Biomedical subjects

J Asai

Publications and source records attributed to J Asai.

At least 19 recordsLinked to original sources

PubMed1997

Bronchiolitis obliterans in ataxia-telangiectasia.

Pulmonary disease was studied in four patients with ataxia-telangiectasia. Immunodeficiency was characterized by lymphopaenia, hypo-gammaglobulinaemia and decreased T-cell response to phytohaemagglutinin stimulation in mixed lymphocyte cultures. All four patients died from respiratory failure. Autopsy revealed that all four patients suffered from bronchiolitis obliterans in all lobes. Immunohistochemical examination demonstrated expression of MHC class II antigens on bronchiolar epithelium. Pulmonary infections in ataxia-telangiectasia patients included a case of mycoplasma pneumonia, one of cytomegalovirus pneumonia and one of Pseudomonas aeruginosa infection. The aetiology and immunological background of bronchiolitis obliterans are discussed. Bronchiolitis obliterans is a characteristic finding in ataxia-telangiectasia and may be due to the underlying immune deficit.

Adolescent↗

PubMed1997

Effect of reactive oxygen species on the elastin mRNA expression in cultured human dermal fibroblasts.

The effects of ultraviolet A (UVA) and reactive oxygen species (ROS), generated by a xanthine and xanthine oxidase (XOD) system, on the mRNA expression of elastin, were investigated using cultured human dermal fibroblasts. Total RNA was isolated and subjected to Northern blot analysis using synthesized 530 base cDNA probe for elastin with primers derived from exon 10 and 1 of human elastin. UVA irradiation did not affect elastin mRNA expression. In contrast, ROS resulted in a dose-related increase in the level of elastin mRNA up to 1.8-fold in cultured human dermal fibroblasts. Catalase, used as scavenger, essentially prevented the ROS induced alterations in elastin mRNA levels. These results suggest that ROS produced in the dermis may contribute to elastin deposition observed in photoaging skin.

Blotting, Northern↗

PubMed1997

Reduction of the DTH response is related to morphological changes of Langerhans cells in mice exposed to acute immobilization stress.

There is a large body of evidence indicating that stress influences immune competence. For example, psoriasis and atopic dermatitis may be exacerbated by psychic stress and related to abnormalities in the cellular constituents of the immune system in the skin. However, the underlying mechanisms remain unclear. We therefore investigated the potential of acute immobilization stress to affect the DTH response in BALB/c mice. DTH was significantly reduced in an immobilization time-dependent manner when stress exposure was just before sensitization. Although the number of Langerhans cells (LC) did not change under these conditions, marked alteration of LC morphology was observed with a significant decrease in area. Recovery of LC was observed within 24 h when the DTH response was also restored. Expression of the calcitonin gene-related peptide (CGRP), which inhibits LC antigen presentation, was significantly increased up to 1.6-fold in nerve fibres of immobilized mice. We conclude that stress-induced suppression of DTH could be due to reduction of LC antigen presentation with morphological change in association with CGRP elevation.

Acute Disease↗

PubMed1997

Relationship between local immune response to Helicobacter pylori and the diversity of disease: investigation of H. pylori-specific IgA in gastric juice.

In order to evaluate the relationship between local immune response to Helicobacter pylori and the diversity of disease, 77 asymptomatic subjects who underwent a health examination were studied. Helicobacter pylori-specific IgG in serum and H. pylori-specific IgA in gastric juice were measured by ELISA, and the measured IgA titre was classified into two grades, low or high. Histological classification of gastritis was performed according to the Sydney system. Cytokines in gastric juice were also measured, and the cytotoxin-associated gene A (cagA) status of H. pylori was tested by PCR. Of the 65 subjects who were positive for H. pylori-specific IgG in serum, 38 (58.5%) were classified as H. pylori-specific IgA low titre in gastric juice and 27 (41.5%) had high titres. In the IgG-positive, IgA-low group, the rate of peptic ulcers (especially duodenal ulcers) in endoscopic findings was higher (P < 0.05); the score of activity and the density of H. pylori were higher (P < 0.001 and P < 0.05, respectively); the score of metaplasia was lower (P < 0.05); and the level of interleukin-1 beta was lower (P < 0.05) than in the IgG-positive, IgA-high group. The positive rate of the cagA gene was 84.4% and there was no significant difference between the two groups. There were differences in endoscopic and histological findings between the IgG-positive, IgA-low and the IgG-positive, IgA-high groups. It is suggested that persons infected with H. pylori can be divided into two different states of disease according to local immune response.

