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Biomedical subjects

Y Horiguchi

Publications and source records attributed to Y Horiguchi.

At least 163 records · Page 9Linked to original sources
PubMed1990

Simplified procedure for purification of Bordetella bronchiseptica dermonecrotic toxin.

Bordetella bronchiseptica dermonecrotic toxin was purified by a simplified method. The method consisted of SP Toyopearl 650M chromatography and high performance liquid chromatography on a TSK gel G3000SW column. 47.5% of the activity of the crude cell extract was recovered. The purified toxin behaved as a homogeneous protein in sodium dodecyl sulfate polyacrylamide gel electrophoresis, high performance liquid chromatography, and agar gel double diffusion tests.

Animals↗
PubMed1990

Langerhans cells in human allergic contact dermatitis contain varying numbers of Birbeck granules. Double staining immunohistochemistry with OKT6 and Lag antibody.

Dynamic changes in human Langerhans cells (LCs) were studied with OKT6, anti-HLA-DR antibody, and Lag antibody in allergic contact dermatitis (ACD). Both T6-positive (T6+) cells and Lag-positive (Lag+) cells in the epidermis decreased in number from 0 to 48 h, but then gradually increased after day 7 of ACD. Lag+ cells after day 7 manifested a variety of staining intensities from weak to strong. It was also shown, after day 7, that some T6+ cells were Lag negative whereas all Lag+ cells were T6 positive. Flow cytometric analysis suggested that Lag-strongly-positive cells and Lag-weakly-positive cells belonged to the same population, and that the relative amount of Lag antigens in T6+ LCs gradually increased after day 7. Immunoelectron microscopy revealed that the Lag-strongly-positive cells contained numerous Lag-reactive Birbeck granules (BGs) whereas the Lag-weakly-positive cells contained fewer BGs in the cytoplasm. In some Lag-weakly-positive cells, no BGs were detected.

Adult↗
PubMed1990

Ultrastructural localization of the core protein of a basement membrane-specific chondroitin sulfate proteoglycan in adult rat skin.

Basement membranes are complex extracellular matrices present at epithelial/mesenchymal interfaces of tissues. The dermal-epidermal junction has been shown to contain numerous components, some of the most well known being laminin, types IV and VII collagens, heparan sulfate proteoglycan, fibronectin, and entactin/nidogen. IN this paper we show, using core protein-specific antibodies, the presence of a newly described basement membrane-specific chondroitin sulfate proteoglycan at the epithelial/mesenchymal interface of adult rat skin. Ultrastructurally, this antigen was proven to reside primarily within the basal lamina, apparently concentrated in the lamina densa. In addition, some of the proteoglycan was also present beneath the lamina densa, associated with the reticular lamina collagen fibrils.

Animals↗
PubMed1990

Decreased secretion due to a Ca2+ influx defect in frog peptic cells isolated with EGTA.

Cells prepared from frog esophageal peptic glands by dispersal in low-Ca2+ medium (peptic acini) or 1 mM ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA)-containing medium ("EGTA cells") were compared. EGTA cells were characterized by decreased secretory responses to agonists [bombesin (BB), acetylcholine, and isoproterenol] and intracellular messenger activators (forskolin, 12-O-tetradecanoyl-phorbol-13-acetate), decreased relative intrinsic efficacies of muscarinic agonists, and somatostatin insensitivity. Decreased BB and muscarinic receptor responses were not associated with changes in receptor number or characteristics. The time course of BB- and acetylcholine-stimulated pepsinogen secretion indicated that the marked reduction was confined largely to the late secretory phase (2-30 min), dependent on extracellular Ca2+, rather than early phase (less than 2 min) secretion, which is related to release of intracellular Ca2+. The defect could be reversed by the Ca2+ ionophore A23187. BB-stimulated intracellular Ca2+ mobilization measured with fura-2/AM was similar in the two cell preparations, whereas BB-stimulated 45Ca2+ uptake was reduced threefold in EGTA cells, and this defect was also reversed by A23187. Somatostatin inhibited both BB-stimulated secretion and 45Ca uptake by peptic acini, but it had no significant effect on these parameters in EGTA cells. Cytochalasin B inhibited BB stimulation in peptic acini but not EGTA cells. These findings suggest that peptic cells isolated with EGTA exhibit decreased secretory responses that are due at least in part to impairment of a mechanism for uptake of extracellular Ca2+.

