Search PubMed⌕ Search

Biomedical subjects

Y Satoh

Publications and source records attributed to Y Satoh.

At least 55 records · Page 3Linked to original sources
PubMed2001

The N-terminal region of Sgs1, which interacts with Top3, is required for complementation of MMS sensitivity and suppression of hyper-recombination in sgs1 disruptants.

The SGS1 gene of Saccharomyces (cerevisiae is a homologue of the genes affected in Bloom's syndrome, Werner's syndrome, and Rothmund-Thomson's syndrome. Disruption of the SGS1 gene is associated with high sensitivity to methyl methanesulfonate (MMS) and hydroxyurea (HU), and with hyper-recombination phenotypes, including interchromosomal recombination between heteroalleles. SGS1 encodes a protein which has a helicase domain similar to that of Escherichia coli RecQ. A comparison of amino acid sequences among helicases of the RecQ family reveals that Sgs1,WRN, and BLM share a conserved region adjacent to the C-terminal part of the helicase domain (C-terminal conserved region). In addition, Sgs1 contains two highly charged acidic regions in its N-terminal region and the HRDC (helicase and RNaseD C-terminal) domain at its C-terminal end. These regions were also found in BLM and WRN, and in Rqh1 from Schizosaccharomyces pombe. In this study, we demonstrate that the C-terminal conserved region, as well as the helicase motifs, of Sgs1 are essential for complementation of MMS sensitivity and suppression of hyper-recombination in sgs1 mutants. In contrast, the highly charged acidic regions, the HRDC domain, and the C-terminal 252 amino acids were dispensable for the complementation of these phenotypes. Surprisingly, the N-terminal 45 amino acids of Sgs1 were absolutely required for the suppression of the above phenotypes. Introduction of missense mutations into the region encoding amino acids 4-13 abolished the ability of Sgsl to complement MMS sensitivity and suppress hyper-recombination in sgs1 mutants, and also prevented its interaction with Top3, indicating that interaction with Top3 via the N-terminal region of Sgs1 is involved in the complementation of MMS sensitivity and the suppression of hyper-recombination.

Amino Acid Sequence↗
PubMed2001

Sexual differences and effects of castration on secretory mode and intracellular calcium ion dynamics of golden hamster Harderian gland.

The aim of the present work was to study the sexual differences in secretory mechanisms and intracellular calcium ion dynamics in the Harderian gland of the golden hamster. In both sexes the Harderian gland consisted of small and large lobes. In the intact control male glands the secretory portions of both lobes showed wide lumina that contained secretory material and cytoplasmic fragments, suggestive of the occurrence of exocytosis and apocrine secretion. After perfusion with HEPES-buffered Ringer's solution containing 10 microM carbamylcholine (CCh), the glandular cells showed features of enhanced secretion and a rise in intracellular calcium concentration ([Ca2+]i). In the intact control female gland the lumina of most secretory portions in the large lobe contained porphyrin accretions, and exocytosis was the sole secretory mechanism. Stimulation of the large lobe with 10 microM CCh did not raise [Ca2+]i or cause enhanced secretion. The small lobe in females resembled the male gland in secretory functions, and CCh administration caused enhanced secretion and a rise in [Ca2+]i. Castration in males abolished apocrine secretion; exocytosis became the sole secretory mechanism, and stimulation of the glandular cells with CCh did not cause enhanced secretion or induce a rise in [Ca2+]i. To the contrary, in females, castration restored apocrine secretion and CCh administration caused enhanced secretion and a rise in [Ca2+]i. Castration did not affect the secretory mechanisms and the effect of CCh on the glandular cells in the small lobes of both male and female glands. The present study points to the possibility that sex hormones may control the functioning or expression of muscarinic receptors in the Harderian gland of the golden hamster.

Animals↗
PubMed2001

Cholangiographic findings of early-stage extrahepatic bile duct carcinoma.

