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Biomedical subjects

Y Muto

Publications and source records attributed to Y Muto.

At least 577 records · Page 32Linked to original sources
PubMedDate not supplied

Mucosa-associated lymphoid tissue (MALT) of the gallbladder: a clinicopathological correlation.

OBJECTIVE: Lymph follicles are frequently found on histological examination of a surgically removed gallbladder. The significance of these lymph follicles is not clearly understood. The aim of this study was to examine the clinicopathological correlation between the lymph follicles in the gallbladder morphologically and the mucosa-associated lymphoid tissue (MALT) in the gut. METHODS: The gallbladders were fixed and cut serially. The tissue slices were processed in the routine manner for a histological examination. The histological criteria for MALT in this study was defined as the presence of lymph follicles with germinal centers in the lamina propria mucosae in approximately equal numbers in all portions of the gallbladders from the neck to the fundus. Biliary bile obtained at surgery was cultured for a bacteriological examination in the hospital laboratory. The types of gallstones were classified according to the Classification of Gallstones by the Japanese Society of Gastroenterology. RESULTS: Of the 1341 patients, 158 (11.8%) patients fulfilled the histological criteria, including 64 men and 94 women with an average age of 64.2 years. Gallstones were present in 89.2% of the patients, and 74.5% of these were calcium bilirubinate gallstones. Cultures of the bile were positive in 95.4% of the patients. A variety of bacterial species were thus found, most commonly Escherichia coli and Klebsiella spp. Grossly, the gallbladders usually showed a granular appearance of the mucosa. CONCLUSION: The MALT in the gallbladder is not a rare condition and is frequently encountered in clinical practice. This lymphoid tissue may represent a mucosal and morphological immune phenomenon for infection rather than a substrate for the development of low-grade B-cell lymphoma.

Adult↗
PubMedDate not supplied

Percutaneous transhepatic cholangioscopic lithotripsy and change of biliary manometry patterns.

BACKGROUND/AIMS: Percutaneous transhepatic cholangioscopic lithotripsy (PTCSL) is used to remove bile duct stones. This work aims to evaluate the clinical usefulness of PTCSL and the reversibility of the terminal bile duct dysfunctions after PTCSL. METHODOLOGY: Thirty patients who underwent PTCSL using mechanical and/or electrohydraulic lithotripsy over the past 10 years (20 patients with common bile duct stones and 10 with intrahepatic bile duct stones) were evaluated. Terminal bile ductal pressure was measured using the percutaneous transhepatic biliary drainage (PTBD) tube prior to and after lithotripsy by means of variable-load cholangiomanometry. RESULTS: Complete stone extraction was possible in 26 patients (86.7%). The other 4 patients had intrahepatic stones. Complications included 2 cases of hemobilia, one of pneumonia, and 3 of localized peritonitis. Of 26 patients without residual stones, only 4 patients had a linear pressure flow (P-F) pattern which indicates normal biliary tract function prior to lithotripsy. In 17 of 22 patients with other type P-F patterns, however, these types also changed to a linear pattern after complete removal of stones. The P-F pattern of the other 5 patients remained unchanged. CONCLUSIONS: PTCSL is a safe and efficient method treating biliary tract lesions while preserving the function of the sphincter of Oddi. The terminal biliary tract function normalized after stone removal. Thus, PTCSL was useful for patients with complicated bile duct stones not accessible to endoscopic retrograde management.

Bile Ducts↗
PubMedDate not supplied

Vascular reconstruction of the hepatic artery using the gastroepiploic artery: a case report.

A 59 year-old woman with obstructive jaundice secondary to proximal bile duct carcinoma underwent percutaneous transhepatic biliary drainage (PTDB). This revealed complete obstruction of the bifurcation of the hilar hepatic duct and encasement of the right hepatic artery. Wedged hilar hepatectomy with combined resection of the extrahepatic bile duct, gallbladder, and the encased right hepatic artery was performed. The hepatic artery was reconstructed using an in situ right gastroepiploic artery (GEA) pedicle graft. The anastomosis was protected with fatty tissue from the greater omentum. This technique can be used to reconstruct the hepatic artery after radical surgery for malignant hepatobiliary and pancreatic disease.

