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Biomedical subjects

H Masuda

Publications and source records attributed to H Masuda.

694 records · Page 39Linked to original sources
PubMedDate not supplied

Relationship between fatty liver and liver metastasis in rats given injection of rat colon cancer cell line.

BACKGROUND/AIMS: In a previous study we described that colorectal cancer patients with fatty liver had few liver metastases. To clarify whether this clinical finding is correct, we studied whether rats with fatty liver had infrequent liver metastases using experimental colon cancer. METHODOLOGY: Twenty male inbred F344/DuCrj rats (CLEA JAPAN Inc.), 8 weeks of age, were used in this study. These 20 rats were divided into two groups: Fatty liver group (FL group, n = 10) and Non-fatty liver group (NFL group, n = 10). 1.0 ml of tumor-cell suspension containing 1 x 10(7) RCN-9 cells was injected just under the capsule of the spleen. All animals were sacrificed 2 weeks after tumor inoculation. RESULTS: 1) Four rats out of 10 in the FL group (40%) had at least one metastatic nodule on the surface of the liver, while there were 10 rats with metastatic nodules in the NFL group (100%) (p < 0.01). 2) The ratio of the liver metastasis area against the largest section of the left lobe of the lateral segment (RLML) was examined. The average RLML of the FL group was 0.45%, which was significantly lower than that of the NFL group (7.11%) (p < 0.0001). CONCLUSIONS: Rats with fatty liver seldom had liver metastases compared to normal rats. This means that fatty liver itself can possibly bring about situations with infrequent liver metastases.

Animals↗
PubMedDate not supplied

Gastroduodenal intussusception secondary to a gastric carcinoma.

A case of gastroduodenal intussusception secondary to transpyloric prolapse of a primary gastric carcinoma is reported. Both the condition itself and the leading tumor, gastric carcinoma, are extremely exceptional. A diagnosis of this rare entity was established pre-operatively by endoscopy that demonstrated spontaneous reduction of the intussusception. This may be the first documentation of spontaneous reduction of the gastroduodenal intussusception during endoscopy.

Adenocarcinoma↗
PubMedDate not supplied

Two types of sporadic multiple colorectal cancers with and without HNPCC-like genetic instability.

BACKGROUND/AIMS: Sporadic multiple colorectal cancers (MCCs) potentially have similar genetic alterations to hereditary nonpolyposis colorectal cancers (HNPCCs), but genetically unstable MCCs other than HNPCCs are not well characterized. We report the frequency of HNPCC-like sporadic multiple colon cancers and their characterization as for HNPCC-related gene mutations. METHODOLOGY: Microsatellite instability (MSI) at 12 microsatellite loci was examined by a polymerase chain reaction in 19 cases each of MCC and single colorectal cancer (SCC). The target sequences of MSI, transforming growth factor beta type II receptor (TGF beta RII) gene, and the HNPCC genes, hMSH2 and hMLH1, were amplified and analyzed for mutations by sequencing. RESULTS: In 5 of 19 cases with MCC, MSI was observed at more than 4 microsatellite loci, and the other cases including all SCCs showed no MSI or MSI(+) at a single locus. In 4 of the 5 severe MSI(+) cases, a 10-bp adenine tract at codons 125-128 of the TGF beta RII gene was mutated. In terms of the hMSH2 and hMLH1 genes, only silent mutations and non-critical amino acid substitutions were found. CONCLUSIONS: We found severe MSI in 26% of sporadic multiple colorectal cancers. Mutations of the TGF beta RII gene are closely associated with severe MSI(+) MCCs as observed in HNPCC, suggesting that these MCCs develop by the similar carcinogenic process to HNPCC.

Adaptor Proteins, Signal Transducing↗
PubMedDate not supplied

Fatty liver suppressed the angiogenesis in liver metastatic lesions.

