[Serum laminin and collagen in diabetes mellitus].
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Animals↗
Biomedical subjects
N Kato
Publications and source records attributed to N Kato.
[Urinary excretions of laminin and collagens].
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Biomarkers↗
[Current status of transplantation of lungs from living donors].
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Humans↗
[Running fit and generalized tonic-clonic seizure are differently controlled by different subtype receptors in the brainstem].
Rats neonatally treated with 0.02% propylthiouracil (PTU) through mother's milk showed a high incidence of audiogenic seizures after maturation. These audiogenic seizures were differently modified by MK-801 and NBQX; while intraperitoneal MK-801 equally inhibited running fit (RF) and generalized tonic-clonic seizure (GTCS), NBQX administered into cisterna ambiens significantly inhibited RF but not GTCS. The possible involvement of glutamate receptors in the inferior colliculus was further investigated using naive Sprague-Dawley rats injected with NMDA, AMPA or cyclothiazide, known as an inhibitor of desensitization of AMPA action. All drugs tested successfully induced RF followed by GTCS, resembling audiogenic seizures in PTU-treated rats. However, sound stimulation could augment AMPA-induced, but not NMDA-induced GTCS. Systemic administration with MK-801 potently blocked GTCS induced by AMPA/cyclothiazide, but the same drug failed to block RF after intracisternal injection with AMPA/cyclothiazide. Furthermore, intracisternal administration with NBQX significantly inhibited only RF induced by AMPA/cyclothiazide. The present study suggests that: 1) glutamate receptors in the brainstem, possible in the inferior colliculus, play a crucial role in audiogenic seizures, namely the initiation of RF and propagation into GTCS; and 2) the initiation mechanism is regulated by both NMDA and AMPA receptors, whereas propagation is mainly controlled by NMDA receptors.
Acoustic Stimulation↗
Estimation of Young's modulus in swine cortical bone using quantitative computed tomography.
The cortical bones of swine were cut into plates measuring 40 x 10 x 2 mm and scanned by quantitative computed tomography (QCT). Compressive loading tests were performed at 100 Newtons, and the strain on the bone was measured with strain gauges. The mean Young's modulus and Poisson's ratio of one hundred specimens were 19.4 +/- 5.8 GPa and 0.34 +/- 0.09, respectively. A positive correlation (r = 0.47 +/- 0.11, p < 0.001) was observed between Young's modulus and the bone density of specimens determined by QCT, which suggests that QCT values might directly predict Young's modulus of cortical bone.
Animals↗
Effect of aging on the concentrations of nitrous oxide in exhaled air.
Trace gases in exhaled air have been used as a simple means of assessing metabolic reactions. The investigations of trace gases derived from bacteria in human exhalation are usually hydrogen (H2) or methane (CH4). On the other hand, nitrous oxide (N2O) is also derived from microorganisms, especially denitrifying bacteria. Although many kinds of denitrifying bacteria have been isolated on and in the human body, there has been few concerning N2O. We studied 222 healthy people from the age of 5 to 85 years. The analysis of N2O in exhaled air was carried out by a infrared-photoacoustic (IR-PAS) analyzer. It was found that N2O ranged from 0 to 1670 ppbv in exhaled air and that 59% (131) of the subjects were producers of N2O. A highly significant relationship was observed between age and concentrations of N2O (r = 0.40, P < 0.01). The rate of production in young children and in the aged was significantly higher than that in adults aged 20-39 years (P < 0.01), and less than 30% were producers during puberty. The change of normal microflora on and in human body with aging may have caused the significant relationship between age and emissions of N2O.
Adolescent↗
Does dual infection by hepatitis B and C viruses play an important role in the pathogenesis of hepatocellular carcinoma in Japan?
