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Biomedical subjects

H Tada

Publications and source records attributed to H Tada.

At least 199 records · Page 11Linked to original sources
PubMed1997

Usefulness of HCV-RNA assays in efficacy evaluation of interferon treatment for chronic hepatitis C: Amplicor HCV assay and branched DNA probe assay.

We investigated the usefulness of Amplicor HCV assay and branched DNA probe assay in efficacy evaluation of interferon therapies for chronic hepatitis C. Subjects were 164 HCV-RNA positive chronic hepatitis C patients who received interferon-alpha (IFN-alpha, HLBI) 3-6 MU per day for 14-24 weeks. Their HCV-RNA levels were examined five times by using reverse transcription-polymerase chain reaction (RT-PCR) assay, Amplicor HCV assay, and branched DNA probe assay. Complete response rate in the low virus level patients was significantly higher than in the high virus level patients (P < 0.001). In complete responders, the rate of HCV-RNA disappearance 2 weeks after the initiation of IFN therapy was higher than in non-responders (P < 0.001). The HCV-RNA positive rates in RT-PCR assay and Amplicor HCV assay agreed by 98% or more. The HCV-RNA negative patients 6 months later were still negative 12 months later by Amplicor HCV assay. Before starting interferon therapy for chronic hepatitis C, it is advisable to make a prediction of treatment efficacy by using branched DNA probe assay. In addition, disappearance of HCV-RNA after 2 weeks of treatment could be a useful predictor of the therapeutic efficacy of IFN. Amplicor HCV assay is useful in detecting HCV-RNA and for efficacy evaluation during and after a given interferon therapy.

Adult↗
PubMed1997

Unilateral acoustic neuroma in childhood.

Three cases of unilateral acoustic neuroma in childhood that are associated with neither neurofibromatosis type 1 nor type 2 were reported. All three cases had a hearing disorder as an initial symptom. Two of them had a large neuroma and had considerable abnormal findings in neurootological examinations, and one case with an intracanalicular tumor showed a unilateral progressive sensorineural hearing loss that had no response to steroid administration. Surgical removal of the tumor was carried out for these cases. Different approaches were used in each case; suboccipital approach, one-stage suboccipital and middle fossa approach, and middle fossa approach. Although the facial nerve functions were fairly well maintained, hearing preservation could not be attained in all. Papers dealing with this tumor were reviewed, and certain characteristics of cases with acoustic neuroma in childhood were discussed.

Adolescent↗
PubMed1997

Alternating hemiplegia of childhood: report of a case having a long history.

We examined a patient with alternating hemiplegia of childhood (AHC) who had over a 23-year history of AHC to investigate the origin of the neurological deterioration with increasing age. Hemiplegic attacks had occurred consistently at a frequency of a few per week since infancy, and he first experienced attacks of cerebellar ataxia at the age of 23 years. Intellectual impairment, dysarthria, dystonic posturing, and a wide-based gait had been slowly progressive, but they had been stable since he turned twenty. The electromyographic response to transcranial magnetic stimulation was normal between attacks and showed reversible alteration during an attack. MRI revealed slight dilatation of the lateral ventricles, and MR angiography showed normal cerebral blood flow. Proton MR spectroscopy between attacks showed normal peak area ratios for N-acetyl groups, choline-containing compounds, and creatine and phosphocreatine, and it also demonstrated no lactic peak. 123I-IMP SPECT between attacks demonstrated diffuse cerebral hypoperfusion despite no evidence of ischemic change in the above MR study. These results suggest that the slowly progressive neurological deficits are due to the primary underlying pathology rather than the secondary neuronal loss as a result of frequent ischemic attacks.

Adult↗
PubMed1997

Risk of arterial thrombosis in patients with anticardiolipin antibodies and lupus anticoagulant.

