Biomedical subjects

S Arai

Publications and source records attributed to S Arai.

At least 217 records · Page 12Linked to original sources

PubMed1995

[Multiple dural arteriovenous shunts presenting as subarachnoid hemorrhage: a case report].

We present here an interesting case of multiple dural arteriovenous shunts (dAVS) in different locations at the same time. There have been very few reports on multiple dAVS. A 63-year-old man was admitted with a sudden onset of headache and vomiting. CT scan showed a typical subarachnoid hemorrhage (Fisher Group 3). Cerebral angiogram (6 vessel study) revealed two dural arteriovenous shunts at the same time. One was located on the anterior fossa fed by the anterior ethmoidal artery, and the other was located on the posterior fossa near the marginal sinus fed by the left ascending pharyngeal and occipital arteries. At first, transarterial embolization was performed for dAVS located on the posterior fossa. Radical operation was performed for both anterior and posterior fossa dAVS. Both dAVS had disappeared on postoperative angiograms.

Cerebral Angiography↗

PubMed1995

[A neonate case of dural arteriovenous shunt presenting with cerebellar hemorrhage].

A rare case of dural arteriovenous shunt (dAVS) manifested as cerebellar hemorrhage in a neonate is reported. Seven days after birth, a neonate was referred to our hospital because of consciousness disturbance. CT scan revealed cerebellar hemorrhage, subarachnoid hemorrhage, subdural hematoma, and a high density mass lesion at the torcular herophili. Retrograde brachial angiogram failed to show any vascular lesions. He underwent an evacuation of the cerebellar hematoma. Postoperative course was uneventful. However, at the age of four months, he was admitted again because of consciousness disturbance and cardiac failure. CT scan revealed hydrocephalus and an enlarged mass lesion at the torcular herophili. Angiogram disclosed dural AVS. Its feeding arteries were as follows; the bilateral middle meningeal arteries (MMA), the occipital arteries (OA), dural branches of the bilateral posterior inferior cerebellar arteries, arteries consisting of transdural anastomosis from the left posterior cerebral artery. The arterial flow from these feeding arteries was shunting directly to the torcular herophili, the posterior part of the superior sagittal sinus, and the straight sinus. He underwent a venticulo-peritoneal shunting. Then, after treatment for cardiac failure, superselective embolization of the bilateral MMAs and the OAs resulted in diminution of shunting flow. The initial onset of this case was at seven days after his birth. Dural AVS is very rare in the pediatric population, particularly in the neonate. The clinical features, pathogenesis, and the treatment for this rare entity are discussed.

Arteriovenous Malformations↗

PubMed1995

[Telepathology].

Telepathology, introduced in 1986 by Weinstein, was not adopted in Japan because its image could not be transmitted by the National Television Standard Committee (NTSC) transmission. In 1990 a new system of Hi-Vision (HDTV) with 1125 lines, was implemented in Yamagata University and was highly evaluated. This success was followed by new developments both in NTSC and HDTV telepathology systems. Real-time HDTV images are transmitted via optical fiber cables for in-house hospital operations. Static HDTV and NTSC images are transferred via integrated services digital network (64 Kbit/s and 1.5 Mbit/s). Today telepathology networks are extending all over the country.

Computer Communication Networks↗

PubMed1995

[A surgical repair of partial anomalous pulmonary venous drainage to the high superior vena cava].

A 7-year-old boy with partial anomalous pulmonary venous drainage to the high superior vena cava (SVC) underwent surgical repair by Williams procedure. Right upper pulmonary vein was drained to the left atrium via the SVC and the surgically enlarged sinus venosus type ASD. SVC was ligated and divided. SVC was then anastomosed to RA appendage pedicle directly. Autologous pericardium was patched anteriorly to create a new SVC pathway. The postoperative course was uneventful without arrhythmia and cardiac catheterization 1 month postoperation revealed no stenosis of the SVC and right upper pulmonary venous return.

