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Biomedical subjects

Y Nimura

Publications and source records attributed to Y Nimura.

At least 199 records · Page 11Linked to original sources
PubMed1996

Preoperative intrahepatic segmental cholangitis in patients with advanced carcinoma involving the hepatic hilus.

BACKGROUND: Major hepatic resection for biliary tract carcinoma continues to be a risky operation. In this study we examined the influence of preoperative intrahepatic segmental cholangitis on posthepatectomy mortality. METHODS: We analyzed retrospectively the clinical features of 118 patients who underwent liver resection including more than two segments for biliary tract carcinoma involving the hepatic hilus. RESULTS: Intrahepatic segmental cholangitis was encountered before operation in 22 cases. The morbidity and mortality rates for these patients were significantly higher than those of patients without preoperative cholangitis. Selective percutaneous transhepatic biliary drainage was performed before operation in 11 patients for segmental cholangitis. The morbidity rate of patients after hepatectomy was significantly lower than that of patients treated without percutaneous transhepatic biliary drainage. CONCLUSIONS: The presence of preoperative intrahepatic segmental cholangitis is a major prognostic factor in the outcome of major hepatic resection for biliary carcinoma. Selective percutaneous transhepatic biliary drainage for preoperative intrahepatic segmental cholangitis plays an important role in reducing complications after major hepatic resection.

Adult↗
PubMed1996

Urinary microalbumin as a marker for intermittent claudication.

OBJECTIVE: The urinary microalbumin concentration was analysed in patients with intermittent claudication in order to investigate its usefulness as a marker for intermittent claudication. MATERIALS AND METHODS: Urinary samples were collected prior to and following exercise in 15 patients with claudication. The patients walked on a treadmill as far as possible until they were stopped by pain. Urinary microalbumin concentration was measured by a latex agglutination system, and the result was considered abnormal when the concentration exceeded 10 mg/g creatinine. The ankle brachial pressure index (ABI) at rest and the time taken for the ankle pressure to return to the resting level following exercise (ABI recovery time) also were measured. RESULTS: In seven (47%) of the patients, the urinary microalbumin concentration was elevated to more than 10 mg/g creatinine following exercise, while in eight (53%) it remained normal. The ABI recovery time was significantly longer in the patients in whom the microalbumin concentration was elevated, compared to that in patients without an elevated concentration. The urinary microalbumin concentration following exercise was reduced significantly when the walking distance was decreased 50% or 15%. Following vascular bypass surgery, the elevation in urinary microalbumin concentration was reduced. CONCLUSIONS: The use of urinary microalbumin as a diagnostic marker for intermittent claudication is limited. However, in cases where the concentration is elevated, it can be used to follow the course of the disease.

Albuminuria↗
PubMed1996

Expression of cytochrome P450s and glutathione S-transferases in human esophagus with squamous-cell carcinomas.

In order to clarify the expression of cytochrome P450 and glutathione S-transferase in human esophagus, 41 samples of human esophagus with squamous-cell carcinoma were investigated by immunoblot analysis and enzyme assays. Cytochrome P450 1A2/1 was clearly expressed in microsomes, and the amount in samples with tumorous tissue was significantly greater than that in samples without tumourous tissues or in liver; cytochrome P450 2B6 and 3A4/3 were expressed polymorphically. Aryl hydrocarbon hydroxylase activity was detected in microsomes and was greater in samples from smokers than non-smokers. Patients who both smoked and drank alcohol, however, had activity similar to that of patients without these habits. Glutathione S-transferase M1 and A1/2 protein existed polymorphically in cytosol, and glutathione S-transferase P1-1 was detected in all samples. The frequency of expression of the glutathione S-transferase A1/2 protein was greater in patients with M1 protein than in those without; no difference in the expression was seen for glutathione S-transferase P1-1. Neither smoking nor drinking influenced the expression or activity of glutathione S-transferase. Our data support the idea that some carcinogens can be directly activated or inactivated in human esophageal epithelium.

Alcohol Drinking↗
PubMed1996

Changes in hepatic lobar function after right portal vein embolization. An appraisal by biliary indocyanine green excretion.

