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Biomedical subjects

M Shingu

Publications and source records attributed to M Shingu.

At least 37 records · Page 2Linked to original sources
PubMed1990

A trial of molecular epidemiology using bovine enteroviruses isolated monthly from cattle.

Enteroviruses were isolated monthly for one year from feces in the intestine of 47 cattle. Judging from the isolation panel, it was suggested that endemic infection occurs. Genetic changes of isolated enteroviruses were traced using RNase T1 oligonucleotide fingerprint analysis and nonparametric distance scaling. Using some characteristics transitions of fingerprint patterns we could also trace some strains. These analyses suggested that in some strains drastic genetic changes may occur, which coincide with additional infections transmitted from other cows. Furthermore, it was indicated that the genetic changes of viruses isolated from cow R13 were not very drastic, but genetic changes were drastic for viruses isolated from cow R19. Overall, we could never observe the same fingerprint pattern using RNase T1. This study suggests that genetic changes tend to accumulate as time elapses, and at the same time, infection decreases.

Animals↗
PubMed1990

The specificity of antiglobulin autoantibodies in patients with primary Sjögren's syndrome.

Antiglobulin autoantibodies have already been demonstrated in the sera of patients with primary Sjögren's syndrome (primary SS). In our study, the specificity of primary SS antiglobulins for different regions of IgG molecules was examined by employing both direct binding and competitive inhibition enzyme-linked immunosorbent assay. We found that a considerable amount of total antiglobulins in primary SS was specific for the Fab portion, although the remainder was specific for the Fc portion, namely rheumatoid factor (RF). In contrast, most of the antiglobulins in RA were specific for the Fc portion of IgG. These results indicate that in primary SS, antiglobulins directed against epitopes different from those of RF are produced. These antiglobulins may prove to have a different role in primary SS than that ascribed to RF in RA.

Antibodies, Anti-Idiotypic↗
PubMed1990

Rheumatoid factor modulation of neutrophil superoxide generation enhancing activity of preformed immune complexes.

Heat aggregated human (HAG) IgG pretreated with total rheumatoid factors isolated from the serum of rheumatoid arthritis patients showed decreased superoxide generation enhancing activity as compared with HAG pretreated with buffer alone. Similarly, monoclonal IgM rheumatoid factor isolated from the serum of a patient with macroglobulinemia complicated by rheumatoid arthritis inhibited superoxide generation enhancing activity of HAG. On the other hand, superoxide generation enhancing activity of BSA-antiBSA immune complexes was not affected by preincubation with rheumatoid factors isolated from the sera of either rheumatoid arthritis patients or the macroglobulinemia patient. Rheumatoid factors isolated from rheumatoid arthritis serum were fractionated by high performance liquid chromatography and IgM-class and IgG-class rheumatoid factors were obtained. IgG-class rheumatoid factor significantly enhanced the superoxide generation enhancing activity of HAG, whereas IgM rheumatoid factor inhibited it. Rheumatoid arthritis sera showed significantly higher superoxide generation enhancing activity than normal sera. HAG preincubated with rheumatoid arthritis sera showed significantly lower superoxide generation enhancing activity than HAG preincubated with normal sera. These results suggest that factors inhibiting superoxide generation enhancing activity of HAG are present in rheumatoid arthritis sera, and that the responsible is IgM rheumatoid factor, whereas IgG rheumatoid factor enhances it. The factors that express superoxide generation enhancing activity in rheumatoid arthritis sera are suggested to be intermediate size immune complexes.

Antigen-Antibody Complex↗
PubMed1990

Monocyte activation in early onset rheumatoid arthritis.

Monocytes from peripheral blood and synovial fluid of patients with definite and classic rheumatoid arthritis spontaneously produced significantly greater amounts of prostaglandin E2 (PGE2), leukotriene B4 (LTB4), and interleukin-1 beta (IL-1 beta) than samples of peripheral blood from normal controls. Peripheral blood monocytes from patients with rheumatoid arthritis produced significantly greater amounts of PGE2 than control samples when stimulated with lipopolysaccharide. There were no significant differences in the spontaneous release of superoxide or N-acetyl-beta-D-glucosaminidase by peripheral blood monocytes between patients and healthy controls. Both stimulated and unstimulated peripheral blood monocytes from patients with definite or classic rheumatoid arthritis produced significantly greater amounts of PGE2 than samples from normal controls. This was true, regardless of the stage of disease and the presence or absence of roentgenological joint abnormalities. Amounts of N-acetyl-beta-D-glucosaminidase released by peripheral blood monocytes from patients correlated positively with the erythrocyte sedimentation rate (ESR) and negatively with duration of disease. Amounts of IL-1 beta and N-acetyl-beta-D-glucosaminidase released from the peripheral blood monocytes of patients who had had their disease for less than one year were significantly higher than those of normal controls. There were no significant correlations between the types of treatment and the amounts of PGE2, LTB4, IL-1 beta or N-acetyl-beta-D-glucosaminidase released by peripheral blood monocytes in patients with rheumatoid arthritis. The findings suggest that monocytes are activated in patients with rheumatoid arthritis both at the onset of disease and during its chronic phase, and that they produce large amounts of mediators which may have a role in the induction and extension of the inflammatory process which leads to tissue damage.

