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Biomedical subjects

A Kitano

Publications and source records attributed to A Kitano.

At least 37 records · Page 2Linked to original sources
PubMed1996

Thymocyte proliferation-inducing activity of high molecular weight fraction from the culture supernatant of thymic epithelial cell line established from normal rat thymus.

Precursor T cells originated from bone marrow proliferate, differentiate and maturate (thymic education process) to relatively mature T cells under the influence of thymic epithelial cells (TECs). Thymic hormonal factors (THFs) released from TECs presumably play a pivotal role in the thymic education. The THFs related to the thymocyte differentiation and maturation were carefully examined and some of them identified. However, the relation of THFs with thymocyte proliferation (TPIFs) are poorly understood. Consequently we attempted to study the activities of TPIFs under physiological conditions. In this investigation, we employed a TEC line derived from normal rat thymus, disposable reversed-phase column cartridge for concentrating the culture supernatant of TEC (TECS) and high-performance liquid chromatography. By separating TECS sample with ion exchange chromatography, the thymocyte proliferation-inducing activity (TPIA) was efficiently separated from the thymocyte proliferation-suppressing activity. The TPIA was detected in the fraction with high molecular weight (198 to 310 kDa) by gel filtration chromatography. The TPIA was completely reduced by trypsin digestion, while heat-treatment affected only slightly the TPIA.

Animals↗
PubMed1995

Detection of anti-cord factor antibodies in intestinal tuberculosis for its differential diagnosis from Crohn's disease and ulcerative colitis.

We have developed a diagnostic method for pulmonary tuberculosis by detecting antibody to cord factor using enzyme-linked immunosorbent assay (ELISA). This study was to evaluate the usefulness of our method for a diagnosis of intestinal tuberculosis, and especially its ability to differentiate this disease from other inflammatory bowel diseases. Antibodies of the immunoglobulin G class against cord factor (trehalose-6,6'-dimycolate) from 27 patients with intestinal tuberculosis, 16 patients with Crohn's disease (CD), and 27 patients with ulcerative colitis (UC) were tested by ELISA with cord factor purified from Mycobacterium tuberculosis H37Rv as the antigen. Twenty-three of the 27 patients with intestinal tuberculosis (85%) showed elevated values distinct from healthy controls. None of the patients with CD showed an elevation of antibody titers. Of the 27 patients with UC, 26 (96%) did not show any anti-cord factor antibody elevation. We conclude that this method is simple and results are reproducible. The results of our study justify undertaking the detection of anti-cord factor antibodies to diagnose intestinal tuberculosis.

Adult↗
PubMed1995

Multifocal fibrosclerosis with intracranial pachymeningitis.

A 29-year-old woman with a 4-year history of multifocal fibrosclerosis showed unique neurologic complications. Episcleritis, orbital pseudotumor, and eosinophilic phlegmon preceded intracranial inflammatory pachymeningitis. The pachymeningitis was associated with disturbance of the visual field, incomplete Gerstmann's syndrome, and pseudotumor cerebri. T2-weighted magnetic resonance images revealed a high signal intensity lesion in the left temporal and occipital lobes, and gadolinium-enhanced T1-weighted images revealed the enhancement of the thickened left tentorial leaf. The laboratory data suggested that the etiology might be autoimmunological. The disease and MRI abnormalities improved following administration of corticosteroids.

Adult↗
PubMed1995

Adhesion molecule expression on vascular endothelium and nitroblue tetrazolium reducing activity in human colonic mucosa.

BACKGROUND: Expression of adhesion molecules is increased in inflamed colonic mucosa, but little is known about their functional activity in vascular endothelium. METHODS: We studied in situ nitroblue tetrazolium reducing activity and expression of E-selectin, ICAM-1, CD31, and VCAM-1 by immunohistochemistry in the same biopsy specimen in controls and patients with ulcerative colitis (UC). RESULTS: VCAM-1 expression was negative in mucosal vessels. E-selectin-positive vessels were significantly increased in endoscopically active colitis compared with normal mucosa. ICAM-1-positive vessels were consistently found in normal, quiescent UC and active UC. CD31-positive vessels were not significantly increased in quiescent UC and active UC compared with control. Only E-selectin significantly correlated with the histologic grade of inflammation. Nitroblue tetrazolium reducing vessels were increased in inflamed mucosa, and these vessels expressed ICAM-1 and CD31. E-selectin positivity in association with nitroblue tetrazolium reduction was mainly seen in the large mucosal vessels, but capillaries showing nitroblue tetrazolium reduction were rarely positive for E-selectin. CONCLUSIONS: Phenotypic and functional activation of vascular endothelium might be involved in the recruitment of leukocytes and tissue destruction of inflamed colonic mucosa.

Adult↗
PubMed1995

Deficiency of blood coagulation factor XIII in Crohn's disease.

