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Biomedical subjects

M Takayanagi

Publications and source records attributed to M Takayanagi.

At least 91 records · Page 5Linked to original sources
PubMed1995

Interferon gamma production by peripheral blood lymphocytes to hepatitis C virus core protein in chronic hepatitis C infection.

Evidence suggests that cellular immunity to hepatitis C virus (HCV) core protein may be important in the pathogenesis of viral infection. Therefore, interferon gamma (IFN-gamma) production by peripheral blood mononuclear cells (PBMC) derived from patients with chronic HCV infection (genotype 1b) was examined. The cellular immune response was evaluated with a recombinant HCV core fusion protein derived from a patient with genotype 1b. To identify the immunodominant epitopes, IFN-gamma production in responders was also assessed with a panel of nine synthetic peptides that covered the entire core region. It was found that mononuclear cells from 24 (52%) of 46 patients with chronic liver disease responded to the core protein; asymptomatic HCV carriers demonstrated a lower response rate (14%, P < .05). More important, individuals who had received IFN-alpha treatment and went into clinical and virological remission had a higher response rate (75%, P < .05) compared with those with ongoing hepatitis whose treatment failed (31%). Of 25 patients whose mononuclear cells responded to HCV core protein, 18 had a significant response to one or more peptides; 12 patients reacted to a peptide mixture containing hydrophilic sequences. The core peptide amino acid sequence 141 to 160 was recognized in 9 patients. Interestingly, 7 of 8 patients bearing HLA DR 4 and w53 haplotypes recognized the peptide sequence 141 to 160. Thus, IFN-gamma production of the mononuclear cell response appeared to be HLA DR restricted, and the responding cells were identified as CD4+ T cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Immunocytochemical colocalizations of serotonin, aromatic L-amino acid decarboxylase and polypeptide hormones in A- and PP-cells of the chicken endocrine pancreas.

The colocalization of serotonin and aromatic L-amino acid decarboxylase (AADC) in the avian pancreatic polypeptide-containing PP-cells and glucagon-storing A-cells of the chicken endocrine pancreas was investigated using combined pre-embedding immuno-peroxidase and post-embedding immunogold electron microscopic immunocytochemistry. The avian pancreatic polypeptide-immunoreactive cells manifested by the labeling of immunogold particles on secretory granules were also immunoreactive with antisera directed against serotonin and AADC, an enzyme involved in the synthesis of serotonin. In PP-cells immunoreactivity against the anti-serotonin serum was stronger in secretory granules than in the cytoplasmic matrix, whereas immunoreaction with the anti-AADC serum was observed to be more intense in the cytoplasmic matrix. Immunoreactions with the serotonin and AADC antisera were also found in secretory granules of glucagon-storing A-cells. These results indicate that serotonin is co-stored within secretory granules of both A- and PP-cells, and that AADC is localized within secretory granules of A-cells, and may be present in the cytoplasmic matrix of PP-cells. It is probable that serotonin is synthesized and released simultaneously with secretory granules from both A- and PP-cells of the chicken endocrine pancreas.

Animals↗
PubMed1995

Bronchial hyper-responsiveness to inhaled histamine in children with congenital heart disease.

In order to assess bronchial responsiveness in patients with congestive heart failure secondary to congenital heart disease, we performed a histamine inhalation test while monitoring transcutaneous oxygen tension and compared the respiratory threshold to histamine with that obtained in patients with bronchial asthma. The inhalation test was performed by doubling concentrations of histamine solution for 2 min at 1 min intervals. The respiratory threshold of histamine was defined as the minimal concentration causing a drop in transcutaneous oxygen tension greater than 10% from baseline. Six of 10 patients with congenital heart disease and all of 12 patients with bronchial asthma had bronchial hyper-responsiveness to histamine. The mean of histamine concentration was 2750 micrograms/mL and 937 micrograms/mL, respectively. During the histamine inhalation test, respiratory resistance gradually increased in congenital heart disease patients. This was measured by the linear slope of transcutaneous oxygen pressure (-1.08 +/- 0.75 mmHg/min), whereas in the bronchial asthma patients it rapidly decreased at the infection point (-4.19 +/- 1.86 mmHg/min). We conclude that children with congestive heart failure had bronchial hyper-responsiveness. We suggest bronchial hyper-responsiveness to inhaled histamine in congestive heart failure was caused by the gradual increased respiratory resistance, which was different from that of bronchial asthma.