BACKGROUND: To clarify the cholangiographic findings of early-stage (T1, tumor confined to the mucosal or fibromuscular layer) extrahepatic bile duct carcinoma. METHODS: Cholangiographic images were retrospectively analyzed without other information in 55 patients with extrahepatic bile duct carcinoma who underwent surgical treatment. Tumor stages were T1 (n = 10). T2 (n = 17), and T3 (n = 28). Cholangiographic findings were classified as "diffuse sclerosis," "stenosis," "papillary polypoid filling defect," or "nodular polypoid filling defect". "Papillary polypoid filling defect" was the term used when the width of the base was smaller than the width of the polypoid filling defect. RESULTS: T1 patients showed papillary polypoid filling defects (n = 8) or nodular polypoid filling defects (n = 2) on cholangiography. When cholangiography showed papillary polypoid filling defects, 8 of the 14 resected patients showed T1 stage tumor histologically. CONCLUSIONS: In this study, 57% (8/14) of resected patients with papillary polypoid filling defects showed T1 stage tumor. No T1 stage tumor showed stenosis or diffuse sclerosis.

Adult↗
PubMed2001

Looping technique for transpapillary selective biopsy of the left hepatic duct.

PURPOSE: Because biopsy forceps tend to turn towards the right hepatic duct during endoscopic retrograde cholangiopancreatography (ERCP), selective access to the left hepatic duct is difficult. METHODS: In this study, we managed to insert biopsy forceps selectively into the left hepatic duct, by using a looping technique, in three patients. Biopsy forceps were inserted into the right hepatic duct by the conventional method. The elevator of the endoscope was kept down, and the shaft of the biopsy forceps was then advanced to the duodenal cavity until it formed a loop between the endoscope and the papilla. During the procedure, the tip of the forceps was kept at the hepatic hilus. RESULTS: In this condition, we were able to slowly rotate the tip of the forceps and direct the forceps towards the left. Sufficient material from the left hepatic duct was obtained in all patients. CONCLUSIONS: The looping technique was useful for selective access to the left hepatic duct.

Adult↗
PubMed2001

Annuloaortic repair in the treatment of aortic regurgitation and aortic root pathology.

We developed a new technique of aortic root repair which may be able to eliminate the potential problem of leaflet damage, resulting from the direct contact of the aortic leaflets with synthetic vascular grafts during systole. This report describes our technique of annuloaortic repair and the operative results. Between February 1995 and October 1998, 13 patients underwent annuloaortic repair. The patients included 8 males and 5 females (mean age 50 years). Four patients had grade IV/IV aortic regurgitation (AR), 5 had III/IV AR, 2 had II/IV AR, and 1 had no AR preoperatively. Regarding the preoperative functional status, 1 patient was classified as New York Heart Association class IV, 5 were class III, 6 class II, and 1 class I. Concomitant cardiovascular procedures were performed in 12 cases. Aortic valvuloplasty or annuloplasty was performed in 7 patients. Both operative and short-term postoperative results with pre- and postoperative echocardiographic findings were studied retrospectively. The mean total cardiopulmonary bypass time was 212 min. The mean aortic cross-clamp time was 130 min. Circulatory arrest was induced in 5 patients. Postoperatively, 7 patients had no AR. Three patients had grade I/IV AR and 3 had grade II/IV AR. Perioperative changes in aortic annulus, mid-sinus portion, and sinotubular junction diameters were determined echocardiographically in 5 patients. The preoperative diameters were 2.7 +/- 0.4, 5.4 +/- 0.5, and 4.7 +/- 1.0 cm, respectively. The postoperative diameters were 2.3 +/- 0.5, 4.2 +/- 0.5, and 3.5 +/- 0.5cm, respectively. Ten patients were class I and 2 were class II. This technique of annuloaortic repair with or without aortic valvuloplasty is applicable to a certain subset of patients with aortic root disease and AR. Both the indications for this procedure and the long-term results should be confirmed.

Adolescent↗
PubMed2001

Transpapillary intraductal US prior to biliary drainage in the assessment of longitudinal spread of extrahepatic bile duct carcinoma.