OBJECTIVE: Refractory fistula formation is one of most intractable complications in Crohn's disease. Recently, the role of blood coagulation Factor XIII has been recognized as an important wound-healing factor. We investigated the plasma concentration and functional activity of blood coagulation Factor XIIIa, active subunit of the Factor XIII, in patients with Crohn's disease and in healthy volunteers. METHODS: Peripheral blood was obtained from 24 patients with Crohn's disease and from 10 healthy volunteers. The functional activity of Factor XIIIa was measured by its transglutaminase activity, and plasma concentration was measured by the immunoelectrophoresis method. RESULTS: The differences in Crohn's disease patients and healthy volunteers were not significant. However, Crohn's disease patients with fistula had significantly lower functional activity than Crohn's disease patients without fistula. CONCLUSIONS: The deficiency in this wound-healing factor might be one reason for refractory fistulas in Crohn's disease, and supplementation of the factor might be useful therapeutically.

Adult↗
PubMed1995

Double-blind comparative study of sulfasalazine and controlled-release mesalazine tablets in the treatment of active ulcerative colitis.

To evaluate the effect of a controlled-release mesalazine tablet, in patients with ulcerative colitis (UC), a multicenter double-blind study was carried out, using sulfasalazine (500 mg tablet) as the control drug. The mesalazine tablet contained 250 mg of ethyl cellulose-coated mesalazine granules. The patients were assigned to two groups, one to receive mesalazine tablets (1500 mg/day) and a sulfasalazine placebo (group M) and the other to receive sulfasalazine tablets (3000 mg/day) and a mesalazine placebo (group S). The test medications were administered orally for 4 consecutive weeks. The study subjects were selected from among patients with mild to moderate active UC, and 118 patients were enrolled. Concomitant use of steroids and immunosuppressors was prohibited during the study period. Of the 118 patients, 9 dropped out. A total of 109 complete records were thus obtained, 52 in group M and 57 in group S. There was no difference in the improvement of clinical symptoms and endoscopic findings between the two groups. The overall safety, based on adverse reactions and laboratory data, was higher, at 86.5%, for group M (n = 52), compared to 66.7% for group S (n = 57). The general usefulness, based on the improvement and safety, was higher, at 65.3%, for group M (n = 49), compared to 45.6% for group S (n = 57). The controlled-release mesalazine tablet thus appears to be useful in the treatment of mild to moderate active UC.

Adult↗
PubMed1995

Corticosteroids for the management of ulcerative colitis.

Two studies were carried out. In the first, 24 patients with severe ulcerative colitis (UC) were prospectively studied by the Research Group of Inflammatory Bowel Disease, sponsored by the Ministry of Health and Welfare of Japan. Patients were randomly assigned to two groups; one group (n = 13) was given prednisolone, 1.0 mg/kg body weight, daily, the other group (n = 11) was given prednisolone, 1.5 mg/kg body weight, daily. The 13 patients given 1.0 mg/kg prednisolone consisted of 7 with left-sided colitis and 6 with total colitis; 11 patients given 1.5 mg/kg prednisolone consisted of 5 with left-sided and 6 with total colitis. There were no statistically significant differences in clinical, endoscopic, and overall improvement between the two groups; however, 1.5 mg/kg prednisolone was significantly more effective in the treatment of the patients exhibiting the first attack. In the second study, 6 patients with severe and 7 with moderately severe UC were given megadose pulsed steroid therapy. Five hundred or 1000 mg of either hydrocortisone-21-sodium succinate or methylprednisolone was given once a day intravenously. Ten patients achieved clinical remission, 1 patient improved, and 2 patients did not respond. Endoscopically, 5 patients achieved remission, 6 patients improved, and 2 did not respond. Adverse effects severe enough to stop the medication were not noted. Steroid withdrawal syndrome also was not noted.

Adult↗
PubMed1994

Structural organization and analysis of the human fumarylacetoacetate hydrolase gene in tyrosinemia type I.

Fumarylacetoacetate hydrolase (FAH) is a metabolic enzyme functioning at the last step of tyrosine catabolism. Deficiency in this enzyme activity is associated with tyrosinemia type I, characterized by hypertyrosinemia, liver dysfunction, renal tubular dysfunction, liver cirrhosis, and hepatic tumors. We isolated from a human gene library a chromosomal gene related to FAH. The human FAH gene is 30 kilobases long and is split into 14 exons. All of the splice donor and acceptor sites conform to the GT/AG rule. We also analyzed findings in a patient with tyrosinemia type I with respect to the mutation responsible for defects in the enzyme. A nucleotide change from T to G was found in the exon 2 of the gene and this change was accompanied by an amino acid substitution (Phe62Cys). Transfection and expression analysis of the cDNA in cultured BMT-10 cells with the nucleotide substitution demonstrated that the substitution was indeed responsible for the decreased activity of the enzyme in the patient. These results confirmed that the T to G mutation was one of the causes of tyrosinemia type I. Structure of the FAH gene and tests for expression of the mutant FAH will facilitate further understanding of various aspects of FAH.

Base Sequence↗
PubMed1994

Characterization of a point mutation in the pyruvate dehydrogenase E1 alpha gene from two boys with primary lactic acidaemia.

