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Biomedical subjects

E Shimizu

Publications and source records attributed to E Shimizu.

At least 73 records · Page 4Linked to original sources
PubMed1999

Analysis of antibodies to p16INK4A tumor suppressor gene products in lung cancer patients.

We examined by immunoblotting antibodies that bind to p16INK4A tumor suppressor gene products in the sera of patients with lung cancer. Sera from 15 to 102 patients, including 6 with adenocarcinoma, 3 with squamous cell carcinoma, 2 with large cell carcinoma and 4 with small cell carcinoma, reacted with a glutathione-S-transferase (GST) fusion protein containing whole human anti-p16INK4A, produced by Escherichia coli. However, sera from 30 normal volunteers did not react with the GST-p16INK4A fusion protein. The background such as age, gender, performance status, histology, stage, smoking history, and prior treatment was not significantly different between the patients with and without anti-GST-p16INK4A antibodies. Circulating p16INK4A tumor suppressor products were not detected in any individuals with lung cancer or in the normal controls.

Adult↗
PubMed1999

Activation of RB tumor suppressor protein and growth suppression of small cell lung carcinoma cells by reintroduction of p16INK4A gene.

The p16INK4A tumor suppressor gene is frequently inactivated in non-small cell lung carcinoma (NSCLC) and is less frequently inactivated in small cell lung carcinoma (SCLC) by mutation, deletion or DNA methylation. There are several reports that the reintroduction of the p16INK4A gene into p16(-) NSCLC cells results in significant growth suppression. However, there have been no reports of reintroduction of the p16INK4A gene into SCLC cells. To assess the biological significance of p16INK4A inactivation in the development of SCLC, full-length p16INK4A cDNA was introduced into an SCLC cell line, Ms-13, in which the p16INK4A protein was not detected. SCLC cells stably transfected with the p16INK4A expression vector formed only 2-16% of the number of neomycin-resistant colonies formed by cells transfected with a control vector, and no expression of exogenous p16INK4A protein was detected in any of 16 expanded clones. Transient transfection of the p16INK4A gene into SCLC cells resulted in exogeneous p16INK4A protein expression and dephosphorylation of endogenous retinoblastoma (RB) protein. These results suggest that the restoration of the p16INK4A function suppresses the growth of SCLC cells by dephosphorylation of the RB protein. Therefore, inactivation of p16INK4A may play an important role in the enhancement of growth of p16INK4A(-) RB(+) SCLC tumors in vivo.

Adult↗
PubMed1999

Characterization of native human thrombopoietin in the blood of normal individuals and of patients with haematologic disorders.

Thrombopoietin (TPO) isolated from thrombocytopenic plasma of various animal species has previously been shown to comprise only truncated forms of the molecule, presumably generated by proteolysis. Native TPO has now been partially purified from normal human plasma by immunoaffinity chromatography and was confirmed to be biologically active. Gel filtration in the presence of SDS revealed that TPO eluted in two peaks: a major peak corresponding to the elution position of fully glycosylated recombinant human TPO (rhTPO) consisting of 332 amino acid residues, and a minor peak corresponding to a smaller molecular size. Immunoblot analysis also revealed that most plasma-derived TPO migrated at the same position as fully glycosylated rhTPO, corresponding to a molecular size of approximately 80 to 100 kDa. Furthermore, the size distribution of circulating TPO in patients with various haematologic disorders did not differ markedly from that of plasma-derived TPO from healthy individuals. These results indicate that the truncation of circulating TPO is not related to disease pathophysiology, and that the predominant form of TPO in blood is a biologically active approximately 80- to 100-kDa species. The size distribution of TPO extracted from normal platelets was similar to that of TPO in plasma; the proportion of truncated TPO was decreased by prior incubation of platelets with hirudin. indicating that the endogenous truncated TPO, at least in platelet extract, was generated by thrombin-mediated cleavage.

Hematologic Diseases↗
PubMed1998

High frequency expressions of CD44 standard and variant forms in non-small cell lung cancers, but not in small cell lung cancers.

