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Biomedical subjects

M Ueda

Publications and source records attributed to M Ueda.

At least 685 records · Page 38Linked to original sources
PubMed1995

Type VI collagen in mouse masseter tendon, from osseous attachment to myotendinous junction.

BACKGROUND AND METHODS: The association of masseter tendon type VI collagen with other extracellular matrix (ECM) components was examined from osseous attachment to myotendinous junction by immunohistochemistry and transmission electron microscopy with ATP treatment and enzyme digestion. RESULTS: In the tendon proper, fibrocytes extended their processes among bundles of striated collagen fibrils and associated with adjacent cells through amorphous materials, thus forming a three-dimensional network. The amorphous or filamentous material was observed around the fibrocyte cell body and along the cell processes, where the localization of type VI collagen was confirmed by immunohistochemistry using anti-type VI collagen antibody. After treatment with 20 mM adenosine 5'-triphosphate (ATP), 100 nm periodic fibrils, an aggregated form of type VI collagen, were formed in the place where amorphous or filamentous material was present before the treatment. In myotendinous junction, the ATP-aggregated periodic fibrils were observed to associate with the external lamina of the muscle cells as well as among junctional tendon collagen fibrils. In the tendon-bone boundary, ATP-aggregated periodic fibrils were observed around fibrocartilage-like cells in the uncalcifying area but not in the calcification front. Prolonged ATP treatment or hyaluronidase predigestion caused the formation of type VI collagen periodic fibrils in the area near the calcified matrix. CONCLUSIONS: The distribution of type VI collagen in mouse masseter tendon is different in different anatomical position. This may reflect the different functional demand for this collagen.

Adenosine Triphosphate↗
PubMed1995

Preoperative assessment of lymph nodes in the prediction of disease spread and outcome in cancer of the thoracic oesophagus.

Prospective assessment of lymph node status, based on the findings of computed tomography, external ultrasonography and palpation, was compared with clinical results in 179 patients who underwent oesophagectomy with systematic node dissection. Preoperative findings for each node group were classified into four grades: involvement not suspected (-); possible involvement (+/-); probable involvement (+); and definite involvement (++). When only (++) or (+) assessment was categorized as positive, the specificity was more than 94 per cent, although the sensitivity was less than 40 per cent. The preoperative assessment correlated significantly with the incidence of node involvement (P < 0.02), the degree of lymphatic invasion (P < 0.0001) and outcome after operation. For patients with all nodes assessed as (-), the 5-year survival rate was 70 per cent, compared with 26 per cent for those with nodes assessed as (++), P = 0.001. Preoperative assessment provided useful information on nodal status.

Carcinoma, Squamous Cell↗
PubMed1995

Analysis of v-Ha-ras and v-fos oncogene transduction into a mouse epidermal cell line with "initiated" phenotype in culture but normal skin phenotype in vivo.

Cell line SCR722 was derived from adult SENCAR mouse epidermal cells initiated in culture by treatment with the carcinogen N-methyl-N'-nitro-N-nitrosoguanidine and selection for foci proliferating in medium with calcium levels that induce terminal differentiation in normal cells. Expansion of one of these foci and two additional cell clonings produced cell line SCR722, which was near-tetraploid and formed normal skin when grafted to athymic nude mouse hosts. However, unlike normal keratinocytes, SCR722 cells fail to suppress papilloma formation when grafted along with papilloma cell line SP-1. For optimum growth in culture, SCR722 cells required fibroblast-conditioned medium and 0.5 mM Ca2+. SCR722 cells had a wild-type c-Ha-ras gene but had lost their requirement for conditioned medium in culture and produced dysplastic papillomas in grafts when transduced with the v-Ha-ras gene. SCR722 cells stably expressing the v-fos gene produced normal epidermis in grafts, but when these cells were transduced with the v-Ha-ras gene, they produced carcinomas. Clones with greater expression of the transfected v-fos gene had a more invasive phenotype in vivo. These results indicate that carcinogen treatment of epithelial cells can result in an altered but nontumorigenic phenotype that may be at risk for becoming a more advanced neoplastic state with additional genetic alterations.

Animals↗
PubMed1995

Characterization of a human glycoprotein (erythropoietin) produced in cultured tobacco cells.