Anastomosis, Surgical↗

PubMed1995

T cell adherence and mucosal injury in ulcerative colitis: involvement of integrin-fibronectin interaction in situ.

The mechanism whereby mononuclear cells, including T lymphocytes, accumulate in the mucosal lesions of patients with ulcerative colitis (UC) is unknown. Although the role played by vascular adhesion molecules in the abnormal recruitment of leukocytes has been emphasized, it does appear that fibronectin (FN), an extracellular matrix (ECM) protein, can play an important role in the persistence of active inflammation because of its effects on the proliferation, differentiation, and migration of cells. beta 1-integrins (VLA proteins) mediate cell adhesion to ECM proteins such as fibronectin, laminin, and collagen. Peripheral blood T lymphocytes (PBL-T) showed increased expression of VLA proteins after activation, although the expression of VLA proteins by lamina propria lymphocytes (LPL) is not known. In an in-vitro binding assay, PBL-T showed increased adherence to inflamed mucosa from patients with UC after stimulation with CD3 crosslinking. This adherence was partially inhibited by antibodies specific for plasma FN, VLA-4, VLA-5, and VLA-beta 1, and by the synthetic peptide RGDS. These findings suggest that infiltrating T cells derived from blood use FN receptors to anchor at inflammatory sites. It is conceivable that the inhibition of T cell adherence to ECM by antibodies or synthetic peptides could suppress inflammatory activity in UC.

Cell Adhesion Molecules↗

PubMed1995

Salt-dependent structural changes of chromatin in isolated chicken liver nuclei as visualized by scanning electron microscopy.

MgCl2- and KCl-dependent structural changes of chromatin in isolated chicken liver nuclei were examined by scanning electron microscopy. In the absence of salts, the chromatin appeared as granular or knobby fibrillar structures, 15-30 nm in diameter. At 0.2 mM MgCl2, the structures condensed into 30-60 nm fibers. At 2 mM MgCl2, most chromatin was present as condensed chromatin masses. Above 50 mM MgCl2, the condensed chromatin masses were loosened. At KCl concentrations higher than 25 mM, the chromatin appeared as discrete 30-60 nm fibers. However, no condensed chromatin masses were formed at any of the KCl concentrations examined in this study. These results indicate that the MgCl2- or KCl-dependent transitions from a lower to a higher level of chromatin organization in the isolated nuclei are comparable to those reported in isolated chromatin fragments, and that KCl is ineffective in the formation of condensed chromatin.

Animals↗

PubMed1994

MK-801 inhibits the induction of immediate early genes in cerebral cortex, thalamus, and hippocampus, but not in substantia nigra following middle cerebral artery occlusion.

Middle cerebral artery (MCA) occlusion in rats induced c-fos and junB mRNA 4h later in all ipsilateral cortex outside the MCA distribution and in many subcortical structures: medial striatum; most of thalamus including medial and lateral geniculate nuclei: substantia nigra; and hippocampus. The N-methyl-D-aspartate (NMDA) antagonist, MK-801 (4 mg/kg, i.p.) inhibited c-fos and junB mRNA induction in the cortex, striatum, thalamus, and hippocampus but not in the substantia nigra. These data show that c-fos and junB mRNA induction in cortex, striatum, thalamus, hippocampus involves the activation of NMDA receptors whereas different receptors must be implicated in the induction in substantia nigra.

Animals↗

PubMed1994

Immobilized anti-TCR mAb induces split functions in a CD8+ CTL clone.

A signal through the T cell receptor (TCR) without a second costimulatory signal provided by antigen-presenting cell (APC) generally causes a state of anergy in CD4+ T helper (Th) 1 cells, but not in CD4+ Th2 cells. In contrast, less is known about anergic CD8+ T cells. We have examined whether a CD8+ cytotoxic T lymphocyte (CTL) clone incapable of producing IL-2 could be rendered into a state of unresponsiveness by treatment with immobilized anti-TCR mAb in the absence of a secondary stimulation. The CD8+ CTL clone was induced into nonproliferative response to subsequent antigen stimulation while it was bound to immobilized anti-TCR mAb. The immobilized anti-TCR mAb-treated CTL clone also failed to significantly produce cytokine with antigen stimulation. In contrast, the ability of the CTL clone to specifically lyse target cells was apparently retained. The results suggest that there might be intracellular signal pathways via the TCR for CTL functions such as proliferative response, cytokine production, and CTL killing.