Blood Gas Monitoring, Transcutaneous↗
PubMed1995

Predictive factors in the response to interferon therapy in chronic hepatitis C.

Factors predicting the efficacy of interferon therapy were statistically analyzed on 111 patients with chronic hepatitis C. Of the treated patients (total doses of interferon; 96-468 MU), 35 (31.5%) had a long-term remission. On multivariate analysis, hepatitis C virus genotype (p < 0.0001), histological diagnosis (p < 0.05), fibrosis score of histological activity index (p < 0.01) and source of infection (p < 0.05) were found useful for predicting the response to interferon therapy. Our findings suggest that the outcome of interferon therapy can be predicted to some degree from pretreatment data, and that a new therapeutic strategy is necessary for the group of patients who are predicted to be nonresponders.

Adult↗
PubMed1995

Additional evidence for blepharismin photoreceptor pigment mediating step-up photophobic response of unicellular organism, Blepharisma.

In the ciliated protozoan, Blepharisma japonicum, the pink-colored pigment (blepharismin) contained in the pigment granules is believed to be the photoreceptor pigment responsible for the step-up photophobic response. When the cells partially bleached by extrusion of the pigment granules caused by cold shock were subsequently cultured under illuminated conditions, the pigment-less granules regenerated and the cells were further bleached (pigment content below 0.5%). The photosensitivity of such colorless cells disappeared completely. In contrast, the blepharismin pigment regenerated gradually when such colorless cells were transferred to darkness. The photosensitivity of the cells also recovered with regeneration of the pigment. We found that blepharismin pigment was not photobleached in the absence of O2. The step-up photophobic response was also completely repressed in the absence of O2. These results strongly confirm that blepharismin is a photoreceptor pigment mediating photobehavior of Blepharisma and that O2 is required for the early step in the phototransduction of the light-excited pigment.

Animals↗
PubMed1995

Insulin resistance associated with decreased levels of insulin-receptor messenger ribonucleic acid: evidence of a de novo mutation in the maternal allele.

Mutations in the insulin receptor gene may lead to insulin resistance and diabetes mellitus in some patients. We have studied an insulin-resistant patient with leprechaunism. Insulin binding to the patient's fibroblasts was markedly decreased. Determination of the nucleotide sequence of the patient's insulin receptor gene revealed heterozygosity for a 2-basepair deletion in exon 15. If the premessenger ribonucleic acid (pre-mRNA) is spliced normally, it causes a replacement of codon 970 in the beta-subunit with a premature chain termination codon, thereby deleting most of the intracellular domain of the receptor. The mRNA transcribed from the allele with a 2-base-pair deletion is likely to be unstable because mRNA transcripts from this allele could not be detected by complementary DNA sequencing. Northern blot analysis showed that the patient's insulin receptor mRNA was decreased by 90% compared with that of a control subject, thus suggesting that the patient is a compound heterozygote for two mutations that decrease levels of insulin receptor mRNA. This deletion mutation in exon 15 seems to be a de novo mutation, because it was not detected in either parent. Investigation of the inheritance of a silent sequence polymorphism in exon 17 provided that the deletion occurred in the maternal allele. Furthermore, linkage analysis suggests that the second mutation is derived from the patient's father, although we could not directly identify it by sequencing the coding region of the insulin receptor gene. Therefore, it is possible that this mutation is present in a regulatory domain of the insulin receptor gene, acting in cis-dominant fashion to reduce the levels of insulin receptor mRNA. Analyses of the hypervariable region in the myoglobin and pMCT118 loci were consistent with the assumption that the father and mother studied here are indeed the biological parents of the diseased patient. We hereby conclude that the patient is a compound heterozygote for two mutant alleles, both of which are responsible for the reduced levels of insulin receptor mRNA and insulin binding.

