Biomedical subjects

Y Satoh

Publications and source records attributed to Y Satoh.

At least 127 records · Page 7Linked to original sources

PubMed1999

No psychological emergence reactions in schizophrenic surgical patients immediately after propofol, fentanyl, and ketamine intravenous anesthesia.

PURPOSE: We attempted to determine the frequency of adverse psychological events after total intravenous anesthesia with propofol-fentanyl-ketamine (PFK) in surgical schizophrenic patients. METHODS: PFK was used in 25 schizophrenic patients undergoing various surgical procedures from 1995 to 1997. Adverse events occurring during and after anesthesia were recorded. Psychiatric follow-up was also done during the first 3 postoperative weeks at least. RESULTS: One patient died postoperatively of airway obstruction from concomitant severe malignant thyroid disease, but in the remaining patients neither respiratory nor cardiovascular states during or after anesthesia became unstable. None of the patients developed adverse psychological emergence reactions immediately after anesthesia. Two patients undergoing major surgical procedures exhibited delirium in the early postoperative days despite taking their routine antipsychotic drugs postoperatively. CONCLUSIONS: We suggest that PFK maintains stable respiratory and cardiovascular states, and causes no psychological emergence reactions in schizophrenic surgical patients. However, adverse psychological events may occur postoperatively, probably due to continued psychic stress. We therefore recommend appropriate perioperative management and further psychological studies for such patients.

Journal Article↗

PubMed1999

Preoperative assessment of congenital bile duct dilatation using intraductal US.

BACKGROUND: Although congenital bile duct dilatation is frequently associated with biliary tract cancer, conventional cholangiography often does not demonstrate small ductal tumors. This is the first prospective study of the value of intraductal ultrasonography (US) in the examination of the extrahepatic bile ducts in patients with congenital bile duct dilatation. METHODS: Intraductal US via a transpapillary route was used in consecutive patients with congenital bile duct dilatation. A 2.0 mm diameter, 20 MHz frequency catheter probe was used. The images were correlated with the results of histologic examination of the resection specimens. RESULTS: Intraductal US was performed successfully via the transpapillary route in 8 of 10 patients. In the other 2 patients, the percutaneous transhepatic route was used. In the 6 patients with cylindrical dilatation, intraductal US demonstrated the entire extrahepatic bile duct. In 1 patient, it showed a bile duct cancer not demonstrated by cholangiography. In 2 of the 4 patients with cystic dilatation, intraductal US did not demonstrate the entire extrahepatic bile duct because of the low penetration depth of the probe. Percutaneous transhepatic cholangioscopy was required in these patients. CONCLUSIONS: Intraductal US is useful for demonstrating cancers in the extrahepatic bile ducts in patients with congenital cylindrical ductal dilatation.

Adult↗

PubMed1999

Preoperative assessment of extrahepatic bile duct carcinoma using three-dimensional intraductal US.

BACKGROUND: We investigated the utility of a new imaging modality, three-dimensional intraductal ultrasonography (US), for staging bile duct cancer. METHODS: In eight patients with extrahepatic bile duct carcinoma, two- and three-dimensional intraductal US was used to assess tumor invasion of the right hepatic artery, portal vein, and pancreatic parenchyma before resection. The findings were correlated with histologic information from the resected specimen. RESULTS: Three-dimensional intraductal US enabled accurate assessment of tumor invasion of the right hepatic artery in 88% of cases, the portal vein in 100%, and pancreatic parenchyma in 100%. Two-dimensional intraductal US enabled accurate assessment of invasion of these structures in 88%, 88%, and 88% of cases. CONCLUSIONS: Three-dimensional intraductal US is useful in assessing tumor stage in bile duct carcinoma.

Aged↗

PubMed1999

Bile duct wall thickness measured by intraductal US in patients who have not undergone previous biliary drainage.

