Biomedical subjects

Y Ueyama

Publications and source records attributed to Y Ueyama.

At least 127 records · Page 7Linked to original sources

PubMed1995

Immortalisation of human oesophageal epithelial cells by a recombinant SV40 adenovirus vector.

We introduced the origin-defective SV40 early gene into cultured human oesophageal epithelial cells by infection of a recombinant SV40 adenovirus vector. The virus-infected cells formed colonies 3-4 weeks after infection in medium containing fetal calf serum. When the cells derived from 'serum-resistant' colonies were then maintained in the serum-free medium with a low calcium ion concentration, some of them passed the cell crisis and kept growing for over 12 months. These cells, regarded as immortalised cells, resembled the primarily cultured oesophageal epithelial cells in morphology and had some of their original characteristics. Treatment of the cells with a high calcium concentration induced phenotypic changes. These cells still responded to transforming growth factor beta. When the immortalised cells were injected into severe combined immunodeficient mice, they transiently formed epithelial cysts, although the typical differentiation pattern of the oesophageal epithelium was not observed. These cysts regressed within 2 months without development into tumours. The results indicated that human oesophageal epithelial cells were reproducibly immortalised by infection with a recombinant SV40 adenovirus vector at relatively high efficiency. The immortalised cells should be useful in studies on oesophageal carcinogenesis and in assessing the cooperative effects with other oncogene products or carcinogens.

Animals↗

PubMed1995

Prolonged survival of mice with human gastric cancer treated with an anti-c-ErbB-2 monoclonal antibody.

A monoclonal antibody (MAb), 4D5, specifically recognising an extracellular epitope of the c-ErbB-2 protein, inhibited the growth of human gastric cancer overexpressing c-ErbB-2 severe combined immunodeficient (SCID) mice. This antibody also reduced the mass of established tumours xenografted into SCID mice, whereas gastric cancer not expressing c-ErbB-2 exhibited no regression in response to 4D5 treatment. In addition, administration of 4D5 prevented colonisation of cancer cells and prolonged the survival of host SCID mice inoculated i.v. with c-ErbB-2-overexpressing tumour cells. This is the first reported study to show that treatment with a single antibody specific to c-ErbB-2 prolongs the survival of host SCID mice bearing xenotransplanted tumours.

Animals↗

PubMed1995

Expression of the multidrug resistance-associated protein (MRP) gene in non-small-cell lung cancer.

We examined the levels of expression of the multidrug resistance-associated protein (MRP) gene quantified by Northern blot analysis in comparison with those of the MDR1 gene determined by reverse transcription-polymerase chain reaction (RT-PCR) in 104 non-small-cell lung cancer (NSCLC) specimens [59 adenocarcinoma (Ad), 40 squamous cell carcinoma (Sq), four large cell carcinoma (La) and one adeno-squamous carcinoma (AdSq)]. Thirty-three (31.7%) of the 104 NSCLC expressed the MRP gene at various levels. The NSCLC showing high (++) levels of MRP gene expression (19 out of 33, 57.6%) were predominantly squamous cell carcinomas (Ad, 5; Sq, 13; La, 1) (P < 0.05). Six of the eight NSCLCs expressing high levels of MRP mRNA and no MDR1 (MRP ++, MDR1-) were squamous cell carcinomas. Sixty-one of the 104 NSCLC patients received chemotherapy with MRP-related anti-cancer drugs [vindesine (VDS) and etoposide (VP-16)]. Twenty-three patients (37.7%) with tumour expressing high or moderate levels of MRP showed significantly worse prognoses than those with non- or low-MRP-expressing tumours (P < 0.05). These results suggest that the level of MRP gene expression is related to the histopathology and prognosis of NSCLC.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1995

Failure of genotoxic carcinogens to produce tumors in human skin xenografts transplanted to SCID mice.

Chemical carcinogenesis of human skin was investigated using human skin xenografts (16 full thickness and 48 split thickness skin grafts) transplanted to CB-17-scid (SCID) mice. Topical application of a carcinogen, i.e. 7,12-dimethylbenz[a]anthracene (DMBA), benzo[a]pyrene, methylcholanthrene or N-methyl-N'-nitro-N-nitrosoguanidine, to the human skin xenografts once a week for 25-30 weeks failed to produce skin tumors. Both DMBA application plus UV-B irradiation and alternate applications of the above four carcinogens in combination with UV-B irradiation also failed to produce tumors. All of these treatments induced skin papillomas in skins of host SCID mice. DMBA induced skin papillomas in allogenic CD-1 mouse skin grafts transplanted to SCID mice. These results indicate that susceptibility of human skin to these carcinogenic stimuli is much lower than that of mouse skin.

