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Biomedical subjects

T Shida

Publications and source records attributed to T Shida.

At least 55 records · Page 3Linked to original sources
PubMed1996

Analysis of substrate specificity of the RuvC holliday junction resolvase with synthetic Holliday junctions.

The Escherichia coli RuvC protein endonucleolytically resolves Holliday junctions, which are formed as intermediates during genetic recombination and recombination repair. Previous studies using model Holliday junctions suggested that a certain size of central core of homology and a specific sequence in the junction were required for efficient cleavage by RuvC, although not for binding. To determine the minimum length of sequence homology required for RuvC cleavage, we made a series of synthetic Holliday junctions with various lengths of homologous sequence in the core region. It was demonstrated that a monomobile junction possessing only 2 base pairs of the homology core was efficiently cleaved by RuvC. To study the sequence specificity for cleavage, we made 16 bimobile junctions, which differed only in the homologous core sequence. Among them, 6 junctions were efficiently cleaved. Cleavage occurred by introduction of nicks symmetrically at the 3'-side of thymine in all cases. However, the nucleotide bases at the 3'-side of the thymines were not always identical between the two strands nicked. These results suggest that RuvC recognizes mainly topological symmetry of the Holliday junction but not the sequence symmetry per se, that the thymine residue at the cleavage site plays an important role for RuvC-mediated resolution, and that a long homologous core sequence is not essential for cleavage.

Bacterial Proteins↗
PubMed1996

Laser Spectroscopy of the CCO Radical in the 0.77-μm Region: Analysis of the A(020)kappa3Pi and A3Pii(001) States

The A(020)kappa3Pi-X3Sigma-(000) and A3Pii(001)-X3Sigma-(000) bands of the CCO radical have been investigated by laser spectroscopy with two types of tunable laser system. An analysis was made simultaneously for both the bands to establish line assignments and determine molecular constants for both the A(020) and A(001) states. A coupling constant between these two states was also determined by assuming the interaction to be of Fermi type.

Journal Article↗
PubMed1996

Seasonal changes in mite allergen (Der I and Der II) concentrations in Japanese homes.

BACKGROUND: There has been no report on seasonal changes in Der II allergen in floor and bedding dust. OBJECTIVE: The purpose of this study was to examine the extent of seasonal changes in Der I and Der II allergens in the floor and bedding dust found in houses. METHODS: We measured the absolute concentrations of mite allergens in dust collected monthly for 1 year from both the floors and bedding of eight houses in Tokyo. Dust samples were obtained from eight families without regard to their allergy histories. The concentrations of the Der p I, Der f I, and Der II allergens were measured by fluorometric sandwich ELISA. RESULTS: We found seasonal changes in the concentrations of these mite allergens. The highest concentrations of Der I (Der p I plus Der f I) and Der II (Der p II plus Der f II) were present from August to October, and the lowest ones from March to April. In floor dust, the mean highest concentrations of Der I and Der II (35.0 and 20.2 microgram of fine dust) were sevenfold and fivefold respectively, times the mean lowest concentrations. In bedding dust, the mean highest concentrations of Der I and Der II (51.3 and 29.6 microgram/g of fine dust) each were fourfold times the mean lowest concentrations. CONCLUSIONS: The patterns of seasonal changes in Der II in floor and bedding dust were similar to those of Der I.

Allergens↗
PubMed1996

Characterization and comparison of synthetic immobile and mobile Holliday junctions.

