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Biomedical subjects

S Satoh

Publications and source records attributed to S Satoh.

At least 145 records · Page 8Linked to original sources
PubMed2000

Effects of NKH477 on endothelin-1-induced renal responses in anaesthetized dogs.

1. Intrarenal arterial infusion of a direct adenylate cyclase activator (NKH477; 300 ng/kg per min) increased renal blood flow, urine flow rate and urinary sodium excretion in anaesthetized dogs. 2. Intrarenal arterial infusion of endothelin (ET)-1 (2 ng/kg per min) reduced basal values of these parameters and glomerular filtration rate, which were recovered by the addition of NKH477 during ET-1 infusion. 3. These results demonstrate that NKH477 can counteract ET-1-induced antinatriuresis, mainly by restoring glomerular filtration.

Anesthesia↗
PubMed2000

An autopsy case of Alzheimer's disease with a progressive supranuclear palsy overlap.

A 74-year-old man developed abnormal forgetfulness, soon followed by unstable speech content and marked disorientation. At 77 years of age, the patient started to occasionally fall, an aspect of progressive supranuclear palsy. He then became bedridden. The patient eventually died of pneumonia at 79 years of age. Neuropathological examination revealed profiles of both progressive supranuclear palsy and Alzheimer's disease. Although the two conditions both belong to tauopathy, their pathologically proven combination was rare. Furthermore, the case had the possibility of being a subgroup of tauopathy.

Aged↗
PubMed2000

Complicating risk factors for pyelonephritis after extracorporeal shock wave lithotripsy.

PURPOSE: The score to predict the risk of post-extracorporeal shock wave lithotripsy (ESWL) pyelonephritis was evaluated. The score was based on the multivariate analysis of risk factors available pre-operatively. Stone size, pyuria, bacteriuria, previous pyelonephritis and other adjunctive procedures had been selected and scored. METHODS: Three-hundred and forty-eight adult patients without active urinary infection undergoing ESWL therapy were studied. One of three regimens were selected by either doctor or patient: (i) no antimicrobial treatment; (ii) one dose of levofloxacin; or (iii) 1 week course of levofloxacin. Who and why selected it were described. Post-ESWL fever over 38 degrees C was defined as the unfavorable event. RESULTS/CONCLUSION: With increasing score, doctors recommend taking an antimicrobial. There were 11 bacteriuric patients and post-ESWL pyelonephritis developed in one of them. Bacteria within the stone and post-ESWL ureteral obstruction caused by the stone fragments were considered to be important in developing pyelonephritis. However, multiple factors were related with it. Although their decision was not based simply on the score, the score was confirmed to be useful in identifying the high-risk patients and, therefore, to implement cost-effective antimicrobial use.

Adolescent↗
PubMed2000

Comprehensive allelotype study of hepatocellular carcinoma: potential differences in pathways to hepatocellular carcinoma between hepatitis B virus-positive and -negative tumors.

To examine the role of the loss of heterozygosity (LOH) in hepatitis-related carcinogenesis, we performed a genome-wide scan of LOH in 44 tumors of hepatocellular carcinoma (HCC) using 216 microsatellite markers throughout all human chromosomes. A high frequency of LOH (>30% of informative cases) was observed at 33 loci on chromosome arms 4q, 6q, 8p, 8q, 9p, 9q, 13q, 16p, 16q, 17p, and 19p. LOH on 19p has not yet been reported, and that appears to be a new candidate in the search for tumor suppressor genes. High rates of LOH are correlated with hepatitis B virus (HBV) positivity, poorly differentiated tumors, vascular invasion, and intrahepatic metastasis (P <.0001). LOH on 13q and 16q occurred more frequently in HBV(+) patients (P <.0001), and LOH on 6q occurred more frequently in virus-negative patients (P <.001). The frequency of LOH on 4q and 13q was significantly lower in well-differentiated tumors than in moderately and poorly differentiated tumors (P <.01). In contrast, LOH on 6q was frequently detected in well-differentiated tumors compared with other histological subclasses (P <.001). Our results suggest that LOH on 6q may play an important role in the early stage of hepatocarcinogenesis in virus-negative patients, but different mechanisms might underlie the initial step to carcinogenesis in HBV(+) patients. LOH on 13q and 16q may play an essential role in the progression of HBV(+) tumors. Further studies of fine deletion mapping on chromosomes 13q and 16q are required to define the genomic segments on which putative tumor suppressor genes responsible for HBV(+) tumors exist.