The relationship between arterial or venous thrombosis and the levels of anticardiolipin antibodies (aCL) and/or existence of lupus anticoagulant (LA) was studied. The 141 patients with systemic lupus erythematosus (SLE) were divided into four groups: aCL single positive (25 cases), LA single positive (11 cases), aCL and LA double positive (25 cases), aCL and LA double negative (80 cases). The prevalence of thrombosis was higher in aCL and LA double positive patients (21/25 cases, 84.0%, P <0.01) than that in aCL single positive patients (4/25 cases, 16.0%), LA single positive patients (1/11 cases, 9.1%) and double negative patients (3/80 cases, 3.8%). Furthermore, in these double positive patients, all patients (10/10 cases) with a high positive level of aCL (> 10 units/ml) had arterial thrombosis, whereas only 2/15 patients (13.3%) with a low positive level of aCL (3-10 units/ml) were affected. Venous thrombosis was frequently found in the low positive group (9/15 cases, 60.0%). On the contrary, none of 105 LA negative patients had arterial thrombosis and only seven (6.7%) had venous thrombosis. These findings indicate that a high aCL activity combined with a LA positive result might be a risk factor for arterial thrombosis.

Adolescent↗
PubMed1997

Tissue-specific expression of pancreatic-type RNases and RNase inhibitor in humans.

The tissue-specific expression of five human pancreatic-type RNases and RNase inhibitor was analyzed by Northern hybridization against poly(A)+ RNA prepared from 16 normal tissues. The widespread expression of RNase 1 was observed in almost all of the tissues. RNase 4 and angiogenin showed a similar distribution of expression abundantly present in the liver. This suggested the identity of the cell types producing these two molecules. However, no relativity appeared to be present between the vascularization of the tissues and the angiogenin expression. A narrow range of expression of the eosinophil-derived neurotoxin gene was observed. This localization seems related to the phagocytic cells in the tissues. The undetectable level of the eosinophil cationic protein mRNA in normal tissues suggests that the differentiation of eosinophils, triggered by inflammation and/or atopy, is required. The expression of RNase inhibitor was found to be ubiquitous. The regulatory function of inhibitor against RNases in the cell should be considered in studying the physiological significance of the pancreatic-type RNase family.

DNA, Complementary↗
PubMed1997

Subtypes of anti-TSH receptor antibodies classified by various assays using CHO cells expressing wild-type or chimeric human TSH receptor.

To analyze the heterogeneity of anti-TSH receptor antibodies (TSHRAb), we measured serum TSH-binding inhibitory immunoglobulin (TBII), thyroid-stimulating antibody (TSAb), and thyroid stimulation blocking antibody (TSBAb) activities in 31 patients with positive TSHRAb, using CHO cells expressing wild-type TSHR (WT) or TSHR chimera (Mc2) wherein residues 90-165 were substituted by the LH/CG receptor. Using membranes from WT cells, we detected TBII activity in all 31 patients; 10 (32%), all with TSAb activity only, completely lost TBII activity using Mc2 membranes. TSAb activity was found in 26 sera using WT cells; 20 (77%) completely lost TSAb activity in Mc2 cells. Comparisons of TBII and TSAb activity in WT cells did not exhibit a strong positive correlation (r = 0.52). Of the 20 sera that completely lost TSAb activity in Mc2 cells, 10 retained some TBII activity in Mc2 cells. In each of the sera with retained TBII activity, TSAb activity was recovered in Mc2 cells using the conversion assay, which measures the conversion of a nonstimulating TSHRAb to a TSAb by the action of an anti-human IgG. Additionally, the TBII and conversion assay values in Mc2 cells exhibited a strong positive correlation (r = 0.86). Of the 31 sera, TSBAb was found in 7 samples, with no difference in WT and Mc2 cells. TBII activity was detected in all 7 sera with WT cells; TSAb activity in only 2. In the 5 sera with TSBAb but no TSAb activity, and with only a minimal or no decrease in TBII activity in Mc2 cell membranes, the in vitro conversion assay uncovered TSAb activity. Analyzing these data, we classify the sera into 5 groups containing multiple, different TSHR autoantibodies, including two different TSAbs, three different TBIIs, and one nonfunctional antibody. The heterogeneity of TBIIs as well as TSAbs provides a basis to explain the lack of correlation between TBII and TSAb activities in some past studies of Graves' sera.

