Biomedical subjects

K Sagawa

Publications and source records attributed to K Sagawa.

At least 73 records · Page 4Linked to original sources

PubMed1995

[Inhibitory effects of prostaglandin E1.alpha-cyclodextrin (PGE1.CD) on dimethylnitrosamine-induced acute liver damage in rats].

The effects of PGE1.CD on dimethylnitrosamine (DMN)-induced acute liver damage with intravascular coagulation in rats were biochemically and histopathologically investigated. PGE1.CD was administered i.v. from 30 min before to 24 hr after DMN-intoxication (pretreatment) and from 30 min after or from 4 hr after to 24 hr after DMN-intoxication (post-treatment). Pretreatment with PGE1.CD (0.2-2 micrograms/kg/min) dose-dependently suppressed the decrease of platelet counts and the elevation of blood biochemical parameters (PT, HPT, GOT, GPT, LDH, LAP, T-Bil) caused by DMN-intoxication. PGE1.CD (0.5 microgram/kg/min and over) significantly suppressed the DMN-induced histopathological changes (occurrence of hemorrhage and necrosis). Post-treatment with PGE1.CD (2 micrograms/kg/min) also suppressed the liver damage. Furthermore, pretreatment with PGE1.CD (2 micrograms/kg/min) not only suppressed the disruption of hepatocytes, but also prevented the damages of sinusoidal endothelial cells and lysosomal membrane, and it reduced the increase of lipid peroxidation. PGE1.CD (1 microgram/kg/min and over) significantly suppressed the decrease of hepatic tissue blood flow caused by DMN-intoxication. These results demonstrate that PGE1.CD has therapeutically efficacy against DMN-induced acute liver damage in rats; Therefore, it will be clinically useful for the treatment of severe hepatitis such as fulminant hepatitis with intravascular coagulation in the sinusoid.

Acute Disease↗

PubMed1995

A novel adult T cell leukemia-derived cell line (SALT-3) susceptible to human immunodeficiency virus type 1 infection.

A novel human T cell line (SALT-3) was established from the pleural effusion of a patient with adult T cell leukemia (ATL) of lymphoma type. SALT-3 showed atypical T cell markers such as CD1-CD2-CD3-CD4+CD5+CD7+CD8-CD19-CD20-CD25+HLA-DR+. T cell receptor alpha/beta and gamma/delta were undetectable. Human T cell lymphotropic virus type 1 (HTLV-I) particles were seen on SALT-3 cells by electron microscopic analysis. HTLV-I gag p19, proviral DNA and mRNA of HTLV-I genes were also detected in the cells. Chromosome analysis showed abnormal karyotypes as 47, XY, partial trisomy of No.3 chromosome, and trisomy of No. 7 chromosome. Furthermore, SALT-3 were susceptible to the infection of human immunodeficiency virus type 1 (HIV-1) and the cells were rapidly killed after HIV-1 infection. This newly established HTLV-I-infected human T cell line would be a useful tool to study biological activities of atypical type of ATL cells and to examine the cytotoxic effects of HIV-1 and it's modulators.

Aged↗

PubMed1995

Murine monoclonal antibodies (MCS-1 and MCS-2) reactive with human myeloid leukemia cells.

In an attempt to identify the antigens expressed on human myeloid leukemia cells, two murine monoclonal antibodies (mAb) designated as MCS-1 (isotype; IgG3) and MCS-2 (IgG1) were raised. MCS-1 reacted with peripheral blood granulocytes, but not with monocytes, whereas MCS-2 reacted with both granulocytes and monocytes. The incidence of MCS-1 and MCS-2 reactivity with the cells from a total of 121 patients with various type of leukemias was as follows: 25/46 (54%) and 39/47 (83%) in acute myeloblastic leukemia and acute monoblastic leukemia, 8/16 and 16/16 in chronic myeloid leukemia in blastic crisis (CML-BC) of myeloid type, 0/7 and 2/7 in CML-BC of lymphoid type, 0/26 and 2/32 in acute lymphoblastic leukemia (ALL), 7/7 and 7/7 in chronic phase of CML, respectively. Two cases of MCS-2 positive ALL had a Philadelphia chromosome marker (Ph1). In contrast, neither MCS-1 nor MCS-2 reacted with lymphocytes or any of leukemic and non-leukemic lymphoid cell lines tested. These results indicate that MCS-1 and MCS-2 mAb recognized two different differentiation antigens expressed on granulocytes and monocytes. These mAb would be useful reagents to determine differentiation antigens on the cells in granulocyte and monocyte lineage.