BACKGROUND: We investigated the bile duct wall thickness measured on intraductal US in patients who had not undergone biliary drainage, with special attention to the influence of cancer at the distal bile duct, bile duct stones, obstructive jaundice, longitudinal cancer extension, and primary sclerosing cholangitis on wall thickness. METHODS: The study included 183 patients. Patients who had undergone previous biliary drainage were excluded. Intraductal US was performed by the transpapillary route with use of a thin-caliber ultrasonic probe (2.0 mm diameter, 20 MHz frequency). The bile duct wall thickness (width of the inside hypoechoic layer) was retrospectively measured on US images. RESULTS: Bile duct wall thicknesses of the common hepatic duct for the control group (n = 95), cancer at the distal bile duct group (n = 9), bile duct stone group (n = 56), and obstructive jaundice group (n = 17) were 0.6 +/- 0.3 mm (mean +/- SD), 0.8 +/- 0.5 mm, 0.8 +/- 0.6 mm, and 0.8 +/- 0. 5 mm, respectively. No significant differences (p > 0.05) were found between them. However, wall thickness for the cancer extension to the common hepatic duct group (n = 4, 2.0 +/- 0.4 mm) and sclerosing cholangitis group (n = 2, 2.5 +/- 0.4 mm) were significantly greater than in the other groups (p < 0.005). CONCLUSIONS: In patients who have not undergone previous biliary drainage, the bile duct wall thickness was not thicker in patients with obstructive jaundice. However, the duct wall was significantly thicker in patients with either longitudinal cancer extension or primary sclerosing cholangitis compared with that of other groups.

Adult↗

PubMed1999

How many biopsies should be performed during percutaneous transhepatic cholangioscopy to diagnose biliary tract cancer?

BACKGROUND: The sensitivity of biopsy in the diagnosis of cholangiocarcinoma using percutaneous transhepatic cholangioscopy is not well defined. METHODS: Patients with a biliary tract malignancy (n = 52) underwent directed biopsy during percutaneous transhepatic cholangioscopy using a 1.8 mm diameter forceps. Histologic findings were correlated with endoscopic appearance. RESULTS: A diagnosis of carcinoma was made in all four patients with a tumor of the major duodenal papilla and in all 15 patients with a polypoid bile duct tumor with two biopsies from the mass. In 19 patients with stenotic bile duct cancer, a positive diagnosis was made in 95% of cases when three biopsies were taken from the margin of the stenotic area. When cholangioscopy showed a tortuous, dilated vessel (n = 10), the diagnosis of cancer was made with two biopsies taken from the margin of the stenosis. In 14 patients with metastatic bile duct cancer, the diagnosis was made in only 43% of cases when three biopsies were taken from the margin of the stenosis. When combined with results from the three biopsies taken from within the area of stenosis, the sensitivity for diagnosing pancreatic cancer improved from 20% to 60%. CONCLUSIONS: Directed cholangioscopic biopsies are highly sensitive for the diagnosis of cholangiocarcinoma but less sensitive for cancer metastatic to the bile duct. The numbers and locations of the biopsies required to make a diagnosis of carcinoma depend on the origin and cholangioscopic appearance of the tumor.

Adult↗

PubMed1999

Utilization of a model lung system to assess the effects of an inspiratory impedance threshold valve on the relationship between active decompression and intra-thoracic pressure.

Use of an inspiratory impedance valve has recently been shown to increase the efficacy of standard and active compression-decompression cardiopulmonary resuscitation. We evaluated the effects of a prototypic impedance valve on the relationship between the active decompression and intra-thoracic pressure using a mechanical model lung system. Intermittent impedance to inspiratory flow of respiratory gases during the decompression phase of active compression-decompression cardiopulmonary resuscitation significantly decreased the intra-thoracic pressure, while the pressure was almost zero cm H2O during the cardiopulmonary resuscitation cycle when the impedance threshold valve was not functioning. Thus, this mechanical model will help in evaluating the valve as well as in optimizing its function by simulating various forms of lung disease.

Cardiopulmonary Resuscitation↗

PubMed1999

The interaction of mitogen-activated protein kinases to Epstein-Barr virus activation in Akata cells.