BACKGROUND: The utility of intraductal US via the transpapillary route prior to biliary drainage in the assessment of longitudinal extension of extrahepatic bile duct carcinoma was investigated. METHODS: In 19 patients with extrahepatic bile duct carcinoma who underwent surgical resection, an ultrasonic probe (diameter, 2.0 mm; frequency, 20 MHz) was inserted into the bile duct via the transpapillary route prior to biliary drainage. Longitudinal cancer extension along the bile duct was prospectively determined and compared with the histologic findings in the resected specimens. RESULTS: Results on the hepatic side were as follows: Intraductal US demonstrated more extensive longitudinal cancer spread than cholangiography in 9 of 19 patients with one instance of overdiagnosis. The accuracy of intraductal US in assessing the extent of spread (84%) was superior to that of cholangiography (47%) (p < 0.05). Results on the duodenal side were as follows: In patients with suprapancreatic bile duct cancer (n = 14), intraductal US demonstrated more extensive longitudinal cancer spread than cholangiography in 8 of 14 patients. The accuracy of intraductal US in assessing the extent of the spread (86%) was superior to that of cholangiography (43%) (p < 0.05). CONCLUSIONS: Transpapillary intraductal US prior to biliary drainage is useful in demonstrating longitudinal extension of bile duct cancer. However, the surgical margins were inaccurate in some patients.

Aged↗
PubMed2001

Topographical analysis of p53 expression and DNA ploidy in early bronchial squamous cell carcinoma and preneoplastic lesions.

The significance of p53 mutations and DNA aneuploidy in carcinoma cells has been investigated on the basis of a multi-step development theory of carcinogenesis. It has, however, not been determined whether these alterations can be used as diagnostic markers for the early detection of bronchial squamous cell carcinoma (BSqCC). To address this problem, we topographically investigated p53 alterations and DNA aneuploidy in 24 X-ray-negative, early BSqCC patients with various preneoplastic lesions and in 25 non-carcinoma patients with preneoplastic lesions. Bronchial lesions (n=88) were morphologically classified as hyperplasia (HP, n=5), squamous metaplasia (SM, n=23), low-grade dysplasia (LGD, n=14), high-grade dysplasia (HGD, n=11), intraepithelial carcinoma including 'carcinoma in situ' (CIS) (IEC, n=15), and microinvasive carcinoma (MIC, n=20). Immunohistochemistry for the p53 protein and image cytometry for DNA ploidy detection were performed in serial sections of each lesion. Overexpression of p53 protein was detected in 36, 73, and 65% of the HGD, IEC, and MIC lesions, respectively. Aneuploid DNA profiles were found only in carcinoma lesions, 33% in IEC and 85% in MIC. The topographical analysis revealed two types of early BSqCCs, one with adjacent preneoplastic lesions (sequential type, n=8) and another without such lesions (de novo type, n=16). The p53 protein was frequently overexpressed in both types (sequential type, 79%; de novo type, 62%). In the sequential type, however, the p53 protein was overexpressed in HGD lesions that were directly adjacent to p53-overexpressing carcinoma lesions without exception. The present topographical study suggests that p53 mutations play an important role in the carcinogenesis of BSqCC and that p53-overexpressing HGD lesions in sequential types should be regarded as 'truly' preneoplastic lesions that actually develop into carcinomas. In addition, our study demonstrated that DNA aneuploidy might occur at times after p53 alteration with increasing frequency, as invasive growth begins. Such combination analysis of p53 immunohistochemistry and nuclear DNA ploidy in routine histology may contribute to estimates of malignant potential in preneoplastic and intraepithelial squamous lesions and provide additional information for early detection of BSqCC.

Aneuploidy↗
PubMed2001

Comparison of intraductal ultrasonography with percutaneous transhepatic cholangioscopy for the identification of residual bile duct stones during lithotripsy.