Animals↗

PubMed1995

Renal adaptation to altered dietary sulfate in rats.

Proximal tubular reabsorption is of primary importance in the regulation of the homeostasis of inorganic sulfate, an electrolyte that is necessary for biosynthetic and detoxification reactions. The objective of the present investigation was to determine the effect of dietary sulfate deprivation, produced by a diet low in methionine, on the renal transport of sulfate. Female Lewis rats were fed a diet containing negligible amounts of sulfate and cystine and low in methionine (0.37%) or a control diet (methionine 1.12%, cystine 0.07%) for 8 days to examine the urinary excretion rate and renal clearance of sulfate. The sulfate excretion rate was decreased by day 4 of the low methionine diet and remained low. Both the urinary excretion rates and renal clearance values were significantly decreased on day 8 (144 +/- 71 vs. 517 +/- 264 mumol/12 hr in controls, mean +/- S.D., n = 7, P < .005 and 0.38 +/- 0.19 vs. 1.07 +/- 0.61 ml min-1 kg-1 in controls, n = 5-6, P < .05, respectively), although the serum sulfate concentrations were unchanged. In vitro transport studies were performed in kidney cortex brush border membrane (BBM) and basolateral membrane vesicles isolated from rats fed either the low methionine or control diet for 7 to 9 days. The Vmax for BBM sodium/sulfate cotransport was increased in kidneys from animals that received the low methionine diet (1.1 +/- 0.10 vs. 0.75 +/- 0.08 nmol mg of protein-1 10 sec-1 in controls, n = 5, P < .001); there were no significant differences in the Km.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1995

Polyclonal use of T-cell receptor alpha for human T-cell lymphotropic virus type 1-infected T cells.

PURPOSE: To understand better the immunopathology of HTLV-I uveitis by investigating the clonality of HTLV-I-infected T-cell clones. METHODS: Eleven T-cell clones were established from the aqueous humor (six clones) and the peripheral blood (five clones) of a patient with HTLV-I uveitis, and the clonality of the HTLV-I-infected T cells was investigated by sequencing the T-cell receptor (TCR) alpha gene after the amplification of TCR alpha cDNA using an adaptor-ligation method and reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: TCR alpha use was different for each of 11 T-cell clones, encompassing eight different HTLV-I-infected T-cell clones (four from the aqueous humor and four from peripheral blood) and three HTLV-I-negative T-cell clones. CONCLUSIONS: This study demonstrated polyclonal use of TCR alpha for HTLV-I-infected T cells in the ocular lesion and the peripheral blood. Results suggested that these T cells are not precursors of the leukemic cells associated with malignant transformation. Instead, they might be randomly infected with HTLV-I in the process of HTLV-I uveitis.

Amino Acid Sequence↗

PubMed1995

Influence of pulmonary blood pressure and flow on endothelin-1 production in humans.

To investigate the regulation of endothelin-1 (ET-1) production, cardiac catheterization was performed in young patients with congenital heart disease (27 +/- 5 months old, mean +/- SEM), and plasma levels of ET-1 in the inferior vena cava were measured by a sandwich-enzyme immunoassay. Plasma ET-1 levels of age-matched healthy controls were 1.55 +/- 0.07 pg/ml (n = 6). In patients with atrial septal defect [without pulmonary hypertension (PH)] who had volume but not pressure overload to the pulmonary circulation (PC), plasma ET-1 levels were significantly lower than in controls. In patients with PH due to ventricular septal defect (VSD) who had both volume and pressure overload to PC, the levels were significantly higher than in controls. In patients with PH and severe pulmonary congestion due to pulmonary venous stenosis (PVS), plasma ET-1 levels were significantly higher than in those with VSD, suggesting that ET-1 production is also augmented by pulmonary congestion. The present findings suggest that ET-1 production is increased by pressure overload to PC but decreased by volume overload to PC.