BACKGROUND: There are contradictory data concerning the synergistic effect of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection on the progression from chronic hepatitis to hepatocellular carcinoma (HCC). METHODS: To clarify the role of coinfection with HBV and HCV in the progression and pathogenesis of HCC, viral and clinicopathologic features were studied in 368 consecutive HCC patients at the University of Tokyo from 1991-1995. RESULTS: Approximately 83% of patients (305 patients) were seropositive for the HCV antibody ("C-viral") and approximately 10% (37 patients) were positive for the hepatitis B surface antigen ("B-viral"). Positivity for both (dual infection) was found in only 2% of patients, and negativity for both in 5%. The incidence of dual infection in HCC patients was Similar to that in 549 patients with chronic hepatitis (1%) and 119 patients with cirrhosis (1%). Of the six HCC patients with dual infection, five patients were positive for the HBV early antigen and HBV DNA was less than measurable, whereas HCV RNA was detected and ranged from 10(3)-10(6) copies/50 microL of serum by competitive reverse transcriptase-polymerase chain reaction, and the clinical features resembled those of "C-viral" HCC. The remaining patient was early antigen positive and had HBV DNA by slot blot analysis, but the serum HCV RNA level was less than measurable. These data indicate that mutually exclusive viral replication occurred in patients with persistent coinfection. To further clarify further the possible involvement of HBV infection in "C-viral" HCC, HBV core antibody (HBcAb) was tested in 192 patients and was found to be positive in 111 and negative in 81. The serum HCV RNA level and clinicopathologic features (such as age and the severity of liver disease) were similar among the "C-viral" HCC patients irrespective of the presence or absence of HBcAb. CONCLUSIONS: Based on these results, coinfection was found to be much less prevalent than generally is claimed, and even in a few HCC patients with the coinfection the mutually exclusive viral replication was noted, suggesting that coinfection plays little if any role in the development of HCC.
Adult↗
Changes of immunoreactive neuropeptide Y, somatostatin and corticotropin-releasing factor (CRF) in the brain of a novel epileptic mutant rat, Ihara's genetically epileptic rat (IGER).
Ihara's genetically epileptic rat (IGER) is a rat mutant with genetically scheduled spontaneous convulsions mimicking human limbic seizures. In the present study, the possible changes of three neuropeptides, neuropeptide Y (NPY), somatostatin (SRIF) and corticotropin-releasing factor (CRF), in the brains of IGER were investigated. Increased contents of immunoreactive (IR) NPY were found only in the hippocampus of 2-month IGERs before developing convulsive seizures, while similar increases of IR-NPY were discovered in the striatum and pyriform and entorhinal cortex as well as hippocampus in 8-month IGERs with repetitive seizures. There were no significant differences in the brain contents of IR-SRIF and IR-CRF between IGERs and the controls at both ages. These findings indicate an enhanced rate of NPY synthesis in this experimental model of epilepsy which may play a critical role in the development of epileptogenesis.
Animals↗
Hepatitis G virus replication in human cultured cells displaying susceptibility to hepatitis C virus infection.
We recently developed a hepatitis C virus (HCV) replication system using two cultured human cell lines: MT-2C, a human T-cell leukemia virus type I-infected cloned T cell line, and PH5CH, a non-neoplastic human hepatocyte line. In the course of the study, we found evidence that replication of hepatitis G virus (HGV), which has recently been identified, was supported in both MT-2C and PH5CH cells. When these cells were inoculated with serum 1B-3 containing both HCV and HGV obtained from a blood donor, the 5'-noncoding (5'-NC) regions of HCV RNA and HGV RNA were detected by RT-nested PCR in both cell lines more than 30 days postinoculation, and the 3'-noncoding region of HGV RNA was also detected in the both cell lines more than 30 days postinoculation. Sequence analysis of the 5'-NC region of HGV RNA revealed the quasispecies nature of HGV, although the 5'-NC region was highly conserved among HGV isolates. This HGV-infected culture system will be useful for various biological and virological studies of HGV.
Base Sequence↗
Development of MK-801, kainate, AMPA, and muscimol binding sites and the effect of dark rearing in rat visual cortex.
