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Biomedical subjects

S Kano

Publications and source records attributed to S Kano.

At least 145 records · Page 8Linked to original sources

Nitric oxide synthesis in rat mesangial cells induced by cytokines.

The production of nitric oxide (NO) is increased in experimental nephritis, with NO thought to be an important mediator of cell damage. The cytokines interleukin 1 beta (IL-1 beta), IL-6, IL-8, monocyte chemotactic protein-1 (MCP-1) and transforming growth factor-beta (TGF-beta) are released from mesangial cells in vitro or are expressed in various forms of glomerulonephritis. We investigated the effects of these cytokines on NO synthesis in cultured rat mesangial cells. Incubation of mesangial cells with IL-1 beta (10 ng/ml) for 24 h increased the accumulation of NO and guanosine 3',5'-cyclic monophosphate (cGMP). IL-6, IL-8, MCP-1 and TGF-beta showed no significant effect on the production of NO or cGMP. Transcripts of the inducible NO synthase (iNOS) gene were not detected in unstimulated mesangial cells. However, exposure of cells to IL-1 beta (10 ng/ml) for 24 h resulted in the appearance of iNos mRNA. IL-1 beta-induced NO synthesis was significantly inhibited by NG-monomethyl-L-arginine, cycloheximide, actinomycin D, dexamethasone, and TGF-beta. These results indicate that, of the various cytokines studied, only IL-1 beta stimulates iNOS mRNA accumulation and NO synthesis in mesangial cells. NO may function in an autocrine manner to modulate the glomerular response to inflammation.

1-Methyl-3-isobutylxanthine↗

Dietary modifications of the biliary bile acid glycine:taurine ratio and activity of hepatic bile acid-CoA:amino acid N-acyltransferase (EC 2.3.1) in the rat.

Effects of dietary manipulations on the biliary bile acid glycine:taurine (G:T) ratio and the activity of hepatic bile acid-CoA:amino acid N-acyltransferase (EC 2.3.1) in the post-mitochondrial fraction of liver homogenates were examined in the rat. The G:T ratio in rats fed on the diet containing 100 g pectin/kg (2.18) was markedly higher than that in the animals fed on the diet containing 100 g cellulose/kg (0.09). The diets containing either 10 g cholesterol/kg or 5 g sodium cholate/kg, especially the latter, also increased the G:T ratio (0.77 and 2.33 respectively) compared with a control diet free of these steroids (0.34). When the saturating concentrations of taurine (20 mM) and glycine (100 mM) were the substrates, dietary pectin relative to cellulose significantly increased the activity of both taurine- and glycine-dependent bile acid-CoA:amino acid N-acyltransferase, but neither dietary bile acid nor cholesterol influenced it. In spite of the marked difference in the G:T ratio among the rats given various types of experimental diet, the bile acid-CoA:amino acid N-acyltransferase reaction produced taurine-but little glycone-conjugated bile acid when both taurine and glycine coexisted at physiological concentration ranges in the assay media. Dietary manipulations modified the hepatic taurine concentrations and the changes were inversely correlated with those in the G:T ratio. However, hepatic concentration of taurine (1.67-4.82 mumol/g) in rats given various types of experimental diet was comparable with or even higher than the reported Michaelis constant (Km) value of N-acyltransferase for this compound (0.8-2.5 mM).(ABSTRACT TRUNCATED AT 250 WORDS)

Acyltransferases↗

Neutrophil adherence to rat cardiac myocyte by proinflammatory cytokines.

