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Biomedical subjects

H Maeda

Publications and source records attributed to H Maeda.

At least 1,171 records · Page 65Linked to original sources
PubMed1984

A quantitative assessment of scintigraphy of the legs using 201Tl.

201Tl perfusion scintigraphy of the legs was evaluated to define intermittent claudication quantitatively, based on Sapirstein's indicator fractionation principle. After intravenous injection of 201Tl with or without exercise, the distribution of the radiotracer throughout the body was obtained using the whole blood scanner. Regional blood flow of cardiac output for three segments of the leg was estimated as a regional fractional uptake (rFU) distributed in these segments compared with the whole body distribution. The validity of the principle was confirmed by a comparative study with 99mTc-MAA (r = 0.979). Normal rFUs (%) for each section at rest and after stress, respectively, were 5.49 +/- 0.69 and 19.40 +/- 2.04 (whole leg); 3.57 +/- 0.49 and 12.26 +/- 1.91 (thigh); 1.59 +/- 0.34 and 6.58 +/- 0.61 (calf). The rates of rFU change from the state of rest to stress (delta rFU) in normals were 3.41 +/- 0.45 (whole leg), 3.44 +/- 0.61 (thigh), and 4.30 +/- 1.03 (calf). Although rFU was within normal limits in patients with arteriosclerosis obliterans (ASO) and thromboangitis obliterans (TAO), delta rFU of the whole leg was significantly decreased from the normal value of 3.41 +/- 0.45 to 1.95 +/- 0.40 for ASO (P less than 0.001) and 1.82 +/- 0.47 for TAO (P less than 0.001). A defect or decreased activity on the stress scintigraph was well correlated with the angiographic findings.

Adult↗
PubMed1984

Separation of four class II molecules from DR2 and DRw6 homozygous B lymphoid cell lines.

Four human class II molecules, one FA, one DC1, and two DR-like molecules, were isolated from DR2 and DRw6 homozygous cell lines by means of a variety of monoclonal antibodies and were compared with each other by two-dimensional (2-D) gel electrophoresis. Anti-DR2 or anti-DR3 + 5 + w6 sera immunoprecipitated two distinct light chains (L1 and L2) and one heavy chain (H1) from a DR2 or DRw6 homozygous cell line, respectively. One or both of these two class II molecules were also immunoprecipitated by "DR-specific" monoclonal antibodies and were considered to constitute a "DR" family of molecules. Three DC1-specific monoclonal antibodies, SDR4.1, Tu22, and PLM5, immunoprecipitated a set of heavy (H2) and light (L3) chains distinct from those of two DR-like molecules. The heavy chains of the DC1 antigens from DR2 and DRw6 cell lines were indistinguishable, whereas the light chains were structurally distinct from each other. A fourth molecule, FA, was identified by a novel monoclonal antibody and was also detected by two additional antibodies, Tu39 and SG171, that blocked the SB-specific T-cell proliferative response. The FA light chain (L4) was distinct from those of the former three antigens on both cell lines, whereas the FA heavy chain was indistinguishable from the DC1 heavy chain (H2) in this 2-D gel analysis. Thus, four light chains and two heavy chains were isolated from both DR2 and DRw6 homozygous cell lines. A possible gene-antigen organization of the DC-like antigens was also discussed.

B-Lymphocytes↗
PubMed1984

Mixed connective tissue disease with fatal pulmonary hypertension and a review of literature.

The paper presents an autopsy case of mixed connective tissue disease (MCTD) with pulmonary hypertension (PH) and a review of literature. A 33-year-old woman with Raynaud's phenomenon and dyspnea of one year duration was diagnosed as having MCTD on the basis of a higher titer (1:163,840) of serum antibodies to the ribonucleoprotein (RNP). Cardiac catheterization showed complicating PH, confirmed an autopsy by the findings of concentric intimal cellular proliferation and typical plexiform lesions in the small arteries and arterioles of the lung, suggesting primary PH. Fatal PH with MCTD has been reported only 6 cases in literature including our case. All were young females, with histopathological findings consistent with plexogenic pulmonary arteriopathy in 5 cases and with recurrent pulmonary thromboembolism in the other. The aetiology of PH is still unknown, but it may be due to vasoconstriction evoked by the hyper-reactivity of the vessels.