BACKGROUND AND OBJECTIVES: Organ specificity has been demonstrated in the mode of CD44 expression among several cancers. METHODS: We examined the expressions of CD44 standard (CD44s) and CD44 variants (CD44v) in 14 cell lines (small cell lung cancer (SCLC): 5, non-small cell lung cancer (NSCLC): 9 and 20 surgically resected samples (SCLC: 7, NSCLC: 13) of lung cancer using reverse transcription polymerase chain reaction and immunohistochemistry. RESULTS: Although both NSCLC and SCLC expressed CD44s, the frequency and intensity of CD44s expression in NSCLC were different from those in SCLC: cell lines, 89% vs. 40%; tumor samples, 100% (diffusely stained) vs. 57% (focally stained). CD44s expression was partially or completely repressed in SCLC. However, NSCLC frequently expressed CD44v, but SCLC expressed infrequently: cell lines, 67% vs. 20%; tumor samples, 69% vs. 0%. The N-417 line, which only expressed some CD44v in SCLC, falls SCLC and NSCLC both in biomarkers and in growth patterns. CONCLUSIONS: CD44 expression was repressed in SCLC but was enhanced in NSCLC.

Adenocarcinoma↗
PubMed1998

Failure to respond to interferon-alpha 2a therapy is associated with increased hepatic iron levels in patients with chronic hepatitis C.

Recent reports suggest the hepatic iron concentration (HIC) may influence the activity of hepatitis and the response to interferon (IFN) therapy in patients with chronic hepatitis C (CH-C). We have evaluated iron status in 28 patients with CH-C and determined if pretreatment iron status can predict the response to IFN-alpha therapy in these patients. Increased serum iron, transferrin saturation, and ferritin levels were observed in 3 (11%), 11 (39%), and 5 (18%) patients, respectively. Hepatic iron deposits were histologically detected in 17 (61%) patients, and 14 of them had stainable hepatocytic iron. However, all HIC values were within the normal range (203-1279 microg/g). Seven of 17 patients treated with IFN-alpha for 6 mo had normalization of serum transaminases and disappearance of serum HCV-RNA (responders). Nonresponders had a significantly higher median HIC compared with responders (710 vs 343 microg/g, respectively; p < 0.05). There was no significant difference in other pretreatment iron parameters, serum HCV-RNA level, or HCV-genotype between responders and nonresponders. In conclusion, mild hepatic iron accumulation occurs in patients with CH-C. Increased hepatic iron stores are associated with poor response to IFN therapy. Pretreatment HIC may be an additional host-specific parameter with a predictive value for responsiveness to IFN therapy, in addition to well-known predictive viral factors.

Adult↗
PubMed1998

Endothelin-1 stimulates sodium-dependent calcium efflux from bovine adrenal chromaffin cells in culture.

1. The effect of endothelin (ET)-1 on Ca2+ efflux from cultured bovine adrenal chromaffin cells was examined. ET-1 (10(-7) M) significantly increased intracellular free Ca2+ level ([Ca2+]i), 45Ca2+ uptake and catecholamine secretion in the cells. 2. ET-1 stimulated the efflux of 45Ca2+ from the cells preloaded with 45Ca2+ in a concentration-dependent manner (10(-9)-10(-7) M). This stimulatory effect was inhibited by ET(B) receptor antagonist BQ788, but not by ET(A) receptor antagonist BQ123. Selective ET(B) receptor agonists Suc-[Glu9, Ala11.5]-ET-1 and sarafotoxin S6c (SRTX) also stimulated 45Ca2+ efflux from the cells. 3. ET-1, Suc-[Glu9 Ala11.15]-ET-1 and SRTX increased the level of cyclic GMP in the adrenal chromaffin cells. ET-1 induced an increase in the nitric oxide (NO) level in the cells. The stimulatory effects by which ET- increases NO level and 45Ca2+ efflux were inhibited by NG-monomethyl-L-arginine acetate (L-NMMA), a competitive inhibitor of NO synthase. 4. The 45Ca2+ efflux stimulated by ET-1 was inhibited by deprivation of extracellular Na+, but not by deprivation of Ca2+. 5. These results suggest that ET-1 stimulates an extracellular Na+-dependent Ca2+ efflux through the activation of NO synthase in cultured bovine adrenal chromaffin cells.

Adrenal Glands↗
PubMed1998

Decreased mitogen response of splenic lymphocytes in obese Zucker rats is associated with the decreased expression of glucose transporter 1 (GLUT-1).