Animals↗

PubMed1994

Mycoplasma stimulates HIV-1 expression from acutely- and dormantly-infected promonocyte/monoblastoid cell lines.

Treatment of a myelo-monocyte cell line, J22HL-60, dormantly infected with human immunodeficiency virus type 1 (HIV-1) with heat-inactivated extracts of Acholeplasma (A) laidlawii (250 micrograms/ml) enhanced virus production more than 45-fold as assessed by p24 viral core antigen assay. When treated with a suboptimal dose of TPA or TNF-alpha, Acholeplasma extracts further augmented virus production in J22HL-60 cells. H7, an inhibitor of protein kinase C(PKC), almost completely abrogated HIV-1-inducing ability of Acholeplasma extracts in the cells. A. laidlawii and several other mycoplasmas also enhanced acute infection of U937 cells as shown by increased virus-positive cells and augmentation of HIV-1 production in the culture supernatant independent of their pathogenicity to humans.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

PubMed1994

The inhibitory effect of FK506 on cytotoxic T-lymphocyte killing.

The immunosuppressant FK506 inhibits N-alpha-benzyloxylcarbonyl-L-lysine thiobenzyl ester (BLT) esterase release from cytotoxic T lymphocytes (CTL). In addition, serine esterase has been demonstrated to be strongly associated with CTL killing. In the present study, the effect of FK506 on the activity of CTL killing against target cells was examined. FK506 inhibited lysis of antigen (Ag)-treated CTL target cells by auto-CTL, but failed to inhibit lysis of conventional P815 target cells by CTL. Moreover, FK506 inhibited DNA fragmentation of CTL target cells lysed by auto-CTL. Killing of CTL target cells by FK506-pretreated auto-CTL was inhibited, but FK506-pretreated CTL target cells were killed by auto-CTL. Incubation of both FK506 and Ag-pretreated CTL target cells with untreated auto-CTL induced DNA fragmentation. These indicated that FK506 inhibited CTL killing by influencing effector, but not CTL target cells. These results suggest that FK506 may function by inhibiting alloreactive CTL killing in organ transplantation in addition to the interruption of the T-cell receptor signal transduction leading to cytokine production.

Animals↗

PubMed1994

Corn cystatin I expressed in Escherichia coli: investigation of its inhibitory profile and occurrence in corn kernels.

Corn cystatin I was expressed in Escherichia coli as a mature protein. It was purified by gel filtration on Sephadex G-50, ion-exchange HPLC, and reversed-phase HPLC. The purified protein showed strong inhibitory activities against papain (Ki: 3.7 x 10(-8) M), and cathepsins H (Ki: 5.7 x 10(-9) M) and L (Ki: 1.7 x 10(-8) M), whereas it inhibited cathepsin B to a lesser extent (Ki: 2.9 x 10(-7) M). Western blot analysis using antibody raised against corn cystatin I revealed that in the corn kernel, the protein occurs with a molecular mass of approximately 13 kDa. Localization in the aleurone layer and embryo of the corn kernel was shown by immunostaining microscopy.

Cloning, Molecular↗

PubMed1994

Antibody response to measles immunization in rural Ghanaian infants.