Eight synthetic Holliday junction (HJ) oligonucleotides containing an immobile or a mobile junction were characterized by gel electrophoresis, ultraviolet absorption and circular dichroism (CD) spectroscopy. Four 24-mer deoxyribonucleotides formed stable immobile and mobile HJs in 0.1 M NaCl at 5 muM strand concentration at room temperature. However, the immobile HJ constructed from four 18-mers was less stable, and four 12-mers did not form the HJ structure under the conditions used. A comparison of the melting profiles of the HJs with those of the duplexes corresponding to the arms of four-way junctions indicated that the thermal stability of the HJ was similar to that of the individual arm and the cooperativity of the melting behavior of the HJ was relatively higher than that of the individual arm duplex. The Tms of the mobile HJs containing 4, 6, 8, and 10 base-pair homologous cores at junctions were essentially identical with that of the immobile HJ of the same size. There is a tendency that the HJ containing a larger homologous core region becomes more resistant to thermal denaturation. The addition of divalent metal cations, Mg2+ and Ca2+, to the solutions of the HJs raised their melting temperatures. The difference found for the CD spectra of the HJs which differ only in the arrangement of the HJ depended primarily upon the DNA sequence flanking the junction. The RuvC protein binds to the immobile and mobile HJs, regardless of the presence and the size of the homologous core at the junction.

Bacterial Proteins↗
PubMed1996

Allergenicity of acid protease secreted by Candida albicans.

We have previously reported the cases of Candida albicans (C. alb) acid protease (CAAP)-induced atopic asthma. In this study, the allergenicity of the released enzyme CAAP was examined among asthmatic patients with positive immediate skin response to crude C. alb antigen. Among 49 patients with positive skin response to crude C. alb, anti-crude C. alb IgE antibodies were detected in 40 and anti-CAAP IgE antibodies were detected in 18. Moreover, anticrude C. alb IgE antibodies were detected in all of the patients in whom anti-CAAP IgE antibodies were detected. No correlations between IgG antibodies to both antigens or between IgE and IgG antibodies to CAAP were observed. CAAP induced significant T-cell proliferation in 20/28 patients showing positive T-cell proliferation response to crude C. alb antigen. Most of the patients showing positive conjunctival response to crude C. alb antigen also showed positive response to CAAP. Most of the patients showing high levels of serum IgE antibody and positive histamine-release response of peripheral blood leukocytes to CAAP showed positive conjunctival response. The results indicate that CAAP is an important allergen in C. alb-related mucosal allergy.

Allergens↗
PubMed1996

Morphological study on a case of canine hepatic nodular fibrosis.

Hepatic nodular fibrosis occurred in an 8-year-old male Papillon dog. Fibrous nodules, consisting of broad bands of collagen fibers, spindle cells, and lipofuscin-laden foamy macrophages, were well-circumscribed and frequently linked up with the portal areas. Because the spindle cells were positive for desmin and/or alpha-smooth muscle actin, they might be Ito cells or myofibroblasts. These results suggest that both the spindle cells and macrophages play an important role in the pathogenesis of hepatic nodular fibrosis, which might arise from the portal area.

Actins↗
PubMed1996

[A case report of an infective endocarditis caused by methicillin-resistant Staphylococcus aureus with successful mitral valve replacement].

We report a case of successful mitral valve replacement performed on the patient who is an infective endocarditis due to MRSA. She was 27-year-old female and treated by antibiotics medication because of remittent fever two years ago. On August 1995, cerebral infarction occurred and she was pointed out endocarditis. After high fever continued, blood cultures demonstrated MRSA. Furthermore, echocardiography showed vegetation on posterior mitral valve leaflet and moderate mitral regurgitation so, mitral valve replacement with a S.J.M. 25 mm performed to control MRSA sepsis condition. During operation, we used VCM 2 g into the extracorporeal circulation and after operation 0.5 g intravenously every 6 hours. Two weeks later we changed antibiotics to FOM, Viccillin and ABK according to the result of minimum inhibitory concentration (MIC) obtained through blood culture. The patient was discharged on the 44 th postoperative day because of her uneventful postoperative course.

Adult↗
PubMed1996

[Rupture of the aneurysm of the sinus valsalva: thirteen years after the initial diagnosis].

