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N Kameoka

Publications and source records attributed to N Kameoka.

At least 19 recordsLinked to original sources
PubMed2000

Gadolinium pretreatment decreases survival and impairs liver regeneration after partial hepatectomy under ischemia/reperfusion in rats.

BACKGROUND: Modulation of Kupffer cell functions by treatment with gadolinium chloride protects the liver against reperfusion injury. However, its effect on liver regeneration after hepatectomy under ischemia/reperfusion has not been studied. Using a common clinical ischemia/reperfusion technique, we examined the effect of gadolinium on liver regeneration after hepatectomy in rats. METHODS: After an initial 15-minute ischemia and 15-minute reperfusion, 70% hepatectomy was performed during the second 15-minute ischemia period in gadolinium-pretreated (gadolinium group) and saline solution--pretreated (control group) rats. The 24-hour survival rate, relative liver weight, DNA synthesis rate, and hepatic adenosine triphosphate level were examined immediately after hepatectomy and on postoperative days (PODs) 1, 2, 3, and 7. Serum levels of total bilirubin, glutamic pyruvic transaminase, and endotoxin were also measured. RESULTS: The 24-hour survival rate was significantly lower in the gadolinium group (67%) than in the control group (100%). On POD 1, the relative liver weight and DNA synthesis rate were significantly lower in the gadolinium group than in the control group. On POD 1, serum total bilirubin and endotoxin levels were significantly higher in the gadolinium group than in the control group. Immediately after hepatectomy, the hepatic adenosine triphosphate level was significantly lower in the gadolinium group than in the control group. CONCLUSIONS: Under ischemia/reperfusion, gadolinium pretreatment impairs liver regeneration and energy status after hepatectomy and decreases postoperative survival.

Adenosine Triphosphate↗
PubMed2000

Effect of preoperative portal vein embolization on liver volume and hepatic energy status of the nonembolized liver lobe in humans.

Clinically portal vein embolization (PVE) is presently preferred to extended hepatectomy. Nevertheless, its effect on hepatic adenosine triphosphate (ATP) and energy charge levels, which are essential for organ viability, has been little studied in humans. Fourteen patients with (n = 7) and without (n = 7) preoperative right PVE participated in this study. Changes in hepatic lobar volume and serum liver function tests were examined before and after percutaneous transhepatic right PVE. Liver volume (cm(3)) was calculated on computed tomograms before and 20+/-3 days after PVE. At the time of surgery (mean of 25 days after PVE), small liver specimens were obtained from portal vein (PV) nonembolized left lobes immediately after laparotomy without any ischemic procedures. Concentrations of adenine nucleotides were measured by high performance liquid chromatography, and hepatic energy charge levels were calculated. These values were compared with those in control patients who had not undergone preoperative PVE. Serum liver function tests including the indocyanine green retention rate did not differ significantly before and after PVE. The volume of the PV-nonembolized left lobe significantly increased after right PVE (from 473+/-32 to 624+/-66 cm(3)), with a significant increase in the percentage of the left lobe to total liver volume. The concentrations of AMP, ADP, and ATP, and hepatic energy charge levels in the PV-nonembolized left lobe were similar to those of the control liver. These results suggest that preoperative right PVE increases the volume of the nonembolized left lobe, keeping the hepatic engery charge and ATP levels similar to the control liver, thereby increasing the total amount of ATP and hepatic energy reserve of the PV-nonembolized lobe in proportion to its volume increase at the time of surgery.

Adenine Nucleotides↗
PubMed1999

Rotational Digital Angiography for the Evaluation of Iliac Artery Disease.

Ten cases with iliac artery disease were evaluated using rotational angiography with revolution of the arm of the X-ray tube support unit. The tip of the catheter was advanced to the infrarenal aorta, and contrast medium was injected at a rate of 6-10 ml/second. Digital angiographic images from multiple projection angles were acquired at 15 frames/second with a rotation speed at about 10 degrees/second and a range of greater than 90 degrees. This method made it possible to detect ulcerations of the artery, which could not be visualized using conventional single-plane angiography. The three-dimensional structure of a dissection could also be visualized. In seven cases of occlusive iliac artery disease, comparison with rotational angiography revealed that anteroposterior views of single-plane angiography underestimated the extent of the disease in four cases and overestimated the extent of the disease in one case. In two cases, no additional clinical information was obtained. In conclusion, rotational angiography provides accurate three-dimensional information concerning the lumen of the iliac arteries.