OBJECTIVE: The changes in the functional capacity of the hepatic lobe after right portal vein embolization (RPE) were investigated in patients with complete obstruction of the hepatic hilus who had undergone multiple percutaneous transhepatic biliary drainage catheterizations. METHODS: After injection of 0.5 mg/kg of indocyanine green (ICG), bile draining from each hepatic lobe was collected separately for 6 hours. Biliary ICG excretion in each hepatic lobe was estimated and compared with hepatic lobar volume measured by computed tomographic volumetry before and an average of 11 days after RPE. RESULTS: Right portal vein embolization produced a significant increase in bile volume and biliary ICG concentration in the left lobe, resulting in a significant increase in ICG excretion in the left lobe. The percentage of ICG excretion in the left lobe to the whole-liver excretion showed a mean increase of 20.1%, which was statistically significant. In contrast, the percentage of left lobar volume to the total liver volume increased by only 8.3%. CONCLUSIONS: Measurement of biliary ICG excretion is useful for estimating changes of hepatic lobar function and has revealed that within 11 days RPE enhances functional capacity in the left lobe compared with volume gain without affecting total liver function.

Adult↗
PubMed1996

Selective percutaneous transhepatic embolization of the portal vein in preparation for extensive liver resection: the ipsilateral approach.

The ipsilateral approach was used at preoperative portal vein embolization in 38 patients with hepatobiliary malignancy. The right anterior portal branch was punctured. Two different 5.5-F triple-lumen balloon catheters were used, and fibrin glue and iodized oil were injected. Portal vein embolization was successful in all cases (right lobe, 24 patients; left lobe and right anterior segment, six; right lobe and left medial segment, three; right posterior segment, two; right anterior segment, one; left lobe, one; and right and caudate lobes, one).

Bile Duct Neoplasms↗
PubMed1996

[Prospective randomized trial comparing 1/2 FAM (5-fluorouracil (5-FU) + adriamycin + mitomycin C) versus palliative therapy for the treatment of unresectable pancreatic and biliary tract carcinomas (the 2nd trial in non-resectable patients). Japanese Study Group of Surgical Adjuvant Therapy for Carcinomas of the Pancreas and Biliary Tract].

The efficacy of 1/2 FAM, which consists of 5-fluorouracil (5-FU), adriamycin (ADM) and mitomycin C (MMC), was compared with that of palliative treatment in patients with unresectable pancreatic and biliary tract carcinomas in a multicenter randomized trial. The patients assigned to 1/2 FAM group were treated with 5-FU 200 mg/m2/day IV, ADM 15 mg/m2/day IV and MMC 5 mg/m2/day IV. These 3 drugs were given concurrently as the initial dose within a week after palliative operation, and this regimen was repeated for at least 2 whole courses, at 4-week intervals before the next course of therapy. Those randomized to the control group were subjected to palliative treatment alone. Completely eligible for analysis were 42 cases of the 1/2 FAM group and 41 of the control group. There was no significant difference between the groups with respect to the overall and differentiated survival times according to the tumor sites and the clinical efficacy. As for the duration of 50% inhibition of tumor progression, a significantly better outcome was obtained in 1/2 FAM group. Tumor progression was most significantly inhibited in patients with gallbladder carcinoma. In 1/2 FAM group, tumor reduction was achieved in 1 CR and 2 PR patients. The most frequent adverse reaction was gastrointestinal manifestations, along with diarrhea and alopecia. 1/2 FAM did not contribute to the life prolongation, but inhibited the tumor progression for a significantly longer duration and, to a lesser extent, reduced the tumor size in unresectable pancreatic and biliary tract carcinomas. This regimen is suggested to be useful particularly in the treatment of the latter carcinoma.

Adult↗
PubMed1996

Point mutations of the c-Ki-ras gene in carcinoma and atypical epithelium associated with congenital biliary dilation.