Adult↗
PubMed1995

Inhibition of doxorubicin-induced cell death in vitro and in vivo by cycloheximide.

We studied the effects of the protein synthesis inhibitor, cycloheximide (CH), on cell killing by doxorubicin (DOX) in vitro and in vivo. At the concentration of CH used (1 microgram/ml) the cytotoxicity of DOX was reduced in cultured P388 leukemia cells. An analysis of the DNA histogram obtained by flow cytometry showed that DOX exerts its growth-inhibitory effect by blocking the cell cycle at the G2/M phase in P388 cells. Treatment with CH diminished this blocking effect. When CH was added to the growth medium before DOX exposure, no change in intracellular DOX accumulation was observed. Treatment with CH (15 mg/kg) significantly diminished the lethality of DOX (20 mg/kg) in mice and it also reduced the antitumor activity of mice with P388 leukemia. Thus, CH inhibited cell death induced by DOX in vitro and in vivo. These results suggest that CH has an antagonistic effect on the pharmacological actions of DOX in cells and mice. The cytoprotective effect of CH may be due to protein synthesis inhibition.

Animals↗
PubMed1995

[Airborne Japanese cedar allergens studied by immunoblotting technique using anti-Cry j I monoclonal antibody--comparison with actual pollen counts and effect of wind speed and directions].

We collected airborne particles of Japanese cedar pollen with Burkard's sampling tape in Toyama from February to April 1992. The tape was cut into two pieces in parallel to time axis. The one of piece of the tapes was stained with glycerin-jerry and stained pollens were counted with a microscope. The other piece was treated according to the immunoblotting technique. The airborne pollen allergens, reacting with anti-Cry j I monoclonal antibody, were stained as blue spots. The spots were classified by diameter into two groups, large spots (> 50 microns) and small spots (< 50 microns). There were significant correlations found between the airborne Cry j I allergen spots (in large and small) and actual pollen counts obtained with the Burkard's sampler and the Durham's sampler (r = 0.729, 0.586 in large spots and r = 0.676, 0.489 in small spots, p < 0.001). The counts of small spots stayed in high level even in April when actual pollen counts decreased. We concluded that this discrepancy was caused by allergenic crushed cedar pollen particles staying floating longer than actual pollens. Secondly we set a gauge of wind speed and direction at the same point as the samplers. The actual pollen counts and large spots counts were significantly larger in the wind (SE wind in Toyama city) from cedar trees blooming area than other areas. However small spots counts did not differ significantly according to wind directions. Wind speed did not effect on actual pollen counts, large spots counts and small spots count.

Air↗
PubMed1995

[Study of cockroach allergy in asthmatic children. The positive rates and antigenicity of cockroach allergen].

The specific IgE antibodies to 4 species of cockroach were measured in sera from 51 asthmatic children 6 to 16 years old by RAST and CAP system. Positive rates of RAST to Periplaneta fuliginosa, Blattela germanica, Periplaneta americana and Periplaneta japonica were 17.6%, 29.4%, 19.6% and 15.7%, respectively and those of CAP system to Periplaneta fuliginosa and Blattela germanica were 15.7%, respectively. Among those with positive RAST to 4 species of cockroach there were significant correlations. Significant correlations were observed also between the RAST titer for the whole bodies and feces of Periplaneta fuliginosa and Blattela germanica and immunoblotting analysis of sera obtained from two cockroach-positive patients revealed common sensitive fraction between whole body and feces. Immediate bronchial response was detected by bronchial provocation test. RAST inhibition study indicated no cross-reacting allergenicity between cockroach and mite. Collectively, cockroach is one of important inhalent allergens in asthmatic children.