We report a case of an unruptured aneurysm of the sinus Valsalva (URASV) which was followed thirteen years without surgery. A 47-year-old female had a heart murmur detected at age 34 during pregnancy. Though an URASV was diagnosed, because the aneurysm was less than 1 cm in size, no surgery was advised at that time. Thirteen years later, she gradually noticed of increased heart beats and also dyspnea on exertion. Echocardiogram showed an aneurysm of the sinus Valsalva ruptured to the RV cavity. In June 1994, resection of the aneurysm was performed. One year later, the patient was asymptomatic. This may be the second longest long-term follow-up report of the patient with an unruptured aneurysm of the sinus Valsalva.

Aneurysm, Ruptured↗
PubMed1996

[A comparison of the pharmacological actions between DSCG (disodium cromoglycate) and BDP (beclomethasone dipropionate) in the treatment of bronchial asthma].

Effects and actions of DSCG and corticosteroids in the airways could not essentially evaluated at the same situation, before the inhaled BDP had been used. Each of the drugs have been shown to reduce both immediate and late phase responses in experimentally induced asthma, exercise induced bronchospasm, and bronchial hypersensitivity to histamine especially after the prolonged pretreatment of BDP. DSCG probably targets nonspecifically the surfaces of relevant cells including mast cells and eosinophils, but BDP are known to act specifically and/or nonspecifically on the gene transcription in the various types of cells including eosinophils, lymphocytes, and resident cells. Many informations on the systemic side effects of BDP will be still required.

Anti-Inflammatory Agents↗
PubMed1995

Expression of glutamate (AMPA type) and gamma-aminobutyric acid (GABA)A receptors in the rat caudal trigeminal spinal nucleus.

The localization of GABAA receptor gamma 1 and gamma 2 subunits and the AMPA-type glutamate receptor subunits GluR1 and GluR2/3 were identified in the caudal trigeminal spinal tract nucleus (TNC) by immunohistochemistry using specific antibodies. The receptor species on the projecting neurons to the thalamus in TNC were also examined. A retrograde tracer, Fluoro-gold (FG), was injected into the thalamus, and the sections were simultaneously labeled with the antibodies. Injection of FG into the ventral posteromedial nucleus of the thalamus resulted in labeling of scattered neurons contralaterally in the TNC. Most of the neurons labeled by retrograde tracing also showed gamma 1- and gamma 2-like immunoreactivity, while many of the neurons containing FG lacked GluR1- and GluR2/3-like immunoreactivity. These findings show that neurons projecting to the thalamus from the TNC receive GABAergic input via GABAA receptors containing gamma 1 and gamma 2 subunits, while many neurons expressing the AMPA-type receptor did not project to the thalamus.

Animals↗
PubMed1995

Role of amino acids in salivation and the localization of their receptors in the rat salivary gland.

