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Biomedical subjects

M Matsui

Publications and source records attributed to M Matsui.

At least 469 records · Page 26Linked to original sources
PubMed1986

Bietti's crystalline retinopathy.

The authors reported a case of Bietti's crystalline retinopathy in 1981. In the present paper they report three additional cases studying the stages of this disease and the clinical findings at each stage. Conclusions obtained are as follows: This disease is a type of total RPE-choriocapillaris dystrophy, the process of which starts at the posterior pole. This disease can be divided into three stages, based on the clinical findings: Stage 1: RPE atrophy with uniform fine white crystalline deposits is observed at the macular area. Stage 2: RPE atrophy extends beyond the posterior pole. Choriocapillaris atrophy in addition to the RPE atrophy appears markedly at the posterior pole. Crystalline deposits in the lesion vary in shape and size and have a tendency to conflue. The number of crystalline deposits is less in the advanced atrophic areas of the RPE-choriocapillaris complex. Stage 3: RPE-choriocapillaris complex atrophy is observed throughout the fundus. The total number of crystalline deposits decreases because the crystalline deposits that disappear number more than those that appear in Stage 3. Crystalline deposits which are observed at the corneal limbus are possibly prominent in the advanced stage of atrophy of the RPE-choriocapillaris complex.

Adult↗
PubMed1985

On the degradation of dermorphin and D-Arg2-dermorphin analogs by a soluble rat brain extract.

Degradation of dermorphin, [D-Arg2]dermorphin and [D-Arg2, Gly3, Phe4]dermorphin in a soluble rat brain extract was examined. The former two heptapeptides were degraded in a similar fashion to produce corresponding N-terminal tetrapeptide as the main degradation product along with the parallel release of Tyr5, Pro6 and Ser7-NH2. Tyr-D-Arg-Phe-Gly showed a good enzymatic stability. When captopril, an angiotensin-converting enzyme inhibitor, was present in the incubation mixture, hydrolysis of the Gly4-Tyr5 bond was markedly suppressed and resulted in release of the corresponding N-terminal hexapeptide as the main degradation product. Combined use of captopril and amastatin, an aminopeptidase inhibitor, markedly suppressed the hydrolysis of these peptides. On the other hand, [D-Arg2, Gly3, Phe4]dermorphin was hydrolyzed easier than the other two heptapeptides and considerable amounts of Tyr1 and Phe4 were released after 20 hr incubation while the N-terminal tetrapeptide, Tyr-D-Arg-Gly-Phe, showed a good enzymatic stability. On the basis of these results, possible degradation pathways of these heptapeptides were discussed.

Amino Acids↗
PubMed1985

Sites of dnaA protein-binding in the replication origin of the Escherichia coli K-12 chromosome.

On the basis of the observation that dnaA protein binds preferentially to DNA fragments carrying the Escherichia coli chromosomal replication origin (oriC), the binding sites were investigated by DNase I footprinting. As a result, three strong binding sites were identified in the minimal oriC sequence. The respective binding sites were 16 to 17 base-pairs long, and contained a common sequence (5') T-G-T-G-(G/T)-A-T-A-A-C (3') in the middle, although their polarities were not the same. Since mutants defective in function for autonomous replication have been isolated in the corresponding positions of the common sequence at each binding site, dnaA protein-binding at these sites seems to be significant for replication initiation.

Bacterial Proteins↗
PubMed1985

The analgesic activity of D-Arg2-dermorphin and its N-terminal tetrapeptide analogs after subcutaneous administration in mice.

D-Arg2-dermorphin and its nineteen N-terminal tetrapeptide analogs were prepared, and their analgesic activities after subcutaneous administration in mice and the stability of a D-Arg2-dermorphin tetrapeptide to enzymatic degradation were examined. The analgesic effect was assessed by the tail pressure test. D-Arg2-dermorphin was found to have analgesic potency equal to or slightly greater than that of dermorphin. In a series of tetrapeptide analogs, a very pronounced activity greater than that of morphine was observed for analogs of the following structure, H-Tyr-D-Arg-Phe-X-OH (X = Gly, sarcosine and D-Ala) or its esters. Replacement of D-Arg2 by D-Arg(NO2), D-homoarginine or D-Lys resulted in a decrease in potency, suggesting that the guanidino group and side chain length of D-Arg2 are of great importance for a higher activity. D-Arg2-tetrapeptide (H-Tyr-D-Arg-Phe-Gly-OH) was found to be more stable than the parent tetrapeptide (H-Tyr-D-Ala-Phe-Gly-OH) to cleavage both by aminopeptidase M and by carboxypeptidase Y.

Analgesics, Opioid↗
PubMed1985

Heterogeneity of rat liver sulfotransferases.

