Biomedical subjects

M Takayanagi

Publications and source records attributed to M Takayanagi.

At least 73 records · Page 4Linked to original sources

PubMed1997

[The storage technology of blood, the latest advances--cryopreservation of red blood cells].

In the field of red blood cell cryopreservation, the latest research informations were mainly divided into two parts as follows: 1) The improvement of the frozen storage bag. 2) The long-term storage of the frozen and thawed red blood cells. That was based on the research for changing the film of frozen storage bags from polyvinyl chloride to polyolefin. In consequent, the broken ratio of the bags in the period of frozen storage was expected to reduced, immediately. And this was studied for establishment of the closed bag system and introduction of the mannitol-adenine-phosphate(MAP) solution. From these results, it was made clear that the frozen and thawed red blood cells could be stored in MAP solution at 4 degrees C for 3 weeks.

Cryopreservation↗

PubMed1997

[Nutritional support in terminal patients--evaluation of 109 cases receiving home parenteral nutrition].

For end-stage patients with malignant disease, home parenteral nutrition (HPN) is an effective and useful treatment in terms of pain control and nutritional support. Therefore, these patients are able to spend their final days at home with their family. In 1990, we started the treatment and have been experienced 109 cases. In this report, we evaluate these cases and which condition or circumstance are necessary to perform HPN for the terminal patients.

Adult↗

PubMed1996

Serial analysis of hepatitis B virus core nucleotide sequence of patients with acute exacerbation during chronic infection.

Recent studies suggest that hepatitis B virus (HBV) core region could be an immunological target and that amino acid (aa) substitutions are mostly restricted to a small segment located in the middle of the core region. We sequenced the middle portion of HBV core gene during the course of acute exacerbation of chronic hepatitis B, and compared aa variations between the region including ideal HLA-A2 binding motifs and the nonbinding region. Five HBeAg+ chronic hepatitis patients with subtype adr (three with HLA-A2 and two without HLA-A2) were selected and using polymerase chain reaction (PCR) and cloning system, the central part of core region (nt 2063 to 2365, 303 bp) was sequenced in sera from each patient at three time points; before, at the peak of, and after exacerbation of hepatitis. The second set of sera showed higher aa substitution rates in five and in three out of five patients compared with those of the first and third sera, respectively. No significant difference was found in the aa substitution rates for the region with ideal HLA-A2 binding motifs between patients with and without HLA-A2. In asymptomatic HBV carriers with persistently normal aminotransferase values, alterations of the aa sequence were not observed within the same time frame. The results suggest that aa substitutions often occur at some particular positions in the middle of HBV core region during acute exacerbation of the disease under possible host immune pressures. Furthermore, unidentified epitopes appear to exist in the central part of HBV core region and HLA-unrestricted lymphocytes may play a role in the immune response of chronic HBV carriers.

Adult↗

PubMed1996

Hypervariable region sequence in cryoglobulin-associated hepatitis C virus in sera of patients with chronic hepatitis C: relationship to antibody response against hypervariable region genome.

Essential mixed cryoglobulinemia is frequently associated with hepatitis C virus (HCV) infection, with the formation of HCV antigen/antibody complexes. The hypervariable region (HVR) of the HCV E2/NS1 region is thought to include epitopes for neutralizing antibodies, but it remains uncertain whether cryoglobulins (CGs) contain such antibody-bound HCV. Thus, we studied HVR clones isolated from cryoprecipitate and supernatant in the sera of four chronic hepatitis C patients with cryoglobulinemia, and expressed as fusion proteins with glutathione S-transferase (GST). Patients' sera were tested for antibody binding to the proteins. The rate of anti-HVR antibody-positive clones was significantly higher in cryoprecipitate (89% +/- 13%, P < .05) than in supernatant (41% +/- 25%). Both HCV RNA and anti-HVR antibody were more concentrated in cryoprecipitates compared with those of serum and supernatant in two patients tested. Anti-HVR antibody-positive clones in cryoprecipitate showed common amino acid (aa) sequences in each of the four patients. Similarly, all the antibody-positive clones in supernatant showed the same aa sequences for three of the four patients. When aa sequences were compared with those of reported isolates with genotype 1b, the mean percentage of aa difference was greater in the clones from supernatant and in anti-HVR antibody-negative clones than in the clones from cryoprecipitate and in the antibody-positive clones, respectively. These findings indicate that serum CG contains anti-HVR antibody-bound HCV in patients with chronic hepatitis C. Anti-HVR antibody-free individual clones, which were more frequently noted in supernatant, showed closely related sequences, but which were of a heterogeneous quasispecies nature.

