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Biomedical subjects

S Masuda

Publications and source records attributed to S Masuda.

At least 217 records · Page 12Linked to original sources
PubMed1994

[The evaluation of hyposensitization with house dust in patients with nasal allergy to house dust-mite].

We evaluated the clinical and pathophysiological efficacy of hyposensitization with house dust extracts to perennial nasal allergy. Fifty-one patients with allergic perennial rhinitis completed 5 months to 15 years with a mean of 2.4 years course of hyposensitization treatment with house dust extracts, and analyzed clinical symptoms, nasal provocation testing, nasal hypersensitivity to histamine, mast cells and eosinophils in nasal scraping, specific IgG and IgG4 antibody in serum, and blood eosinophils and basophils in relation to therapeutic duration. The improvement in nasal symptoms was found in 74.1% in adults and 66.7% in child and the continuation of hyposensitization with house dust extracts for a half to one year showed significant improvement of clinical symptoms. In objective examination, nasal provocation testing, nasal hypersensitivity to histamine, the number of mast cells and eosinophils in nasal scraping, and blood basophils showed significant improvement at 6 to 12 months the same as clinical symptoms. These findings suggest that the continuation of hyposensitization with house dust extracts is recommendable as a basic treatment against perennial nasal allergy.

Adolescent↗
PubMed1994

[The evaluation of hyposensitization with sugi pollen extracts in patients with nasal allergy to Japanese sugi pollen].

We evaluated the clinical and pathophysiological efficacy of hyposensitization with Japanese sugi pollen extracts to sugi pollinosis. Twenty patients with Japanese cedar pollinosis received hyposensitization with Japanese cedar pollen extracts for one to 15 years with a mean of 9.5 years were compared with 18 patients without hyposensitization. The improvement of nasal symptoms was not found in patients with hyposensitization of sugi pollen extracts compared with patients with non-hyposensitization, but the number of mast cells in nasal scraping, nasal hypersensitivity to histamine, and specific sugi IgG4 antibody in serum was improved significantly compared with non-hyposensitization group. These findings suggest that the continuation of hyposensitization with sugi pollen extracts is recommendable as a basic treatment against seasonal nasal allergy.

Adult↗
PubMed1993

Specific uptake of succinylated proteins via a scavenger receptor-mediated mechanism in cultured brain microvessel endothelial cells.

Cellular uptake of succinylated catalase (Suc-CAT; Mw 227 kDa), bovine serum albumin (Suc-BSA; Mw 70 kDa), superoxide dismutase (Suc-SOD; Mw 34 kDa) and soybean trypsin inhibitor (Suc-STI; Mw 21 kDa) was studied using primary cultures of bovine brain microvessel endothelial cells (BMECs) developed as an in vitro model of the blood-brain barrier. Large succinylated proteins (Suc-CAT, Suc-BSA) were taken up by BMECs whereas significant uptake was not observed for native proteins and small succinylated proteins (Suc-SOD, Suc-STI). Uptake of Suc-BSA was significantly inhibited at 4 degrees C and in the presence of endocytosis inhibitors. Large succinylated proteins, maleylated BSA and dextran sulfate also showed competitive inhibition against Suc-BSA uptake while small succinylated proteins and carboxymethyl dextran did not show any effect. These results indicate that microvessel endothelial cells obtained from the brain endocytose succinylated proteins via a scavenger receptor-mediated mechanism for polyanions, and in addition, the importance of molecular weight or total numbers of anionic charges per one molecule of proteins is suggested. Usefulness of direct succinylation of proteins for their delivery to the brain capillary endothelium is thus demonstrated.

Animals↗
PubMed1993

Prognostic factors of malignant fibrous histiocytoma of bone. A clinical and histopathologic analysis of 34 cases.

BACKGROUND: Malignant fibrous histiocytoma (MFH) of bone is a rare bone tumor, and its prognosis has been controversial. METHODS: Thirty-four patients with MFH of bone were examined clinicopathologically for prognostic factors. RESULTS: The most common skeletal site of the tumor was the femur (15 cases), followed by the pelvic bones (6 cases), tibia (5 cases), and fibula (5 cases). Of 29 patients available for follow-up, the 5-year survival rate of 17 who underwent adequate surgical treatment was 63%. The 5-year survival rate of the remaining 12 patients, including 5 with MFH of the pelvic bone who received inadequate or palliative surgery, was 17%. All six patients who received intensive chemotherapy combined with adequate surgical treatment were alive and well 5 years after the initial treatment. Histologically, the presence of desmoplasia and chronic inflammatory infiltration in the tumor tended to be prognostic indicators, although not to a statistically significant extent. Patients whose tumors contained wide areas of desmoplasia had a worse prognosis (5-year survival rate, 20%). In contrast, those with a prominent chronic inflammatory infiltrate had a 5-year survival rate of 78%. CONCLUSIONS: These histologic variables would be helpful for predicting the prognosis of MFH of bone. Adjuvant intensive chemotherapy combined with adequate initial surgery may effect a clinical cure.

