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Biomedical subjects

T Tsuji

Publications and source records attributed to T Tsuji.

At least 127 records · Page 7Linked to original sources

Loss of nuclear localization of the S100C protein in immortalized human fibroblasts.

It is well known that cancer develops through a multistep process. In vitro transformation studies of normal human cells have shown that the immortalization step is critical for neoplastic transformation of cells. Furthermore, studies of cell fusion between normal and immortalized cells have indicated that the normal phenotype is dominant and the immortal phenotype is recessive. Thus we looked for cellular proteins that were down-regulated in immortalized human cells by two-dimensional gel electrophoresis to elucidate the mechanisms of immortalization of human cells. We found that the S100C protein was down-regulated in immortalized cells. This protein was localized in the cytoplasm of cells at the semiconfluent stage, while at the confluent stage it moved into the nuclei of normal cells but not into those of immortalized cells. Microinjection of an S100C antibody into normal confluent cells diminished the level of nuclear S100C protein, resulting in DNA synthesis. Taken together, loss of nuclear localization of the S100C protein, which may be related to DNA synthesis, is thought to be one of the mechanisms of immortalization.

Amino Acid Sequence↗

Immunolocalization of keratan sulfate proteoglycan in rat calvaria.

We investigate, by the immunogold method, the localization of keratan sulfate (KS) proteoglycan in rat calvaria in order to clarify the detailed process of intramembranous ossification. KS was localized in bone nodules corresponding to calcified nodules, close to the saggital suture of calvaria. The immunoreactivity decreased in fully calcified regions distant from the suture. Electron microscopic observation revealed that KS was distributed in and around matrix vesicles, among collagen fibrils at the initial crystal deposition stage, and then concentrated in bone nodules. According to the progress of mineralization, KS tended to be localized in the peripheral region of the nodules. In addition, these nodules came in contact with collagen fibrils which also showed KS-positive reactivity. In cell organelles of osteoblasts, KS was detected in the Golgi apparatus. These findings suggest that osteoblasts in intramembranous ossification sites actively synthesize KS. KS in the calcified nodules, as well as other glycosaminoglycans in osteoid, may play an important role in additional and/or collagenous calcification by trapping calcium ions through its negative charge.

Animals↗

Cold activation of serum complement in patients with chronic hepatitis C: study on activating pathway and involvement of IgG.

It has been documented that the serum complement activities measured by hemolytic assay (CH50) are decreased after storage of sera at a low temperature in some patients with chronic hepatitis C. However, the mechanism of this phenomenon has not been identified yet. Here, we tried to elucidate factors involved in the cold activation of complement (CAC). To clarify what pathway is activated in CAC, we measured complement cleavage products after cold storage of sera. C4d increased significantly after 12 h-storage at cold temperatures in 5 CAC (+) sera compared with 5 CAC (-) (P < 0.01) and 3 control sera (P < 0.05), while Bb did not increase in any of the groups. In order to determine whether IgG or IgG complex is necessary for CAC, 8 CAC (+) sera were incubated with Protein G Sepharose gel beads, and all of them retained hemolytic activities to some extent after cold storage. Column chromatography through Superose 6HR of CAC-positive serum identified the fractions containing molecules that induced CAC in normal serum, which were depleted by treatment with protein G Sepharose. In conclusion, CAC in hepatitis C seems to occur via a classical or lectin pathway, and the IgG complex produced in hepatitis C virus infection may be an important factor in inducing CAC, a common extrahepatic manifestation of hepatitis C.

Adult↗

Therapeutic effects of azathioprine in combination with low-dose prednisolone in patients with intractable autoimmune hepatitis type 1.

This study evaluated the effects of azathioprine in combination with low-dose prednisolone in the management of patients with intractable autoimmune hepatitis. Thirteen patients with intractable autoimmune hepatitis who had an incomplete or arrested response to conventional prednisolone therapy, or who relapsed during prednisolone maintenance therapy were additionally administered 50 or 100 mg/day of azathioprine in combination with prednisolone. This regimen reliably induced complete remission in 12 of 13 patients, and these 12 remained in remission during the follow-up period with maintenance therapy of 50 mg/day of azathioprine in combination with 5 mg/day of prednisolone. The findings of the current study indicate that the azathioprine and low-dose prednisolone combined therapy may offer a satisfactory alternative therapy for patients with intractable autoimmune hepatitis who have an incomplete or arrested response to conventional prednisolone therapy, or who relapse during prednisolone maintenance therapy.