We report here a novel mutation in the codon for amino acid 263 resulting in the change from arginine to glutamine in the pyruvate dehydrogenase (PDH) E1 alpha gene, in two boys with primary lactic acidaemia, from independent families. The mutation changes an amino acid located between the two serine residues which are the sites of phosphorylation of the subunit protein. In one family, the mutation was de novo and in the other it was transmitted from mother to son. The amino acid substitution may affect function of the PDH complex via phosphorylation and dephosphorylation of the E1 alpha subunit. Derangement in the regulation of activity of the PDH complex may explain the primary lactic acidaemia in the patients.

Acidosis, Lactic↗
PubMed1994

Platelet superoxide dismutase in migraine and tension-type headache.

Superoxide dismutase (SOD) is a radical-scavenging enzyme. We determined Cu, Zn-SOD concentrations and activities in platelets from subjects with migraine and tension-type headaches. Thirty migraine without aura (MWoA) patients, 9 migraine with aura (MWA) patients, and 53 tension-type headache patients were selected for study. Thirty healthy volunteers composed the control group. Concentrations of platelet SOD were determined using enzyme-linked immunosorbent assay techniques. The activity of platelet SOD was determined by measuring reductivity of nitroblue tetrazolium. Low concentrations of platelet SOD were found in patients with MWA and MWoA. Platelet SOD activity decreased in MWA patients but not in patients with MWoA or tension-type headaches. These findings suggest vulnerability to oxidative stress in patients with migraine. It is suggested that low platelet SOD levels may play an important role in the etiology of migraine.

Adult↗
PubMed1994

Isolation and characterization of the prolyl aminopeptidase gene (pap) from Aeromonas sobria: comparison with the Bacillus coagulans enzyme.

The Aeromonas sobria pap gene encoding prolyl aminopeptidase (PAP) was cloned. It consists of 425 codons and encodes a homotetrameric enzyme of 205 kDa. The purified enzyme showed an almost absolute specificity for amino-terminal proline. Proline and hydroxyproline residues from many peptide and amide substrates could be easily removed, while no activity was detected for substrates having other amino terminals. The enzyme was very similar to that from Bacillus coagulans in many aspects, such as the strong inhibition caused by PCMB and the weak or no inhibition caused by DFP and chelators, respectively. However, these enzymes show only 15% identity in their amino acid sequences. Differences were also observed in their molecular weight, stability and activity toward some peptide substrates. When aligning the deduced amino acid sequence with known sequences from other microorganisms, conserved sequences were found at the amino-terminal region; the significance of these conserved regions is discussed. Based on the results of this work, and on the studies available to date, the occurrence of at least two types of PAPs is postulated. One group would be formed by the Bacillus, Neisseria, and Lactobacillus enzymes, and the other by enzymes such as the Aeromonas PAP.

Aeromonas↗
PubMed1994

Increased 11-dehydrothromboxane B2 in migraine: platelet hyperfunction in patients with migraine during headache-free period.

Several disturbances in platelet function have been reported in migraine and tension-type headache (TH). The plasma 11-dehydrothromboxane B2 (11-dTXB2) is free from artifactual increase during blood sampling, and it can be a reliable indicator of thromboxane A2 (TXA2) production in vivo. TXA2 is a very potent proaggregatory and vasoconstrictory metabolite formed in the platelets. We investigated plasma 11-dTXB2 and 5-hydroxytryptamine (5-HT) levels in patients with migraine during headache-free periods and in patients with chronic TH. The mean value of plasma 11-dTXB2 levels in migrainous patients was significantly higher than those in TH patients and healthy controls. The mean value of plasma 5-HT levels in TH patients was significantly lower than those in migrainous patients and healthy controls. There was no correlation between plasma 11-dTXB2 levels and plasma 5-HT levels in any group. The results suggest the existence of continuous platelet activation in migrainous patients.

Adolescent↗
PubMed1993

Identification of two missense mutations in a dihydrolipoamide dehydrogenase-deficient patient.

The molecular basis of dihydrolipoamide dehydrogenase (E3; dihydrolipoamide:NAD+ oxidoreductase, EC 1.8.1.4) deficiency in an E3-deficient patient was studied. Fibroblasts cultured from the patient contained only approximately 6% of the E3 activity of cells from a normal subject. Western and Northern blot analyses indicated that, compared to control cells, the patient's cells had a reduced amount of protein but normal amounts of E3 mRNA. Direct sequencing of E3 cDNA derived from the patient's RNA as well as each of the subclones of the cDNA revealed that the patient had two substitution mutations in the E3 coding region. One mutation changed a single nucleotide from A to G, resulting in substitution of Glu (GAA) for Lys-37 (AAA). The other point mutation was a nucleotide change from C to T, resulting in the substitution of Leu (CTG) for Pro-453 (CCG). These mutations appear to be significant in that they alter the active site and possibly the binding of FAD.

Amino Acid Sequence↗