Arteries↗
PubMedDate not supplied

Extracorporeal bypass using a centrifugal pump during resection of malignant liver tumors.

BACKGROUND/AIMS: Total hepatic vascular exclusion (THVE) during extracorporeal bypass is used for hepatic resection in patients with malignant liver tumors. The aim of this study was to determine the efficacy of hepatectomy during total hepatic vascular exclusion using a centrifugal pump (Bio-pump). METHODOLOGY: Fourteen patients with malignant liver tumors who underwent hepatectomy during total hepatic vascular exclusion using the Bio-pump were studied retrospectively. RESULTS: In 3 of 14 patients, insufficient hepatic vascular exclusion was achieved. Six patients underwent tumor resection during total hepatic vascular exclusion, without extracorporeal bypass. In the remaining 5 patients, flow exclusion averaging 1500 ml was achieved with the Bio-pump, and hepatectomy was performed during the procedure. In these 5 patients, the mean operative time and blood loss were 11 hours 38 minutes and 6850 +/- 2451 ml. The Bio-pump bypass time, the excluded blood flow and the mean blood pressure were 82 minutes, 1650 ml and 108/53 mmHg, respectively. The arterial ketone body ratio (AKBR) decreased from a pre-operative value of 1.85-0.32 during total hepatic vascular exclusion. CONCLUSIONS: Total hepatic vascular exclusion was useful for hepatectomy in patients with tumor invasion into the hepatic vein and inferior vena cava, or tumor thrombus in the inferior vena cava and right atrium. However, this technique did not decrease blood loss or improve outcome in patients undergoing hepatectomy.

Aged↗
PubMedDate not supplied

Results of retrograde transhepatic biliary drainage after a common bile duct exploration for choledocholithiasis.

BACKGROUND/AIMS: The purpose of this study is to assess the benefits of retrograde transhepatic biliary drainage (RTBD) and a primary closure after a common bile duct (CBD) exploration for patients with choledocholithiasis. METHODOLOGY: We analyzed 143 patients with choledocholithiasis who had been managed by RTBD after undergoing a CBD exploration retrospectively over a 12-year period. The main outcome criteria were frequency of occurrence of post-operative complications which needed a relaparotomy and the clinical long-term results. In addition, the radiographic diameter changes of the CBD at the site of the primary closure and liver function tests after RTBD were also evaluated. RESULTS: The frequency of bile peritonitis in the patients undergoing the RTBD procedure was only 0.7% (1 out of 143 cases). Cholangiography via the RTBD tube revealed no severe stenosis at the site of primary closure. Liver function returned to normal on day 3 after RTBD (p<0.05). Recurrence of common bile duct stones developed in 2 patients in this series during the follow-up (1-12 years). CONCLUSIONS: RTBD and a primary closure of the CBD after CBD exploration appears to be a clinically safe and effective method for such patients with choledocholithiasis who had undergone a complete stone removal intra-operatively.

Adult↗
PubMedDate not supplied

Pharmacokinetics of isolated hepatic perfusion with high dose tumor necrosis factor in rat model.