We reported previously that obesity is a risk factor for deteriorating cellular immune functions in aging. However, the mechanism by which obesity decreases cellular immunity remains to be elucidated. To determine the mechanism of the decrease in cellular immunity with obesity, lean (Fa/?) and obese (fa/fa) 12-mo-old Zucker rats were used. The mitogen response of splenic lymphocytes in obese Zucker rats was significantly lower than that of lean Zucker rats, which was not restored by in vitro treatment with indomethacin (10 micromol/L), an inhibitor of prostaglandin E2 (PGE2). In addition, PGE2 production by splenic lymphocytes was not greater in obese than in lean Zucker rats. Glucose consumption by splenic lymphocytes after in vitro incubation with concanavalin A (conA) for 48 h was also significantly lower in obese Zucker rats. Expression of glucose transporter 1 (GLUT-1), analyzed by Western blot analysis, was lower in splenic lymphocytes of obese than in lean Zucker rats. However, the expression of the conA receptor in splenic lymphocytes, analyzed by flow cytometry with fluorescein isothiocyanate-conjugated conA, was not significantly different between lean and obese Zucker rats. In conclusion, the decreased mitogen response of splenic lymphocytes in obese Zucker rats may be due in part to the decreased uptake of glucose as the main energy source for lymphocytes at the stage of proliferation and may be associated with the decreased expression of GLUT-1.

Animals↗
PubMed1998

Exercise training restores decreased cellular immune functions in obese Zucker rats.

This study investigated whether exercise training had a beneficial effect on the decreased mitogen response and improved a decreased expression of glucose transporter 1 (GLUT-1) in splenocytes from obese Zucker rats. Experimental groups were lean and sedentary and exercise-trained obese Zucker rats. Exercise training, running on a motor-driven treadmill for 5 days/wk for 40 wk, did not induce a significant decrease in body weight in obese Zucker rats. The plasma insulin concentration, showing a significant increase compared with lean Zucker rats, was unaffected by exercise training. However, the plasma triglyceride concentration in obese Zucker rats was significantly depressed by exercise training, whereas it was still higher than that in lean Zucker rats. In addition, natural killer cell activity and concanavalin A-induced mitogenesis of splenic lymphocytes of obese Zucker rats were significantly restored. In these splenic lymphocytes, glucose uptake was significantly lower compared with that in lean Zucker rats, which was also improved by exercise training. Although the expression of GLUT-1, the major glucose transporter in immune cells, was depressed in splenic lymphocytes of obese Zucker rats, exercise training induced a significant improvement. These results suggest that exercise training has a beneficial effect on the decreased cellular immune functions in obese Zucker rats, which is associated, in part, with the improvement in GLUT-1 expression.

Animals↗
PubMed1998

Purification and characterization of an isomaltotriose-producing endo-dextranase from a Fusarium sp.

An isomaltotriose-producing endo-dextranase was simply purified from cell-free culture broth of a Fusarium sp. by ethanol fractionation and consecutive column chromatographies using DEAE-Toyopearl and Bio-Gel P-100. The purified enzyme was judged to be homogeneous on PAGE and SDS-PAGE as well as isoelectric focusing. The molecular mass of the enzyme was estimated to be about 69 kDa by SDS-PAGE. The enzyme is an acidic protein with a pI of 4.6. The optimum pH and temperature were pH 6.5 and 35 degrees C, respectively. The enzyme was completely stable over the range of pH 4.5-11.8 at 4 degrees C for 24 h and at temperatures below 45 degrees C. Inactivation of the enzyme was found to be partial with 5 mM Cu2+, being about 70% inhibition and complete with 5 mM of Fe3+, Hg2+, Ag+ or NBS. The enzyme split dextran in an endo-lytic action to produce a large amount of isomaltotriose and a slight amount of isomaltose and glucose. The anomeric configurations of the reaction products formed by the enzyme were alpha-form, indicating that the alpha-glycoside linkages in the substrate are retained. The final yield of isomaltotriose from dextran T-2000 was about 62%.

Amino Acids↗
PubMed1998

An autopsy case of cytokeratin 7-positive minute adenocarcinoma of the lung with systemic metastases.

We describe a 60-year-old woman with leg pain. Although metastatic bone tumor and atypical cells mimicking signet-ring cells in the bone marrow picture were observed, systemic survey revealed no primary lesion. The patient died two months after admission from systemic progress of the disease. Autopsy revealed a small focus of adenocarcinoma within the right upper lobe of the lung and systemic metastases without any particular changes in the gastrointestinal tract. The tumor cells of the lung were diffusely positive for cytokeratin 7, whereas cytokeratin 20 immunoreactivity was weak and focal, and that supported the lung origin of the present tumor. Moreover, the tumor cells in the bone marrow showed a similar pattern in immunoreactivity. These findings suggest that cytokeratin 7 and cytokeratin 20 immunoreactivity is helpful for the premortem diagnosis of the metastatic tumor of unknown origin.