Erythropoietin (Epo), a glycoprotein that regulates the formation of erythrocytes in mammals, was produced in cultured tobacco BY2 cells (Nicotiana tabacum L. cv. Bright Yellow 2) by introducing human Epo cDNA via Agrobacterium tumefaciens-mediated gene transfer. Epo was correctly processed and subsequently penetrated the plasma membrane of tobacco cells. However, it remained attached to the cell wall and was not released into the culture medium. Although Epo produced by tobacco cells was glycosylated with N-linked oligosaccharides, these carbohydrates were smaller than those of the recombinant Epo produced in mammalian cells. Epo produced in tobacco exhibited in vitro biological activities by inducing the differentiation and proliferation of erythroid cells. However, it had no in vivo biological activities. A lectin-binding assay indicated the lack of sialic acid residues in the N-linked oligosaccharides of Epo, suggesting that Epo was removed from the circulation before it reached erythropoietic tissues.

Amino Acid Sequence↗
PubMed1995

Novel NADP-linked isocitrate dehydrogenase present in peroxisomes of n-alkane-utilizing yeast, Candida tropicalis: comparison with mitochondrial NAD-linked isocitrate dehydrogenase.

Peroxisomal NADP-linked isocitrate dehydrogenase (Ps-NADP-IDH) was purified for the first time from Candida tropicalis cells grown on n-alkane as a carbon source, which was effective in proliferation of peroxisomes. The properties of Ps-NADP-IDH were compared with those of mitochondrial NAD-linked isocitrate dehydrogenase (Mt-NAD-IDH) purified from the cells grown on acetate, in which peroxisomes did not proliferate. Ps-NADP-IDH was a homodimer of identical subunits (45 kDa), while Mt-NAD-IDH was suggested to be a heterooctamer composed of two types of subunits with different molecular masses (41 and 38 kDa). Kinetic studies revealed that Ps-NADP-IDH gave Michaelis-Menten saturation curves against isocitrate and NADP concentrations, whereas Mt-NAD-IDH was an allosteric enzyme regulated by ATP, AMP, and citrate. Inhibition by 2-oxoglutarate, a precursor of glutamate, was observed only for Ps-NADP-IDH. Both enzymes were inhibited by concomitant addition of oxalacetate and glyoxylate. The function of Ps-NADP-IDH seems to be completely discriminated from that of Mt-NAD-IDH as reflected by their distinct subcellular localizations. Furthermore, the properties of Ps-NADP-IDH were also compared with those of other mitochondrial and cytosolic IDHs from sources reported previously.

Acetates↗
PubMed1995

The upstream region of the isocitrate lyase gene (UPR-ICL) of Candida tropicalis induces gene expression in both Saccharomyces cerevisiae and Escherichia coli by acetate via two distinct promoters.

The upstream region of the isocitrate lyase gene (UPR-ICL, 1530bp) of an n-alkane-utilizable yeast, Candida tropicalis, induced gene expression in another yeast, Saccharomyces cerevisiae, when the yeasts were grown on acetate. Surprisingly, UPR-ICL displayed the same regulatory function in the bacterium Escherichia coli when grown on acetate. We determined the interesting nucleotide sequence of UPR-ICL. The deletion analysis of UPR-ICL in both cells revealed the presence of two distinct promoters: one was localized at -394 to -379 and regulated gene expression in S. cerevisiae; the other was located near the initiation codon and regulated gene expression in E. coli. The two promoter sequences were similar, but not identical to regulatory elements that have been previously reported in S. cerevisiae and E. coli, respectively. Accordingly, the possibility of novel regulatory mechanisms could not be excluded. This is an interesting example of the presence of distinct cis-acting regulatory elements responsible for the induction of gene expression in one gene by acetate in both S. cerevisiae and E. coli. Preservation of such promoters through evolution is also discussed.

Acetates↗
PubMed1995

Tissue-specific activation of tumor marker glutathione transferase P transgenes in transgenic rats.

