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Biomedical subjects

T Shibata

Publications and source records attributed to T Shibata.

At least 595 records · Page 33Linked to original sources
PubMed1993

[Evaluation of colorectal hepatic metastases with combined modality therapy].

We treated synchronous hepatic metastases in colorectal cancers with combined modality therapy including hepatic resection, selective intra-arterial infusion chemotherapy, and thermocoagulation therapy using a microwave tissue coagulator and compared the value of such therapies. Synchronous hepatic metastases were noted in 563 patients with colorectal cancer who had undergone surgery in our department over the past ten years. Forty-four patients were studied. Six patients underwent hepatic resection only (group A). Another six were subjected to hepatic resection and the residual lesions were treated with selective intra-arterial infusions and thermocoagulation therapy (group B). Fourteen patients were treated with either selective or subselective intra-arterial infusions (group C). The remaining 18 patients were treated in other ways (group D). Cumulative survival, estimated by the Kaplan-Meier method, was compared. One- and three-year cumulative survival rates of patients were 100% and 74% in group A, 100% and 67% in group B, 62% and 0% in group C, and 38% and 5% in group D, respectively. H1 patients accounted for 83% in group A, 33% in group B, 7% in group C, and 22% in group D. The high rate of survival in group A was because of the greater number of H1 patients. One- and three-year survival rated among H2-H3 patients were 100% and 54% in group B, 62% and 0% in group C, and 35% and 14% in group D, respectively. Survival of H2-H3 patients was higher in group B than in group C or D.

Antineoplastic Agents↗
PubMed1993

[Liver metastases from breast cancer: survival and an attempt at cauterization and thermocoagulation therapy combined with selective intra-arterial infusion chemotherapy].

During the past thirteen years, 599 patients with primary breast cancer underwent surgery in our hospital. Nine of them died of liver metastases and the median survival time after detection of liver metastases was five months (range 1-32 months). Four are still alive with liver metastases. Based upon these results, we attempted intraoperative, ultrasound-guided cauterization and thermocoagulation for three patients to improve their prognosis and postoperatively treated them with hepatic arterial infusion chemotherapy. During surgery, a monopolar electrode was inserted with an ultrasonic guide. One round of cauterization lasted for 10 seconds at 100 W, and was repeated until the tissue around the tumor became hyperechoic. The antitumor effect of the therapy was assessed by histological examination of resected liver tissues. Tumor coagulation and necrosis were observed to be consistent with the cauterized area. On CT scanning, treated areas were shown to be of low density and homogeneous. Since this therapeutic approach acts directly on unresectable tumors and is safe, it seems to provide a useful means for intraoperative regional treatment of tumors.

Breast Neoplasms↗
PubMed1993

[Evaluation of subselective intraarterial infusion chemotherapy in far advanced gastric and colorectal cancer].

We investigated the usefulness of subselective intraarterial infusion chemotherapy in far advanced gastric and colorectal cancer. Among gastric and colorectal cancer cases undergoing surgery at our hospital for the past ten years, patients with and without palliative resection were studied. Forty gastric cancer patients and 29 colorectal cancer patients were treated by subselective intraarterial infusion chemotherapy. In gastric cancer cases without resection, a significantly longer survival was noted in patients undergoing this therapy with over 5 g of 5-FU than those treated with conventional chemotherapy. In gastric cancer patients with palliative resection and colorectal cancer patients, survival time was longer by intraarterial infusion with over 5 g of 5-FU, but not significant. Partial response was obtained in 5 cases of gastric cancer and 3 cases of colorectal cancer, and clinical symptoms were improved in 44% of the patients. The main complications of this therapy were myelosuppression and occlusion of the catheter, but none of them were serious. For the improved quality of life of cancer patients, subselective intraarterial infusion chemotherapy is considered a safe and useful form of treatment.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1993

[Significance of urinary fibrin/fibrinogen degradation products (FDP) measured by highly sensitive ELISA method in various renal diseases].

In order to clarify the abnormalities of intra-glomerular coagulation and fibrinolysis in patients with various renal diseases, urinary fibrin/fibrinogen degradation products (FDP) have been examined by several methods. We established a highly sensitive new method of enzyme-linked immunosorbent assay for urinary FDP. The results were as follow: 1) The mean +/- SD of urinary FDP in normal subjects was 10.30 +/- 9.08ng/ml. 2) The urinary FDP levels in chronic glomerulonephritis, nephrotic syndrome and chronic renal failure patients were significantly higher than normal subjects, and the levels in SLE, Alport's syndrome patients were higher than normal subjects. 3) The urinary FDP levels were a little bit higher in the patients with proliferative glomerulonephritis than in chronic glomerulonephritis patients with minor lesion or membranous nephropathy. 4) There was significant correlation between urinary FDP and urinary protein in chronic glomerulonephritis, while there was no correlation in nephrotic syndrome. 5) There was no correlation between urinary FDP and intra-glomerular fibrin deposits examined by immunofluorescent study in chronic glomerulonephritis, while in nephrotic syndrome, there were high levels of urinary FDP in the positive fibrin deposits cases. These results suggested that the most of the part of excretion of the urinary FDP in chronic glomerulonephritis is associated with the filtration of blood FDP to urine through the glomerular basement membrane, while in the nephrotic syndrome cases the origin of urinary FDP is related to the filtration and/or the intra-glomerular coagulation abnormalities.

