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Biomedical subjects

M Ryu

Publications and source records attributed to M Ryu.

At least 19 recordsLinked to original sources

SNCA multiplication is not a common cause of Parkinson disease or dementia with Lewy bodies.

The authors recently have shown that triplication of the alpha-synuclein gene (SNCA) can cause Parkinson disease (PD) and diffuse Lewy body disease within the same kindred. The authors assessed 101 familial PD probands, 325 sporadic PD cases, 65 patients with dementia with Lewy bodies, and 366 neurologically normal control subjects for SNCA multiplication. The authors did not identify any subjects with multiplication of SNCA and conclude this mutation is a rare cause of disease.

Adult↗

Lidocaine-metabolizing activity after warm ischemia and reperfusion of the rat liver in vivo.

The effect of warm ischemia on lidocaine-metabolizing activity was examined in vivo. Total liver ischemia was produced for 1 hr in Sprague-Dawley rats by clamping the portal vein and hepatic artery at the hilum. Livers were then reperfused, and liver microsomes were prepared before and 0, 2, 6, and 24 hr, and 3, 6, and 10 days after reperfusion. Microsomal lidocaine-metabolizing activity and cytochrome P-450 content were examined. Lidocaine N-deethylase activity was decreased from 2.25 +/- 0.33 to 0.97 +/- 0.21 nmol/mg protein/min (mean +/- SD) 24 hr after reperfusion. This inhibition was prolonged, and activity gradually recovered after 10 days. The cytochrome P-450 content showed the same tendency. On the other hand, serum levels of alanine aminotransferase increased significantly 2 hr after reperfusion and returned to control levels 3 days after reperfusion. Liver blood flow recovered rapidly after unclamping and reached baseline levels within 6 hr. Our results suggest that after warm ischemia, prolonged hepatic dysfunction in drug metabolism, which cannot be detected by evaluating serum enzymes or liver blood flow, exists at the microsomal level.

Alanine Transaminase↗

Distal pancreatectomy with resection of the celiac axis and reconstruction of the hepatic artery for carcinoma of the body and tail of the pancreas.

Distal pancreatectomy with resection of the celiac axis can increase resectability of carcinoma of the body and tail of the pancreas. We performed reconstruction of the hepatic artery to avoid complications caused by a decrease in hepatic arterial flow. We carried out distal pancreatectomy with resection of the celiac axis for carcinoma of the body and tail of the pancreas in four patients. When pulsation in the proper hepatic artery was weak after occlusion of the celiac axis, we performed reconstruction of the hepatic artery, using the splenic artery, which had been taken beforehand from the resected specimen. In two patients, we performed reconstruction of the hepatic artery. These two patients underwent reconstruction of the portal vein combined with prolonged clamping of the portal vein. Levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were elevated just after the operation, but recovered to normal levels within 10 days. No complications related to hepatic ischemia were observed. These results suggested that reconstruction of the hepatic artery allowed us to safely perform distal pancreatectomy with resection of the celiac axis for carcinoma of the body and tail of the pancreas.

Aged↗

Epithelioid hemangioendothelioma of the liver.

Epithelioid hemangioendothelioma (EH) of the liver is a rare tumor and is difficult to differentiate from cholangiocellular carcinoma or metastatic liver tumor on image diagnosis. A case of curatively resected EH of the liver is reported. A 48-year-old woman was admitted because she had a mass in the liver. Cholangiocellular carcinoma was suspected preoperatively. Right trisegmentectomy of the liver, combined with bile duct resection and portal vein resection and reconstruction, was performed. Characteristic macro- and microscopic findings of the resected specimen revealed EH of the liver. The patient has survived for more than 6 years without recurrence. Because of the tendency of EH of the liver to appear in multiple or scattered forms, only 12 cases of resection for EH have been reported.

Female↗

Intrahepatic inflow areas of the drainage vein of the gallbladder: analysis by angio-CT.

