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Biomedical subjects

Y Asanuma

Publications and source records attributed to Y Asanuma.

At least 127 records · Page 7Linked to original sources

Evaluation of hemodynamics and hepatic mitochondrial function on extrahepatic portal obstruction in the rat.

An animal model resembling clinical cases with extrahepatic portal vein obstruction was developed. The changes in hepatic mitochondrial function and the hepatic hemodynamics including hepatic regional blood flow, portal venous pressure, and portogram were evaluated to assess the effect of portal vein obstruction in the model. Portal vein ligation in this model was a simple and easy maneuver and could produce collateral veins to the liver--cavernomatous transformation--which were obviously seen in clinical patients with extrahepatic portal obstruction. Hepatic blood flow was significantly decreased until 5 days after portal vein ligation; however, hepatic blood flow was gradually increased and reached the normal value at 3 weeks after portal vein ligation due to the formation of the collateral veins to the liver. Respiratory parameters of mitochondria were gradually decreased and reached the lowest levels at 5 days after portal vein ligation, while they recovered to normal values in accordance with increasing hepatic blood flow at 3 weeks after portal vein ligation. In extrahepatic portal obstruction, although the liver is temporarily deteriorated by portal vein obstruction such as portal vein thrombosis, hepatic blood flow and the liver functions are to be normally improved with the formation of collateral veins to the liver.

Animals↗

Retroperitoneal liposarcoma: sonographic findings.

This study, based on sonographic (US) results of 10 cases with histologically proven retroperitoneal liposarcoma (eight well-differentiated and two pleomorphic types), shows that the presence of fine echogenic lines within the tumor is a useful sign for diagnosing a well-differentiated liposarcoma. Presence of numerous fine fibrous septa in the lipomatous tumor tissue is thought to be responsible for this interesting phenomenon. Of interest is the fact that the direction of these lines changed according to the probe format used: parallel horizontal lines when using a linear probe and concentric lines converging toward the probe when using a sector or curved linear probe. In contrast, pleomorphic liposarcoma does not show this US sign. Knowledge of these US findings is useful for the diagnosis of retroperitoneal liposarcoma.

Adult↗

Color Doppler findings of gastrointestinal varices.

BACKGROUND: Compared with esophageal varices, gastrointestinal varices are relatively rare, but they are clinically important because they tend to bleed massively. Color Doppler sonography is now widely used to diagnose the collaterals, but few color Doppler findings of gastric or intestinal varices have been reported. The aim of this study was to investigate the sonographic and color Doppler findings of gastrointestinal varices and to determine the role of color Doppler sonography in the diagnosis of these varices. METHODS: We studied 30 patients who were diagnosed by endoscopy as having gastrointestinal varices (24 gastric, four duodenal, two intestinal) with color Doppler sonography and compared the results with the clinical data. The causes of gastric varices included liver cirrhosis (16/24, 66.7%), idiopathic portal hypertension (3/24, 12. 5%), chronic pancreatitis with splenic vein thrombosis (2/24, 8.3%), congenital biliary atresia (1/24, 4.2%), congenital hepatic fibrosis (1/24, 4.2%), and unknown (1/24, 4.2%). The causes of duodenal varices included idiopathic portal hypertension with portal thrombosis (3/4, 75%) and liver cirrhosis (1/4, 25%). RESULTS: The gastric wall at the fundus was thickened in 17 of 24 cases (70.8%) with gastric varices, and the duodenal wall was thickened in four of four cases (100%) with duodenal varices. Sonography revealed thrombosis in the splenic vein in two of two cases with gastric varices secondary to chronic pancreatitis and in the confluence of the superior mesenteric vein and the splenic vein in three of four cases with duodenal varices. Color Doppler sonography demonstrated multiple, slow constant blood flows in the thickened wall in 15 of 24 cases (62.5%) with gastric varices and in four of four cases (100%) with duodenal varices. It demonstrated accumulated slow constant blood flows in the cecum in the case with cecal varices. Color Doppler showed also the communication between the varices and the neighboring vascular system (superior mesenteric vein and inferior vena cava) in the case with cecal varices, but it did not directly reveal such a communication in the other 29 cases (96.7%). Color Doppler showed a hepatofugal flow in the left gastric vein in all the hemorrhagic gastric varicose patients with esophageal varices, but it showed a hepatopetal flow in the left gastric vein in the isolated nonhemorrhagic gastric varicose patients. CONCLUSION: Color Doppler sonography was very useful for the diagnosis of gastric and duodenal varices and for visualizing fine venous flows in the thickened gastric or duodenal wall. When it shows portal thrombosis in the confluence of the splenic vein and the superior mesenteric vein, duodenal varices should be suspected. The flow direction of the left gastric vein helps to differentiate hemorrhagic gastric varices from nonhemorrhagic ones.

Adolescent↗

Small bowel varices: report of two cases.