Animals↗
PubMed1997

Vulval reconstruction using rectus abdominis musculocutaneous flap transfer with secondary liposuction in extramammary Paget's disease.

Two female patients with vulval skin defects after extramammary Paget's disease were reconstructed using a pedicled, distally based rectus abdominis musculocutaneous flap. After the operation, the bulkiness of the flap, which might be a major problem in the application for a vulval skin defect, was improved successfully by flap volume reduction with secondary liposuction. We conclude that rectus abdominis musculocutaneous flap transfer with secondary liposuction is one of the acceptable methods for reconstructing vulval skin defects.

Biopsy↗
PubMed1997

Long term results using a modified King's method for cubital tunnel syndrome.

Forty-six elbows in 40 patients with cubital tunnel syndrome were evaluated after using a modified King's method. The average postoperative followup period was 79 months. The severity of cubital tunnel syndrome was graded before and after operation by the modified method of Stuffer et al which evaluated the amount of numbness, sensation, muscle strength, and muscle atrophy. The results were positively correlated with the preoperative severity of the disease and the ulnar nerve sulcus angle as measured in the axial view of the elbow. When the amount of the medial epicondylectomy was large, a good result was obtained, but the risk of medial collateral ligament insufficiency increased. Because the results of medial epicondylectomy are inconsistent with stability of the elbow, when doing a modified King's operation, careful repair of the medial collateral ligament is essential to minimize instability of the elbow.

Adult↗
PubMed1997

Glibenclamide, a specific inhibitor of ATP-sensitive K+ channels, inhibits coronary vasodilation induced by angiotensin II-receptor antagonists.

The purpose of our study was test the hypothesis that endogenous angiotensin II contributes to the basal coronary artery tone by acting at vascular ATP-sensitive K+ (K+ATP) channels. Coronary blood flow (CBF) and other hemodynamic parameters were measured in anesthetized dogs. Intracoronary infusion of the selective antagonists of angiotensin II AT1 receptors (L-158,809 and E4177) increased CHF without affecting other hemodynamic parameters, indicating that endogenous angiotensin II caused coronary vaso-constriction through the AT1 subtype receptors. Coronary vasodilation in response to AT1 receptor antagonists was blunted by pretreatment with glibenclamide (a specific inhibitor of K+ATP channels; p < 0.01) but not by either an adenosine-receptor antagonist or an inhibitor of nitric oxide synthesis. Coronary vasodilation in response to AT1-receptor antagonists was partly reduced (p < 0.01) by PD-123319 (the AT2-receptor antagonist). Glibenclamide had no effect on coronary vasodilation induced by sodium nitroprusside. These results indicate that in dogs in vivo, coronary vasodilation in response to AT 1-receptor antagonists inhibited markedly by glibenclamide and partly by PD-123319, suggesting that endogenous angiotensin II contributes to the maintenance of basal coronary vascular tone by acting at K+ATP channels through its receptors.

Angiotensin Receptor Antagonists↗
PubMed1997

Increased serum concentration of soluble CD30 in patients with Graves' disease and Hashimoto's thyroiditis.