Adult↗

PubMed1996

Two novel gene mutations (Glu174-->Lys, Phe383-->Tyr) causing the "hepatic" form of carnitine palmitoyltransferase II deficiency.

Carnitine palmitoyltransferase II (CPT II) deficiency has two different clinical forms, one with "hepatic" and the other with "muscular" symptoms. We studied the molecular basis of the "hepatic" form in two Japanese siblings. Their CPT II activity in lymphoblasts was reduced to 3% of the level observed in normal controls. cDNA analysis showed that the proband was a compound heterozygote. One allele carried a new mutation, G621-->A (Glu174-->Lys). The other carried three single-base substitutions; a new mutation, T1249-->A (Phe383-->Tyr), and two previously reported polymorphisms. The brother had the same four substitutions. Neither of the two new mutations in this study was detected in the 60 alleles of 30 Japanese control subjects. Secondary structure prediction analysis of the mutated CPT II protein was different from that of the normal protein. We concluded that these mutations caused the "hepatic" form of CPT II deficiency in the probands.

Alleles↗

PubMed1996

Somatostatin-14 and somatostatin-28 in chicken pancreatic islet D-cells.

Somatostatin (SST)-14 and mammalian (m) SST-28[1-14] immunoreactivities of chicken pancreatic islets were investigated by using light microscopic immunohistochemistry. Chicken D-cells in both A- and B-islets showed immunoreactivity to SST-14, but not to mSST-28[1-14]. The acid-extract from both splenic and ventral lobes of pancreas was fractionated by reverse-phase high-performance liquid chromatography, and the SST-like immunoreactivity was measured in the radioimmunoassay using anti-SST-14 serum. In both lobes, the SST-like immunoreactivity was detected in the fraction which corresponded to that of SST-14 standard, but was not found in that of mSST-28 standard. Immunohistochemically, pancreatic endocrine D-cells of 1 amphibian, 4 reptiles and 12 birds showed the same immunostaining property as chicken D-cells. By contrast, both SST-14- and mSST-28[1-14]-immunoreactive D-cells were observed in the pancreatic islets of 16 mammals. From these results, we concluded that chicken islet D-cells contain only SST-14-like peptide, but not SST-28-like peptide, and that this phenomenon may be common to the avian species.

Amphibians↗

PubMed1996

Immunocytochemical colocalizations of insulin, aromatic L-amino acid decarboxylase, dopamine beta-hydroxylase, S-100 protein and chromogranin A in B-cells of the chicken endocrine pancreas.

The colocalization of aromatic L-amino acid decarboxylase (AADC), dopamine beta-hydroxylase (DBH), S-100 protein and chromogranin A (CgA) in the insulin-containing B-cells of the chicken endocrine pancreas was investigated by using light microscopic immunohistochemistry and combined pre-embedding immunoperoxidase and post-embedding immunogold electron microscopic immunocytochemistry. Using the post-embedding method, immunoreactivity against the anti-insulin serum by protein A-gold technique was observed in the core of all types of B-cell granules. Immunoreaction with anti-S-100 protein serum was detected in the core of all types of B-cell granules. Immunoreaction with anti-S-100 protein serum was detected in the core of all types of B-cell granules from non-osmicated tissues even by post-embedding method, but immunoreactivities against the anti-AADC, DBH and CgA sera were only demonstrable in crystalloid granules of B-cells by pre-embedding method. Immunoreaction with the anti-CgA serum was also detected in the cytoplasmic matrix around crystalloid granules and also in the dense bodies showing immunonegative with anti-insulin serum. From these results, it seems likely that S-100 protein co-stored all types of B-cell granules involved in the maturation of granules, and AADC, DBH and CgA are related to the synthesis of noradrenaline in crystalloid granules of B-cells.

Animals↗

PubMed1996

Deficiency of antibody response to hypervariable region of hepatitis C virus in patients with chronic hepatitis C.

BACKGROUND/AIMS: Frequent mutations in the hypervariable region of hepatitis C virus have been suggested to be a cause of persistent infection by providing a way for the virus to escape host immunity. However, the variation rate in the hypervariable region is often low in patients with chronic hepatitis. The aim of this study was to elucidate the mechanism of persistent infection in patients with chronic hepatitis by investigating the relationship between the antibody response to and the variation in hypervariable region. METHODS: The hypervariable regions of 26 clones of six patients with chronic hepatitis C were expressed as proteins fused with glutathione S-transferase, and sera of the patients were serially tested for antibody to these proteins. RESULTS: The extent of antibody response to the hypervariable region differed considerably among the patients. Three patients showed no or only scanty antibody response. These had a lower variation rate in the hypervariable region (0-1.3/year) than in the others with frequent or persistent antibody response (2.1-14.6/year). In two patients, serum samples were found to be reactive with the clones even before the appearance of the clones. In three patients, coexistence of the antibodies and corresponding clones were noted. An augmentation of antibody response always followed rises in serum alanine aminotransferase levels. CONCLUSION: Deficiency of antibody response to the hypervariable region may be one of the causes of persistency in hepatitis C virus infection.

