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Biomedical subjects

M Kokubun

Publications and source records attributed to M Kokubun.

At least 19 recordsLinked to original sources
PubMed1998

Apoptosis-mediated regulation of recombinant human granulocyte colony-stimulating factor production by genetically engineered fibroblasts.

We investigated the feasibility of an inducible apoptosis system to regulate cells genetically engineered for ectopic cytokine production. In a previous study, cDNA encoding the ligand-binding domain of the rat estrogen receptor was fused to the sequence for murine Fas transmembrane and cytoplasmic regions, and expression of the fusion protein (MfasER) in L929 fibroblasts resulted in estrogen-dependent apoptosis. We applied this MfasER/estrogen strategy to apoptosis-mediated regulation of cytokine production, using the human granulocyte colony-stimulating factor (G-CSF) as a model. Upon estrogen treatment, the G-CSF producers expressing MfasER showed an apoptotic phenotype and died in several hours, with termination of G-CSF production. This estrogen-induced apoptosis was not influenced by whether the target cells were proliferating or resting, unlike a conventional suicide system involving the herpes simplex virus 1 thymidine kinase (HSVtk). That is, estrogen induced prompt and extensive apoptosis in the resting cells which expressed MfasER, while ganciclovir treatment induced only partial reduction of the resting cells which expressed HSVtk. These results imply the feasibility of apoptosis-mediated regulation of cytokine production by genetically modified cells for supplement gene therapy.

Animals↗
PubMed1998

Primary Sjögren's syndrome complicated by sarcoidosis.

Sjögren's syndrome and sarcoidosis share several common features, such as keratoconjunctivitis sicca, swelling of parotid glands, lung involvement, cutaneous anergy, T cell-mediated immunodeficiency, an increased CD4+/CD8+ lymphocyte ratio, and association with the human leucocyte antigen (HLA)-B 8 and DR 3 haplotypes. However, only five patients with primary Sjögren's syndrome and sarcoidosis have been previously reported in the English language literature. The rare case of a 49-year-old Japanese woman with primary Sjögren's syndrome complicated by sarcoidosis is described. The serum angiotensin-converting enzyme level was increased, and histological examination of lung and skin biopsies revealed noncaseating granulomas, indicating that her primary Sjögren's syndrome was complicated by sarcoidosis.

Female↗
PubMed1997

Development of a novel selective amplifier gene for controllable expansion of transduced hematopoietic cells.

To overcome the low efficiency of gene transfer into hematopoietic cells, we developed a novel system for selective expansion of transduced cells. To this end, we constructed a chimeric cDNA (GCRER) encoding the fusion protein between the granulocyte colony-stimulating factor receptor (G-CSFR) and the hormone-binding domain (HBD) of the estrogen receptor (ER) as a selective amplifier gene. Use of the intracellular signaling pathway of G-CSFR was considered to be appropriate, because G-CSF has the ability not only to stimulate the neutrophil production, but also to expand the hematopoietic stem/progenitor cell pool in vivo. To activate the exogenous G-CSFR signal domain selectively, the estrogen/ER-HBD system was used as a molecular switch in this study. When the GCRER gene was expressed in the interleukin-3 (IL-3)-dependent murine cell line, Ba/F3, the cells showed IL-3-independent growth in response to G-CSF or estrogen. Moreover, the Ba/F3 cells transfected with the Delta(5-195)GCRER, whose product lacks the extracellular G-CSF-binding domain, did not respond to G-CSF, but retained the ability for estrogen-dependent growth. Further, murine bone marrow cells transduced with the GCRER or Delta(5-195)GCRER gene with retroviral vectors formed a significant number of colonies in response to estrogen, as well as G-CSF, whereas estrogen did not stimulate colony formation by untransduced murine bone marrow cells. It is noteworthy that erythroid colonies were apparently formed by the bone marrow cells transduced with the GCRER gene in the presence of estrogen without the addition of erythropoietin, suggesting that the signals from the G-CSFR portion of the chimeric molecules do not preferentially induce neutrophilic differentiation, but just promote the differentiation depending on the nature of the target cells. We speculate that when the selective amplifier genes are expressed in the primitive hematopoietic stem cells, the growth signal predominates and that the population of transduced stem cells expands upon estrogen treatment, even if some of the cells enter the differentiation pathway. The present study suggests that this strategy is applicable to the in vivo selective expansion of transduced hematopoietic stem cells.

