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Biomedical subjects

Kazuo Watanabe

Publications and source records attributed to Kazuo Watanabe.

72 records · Page 4Linked to original sources
PubMed2002

Chronic intestinal pseudoobstruction ileus in a patient with rheumatoid arthritis: outcome of a stoma construction and its histopathological features.

We report the first case of a chronic intestinal pseudoobstruction (CIPO) in a patient with rheumatoid arthritis (RA) in whom a stoma was constructed at the sigmoid colon to decompress intracolonic pressure. The treatment improved quality of life in this patient, suggesting that surgical resection of the colon to decompress intracolonic pressure would be one of the options for the treatment of intractable CIPO. The resected specimen obtained from the sigmoid colon was found to be palisaded, with nuclei crowded in some areas of the inner circular muscle layer and thickened, with zonal or focal myxoid regions with interstitial fibrosis, composed of collagenous and elastic fibers, in the outer longitudinal muscle layer. Some of the smooth muscle cells in the outer longitudinal muscle layer showed mild degeneration with cytoplasmic vacuolar changes, but no inflammatory changes. However, further studies are required to determine whether these histopathological changes are unique to RA.

Arthritis, Rheumatoid↗
PubMed2002

Surgical procedures for digestive fistulae caused by radiation therapy.

PURPOSE: We evaluated the effectiveness of surgery to treat ileal fistulations associated with radiation exposure. SUBJECTS. An ileal fistula developed in eight patients, 13-102 months after 60 Gy of irradiation to the pelvic cavity, given as initial treatment or supportive therapy following resection of the primary tumor. The underlying diseases were cervical cancer in seven women and bladder cancer in one man. RESULTS: Two patients had an ileorectal fistula, two had an ileosigmoidal fistula, three had an ileovesical fistula, and one had an ileourethral fistula. We performed a partial enterectomy in one patient, a simple bypass operation without exclusion in one, and bypass operations with exclusion in the other six. Intestinal expansion in the exclusion site occurred in one patient, but there were no other complications related directly to surgery, such as sutural insufficiency. The patient who underwent a simple bypass operation died of emaciation 2 months after the surgery, but all of the other patients were discharged capable of oral ingestion. CONCLUSION: Our findings showed that surgery was beneficial for alleviating the various conditions related to digestive fistulation following radiation therapy.

Adult↗
PubMed2002

Phenolic compounds from Gastrodia rhizome and relaxant effects of related compounds on isolated smooth muscle preparation.

Gastrol (1), together with 10 known phenolic compounds, has been isolated from the MeOH extract of the rhizomes of Gastrodia elata Blume (Orchidaceae), and their structures were elucidated by detailed spectral analyses including by 2D NMR spectroscopic analyses. The relaxant effects of these constituents on smooth muscle preparations isolated from guinea-pig ileum were also studied in order to reveal their characteristic pharmacological activities.

Animals↗
PubMed2002

Contribution of N-methyl-d-aspartate receptors in the anteroventral third ventricular region to vasopressin secretion, but not to cardiovascular responses provoked by hyperosmolality and prostaglandin E2 in conscious rats.