Antibodies, Bacterial↗

PubMed1997

Immunohistochemical study of necrotizing lymphadenitis: a possible mechanism for apoptosis involving perforin and granzyme-producing cytotoxic T cells.

Twelve lymph node specimens with necrotizing lymphadenitis and which had florid necrotic lesions were studied immunohistochemically. The majority of viable lymphoid cells in the necrotic foci were CD8+ lymphocytes and KP1+ or PGM1+ phagocytizing macrophages. The CD8+ T cells were Leu1+, Leu2+, Leu3-, Leu4+, Leu5b+, Leu7-, Leu11b- and Leu19-, indicating a suppressor/cytotoxic T cell phenotype. In addition, the cytoplasm of these cells was immunoreactive for perforin and granzyme B in a granular pattern. With a nick end-labeling technique, fragmented nuclei and some lymphoid cell nuclei were positively stained. These results suggest that the necrosis in necrotizing lymphadenitis is apoptotic necrosis of T cells targeted by CD8+, perforin and granzyme-producing, activated cytotoxic T cells, supporting a viral infection etiology.

Apoptosis↗

PubMed1997

Monoclonal antibodies against mouse splenic stromal cells.

A panel of rat monoclonal antibodies directed against mouse splenic stromal cells were isolated. These monoclonal antibodies were immunohistochemically divided into four groups which reacted with non-lymphoid cells of the murine spleen; (I) in the white pulp, (II) at the marginal zone, (III) in the red pulp, and (IV) on the endothelium of splenic blood vessels. These monoclonal antibodies were studied immunohistochemically in lymphoid organs by means of light and electron microscopy. Monoclonal antibodies SS-4 (group I) reacted with fibroblastic reticulum cells that were distributed only in the white pulp of the spleen and in the follicular areas of lymph nodes. The SS-4 staining cell, in clustered splenic stromal cells, formed colonies which included a small number of Thy-1 positive lymphocytes. Therefore, we concluded that SS-4 staining stromal cells comprise the lymphoid compartment. In contrast, monoclonal antibodies SS-1, SS-3 and SS-5 (group II) reacted with dendritic shaped cells in the marginal zone of the spleen. Examination of splenic extramedullary hematopoiesis in mice rescued by bone marrow transplantation after lethal irradiation revealed that SS-3 and SS-5 reacted with dendritic shaped stromal cells in clonal nodules of engrafted marrow in the red pulp. SS-3 and SS-5 staining cells could not be observed in physiologic hematopoiesis of non-transplanted mice. It was suggested that SS-3 and SS-5 staining stromal cells are involved in primitive hematopoiesis. Monoclonal antibodies SS-2, SS-6 and SS-7 (group III) mainly reacted with dendritic cells and macrophages in the red pulp. Monoclonal antibodies SS-B and SS-9 (group IV) reacted with endothelial cells of blood vessels and sinuses. These findings of heterogeneity in mouse splenic stromal cells are further evidence that specific micro-environments are composed by specialized stromal cells.

Animals↗

PubMed1997

Meningoencephalocele associated with Tripterygium wilfordii treatment.