By means of transgenic rats, we have recently shown that the GPEI enhancer of the glutathione transferase P (GST-P) gene, which has two one-base-missmatched AP-1 sites locating palindromically with three-base spacing in between, is sufficient for conferring tumor-specific activation of the gene in vivo. It is noted that there is another consensus AP-1 site near the promoter of this gene. By using seven independent transgenic rats, bearing distinct areas of the GST-P gene that are connected to the chloramphenicol acetyltransferase (CAT) coding sequence, we analyzed CAT expression in various tissues (brain, lung, liver, kidney, spleen) in these transgenic rats. We found that the ECAT gene, which has sufficient of the upstream regulatory region (approx. 2.9 kb) of the gene containing GPEI, is trans-activated in the kidney and lung of transgenic rats in a similar manner to endogenous GST-P. When either the GPEI core sequence or the AP-1 site near the promoter is deleted, CAT expression decreases to almost background level. Substitution of the GPEI core or the AP-1 site near the promoter to this silent construct (5CATGPEIcore) reconstituted CAT expression in the transgenic rats. In these rats, CAT was expressed in the brain and lung rather than in the kidney, showing a somewhat different pattern from the endogenous GST-P. In the brain tissue of the 5CATGPEIcore transgenic rat, CAT was demonstrated in the glia cells, which is consistent with endogenous GST-P expression. These results suggest that a relatively long upstream region (approx. 2.9 kb) is required for tissue-specific expression of the GST-P gene and that GST-P expression in the brain may be regulated differently from its expression in other organs.

Animals↗
PubMed1995

Can esophagectomy cure cancer of the thoracic esophagus involving the major airways?

To evaluate the effects of aggressive operation for esophageal cancer invading the trachea and main bronchi, we investigated retrospectively 62 patients with proven tracheobronchial involvement who underwent thoracotomy for esophagectomy between 1973 and 1993. We operated unless the tumor was assessed to be definitely unresectable. Esophagectomy was possible in 55 patients, and the resectability rate was 95% after preoperative computed tomography and bronchoscopy became routine. After esophagectomy, no residual cancer lesion was recognizable macroscopically in 53% of patients. The hospital mortality rate in esophagectomy cases was 7% in the past 8 years. The outcome in patients who underwent curative resection was significantly favorable (p < 0.0001), and the 2-year survival was 51%. The patients with nonresectable cancer all died within 6 months compared with a 23% 1-year survival rate for palliative esophagectomy cases (p < 0.006). Among patients with tracheobronchial involvement assessed as resectable on computed tomography and bronchoscopy, a considerable proportion benefited from aggressive therapy with esophagectomy. The possibility of complete cure was high, especially when the cancer responded well to preoperative therapy and no lymph nodes were involved.

Adult↗
PubMed1995

Electron-microscopic and immunohistochemical studies of Langerhans cells and Thy-1-positive cells in mouse tongue epithelium subjected to local hyperthermia.

Local hyperthermia via skin has been used to treat cancer but may suppress local immune responses as a side-effect. To examine effects of heat on immunologically responsive cells in oral mucosa, mouse tongues were heated by an implant system at 43 degrees C for 20 min. The densities of Langerhans cells and Thy-1-positive cells rapidly increased within 3 h after the treatment, then returned to a normal level after 7 days. Electron microscopy confirmed that Langerhans cells in the tongue epithelium formed clusters with lymphocytic cells, suggesting an active response to the hyperthermia.

Adenosine Triphosphatases↗
PubMed1995

Type VI collagen periodic fibrils in the synovium of the mouse temporomandibular joint.

Immunohistochemical staining with anti-type VI collagen antibody was strongly positive in the intimal layer and moderately positive in the subsynovium. After treatment with 20 mM ATP, numerous structures with a periodicity of 100 +/- 10 nm (type VI collagen fibrils) appeared around the synovial cells. As the periodic dark bands were stained by ruthenium red, proteoglycan(s) or glycosaminoglycan(s) were probably associated with the type VI collagen fibrils. When the tissue was digested with testicular hyaluronidase before ATP treatment, the periodic fibrils were not found, and only a filamentous network of 100-nm interval was seen around the cells. Thus, type VI collagen is abundant in the synovium of the mouse mandibular joint and is associated with proteoglycans or glycosaminoglycans, which might have a role in its formation.

Animals↗
PubMed1995

Opioidergic inhibition of capsaicin-evoked release of glutamate from rat spinal dorsal horn slices.