Acetylglucosaminidase↗
PubMed1990

Enhanced growth of mycobacteria by culture filtrate of Gemella haemolysans.

The culture filtrate of G. haemolysans enhanced the growth of mycobacteria. The enhancing substance seemed to be effectively produced in BHI broth supplemented with human blood. The mycobacterial growth was inhibited by high concentrations of the culture filtrate, but was markedly enhanced at low concentrations such as 1/32 or 1/64 dilutions. The generation time at log phase was 7 to 9 hours compared with 14 hours for the control, leading to rapid detection of mycobacteria in culture. With sputa specimens from tuberculosis patients, the culture time to visual detection of mycobacterial growth was decreased by 59 to 67%.

Bacteriological Techniques↗
PubMed1990

Effects of protein phosphorylation with p43v-abl and protein kinase A catalytic subunit on fluorescence intensity.

To study the effect of phosphorylation on protein conformation, a fluorescence spectroscopic study was performed on phosphorylated enolase and histoneH1 proteins. The peak of fluorescence was 330 and 360 nm for each protein, respectively, when excited at 287 nm. The intensities of the fluorescence were measured during the phosphorylation reactions with the protein kinase A and p43v-abl, for serine, threonine and tyrosine, respectively. Slightly increased intensities at 330 and 360 nm for enolase and histoneH1 protein were observed by phosphorylation with p43v-abl, whereas decreased intensities occurred with the protein kinase A catalytic subunit. These data suggest that micro-structural changes are induced at the residue, either tyrosine, serine or threonine in the protein.

Histones↗
PubMed1990

An in vitro kinetic assay of ATPase by phosphorus-31 NMR.

The ATPase activity of RecA protein was examined by monitoring the changes of NMR phosphorus signals of ATP, ADP and inorganic phosphate. The areas of phosphorus-31 NMR peaks from inorganic phosphate and ADP, which increased with time, and the signals from ATP, which decreased with time, were fitted by a linear least square method to obtain the initial rate constants. The rate constants were examined for dependence on RecA protein concentration, temperature and pH. This assay system is useful for testing extrinsic physico-chemical effects on ATPase activity; because only essential components are present in a confined system, and the rate constants can be measured with a single step.

Adenosine Triphosphatases↗
PubMed1990

Natural killer (NK) cell activity of mice treated with herpes simplex virus type-2, sarcoma-180 cells, cyclosporine and cimetidine.

NK cell activity in beige mice was compared with that in control BALB/c mice and BALB/c mice treated with HSV-2, sarcoma-180 cells, cimetidine and cyclosporine. The NK cell activity in five week-old beige mice was lower than in three week-old BALB/c mice. The NK cell activity in eight week-old BALB/c mice was four to eleven times the activity in BALB/c mice that were three weeks of age. BALB/c mice, injected with 2 mg cyclosporine or 10(7) plaque forming units (PFU) of HSV-2, had decreased NK cell activity. BALB/c mice, injected with 2 mg cimetidine, 10(6) sarcoma-180 cells and 6.0 x 10(5) PFU of HSV-2, had high NK cell activities compared with the control mice. Cimetidine further increased the effect of HSV-2 or sarcoma-180 on NK activity. BALB/c mice that received a transfer of less than 10(7) NK cells developed a high resistance against viral infections, but mice that received more than 10(7) transferred NK cells had a lower resistance to viral infections than the control mice or mice receiving less than 10(7) NK cells.

Animals↗
PubMed1990

Subcloning and trial of expression of the protein kinase catalytic domain of RSV-src gene.

The gene of catalytic domain of the protein kinase of RSV-scr was cloned into the BamHI cloning site of translation vector pET-8c which containing T7 RNA polymerase promotor, and transformed BL21 (DE3) pLys S (Studier and Moffatt, 1986). The putative molecular weight of the protein was about 33 kd as evaluated on the basis of its nucleotide size showed the identical mobility in SDS-polyacrylamide gel electrophoresis. However, yield of protein production was not high, probably, because of its instability in Escherichia coli.