Adolescent↗
PubMed1994

Hepatitis C virus genotypes are not responsible for development of serious liver disease.

Although hepatitis C virus (HCV) is known to have at least four kinds of genotypes, no clear relationship has yet been established between the genotype and the severity of liver disease. Therefore, we determined HCV genotypes in sera of 251 Japanese patients with type C chronic liver disease, using polymerase chain reactions with six independent primers. One set of primers and a probe derived from 5'-noncoding region of HC-J1 was supposed to detect all four genotypes, while the other five were devised to detect each of the genotypes. Among the patients, the major genotype was type II (69%) and the second most common was type III (18%). Type IV was found in 7%, while none had type I genotype. There was no significant difference in the distribution of any genotype among different stages of liver disease, although the ratio of type II to type III tended to be higher in the group of cirrhosis and hepatocellular carcinoma than in the chronic hepatitis group (5.5 vs 3.0). The amounts of HCV RNA were significantly greater in patients with type II (P < 0.001) compared with those with types III and IV. However, HCV concentrations of each genotype were not associated with the disease status. These results suggest that HCV genotypes are unlikely to be responsible for the development of more serious liver disease.

Adult↗
PubMed1994

Colorimetric determination of urinary xanthurenic acid using an oxidative coupling reaction with N,N-diethyl-p-phenylenediamine.

A simple enzymatic method for the spectrophotometric determination of xanthurenic acid (XA) in urine is described. The method is based on the formation of a pigment derived from an oxidative coupling reaction with XA and N,N-diethyl-p-phenylenediamine (DE-PPD) in the presence of hydrogen peroxide and horseradish peroxidase. The color of the reaction mixture was developed with a peak absorbance at 750 nm. The recoveries against XA added to urine ranged from 91.0 to 96.5%. With this method, XA can be determined within 5 min, without a time-consuming sample preparation. The detection range of this method was between 5 and 150 microM, with a coefficient of variation of 2.7% or less. The correlation between this and the fluorometric method was good.

Calibration↗
PubMed1994

[A case of chronic neutrophilic leukemia accompanied with severe bone marrow fibrosis which was effectively treated by hydroxyurea].

A 57-year-old man was admitted to hospital because of leukocytosis. He showed mild splenomegaly and, laboratory studies revealed elevated mature neutrophil count without morphological abnormality, mild anemia and elevated neutrophil alkaline phosphatase score. The serum granulocyte colony stimulating factor concentration was below 30 pg/ml. Bone marrow was a dry tap, and biopsy specimen revealed severe fibrosis. The peripheral blood karyotype was 46, XY with no rearrangement of bcr-abl. The patient was diagnosed as having chronic neutrophilic leukemia (CNL) with bone marrow fibrosis. He was successfully treated with hydroxyurea (HU) 1000 mg/day. The peripheral blood leukocyte was decreased to the normal level and, the bone marrow biopsy specimen changed mild fibrosis. During the follow up period of 11 months, the neutrophil count was well controlled without any side effect. This is a rare case of CNL accompanied with bone marrow fibrosis which was effectively treated by the administration of HU.

Humans↗
PubMed1994

[Bronchial hypersensitivity and development of bronchial asthma in children with atopic dermatitis].

Using histamine inhalation tests, we followed changes in bronchial hypersensitivity in 48 children with atopic dermatitis (AD) who were nonasthmatic on their initial visit. Twenty-three of these subjects became asthmatic during the follow-up period. The respiratory thresholds to histamine RT-Hist) of children with AD were widely distributed, ranging from 156 to more than 5000 micrograms/ml. There was a statistical difference in RT-Hist, as those who became asthmatic showed lower levels (< or = 625 micrograms/ml) at 2-6 yr of age. The percentage of peripheral eosinophil counts and IgE level was significantly elevated in those who became asthmatic. Subjects who developed asthma were more likely to have had positive D.p. RAST when they were less than 2 yr of age. The development of asthma in children with AD showed no significant relationship with family history of bronchial asthma.