We investigated the effects of opioid agonists on the capsaicin-evoked release of glutamate from nociceptive primary afferent fibers of the rat (6-8 weeks) using a fluorometric on-line continuous monitoring system for glutamate. In the presence of 0.3 microM tetrodotoxin, the application of 3 microM capsaicin to spinal dorsal horn slices produced an evoked glutamate release (55.9 +/- 4.02 pmol.mg-1 protein, n = 15). DAMGO ([D-Ala2,N-Me-Phe4,Gly5-ol]enkephalin; 0.3-10 microM) and morphine (1-30 microM), mu-opioid agonists, produced a concentration-dependent reduction (approximately 85 and approximately 77% reduction, respectively) in the capsaicin (3 microM)-evoked release of glutamate. These inhibitory effects were significantly antagonized by naloxone (1 microM). DPDPE ([D-Pen2,5]enkephalin; 1-10 microM), a delta-opioid agonist, also reduced the capsaicin-evoked release in a concentration-dependent manner (approximately 59% reduction). Naltrindole (1 microM), a selective delta-antagonist, significantly antagonized the inhibitory effect of DPDPE (10 microM). In contrast, neither U-50,488H (1-10 microM) nor U-69,593 (10 microM), kappa-opioid agonists, had any effects on the evoked release of glutamate. These results suggest that mu-, and delta-opioid agonists modulate pain transmission in the spinal dorsal horn, at least in part, by inhibiting the release of glutamate from capsaicin-sensitive primary afferents.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1995

Effect of endogenous and exogenous EGF on the growth of EGF receptor-hyperproducing human squamous cell carcinoma implanted in nude mice.

The effect of epidermal growth factor (EGF) on the biological behaviour of human tumours in vivo is still controversial. We investigated the effect of EGF on the growth of an EGF receptor-hyperproducing human epidermoid carcinoma, A431 tumour, and on a human small-cell lung carcinoma, H69 tumour, without detectable EGF receptor by using sialoadenectomised (sialex) mice as an endogenous EGF-suppressed animal model. The plasma EGF concentration in the sialex athymic mice was significantly lower than that in the sham-operated mice (P < 0.05). After exogenous EGF replacement with an implanted minipump, the plasma EGF concentration was significantly increased in both groups (P < 0.05). There was no significant difference between the body weight growth curves of sialex and sham-operated mice with and without EGF treatment. The tumour weight of A431, both estimated and measured in sialex mice, was significantly lower than that in sham-operated control mice (P < 0.05), and the growth of A431 tumour was significantly increased by exogenous EGF treatment (P < 0.05). Mitotic activity of these tumours detected by immunohistochemical staining for incorporated bromodeoxyuridine indicated a mitosis-stimulatory effect of endogenous and exogenous EGF on A431 tumours. In contrast to these findings on A431 tumours, a growth-stimulatory effect of endogenous and exogenous EGF was not observed in the H69 tumour. These results suggest a growth-promoting effect of physiological levels of endogenous EGF on EGF receptor-hyperproducing human tumours in vivo.

Animals↗
PubMed1995

A mouse monoclonal antibody, S2n8, detects a 140 kDa protein on the surface of human endometrial stromal cells and decidual cells.

We developed a mouse monoclonal antibody, S2n8, by immunizing mice i.p. with human decidual cells collected in the first trimester of pregnancy. By indirect immunofluorescence staining of frozen sections, S2n8 was found to react with decidual cells and endometrial stromal cells throughout the menstrual cycle, but not with endometrial glandular cells or with the endometrial surface epithelium. Judging from the fluorescence intensity, the antigen expression on stromal cells was weak in the proliferative phase, and became stronger in the secretory phase. Decidual cells in the first trimester of pregnancy and decidual cells at term showed strong expression of this antigen. Indirect immunofluorescence staining of enzymatically dispersed decidual tissue revealed that the S2n8 antigen was expressed on the decidual cell surface. Flow cytometric analysis of 12 freshly prepared stromal cell-enriched cell suspensions showed that 74.8-94.2% (mean +/- SD 86.1 +/- 6.6%) of the cells carried the antigen. The expression of S2n8 antigen on cultured stromal cells was enhanced by the addition of oestradiol and/or progesterone. The antigenic molecule was purified by immunoaffinity chromatography from decidua collected in the first trimester of pregnancy, and the molecular weight was estimated to be approximately 140 kDa. These findings indicate that the S2n8 antigen is a useful cell surface marker for stromal cells/decidual cells and is associated with their differentiation.