To understand the mechanism by which Epstein-Barr virus (EBV) is activated in Akata cells by cross-linking of surface immunoglobulin, the interaction between mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) and EBV activation was investigated. Immunoblotting using an anti-phosphoMAPK antibody (Ab) revealed that anti-IgG Ab induced rapid phosphorylation of MAPK in the cells. The phosphorylation was inhibited by MAPK/ERK kinase specific inhibitor, PD98059. The expressions of the EBV immediate early BZLF1 mRNA and its protein product ZEBRA, and early antigen were also inhibited by the inhibitor. These results indicate that MAPK is involved in the pathways of EBV activation.

B-Lymphocytes↗

PubMed1999

Heat shock protein 60 (HSP60) immunoreactivity in gastric epithelium associated with Helicobacter pylori infection: a pitfall in immunohistochemically interpreting HSP60-mediated autoimmune responses.

Previous studies have suggested that heat shock proteins (HSP) of Helicobacter pylori (H. pylori) are involved in the induction of autoimmunity mediated gastritis. In the present report, the cross-reactivity between H. pylori-related HSP60 and gastric epithelial cells was investigated by the indirect immunoperoxidase method using two monoclonal antibodies (mAb) against H. pylori-derived HSP60, H9 and H20. H9 is reactive with an epitope common to bacterial HSP60, while H20 is specific to H. pylori HSP60. A total of 70 paraffin-embedded gastric biopsy specimens were analyzed after heat-induced epitope retrieval. Both mAb were cross-reactive with the gastric epithelial cells, with a higher frequency seen for the H9-reactive epitope. The frequency of positive epithelial decoration was not significantly different between H. pylori-positive and H. pylori-negative gastric mucosae. A variety of epithelial and non-epithelial cells were immunostained with mAb H9, while mAb H20 was cross-reactive only with small intestinal epithelia. Reactivity was mainly located in the Golgi area and rarely in the cytoplasm. These results suggest a noteworthy pitfall in immunohistochemical interpretations of HSP60-associated autoimmune reactions in the gastric mucosa.

Antibodies, Bacterial↗

PubMed1999

Suppression of late asthmatic response by low-dose oral administration of interferon-beta in the guinea pig model of asthma.

We investigated the anti-asthmatic effects of low-dose oral and subcutaneous administration of interferon-beta (IFN-beta) on an ovalbumin (OVA)-sensitized and challenged guinea pig model of asthma. Subcutaneous administration of IFN-beta suppressed the eosinophil infiltration by 14.2% of the control and the respiratory resistance (Rrs) by 58.2% at 2.0 MIU/kg. Oral administration of IFN-beta inhibited the late asthmatic response (LAR) by suppressing the increase of Rrs by 29% of the control at 1 IU/ml and the eosinophil infiltration into the trachea and lung by 34.6% at the optimum dosage of 10 IU/ml. Both subcutaneous and oral administration could not inhibit the early asthmatic response (EAR). Additionally we found 2',5'-oligoadenylate synthetase (2',5'-OAS) induction by low-dose oral administration (LDOA) of IFN-beta to the same extent as by subcutaneous administration in whole blood in vivo. These data suggest that LDOA of IFN-beta would have some clinical benefit for patients with asthma.

2',5'-Oligoadenylate Synthetase↗

PubMed1999

Clinical application of a nonpenetrating microvascular stapling device for vascularized free tissue transfer.

It is essential to develop a method that is technically easier and faster to perform microvascular anastomosis. Therefore the authors have utilized a nonpenetrating microvascular stapling device (VCS; Auto Suture, Tokyo, Japan). Eight vascularized free tissue transfers were performed using this stapling device. All of the transferred tissues were grafted successfully. The time required to perform the stapled microvascular anastomosis ranged from 8 to 18 minutes (mean, 12 minutes). Two arterial anastomoses required suture repairs because they could not be repaired with the use of this stapling device due to thickened vessel walls and intimal dissections. The microvascular stapling device proved useful for vascularized free tissue transfers, but the vessels suitable for this technique should be chosen carefully. Not only the surgeon but also the assistant must be experienced in microscopic surgery.

