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Biomedical subjects

Y Niho

Publications and source records attributed to Y Niho.

At least 91 records · Page 5Linked to original sources
PubMed1999

Two polymorphisms within interleukin-3 (hIL3) gene detected by mismatch PCR/RFLP.

Two alleles of IL-3 have been reported to GenBank (GenBank M14743, M20137). The sequence difference between these two alleles is at the first nucleotide of the 27th codon (the 131st nucleotide from the initiation site): thymine and cytosine, and leading the amino acid difference: proline and serine (Pro27Ser). The other allelism, thymine and cytosine, was also observed at position -16 of the IL-3 upstream promotor region (GenBank L10616, M60870). We clarified that these substitutions were frequent polymorphisms in the Japanese population by using the mismatch-PCR (polymerase chain reaction)/RFLP (restriction fragment length polymorphism) method.

Alleles↗
PubMed1999

Multiple autoimmune haemopoietic disorders and insidious clonal proliferation of large granular lymphocytes.

We report a patient with clonal proliferation of CD3+8+TCRalphabeta+ large granular lymphocytes (LGL) presenting multiple episodes of autoimmune cytopenia, including autoimmune neutropenia, idiopathic thrombocytopenic purpura, autoimmune haemolytic anaemia, and pure red cell aplasia. Each disorder appeared separately or as a combination during an 11-year clinical course. The increase of blood CD3+8+TCRalphabeta+ LGL was detected 6 years after the initial diagnosis of cytopenia, but the absolute number of LGL cells was always < 1.0 x 109/l. LGL cells were of monoclonal origin and had a chromosomal abnormality. LGL cells transiently responded to cyclosporine A therapy, which was also effective on all of these autoimmune cytopenias. Accordingly, an undetectable level of proliferation of a clonal LGL population could cause various autoimmune haemopoietic disorders.

Adolescent↗
PubMed1999

Selective DNA-binding activity of interleukin-10-stimulated STAT molecules in human monocytes.

It has been demonstrated that interferon-gamma (IFN-gamma) and interleukin-10 (IL-10) have various reverse effects on macrophages; however, the molecular mechanism of this difference has not been fully understood. In this study, we analyzed the binding activity of IL-10- and IFN-gamma-activated STAT molecules to two kinds of GAS-motif sequences. IL-10-activated STAT1 could bind to the GAS-motif sequence in the promoter region of the Fcgamma receptor, but not to that in the promoter region of the COX-2 gene, whereas IFN-gamma-activated STAT1 and STAT5 could bind to both sequences. IL-10 inhibited IFN-gamma-induced STAT activation without newly synthesized protein. We further demonstrated that aspirin, but not dexamethasone, suppressed IFN-gamma-induced STAT activation. Taken together, these results suggest that IL-10-activated STAT1 has a specificity in binding to the GAS-motif sequences, whereas IFN-gamma-activated STAT1 and STAT5 have a broader spectrum in binding to the GAS-motif sequences. This may explain the difference between IL-10 and IFN-gamma in biological activity, and the inhibitory effect of IL-10 on IFN-gamma activities.

Aspirin↗
PubMed1999

Polymorphisms within the interleukin-10 receptor cDNA gene (IL10R) in Japanese patients with systemic lupus erythematosus.

OBJECTIVE: To assess the association between polymorphisms within the interleukin-10 receptor cDNA gene (IL10R) and systemic erythematosus (SLE) in Japanese people. METHOD: We examined the IL-10 receptor genotype of 109 SLE patients and 102 healthy subjects by the reverse transcription-polymerase chain reaction-restriction fragment length polymorphism (RT-PCR-RFLP) method. RESULTS: There was no difference in the IL10R genotype frequencies of these two groups. CONCLUSION: The IL10R genotype does not determine susceptibility to SLE in Japanese people.

Adolescent↗
PubMed1999

Establishment and characterization of a Fas-resistant T cell line.

Fas is a cell surface receptor that controls a signal transduction pathway leading to apoptosis. We established an antihuman Fas monoclonal antibody (mAb)-resistant variant, kit-225-FR, from the human T cell line, kit-225. Flow cytometric analysis revealed that the expression of Fas molecules on kit-225-FR was preserved. The defect in Fas molecule was not detected either by reverse transcription polymerase chain reaction (PCR) analysis of the Fas transcript or by PCR-single strand conformation polymorphism analysis of the Fas gene in kit-225-FR. Although kit-225-FR was resistant to a high concentration of anti-Fas mAb, apoptosis could be induced, as with the wild type, by exogenous C2-ceramide exposure. MORT1/FADD was expressed at wild-type level in kit-225-FR, as determined by Western blot analysis. It therefore appears that the apoptotic signal transduction in kit-225-FR is defective between FADD and the sphingomyelin-ceramide pathway. By comparing the differences from the wild-type kit-225, kit-225-FR would serve as a useful cell line for analyzing Fas-specific signal transduction pathways in detail.

Apoptosis↗
PubMed1999

Heart rate variability analysis of patients with idiopathic left ventricular outflow tract tachycardia: role of triggered activity.