The aim of this study is to pursue roles of N-methyl-d-aspartate (NMDA) receptors in the anteroventral third ventricular region (AV3V; a pivotal area for autonomic functions) in controlling vasopressin (AVP) release and cardiovascular system. In conscious rats, we examined effects of AV3V infusion of MK-801 (a selective antagonist for NMDA receptor) on plasma AVP, osmolality, electrolytes, arterial pressure and heart rate, in the absence or presence of NMDA, hyperosmotic or prostaglandin (PG) E2 stimulus. The AV3V infusion of NMDA caused significant increases in plasma AVP, osmolality and sodium, hematocrit, arterial pressure and heart rate after 5 or 15min. When NMDA was administered into the cerebral ventricle, relatively smaller elevations were observed only in plasma AVP and arterial pressure. The effects of AV3V infusion of NMDA were nearly completely prevented by MK-801 applied to the same region before 15min. The application of MK-801 was also potent to block rises of plasma AVP elicited by AV3V injection of PGE2 or i.v. infusion of hypertonic saline. However, it inhibited neither increases of arterial pressure and heart rate due to the PGE2 treatment nor those of arterial pressure, plasma osmolality and sodium in response to the osmotic load. Histological analysis on the AV3V infusion sites of NMDA, MK-801 and PGE2 indicated that they had been located in the structures such as the median and medial preoptic nuclei, periventricular nucleus and medial preoptic area. These results suggest that stimulation of AV3V NMDA receptors in the basal state may facilitate AVP secretion and cause pressor and tachycardiac actions, and that these receptors may be involved in both the hyperosmolality- and PGE2-induced hormone release, but not in the cardiovascular responses to these stimuli.

Animals↗
PubMed2002

Determination of 36Cl in biological shield concrete using pyrohydrolysis and liquid scintillation counting.

A method for the determination of 36Cl in biological shield concrete of nuclear reactors was developed. Cl in the concrete sample was extracted quantitatively by pyrohydrolysis at 900 degrees C and recovered in Na2CO3 solution for subsequent measurement of 36Cl by liquid scintillation counting. WO3 was used as an accelerator in the pyrohydrolysis. The Cl extraction procedure was optimized by investigating experimental conditions with the use of ion chromatography and its recovery was evaluated by the analysis of the geochemical reference samples. The detection limit of 36Cl was 0.02 Bq g(-1) for a sample weight of 2 g. The relative standard deviation was 3-7% for the samples containing 0.5 Bq g(-1) levels of 36Cl. The method was applied to determine 36Cl in biological shield concrete of the Japan Power Demonstration Reactor.

Journal Article↗
PubMed2002

The product of duration and amount of proteinuria (proteinuria index) is a possible marker for glomerular and tubulointerstitial damage in IgA nephropathy.

BACKGROUND/AIMS: IgA nephropathy (IgAN) is one of the major causes for chronic renal failure (CRF). Presence of massive proteinuria, hypertension, increased serum creatinine level and sclerotic histopathological changes of the glomerulus are known to be determinants for the progression of CRF. However, the relationships between duration of proteinuria/hematuria and histopathological changes, which may be correlated with the renal prognosis, have not been clarified. METHODS: A cross-sectional, univariate analysis of clinical parameters on the four glomerular and three tubulointerstitial histopathological grades in 57 untreated biopsy-proven IgAN patients (M/F = 32/25) was performed. RESULTS: The age at the time of renal biopsy (35.2 +/- 13.0 years; mean +/- SD), average duration of proteinuria (5.3 +/- 5.8 years), mean urinary protein excretion (0.99 +/- 1.22 g/day), serum creatinine (Cr 0.97 +/- 0.28 mg/dl), Cr clearance (Ccr 75.5 +/- 29.4 ml/min), and blood urea nitrogen (BUN 15.4 +/- 3.9 mg/dl) were well correlated with both histopathological grades. The product of duration (years) and urinary protein excretion (g/day) at the time of renal biopsy was more significantly correlated with glomerular and tubulointerstitial histopathological grades and serum Cr. CONCLUSION: The natural course of IgAN is steadily progressive depending on the duration and amount of proteinuria. The product of these two factors (proteinuria index) may be a useful predictor for glomerular and interstitial histopathological changes and the fate of renal function in IgAN.

Adult↗
PubMed2002

Stimulatory effects of centrally injected nitric oxide donors on gastric acid secretion in anesthetized rats.