Cytokine induction of intercellular adhesion molecule-1 (ICAM-1) in cardiac myocytes may be a critical step in inflammation associated with ischemia-reperfusion injury. We investigated the involvement of tumor necrosis factor-alpha (TNF-alpha), interleukin 6 (IL-6), and interleukin 8 (IL-8) on neutrophil-myocyte adhesion; These cytokines are increased in plasma of patients with acute myocardial infarction (AMI). ICAM-1 expression on cultured neonatal rat cardiac myocytes was determined through immunohistochemical and enzyme-linked immunosorbent assay (ELISA) analysis. ICAM-1 mRNA expression in myocytes was investigated by Northern blot hybridization. Rat neutrophils isolated from peripheral blood (PB) were used for adherence assay. In immunohistochemical study, cultured neonatal rat cardiac myocytes constitutively expressed ICAM-1 molecules. In ELISA analysis, ICAM-1 molecule expression on myocytes was significantly stimulated by TNF-alpha (100 U/ml), but not by IL-6 (100 U/ml) or IL-8 (100 ng/ml) dose dependently. The effect of TNF-alpha was observed as early as 6 h after stimulation. Levels of ICAM-1 mRNA were very low or almost undetectable in unstimulated myocytes, but its expression was markedly induced after exposure to TNF-alpha for 3 h. IL-6 and IL-8 showed no effect on ICAM-1 mRNA accumulation. Adhesion of rat neutrophils to myocytes was stimulated by TNF-alpha, and the effect of TNF-alpha on adherence was significantly inhibited by an anti-ICAM-1 monoclonal antibody (MoAb). These results show that TNF-alpha, but not IL-6 and IL-8, promotes neutrophil-myocyte adhesion through ICAM-1 expression, suggesting involvement of TNF-alpha in inflammation associated with ischemia-reperfusion injury.

Animals↗

[A case of Plasmodium falciparum malaria successfully treated with halofantrine].

A 44-year-old male, who had been to Lagos, Nigeria, was admitted to our hospital because of a high grade fever on July 20, 1993. On admission, Plasmodium falciparum was detected in his blood smears and the antibody titers against P. falciparum and Plasmodium vivax antigens were 1:256 and < 1:4 respectively by the indirect fluorescent antibody test. Therefore, he was diagnosed as having P. falciparum malaria. He was treated with halofantrine (Halfan: Smith Kline Beecham Pharmaceuticals, England), two tablets at six-hourly intervals, a total of six tablets (1500 mg). Parasites were cleared rapidly and remission was achieved without any adverse reactions. Halofantrine can therefore be recommended for the treatment of imported P. falciparum malaria.

Adult↗

Influence of nonlinearities on estimates of respiratory mechanics using multilinear regression analysis.

To investigate the influence of nonlinearities on estimates of respiratory mechanics, differing patterns of mechanical ventilation patterns were analyzed from 8 puppies and 14 children. Respiratory mechanics were calculated using multiple linear regression to fit a linear single-compartment model, a volume-dependent single-compartment model (VDSCM), and a flow-dependent single-compartment model. The ratio of the compliance of the last 20% of the dynamic volume-pressure (V-P) curve to the total compliance (C20/C) and the contribution of a volume-dependent elastance to total elastance [%E2 = E2 (VT)/[(E1 + E2)VT], where E1 + E2 is total elastance, E2 is the volume-dependent component, and VT is tidal volume] were used as the indexes of over-distension. By positioning the dynamic loops on the static V-P curves, ventilation patterns were classified as overdistended or nonoverdistended. In the overdistended group, the C20/C was significantly lower (0.71 +/- 0.10 vs. 0.92 +/- 0.16; P < 0.0001) and %E2 was significantly higher (43.4 +/- 15.0 vs. 0.51 +/- 18.02%, P < 0.0001) than in the nonoverdistended group. The mode of ventilation (pressure controlled vs. volume controlled) and the resistive pressures that resulted in widening of the dynamic V-P loop were found to alter C20/C but not %E2. When the respiratory system was overdistended, i.e., ventilated up to the flattened portion of the V-P curve, the VDSCM gave more accurate estimates of respiratory mechanisms. Furthermore, %E2 calculated from VDSCM is a useful parameter for estimating respiratory system overdistension that is not affected by resistive pressures.

Animals↗

Time course of changes in lung mechanics following fetal steroid treatment.

We studied the effect of a single-dose, corticosteroid treatment on preterm lambs (gestational age: 128 d). A low, medium, or high betamethasone dose (0.1, 0.5, and 2.0 mg/kg) or saline control was administered directly to the fetus by ultrasound-guided intramuscular injection 48 h before delivery. A second group received either the high dose of betamethasome or saline 24 h before delivery. The lambs were delivered at 128 d gestation, anesthetized with ketamine, and ventilated for 50 min. Respiratory system elastance and resistance were measured at 10-min intervals using multiple linear regression analysis of pressure, flow, and volume. Similarly, estimates of lung mechanics were calculated from transpulmonary pressure. The viscoelastic time constant (tau) was calculated by fitting an exponential to the pressure changes occurring after occluding the airway during expiration. Excised lung volume at 40 cm H2O and lung weight were used to calculate specific elastance and resistance correcting for lung size using volume or weight, respectively. Of the 13 lambs in the 48-h high-dose betamethasone group, five developed pulmonary interstitial emphysema (PIE) as did 3 of 11 animals in the high-dose group treated 24 h before delivery. These animals were analyzed separately. The lambs receiving medium- or high-dose (24 and 48 h predelivery) betamethasone had significantly lower elastance and a trend toward lower resistance when compared with the control groups. Ten minutes after delivery, the animals that developed PIE all had elastance values comparable to that of the control animals despite corticosteroid treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗

