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Biomedical subjects

S Tamura

Publications and source records attributed to S Tamura.

At least 361 records · Page 20Linked to original sources
PubMed1995

[Correlation between the intercellular adhesion molecule (E-cadherin) and its associated protein (alpha-catenin) expression and metastasis in human digestive cancers].

The immunostaining (ABC method) of E-cadherin and alpha-catenin were performed on 46 esophageal cancers, 67 gastric cancers, 100 colon cancers. E-cadherin and alpha-catenin expression was evaluated as preserved and reduced according to the proportion of positive cells, respectively. The reduction of alpha-catenin expression was more significantly related to lymph node metastasis than that of E-cadherin. Furthermore, the frequency of hematogenous liver metastasis in preserved E-cadherin expression and reduced alpha-catenin expression was significantly higher than that in another combination of E-cadherin and alpha-catenin expression, in gastric and colon cancer. The reduction of alpha-catenin expression was associated with declined intercellular adhesiveness, which occasionally was not accompanied by reduction of E-cadherin. Therefore, the expression of alpha-catenin might more sensitively indicated cell-cell adhesion, predicting tumor metastasis.

Cadherins↗
PubMed1995

The SH2 domain of ABL is not required for factor-independent growth induced by BCR-ABL in a murine myeloid cell line.

Chronic myelogenous leukemia (CML) is characterized by the presence of a specific chromosomal translocation between the long arms of chromosomes 9 and 22 that results in the fusion of BCR encoded sequences upstream of exon 2 of c-ABL. This fusion gene produces a 210-kDa chimeric BCR-ABL protein that has elevated tyrosine kinase activity. Several substrates of this activated tyrosine kinase have been reported. However, their necessity for the transforming functions of BCR-ABL has not been determined. A specific deletion of the SH2 domain of ABL was created to determine whether this mutation would alter the ability of BCR-ABL to induce factor-independent growth of a murine myeloid cell line and to determine whether the SH2 domain mediates the interaction of BCR-ABL with any of its substates. Our results indicate that the SH2 domain of BCR-ABL is not required for the induction of growth factor independence and is not required for the association of BCR-ABL with rasGAP or SHC. However, myeloid cells expressing this mutant lack the tyrosine phosphorylation of a 62-kDa rasGAP associated protein.

Animals↗
PubMed1995

PP2C phosphatase activity is coupled to cAMP-mediated pathway in rat parotid acinar cells.

A 26 kDa particulate protein is phosphorylated during stimulation of amylase secretion by a beta-adrenergic agonist in the rat parotid gland. Previous study has shown that PP2C phosphatase is involved in dephosphorylation of this 26 kDa protein [Yokoyama, N. et al. (1994) Biochem. Biophys. Res. Commun. 200, 497-503]. In this study, immunotransblot analysis using anti-PP2C phosphatase antibody showed that PP2C phosphatase was found prominently in the cystolic fractions and less in secretory granule membranes. When cells were stimulated by isoproterenol, cytosolic PP2C phosphatase activity increased to 145% at 5 min and returned to basal level at 30 min. Forskolin increased PP2C phosphatase activity. H89 inhibited increase of PP2C phosphatase activity following beta-adrenergic stimulation. These results suggest that PP2C phosphatase activity is regulated by cAMP-mediated signaling following beta-adrenergic stimulation and participates in dephosphorylation of this 26 kDa protein.

Adrenergic beta-Agonists↗
PubMed1995

[Factors affecting continuation of home medical care--based on the relationship between patient and caregiver status].

In recent years it has gradually become possible to have some control over the medical condition of the end-stage cancer patient. However, there are various problems involved in the continuation of home care. In order to clarify how the mutual relationship between patient and caregiver effects the continuation of home care, we conducted a study on 28 end-stage cancer patients who made the transition from our hospital to home care by means of our HOme Care Service. Using the Kaneda Assessment Score, we obtained information from patients' charts, added reasons for rehospitalizations and analyzed the data. The results showed that the group of patients who remained on home care, despite the fact that their condition was significantly poorer than that of the group who discontinued home care, showed a significantly higher proportion of "wishing to be cared for at home to the last," in the view of the caregiver, a joint commitment of the caregiver together with the family, and a suitable response to changes in the patient. As a direction for forthcoming support in this area, there is a need for sufficient assessment in order to evaluate the balance between caregiver and family. It was suggested that guidance in each case and the use of community resources will be very important.