BACKGROUND: The drainage veins of the gallbladder (cystic veins) are important hepatic metastatic routes of gallbladder cancer. We studied the cystic vein inflow portions of the intrahepatic vessels by computed tomography during angiography (angio-CT). METHODS: The subjects were 27 unoperated pancreatic-biliary patients. After superselective catheterization of the cystic artery, angio-CT was performed, and cystic veins and sinusoidal filling were visualized. We identified the cystic vein inflow routes and the vessels they fed. RESULTS: We found 72 cystic veins in 26 patients. All cystic veins flowed into the intrahepatic portal branches or sinusoids. The cystic veins took either of two routes: one into the liver through the hepatic hilum (17 patients, 21 veins), taken mainly by the portal branch for subsegment 4a (P4a), the anterior portal branch, and the umbilical portion of the portal branch; and the other through the hepatic bed (23 patients, 51 veins), taken mainly by S4a sinusoid, S5 sinusoid, P4a, and P5. CONCLUSIONS: Angio-CT is useful for detecting the cystic vein inflow portions of the intrahepatic vessels. It makes possible identification of areas where there is a possibility for micrometastasis of the gallbladder cancer.

Adult↗

Anatomy of the right anterosuperior area (segment 8) of the liver: evaluation with helical CT during arterial portography.

PURPOSE: To evaluate the segmental anatomy of the right anterosuperior area (segment 8) of the liver by using helical computed tomography during arterial portography (CTAP). MATERIALS AND METHODS: Twenty-seven patients without lesions at segment 8 underwent helical CTAP. Three-dimensional portograms were reconstructed to verify the course of the portal veins. The number of subsegmental branches, in addition to the branching point and the distribution in segment 8, was assessed. RESULTS: In 25 (93%) patients, the dorsal branch of segment 8 gave rise to dorsally directed branches posterior to the right hepatic vein. In only four (25%) of 16 patients in whom the medial branch of segment 8 arose near the porta hepatis, the long paracaval portal branch of the caudate lobe extended upward above the interval between the middle and right hepatic veins. CONCLUSION: In most of the patients, the dorsal branches of segment 8 supplied the dorsocranial area of the right lobe posterior to the right hepatic vein. The paracaval portion of the caudate lobe was limited to below the interval between the middle and right hepatic veins in the majority of patients who showed medial branches of segment 8 arising near the porta hepatis. Recognition of this vascular anatomy is clinically important for preoperative evaluation of hepatic tumors in segment 8 because it may contribute to a safer surgical approach.

Adult↗

Comparison of CT findings with resected specimens after chemoembolization with iodized oil for hepatocellular carcinoma.

OBJECTIVE: We assessed the role of dynamic CT in the evaluation of the efficacy of transarterial chemoembolization with iodized oil for hepatocellular carcinoma. MATERIALS AND METHODS: We examined 41 hepatocellular carcinoma lesions (mean diameter, 5.0 cm) in 40 patients (mean age, 60.6 years) who underwent transarterial injection of iodized oil alone (n = 3) or emulsion of iodized oil and doxorubicin hydrochloride (n = 10) followed by gelatin sponge particles (n = 27) and subsequent hepatectomy. On dynamic CT performed within 3 weeks before oily transarterial chemoembolization and within 4 weeks before surgery, we calculated the rate of necrosis on the basis of the assumption that the portion that retained iodized oil represented necrosis. We also calculated the reduction rate of the tumor. CT findings were compared with pathologic findings of resected specimens. RESULTS: Pathologic specimens and the necrosis rate measured on CT showed a good correlation (r = 0.83) when the portion of tumor that retained iodized oil was considered necrosis. No correlation existed if the portion that retained iodized oil was considered viable. We noted no significant correlation (r = 0.38) between the reduction rate of the tumor and necrosis rate. Also, we noted no correlation (r = 0.52) between the interval between transarterial oily chemoembolization and surgery and the reduction rate of the tumor. CONCLUSION: CT is suitable for the evaluation of the efficacy of oily chemoembolization for hepatocellular carcinoma on the basis of the assumption that the portion of tumor that retains iodized oil is necrotic. The rate of tumor size reduction measured on CT did not correlate with the therapeutic effect of chemoembolization.

Aged↗

Microsomal cytochrome P-450 monooxygenase system and its drug-metabolizing activity after partial portal vein ligation in the Rat.