Pulmonary hypertension in systemic lupus erythematosus: a report of an autopsied case.

An autopsied case of systemic lupus erythematosus with pulmonary hypertension is reported. A 29-year-old woman with a seven-year history of polyarthralgia, butterfly rash, nephrotic syndrome and Raynaud's phenomenon was admitted because of progressive dyspnea on exertion. Tests for antinuclear antibody, anti-cardiolipin antibody and lupus anticoagulant were positive. Echocardiographic examination revealed right ventricular hypertrophy and a moderate pericardial effusion. Estimated systolic pulmonary arterial pressure was 53 mmHg. Despite treatment with corticosteroids including pulse methylprednisolone therapy, lipo-PGE1 and warfarin, she died of progressive congestive heart failure. Postmortem examination of the pulmonary vasculature revealed findings consistent with plexogenic pulmonary arteriopathy, without evidence of vasculitis, fibrinoid necrosis, or thromboemboli.

Adult↗

Diffuse panbronchiolitis and rheumatoid arthritis: a possible correlation with HLA-B54.

We analyzed the HLA antigens in two patients with rheumatoid arthritis accompanied by diffuse panbronchiolitis in whom HLA typing could be done and found the presence of B54 and DR4 alleles. We previously reported that the frequency of HLA-B54 is significantly increased in patients with diffuse panbronchiolitis. This allele demonstrates a linkage disequilibrium with DR4 (or DR4.1) in Japanese individuals. The association of rheumatoid arthritis with HLA-DR4 is well established in various ethnic groups including Japanese people. Since both diseases show the same pattern of HLA correlation, more Japanese patients with these two diseases are likely to be encountered.

Arthritis, Rheumatoid↗

[Effects of goal setting and real-time feedback on performance and time estimation during VDT operation].

The problem of serious occupational fatigue of software operators has come up for discussion. Along with the outcome of a survey showing that their working hours are longer than those of other types of workers, with the former reporting for duty unconsciously early in the morning, it is pointed out that their time estimation and crookedness of time cognition are reduced. As a result of the survey, it was also found that in visual display terminal task, the work is carried on while receiving real-time feedback, and those engaged in development work, set their goal to complete a specific amount of work within a specific time-limit. Thus, in order to examine the effects of these two factors on these workers' performance and their subjective time estimation, 76 subjects (undergraduate students) were asked to engage in task of six terms. The results indicated that the group with its goal set and real-time feedback given had higher performance and motivation for task, and showed more time reduction than did other groups to a significant extent. It is noteworthy that it was proved that the subjects were not conscious of this time reduction.

Adult↗

Antiendothelial cell antibodies and their relation to pulmonary hypertension in systemic lupus erythematosus.

OBJECTIVE: Antiendothelial cell antibodies (aECA) have been demonstrated in patients with systemic lupus erythematosus (SLE), but their role in the pathogenesis of this disease remains unclear. We investigated the association of aECA and anticardiolipin antibodies (aCL) with clinical and laboratory findings in patients with active SLE. METHODS: Sera from 28 patients with active SLE and 22 healthy controls were assayed for IgG and IgM-aECA by cellular ELISA method using cultured human umbilical vein endothelial cells and IgG-aCL by ELISA method. RESULTS: Serum titers of both IgG and IgM-aECA were significantly higher in active SLE than in healthy controls. Titers of IgG-aECA were unrelated to titers of IgG-aCL. Patients with pulmonary hypertension demonstrated a marked elevation of serum titer of both IgG and IgM-aECA compared with patients without pulmonary hypertension. In addition, patients with digital vasculitis showed a significant elevation of serum titer of both IgG and IgM-aECA compared with patients without digital vasculitis. Serum titers of IgG-aECA in patients with Raynaud's phenomenon and of IgM-aECA in patients with serositis were each significantly increased compared with patients without such findings. CONCLUSION: aECA were unrelated to aCL. Serum titers of aECA are elevated in patients with active SLE, especially with pulmonary hypertension, digital vasculitis, Raynaud's phenomenon or serositis. Since pulmonary hypertension in SLE has been associated with digital vasculitis, Raynaud's phenomenon and serositis, aECA may be involved in the pathogenesis of vascular injury, leading to these manifestations.