Acetylcholine↗
PubMed1990

Effects of formaldehyde on cardiac function.

This investigation examined the effect of formaldehyde (HCHO) on cardiac function in in vitro cardiac preparations and in situ hearts of guinea pigs and rabbits. Though HCHO (0.2-4 mg/kg, i.v.) produced noticeable bradycardiac and negative inotropic responses in anesthetized guinea pigs and rabbits, the responses to HCHO were far less in isolated guinea pig auricles and perfused hearts (Langendorff's preparations). The inhibitory responses to HCHO in the isolated auricles and perfused hearts were obtained at concentrations 200-400 times and 4-8 times higher than the blood concentrations attained in anesthetized animals, respectively. The responses in the isolated preparations were not significantly affected by propranolol. The bradycardiac response to the intravenously administered HCHO in anesthetized animals was not significantly affected by atropine or vagotomy, but was markedly attenuated by propranolol, reserpine or surgical denervation of the heart. These results indicate that the direct action of HCHO on the heart plays only a small role in the negative chronotropic response to HCHO in anesthetized animals. Furthermore, the negative chronotropic effect of HCHO in animals seems to be caused mainly by the inhibition of sympathetic nervous activity through the central nervous system.

Anesthesia↗
PubMed1990

Production and characterization of monoclonal antibodies against Actinobacillus (Haemophilus) pleuropneumoniae serotype 2.

Four hybridoma cell lines producing monoclonal antibodies (MAbs) against Actinobacillus (Haemophilus) pleuropneumoniae were established by fusion of mouse myeloma and spleen cells obtained from mice immunized with a serotype 2, strain SH-15. Enzyme-linked immunosorbent assay-inhibition tests with antigens obtained from 12 serotype strains of A. pleuropneumoniae and 9 other gram-negative bacteria showed that all the MAbs bound to only serotype 2 strains of A. pleuropneumoniae. The epitopes recognized by the MAbs were located on a carbohydrate moiety of lipopolysaccharide (LPS) of the organism, which was sensitive to periodate oxidation. In immunoblotting analyses of LPS obtained from A. pleuropneumoniae serotype 2, all the four MAbs reacted specifically with the characteristic ladder bands of LPS detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. These results suggest that O-antigen side chains of the LPS are one of the antigenic determinants responsible for the serotype-specificity of A. pleuropneumoniae.

Actinobacillus↗
PubMed1990

Intraepidermal type VII collagen. Evidence for abnormal intracytoplasmic processing of a major basement membrane protein in rare patients with dominant and possibly localized recessive forms of dystrophic epidermolysis bullosa.

Of 84 patients with dystrophic forms of epidermolysis bullosa consecutively enrolled in the National Epidermolysis Bullosa Registry, four were noted by indirect immunofluorescence with the LH 7:2 monoclonal antibody to have granular basilar keratinocyte intracytoplasmic deposits, rather than exclusively linear basement membrane deposits, of type VII collagen. Indirect immunoelectron microscopy demonstrated that these deposits were primarily perinuclear, although lesser amounts were also detectable between tonofibril bundles, within hemidesmosomes, and within and beneath the lamina densa. In two patients the mode of transmission was autosomal dominant; in two others the inheritance pattern was unknown. Whereas widespread lesions were present at birth, in each case blistering ceased within the first year of life, reminiscent of the findings in transient bullous dermolysis of the newborn. We interpret these laboratory findings as indicative of the presence of a defect in the intracytoplasmic packaging or in the transport of type VII collagen within basilar keratinocytes.