Biomarkers, Tumor↗
PubMed1998

Expression level of G1-cyclins and cell proliferation in human cultured leukemia/lymphoma cell lines.

We observed the expression of wild-type retinoblastoma protein (RB) in all 17 hematologic cultured cell lines tested. However, no p16INK4 expression was detected in any cell line among 16 leukemia/lymphoma cell lines, although an EBV-transformed cell line expressed p16INK4. The expression levels of cyclin D1 and CDK4 varied widely among the cell lines. The correlation coefficient (r2) between doubling time (DT) and cyclin D1 in the 14 cell lines that doubled within 47.2 h was 0.4856, while the r2 between DT and cyclin dependent kinase 4 (CDK4) and that between DT and RB among those cell lines were 0.3761 and 0.0874, respectively. The levels of protein expression in vincristine (VCR)-resistant cell lines was not different from those in corresponding wild-type cell lines. Thus, we concluded that the loss of p16INK4 protein and inactivation of RB protein could be an essential step for oncogenesis of leukemia/ lymphoma, and that cyclin D1 may possibly be a target protein to control cell growth of hematologic cell lines which lack the expression of p16INK4.

Cell Division↗
PubMed1997

Glutamate dehydrogenase mRNA is immediately induced after phencyclidine treatment in the rat brain.

To clarify the molecular mechanism of phencyclidine (PCP)-induced schizophreniform psychosis in humans and of behavioral abnormalities in experimental animals, we used differential screening of a cDNA library from the cerebral cortex of rats treated with PCP. We identified a PCP-induced cDNA clone as the gene encoding glutamate dehydrogenase (GDH), an enzyme central to glutamate metabolism. GDH mRNA levels significantly increased as early as 15 min following PCP administration in both the cerebral cortex and the cerebellum. This effect was observed even in the presence of a protein synthesis inhibitor, cycloheximide. In contrast to a transient increase in c-fos expression, the elevation of GDH mRNA levels lasted up to 8 days after a single PCP injection. These results suggest that GDH mRNA induction may be involved in the pathology of PCP-induced psychosis, and that GDH may be one of the candidate genes that are vulnerable in subjects with schizophrenia.

Animals↗
PubMed1997

Stimulatory effect of reconstituted basement membrane components (matrigel) on the colony formation of a panel of human lung cancer cell lines in soft agar.

Lung cancers have been distinguished into small-cell lung cancer (SCLC) and non-small cell-lung cancer (NSCLC) types on the basis of their clinical behaviors and their responses to treatment. Moreover, growth of most SCLC cell lines in liquid culture medium is nonadherent, while that of most NSCLC cell lines is adherent. In this study, we examined the effect of matrigel (reconstituted basement membrane components), which is known to have growth-stimulatory activity on various human tumor cell lines in immunodeficient mice, on soft-agar colony formation of a panel of SCLC and NSCLC cell lines to clarify its mechanism of growth stimulation of cancer cells. Matrigel enhanced colony formation of all 9 NSCLC cell lines and 4 of 9 SCLC cell lines. There was a statistically significant difference (P < 0.01) between colony formations with and without matrigel of NSCLC cell lines, but not for SCLC cell lines. In liquid culture medium, all 9 NSCLC lines and 3 of 9 SCLC lines adhered to plastic dishes, whereas the other SCLC lines did not. Matrigel enhanced colony formation of all 3 adherent-type SCLC lines and 1 of 6 nonadherent-type NSCLC lines. Matrigel enhanced colony formation of both of 2 adherent-type non-lung cancer cell lines and 1 of 2 nonadherent-type leukemia cell lines. Neither transforming growth factor beta, collagen type IV, fibronectin, nor laminin, which are components of matrigel, enhanced colony formation of an NSCLC cell line in soft agar. The increase in the colony number of the NSCLC cell line by matrigel was abrogated by the protein kinase inhibitors staurosporine and UCN-01.

Adult↗
PubMed1997

Differential expressions of cyclin A and the retinoblastoma gene product in histological subtypes of lung cancer cell lines.