Antibodies, Anticardiolipin↗

Differential malaria prevalence among villages of the Gidra in lowland Papua New Guinea.

Antibody titres against Plasmodium falciparum and P. vivax were examined using the indirect fluorescent antibody test (IFAT) for 183 Gidra-speaking adults and adolescents in four ecologically different villages of lowland Papua New Guinea. The findings highlight that 1) in Gidraland P. falciparum was more prevalent than P. vivax, 2) the proportion of antibody titres of 1:64 or higher markedly differed among the villages, ranging from 35.3% to 100% for males and from 31.6% to 100% for females, and 3) in the two villages with high prevalences, these were higher among males than females. The inter-village and sex differences can be largely explained by microenvironmental conditions and behavioural patterns of the population. The population-based analyses of this study intend to contribute to a better understanding of the prevalence of malaria in human-environment settings and thus to the planning of malaria prevention.

Adolescent↗

Application of hydroxyapatite-sol as drug carrier.

The application of hydroxyapatite-sol as a drug carrier is being developed. Hydroxyapatite-sol which is a suspension consisting of hydroxyapatite nano-crystals, was synthesized using an ultrasonic homogenizer. The size of the crystals was 40 x 15 x 10 mm3 on average and their specific surface area was 100 m2/g. An amount of a glycoside antibiotics adsorbed onto hydroxyapatite nano-crystals was measured. The drug adsorbed 0.2 mg per 1 mg of hydroxyapatite. The affect of the drug adsorbed onto the hydroxyapatite was investigated using cancer cells. The drug, adsorbed onto the hydroxyapatite nano-crystals, inhibited cancer cell growth.

Adsorption↗

[A case of psittacosis with prolonged lymphocytosis in bronchoalveolar lavage fluid after resolution of pneumonia].

A 52-year-old man was admitted to another hospital with complaints of fever and dyspnea. Chest roentgenogram revealed bilateral widespread infiltrative opacities, and laboratory examinations showed severe hypoxia, hepatic injury and acute renal failure. In addition, hemosputum and eruption appeared, and he was transferred to our department because of the development of multi-organ failure. Moreover, about 2 weeks prior to admission, a budgerigar he had been breeding died. Although the treatment was supportive therapy alone, the abnormal shadow on chest roentgenogram and laboratory findings improved markedly. Thereafter, we made the diagnosis of psittacosis, because the serum titer of a complement fixation test against Chlamydia rose from 1:8 on admission to 1:512 after 2 weeks. On admission, PMN and lymphocyte populations increased in bronchoalveolar lavage fluid (BALF), and 2 weeks later lymphocytes alone increased markedly. Thereafter, we observed lymphocytosis in serial BALF findings for 12 weeks. These findings indicate that lymphocyte alveolitis persisted long after the pneumonia had resolved. Moreover, Ga scintigraphy also revealed accumulation in the filed of shadows which had been absorbed and disappeared on the chest roentgenogram. These results suggest that lymphocytes play a leading role in immune host defenses and that immunological reactivity is prolonged in psittacosis.

Bronchoalveolar Lavage Fluid↗

Interindividual variability of carbonyl reductase levels in human livers.