Cloning, Molecular↗
PubMed1990

[Decrease of Leu7 positive cells in peripheral blood from patients with aseptic meningitis].

In order to clarify the role of natural killer cell in the central nervous system (CNS) infection, we examined Leu7 positive cells in peripheral blood of aseptic meningitis by flow cytometry. We studied 10 patients with aseptic meningitis (5 echo virus type 6 and 5 suspected viral meningitis). Also 3 patients with Japanese encephalitis, 3 with fungal meningitis, each one with bacterial meningitis, tuberculous meningitis and brainstem encephalitis were analyzed. Blood samples of acute phase and after recovery were obtained by the first examination on admission and the latest examination after normalization of cerebrospinal fluid findings, respectively. All aseptic meningitis patients showed decrease of Leu7 positive cells in acute phase (mean +/- SD = 6.8 +/- 3.12%, from 3 to 25 days of illness) and continued after recovery (8.3 +/- 4.27%, from 35 to 503 days of illness) in all but one. The number of the cells found in the aseptic meningitis patients during the acute phase and after recovery was significantly lower than in normal subjects (p less than 0.01). The change did not differ statistically between the acute phase and post recovery. The date suggest that decreased Leu7 positive cells is present before infection. As concerning other CNS infections, the positive cells decreased from acute phase to after recovery in two Japanese encephalitis and one tuberculous patients. But because of small number, it was not decided whether the decrease significantly was low value or not. Since natural killer cells is related to defence mechanism of viral infection in acute phase, it seems that low natural killer activity may develop the viral infection. Therefore the date raises the possibility that the people who has originally less the natural killer cells tend to be susceptible, as far as viral meningitis.

Adolescent↗
PubMed1990

Detection of anti-heart antibody in sera from patients with myocarditis or myocardiopathy by use of microcalorimetry.

Circulating autoantibodies have been commonly demonstrated in patients with viral heart disease. However, most of the previously established methods are limited to detection of circulating autoantibodies in sera, and the results correlate poorly with each other and with disease activity. Therefore, there is a need for new methods which can be used to study the resulting cellular effects after binding of autoantibodies to cell surface receptors and to correlate serum autoantibodies with disease activity. A microcalorimetric method was applied to detect circulating autoantibodies by measuring heat production of a line of cells from human embryo heart tissue. The instrument used was a thermoactive cell analyzer ESCO-3000 (Denshi kagaku Co, Musashino-shi, Tokyo). With the microcalorimeter, decreased heat production by cultured cells was demonstrated after admixture of anti-cellular antibody in vitro. Cardiac-specific autoantibodies were found in 53% of patients with viral heart disease. The microcalorimetric method of measuring anti-cellular antibody by monitoring heat production can be very useful and informative.

Animals↗
PubMed1989

C1q binding to human vascular smooth muscle cells mediates immune complex deposition and superoxide generation.

Evidence was obtained for the binding of C1q to the membrane of cultured vascular smooth muscle cells derived from human umbilical cord veins. C1q was fixed to the cell membrane at 4 degrees C, whereas it was ingested into the cytoplasm, as a cytoplasmic inclusion, when tested at 37 degrees C. The addition of C1q in advance inhibited the subsequent binding of C1q. Neither fibronectin nor laminin was detected on the cell membrane. Aggregated IgG bound to vascular smooth muscle cells in the case of preincubation with C1q at 4 degrees C, whereas aggregated IgG did not bind to the cells in the absence of C1q. The addition of C1q molecules to the cells in suspension enhanced superoxide generation by vascular smooth muscle cells. There was no effect of C1q on superoxide generation by the cells in monolayer. These results suggest that C1q binds on the membrane of vascular smooth muscle cells via its specific receptor that mediates immune complex binding to the cells and superoxide generation. These properties elucidate the mechanisms by which circulating immune complexes deposit in the vascular wall, and subsequent degradation of tissue components surrounding vascular smooth muscle cells occurs through oxidative burst of the cells.

Antigen-Antibody Complex↗
PubMed1989

Iron-binding proteins and free iron in synovial fluids of rheumatoid arthritis patients.

Iron-binding proteins (lactoferrin, transferrin and ferritin) and free iron were measured in synovial fluid (SF) from 30 patients with rheumatoid arthritis (RA) and 20 osteoarthritis (OA) patients. The iron-binding proteins except transferrin were significantly increased in RA SF as compared with OA SF. Similarly, free iron was also significantly higher in RA SF than in OA SF, whereas the ferritin saturation index, transferrin saturation index and bound iron were more significantly decreased in RA SF than in OA SF. These results suggest that RA SF contains sufficient micromolar amounts of free iron to allow hydroxyl radical formation. Also the capacity of iron-binding proteins to bind free iron is inadequate in the presence of a large amount of iron-binding proteins which are present in RA SF.