Endothelins↗

PubMed1995

A case of autoimmune hemolytic anemia induced by IFN-beta therapy for type-C chronic hepatitis.

A 51-year old woman who had type-C chronic hepatitis developed autoimmune hemolytic anemia after 4 weeks treatment with a total 48 million interferon-beta, 6 million 8 times. Indirect Coomb's test turned from negative to positive through IFN therapy and a complication of asymptomatic primary biliary cirrhosis was confirmed by histologic findings of the biopsied liver which was performed during IFN therapy and a presence of anti-mitochondrial antibody. After stopping IFN therapy and adding prednisolone anemia improved in getting negative indirect Coombs test but remaining positive direct Coombs test.

Anemia, Hemolytic, Autoimmune↗

PubMed1995

Idiopathic thrombocytopenic purpura complicated by intracranial hemorrhage in a 78-year-old male.

A 78-year-old male was admitted to our hospital with cutaneous hemorrhage, aphasia and somnolence. On physical examination, he appeared drowsy and complained of epistaxis and multiple purpura. His platelet count was 8,000/microliters with a high level of PA-IgG, but the coagulation time was normal. A CT scan of the head revealed a left temporal and right frontal hemorrhage. Bone marrow aspiration revealed abundant megakaryocytes. He was diagnosed as having idiopathic thrombocytopenic purpura with intracranial hemorrhage. He was treated with prednisolone and azathioprine in addition to platelet infusions and high doses of gamma-globulin. After two months of treatment, the platelet count had risen to 40,000/microliters and his symptoms had subsided.

Aged↗

PubMed1994

Lymphocyte activation in HIV-1 infection. II. Functional defects of CD28- T cells.

OBJECTIVES AND DESIGN: The expression of the accessory molecule CD28 was compared in various populations of T and natural killer (NK) cells from HIV-1-negative and HIV-1-positive individuals and correlated with activation using mitogens in vitro. METHODS: Multiparameter flow cytometric analysis using combinations of CD3 CD28 and other markers was performed together with absolute cell counting in peripheral blood. Blast transformation and proliferative responses were also quantitated using the Cytoronabsolute after stimulation with phytohaemagglutinin (PHA) and anti-CD3. CD28- cells were also purified to confirm the observations. RESULTS: In HIV-1-negative individuals > 90% of CD3+ T cells were CD28+ and responded to stimulation, while CD3- CD16+ CD57+ NK-like cells were CD28- and failed to respond. In HIV-1-positive individuals the expression of CD28 was greatly reduced and the proportion of CD3+CD28- T cells expanded. CD8 lymphocytosis was caused entirely by the accumulation of CD28- T cells and many of these expressed activation markers human lymphocyte antigen-DR, CD38 and CD45RO on their membrane and molecules such as TIA-1 and perforin, associated with cytolytic function, in their cytoplasm. The strong positive correlation (r = 0.66) between the lack of CD28 expression and the poor proliferation from HIV-1-positive individuals was confirmed by demonstrating that only CD28+ cells transformed into lymphoblasts and proliferated. Although the CD28- including CD3+ T cells transiently expressed CD25 (interleukin-2R alpha), they did not undergo blastogenesis or activation measured by bromodeoxyuridine uptake and died after 3-4 days in culture. These observations were confirmed in costimulation experiments with anti-CD2 and anti-CD28. CONCLUSION: In HIV-1 infection activated CD3+CD28- T cells accumulate but are unresponsive to mitogens and anti-CD28. These cells appear to represent terminally differentiated effector cells which fail to respond to further stimuli because of the absence of a CD28 second signal.

Adult↗

PubMed1994

Co-stimulation with anti-CD28 (Kolt-2) enhances DNA synthesis by defective T cells in common variable immunodeficiency.