Adult↗
PubMed1984

Plasticity of fat cell number.

Rats fed ad libitum (group 1) had little change in fat cell number in epididymal depots from 6 to 27 months of age, but a marked increase in fat cell number in perirenal depots between 6 and 18 months. Food restriction of rats to 60% of group 1 from 6 weeks of age on (group 2) reduced fat cell number in both depots throughout life and prevented an increase between 6 and 18 months in perirenal depots. Food restriction of rats to 60% of group 1 from 6 weeks to 6 months of age and then feeding ad libitum (group 3) markedly reduced fat cell number in both depots at 12 months compared to group 1. However, by 18 months of age, group 3 rats had the same fat cell number as group 1 rats in both depots. Food restriction of rats to 60% of the intake of group 1 started at 6 months of age (group 4) had no effect on fat cell number in epididymal depots but prevented an increase between 6 and 18 months in perirenal fat cell number. Group 5 rats fed ad libitum but restricted in protein (same caloric intake as group 1 rats) had epididymal and perirenal depots with the same characteristics as those of group 1. These findings and others in the literature show that modifying fat cell number is a widely used means of modifying fat mass during both early and adult life.

Adipose Tissue↗
PubMed1984

A kinetic study on the binding of monomeric and polymeric derivatives of NAD+ to yeast alcohol dehydrogenase.

The binding to yeast alcohol dehydrogenase of NAD+ and its five derivatives (N6-[2-[N-[2-[N-(2-methacrylamidoethyl)carbamoyl]ethyl] carbamoyl]ethyl]-NAD (I), N6-[N-[2-[N-(2-methacrylamidoethyl) carbamoyl]ethyl]carbamoylmethyl]-NAD (II), copolymer of I with acrylamide (PA-I), copolymer of II with acrylamide (PA-II), and copolymer of I with N,N-dimethylacrylamide (PDMA-I] were studied statically and kinetically by the stopped-flow method by using the quenching of the enzyme fluorescence in the presence of pyrazole. Apparent dissociation constants and apparent rate constants were determined therefrom. It was concluded that (1) the N6-CH2CH2CO group (of I) is effective in making the derivative bind more strongly as well as faster than NAD+, while the N6-CH2CO group (of II) is not; and (2) the binding of the polymer derivatives of NAD+ to the enzyme is not essentially weaker and slower than that of native NAD+, but is even faster in some cases. The coenzymic activities of the above compounds were also determined with yeast alcohol dehydrogenase, pig heart malate dehydrogenase, and rabbit muscle lactate dehydrogenase.

Alcohol Dehydrogenase↗
PubMed1984

Pathogenesis of serratial infection: activation of the Hageman factor-prekallikrein cascade by serratial protease.

A serratial protease with an apparent molecular weight of 56,000 (56K protease), which had been purified from the culture supernatant of a strain of Serratia marcescens isolated from a corneal lesion of a human eye [Matsumoto, K. et al. (1984) J. Bacteriol. 157, 225-232], greatly enhanced vascular permeability when injected into guinea pig skin. The 56K protease, which requires zinc ion for activity, was found to possess plasma kallikrein-like properties in vitro as judged by (i) preferential amidolysis of carbobenzoxy-Phe-Arg-4-methylcoumaryl-7-amide and Pro-Phe-Arg-4-methylcoumaryl-7-amide, which are known substrates for plasma kallikrein; (ii) release of kinin from high-molecular-weight kininogen; and (iii) prompt activation of Hageman factor followed by generation of kallikrein from plasma prekallikrein. These results suggest that the 56K protease enhances vascular permeability through activation of a Hageman factor-kallikrein-kinin pathway in vivo, and this molecular process appears to be a rational mechanism of enhancement of permeability and serratial pathogenesis.

