Biomedical subjects
Publications and source records attributed to Y Horiguchi.
Guinea-pigs were fed diets containing 48, 200 or 2000 mg/kg ascorbic acid (AsA) for 20-30 days and given a single oral dose of 50 mg N-nitrosopiperidine (NPIP)/kg body weight. The levels of glutaric acid, 3-hydroxy-NPIP and 4-hydroxy-NPIP, but not of 1,5-pentanediol, in urine increased with the dose of AsA in the diet.
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Histological examination of ultraviolet light (UVL)-induced blister formation in guinea pig skin is reported. Light and electron-microscopic examination was performed on skin exposed to single and multiple exposures of a large dose of UVB. In light microscopy, intracellular edema was prominent, especially in the lower part of the epidermis, where it developed into a blister. It seemed to be a subepidermal bulla. The PAS-positive basement membrane was observed at the floor of the blister. The positive Nikolsky's sign seemed to be due to a separation between the degenerated and regenerated epidermis. Electron microscopy revealed a marked intercellular as well as intracellular edema and well-preserved desmosomes. The basal lamina was always located at the floor of the blister. The difference in UVL-induced blister formation between normal and pathological conditions is discussed.
We investigated the role of extracellular Ca2+ in the Clostridium perfringens enterotoxin-induced alteration of the permeability of the plasma membrane. Enterotoxin released 86Rb and 51Cr from the Vero cells preloaded with the isotope. In the presence of EGTA, however, it released 86Rb but not 51Cr. The binding of enterotoxin to the cells was not influenced by Ca2+ or Mg2+. The effects of various cations on the enterotoxin-induced 51Cr release was also studied. The release depended on extracellular Ca2+ but not on Mg2+; it was inhibited by each of Zn2+, La3+ and Co2+. Zn2+ and Co2+ also inhibited 51Cr release caused by the enterotoxin previously bound to the cell membrane. In contrast, antibody against enterotoxin did not neutralize the toxin once it was bound to the Vero cells. When the cells were treated with enterotoxin, 45Ca influx occurred and reached the plateau in a few minutes, as did 86Rb release.
The ultrastructural localization of immunoglobulin deposits in the dermoepidermal junction of MRL/l mice was examined using immunoperoxidase staining. All specimens that showed positive findings at the basement membrane zone of the skin on light microscopy had reaction products at the sub-basal laminar area when observed by electron microscopy. In the skin that had no distinct eruptions or which was distant from the lesions, the reaction products were distributed mostly just beneath the basal lamina in fine to course granular deposits. In the lesional skin, they formed a rather uniformly granular pattern among the irregularly arranged collagen fibrils and increased fine fibrillar amorphous material under the highly infolded basal lamina. Some of the reaction products were located just on the collagen fibrils and some appeared to be related to the free basal lamina. From the perspective of immunoelectron microscopy, the skin eruptions of MRL/l mice may serve as a good dermatological model of human systemic lupus erythematosus.
Chemical studies were performed on all or part of four X-ray translucent (nonopaque) concretions and one protein plug to investigate a possible relationship between these substances, and to find the similarities and differences between these materials and pancreatic stone protein. Through elemental analysis, infrared absorption spectrometry, quantitative analysis of protein, and amino acid analysis, nonopaque concretions and protein plug were found to consist mainly of protein. One nonopaque concretion contained a very small amount of crystalline which differed greatly from calcite type calcium carbonate as observed in pancreatic calcified stones. The pattern of amino acid composition was very similar between the concentrations and the protein plug: rich in acidic amino acids, but poor in basic and aromatic residues. The aspartic acid content was the highest among detected amino acids. Comparison of amino acid composition between the nonopaque concretions which we analyzed and the pancreatic stone protein reported from Sarles' laboratory suggested that the concretions seem to contain some stone protein.
A 16-month-old boy exhibited vesicobullous skin lesions on the lower part of his abdomen, in his genital region, and on the buttocks and extremities. The eruptions presented small, tense bullae with or without erythematous changes of the surrounding skin, some of which clustered around the resolving lesions. Histologic examination of the eruptions showed subepidermal, ultrastructurally suprabasal laminar blister formation with infiltration of the polymorphonuclear cells and large mononuclear cells in the blister cavity. Immunoelectron microscopy revealed IgA deposits at the basilar surface of the basal keratinocytes of the lesional skin, as well as the presence of circulating IgA-class antibodies reacting to the basilar surface of the hemidesmosomes. The eruptions responded well to a combination therapy of small doses of a corticosteroid agent and a sulfonamide. There were neither clinical nor laboratory findings suggesting dermatitis herpetiformis. This case, diagnosed as linear IgA bullous dermatosis of childhood by immunofluorescence microscopy, ultrastructurally had a pathogenic site close to that observed in bullous pemphigoid.
We prepared a mouse monoclonal antibody that reacts specifically to human Langerhans cells (LC). The protein recognized by this antibody was mainly in the membranes of Birbeck granules and related structures. Using this antibody, we could identify LC in various tissues; these cells were in the skin, stratified squamous mucosal epithelia, lymph nodes, and the thymus. The antibody did not react with monocytes, tissue macrophages, lymphoid dendritic cells, follicular dendritic cells, or interdigitating cells. The antigen purified with this antibody was a heterogeneously glycosylated protein of Mr approximately 40,000 without interchain disulfide bonds. This antibody may be useful for identifying LC in various human tissues with or without abnormalities, and for studying the origin and fate of Birbeck granules of LC.
