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S Murakami

Publications and source records attributed to S Murakami.

At least 595 records · Page 33Linked to original sources
PubMed1991

Hydrogen peroxide inhibits iodide uptake and iodine organification in cultured porcine thyroid follicles.

We investigated the effect of hydrogen peroxide on the process of thyroid hormone formation in a physiologic culture system of porcine thyroid follicles that we recently established. Porcine thyroid follicles cultured in medium containing 1 mU/mL TSH were exposed to 0 to 500 microM hydrogen peroxide in the presence of 0.1 microCi carrier-free Na125 and sodium iodide for 2 h. Iodide uptake and iodine organification were measured in this incubation system. The kinetics of iodide uptake were used to explain the action of hydrogen peroxide. In addition, cAMP content and Na+,K(+)-ATPase activity (an enzyme necessary for iodide uptake) were measured to investigate the mechanism of hydrogen peroxide action. Hydrogen peroxide at concentrations of 100, 200, and 500 microM inhibited iodide uptake in a dose-dependent manner. Iodide organification was inhibited only when the concentration of hydrogen peroxide was greater than 200 microM. The kinetics of iodide uptake indicated that hydrogen peroxide was a noncompetitive inhibitor with iodide. Inhibition of iodide uptake and iodine organification by hydrogen peroxide were not mediated by alteration of cAMP content of Na+,K(+)-ATPase activity, since exposure to even 500 microM hydrogen peroxide did not change these parameters in the follicle when compared with those of control samples. Our results suggest that the iodide transport system in the thyroid follicle is inhibited at 200 microM hydrogen peroxide or greater.

Analysis of Variance↗
PubMed1991

Increased activities of thymidylate synthetase and thymidine kinase in human thyroid tumors.

Thymidylate synthetase (TS) is known to catalyse the methylation of deoxyuridine monophosphate (dUMP) for the de novo synthesis of deoxythymidine monophosphate (dTMP). Thymidine kinase (TK) catalyzes the formation of dTMP by the phosphorylation of thymidine via the pyrimidine salvage pathway. High TS and TK activities have been observed in rapidly proliferating tissues. Both TS and TK activities in human thyroid adenocarcinoma increased to approximately 2-fold that in normal thyroid tissue. The thyroid TK isozymes can be separated into two types by DEAE-cellulose column chromatography. One of them is associated with the cytosol cell fraction of rapidly proliferating cells, such as fetal or neoplastic cells. Its activity is not affected by low concentration of deoxycytidine triphosphate (dCTP), and its molecular weight and Km value for thymidine are 120 kD and 0.5 x 10(-6) M, respectively. The average activity of this cytosol-associated isozyme in thyroid adenocarcinoma was increased slightly to 2.3-fold that of normal thyroid tissue. These results obtained from the activities of TK and its isozyme may be indicative of the slow-growing property of thyroid adenocarcinoma compared to mammary or colonic adenocarcinoma, which has high activities of TK and its isozyme.

Adenocarcinoma↗
PubMed1991

Beneficial effect of upper thoracic epidural anesthesia in experimental hemorrhagic shock in dogs: influence of circulating catecholamines.

The question as to whether reduction of plasma catecholamine concentration contributes to the beneficial effects of upper thoracic epidural anesthesia on survival during hemorrhagic shock was examined. Twenty-six dogs were anesthetized with halothane and nitrous oxide, and blood was withdrawn to reduce the mean arterial blood pressure (MAP) to 40 mmHg. The 12 dogs in group A received both upper thoracic epidural anesthesia before the hemorrhage and intravenous infusion of epinephrine (450 ng.kg-1.min-1) and norepinephrine (150 ng.kg-1.min-1) during hemorrhage. The 14 dogs in group B received none of these. At 20 min after the start of the bleeding, plasma catecholamine concentrations were increased in both groups more than ten-fold. There were no significant intergroup differences with respect to these concentrations at any point during the experimental period. During the 100-min period of hemorrhage, 1 of the 12 animals in group A and 10 of the 14 in group B died. A significant difference in survival was seen between the two groups over the 100-min hypotensive period (P less than 0.01 by the generalized Wilcoxon test). These results suggest that the survival benefit of upper thoracic epidural anesthesia cannot be explained simply by differences in the level of catecholamines in the plasma, and that perhaps differences in the level of catecholamines at the nerve endings or other factors may be more important.

Anesthesia, Epidural↗
PubMed1991

Epidermolysis bullosa acquisita in identical twins.

