained from ten patients with IgA nephropathy and membranous nephropathy were embedded in gelatin or paraffin matrix. Renal biopsy specimens embedded in paraffin matrix were digested with 0.05% protease. The specimens were stained with FITC-conjugated anti-human IgA, IgG, IgM or C3 antisera at 4 degrees C overnight. IgA, IgG or IgM were markedly observed in glomeruli using unfixed materials embedded in gelatin matrix or 10% neutral buffered formalin fixed materials embedded in paraffin matrix from patients with IgA nephropathy and membranous nephropathy. There was no significant difference in the intensity or distribution of IgA, IgG or IgM deposition among the two different conditions of immunofluorescence in patients with such diseases. Although the deposition of IgA using unfixed materials embedded in gelatin matrix was prominently coarse granular or lumpy in glomeruli from patients with IgA nephropathy, that of IgA using 10% formalin fixed materials embedded in paraffin matrix was fine granular and/or interrupted linear in glomeruli. It was suggested that the immunofluorescence in renal biopsy specimens embedded in paraffin matrix after digestion with protease is useful for the evaluation of immunoglobulins in glomeruli from patients with IgA nephropathy or membranous nephropathy.

Biopsy↗
PubMed1985

Immunofluorescence staining in unfixed or fixed renal biopsy specimens from patients with diabetic nephropathy.

Immunofluorescence staining in unfixed or fixed renal biopsy specimens were evaluated in nine patients with diabetic nephropathy in order to elucidate if immunofluorescence staining is applicable in fixed renal tissues in such patients. Renal biopsy specimens were embedded in gelatin or paraffin matrix. Renal biopsy specimens embedded in paraffin matrix were digested with 0.05% protease. Immunofluorescent studies of kidney tissues were performed by staining with FITC-labeled heavy chain specific anti-human IgG, IgA, IgM, acute phase reactant (APR) proteins such as alpha 1-anti-trypsin (alpha 1-AT), haptoglobin (Hpt) and beta-lipoprotein (beta-Lp) antisera, and then examined with a fluorescent microscope. Linear and nodular deposition of IgG, IgA, IgM, alpha 1-AT, Hpt, and beta-Lp were observed in the glomerular capillary walls of the renal specimens embedded in paraffin matrix. The staining patterns in specimens embedded in paraffin matrix was similar to that embedded in gelatin matrix. There was no significant difference in the intensity or distribution of IgG, IgM, alpha 1-AT, and beta-Lp deposition among the two different conditions of immunofluorescence in patients with diabetic nephropathy. It was suggested that immunofluorescence staining in renal biopsy specimens embedded in paraffin matrix after digestion with protease is useful for the evaluation of IgG, IgM, APR proteins, and beta-Lp in glomeruli from patients with diabetic nephropathy.

Diabetes Mellitus↗
PubMed1985

IgG, IgA and IgM rheumatoid factors in patients with glomerulonephritis.

Rheumatoid factors (RF), autoantibodies to IgG, have been postulated to have some pathogenetic role in the development of some types of glomerulonephritis. A simple and sensitive solid-phase fluorescence immunoassay was employed to determine whether IgG, IgA and IgM RF were detectable in sera from patients with various types of glomerulonephritis, rheumatoid arthritis (RA) and those with various streptococcal infections. IgG, IgA and IgM RF were significantly increased in the majority of patients with RA, lupus nephritis (SLE), acute poststreptococcal glomerulonephritis (APSGN) and various streptococcal infections. The titers of IgG and IgA RF were significantly higher in patients with APSGN than in those with simple pharyngitis. IgM RF was increated in patients with IgA nephropathy (IgA-N) and in those with membranoproliferative glomerulonephritis type I (MPGN). No significantly high RF was observed in membranous nephropathy (MN) or chronic mesangial proliferative glomerulonephritis without IgA deposition (PGN). It is suggested that some autologous immune mechanisms may be involved in the pathogenesis of some types of glomerulonephritis.

Arthritis, Rheumatoid↗
PubMed1985

Effects of some anti-inflammatory drugs on biochemical values and on hepatic peroxisomal enzymes of rat.

