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T Maeba

Publications and source records attributed to T Maeba.

At least 19 recordsLinked to original sources
PubMed1999

Castleman disease of the pararenal retroperitoneum: report of a case.

We describe herein the case of a 21-year-old woman in whom Castleman disease of the pararenal retroperitoneum was successfully resected. The patient was referred to our hospital from another hospital for investigation of a retroperitoneal mass in the right middle abdomen. Ultrasonography, computed tomography, and magnetic resonance imaging demonstrated a large retroperitoneal mass with heterogeneous imaging characteristics. An aortogram showed arterial feeding to this mass from a few lumbar arteries. Although a definitive preoperative diagnosis could not be made, surgical excision was performed and histopathological examination confirmed a diagnosis of the hyaline type of Castleman disease. The patient had an uneventful postoperative course and was discharged 14 days after her operation. She now leads an active social life without any signs of sequelae or recurrence 14 months later. To the best of our knowledge, only 2% (6/315) of all reported cases of Castleman disease have been located in the pararenal and retroperitoneal area.

Adult↗
PubMed1999

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↗
PubMed1998

Wound healing of intestinal anastomosis after digestive surgery under septic conditions: participation of local interleukin-6 expression.

This study aimed to evaluate the integrity of anastomotic wound healing after digestive surgery under septic conditions and to observe local interleukin-6 (IL-6) expression around the anastomotic segment. Experimental animals were separated into lipopolysaccharide (LPS) and control groups. Each was injected with LPS or normal saline solution into the peritoneal cavity 24 hours before transection and anastomosis of the colon. The anastomotic bursting pressure (ABP) and tissue hydroxyproline concentration (HP) were measured as indicators of wound healing. Immunohistochemical staining for IL-6 was performed on tissue samples obtained from the anastomotic segment, lung, liver, and kidney. The reactive cells were counted by light microscopy. The ABP and HP were significantly lower in the LPS group than the control group 7 days after the surgery. In the LPS group, IL-6 expression around the anastomotic segment was enhanced 1 and 6 hours after surgery but suppressed 24 hours afterward. In contrast, IL-6 expression in lung, liver, and kidney was enhanced in the LPS group 24 hours after surgery but not in the control group. It is suggested that anastomotic wound healing is impaired after digestive tract surgery under septic conditions, and local IL-6 expression participates in wound healing.

Anastomosis, Surgical↗
PubMed1998

Morphological and functional alterations to sinusoidal endothelial cells in the early phase of endotoxin-induced liver failure after partial hepatectomy in rats.

Liver failure following major hepatectomy is characterized pathologically by massive hepatic necrosis, which is thought to begin with injury of sinusoidal endothelial cells (SECs). To examine the early events of SECs leading to hepatic damage, we performed time-course analyses of the morphological and functional perturbation of SECs after endotoxin administration to hepatectomized rats. At 1.5 h after endotoxin injection, when hepatocellular damage was not yet evident, SECs showed augmented expression of intercellular adhesion molecule-1, with frequent adherence of infiltrating leucocytes and ultrastructural features of defenestration and hypertrophied cytoplasm enriched with cell organelles. The serum level of hyaluronate, as an indicator of the functional state of SECs, was significantly elevated. At 3 h, SECs underwent necrosis and disruption, accompanied by fibrin deposits with concomitant hepatocellular necrosis. The morphological and functional alterations of SECs precede necrotic changes in hepatocytes and SECs in endotoxin-induced liver failure after partial hepatectomy.

Animals↗
PubMed1998

Modified hepatoduodenal ligamentectomy for advanced carcinoma of the biliary tract: the importance of preservation of the replaced left hepatic artery.

Hepatoduodenal ligamentectomy (ligamentectomy) is the ultimate surgery for biliary tract carcinoma involving perioperative difficulties such as total hepatic ischemia during revascularization of the hepatic artery and the portal vein, patency of the reconstructed hepatic artery, and high incidence of related operative mortality. In the present study, modified ligamentectomies with extended right hepatic lobectomy, including resection of the caudate lobe, were performed on three patients with advanced biliary tract carcinoma in whom the left hepatic artery had been replaced and the original artery was preserved. In all patients, postoperative courses were uneventful: success of the resection was confirmed by histological examination. This procedure enabled en bloc resection of hepatoduodenal ligament with positive cancer invasion to take place. It was carried out safely without concern for the difficulties described above. In our view, ligamentectomy should be performed in all such cases.

Aged↗
PubMed1998

The effects of intraportal administration of prostaglandin E1 on liver ischemia and hepatectomy in rats.