BACKGROUND/AIMS: We have demonstrated that colorectal cancer with fatty liver had few liver metastases clinically as well as experimentally. In this study, to clarify why colorectal cancer with fatty liver had few liver metastases, we focused on the angiogenesis of carcinomas. METHODOLOGY: The rat colon cancer cells (RCN-9) were injected into 40 rats (the fatty liver group = FL group includes 20 rats, the non-fatty liver group = NFL group includes 20 rats). In each group, the PyNPase (pyrimidine nucleoside phosphorylase) activity in the metastatic lesion of the liver was examined using the high-performance liquid chromatographic method. In addition, the microvessel density in the metastatic lesion of the liver was assessed by Von Willebrand factor-related antigen immunostaining. RESULTS: 1) The PyNPase activity in the FL group was 33.34 +/- 6.27 (microgram FU/mg protein/hr), which was significantly lower than that of the NFL group (49.30 +/- 14.82) (P = 0.0021). 2) Microvessel density in the FL group was 1.845 +/- 0.357 (%), while that in the NFL group was 2.777 +/- 1.371 (%). The microvessel density of the FL group was significantly lower than that of the NFL group (P = 0.0365). 3) The regression coefficient between PyNPase activity and microvessel density was 0.480, which indicated a significant correlation (P = 0.0098). CONCLUSIONS: We think that, in colorectal carcinomas with fatty liver, the decreased activity of PyNPase and the decreased neovascularization in the metastatic lesion are closely related to fewer liver metastasis compared with colorectal cancer patients without fatty liver.

Animals↗
PubMedDate not supplied

Distinct relationship between polypoid growth type and sporadic colorectal carcinomas with microsatellite instability.

BACKGROUND/AIMS: This study was carried out to clarify whether colorectal carcinomas with MSI (microsatellite instability) is correlated with growth types of invasive carcinomas. METHODOLOGY: Samples of tumor tissue and adjacent normal mucosa were obtained from 45 patients with sporadic advanced colorectal cancer. The MSI was assessed by the mobility shift assay of microsatellite and VNTR (variable numbers of tandem repeat) alleles using 12 markers. Tumors with four or more positive loci were determined to be MSI positive. The polyadenine tract (A)10 of the third exon in TGF beta RII was also assessed by mobility shift assay of DNA fragments amplified with primers. Histological examination was performed to divide all tumors into polypoid growth carcinoma and nonpolypoid growth carcinoma, according to Shimoda et al.'s classification. RESULTS: Ten of 11 cases with MSI had a 1-base pair deletion in a polyadenine tract in the TGF beta RII gene. Fifteen cases showed polypoid growth and 30 cases indicated nonpolypoid growth. There were 9 polypoid growth cases and 2 nonpolypoid growth cases with MSI, while there were 6 polypoid growth cases and 28 nonpolypoid growth cases without MSI. Colorectal cancer cases with MSI had a significantly higher incidence of cases with polypoid growth (9/11) compared to those without MSI (6/34) (P = 0.0004). CONCLUSIONS: Sporadic colorectal carcinomas with MSI tend to show a polypoid growth type. We think that there are two types including "adenoma-carcinoma sequence" type and "RER" type in colorectal carcinomas that show adenoma-carcinoma progression.

Adult↗
PubMedDate not supplied

A rare type of lesser sac hernia.

We report herein the case of a female who developed a lesser sac hernia which was a rare type and was strangulated by a hole in the posterior layer of the lesser omentum. In our patient, abdominal computed tomography showed a loop of distended intestines among the liver, gallbladder and stomach. To our knowledge, there has been no previous report of transomental hernia exactly like our present case.

Diagnosis, Differential↗
PubMedDate not supplied

Pretreatment with 5-fluorouracil enhances cytotoxicity and retention of DNA-bound platinum in a cisplatin resistant human ovarian cancer cell line.