BACKGROUND: An imaging modality that can be used to identity small stones after a biliary lithotripsy is required. Intraductal ultrasonography was evaluated by using percutaneous transhepatic cholangioscopy as the gold standard. METHODS: Lithotripsy, under percutaneous transhepatic cholangioscopy guidance, was performed in 20 patients. A thin-caliber ultrasonic probe (2.0 mm in diameter and 20 MHz frequency) was inserted into the bile duct through the percutaneous tract after lithotripsy, and residual stones were identified. This was followed by percutaneous transhepatic cholangioscopy. RESULTS: In the extrahepatic bile ducts, intraductal ultrasonography provided images of all the stones demonstrated on cholangioscopy (n = 11). The sensitivity was superior to that of cholangiography (P < 0.005). However, in the intrahepatic bile ducts, intraductal ultrasonography only visualized the stones located in the cannulated lobe. Extrahepatic stones smaller than 5.0 mm in diameter or in a common hepatic duct larger than 15.0 mm in diameter were missed by cholangiography, but were visualized by the use of intraductal ultrasonography (P < 0.05). CONCLUSIONS: Intraductal ultrasonography is equivalent to cholangioscopy in the extrahepatic bile ducts. Cholangiography and intraductal ultrasonography should be used in combination to image intrahepatic and extrahepatic stones.

Aged↗
PubMed2001

Epinephrine irrigation for the prevention of pancreatic damage after endoscopic balloon sphincteroplasty.

BACKGROUND AND AIM: Endoscopic balloon sphincteroplasty (EBS) is an alternative to sphincterotomy for the treatment of bile duct stones. The purpose of this study was to determine if epinephrine irrigation of the papilla can prevent the pancreatic damage associated with EBS. METHODS: A total of 173 patients with bile duct stones were treated by EBS. After conventional endoscopic retrograde cholangiography, EBS was performed by using a biliary dilatation catheter (balloon diameter: 8 mm). The duct was then cleared by using Dormia baskets or retrieval balloon catheters. Mechanical lithotripsy was performed before extraction when the stones were greater than 8 mm in diameter. In 81 patients, the dilated orifice was irrigated with 40-120 mL (50 +/- 37 mL) of 1:1,000,000 epinephrine (epinephrine group). In the remaining 92 patients, epinephrine irrigation was not performed (control group). Acute pancreatitis was defined by a serum amylase concentration fivefold greater than the upper limits of normal in association with abdominal pain. RESULTS: After EBS, serum amylase concentrations were significantly increased in both groups. However, the degree of hyperamylasemia was less in the epinephrine group than in the control group (617 +/- 611 vs 1037 +/- 1491 IU/L, P < 0.05). The incidence of pancreatitis was lower in the epinephrine group than in the control group (1.2 vs 7.6%, P < 0.05). CONCLUSIONS: Epinephrine irrigation is a simple and useful method to prevent post-EBS pancreatic damage and pancreatitis.

Adult↗
PubMed2001

Intraductal ultrasonography for hepatocellular carcinoma with tumor thrombi in the bile duct: comparison with polypoid cholangiocarcinoma.

BACKGROUND AND AIM: Tumor thrombi in the bile duct caused by hepatocellular carcinoma (HCC), and cholangiocarcinoma show polypoid lesions on cholangiographic findings. This study prospectively compared the images of intraductal ultrasonography between HCC and polypoid cholangiocarcinoma. METHODS: In five patients with tumor thrombi in the bile duct caused by HCC, a 2.0 mm diameter ultrasonic probe with a frequency of 20 MHz was inserted into the bile duct via the transpapillary route (n = 4) or the transhepatic route (n = 1). The images were compared to that of 65 patients with cholangiocarcinoma. RESULTS: In all patients with HCC, intraductal ultrasonography showed a 'polypoid tumor with a narrow base'. In 16 of 65 patients with cholangiocarcinoma, it showed a 'polypoid tumor with a narrow base'. When intraductal ultrasonography showed a 'polypoid tumor with a narrow base', the findings of a positive 'nodule within a nodule' (40 vs 0%; P < 0.05), and the absence of a 'papillary-surface pattern' (80 vs 13%; P < 0.05) were more highly associated with tumor thrombi caused by HCC than to polypoid-type cholangiocarcinoma. CONCLUSIONS: Intraductal ultrasonography was useful to distinguish between tumor thrombi caused by HCC and polypoid-type cholangiocarcinoma.

Aged↗
PubMed2001

p53 expression in the gastric mucosa before and after eradication of Helicobacter pylori.

