Tatsuhiro Nakata

Sequential Percutaneous Microwave Coagulation Therapy for Liver Tumor

BACKGROUND Percutaneous microwave coagulation therapy (PMCT) is effective for small liver tumors. To enhance the radicality of PMCT, we developed a sequential coagulation technique. METHODS After inserting the first guide-needle under sonography, multiple needles were placed through a disk-type introducer that was devised to guide needle puncture at regular intervals, and microwaves were irradiated. Six patients, including 4 with hepatocellular carcinoma and 2 with liver metastasis, underwent this technique for tumors of 15 to 80 mm in diameter. RESULTS This technique can coagulate an area up to 60 mm in diameter in one session. Insertion of multiple needles, ranging from 2 to 11, was successful without complications. Three patients undergoing curative PMCT developed no tumor recurrence. The other 3 received incomplete PMCT due to the large size and location of the tumor. CONCLUSIONS This preliminary study indicates the efficacy of this technique to facilitate and secure PMCT in selected patients with liver tumors.

Double-Chambered Right Ventricle in Adulthood

Patients with double-chambered right ventricle presenting with symptoms in adulthood are rare. From 1990 to 2004, 4 adults and 9 children with double-chambered right ventricle underwent surgical correction. The surgical results and clinical data of the adults were compared with those of the pediatric patients. All adult patients had dyspnea on exertion, 3 children showed growth delay but the others were asymptomatic. The mean age at operation was 44.5 ± 6.3 years in adults and 5.2 ± 1.9 years in children. The mean pressure gradient between the anatomically lower right ventricle and the pulmonary artery was significantly higher in adults than in children (91.8 ± 14.1 vs. 42.2 ± 5.9 mm Hg). The pulmonary-to-systemic flow ratio in adults was significantly lower than in pediatric patients (1.2 ± 0.2 vs. 1.8 ± 0.3). All adults and 8 of the 9 children survived. There were no late deaths or re-operations, and all survivors were in New York Heart Association functional class I. Surgical correction of double-chambered right ventricle in adults gave satisfactory midterm results although right ventricular outflow tract obstruction and clinical symptoms were severe in these patients.

Transient ischemia-induced paresis and complete paraplegia displayed distinct reactions of microglia and macrophages

In this study, we perform a detailed analysis of the microglial and macrophage responses in a model of spinal cord ischemia and reperfusion (SCI/R) injury in Wistar rats. The rats underwent occlusion across the descending aorta for 13min, causing paraplegia or paresis of varying severity. They were divided into four groups based on neurological assessment: sham, mild paresis, moderate paresis, and severe (complete) paraplegia. To examine the origin of microglia and macrophages in the ischemic lesion, bone marrow from rats expressing green fluorescent protein (GFP) was transplanted into test subjects one month before performing SCI/R. Many GFP(+)/CD68(+) microglia and macrophages were present 7d after SCI/R. Resident (GFP(-)/Iba1(+)/CD68(-)) microglia and bone marrow-derived macrophages (BMDMs; GFP(+)/Iba1(+)/CD68(+)) colocalized in the mild group 7d after SCI/R. In the moderate group, BMDMs outnumbered resident microglia. A greater accumulation of BMDMs expressing insulin-like growth factor-1 (IGF-1) was observed in lesions in the severe group, relative to the moderate group. BMDMs in the severe group strongly expressed tumor necrosis factor α, interleukin-1β, and inducible nitric oxide synthase, in addition to IGF-1. A robust accumulation of BMDMs occupying the entire ischemic gray matter was observed only in the severe group. These results demonstrate that the magnitude of the microglial and BMDM responses varies considerably, and that it correlates with the severity of the neurological dysfunction. Remarkably, BMDMs appear to have a beneficial effect on the spinal cord in paresis. In contrast, BMDMs seem to exhibit both beneficial and harmful effects in severe paraplegia.

Intestinal ischemia/reperfusion-induced bacterial translocation and lung injury in atherosclerotic rats with hypoadiponectinemia.