Antigen-Antibody Complex↗
PubMed1989

Hydrogen-1 nuclear magnetic resonance studies of staphylococcal nuclease variant H124L: pH dependence of histidines and tyrosines.

The pH dependence of the 1H NMR spectrum of staphylococcal nuclease H124L was investigated as a function of the binding of Ca2+, the ion required for enzymatic activity, and deoxythymidine-3',5'-diphosphate (pdTp), a competitive inhibitor. The protein studied was the product of a cloned gene expressed in Escherichia coli which yields a protein having a sequence identical to that of the nuclease isolated from the V8 strain of Staphylococcus aureus. Of the observable ring protons of the three histidine residues, only the C delta 1H of His46 shows a large chemical shift perturbation on formation of the ternary complex, (nuclease H124L).pdTp.Ca2+. The pKa of His46 is lowered by 0.2 pH unit in the binary complex. All seven tyrosines titrate with normal pKa values between 9 and 11 in the unligated nuclease. In the ternary complex, however, the pKa values of Tyr85 and Tyr93 increase above pH 11.0. The chemical shift perturbations of the ring protons of the Tyr27, Tyr85, Tyr113, and Tyr115 were observed between pH 4 and 6; these spectral perturbations are attributed to interactions with carboxylate groups. Binding Ca2+ alone acted opposite to the perturbation in Tyr113 and Tyr115. Ca2+ binding leads to deshielding the ring protons of Tyr113, but this effect is removed in the ternary complex. Binding of pdTp and Ca2+ stabilizes the protein against high pH denaturation up to pH 11.5.

Binding Sites↗
PubMed1989

Stimulation of prostaglandin synthesis by cholecystokinin in primary culture cells of bovine gallbladder muscle.

Primary culture cells derived from bovine gallbladder muscles synthesize PGE2 as a major cyclooxygenase product with a trace amount of 6-keto-PGF1 alpha-like material. The synthesis of PGE2 and total cyclooxygenase products was enhanced in response to cholecystokinin (CCK). In the presence of indomethacin the synthesis of PG was inhibited and the release of arachidonic acid (AA) in response to CCK was enhanced. These data suggest that CCK may stimulate the release of AA, probably by activating phospholipase A2/C, from membrane phospholipids in the gallbladder muscle.

Animals↗
PubMed1989

Possible role of H2O2-mediated complement activation and cytokines-mediated fibroblasts superoxide generation on skin inflammation.

The degree of complement activation produced by hydrogen peroxide was estimated by the inhibition of serum homolytic activity (% IHA). Sera from patients with systemic lupus erythematosus and psoriasis vulgaris were resistant to hydrogen-peroxide-mediated complement activation. %IHA negatively correlated with ceruloplasmin level or catalase activity in systemic lupus erythematosus sera, but did not correlate with transferrin level. The addition of free metal ions, FeCl2 or CuCl2, promoted hydrogen-peroxide-mediated complement activation. These results suggest that hydroxyl radical is involved in complement activation and that the factors responsible for the insensitivity of pathological sera to H2O2 are catalase and ceruloplasmin in the sera. Human skin fibroblasts generate superoxide and tumor necrosis factor enhanced it, but interleukin-1 beta inhibited it. Normal serum cultured with fibroblasts for 24 h showed complement activation via catalase-inhibitable process, suggesting that hydrogen peroxide has an important role in fibroblast-mediated complement activation. It is speculated that fibroblasts and complement activation by oxygen radicals have an important role in inflammation and subsequent tissue damage at the site of skin lesion.

Cells, Cultured↗
PubMed1989

Laboratory diagnosis of viral myocarditis. A review.

This review delineates the impact of molecular biology on the diagnosis and pathogenesis of coxsackie B viral myocarditis. The etiological role of the coxsackie B viruses in acute myocarditis is well established. A hallmark of most coxsackie B virus infections is extension cytopathology of the host cell. Recent evidence from studies of a nonlytic infection show that a coxsackie B virus can alter an infected cell which results from persistent infection. There are two other mechanisms for cardiac injury during coxsackie B virus infection. The first phase usually occurs during the first week after infection, and is probably a direct result of lytic infection to the myocytes and of the accompanying inflammatory response. The second phase of coxsackie B virus-induced myocarditis is accompanied by an autoimmune response to heart tissue, which occurs 2 weeks after infection. Genetic factors probably play a role, but their contribution has not yet been evaluated.

Antibodies, Viral↗