OBJECTIVES: Congenital biliary dilation (CBD) may be accompanied later by gallbladder carcinoma or bile duct carcinoma. These cancerous lesions are frequently associated with atypical epithelium that was suspected of being precancerous. To determine whether atypical epithelium may be precancerous, we examined the DNA sequence of the c-Ki-ras gene at codon 12 in nine cases of CBD concurrent with seven gallbladder carcinomas, one bile duct carcinoma, and one bile duct atypical epithelium. METHODS: Tumor specimens were surgically removed from nine patients with CBD at Nagoya University Hospital between 1979 and 1988. Tumor was isolated by microdissection, and DNA was amplified by a two-step polymerase chain reaction which then was directly sequenced. RESULTS: Four of seven gallbladder carcinomas and one bile duct carcinoma contained the c-Ki-ras point mutation at codon 12, and atypical epithelium associated with these carcinomas had the same mutation. One case of atypical bile duct epithelium also contained the mutation. CONCLUSIONS: These results indicate that the c-Ki-ras point mutation at codon 12 may be responsible for either cancer or atypical epithelia associated with CBD.

Adult↗
PubMed1995

IL-10 is involved in the protective effect of dibutyryl cyclic adenosine monophosphate on endotoxin-induced inflammatory liver injury.

The effects of exogenous cAMP, dibutyryl cAMP (DBcAMP) on LPS-induced liver injury were examined in mice made hypersensitive to LPS by treatment with i.v. injection of Propionibacterium acnes. In vivo administration of DBcAMP significantly protected P. acnes-treated mice from LPS-induced liver injury, including apoptosis of hepatocytes. DBcAMP significantly increased circulating IL-10 level in correlation with suppression of the TNF-alpha level after LPS challenge in P. acnes-treated mice. Treatment with anti-IL-10 mAb abrogated the protective effect of DBcAMP on LPS-induced liver injury. Similar to in vivo findings, addition to DBcAMP to in vitro culture of liver adherent cells from P. acnes-treated mice enhanced IL-10 synthesis after LPS stimulation. These results suggest that the increment in IL-10 production by liver adherent cells is involved in the protective effect of DBcAMP on LPS-induced inflammatory liver injury.

Animals↗
PubMed1995

Endogenous interleukin 10 prevents apoptosis in macrophages during Salmonella infection.

To elucidate the biological roles of endogenous interleukin 10 (IL-10) in macrophage responses during bacterial infection, we examined in vitro effects of neutralizing IL-10 by anti-IL-10 monoclonal antibodies (mAb) on apoptosis of the peritoneal macrophages following Salmonella choleraesuis infection. Marked increments of TNF-alpha production were observed in the culture supernatant later than 6 h after in vitro culture with anti-IL-10 mAb. These macrophages succumbed to apoptosis at this stage accompanied by marked increment of IL-1 release, despite the expression of higher amount of endogenous heat shock protein 70, an inhibitor of TNF-alpha-mediated apoptosis. These results suggest that endogenous IL-10 plays an essential role in protection of Salmonella-infected macrophages from autocrine suicide caused by excessive production of TNF-alpha after killing of Salmonella.

Animals↗
PubMed1995

Comparison of laser vascular welding, interrupted sutures, and continuous sutures in growing vascular anastomoses.

BACKGROUND AND OBJECTIVES: The argon laser-assisted vascular anastomosis may solve the problems of conventional sutured anastomosis, such as vascular stenosis and arrest of growth owing to a foreign-body reaction to suture material. STUDY DESIGN/MATERIALS AND METHODS: Twelve argon laser-assisted vascular anastomoses, seven conventional anastomoses with interrupted sutures, and five conventional anastomoses with continuous sutures were performed in 12 young mongrel dogs. RESULTS: Five months later, the external diameter at the anastomosis had increased 70.5% in the laser group, 67.0% in the interrupted suture group, and 22.9% in the continuous suture group. Histological examination of the laser-assisted anastomoses showed almost complete healing, with no granulomatous response around the anastomotic site. In the interrupted suture group, marked scaring and foreign body reactions were observed on the vessel wall at the site of the anastomosis. The continuous suture group showed more remarkable disorientation of the vascular layer and intimal hyperplasia than the interrupted suture group. CONCLUSION: Vascular anastomosis using the argon laser offers advantages over the conventional procedure in growing vessels.

