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Biomedical subjects

Y Shimokawa

Publications and source records attributed to Y Shimokawa.

At least 37 records · Page 2Linked to original sources
PubMed1990

Influence of captopril on urinary excretion of furosemide in hypertensive subjects.

Influence of captopril on urinary excretion of furosemide was examined in a placebo-controlled, crossover design. Furosemide (20 mg) was injected intravenously in eight hypertensive subjects with pretreatment with captopril (25 mg) or matching placebo. Urine samples for furosemide and sodium were collected during the following intervals: -60-0, 0-60, 60-120, and 120-180 minutes after furosemide. Blood samples for plasma renin activity (PRA) and angiotensin II (AII) were obtained, and blood pressure was measured at -60, 0, 60, 120, and 180 minutes after furosemide. No significant difference was observed in urinary excretion of furosemide, volume or sodium between these trials. Although PRA increased following furosemide with captopril, as predicted plasma AII did not increase. Blood pressure significantly decreased following the combined therapy, but not furosemide alone. These data indicate that the urinary excretion of furosemide and its subsequent diuretic effects are not influenced by captopril.

Adult↗
PubMed1990

A monoclonal antibody, RbM2, specific for a lysosomal membrane antigen of rabbit monocyte/macrophages.

An anti-macrophage monoclonal antibody (mAb), RbM2, was produced using thioglycolate-elicited rabbit peritoneal macrophages as immunogen. The immunohistochemical approach revealed an intense reactivity of this mAb to macrophages, particularly those engaged in phagocytosis, in different organs and tissues, and to peripheral blood monocytes. Immunoelectron microscopy demonstrated reaction products of RbM2 in the lysosomes of macrophages and monocytes. This selective reactivity with the mAb was further confirmed in various experiments by endocytosis of Latex particles with different diameters or IgG-coated sheep erythrocytes. The results indicate that RbM2 recognizes a lysosomal membrane antigen of 50,000 molecular weight (MW). In contrast, dendritic cells, such as follicular dendritic cells (FDC) of lymphoid follicles, interdigitating cells (IDC) of lymphoid T zones, or epidermal Langerhans' cells, were not reactive with the antibody. Thus, RbM2 is useful not only in differentiating the phagocytic macrophages from the immunologically accessory dendritic cell populations but also in identifying lysosomes and their related structures in macrophages.

Animals↗
PubMed1989

Heterogeneity of rat macrophages recognized by monoclonal antibodies: an immunohistochemical and immunoelectron microscopic study.

Three monoclonal antibodies, designated RM-1, TRPM-1, and TRPM-2, were raised against rat peritoneal macrophages. By the immunoperoxidase method, antigens recognized by these antibodies were distributed throughout most tissue and free macrophages examined, including those of splenic red pulp, lymphatic sinus, connective tissue, and peritoneal cavity, as well as Kupffer cells of liver and alveolar macrophages. The numbers of positive cells were different for each antibody. RM-1 and TRPM-1 were also reactive with interdigitating cells (IDCs) in the thymus-dependent area and with Langerhans cells in the skin, whereas TRPM-2 failed to demonstrate IDCs in thymic medulla and Langerhans cells. The reactions of each antibody were observed by immunoelectron microscopy in the different ultrastructural compartments of the cells. RM-1 recognized a cell surface antigen; reaction products for TRPM-1 were found on a part of the cell membrane and in the cytoplasmic vacuoles; and those of TRPM-2 were present along the nuclear envelope and intracytoplasmic vacuoles. These antibodies seem to be useful not only for the detection of macrophages in tissue sections but also for investigation of macrophage heterogeneity in different tissues.

Animals↗
PubMed1987

Primary aortoduodenal fistula--report of an autopsy case.

This report describes a case of primary aortoduodenal fistula (PADF) in an 83 year-old male admitted a local hospital with massive hematemesis. Endoscopy failed to reveal the site of hemorrhage. During his course, he had two episodes of hematemesis and melena. On the 77th hospital day, he died of acute hemorrhagic shock resulting from massive hemorrhage in the gastrointestinal tract. An autopsy revealed adhesion and a fistulous communication between an atherosclerotic abdominal aneurysm and the third portion of the duodenum. Primary aortoenteric fistula (PAEF), including PADF, is an uncommon but lethal complication of aortic aneurysm. Since fistula formation occurs most frequently between the abdominal aorta and duodenum, upper gastrointestinal endoscopic examination and aortography at the earliest possible moment are necessary to obtain a correct diagnosis before surgery.