Adolescent↗
PubMed1993

[MR imaging of associated brain injuries in cases with acute extradural hematoma].

To assess the efficacy of magnetic resonance (MR) imaging for detection of associated brain injuries in cases with extradural hematoma (EDH), 32 patients of EDH were examined by MR. CT detected associated lesion in eleven patients (34%), while MR detected them in 24 patients (75%). MR is more sensitive than CT in detecting associated lesions, especially when T2 weighted imaging is used. Non-hemorrhagic contusions adjacent to EDH, and near the cranial base were well shown by MR, however they tended to be missed by CT. EEG findings were clearly related to abnormalities detected by MR. Coupling between functional change and organic change was confirmed. The improved detection and anatomic localization of associated brain injuries by MR should allow more accurate assessment of brain injuries, and sophisticated management of EDH patient. The authors also discussed on the cardiorespiratory monitoring and support during MRI examination in critically ill patients.

Adolescent↗
PubMed1993

Differences in subcellular distribution of catechol-O-methyltransferase and tyrosinase in malignant melanoma.

The activities of catechol-O-methyltransferase (COMT) and tyrosinase were measured in subcellular fractions obtained from transplantable melanotic and amelanotic hamster melanoma. The results showed that there was a substantial difference between the localization of these enzymes. Whereas tyrosinase was localized mainly in the large granule fraction, the highest COMT activity was found to be in fractions abundant in microsomal structures. As expected, subcellular fractions obtained from amelanotic melanoma contained low or undetectable tyrosinase activity. On the other hand, the same fractions exhibited higher COMT activity than those from the pigmented tumor. Relatively low specific activity of COMT in fractions containing coated vesicles does not support the idea that this enzyme could be responsible for the inhibition of melanin polymerization in these structures. Because melanogenic intermediates, such as 5,6-dihydroxyindole and 5,6-dihydroxyindole-2-carboxylic acid, are compartmentalized within membraneous structures, the preferential localization of COMT in cytosol and cytosolic membrane network might be advantageous for a detoxification role in (melanotic) melanocytes that produce dihydroxyindoles.

Animals↗
PubMed1993

Non-melanosomal regulatory factors in melanogenesis.

The enzyme activity of tyrosinase, catalase, and peroxidase and the number of metal ions in melanogenic subcellular compartments in pigment cells were measured. Coated vesicles were richest in tyrosinase and catalase, whereas premelanosomes had the highest amount of peroxidase. Among metals ions examined, copper, zinc, and iron were more concentrated in pre-melanosomes than in coated vesicles. A quantitative analysis revealed that peroxidase served to enhance eumelanin polymer formation from monomers in the presence of hydrogen peroxide and metal ions, especially copper ions, which had the greatest enhancing effect on the conversion of monomers to polymers.

Animals↗
PubMed1993

Inhibitory effect of intraduodenal infusion of loxiglumide on pancreatic exocrine secretion.

Inhibitory effect of loxiglumide (D,L-4-(3, 4-dichlorobenzoylamino)-5-(N-3-methoxypropyl-pentylamino)-5- oxo-pentanoic acid, CAS 107097-80-3) on exocrine pancreatic secretion was compared between intraduodenal and intravenous administration. Doubling doses of intravenous cholecystokinin octapeptide (CCK-8) resulted in a dose-dependent increase of pancreatic secretion from 50 to 400 ng/kg/h. Both intraduodenal and intravenous loxiglumide of 5 and 10 mg/kg/h produced a dose-dependent inhibition of the pancreatic protein secretion to all doses of CCK-8. Cumulative increment of pancreatic protein output was inhibited by 79% and 77% at 10 mg/kg/h of intraduodenal and intravenous loxiglumide, respectively. Extents of the inhibition were similar to each other between the two routes of loxiglumide infusion. However, plasma levels of loxiglumide after intraduodenal administration were about half of those observed after intravenous administration of the corresponding dose, although plasma CCK levels were not different. Intraduodenal loxiglumide is as effective as intravenous loxiglumide in inhibitory potency on pancreatic secretion. Therefore, possible therapeutic indications of oral loxiglumide could be expected.

Animals↗
PubMed1993

[Clinical application of recombinant human SOD for the protection of ischemia reperfusion injury during open heart surgery].