The effects of centrally injected nitric oxide (NO) donors on gastric acid secretion were investigated in continuously perfused stomach of anesthetized rats. The lateral cerebroventricular (LV) injection of NOC5 (30 - 100 microg) and NOC12 (10 - 100 microg) dose-dependently stimulated gastric acid secretion. The LV injection of NOC18 (30 microg) also stimulated gastric acid secretion. The other type of NO donor, sodium nitroprusside (3 - 30 microg, LV), also dose-dependently stimulated gastric acid secretion. The effect of NOC5 at 100 microg was blocked by carboxy-PTIO, an NO scavenger, and by cervical vagotomy. Furthermore, NOC12 (30, 100 microg) dose-dependently stimulated gastric acid secretion in pylorus-ligated conscious rats. These results suggest that centrally injected NO donors stimulate gastric acid secretion in both conscious and anesthetized rats through vagus activation.

Animals↗
PubMed2002

Fabry disease with few clinical signs and symptoms.

We describe a 25-year-old man with Fabry disease who remained undiagnosed until progressive renal involvement had begun, because of few clinical signs or symptoms except intermittent acroparesthesia. He had non-nephrotic proteinuria and normal renal function. Renal biopsy revealed focal and segmental glomerular sclerosis with vacuolated podocytes. Electron microscopy demonstrated characteristic lamellated bodies. Alpha-galactosidase A (alpha-galA) activity was markedly decreased. Early diagnosis of Fabry disease is becoming important because of the prospect of recombinant alpha-galA replacement therapy. Careful history taking, physical examinations, and renal histology with electron microscopy are essential for the diagnosis in the course of the disease.

Adult↗
PubMed2002

[Long-term result of the transcatheter arterial embolization for ruptured renal angiomyolipoma].

PURPOSE: The long-term results were studied in patients who underwent transcatheter arterial embolization (TAE) for the spontaneous rupture of renal angiomyolipoma (AML). MATERIAL AND METHODS: Five cases (1 male, 4 females) who underwent TAE for spontaneous AML rupture between November, 1996 and February 2000 were studied. Spontaneous rupture of AML was diagnosed with CT. TAE were carried out by injection of ethanol and lipiodol and application of either a metal coil or gelform. RESULT: In 4 cases, after performing TAE only one time, the tumor size was reduced and there has been no re-rupture or re-bleeding during the ongoing follow-up. In the other case, an enucleation operation was carried out 11 days after TAE in accordance with the patient's request. DISCUSSION: Recently, there have been a few reports on the long-term effectiveness of TAE, a conservative treatment for renal AML rupture. Our study indicated that TAE might be recommended for patients with renal AML rupture not only for stanching and pre-operative treatment but also for a conservative treatment with regular follow-up.

Adult↗
PubMed2002

Decreased expression of the CCAAT/enhancer binding protein alpha gene involved in hepatocyte proliferation in human hepatocellular carcinomas.

CCAAT/enhancer binding protein alpha (C/EBPalpha), expressed at a high level in liver, plays an important role in proliferation and differentiation of hepatocytes. Previous studies showed that an expression level of the C/EBPalpha gene in hepatocytes was downregulated in response to proliferation signals and that forced expression of the C/EBPalpha gene in a number of cells caused cell cycle arrest. We compared the expression level of the C/EBPalpha gene in surgical specimens between hepatocellular carcinoma and non-tumorous regions of the same patients. In 9 out of 13 cases, the expression level in the tumors was decreased compared with that in corresponding non-tumorous regions. Transfection of the C/EBPalpha gene into C/EBPalpha-negative human hepatocellular carcinoma HLF cells, however, did not influence the rate of cell proliferation or cell cycle. Our present data suggest that the expression of the C/EBPalpha gene was downregulated in the majority of human hepatocellular carcinoma but the expression may not be directly associated with impaired proliferative activity of hepatocellular carcinoma cells.

Animals↗
PubMedDate not supplied

Fibronexus in "malignant fibrous histiocytoma" of the bone: a case report of pleomorphic myofibrosarcoma.