Adolescent↗
PubMed1993

Dantrolene protects against ischemic, delayed neuronal death in gerbil brain.

The effect was examined of dantrolene, a drug for malignant hyperthermia acting through preventing release of Ca from the ryanodine-type intracellular stores in muscle cells, on ischemic delayed neuronal death in field CA1 of gerbil hippocampus. Dantrolene (1.6 mM in concentration, 3 microliters each in volume), when administered bilaterally in the lateral ventricles 30 min after reperfusion after transient forebrain ischemia for 3 min at 37 degrees C, significantly protected against the neuronal death. It is proposed that the dantrolene-sensitive (most likely, the ryanodine-type) intracellular Ca stores in CA1 pyramidal cells play a pivotal role in the development of ischemic neuronal damage.

Animals↗
PubMed1993

Functional erythropoietin receptor of the cells with neural characteristics. Comparison with receptor properties of erythroid cells.

Radioiodinated erythropoietin (Epo) was bound specifically to the cells of two non-erythroid clonal lines, PC12 and SN6, which expressed neuronal characteristics. The binding was time-, cell number-, and dose-dependent and was reversible. Although the cloned Epo receptor from PC12 cells (derived from rat adrenal medulla) was identical to that from rat erythroid cells, significant differences in the ligand binding properties between two cell lineages were found; 1) PC12 cells had a single class of binding sites with very low affinity (Kd = 16 nM), whereas erythroid cells had two classes of binding sites with different affinities (Kd = 95 pM for high affinity sites and 1.9 nM for low affinity sites), and 2) cross-linking experiments revealed one cross-linked product of 105 kDa for PC12 cells and two products of 140 and 120 kDa for erythroid cells. Taken together with additional results, the presence of a putative accessory protein(s) that may alter the ligand binding affinity through interaction with Epo receptor is discussed. The binding of Epo to PC12 cells caused a rapid increase in the cytosolic concentration of free calcium. The presence of EGTA had no effect on the Epo binding but completely inhibited the calcium increase, indicating that Epo stimulated the calcium influx from outside of the cells. The addition of Epo to the culture media of PC12 cells elevated the intracellular concentrations of monoamines.

Adrenal Medulla↗
PubMed1993

Effect of tunicamycin treatment on ligand binding to the erythropoietin receptor: conversion from two classes of binding sites to a single class.

Scatchard analyses of erythropoietin (EPO) binding to its receptor (EPO-R) have shown that some erythroid cells display a biphasic nature of the ligand-saturation curve, indicating the presence of two classes of binding sites with different affinities. The biochemical basis accounting for this observation is unknown. We found that the culture of a human erythroleukemia cell line with tunicamycin, an inhibitor of N-glycosylation, converted the biphasic Scatchard plot to a single phase with high-affinity sites. Scatchard plots of baby hamster kidney (BHK) cells that had been engineered to express cloned mouse EPO-R were also biphasic and the plots of cells cultured with tunicamycin became a single phase with high-affinity sites. Mouse EPO-R is glycosylated at one asparagine residue in the extracellular region. The mutant EPO-R, in which asparagine residue responsible for N-glycosylation was replaced with glutamine residue, was expressed on BHK cells. Unexpectedly, mutant EPO-R was similar in ligand binding to wild-type EPO-R. BHK cells that expressed mutant EPO-R showed biphasic Scatchard plots that were converted to single-phase plots with only high-affinity sites by tunicamycin treatment. These results indicate that the N-linked sugar of EPO-R is not involved in the manifestation of two classes of binding sites, and that there is a yet unidentified glycoprotein crucial for the ligand-saturation characteristics of EPO-R.

Amino Acid Sequence↗
PubMed1993

Infrared studies of octopus rhodopsin. Existence of a long-lived intermediate and the states of the carboxylic group of Asp-81 in rhodopsin and its photoproducts.