Activities of Daily Living↗
PubMed1995

[The effectiveness of discharge planning (DSP) in home care--comparison of conditions of cancer patient shifted to home treatment before and after DSP introduction].

We developed a discharge planning (DSP) procedure as a method to assess the family and cancer patient situation when making the shift to home care, and we herewith report its significance. DSP is intended to sustain the patient's quality of life (QOL) and improve it; for a smooth transition to treatment at home, the family and patient situation must be assessed from various perspectives. The prospective illness conditions, needed medical treatment and care should be appropriately planned, with due recognition of the roles to be played and the requisite pooling of professional information in order to handle emergencies and the like when such arise. In the present study, in order to clarify issues dealing with DSP effectiveness, we compared 34 patients on home care, 17 before DSP and 17 thereafter. The results indicated that following the introduction of DSP, the home care increased for patients with gastroenterological problems such as pain, general debilitation, poor appetite, constipation, diarrhea and the like and those impulsiveness, vomiting and mental symptoms overlapping. With the proper assessment at the time of the transition to home care, this care could be continued. Moreover, with patient satisfaction, there was the need for assessment over the course in order to evaluate treatment and care. In the days to come, there is the need to improve this approach with a scoring system in the evaluation.

Activities of Daily Living↗
PubMed1995

Involvement of human interleukin 6 in experimental cachexia induced by a human uterine cervical carcinoma xenograft.

A human tumor xenograft model for cancer cachexia was established by growing a uterine cervical carcinoma, Yumoto, in nude mice. The tumor transplanted into the mice induced severe body weight loss (30% of body weight) when the tumor weight was only 1 g. In addition, other indicators for cachexia, such as adipose tissue and muscle wasting and hypoglycemia, were also observed in the tumor-bearing mice, suggesting that this is a proper model for experimental cachexia induced by a human tumor. We then examined the association of this model with various cytokines, such as tumor necrosis factor alpha, interleukin (IL)-1alpha, IL-1beta, IFN-gamma, IL-6, and leukemia inhibitory factor, and identified human IL-6, which was produced by the tumor cells, as a mediator of cachexia. A neutralizing antibody against hIL-6 administered to the mice after the development of cachexia symptoms significantly improved body weight loss, adipose tissue wasting, hypoglycemia, acute phase reaction, and leukocytosis, although it did not suppress the tumor growth. These results demonstrate that the hIL-6 produced by the tumor cells is an essential mediator of the cachexia induction in this model.

Animals↗
PubMed1994

The cDNA sequence encoding mouse Mg2+ -dependent protein phosphatase alpha.

The complete cDNA sequence encoding Mg2+ -dependent protein phosphatase (MPP) alpha from mouse brain was cloned. It encodes a protein of 382 amino acids with a calculated M(r) of 42,432. The putative sites of phosphorylation by casein kinase II, found originally in rat MPP alpha, are conserved in the mouse ortholog.

Amino Acid Sequence↗
PubMed1994

Plasma transforming growth factor-beta 1 in patients with hepatocellular carcinoma. Comparison with chronic liver diseases.