BACKGROUND: Accumulation of p53 has been recognized in the gastric mucosa infected with Helicobacter pylori. We investigated the prevalence of p53-positive cells in the gastric mucosa before and one month after eradication of H. pylori and the relationship between p53 positivity and inflammation and cell proliferation. METHODS: The subjects included 24 H. pylori-positive patients. They achieved eradication one month after anti-H. pylori therapy. Biopsies were taken from the greater curvatures of the antrum and middle body. H. pylori status was assessed using culture and tissue section (Giemsa stain). Serial sections were used for examination of gastritis (hematoxylin and eosin stain) and for immunostaining of p53, Ki-67 and myeloperoxidase (MPO). p53 index and Ki-67 labeling index (LI) were calculated by counting p53-positive and Ki-67-positive cells in the entire gastric pits longitudinally sectioned and expressing them as a percentage of the total cells in a gastric pit. In the neck regions with and without p53-positive cells, polymorphonuclear leukocytes (PMNs) were counted in the corresponding area (/50 x 50 microm2) of the sections stained both with p53 and MPO. RESULTS: p53-positive cells decreased significantly after eradication of H. pylori. Before eradication, the number of PMNs was significantly higher in the neck regions with p53-positive cells than in those without. CONCLUSIONS: In the gastric mucosa infected with H. pylori, p53-positive cells were found in the neck region infiltrated with PMNs. p53 expression decreased significantly one month after eradication of H. pylori.

Adult↗
PubMed2001

Modes of secretagogue-induced [Ca(2+)](i) responses in individual chromaffin cells of the perfused rat adrenal medulla.

Chromaffin cells in the perfused rat adrenal medulla were loaded with indo-1 for confocal image analyses. Resting levels of [Ca(2+)](i) in chromaffin cells were similar and were stable with time. This is in contrast to the situation in isolated rat chromaffin cells, in which spontaneous oscillations of [Ca(2+)](i) are known to occur. When chromaffin cells were stimulated for 3-4 min by high K(+) or nicotine, [Ca(2+)](i) increased to a peak in 20-30 s and then declined rather smoothly. In contrast, chromaffin cells stimulated by muscarine or low pH (6.5) commonly exhibited irregular oscillations in [Ca(2+)](i). This provides additional evidence supporting the previous claim that muscarine and low pH evoke catecholamine secretion using partly shared mechanisms. Although muscarine and low pH were speculated to produce weaker responses in noradrenaline-secreting cells due to their selective stimulation of adrenaline secretion, no clear indications for segregation of cell types from [Ca(2+)](i) responses to these stimulants were found. The perfused adrenal medulla loaded with Indo-1 was also employed for simultaneously monitoring integrated changes in [Ca(2+)](i)(Ca responses) by conventional microfluorometry and in catecholamine secretion from a whole medulla (secretory responses). When the profiles of secretory responses were approximated by the kth power of the profiles of Ca responses, the k-values were estimated to be 2.2 and 2.3 for high-K(+)- and nicotine-elicited responses, respectively, whereas a k-value of 1.4 was obtained for both muscarine- and low-pH-elicited responses. An analysis showed that the significant difference in the k-value with these two classes of stimulants is accounted for by the stimulant-dependent patterns of [Ca(2+)](i) responses found in confocal image analysis.

Adrenal Medulla↗
PubMed2001

Endoscopic partial resection of a duodenal duplication cyst.

A case of symptomatic duodenal duplication cyst is reported. The patient underwent endoscopic partial resection of the cystic wall using the O-ring ligation kit. After resection, the abdominal pain disappeared. Endoscopic partial resection is useful for diagnosis and treatment of duodenal duplication cyst.

Adult↗
PubMed2001

Ropeway-type bile duct biopsy forceps with a side slit for a guidewire.

