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Biomedical subjects

M Ohta

Publications and source records attributed to M Ohta.

At least 145 records · Page 8Linked to original sources

Crohn's disease of the esophagus: report of a case.

We report herein the case of a 27-year-old man with Crohn's disease of the esophagus. The patient presented with large ulcers in the esophagus for which treatment based on a diagnosis of reflux esophagitis was commenced. Although his symptoms were initially resolved, the ulcers did not improve and he was readmitted to hospital 3 months later for progressive heartburn. An esophagoscopy revealed large ulcers in the esophagus, and a colonoscopy revealed a longitudinal ulcer in the terminal ileum. Histological examination of specimens from the terminal ileum showed severe inflammation without granuloma formation, which led to a diagnosis of Crohn's disease. The oral administration of prednisolone and salazosulfapyridine controlled his symptoms and the esophageal ulcers were observed to be healing 2 weeks after this treatment was initiated. A review of the English literature revealed only 77 cases of this disease. Isolated esophageal lesions were reported in ten patients (13.0%), none of which were able to be diagnosed as Crohn's disease preoperatively. Ileocolic lesions developed after esophageal lesions in only five patients (6.5%) including ours. In the remaining 62 patients (80.5%), ileocolic lesions had existed synchronous with or prior to the esophageal lesions. This suggests that ileocolic lesions may often coexist in Crohn's patients with esophageal lesions, and that examination of the terminal ileum must be performed to confirm a diagnosis of Crohn's disease of the esophagus.

Adult↗

Videothoracoscopic surgery for thoracic neurogenic tumors: a 7-year experience.

While videothoracoscopic surgery has rapidly become accepted as an effective method of performing minimally invasive surgery, the advantages and feasibility of using this surgical technique for the treatment of neurogenic tumors of the thorax are not yet well defined. Between August 1992 and May 1999, 15 solitary thoracic neurogenic tumors were surgically excised using videothoracoscopic surgery in our hospital. The patients comprised six women and nine men, with a mean age of 38.1 years. The mean tumor size was 3.5 cm, with a range of 1.5-6.5 cm and included 12 schwannomas, 2 ganglioneuromas, and 1 neurofibroma. Among the 15 patients, 4 were treated using videothoracoscopic surgery plus minithoracotomy. The only complication associated with videothoracoscopic surgery was hoarseness which developed in one patient. Our experience indicates that videothoracoscopic surgery is a useful alternative to facilitate the excision of small thoracic neurogenic tumors.

Adolescent↗

Endobronchial metastasis from renal cell carcinoma: report of a case.

A case of endobronchial metastasis from renal cell carcinoma developing 5 years after a right nephrectomy in a 63-year-old man is reported. Bronchoscopic examination performed after the patient presented with hemoptysis showed a polypoid tumor obstructing the entrance to the left upper bronchus. A snare was introduced through a bronchofiberscope to remove the endobronchial tumor, following which his atelectasis improved remarkably and his hemoptysis resolved. No side effects were observed. Electrosurgical snaring proved useful as palliative treatment to relieve bronchial obstruction due to an endobronchial metastasis in this patient.

Bronchial Neoplasms↗

Medium compositions and culture conditions for the assay of fosfomycin susceptibility by Etest.

The Etest (AB Biodisk, Solna, Sweden), a susceptibility testing method, was used for fosfomycin and was evaluated by comparison with the agar dilution method for 73 clinical isolates of Escherichia coli, including two resistant strains, and an optimal Etest method for fosfomycin was determined. Media and culture conditions greatly affected the minimum inhibitory concentrations (MICs) determined by the Etest for fosfomycin, as shown for the agar dilution methods. Our results showed that the most favorable conditions for the Etest for fosfomycin were with Mueller-Hinton agar (Becton-Dickinson Japan, Tokyo, Japan) under aerobic conditions. However, the MICs for the resistant strains were much higher than those determined by agar dilution methods, using Nutrient agar (Becton-Dickinson Japan) under anaerobic conditions. The addition of glucose-6-phosphate did not significantly affect the Etest results.

Agar↗

Association between type 1 diabetes age-at-onset and intercellular adhesion molecule-1 (ICAM-1) gene polymorphism.