Aged↗
PubMed1986

Fluorescence labeling of a single sulfhydryl group in human plasma alpha 1-proteinase inhibitor and characterization of the labeled inhibitor.

A single cysteine residue present in human plasma alpha 1-proteinase inhibitor was labeled with a fluorescent sulfhydryl reagent, N-iodoacetyl-N'-(5-sulfo-1-naphthyl)ethylenediamine. The resulting fluorescent inhibitor retained nearly full inhibitory activity and formed complexes with bovine chymotrypsin, porcine pancreatic elastase, and bovine trypsin as revealed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Association rate constants for the interactions of the labeled inhibitor with the proteinases were determined to be 1.5 (+/- 0.4) X 10(6), 3.3 (+/- 0.3) X 10(5), and 1.4 (+/- 0.3) X 10(5) M-1 X s-1 for chymotrypsin, elastase, and trypsin, respectively. These values were found to be only slightly lower than those of the unlabeled inhibitor. Fluorescence emission spectra of the labeled inhibitor in the absence and presence of each proteinase were also examined, and little difference was observed between them.

Blood Proteins↗
PubMed1985

New fluorogenic substrate for esterase activity of alpha-chymotrypsin and related enzymes.

A new fluorogenic substrate, benzyloxycarbonyl-L-phenylalanine 4-methylcoumaryl-7-ester, has been developed for determination of the esterase activity of alpha-chymotrypsin and related enzymes. Synthesis of the substrate was achieved simply by the carbodiimide condensation of benzyloxycarbonyl-L-phenylalanine and 7-hydroxy-4-methylcoumarin in a 86% yield. The esterase activity was measured by increase of the fluorescence intensity at excitation and emission wavelengths of 325 and 465 nm, respectively. An initial rate of hydrolysis was linear over a 100-fold range of the enzyme concentration. As little as 2 ng of alpha-chymotrypsin could be detected in the standard assay. A typical enzyme assay, stability of the substrate, kinetic parameters, and specific activity have been reported.

Chymotrypsin↗
PubMed1984

Quantitative evaluation for the role of beta 146 His and beta 143 His residues in the Bohr effect of human hemoglobin in the presence of 0.1 M chloride ion.

Two different methods were used to determine the number of Bohr protons released upon oxygenation of human hemoglobin (Hb A) and Hb A lacking beta 146 His (des-His Hb A) at the pH ranging from pH 5.0 to 9.0 in the presence of 0.1 M Cl- at 25 degrees C. One is the direct differential titration method, the other is based on the measurement of oxygen affinity as a function of pH. The results obtained for Hb A or des-His Hb A with two methods were completely mutually consistent. The number of Bohr protons released from des-His Hb A upon oxygenation at pH 7.5 was about 44% less than that from Hb A, while at pH 5.5 the number of Bohr protons taken up by des-His Hb A was 20% greater than that by Hb A. The differences in the number of Bohr protons between Hb A and des-His Hb A could not be simply ascribed to the lack of beta 146 His from Hb A. The pK alpha values, which were determined by the deuterium exchange method using 1H NMR, were 8.0 for beta 146 His of deoxy-Hb A and 6.5 for that of CO Hb A, while those of beta 143 His were 5.2 for deoxy-Hb A and 6.0 for CO Hb A. From these pK alpha values, in addition to those of alpha 1 Val proposed for the modified CO and deoxy-Hb A with carbamylated beta chains by Van Beek and De Bruin (Van Beek, G. M., and De Bruin, S. H. (1980) Eur. J. Biochem. 105, 353-360), it became evident that almost all (about 92%) of the alkaline Bohr protons released upon oxygenation of Hb A in the presence of 0.1 M Cl- could be accounted for by the protons from these 2 residues, although the involvement of other histidine residues could not be denied. About half the acid Bohr protons from Hb A, which corresponds to the higher pH part (above pH 5.0) of the acid Bohr effect, could be explained by the involvement of beta 143 His residue. The residual acid Bohr effect in the more acidic pH region was presumably contributed by an amino acid residue with pK alpha values of 4.05 and 5.95 for the deoxy- and CO Hb A, respectively, although the amino acid residue was unspecified.(ABSTRACT TRUNCATED AT 400 WORDS)

Chlorides↗
PubMed1984

Primary structure of Vicia angustifolia proteinase inhibitor.