Age Factors↗
PubMed1989

The major source of endogenous prostaglandin D2 production is likely antigen-presenting cells. Localization of glutathione-requiring prostaglandin D synthetase in histiocytes, dendritic, and Kupffer cells in various rat tissues.

The cellular localization of glutathione-requiring PGD synthetase, which catalyzes the predominant formation of PGD2 in various peripheral tissues, was investigated in adult rats by immunoperoxidase-staining with a polyclonal antibody specific for this enzyme. Although the 25 N-terminal amino acid residues of synthetase are 56% identical and 76% similar to those of several rat glutathione S-transferase subunits, the antibody cross-reacted only with synthetase in dot blotting and was nearly completely inactive with all transferase isozymes thus far purified. In Western blotting after SDS-PAGE of crude extracts of rat spleen, the antibody showed a single positive band at the same position as that of the purified enzyme (Mr = 26,000). The positive immunocytochemical stain was found in a number of histiocytes and/or dendritic cells in spleen, thymus, and Peyer's patch of intestine. The immunostain was also observed in such cells in lamina propria of the villus in small intestine and colon, in submucosal layer of stomach, and in Kupffer cells in liver. Immunoelectron microscopy confirmed that immunoreactivity of this enzyme was distributed in cytoplasm of those cells. Such immunoreactive cells were not observed in brain, spinal cord, kidney, heart, testis, and skeletal muscle. These observations suggest that PGD2 is produced by glutathione-requiring PGD synthetase localized in these types of APC in various tissues and may play a critical role in dictating the progression of immune responses.

Amino Acid Sequence↗
PubMed1989

19-DEJ-1, a hemidesmosome-anchoring filament complex-associated monoclonal antibody. Definition of a new skin basement membrane antigenic defect in junctional and dystrophic epidermolysis bullosa.

A murine monoclonal antibody (19-DEJ-1) was recently produced that recognizes a unique antigenic epitope of human skin basement membrane localized to the midlamina lucida exclusively in those areas bordered by overlying hemidesmosomes. To determine whether the antigen defined by 19-DEJ-1 is normally expressed in one or more forms of epidermolysis bullosa (EB) known to have structural and antigenic defects in skin basement membrane, we examined by indirect immunofluorescence 46 specimens of clinically normal skin from 43 patients representing each of the four forms of inherited EB (simplex, 15 patients; junctional, nine patients; dominant dystrophic, seven patients; and recessive dystrophic, 15 patients). All nine junctional EB specimens revealed absent 19-DEJ-1 binding; similarly, seven of 15 and one of six recessive and dominant dystrophic EB skin specimens, respectively, showed lack of antibody recognition. In contrast, binding was normal in 15 of 15 EB simplex specimens and five of six dominant dystrophic EB specimens. Absent binding of 19-DEJ-1 to junctional EB skin correlates well with the localization of this antigen to the region of the midlamina lucida. Its absence in approximately 50% of patients with recessive dystrophic EB further suggests, for the first time, that an inherited defect in basement membrane is shared in patients with junctional and some recessive dystrophic EB. The difference in site of skin cleavage in the latter two disorders gives additional support to the hypothesis that 19-DEJ-1 recognizes a structure, such as the anchoring filament, which both bridges the entire basement membrane and contributes to epidermal-dermal adhesion.

Adult↗
PubMed1989

Autosomal recessive epidermolysis bullosa simplex. Generalized phenotypic features suggestive of junctional or dystrophic epidermolysis bullosa, and association with neuromuscular diseases.

With few exceptions, epidermolysis bullosa (EB) simplex is an autosomal dominant disorder characterized by rather localized and recurrent nonscarring blister formation; mucous membranes and other organs are usually uninvolved. Recently, two patients were described with an autosomal recessive form of EB simplex associated with muscular dystrophy. We now describe four additional patients with autosomal recessive EB simplex, three of whom had associated muscular dystrophy or congenital myasthenia gravis. These patients had generalized cutaneous findings, including milia, atrophic scarring, nail dystrophy, and scalp alopecia, which have been classically attributed to either junctional or dystrophic EB. Each patient had significant oral cavity involvement, and in two, marked growth retardation and anemia were also present. Our findings suggest that autosomal recessive EB simplex may be characterized by rather severe cutaneous and extracutaneous disease activity, and may be associated with at least two distinct neuromuscular diseases.