We investigated the intercellular adhesion molecule-1 (ICAM-1) gene polymorphism in 90 patients with young-onset type 1 diabetes, 74 with adult-onset type 1 diabetes, and 171 control subjects. The distribution of C-T genotypes and allele frequencies in exon 6 of the ICAM-1 gene was significantly different between adult-onset type 1 diabetes patients and controls (chi(2) = 9.76, p = 0.0076), and between patients with adult-onset and young-onset type 1 diabetes (chi(2) = 11.28, p = 0.0036). In contrast, we failed to detect any association between patients with young-onset type 1 diabetes and controls. Our data suggest that ICAM-1 exon 6 gene polymorphism affects the age-at-onset of type 1 diabetes and that different pathogenetic mechanisms may exist between young-onset and adult-onset type 1 diabetes.

Adolescent↗

SPECT in focal enterovirus encephalitis: evidence for local cerebral vasculitis.

We report a 4-year-old, left-handed male with focal coxsackievirus A3 encephalitis who presented with seizures and acquired aphasia. Electroencephalography exhibited focal spike discharges over the right frontal regions, but cranial magnetic resonance imaging did not reveal any structural abnormalities. However, brain single-photon emission computed tomography performed during the acute phase disclosed focal hypoperfusion in the right frontal lobe, consistent with decreased regional cerebral blood flow in the territory of some branches of the right cerebral anterior artery. Without specific treatment, the patient recovered completely within 1 month, when brain single-photon emission computed tomography images returned to normal and cranial magnetic resonance imaging still demonstrated no abnormalities. The present case suggests the possible role of transient local cerebral vasculitis in the pathogenesis of focal enterovirus encephalitis.

Child, Preschool↗

Effectiveness of gastric devascularization and splenectomy for patients with gastric varices.

BACKGROUND: Bleeding from gastric varices is difficult to control and has a high mortality rate. Recently, newly developed treatments for this serious lesion have been used, but surgical intervention is still advocated by several studies. We report our experience with gastric devascularization and splenectomy and its effectiveness for patients with gastric varices. STUDY DESIGN: Gastric devascularization and splenectomy was successfully performed to treat patients with isolated gastric varices (n = 42). The patients included 27 men and 15 women who ranged from 29 to 73 years of age (average 53.7 years). We analyzed the findings of gastric varices using endoscopy, the results of gastric devascularization and splenectomy, and survival after the operation. RESULTS: No patient had tortuous varices (F1). Twenty-seven patients (64.3%) had nodular varices (F2) and 15 (35.7%) had tumorous varices (F3). Twenty-five patients (59.5%) had large varices that occupied two or more areas. Twenty-nine patients (69.0%) had varices with a positive red color sign. No major complications during or after the operation were observed, and peri-operative death did not occur. Gastric varices were eradicated in all 42 patients. Survival rates were 97.6% after 1 year, 88.1% after 3 years, 76.2% after 5 years (mean followup period, 46 months). CONCLUSIONS: This study showed that gastric devascularization and splenectomy provides satisfactory results for patients with gastric varices that are likely to bleed and that it can be performed even on patients who have had other treatments.

Adult↗

A multicenter validation study of sentinel lymph node biopsy by the Japanese Breast Cancer Society.

Several pilot studies have indicated that SLN biopsy can be used to identify axillary lymph node metastases in patients with breast cancer. To confirm this finding, a multicenter study in a variety of practice settings was performed. A total of 674 patients with breast cancer at five institutions were enrolled. The techniques of SLN identification included the vital dye-guided and the vital dye- and gamma probe-guided methods. The SLN was removed, and complete axillary lymph node dissection (ALND) was performed. SLN and ALND specimens were examined separately. The SLN was successfully identified in 214 (94%) of 227 patients using the combined dye- and gamma probe-guided methods. The SLN was identified in 332 (74%) of 447 patients using vital dye-guided method alone. Patient age of at least 21 years, medially located primary tumor, and clinically positive nodes were correlated with failure to identify the SLN. The accuracy of SLN biopsy for the detection of metastatic disease was 96% (522 of 546), and the sensitivity was 90% (203 of 226). Accuracy of 100% was achieved in the patients with tumors less than 1.6 cm in diameter. All 23 false negative results occurred with larger primary tumors. SLN biopsy can accurately predict the presence or absence of axillary lymph node metastases, particularly in patients with small (< or = 1.5 cm) breast cancers.

Adult↗

Postoperative radiation therapy for pituitary adenoma.

