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S Shimada

Publications and source records attributed to S Shimada.

At least 361 records · Page 20Linked to original sources
PubMed1987

Nicotinamide N-oxide reductase activity in bovine and rabbit eyes.

The nicotinamide N-oxide reductase activity of a variety of ocular tissues was investigated. The 9,000g supernatant of ciliary body, retinal pigment epithelium-choroid, iris, retina and cornea, but not lens, exhibited reductase activity under anaerobic conditions when supplemented with 2-hydroxypyrimidine, an electron donor of aldehyde oxidase. Among these tissues, the highest activity was observed with ciliary body. When the 9,000g supernatant of ciliary body was fractionated, the 2-hydroxypyrimidine-linked reductase activity was mainly associated with the cytosolic fraction and was markedly inhibited by menadione, an inhibitor of aldehyde oxidase. Similarly, in the presence of 2-hydroxypyrimidine, the cytosolic fraction of rabbit ciliary body exhibited nicotinamide N-oxide reductase activity which was susceptible to inhibition by menadione. These facts strongly suggest that aldehyde oxidase present in mammalian eyes is involved in the reduction of nicotinamide N-oxide to nicotinamide.

Aldehyde Oxidase↗
PubMed1987

Surfactant replacement therapy: clinical and experimental studies.

Surfactant replacement therapy has been investigated extensively both in animal models and clinical studies. Although not yet available for routine clinical treatment, surfactant replacement in HMD holds great promise. This article reviews the current literature in this area.

Animals↗
PubMed1987

Pulmonary surfactant replacement in respiratory distress syndrome.

Exogenous surfactant therapy in infants with HMD leads to dramatic improvement in oxygenation and disease course. Both prophylactic and rescue treatments have shown a significant reduction in morbidity and mortality from the disease. There are several questions yet to be answered regarding the most effective surfactant, the appropriate time of treatment, and the appropriate dose, as well as the number of treatments required. Based on the available data, surfactant TA has shown promising and consistent results. Another important question to be answered is the role of surfactant in milder cases of HMD and its impact on the cost of hospitalization. Hopefully, future studies will be able to provide answers to these questions.

Humans↗
PubMed1986

In vivo treatment with anti-I-A antibodies: differential effects on Ia antigens and antigen-presenting cell function of spleen cells and epidermal Langerhans cells.

The in vivo activation of T cells by a variety of antigens can be inhibited by the administration of anti-I-A antibodies (Ab) at the time of antigen priming. This inhibition can partially be explained by the temporary loss of Ia molecules from Ia-bearing antigen-presenting cells (APC) in the spleen. In this study, the effects of i.p. injected monoclonal Ab specific for I-A glycoproteins of different H-2 haplotypes on Ia antigen expression and APC function of spleen cells and epidermal Langerhans cells were compared. It was found that anti-I-A Ab quickly bound to both spleen cell and Langerhans cell Ia antigens. Although spleen cell Ia antigens were modulated and thus temporarily disappeared, Ia antigen expression by epidermal Langerhans cells was not modulated. In functional studies, the capacity of spleen cells and epidermal cells from anti-I-A Ab treated vs control animals to function as APC for antigen-specific, I-A- or I-E-restricted T cell clones was tested. A single injection of anti-I-A Ab completely abolished the APC function of spleen cells as shown in several inbred mouse strains, F1 animals, and with the use of several different Ab and T cell clones. In contrast, Langerhans cell-dependent APC function of epidermal cells remained completely unaltered. Even multiple injections of high doses of Ab never caused any inhibition of Langerhans cell function. Experiments with anti-I-Ak or anti-I-Ad Ab in an (H-2k X H-2d)F1 animal showed abrogation of APC function of spleen cells, but again not of Langerhans cells. Thus in vivo anti-I-A Ab administration appears to differentially affect Ia antigen expression and APC function from spleen and epidermis: Ia antigens are modulated from spleen cells but not from epidermis, and APC function disappears in the spleen but not in the epidermis. The abrogation of splenic but not of Langerhans cell APC function with anti-I-A Ab will facilitate the dissection of the relative contributions of Langerhans cells as compared with other APC in the generation of cutaneous immune responses.