We investigated optimal age of measles immunization in infants aged 3-11 months in rural villages of Ghana, and determined seroconversion rate in the same infant population following further attenuated measles vaccination with Schwarz vaccine. The prevalence of passively acquired antibody was 11 per cent in infants younger than 6 months, 10 per cent in infants 6 months old, and 3 per cent in infants 7 months old or older. Seroconversion rates in each age group were less than 50, 87, and 92 per cent, respectively. We then immunized 47 7-month-old infants. The seroconversion rate was 92 per cent in this group. There were no clinical adverse effects due to the vaccination. We conclude that measles vaccination could be administered effectively at the age of 7 months with an excellent seroconversion rate.

Antibody Formation↗

PubMed1994

Gene expression of tumor necrosis factor alpha and interferon gamma in the lungs of Mycoplasma pulmonis-infected mice.

ICR mice were infected intranasally with Mycoplasma pulmonis isolated freshly from the lungs of a rat with pneumonia. We demonstrated with high reproducibility the expressions of messenger RNAs of cytokines, tumor necrosis factor alpha (TNF alpha) and interferon gamma (IFN gamma) in the lung tissue of M. pulmonis-infected mice by the reverse transcriptase-polymerase chain reaction and confirmed specific mRNA of the cytokines by restriction endonuclease digestion. Both the viable population of M. pulmonis in the lung tissue and the titers of the neutralizing antibody in the serum increased between 7 and 21 days, and reached their maximum 35 days after infection. The pneumonia in mice progresses with the development of lung lesions after 7 days of infection. The early lesions are characterized primarily by neutrophils and edema in the alveolar spaces. mRNAs prepared from the lung tissue of M. pulmonis-infected and -uninfected mice were also tested for the presence of messages specific to TNF alpha and IFN gamma by the reverse transcriptase-polymerase chain reaction. The expression of the genes encoding TNF alpha and IFN gamma was constitutively demonstrated from 24 hr through 35 days after the intranasal inoculation of M. pulmonis. Furthermore, cells of two types, adherent and nonadherent cells, in bronchoalveolar lavage fluids obtained from the mice 3 weeks after inoculation of M. pulmonis were also found to express the genes of TNF alpha and IFN gamma respectively. These data suggest that these cytokines would play a role in both stimulation in the development of pathological changes in mycoplasmal infection, affecting the inflammatory responses.

Administration, Intranasal↗

PubMed1994

[Susceptibility to macrolides against Mycoplasma pneumoniae isolated during 7 years].

The efficacies of macrolide antibiotics, rokitamycin, leukomycin, josamycin and erythromycin were investigated against 63 strains of M. pneumoniae included FH strain which were isolated from clinical specimens obtained in 1986-1987, 1991, 1992-1993. Values of MICs and MBCs of these antibiotics were evaluated by two methods, broth dilution method and M. pneumoniae L cell infection system. In broth dilution method, MIC50 and MBC50 of rokitamycin were 0.0063-0.025 microgram/ml and 0.025-0.2 microgram/ml respectively. The ratios of MBC50/MIC50 were 1-32. MIC50 of leukomycin, josamycin and erythromycin were 0.0063-0.05 micrograms/ml, 0.0025-0.05 microgram/ml, and 0.0125-0.05 microgram/ml respectively. MBC50 of these drugs were 0.0125-50 micrograms/ml, 25-50 micrograms/ml, and 25-50 micrograms/ml respectively. The ratios of MIC50/MBC50 were 2-800, 500-2000, 500-4000. MIC50 of rokitamycin and leukomycin to the isolates during period from 1992-1993 were higher as compare to those of isolates during 1986 to 1991. On the other hand, rokitamycin markedly reduced the numbers of CFU in the growth phase when added at the concentrations of 16 and 4 times the MIC, but the other macrolides were reduced slightly CFU at the concentrations of 4 times, the MIC. In L cell infectious system, MIC50 and MBC50 of rokitamycin were 0.005-0.0125 microgram/ml and 0.05-0.1 microgram/ml respectively. The ratios of MBC50/MIC50 were 1-2 Ratios of leukomycin, josamycin, and erythromycin were 0.05-0.1 microgram/ml, 0.05-0.2 microgram/ml and 0.050-0.1 microgram/ml respectively. The MBC50 of these drugs were 0.2-0.4 micrograms/ml, 0.8-1.6 microgram/ml, 0.8-1.6 microgram/ml. Ratios of MBC50/MIC50 were 2-8, 4-32, 8-32.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Bacterial Agents↗

PubMed1994

Association of Mycoplasma pneumoniae antigen with initial onset of bronchial asthma.