Adult↗

PubMed1999

[Study on the verotoxin-producing Escherichia coli--isolation of the bacteria from deer dung].

To identify the source and route of verotoxin-producing Escherichia coli (VTEC) infection in humans, we tried to isolate VTEC from fresh deer dung collected from free-range animals in two parks during the period from August 1997 to January 1998. The results are presented below. 1) VTEC were isolated from 21 of 200 deer dung samples (10.5%), consisting of 15 of 100 samples (15.0%) collected in park A and 6 of 100 samples (6.0%) collected in park B, suggesting that the incidence of VTEC isolation differs depending on location. 2) With respect to typing of verotoxin, the 21 isolated VTEC strains consisted of 10 strains (47.6%) as VT1 producer, 5 strains (23.8%) as VT2 producer, and 6 strains (28.6%) as double producer of both types. 3) With respect to serogroup of the isolated VTEC strains, 2 strains belonged to O128:H2.1 strain each belonged to the O8:H10, O128:H12, and O169:HUT groups. The remaining 16 strains failed to be identified as particular serotypes. Regarding local distribution of the serotype, in park A, 1 strain each belonged to the O128:H2, O8:H10, and O169:HUT groups. The remaining 12 strains did not clearly show particular serotypes. In park B, 2 strains belonged to O128:H2, and 4 strains failed to show particular serotypes. The remaining 1 strains showed autoagglutination. In conclusion, we isolated VTEC strains from deer that showed types of toxin and serogroups identical to those of human VTEC. Therefore, VTEC found in deer dung could well be a source of VTEC-infectious diseases in humans.

Animals↗

PubMed1999

Left colon substitution with His' angle following total gastrectomy. Surgical technique using stapling devices.

To resolve the disadvantages of jejunal Roux-en-Y reconstruction following total gastrectomy, we attempted the use of left colon substitution with all anastomoses conducted using mechanical stapling devices. A His' angle was formed to reduce regurgitation esophagitis. About 25 cm of the left colon with the ascending branch of the left colic artery with an adequate blood supply was brought up to the remnant esophagus without tension on the mesentery. The colon graft was interposed between the esophagus and duodenum in an isoperistaltic fashion. Three anastomoses, esophagocolic, duodenocolic and colocolic, were completed with a circular stapling device. An end-to-side esophagocolonostomy was positioned about 3 cm distal from the blind end of the proximal colon stump. The proximal end of the left colon was pexied to the esophagus using 3-4 stitches to make a new His' angle. Gastrointestinal continuity was restored by a side-to-end colonoduodenostomy and an end-to-end colonocolonostomy. Fifteen gastric cancer patients underwent left colon substitution following total gastrectomy. The circular staple used for esophagocolonostomy and colonoduodenostomy was 25 mm in all patients, and for colonocolonostomy was 29 mm in 9 patients and 33 mm in 6 patients. No problems were encountered in any steps of the procedure, and faulty stapling was avoided. Neither anastomotic leakage nor necrosis of the interposed colon segment was seen, nor was late anastomotic stricture, in any patient. Barium radiograms of the interposed colon segment showed that the capacity and passage of the interposed colon were adequate, and regurgitation did not occur. Diet volume was satisfactory and weight loss minimal.

Adult↗

PubMed1999

An enzyme-linked immunosorbent assay using nuclear antigen for detection of feline herpesvirus 1 antibody.

To detect antibody against feline herpesvirus 1 (FHV-1) in the sera of cats, the sensitivity and specificity of an enzyme-linked immunosorbent assay (ELISA) using nuclear antigen was investigated. The standardized optical density readings (ODs) of the ELISA obtained by the 1-step serum dilution (1:80) method were compared with the serum neutralization test (SNT) results, with a correlation of 0.993, and with the hemagglutination inhibition (HI) test results, with a correlation of 0.851. The ODs for the ELISA titers were obtained using the serial serum dilution method and were compared with the SNT results, with a correlation of 0.933, and with the HI test results, with a correlation of 0.987. In the experimental infection of 4 specific-pathogen-free cats, the results of different serologic tests (SNT and HI) and the ELISA using the serial serum dilution method revealed rapid production of antibodies after inoculation, whereas the ELISA using the one-step serum dilution method indicated that titers increased more slowly. These results indicate that with the present ELISA using nuclear antigen, there are fewer demands on time and labor, making the method convenient for monitoring FHV-1 infection.