Journal Article↗
PubMed1998

Advantage of preoperative portal vein occlusion for hepatectomy that exceeds portal vein occluded lobes.

BACKGROUND: The purpose of our study was to examine the effect of preoperative portal vein (PV) occlusion on hepatic reserve function after extended hepatectomy that is an excision of areas beyond the PV occluded lobes. METHODS: Male Wistar rats were divided into three groups and underwent a two-stage operation: a PVL-hepatectomy group (ligation of the PV [PVL] of the left and median lobes followed by hepatectomy of the right lobes together with the PV occluded lobes), a sham-88% hepatectomy group (sham operation without PVL followed by hepatectomy corresponding to the lobes excised in the PVL-hepatectomy group), and a sham-67% hepatectomy group (sham operation followed by hepatectomy of the left and median lobes to approximate the volume excised in the PVL-hepatectomy group). In all subjects, hepatectomy was carried out 7 days after the PVL or sham operation. On days 0, 1, 2, and 3 after hepatectomy, liver weight, histologic elements, DNA synthesis rates, energy charge, adenine nucleotides, and lipoperoxide levels of the remaining liver were determined. RESULTS: In the sham-88% hepatectomy group, the volume of resected liver was 88.2% +/- 0.5%. In the PVL-hepatectomy group it was 69.1% +/- 0.8%, although anatomically identical lobes were excised. At the time of hepatectomy, DNA synthesis, hepatic concentrations of adenine nucleotides and lipoperoxide, and serum liver function tests showed similar results in all three groups. The survival rate 3 days after hepatectomy was significantly low (53%) in the sham-88% hepatectomy group, whereas it was 100% in the PVL-hepatectomy and sham-67% hepatectomy groups. The gain in liver weight per day was significantly lower in the sham-88% hepatectomy group than in the other two groups. The decline in hepatic energy charge after hepatectomy was less, with less activated DNA synthesis, in the PVL-hepatectomy group compared with the sham-88% hepatectomy and sham-67% hepatectomy groups. Lipoperoxide concentration in the PVL-hepatectomy group was significantly lower than that in the sham-88% hepatectomy and sham-67% hepatectomy groups. CONCLUSIONS: Preoperative PV occlusion not only increases the remaining liver volume but also is advantageous to hepatic reserve after hepatectomy that exceeds PV occluded lobes.

Adenine Nucleotides↗
PubMed1997

Cholesterol and bile acid metabolism after selective portal vein ligation.

AIM: To examine the regulatory effect of bile acid level on bile acid synthesis in the liver. METHODS: The portal branch perfusing left lateral and median lobes of the liver was ligated in rats and the activities of hepatic microsomal cholesterol 7 alpha-hydroxylase, the rate-limiting enzyme of bile acid synthesis, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, and intrahepatic concentrations of cholesterol and bile acids were determined in the liver lobes deprived of and supplied with portal blood on Days 0, 1, 2, 4, and 7 after selective portal vein ligation (SPVL). RESULTS: In the portal vein (PV)-ligated lobes, liver weight decreased, hepatic cholesterol concentration was unchanged, and microsomal cholesterol concentration increased after SPVL. In the PV-nonligated lobes, liver weight increased, hepatic cholesterol concentration increased, and microsomal cholesterol concentration was unchanged. There were no significant differences in the activities of HMG-CoA reductase and cholesterol 7 alpha-hydroxylase among the PV-ligated and PV-nonligated lobes and the sham-operated controls. Intrahepatic bile acid level increased significantly in the PV-nonligated lobes for 4 days after SPVL, whereas those were essentially constant in the PV-ligated and the sham-operated control liver. Despite significant changes in the concentrations of intrahepatic cholesterol and bile acid, no significant correlations were observed between these concentrations and the activities of cholesterol 7 alpha-hydroxylase. CONCLUSIONS: SPVL causes atrophy and hypertrophy of the PV-ligated and nonligated liver lobes, respectively, without any significant changes in cholesterol and bile acid synthesis. Intrahepatic concentrations of bile acids and cholesterol have no regulatory effect on cholesterol 7 alpha-hydroxylase activity in the SPVL rat model.