Although mycoplasmal airway infection frequently exacerbates bronchial asthma, the cause of the initial onset of asthma remains unclear at present. In this report, we describe a patient in whom a previous acute mycoplasmal respiratory infection led to an initial onset of bronchial asthma. One month after the onset of the illness, cough and wheezing appeared. Pulmonary function studies revealed an airway obstructive dysfunction. Oral administration of bronchodilators resulted in a marked improvement of the asthmatic symptoms. An airway hyperresponsiveness to methacholine was demonstrated even 2 yrs after the initial onset of the illness, and IgE antibody specific to Mycoplasma pneumoniae was detected in the serum by use of enzyme-linked immunosorbent assay. An immediate skin test for M. pneumoniae was positive in addition to multiple positive skin tests. A bronchial inhalation challenge test with M. pneumoniae antigen also yielded a positive result. We conclude that the effects of mycoplasmal respiratory infections on the airway are multifactorial and involve a complex interplay of airway inflammation and IgE-mediated hypersensitivity.

Adult↗

PubMed1994

Oryzacystatin exogenously introduced into protoplasts and regeneration of transgenic rice.

Oryzacystatin (OC) is a proteinaceous cysteine proteinase inhibitor involved in the biodefense of rice seeds. To create transgenic rice plants with increased OC activity, we introduced an OC expressing vector into rice protoplasts and obtained transformed calli. The expression vector contained a bacterial inaA DNA fragment in the 3'-noncoding region as a tag to distinguish the introduced DNA from the intrinsic OC gene. The OC vector and a selection marker gene conferring hygromycin resistance were used together to transfect into rice protoplasts. A number of hygromycin-resistant calli were obtained and studied by polymerase chain reaction and genomic Southern blotting to find if the exogenous OC gene had been integrated. The calli were studied by northern blotting as well to examine mRNA expression. The results showed that integration and expression of the introduced OC gene occurred in 51% and 27%, respectively, of 156 subcultures from 15 hygromycin-resistant calli. As a final step, transgenic rice plants were regenerated from the calli expressing OC. Leaves and seeds from the plants had higher OC activities than those from nontransgenic plants.

Base Sequence↗

PubMed1994

Cloning and sequencing of an ice nucleation active gene of Erwinia uredovora.

An ice nucleation activity gene, named inaU, of the bacterium Erwinia uredovora KUIN-3 has been sequenced. This gene encodes a protein of 1034 amino acid residues, and its expression product, inaU protein, has an 832-amino acid residue segment consisting of 52 repeats of closely related 16-amino acid motifs (R-domain), flanked by N- and C-terminal sequences (N- and C-domains, respectively). The primary structure of the inaU protein is similar to those of the inaA, inaW, and inaZ gene products of Erwinia ananas, Pseudomonas fluorescens, and Pseudomonas syringae, respectively, but is smaller than any of these products in terms of the size of the R-domain.

Amino Acid Sequence↗

PubMed1994

Mixed connective tissue disease associated with multicentric Castleman's disease.

We describe a 60-year-old woman who developed mixed connective tissue disease (MCTD) associated with multicentric Castleman's disease (MCD) and Crow-Fukase syndrome (CFS). She showed HLA DR-4 antigen and an abnormal X chromosome (47,XXX). The serum interleukin-6 (IL-6) level was markedly increased and IL-6 mRNA was detected in enlarged lymph node cells. After prednisolone was administered, her IL-6 level decreased and the symptoms of MCTD, MCD, and CFS all improved. Thus, IL-6 may be involved in the modification of the pathologic condition in this patient.

Castleman Disease↗