Animals↗

PubMed1999

Monoamine oxidase inhibitory naphthoquinone and/or naphthalene dimers from Lemuni Hitam (Diospyros sp.), a Malaysian herbal medicine.

From the extract of a Malaysian herbal medicine, Lemuni Hitam (Diospyros sp.), which exhibited monoamine oxidase (MAO) inhibition, three new naphthoquinone and/or naphthalene dimers (lemuninols A-C, 1-3) were isolated together with 4,6-dihydroxy-5-methoxy-2-methyl-naphthalene (8) and six known monomers (4-7, 9 and 10). The structures were determined by spectroscopic methods including 2D-NMR techniques. Among them, lemuninol A showed 45% inhibition of MAO (mouse liver) at 5.0 x 10(-6) g/ml, and lemuninols B and C and a naphthoquinone (9) indicated weak activity. Some related quinones were also tested for their MAO inhibitory activities.

Animals↗

PubMed1999

[Analysis of intracellular calcium dynamics in enterochromaffin cells of small intestine].

Although serotonin (5-HT) release from enterochromaffin (EC) cells is considered to be regulated by multiple receptor-mediated mechanisms, little is known about the signal transduction. Here, we introduce the methods to isolate the mouse ileal crypts, which consist of various types of cells including EC cells, and to analyze the intracellular calcium dynamics. Ileal tissue was inserted with a plastic straw and the smooth muscle layers were peeled off. The mucosa were digested with collagenase and then suspended by moderate pipetting. Ileal crypts were separated by stepwise filtrations through 2 different nylon-meshes. The isolated crypt contained 0-3 EC cells as identified by immunostaining using anti-5-HT antibody followed by confocal microscopy. Isolated crypts were attached to a coverglass by an adhesive material (Cell-Tak) and loaded with fura-2/AM. Intracellular calcium dynamics in EC cells were obtained by digital video-imaging analysis of fura-2 fluorescence followed by the identification of EC cells with immunostaining of 5-HT granules. By these methods, it was suggested that norepinephrine elicited a transient elevation of intracellular calcium concentration in EC cells via alpha 2-adrenoceptors. These methods could be also useful to analyze the signal transduction system in intestinal endocrine cells that contain various intestinal hormones such as gastrin, cholecystokinin or secretin.

Animals↗

PubMed1999

Effects of a class III antiarrhythmic drug, dofetilide, on the in situ canine heart assessed by the simultaneous monitoring of hemodynamic and electrophysiological parameters.

The cardiovascular profile of dofetilide was examined using halothane-anesthetized, closed-chest in vivo canine model (n=6). Dofetilide was administered at the dose of 1, 10 or 100 microg/kg, i.v. over 10 min with a pause of 20 min. After the lowest infusion rate, no significant change was detected in any of the cardiovascular parameters. Infusion of 10 microg/kg dofetilide, which was close to the submaximal clinically effective antiarrhythmic dose, decreased the heart rate and prolonged the ventricular repolarization phase and refractory period. After the highest dose of dofetilide, the cardiac output and left ventricular contraction decreased during sinus rhythm, the latter of which was not changed during the constant heart rate of 150 beats/min, while the dose-related effects were observed on the heart rate, repolarization phase and refractory period. The afterload and preload to the left ventricle and AV nodal as well as intraventricular conductions were hardly affected even at 100 microg/kg, i.v. These results obtained in the in vivo canine model support the previous reports describing that dofetilide possesses a highly selective blocking property for I(Kr). Moreover, the absence of effects on the afterload and preload to the left ventricle and the cardiac conduction makes dofetilide favorable as an antiarrhythmic drug because it is often used for patients with moderate to severe left ventricular dysfunction.