Animals↗
PubMed1986

Immunohistochemical detection of glycogen phosphorylase isoenzymes in rat and human tissues.

Glycogen phosphorylase has at least three isoenzymes, i.e. muscle-, liver-, and brain-types. Antibodies have been raised against highly purified isoenzymes from rat muscle, liver and brain and found to react specifically to extracts from human muscle, liver and brain, respectively. Using these antibodies and the unlabelled antibody-enzyme method, each of the three isoenzymes has been localized in both rat and human tissues.

Animals↗
PubMed1986

Sensitive double-labeling technique of retrograde biotinized tracer (biotin-WGA) and immunocytochemistry: light and electron microscopic analysis.

We developed a simple method to identify fiber projections that contain bioactive substances using biotinized wheat-germ agglutinin. Tracer that accumulated retrogradely in the soma was made visible under the light microscope by linking it with streptavidin-Texas red, which has a red fluorescence, while antigen was demonstrated in the same section by indirect immunofluorescence using fluorescein isothiocyanate with green fluorescence as a marker. Under the electron microscope, the tracer was identified using streptavidin-colloidal gold particles, while the antigen was demonstrated in the same ultrathin section using the peroxidase-antiperoxidase technique. This method makes it possible to demonstrate the locations of both the biotinized retrograde tracer and the antigen in the soma of the same neuron at both light and electron microscopic levels.

Animals↗
PubMed1986

Ia+ murine epidermal Langerhans cells are deficient in surface expression of the class I major histocompatibility complex.

Murine epidermal Langerhans cells were analyzed with fluorescence microscopy and multicolor flow cytometry for the surface expression of major histocompatibility complex (MHC) class I and class II antigens. Langerhans cells of H-2k haplotype were identified in situ or in epidermal-cell suspensions by their surface expression of the MHC class II determinants I-Ak and I-Ek. More than 90% of class II-positive Langerhans cells in epidermal-cell suspensions expressed no or barely detectable amounts of MHC class I antigens. Quantitation by flow cytometry revealed that H-2k Langerhans cells expressed only 1.6-3.3% as much H-2Kk as did class II-negative keratinocytes in the same epidermal-cell suspensions. By fluorescence microscopy, class I MHC antigens were not detectable on Langerhans cells in situ when analyzed on sheets of intact epidermis. The deficient expression of class I MHC permitted highly purified Langerhans cell populations to be isolated from epidermal cell suspensions by treatment with anti-class I MHC monoclonal antibody and complement. It is likely that the uniquely low cell-surface expression of class I MHC antigen by Langerhans cells has relevance to both immune responses in the skin as well as to mechanisms of skin allograft rejection. In addition, it is conceivable that regulation of class I MHC expression on antigen-presenting cells in general is an important but hitherto unrecognized mechanism of immune regulation.

Animals↗
PubMed1986

Isolation and amino acid sequence of a peptide containing an epoxide-reactive residue from the thermolysin-digest of Scytalidium lignicolum acid protease B.

Scytalidium lignicolum acid protease B, a pepstatin-insensitive acid protease, was modified by 1,2-epoxy-3-(p-nitrophenoxy)propane (EPNP) with the concomitant loss of its enzyme activity, and an EPNP-labeled peptide was isolated from the thermolysin-digest of the modified enzyme by HPLC. The amino acid sequence of the peptide was determined to be Ile-Leu-Glu-Thr-Gly, which corresponds to the sequence of residue Nos. 51-55 of the enzyme. The results of treatment of the labeled peptide with hydroxylamine suggested that the EPNP moiety is ester-linked to Glu53 of the enzyme. The amino acid sequence around Glu53 of the acid protease B showed high homology with those around the active site Asp residues of calf chymosin and porcine pepsin. These results show that it is highly possible that Glu53 of the acid protease B is one of the amino acid residues involved in its catalytic activity.

Amino Acid Sequence↗
PubMed1986

Immunologic aspects of acute cutaneous graft-versus-host disease: decreased density and antigen-presenting function of Ia+ Langerhans cells and absent antigen-presenting capacity of Ia+ keratinocytes.