There have been several reports with respect to idiopathic ventricular tachycardias (VTs) originating from the left ventricular outflow tract (LVOT). A previous report suggested that triggered activity plays a partial role in idiopathic LVOT tachycardia from the electrophysiological as well as the electropharmacological viewpoint. However, the exact role of triggered activity in this type of VT remains unknown. In the present study the relationship of the frequency of premature ventricular contractions (PVCs) and heart rate was examined and heart rate variability (HRV) was analyzed in 2 cases of LVOT tachycardia using 24-h Holter electrocardiographic (ECG) monitoring. The relation between the PVCs frequency and heart rate showed a persistently positive correlation, indicating frequent PVCs as heart rate increased. In HRV analysis, NN50(%), a time-domain variable of parasympathetic activity, showed no change prior to ventricular arrhythmias. In frequency-domain analysis of HRV, the high frequency (HF) component tended to fall prior to repetitive PVCs and VTs. The ratio of the low frequency to high frequency (LF/HF) components increased prior to single PVCs, repetitive PVCs and VTs. Sympathetic predominance predisposes the genesis of these kinds of arrhythmias originating from the LVOT and it is suggested that triggered activity plays an important role in LVOT tachycardia, at least in its initiation.

Electrocardiography↗
PubMed1999

Experimental ablation study using a new long linear probe in isolated porcine hearts.

We studied a new technique for creating long linear lesions in hearts using a custom-made linear probe. Radiofrequency (RF) energy applications using a 25-mm long stainless steel linear probe and a corresponding 500-kHz energy generator were tested, creating 90 lesions in isolated porcine hearts. The RF current was applied between the linear probe and a large patch electrode attached to the back of the specimen. Three parameters, comprising the power of the delivered energy, the pressure of contact between the probe and the specimen, and the duration of energy delivery were changed independently and the size of the resulting lesions was measured. All 90 lesions were transmural, well demarcated and created by a single stationary RF application. Lesion length and width increased with: 1) increasing power, when the other two parameters were maintained at constant levels, 2) increasing contact pressure, when the other two parameters were maintained at constant levels, and 3) increasing duration of energy delivery when the other two parameters were maintained at constant levels. The maximum width of the lesions was 3.7 mm. No overheating of any of the specimens was observed. In conclusion, the new original long linear probe used in this study was effective for creating transmural linear lesions, presenting the possibility of a worthwhile contribution to the maze surgical procedure applied to atrial fibrillation.

Animals↗
PubMed1999

Possible evidence for transmembrane K(+)-H+ exchange system in guinea pig myocardium.

The aim of this study was to obtain evidence for a transmembrane K(+)-H+ exchange system in Langendorff-perfused whole hearts and isolated ventricular myocytes of guinea pig. Effluent relation between K+ and pH in the whole hearts perfused with HEPES-buffered Tyrode's solution indicated a significant (p < 0.05) functional coupling of K+ uptake and H+ extrusion that was energy-dependent and omeprazole (OPZ)-sensitive. Administration of OPZ (0.3 mM) or dimethylamiloride (0.1 mM), an inhibitor of Na(+)-H+ antiport, to whole hearts subjected to the repetitive NH4Cl applications implied that both Na(+)-H+ and putative K(+)-H+ countertransports contribute to the regulation of intracellular pH. In isolated myocytes, voltage-dependent L-type Ca current (ICa) was inhibited by OPZ (0.3 mM) under K(-)- and Na(+)-free condition by 11 to 14%, and was inhibited to a greater extent (i.e., by 36 to 40%) by this agent in the presence of K+. OPZ-induced inhibition of the putative K(+)-H+ exchanger likely resulted in subsarcolemmal acidification which was responsible for the rate-independent suppression of ICa. In conclusion, these data provide functional evidence for a myocardial transmembrane K(+)-H+ exchanger.

Animals↗
PubMed1999

Dermatomyositis associated with invasive thymoma.

We report a case of dermatomyositis (DM) associated with invasive thymoma in a 22-year-old woman who was admitted to our hospital complaining of dyspnea which required ventilation support. The reddened elevated scaly eruptions were prominent over the extensor surfaces. Chest X-ray and computed tomography showed mediastinal masses, which were diagnosed as mixed type thymoma. Muscle and skin biopsy specimens were compatible with DM. She was treated with methylprednisolone pulse therapy followed by extended removal of the anterior mediastinal tumor and subsequent radiotherapy. She has had a good clinical course without recurrence of thymoma or DM for more than 3 years. The role of thymoma in the development of DM is discussed.

Adult↗
PubMed1999

[A case of systemic sclerosis with crescentic glomerulonephritis associated with perinuclear-antineutrophil cytoplasmic antibody (p-ANCA)].