Alleles↗
PubMed2000

Posterior sagittal anorectoplasty for failed imperforate anus surgery: lessons learned from secondary repairs.

PURPOSE: The aim of this study was to evaluate secondary operations using a posterior sagittal approach in patients with fecal incontinence and impaction after primary repair of anorectal malformations. METHODS: Twenty patients (14 boys, 6 girls) who had previous failed surgery for imperforate anus underwent secondary operations. The indications for surgery included fecal incontinence (n = 16) and fecal impaction (n = 4). Patients ranged in age from 2 to 30 years (mean, 11 years), with 4 over the age of 20 years. The primary procedures included abdominosacroperineal (n = 7), sacroperineal (n = 10), and perineal (n = 3) pull-throughs. At surgery, none of the patients underwent a diverting colostomy. The rectum was mobilized from the surrounding structures through a posterior sagittal approach. The surgical findings included anteriorly displaced anus (n = 17), laterally displaced anus (n = 3), mesenteric fat surrounding the rectum (n = 4), mega-rectosigmoid (n = 2), and others (n = 3). The rectum underwent reconstruction, which involved relocation of the rectum and anus to surround them with the muscle complex. RESULTS: Patients underwent follow-up for periods ranging from 8 months to 6 years after surgery (mean, 3 years). To evaluate the functional results, fecal continence scores (Templeton and Ditesheim) were calculated for incontinent patients. Of the 16 incontinent patients, 12 achieved continence and 4 some improvement. Of the 4 patients with fecal impaction, 2 achieved daily voluntary bowel movement, whereas the other 2 have mild constipation and need occasional enemas. CONCLUSIONS: Our study suggests that (1) a secondary operation through a posterior sagittal approach can restore fecal continence and is efficacious even in adolescents and adults and (2) a posterior sagittal procedure can be safely performed without a diverting colostomy.

Adolescent↗
PubMed2000

Clinicopathologic evaluation of hepatocellular carcinoma with bile duct thrombi.

BACKGROUND: The aim of this study was to evaluate the clinicopathologic characteristics of patients with hepatocellular carcinoma (HCC) and bile duct thrombi (BDT). PATIENTS: Seventeen patients with HCC and BDT among 671 patients with HCC who underwent hepatic resection were enrolled in this study. RESULTS: There were no significant differences in the survival rates between patients with and those without BDT, although the rate of stage IV or portal vein invasion was significantly higher in patients with HCC and BDT than in those with HCC but without BDT. In 9 of 17 patients with BDT, preoperative jaundice was observed. Five of the 17 patients underwent a bile duct resection combined with hepatic resection, and 12 patients underwent hepatic resection with removal of the BDT without bile duct resection. None of the patients had histopathologic evidence of direct tumor invasion into the bile duct wall or of any tumor recurrence related to the BDT. There were no significant differences in the survival rates between patients who underwent bile duct resection and those who did not. CONCLUSION: Hepatic resection and the removal of BDT without bile duct resection were sufficient surgical interventions to treat patients with HCC and BDT.

Adult↗
PubMed2000

Transmission electron microscopic study of hepatocytes in bioartificial liver.

A bioartificial liver (BAL) was prepared by simple inoculation of hepatocytes into the inner space of hollow fibers of a hemodialyzer and it was maintained in a closed circuit for in vitro culture. Morphology of hepatocytes in the hollow fibers was studied in detail using transmission electron microscopy (TEM). The hepatocytes formed three-dimensional, rod-shaped aggregates of 200 microm in diameter throughout the whole dimension of the hollow fibers after 1 day of culture. Approximately five hepatocyte layers existed from the surface to the center of the aggregate. The hepatocytes in the aggregate displayed mostly polygonal shapes and were surrounded by five to six cells. Abundant bile canaliculi were formed between the hepatocytes and were sealed by tight junctions. The distance between the adjacent hepatocytes except the bile canaliculus domain was approximately 20 nm, and interdigitation was observed between some hepatocytes. These observations indicate that the hepatocytes formed functionally associated aggregates, that is, organoids. Although the cells facing the inner surface of the hollow fiber lost their polygonal shape and became flattened during the following several-day culture, no drastic change was observed in the morphology of the hepatocytes located inside the aggregate. After 14 days of culture, the number of living cells decreased and most of these had a deformed nucleus, few numbers of organelles, and intermittent lipid droplets.