Animals↗
PubMed1997

Enhanced interleukin-8 production by cultured Chang liver cells subjected to ethanol exposure and subsequent stimulation with tumor necrosis factor-alpha.

We investigated the production of interleukin-8 (IL-8) and chemotactic activity released from Chang liver cells subjected to long-term treatment with ethanol (Et) and subsequent stimulation with tumor necrosis factor-alpha (TNF-alpha). Chang liver cells were cultured in the presence of 5, 50 or 100 mmol/l Et for 4 weeks and then treated with recombinant TNF-alpha (1, 10, 100 U/ml). The culture supernatants were assayed for IL-8 using a sandwich ELISA and chemotactic activity was measured using a chemotactic chamber. Total RNA was also extracted from these cells and IL-8 mRNA was assayed by RT-PCR. In addition, TNF-receptor expression on the Et-treated cells was analyzed by flow cytometry. IL-8 levels in supernatants of cells stimulated with 100 U/ml of TNF-alpha for 48 h rose significantly with increasing concentrations of Et and values obtained were as follows: 4,918 +/- 244.4 pg/ml at 0 mmol/l Et, 5,335 +/- 266.2 pg/ml at 5 mmol/l Et, 8,726 +/- 873.4 pg/ml at 50 mmol/l Et and 9,134 +/- 866.0 pg/ml at 100 mmol/l Et. The chemotactic activity also increased with increasing concentrations of Et and was almost completely suppressed by anti-IL-8 antibody. Using semiquantitative analysis of radioactivity of IL-8 mRNA using a 32P gamma ATP-labeled primer for IL-8 mRNA, Et-treated cells were shown to have markedly higher levels of radioactivity than untreated cells. In addition, TNF-receptor expression was significantly higher in cells treated with 100 mmol/l Et. These data suggest that long-term Et treatment of Chang liver cells stimulated with TNF-alpha may enhance transcription of the IL-8 gene with up-regulation of the TNF receptor.

Antibodies↗
PubMed1997

Comparison of postural control of children with Down syndrome and those with other forms of mental retardation.

To confirm the 1994 findings of Okuzumi, Haishi, and Kokubun, the displacement of the center of foot pressure, one-foot balance and head sway were measured in children with Down syndrome (n = 11) compared to those with other types of mental retardation (n = 17). The magnitudes of the displacement of the center of foot pressure and head sway were not significantly different between the Down group and other forms of mental retardation, whereas the performance of one-foot balance was significantly lower in the Down group. The mean frequencies of sway waves were generally higher in the Down group, and the differences between the two groups were significant except for sagittal head sway. The results generally supported the prior findings. We proposed that it was not the magnitude of the displacement of the center of foot pressure but rather the manner of the whole body's sway which might be related to postural control.

Adolescent↗
PubMed1997

Synoviocyte proliferation in joints of SCID mice induced by toxic shock syndrome toxin-1 stimulated T cells from patient with rheumatoid arthritis.