The effects of intraportal administration of prostaglandin E1 (PGE1) on portal venous flow, hepatic arterial flow, peripheral tissue blood flow, and systemic arterial flow before and after 60 min total liver ischemia followed by 70% partial hepatectomy in rats were investigated. Total liver ischemia was induced by occluding the hepatoduodenal ligament for 60 min. PGE1 at a dose of 0.5 microg/kg/min was infused intraportally for 15 min before inducing hepatic ischemia (preischemic period) and for 60 min after ischemia (postischemic reperfusion period) in the treatment group. Normal saline was infused in the control group. Seventy percent partial hepatectomy was performed during ischemia. Serum biochemical analysis and liver tissue histology were carried out 1, 3, and 24 h, and 1 and 24 h after reperfusion respectively. One-week survival of the PGE1 group was improved to 70% compared to that of the control group of 30%. Postischemia reperfusion values of portal and peripheral tissue blood flows in the PGE1 group were 6.33 +/- 0.600 ml/min and 27.2 +/- 23.5 (arbitrary), and were significantly different from those of the control group of 4.34 +/- 0.400 ml/min and 23.5 +/- 5.54 (arbitrary), respectively. There was no significant difference in hepatic arterial flow between the two groups. Serum alkaline phosphatase decreased significantly in the prostaglandin group. Histological examination revealed a significant portal venous congestion in the control group 1 and 24 h after reperfusion. The extent of the sinusoidal congestion was also severe in the control group 24 h after reperfusion. It was concluded that PGE1 has a protective effect against liver damage when the liver was injured by warm ischemia and reperfusion followed by partial resection.

Alprostadil↗
PubMed1998

Treatment of recurrent hepatocellular carcinoma by hepatectomy with right and middle hepatic vein reconstruction using total vascular exclusion with extracorporeal bypass and hypothermic hepatic perfusion: report of a case.

We report herein the case of a patient who had previously undergone a lateral segmentectomy for hepatocellular carcinoma (HCC) in whom recurrent HCC invading the trunk of the right and middle hepatic veins in a damaged liver was treated by reconstruction of both hepatic veins, using total vascular exclusion with extracorporeal bypass and hypothermic hepatic perfusion. Reconstruction was performed using a graft taken from the left external iliac vein and divided into two pieces. Hepatic ischemia lasted for 91 min during the procedure and the intrahepatic temperature, as monitored by inserting a needle-type thermometer, was decreased to 11 degrees C throughout the procedure. The peak levels of serum glutamic pyruvic transaminase, lactate dehydrogenase, and total bilirubin were 363 IU/l, 1198 IU/ml, and 2.8 mg/dl, respectively, on postoperative day (POD) 2. The patient's postoperative course was uneventful except for mild, temporary swelling of the left leg. Postoperative computed tomography and magnetic resonance imaging examinations disclosed no obstruction of either graft, and the patient was discharged on POD 40.

Carcinoma, Hepatocellular↗
PubMed1997

Effect of preoperative portal vein embolization on major hepatectomy for advanced-stage hepatocellular carcinomas in injured livers: a preliminary report.

With the aim of minimizing postoperative liver dysfunction and promoting increased resectability, we employed portal vein embolization (PVE). In this study, the effect of PVE on major hepatic resection for advanced-stage hepatocellular carcinoma (HCC) in injured livers was evaluated. PVE was performed prior to hepatectomy in 13 patients with stage III and IV HCCs. Following PVE, right trisegmentectomy was performed in 3 patients, extended right lobectomy in 3 and right lobectomy in 7. To evaluate the effect of PVE, the changes in liver functional capacity and estimated remnant liver volume (ERLV), determined by computed tomography, were examined before and after PVE. The operative morbility, mortality, and survival rates after hepatectomy were also assessed. By 2 weeks after PVE, ERLV had increased in all patients, by an average of 28%, and the mean resection rates had decreased from 70.0% to 62.2%. Postoperatively, the 30-day mortality rate was 15.3%, and the 1- and 2-year survival rates were 69% and 46%, respectively. The results of this study indicate that resectability can be increased, and major hepatectomy can be made safer by employing PVE preoperatively, in view of the fact that major hepatectomy was not considered feasible without PVE in these patients.

Aged↗
PubMed1997

Hepatic protein synthesis in the regenerating rat liver after hepatopancreatectomy.