We treated a male infant with occipital meningoencephalocele associated with the taking of Tripterygium wilfordii. The infant was delivered normally at 38 weeks of gestation with a huge cystic mass protruding from the occiput. He was diagnosed with occipital meningoencephalocele and cerebellar agenesis. His mother had taken T. wilfordii for rheumatoid arthritis early in her pregnancy. T. wilfordii is a herbal medicine used for rheumatoid arthritis and male contraception. Since its toxicity is high and its use during pregnancy is restricted, it is the most likely cause of this infant's anomalies.

Abnormalities, Drug-Induced↗

PubMed1997

Kinetics of fibroblasts in ulcer healing in rats: interference with indomethacin.

OBJECTIVE: The authors reported that the repair of submucosal tissue is important in ulcer healing. The kinetics of fibroblasts have not been well known in gastric ulcer healing. The effect of subcutaneous administration of indomethacin (1 mg/kg) to submucosal tissue was also examined. METHOD: Immunohistological staining was done using the antibodies for the proliferating cell nuclear antigen prolyl 4-hydroxylase and alpha-smooth muscle actin in acetic acid induced gastric ulcers in rats. The terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate-biotin nick end labeling method was also employed. RESULTS: The granulation tissue consisted predominantly of lymphocytes in indomethacin-treated rats. In the control group, proliferative cell nuclear antigen positive cells were at their peak 5 days after ulcer formation (day 5). Prolyl 4-hydroxylase positive fibroblasts were maximal on day 10. Alpha-smooth muscle actin positive myofibroblasts were few on day 5 and increased on day 15. In terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate-biotin nick end labeling, positive cells were sporadically seen on days 20 and 30. In indomethacin-administered rats, the fibroblasts proliferated weakly. The numbers of prolyl 4-hydroxylase and alpha-smooth muscle actin positive spindle-shaped cells were fewer and their appearance delayed. Nick end labeling positive cells were few before day 30 and sporadically observed on days 50 and 80. CONCLUSION: The results indicate that fibroblasts differentiated into several phenotypes and finally underwent apoptosis.

Acetic Acid↗

PubMed1997

[Immunohistochemical and immunogenetic analysis of ocular adnexal lymphoid proliferations].

We examined 20 cases (21 specimens) of ocular adnexal lymphoid proliferations, using the histological, immunohistochemical and molecular genetic methods. The latter two protocols were performed to detect the light chains restriction of immunoglobulin with peroxidase-antiperoxidase (PAP) methods, and the clonality of immunoglobulin heavy chain gene with the hemi-nested polymerase chain reaction (PCR) method, respectively. Although in 8 cases it could not be morphologically determined whether they were neoplastic or not, clonality was revealed in 1 case with immunohistochemistry and in 4 cases with PCR. Two cases showed discordant results between immunohistochemistry and PCR probably due to somatic mutation of the framework region of the immunoglobulin heavy chain gene. Therefore, we, concluded that examination with these methods contribute to a better understanding of the nature of the ocular adnexal lymphoid proliferations. Furthermore, the immunoglobulin gene PCR method is very useful in practical examination, as it can be used with formalin-fixed paraffin-embedded specimens.

Adult↗

PubMed1997

[A case of spontaneous middle cerebral artery occlusion associated with a cerebral aneurysm angiographically disappearing after STA-MCA anastomosis].