Animals↗
PubMed1997

Serum hyaluronic acid level reflects volume and ATP levels of the liver after extended hepatectomy with and without preoperative portal vein occlusion.

The purpose of this study was to examine the hypothesis that the serum hyaluronic acid (HA) level reflects the volume and adenosine triphosphate (ATP) levels of the liver after extended hepatectomy (ExHx) with and without preoperative portal vein occlusion (PVO). Rats were randomly divided into two groups, PVO-ExHx and sham-ExHx. At the first stage, they underwent PVO or sham surgery by an occlusion of the portal vein supplying the left lateral and median lobes or by similar manipulation but without PVO, respectively. Seven days after first-stage surgery, both groups received ExHx exceeding portal vein-occluded lobes, which was the excision of the left lateral, median, and right lateral lobes of the liver reported as a 90% hepatectomy model. On Days 0, 1, 2, and 3 after ExHx, the serum HA concentrations, liver weights, and hepatic ATP levels were determined. Liver volumes were restored to similar levels in both groups, but restoration was faster in the PVO-ExHx group because preoperative PVO allowed the excised liver less volume. Lower serum HA levels were significantly associated with significantly higher hepatic ATP levels and with a lower mortality rate in the PVO-ExHx group. The serum HA level correlated significantly (P < 0.001) with the liver weight and hepatic ATP level. The serum HA level serves as a proxy for clinically important parameters following major hepatic surgery.

Adenosine Triphosphate↗
PubMed1996

Functional contribution of preoperative portal vein occlusion to hepatectomy. With special reference to hepatic energy charge and DNA synthesis after hepatectomy in rats.

OBJECTIVE: To examine possible functional contributions of preoperative portal branch ligation before hepatectomy (PBL-Hx). DESIGN: Rats were randomly divided into 3 groups. In the PBL-Hx group, the portal branch supplying the left lateral and median lobes of the liver was ligated and the corresponding lobes (48% of the whole liver) were excised 2 days later. In the sham groups (one 68% Hx; the other 47% [hereafter, sham-67% Hx, and sham-47% Hx]), originally ligated lobes and left lateral and caudate lobes, similar to the excised liver volume in the PBL-Hx group, respectively, were excised 2 days after sham operation without PBL. MAIN OUTCOME MEASURES: Hepatic adenine nucleotides and energy charge, which are essential for vital function of hepatocytes, and liver regeneration were assessed by the DNA synthesis rate and weight before Hx and on days 1, 2, 3, and 7 after Hx. RESULTS: The remaining liver weight was restored similarly in the PBL-Hx and sham-47% Hx groups and more rapidly than in the sham-68% Hx group. Further enhancement of DNA synthesis did not occur after Hx in the PBL-Hx group, and hepatic energy charge did not decrease. In contrast, hepatic DNA synthesis was significantly activated depending on the excised liver volume in both the sham-Hx groups and was accompanied by corresponding decreases in hepatic energy charge. CONCLUSION: Preoperative PBL has a functional advantage because the recovery of the remaining liver volume is not impaired and hepatic energy charge is preserved with no further enhancement of DNA synthesis after Hx.

Adenine Nucleotides↗
PubMed1996

Postprandial responses of liver blood flow prior to and following hepatectomy in conscious dogs.

The responses of the portal and hepatic arterial blood flows to various diets and nutrients were measured simultaneously in conscious dogs prior to and following hepatic resection. Prior to hepatectomy, the increase in the portal blood flow was significantly larger in response to an elemental diet, fats, or amino acids than to glucose or water. The peak increase was 60.2 +/- 14.4 ml for water, 144.7 +/- 22.1 ml for a 150-cal elemental diet, 168.5 +/- 16.1 ml for a 300-cal elemental diet, 86.7 +/- 14.0 ml for a glucose solution, 159.3 +/- 16.7 ml for an amino acid meal, and 188.5 +/- 25.3 ml for a fat meal. Following partial hepatectomy, fats and amino acids induced an increase in the portal blood flow similar to that prior to hepatectomy. Glucose and the elemental diet, on the other hand, induced a significantly larger increase in portal blood flow following the surgery although water did not. The peak increase was 144.4 +/- 27.8 ml for glucose (166% of the peak increase prior to hepatectomy) and 221.8 +/- 32.5 ml for the 300-cal elemental diet (132%). The postprandial response of the hepatic artery to every diet was quite different among the dogs and there were no significant changes both prior to and following surgery. The different response of the portal flow to intraluminal glucose following partial hepatectomy may be due to alterations in glucose metabolism following hepatectomy. We have shown that the postprandial response of the portal blood flow varies with the type of nutrient, and it can be altered by hepatectomy.