Animals↗

PubMed1995

Determination of sulfamethazine residue in chicken serum and egg by high-performance liquid chromatography with chemiluminescence detection.

A sensitive method that involves high-performance liquid chromatography with chemiluminescence detection is developed for the determination of sulfamethazine residue in samples of chicken serum and egg. Sulfamethazine is extracted from the samples and derivatized with fluorescamine. The derivatized samples are eluted by reversed-phase chromatography using a mixture of 10 mM potassium phosphate and 30% acetonitrile on a Nova-Pak C18 column. The post-column reagents in the chemiluminescence system are 1 mM bis[2-(3,6,9-trioxadecanyloxycarbonyl)-4-nitrophenyl] oxalate and 0.3M hydrogen peroxide in acetonitrile. The detection limit in the standard solution is 1 ng/mL, and the calibration curve is linear between 1 and 100 ng/mL. The recoveries of spiked samples (50 ppb) are 95.8 +/- 9.7% in chicken serum samples and 84.9 +/- 10.7% in egg samples. In actual sample analysis, the lowest detectable concentration of sulfamethazine (0.073 microgram/mL) was found at 48 h in serum and on day 9 (0.017 microgram/g) in egg after oral administration of a dose of 100 mg/kg body weight to hens.

Animals↗

PubMed1995

Marked hypocholesterolemia in a case with adrenal adenoma--enhanced catabolism of low density lipoprotein (LDL) via the LDL receptors of tumor cells.

A 16-yr-old girl was hospitalized because of amenorrhea and virilism, and was diagnosed with an adrenal tumor on the right side. Her serum androgen levels were markedly elevated, and severe hypocholesterolemia (total cholesterol, 0.59 mmol/L) was observed. After resection of the tumor, her serum cholesterol level dramatically rose to normal, suggesting a role of this tumor in her marked hypocholesterolemia. To investigate the mechanism of hypocholesterolemia in this case, we examined the effects of dehydroepiandrosterone and dehydroepiandrosterone sulfate on the low density lipoprotein (LDL) receptor activity of fibroblasts. These hormones did not have any effect on LDL receptor activity. Northern blot analysis demonstrated that the LDL receptor messenger ribonucleic acid level of this tumor tissue was increased about 8-fold compared with that of normal adrenal cortex. The LDL receptor activity of the cultured cells established from this tumor was 2-fold higher than that of Hep G2 cells. Furthermore, the LDL receptor activity could not be down-regulated by an excessive dose of 25-hydroxycholesterol. These results suggest that increased LDL receptor activity and unrestricted uptake of LDL by the adrenal tumor may have caused the marked hypocholesterolemia in this patient.

Adenoma↗

PubMed1994

Ultrastructural localization of P-glycoprotein on capillary endothelial cells in human gliomas.

The P-glycoprotein (P-Gp) encoded by the human multidrug-resistance gene MDR1 has been suggested to play certain roles in the blood-brain barrier (BBB). However, the detailed mechanism of the activity of P-Gp in multidrug-resistance (MDR) remains unclear in human glioma. We examined the localization of P-Gp in human glioma by immunohistochemical (IHC) and immunoelectron microscopic (IEM) methods with anti P-Gp monoclonal antibodies (C219, MRK16). We also examined MDR1 expression in primary glioma and xenografts by reverse transcription-polymerase chain reaction (RT-PCR) with human MDR1-specific primers. The IHC study showed no P-Gp expression on tumour cells but it was present on capillary endothelial cells and IEM analysis showed definitive localization on their luminal surface. MDR1 gene expression was detected in eight primary glioma and three normal brain specimens by RT-PCR, but not in glioma xenografts. The lack of MDR1 expression in these cells appears to be a consequence of the replacement of the original human stroma, including blood vessels, by murine stroma in glioma xenografts. The unique distribution of P-Gp on the capillary blood vessels was confirmed in human glioma by the results of immunohistochemical and molecular biological studies.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1994

Parvalbumin-like immunoreactivity in nerve fibres within human molar tooth pulps.