In normal T cells, an anti-CD28 MoAb (Kolt-2) will synergize with the mitogenic stimuli phytohaemagglutinin (PHA), anti-CD3 (OKT3) or a combination of anti-CD2 antibodies (OKT11 and GT2) in the induction of DNA synthesis. A subgroup of patients with common variable immunodeficiency (CVID) show a defect in DNA synthesis by T cells stimulated in vitro with the above mitogens. We have now investigated whether anti-CD28 will correct the defect. This strategy partially restored DNA synthesis, providing evidence that the CD28 co-stimulatory pathway in CVID T cells is normal. Ligation of CD28 acts through co-stimulating IL-2 secretion. The natural ligand (B7) for CD28 on antigen-presenting cells from CVID patients is expressed normally. We conclude that the defect in CVID T cells lies in pathways that lead to transcription of the IL-2 gene other than that induced by ligation of CD28 with Kolt-2.

Antibodies, Monoclonal↗

PubMed1994

Induction and subcellular localization of metallothionein in regenerating rat liver.

A highly specific antiserum against rat liver metallothionein (MT) was raised in a Japanese white rabbit. Using this anti-MT antiserum, we found that MT was localized in the nuclei as well as in the cytoplasm of hepatocytes in newborn rats. Since it is known that these cells are growing actively, we suspected that there was a relationship between the localization of MT in cell nuclei and the cell proliferation. Therefore, the induction and subcellular localization of MT were examined in rat liver remaining after 70% removal. MT was induced in the remnant liver rapidly after the hepatectomy, its concentration being about 80-fold higher than that of the intact liver. Flow cytometric analysis revealed that MT was translocated into the nuclei from the cytoplasm of hepatocytes during liver regeneration after partial hepatectomy. The highest MT level in the nuclei was observed 24 h after hepatectomy. MT-stained positive nuclei were in S to G2M phases of the cell cycle of regenerating hepatocytes, and the nuclei in G1 phase were not stained with anti-MT antiserum. The increase in hepatic MT levels did not directly cause MT translocation into the nuclei. These results suggested that MT was a cell cycle-dependent, nuclear protein.

Animals↗

PubMed1994

The distribution of T-cell subsets among HTLV-I carriers in Japan.

Data on T-cell subsets from 89 human T-cell lymphotropic virus-I (HTLV-I) carriers and 25 seronegative people were analyzed to identify differences in T-cell subset values among three subgroups: HTLV-I carriers with abnormal lymphocytes (Ably; n = 24), carriers without Ably (n = 65), and HTLV-I seronegatives (n = 25). Estimates of mean values were adjusted for age, sex, smoking, and alcohol drinking, as appropriate. The percentage of CD25+ T cells was elevated in carriers with Ably (mean, 16.7 +/- 1.0) compared with the seronegatives (11.4 +/- 1.4; p = 0.0002); individuals with CD25 T-cell percentages above the median for the seronegatives had a corresponding 5.4-fold risk for being a carrier with Ably. Similarly, the percentage of CD4 T cells was elevated in carriers with Ably. Conversely, the percentage of CD8 T cells was lower among both groups of HTLV-I carriers than in the seronegatives. There was a corresponding significant increase (p = 0.0004) of the CD4/CD8 ratio among carriers with Ably (1.57 +/- 0.12) compared with the seronegatives (1.22 +/- 0.12). Among subjects with CD4/CD8 ratios above the median for the seronegatives, there were 6.8- and 4.5-fold risks for being carriers with or without Ably, respectively. The percentage of CD7 was lower among carriers with Ably (75.6 +/- 1.6) than among seronegatives (78.9 +/- 1.5; p = 0.13). The percentage of beta-interleukin-2-receptor-positive T cells did not vary among the three subgroups.(ABSTRACT TRUNCATED AT 250 WORDS)

Alcohol Drinking↗

PubMed1993

Tissue-specific distribution and age-dependent increase of human CD11b+ T cells.