The immunoelectron microscopic reaction products showing in vivo bound immunoglobulins or complement in the basement membrane zone (BMZ) of the lesional skin of 12 patients with bullous pemphigoid (BP) were homogeneously distributed in the lamina lucida in 3 cases, just beneath the basilar surface of the basal cells in 5 cases, and were associated with the basal lamina in 4 cases. No reaction products could be found beneath the melanocytes in any of the first 2 groups; however, positive reaction products were found on the basal lamina beneath some melanocytes, and were associated with the detached basal lamina in the dermis in the latter 4 cases. In vitro binding sites of circulating anti-BMZ antibodies in the sera from 7 patients with BP indicated that the antibodies reacted with the basilar surface of the hemidesmosomes, with a weak reaction on the basal lamina in 5 cases and with no reaction in 2 cases. No positive findings were obtained beneath the melanocytes or on the basal lamina under the melanocytes. The discrepancy between the antigenic sites and the localization of immune deposits in BP is assumed to be due to the renewal of the hemidesmosomes and constant clearance of immune deposits in vivo. The in vivo bound immunoglobulins and complement seen in the BP skin are the result of their accumulation in the lamina lucida or in association with the basal lamina.
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Bone marrow aspirates from 10 patients with multiple myeloma (6 IgG myeloma, 3 IgA myeloma, 1 Bence Jones myeloma) were examined for nucleolus-associated localization of J chains. On light microscopy using the PAP method, almost all or a significant number of myeloma cells exhibited intranuclear spots stained with anti-J chains in 3 (IgG myeloma) out of the 8 cases positive for cytoplasmic J chains. In contrast, the nucleus of myeloma cells examined was constantly negative for anti-heavy and -light chains. Immunoelectron microscopically, J chain was identified as dicrete round electron-dense precipitates, corresponding to the whole nucleolus, and as sparsely distributed, small electron-dense deposits in the nucleus. In addition, some connections were found between nuclear and nucleolar electron-dense precipitates. Several possible explanations have been proposed to account for this localization of J chains.
Four hybridoma cell lines producing monoclonal antibodies to Clostridium perfringens enterotoxin were established by fusion of mouse myeloma and spleen cells obtained from mice immunized with the enterotoxin and its toxoid. An enzyme-linked immunosorbent assay indicated that the two antibodies, 2-B-4 and 3-G-10, bound to those regions that were located close each other; the others, 3-B-2 and 2-H-2, bound to other independent regions on the enterotoxin. Release of 51Cr from Vero cells with the enterotoxin was inhibited by either 2-B-4 or 3-G-10, both of which inhibited the binding of 125I-labeled enterotoxin to the cells. Neither binding nor cytotoxicity of the enterotoxin was affected by 2-H-2; 3-B-2 only barely inhibited the binding but neutralized the enterotoxin shown by 51Cr release. It seems justified to conclude that 3-B-2 blocks the toxic action after the enterotoxin has bound to Vero cells.
The mechanisms of the marked inhibitory effects of 10 ppm formaldehyde (HCHO) inhalation on heart rate and respiratory movement were investigated in unanesthetized rabbits. Inhibition of the heart rate and respiratory movement induced by HCHO inhalation was caused by a reflex reaction during sensory irritation of the upper respiratory tract, mainly the nasal mucosa, but not of the lower respiratory tract, mainly the lung. These reflex reactions, particularly decreases in the heart rate, were not blocked by vagotomy, atropine or prazosin, but were blocked by propranolol, phenoxybenzamine, phentolamine, yohimbine and guanethidine. These results suggest that these reflex reactions are derived from sympathetic nervous activity rather than parasympathetic nervous activity, and the reflex bradycardia is caused by inhibiting the transmitter release at the adrenergic nerve endings.
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Thirty-eight biopsy specimens from 18 cases of bullous pemphigoid (BP) were observed using direct immunofluorescence (IF) techniques with fluorescein isothiocyanate (FITC)-labelled antisera against human serum factors. In addition to deposits of immunoglobulins and serum components at the basement-membrane zone (BMZ), 15 specimens from eight cases displayed homogeneous and globular fluorescent bodies in the uppermost dermis and/or the blisters when FITC-labelled antisera to human IgM and other serum factors were used. Using immunoperoxidase staining, haematoxylin/eosin (HE) and periodic acid-Schiff (PAS) staining, these immunoglobulin and/or complement-positive cell-sized bodies were shown to be slightly eosinophilic and PAS positive. Electron microscopy revealed entangled networks of microfilaments approximately 7-8 nm in diameter. These homogeneous, fibrillar bodies were histologically, immunohistologically and ultrastructurally indistinguishable from the colloid bodies found in lesional skins of lichen planus, lupus erythematosus, dermatomyositis and several other dermatoses. In BP, degenerated keratinocytes adjacent to the blister roof, may, after undergoing a filamentous change, drop off into the dermis and subsequently form homogeneous, fibrillar bodies in the uppermost dermis when reepithelization is completed.
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