OBJECTIVE: To investigate the histopathological arthropathy in severe combined immunodeficient (SCID) mice given intraarticular injection of toxic shock syndrome toxin-1 (TSST-1) stimulated T cells from patients with rheumatoid arthritis (RA). METHODS: Unstimulated or TSST-1 stimulated T cell blasts (TB-TSST) of synovial fluid mononuclear cells from patients with RA (RASFMC) were intraarticularly injected into the knee joint of SCID mice. Four weeks later, the knee joints were histopathologically examined and the numbers of fibroblasts in the synovial tissues were compared with those of controls. Total RNA of the SCID mouse knee joints was isolated and Southern analysis for human T cell receptor (TCR) V beta 2 and human tumor necrosis factor-alpha (TNF-alpha) was carried out. RESULTS: Hyperplasia and increased numbers of the fibroblasts as well as neovascularization of the synovial tissues were observed in the SCID mouse knee joint tissues injected with TB-TSST of RASFMC compared with those injected with unstimulated T cells from RASFMC or with TB-TSST from peripheral blood of healthy controls. Messenger RNA for human TCR V beta 2 and TNF-alpha were detected in the SCID mouse knee joint tissues injected with TB-TSST from RASFMC. CONCLUSION: Superantigen TSST-1 stimulated T cells from RASFMC have the ability to induce chronic arthropathy with fibroblast proliferation and neovascularization in the SCID mouse.

Animals↗
PubMed1996

Antibodies to E1 and E2/Protein X components of pyruvate dehydrogenase complex in sera of patients with primary biliary cirrhosis.

AIMS/METHODS: Using purified E1 component of pyruvate dehydrogenase complex (PDC) from bovine heart, we measured the levels of anti-E1 antibodies in PBC sera using ELISA and determined the degree of inhibition that these antibodies exerted on E1 enzyme activity. We also estimated levels of anti-E2/Protein X (Pro-X) antibodies in PBC sera using purified E2 and Pro-X of PDC which were copurified with E1. RESULTS/CONCLUSIONS: Anti-E1 antibodies were detected in 87.5% (35/40) of PBC sera. Some of these sera inhibited E1 enzyme activity but inhibition did not correlate with levels of anti-E1 antibodies. A high positive correlation (r = 0.918) was found between levels of anti-E1 and anti-E2/Pro-X antibodies, suggesting that anti-PDC antibody production was stimulated by PDC itself. Levels of IgG class anti-E2/Pro-X antibodies were significantly higher in sera of symptomatic PBC patients than in those of asymptomatic PBC patients. It was also found that patients who were positive for only IgM class anti-E2/Pro-X antibodies had early-stage PBC.

Animals↗
PubMed1996

Interleukin-6 induces proliferation of rat hepatocytes in vivo.

BACKGROUND/AIMS: The aim of this study was to assess the effect of interleukin-6 (IL-6) on the proliferation of hepatocytes and to study the interaction between IL-6 and hepatocyte growth factor (HGF) in vivo. METHODS: IL-6 was injected at a dose of 200 micrograms/mg subcutaneously into rats every day for 14 days. Liver and blood samples were obtained at 1, 3, 7 and 14 days during IL-6 administration. Hepatocyte proliferative activity of sera was measured using 3H-thymidine incorporation into cultured rat hepatocytes. To evaluate the proliferative activity of the hepatocytes in tissue sections, hepatic DNA content and immunostaining of the liver tissue sections for proliferating cell nuclear antigen (PCNA) were performed. Plasma HGF levels were measured using specific EIA. In addition, total RNA was extracted from the liver and expression of HGF mRNA was detected by RT-PCR. RESULTS: The DNA contents of liver taken from IL-6-treated rats were increased during IL-6 administration compared with untreated rats. Sera taken from IL-6-treated rats at various intervals during administration also significantly increased 3H-thymidine incorporation by cultured rat hepatocytes compared with sera from untreated rats, suppressing 3H-thymidine incorporation at day 1 and 3 by anti-HGF antibody. IL-6 itself did not increase 3H-thymidine incorporation. Increased expression of PCNA in these hepatocytes was noted from 1 day after IL-6 administration, and at 14 days, the number of PCNA-positive cells was sevenfold greater than in the livers of untreated rats. However, plasma HGF levels showed a peak at day 1, decreased gradually from day 3, and became undetectable by day 14. HGF mRNA expression in livers of IL-6-treated rats was suppressed from day 3 to day 14 of IL-6 administration. CONCLUSIONS: These data show that IL-6 induces an early phase of liver cell growth in vivo and suggest that an increase level of HGF mediates this effect.