The infrared absorption spectra of octopus rhodopsin and its photoproducts have been observed at 282K and 210K under irradiation of blue and orange light in a neutral condition. The acid metarhodopsin-minus-rhodopsin and lumirhodopsin-minus-rhodopsin difference spectra have been obtained. A new intermediate (called transient acid metarhodopsin) with a lifetime of about 5 s has been found to exist prior to acid metarhodopsin. The present results, together with the data obtained previously, give information on the state of the carboxylic group in the side chain of Asp-81, which is the only acidic amino-acid residue in the part of opsin buried inside the membrane. This carboxylic group is protonated throughout the transformation series, but its state changes on going from transient acid metarhodopsin to acid metarhodopsin. It is probable that these two photoproducts are different from each other only in the opsin moiety.

Animals↗
PubMed1993

Case report 793. Periosteal osteosarcoma of the clavicle.

A case of periosteal osteosarcoma in an 18-year-old boy has been reported. This is the first reported case of periosteal osteosarcoma arising in the clavicle. The radiological features in this case were entirely similar to those in long bones such as the femur and tibia. In addition to the radiological features and pathologic findings, various clinical aspects and prognosis were also discussed.

Adolescent↗
PubMed1993

Primary rhabdomyosarcoma of the iliac bone in an adult: a case mimicking fibrosarcoma.

Primary rhabdomyosarcoma of bone is exceedingly rare. We present a case of rhabdomyosarcoma of the iliac bone in a 32-year-old male. Histologically, the tumour consisted mainly of a uniform proliferation of elongated spindle cells arranged in a herring bone pattern, simulating fibrosarcoma. Focally there was a conventional embryonal pattern with scattered rhabdomyoblasts possessing an eosinophilic cytoplasm. Immunohistochemical studies disclosed expression of muscle markers such as desmin and muscle-specific actin, in both the embryonal and spindle-cell areas and myoglobin only in the embryonal areas. Such histological features are unusual for classical embryonal rhabdomyosarcoma. The anatomical site and age of the patient are also atypical.

Adult↗
PubMed1993

Adenomatous hyperplasia of the liver resembling focal nodular hyperplasia in patients with chronic liver disease.

Two nodules of hepatic adenomatous hyperplasia (AH) resembling focal nodular hyperplasia were found in two patients with cirrhosis or chronic active hepatitis. Imaging techniques suggested that the nodules were hepatocellular carcinoma. Pathological examination showed that the nodules (approximately 1.0 cm in diameter) were clearly demarcated from the surrounding liver tissue, and contained foci of scar-like fibrosis in the centre of the nodules. Microscopically, they contained portal tracts and fulfilled the criteria of AH. A large number of arteries were present in the central scar-like fibrosis as well as in the parenchyma of the nodules. There were foci of mildly atypical hepatocytes in one nodule but no cellular atypia in the other. Morphometric analysis showed that the cumulative luminal area of arteries per unit area was much greater in the nodules than in the extranodular liver tissues, while the cumulative luminal area of portal veins per unit area was much less in the nodules than in the extranodular liver tissues. Although the pathogenesis is unclear, these nodules might have developed through localized vascular changes associated with chronic liver disease, may have arisen from pre-existing arterial malformation, or may represent the early stages of angiogenesis in hepatocarcinogenesis.

Adenoma↗
PubMed1993

Clinical and pathophysiological evaluation of tranilast in patients with pollinosis: the effects of pre-seasonal treatment.

Tranilast is an orally effective anti-allergic agent evaluated for clinical activity in prevention of symptoms of allergic rhinitis. It was investigated in a randomized, pre-seasonal, and in-seasonal treatment of tranilast to test the clinical efficacy and pathophysiological changes on the onset of nasal symptoms in season. Thirty-eight patients with a history of Sugi pollinosis and positive allergic tests were treated with tranilast 300 mg daily 6 to 7 weeks before the onset of the pollen season and continuously during the season or no medication including tranilast until the onset of clinical symptoms in season. The number of sneezing and the grade of stuffiness at the onset of pollen season were inhibited significantly in pre-seasonal treatment. The number of mast cells and eosinophils in season increased compared with off-season and the threshold of nasal hypersensitivity in season decreased compared with off-season in inseasonal treatment, but not in pre-seasonal treatment. This study indicates that tranilast may have the prophylactic effect for Sugi pollinosis.

Adolescent↗
PubMed1993

Efficient adsorption of lysostaphin on bacterial cells of lysostaphin-resistant Staphylococcus aureus mutant.

A simple and efficient method for the purification of staphylolytic endopeptidase (lysostaphin) contained in culture supernatant of Staphylococcus simulans biovar staphylolyticus strain by adsorption of the enzyme on bacterial cells of lysostaphin-resistant S. aureus mutant was successfully devised. Lysostaphin was sufficiently absorbed on the heat-killed mutant cells derived from S. aureus Cowan I and efficiently eluted by 3 M KSCN. Enzyme preparation obtained by a single procedure of the affinity purification was pure enough for practical use. The yield of the enzyme was 25 mg from 1 liter culture and recovery rate was 64%.