This study investigated serum levels of the soluble form of CD30 (sCD30), which is mainly secreted from T helper 2(Th2) cells, in autoimmune thyroid diseases. The possible relationship of sCD30 to autoantibody production was also evaluated. Serum levels of sCD30 were determined by an enzyme-linked immunosorbent assay in 71 patients with Graves' disease, 37 patients with Hashimoto's thyroiditis, and 21 normal donors. Compared with normal subjects (7.1 +/- 4.5 U/mL), sCD30 was increased in patients with Graves' disease (29.2 +/- 25.2 U/mL, P < 0.0001) and in patients with Hashimoto's thyroiditis (29.9 +/- 26.9 U/mL, P < 0.0001). In Graves' disease, sCD30 levels were higher in thyrotoxic patients (41.7 +/- 31.2 U/mL, P < 0.001) than in remission patients (15.8 +/- 11.0 U/mL), and a significant correlation was observed between sCD30 levels and serum activities of TSH receptor antibody (r = 0.444, P < 0.0001). In Hashimoto's thyroiditis, sCD30 levels were higher in patients with transient destructive thyrotoxicosis caused by the aggravation of the disease (48.8 +/- 34.4 U/mL, P < 0.05) than in euthyroid patients (24.2 +/- 19.4 U/mL). These data suggest that serum sCD30 is a valuable marker of disease activity and support an important role of the Th2-type immune response in the pathogenesis in Graves' disease and Hashimoto's thyroiditis.

Adult↗
PubMed1997

A peptide antagonist derived from platelet-derived growth factor induces histamine release from rat peritoneal mast cells.

A synthetic peptide (ANFLVWEIVRKKP) designed from the platelet-derived growth factor (PDGF) B-chain, which is known to act as a PDGF antagonist, induced histamine release from rat peritoneal mast cells. Maximal release by the peptide reached about 50% of the total histamine content in mast cells and half-maximal release occurred at 15 microM. The histamine release induced by the PDGF antagonist was required for the presence of Ca2+ in the medium. Treatment of kinase inhibitors (staurosporine and genistein) with mast cells before exposure to the PDGF antagonist inhibited the release to some extent, while calmodulin antagonists (W-7 and R24571) had little effect. The PDGF antagonist induced the secretion of actin from mast cells concurrently with histamine release, though it had no effect on the distribution of tubulin. These results suggest the possibility that PDGF and its agonists may stimulate and induce exocytosis of peritoneal mast cells.

Animals↗
PubMed1997

Novel renin inhibitors containing (2S,3S,5S)-2-amino-1-cyclohexyl-6-methyl-3,5-heptanediol fragment as a transition-state mimic at the P1-P1' cleavage site.

A series of renin inhibitors containing the (2S,3S,5S)-2-amino-1-cyclohexyl-6-methyl-3,5-heptanediol (2-amino-3,5-anti-diol) fragment as a novel transition-state mimic was synthesized, and their biological activities were evaluated. All of the synthesized compounds containing the 2-amino-3,5-anti-diol fragment at the P1-P1' position showed high in vitro renin-inhibitory activity with IC50 values in the 10(-8)-10(-10) M range, and most of them caused a reduction of blood pressure when administered orally to salt-depleted, conscious marmosets. The inhibitor (29) with the 4-hydroxypiperidine residue at the P4 position showed the highest activity in terms of both potency and duration of the blood pressure-lowering effect.

Administration, Oral↗
PubMed1997

Role of platelets in myocardial ischemia-reperfusion injury in dogs.

We investigated the involvement of circulating platelets in myocardial ischemia-reperfusion injury in canine autoperfused heart-lung preparations using filters to deplete platelets and/or leukocytes. The left anterior descending (LAD) coronary artery was occluded for 40 min, followed by 40 min reperfusion, in 3 groups: a leukocyte-platelet-depleted (LPD) group, in which both leukocytes and platelets were depleted; a leukocyte-depleted (LD) group, in which leukocytes alone were depleted; and a control group. There were no differences in hemodynamics or arrhythmias among groups before or during coronary occlusion. After reperfusion, the maximum rate of change in left ventricular pressure during systole and diastole was significantly higher in the LPD group than in the control and LD groups. The LPD group also showed gradual recovery of regional myocardial function and a decrease in the frequency of premature ventricular contractions. The LD group showed a slight improvement in cardiac function and arrhythmias compared with the control group. Although there was no significant difference in the pulmonary arterial plasma level of thromboxane B2 at any stage among groups, the control group showed an increase after reperfusion. These results suggest that platelets are important in reperfusion injury and that the depletion of both leukocytes and platelets effectively protects against reperfusion injury.