Action Potentials↗

PubMed1999

Mediators of nonadrenergic, noncholinergic relaxation in longitudinal muscle of the intestine of ICR mice.

Mediators of nonadrenergic, noncholinergic (NANC) relaxation in longitudinal muscle of several regions of ICR mouse intestine were studied. An inhibitor of synthesis of nitric oxide, N(G)-nitro-L-arginine (L-NOARG) at 10 microM significantly inhibited NANC relaxations induced by electrical field stimulation (EFS) in the jejunum, ileum, and the proximal and distal colon. Especially in the ileum extent of the inhibition was more than 80%. An antagonist of vasoactive intestinal peptide (VIP) receptors, VIP(10-28) at 3 microM partially inhibited the EFS induced relaxations in the jejunum and proximal colon, but very slightly in the distal colon and had no effect in the ileum. An antagonist of pituitary adenylate cyclase activating peptide (PACAP) receptor, PACAP(6-38) at 3 microM partially inhibited the EFS-induced relaxations in the proximal and distal colon, but not in the jejunum and ileum. Totals of the percentages of relaxant components mediated by nitric oxide, VIP and PACAP in every region are roughly equal to a hundred percent. In another series of experiments, EFS-induced relaxations were almost completely inhibited by the treatment of the segments with L-NOARG and VIP(10-28) in the jejunum, with L-NOARG, VIP(10-28) and PACAP(6-38) in the proximal colon, and with L NOARG and PACAP(6-38) in the distal colon. The present results suggest that nitric oxide solely mediates the relaxation of longitudinal muscle of the ileum of ICR mice, whereas nitric oxide and VIP co-mediate it in the jejunum, nitric oxide, VIP and PACAP in the proximal colon, and nitric oxide and PACAP in the distal colon.

Animals↗

PubMed1999

Effects of ATP and its analogues on [Ca2+]i dynamics in the rabbit corneal epithelium.

Adenosine-5'-triphosphate (ATP) plays a pivotal role in various tissues as an extracellular transmitter. ATP released from nerve endings and/or damaged cells may elicit reactions in adjacent cells. To identify such reactions, we investigated the dynamics of the intracellular calcium ion concentrations ([Ca2+]i) in the rabbit corneal epithelium during ATP-stimulation. Intact epithelial sheets isolated from corneal tissue were loaded with Fura-2, and [Ca2+]i dynamics in each cell layer were analyzed using a digital imaging system (Argus 50/CA). Normal architecture was preserved, suggesting that functional integrity remained intact. Perfusion with HEPES-buffered Ringer's solution containing ATP (10 microM) and uridine-5'-triphosphate (UTP; 10 microM) caused a biphasic [Ca2+]i increase in the superficial layer that manifested itself as a rapid initial spike followed by a long-lasting plateau phase. Adenosine-5'-diphate (10 microM) elevated the [Ca2+]i level, but induced only the initial spike, which was smaller than those induced by ATP and UTP. Adenosine (10 microM) did not elicit any [Ca2+]i changes in the epithelial cells. Suramin (10 microM; a P2 receptor antagonist) blocked the ATP-induced [Ca2+]i increase, whereas the P2X receptor agonists, alpha, beta-methylene ATP (10 microM), 2-methyl-thio ATP (10 microM) and Benzoylbenzoyl ATP (10 microM), did not elicit any increases in [Ca2+]i. In the basal cell layer, ATP-induced [Ca2+]i dynamics were biphasic, while oscillatory fluctuations of [Ca2+]i were induced in the wing cells of the mid layer of the corneal epithelium by ATP stimulation. Ca2+ oscillations were sometimes synchronized among adjacent wing cells, but these waves did not propagate to other cell layers. These results suggest that extracellular ATP elicits a [Ca2+]i increase mainly via P2Y receptors. In addition, synchronized Ca2+ oscillation in the wing cell layer indicates that intracellular events may spread to neighboring cells within the layer.

Adenosine Triphosphate↗