Adult↗

PubMed1996

Sequence analysis of hypervariable region of hepatitis C virus (HCV) associated with immune complex in patients with chronic HCV infection.

Immune complex (IC) frequently exists in sera of patients with hepatitis C virus (HCV) infection. When circulating HCV particles are fractionated by differential flotation ultracentrifugation, HCV in the bottom fraction appears to be in the form of IC. Flotation ultracentrifugation of serum was done in 7 patients positive for serum anti-C3d-binding circulating IC and in 7 negative patients. In all IC-positive patients, HCV RNA was detected in the bottom fraction but not in the top fraction of 3 patients. Amino acid sequences of hypervariable region (HVR) of HCV in the bottom fraction of IC-positive patients were almost the same as those of whole serum, while those of the top fraction considerably differed from those of whole serum except for 1 case. These data suggest that the major population of HCV forms IC in IC-positive patients, and antibody response to the HVR of HCV is responsible for IC formation.

Aged↗

PubMed1996

Acute disseminated encephalomyelitis associated with Mycoplasma pneumoniae infection.

An 8 year old girl with acute disseminated encephalomyelitis (ADEM) is described. Elevated serum antibody titers suggested recent Mycoplasma pneumoniae infection. T2-weighted image of magnetic resonance imaging (MRI) disclosed multiple lesions of high signal intensity in bilateral basal ganglia and thalami as well as in the white matter. Postcontrast T1-weighted image revealed an enhanced lesion in the deep white matter. She showed rapid clinical improvement in response to corticosteroid therapy. The lesions had disappeared completely on MRI performed 10 weeks after the onset. ADEM is believed to be a demyelinating disorder of probable autoimmune etiology. MRI findings in this case may support the hypothesis that the primary pathological event is vascular injury and demyelination occurs only as a secondary phenomenon.

Basal Ganglia↗

PubMed1996

The enhancing effect of tumour necrosis factor-alpha on oxidative stress in endotoxemia.

The enhancing effect of tumour necrosis factor-alpha (TNF-alpha) on oxidative stress with or without a sublethal dose of endotoxin was examined. The mortality of mice treated with recombinant human TNF-alpha (1 x 10(4) units/mouse, intravenously) and endotoxin (0.01-1 mg/kg, intraperitoneally) was dependent on the dose of endotoxin. The liver lipid peroxide level, superoxide anion generation and serum lactate dehydrogenase activity, especially serum lactate dehydrogenase-5 isozyme leakage, in mice 2-4 hr after administration of recombinant human TNF to endotoxin-pretreated mice (0.5 mg/kg, intraperitoneally) were markedly higher than in those without endotoxin, whereas the administration of recombinant human TNF significantly decreased the non-protein sulfhydryl level, superoxide dismutase and glutathione peroxide activities in the liver of endotoxin-injected mice compared with those in mice treated with recombinant human TNF or endotoxin alone. Furthermore, findings clearly demonstrated that J774A.1 cells stimulated with recombinant human TNF (1 x 10(4) units/ml) can effectively produce nitric oxide in the presence of endotoxin, and the production was dependent on the dose of endotoxin (0.01-10 micrograms/ml). The level of lipid peroxide in mice 4 hr after administration of recombinant human TNF and lead acetate (50 mg/kg, intravenously) was markedly higher than that in the mice treated with recombinant human TNF alone. By contrast, injection of polymyxin-B (20 mg/kg, intraperitoneally, an anti-endotoxin drug) markedly decreased the lipid peroxide level in the liver of the mice treated with recombinant human TNF and lead acetate. These findings suggest that the oxidative stress caused by TNF occurs as a enhancing effect of endotoxin or by bacterial translocation from the intestinal gut under reduction of reticuloendothelial system function in various disease states, and that the effect of TNF may cause a marked increase of toxicity of oxidative stress by endotoxin.

Animals↗

PubMed1996

Effects of antitumor activity and protection of shock symptoms by a traditional Chinese medicine (sho-saiko-to) in recombinant human tumor necrosis factor administered mice.