BACKGROUND: Although the application of an isolation procedure with tumor necrosis factor (TNF) to the liver is quite attractive, an animal model is not yet available to evaluate antitumor effects by TNF in isolated hepatic perfusion (IHP). To establish the rat model in IHP, the pharmacokinetics of TNF, both in a perfusate and in a systemic circuit should be examined. METHODS: All rats underwent IHP with TNF. After a 10 min perfusion, a washout procedure was performed for 5 min, after which isolation was terminated. Throughout the procedure and afterward, blood samples were obtained from the systemic blood and concentrations of TNF were assayed by L-929 cytotoxicity. RESULTS: After the administration of 240 micrograms of TNF in the circuit, TNF reached a plateau at about 12.7 micrograms/ml of perfusion fluid, lasting until the end of IHP. As a result of the washout procedure, regional TNF concentrations declined from 12.7 micrograms/ml to 1.5 micrograms/ml. At the beginning of the IHP, all rats exhibited no detectable level of TNF activity in the systemic circulation (< 100 pg/ml). With time, TNF plasma levels quickly increased to reach a plateau of about 0.2 microgram/ml at 15 min. Systemic leakage of TNF is calculated as less than 2% of the total TNF in perfusate during perfusion. CONCLUSION: Rat IHP models with TNF showed that systemic leakage of TNF was higher than that of pig models, although a large enough amount of TNF in perfusate was achieved without death. Rat models might be feasible to evaluate antitumor effect of IHP against liver metastatic tumors.

Animals↗
PubMedDate not supplied

Reduction of hepatotoxicity of tumor necrosis factor in isolated hepatic perfusion by administration of glucocorticoid as well as lipopolysaccharide.

BACKGROUND: The application of an isolation procedure with tumor necrosis factor (TNF) to the liver is quit attractive, however, one of problems to overcome is reducing the toxicity to the liver caused by high doses of TNF. MATERIALS AND METHODS: Rats underwent isolated hepatic perfusion (IHP) with TNF and pre-treatment of subcutaneous administration of dexamethasone (4 mg/kg) and/or intradermal administration of LPS (50 micrograms/rat). After a 10 min perfusion, a washout procedure was performed for 5 min, after which isolation was terminated. RESULTS: SD or Wister rats and F344 rats tolerated up to 120 mg/rat or 4 micrograms/rat, respectively. Dexamethasone and/or LPS was tolerated at 40 micrograms/rat of TNF in F344 rat and showed a significant reduction of hepatotoxicity, and indicated histologically the suppression of ballooning and of necrosis during and after perfusion by TNF. CONCLUSION: We propose new a protocol for IHP as follows: 1. the intradermal administration of LPS for protection against toxicity of TNF, 2. IHP with TNF-SAM2, a mutain of TNF-alpha, having less toxicity than conventional TNF-alpha, and 3. simultaneous perfusion with chemotherapeutic agents such as 5-fluorouracil (5-FU).

Adult↗
PubMedDate not supplied

Avoiding an overdiagnosis of pancreatic pseudocysts.

BACKGROUND/AIMS: Thirty-six cases of pancreatic pseudocysts were retrospectively analyzed, to evaluate the clinical features of the pseudocysts which could not be differentiated from the neoplastic cysts until laparotomy. METHODOLOGY: Thirty-one out of 36 cases were diagnosed correctly to be a pseudocyst, in which 10 cases (32.3%) were treated by surgery. Five out of 36 cases were diagnosed to be neoplastic pancreatic cysts (mucinous cystadenoma or cystadenocarcinoma in 4 cases, serous cystadenoma in 1) in which all cases were treated by surgery (100%). To determine the clinical factors contributing to a correct or false diagnosis of pseudocysts, 14 clinical objects were categorized into several factors and analyzed using a contingency table. RESULTS: The clinical factors, including a "history of pancreatitis" (P = 0.070), "upper abdominal pain" (P = 0.083), an "age of less than 42 years" (P = 0.070), and an "elevated serum amylase level on admission" (> or = 200 IU/L, P = 0.067) were all thought to be helpful in establishing a correct diagnosis of pancreatic pseudocyst. In the morphological studies of computed tomography and ultrasonography, "multicystic lesions" (P = 0.045) and "nodular or irregular thickening of the cyst wall" (P = 0.006) significantly mislead us into making a diagnosis of a neoplastic cyst. CONCLUSIONS: In conclusion, the morphological features of a multicystic pattern, with either nodular or irregular thickening of the cyst wall, also belong to the common features of the pancreatic pseudocysts. Since these features tended to be diagnosed as neoplastic, other clinical factors should thus be referred to, in a comprehensive manner, to establish a correct diagnosis of pancreatic pseudocyst.

