Biomedical subjects

K Hamazaki

Publications and source records attributed to K Hamazaki.

83 records · Page 5Linked to original sources

PubMedDate not supplied

Enhanced expression of cyclin E and cyclin A in human hepatocellular carcinomas.

BACKGROUND: Disruption of the G1/S check point leads to uncontrolled cell growth, resulting in the development of cancers. MATERIALS AND METHODS: Cell cycle regulatory molecules were investigated in 33 surgically resected hepatocellular carcinoma (HCC) samples from 30 patients by Western blotting. RESULTS: Enhanced expressions of cyclin E and cyclin A were detected at frequencies of 18/33 and 26/33 in HCCs, respectively, as compared with their neighboring noncancerous tissues. The enhanced expression of cyclin E, but not that of cyclin A, correlated with hyperphosphorylation of pRb and high frequency of Ki-67-positive cells. Thus, the HCCs with enhanced cyclin E expression probably contain a relatively large number of proliferating cancer cells. CONCLUSIONS: The degree of cyclin E expression can be used as a prognostic parameter of HCC. In addition, cyclin E may become a molecular target in the treatment of HCCs.

Aged↗

PubMedDate not supplied

Effect of HSP70 induced by warm ischemia to the liver on liver function after partial hepatectomy.

BACKGROUND/AIMS: The purpose of this study was to determine if induction of HSP70 (heat shock protein 70), a stress protein which plays a cytoprotective role in response to various stimuli, protects hepatocytes from damage caused by partial hepatectomy and, if so, to elucidate the mechanism of such protection. METHODOLOGY: One hundred and eight male F344 rats weighing 190-220 g were randomly assigned to two groups with or without the presence of preconditioning. Fifteen-minute warm ischemia was applied to the liver of rats to induce HSP70, and 70% hepatectomy was performed 48 hours after the induction of HSP70 (ischemia group; n = 72). The rats in the nonischemia group did not undergo 15-min warm ischemia prior to 70% hepatectomy (nonischemia group; n = 36). Six rats, selected randomly from each group, were sacrificed at each measurement point to obtain blood and liver tissue samples. The levels of HSP70 in the liver, serum nitric oxide, levels of catalase and superoxide dismutase activity in the liver as antioxidative enzymes, and levels of Bcl-xL and Bax proteins and caspase-3-like activity in the liver as indices of apoptosis, were measured. RESULTS: The mean +/- SD level of HSP70 in the ischemia group (100 +/- 42 arbitrary unit (au)) was significantly higher than that of the nonischemia group (2 +/- 0.7 au) immediately before hepatectomy (P < 0.05). The ischemic preconditioning attenuated the liver damage caused by the subsequent partial hepatectomy. The levels of superoxide dismutase and catalase activity, serum nitric oxide level, and Bax protein level of the ischemia and nonischemia groups showed no significant differences after the partial hepatectomy. In contrast, the mean +/- SD level of Bcl-xL in the liver of the ischemia group (261 +/- 52 au) was significantly higher than that in the nonischemia group (114 +/- 33 au) 12 hours after the hepatectomy (P < 0.01). Furthermore, the mean +/- SD level of caspase-3-like activity in the liver of the ischemia group (18.1 +/- 4.6 au) was significantly lower than that of the nonischemia group (26.0 +/- 4.8 au) at 12 hours after the hepatectomy (P < 0.05). CONCLUSIONS: HSP70 induced by ischemic preconditioning prior to the partial hepatectomy was considered to protect the liver itself. In addition, the induced HSP70 may affect the Bcl-xL level after partial hepatectomy. Therefore, Bcl-xL seems to be involved in the reduction of liver damage after partial hepatectomy along with HSP.

Alanine Transaminase↗

PubMedDate not supplied

Evaluation of hepatic functional reserve in rats with obstructive jaundice by asyaloglycoprotein receptor.

BACKGROUND/AIMS: Until now, there has been no adequate means of evaluating the liver functional reserve in cases with obstructive jaundice. 99mTC-GSA (99mTechnetium-DTPA-Galactosyl-human serum albumin) is a new liver-imaging agent which binds specifically to the asyaloglycoprotein-receptor on the membrane of hepatocytes. So, the liver imaging by GSA excludes the influence of the reticuloendothelial system. Therefore, the uptake of 99mTC-GSA is considered to be a useful method for the estimation of liver functional reserve in cases with obstructive jaundice. METHODOLOGY: In this study, we examined the uptake rate and specific binding capacities of 99mTC-GSA to receptors on the membrane of hepatocytes following 1, and 2 weeks of bile-duct ligation and 1 week after reduction of jaundice using the rat model. RESULTS: The hepatic uptake rate decreased as the period of jaundice was prolonged and returned to nearly normal by the reduction of jaundice. The value of specific binding capacities at 2 weeks after bile-duct ligation decreased significantly compared to the value of the control and the reduced group (P < 0.05). The cause of decrease in specific binding capacities was indicated as the decrease of affinity constant especially in the high affinity part. These results coincide with the change of binding capacities of insulin and glucagon receptors with obstructive jaundice, which accurately reflect the severity of hepatocyte injury. CONCLUSIONS: Taking together these results, 99mTC-GSA liver scintigraphy is thought to be a useful method to evaluate the liver functional reserve in cases with jaundice.