Adult↗

Effects of zinc deficiency/zinc supplementation on ammonia metabolism in patients with decompensated liver cirrhosis.

Hepatic encephalopathy is one of the major complications in decompensated liver cirrhosis. The current study was conducted to clarify the mechanisms of zinc deficiency in liver cirrhosis and its involvement in hepatic encephalopathy via ammonia metabolism. Ten patients each with compensated or decompensated liver cirrhosis and 11 healthy volunteers were enrolled in the study. Serum zinc levels and its daily urinary excretion were measured, an oral zinc-tolerance test was performed to examine zinc malabsorption, and the effects of diuretics on zinc excretion and of zinc supplementation on ammonia metabolism in the skeletal muscle were studied. The mean serum zinc levels in patients with decompensated liver cirrhosis were found to be significantly lower than the levels in controls and patients with compensated liver cirrhosis. The serum zinc levels were inversely correlated with blood ammonia in the fasting state. In the oral zinc-tolerance test, the percent increase in serum zinc levels 120 and 180 min after ingestion was less in cirrhotic patients than in controls. A diuretic administration resulted in a significant reduction in serum zinc levels. An increased uptake of ammonia by and an increased release of glutamine from leg skeletal muscle after oral supplementation of zinc sulfate were evident. Taken together, zinc deficiency in decompensated cirrhotic patients appears to be due to low absorption and to high urinary excretion, for which excessive diuretic administration is, in part, responsible, and zinc supplementation might play an important role in the prevention of hepatic encephalopathy by activating glutamine synthetase.

Ammonia↗

The effect of antimicrobial periodontal treatment on circulating tumor necrosis factor-alpha and glycated hemoglobin level in patients with type 2 diabetes.

BACKGROUND: Tumor necrosis factor-alpha (TNF-alpha) may play an important role in insulin resistance. In this study, we hypothesized that TNF-alpha produced due to periodontal inflammation synergistically affects insulin resistance as well as TNF-alpha produced from adipose tissues in insulin-resistant type 2 diabetes patients. Therefore, to understand the effects of antimicrobial periodontal therapy on serum TNF-alpha concentration and subsequent metabolic control of diabetes, we examined the periodontal and diabetic status on 13 type-2 diabetes patients. METHODS: These patients were treated with local minocycline administration in every periodontal pocket around all existing teeth once a week for a month. Before and after treatment, the number of total bacteria in the periodontal pockets and circulating TNF-alpha concentration were measured and the HbA1c value was assessed. RESULTS: Antimicrobial therapy significantly reduced the number of microorganisms in periodontal pockets (P <0.01). After treatment, the circulating TNF-alpha level was significantly reduced (P <0.015). The HbA1c value was also reduced significantly (P <0.007). In addition, the 6 patients who were not receiving insulin therapy demonstrated decreased fasting insulin levels (P <0.03), and HOMA-R (P <0.03) indices. The average reductions in circulating TNF-alpha concentration and HbA1c value were 0.49 pg/ml and 0.8%, respectively. CONCLUSION: The results indicate that anti-infectious treatment is effective in improving metabolic control in diabetics, possibly through reduced serum TNF-alpha and improved insulin resistance.

Adult↗

No dependency of a new index for oxygen cost of left ventricular contractility on heart rates in the blood-perfused excised rat heart.

We have reported the linear relation of myocardial oxygen consumption per beat (VO(2)) and systolic pressure-volume area (PVA) in the left ventricle of the cross-circulated rat heart. The VO(2) intercept (PVA-independent VO(2)) is primarily composed of VO(2) for Ca(2+) handling in excitation-contraction coupling and basal metabolism. Recently, we proposed a new index for oxygen cost of contractility obtainable as a slope of a linear relation between PVA-independent VO(2) and left ventricular contractility. This index indicates the Ca(2+) handling VO(2) per unit contractility change. However, a dependency of this index on heart rate has not yet been investigated. The aim of the present study was to investigate the dependency of oxygen cost of contractility on heart rate. This is a critical point to compare this cost under different heart rates. At first we found no differences of VO(2)-PVA relations at 240 and 300 beats/min (bpm). Therefore, after control VO(2)-PVA relation at 300 bpm, we gradually enhanced left ventricular contractility by Ca(2+) at a midrange left ventricular volume and obtained the gradually increased PVA-independent VO(2). At each contractility level, the pacing rate was alternately changed at 240 and 300 bpm. We obtained the two composite VO(2)-PVA relation lines and found no significant differences between the slopes of PVA-independent VO(2) and left ventricular contractility relations at 240 and 300 bpm. The present results indicated no dependency of oxygen cost of left ventricular contractility on heart rates within 240--300 bpm. Based on this fact, we concluded that even under the different pacing rates within 240--300 bpm, this oxygen cost is valid for assessing cardiac mechanoenergetics, especially the economy of total Ca(2+) handling in E-C coupling.