Adult↗
PubMedDate not supplied

Long-term results of arterial reconstruction of lower extremities determined by flow waveform analysis.

Arterial reconstructions of the lower extremities were reviewed to assess the usefulness of flow waveform analysis. Six hundred and thirty-four arterial reconstructions were divided into two groups: a former (1965-1973) group of 218 reconstructions not assessed by flow waveform analysis and a recent (1974-1985) group of 416 reconstructions analyzed according to flow waveform. The cumulative patency rates of the former and the recent group at 5 years were as follows: aorto-femoral, 75.2% and 86.7% (P less than 0.05); femoral-distal, 34.6% and 61.5% (P less than 0.001); extra-anatomical, 63.6% and 80.2% (P = 0.06), respectively. Based on the various flow waveforms evidenced intraoperatively, the cumulative patency rate of cases in the recent group with type 0 and I flow waveform was compared to the rate of those with type II flow waveform. The cumulative patency rates at 5 years were as follows: aorto-femoral, 92% and 82.7% (P = 0.15); femoral-distal, 77.7% and 49.3% (P less than 0.001); extra-anatomical, 91.8% and 68.9% (P less than 0.05), respectively. These results indicate that intraoperative flow waveform analysis is a simple and useful indicator for predicting the long-term results of arterial reconstruction.

Arterial Occlusive Diseases↗
PubMedDate not supplied

Point, minute and small cancers of the stomach at the early developmental stage detected by improved chymotrypsin lavage method for diagnostic cytology.

The improved selective chymotrypsin lavage method under fluoroscopy for cytologic detection led to the discovery of 12 point or minute gastric cancer lesions of less than one cm maximum diameter among 420 patients. It is reported herein how tiny cancers of the stomach can be found by the method, and how valuable it is to employ morphologic criteria for correct identification of the individual atypical cells in these tiny gastric cancers.

Adult↗
PubMedDate not supplied

Aneurysm in a double velour knitted Dacron graft.

Double velour knitted Dacron grafts are currently used for aorto-iliac arterial reconstructions to increase encapsulation and enable rapid intimization of the grafts. Reports of an aneurysm arising in the body of a double velour knitted Dacron graft are rare. We experienced a case of aneurysm arising in the body of an innominate-abdominal aortic bypass graft four years after implantation. Microscopically, this focal aneurysm seemed to be related to a structural defect in the manufacturing process. We wish to stress that patients with implanted commercial Dacron prostheses should be carefully and regularly followed.

Adult↗
PubMedDate not supplied

Initial histopathology of the autovein graft in late occlusion after arterial reconstruction.

Five patients developed local stenosis of autologous vein grafts implanted for femoro-popliteal arterial occlusive lesions. This stenosis occurred in the vein grafts 2 months to 5 years after the initial operation. Histopathologic study revealed that the stenotic segments had a thickened intima with a prominent proliferation of smooth muscle cells associated with fibrous extracellular matrix. There were no findings showing deposition of mural thrombi, as has heretofore been reported. The intimal thickening due to excessive fibromuscular proliferative response of the vein graft may possibly play an important role in the development of late graft occlusion.

Adult↗
PubMedDate not supplied

Cytologic detection of small pancreaticoduodenal and biliary cancers in the early developmental stage.

Employing pancreozymin-secretin stimulation and percutaneous transhepatic cholangiographic aspiration, cytologic examination for pancreaticoduodenal and biliary tract cancers was carried out in 763 patients, with 47 of 61 cancers cytologically detected (79%). The cancers detected included seven minute or small cancers less than 1.0 cm in maximum diameter, all of which were successfully surgically extirpated. The results indicate that diagnostic cytology contributed to the detection of cancers in these anatomic sites at an early developmental stage.

Adult↗
PubMedDate not supplied

The use of intraoperative ultrasonography for detecting tumor extension in bile duct carcinoma.