The complete amino acid sequence (72 amino acid residues) of a double-headed proteinase inhibitor from seeds of Vicia angustifolia L. var. segetalis Koch has been determined and compared with those of other double-headed inhibitors of known structure. Sequencing was performed by conventional methods with the aid of the fragments produced by reduction and S-carboxymethylation of the enzymatically modified inhibitors, and also using tryptic and chymotryptic peptides. The positions of the 14 half-cystine residues agreed among all the reported primary structures of the legume double-headed inhibitors. However, V. angustifolia inhibitor possessed extensive amino acid differences compared to the others. The phylogenetic relationship among these inhibitors was established using the unweighted pair-group method and revealed that the V. angustifolia inhibitor and the peanut inhibitor B-III had diverged at a relatively earlier stage compared to the other inhibitors.

Amino Acid Sequence↗
PubMed1984

Lymphocyte chemotaxis in inflammation. IX. Further characterization of lymphocyte chemotactic lymphokines produced by purified protein derivative-stimulation in vitro and in vivo.

As recently reported, one lymphocyte chemotactic factor (beta-LCF, mol. wt. about 27,000) released from activated guinea-pig lymphocytes appeared to be identical to one of the LCFs (LCF-d) isolated from extract of purified protein derivative (PPD)-induced delayed-type hypersensitivity skin reaction sites in guinea-pigs with respect to antigenicity and chemotactic effect for T cells. However, the mol. wt. of LCF-d (about 300,000) was clearly distinct from beta-LCF. The experiments were undertaken to clarify the problem. beta-LCF appeared to be bound to some protein of normal guinea-pig serum (GPS) because the chemotactic activity was revealed in the fraction corresponding to that of LCF-d when the mixtures of beta-LCF with GPS were applied to a Sephadex G-200 column. Additionally, binding experiments using fluorescein isothiocyanate (FITC)-labelled beta-LCF were performed; fluorescence was only detected in the chemotactic fraction. It was thus assumed that the lymphokine (beta-LCF) would be released from activated lymphocytes around the inflammatory tissue, then bound with serum protein exuded in the site and function as LCF-d. The possibility was supported by the evidence that beta-LCF like-chemotactic substance (mol. wt. about 27,000) was dissociated from LCF-d under acid conditions. The factor dissociated from LCF-d was also bound with GPS protein under neutral conditions and converted to high molecular substance resembling LCF-d physiochemically. Furthermore, the chemotactic activity of LCF-d was almost completely absorbed by antibody against GPS. It is thus considered that the chemotactic activity of LCF-d may be attributed to beta-LCF released from activated lymphocytes and that some serum protein which binds beta-LCF may function as a carrier protein in the DTH sites.

Animals↗
PubMed1984

Lymphocyte chemotaxis in inflammation. VII. Isolation and purification of chemotactic factors for T lymphocytes from PPD-induced delayed hypersensitivity skin reaction site in the guinea-pig.

Four types of lymphocyte chemotactic factor (LCF-a, -b, -c and -d) could be isolated from extract of 24-hr-old delayed-type hypersensitivity (DTH) skin reaction sites induced with purified protein derivative (PPD) in guinea-pigs by gel filtration on Sephadex G-100 followed by chromatography with DEAE-Sephadex. Partially purified LCF-b was thought to be a heat-stable protein with a molecular weight (mol. wt.) of about 14,000. LCF-c separated from LCF-d by chromatography with DEAE-Sephadex was highly purified by chromatography with CM-Sephadex, immunoadsorbent chromatography coupled with anti-IgG antibody, and chromatofocusing in that order. It was considered to be a heat-labile protein with a mol. wt. of about 160,000 and with pI of 8.1 +/- 0.2. LCF-d first separated from LCF-c was also highly purified by chromatography with CM-Sephadex followed by preparative isotachophoresis. The factor was considered to be a heat-labile protein with a mol. wt. of approximately 300,000 and with pI of 6.2 +/- 0.2. These factors were similarly active for non-adherent cells (mostly T cells) but not for cells (mostly B cells) adherent to anti-IgG antibody-coated petri-dishes. Since LCF-a was active for B cells as described earlier, it is thus suggested that LCF-b, LCF-c and LCF-d may be important for T cell migration in the DTH site to PPD.