Animals↗
PubMed1996

Sequential changes of energy charge, lipoperoxide level, and DNA synthesis rate of the liver following biliary obstruction in rats.

To clarify the effects of obstructive jaundice on the liver, sequential changes of hepatic energy charge, the concentrations of adenine nucleotides and malondialdehyde, DNA synthesis rate, and histology of the liver were examined on the day before and Days 1, 2, 4, 7, and 14 after biliary obstruction in rats and compared with those of sham-operated controls. Foci of necrotic hepatocytes were present on Days 1 and 2 and mitoses of the hepatocytes were frequently observed with a peak on Day 2 in the jaundiced liver. Marked proliferation of bile ductules were subsequently observed on Days 7 and 14, resembling biliary cirrhosis. The DNA synthesis rate was significantly activated after bile duct obstruction with its peak on Day 2, more than nine times higher than the control value and returned to the control level on Day 14. Hepatic ATP concentration and energy charge gradually declined with prolonged jaundice and significantly lower levels persisted after Day 7 compared with the controls. The malondialdehyde level in the jaundiced liver gradually increased and became significantly higher on Day 14. We conclude that obstructive jaundice decreases hepatic energy charge and increases the lipoperoxide level. In the initial stage of obstructive jaundice, the hepatocytes proliferate associated with activated DNA synthesis probably to compensate hepatic damage; however, prolonged obstructive jaundice induces functional hepatic injury possibly necessitating biliary drainage.

Adenosine Triphosphate↗
PubMed1996

Changes in liver blood flow after hepatectomy in conscious dogs.

Hepatic circulation after hepatectomy was investigated in conscious dogs under fasting and feeding conditions. After a 40% hepatectomy, both the hepatic arterial and portal blood flow were measured simultaneously using ultrasonic transit time flowmeters. During fasting, the total hepatic blood flow (i.e., the sum of arterial and portal blood flow) changed in a biphasic pattern after hepatectomy. The first peak (517.9 +/- 42.7 ml/min; 130.1% of preoperative flow) was seen on the 1st postoperative day (POD) and the second peak (444.8 +/- 25.6 ml/min; 112.7% of preoperative flow) occurred on the 7th POD. The portal flow demonstrated the same biphasic changes as the total hepatic flow, although the hepatic arterial flow showed only the first peak. A heart rate analysis suggested that the first peak was probably due to hyperdynamic circulatory conditions, as has been previously reported. In addition, the existence of the second peak was established by the present study. The postprandial hepatic blood flow decreased during the first 2 weeks postoperatively, but exceeded the presurgical levels on PODs 21 and 28.

Animals↗
PubMed1996

Hepatic adenine nucleotides and DNA synthesis during the regenerative and atrophic process of the liver lobes after selective portal vein ligation.