BACKGROUND: Many kinds of human malignant tissue, including hepatocellular carcinoma (HCC), were reported to overexpress transforming growth factor-beta 1 (TGF-beta 1) gene. However, little work has been done on the circulating TGF-beta 1 in patients with malignant tumors. METHODS: Plasma TGF-beta 1 levels in patients with HCC (n = 26) were compared with those in patients with chronic hepatitis (CH) (n = 12) and cirrhosis (n = 11) and in normal subjects (n = 20) using an enzyme-linked immunosorbent assay system after acid/ethanol extraction. RESULTS: The patients with HCC had significantly higher plasma TGF-beta 1 levels (19.3 +/- 19.5 ng/ml; mean +/- standard deviation [SD]) than those in normal subjects (1.4 +/- 0.8 ng/ml) and in patients with CH (3.0 +/- 3.1 ng/ml) and cirrhosis (3.7 +/- 2.1 ng/ml) (P < 0.01). Plasma TGF-beta 1 concentrations in the patients with cirrhosis were also significantly higher than those in the normal subjects (P < 0.05). The extracted plasma TGF-beta 1 from the patients with HCC had biologic activity according to a growth inhibitory assay using mink lung epithelial cells. No significant correlation was found between the plasma TGF-beta 1 levels in the patients with HCC and serum alpha-fetoprotein levels. After successful treatment for HCC, the amount of plasma TGF-beta 1 significantly decreased from 22.6 plus or minus 16.7 ng/ml (mean +/- SD) to 10.2 plus or minus 6.5 ng/ml (P < 0.05). CONCLUSIONS: We demonstrated higher levels of plasma TGF-beta 1 in the patients with HCC than those in patients with chronic hepatitis and cirrhosis. Plasma TGF-beta 1 might be a candidate for a novel tumor marker for hepatocellular carcinoma.

Biomarkers, Tumor↗
PubMed1994

Involvement of type 2C phosphatase in the dephosphorylation of 26 kDa phosphoprotein in rat parotid acinar cells.

Phosphorylation of three particulate proteins with molecular masses of 34, 26, and 22 kDa was stimulated in the presence of cyclic AMP/3-isobutyl-1-methylxanthine in saponin-permeabilized rat parotid acinar cells. When the particulate fraction isolated from the cells labeled with [gamma-32p]ATP was incubated at 30 degrees C, dephosphorylation of the 26 kDa phosphoprotein occurred in the presence of Mg2+ or Mn2+. Okadaic acid had no effect on the Mg(2+)-dependent dephosphorylation of the 26 kDa phosphoprotein. Addition of the recombinant type 2C phosphatase, Mg(2+)-dependent and okadaic acid-insensitive phosphatase, caused a remarkable dephosphorylation of the 26 kDa phosphoprotein. These observations strongly suggest type 2C phosphatase is involved in the dephosphorylation of the 26 kDa phosphoprotein.

1-Methyl-3-isobutylxanthine↗
PubMed1994

Inhibition by topiramate of seizures in spontaneously epileptic rats and DBA/2 mice.

The effects of topiramate, a novel antiepileptic drug, on tonic and absence-like seizures in spontaneously epileptic rats (SER; zi/zi, tm/tm) and on sound-induced seizures in DBA/2 mice were investigated. Topiramate (20 and 40 mg/kg i.p.) inhibited both tonic and absence-like seizures in a dose-dependent manner, whereas phenytoin (20 mg/kg i.p.) and zonisamide (40 mg/kg i.p.) inhibited only the tonic seizures. The inhibitory effects of topiramate on absence-like seizures were antagonized by pretreatment with haloperidol (0.5 mg/kg i.p.), but those on the tonic seizures remained unaffected. Topiramate inhibited sound-induced seizures in DBA/2 mice (ED50 = 8.6 mg/kg p.o.). These findings suggest that topiramate may be effective for treatment of both convulsive and absence seizures of human epilepsy. The inhibitory effect of topiramate on absence-like seizures in SER may be mediated through the central dopaminergic system.

Acoustic Stimulation↗
PubMed1994

Heparin-binding EGF-like growth factor is a potent mitogen for rat hepatocytes.