To evaluate the effects of hepatopancreatectomy on the regenerative process of the liver, the serum protein changes, hepatic protein synthesis (HPS), and bromodeoxyuridine (BrdU) labeling index were measured in rats. Sprague-Dawley rats were divided into four groups according to the type of resection: A simple laparotomy was performed in the sham group; 68% of the liver was excised in the Hx group; 45% of the pancreas was excised in the Px group; and 45% of the pancreas and 68% of the liver were excised simultaneously in the HPx group. Serum total protein and albumin levels were significantly lower in the HPx group compared to the other three groups on postoperative day (POD) 3 (P < 0.05). HPS was markedly increased in the Hx and HPx groups. In the Hx group, it was significantly higher, peaking on POD 2, compared to the HPx group (P < 0.05), while in the HPx group, it was significantly higher compared to the Hx group (P < 0.05), peaking on POD 3. The BrdU labeling index, as a marker of DNA synthesis, was significantly suppressed in the HPx group on POD 1 compared to the Hx group (P < 0.05). Thus, compared to hepatectomy alone, hepatopancreatectomy suppresses DNA synthesis, causing a delay in the increase of protein synthesis in the regenerating liver, resulting in a more marked decrease in the serum protein level.

Alanine Transaminase↗
PubMed1997

Effects of an immunosuppressive agent, tacrolimus (FK-506), on the activities of cytochrome P-450-linked monooxygenase systems in rat liver microsomes.

The effects of an immunosuppressive agent, tacrolimus (FK-506), on the activities of cytochrome P-450-linked monooxygenase systems with respect to three cytochrome P-450 isozymes in rat liver microsomes were investigated. FK-506 non-competitively inhibited the aniline p-hydroxylase, p-nitroanisole O-demethylase and lidocaine N-deethylase activities of cytochrome P-450-linked monooxygenase systems, these activities being mainly catalyzed by cytochromes P-450 CYP2E1, CYP2C11 and CYP3A4, respectively, and the Ki values of the activities for FK-506 were determined to be 605, 491 and 97 microM, respectively. The inhibition of cytochrome P-450-linked monooxygenase systems by FK-506 seemed to involve the direct inhibition of cytochromes P-450 because the NADPH-cytochrome c reductase and NADPH-ferricyanide reductase activities of NADPH-cytochrome P-450 reductase were not affected by the presence of 1 mM FK-506 at all. A spectrophotometric study showed that a reverse type I spectral change was induced on the addition of FK-506 to rat liver microsomes, and the Ks value was apparently 125 microM. On the other hand, the EPR spectra of cytochromes P-450 in rat liver microsomes were not affected by 1 mM FK-506. These results suggest direct interaction between FK-506 and cytochrome P-450 apoproteins, except for the heme iron regions of cytochromes P-450, resulting in inhibition of the drug-metabolism activities catalyzed by cytochromes P-450.

Aniline Hydroxylase↗
PubMed1996

Effects of cold preservation and reperfusion on microsomal cytochrome P-450-linked monooxygenase system of the rat liver.

The effects of cold preservation and reperfusion of the liver on the hepatic microsomal cytochrome P-450-linked monooxygenase system (P-450 system) were investigated. Rat livers were preserved with cold University of Wisconsin solution for 0, 12, 24, 36, and 48 hr. Half of them in 0-, 24-, and 48-hr groups were reperfused for 1 hr at 37 degrees C with oxygenated Krebs-Henseleit buffer. After preservation or reperfusion, the liver microsomes were prepared and the concentration of each component of the P-450 system [NADPH-cytochrome b5 reductase (b5 reductase), cytochrome b5 (b5), NADPH-cytochrome P-450 reductase (P-450 reductase) and cytochrome P-450 (P-450)] and their drug metabolizing activities and concentration of apo-cytochrome P-450 2E1 (apo-P-450 2E1) were measured. After 48-hr preservation, b5 concentration did not decrease, whereas the concentration of P-450, P-450 reductase, and b5 reductase decreased from 0.865 to 0.676 nmole/mg protein, from 0.262 to 0.233 micromole/mg protein/min and from 5.34 to 4.86 micromole/mg protein/min, respectively. During cold preservation, the activities of p-nitroanisole O-demethylase and aniline p-hydroxylase did not change. Aminopyrine N-demethylase activity was inhibited from 4.45 to 3.34 nmole/mg protein/min after 48-hr cold preservation. Apo-P-450 2E1 was gradually decreased during cold preservation. Reperfusion caused a further decrease in the activities and concentration of the components of the P-450 system and concentration of apo-P-450 2E1 to 80-90% after 1-hr reperfusion. It was suggested that the prolonged preservation caused deterioration of the P-450 system and the loss of the abilities of metabolism and detoxication of xenobiotics.

Animals↗
PubMed1996

Increase in portal blood interleukin-6 soon after the commencement of digestive surgery.