We report a case of a rapidly growing cerebral aneurysm in the basal abnormal vascular network associated with spontaneous middle cerebral artery (MCA) occlusion. The aneurysm disappeared spontaneously shortly after performing STA-MCA anastomosis. A 54-year-old female was admitted to our hospital because of repeated attacks of right hemisensory disturbance and dysarthria. CT scan and MRI images showed the infarcted focus in the left parieto-occipital lobe. Bilateral MCAs were undetectable on MRI images. Cerebral angiography revealed that the bilateral MCAs were occluded in their proximal origin with basal abnormal vascular networks. The distal MCA branches were perfused via the vascular networks. A small aneurysm was detected in the distal portion of the left Heubner's artery. There were no abnormalities in the bilateral internal carotid arteries, the anterior cerebral arteries, and the basilar artery. The follow-up angiography performed 29 days after admission revealed a growing aneurysm with a diameter of 3 mm in the distal enhanced lesion consistent with the aneurysm observed in the angiography. An STA-MCA anastomosis was performed for improvement of cerebral misery perfusion. Single photon emission tomography (SPECT) performed 9 days after the bypass operation revealed improvement of cerebral blood flow in the left parieto-occipital lobe, and her TIA attacks disappeared. The aneurysm was undetected in the cerebral angiography performed 24 days after the bypass operation. Spontaneous MCA occlusion is a rare condition of chronic cerebrovascular occlusive diseases. Diagnostic criteria of the disease includes the MCA occlusions or stenosis with basal abnormal vascular networks. Usually the phenomenon is seen unilaterally, which differs from moyamoya disease. Diagnosis must exclude diseases caused by the etiologies such as those of arteriosclerotic origin. There have been 24 reported cases of spontaneous MCA occlusion including our case. Among them, 9 cases presented cerebral aneurysm located in abnormal vascular networks, and all the reported cases presented cerebral hemorrhage at their onset. The abnormal basal vascular network may be developed as collateral vessels to supply blood to the ischemic regions in this disease. An increased hemodynamic stress in the abnormal basal vascular network may produce a true aneurysm in the distal portion of the perforating arteries. STA-MCA anastomosis reduced the TIA attacks, but also decreased the hemodynamic stress on the abnormal basal vascular network and resulted in reduction in size or thrombosis of the aneurysm. STA-MCA anastomosis can be considered effective to treat cerebral aneurysms located in vessels with increased hemodynamic stress.

Arterial Occlusive Diseases↗

PubMed1997

Effect of histamine on human fibroblast in vitro.

The effects of histamine (CAS 51-45-6) on cell growth, collagen synthesis of fibroblasts derived from human foreskin, and on fibroblast-mediated collagen remodelling were studied. The cellmat DNA content was measured 2 days after human fibroblasts were plated at a split ratio of 1:10. Effect of histamine (10(-9)-10(-4) mol/l) on the increase of DNA content was not observed. Fibroblasts at confluence were cultured with histamine only, and with pyrilamine or cimetidine in addition to histamine for 2 h. Type I procollagen C-peptide in the medium was measured by enzyme immunoassay and was corrected by DNA content. Type I collagen synthesis was stimulated by histamine (10(-6)-10(-4) mol/l) and its stimulation was inhibited by cimetidine, but not by pyrilamine. Collagen solution containing fibroblast was incubated until gelation. It was incubated with histamine only, and with pyrilamine or cimetidine in addition to histamine. The gel contraction was stimulated by histamine (10(-4) mol/l) and its stimulation was inhibited by pyrilamine, but not by cimetidine. These facts suggests that histamine stimulates type I collagen synthesis of fibroblast and collagen remodeling via H2 and H1 receptors, respectively.

Cell Division↗

PubMed1997

Structure and function of the hemolymph node in rats.

Hemolymph nodes (HLs) are unique lymph nodes, in that their lymphatic sinuses contain numerous erythrocytes. In this study, we compared the internal structure and immunologic function of HLs with those of ordinary lymph nodes (OLs) and the spleen. Electron microscopy revealed erythrocytes passing through the walls of blood vessels in the intermediate sinus area (IMSA) of a HL between expanded endothelial cell junctions. However, no direct communication was found between lymphatic sinuses and blood vessels. Numerous carbon particles appeared in the IMSA of HLs on 5 days after intravenous carbon particle injection, while OLs lacked particle deposition. Immunohistochemical studies showed that lipopolysaccharide (LPS) reached the IMSA of HLs and extravasated into medullary cords 4 hours after intravenous LPS injection, resulting in the appearance of more IgM-stained lymphocytes in the IMSA of HLs than in that of OLs on day 5. The ability of organs to produce antibodies was determined by counting the number of plaque forming colonies after intravenous injection of sheep red blood cells (SRBC). The HLs antibody-producing ability was between that of OLs and the spleen. These results suggest that HLs possess functionally open blood vessels in the IMSA and their immunologic capability is between that of OLs and the spleen. These findings suggests that HLs are lymphoid organs that have characteristics between those of the OLs and the spleen, both ultrastructurally and functionally.