We have applied recombinant human superoxide dismutase (RH-SOD) to prevent ischemia reperfusion injury in the patients who received open heart surgery. Twenty-four patients were divided into 2 groups; group A had no treatment as control and group B received bolus injection of RH-SOD (35,000 IU/kg) into cardiopulmonary bypass 5 minutes before reperfusion. Arterial and coronary sinus blood was collected to measure chemiluminescence (ChL) value, SOD activity, lactate and pyruvate level, and several parameters of myocardial oxygen metabolism after reperfusion. Arterio-venous difference of ChL value showed the tendency of less ChL generation of the heart in group B compared with those in group A. But no other parameters showed significant difference between the two groups. Our data suggested that this way of the administration of RH-SOD failed to improve the myocardial protection during open heart surgery. Further investigation, such as dose response study, might be required to determine whether RH-SOD possess beneficial effects or not in the clinical setting.

Heart Arrest, Induced↗
PubMed1992

Effect of verapamil on the class I major histocompatibility complex antigen expression in K562 chronic myelogenous leukemia cells treated with recombinant human interferon-gamma.

The effects of various compounds which modulated the intracellular signal transduction on the induction of class I major histocompatibility complex (MHC) antigens by recombinant human interferon-gamma (rIFN-gamma) were investigated using K562, chronic myelogenous leukemia cells. Class I or class II MHC antigens were not expressed in untreated K562 cells and rIFN-gamma (600 units/ml) weakly induced class I antigens on the cells. Among the compounds tested, verapamil but not the calcium ionophore A23187 enhanced the rIFN-gamma-induced class I antigen expression at both the surface molecule and mRNA levels and enhancement by verapamil occurred in a dose-dependent manner at non-toxic concentrations examined (approximately 50 microM). Verapamil alone had no inducible effect on MHC antigen expression. Deprivation of Ca2+ in culture medium by ethylene glycol-bis(beta-aminoethyl ether) N,N,N',N'-tetraacetic acid (EGTA) could not cause an enhancement of class I antigen induction by rIFN-gamma. Simultaneous exposure of K562 cells to rIFN-gamma (600 units/ml) and recombinant human tumor necrosis factor (rTNF; 1000 units/ml) in combination with verapamil (50 microM) resulted in a further increase of class I antigens in the cells. The expressions of c-myc oncogene in K562 cells were not changed when the cells were treated with rIFN-gamma (600 units/ml) or verapamil (50 microM), either alone or in combination. These results indicate that verapamil synergistically interacts with rIFN-gamma on the class I antigen induction in K562 cells irrespective of c-myc gene expression and that class I antigen induction in this cell line may not be relevant to calcium influx triggered by IFN-gamma.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1992

The rat angiotensin II AT1A receptor couples with three different signal transduction pathways.

To examine whether the subpopulation of the rat type 1 angiotensin II (AII) receptor (AT1A) couples with a single or multiple signal transduction pathways, we constructed Chinese hamster ovary (CHO) cell lines producing the recombinant receptor. The expressed AT1A receptor exhibits typical pharmacological characteristics of the AT1 receptor, known to mediate the main physiological function of AII. Addition of AII to the CHO cells induced a rapid, transient increase in intracellular free Ca2+ concentrations ([Ca2+]i) followed by a lower, sustained phase. Nicardipine, a blocker of voltage-dependent L-type Ca2+ channels, attenuated the transient [Ca2+]i response and abolished the sustained phase. The transient phase was also reduced dose-dependently by the phospholipase C inhibitor neomycin. Furthermore, AII inhibited forskolin-evoked cAMP accumulation. These data suggest, although another subpopulation named AT1B is present, that the rat AT1A receptor can independently couple with all three signal transduction pathways known to be induced by AII: i.e., i) activation of phospholipase C resulting in InsP3 generation with a subsequent release of intracellularly stored Ca2+, ii) activation of dihydropyridine-sensitive voltage-dependent Ca2+ channels, and iii) inhibition of adenylate cyclase activity.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1992

Glycosylation of lipoprotein lipase in human subcutaneous and omental adipose tissues.

Human adipose tissues from the abdomen (subcutaneous), thigh (subcutaneous) and omentum were incubated for 2 h with [35S]methionine. Then glycosylation of lipoprotein lipase (LPL) was analyzed by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of endoglycosidase H (endo H)-digested subunits of the 35S-labeled lipase. Adipose tissues from the abdomen, thigh, and omentum all synthesized LPL subunits with Mr = 57,000 composed of two types of subunits. One type was partially endo H-sensitive yielding a product with Mr = 55,000, indicating that it had one endo H-resistant and one endo H-sensitive oligosaccharide chain. The other type of subunit was totally endo H-sensitive yielding a product with Mr = 52,000. Subcutaneous adipose tissues contained nearly equal amounts of partially and totally endo H-sensitive subunits of LPL, whereas omental adipose tissues contained mainly partially endo H-sensitive subunits of LPL.