We used quantitative autoradiography to determine whether the development of glutamate receptors correlates with the plastic period for monocular deprivation in rat visual cortex. To study glutamate receptors, we incubated sections of rat visual cortex with tritiated (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]-cyclohepten-5,10imin e maleate (MK-801), tritiated kainate, and tritiated amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid (AMPA). [3H]MK-801 is a noncompetitive ligand for the N-methyl-D-aspartate (NMDA) receptor. [3H]kainate and [3H]AMPA are competitive ligands for non-NMDA receptors. To compare glutamate binding sites with a nonglutamate binding site, we studied [3H]muscimol, which binds to gamma-aminobutyric acid (GABA)A receptors. [3H]MK-801 binding was maximal at postnatal day 26 (P26) and decreased in adulthood. [3H]AMPA binding was maximal at P18. [3H]kainate binding and [3H]muscimol binding were not age dependent. Dark rearing partially prevented the age-dependent decrease in [3H]MK-801 binding but had no effect on [3H]kainate or [3H]AMPA binding. Dark rearing decreased muscimol binding in adult animals. These results suggest that NMDA receptors, but not other glutamate receptors or GABAA receptors, are likely to be critical for developmental plasticity in rat visual cortex.
Animals↗
[A case of post-kidney transplantation liver failure with hepatitis B carrier state].
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Adult↗
Cloning of poly(3-hydroxybutyrate) depolymerase from a marine bacterium, Alcaligenes faecalis AE122, and characterization of its gene product.
A DNA fragment that carries the gene coding for poly(3-hydroxybutyrate) (PHB) depolymerase was cloned from the chromosomal DNA of Alcaligenes faecalis AE122 isolated from seawater. The open reading frame encoding the precursor of the PHB depolymerase was 1905 base pairs (bp) long, corresponding to a protein of 635 amino acid residues (M(r) = 65,208). The promoter site, which could be recognized by Escherichia coli RNA polymerase, was upstream from the gene, and the sequence adhering to the ribosome-binding sequence was found in front of the gene. The deduced amino acid sequence agreed with the N-terminal amino acid sequence of the purified PHB depolymerase from amino acid 28 onwards. Analysis of the deduced amino acid sequence revealed the domain structure of the protein; a signal peptide of 27 amino acids long was followed by a catalytic domain of about 400 amino acids, a fibronectin type III module sequence, and a putative substrate binding domain. The molecular mass (62,526) of the mature protein deduced from the nucleotide sequence was significantly lower than the value (95 kDa) estimated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, but coincided well with the value (62,426) estimated from matrix-assisted laser desorption ionization mass spectra. By comparison of the primary structure with those of other PHB depolymerases, the substrate binding domain was found to consist of two domains, PHB-specific and poly(3-hydroxyvalerate)-specific ones, connected by a linker region. The PHB depolymerase gene was expressed in Escherichia coli under the control of the tac promoter. The enzyme expressed in E. coli was purified from culture broth and showed the same catalytic properties as the enzyme from A. faecalis.
Alcaligenes↗
Detection of a prothrombotic state after acute aerobic exercise.
Angina, myocardial infarction, and sudden cardiac death are associated with thrombus formation in coronary arteries. It is generally believed that these conditions benefit from long-term exercise. However, the evidence for such amelioration or prevention is inconclusive and so is the mechanism through which long-term exercise exerts its beneficial effect on various ischaemic conditions. Because of the thrombotic events, the effects of exercise on platelet reactivity, blood coagulation and fibrinolysis have been extensively studied, but the findings are not consistent (1-9). This is mainly due to methodological problems. Analysis of platelet response to a variety of agonists and the dozen of coagulation and fibrinolysis variables makes the assessment of the overall platelet function, coagulation and fibrinolysis status extremely difficult.
Adult↗
Antirheumatic agents: novel methotrexate derivatives bearing a benzoxazine or benzothiazine moiety.