Animals↗
PubMed2000

Role of the gynoecium in natural senescence of carnation (Dianthus caryophyllus L.) flowers.

Although the role of the gynoecium in natural senescence of the carnation flower has long been suggested, it has remained a matter of dispute because petal senescence in the cut carnation flower was not delayed by the removal of gynoecium. In this study, the gynoecium was snapped off by hand, in contrast to previous investigations where removal was achieved by forceps or scissors. The removal of the gynoecium by hand prevented the onset of ethylene production and prolonged the vase life of the flower, demonstrating a decisive role of the gynoecium in controlling natural senescence of the carnation flower. Abscisic acid (ABA) and indole-3-acetic acid (IAA), which induced ethylene production and accelerated petal senescence in carnation flowers, did not stimulate ethylene production in the flowers with gynoecia removed (-Gyn flowers). Application of 1-aminocyclopropane-1-carboxylate (ACC), the ethylene precursor, induced substantial ethylene production and petal wilting in the flowers with gynoecia left intact, but was less effective at stimulating ethylene production in the -Gyn flowers and negligible petal in-rolling was observed. Exogenous ethylene induced autocatalytic production of the gas and petal wilting in the -Gyn flowers. These results indicated that ethylene generated in the gynoecium triggers the onset of ethylene production in the petals of carnation during natural senescence.

Aging↗
PubMed2000

Vascular tissue-specific gene expression of xylem sap glycine-rich proteins in root and their localization in the walls of metaxylem vessels in cucumber.

Root-specific cDNAs of glycine-rich protein (cucumber root glycine rich protein-1 and -2; CRGRP-1 and CRGRP-2) were cloned previously by use of an antiserum raised against whole xylem sap of Cucumis sativus. The accumulation of the corresponding mRNA at high levels was detected in the root-hair zone of cucumber tap root [Sakuta et al. (1998) Plant Cell Physiol. 39: 1330]. The RNA gel blot analysis with the CRGRP-1- and -2-specific probes revealed that the CRGRP genes expressed only in root but not at all in aboveground organs. When the localization of these mRNAs were examined by in situ hybridization, CRGRP mRNAs were found only in the parenchyma cells in the central cylinder of young lateral roots and it was most abundant in the cells that surrounded xylem vessels in the root-hair zone of the tap root. In immunoblotting of xylem sap collected from cucumber stem with an antiserum raised against CRGRP-1 that had been produced in an E. coli expression system, the antibodies, which did not cross-react with GRP1.8 of kidney bean, reacted with two proteins, whose mobilities corresponded to those of proteins deduced from the CRGRP-1 and -2 cDNAs. Immunohistochemical staining revealed that the CRGRPs accumulated specifically in the lignified walls of metaxylem vessels in the root, stem and leaf and in the lignified cell walls of perivascular fibers in cucumber stems. Immunostaining was also detected in the walls of metaxylem vessels and in the cell walls of adjacent sclerenchyma in the hypocotyl of kidney bean. These data clearly indicate that the novel glycine-rich proteins were produced in the vascular tissue of the root, transported systemically over a long distance via the xylem sap and immobilized in the walls of metaxylem vessels and sclerechyma cells in aboveground organs.

Cucumis sativus↗
PubMed2000

Interaction between norepinephrine release and intrarenal angiotensin II formation during renal nerve stimulation in dogs.

We examined possible interactions between intrarenal angiotensin II (ANG II) formation and norepinephrine (NE) release during renal sympathetic nerve stimulation (RNS) in anesthetized dogs. During 10 min of continuous RNS (1.5-2 Hz), the ANG II formation rates (ANG II-FR) and NE secretion rates (NE-SR) were determined at 1 and 10 min. Under control conditions, almost the same extent of increase in the NE-SR was observed at 1 and 10 min of RNS, whereas a significant increase in ANG II-FR was observed at 10 min but not at 1 min. During intrarenal arterial infusion of enalaprilat or losartan, the increase in NE-SR and reduction in renal blood flow at 10 min of RNS were suppressed, whereas the NE release and vasoconstriction responses at 1 min remained unaffected. The RNS-induced increases in ANG II-FR were completely abolished during infusion of enalaprilat. These results suggest that NE release on continuous RNS is enhanced by concomitantly formed ANG II, and this interaction depends on the time-related changes in intrarenal ANG II formation during RNS in the canine kidney.