Distribution of CD11b Ag, a member of the leukocyte integrin (beta 2 integrin) family, on human T cells is not well characterized. We investigated in this study the tissue distribution and age-related alteration of human CD11b+ T cells. Significant proportions of CD11b+ cells were found in T cells from adult peripheral blood (18-58 yr) (20%), liver (32%), and spleen (16%), but were rarely observed in those from thymus, lymph nodes, intraepithelial lymphocytes, lamina propria lymphocytes, and lung. In contrast, percentages of CD28+ T cells, a counter population of CD11b+ T cells, were highest in lymph nodes (91%), modest in intraepithelial lymphocytes (82%), lamina propria lymphocytes (77%), PBL (77%), spleen (73%) and lower in thymus (62%), lung (60%) and liver (56%). The CD11b+ T cells from peripheral blood gradually increased with age, whereas the CD28+ T cells showed an age-dependent decrease. Namely, the percentages of CD11b+ T cells were 6% in newborns (cord blood), 15% in young adults (18 to 22 yr), 25% in middleaged adults (45 to 58 yr), and 27% in aged adults (72 to 86 yr), whereas those of CD28+ T cells were 96%, 83%, 72%, and 71%, respectively. Proportions of CD11b+ T cells in TCR-gamma delta+ or CD8+ T cells were, respectively, higher than those in TCR-alpha beta+ or CD4+ T cells. Age-dependent increase of CD11b+ T cells in CD8+ T cells was more obvious than that of CD4+ T cells. Furthermore, CD11b+ CD28+ T cells increased in the peripheral blood only of aged adults. The percentage of CD11b+ CD28+ T cells in TCR-gamma delta+ T cells was highest in young adults (25%), whereas that in CD4+ T cells was highest in aged adults (15%). CD11b+ CD28+ T cells expressed much potent IFN-gamma, IL-2, and IL-4 at mRNA level than CD28+ CD11b- T cells or CD11b+ CD28- T cells, and had potential cytotoxic activity. Roles of CD11b+ T cells in vivo were discussed.

Adolescent↗

PubMed1993

A monoclonal antibody (H227) recognizing a new epitope of 4F2 molecular complex associated with T cell activation.

We developed and characterized a monoclonal antibody (mAb), H227, recognizing a new epitope of human 4F2 molecular complex whose roles remain to be identified. Both staining patterns and molecular sizes recognized by H227 mAb were the same to those of 4F2 mAb. Thus, both H227 and 4F2 mAbs were reactive to monocytes, thymocytes, and activated lymphocytes and immunoprecipitated the 125-kDa molecular weight membrane protein under nonreducing conditions and 85-kDa heavy-chain and 40-kDa light-chain proteins under reducing conditions. These two mAbs immunoprecipitated only the 85-kDa heavy-chain protein when the cell lysate was initially treated with dithiothreitol. Sequential immunoprecipitation proved their cross-reactivity. Both the mAbs inhibited phytohemagglutinin- or concanavalin A-induced proliferation of peripheral blood mononuclear cells (PBMC). In contrast to these similarities, the pretreatment of cells with one mAb failed to block the reactivity to the other, suggesting that their epitopes were different from each other. Furthermore, only H227 mAb augmented phorbol myristate acetate (PMA)-induced PBMC proliferation in association with increase in interleukin 2 receptor expression. In summary, H227 mAb recognizes a new epitope of 4F2 heavy chain that might be involved in the PMA-induced T cell activation pathway and therefore shall be a useful tool for understanding the roles of the 4F2 molecular complex.

Antibodies, Monoclonal↗

PubMed1993

A novel antigen (H47 Ag) on human lymphocytes involved in T cell activation.

Surface molecules involved in human T cell activation were investigated using a newly developed monoclonal antibody (H47 mAb). H47 antigen (Ag) recognized by H47 mAb was expressed on approximately 10% of resting T cells (mostly CD4-CD8+), 30% of phorbol 12-myristate 13-acetate (PMA)-activated T cells (both CD4+CD8- and CD4-CD8+), and most NK, B cells, and monocytes in the peripheral blood mononuclear cells (PBMC). H47 mAb respectively immunoprecipitated a 100 or 120-kD molecular weight (MW) membrane protein of T cells and monocytes under nonreducing or reducing conditions, suggesting that H47 Ag consists of a single polypeptide that has intramolecular disulfide bonds. H47 mAb significantly enhanced PMA-induced proliferation of PBMC in a monocyte-independent fashion. H47 mAb, however, failed to enhance T cell proliferation induced by anti-CD3 mAb, anti-CD2 mAb, or phytohemagglutinin (PHA). H47 mAb also enhanced PMA-induced interleukin-2 receptor (IL-2R) expression and IL-2 synthesis, but did not induce a change in intracellular free calcium ([Ca2+]i) of T cells. These results suggest that H47 Ag is a new membrane molecule involved in PMA-induced T cell activation.

