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Biomedical subjects

T Teramoto

Publications and source records attributed to T Teramoto.

At least 163 records · Page 9Linked to original sources
PubMed1993

Cholesteryl ester transfer protein deficiency caused by a nonsense mutation detected in the patient's macrophage mRNA.

Cholesteryl ester transfer protein (CETP) deficiency causes marked elevation of plasma high-density lipoproteins, termed hyperalphalipoproteinemia. Only one CETP mutation has been found previously, partly because the relative unavailability of CETP mRNA has hampered analysis. We demonstrated CETP mRNA expression in the monocyte-derived macrophages and identified a new CETP mutation by analyzing the macrophage mRNA of a homozygous patient with familial form of hyperalphalipoproteinemia. The nonsense mutation at codon 309 in exon 10 of the CETP gene was thought to delete the carboxy-terminal third and caused a decrease in the level of CETP mRNA. Our findings provide more evidence that CETP mutations may underlie a subset of familial hyperalphalipoproteinemia.

Base Sequence↗
PubMed1993

A suitable model for experimental liver metastasis of human colon cancer xenografts using mice with severe combined immunodeficiency.

Studies on liver metastasis of human colon cancer are limited because of a lack of suitable animal models. In this study, the usefulness of mice with severe combined immunodeficiency (SCID), which congenitally lack functional T and B lymphocytes, was evaluated in comparison with currently available nude mice. Three human colon cancer xenografts transplantable into nude mice were disaggregated enzymatically to obtain tumor cell suspensions, and implanted intrasplenically into SCID and nude mice. The incidence of splenic tumorigenesis and of liver metastases were significantly greater in SCID mice for all xenografts, in comparison with nude mice. In total, 33 of 36 SCID mice and 17 of 43 nude mice developed liver metastases. On the basis of this result, we conclude that SCID mice would be a more suitable model than nude mice for studying liver metastasis of human colon cancer.

Adenocarcinoma↗
PubMed1993

Experimental cancer chemotherapy using a liver metastatic model of human colon cancer transplanted into the spleen of severe combined immunodeficient mice.

We have developed a liver metastatic model of human colon cancer using severe combined immunodeficient (SCID) mice. Liver metastases were observed in all the SCID mice on day 28 after intrasplenic injection with 5 x 10(6) dissociated tumor cells of COL-2-JCK, a human colon cancer strain serially transplanted in nude mice. When this model was applied for chemotherapeutic experiments, 5-fluorouracil (5-FU) demonstrated significant antitumor effects in preventing liver metastases, whereas the efficacy of 5-FU was limited in the currently used sc-ip chemosensitivity assay in nude mice. When the human LDH-5 isozyme was evaluated in the homogenized metastatic liver tissue of SCID mice, a good correlation was obtained between the liver tumor weights and LDH-5 isozyme, suggesting that it could be a promising quantitative indicator for metastases. This model would be useful for further studies on the treatment of liver metastases of colon cancer.

Animals↗
PubMed1993

Indium-111-labelled liposomes: dosimetry and tumour detection in patients with cancer.

Neutral phospholipid vesicles (VesCan), which had been prepared for clinical use, were loaded with 37 MBq indium-111 and administered to seven patients with malignant tumours. The median lipid dose was 2.0 mg/kg. Sequential images showed rapid blood clearance at the early stage, with homogeneous uptake of 111In-labelled VesCan (111In-labelled V-liposomes) in the liver and spleen. Dosimetric estimates for these organs were 1.2 and 1.5 mGy/MBq, respectively, with a whole-body exposure dose of 0.076 mGy/MBq. Total renal excretion of 111In was less than 10% of the injected dose, occurring mainly as 111In-EDTA in three patients. Gamma camera images 24-48 h after administration revealed increased activity in the tumours of four patients. 111In-labelled V-liposomes may enable the demonstration of the tumour site without toxicity and with radiation doses comparable to other radionuclide imaging techniques.

Aged↗
PubMed1993

A metastatic model of human colon cancer constructed using cecal implantation of cancer tissue in nude mice.