Angiotensin II↗
PubMed2000

Effect of angiotensin II on aldosterone secretion in canine adrenal gland in situ.

To investigate the effect of angiotensin (ANG) II on aldosterone (ALDO) secretion, we measured arterial and adrenal venous plasma aldosterone concentrations in anesthetized dogs. The intraadrenal arterial infusion of ANG II (0.3 ng/kg/min) or potassium chloride (KCl) (0.6 mg/min) increased ALDO secretion. The changes in ALDO secretion in response to ANG II were tested during the concomitant arterial infusion of two graded doses of losartan (10 and 100 ng/kg/min), PD 123319 (50 and 500 ng/kg/min), nifedipine (25 and 250 ng/kg/min), or TMB-8 (2 and 20 microg/kg/min). All of these test drugs except PD123319 inhibited the ANG II-induced increase in ALDO secretion. Losartan did not affect the KCl-induced increase in ALDO secretion. These results indicate that ANG II acts on ANG II type 1 receptors in the adrenal gland and enhances ALDO secretion. They also suggest the involvement of both intracellular and extracellular calcium in the aldosterone response to stimulation by ANG II. Under these in vivo experimental conditions, the KCl-stimulated ALDO secretion does not appear to involve ANG II formation in the adrenal gland.

Adrenal Glands↗
PubMed2000

Isolation and characterization of human NBL4, a gene involved in the beta-catenin/tcf signaling pathway.

beta-Catenin, a key regulator of cellular proliferation, is often mutated in various types of human cancer. To investigate cellular responses related to the beta-catenin signaling pathway, we applied a differential display method using mouse cells transfected with an activated form of mutant beta-catenin. This analysis and subsequent northern-blot hybridization confirmed that expression of a murine gene encoding NBL4 (novel band 4.1-like protein 4) was up-regulated by activation of beta-catenin. To examine a possible role of NBL4 in cancer, we isolated the human homologue of the murine NBL4 gene by matching mNBL4 against the human EST (expressed sequence tag) database followed by 5' rapid amplification of cDNA ends (5'RACE). The cDNA of hNBL4 encoded a protein of 598 amino acids that shared 87% identity in amino acid sequence with murine NBL4 and 71% with zebrafish NBL4. A 2.2-kb hNBL4 transcript was expressed in all human tissues examined with high levels of expression in brain, liver, thymus and peripheral blood leukocytes and low levels of expression in heart, kidney, testis and colon. We determined its chromosomal localization at 5q22 by fluorescence in situ hybridization. Expression of hNBL4 was significantly reduced when beta-catenin was depleted in SW480 cells, a human cancer cell line that constitutionally accumulates beta-catenin. The results support the view that NBL4 is an important component of the beta-catenin / Tcf pathway and is probably related to determination of cell polarity or proliferation.

Amino Acid Sequence↗
PubMed2000

Role of potassium channels in catecholamine secretion in the rat adrenal gland.

We elucidated the functional contribution of K(+) channels to cholinergic control of catecholamine secretion in the perfused rat adrenal gland. The small-conductance Ca(2+)-activated K(+) (SK(Ca))-channel blocker apamin (10-100 nM) enhanced the transmural electrical stimulation (ES; 1-10 Hz)- and 1, 1-dimethyl-4-phenyl-piperazinium (DMPP; 5-40 microM)-induced increases in norepinephrine (NE) output, whereas it did not affect the epinephrine (Epi) responses. Apamin enhanced the catecholamine responses induced by acetylcholine (6-200 microM) and methacholine (10-300 microM). The putative large-conductance Ca(2+)-activated K(+) channel blocker charybdotoxin (10-100 nM) enhanced the catecholamine responses induced by ES, but not the responses induced by cholinergic agonists. Neither the K(A) channel blocker mast cell degranulating peptide (100-1000 nM) nor the K(V) channel blocker margatoxin (10-100 nM) affected the catecholamine responses. These results suggest that SK(Ca) channels play an inhibitory role in adrenal catecholamine secretion mediated by muscarinic receptors and also in the nicotinic receptor-mediated secretion of NE, but not of Epi. Charybdotoxin-sensitive Ca(2+)-activated K(+) channels may control the secretion at the presynaptic site.