Animals↗
PubMed1996

Predictive value of age of walking for later motor performance in children with mental retardation.

The purpose of the present study was to clarify the predictive value of age of walking for later motor performance in children with mental retardation. While paying due attention to other factors, our investigation focused on the relationship between a subject's age of walking, and his or her subsequent beam-walking performance. The subjects were 85 children with mental retardation with an average age of 13 years and 3 months. Beam-walking performance was measured by a procedure developed by the authors. Five low beams (5 cm) which varied in width (12.5, 10, 7.5, 5 and 2.5 cm) were employed. The performance of subjects was scored from zero to five points according to the width of the beam that they were able to walk without falling off. From the results of multiple regression analysis, three independent variables were found to be significantly related to beam-walking performance. The age of walking was the most basic variable: partial correlation coefficient (PCC) = -45; standardized partial regression coefficient (SPRC) = -0.41. The next variable in importance was walking duration (PCC = 0.38; SPRC = 0.31). The autism variable also contributed significantly (PCC = 0.28; SPRC = 0.22). Therefore, within the age range used in the present study, the age of walking in children with mental retardation was thought to have sufficient predictive value, even when the variables which might have possibly affected their subsequent performance were taken into consideration; the earlier the age of walking, the better the beam-walking performance.

Adolescent↗
PubMed1996

A case of idiopathic portal hypertension complicated with narrowing of intrahepatic bile ducts.

A 37-year-old woman who had portal hypertension followed by splenomegaly, developed collateral blood flow of spleno-renal shunt and paraesophageal veins, esophageal varices and further with narrowing of intrahepatic bile ducts shown by endoscopic retrograde cholangiography was described. Liver function was almost normal except the slight elevation of serum alkaline phosphatase and gamma-glutamyl transpeptidase levels. However, endoscopic retrograde cholangiography revealed the narrowing of the intrahepatic bile ducts. The histological examination of biopsied specimen showed no prominent change in portal tracts and bile ducts without cell infiltration or fibrosis in the portal area. This case will be considered as idiopathic portal hypertension complicated by narrowing of the intrahepatic bile ducts.

Adult↗
PubMed1995

Primary biliary cirrhosis (PBC)-CREST (calcinosis, Raynaud's phenomenon, esophageal dysfunction, sclerodactyly and telangiectasia) overlap syndrome complicated by Sjögren's syndrome and arthritis.

A 36-year-old woman with primary biliary cirrhosis (PBC)-CREST (calcinosis, Raynaud's phenomenon, esophageal dysfunction, sclerodactyly and telangiectasia) overlap syndrome complicated by Sjögren's syndrome and arthritis is reported. She had suffered from Raynaud's phenomenon, sclerodactyly, morning stiffness, arthralgia and sicca symptoms since 34 years of age. She exhibited an increased level of alkaline phosphatase and hyperglobulinemia at 2.8 g/dl without any symptoms, and histological findings from the biopsy specimen of the liver were consistent with those of PBC. Her human leukocyte antigen (HLA) typing was DR8 homozygous.

Adult↗
PubMed1995

Factors affecting age of walking by children with mental retardation.

The relationship between age of walking and two factors of severity of intellectual disability and clinical types (autism, Down syndrome, epilepsy, and "residual") in children with mental retardation was investigated. Subjects were 118 children whose disabilities ranged from severe to mild. Measures by clinical type were significant, and the differences of any two clinical types except between children with epilepsy and the "residual" group were significant, but severity of intellectual disability was not significant. Most children with autism (27 subjects, 93%) walked by the normal time limit of 18 months. Only 3 children (11%) with Down syndrome began to walk within that limit, and 9 of them (33%) walked after 2 years of age. In the "residual" group (including children with epilepsy), 37 children (60%) walked within the normal limit but 15 (25%) only after 2 years of age.