COL-2-JCK, a human colon cancer xenograft line able to be transplanted into nude mice, was implanted in the subserosal layer of the cecum, either as cancer tissue or as a single cell suspension. When cancer tissue was used for the cecal implantation, 100% extensive local tumor growth and a high incidence of metastases to the regional lymph nodes, peritoneum, liver, and lung was observed. In contrast, when the cell suspension of this line was injected into the cecal wall, no metastases were observed, with significantly reduced local tumor growth. The use of cancer tissue maintaining the original cancer tissue structure is therefore considered imperative for allowing full expression of the biological characteristics of cancer cells. This nude mouse model using the cecal implantation of cancer tissue should thus prompt further study on the biology of human colon cancer.

Animals↗
PubMed1993

The modulation by L-leucovorin of 5-fluorouracil antitumor activity on human colon carcinoma cells in vitro and in vivo.

We investigated the modulating effect of L-leucovorin (LV) on the antitumor effect of 5-fluorouracil (5-FU) against human colon carcinoma cells (C-1) in vitro and human colon carcinoma xenografts (Co-4) in nude mice. The modulating effect of LV on 5-FU reached an optimal concentration of 40-80 micrograms/ml in vitro which was detected by a colorimetric MTT assay. An optimal dose of 200 mg/kg was also observed in the nude mouse system. The modulating effect of LV increased according to the increment of thymidylate synthetase inhibition in vivo. Since the pharmacokinetic pattern of LV in the nude mice administered LV at 200 mg/kg was similar to that in patients treated with LV at a dose of 100 mg/m2, this clinical method of administration was thought to be adequate for modulating the antitumor activity of 5-FU against clinical colon carcinomas.

Adenocarcinoma↗
PubMed1993

Characterization of serum lipoproteins from Suncus: a candidate animal model for abetalipoproteinemia.

We have previously reported that fatty liver was induced in a novel experimental animal, Suncus murinus (suncus), by 24-h fasting and that apolipoprotein B (apo B) was not actively synthesized in the liver. However, a faint signal of apo B mRNA was detected in the liver, suggesting possible synthesis of apo B. Small amounts of VLDL and LDL have been separated from suncus serum by ultracentrifugation. Electron microscopic study of the lipoproteins revealed the existence of small particles in VLDL. High performance liquid chromatographic analysis of the lipoproteins showed that the peaks of TG and cholesterol were mainly at the HDL fraction. These results indicate the existence of lipoproteins as small as HDL which were rich in TG and floated at the density of VLDL upon ultracentrifugation. Apolipoprotein analysis showed two bands of 500- and 200-kDa proteins in VLDL and LDL. Western blot analysis using antibody against the 500-kDa protein revealed reaction not only with suncus 500- and 200-kDa proteins but also with human apo B-100. In conclusion, a small amount of apo B is transported in the suncus serum as VLDL and LDL, although almost all lipid is packed in HDL-size particles.

Abetalipoproteinemia↗
PubMed1993

Absence of DNA repair deficiency in the confirmed heterozygotes of xeroderma pigmentosum group A.

This study was performed to elucidate whether xeroderma pigmentosum complementation group A (XPA) carrier has DNA repair abnormality against sun-exposure and ultraviolet (UV)-mimetic chemical carcinogen 4-nitroquinoline 1-oxide (4NQO). Here we report three sporadic cases of XP that were defined as group A by genetic complementation test as well as polymerase chain reaction (PCR) analysis to detect the point mutation in the responsible gene for XPA. DNA repair analyses in the skin fibroblasts revealed that the cells from the patients were much more sensitive to UV and 4NQO and had extremely low UV-induced unscheduled DNA synthesis (UDS) than control cells, whereas the cells from the carriers (heterozygotes of XP) had sensitivity to UV and 4NQO and levels of UV-induced UDS similar to normal cells. These results indicate that the obligate heterozygotes, despite having a mutated allele in XPA complementing gene demonstrated by PCR, have no DNA repair abnormality after UV irradiation and UV-mimetic 4NQO treatment. Our observations imply that XPA heterozygotes do not have higher risk of skin cancers than normal subjects based on their DNA repair abnormality.

4-Nitroquinoline-1-oxide↗
PubMed1993

Studies on thermophile products. VI. Activation of mouse peritoneal macrophages by bis(2-hydroxyethyl) trisulfide.