Acetylcholine↗
PubMed2000

Interaction of SK(Ca) channels and L-type Ca(2+) channels in catecholamine secretion in the rat adrenal gland.

We elucidated the interaction of small-conductance Ca(2+)-activated K(+) (SK(Ca)) channels and L-type Ca(2+) channels in muscarinic receptor-mediated control of catecholamine secretion in the isolated perfused rat adrenal gland. The muscarinic agonist methacholine (10-300 microM) produced concentration-dependent increases in adrenal output of epinephrine and norepinephrine. The SK(Ca) channel blocker apamin (1 microM) enhanced the methacholine-induced catecholamine responses. The facilitatory effect of apamin on the methacholine-induced catecholamine responses was not observed during treatment with the L-type Ca(2+) channel blocker nifedipine (3 microM) or Ca(2+)-free solution. Nifedipine did not affect the methacholine-induced catecholamine responses, but it inhibited the responses during treatment with apamin. The L-type Ca(2+) channel activator Bay k 8644 (1 microM) enhanced the methacholine-induced catecholamine responses, whereas the enhancement of the methacholine-induced epinephrine and norepinephrine responses were prevented and attenuated by apamin, respectively. These results suggest that SK(Ca) channels are activated by muscarinic receptor stimulation, which inhibits the opening of L-type Ca(2+) channels and thereby attenuates adrenal catecholamine secretion.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed2000

An accessory spleen mimicking a nonfunctional adrenal tumor: a potential pitfall in the diagnosis of a left adrenal tumor.

We describe a case of accessory spleen mimicking a left adrenal tumor. A 66-year-old woman was referred to our hospital because of a suspected left adrenal mass detected by US. A laparoscopic adrenalectomy was performed, and examination of the surgical specimen revealed that the resected adrenal gland contained no tumorous lesion. A further investigation of the intraperitoneal space revealed an accessory spleen. This indicates that urologists should be aware of the possible existence of accessory spleens when left adrenal tumors are suspected on CT and MRI.

Adrenal Gland Neoplasms↗
PubMed2000

A new model of cerebral microthrombosis in rats and the neuroprotective effect of a Rho-kinase inhibitor.

BACKGROUND AND PURPOSE: The aim of this study was to develop a new model of stroke based on endothelial damage and thrombotic occlusion in a perforating artery, leading to small cerebral infarcts and neurological deficits in rats. Moreover, the neuroprotective efficacy of fasudil, a rho-kinase inhibitor, was investigated in this model. METHODS: Fifty-six male Sprague-Dawley rats were used in the present study. Rats were anesthetized with sodium pentobarbital, and 100 microg of sodium laurate was injected into the left internal carotid artery on days 1 and 3. The thrombus induction and consequent of ischemic brain damage were examined by histopathological analyses and neurological deficit scoring in a posture reflex test. To investigate the neuroprotective effects of fasudil, 1 or 10 mg/kg was administered intraperitoneally 5 minutes after the first injection of sodium laurate and once daily thereafter on the following 2 days. RESULTS: One hour after the injection of sodium laurate, microscopic examination of phosphotungstic acid hematoxylin-stained sections (n=5) revealed that microthrombi containing fibrin strands obstructed the perforating arteries in the ipsilateral hemisphere. Under a transmission electron microscope (n=6), endothelial cells appeared exfoliated and the vascular lumen was obstructed by a thrombus composed of degranulated platelets, fibrin, leukocytes, and erythrocytes. No evidence of endothelial cell damage or thrombus could be found in the ipsilateral side of the pial artery (middle cerebral artery). Twenty-four hours after the second injection of sodium laurate (day 4), 13 of 15 rats (86.6%) showed mild to severe neurological deficits. Multiple small cerebral infarcts were observed in the hippocampus, cortex, and thalamus. Treatment with fasudil (1 and 10 mg/kg, n=15 each) resulted in a significant improvement in neurological deficits. Fasudil also significantly reduced the area of cerebral infarction. CONCLUSIONS: We present a new model of stroke in rats, in which the perforating arteries are selectively occluded by microthrombi. This model is useful to investigate the pathophysiology and treatment of small cerebral infarction, which is caused by perforating arterial occlusive diseases such as lacunar infarcts. Fasudil may be beneficial in the treatment of acute ischemic stroke.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