Selective portal vein occlusion prior to aggressive hepatic resection is now an alternative way to decrease postoperative morbidity and mortality rates. However, the detailed changes in the hepatic energy status and DNA synthesis rate in both portal vein ligated (PVL) and nonligated (PVNL) lobes of the liver are not clear. In rats, the portal branch that supplies 70% of the liver volume was ligated, and changes in arterial ketone body ratio (AKBR), liver weight, histology, DNA synthesis rate and adenine nucleotides of the PVL and PVNL liver lobes were determined before and 1, 2, 4 and 7 days after portal vein ligation, and compared with those in sham-operated rats. The weight of the PVL lobes decreased, while that of the PVNL lobes increased depending on time. The DNA synthesis rates of the PVNL lobes were significantly higher than those in sham-operated control liver during the first 4 days with the maximal value on the 2nd day, while those of PVL lobes were essentially similar to the control values. Energy charge (EC) in both PVL and PVNL lobes significantly decreased on day 1 and recovered gradually, but with less extent in the regenerating PVNL lobes. The concentrations of total adenine nucleotides (TAN) in both the PVL and PVNL lobes were essentially similar during the first 2 days, but became significantly lower in PVL lobes after day 4. A decrease in EC preceded an increase in DNA synthesis only in the PVNL lobes, in contrast to the PVL lobes. Mitosis of hepatocytes on day 2 and subsequently enlarged lobules with an increased number of hepatocytes were histologic features in the PVNL liver. The AKBR was not correlated with hepatic energy charge of the liver. In conclusion, PVNL liver regenerates preceded by a decrease in EC and a subsequent increase in DNA synthesis keeping TAN constant, while PVL liver becomes atrophic, with a similar change in EC of the PVNL liver but ultimately decreased TAN without any change in DNA synthesis. AKBR is not a parameter reflecting the hepatic EC after portal branch ligation.

Adenine Nucleotides↗
PubMed1995

Treatment of choice for choledocholithiasis in patients with acute obstructive suppurative cholangitis and liver cirrhosis.

OBJECTIVE: To identify the treatment of choice for choledocholithiasis in patients with versus without acute obstructive suppurative cholangitis (AOSC) or liver cirrhosis, the outcomes of surgical treatment and endoscopic sphincterotomy (EST) were compared. PATIENTS AND METHODS: Three hundred sixty-two consecutive patients with choledocholithiasis were divided into three groups: 27 with AOSC (Group 1), 12 with cirrhosis (Group 2), and 323 with neither AOSC nor cirrhosis (Group 3). RESULTS: Seventeen patients (63%) in Group 1 underwent emergent treatment, and 3 of them died. Two were treated by emergency surgery and both died; only 1 (7%) of 15 treated by emergent EST died. For all patients with AOSC, morbidity and mortality rates were 67% and 33% with surgery, and 24% and 5% with EST. In Group 2, 2 patients with Child C cirrhosis died after elective EST. One patient in Group 3 died. Mortality rates were significantly higher in Group 1 (11%) and Group 2 (17%) than in Group 3 (0.3%). Although comparisons between the two treatment approaches did not achieve statistical significance, EST had lower morbidity rates than surgery in both Group 1 (24% versus 67%) and Group 2 (22% versus 67%). The required hospital stay was half as long with EST as with surgery. CONCLUSIONS: EST is the recommended treatment for patients with choledocholithiasis associated with AOSC or liver cirrhosis.

Acute Disease↗
PubMed1995

Hepatic resection for hepatolithiasis and long-term results.

BACKGROUND: Hepatic resection is an established procedure for treating patients with hepatolithiasis. The long-term results after hepatic resection for hepatolithiasis were appraised. STUDY DESIGN: Of 127 patients with hepatolithiasis seen between 1973 and 1993, 43 patients underwent hepatic resection, and constituted the basis of this study. RESULTS: There was one operative death (operative mortality rate of 2.3 percent) and three deaths as a result of concomitantly associated cholangiocellular carcinoma. Of the remaining 39 patients, the complete stone clearance rate was 67 percent with operation alone, but reached 87 percent when cholangioscopy was used. Operative morbidity was recorded in five patients (12 percent), but they recovered with conservative therapy. Stones recurred in 15 percent of patients after a mean follow-up period of four years (range of three to six years). Eleven (28 percent) of 39 patients died after hepatectomy as a result of related diseases after a mean follow-up of 6.2 years. These 11 patients had associated biliary drainage procedures. They experienced a higher mortality rate (p < 0.05) than patients who did not have biliary drainage. CONCLUSIONS: We conclude that hepatic resection is adequate treatment for hepatolithiasis. The patients having additional biliary drainage procedures had a higher mortality, but one cannot reach conclusions about the negative effect of the drainage procedures because the drainage procedures were done in a selected and not a randomized manner.

Adult↗
PubMed1994

Impaired hepatic ketogenesis and regeneration after partial hepatectomy in cirrhotic rats.