A combination of 5-fluorouracil (5-FU) and cisplatin (cis-Diamminedichloroplatinum(II); CDDP) was administered to CDDP-sensitive (A2780) and -resistant (2780CP) human ovarian cancer cell lines in vitro in order to investigate the effects of 5-FU pretreatment on CDDP cytotoxicity, removal of DNA-bound platinum (Pt-DNA) and cellular glutathione (GSH) level. The cells were incubated with various doses of 5-FU for 24 hours, and then exposed to various doses of CDDP after a drug-free interval of 24 hours. Pretreatment with 5-FU (0.5 - 2.0 microg/ml) augmented the cytotoxicity of CDDP in 2780CP cells, but did not affect A2780 cells. 2780CP cells lost 23.0 to 41.9% of their total Pt-DNA determined by flameless atomic absorption spectrophotometry at 6 to 24 hours after exposure to 10.0 microg/ml CDDP alone; nevertheless, 1.0 microg/ml 5-FU pretreatment caused a significant delay in removal of Pt-DNA (3.8, 1.5 and 7.2% at 6, 12 and 24 hours after exposure to CDDP, respectively). At 24 hours after 15.0 microg/ml CDDP exposure, 2780CP cells pretreated with 5-FU lost only 15.7% of their total Pt-DNA, although the platinum removal rate with CDDP alone was 28.4%. The GSH levels in 2780CP cells were similar in the presence or absence of 5-FU pretreatment. These data indicated that 5-FU pretreatment enhances the cytotoxicity of CDDP and reverses CDDP resistance in 2780CP cells and that its mechanism is related to the inhibitory effect of 5-FU on DNA repair, and not to cellular GSH levels.

Antineoplastic Combined Chemotherapy Protocols↗
PubMedDate not supplied

Liver metastasis rare in colorectal cancer patients with fatty liver.

BACKGROUND/AIMS: As no reports in terms of the relationship between fatty liver and liver metastasis of colorectal cancer clinicopathological analysis of colorectal cancer patients with fatty were found a liver was carried out. PATIENTS AND METHODS: Among 839 patients with single colorectal carcinoma who underwent operations at our department between 1985 and 1994, 121 patients were designated as fatty liver using ultrasonography (FL group). The remaining 718 non-fatty liver patients with colorectal cancer (NFL group) were compared to the FL group regarding clinicopathological aspects. RESULTS: (1) There were only two patients who had liver metastasis in the FL group (1.7%), while the NFL group included 115 patients with liver metastasis (16.0%) (p < 0.01). (2) The five-year survival rate of the FL group was 95.7%, which was significantly higher than that in the NFL group (9.8%) (p < 0.001). (3) In the multivariate analysis, the fatty liver was identified as an independent prognostic factor. CONCLUSIONS: The FL group had a much better prognosis compared to the NFL group. Especially, liver metastasis was extremely rare in the FL group. We believe that these results will lead to the clarification of the liver metastasis mechanism.

Adenocarcinoma↗
PubMedDate not supplied

Hyperthermic enhancement of cisplatin-induced generation of active oxygen radicals in a cell-free system.

The interaction of cisplatin [cis-diamminedichloroplatinum (II), or DDP] with calf thymus DNA has previously been shown to result in the generation of superoxide anions (O2-) and hydroxyl radicals (OH) in a cell-free system. The effect of hyperthermia (42 degrees C) on the generation of such active oxygen radicals was examined by chemiluminescence of a Cypridina luciferin analog (CLA) with DNA extracted from a human ovarian cancer cell line (A2780). Hyperthermia significantly increased chemiluminescence of CLA (CCLA) 1.17- to 1.51-fold at DDP concentrations of 10 to 40 uM, relative to values at 37 degrees C. The extent of DDP-induced CCLA correlated significantly (r = 0.973) with that of DDP cytotoxicity in A2780 cells. These results suggest that hyperthermic enhancement of DDP-induced generation of active oxygen radicals contributes to the hyperthermic potentiation of DDP cytotoxicity.

Cell Line↗