Percutaneous transhepatic portal vein embolization (PTPE) has been used to decrease the risk of hepatic failure after hepatectomy in patients with poor liver function. The effect of PTPE on hepatic drug-metabolizing activities is not clear. Therefore we examined the effect of portal vein branch ligation, a model of PTPE, on hepatic drug-metabolizing activities in Sprague-Dawley rats. Ligated and nonligated lobes were harvested separately. Drug-metabolizing activities and concentrations of components of the microsomal cytochrome P-450 monooxygenase system were examined. In ligated lobes, drug-metabolizing activities (lidocaine and aminopyrine) and enzymatic concentrations of the microsomal cytochrome P-450 monooxygenase system gradually decreased over 10 days. In nonligated lobes these functions were depressed rapidly to 60% of those before PBL but then recovered 10 days after PBL. From the viewpoint of drug metabolism, hepatic dysfunction occurred in both ligated and nonligated lobes.

Aminopyrine↗

The histological basis of detection of adenoma and cancer in the colon by autofluorescence endoscopic imaging.

BACKGROUND AND STUDY AIMS: The reason for the difference in fluorescence between normal and diseased tissues (carcinoma and adenoma) in the colon observed on autofluorescence endoscopy is unclear, flavins, NADPH and collagen being regarded as possible major sources of fluorescence. The purpose of this study was to identify the reason for this difference in fluorescence. PATIENTS AND METHODS: Samples of human colonic tissues (adenoma: n = 6, cancer: n = 11, normal: n = 11) were obtained from resected specimens. The flavin content of human colonic tissue was measured by high performance liquid chromatography. Fluorescence microscopy under blue light excitation (400-440 nm) was performed using frozen sections of normal, adenomatous and cancerous tissues, and examining them for the presence and characteristics of fluorescence. RESULTS: The flavin content of normal and diseased tissue was not significantly different. Fluorescence microscopy of normal colonic tissue revealed strong fluorescence in the submucosal layer, which corresponded to collagen. Tissue fluorescence did not decrease in reducing agent or acid solution. No difference in fluorescence was detected in normal mucosa, adenoma or cancerous tissue on fluorescence microscopy. These findings indicate that flavins and NADPH do not affect tissue fluorescence, and that submucosal collagen is the main source of tissue fluorescence in the colon. CONCLUSION: The reason for the decreased fluorescence in diseased tissues appears to be a decrease in collagen fluorescence due to the screening effect of mucosal thickening or replacement of submucosa by cancer cells.

Adenoma↗

Clinical significance of magnetic resonance cholangiopancreatography for the diagnosis of cystic tumor of the pancreas compared with endoscopic retrograde cholangiopancreatography and computed tomography.

BACKGROUND: Cystic tumor of the pancreas has been investigated by a variety of imaging techniques. Magnetic resonance cholangiopancreatography (MRCP) is being widely used as a non-invasive diagnostic modality for investigation of the biliary tree and pancreatic duct system. The purpose of this study was to compare MRCP images with those of endoscopic retrograde cholangiopancreatography (ERCP) and computed tomography (CT) in order to clarify the diagnostic efficacy of MRCP for cystic tumor of the pancreas. METHODS: We retrospectively studied 15 patients with cystic tumor of the pancreas that had been surgically resected and histopathologically confirmed. There were five cases of intraductal papillary adenocarcinoma, five of intraductal papillary adenoma, two of serous cyst adenoma, two of retention cyst associated with invasive ductal adenocarcinoma and one of solid cystic tumor. RESULTS: In all cases MRCP correctly identified the main pancreatic duct (MPD) and showed the entire cystic tumor and the communication between the tumor and the MPD. On the other hand, the detection rate by ERCP of the cystic tumor and the communication between the cystic tumor and the MPD was only 60%. Although the detection rates by CT for the septum and solid components inside the cystic tumor were 100 and 90.0%, respectively, those of MRCP for each were 58.3 and 20.0%. CONCLUSION: MRCP is capable of providing diagnostic information superior to ERCP for the diagnosis of cystic tumor of the pancreas. Although MRCP may provide complementary information about the whole lesion of interest, the characteristic internal features of cystic tumor of the pancrease should be carefully diagnosed in combination with CT.

Adenocarcinoma↗

Computed tomography under endoscopic retrograde pancreatography (ERP-CT) to investigate the drainage area of the pancreatic head.