Animals↗

PubMed1996

The effects of ultraviolet A and reactive oxygen species on the mRNA expression of 72-kDa type IV collagenase and its tissue inhibitor in cultured human dermal fibroblasts.

The effects of ultraviolet A (UVA) radiation and reactive oxygen species (ROS), generated with a xanthine and xanthine oxidase (XOD) system, on collagen enzymatic degradation involving the matrix metalloproteinase (MMP) and its tissue inhibitor of metalloproteinase (TIMP) were investigated using cultured human dermal fibroblasts. Total RNA was isolated and subjected to Northern blot analysis using cDNA clones for human interstitial collagenase (MMP-1), 72-kDa type IV collagenase (MMP-2) and TIMP-2. UVA irradiation resulted in an increase in MMP-1 mRNA up to 2.3-fold, but did not stimulate MMP-2 or TIMP-2 mRNA expression. In contrast, ROS induced by the xanthine and XOD system resulted in a dose-related increase in the level of MMP-2 mRNA up to 2.1-fold and a decrease in the level of TIMP-2 mRNA by 49% in the same fibroblasts. Catalase, used as scavenger, essentially prevented the ROS-induced alterations in MMP-2 and TIMP-2 mRNA levels. These results suggest that ROS produced in the dermis may contribute to biological changes in the connective tissue matrix observed in photoaging skin by accelerating the MMP-2-related matrix degradation system.

Cells, Cultured↗

PubMed1996

Chronic active Epstein-Barr virus infection with giant coronary aneurysms.

Chronic active Epstein-Barr virus infection (CAEBV) is a nonfamilial syndrome that shows a specific immunodeficiency for the Epstein-Barr virus (EBV). Prolonged fever, hepatosplenomegaly, lymphadenopathy, and liver dysfunction were seen in CAEBV, but cardiac complications are rare. An autopsy case of CAEBV with giant coronary aneurysms and aortic aneurysms is reported. The patient was a 5-year-old Japanese girl. At autopsy, the heart weighed 110 g, and bilateral coronary aneurysms were found. Microscopic studies revealed lymphoid vasculitis of coronary arteries, coronary venules, and aortic arteries. Immunohistochemically, infiltrating small lymphocytes were positive for CD3, CD45RO(UCHL-1), CD43(DF-T1). The presence of EBV in most of these T lymphocytes was proven by in situ hybridization using an EBV-encoded RNA-1 (EBER1) probe. To the best of the author's knowledge, pathology of aneurysms caused by lymphoid vasculitis in CAEBV has not been reported until now.

Child, Preschool↗

PubMed1996

Pyothorax-associated lymphoma. An unusual case with biphenotypic character of T and B cells.

Pyothorax-associated lymphoma is known to develop in patients who received an artificial pneumothorax for pulmonary tuberculosis some 30 to 40 years previously. Such patients exhibit large, immunoblastic lymphoma cells and often have a B-cell phenotype. We present a patient with an artificial pneumothorax and such a late developing lymphoma but with the unique finding of aberrant T- and B-cell phenotypes. Southern blot hybridization using immunoglobulin gene JH and T-cell receptor beta chain receptors revealed germline configurations. Lymphomas developing in immunocompromised patients, such as those with acquired immunodeficiency syndrome, may show such unusual phenotypes. The unusual phenotypes found in this patient provide evidence that his pyothorax-associated lymphoma was related to an immunocompromised state.