Anastomosis, Surgical↗
PubMed1995

Thoracoscopic sympathectomy for Buerger's disease: a report on the successful treatment of four patients.

We describe herein the successful treatment of four patients with ischemic ulcers or gangrene of the fingers due to Buerger's disease by thoracoscopic sympathectomy, a new method of surgery which eliminates the difficulties associated with the traditional "open" approaches to the thoracic sympathetic chain, such as poor exposure, risk of damage to the adjacent structures, and postoperative pain. After the patients were placed in the lateral decubitus position with unilateral pulmonary ventilation, the thoracic sympathetic ganglia (T) from the lower third of T1 to T3 were resected endoscopically. The operative results were excellent, with improvement or complete resolution of the ulcer being achieved in all four patients. All of the patients were satisfied with the results in terms of ulcer healing, postoperative pain, and cosmetic appearance. Although a postoperative air leakage developed in one patient with a history of pulmonary tuberculosis, it was successfully treated with an adhesive agent. None of the patients developed Horner's syndrome. Thus, because thoracoscopic sympathectomy is easier to perform with a lower risk of complications than conventional thoracic sympathectomy, we recommend this operative approach as the procedure of choice for surgical thoracic sympathectomy.

Fingers↗
PubMed1995

The influence of excess body weight on the surgical treatment of patients with gastric cancer.

Sixty-two overweight gastric cancer patients were compared with 201 normal-weight patients to clarify the influences of excessive weight on the surgical treatment of gastric cancer. The frequencies of hypertension and diabetes mellitus were significantly higher in the overweight group (P < 0.01), but no pathologic differences in the resected tumor were found between the two groups. The operative times were longer (P < 0.01) and the number of lymph nodes extirpated and examined was smaller (P < 0.01) in the overweight group. The incidence of postoperative complications was not higher in the overweight group. The postoperative survival rate of patients with nodal metastasis was statistically lower in the overweight group (P < 0.05). Regarding the causes of death in patients with nodal metastasis, 61.1% of overweight patients and 43.8% of normal-weight patients died of recurrence of gastric cancer. In conclusion, surgical treatment of overweight patients with gastric cancer was found to be technically more difficult and the prognosis of such patients with nodal metastasis may thus be worse than that of their normal-weight counterparts.

Body Weight↗
PubMed1995

Spatial distribution and pattern of extrinsic nerve strands in the aganglionic segment of congenital aganglionosis: stereoscopic analysis in spotting lethal rats.

The distribution and pathways of extrinsic enteric nerves in the aganglionic segment in Hirschsprung's disease have not completely delineated. The zinc iodide-osmic acid method was used to investigate nerve fibers of the intestine in aganglionic rats. A light microscope equipped with a polarizing filter system clarified the major pathways and the fine distribution of extrinsic nerves in the aganglionic segment of a long-segment aganglionic rat model. Two sets of extrinsic nerve strands were observed in the distal aganglionic colon; one consisted of a continuous hypertrophied network located between the longitudinal and circular muscle coats, and the other involved branches that coursed along the blood vessels in the submucosal layer and that originated in the nearby mesentery. These two sets of nerve strands were connected by fine nerve fibers. Hypertrophied myenteric nerve strands were also present in normal (ganglionic) colon, fewer strands were found in the proximal aganglionic colon, and none were found in the ileum. The authors speculate that the ascending extrinsic nerve strands disappear from the ileum in cases of long-segment colonic aganglionosis, by the same mechanism that occurs in normally innervated bowel.

Animals↗
PubMed1995

Expression of ret proto-oncogene products in the hypoganglionic segment of the small intestine of congenital aganglionosis rats.