The root pulp contained two types of parvalbumin-immunoreactive nerve fibres, smooth and varicose. The smooth were relatively thick (mostly 3-5 microns in diameter) and sometimes had large swellings, whereas the varicose consisted of oval varicosities of 1-3 microns in long diameter with very fine strands interconnecting them. Most of the parvalbumin-immunoreactive root fibres were smooth, and the varicose were rare. Upon entering the pulp chamber, both types of fibre splayed out and ran towards the roof of the chamber and the pulp horn. In the subodontoblastic layer of the roof and horn, parvalbumin-immunoreactive fibres showed relatively straight chains of granules; they sent their granular terminals to the odontoblastic layer. Some parvalbumin-immunoreactive granules were observed in the predentine and some even in the dentine. The diameter of axons in the root pulp and the spatial distribution of terminals strongly suggest that the parvalbumin-immunoreactive fibres are mostly myelinated and sensory.

Dental Pulp↗

PubMed1994

Effects of antibiotics on human polymorphonuclear leukocyte chemotaxis in vitro.

The effects produced in vitro by minocycline (MINO), aminobenzyl penicillin (ABPC) and cefotiam (CTM) on polymorphonuclear leukocytes (PMN) chemotaxis were investigated in this study using the Boyden chamber technique and polarization assay. The following results were obtained: CTM brought about a significant increase of PMN chemotaxis at the therapeutic dose (10, 100 micrograms/ml), MINO reduced PMN chemotaxis significantly at a concentration as low as 1 microgram/ml and ABPC did not influence PMN chemotaxis at concentrations up to 100 micrograms/ml in both methods. Furthermore, using a checkerboard assay, it was shown that CTM worked as a chemokinetic factor.

Cefotiam↗

PubMed1994

Expression of the multidrug resistance gene (MDR1) in non-small cell lung cancer.

To ezamine the clinical relevance of P-glycoprotein, encoded by the human multidrug resistance gene (MDR1), to multidrug resistance in lung cancer, we examined the expression of MDR1 in 107 non-small cell lung cancer (NSCLC) specimens and 20 corresponding specimens of normal lung tissues. We also evaluated the relationship between MDR1 expression and the histopathology and pathological staging of NSCLC. The tumors consisted of 60 adenocarcinomas, 38 squamous cell carcinomas, 8 large cell carcinomas, and 1 adenosquamous carcinoma. MDR1 expression was semi-quantified by use of the reverse transcriptase-polymerase chain reaction method. We subclassified the NSCLC into 3 grades according to the MDR1 expression level (-, +, ++). Sixty-one of the 107 tumor specimens (57%) and 18 of the normal lung tissue specimens (90%) expressed various levels of the MDR1 gene. Only one tumor specimen showed higher MDR1 expression than the corresponding normal lung tissue. The relationship between pathological stage and MDR1 expression levels was not significant. These results suggest that the level of MDR1 expression in lung cells is decreased as cells progress from the normal to the transformed state.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1994

Familial hypercholesterolaemia-like syndrome with apolipoprotein E-7 associated with marked Achilles tendon xanthomas and coronary artery disease: a report of two cases.

We observed two patients with hypercholesterolaemia and tendon xanthomas associated with apolipoprotein (apoE-7) E-7, a rare variant of the apoE isoforms. Both suffered from coronary artery disease and had undergone a coronary bypass operation. Their cholesterol levels were 268 and 310 mg dl-1, respectively. Both patients had marked xanthomas in the Achilles tendons. Both also suffered from diabetes. Although their clinical and laboratory findings were compatible with typical familial hypercholesterolaemia (FH), the analysis of low-density lipoprotein (LDL) receptors in cultured fibroblasts showed no abnormality of binding, internalization or degradation of 125I-LDL. Diabetic control with a low-calorie, low-fat diet led to the rapid reduction of serum cholesterol. Other family members of the patients with apoE-7, who were normoglycaemic, showed normal cholesterol levels and no xanthomas. These findings suggest that coexistent diabetes mellitus may induce overt hyperlipidaemia and accumulation of lipids in tissues in subjects with apoE7.

Achilles Tendon↗

PubMed1994

Expression of the human multidrug resistance gene (MDR1) and prognostic correlation in human osteogenic sarcoma.