Aged↗

PubMed1996

Crystallization of an R-form lipopolysaccharide from Klebsiella pneumoniae.

An R-form lipopolysaccharide (LPS) from Klebsiella pneumoniae strain LEN-111 (03-:K1-) formed crystals, whose shapes were elongated hexagonal plates, trapezoid plates, and rhomboid plates, and whose greatest dimensions were 3.1 x 0.8 microns, when it was suspended in 50 mM Tris buffer at pH 8.5 containing 5 mM MgCl2 and kept at 4 C for as long as 870 days. K. pneumoniae LEN-111 synthesized LPS molecules possessing incomplete repeating units of the O-antigenic polysaccharide portion besides the R-form LPS because of a leaky characteristic, but crystals consisted exclusively of the R-form LPS. Although the size of crystals was not large enough for X-ray analysis and limited crystallographic information was available, it was suggested that the crystals consist of hexagonal lattices with an alpha axis of 4.62 A and c axis of 79.8 +/- 2.6 A. The present results showed that R-form LPS lacking the O-antigenic polysaccharide portion tends to form crystals during long-term incubation in Tris buffer at pH 8.5 containing MgCl2 at 4 C.

Crystallography, X-Ray↗

PubMed1996

Effect of the hydroxyl radical on fibroblast-mediated collagen remodelling in vitro.

1. It has been reported that free radicals prevent wound healing. However, the mechanism of this effect is not yet clear. We attempted to clarify the influence of hydroxyl radicals on wound healing in vitro. 2. We used an ascorbate-copper ion system (ACS) to produce hydroxyl radicals in accordance with variables of time elapsed and concentration of copper ion. The effects of hydroxyl radical on fibroblast-mediated collagen remodelling, cell viability, the functions of fibroblasts and collagen fibrils were studied. 3. With a copper ion concentration of 100 mumol/L ACS significantly reduced contraction, while 10 mumol/L stimulated contraction. Hydrogen peroxide (H2O2) was employed in observing these findings. ACS did not influence cell viability, the expression of alpha 2 beta 1 integrin and cellular fibronectin, or the cytoskeletal organization of fibroblasts involving actin until 3 h. A concentration of ACS at 10 mumol/L of copper ion induced the polymerization of collagen after 30 min, while ACS at 100 mumol/L induced collagen degradation; this finding was also established by using H2O2. Collagen reduced the amount of formaldehyde produced by trapping hydroxyl radical with dimethyl sulfoxide. 4. Our findings suggest that collagen is denatured by scavenging the hydroxyl radical before fibroblasts are damaged, so that the radical may influence the remodelling of collagen.

Cell Survival↗

PubMed1996

Kinetics of monocytoid B lymphocytes in localized inflammatory lesions induced by lipopolysaccharide in mice.

Immunohistochemistry was used to study the kinetics of B lymphocytes (B-lys) in the early stages of the localized inflammatory response induced in SMA mice by the subcutaneous injection of lipopolysaccharide (LPS). At the injection sites, medium-sized B-lys formed early inflammatory lesions with neutrophils and activated macrophages on days 1 and 2. The B-lys were morphologically similar to monocytes, but were not stained with Mac1 antibody. Remarkably the B-lys showed the phenotypes of B220+, IgM+, IgD (slight to negative), Ly-1- and CD23- by double immunohistochemical staining. The B-lys were also positive for alkaline phosphatase. Consequently the B-lys could be identified as monocytoid B-lys or marginal zone B-lys. Plasmacytic B-lys and plasma cells were first observed on days 3 and 4, but no lymphoid follicles were found at the injection sites. In the inguinal lymph nodes, the same B-lys responses were mainly induced in the paracortical lesions (T cell areas) preceding the formation of activated germinal centers (GC). These findings suggested that the B-lys, induced by injections of LPS, matured into plasma cells in the localized inflammatory lesions independent of GC, and that they were different from follicular B-lys.

Animals↗