BACKGROUND: We evaluated the efficacy of postoperative radiation therapy (RT), prognostic factors for local control probability, dose response relationship and treatment sequelae in 75 patients with pituitary adenoma. MATERIALS AND METHODS: A total dose of 48-60 Gy (median: 50 Gy) was delivered with a conventional fractionation schedule after surgery. Of 75 patients, 55 (73%) were followed for more than 5 years and 27 (36%) were followed for more than 10 years with a median of 95 months. RESULTS: Five- and 10-year local control probabilities were 87.1% and 85.0%, respectively. Univariate analysis revealed that age (p = 0.007), tumor volume smaller than 30 cm3 (p = 0.018) and the absence of prolactin secretion (p = 0.003) were significantly favorable prognostic factors for local control probability. After multivariate analysis combining these 3 factors, tumor volume smaller than 30 cm3 (p = 0.017) and age (p = 0.039) were statistically significant. Patients with prolactinoma greater than 30 cm3 showed particularly poor local control rates. No significant improvement of the local control rate was detected with increasing total irradiation doses between 48 and 60 Gy (p = 0.29). The most common side effect was hypopituitarism, and there were no severe sequelae such as optic neuropathy or brain necrosis. CONCLUSION: Except with prolactinoma, the dose of postoperative RT for pituitary adenoma should not exceed 50 Gy. Large prolactinoma, however, was very difficult to control with the irradiation doses between 50 and 60 Gy, and would be good candidates for stereotactic radiosurgery or stereotactic radiation therapy.

Adenoma↗

Precipitation behavior of Ag-Pd-In dental alloys.

Age-hardening characteristics and precipitation behavior of Ag-25%Pd-3%In-1%Zn-0.5%Ir alloy were investigated in detail by means of hardness testing, X-ray diffraction, electron microscopy and resistivity measurement. The solution treating could be accomplished at 980 degrees C and the aging in the temperature range from 950 to 850 degrees C occurred by continuous precipitation. The aging in the temperature range from 850 to 450 degrees C occurred first, forming GP-zones with a hardness increase and then in overaging stage by forming discontinuous precipitation, which consisted of lamellae of solute (Pd, In, Zn) depleted Ag-rich phase and (Pd,Ag)3(In,Zn) intermetallic phase. The hardness increased very fast to its peak in 10 min during aging at temperatures between 450 and 550 degrees C.

Journal Article↗

Precipitation of (PdxAg1-x)3 In in Ag-25% Pd-In alloys and the partial phase diagram of ternary Ag-Pd-In alloys.

A study was carried out to determine the partial phase diagram for the system Ag-25 wt % Pd-y wt% In with y </= 8 by X-ray powder diffraction and differential thermal analysis. The liquidus and solidus temperatures decreased with increasing indium content up to 8 wt % In for a given 25 wt % Pd. The solvus curve of gamma phase identified as (PdxAg1-x)3 In was determined by the parametric method and the temperature dependence of In-solubility in Ag-25 wt % Pd was very strong above 900 degrees C.

Journal Article↗

Molecular structure of bacterial endotoxin (Escherichia coli Re lipopolysaccharide): implications for formation of a novel heterogeneous lattice structure.

Analyses of crystals of Escherichia coli Re lipopolysaccharide (LPS) formed after storage in 1% triethylamine indicate that the LPS molecules are assembled to form a monolayered structure consisting of a novel heterogeneous lattice structure, the greater part of which is occupied by one kind of lattice (lattice I), corresponding to the acyl chain portion of lipid A, and the remainder is occupied by the other kind of lattice (lattice II), corresponding to the 3-deoxy-Dmanno-octulosonic acid (dOclA) dimer and the N-acetylglucosamine disaccharide of lipid A. X-ray diffraction reveals that the type of cell is monoclinic (a = 5.53 A, b = 27.2 A, c = 6.47 A, alpha = 90 degrees, beta = 125.8 degrees, gamma = 90 degrees ). Atomic force microscopy shows that crystals consist of multiple layers; the thickness of a layer corresponds to the b-axis value, and two types of surface topographies are visualized. One, regarded as the view onto the acyl chain ends, is two-dimensional arrays of oval bodies that constitute the lattice, with the lattice constants corresponding to the a- and c-axes and the angle of beta (lattice I). The other, regarded as the view onto the dOclA dimers, is two-dimensional arrays of dromedary-back-like bodies that constitute the lattice with axes of 9.0 and 10.7 A and the angle of 65 degrees formed by both axes (lattice II). Based on these results, we present the molecular model of E. coli Re LPS.

Carbohydrate Conformation↗

Three ethylene-responsive transcription factors in tobacco with distinct transactivation functions.