Cutaneous graft-versus-host disease (GVHD) provides a unique model for studying the pathogenesis of several important lymphocyte-mediated skin diseases. Morphologic studies have suggested that Ia antigen (Ia)-bearing epidermal Langerhans cells (LC) may be specific targets for destruction in these conditions. Keratinocytes synthesize and express Ia in GVHD and some other lymphocyte-mediated skin disorders; Ia+ keratinocytes, constitutively able to secrete epidermal cell-derived thymocyte activating factor (ETAF)/interleukin 1, may possess antigen-presenting capacity, thus leading to enhanced cutaneous immune responses and disease chronicity. We therefore investigated the fate of Ia+ LC, and the potential antigen-presenting capacity of Ia+ keratinocytes, in a murine model of GVHD. Lethally irradiated C3H/He (H-2k) mice developed acute cutaneous GVHD, and expressed keratinocyte Iak, 8 days after injection of BALB/c (H-2d) bone marrow and spleen cells. Immunofluorescence studies showed a progressive decrease in the density of Ia+ epidermal LC during the evolution of GVHD. This decrease was paralleled by a progressive reduction in the allostimulatory capacity of GVHD epidermal cells (EC) in the allogeneic EC-lymphocyte reaction (ELR). The fall in the density of Ia+ LC, and in EC allostimulatory capacity in both primary and secondary ELRs, was consistently greater in GVHD mice than in mice treated only with x-irradiation. The allostimulatory capacity of GVHD and x-irradiated EC could not be restored by addition of indomethacin or exogenous ETAF to ELR cultures. The decreased allostimulatory capacity was not the result of inhibition of the ELR, since EC from GVHD and x-irradiated mice did not cause suppression when added to control ELR cultures. The capacity of EC to present ovalbumin, purified protein derivative of tuberculin, 2,4,6-trinitrobenzenesulfonic acid coupled to EC, and native cytochrome c (CYTc) to antigen-specific T-cell lines, clones, or hybridomas was reduced in x-irradiated mice and markedly decreased in GVHD mice. The capacity of EC from x-irradiated and GVHD mice to present CYTc fragment 81-104, which does not require further processing or catabolism by accessory cells, was similarly decreased. Taken together, the results indicate that: the function of LC is markedly and progressively impaired in acute GVHD; LC function is also decreased, but to a lesser extent, following x-irradiation alone; and Ia+ keratinocytes from lethally irradiated mice undergoing GVHD do not exhibit antigen-presenting capacity.

Acute Disease↗
PubMed1986

Development and characterization of trinitrophenyl-specific L3T4+ T-cell clones.

Two antigen-specific, L3T4+, Lyt-2- T-cell clones have been developed from (C57BL/6 x C3H/HeN) F1 mice epicutaneously sensitized to trinitrochlorobenzene. Genetic mapping and antibody blocking studies demonstrated that both of these clones have specificity for trinitrophenyl in association with Ek beta:Ek alpha or Eb beta:Ek alpha Ia molecules. One of the clones (D-8) also recognizes nonhaptenated cells expressing Es beta:Ek alpha. These clones should provide useful tools for the assessment of the signals required for triggering immune responses to haptenated self antigens.

Animals↗
PubMed1986

The production of a cytotoxic factor by mouse peritoneal macrophages and macrophage hybridomas treated with various stimulating agents.

Murine peritoneal macrophages elicited with a streptococcal preparation, OK-432, produced as much of a cytotoxic factor after stimulation with lipopolysaccharide (LPS) as BCG-elicited macrophages did. Proteose peptone-elicited macrophages produced a very small amount, if any, of the factor, and resident peritoneal macrophages did not release it at all even after LPS-stimulation. A newly established macrophage hybridoma, D/O-3.3, produced the factor after LPS-stimulation, but another hybridoma, D/O-3.2, did not. Experiments using these peritoneal macrophages and macrophage hybridomas demonstrated that macrophages can be divided into three subpopulations with regard to stages of activation for production of the cytotoxic factor. The first is fully activated macrophages which produce the factor after stimulation with LPS or MAF-C alone, the second is partially activated macrophages which produce the factor only after stimulation with a combination of recombinant interferon-gamma (rIFN-gamma) and LPS or rIFN-gamma and macrophage activating factor for cytotoxicity (MAF-C), and the third is nonactivated macrophages which cannot produce the factor at all.