Sulfotransferases (STs)active on androsterone (AD), cortisol (CS) and 4-nitrophenol (NP) were separated by diethylaminoethyl-cellulose chromatography from cytosolic fractions of female rat liver and were divided into five ST fractions (peaks I-V) with different activities toward three substrates. The precipitates obtained in the 68% of saturation of ammonium sulfate were passed through a Sephadex G-100 column and purified by agarose-hexane adenosine 3',5'-bisphosphate affinity chromatography. AD-ST isoenzyme (peak I) was purified 85-fold, had low CS-ST activity, was devoid of NP-ST activity and appeared to correspond to hydroxysteroid ST 1. Peaks II and V appeared to consist mainly of hydroxysteroid ST and aryl ST, respectively.

Ammonium Sulfate↗
PubMed1985

Multiple forms and a deficiency of uridine diphosphate-glucuronosyltransferases in Wistar rats.

Uridine diphosphate (UDP)-glucuronosyltransferase (GT) active on androsterone (AD) and 4-nitrophenol (NP) was solubilized from male rat liver microsomes of the Wistar strain. The precipitate obtained in the 60%-satd. ammonium sulfate was purified by diethylaminoethyl (DEAE)-cellulose chromatography and affinity chromatography on UDP-hexanolamine Sepharose 4B. DEAE-cellulose chromatography showed the existence of two peaks of GT active on AD and NP. Peak I was found in rats with the high-activity and low-activity phenotypes in terms of AD glucuronidation and had high NP-GT and low AD-GT activities. In contrast, peak II was found only in rats with the high-activity phenotype, corresponded to high AD-GT activity and had comparatively low NP-GT activities. The corresponding peak in rats with the low-activity phenotype had only NP-GT activity. Comparison of Km values for AD obtained from microsomes and purified enzymes provides evidence that AD-GT isoenzyme should be deficient in Wistar rats with the low-activity phenotype and that AD glucuronidation should be catalyzed poorly by other GT isoenzyme in these rats.

Animals↗
PubMed1985

Heterogeneous expression of melanoma-associated antigens and HLA antigens by primary and multiple metastatic lesions removed from patients with melanoma.

Indirect immunofluorescence staining with a large battery of monoclonal antibodies of primary and autologous metastatic lesions removed from seven patients with melanoma has detected heterogeneity in the expression of various types of melanoma-associated antigens (MAAs), of distinct determinants of the high molecular weight melanoma-associated antigen (HMW-MAA), of the two subunits of Class I HLA antigens, and of the gene products of the HLA-D region. Among the 10 MAAs tested, the HMW-MAA had the highest frequency and the Mr 87,000 MAA the lowest. Furthermore, the HMW-MAA displayed the lowest heterogeneity. These findings, in conjunction with the restricted tissue distribution of the HMW-MAA, its lack of susceptibility to antibody-mediated modulation, and the high affinity of the available anti-HMW-MAA monoclonal antibodies, indicate that this antigen may be a useful marker for radioimaging and immunotherapy in patients with melanoma. The common acute lymphoblastic leukemia antigen was detected only in five lesions. Class I HLA antigens were detected in a larger number of lesions than HLA-DR antigens, which had a significantly higher frequency than HLA-DQ antigens. The degree of antigenic heterogeneity did not appear to correlate with the histopathological features of the lesions and/or with the clinical course of the disease. The results of the present study indicate that immunodiagnostic and immunotherapeutic approaches to melanoma should rely on the use of combinations of monoclonal antibodies to distinct MAAs.

Animals↗
PubMed1985

Suppression of human melanoma growth in nude mice injected with anti high-molecular-weight melanoma-associated antigen monoclonal antibody 225.28S conjugated to purothionin.

The cytotoxic agent purothionin purified from barley was covalently conjugated to the anti-human high-molecular-weight melanoma-associated antigen (HMW-MAA) monoclonal antibody (MoAb) 225.28S by utilizing water-soluble carbodiimide. Injection of the conjugate (0.1 mg/injection) significantly increased the life span of nude mice injected with ascitic-form human melanoma cells (Colo 38), and caused 40% inhibition on day 25 of the growth of solid-form human melanoma cells in nude mice. The effect is specific and is markedly influenced by the site of growth of tumors and by the schedule of administration of the conjugate.

Animals↗
PubMed1985

[Radiotherapy of pancreatic carcinoma].

During the 10-year period between 1974 and 1984, we treated 34 pancreatic carcinomas by radiotherapy as follows: Eight by intraoperative radiotherapy (IOR), five by external radiotherapy (ERT), and 21 by IOR in combination with ERT. The mean survival time of the eight patients treated by IOR was 5.6 months, and that of the 21 receiving the combination therapy 7.2 months. Although it is not statistically significant, patients treated by the combined regimen survived longer than those treated by IOR alone.

Aged↗