The effects of a traditional Chinese medicine Sho-saiko-to (Kampo prescription) were investigated on the various metabolic disorders and antitumor activity of recombinant human tumor necrosis factor (rhTNF) administered to mice. The glycogen level in liver of rhTNF (5 x 10(4) units/mouse, i.v.)-injected mice was markedly lower at 4 h post-intoxication than that in the control, whereas the administration of rhTNF to Sho-saiko-to (500 mg/kg/d, p.o.)-pretreated mice resulted in a greater level of glycogen than that in rhTNF alone-treated mice. In mice pretreated with Sho-saiko-to, the level of fibrinogen 4 h after rhTNF injection markedly increased as compared to that in mice treated with rhTNF alone. We also estimated the NO2 in murine macrophage cell line J774A.1 using mice serum after administration of Sho-saiko-to. Our results clearly demonstrated that J774A.1 cells stimulated with endotoxin (1 micrograms/ml) and rhTNF (1 x 10(4) units/ml) can effectively produce nitric oxide (NO), and ascertained the suppressive effect of Sho-saiko-to (500 mg/kg/d, p.o)-pretreated serum on NO generation by endotoxin/TNF-activated J774A.1 cells. When the cells were incubated with endotoxin/TNF and Sho-saiko-to pretreated serum (10-100 microliters), the NO level was significantly lower than that in control serum incubated with endotoxin/TNF alone. The effect of Sho-saiko-to (1 and 10 micrograms/ml) on in vitro cytotoxicity by rhTNF in Meth-A Sarcoma cells was observed to be in a dose dependent fashion. In addition, there was a remarkable enhancement of antitumor activity of rhTNF by Sho-saiko-to pretreatment in mice. These findings suggest that the Kampo prescription Sho-saiko-to may protect mice from severe shock syndrome by rhTNF, and that it may enhance rhTNF-induced activity.

Animals↗

PubMed1996

[Studies on reversing effect of multidrug resistance by dipyridamole. I. modulation of epirubicin-induced effects on cell proliferation and cell cycle by dipyridamole].

Dipyridamole, a nucleoside membrane transport inhibitor, enhanced the cytotoxicity of epirubicin for mouse leukemia P388 cells by a factor of 1.8-fold and that for 30-fold doxorubicin-resistant sublines of P388 cells (P388/DOX) by a factor of 6.5-fold. This interaction was shown to be truly synergistic by DNA histogram and median effect analysis. The dipyridamole enhancement of the cytotoxicity of epirubioin was a dose-dependent effect; it was greatest when cells were exposed to dipyridamole before treatment with epirubicin. In cell cycle experiments, 1-5 microM dipyridamole increased the accumulation of G2 + M phase produced by the treatment with 0.5-1 microM epirubicin. Dipyridamole, however, did not appear to alter the patterns of DNA histogram in sensitive cells. These results suggest that the increase of the accumulation of G2 + M phase in resistant cells is an important factor for the interaction between epirubicin and dipyridamole.

Animals↗

PubMed1996

[Studies on reversing effect of multidrug resistance by dipyridamole. II. Inhibition of epirubicin efflux from resistant cells by dipyridamole and its pharmacological effect].

We have previously reported that dipyridamole increases the cytotoxicity of epirubicin and alters the cell cycle in doxorubicin-resistant (P388/DOX) cells, increasing the accumulation of G2/M phase by blocking the cell cycle. In cultured cells, dipyridamole increased dose-dependently the intracellular accumulation of epirubicin in the resistant cells. Simultaneous exposure of the resistant cells to epirubicin and 100 microM dipyridamole resulted in a 4.2-fold increase in proportion to the control level of epirubicin after 60 min. Dipyridamole inhibited the enhanced efflux of epirubicin in doxorubicin-resistant cells. However, dipyridamole had no effect on both the influx and efflux of epirubicin in doxorubicin-sensitive cells. In mice, lethal and bone marrow toxicity induced by epirubicin were potentiated by administration of high-dose of dipyridamole. In addition, in vivo results also demonstrated that dipyridamole in combination with epirubicin produced a significant reversal of the in vivo antitumor activity of epirubicin in mice bearing P388/DOX cells. These data imply the enhancement effects of dipyridamole on the efficacy and toxicity of epirubicin.

Animals↗

PubMed1996

Augmentation of epirubicin cytotoxicity by cycloheximide.

The effect of cycloheximide (CH) on the cytotoxic activity of the anthracycline antibiotic epirubicin (EPI) was examined in cell cultures of murine leukemia doxorubicin (DOX)-sensitive P388 and -resistant P388 cells. The addition of CH (0.002 mu g/ml) to the growth medium markedly enhanced the EPI-induced cytotoxic effect in sensitive cells as well as that observed in resistant cells. CH, however, did not affect the intracellular content of EPI. The inhibition of DNA synthesis in leukemia cells was remarkable with the combination of EPI and CH compared with each drug alone. These results suggest that the combination of EPI and CH appears to be useful in killing mouse leukemia cells.