Animals↗
PubMed1984

Role of the zinc atom in the activity and conformational stability of serratial 56K protease. A fluorometric study.

We found a zinc content of 1 atom per mol in 56K protease (produced by the gram-negative bacterium Serratia marcescens kums 3958) by the neutron activation method. Selective removal of the functional zinc ion from 56K protease with 10 mM tetraethylenepentamine (TEP) in the presence of 10 mM CaCl2 at room temperature at pH 8.0 resulted in complete loss of the enzyme activity without affecting the lambda max of the enzyme, but with a 10% decrease in fluorescence intensity. Ethylenediaminetetraacetic acid (EDTA) at 10 mM gave similar results at pH 5.0, but produced a 30% decrease in fluorescence intensity. Melting profile experiments carried out by monitoring the fluorescence intensity at 333 nm showed a melting temperature (Tm) of about 61.0, 62.5, and 60.0 degrees C at pH 5.0, 7.0, and 8.0, respectively. Tm became much lower upon removal of the zinc ion, falling to 42.5 degrees C with 10 mM TEP or to 47.5 degrees C with 10 mM EDTA in the presence of 10 mM CaCl2. The CD data showed very little change in conformation upon removal of the zinc ion under physiological conditions, but the conformation appears to be readily disrupted to a denatured form by changing either temperature or pH or by exposure to denaturants. These results suggest that a single zinc ion is essential for the enzyme function and contributes to the conformational integrity of the enzyme, but tryptophan residues appear to be not directly related to the enzyme activity.

Circular Dichroism↗
PubMed1984

Mouse monoclonal antibody detects a new polymorphic Ia determinant other than HLA-DR antigen: a possible allele of DC-1.

Using a hybridoma technique, a monoclonal antibody ( TA10 ) reactive with a new polymorphic B-cell antigen was obtained. The TA10 antibody reacted with 12 (24%) of B cells from 50 healthy individuals, but not with T cells. In contrast with the HLA-DR antigen, the TA10 antigen was preferentially detected on B cells, but not on monocytes. The reactive pattern of TA10 was closely associated with DR5 and its related DR antigen NJ2 , and also found with DR4 or DRw9 . The linkages of TA10 to these DR antigens were confirmed in the family study, indicating that the TA10 antigen is controlled by a closely linked but distinct locus from HLA-DR. Furthermore, two-dimensional gel analysis demonstrated that the TA10 determinant was expressed on a class II molecule whose heavy and light chains were different from those carrying the DR determinant. Thus, this monoclonal antibody might detect an allele of DC-1 which is found in association with DR5 and DRw6.2.

Alleles↗
PubMed1984

Purification and characterization of four proteases from a clinical isolate of Serratia marcescens kums 3958.

Four distinct proteases were purified to homogeneity from culture filtrates of Serratia marcescens kums 3958, a fresh isolate from a patient with a severe corneal ulcer. Purification was achieved by ammonium sulfate precipitation, DEAE-cellulose ion-exchange chromatography, and Sephadex gel filtration chromatography. The proteases were differentiated from each other by polyacrylamide gel electrophoresis with or without sodium dodecyl sulfate and by immunodiffusion in agarose gels. The molecular weights of these purified proteases were estimated to be 56 X 10(3), 60 X 10(3), and 73 X 10(3) (hereafter designated 56K, 60K, and 73K proteases, respectively). The 73K protease was separated into 73Ka and 73Kb upon isoelectricfocusing. The isoelectric points of the 56K (major) and 60K, 73Ka, and 73Kb proteases (minors) were approximately 5.3, 4.4, 5.8, and 7.3, respectively. Both 56K and 60K enzymes were completely inactivated by EDTA at pH 5.0 and were reactivated by zinc ion; thus, they are metalloenzymes, whereas 73K (73Ka and 73Kb) enzymes appear to be thiol proteases. Carbohydrate, cysteine, and cystine were not detected in the 56K and 60K proteases. Amino acid compositions, partial amino acid sequence, and enzymological and immunological properties revealed that these four enzymes are distinct from each other.