Cell-cycle-dependent phosphorylation of the tumor-suppressor protein product of the retinoblastoma gene (RB) is mediated by a family of cyclin-dependent kinases and cyclins. We examined the expressions of RB protein and cyclin A protein in 13 small-cell lung cancer (SCLC) lines and 14 non-small-cell lung cancer (NSCLC) lines by immunoblotting. RB protein was not present or was of a mutant type in 77% of the SCLC lines (10/13) but was present in all the NSCLC lines. Cyclin A was expressed in 38% of the SCLC lines (5/13) and in 86% of the NSCLC lines (12/14). A positive correlation (P = 0.0034) between expression of cyclin A and wild-type RB protein was found by Fisher's exact probability test. Densitometric analysis of the expression of RB protein in RB(+) lung cancer lines showed that the phosphorylated form was predominant in 2/3 of the SCLC and 8/14 of the NSCLC lines. The positive correlation between the expressions of RB protein and cyclin A suggests that RB protein in most RB(+) lung cancer cell lines is a target of cyclin-A-dependent kinase and that the tumor-suppressor function may be inactivated by phosphorylation.

Adenovirus E1A Proteins↗
PubMed1997

Purification and characterization of polyamine aminotransferase of Arthrobacter sp. TMP-1.

Polyamine aminotransferase of Arthrobacter sp. TMP-1 was induced by 1,3-diaminopropane (DAP), N-3-aminopropyl-1,3-diaminopropane (norspermidine), spermidine, and spermine, but not by putrescine. The enzyme was purified to homogeneity. Its molecular weight and subunit size were 129,000 and 64,000, respectively. Its absorption spectrum had maxima at 280 and 420 nm and a shoulder at about 350 nm, and changes were observed upon the addition of DAP, putrescine, and sodium borohydride. The spectrum and its changes indicated that the enzyme contained pyridoxal-5'-phosphate as the coenzyme. The coenzyme content was found to be 1 mol per mol of subunit. DAP, putrescine, norspermidine, spermidine, and spermine were active amino donors and gave relative rates of 100, 73, 24, 30, and 23%, respectively. Pyruvate was the most active amino acceptor, while 2-ketoglutarate and oxaloacetate were inert. The equilibrium constant of the DAP-pyruvate transamination was 0.34. DAP was suggested to be a minor product of the norspermidine-pyruvate reaction.

Arthrobacter↗
PubMed1997

Action of polyamine aminotransferase on norspermidine.

The norspermidine-pyruvate reaction catalyzed by polyamine aminotransferase from Arthrobacter sp. TMP-1 formed N-3-aminopropyl-3-aminopropionaldehyde (APAPAL), L-alanine, 1,3-diaminopropane (DAP), allylamine, and acrolein, and the relative rates of formation of the latter four products were 24, 3.3, 2.3, and 1.2%, respectively, of the rate of the DAP-pyruvate transamination. The identification of APAPAL was done by 13C-NMR after it had been enzymatically oxidized to N-3-aminopropyl-beta-alanine followed by isolation of the oxidized product. The DAP was also isolated and identified by 13C-NMR. The allylamine and acrolein were identified by HPLC and a specific color reaction with m-aminophenol, respectively. In the absence of pyruvate, the enzyme catalyzed the elimination of DAP from norspermidine to yield allylamine, and the addition of DAP to allylamine to yield norspermidine with relative rates of 0.007 and 0.095%, respectively. When allylamine was incubated with the enzyme as the sole substrate, it was converted to N-allyl-1,3-diaminopropane and an unidentified product.

Acrolein↗
PubMed1997

Recovery from neuroendocrinological abnormalities and frontal hypoperfusion after remission in a case with rapid cycling bipolar disorder.

A 51-year-old Japanese woman who had been suffering from a rapid cycling affective disorder (RCAD) for 24 years responded to combined clonazepam and carbamazepine therapy. Before remission, she showed neuroendocrinological and neuroimaging abnormalities such as subclinical hypothyroidism with exaggerated response to thyrotropin releasing hormone (TRH) injection, non-suppression on the dexamethasone suppression test (DST) and hypofrontality in cerebral blood flow. Her symptoms improved remarkably soon after adjunctive clonazepam treatment. After remission, her biological markers gradually returned to normal. First, subclinical hypothyroidism improved 2 months after remission. Next, hypofrontality disappeared 18 months later. Furthermore, non-suppression on the DST normalized 24 months later. The normalization of biological markers with apparent recovery from RCAD suggests a decreased risk of relapse into mood disorder. These findings reiterate the importance of following-up on the biological markers in RCAD for years after remission.

Anticonvulsants↗