The ret proto-oncogene (proto-ret) encodes a receptor tyrosine kinase that contains a cadherin-related sequence in the extracellular domain, which plays an important role in control of normal cell growth and differentiation. Recent studies have shown that familial Hirschsprung's disease is closely linked to the proto-ret locus. Immunohistologically studies on congenital aganglionosis rats were made using polyclonal antibody generated for the carboxy-terminal sequence of the proto-ret products. Immunoreactivity was investigated in the small and large intestines of mutant and control rats. It was increased in the ganglia of the hypoganglionic segment of the small intestine and was minimal in the normoganglionic small intestinal segment of congenital aganglionosis in rats. The reactivity was also strong in the ganglia of the large intestine of normal rats. Because the proto-ret is preferentially expressed in the neuronal tissue and plays a critical role in differentiation of apparently multipotential neural crest cells to enteric neurons, the results suggest that abnormal development of local vagal neural crest cells, which were influenced by spatially regulating factors, results in the hypoganglionic segment.

Animals↗
PubMed1995

Elevated mitochondrial gene expression during rat liver regeneration after portal vein ligation.

We explored the molecular basis of mitochondrial energy production during rat liver regeneration after portal vein ligation. Ligation of the left branch of the portal vein induces an increase in the weight of the nonligated lobe, counterbalancing the reduced weight of the ligated lobe. Using this model, we investigated changes in mitochondrial DNA-binding proteins, mitochondrial DNA, and mitochondrial messenger RNA (mRNA) in rat hepatocytes of the nonligated lobes. The amount of mitochondrial DNA-binding protein increased maximally (200% to 300% of the preoperative level) at 12 hours after the operation, before an increase (390%) in mitochondrial DNA content at 24 hours, and parallel to an increase (240%) in mitochondrial mRNA levels at 12 hours. These results suggest that the energy supply for liver regeneration is achieved through enhancement of mitochondrial DNA replication as well as transcription, in which the mitochondrial DNA-binding proteins probably play regulatory roles. We also found that in the nonligated lobes, mRNA levels of hepatocyte growth factor increased to a detectable level only 12 hours after the operation. These molecular biochemical data help explain why preoperative portal vein embolization, which is a modification of portal vein branch ligation, is an effective method to prevent posthepatectomy liver failure.

Animals↗
PubMed1995

Disseminated intravascular coagulation after liver resection: retrospective study in patients with biliary tract carcinoma.

BACKGROUND: Disseminated intravascular coagulation (DIC) after hepatectomy is not well understood. The objective of this retrospective study was to evaluate hemostatic changes after extensive liver resection and to elucidate the frequency of posthepatectomy DIC. METHODS: In 100 patients without cirrhosis who underwent resection of two or more segments of the liver for biliary tract carcinoma, various hemostatic parameters were measured before and after resection, and the liver function of each patient was assessed. RESULTS: In patients with posthepatectomy liver failure, platelet count, fibrinogen concentrations, and prothrombin time were significantly lower than in those without such failure. Serum levels of fibrin degradation product did not differ significantly between the two groups. The minimum platelet count was significantly negatively correlated with serum total bilirubin level. Posthepatectomy DIC occurred in 2.0% of the patients. CONCLUSIONS: After extensive liver resection patients exhibited a decreased platelet count with hepatic dysfunction. However, this condition rarely resulted in DIC, at least in patients without cirrhosis and serious postoperative complications.

Adult↗
PubMed1995

Right or left trisegment portal vein embolization before hepatic trisegmentectomy for hilar bile duct carcinoma.

BACKGROUND: Percutaneous transhepatic embolization of the right portal vein plus the left medial portal branch (R3-PE) and the left portal vein plus the right anterior portal branch (L3-PE) is not well described. METHODS: Four patients with far advanced carcinoma of the hepatic hilus underwent R3-PE (n = 1) or L3-PE (n = 3) as preoperative management for right hepatic trisegmentectomy or left hepatic trisegmentectomy. The portal vein embolization was performed with the ipsilateral approach through the right anterior portal branch. RESULTS: In all patients the embolizations were successful without complications. Volumetric study with computed tomography showed sufficient hypertrophy of the nonembolized hepatic segments. Three of the four patients eventually underwent trisegmentectomy. The postoperative courses in two of the patients were uneventful. The remaining patient suffered from posthepatectomy liver failure but recovered. CONCLUSIONS: R3-PE or L3-PE is advisable as preoperative management for trisegmentectomy and appears effective for increasing the safety of the operation. This embolization is achievable only through the ipsilateral approach.

Adult↗