The fibronexus (fibronexus junction) has been thought to be a characteristic ultrastructural feature of myofibroblasts, but it is controversial whether the fibronexus is also a characteristic of various myofibroblastic tumors. We report here a case of pleomorphic bone sarcoma (pleomorphic/storiform malignant fibrous histiocytoma) with fibronexus junctions arising in the head of the left humerus of a 70-year-old woman. By light microscopy the tumor was composed of large spindle or polygonal cells occasionally arranged in fascicles. Foamy giant cells with bizarre nuclei were not uncommon. Immunohistochemically, the tumor cells were positive diffusely for vimentin and focally for muscle actin (HHF35) and alpha-smooth muscle actin but were negative for desmin, high-molecular weight caldesmon, and S-100 protein. Ultrastructurally, the tumor cells had indented nuclei and spindle or polygonal cytoplasm, with little rough endoplasmic reticulum and small vesicles, and rather numerous mitochondria. The tumor cells had myofilaments with focal densities in the periphery, fibronectin fibrils adjacent to intracellular myofilaments, and by definition, therefore, fibronexus junctions. These findings suggest myofibroblastic differentiation, and a diagnosis of pleomorphic myofibrosarcoma is thought to be appropriate. We believe that the fibronexus is a characteristic and useful ultrastructural feature for differentiating myofibroblastic tumors from other pleomorphic myogenic sarcomas.

Actin Cytoskeleton↗
PubMedDate not supplied

Relation of thoracic aorta calcification on computed tomography and coronary risk factors to obstructive coronary artery disease on angiography.

The aim of this study was to investigate whether thoracic aorta calcification (TAC) on computed tomography (CT) and coronary risk factors had any correlation with obstructive coronary artery disease (CAD) on angiography. A total of 225 consecutive Japanese patients underwent both thoracic conventional helical CT and coronary angiography. The thoracic aorta was divided into 4 locations according to the aortic anatomy (inner curve of the aortic arch, aortic arch but not on the inner curve, ascending aorta, and thoracic descending aorta). The classified TAC and coronary risk factors were evaluated for the presence or absence of obstructive CAD. TAC was detected in 185 patients; 141 of 225 patients had significant obstructive CAD. All of the 13 patients with no TAC and no coronary risk factors had no CAD. The obstructive CAD rate with 1 thoracic calcified location and with no, 1, or 2 coronary risk factors was 10%, 58%, and 90%, respectively, and each showed a significant difference (p < 0.0001). The combinations of TAC and coronary risk factors with obstructive CAD were 1 or 2 thoracic calcified locations with 3 coronary risk factors, and 3 thoracic calcified locations with more than 2 coronary risk factors. Increasing thoracic calcified locations and increasing coronary risk factors indicated a higher likelihood of CAD.

Aged↗
PubMedDate not supplied

Down-regulated expression of the CCAAT/enhancer binding protein alpha and beta genes in human hepatocellular carcinoma: a possible prognostic marker.

CCAAT/enhancer binding protein alpha (C/EBP alpha) and C/EBP beta, liver specific transcription factors, are involved in hepatocyte proliferation and differentiation. The expression level of the C/EBP alpha and C/EBP beta genes were examined between tumor and non-tumorous tissues of the same hepatocellular carcinoma patients with quantitative real-time polymerase chain reactions. The expression of both the C/EBP alpha and C/EBP beta genes was down-regulated in the majority of the tumor specimens compared with corresponding non-tumorous tissues. Patients whose expression of either C/EBP alpha or C/EBP beta was higher in tumors than non-tumorous tissues survived longer than those whose expression was lower in tumors. Higher expression of C/EBP alpha or C/EBP beta in tumors was reversibly correlated with the tumor size and progression of the clinical stage. These data imply that the comparison of C/EBP alpha and C/EBP beta expression between tumors and non-tumorous regions could be a prognostic marker for patients with hepatocellular carcinoma.

CCAAT-Enhancer-Binding Protein-alpha↗