Animals↗

[Cytomegalovirus antigenemia assay as a useful tool for early diagnosis and therapy for cytomegalovirus infections in three cases with collagen diseases].

We report here three cases of collagen diseases with cytomegalovirus infections. (1) A 21-year-old female, who had been diagnosed as systemic lupus erythematosus, lupus nephritis and lupus peritonitis, had fever. Cytomegalovirus antigenemia (CMV-Ag) assay was 10/8 positive. (2) A 33-year-old female, who had been diagnosed as Wegener glanulomatosis, had fever and liver dysfunction. CMV-Ag assay was 933/896 positive. (3) A 64-year-old female, who had been diagnosed as microscopic polyangitis, had fever, liver dysfunction and pneumonia. CMV-Ag assay was 6/2 positive. They were considered to be complicated with CMV infections. We could make early diagnoses of CMV infection by using CMV-Ag assay and treat them with anti-CMV therapy effectively.

Adult↗

Reactivation of liver-specific gene expression in an immortalized human hepatocyte cell line by introduction of the human HNF4alpha2 gene.

An immortalized human hepatocyte cell line (OUMS-29) was established from fetal liver by transfection with the SV-40 large T antigen gene that has certain liver-specific functions such as albumin production and enzyme activities of CYP1A1, 1A2, and 2E1. To make OUMS-29 cells express other liver-specific functions, the human hepatocyte nuclear factor 4alpha2 (HNF4alpha2) gene was introduced into the cells, because this gene was found to be markedly down-regulated. The transduced HNF4alpha2 was overexpressed in the nuclei of the transfected cells, and its DNA-binding activity was also detected. The liver-specific genes such as apolipoprotein AI, CII, CIII, blood coagulation factor X, alpha1-antitrypsin, and HNF1alpha were up-regulated. Thus, this cell line is expected to be a useful tool for studying the differentiated human hepatocyte functions.

Apolipoprotein A-I↗

Overexpression of platelet-derived growth factor B and downregulation of PDGF-receptor alpha in human immortalized fibroblasts.

Since immortalization of cells is critical in multistep carcinogenesis, efforts should be made to elucidate the mechanisms of the immortalization. To determine whether platelet-derived growth factor (PDGF) signal pathways play a role in immortalization of cells, we compared mRNA expressions of PDGFs and their receptors in three immortalized human fibroblast cell lines (SUSM-1, OUMS-24F, and KMST-6) with their normal parent cells. As a result, mRNA expression of PDGF-B (oncogene: c-sis) was upregulated in these immortalized cells. Unexpectedly, the expression of alpha- and beta-PDGF receptor genes was downregulated. PDGFR-alpha mRNA was remarkably decreased. When exogenous PDGFR-alpha was expressed transiently in the KMST-6 cells, the morphology of the cells resembled that of normal cells. These results suggest that the overexpression of PDGF-B (c-sis) and downregulation of PDGFR-alpha are related to the phenotypic characteristics of immortalized human cells.

Blotting, Northern↗

Reduced expression of REIC/Dkk-3 gene in non-small cell lung cancer.

Dickkopfs (Dkks) are secretory glycoproteins and are important for inducing amphibian head formation. Some Dkks have the ability to antagonize the Wnt proto-oncoprotein, which can promote cell proliferation and transformation when it is mutated or overexpressed. We recently cloned the REIC/Dkk-3 gene, one of the Dkks, and found that expression of the gene was markedly decreased in many human immortalized and tumor-derived cell lines. To further investigate the function of the REIC/Dkk-3 gene in vivo, the gene expression was quantified in 57 surgically-resected non-small cell lung cancer (NSCLC) tissues and their adjacent normal lung tissues by real-time quantitative PCR analysis based on TaqMan methodology. The REIC/Dkk-3 mRNA level was significantly lower in NSCLC tissues than in normal lung tissues. Reduced expression of REIC/Dkk-3 in NSCLC was observed in 36 (63%) of the 57 tumors. Reduced expression of REIC/Dkk-3 was frequently observed in poorly differentiated adenocarcinoma and squamous cell carcinoma. These results indicate that reduced expression of REIC/Dkk-3 may be correlated with rapid cell proliferation in human NSCLC.