Animals↗
PubMed1986

Induction of in vitro antigen-specific antibody production against NIP-KLH in nonadherent cells derived from human peripheral blood mononuclear cells.

A primary in vitro antibody response to 4-hydroxy-3-iodo-5-nitrophenylacetyl keyhole limpet hemocyanin (NIP-KLH) by plastic dish nonadherent human peripheral blood mononuclear cells (PBMC) was examined. Nonadherent cells of most donors produced an anti-NIP antibody when they were cultured with the antigen at a cell density of 2.5 X 10(6)/ml in the presence of Staphylococcus aureus Cowan I (SAC) at a concentration of 0.003% for 5 days, washed and further cultured in the absence of the antigen and SAC for an additional 5 or 6 days. Nonadherent cells of 'low-responders' responded to NIP-KLH plus SAC and produced anti-NIP antibody when they were cultured with not only NIP-KLH plus SAC but also with the culture supernatant obtained on phytohemagglutinin (PHA) stimulation of a mixture of PBMC from 2 donors. Furthermore, it was found that the PHA supernatants could be very effectively substituted for by human recombinant interleukin-2.

Antibody Formation↗
PubMed1986

A 13-year follow-up study of rheumatic valvular diseases.

A 13-year follow-up study was performed in 301 patients with rheumatic heart disease (RHD). Of these patient, 223 cases, 78 men (average age 59.3 years) and 145 women (average age 60.4 years), survived. Seventy-eight cases including 38 men (mean age of death 72.5 years) and 40 women (mean age of death 64.8 years) died. RHD consisted of 51% mitral valvular diseases, 40% combined valvular diseases and 9% aortic valvular diseases. The mean mortality for all patients with RHD was 25.9%. Seventy percent of the deaths were due to severe, chronic heart failure, sudden death and cerebral emboli. Atrial fibrillation was observed in 50% of the patients. Cerebral emboli occurred frequently in patients with mitral stenosis (MS), mitral stenoregurgitation (MSR) and combined valvular disease (CVD), which were associated with atrial fibrillation. However, cerebral emboli were rarely found in cases with MSR, CVD and aortic valvular disease with sinus rhythm. The mortality of cardiac surgery was low, 13.3%.

Adult↗
PubMed1986

In vivo augmentation of natural killer cell activity with a deoxyribonucleic acid fraction of BCG.

A fraction extracted from BCG and designated MY-1, which was composed of 70.0% DNA and 28.0% RNA, was previously reported to possess strong antitumor activities against various syngeneic mouse and guinea pig tumors. An intraperitoneal injection of MY-1 (100 micrograms) 1 day before rendered mouse peritoneal cells cytotoxic to YAC-1 cells. The effector cells were nonadherent to plastic dishes, and the activity was destroyed by treatment with anti-asialo GM1 antiserum plus complement or carrageenan in vitro, but not with carbonyl-iron or anti-Thy 1.2, suggesting that the cells are natural killer (NK) cells. In vivo augmentation of NK activity was dependent on MY-1 dose, and reached the peak 1 day after MY-1 injection. Since NK activity in lipopolysaccharide (LPS)-nonresponder mice could be augmented by MY-1, the possibility that LPS contaminated the MY-1-augmented NK was excluded. MY-1 digested preliminarily with DNase lost its NK-inducing activity, suggesting that the DNA entity of MY-1 was essential for the activity. When mice were pretreated with anti-asialo GM1 or carrageenan, MY-1 could not render the peritoneal cells cytotoxic. Antitumor activities of MY-1 were also abolished if the animals were pretreated with anti-asialo GM1 antiserum or carrageenan, suggesting that the activities can be ascribed mainly to activated NK cells.

Animals↗