Novel methotrexate (MTX) derivatives bearing dihydro-2H-1,4-benzothiazine or dihydro-2H-1,4-benzoxazine were synthesized and tested for in vitro antiproliferative activities against human synovial cells (hSC) and human peripheral blood mononuclear cells (hPBMC) obtained from patients with rheumatoid arthritis and healthy volunteers, respectively. In vivo antiarthritic activities of these derivatives were also evaluated in a rat adjuvant arthritis model. N-[[4-[(2,4-Diaminopteridin-6-yl)methyl]-3,4-dihydro-2H-1, 4-benzothiazin-7-yl]carbonyl]-L-glutamic acid (3c) exhibited more potent antiproliferative activities in hSC and hPBMC than MTX in vitro. Antiproliferative activities of N-[[4-[(2,4-diaminopteridin-6-yl)methyl]-3,4-dihydro-2H-1, 4-benzoxazin-7-yl]carbonyl]-L-homoglutamic acid (3b) and N-[[4-[(2,4-diaminopteridin-6-yl)methyl]-3,4-dihydro-2H-1, 4-benzothiazin-7-yl]carbonyl]-L-homoglutamic acid (3d) (MX-68) were comparable to that of MTX in these in vitro assays. Compounds 3b,d (MX-68) significantly suppressed progression of the adjuvant arthritis in a dose-dependent manner ranging from 0.5 to 2.5 mg/kg (po). In addition, 3d (MX-68) completely suppressed this progression at the dose of 2.5 mg/kg (po). Importantly, 3d (MX-68) having benzothiazine and homoglutamate, as expected, did not undergo polyglutamation, a process which may be responsible for the associated side effects of MTX. These results suggest that 3d (MX-68) is a potent and safe candidate antirheumatic agent, absent of the side effects of MTX.
Animals↗
Comparison of gelatin particle agglutination and hemagglutination inhibition tests for measles seroepidemiology studies.
The prevalence of measles antibody in Japan was surveyed with a newly developed gelatin particle agglutination (PA) test, and the results compared with those of the hemagglutination inhibition (HI) test. The two age-distribution curves of the PA antibody-positive rates at > or = 1:8 and > or = 1:32 were almost the same in all the age groups, except the less-than-1-year-old group for which the rate at > or = 1:8 was higher than that at > or = 1:32 (p < 0.05, chi 2 test). In the vaccinated children, all groups older-than-1-year of age had antibody-positive levels of 96% or more. In contrast, in the unvaccinated children, there was a sharp increase in antibody-positive rates between the 1- and 4-year-old groups, indicative that about 80% of the children were infected by wild measles virus at these ages. A significant number of PA antibody-positive specimens were antibody-negative (< 1:8) by HI. The percentage of specimens in this category, PA (+) but HI (-), was greatest in infants less than one year old, and least in young children, but it increased with age to 97% of the HI (-) specimens from adults of more than 20 years of age. The PA test therefore detected some measles antibodies that HI could not. This test is simple and useful for making serosurveys in both developed and developing countries.
Adolescent↗
Involvement of Rho family proteins in prostaglandin F2 alpha-induced phospholipase D activation in the osteoblast-like cell line MC3T3-E1.
To examine the role of Rho family proteins in prostaglandin F2 alpha (PGF2 alpha)-mediated phospholipase D (PLD) activation of osteoblast-like cell line MC3T3-E1 cells, we used Toxin-B from Clostridium difficile, which inhibits Rho family proteins by monoglucosylation. Pretreatment of [3H]myristic acid-labeled MC3T3-E1 cells with Toxin B induced rounding-up of the cells and inhibited the PGF2 alpha-induced PLD activation by 60%, but not the phospholipase C (PLC) activation. Cytochalasin D also induced rounding the cells, but showed a small inhibition in the PLD activation. Brefeldin A (BFA) had marginal inhibitory effect on the PGF2 alpha-induced PLD activation. In digitonin-permeabilized MC3T3-E1 cells, [3H]P But formation was stimulated by guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S) or 4 beta-phorbol 12-myristate 13-acetate (PMA) in the presence of Ca2+ (1 microM) and ATP (1 mM), and phosphatidylinositol 4,5-bisphosphate (PIP2) was also required for its full PLD activation. Pretreatment of the digitonin-permeabilized MC3T3-E1 cells with Toxin B reduced the GTP gamma S- and PMA-stimulated PLD activities by 80% and 60%, respectively. On the other hand, C3 toxin which inhibits Rho by ADP-ribosylation, exerted a partial inhibitory effect on the GTP gamma S-stimulated PLD activity. These results suggest that Cdc42 as well as RhoA appear to be involved in the PLD activation mediated by PGF2 alpha and also that the PLD activation may be independent of actin cytoskeleton in MC3T3-E1 cells.