Identical twin sisters developed generalized erythema and bullae on skin and mucous membranes at 18 and 19 years of age. Atrophic scars and milia were formed later. Indirect immunofluorescence (IF) study of the separated skin by incubation in 1.0M NaCl showed antibasement membrane zone (BMZ) antibodies bound to the dermal side. The HLA-DR typing demonstrated DR2/DW11. Pulse therapy resulted in marked clinical improvement. This is the first report of epidermolysis bullosa acquisita (EBA) in identical twins and suggests the possibility that the disease may have a genetic component.

Adolescent↗
PubMed1991

[Clinical evaluation of cefuzonam (CZON) for bacterial pneumonia and lung abscess: comparative study with cefotiam (CTM)].

A double blind study was conducted to objectively evaluate the usefulness of Cefuzonam (CZON) in the treatment of bacterial pneumonia and lung abscess. Cefotiam (CTM) was used as a control drug. Each drug was administered by intravenous drip infusion at 1 g at a time, twice daily, for 14 days as a rule. The results are as follows: 1. Enrolled in this study were 145 cases in total, comprising 72 of CZON group and 73 of CTM group. Of the total cases, 109 (53 of CZON group and 56 CTM group) were evaluated for clinical efficacy by the evaluation committee. Exclusion rate and background of patients were not significantly different between the two groups. 2. Clinical effectiveness assessed by the committee showed the efficacy rates of 84.9% (45 cases out of 53) for the CZON group and 83.3% (47 cases out of 56) for the CTM group, with no significant difference between the two groups. 3. The bacteriological eradication rates were 89.5% (17 strains out of 19) for the CZON group and 78.3% (18 strains out of 23) for the CTM group, with no significant difference between the two groups. 4. The incidence of side effects was 5 cases (7.5%) for the CZON group and 3 cases (4.2%) for the CTM group. The incidence rate of laboratory test abnormality was 28.4% (19 cases out of 67) for the CZON group and 31.3% (12 cases out of 67) for the CTM group. There was no significant difference between the two groups. 5. Usefulness rates calculated by the committee were 79.2% (42 cases out of 53) for the CZON group and 76.8% (43 cases out of 56) for the CTM group. There was no significant difference between the two groups. These results show that CZON is a useful drug in the treatment of bacterial pneumonia and lung abscess.

Adolescent↗
PubMed1991

Structure and organization of the hepatitis C virus genome isolated from human carriers.

Hepatitis C virus (HCV) is a major causative agent of posttransfusion non-A, non-B hepatitis, which often develops into malignant chronic diseases, including liver cirrhosis and hepatocellular carcinoma. We have cloned from human carriers overlapping cDNAs (9,416 bp) covering the entire coding region of the HCV genome. The latter encodes a 3,010-amino-acid polyprotein. In addition, there are 332 and 54 bases of 5' and 3' noncoding sequences, respectively. Our HCV strain has a 77% nucleic acid identity to the HCV strain cloned by workers at Chiron Corporation. The hydrophobicity profile of the putative polyprotein is similar to those of flaviviruses, but it has limited amino acid homology to polyproteins of flaviviruses and other viruses, indicating that HCV is at most distantly related to flaviviruses.

Amino Acid Sequence↗
PubMed1991

Detection of minimal residual myeloma cells by dual parameter analysis of DNA and cytoplasmic immunoglobulin.

We demonstrated the utility of dual parameter analysis of DNA and cytoplasmic immunoglobulin for the detection of minimal residual myeloma cells in bone marrow and peripheral blood. This method is sensitive: even 0.1% of contaminating myeloma cells could be detected in peripheral blood of myeloma patients and in the model experiments using cell lines. This method is useful for the selection of patients undergoing high-dose chemotherapy and autologous blood stem cell transplantation.

Bone Marrow↗
PubMed1991

Serum immunosuppressive acidic protein as a tumor marker for renal cell carcinoma.

Since there are no reliable tumor markers in renal cell carcinoma, the present study was undertaken to evaluate immunosuppressive acidic protein (IAP) in patients with this tumor. Serum IAP levels were measured in 143 consecutive patients before and/or after nephrectomy by turbidimetric immunoassay. IAP levels had increased according to tumor diameter. Positivity rates of IAP were noticed as 45%, 75%, and 100% for patients with stage I/II, stage III, and stage IV diseases, respectively. Three-year survival rates also correlated with IAP: 96%, 81%, and 44% in preoperative levels below 500, of 501-1,000, and of more than 1,001 micrograms/ml, respectively. Serum IAP levels decreased within 3 months after the operation and increased with recurrence. These results suggest that serum IAP may serve as a tumor marker in patients with renal cell carcinoma.

Adult↗
PubMed1991

Effect of lithium on function and growth of thyroid cells in vitro.