The overexpression of P-glycoprotein (P-Gp), encoded by the human multidrug resistant gene (MDRA), decreases lipophilic drug accumulation in multidrug resistant cells in vitro. It is still not clear whether P-Gp contribute to the problem of multidrug resistance (MDR) in osteogenic sarcoma (OS). We examined the MDR1 expression of 20 OS specimens (11 primary tumors, 10 xenografts, 1 overlapping), by Northern blotting and by the reverse transcriptase-polymerase chain reaction (RT-PCR), and evaluated by the relationship between MDR1 expression and patient prognosis. RT-PCR revealed MDR1 expression in 9/20 OS; 5/11 primary tumors and 5/10 OS-xenografts; northern blotting revealed MDR1 expression in only 5/20 OS. One primary OS specimen and its corresponding xenograft had similar levels of MDR1 expression. All 20 patients with OS were treated with chemotherapeutic protocols including doxorubicin, cisplatin, methotrexate and ifosfamide. Eight of 9 OS-patients expressing MDR1 were resistant to chemotherapy and had a poor prognosis. The relationship between MDR1 expression and poor prognosis in the 20 OS-patients was significant (p < 0.01). The results support the assumption that MDR1 expression is related to MDR in human OS.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1994

[Two cases of thyroid cancer resected with trachea].

We described two patients of thyroid cancer with tracheal invasion. A 54-aged female visited our hospital with complaint of the neck pain. Echography showed a tumor in the right lobe of the thyroid. In operation the thyroid tumor invaded the trachea and right recurrent nerve. A 24-aged male visited our hospital with complaint of a mass of the left side neck. Echography showed a tumor in the left lobe of the thyroid. In operation the thyroid tumor invaded the trachea, lymph node and left recurrent nerve. In these two cases we could find thyroid tumors invaded into the trachea by echography. We re-evaluated the utility of echography.

Adult↗

PubMed1993

Extralysosomal degradation of high-density lipoproteins in a human hepatoma cell line, Mahlavu.

Lipoprotein metabolism has been investigated in a novel human hepatoma cell line, Mahlavu, which has been reported to possess the characteristics of hepatocytes. Low-density lipoprotein (LDL) was degraded by Mahlavu cells. LDL taken up by the cells suppressed intracellular cholesterol biosynthesis and promoted cholesterol esterification in a manner similar to that of HepG2 cells. High-density lipoprotein (HDL) was also degraded by Mahlavu cells, whereas it was not degraded by fibroblasts. We compared the mode of intracellular metabolism of HDL to that of LDL. In contrast to the LDL receptor pathway, the degradation of HDL was not inhibited by 100 microM chloroquine added to the medium, indicating that the degradation may not occur in lysosomes. Cholesterol taken up as HDL-cholesterol by the Mahlavu cells had no effect on the intracellular biosynthesis of cholesterol nor on cholesterol esterification. The conditioned media in which Mahlavu cells had been cultured did not promote the degradation of HDL, suggesting that HDL is degraded intracellularly. These data suggest that HDL is taken up and degraded by the liver cells in contrast to extrahepatic peripheral cells such as fibroblasts and macrophages in which the degradation of HDL does not occur. The results indicate that HDL-associated cholesterol may be processed via a pathway different from that of LDL metabolism and that the degradation of HDL occurs extralysosomally.

Carcinoma, Hepatocellular↗

PubMed1993

Autonomous production of granulocyte-colony stimulating factor in tumour xenografts associated with leukocytosis.

Leukocytosis sometimes accompanies malignant neoplasms in the absence of infection. It is thought that the production of colony-stimulating factor by neoplasms is the most potent cause of tumour-induced leukocytosis; several mechanisms have been suggested to explain this. We examined 155 human tumour xenografts established in nude mice, and found that 17 of the xenografts induced remarkable leukocytosis (> 15,000 microliters-1) in nude rats. We examined granulocyte colony-stimulating factor (G-CSF) production by the xenografts to study the mechanisms underlying this tumour-induced leukocytosis. Ten of the 17 xenografted human tumours appeared to express the G-CSF gene. Serum G-CSF increased, to concentrations of 179-37,218 pg ml-1, in host animals transplanted with the ten xenografts expressing the G-CSF gene transcripts. The biological activity of serum G-CSF also increased, to concentrations of 206-9,074 pg ml-1, in the host animals transplanted with the ten xenografts. Immunohistochemical analysis demonstrated G-CSF production at the cellular level in three of the ten xenografts. These results suggested that the production of G-CSF is a common event in human tumour xenografts associated with leukocytosis, but that factors other than G-CSF are also likely to be involved. Leukocytosis induced by neoplasms seems to be a heterogeneous and complex disorder.