UNLABELLED: The purpose of this study was to investigate the clinical feasibility of using intraoperative ultrasonography (IOUS) to detect tumor extension in bile duct carcinoma, especially longitudinal invasion along the bile ducts into either the hepatic parenchyma or adjacent hilar vessels. MATERIALS AND METHODS: The medical records of 14 patients with bile duct carcinoma who underwent surgical treatment at the First Department of Surgery, University of the Ryukyus, were retrospectively analyzed. All patients were examined by IOUS during the operation. The resected specimens were processed in order to compare the ultrasound images with the histological findings. RESULTS: The echo level of the primary lesion was not consistent. Specific echo patterns, such as a thickening of the echogenic layer (TEL) adjacent to the main tumor showing cancerous invasion, were observed in ten patients, 71.4% (nodular invasive 7, invasive 3) which were later confirmed by microscopic examinations and ultrasonic findings. The detection rate of TEL was 87.5% in nodular invasive type and 100% in invasive type, respectively. The TEL histologically coincided with a layer of fibrotic hypertrophy around the infiltrating tumor cells. The intramural invasion beyond the edge of TEL was detected in only 2 out of 11 patients. The accurate detection rate of the involvement of the portal vein and the hepatic artery by IOUS was 83.3% and 60%, respectively. Based on the above findings, IOUS is thus considered to be essential for evaluating tumor extension along the bile ducts, and also greatly helps in selection of the most appropriate operative procedure, especially in hilar cholangiocarcinoma.

Adult↗
PubMedDate not supplied

Villous adenoma of the gallbladder: a case report.

A 76-year-old female with villous adenoma of the gallbladder is herein reported. She presented complaining of upper abdominal pain for some months prior to admission. No tumor mass could be detected by transabdominal ultrasonography, but CT scan demonstrated a sessile tumor measuring some 2 cm in diameter. A simple cholecystectomy was thus performed. The resected gallbladder was filled with mucinous material, and showed a sessile tumor with finger-like processes in the fundus. Both the macro- and microscopical findings of the lesion were almost identical to a typical villous adenoma of the colon. Little information is available on villous adenoma of the gallbladder, because such cases are extremely rare. In this paper, is described e a rare villous adenoma lesion while paying special attention to the morphological findings.

Adenoma, Villous↗
PubMedDate not supplied

Urinary excretion of prostaglandins and renal function after hepatic resection.

BACKGROUND/AIMS: The leading postoperative complication associated with hepatic resection is the accumulation of fluid in the abdominal cavity, which usually develops approximately one week after surgery. This study was undertaken to investigate the role of renal prostaglandins in modulating renal sodium and water retention in patients who underwent hepatic resection. METHODS: Urinary excretion of thromboxane B2 and 6-keto-prostaglandin F1 alpha as well as renal function were investigated serially in 7 patients with hepatocellular carcinoma who underwent hepatic resection. We administered 60 mg of OKY 046, a selective thromboxane A2 synthetase inhibitor, for 6 hours by continuous drip infusion from the commencement of surgery. RESULTS: Urinary sodium excretion was reduced from 165 mEq/day pre-operatively to 73 mEq/day on postoperative day 6 (p = 0.0181), however, there was no decline in urinary osmorality. OKY 046 administration inhibited intrarenal thromboxane A2 production, on the other hand, it significantly increased the production of intrarenal prostaglandin I2 (from 147 +/- 19 to 6339 +/- 1861 pg/mg creatinine, p = 0.0017) on the day of surgery. The level of thromboxane A2 was significantly increased to 2440 +/- 1099 pg/mg creatinine (p = 0.006, vs. pre-operative value), whereas the level of prostaglandin 12 was significantly reduced to 687 +/- 163 pg/mg creatinine (p = 0.0181, vs. the value on the day of surgery) on postoperative day 6. CONCLUSIONS: Urinary thromboxane A2 synthesis might contribute to sodium and water retention after hepatic resection. These results suggest that combined use of OKY 046 and diuretics prevent ascites formation after hepatic resection.

6-Ketoprostaglandin F1 alpha↗