Animals↗
PubMed1984

Lymphocyte chemotaxis in inflammation. VIII. Demonstration of lymphocyte chemotactic lymphokines in PPD-induced delayed hypersensitivity skin reaction site in the guinea-pig.

The experiments were carried out to clarify whether lymphocyte chemotactic factors (LCFs) derived from activated lymphocytes, i.e. lymphocyte chemotactic lymphokines would exist in delayed-type hypersensitivity (DTH) reaction sites in guinea-pigs. To analyse the problem, we attempted to use an immunoadsorbent column conjugated with respective antibodies against LCFs (LCF-b, LCF-c and LCF-d) isolated from purified protein derivative (PPD)-induced DTH skin reaction sites in guinea-pigs. The chemotactic activity of culture supernatants from PPD- or concanavalin A (Con A)-stimulated lymph node (LN) cells was decreased to about 50% by the immunoadsorbent column with anti-LCF-c antibody or anti-LCF-d antibody, while its activity was little or not influenced by the columns with anti-LCF-b, anti-IgG or anti-IgM antibody. Further experiments using successive immunoadsorption with anti-LCF-c antibody followed by anti-LCF-d antibody showed almost the complete adsorption of the chemotactic activity in the above culture fluids. Additionally, the chemotactic lymphokine which was absorbed by anti-LCF-c antibody had a similar mol. wt. to that of LCF-c (mol. wt about 160,000). However, the chemotactic lymphokine which was absorbed by anti-LCF-d antibody had a mol. wt. of about 27,000; it was clearly distinct in mol. wt. from LCF-d (mol. wt. about 300,000). It is thus suggested that at least one of lymphocyte chemotactic lymphokines exists in the DTH reaction sites and functions as LCF-c.

Animals↗
PubMed1983

Highly sensitive method for determination of esterase activity of alpha-chymotrypsin and alpha-chymotrypsin-like enzymes using micro high-performance liquid chromatography.

A new substrate, Dns-L-phenylalanine ethyl ester, with high UV absorption has been developed for the determination of the esterase activity of alpha-chymotrypsin and alpha-chymotrypsin-like enzymes. The product, generated by the enzyme action, Dns-L-phenylalanine, was clearly separated from the ester substrate by micro reversed-phase high-performance liquid chromatography. The substrate was highly stable under the enzyme assay conditions used. As little as 0.15 ng of alpha-chymotrypsin and 1.49 ng of subtilisin BPN' could be detected when a long reaction time was employed. Hydrolyses of the substrate by alpha-chymotrypsin and alpha-chymotrypsin-like enzymes were blocked by specific inhibitors of the enzymes.

Chromatography, High Pressure Liquid↗
PubMed1983

Lyt phenotype of lymphocytes producing murine macrophage chemotactic lymphokine.

Normal or alloantigen (irradiated C57BL/6 mouse spleen cells)-immunized C3H/HeN mouse spleen cells, and dinitrophenyl ovalbumin (DNP-OA)-immunized C3H/HeN mouse lymph node cells were tested after treatment with anti-Thy-1.2, anti-Lyt-1.1, or anti-Lyt-2.1 antibody in the presence of complement for their ability to produce macrophage chemotactic lymphokine in response to stimulation with either mitogen (concanavalin A) or specific antigens. When normal spleen cells were stimulated with Con A or immunized cells were stimulated with specific antigens, it was found that the Lyt-1+2-T-cell subpopulation was primarily responsible for the macrophage chemotactic lymphokine production by T cells.

Animals↗
PubMed1983

Production of two lymphocyte chemotactic factors by antigen-stimulated guinea pig lymphocytes.

Lymph node cells from guinea pigs sensitized by BCG elaborated two chemotactic factors for lymphocytes when stimulated with purified protein derivative in vitro 4 weeks after immunization. Production of the factors occurred within 24 h of incubation. The two factors were termed alpha- and beta-lymphocyte chemotactic factors (alpha-LCF, beta-LCF), relative to their elution order on gel chromatography. The molecular weights were about 160,000 and 27,000, respectively. alpha-LCF was labile to heating at 56 degrees C for 30 min. Both factors were sensitive to digestion by trypsin, and were effective for T cells but not for B cells.

Animals↗