BACKGROUND Intestinal ischemia/reperfusion causes intestinal mucosal injury, which may result in bacterial translocation (BT) and multiple organ failure. Lung injury is a common complication after intestinal ischemia/reperfusion. Adiponectin is an antiinflammatory adipokine, and it plays an important role in the development of metabolic syndrome in hypoadiponectinemia. In atherosclerosis with hypoadiponectinemia, BT also may aggravate injuries induced by intestinal ischemia/reperfusion. METHODS Wistar rats were divided into 3 groups: Normal group (normal diet), Chol group (2% high cholesterol diet), and Chol+1400W group (Chol group plus 1400W, an inducible nitric oxide [iNOS] inhibitor, at 1 mg/kg intraperitoneally 30 minutes preoperatively). The serum concentrations of lipids and adiponectin and vascular responses were measured. After midline laparotomy (time, T0), the superior mesenteric artery was occluded with a microvascular clamp for 30 minutes, followed by 360 minutes of reperfusion (T1). Intestinal injury was assessed from microcirculatory flow, histology, serum diamine oxidase activity, and permeability. Lung injury was assessed by histology, pulmonary permeability index (PPI), and wet-to-dry lung weight (W/D) ratio. Intestinal and lung nitric oxide (NO) concentrations were also measured. BT was assessed by serum peptidoglycan (PG) concentration. RESULTS The Chol and Chol+1400W groups developed hyperlipidemia and hypoadiponectinemia; the 2 groups also had vascular endothelial dysfunction without histological changes, indicating early atherosclerosis. These groups also showed poor recovery of intestinal microcirculatory flow at T1. The serum diamine oxidase activity, histological intestinal damage, and permeability were elevated at T1 in the Chol group; however, these findings were not significant in the Normal and Chol+1400W groups. Histological lung damage and lung PPI and W/D ratio were increased only in the Chol group. Intestinal and lung NO concentrations were significantly elevated at T1 in the Chol group. The serum PG concentration was elevated significantly in the Chol group. CONCLUSION In atherosclerotic rats with hypoadiponectinemia, intestinal microcirculatory flow does not recover adequately after intestinal ischemia/reperfusion because of endothelial dysfunction. Atherosclerosis with hypoadiponectinemia increased the incidence of BT further by aggravating intestinal mucosal injury and, moreover, it aggravated lung injury. Although inhibition of iNOS does not lead to adequate recovery of intestinal microcirculatory flow, it reduces injury by decreasing the amount of NO derived from high enzymatic iNOS activity in the intestine.

Pitavastatin prevents intestinal ischemia/reperfusion-induced bacterial translocation and lung injury in atherosclerotic rats with hypoadiponectinemia

BACKGROUND Atherosclerosis with hypoadiponectinemia can be further aggravated by intestinal ischemia/reperfusion (II/R)-induced injuries, such as bacterial translocation and lung injury. We investigated the effect of statin administration on the risk of II/R-induced injury in atherosclerotic rats with hypoadiponectinemia. METHODS Wistar rats were divided into 4 groups: (1) the Normal group (normal diet), (2) the Chol group (2% high cholesterol diet), (3) the St-1w group, and (4) the St-2w group (Chol group plus pitavastatin administration for 1 or 2 weeks, respectively). The serum concentrations of lipids and adiponectin were measured preoperatively. After midline laparotomy (time, T0), the superior mesenteric artery was occluded with a microvascular clamp for 30 min, followed by 360 min of reperfusion (T1). Intestinal and lung nitric oxide (NO) concentrations were measured. Intestinal injury was assessed by microcirculatory flow, histology, and permeability. Bacterial translocation was assessed by analysis of serum peptidoglycan concentration. Lung injury was assessed by histologic examination, pulmonary permeability index, and wet/dry lung weight ratio. RESULTS The 2-week administration of statins with high-cholesterol feeding (St-2w group) improved hypoadiponectinemia to levels similar to those of the Normal group. Intestinal and lung NO concentrations were significantly lower at T1 in the Normal and St-2w groups than in the Chol group. Statin administration improved poor recovery of intestinal microcirculatory flow in the Chol group. At T1, intestinal and lung injuries were significantly aggravated and serum peptidoglycan concentration was significantly elevated in the Chol group compared with the Normal and St-2w groups. The 1-week administration of statins had no significant influence on serum adiponectin levels, tissue NO concentration, or tissue injury. CONCLUSION Administration of pitavastatin reduces the risk of II/R-induced injury in atherosclerotic rats with hypoadiponectinemia by improving hypoadiponectinemia and inhibiting inducible NO synthase-produced NO. Furthermore, preoperative improvement of hypoadiponectinemia may be important as an index of the protective effect of pitavastatin for II/R-induced injury in atherosclerotic rats with hypoadiponectinemia.

Enteric absorption of FK 506 : Estimation by a block liver perfusion technique in rats

This perfusion model enables a pharmacokinetic study of enteral absorption and hepatic metabolic rate simultaneously. FK 506 is absorbed mainly via the proximal small intestine and metabolized rapidly by the liver during single passage. These results may lead to further analyses of absorption and metabolism of FK 506 under various conditions.

Results from coronary artery bypass surgery combined abdominal aortic aneurysm repair