We examined the hepatotrophic activity of heparin-binding EGF-like growth factor (HB-EGF), a recently identified potent mitogen for vascular smooth muscle cells and fibroblasts. HB-EGF stimulated DNA synthesis of rat hepatocytes in primary culture in a dose-dependent manner up to 30 ng/ml. The maximal stimulation by HB-EGF represented more than 80% of that induced by HGF. In normal rat liver, the transcript of HB-EGF gene was detected in the non-parenchymal cells and very low level in the hepatocytes. In the regenerating liver on the 3rd day after 70% hepatectomy, the HB-EGF mRNA increased in the non-parenchymal cells, suggesting that HB-EGF may contribute to liver regeneration through a paracrine mechanism.

Animals↗
PubMed1994

E-cadherin and alpha-catenin expression in human esophageal cancer.

Intercellular adhesion of the epithelial tissue is mainly regulated by the E-cadherin (E-cad) molecule. alpha-Catenin (alpha-cat) is one of the E-cad-associated cytoplasmic proteins that forms a linkage to the cytoskeleton and regulates E-cad function. To investigate the mechanism of dysfunction in cell-cell adhesion in cancerous tissues, we examined E-cad and alpha-cat expression by immunohistochemical staining on 46 human esophageal cancers using our specific monoclonal antibodies. By grading of E-cad and alpha-cat expression as uniformly positive (+), heterogeneous (+/-), or uniformly negative (-), the 46 tumors could be classified into 9 (20%) E-cad(+)/alpha-cat(+), 15 (33%) E-cad(+/-)/alpha-cat(+/-), 21 (46%) E-cad(+/-)/alpha-cat(-), and 1 (2%) E-cad(-)/alpha-cat(-). Twenty-five (54%) of the 46 tumors showed a similar expression of both molecules, while the other 21 tumors (46%) showed E-cad(+/-)/alpha-cat(-). Thus, although the expression of alpha-cat was significantly correlated with that of E-cad, in some tumors the reduction of alpha-cat was greater. Regarding the clinicopathological features, the reduction of alpha-cat expression, as well as that of E-cad, was significantly associated with tumor dedifferentiation, infiltrative growth, and lymph node metastasis (P < 0.01). Furthermore, the frequency of lymph node metastasis in E-cad(+/-)/alpha-cat(-) tumors was significantly higher (90%) than in E-cad(+)/alpha-cat(+) tumors (22%) (P < 0.01) or in E-cad(+/-)/alpha-cat(+/-) tumors (47%) (P < 0.05). These results suggest that not only E-cad but also alpha-cat are important regulators of intercellular adhesion and that alpha-cat is also involved in invasion and metastasis. In particular, reduction of alpha-cat expression is more correlated with invasive phenotype and lymph node metastasis than E-cad expression in human esophageal cancer.

Adult↗
PubMed1994

Immunohistochemical evaluation of alpha-catenin expression in human gastric cancer.

E-cadherin (E-cad) plays a major role in the maintenance of cell-cell adhesion in epithelial tissues, and impaired E-cad expression correlates with tumour invasion and metastasis. Alpha-catenin (alpha-cat), an undercoat protein of adherens junctions, binds to the cytoplasmic domain of E-cad and is essential for linking E-cad to actin-based cytoskeleton. We investigated E-cad and alpha-cat expression in 60 human gastric cancers immunohistochemically. The 60 gastric cancers were classified into 18 (30%) in which alpha-cat expression was preserved, and 42 (70%) reduced cases. The reduction of alpha-cat expression was significantly related to dedifferentiation, depth of invasion, infiltrative growth and lymph node metastasis. We also examined the co-expression of alpha-cat and E-cad. Seventeen (28%) tumours preserved both molecules [alpha-cat(+)/E-cad(+)] and 33 (55%) tumours reduced both [alpha-cat(-)/E-cad(-)], whereas 9 (15%) tumours exhibited alpha-cat(-)/E-cad(+). The frequency of lymph node metastasis in alpha-cat(-)/E-cad(+) tumour (67%) was significantly higher than that in alpha-cat(+)/E-cad(+) tumours (24%) and was close to that in alpha-cat(-)/E-cad(-) tumours (82%). The frequency of haematogenous liver metastasis in alpha-cat(-)/E-cad(+) tumours (44%) was significantly higher than that in alpha-cat(+)/E-cad(+) tumours (6%) or alpha-cat(-)/E-cad(-) tumours (9%). Thus, in all E-cad(+) tumours, the frequency of lymph node and liver metastasis was higher in alpha-cat(-) tumours than in alpha-cat(+) tumours. alpha-Cat expression is apparently better at predicting tumour invasion and metastasis than E-cad expression.