To determine whether cytokines produced in the operative field during digestive surgery selectively spill over into the portal blood, the changes in interleukin-6 (IL-6) levels in portal and peripheral venous blood were assayed at several points in time from the commencement of surgery until 14 days later, in 11 patients. Similar changes in the IL-6 levels were observed in the portal and peripheral blood samples; however, the IL-6 levels in the portal blood reached a maximum 6-12h after the commencement of surgery, being earlier than in the peripheral venous blood. In fact, between 3 and 12h after the commencement of surgery, the IL-6 levels were higher in the portal blood by 33-81 pg/ml. By 24h or more after the commencement of surgery, the IL-6 levels did not differ significantly in the two types of blood samples. Moreover, the C-reactive protein levels 2 days after surgery were even more closely correlated to the maximum IL-6 levels in the portal blood than to those in the peripheral venous blood. These results suggest that IL-6 produced during intra-abdominal digestive surgery initially enters the portal blood, being trapped by IL-6 receptors in the liver, where it may regulate the synthesis of acute-phase proteins as a hepatocyte-stimulating factor.

Adult↗
PubMed1996

Comparison of University of Wisconsin and University of Pittsburgh solutions for heart transplantation.

The effectiveness of University of Wisconsin (UW) and University of Pittsburgh (UP) solutions for the preservation of rat hearts was compared. Lewis rat hearts were preserved with UW (group A, n = 45) or UP (group B, n = 45) solution for 0 or 24 h and then transplanted heterotopically into the recipients' abdomen. Ten recipients in each group were observed to obtain 1-week graft survival rates. Tissue water content and tissue content of adenine nucleotides were measured 2 h after transplantation in six grafts from each group. Six hearts preserved for 0 h and seven hearts preserved for 24 h were taken from each group 24 h after grafting for histopathology. The 1-week graft survival rates of groups A24 and B24 were 60% and 10%, respectively. In the 24-h preserved grafts, adenosine triphosphate (ATP) and energy charge [(ATP + adenosine diphosphate/2)/(ATP + adenosine diphosphate + adenosine monophosphate)] of groups A and B were 0.972 +/- 0.165 and 0.200 +/- 0.123 mg/g wet tissue (P < 0.05) and 74.4% and 61.1% (P < 0.05), respectively. The tissue water content of group A24 was 71.7%, whereas that of group B24 was 74.1% (P < 0.05). Histopathology revealed more severe muscle edema and necrosis and infiltration of polymorphonuclear cells in group B24 than in group A24. We conclude that UW solution is more appropriate for rat heart preservation than UP solution.

Abdomen↗
PubMed1996

Impact of adhesion molecules of the selectin family on liver microcirculation at reperfusion following cold ischemia.

We investigated the role of adhesion molecules in the early phase of reperfusion following cold ischemia. Livers of male Lewis rats were preserved for 0 h (group A) or 24 h in University of Wisconsin (UW) solution without additives (group B) or in UW solution with anti-ICAM-1 antibody (group C) or anti-E-selectin-1, SLe(x) and SLe(a) antibodies (group D). The livers were then reperfused with diluted rat whole blood (DWB; groups A and B). DWB containing anti-ICAM-1 and LFA-1 antibodies (group C) or DWB containing anti-L-selectin, SLe(x) and SLe(a) antibodies (group D). The reperfusion was performed at 37 degrees C for 1 h at 5 cm H2O of perfusion pressure. During reperfusion, hepatic microcirculation was assessed by monitoring portal and peripheral tissue blood flow. Bile production was significantly reduced in group B livers compared with those in group A. Anti-ICAM-1 and LFA-1 antibodies failed to improve hepatic microcirculation, whereas anti-LECAM-1, SLe(x) and SLe(a) antibodies significantly improved the microcirculation. Bile production in group C and D livers was comparable to that in group B livers. Preservation for 24 h significantly increased the release of TNF-alpha from 0.207 to 43.7 pg/g per hour during reperfusion. Monoclonal antibodies to the adhesion molecules did not suppress the release of TNF-alpha in groups C and D. Histological examination demonstrated a lack of leukocyte infiltration or thrombus in hetapic microvessels. The extent of hepatocyte necrosis did not differ among groups B, C, and D. We conclude that the microcirculatory disturbance in the early phase of reperfusion occurs as a result of the tethering of leukocytes through the interaction of the selectin family and their ligands, and that the ICAM-1-LFA-1 pathway is not involved in this step. The lack of improvement in bile production with antibodies to the selectin family and their ligands strongly suggests that other mechanisms participate in the deterioration of hepatic function.

Adenosine↗