The aim of this study was to evaluate the drainage area of the pancreatic head with computed tomography under endoscopic retrograde pancreatography (ERP-CT). ERP-CT was performed in 26 patients without lesions of the pancreatic head. By comparing ERP-CT images with ERP images, we evaluated the drainage area of the inferior branch of the pancreatic head. In 77% of these cases, the drainage function of Santorini's duct system (including the accessory papilla) was impaired. In 13 cases with the normal duct pattern, all inferior branches from Santorini's duct drained the anterior inferior area and all inferior branches from Wirsung's duct drained the posterior inferior area. In six cases with an ansa-type duct pattern, all inferior branches from Wirsung's duct drained the posterior inferior area, and inferior branches from Santorini's duct were divided into branches draining the anterior inferior area and branches draining the posterior inferior area. ERP-CT is a useful method for evaluating the three-dimensional anatomic variations of the pancreatic duct.

Aged↗

Hepatectomy with microwave tissue coagulation for hepatocellular carcinoma.

From 1984 through 1994, 99 consecutive patients with hepatocellular carcinoma (HCC) underwent hepa-tectomy with microwave tissue coagulation (MTC). We performed limited resection (Hr0) in 28 patients, subsegmentectomy (HrS) in 25 patients, segmentectomy (Hr1) in 21 patients, and lobectomy or extended lobectomy (Hr2) in 25 patients. The patients were divided into two groups: group A, 86 patients with tumors smaller than 1 kg and no tumor thrombi in the main portal trunk; and group B, 13 patients with a tumor 1 kg or larger, or with macroscopic tumor thrombi in the main portal trunk. In group A, mean blood loss was 838 ml for Hr0, 1948 ml for HrS, 1765 ml for Hr1, and 1325 ml for Hr2. The mean operative time in group A ranged from 3 h 43 min for Hr0 to 4 h 57 min for Hr2. In group B, the mean operative time was 6 h 3 min and mean blood loss was 6053 ml. Our MTC method was associated with an in-hospital mortality rate of 3% and a major complication rate of 13.1%. The 5-year survival and disease-free survival rates were 43.4% and 25.4%, respectively. The 5-year survival rate of patients without portal tumor thrombi (50.9%) was significantly better than that of patients with portal tumor thrombi (11.9%) (P < 0.001). The 5-year survival rate of patients who underwent curative resection (58.1%) was significantly better than that of patients who underwent noncurative resection (22.9%) (P < 0.001). The 5-year survival rates of patients in group A without portal tumor thrombi did not differ between those who had cancer-negative margins (54.0%) and those with cancerpositive margins (49.6%) at resection. Recurrence and local recurrence rates did not differ in patients with cancer-positive margins (63.6% and 7.3%, respectively) and patients with cancer-negative margins (56.5% and 8.7%, respectively). These results suggested that microscopic residual cancer in the resected margin was coagulated by MTC. Blood loss, operative time, and clinical outcome in this series of 99 consecutive hepatectomies were comparable with values in earlier reports in which such hemostatic methods as the Pringle maneuver were used. We conclude that hepatectomy with MTC is useful and safe and produces consistent results.

Adult↗

Peroral pancreatoscopy for the diagnosis of pancreatic diseases.

The efficacy associated with peroral pancreatoscopy to diagnose and differentiate pancreatic diseases is herein reviewed and clarified, and problems with this modality are discussed. Three types of pancreatoscopes are presently available: (a) a thin fiberscope with a diameter of 3.3 or 4.5 mm, which has an angulation system and a forceps channel; (b) an ultrathin pancreatoscope with a diameter of 0.75 or 0.8 mm, which can be inserted via an ordinary endoscopic retrograde cholangiopancreatography (ERCP) cannula without endoscopic sphincterotomy; and (c) an ultrathin pancreatoscope combined with a catheter that has an outer diameter of 1.67 mm. Peroral pancreatoscopy facilitates the detection of small lesions of the duct in malignancy or chronic pancreatitis. In particular, it is quite useful in differentiating pancreatic cancer from chronic pancreatitis in cases with local stenosis or elevated lesions of the main pancreatic duct. Among patients with a mucus-producing tumor of the pancreas, pancreatoscopy is also very useful, especially in determining lesion extent. Despite some unresolved problems, we predict that pancreatoscopy will retain a limited or specific and definite role in diagnostic and therapeutic endoscopy for pancreatic diseases.