Activities of Daily Living↗
PubMed1995

Developmental trends in pursuit eye movements among preschool children.

The purpose of this study was to investigate the developmental differences in pursuit eye movements among preschool children. The subjects were 28 children aged 3 to 6 years old and 5 adults aged 22 to 37 years. The target was moved sinusoidally on the horizontal plane at 0.3-, 0.5-, and 0.7-Hz stimulus frequency. The power ratio which represented the smoothness of eye movements and the phase difference between eye movements and target movement was calculated. The power ratio decreased with increased stimulus frequency for all subjects, indicating that eye movements became less smooth. At all stimulus frequencies, the power ratio was higher for adults than for children. Among the three age groups of children, there was no statistically significant difference on this parameter. The phase shifted from a small amount of lead for no lag to the lag with faster stimulus frequency in adults, but the gap was not statistically significant. For children, there was a statistically significant difference across age groups on change in the phase difference. These findings may suggest that the developmental differences in pursuit eye movements of children across ages 3 to 6 years were clear in what related to the phase difference.

Adult↗
PubMed1995

Effect of ethanol on DNA synthesis and c-met induction in Chang liver cells with long-term culture.

This investigation was performed to determine whether ethanol affects induction on Chang liver cells of the c-met protooncogene product (c-met), a cell-surface receptor for hepatocyte growth factor (HGF). These cells were cultured for 4 weeks with 5, 50, or 100 mmol/L ethanol, or 10, 100, or 200 mumol/L acetaldehyde. Ethanol was found to inhibit [3H]thymidine incorporation by cells in a dose-dependent manner. In addition, acetaldehyde at 100 mumol/L also inhibited [3H]thymidine uptake. Treatment with recombinant HGF led to enhanced [3H]thymidine incorporation by cells treated with ethanol or acetaldehyde as well as by those left untreated, with no significant differences in the rates of increase among these three cell groups. The amount of c-met messenger RNA, however, was unaffected by treatment with ethanol or acetaldehyde. Expression of c-met as measured by cell ELISA was also unchanged by both treatments. These results suggest that ethanol has no effect on c-met induction on Chang liver cells and that HGF may not be involved in the ethanol induced inhibition of DNA synthesis.

Cells, Cultured↗
PubMed1993

Metabolic changes in cimetidine treatment for scald injury on the peritoneo-serosal surface in far-advanced gastric cancer patients treated by intraperitoneal hyperthermic perfusion.

Since pretreatment with cimetidine results in the prevention of scald injury on the peritoneo-serosal surface caused by intraperitoneal hyperthermic perfusion (IPHP) for advanced gastric cancer, the diverse influence of IPHP on patients who were either given or not given cimetidine was studied both during and after IPHP treatment. Cimetidine 50 mg/kg was injected intravenously into 12 patients immediately prior to IPHP. There were no statistical background differences between the cimetidine and control groups (those not given cimetidine). The inflow and outflow temperatures of the hyperthermic perfusate in the control and cimetidine groups were 46.1 +/- 0.1 degree C and 44.1 +/- 0.1 degree C and 46.3 +/- 0.1 degree C and 44.2 +/- 0.04 degree C, respectively. Either the pre-IPHP hypothermia or IPHP in the control group resulted in a considerable increase in serum noradrenaline and adrenaline. The intravenous administration of cimetidine led to a stransient but moderate drop in the mean blood pressure as well as a delayed appearance of high concentrations of noradrenaline and adrenaline, induced by high concentrations of circulating histamine released with cimetidine. These results suggest that the sympathetic nervous responses were activated either by hypothermia or hyperthermia. The transient hypotension and delayed increases of both serum catecholamines were attributed to a marked increase in circulating histamine, released with the intravenous cimetidine.

Blood Pressure↗