Animals↗

PubMed1996

Reversal of multidrug resistance by tacrolimus hydrate.

Tacrolimus hydrate, a potent immunosuppressant produced by Streptomyces tsukubaensis, was examined for its effect on epirubicin activity in multidrug-resistant P388 leukemia (P388/R) cells overexpressing P-glycoprotein and the parent (P388/S) cells. In the absence of modulator, the 50% inhibitory concentration for epirubicin after 48-h incubation, determined using a microculture tetrazolium assay, was 0.8 microgram/ml in P388/R cells and 0.009 microgram/ml in P388/S cells. P388/R cells demonstrated a 90-fold reduction in sensitivity to epirubicin. Tacrolimus hydrate (1 and 10 microM) markedly enhanced epirubicin cytotoxicity by 4.2- and 26.7-fold for P388/R cells. A significant increase in LDH release from cells by tacrolimus hydrate was also observed in P388/R cells treated with epirubicin. Tacrolimus hydrate had a marked effect on epirubicin-induced G2/M blockade in the resistant cells. Both tacrolimus hydrate and cyclosporin A dramatically increased the accumulation of epirubicin by the resistant cells, while these compounds had no effect on epirubicin accumulation in the parent cells. Thus, tacrolimus hydrate is able to down-modulate P-glycoprotein-associated resistance through inhibition of P-glycoprotein function, suggesting that the drug may be a candidate for killing drug-resistant tumor cells.

Animals↗

PubMed1995

Heterosexual activity as a risk factor for the transmission of hepatitis C virus.

Hepatitis C virus (HCV), the major causative agent of non-A, non-B hepatitis, is transmitted by parenteral exposure. Transmission by sexual activity, however, is controversial. Possible behavioral risk factors for HCV infection were studied retrospectively among imprisoned men (n = 201, mean age: 45 years [S.D. 13]) who visited a health service center at a Japanese correctional facility for medical examination. Seropositivity of anti-HCV antibody was disproportionately high (49.8%) in comparison with volunteer blood donors. Among possible risk factors significant on univariate analysis, intravenous drug abuse and Tama-Ire, a Japanese custom of sexual behavior that suggests frequent, aggressive or promiscuous heterosexual activity, proved to be independent risk factors for HCV infection (odds ratio = 7.39, 95% CI = 3.41 - 16.05, P < 0.0001; odds ratio = 3.16, 95% CI = 1.16 - 8.64, P = 0.026, respectively) as shown by logistic regression analysis. The data suggest that HCV may be transmitted by sexual activity.

Hepacivirus↗

PubMed1995

Serum HCV RNA titer at the end of interferon therapy predicts the long-term outcome of treatment.

BACKGROUND/AIMS: Serum HCV RNA was quantitated by the competitive polymerase chain reaction before, at the end of, and after interferon therapy. We assessed whether serum HCV RNA titer at the end of interferon therapy predicts the long-term outcome of treatment. METHODS/RESULTS: Of 71 patients treated with various doses of interferons, 21 became negative for HCV RNA persistently during follow up of 2 years, and they were considered as complete responders. The serial determinations of HCV RNA titer for each individual showed that in patients with HCV RNA negative at the end of therapy, the complete response rate was quite high (78.6%), while in patients with HCV RNA titer > or = 10(4) copies/ml at the end of therapy, none became complete responders in long-term follow up. The percentage decreasing to < or = 10(2) copies/ml of HCV RNA at termination of interferon tended to be higher in patients with genotype 2a (14/21, 66.7%) than in those with genotype 1b (18/42, 42.9%). The complete response rate of patients whose viral load was < or = 10(2) copies/ml at termination of interferon was significantly higher in genotype 2a (11/14, 78.6%) than in genotype 1b (5/18, 27.8%) (p < 0.01). Pretreatment HCV RNA titer appeared to correlate to the titer at the end of therapy (r = 0.596, p < 0.001); even when HCV RNA decreased to < or = 10(2) copies/ml, the higher pretreatment titer indicated a lower likelihood of complete response (p < 0.05). CONCLUSIONS: These results indicate that HCV genotype and pretreatment viral titer are important factors in the response to interferon therapy. In addition, our study suggests that it is possible to stop interferon therapy at an appropriate time by monitoring HCV RNA titer.

Adult↗