A 50-year-old female with systemic sclerosis (SSc) developed rapidly progressive renal insufficiency. Laboratory findings showed rapid elevation of serum creatinine level (3.8 mg/dl) and a high titer of perinuclear-antineutrophil cytoplasmic antibody (p-ANCA) (504 EU/ml). Renal pathology revealed crescentic glomerulonephritis (CrGN) without mucoid intimal proliferation of the interlobal arteries and fibrinoid necrosis of the afferent arterioles, Immunofluorescent micrography showed focal segmental granular deposition of IgG and C 3 in the mesangium and along the capillary loop and was in agreement with pauci-immune type. Recently, a subtype of renal involvement in SSc that is associated exclusively with normotensive renal failure and recognizable by p-ANCA is suggested. On the other hand, SSc with p-ANCA-positive glomerulonephritis as this case can be considered to be overlap syndrome of SSc and microscopic polyangitis nodosa (microscopic PN) because in microscopic PN, p-ANCA is detected at the range of 50% to 80% and renal pathology reveals necrotizing glomerulonephritis. In this point, we may describe this case as a suggestive one about p-ANCA-positive glomerulonephritis.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed1999

Association of polymorphism in the NeuroD/BETA2 gene with type 1 diabetes in the Japanese.

NeuroD/BETA2, a transcription factor of the insulin gene, also plays an important role in the development of pancreatic beta-cells. Recently, the NeuroD/BETA2 gene has been mapped to the long arm of human chromosome 2 (2q32) where the IDDM7 gene has previously been mapped, implying its involvement in diabetes. To identify mutations in the NeuroD/BETA2 gene that may predispose patients to develop diabetes, we studied the gene in 50 Japanese subjects with diabetes (4 with type 1 and 46 with type 2) by the polymerase chain reaction (PCR) followed by single-strand conformation polymorphism and sequencing analyses. Further analysis was performed in 392 Japanese subjects (60 with type 1 and 158 with type 2 diabetes and 174 healthy control subjects) by mismatch PCR restriction fragment length polymorphism. We found a DNA polymorphism of the NeuroD/BETA2 gene. A nucleotide G-to-A transition results in the substitution of alanine to threonine at codon 45 (Ala45Thr). The frequencies of heterozygotes for the Ala45Thr variant were 9.8% in the control subjects, 9.5% in the patients with type 2 diabetes, and 25.0% in the patients with type 1 diabetes, a significant difference (P = 0.006). Because the variant of the NeuroD/BETA2 gene (Ala45Thr) is associated with type 1 but not type 2 diabetes, it may be implicated in the loss of pancreatic beta-cells in type 1 diabetes.

Adult↗
PubMed1999

Prognostic significance of polo-like kinase expression in esophageal carcinoma.

PLK (polo-like kinase), which belongs to a family of serine/threonine kinases and represents the human counterpart of structurally related protein kinases, polo of Drosophila melanogaster and CDC5 of Saccharomyces cerevisiae, may be implicated in spindle formation and chromosome segregation during mitosis. There are, however, few reports on the significance of PLK gene expression in human carcinomas. In order to evaluate its clinical significance, we examined the expression of the PLK mRNA in 49 esophageal and 75 gastric carcinomas, using reverse transcription-polymerase chain reaction analysis. In esophageal carcinomas, PLK overexpression was detected in 47 carcinomas (97%) when compared to the corresponding normal tissues. It is noteworthy that the patients with high-grade PLK overexpression represented a significantly poorer prognosis group than those with low-grade PLK overexpression (3-year survival rate: 54.9% vs 24.8%, p<0.05). A multivariate analysis demonstrated that the PLK mRNA expression status was an independent prognostic factor for patients with esophageal carcinoma. On the other hand, 55 gastric carcinomas (73%) were revealed to overexpress PLK mRNA, but the expression status showed no correlation with prognosis. This study demonstrated that the PLK overexpression was frequently observed in esophageal and gastric carcinomas, and appeared to be an independent prognostic factor for patients with esophageal carcinoma.

Adenocarcinoma↗
PubMed1999

Radiofrequency catheter ablation of idiopathic right ventricular tachycardia near the His bundle.

There are only a few reports on successful radiofrequency catheter ablation of idiopathic right ventricular tachycardia (VT) originating from other sites than right ventricular outflow tract. We report here a case of VT which exhibited an inferior-axis and a left bundle branch block pattern and originated near the His bundle. Using the temperature-controlled ablation catheter, prudent observation of the fluoroscopy and intracardiac electrograms during pacemapping, we successfully ablated the origin of the VT without any conduction disturbance. However, further study is required to determine the effectiveness of catheter ablation and the long term prognosis for this type of VT.

Adult↗
PubMed1999

[Malignant lymphoma with c-myc gene rearrangement in a patient receiving long-term treatment for multiple myeloma].

We encountered a 65-year-old woman with diffuse large B-cell lymphoma showing t(8;14)(q24;q32) and c-myc gene rearrangement that developed following 12 years of melphalan-based chemotherapy for multiple myeloma. Short-term remission was obtained by CHOP chemotherapy. However, shortly thereafter the patient died of an aggressive progression of lymphoma. It was suspected that the lymphoma was a secondary malignancy related to the treatment with cytotoxic agents and radiation for prolonged multiple myeloma. The chromosomal abnormality t(8;14)(q24;q32) is rare in secondary malignancies. Overexpression of c-myc by gene rearrangement may be associated with clinical courses manifested by the rapid progression of lymphoma.

Aged↗