Animals↗

PubMed1993

Effects of pentobarbital on inotropic state of isolated canine left ventricle.

Although pentobarbital has been found to depress myocardial function, the magnitude of its direct effects on ventricular contraction at anesthetic concentrations has not been well quantified. The direct effects of pentobarbital on left ventricular function were measured by employing an isolated canine heart preparation with a blood oxygenator. Seven hearts were perfused with blood, dextran, and perfluorochemical artificial blood. Ventricular function was evaluated using the slope of the end-systolic pressure-volume relationship (Ees) and the maximal rate of pressure development (dP/dtmax) in ventricles contracting isovolumically in control, after a low dose (13 micrograms/ml), and after a high dose (48 micrograms/ml) of pentobarbital. These concentrations represent one-half and two times the typical value (25 micrograms/ml) found to produce anesthesia in canines (assessed by tail clamp or blink reflex). The low dose of pentobarbital did not produce clear-cut depression in contractile function. The high dose of pentobarbital produced significant reductions of Ees, and dP/dtmax: Ees decreased 29%, from a control of 4.30 +/- 0.84 to 3.05 +/- 0.49 mmHg/ml and dP/dtmax decreased 24%, from a control of 909 +/- 148 to 695 +/- 173 mmHg/s. Thus, the threshold for the direct depressant effect of pentobarbital on ventricular function falls within the range of half to double the typically-reported anesthetic concentrations.

Animals↗

PubMed1993

Immunopathology and cytokine detection in the skin lesions of patients with Kawasaki disease.

To investigate the pathogenesis of Kawasaki disease, we examined biopsy specimens from the skin lesions of 10 Japanese patients at the site of the polymorphous exanthem on the hip and at the site of an inoculation with BCG (bacillus Calmette-Gruérin) vaccine of two of them. Ten normal patients were also examined for control purposes. The histopathologic features of the skin lesions were characterized by extensive edema with dilation of the small blood vessels in the papillary dermis; the site of BCG vaccine inoculation showed much greater inflammatory change; neutrophil emigration was weak and most of the infiltrates were CD4+ T lymphocytes and CD13+ macrophages. The expression of the DR locus of human leukocyte antigen was detected not only on the epidermal keratinocyte surface but also on the walls of the small blood vessels and the infiltrating cells around these blood vessels. We also detected cytokines in the skin lesions: (1) interleukin-1 alpha and tumor necrosis factor alpha were strongly positive in all patients with acute Kawasaki disease, (2) interleukin-2 and interferon gamma were weakly or partially positive, (3) no cytokines were detected in the convalescent phase, and (4) the amounts of cytokines at the site of BCG vaccine inoculations were larger than those at the site of the polymorphous exanthem. These findings suggest that CD4+ T lymphocytes and CD13+ macrophages are activated and interleukin-1 alpha and tumor necrosis factor alpha may be involved in the pathogenesis of the inflammation of acute Kawasaki disease.

BCG Vaccine↗

PubMed1993

Down-regulation of CD4 molecules by the expression of Nef: a quantitative analysis of CD4 antigens on the cell surfaces.

Nef is one of the non-structural genes encoded by human immunodeficiency viruses. The protein product is associated with the cellular and plasma membranes, and is synthesized soon after entry of the virus. However, little is known about its functions relevant to viral replication and cytopathogenesis. CD4 is considered to be a crucial molecule for the signal transduction and maturation of T cells, and also serves as the receptor for HIV-1. It has been suggested that the down-regulation of cell surface CD4 by Nef proteins is somehow controversial. In order to evaluate the effects of Nef on the CD4 molecule, we constructed a CD4+ monocytoid cell line in which the HIV-1 nef gene was placed under the transcriptional control of the human metallothionein IIA promoter. The analysis of this cellular clone showed that CD4 on the cell surface was down-regulated when Nef proteins were induced. The amount of CD4 antigens on the cell surface correlated inversely with the level of Nef protein expression. This down-regulation of CD4 antigens by Nef was found to occur at the post-translational level. These results showed that the nef gene could modulate the pathophysiology of AIDS by altering the surface CD4 expression.

Blotting, Southern↗