BACKGROUND: Transpapillary procurement of bile duct biopsy specimens is an effective diagnostic technique in cases of biliary structure. The utility of new ropeway-type bile duct biopsy forceps with a side slit for a guidewire was investigated in this study. METHODS: The 12 patients in this study had bile duct cancer (n = 3), cancer of the head of the pancreas (n = 4), gallbladder cancer (n = 1), and benign bile duct stenosis (n = 4). After endoscopic retrograde cholangiography, a guidewire was placed in the bile duct across the stenosis. The new forceps (1.8-mm diameter clamshell-type biopsy forceps without needle) was then introduced through the intact papilla along the guidewire. RESULTS: In all patients, sufficient tissue for histopathologic evaluation was obtained without complication. In one patient, biopsy specimens were selectively obtained of the left hepatic duct, which was impossible with conventional forceps. In another patient, histologic examination of specimens obtained by using this new forceps showed adenocarcinoma, whereas specimens obtained with a conventional forceps did not contain adenocarcinoma. However, in another patient, biopsy specimens obtained with a conventional forceps contained adenocarcinoma that was not evident in specimens obtained with the new forceps. Dislodgement of the guidewire during procurement of biopsy specimens occurred in 1 patient. In the other 11 patients, an endoscopic biliary drain was inserted over the guidewire. CONCLUSION: The new ropeway-type biopsy forceps is useful for selectively obtaining biopsy specimens of the bile duct. With this system, access for subsequent endoscopic biliary drainage is maintained.

Aged↗
PubMed2001

Cardiovascular response to epinephrine-containing local anesthesia in patients with cardiovascular disease.

OBJECTIVE: The purpose of the present study was to examine the safety of epinephrine-containing local anesthesia for use on patients with cardiovascular disease. STUDY DESIGN: Twenty-seven patients with cardiovascular disease were studied. The cardiac functional capacity of 9 patients was New York Heart Association class I; 11, class II; and 7, class III. Hemodynamic responses to intraoral injection of 1.8 mL of 2% lidocaine with 1:80,000 epinephrine were measured with impedance cardiography. RESULTS: Systolic blood pressure and heart rate increased by 4.1% and 5.1%, respectively, immediately after the lidocaine-epinephrine injection. Consequently, rate pressure product increased by 10.0%. Cardiac index increased by 14.2%, and total peripheral resistance decreased by approximately 10%. No patient complained of cardiac symptoms. There were no significant differences in hemodynamic responses related to the extent of the cardiac functional capacity. CONCLUSION: We concluded that lidocaine-epinephrine was safe and had few, if any, hemodynamic consequences in patients with cardiovascular disease.

Aged↗
PubMed2001

Repair of denture base resin using woven metal and glass fiber: effect of methylene chloride pretreatment.

STATEMENT OF PROBLEM: A durable repairing system for denture base fracture is desired to avoid recurrent fracture. Purpose. This study evaluated the strength and modulus of elasticity of repaired acrylic specimens reinforced with various processes. MATERIAL AND METHODS: Transverse strength and modulus of elasticity of repaired acrylic denture base specimens were evaluated with a 3-point bending test and compared with a heat-polymerized control. Autopolymerizing acrylic resin was used with woven metal fiber and glass fiber with and without methylene chloride surface treatment (n = 6 per group). The specimens were cut in half and fixed in a metal mold to obtain a space for placing the repairing resin. A cavity was prepared when metal or glass fiber was used. All specimens were stored in 37 degrees C distilled water for 48 hours before the test. All data were statistically analyzed with 1-way ANOVA, and differences among groups were analyzed with Fisher test (P< or =.05). RESULTS: The mean value of the transverse strength for the control was 87.2 MPa. The specimens repaired by glass fiber with methylene chloride surface treatment exhibited the highest transverse strength (96.8 MPa), which was significantly higher than that of the control (P< or =.05). The elastic modulus of the specimens repaired by glass fiber with methylene chloride surface treatment (4189.3 MPa) was significantly greater than that of the control (2683.7 MPa) at a 95% level of confidence. The values of transverse strength and elastic modulus were highest when the surface treatment was combined with a reinforcing glass fiber. CONCLUSION: Reinforcement with glass fiber and methylene chloride pretreatment produced transverse strength and a modulus of elasticity higher than the control.

Acrylic Resins↗
PubMed2001

The anesthetic management of a patient with hemoglobin M(Iwate).

IMPLICATIONS: Pulse oximetry is now considered essential for anesthetic management. We treated a patient with hemoglobin M(Iwate), a rare inheritable hemoglobinopathy rendering pulse oximetry completely useless because of its anomalous absorption spectrum.

Anesthesia, General↗