Adaptor Proteins, Signal Transducing↗

[Efficacy of lidocaine cream in protecting against thermal stress during hyperthermia].

Hyperthermia is performed in combination with chemotherapy as multimodal treatment for recurrent and advanced cancer. It is generally believed that the temperature cannot be raised higher because of thermal stress. In this study, we examined the efficacy of lidocaine cream in protecting against thermal stress during hyperthermia. We devised a new local anesthetic cream containing 5% lidocaine. The subjects were eighteen patients with stomach cancer, liver cancer, or large intestine cancer. This cream was applied locally to the skin with an occlusive dressing for about one hour before hyperthermia was performed, and was wiped away just before hyperthermia. The pain scores in the treatment group were significantly lower than in the no-treatment group (p < 0.05). The scores for sensation of heat in the treatment group were lower, though not to a significant extent, than those in the no-treatment group. No adverse effects were observed. Plasma concentrations of lidocaine were lower than 0.5 microgram/ml, and percutaneous absorption of lidocaine from the lidocaine cream was minimal.

Anesthetics, Local↗

Regulation of perfusion pressure during cardiopulmonary bypass using sevoflurane.

In hypothermic cardiopulmonary bypass (CPB), various vasodilators are used to control the perfusion pressure. These agents, however, often decrease the pressure excessively, and the low perfusion pressure may persist until the end of CPB. In this study we evaluate the safety and characteristics of the regulation of perfusion pressure during CPB using a volatile anesthetic, sevoflurane which has an extremely low partition coefficient. Twenty adult patients who underwent cardiac surgery were studied. Sevoflurane was applied by a vaporizer inserted into the oxygenator gas supply line. Pump flows were fixed at 2.4 L/min/m2 during the hypothermic period. Sevoflurane concentration was adjusted to keep mean arterial pressure (MAP) between 40 and 70 mmHg during CPB. Hemodynamic and metabolic parameters were measured and compared to the group we previously treated with chlorpromazine. In all cases, MAP could be maintained adequately. In the sevoflurane group, systemic vascular resistance indices (SVRI) during the rewarming period and at the end of CPB were higher, and doses of norepinephrine needed at the end of CPB were significantly lower than in the chlorpromazine group. The regulation of perfusion pressure during CPB using sevoflurane was safe and could easily maintain adequate SVRI.

Aged↗

Increased serum level of sialyl Lewis(x) antigen in blood from the tumor drainage vein in patients with non-polypoid growth type of colorectal cancer.

Two types of colorectal cancer with distinct morphologies have been described in recent studies: polypoid growth type (PG-type) and non-polypoid growth type (NPG-type). We hypothesize that the morphologic differences may correspond to additional biological distinctions. Ratios of sialyl Lewisa (CA 19-9), sialyl Lewisx (SLX), or carcinoembryonic antigen (CEA) in the venous blood drainage from the tumor to that of the respective antigen in the peripheral venous blood (d/p ratio) was examined in order to ascertain whether or not the ratio is correlated with either the PG-type or NPG-type colorectal tumor growth pattern. Blood samples from 118 patients with colorectal cancer were obtained from a peripheral vein and from the tumor drainage vein during surgical excision of the tumor. Statistical tests were conducted by univariate and multivariate (logistic regression) analyses. Among the cancers examined there were 17 PG-type (14.4%) and 101 NPG-type (85.6%). NPG-type cancers had a higher frequency of moderately differentiated adenocarcinoma cells and T3/T4 tumors than PG-type cancers (P<0.0001 and P<0.0001, respectively). NPG-type cancers had a more advanced stage than PG-type cancers (P=0.0007). The d/p ratio of SLX in NPG-type cancers was significantly higher than that in PG-type cancers (P=0.028). Multivariate logistic regression analysis showed that three variables, namely histologic type, T factor, and d/p ratio of SLX, were independently related to tumor growth patterns. In conclusion, NPG-type cancers are characterized by a high SLX d/p ratio, which may be at least partly responsible for a different tumor progression pattern compared to other cancer types.

Adenocarcinoma↗