To examine the difference in hepatic ketogenesis during the regeneration process between cirrhotic and normal liver, arterial ketone bodies (acetoacetate and 3-hydroxybutyrate), free fatty acids and glucose concentrations and liver regeneration rate were determined at 0, 1, 2, 3 and 7 days after partial (70%) hepatectomy in thioacetamide-treated cirrhotic and normal rats. Hepatic ketone body production per unit liver was calculated by total ketone body concentration x blood volume/the remaining liver weight. The regeneration of cirrhotic liver was delayed compared with that of normal liver. In normal rats, total ketone body concentration increased on the 1st day both after hepatectomy and sham operation, and returned to the basal level thereafter. In cirrhotic rats after hepatectomy or sham operation, however, total ketone body concentration did not increase throughout the experimental period although free fatty acids level increased more greatly than in normal rats. Arterial ketone body ratio (acetoacetate/3-hydroxybutyrate) and glucose level decreased on the 1st day after hepatectomy, and recovered after the 2nd day in both cirrhotic and normal rats. Hepatic ketone body production after hepatectomy was significantly greater in normal rats than cirrhotic rats, and hepatectomy itself increased hepatic ketone body production in both rats on the 1st and 2nd postoperative days. In conclusion, hepatic ketone body production is impaired after hepatectomy in cirrhotic rats, which is possibly related to the delayed regeneration of cirrhotic liver.

Animals↗
PubMed1994

Proliferating cell nuclear antigen, plasma fibronectin, and liver regeneration rate after seventy percent hepatectomy in normal and cirrhotic rats.

BACKGROUND: The difference in liver regeneration rate in relation to proliferating cell nuclear antigen (PCNA) and plasma fibronectin level in the cirrhotic and control liver after 70% hepatectomy were examined in the rat. METHODS: Liver cirrhosis was induced by intraperitoneal injection of thioacetamide for 12 weeks; rats without thioacetamide administration served as controls. On the day before and days 1, 2, 3, and 7 after 70% hepatectomy, PCNA labeling index of hepatocyte, plasma fibronectin level, and percentage of the initial liver weight were determined. RESULTS: Liver regeneration rate as expressed by percent of initial liver weight was impaired in the cirrhotic liver, and significantly lower regeneration rate was observed on days 3 and 7 after hepatectomy in the cirrhotic rats as compared with controls. PCNA labeling index was higher in the cirrhotic liver before hepatectomy. Little change of PNA labeling index was observed in the cirrhotic liver, although the index increased significantly in the control liver; significantly higher values were observed on days 1, 2, and 3, with the maximal value on day 2 after hepatectomy. The plasma fibronectin level was significantly lower in the cirrhotic rat before and after hepatectomy. CONCLUSIONS: The results show that liver regeneration is impaired in the cirrhotic liver associated with little activation of PCNA and with lower plasma fibronectin level.

Animals↗
PubMed1994

Postoperative follow-up of patients with type IVA choledochal cysts after excision of extrahepatic cyst.

BACKGROUND: This study concerns patients who have choledochal cyst with intrahepatic and extrahepatic involvement (type IVA cyst). The extent of excision and the necessity of hepatectomy, including the intrahepatic cyst in these patients have not been clarified. STUDY DESIGN: We have performed excision of the extrahepatic cyst with hepaticojejunostomy upon 13 patients with type IVA cyst during a 16 year period. The present study was done to examine the size of the anastomotic opening by direct cholangiography two weeks postoperatively. The long-term results were assessed to find the appropriate operative management for patients with type IVA cysts. RESULTS: Intrahepatic cysts were present in both hepatic lobes in 11 patients (85 percent). None of the patients had carcinoma after excision of extrahepatic cyst during the follow-up period, which ranged from two months to 16 years. Postoperative late complications occurred in three patients (23 percent), hepatolithiasis in two and cholangitis in one. The anastomotic opening of hepaticojejunostomy was 13.3 +/- 4.5 mm in diameter two weeks postoperatively, which was not significantly different when compared with that in ten patients without late complications (13.4 +/- 4.9 mm). The late complications were successfully treated with either antibiotics or percutaneous transhepatic cholangioscopy, and none required a reoperation. CONCLUSIONS: The results suggest that additional hepatectomy is not required because carcinoma has rarely occurred from the intrahepatic cyst. Excision of an extrahepatic cyst with a wide hepaticojejunostomy is an acceptable operative management for patients with type IVA cysts.

Adult↗