Interindividual variability of carbonyl reductase levels in human livers (N = 11) was examined by measuring reductase activity toward various substrates and by western blot analysis using anti-rat ovarian carbonyl reductase CR2 antibody. The carbonyl reductase activity toward p-nitrobenzaldehyde (PNBA) (58.1 +/- 5.4 nmol/mg protein/min, mean +/- SE) was highest among the substrates examined, followed by 4-benzoylpyridine (4BP) (14.4 +/- 2.0 nmol/mg protein/min) and p-nitroacetophenone (PNAP) (2.00 +/- 0.37 nmol/mg protein/min). The reductase activity (6.33 +/- 0.56 pmol/mg protein/min) toward 13,14-dihydro-15-keto-prostaglandin F2 alpha (15KD-PGF2 alpha), which is a diagnostic substrate for rat ovarian carbonyl reductases, was relatively high compared to that in other species. Western blot analysis revealed that each human liver contained several immunoreactive proteins to anti-CR2 antibody. The activities toward 15KD-PGF2 alpha (r = 0.85, P < 0.01) and 4BP (r = 0.84, P < 0.01), but not PNBA (r = 0.53, not significant) or PNAP (r = 0.52, not significant), were closely correlated with the relative amounts of the high molecular weight immunoreactive proteins determined with a densitometer. Thus, the major carbonyl reductases in human liver are similar to those of rat ovarian enzymes.

Acetophenones↗

Expression of intercellular adhesion molecule-1 on rat vascular smooth muscle cells by pro-inflammatory cytokines.

Infiltration of mononuclear cells is an early pathological finding in human and experimental atherosclerosis. However, the cellular and molecular basis for cell infiltration is incompletely understood. While the intercellular adhesion molecule-1 (ICAM-1) is expressed on endothelial cells and promotes the adhesion of mononuclear cells, there is little information on the expression of ICAM-1 on vascular smooth muscle cells (SMC). In this study, we investigated the expression of ICAM-1 on cultured rat SMC and its regulation by pro-inflammatory cytokines, interleukin 1 alpha (IL-1 alpha), interleukin 6 (IL-6) and monocyte chemoattractant protein 1 (MCP-1). In immunohistochemical staining, ICAM-1 molecules were constitutively expressed on the surface of SMC. In flow cytometric and ELISA analyses, ICAM-1 molecule expression on SMC was significantly upregulated by IL-1 alpha and MCP-1, but not by IL-6, in a dose-dependent manner. The effects of IL-1 alpha and MCP-1 were observed as early as 4 h. In Northern blot analysis, ICAM-1 mRNA was slightly detectable in unstimulated SMC, but its expression was clearly observed following exposure to IL-1 alpha or MCP-1. These results suggest that ICAM-1 on SMC, as well as on endothelial cells, could participate in the focal accumulation of mononuclear cells in human atherosclerotic lesions.

Animals↗

Involvement of opioid receptors in shaking behaviour induced by paraquat in rats.

Paraquat (30-70 mg/kg intraperitoneally) caused typical shaking behaviour in rats in a dose-dependent manner. Myoclonus also appeared after the shaking behaviour in several rats treated with the highest dose of paraquat. Morphine (5 mg/kg intraperitoneally, 30 min. before paraquat) significantly reduced the frequency of shaking behaviour. The alleviation by morphine disappeared when naloxone (1.5 mg/kg intraperitoneally 15 min. after morphine) was coadministered. Although there was no histological change in brain slices of paraquat-treated rats (70 mg/kg intraperitoneally), the fluorescein uptake into brain was increased by the treatment. Morphine prevented the increase of fluorescein uptake, but naloxone failed to antagonize this effect. On the other hand, intracerebroventricularly administered paraquat (25.7 micrograms/rat) caused tremor in all rats, but not shaking behaviour nor myoclonus. These findings suggest that paraquat administered systemically as well as centrally may be toxic to the brain. Although the actions of paraquat on the brain seem to be complicated, opioid receptors may play a role in the actions.

Animals↗

[A case of vivax malaria in which remission was achieved by primaquine at 1.5 times the standard dose after two earlier relapses].

A 22-year-old male student, who had been to Indonesia, was admitted to our hospital because of a high grade fever on October 12, 1990. On admission, vivax malaria parasites were detected in his blood smears and the antibody titers against Plasmodium vivax and P. falciparum antigen were respectively 1:1024 and 1:64 by the indirect fluorescent antibody test. Therefore, he was diagnosed as having vivax malaria and was treated with sulfadoxine/pyrimethamine (Fansidar), followed by primaquine at 15 mg/day for 14 days. However, relapse occurred twice after treatment with the above-mentioned standard dose of primaquine. After his second relapse, he was treated with primaquine at 22.5 mg/day for 14 days and remission was finally achieved without any adverse reactions. The antibody titer against P. vivax did not re-increase during the first and second relapses.

Adult↗