The biological effects of a cytotoxic substance (BS-1), isolated from Bacillus stearothermophilus UK563 and identified as bis(2-hydroxyethyl) trisulfide, on elicited mouse peritoneal macrophages induced by a casein injection, were investigated in vitro. BALB/c mouse macrophages treated or pretreated with BS-1 (1-10 micrograms/ml) showed cytotoxicity against syngeneic DBA/2 mouse P815 mastocytoma. BS-1 also showed weak cytotoxicity directly against P815 in the absence of macrophages. BS-1 significantly increased the glucose consumption of macrophages without producing cytotoxicity. This trisulfide compound increased nitric oxide formation, interleukin-1 production and prostaglandin E2 release in macrophages. It did not, however, increase the production of active oxygen species in macrophages, but it reduced cytochrome c in the presence of phagocytes. These results indicate that BS-1 activates macrophages to the cytolytic stage.

Animals↗
PubMed1993

Carbohydrate antigens and liver metastasis in colorectal cancer.

A comparative immunohistochemical study was performed to analyse the expression of cancer-associated carbohydrate antigens by primary and metastatic lesions of colon cancer. We used monoclonal antibodies which reacted with Lea, Lex and Tn as well as their sialylated derivatives. Twenty-one primary lesions in patients without metastasis and 26 primary and metastatic lesions in patients with liver metastasis were studied. Sialyl Lea was expressed by 57% of the primary lesions of patients without metastasis, 65% of the primary lesions of patients with metastasis and 73% of their liver metastases. Sialyl Lex was expressed by 60% of the primary lesions of patients with and without metastasis as well as by approximately 80% of the liver metastases. Sialyl Lea and sialyl Lex showed strong expressions in the liver metastases, significantly greater than in the primary lesions. The findings indicate the increased expressions of sialyl Lea and sialyl Lex to be correlated with liver metastasis of colorectal cancer.

Adenocarcinoma↗
PubMed1993

Determination by PCR-RFLP of apo E genotype in a Japanese population.

We analyzed apolipoprotein E (apo E) genotypes of 104 randomly sampled Japanese subjects by using the polymerase chain reaction-restriction fragment length polymorphism method in which the apo E genomic DNA was amplified between bases 2849 and 3071. We compared the results thus obtained with their corresponding phenotypes assessed by isoelectric focusing (IEF). The overall frequencies of the genotypes were as follows: epsilon 2:2.4%, epsilon 3:86.5%, and epsilon 4:11.1%, which are essentially identical to those previously reported when the IEF method has been used. The phenotypes and genotypes were identical in all but five cases. We could not determine the phenotypes of four cases by IEF because of an atypical IEF pattern presumably caused by sialylation. In one other case the phenotype initially did not correlate with its genotype but eventually did after neuraminidase treatment. These results indicate that apo E polymorphism of most Japanese people can be determined by analyzing the apo E genome between bases 2849 and 3071.

Apolipoproteins E↗
PubMed1993

Anastomotic leakage after colorectal cancer surgery: a risk factor for recurrence and poor prognosis.

In order to discover the incidence of recurrence and prognosis of patients with anastomotic leakage after colorectal surgery, 980 colorectal cancer patients who underwent anastomosis at Keio University Hospital between 1970 and 1990 were examined. Thirty-three patients (leakage group) out of the 980 exhibited anastomotic leakage. The incidence of local recurrence in the leakage group was significantly higher than in the no leakage group (P < 0.01). The disease-free survival rate of the leakage group was significantly lower than that of the no leakage group in Dukes' A, B patients (P < 0.01), but was not so in Dukes' C, D patients. These results suggested that anastomotic leakage after colorectal cancer surgery might enhance the incidence of local recurrence and make the prognosis poor.

Aged↗
PubMed1993

Splenic abscess associated with colon cancer: a case report.

The present report describes a case of colon cancer which presented with a rare complication of splenic abscess. A 52-year-old Japanese man with diarrhea, fever and chills was admitted to our hospital. He complained of fever, with chills at night, and abdominal pain occurring during the last month. The origin of the fever was investigated, and Escherichia coli grew from a blood culture. Multilocular splenic abscesses and wall thickening of the descending colon were revealed by CT scan, magnetic resonance imaging and ultrasound. A cancer of the descending colon was found by barium enema and colonoscopy. A curative resection was performed and the pathological report revealed the splenic abscess to have developed from a direct extension of, and perforation by, the carcinoma of the descending colon.