Albumins↗

PubMedDate not supplied

Changes of insulin and glucagon receptors following bile duct ligation and its release.

The specific bindings of insulin and glucagon to 4 x 10(4) g pellets containing hepatic plasma membrane were measured at 1 and 2 weeks after bile-duct ligation and 1 week after reduction of jaundice. At 1 week of jaundice, insulin binding was not decreased compared to control rats, however, glucagon binding 30(6)% was significantly lower than that 43(8)% in control rats (p < 0.01). At 2 weeks of jaundice, insulin binding 35(3)% was significantly lower than that 40(5)% in control rats (p < 0.05), and glucagon binding 26(4)% was also significantly lower compared to control rats 42(4)% (p < 0.01). The decreased insulin and glucagon receptors returned to nearly the levels of controls after 1 week's reduction of jaundice. These results suggested that the measurement of receptor binding may be useful as an indicator of the severity of hepatocyte injury.

Animals↗

PubMedDate not supplied

Effects of ulinastatin on polymorphonuclear leukocyte elastase and interleukin 6 levels after hepatectomy.

Eight patients undergoing hepatectomy received 15 x 10(4) U of ulinastatin during and after surgery and then twice daily for 4 days, and 11 hepatectomized patients served as untreated controls. Between-group differences in age, duration of surgery, volume of blood loss and transfusion, weight of resected liver, and results of preoperative liver function tests were not significant. On postoperative day 1, mean (+/- SD) polymorphonuclear leukocyte elastase levels were significantly lower in the treated patients than in the controls (310 +/- 69 micrograms/L vs 519 +/- 382 micrograms/L; P < 0.05); interleukin 6 levels also tended to be lower in the treated patients than in controls (42.4 +/- 34.0 pg/mL vs 63.3 +/- 43.1 pg/mL). The results indicate that ulinastatin has beneficial effects on host defenses after surgery.

Alanine Transaminase↗

PubMedDate not supplied

Serum levels of circulating intercellular adhesion molecule 1 in hepatocellular carcinoma.

BACKGROUND/AIMS: This is a comparative study of the relationship between. MATERIAL AND METHODS: Serum levels of circulating intercellular adhesion molecule-1 (cICAM-1) were measured by ELISA assay in four patients with chronic hepatitis (CH), 16 with liver cirrhosis (LC), 38 with hepatocellular carcinoma (HCC), and in nine healthy controls. RESULTS: No significant difference in cICAM-1 levels was observed between LC and HCC. The cICAM-1 level in HCC did not correlate with tumor markers but correlated well with tumor size. cICAM-1 level in HCC Stage III + IV was significantly higher than that of Stage I, and was higher in HCC with liver metastasis as opposed to HCC without metastasis. Furthermore, the cICAM-1 level of HCC decreased significantly after hepatectomy. CONCLUSION: These findings showed a close relationship between cICAM-1 and the progress of intrahepatic metastasis of HCC, indicating a possibility for using cICAM-1 as a prognostic marker.

Biomarkers, Tumor↗

PubMedDate not supplied

Clinicopathological features of gastric cancer in the remnant stomach.

BACKGROUND/AIMS: The clinicopathological features of 34 cases of gastric cancer in the remnant stomach were examined. PATIENTS AND METHODS: Twenty-three patients who underwent primary gastrectomy for benign gastric disease (Group I) and 11 patients who received gastrectomy because of primary gastric cancer (Group II) were studied. RESULTS: The median age at diagnosis of gastric remnant cancer was 62.2 years in Group I and 63.7 years in Group II. The median time interval between the primary operation and the appearance of gastric cancer was 12.6 years in Group I and 6.5 years in Group II. Almost all patients were symptomatic; presenting epigastralgia and constriction. The first diagnostic procedure for these patients was barium examination of the remnant stomach except one patient diagnosed by emergency gastroscopy for hematemesis. Seventy percent of patients in Group I had advanced gastric cancer, most of which were invasive to seromuscular layers, whereas in Group II early gastric cancer was dominant (55%). The prognostic evaluation after the second surgery showed that patients with early stages of cancer had longer survival in both Groups. CONCLUSIONS: These results suggest that early detection of gastric cancer in the remnant stomach by periodical follow up is important and that the application of aggressive surgery for this disease will provide better patient survival.