Chromatography, DEAE-Cellulose↗
PubMed1984

Further characterization of the effects of alpha-1-acid glycoprotein on the passage of human erythrocytes through micropores.

Effects of human alpha-1-acid glycoprotein (AG) on the passage of human red blood cell(s) (RBC) through membrane filters with micropores were examined in vitro. RBCs, with a mean major diameter of 7.2 micron, that had been suspended at 1% in physiological phosphate-buffered saline (PBS), were filtered through membrane filters of various pore diameters under positive pressure. The percentages of cells that passed through the micropores and of cells hemolyzed during filtration were determined. RBCs suspended in PBS did not pass through micropores that had an average pore diameter of 3 micron; instead hemolysis took place. Neither temperature nor applied pressure affected cell passage; but when AG at 0.1 mg/ml or above was added to an RBC-suspension, it promoted cell passage through the 3 micron micropores and reduced the degree of hemolysis. The effects of AG were dose dependent up to a concentration of 0.5 mg/ml. The addition of AG to an RBC-suspension that contained 90% human serum had the same additive effects. Washing AG-treated RBCs with normal saline produced a marked decrease in cell passage through the 3 micron pores. Fluorescence antibody staining revealed that the exogenous AG was localized on the membrane surface of the RBCs. Our results suggest that the AG bound to the surface of the RBCs acts as a lubricant between the RBCs and the wall of the micropore; this would facilitate RBC-passage through the micropores.

Erythrocyte Deformability↗
PubMed1984

Hemoglobin values in adult women of various occupational groups in the community.

In 1966 and 1971, the authors studied hemoglobin values of about 2,000 women of 10 different occupational groups and different social classes in the same district. The mean values of hemoglobin and serum iron were highest in nursing students followed by urban housewives and nutritionists and lowest in 3 groups of farm wives and shoe factory laborers. The difference in the mean values of hemoglobin observed among occupational groups was in principle assumed to be due to the difference of frequency in levels of 11-12 g/dl. Hemoglobin levels between 1966 and 1971 tended to improve as a whole and the differences among occupational groups have been reduced. In this study, some kinds of social conditions as well as some physiological factors related to hemoglobin values were investigated. In the same occupational group, unmarried women had a higher level of hemoglobin than married women. Further, married women with infants showed a relatively lower level than those with no infants. This suggests that hemoglobin values of female workers may be significantly influenced not only by work conditions but also by social conditions including family circumstances.

Adult↗
PubMed1984

Automated continuous measurement of erythrocyte volume under isotonic conditions.

The time course of volume changes of erythrocytes, suspended in isotonic solutions containing permeable substances, was studied using a cell monitoring system which was assembled on the basis of Coulter's principle. For comparison, the hematocrit method was employed. The data obtained demonstrated that urea, glycerol, ethanol, and methanol induced a rapid volume increase, whereas glucose and galactose induced a slow volume increase. These results correspond well to the data obtained by the hematocrit method. The present method, which requires only a minimum volume of blood, showed high accuracy and high reproducibility. Thus, the method was considered applicable to experimental and clinical studies of membrane permeability of erythrocytes.

Cell Membrane Permeability↗
PubMed1984

[Combined treatment with intra-arterial administration of oily anti-cancer agents and transcatheter arterial embolization--clinical and pathological study on 2 cases with resected small hepatoma].

Combined treatment with intraarterial administration of oily anti-cancer agent (SMANCS-Lipiodol; copolymer of styrene maleic acid conjugate of Neocarcinostatin disolved in Ethiodol) and transcatheter arterial embolization (TAE) was employed in 2 patients with small hepatoma. At 3-4 weeks after treatment, hepatic resection was performed. Histopathological examination of the 2 resected specimens showed total cell necrosis; CT and Softex revealed the distribution of lipiodol in the tumor and adjacent regions. This combination treatment showed combined effects, i.e. embolization by TAE, the anti-cancer effect of SMANCS and the selective delivery of lipidol to the hepatoma, especially the area of capsula invasion, the daughter nodule and tumor thrombus.

Antibiotics, Antineoplastic↗