Abscess↗
PubMed1993

Apolipoprotein E enhances lipid exchange between lipoproteins mediated by cholesteryl ester transfer protein.

The direct effect of apolipoprotein (apo) E on cholesteryl ester transfer protein (CETP) activity was studied using lipoproteins from a subject with apoE deficiency (Atherosclerosis. 1991. 88: 15-20) as a model system. The transfer of cholesteryl ester (CE) from discoidal bilayer particles (DBP) to very low density lipoprotein (VLDL) was enhanced by incorporation of apoE into VLDL. This enhancement was induced only in the presence of CETP activity. Moreover, after incubation of CETP with VLDL, CETP activity and immunoreactivity were coeluted with apoE-incorporated VLDL (E-VLDL) on a gel filtration column (Sephadex G-150), but there was little CETP activity and immunoreactivity with apoE-free VLDL (C-VLDL), suggesting that E-VLDL had higher affinity for CETP compared to C-VLDL. The supplementation of the apoE-deficient serum with apoE enhanced the CETP-mediated changes of amount of CE and triglyceride (TG) in the high density lipoprotein (HDL) fraction, which were completely inhibited by the addition of the monoclonal antibody against CETP that blocks CETP activity. Our results suggest that 1) apoE enhances the cholesteryl ester and triglyceride transfer between VLDL and HDL via cholesteryl ester transfer protein, and 2) this effect of apoE may be mediated by enhancing the affinity of CETP for VLDL.

Antibodies, Monoclonal↗
PubMed1992

Different origin of leiomyoblastoma by immunohistochemical study.

Leiomyoblastoma has been regarded as a neoplasm of smooth muscle origin. With recent progress in immunohistostaining techniques, many clinicopathological discrepancies have been pointed out about the origin of leiomyoblastoma. It has been claimed that gastrointestinal non-epithelial tumors should be regarded as stromal tumors in order to study their origin. In the present study, we performed various forms of immunohistostaining in seven cases of leiomyoblastoma to determine their origin. One case expressed desmine and muscle specific actin and was considered to be derived from smooth muscle. Four neoplasms expressed X-100 protein (two cases were also NSE positive) and were thought to be derived from the nerve. Two cases were of unknown derivation. These results suggest that the cells of leiomyoblastoma may arise from a primitive to totipotential cell of neural lineages that may anomalously express smooth muscle filaments.

Actins↗
PubMed1992

Pharmacokinetic analysis of antibody localization in human colon cancer: comparison with immunoscintigraphy.

The biodistribution and imaging characteristics of the 111In-labeled anti CEA monoclonal antibody ZCE-025 were studied in five patients with suspicion of colorectal carcinoma. Evaluation included antibody pharmacokinetics and assessment of antibody distribution in surgical specimen, making a comparison with whole-body imaging with a gamma camera. ZCE-025 localization in tumors was demonstrated by gamma-camera imaging in 4 of the 5 patients, corresponding to surgical findings. Persistent accumulation of 111In in the lymph nodes was observed in one patient, whereas surgical exploration of these lymph nodes showed no gross or microscopic evidence of metastases of colon carcinoma. Analysis of individual plasma by size exclusion HPLC showed two radioactivity peaks, labeled antibody and free DTPA. No transchelation of 111In to circulating transferrin was observed. The blood clearance was fitted to a two-compartment equation and its half-lives were found to be 10.8 +/- 8.7 h and 69.5 +/- 21.8 h for t1/2 alpha and t1/2 beta, respectively. Total urinary excretion averaged 0.3% of the injected dose/h with a small patient to patient variation. At 24 hrs postadministration the predominant radiolabeled species in urine was free DTPA. Thereafter, radioactivity in urine was partly present as a low molecular weight catabolic product. No apparent correlation between CEA content and uptake of 111In-ZCE-025 in tumors resected by surgery could be found. How 111In-labeled antibody is accumulated into tumors as well as into some nontumor tissues needs further study.

Aged↗