Adult↗
PubMed1994

Effects of glucagon on urinary excretion of urea and on plasma ammonia level in argininosuccinate synthetase deficiency.

Glucagon, a potent inducer of urea cycle enzymes, was administered subcutaneously, at a dose of 0.5 mg once a day, for 7 days to two citrullinemic patients. During this period, plasma NH3 levels in case 1 decreased significantly (P < 0.05 compared to levels before administration) and daily urinary excretion of urea N increased significantly (P < 0.05). For 1 week after the cessation of administration, the daily urinary excretion of urea N was significantly higher than the level before administration (P < 0.05), the plasma citrulline level during glucagon administration was lower than that before administration. In case 2, glucagon administration also decreased the plasma NH3 level (although the decrease was not statistically significant), and significantly increased daily urinary excretion of urea N (P < 0.05 compared to levels before administration). For 1 week after the cessation of glucagon administration the plasma citrulline level was significantly lower than that before administration (P < 0.05). These results indicate that glucagon significantly increases the urinary excretion of urea in the late onset form of argininosuccinate synthetase deficiency and that it may also decrease plasma NH3 levels in some patients with the deficiency.

Adult↗
PubMed1994

Expression of heparin-binding epidermal growth factor in human hepatocellular carcinoma.

BACKGROUND/AIMS: Growth factors are involved in the development and progression of cancer. The purpose of this study was to evaluate the possible role of heparin-binding epidermal growth factor-like growth factor (HB-EGF), which is a member of the EGF family, in the neoplastic transformation of hepatocytes. METHODS: Gene expression and protein production of HB-EGF were investigated in samples of human hepatocellular carcinoma (HCC) from 17 patients using Northern hybridization and immunohistochemical methods. RESULTS: The amount of HB-EGF messenger RNA was increased in the patients' HCC specimens compared with the surrounding liver tissues. In noncancerous hepatic tissues, HB-EGF was faintly positive in hepatocytes. Immunoreactive HB-EGF-producing cells were identified in HCC cells of all 17 patients with HCC, indicating that HB-EGF was produced in HCC cells themselves. However, none of the specimens from 10 patients with metastatic adenocarcinoma in the liver was positive for HB-EGF. The EGF receptor, which binds to HB-EGF, was also expressed on HCC cells. CONCLUSIONS: It is hypothesized that the enhanced expression of immunoreactive HB-EGF on the cell suggests a possible role of HB-EGF in the development or progression of human HCC in an autocrine and/or a juxtacrine manners.

Adult↗
PubMed1994

A method for determination of galactosyltransferase I activity synthesizing the proteoglycan linkage region.

An assay method was devised for measuring the activity of galactosyltransferase I (UDP-D-galactose:D-xylose galactosyltransferase), which is one of the enzymes synthesizing the linkage region between the core protein and glycosaminoglycan chains of proteoglycan. For this method, the reaction mixture contained a fluorescent substrate, 4-methylumbelliferyl-beta-D-xyloside as an acceptor, UDP-galactose as a donor and D-galactal as a competitive inhibitor of endogenous beta-galactosidase in the enzyme solution. The reaction mixture was incubated at 37 degrees C with enzyme solution prepared from an extract of cultured cells, and galactosyl-xylosyl-4-methylumbelliferone was produced as a reaction product. Measurement of galactosyltransferase I activity was performed by separation and quantitative analysis of this reaction product using high-performance liquid chromatography. Utilizing this method, easier and more sensitive detection of galactosyltransferase I activity in a cell-free system became possible. Application of the method revealed that cultured human skin fibroblasts contained galactosyltransferase I activity.

Binding, Competitive↗