ADP Ribose Transferases↗
Regeneration of the un-embolized liver parenchyma following portal vein embolization.
BACKGROUND/AIMS: Portal vein embolization (PVE) induces atrophy of the embolized hepatic parenchyma and hypertrophy of the un-embolized liver. It is important to predict hypertrophy of un-embolized liver following PVE to decide a subsequent tactics in patients with liver tumors. The hypertrophy following PVE was evaluated in reference to embolized liver volume and a preceding use of transcatheter hepatic arterial chemoembolization (HACE) in this study. METHODS: Thirty patients with liver tumors were studied. PVE was performed transhepatically. Ethanol (15-65 ml) was injected into portal veins, which perfused the liver segment bearing the tumor until occlusion. Embolization was performed at subsegmental portal branches in five patients, segmental branches in 11 patients and right portal veins in 14 patients. Twenty-three patients with underlying chronic liver disease and hepatocellular carcinoma (HCC) underwent PVE 2-6 weeks after HACE. The remaining seven patients without underlying chronic liver disease had bile duct cancer (6) or liver metastasis (1), and underwent PVE alone. Segmental volume in the liver was measured with computed tomography before and 4 weeks after PVE. RESULTS: The degree of hypertrophy showed a significant correlation with embolized liver volume (r=0.685, p<0.001). Increase in un-embolized liver volume was 2.4+/-5.8% with subsegmental embolization (NS), 15.2+/-6.4% with segmental embolization (p<0.01) and 46.5+/-18.8% with right PVE (p<0.001). In 14 patients with right PVE, degree of hypertrophy in seven patients with HACE was greater than that in seven patients without HACE (56.7+/-21.6% vs 36.4+/-7.4%; p<0.03). CONCLUSIONS: Hypertrophy of the un-embolized liver parenchyma following PVE was correlated with embolized liver volume and was augmented with combined use of HACE.
Adult↗
Quantitative assays for hepatitis C virus in serum as predictors of the long-term response to interferon.
BACKGROUND/AIMS: Interferon therapy has a beneficial effect in patients with chronic hepatitis C who have a low viral load. The aim of this study was to compare the core protein level with HCV RNA levels and to analyze whether virus quantitation predicts the efficacy of interferon therapy. METHODS: HCV core protein level assessed by the recently developed assay was compared with HCV RNA levels measured by three different methods (Amplicor-HCV monitor, competitive RT(CRT)-PCR, and bDNA probe assay) in 352 patients with chronic hepatitis C in relation to viral serotype. RESULTS: From 91% (320/352) to 93% (299/322) of patients with viremia were detected by Amplicor-monitor and CRT-PCR, in contrast to 60% (187/312) and 74% (191/258) by bDNA and HCV core protein assay, respectively. The HCV core protein level was positively correlated with HCV RNA levels measured by the three assays (r = 0.680 to 0.731). Serum HCV RNA and core protein levels were significantly lower in patients with serotype 2 than in those with serotype 1. Viral eradication after interferon therapy was observed in 60-70% of the patients with < 1 x 10(4) copies/ml of HCV RNA by Amplicor-monitor assay, < 2 x 10(5) copies/ml by CRT-PCR, < 0.5 Meq/ml by bDNA assay, and < 20 pg/ml of core protein by HCV core protein assay. Viral eradication was uncommon (< 11%) among the patients with higher viral loads. Bivariate analysis revealed that the outcome of interferon therapy was more closely associated with both HCV core protein and RNA levels than the HCV serotype. CONCLUSIONS: Quantitation of HCV core protein and HCV RNA in useful for prediction of the interferon response.
Adolescent↗