OBJECTIVE Complication from coronary artery disease is a major cause of mortality and morbidity in patients undergoing abdominal aortic aneurysm repair. We report our results from coronary artery bypass surgery performed in combination with abdominal aortic aneurysm repair in patients with coronary artery disease and abdominal aortic aneurysm, each being an indication for an emergency operation. METHODS Seventeen patients underwent combined coronary artery bypass surgery and abdominal aortic aneurysm repair. The mean age of the patients was 67.6 +/- 5.2 years. Four had left main disease, 8 patients had triple-vessel disease, and 12 had a prior myocardial infarction. The average left ventricular ejection fraction was 0.49 +/- 0.13. The average abdominal aortic aneurysm diameter was 6.2 +/- 1.0 cm (range 4.5-8.0 cm). Thirteen patients underwent coronary artery bypass surgery followed by abdominal aortic aneurysm repair after discontinuation of cardiopulmonary bypass. In the remaining four patients, including one patient with severe left ventricular dysfunction, cardiopulmonary bypass was continued as a circulatory assist until the abdominal aortic aneurysm repair was completed. The left internal thoracic artery was used in 14 patients, and the right internal thoracic artery in one patient. RESULTS Postoperative surgical complications occurred in three patients (bleeding in one patient requiring reoperation, abdominal subcutaneous wound infection in another and transient neural disorder in the others). There were no surgical or in-hospital death. There was no late cardiac complication and no late cardiac death after a mean of 29 months follow-up. CONCLUSIONS We concluded that combined surgery was reasonable for selected patients with combined coronary artery disease and abdominal aortic aneurysm, each of which is an indication for an urgent operation. The aortic aneurysm repair during cardiopulmonary bypass for patients with severe left ventricular dysfunction was safe and effective.

The effect of combination splenectomy and low-dose FK506 therapy on graft survival after liver allograft transplantation in rats

The effect of splenectomy on allograft survival was investigated using orthotopic liver transplantation in a rat experimental model (ACI rat liver grafted to LEW rat). Control rats without any immunosuppressive treatment died, on average, 10.4 +/- 1.4 days after operation. Splenectomy alone somewhat prolonged the survival (13.4 +/- 2.0 days), and low-dose FK506 therapy moderately prolonged it (22.7 +/- 7 days). The graft survival period was significantly prolonged (39.7 +/- 6.3 days) when them two treatments were combined. The elevation of cytotoxic antiallograft antibodies was suppressed by splenectomy but not by low-dose FK506 therapy. The development of jaundice was moderately suppressed by FK506 but not by splenectomy. There was no difference between the pattern of body weight decline in either of them two groups and that in control rats. When these two treatments were combined at the same time, the elevation of cytotoxic antibodies, development of jaundice and decline of body weight were suppressed. These data indicate that B cells play an important role in the acute rejection of the rat liver allograft at least partially via production of cytotoxic antiallograft antibody. Splenectomy or other immunosuppressive methods affecting B cells can be a supplement for immunosuppression when using reduced-dose FK506.

Effects of a phosphodiesterase III inhibitor on circulating blood volume after cardiopulmonary bypass

Abstract Using a new method based on pulse dye densitometry, circulating blood volume (BV) was measured without direct sampling in patients undergoing open-heart surgery, and the effects of phosphodiesterase (PDE) III inhibitor administration during cardiopulmonary bypass (CPB) were evaluated. Sixteen patients scheduled for elective coronary artery bypass grafting were randomly assigned to the PDE III inhibitor group or control group. BV was determined before CPB, and immediately, and 4 and 12 h after operation. After declamping of the aorta, the PDE III inhibitor amrinone (1 mg/kg) was infused as a single bolus into the venous reservoir in the PDE III inhibitor group. BV decreased significantly soon after the operation in the control group. It did not decrease in the PDE III inhibitor group (48.6 ± 44 and 60.6 ± 8.0 ml/kg for the control and PDE III inhibitor groups, respectively). Four hours after surgery and beyond no significant changes in BV were observed in either group. The body fluid balance was negative in both groups. In conclusion, a single administration of PDE III inhibitor during CPB was found to sustain BV soon after operation and, therefore, is useful for postoperative management of open-heart surgery.

Early gastric cancer associated with synchronous liver metastasis and portal tumorous embolism: Report of a case

We report herein the first known case of early gastric cancer with synchronous liver metastasis forming a portal tumorous embolism. A 62-year-old man was found to have multiple liver tumors and a portal tumorous embolism by ultrasonography. A gastroscopy subsequently showed Borrmann type III-like gastric cancer in the antrum. His carbohydrate antigen (CA) 19-9 level was elevated to 8280 U/ml, but the α-fetoprotein level was within normal limits. A laparotomy revealed multiple liver metastasis and subpyrolic lymph-node enlargement; a distal partial gastrectomy with group 1 lymph-node dissection for the gastric cancer in the antrum, and cannulation of the proper hepatic artery for postoperative chemotherapy were performed. Histopathologically, the cancer was found to be a medullary type well-differentiated adenocarcinoma. Subpyrolic lymphnode metastasis was noted, but cancer invasion was localized to only the mucosal and submucosal layers of the stomach. Thus, the patient was diagnosed as having early gastric cancer. Adjuvant chemotherapy given through the cannula suppressed further elevation of CA19-9 levels, and a total of 26 Gy irradiation to a liver tumor, which had caused ascites by pressing on the inferior vena cava, diminished the ascites. The patient was able to remain at home with treatment for 7 months after radiation therapy, but finally died of cancer with jaundice 13 months after his operation. Therefore, although adjuvant chemotherapy and radiation therapy contributed to improving his quality of life, it could not prolong survival.