Adult↗
PubMed1989

Synthesis of epidermolysis bullosa acquisita antigen by simian virus 40-transformed human keratinocytes.

The synthesis of epidermolysis bullosa acquisita (EBA) antigen in simian virus 40 (SV40)-transformed human epidermal keratinocytes was studied. Indirect immunofluorescent staining of SV40-transformed keratinocytes employing a serum sample from an EBA patient as a source of antibodies decorated EBA antigen as a perinuclear granular fluorescence. This staining pattern was similar to that of nontransformed epidermal keratinocytes grown in a low Ca2+ medium. In contrast, stratified primary cultures of keratinocytes stained after growth in a high Ca2+ medium showed only small amounts of the antigen localized in the substrate-attached basal cells. To demonstrate biosynthesis of the EBA antigen by SV40-transformed keratinocytes, cells were metabolically labeled with 14C-amino acids and the cell lysates were immunoprecipitated with EBA antiserum. Analysis of immunoprecipitates by sodium dodecylsulfate-polyacrylamide gel electrophoresis and fluorography revealed that the EBA serum precipitated a protein with an apparent molecular weight of 290 kD from extracts of these cells. These results indicate that SV40 induces the synthesis of the 290 kD EBA antigen. Expression of this antigen may be a general feature of nonstratifying, proliferating epidermal cells.

Amino Acids↗
PubMed1989

Entactin: ultrastructural localization of an ubiquitous basement membrane glycoprotein in mouse skin.

Entactin is a recently described sulfated glycoprotein component of mouse endodermal cell-derived extracellular matrix and is present in a number of basement membranes. It has been ultrastructurally localized to both lamina densa and adjacent epithelial cell membranes in rodent kidney. In the present study, we have sought to determine the localization of entactin in mouse skin. Indirect immunofluorescence and immunoelectron microscopy (the latter via immunoperoxidase technique) were performed on both intact and NaCl-separated mouse skin, using a well-characterized IgG class entactin-specific rat x mouse monoclonal antibody. At the light microscopic level, entactin was present in all skin basement membranes. On NaCl-split skin, staining was noted solely on the dermal portion. At the electron microscopic level, in intact skin, entactin was primarily localized to the lamina densa and adjacent upper papillary dermis. However, smaller amounts of immunoreaction products were also detectable within the lamina lucida and in close apposition to overlying hemidesmosomes. In partially separated skin, immunoreactants were similarly noted above the level of the lamina densa. However, in completely separated areas, hemidesmosomal or cell membrane staining was no longer visible. We conclude that entactin is an ubiquitous component of mouse skin basement membranes. Similar to previous findings in rodent kidney, entactin is present in multiple regions of skin basement membrane, although its primary localization remains within and directly beneath the lamina densa.

Animals↗
PubMed1989

Purification and characterization of Bordetella bronchiseptica dermonecrotic toxin.

Dermonecrotic toxin produced by Bordetella bronchiseptica was purified by chromatography on DEAE Toyopearl 650M and on Bio-Gel HTP, gel filtration on Sephadex G-200, and subsequent chromatography on Bio-Gel HTP and on SP Toyopearl 650M. The purified toxin was homogeneous by sodium dodecyl sulfate polyacrylamide gel electrophoresis and high performance liquid chromatography. There was a 90-fold increase in the dermonecrotic titer per mg protein in guinea pigs and the recovery of activity was 17.6% of that of the original cell extract. The purified toxin is a single-chain protein with a molecular weight of 145,000 and an isolelectric point of 6.3-6.7. Its minimal necrotizing dose is approximately 0.4 ng. It was completely inactivated by heating for 20 min at 56 degrees C. It contained no endotoxin, carbohydrates, nucleic acids, or hemagglutinins.

Agglutination↗
PubMed1989

Regressing ulcerative histiocytosis.