Two cases of small bowel (S-B) varices associated with portal hypertension, one with liver cirrhosis and one with portal thrombus, are reported. Detection of S-B varices has been a challenging task and several invasive diagnostic techniques have been used for this purpose. However, in our cases, color Doppler sonography revealed the S-B varices supplied by the superior mesenteric vein and draining to the iliac (one case) or ovarian vein (other case), which helped to establish an early appropriate diagnostic and treatment plan.

Aged↗

Exchange blood transfusion and on-line plasma exchange for sepsis in infants.

During the last 6 years, 19 infants with sepsis have been treated with exchange blood transfusions 47 times, and 13 patients survived. However, this procedure is compromised by antibody formation against WBCs and platelets. Accordingly, a miniature system for on-line plasma exchange (PE) between septic infant and healthy parent has been developed and evaluated using a canine model. Escherichia coli, at a dose of 5 X 10(9) CFU/ml/kg, was injected intravenously into 17 puppies that were divided into 3 groups; untreated; sham treated; and PE in which 80 ml/kg of plasma in each septic puppy was replaced during 2 hr with fresh plasma simultaneously obtained from healthy adult dogs. Four of 5 puppies survived in the PE group, while all other puppies died within 24 hr. In the PE group, viable cell counts of E. coli and endotoxin decreased significantly, and opsonic activity improved. This system is effective and applicable for treatment of sepsis in infants.

Animals↗

A case of bilioduodenal fistula treated with a self-expandable metallic stent.

We report the case of a 72 year-old female patient who suffered from biliary fistulae. The biliobiliary and bilioduodenal fistulae appeared after an operation for biliary bleeding. Conventional therapy for biliary fistula would be the disconnection of the fistula by either conservative or operative treatment. In the present case, however, it was preferable to enlarge the fistula to drain bile juice into the duodenum, rather than to close the fistula because it would have been difficult to achieve a tight adhesion with this operation. The enlargement by a plastic tube stent failed to drain the bile juice into the duodenum, because the sludge made the tube stenotic. Therefore, a self-expandable metallic stent was applied in this case. An expandable stent was used because a large final caliber is necessary to prevent stenosis of the fistula by sludge and mucosal hyperplasia. After insertion of a self-expandable metallic stent by the percutaneous transhepatic biliary drainage route, the patient has not suffered from cholestasis and cholangitis for the last 30 months. It can therefore be concluded that enlargement of the fistula by a self-expandable metallic stent is a convenient therapy for such biliointestinal fistulae.

Aged↗

Efficacy of hepatic arterial infusion of prostaglandin E1 in the treatment of postoperative acute liver failure--report of a case.

Prostaglandin E1 (PGE1) has received attention for its protective effects against various types of liver damage. However, it is known that approximately 70% of PGE1 is inactivated during a single passage through the lung. Therefore, direct infusion of PGE1 into the liver bloodstream is preferable to intravenous infusion. A 66-year-old man with hepatocellular carcinoma with liver cirrhosis developed postoperative acute liver failure following posterior segmentectomy under hepatic total vascular exclusion exceeding 1 hour. Because his liver function did not recover in spite of plasma exchange starting on postoperative day 8 and intravenous infusion of PGE1, hepatic arterial continuous infusion of PGE1 at a rate of 0.01 microgram/kg/min was carried out for 7 days from postoperative day 17. Immediately after the start of the arterial infusion, the bile flow significantly increased compared to before the arterial infusion, and the serum total bilirubin level decreased thereafter and finally recovered from the hepatic failure. In addition to its highly efficient drug delivery, the hepatic arterial infusion of PGE1 seems to be more advantageous in oxygen delivery to the liver compared with intravenous infusion. In conclusion, the hepatic arterial infusion of PGE1 may be useful in the treatment of acute liver failure.

Aged↗

Blood purification for postoperative liver failure with special reference to chronic hepatic support for those awaiting liver transplantation.

Blood purification, mainly plasma exchange (PE), was carried out for 13 cases of acute, and two cases of chronic postoperative liver failure. Four of thirteen acute cases (31%) survived. Although only one of eight with chronic liver disease survived, three of five without chronic liver disease survived. In most of those who lived, other organ failure occurred less often; total bilirubin and blood ammonia were less than 15 mg/dl and 200 micrograms/dl, respectively, before PE: and total bilirubin, blood ammonia, and branched chain amino acid/aromatic amino acid (BCAA/AAA) ratios recovered after five or fewer sessions of PE. Two chronic cases, treated for 1 and 4 years, respectively, were good candidates for liver or multiple organ transplantation. Although both died, PE was effective in reducing jaundice and in improving consciousness and general condition. Plasma exchange should be introduced early after assessing the changes in total bilirubin, blood ammonia, and coma grade in patients with acute postoperative liver failure. Plasma exchange could be useful as a chronic hepatic support system for those awaiting liver transplantation.

Acute Disease↗