Lithium has been reported to alter thyroid function and cause goiter in some patients. To explain the mechanism of lithium action in the thyroid gland, we studied the effect of lithium on thyroid function and cell growth in FRTL-5 rat thyroid cells and on de novo thyroid hormone formation in primary cultures of porcine thyroid follicles. TSH-induced iodide uptake was suppressed at 2 mM lithium in both FRTL-5 cells and porcine follicles. In porcine thyroid follicles, iodide uptake stimulated by 8-bromo-cAMP, iodine organification, and de novo thyroid hormone formation were also reduced by lithium; however, 2 mM lithium did not inhibit TSH-induced cAMP production. In FRTL-5 cells, lithium also inhibited forskolin-stimulated iodide uptake. These results suggested that lithium exerts its effect at a step involving cAMP signal transduction rather than inhibiting cAMP production. In both FRTL-5 thyroid cells and porcine follicles, lithium enhanced cell growth in basal states (lacking TSH) and with TSH treatment. In porcine thyroid cells, the protein kinase C activator, tetradecanoyl phorbol-13-acetate, increased cell growth, and lithium had an additive effect with tetradecanoyl phorbol-13-acetate on cell growth. To examine the possibility that the action of lithium was mediated by the protein kinase C pathway, porcine cells were incubated with lithium and H7, a selective protein kinase C inhibitor. Lithium-induced cell growth was suppressed to the basal level by H7. These results suggest that lithium exerts its growth-promoting effect through the protein kinase C system.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1991

Effects of H2-receptor antagonists on matrix metalloproteinases in rat gastric tissues with acetic acid-induced ulcer.

To investigate the destructive process of connective tissues in gastric ulcer, both collagenolytic and gelatinolytic activities were examined in the homogenates of rat acetic acid-induced gastric ulcer, a typical model of chronic ulcer. Gelatinolytic activity in the ulcerous lesion was significantly higher than that in the normal tissue. However, collagenase was not detected in both normal and ulcerated tissues either by the enzyme assay or by the immunoblotting. By gelatin-gel-zymographic analyses, the gelatinolytic activity was found to be composed of a number of species, mainly 60-, 72- and 92-kDa, all of which were inhibited by ethylenediaminetetraacetic acid. Among the induced matrix metalloproteinases, one crossreacted with a sheep anti-(rabbit prostromelysin)antibody. Thus, in chronic gastric ulcer, it is likely that several metalloproteinases participate in degradation of connective tissue matrices including components of basement membranes. The elevated levels of gelatinolytic activities in the ulcerous tissues and ulcer index were significantly suppressed by treating the animals with famotidine or a new H2-receptor antagonist, 3-amino-4-[4-[4-(1-piperidinomethyl)-2-pyridyloxy]-cis-2- butenylamino]-3-cyclobutene-1,2-dione hydrochloride (IT-066).

Acetates↗
PubMed1991

New polyphenolic 5'-nucleotidase inhibitors isolated from the wine grape "Koshu" and their biological effects.

New 5'-nucleotidase inhibitors designated as NPF-88BU-IA, NPF-88BU-IB, NPF-88BU-IIA and NPF-88BU-IIB, respectively, were isolated from the seeds and skin of the wine grape "Koshu". They were purified by solvent extraction, dialysis, and reversed-phase high performance liquid chromatography (HPLC). Their physico-chemical properties revealed these compounds to be polyphenolic substances. The average relative molecular masses of the four were estimated by gel permeation chromatography (GPC) analysis to be 7850, 5950, 11900, and 11300, respectively. They strongly inhibited 5'-nucleotidase activities from snake venom and rat liver membrane, and displayed significant therapeutic activity against Ehrlich ascites carcinoma. They also showed inhibitory effects on the growth of Streptococcus mutans MT8148(c), a primary cariogenic bacterium. Furthermore, these 5'-nucleotidase inhibitors inhibited the glucan formation from sucrose. These results suggest that the 5'-nucleotidase inhibitors can prevent the cause of caries of tooth.

5'-Nucleotidase↗
PubMed1991

[Regional lymphadenectomy for renal pelvic and ureteral cancers].

Thirty-four patients with renal pelvic and ureteral cancers received regional lymphadenectomy since 1980. The patients consisted of 21 with renal pelvic cancers, 10 with ureteral and 3 with renal pelvic and ipsilateral ureteral. Fifteen patients (44.1%) had metastatic nodes: 13 with renal hilar or para-aortic metastases and 2 with pelvic nodal involvements only. Thirteen of these 15 patients with nodal metastasis had high grade tumors and 14 had high stage tumors. The 5-year survival rate of these 15 patients was 26.3% which was considerably poor when compared with 19 patients without metastasis. Twenty patients with high grade and high stage tumors who received respective operations with regional lymphadenectomy had significantly better prognosis compared with the historical control group (15 patients, from 1961 to 1979). Additional regional lymphadenectomy for renal pelvic and ureteral cancers appears to be a valuable operation for improving prognosis.