Animals↗
PubMed1995

Sleep disturbance in elderly patients with cognitive impairment, decreased daily activity and periventricular white matter lesions.

We investigated how sleep disturbance is correlated with brain lesions, cognitive impairment and decreased daily activity (ADL). Two hundred and four chronically ill patients including patients with vascular dementia were classified into eight groups based on cognitive function, ADL and grades of PVL (periventricular lucency) as shown by computerized tomography. Visual monitoring of the sleep/wake state was performed hourly for 14 consecutive days and the daytime sleep hours and the nighttime sleep hours were determined based on detected disturbances in the sleep/wake pattern. Whether any specific infarcted regions were correlated with sleep disturbance was also evaluated. We found that daytime sleep hours were increased and nighttime sleep hours were decreased by three single factors: cognitive impairment, decreased ADL and the severe grade of PVL. As for an interactive effect of the two factors, daytime sleep hours were increased by dementia with decreased ADL (independent of PVL) and increased by decreased ADL with the severe grade of PVL (independent of dementia). Although three factors affected sleep independently, ADL has an interactive effect on sleep with dementia and with PVL. No specific cortical regions related to sleep disturbance were found.

Activities of Daily Living↗
PubMed1995

A porcine homolog of human integrin alpha 6 is a differentiation antigen of granulosa cells.

To search for new molecules relating to the mechanism(s) of follicular differentiation, we raised a new monoclonal antibody (mAb), POG-2, which reacted with the surface of porcine ovarian granulosa cells. An immunohistological study revealed that the antigen appeared initially on the primary follicles. The antigen expression increased during follicular development, reached the highest level in small follicles 1-2 mm in diameter, and then decreased in the preovulatory follicles. The antigen was not detected on luteal cells in the CL. SDS-PAGE profiles of POG-2 antigen purified from isolated porcine granulosa cells by immunoaffinity chromatography indicated that it consisted of two proteins (120 and 130 kDa) and that the antigenic epitope of POG-2 was on the 120-kDa protein. We next purified a large amount of POG-2 antigen from the homogenate of porcine ovaries by immunoaffinity chromatography. Analysis of the partial amino acid sequence of the 120-kDa protein showed that 16 amino acids from the amino terminus were very similar to those of both human and murine mature integrin alpha 6, with 88% homology. SDS-PAGE profiles revealed that the 120-kDa protein was bound to a 28-30-kDa protein by a disulfide bond; this was compatible with the reported characteristics of human integrin alpha 6. We then examined the immunoreactive distribution of integrin alpha 6 using anti-integrin alpha 6 mAb GoH3. The staining profiles obtained with GoH3 were very similar to those obtained with POG-2. These findings showed that the molecule detected by POG-2 was a porcine homolog of human integrin alpha 6 and that integrin alpha 6 was a differentiation antigen of porcine granulosa cells, suggesting an involvement of integrins in follicular differentiation.

Amino Acid Sequence↗
PubMed1995

The characteristics of cultured mucosal cell sheet as a material for grafting; comparison with cultured epidermal cell sheet.

The characteristics of cultured mucosal cells from the oral mucosa were investigated and compared with those of cultured epidermal cells. Total cell counts showed that mucosal cells possessed greater proliferating ability than epidermal cells. The results of 3(4,5-dimethyle-thiazoyl-2-yl)2,5 diphenyltetrazolium bromide assay confirmed this observation and also suggested that the mucosal cells maintained biological activity longer than epidermal cells. The most important morphological characteristics of mucosal cells in culture were their low grade of differentiation. Interestingly, the epidermal cells showed enucleation and keratinization progressively during culture, whereas the mucosal cells showed no obvious enucleation when examined by light microscopy. Transmission electron microscopy showed a smaller number of desmosomes in cultured mucosal cells than epidermal cells. The results of this study reveal cultured mucosal cell sheets to be a possible material for grafting in addition to cultured epidermal cell sheets.

Cell Count↗