Age of Onset↗
PubMed1994

[Bronchial hypersensitivity to histamine in asthmatic children longitudinal study from first visit to remitted state].

In order to examine the changes in bronchial hypersensitivity, histamine inhalation tests were evaluated in 27 asthmatic children who remitted. The respiratory threshold to histamine (RT-Hist) 2-3 yrs after remission was higher than in the initial test, in their worst periods of the asthma and just before remission (p < 0.001, p < 0.001, p < 0.005, respectively). Eleven subjects (40.7%), showed no improvement of bronchial hypersensitivity 2-3 yrs after remission (RT-Hist was 1250 micrograms/ml or lower). In this group, the asthma score per year two and three years before symptom-free state was higher than in the group with improved bronchial hypersensitivity (p < 0.05). There was no significant difference between % fall of FEV1.0 in RT-Hist in the worst periods of the asthma and 2-3 yrs after remission. FEV1.0/VCP, %V50, %V25 and V25/Ht 2-3 yrs after remission were higher than those in the worst periods of the asthma.

Adolescent↗
PubMed1994

[A case of anaphylaxis caused by sunflower seed].

A 14 years old boy experienced an anaphylactic reaction of dyspnea, vomiting, urticaria and hypotension after he ate sunflower seeds. Specific IgE-mediated hypersensitivity to sunflower seen extract was demonstrated by skin tests and radioallergosorbent test (RAST). By immunoblotting test analysis (SDS-PAGE, Western blotting method), the allergenic activity of sunflower seem were shown to be in the MW range of 13.5 Kd.

Adolescent↗
PubMed1994

Interferon-gamma production specific for hepatitis B virus antigen by intrahepatic T lymphocytes in patients with acute and chronic hepatitis B.

OBJECTIVES: Studies were undertaken to determine whether intrahepatic lymphocytes have a greater cellular immune response specific for hepatitis B virus (HBV) antigen than peripheral blood lymphocytes in HBV-infected man. METHODS: HB nucleocapsid antigen-stimulated interferon-gamma (IFN-gamma) production of lymphocytes was measured in acute self-limited hepatitis (AH) (eight cases) and chronic hepatitis (CH) (14 cases). RESULTS: In both patient groups, basal IFN-gamma levels without any stimulation were higher in the hepatic T cells than in the peripheral T cells. The values in cultures from blood and liver were larger in AH than in CH. Alternatively, IFN-gamma response to HBcAg and HBeAg was less in hepatic T cells than in the corresponding blood cultures; T cell response was HLA class II restricted. Cell flow cytometry study showed that in all patient groups, percentages of CD3+, CD8+, and HLA-DR+ cells were significantly greater in liver than in peripheral blood, whereas the proportion of hepatic CD4+ cells was decreased, compared with that in peripheral CD4+ cells. CONCLUSIONS: These findings suggest that liver infiltrates are already activated in vivo to produce IFN-gamma, particularly in patients with AH. The changes in the proportion of lymphocyte subsets may be responsible for the altered IFN-gamma response of hepatic T cells.

Acute Disease↗
PubMed1993

Cloning and sequence analysis of a full length cDNA encoding human mitochondrial 3-oxoacyl-CoA thiolase.

The cDNA sequence of human mitochondrial 3-oxoacyl-CoA thiolase was determined. The nucleotide sequence contains an open reading frame of 1191 base pairs and encodes an amino acid sequence of 397 residues which exhibits 86.6% homology with that of the rat enzyme. Northern blot analysis gave a single mRNA species of 1.6 kb in the human liver, fibroblasts and intercostal muscle.

Acetyl-CoA C-Acyltransferase↗