Adipose Tissue↗
PubMed1992

Phenol-treatment and a homologous pairing-assay.

Homologous pairing is a key step in homologous genetic recombination. In the early stage of trials for the identification of homologous pairing-promoting proteins from a fission yeast, Schizosaccharomyces pombe, we treated DNA products with phenol in the presence of a salt for the removal of tightly bound proteins from DNA before the assay, but we found that this treatment caused very efficient protein-independent double-strand formation from complementary single-stranded DNAs. Using an assay including the phenol treatment, we detected another species of apparent homologous pairing-promoting proteins in the nuclei, in addition to a homologous pairing-promoting protein consisting of three components which we reported previously. However, studies involving the use of an assay without the phenol-treatments revealed that the second one was not really a homologous pairing-protein. Thus, the protein-independent double-strand formation by phenol-treatment in the presence of a salt could cause the erroneous identification of homologous pairing-promoting proteins.

Bacteriophages↗
PubMed1992

Simultaneous assay of adenosine deaminase and purine nucleoside phosphorylase activity as possible biochemical means to detect non-Hodgkin lymphomas of the oral cavity.

BACKGROUND AND METHODS: This study proposes the usefulness of simultaneous assay of adenosine deaminase (enzyme code [EC] 3.5.4.4; ADA) and purine nucleoside phosphorylase (EC 2.4.2.1; PNP) activities in a biopsy specimen as a biochemical test adjunctive to the histologic diagnosis of oral non-Hodgkin lymphomas (NHL). RESULTS: NHL tissues showed an ADA activity of more than 1428 nmol/h/mg of protein, and more than 3451 nmol/h/mg of protein was the sum of ADA and PNP activity. In contrast to this finding, all the 106 lesional tissues affected by various carcinomas, various benign tumors, various cysts, ameloblastomas, osteosarcomas, gingival hyperplasia, and inflammation showed an ADA activity of less than 1000 nmol/h/mg of protein, except for 2. The sum of ADA and PNP activity was less than 2249 nmol/h/mg of protein in these diseases, except for squamous carcinoma. Different control tissues of the oral cavity showed less than 766 nmol/h/mg of protein in ADA activity, and the highest sum of ADA and PNP activity in these was only 1384 nmol/h/mg of protein. CONCLUSIONS: These findings suggest that a strong suspicion of oral NHL is justified when the sum of ADA and PNP activity in a biopsy specimen exceeds 3000 nmol/h/mg of protein and ADA activity is greater than 1000 nmol/h/mg of protein.

Adenosine Deaminase↗
PubMed1992

Identification of two types of homologous DNA pairing activity in mouse cells.

We have identified two types of homologous DNA pairing activity in mouse cell extracts by a strand-transfer assay. Both activities are separated from each other by anion-exchange chromatography; neither of them needs ATP. One requires magnesium ion and is stimulated by Escherichia coli single-stranded DNA binding protein, whereas the other does not require the ion and shows a higher affinity for a left-handed Z-DNA.

Adenosine Triphosphate↗
PubMed1992

Murine autoimmune hemolytic anemia resulting from Fc gamma receptor-mediated erythrophagocytosis: protection by erythropoietin but not by interleukin-3, and aggravation by granulocyte-macrophage colony-stimulating factor.

We have evaluated the therapeutic activity of recombinant erythropoietin (rEpo), in comparison with recombinant interleukin-3 (rIL-3) and granulocyte-macrophage colony-stimulating factor (rGM-CSF), on a lethal form of acute anemia resulting from Fc gamma receptor-mediated erythrophagocytosis after a single injection (500 micrograms) of a monoclonal anti-mouse red blood cell (MRBC) autoantibody. Continuous perfusion of rEpo before the administration of anti-MRBC monoclonal antibody completely protected animals from death due to anemia with a rapid recovery, while no protection was obtained by rIL-3 perfusion. In contrast, rGM-CSF perfusion markedly accelerated the progression of anemia and the mortality rate. This was found to result from an enhancement of erythrophagocytosis by Kupffer cells and by polymorphonuclear leukocytes that massively infiltrated the livers. Even after the injection of a sublethal dose (100 micrograms) of anti-MRBC monoclonal antibody, rGM-CSF-perfused mice died of a severe form of acute anemia. Furthermore, we have shown that rEpo was able to treat efficiently a spontaneous form of autoimmune hemolytic anemia in a majority of anemic NZB mice, whereas rGM-CSF markedly aggravated anemia. This may be of clinical importance, because GM-CSF administration could exhibit an adverse effect in some autoimmune diseases that involve autoimmune anemia.

Anemia, Hemolytic, Autoimmune↗