Animals↗

PubMed1993

Role of x-linked immunodeficiency (xid) and NK activity in rejection of human tumor xenotransplants in nude mice.

In order to elucidate the factors influencing the takes of human tumor xenografts in nude mice, we compared the transplantability of human tumors in nude mice with additional genetic defects in the immune system. The nude mice strains tested were classified as follows by expression of the beige gene and the x-linked immunodeficiency (xid) gene: 1) high NK nude (C57BL/6N, nu/nu), 2) low NK nude (C57BL/6 bg/bg nu/nu), 3) high NK nude with B-cell defect (CBA/N nu/nu), and 4) low NK nude with B-cell defect (NIH(S)III). Takes of human tumor xenografts including gastric carcinoma, T-cell lymphoma and B-cell lymphoma were better in nude mice with xid (CBA/N and NIH(S) III nude mice) than in nude mice without xid (B6 and beige nude mice). In addition, among the nude mice with xid expression, the takes were slightly better in nude mice with a CBA/N background than in those with a NIH(S) background. Moreover, the xenotransplantation rate in (CBA/N x C57BL/6N)F1 male nude mice with xid expression was higher than in (C57BL/6N x CBA/N)F1 males without xid expression, but did not react the same level as that in CBA/N nude. On the other hand, introduction of the beige gene into nude mice minimally improved the takes of human tumor xenografts under limited experimental conditions (inoculation of 100 x 10(5) T-cell lymphoma and 1 x 10(5) gastric carcinoma cells) despite the reduction of NK activity. In xenotransplantation of human tumors directly from patients, the take rates of the tumors were also better in CBA/N nude mice than in BALB/cA nude mice. The results in the present report confirmed the effect of xid and CBA/N genetic background on human tumor xenografts in nude mice, suggesting the existence of serum factors, possibly present in serum IgM, mediating rejection of the xenografts.

Animals↗

PubMed1993

In vivo acquired drug resistance and multidrug resistance gene (MDR1) expression in the KB carcinoma cell line xenotransplanted in nude mice.

We studied the correlation between in vivo responsiveness of KB xenografts to anticancer drugs and the expression level of the human multidrug resistance gene (MDR1) encoding P-Glycoprotein (P-Gp). We established KB xenografts (xeKB3-1 and xeKB8-5) by inoculating these in vitro lines into nude mice. The responsiveness was evaluated by an in vivo chemosensitivity assay (T/C; sensitive, < 50%). Xenograft xeKB3-1 was sensitive to vincristine (VCR) (T/C, 48%), and xeKB8-5 was resistant to VCR (T/C, 72%). We selected a VCR-resistant variant (xeKB3-1-R, T/C, 76%) by treating xeKB3-1 with VCR (1.2 mg/kg, x3) in vivo. The MDR1 expression was evaluated by a semi-quantitative assay using reverse transcription-polymerase chain reaction. A MDR1 expression pattern in xeKB3-1 and xeKB8-5 in vivo was the same as that to KB3-1 and KB8-5 in vitro. The xenograft xeKB3-1-R expressed definitive but significantly lower levels of MDR1 than xeKB8-5. These results suggest that acquired drug resistance is related to minimally enhanced expression of the P-Gp protein/MDR1 gene in KB xenografts in vivo.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1992

Low-density lipoproteins in hyperalphalipoproteinemic heavy alcohol drinkers have reduced affinity for the low-density lipoprotein receptor.

Heavy alcohol intake causes a marked inhibition of cholesteryl ester transfer protein (CETP) activity resulting in cholesterol ester enrichment of HDL. In this study we have characterized LDL of 35 chronic heavy alcohol drinkers with hyperalphalipoproteinemia to clarify the effect of alcohol on the metabolism of LDL. Serum concentrations of LDL-cholesterol and apolipoprotein B were normal, while the chemical composition of LDL was characterized by depletion of cholesteryl ester and enrichment of triglyceride. The LDL particles of the drinkers were significantly smaller in size than those of controls and had reduced affinity for LDL receptors of normal human fibroblasts. After cessation of alcohol, these abnormal characteristics returned toward normal along with elevation of CETP activity. These results suggest that heavy alcohol intake alters the compositions and particle size of LDL, consequently reducing their affinity for LDL receptors. This may be attributed, at least in part, to the reduction of CETP activity.

Adult↗