Animals↗
PubMed1997

[Laboratory diagnosis before onset and prediction of Graves' disease].

Graves' thyrotoxicosis frequently occurs after delivery through immune rebound mechanism. We tried to establish a systematic method of predicting postpartum onset of Graves' thyrotoxicosis. We followed pregnant women with anti-thyroid microsomal antibody (MCAb) from their early pregnancy to the postpartum period, and analyzed the relation between activities of thyroid stimulating antibodies (TSAb) in early pregnancy and the postpartum occurrence of Graves' disease. Among 71 subjects with positive MCAb, 7 showed positive TSAb in their early pregnancy without any thyroid dysfunction. All 7 developed thyroid dysfunction in postpartum period. Five of seven (70% of TSAb positive subjects) developed Graves' disease. None of 64 TSAb-negative subjects developed Graves' thyrotoxicosis, though 44 developed various types of thyroid dysfunction due to postpartum autoimmune thyroiditis. Graves' thyrotoxicosis also occurs after an attack of allergic rhinitis. A patient who developed Graves' thyrotoxicosis after an attack of allergic rhinitis showed positive TSAb before the attack of allergic rhinitis. These findings suggest that high risk of Graves' thyrotoxicosis onset can be predicted by the detection of TSAb.

Female↗
PubMed1997

Interleukin-8 in bronchoalveolar lavage fluid of patients with diffuse panbronchiolitis or idiopathic pulmonary fibrosis.

This study was designed to clarify the contribution of IL-8 as a specific neutrophil chemotactic factor in the human respiratory tract in various pulmonary diseases. The neutrophil chemotactic activity (NCA), neutrophil counts and IL-8 concentration in the bronchoalveolar lavage fluid (BALF) obtained from normal volunteers (NV), control patients (CP), patients with diffuse panbronchiolitis (DPB) and patients with idiopathic pulmonary fibrosis (IPF) were examined. Neutrophil counts, NCA and IL-8 concentration in BALF obtained from patients with DPB or IPF was significantly higher than that from NV or CP. The IL-8 concentration correlated with neutrophil count and also correlated with NCA in BALF from patients with IPF, whereas there was no correlation between these factors in BALF from DPB. These results suggest that the contribution of IL-8 to neutrophil accumulation of the lower respiratory tract is different between IPF and DPB.

Blood Cell Count↗
PubMed1996

Cloning of the polyketide synthase gene atX from Aspergillus terreus and its identification as the 6-methylsalicylic acid synthase gene by heterologous expression.

Southern blot analysis of genomic DNAs of several fungi that produce polyketide compounds with the 6-methylsalicylic acid synthase (MSAS) gene of Penicillium patulum as a probe indicated the presence of an MSAS-homologous gene in the (+)-geodin-producing strain IMI 16,043 of Aspergillus terreus. The gene, designated atX was cloned from an A. terreus genomic DNA library and 7588 bp of the gene together with its flanking regions were sequenced to reveal the presence of a 5.5 kb open reading frame coding for a protein of 1800 amino acids with 190 kDa molecular mass. The presence of a short (70 bp) intron near the N-terminus of the atX gene was predicted that contains the canonical GT and AG dinucleotides at its 5'- and 3'-splicing junctions. The predicted ATX polypeptide showed high homology with P. patulum MSAS along the whole sequence. On the other hand, slight homology was detected only around the beta-ketoacyl synthase regions of Aspergillus nidulans wA, PKSST and Colletotrichum lagenarium PKS1. No transcription of atX was observed throughout the culture period by Northern blotting analysis. To identify the function of the polypeptide encoded by the atX gene, its coding region was introduced into the fungal expression vector pTAex3 under the control of the amyB promoter. The constructed expression plasmid was introduced into A. nidulans. The transformant produced significant amounts of 6-methylsalicylic acid, the structure of which was identified by physicochemical analysis. This result unambiguously demonstrated that the atX gene codes for MSAS of A. terreus.

Acyltransferases↗