Ethylene-responsive factors (ERFs) have conserved DNA-binding domains and interact directly with the GCC box in the ethylene-responsive element that is necessary and sufficient for the regulation of transcription by ethylene. ERFs were shown to be localized to nucleus in transient transfection experiments. Transient expression assays using tobacco protoplasts and a heterologous system in yeast were used to examine the transactivation functions of ERFs. ERF2 and ERF4 enhanced the GCC box-mediated transcription of a reporter gene in tobacco protoplasts. When fused to the DNA-binding domain of yeast GAL4, a carboxy-terminal region of ERF2, as well as both amino-terminal and carboxy-terminal regions of ERF4, functioned as a transactivation domain in tobacco protoplasts. The amino-terminal regions of ERF2 and ERF4 functioned as transactivation domains in yeast. In contrast to ERF2 and ERF4, ERF3 reduced the transcription of the reporter gene in tobacco protoplasts, indicating that ERF3 functions as a repressor. Thus, it appears that ERFs exert their regulatory functions in different ways, with ERF2 and ERF4 being activators and ERF3 being a repressor of transcription.

Base Sequence↗

Prognostic significance of tumor grade for renal cell carcinoma.

BACKGROUND: The natural history and prognosis of renal cell carcinoma cannot be predicted. Based on the Japanese classification system, the value of nuclear grade were assessed as a possible prognostic factor for renal cell carcinomas. METHODS: In this retrospective study of 116 patients with renal cell carcinoma, radical nephrectomy was performed. Survival rates were calculated using the Kaplan-Meier method and multivariate analysis was performed using Cox's proportional hazard model. RESULTS: Distribution by stage and grade in the population of renal cell carcinomas was as follows: pT1 in 13 cases (11.3%), pT2 in 65 cases (56.5%), pT3 in 36 cases (31.3%) and pT4 in one case (0.9%) and grade 1, 28 (24.1%), grade 2, 69 (59.5%) and grade 3, 16 (13.8%). Three cases could not be determined because of pre-operative embolization of the renal cell carcinomas. Nuclear grade was correlated with stage (P=0.0002), the presence of perirenal fat involvement (P=0.003) and metastases (P=0.007). A significant difference in survival was found between grades 1 and 3 (P=0.0001) and grades 2 and 3 (P=0.0001), respectively. Survival was significantly correlated with sex (P=0.0125), tumor size (P=0.0001), the presence of lymph node metastasis (P=0.0001), renal vein involvement (P=0.0001), perirenal fat involvement (P=0.002) or distant metastasis (P=0.0001). The multivariate analysis showed that the occurrence of tumor grade (P=0.0006) or distant metastasis were independent prognostic values. CONCLUSION: The observations lead us to conclude that the nuclear grade according to the Japanese classification system appears to be of reliable prognostic value for renal cell carcinomas.

Adult↗

Cardiac infarcts increase sodium transporter transcripts (rBSC1) in the thick ascending limb of Henle.

BACKGROUND: Enhanced expression of the kidney-specific sodium transporter, rBSC1, in the thick ascending limb of Henle (TAL) and of the renal water channel, aquaporin-2 (AQP2), in collecting duct has been identified in rats with congestive heart failure (CHF) as a cause for enhanced sodium and water retention in this condition. However, the mechanism of impaired urinary sodium excretion observed even in rats with mild cardiac dysfunction remains unknown. METHODS: Male Sprague-Dawley rats with myocardial infarctions measuring 15 to 30% of the left ventricular circumference with no overt CHF were prepared. We measured the amount of rBSC1 or AQP2 mRNA using competitive polymerase chain reaction (PCR) by inducing a point mutation at the middle of the PCR product for rBSC1 or by deleting 180 bp from the 760 bp PCR product for AQP2, respectively. The results were confirmed by in situ hybridization. rBSC1 protein expression was examined by immunohistochemistry and Western blot analysis using a specific antibody against rBSC1. RESULTS: Although plasma renin activity was slightly elevated in rats with myocardial infarction (MI), no significant differences in lung weight or plasma concentrations for aldosterone and atrial natriuretic peptide were observed between control rats and MI rats. Competitive PCR showed a significant increase in rBSC1 mRNA in the renal outer medulla and cortex of MI rats, which was confirmed by in situ hybridization. However, the AQP2 mRNA of these rats remained unchanged throughout the kidney. Renin-angiotensin II blockade by oral captopril administration did not influence the alteration in rBSC1 mRNA induced by myocardial infarction. Immunohistochemistry and Western blots showed the enhanced expression of rBSC1 protein in TAL of rats with small to moderate cardiac infarcts. CONCLUSIONS: rBSC1 is up-regulated even in rats with small to moderate myocardial infarctions, which may enhance the sodium transport in the TAL in this pathophysiologic condition.