Effects of tolmetin, diclofenac Na, fenbufen, alclofenac, aminopyrine, mepirizole, thiaramide and aspirin as a positive control, which are widely used in this country as anti-inflammatory drugs, and on body and liver weights, triglyceride and cholesterol level and hepatic peroxisomal enzymes of normolipemic rats were examined. All of these drugs except diclofenac Na affected the enzyme composition of hepatic peroxisomes. Tolmetin (100 mg/kg) and fenbufen (50 mg/kg) increased carnitine acetyltransferase (CAT) and fatty acyl-coenzyme A oxidizing system (FAOS) activities, which participate in hepatic lipid metabolism. The latter also increased the activity of D-amino acid oxidase slightly. Alclofenac (300 mg/kg) increased the activities of FAOS, CAT and carnitine palmitoyltransferase which has been known as the rate-limiting enzyme of fatty acid oxidation in mitochondria, and decreased those of catalase and urate oxidase. Aminopyrine (300 mg/kg) increased the activities of catalase and FAOS. However, none of the above drugs influenced liver weight, serum or liver lipid levels. Mepirizole (300 mg/kg) increased the activities of FAOS and CAT about 2-fold, whereas the activities of catalase and urate oxidase and serum triglyceride level were decreased. Furthermore, these drugs showed no enhancement of the biosynthesis of peroxisome proliferation associated polypeptide having a molecular weight of 80000. From these results, it is concluded that although these drugs have an influence on the enzyme composition of hepatic peroxisomes, they may not induce the peroxisome population in hepatic cells. Thus, the possibility of hepatocarinogenicity and lipid lowering effect through the peroxisome-proliferation would be excluded.

Animals↗
PubMed1985

7-Hydroxyguanine, a novel antimetabolite from a strain of Streptomyces purpurascens. II. Physico-chemical properties and structure determination.

The molecular formula of a new antimetabolite produced by Streptomyces purpurascens was determined to be C5H5N5O2 by elemental analysis, FD-MS and 13C NMR. Reduction of this antimetabolite with Raney nickel yielded guanine. The antimetabolite was distinguishable from known N-hydroxyguanines by comparison of their UV spectra. The structure of the antimetabolite was finally established to be 7-hydroxyguanine by X-ray crystallography.

Antimetabolites, Antineoplastic↗
PubMed1985

Immunofluorescent studies on alpha 2-plasmin inhibitor (alpha 2-PI) in glomeruli from patients with IgA nephropathy.

Detection of alpha 2-plasmin inhibitor (alpha 2-PI) and/or fibrinogen in glomeruli by immunofluorescence in 26 patients with IgA nephropathy was described. The present study showed that glomerular injuries such as glomerular adhesion to Bowman's capsule and the cellular and/or fibrous crescent were predominantly observed in glomeruli with alpha 2-PI and/or fibrinogen deposits in patients with IgA nephropathy. Alpha 2-PI coexisted with fibrinogen in glomeruli from patients with IgA nephropathy. It was postulated that the deposition of alpha 2-PI in vivo might lead to the accumulation of glomerular fibrinogen deposits in patients with IgA nephropathy. It was suggested that the depositions of alpha 2-PI and/or fibrinogen in glomeruli may be one of the exacerbative factors in glomeruli from patients with IgA nephropathy.

Adult↗
PubMed1984

Participation of peroxisomal beta-oxidation system in the chain-shortening of a xenobiotic acyl compound.

A drug, (E)-3-[4-(1-imidazolylmethyl)phenyl]-2-propenoic acid, was metabolized to 4-(1-imidazolylmethyl)benzoic acid in isolated hepatocytes of rats, which was enhanced markedly by the pretreatment of rats with clofibrate. With liver homogenates, the formation of the CoA-ester of this drug and its subsequent chain-shortening were demonstrated. In the series of these reactions, acyl-CoA synthetase, CoA, ATP and NAD were required, whereas cyanide did not inhibit the reaction. These results indicate that peroxisomes are capable of shortening the acyl side-chains of drugs by the beta-oxidation, giving an additional suggestion on the functions of peroxisomes.

Acrylates↗
PubMed1984

Effects of long-term vitamin E deficiency and restoration on rat hepatic peroxisomes.

Effects of vitamin E deficiency and its restoration on biochemical characteristics of hepatic peroxisomes were studied. Rats were maintained on the vitamin E-deficient diet for 25 weeks and then on a diet supplemented with vitamin E for 5 weeks. Blood hemolysis by hydrogen peroxide and lipid peroxidation in the liver increased markedly in vitamin E-deficient rats. The former returned to the control level after the resupplying of vitamin E, but the latter did not. Of liver peroxisomal enzymes, the activities of catalase, D-amino-acid oxidase and urate oxidase decreased in vitamin E-deficient rats. On the other hand, activities of fatty acyl-CoA oxidase and carnitine acetyltransferase increased significantly in vitamin E-deficient rats. All activities of these peroxisomal enzymes were restored to the control levels in vitamin E-supplemented rats. The activities of the mitochondrial, lysosomal and microsomal enzymes tested showed no apparent change except that the change of mitochondrial palmitoyltransferase was shown to be similar to that of peroxisomal fatty acid oxidation. These results were also supported by cell fractionation techniques. Following the methods of aqueous polymer two-phase systems, the characteristics of peroxisomal surface membranes altered in respect of their hydrophobicity, but not in respect of the surface charge of peroxisomal membranes. These results indicate that peroxisomal functions, especially those of the fatty acid oxidation system, change their activities more sensitively than other intracellular organelles in response to the condition of vitamin E deficiency.

Animals↗