Adult↗

PubMedDate not supplied

Needle tract implantation of hepatocellular carcinoma after ultrasonically guided needle liver biopsy: a case report.

Cancer spread along the needle tract following fine needle biopsy is reported to be a rare complication. We report a case of subcutaneous implantation of hepatocellular carcinoma (HCC) following ultrasonically (US)-guided fine needle liver biopsy. The patient, a 53-year-old male was found to have a HCC at the medial segment of the liver confirmed by fine needle biopsy. Three year and four months after segmentectomy, the patient felt a subcutaneous growing lump at the previous biopsy site. The tumor was resected and confirmed histologically as HCC. We herein document other reports of such an occurrence following fine needle biopsy of HCC in Japan and consider this problem in liver biopsies.

Biopsy, Needle↗

PubMedDate not supplied

Interruption of hepatic arterial blood flow after resection of pancreaticobiliary carcinoma.

BACKGROUND/AIMS: We reviewed 17 cases of patients with interrupted hepatic arterial blood flow to determine the effect of such an interruption. MATERIALS AND METHODS: In 17 patients undergoing radical resection of pancreaticobiliary carcinoma with simultaneous hepatic artery excision (n=15) or intraoperative hepatic artery obstruction (n=2), morbidity and mortality were reviewed. Nine hepatic artery anastomoses were performed in 7 of these patients, and postoperative patency was obtained for 5 anastomoses. The patients were classified into the following groups: group I was 6 patients with complete interruption of hepatic arterial flow to the whole liver or the remnant liver, group II was 6 patients with interruption of hepatic arterial flow to a lobe of the liver, and group III was 5 patients with preservation of hepatic arterial flow. RESULTS: Disruption of the bilioenteric anastomosis occurred in all 6 patients from group I versus none of those in groups II and III (p<0.05). Liver abscess and liver failure developed in 1 patient each from group I, but the mortality rate in this group was not high. CONCLUSIONS: Hepatic artery reconstruction in patients with complete interruption of hepatic arterial blood flow appears to be necessary to avoid ischemic breakdown of the bilioenteric anastomosis.

Anastomosis, Surgical↗

PubMedDate not supplied

Promoter-independent loss of mRNA and protein of the Rb gene in a human hepatocellular carcinoma.

BACKGROUND: Inactivation of the retinoblastoma (Rb) gene is considered to play a fundamental role in the genesis and progression of several human cancers. In retinoblastoma, the inactivation of Rb promoter by mutations or hypermethylation has been reported. Although genetic changes of Rb gene have been described in hepatocellular carcinoma (HCC), an epigenetic change such as hypermethylation of the Rb promoter as reported in retinoblastoma has not been described. MATERIALS AND METHODS: We examined the hypermethylation in the promoter region of Rb gene by restriction fragment length polymorphism in 19 HCCs, as well as the expression of Rb mRNA and protein by RT-PCR and by immunoblotting, respectively. RESULTS: We found no evidence of hypermethylation in the promoter region of the Rb gene in all HCCs analyzed. However, the expression of Rb mRNA and protein was lost in one HCC, and no mutation was detected in the Rb promoter region of this patient. The inactivation of Rb promoter by hypermethylation or by inhibition of binding of transcription factors due to point mutations did not contribute to the loss of mRNA and protein in the patient. CONCLUSIONS: Hypermethylation in the Rb promoter region appeared to have little causal effect on HCC.

Aged↗

PubMedDate not supplied

Experimental evaluation of hepatic functional reserve using 111In colloid for clinical application.

We have postulated that reduced hepatic blood flow is the primary factor responsible for postoperative hepatic insufficiency, and have shown the usefulness of the hepatic blood flow index (KL) estimated by 198Au colloid. However, 198Au colloid has became unavailable due to its intense exposure activity. Therefore, we prepared 111In colloid as a substitute for 198Au colloid to evaluate hepatic functional reserve. In the present study, a 111In colloid was administered to rats to investigate the possibility of clinical application. First, liver cirrhosis was induced in rats using CCl4 Changes in KL and hepatic tissue blood flow were measured by hydrogen gas clearance (HL) after CCl4 injection, and was shown to correlates well with it. The correlation between KL and HL, together with normal and cirrhotic liver, was significant (r = 0.83, p < 0.01) Second, reticuloendothelial function was modulated with Zymosan A (stimulation) and Silica (suppression). The KL value remained unchanged in spite of the addition of an activator or suppressor to the reticuloendothelial system. Third, 30% and 70% hepatectomy models were studied according to the method of Higgins-Anderson. KL and HL was measured before and 1, 3 and 7 days after hepatectomy. KL and HL after 30% and 70% hepatectomy showed similar changes. These results indicate that the clearance of 111In colloid can be used clinically as an index of the hepatic blood flow.

Animals↗