Animals↗

Water vapor adsorption properties of amorphous cefditoren pivoxil evaluated by adsorption isotherms and microcalorimetry.

Water vapor adsorption of ground cefditoren pivoxil was studied. The amount of water adsorbed increased with a decrease in the crystallinity of cefditoren pivoxil. It was found from the microcalorimetric measurements that the differential heat of water vapor adsorption at 1.5% adsorbed water increased with decreasing crystallinity of cefditoren pivoxil, suggesting that hygroscopicity of cefditoren pivoxil was enhanced by grinding. These results indicated that hydrophilic adsorption sites in cefditoren pivoxil increased through the grinding process. The results of infrared (IR) spectra examination suggested that the increment of hydrophilic adsorption sites through the grinding process resulted from the change of the environment of the carbonyl groups in two esters and amide.

Anti-Bacterial Agents↗

Human alpha-N-acetylgalactosaminidase: site occupancy and structure of N-linked oligosaccharides.

Human alpha-N-acetylgalactosaminidase (alpha-GalNAc; also known as alpha-galactosidase B) is the lysosomal exoglycohydrolase that cleaves alpha-N-acetylgalactosaminyl moieties in glycoconjugates. Mutagenesis studies indicated that the first five (N124, N177, N201, N359, and N385) of the six potential N-glycosylation sites were occupied. Site 3 occupancy was important for enzyme function and stability. Characterization of the N-linked oligosaccharide structures on the secreted enzyme overexpressed in Chinese hamster ovary cells revealed highly heterogeneous structures consisting of complex (approximately 53%), hybrid (approximately 12%), and high mannose-type (approximately 33%) oligosaccharides. The complex structures were mono-, bi-, 2,4-tri-, 2,6-tri-, and tetraantennary, among which the biantennary structures were most predominant (approximately 53%). Approximately 80% of the complex oligo-saccharides had a core-region fucose and 50% of the complex oligosaccharides were sialylated exclusively with alpha-2,3-linked sialic acid residues. The majority of hybrid type oligo-saccharides were GalGlcNAcMan(6)GlcNAc-Fuc(0-1)GlcNAc. Approximately 54% of the hybrid oligosaccharide were phosphorylated and one-third of these structures were further sialylated, the latter representing unique phosphorylated and sialylated structures. Of the high mannose oligosaccharides, Man(5-7)GlcNAc(2) were the predominant species (approximately 90%) and about 50% of the high mannose oligosaccharides were phosphorylated, exclusively as monoesters whose positions were determined. Comparison of the oligosaccharide structures of alpha-GalNAc and alpha-galactosidase A, an evolutionary-related and highly homologous exoglycosidase, indicated that alpha-GalNAc had more completed complex chains, presumably due to differences in enzyme structure/domains, rate of biosynthesis, and/or aggregation of the overexpressed recombinant enzymes.

Animals↗

Three cases of malignant lymphoma of the breast.

We report three cases of malignant lymphoma (ML) of the breast and discuss diagnosis and management. The first case is a 35-year-old woman who had a left breast tumor. Fine needle aspiration cytology (FNAC) showed ML. Mastectomy was performed without any adjuvant chemotherapy. Histology revealed diffuse large B-cell lymphoma of REAL classification. Seventy one months after surgery, lesions indicating relapse were detected in nodes of the right axilla, mediastinum and para-aorta. She underwent eight cycles of CHOP regimen, but 1 month after the chemotherapy a brain metastasis was detected. The patient then received a high-dose methotrexate regimen with whole-skull irradiation. The second case is a 47-year-old woman who had anterior neck swelling and bilateral breast tumors. Histology of the tumor revealed diffuse large B-cell lymphoma. The patient underwent eight cycles of CHOP regimen and high-dose chemotherapy (HDC) with peripheral blood stem cell transplantation (PBSCT). Forty eight months after the PBSCT, there is no evidence of disease. The third case is a 38-year-old woman who had a right breast tumor. FNAC of the breast tumor showed ML and a CT scan of the chest revealed lymphadenopathy at the crus of the diaphragm. Histology of the tumor revealed low-grade B-cell lymphoma of MALT type. The patient underwent six cycles of CHOP regimen and HDC supported by PBSCT. Eighteen months after the PBSCT, relapse lesions were detected in nodes of the neck, mediastinum and renal hilum. The patient received nine cycles of a THP-COP regimen.

Adult↗