Endoscopy, Digestive System↗

Stomach-preserving gastric bypass for unresectable pancreatic cancer.

From 1992 to 1995, we treated 25 patients who had unresectable pancreatic cancer with a stomach-preserving gastric bypass (SPGB). After as much of the stomach as possible was preserved, it was bypassed to the jejunum by end-to-side anastomosis. During the same period, five patients underwent other types of bypasses while 47 similar patients did not undergo gastric bypass. Although the mean operative time for SPGB was significantly longer than for other types of bypass, the mean intraoperative blood loss was similar. Operative morbidity with SPGB was 28%, and there were no operative deaths. In patients undergoing SPGB, the incidence of delayed gastric emptying was high (24%), but the comfort index (ratio of duration of good palliation to duration of survival) exceeded 50% when metastases were either regional or systemic but limited. The comfort index of patients undergoing other types of bypass or not undergoing bypass was less than 40%. However, the patients with extensive systemic metastases survived less than 100 days and the comfort index was less than 30% for all treatment groups. Our results thus suggest that SPGB is safe and effective for patients with either regional metastases or limited systemic metastases.

Cholestasis↗

Comparison of clinical features and survival in patients with hepatitis B and C virus-related hepatocellular carcinoma.

We analyzed the clinical characteristics and survival of 185 patients with hepatitis B virus-related hepatocellular carcinoma (HBV group) and 1033 with hepatitis C virus-related hepatocellular carcinoma (HCV group) by multi center study. The patients in the HBV group (mean age 52.1 yr) were about 10 years younger than those in the HCV group (mean age 62.9 yr). Liver function, as measured by indocyanine green retention at 15 min, was better in the HBV group (17.5%) than in the HCV group (25.4%). A higher proportion of the HBV group (55%) than the HCV group (44%) had clinical stage I, T-factor differed significantly between the groups: 53% of the HBV group were T3-4 compared with 41% of the HCV group. Furthermore, a higher proportion of the HBV group were graded 2-3 for tumor thrombus in the portal vein (20.3%) and had poorly differentiated hepatocellular carcinoma (7%) compared with the HCV group (7.1% and 5% respectively). Univariate analysis identified poor prognostic factors for hepatocellular carcinoma as HBV, age < or = 50 yr, clinical stage II-III, a high AFP level, higher number of tumors, larger tumor size, tumor thrombus in the portal vein 2-3 and in the hepatic vein 2-3. On multivariate analysis, poor prognostic factors were a high AFP level, higher number of tumors, tumor thrombus in the portal vein 2-3 and in the hepatic vein 2-3, but not HBV, age, clinical stage or tumor size. These results suggest that HBV itself is not a stronger prognostic factor than HCV.

Aged↗

Therapeutic results of resection, transcatheter arterial embolization and percutaneous transhepatic ethanol injection in 3225 patients with hepatocellular carcinoma: a retrospective multicenter study.

The outcome in 3225 patients with hepatocellular carcinoma (HCC) was studied in groups with equivalent prognosis treated with resection, transcatheter arterial embolization (TAE), and percutaneous transhepatic ethanol injection (PEI). Significant factors for better clinical background included a tumor diameter of < or = 30 mm, tumor number < or = 3 and (clinical) Stage I. In patients with Stage I disease having tumors of < or = 30 mm and < or = 3 in number, survival afer resection and PEI did not differ, while survival after TAE was significantly worse. In those patients with Stage II disease, survival after PEI was significantly better than after resection or TAE. In patients with Stage I or II disease having tumors > or = 31 in size and < or = 3 number, survival after resection was significantly better than after TAE. In patients with Stage I disease having tumors of > or = 31 mm and > or = 4 in number, survival after resection was significantly better than after TAE. Our conclusions are as follows. Firstly, resection or PEI is recommended for patients with Stage I disease having < or = 3 tumors all < or = 30 mm in size. Secondly, PEI is recommended for patients with Stage II disease having < or = 3 tumors all < or = 30 mm in size. Thirdly, for patients with Stage I disease having tumors 31 mm or larger in size, whatever the number of tumors, resection should be selected rather than TAE.

Adolescent↗