A 15-year-old girl presented with many round to oval erythematous indurated plaques on the trunk, scalp, and proximal portion of the extremities. The individual lesions showed ulceration within a short period but spontaneously healed after 2 or 3 months. The main histological feature was dermal proliferation of rather mature histiocytes that were regarded as neither inflammatory nor neoplastic, with subsequent destruction of normal dermal tissue architectures. Lymph nodes, bone marrow, and internal organs were not involved. The lesions were improved neither by potassium iodide therapy nor by combined therapy of corticosteroid and cyclophosphamide, but the patient recovered by clofazimine after a 2-year course. We considered this case to be an unusual form of cutaneous histiocytic proliferation, which we tentatively termed "regressing ulcerative histiocytosis."

Adolescent↗
PubMed1989

Detection and partial characterization of a midlamina lucida-hemidesmosome-associated antigen (19-DEJ-1) present within human skin.

A murine anti-human monoclonal antibody (19-DEJ-1) has been produced that binds to basement membranes (BMs) of the dermoepidermal junction and arrector pili muscles but not to either dermal glandular or vascular BMs. 19-DEJ-1 also recognizes BMs underneath epithelia of buccal mucosa, tongue, esophagus, cervix, and cornea, and BMs surrounding smooth muscle in medium-sized vessels, placenta, uterus, and esophagus. When 16 human fetal skins (aged 54-142 gestational days) were examined, the antigen was first detected at 81 days. Using immunoperoxidase and immunogold staining techniques, indirect immunoelectron microscopy demonstrated localization of 19-DEJ-1 to the level of the midlamina lucida, directly underneath hemidesmosomes; absent staining was noted beneath melanocytes. 19-DEJ-1 antigen was detectable in unfixed A431 cells grown on coverslips. After radioincorporation of 35S-methionine into A431 cells, 19-DEJ-1 monoclonal antibody specifically precipitated 2.75% of the total radiolabeled proteoglycans produced in culture supernatant and isolated by anion exchange chromatography. On the basis of our present findings, we conclude that 19-DEJ-1 monoclonal antibody defines a unique primate-specific proteoglycan that is present within BMs along the epithelial-connective tissue interface and around smooth muscle in skin and other selected organs. Its unique ultrastructural localization suggests the possibility that 19-DEJ-1 may recognize an antigenic epitope of either anchoring filaments or alternatively, the subbasal dense plate.

Antibodies, Monoclonal↗
PubMed1989

Lymphomatoid papulosis: ultrastructural, immunohistochemical and gene analytical studies.

Ultrastructural, immunohistochemical and gene analytical studies were carried out on a 39-year-old patient with lymphomatoid papulosis. Two different cell groups were demonstrated in the papulonodular eruptions: large atypical cells with multiple nuclei that were well stained with anti-Tac, but not with Leu 3a, and other cells that possessed prominent hyperchromatic nuclei and which stained well with Leu I and Leu 3a but not with anti-Tac. Gene analytical studies using EcoRI, BamHI and HindIII revealed no rearrangement, indicating a non-clonal T-cell proliferation unlike malignant T-cell lymphoma. These results suggest that the present case was benign.

Adult↗
PubMed1989

Late onset erythropoietic porphyria.

A 51-year-old Japanese man and his 56-year-old sister of consanguineous parents had skin lesions with areas of dark-brown pigmentation and blisters with minimal trauma on sun-exposed skin which resembled those seen in porphyria cutanea tarda. Their fresh urine was wine-red in colour and fluoresced with ultraviolet light. The peripheral blood contained fluorocytes and porphyrin analysis of the red blood cells, urine and faeces of the patients revealed an increase of the isotype I of uro- and coproporphyrin and normal concentrations of delta-aminolaevulinate and porphobilinogen, suggesting the diagnosis of erythropoietic porphyria. No other members of this family had symptoms or biochemical findings suggestive of porphyria. We consider these two cases to be that of late onset erythropoietic porphyria.

Erythropoiesis↗