Adult↗
PubMed1991

Isolation and characterization of the alkaline protease gene of Aspergillus oryzae.

The genomic DNA for the alkaline protease (Alp) of the fungus Aspergillus oryzae was isolated using synthetic oligonucleotides as hydridization probes, and the complete nucleotide sequence was identified. The Alp gene is 1374 nucleotides long and contains three introns, one of which is in the pro region and two in the mature coding region. Sequences related to the TATA box (TATAAAT) and the CAAT box (CCAAAT) were found in the 5'-noncoding region. Primer extension analysis showed that three transcriptional start points are present.

Amino Acid Sequence↗
PubMed1991

Oleic acid as an inhibitor of gastric H+, K(+)-ATPase.

A study was made of the effects of oleic acid on gastric H+, K(+)-ATPase. Oleic acid inhibited both H+, K(+)-ATPase and K(+)-pNPPase from pig gastric mucosa. The concentrations for 50% inhibition were 7.8 x 10(-6) M and 5.0 x 10(-6) M respectively. Oleic acid also inhibited Na+, K(+)-ATPase with an IC50 value of 1.2 x 10(-5) M. Double reciprocal plots demonstrated the inhibition of gastric H+, K(+)-ATPase by oleic acid to be noncompetitive with respect to K+ and competitive with respect to ATP. A proton transport experiment also showed oleic acid to inhibit H+, K(+)-ATPase mediated acid secretion. Oleic acid may thus possibly be a potent inhibitor of gastric H+, K(+)-ATPase and that the inhibition of H+, K(+)-ATPase may be responsible for the antisecretory effect of oleic acid.

4-Nitrophenylphosphatase↗
PubMed1991

[A case of lupus erythematosus preceded by right heart failure due to pulmonary hypertension].

A 40-year-old woman was admitted because of increasing exertional dyspnea. Right heart failure was suggested by the presence of hepatomegaly, pretibial edema and also echocardiographic findings. Physical examination and echocardiography showed no evidence of valvular disease or congenital heart disease except for right ventricular dilatation and tricuspid regurgitation. The ventricular septum deviated toward the left ventricle throughout the cardiac cycle, but left ventricular function was preserved. Severe pulmonary hypertension averaging 44 mmHg was revealed by cardiac catheterization. Digital subtraction angiography and pulmonary blood flow scintigraphy showed no evidence of pulmonary artery embolism, and no interstitial pulmonary lesions that might have caused pulmonary hypertension were recognized. Hypergammaglobulinemia suggested an autoimmune disorder, and signs of systemic lupus erythematosus (SLE), such as pleural effusion, proteinuria, lymphocytopenia, LE cell phenomenon and antinuclear antibodies were present. Several autoimmune diseases are known to be causative factors of pulmonary hypertension. However, only ten cases of SLE complicated by pulmonary hypertension have been reported the present one. These cases were characterized by a high incidence of Raynaud's phenomenon and positivity for anti-RNP antibody. In our present case, SLE activity was suppressed using prednisolone, but pulmonary hypertension persisted and the patient eventually died due to right cardiac failure. Judging from the clinical course of the ten reported cases of SLE-pulmonary hypertension, there seems to be no hope of improving the pulmonary hypertension once it has become established. Therefore it is important to detect and cure pulmonary hypertension as early as possible.

Angiography, Digital Subtraction↗
PubMed1991

[Leiomyosarcoma of the esophagus associated with pulmonary edema by the compression of the left atrium].

Leiomyosarcoma of the esophagus is a rare neoplasm. We reported a very rare case of esophageal leiomyosarcoma associated with pulmonary edema by the compression of the left atrium. A 67-year-old man was admitted with a 3-month history of chest pain, exertional dyspnea and dysphagia. Chest X-ray computed tomography showed posterior mediastinal tumor. Esophageogastroscopy and fiberoptic bronchofiberscopy showed no direct invasion of the tumor. By echocardiography, the left atrium was found to be compressed by the tumor and pulmonary hypertension (58/25 mmHg) and increased pulmonary wedge pressure (25 mmHg) was present. Open biopsy specimen demonstrated elongated cells suggestive of sarcoma. At autopsy, the tumor was confirmed to be leiomyosarcoma and to be originated from the lower esophagus.

Aged↗