Adsorption↗
PubMed1993

Effects of cytochalasins B and D on Staphylococcus aureus adherence to and ingestion by mouse renal cells from primary culture.

Cytochalasin B (CB) and cytochalasin D (CD), inhibitors of microfilament function of host cell, were examined for their effects on Staphylococcus aureus Cowan I adherence to and ingestion by several types of the hyperosmolarity-tolerant (HOT) cells obtained from primary culture of mouse kidney. Staphylococcal adherence to the HOT cells with epithelial appearance was extraordinarily enhanced by the treatment of those cells with both 5 micrograms/ml of CB and CD. In particular, staphylococci adhered to the periphery rather than the center of each cytochalasin-treated cell. Staphylococcal ingestion by all types of the HOT cells was markedly inhibited by CD in spite of the enhanced adherence. Contrary to our expectation, inhibition by CB was incomplete, and the enhanced adherence of staphylococci to CB-treated cells resulted in the enhanced ingestion.

Actin Cytoskeleton↗
PubMed1993

Lung carcinoma mimicking malignant lymphoma: report of three cases.

Three cases of lung carcinomas with unusual histologic appearances that have received little or no comment in the literature are presented. They were initially confused with malignant lymphoma because of a diffuse proliferation of relatively monotonous cells simulating large-cell immunoblastic lymphoma. In each case, the possibility of malignant lymphoma was excluded with confidence after the immunohistochemical study (leucocyte common antigen negative and cytokeratins positive), although with conventional microscopy several foci of cohesive groups of tumor cells were observed. The tumors were ranked at the clinical stage II or III when they were initially discovered, but all patients died of disease within 1 year. The present three tumors show an aggressive behavior and could be classified into a peculiar variant of 'large cell' carcinoma. It is necessary for surgical pathologists to have an idea of these variants of lung carcinoma in order to avoid erroneous diagnosis.

Adult↗
PubMed1993

Characterization of erythropoietin isolated from rat serum: biochemical comparison of rat and human erythropoietins.

We isolated erythropoietin (Epo) from anemic-rat serum with 1.3 x 10(6)-fold purification and 38% recovery using immunoaffinity chromatography. The isolated Epo migrated in SDS polyacrylamide gel with a molecular size of 37 kDa. Biological properties of rat Epo were compared with those of human Epo using target cells of primate and murine origins. When murine cells were used as target cells for assaying Epo, rat Epo stimulated proliferation of the cells with a 50% lower potency than did human Epo. The activity of rat Epo on human cells was only 25% of that of human Epo. Studies of Epo binding to the receptor indicated that rat and human Epos were not distinguishable in binding to murine cells; however, rat Epo bound to the receptor on human cells with an affinity much lower than that of human Epo. Rat Epo was digested with N-glycanase. Complete removal of N-linked sugars converted the native Epo to the deglycosylated form with 18 kDa. The in vitro activity of deglycosylated Epo was 2.5-fold higher than that of the native Epo.

Amino Acid Sequence↗
PubMed1993

Gross and separative determination of 1 alpha,25-dihydroxyvitamin D2 and D3 in plasma using calf thymus receptor.

Determination of 1 alpha,25-dihydroxyvitamin D [1,25(OH)2D, gross amounts of 1,25(OH)2D2 and 1,25(OH)2D3] and separative determination of 1,25(OH)2D2 and 1,25(OH)2D3 in plasma using calf thymus receptor have been investigated. A lipid extract from 1 ml of plasma is applied to a Bond Elut C18OH column and an eluate corresponding to 1,25-(OH)2D including both 1,25(OH)2D2 and 1,25(OH)2D3 is applied to calf thymus receptor to assay a gross amount of the two compounds. On the other hand, when separative assay of the two compounds is performed, the 1,25(OH)2D eluate obtained from the Bond Elut C18OH column is further applied to HPLC using a Zorbax SIL column with 5% isopropanol in methylene chloride as a developing solvent to separate the two compounds from one another. The separated eluates are independently applied to the receptor to assay the two compounds. Since less amounts of unknown components non-specifically bound to interfering concomitants besides 1,25(OH)2D exist in the calf thymus receptor, complicated purification steps to eliminate the concomitants are unnecessary. The detection limit by this method is 1.25 pg/tube which is sensitive enough for a routine method to assay 1,25(OH)2D in plasma.

Animals↗