The distribution of gamma-aminobutyric acid (GABA) receptor subunits such as GABAAR-gamma 1 and GABAAR-gamma 2, and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) type receptor subunits such as GluR-1, GluR-2/3 and GluR-4, and N-methyl-D-aspartic acid (NMDA) type subunits such as NR1 were investigated by immunocytochemistry. Furthermore, the roles of these amino acids, GABA and glutamate, on salivation were analyzed in the rat submandibular and sublingual glands. Some similarities were observed in the distribution patterns of GABAA type receptors and AMPA receptors. In the submandibular ganglion cells, collecting ducts and striated ducts, these subunits were expressed strongly; however, there were some differences in their expression patterns between the submandibular and sublingual gland acinar cells. Since these receptor subunits were expressed in the acinar cell bodies of the submandibular gland, they were not expressed in the acinar cells but were expressed in the myoepithelial cells in the sublingual gland. On the other hand, no NR1 expression was observed. To examine the roles of GABA and glutamate in salivation, the submandibular and sublingual glands were perfused partially with Ringer's solution via a facial artery to avoid systemic influence, and substrates were infused into the perfusion solution. No salivary secretion was evoked by GABA or glutamate infusion in the absence of electrical stimulation (2-3 V, 5 ms, 20 Hz). Salivary flow evoked by electrical stimulation of the chorda-lingual nerve caused significant inhibition by GABA (10(-6), 10(-5), 10(-4) and 10(-3) M) and the GABAAR agonist muscimol 10(-3) and 10(-6) M) (n = 6, P < 0.05). Such GABA-induced inhibition was antagonized by the GABAAR antagonists bicuculline (BCC; 10(-6) and 10(-3) M) and picrotoxin (PTX; 10(-6) and 10(-3) M). On the other hand, salivary flow evoked by electrical stimulation (8-10 V, 5 ms, 20 Hz) of the superior cervical ganglion (SCG) was not affected by GABA. While high doses of glutamate (10(-1) M) and NMDA (10(-1) M) showed no effects on salivary flow despite application of electrical stimulation, AMPA at a high concentration (10(-1) M) significantly inhibited salivary secretion (n = 6, P < 0.05). These studies revealed that inhibitory and excitatory amino acid receptors such as GABAA and AMPA type receptors are coexpressed in the rat salivary glands, and that GABA inhibits salivary secretion via GABAA receptors which may act with acetylcholine. However, the role of glutamate in salivation remains unclear despite the presence of AMPA type receptors. The present findings suggest that glutamate does not act alone but with other substances such as peptides and/or other amino acids.

Animals↗
PubMed1995

Vascular pattern of a metastatic liver tumor in a dog:--a scanning electron microscopic study of resin casts.

Metastasis of a malignant mixed tumor occurring in the abdominal wall was found in the liver of a 15-year-old dog male. The vascular system of the metastatic lesion was examined by scanning electron microscopy using the resin cast technique. The existence of arterio-portal shunts was confirmed. The shunts arose from branches of the hepatic artery in retrograde or vertical direction and merged into the capillary plexus replacing the branches of the portal vein, forming the so-called thread and streaks vessel in the field of hepatic angiography. Vessels with the thread and streaks appearance histologically represented tumor emboli growing in the lumen of a large branch of the portal vein. There were capillaries running inside along the portal vein and forming a longitudinal dense network in the vein. Branches of the hepatic artery feeding the metastatic lesion were well developed and formed a coarse arterial network in their course. Tributaries of the hepatic vein from the lesion were also well developed.

Animals↗
PubMed1995

[Simultaneous operations for both the repair of the aortic arch aneurysm and repeated CABG].

A 73-year-old female complaining of left thoracic pain was referred to our hospital. In 1988, she had the first CABG of the left circumflex coronary artery (CX) and right coronary artery. On admission in April 1994, chest X-ray and CT scan revealed a saccular aortic aneurysm, 5 x 5 cm in size, extending to the distal to the left subclavian artery. Coronary arteriography showed a patency of the CX graft, but 99% stenosis of the proximal left anterior descending branch (LAD) with delayed opacification. After the repeated median sternotomy, cardiac arrest was achieved with the aortic cross clamping and St. Thomas Hospital solution infusion. CABG to the LAD branch using a saphenous vein was accomplished. Following this, the replacement of the aortic aneurysmal lesion with a prosthetic graft was performed under the selective cerebral perfusion with deep hypothermia. Proximal anastomosis of the vein graft was completed during a rewarming period. The operation was performed without complications. Postoperative course was satisfactory except a few minor transient complications such as athelectasis of the left upper lobe and the intra-thoracic hematoma. After one month's hospitalization, she was discharged, and currently (six months postoperative) remains asymptomatic.

Aged↗
PubMed1995

[A case of mitral valvuloplasty with concomitant CABG in an aged patient].

A 79-year-old man was referred to our hospital complaining of the manifestation of mild heart failure. Echo cardiography and LV gram showed sever mitral regurgitation by the prolapse of posterior leaflet. CAG revealed coronary artery disease affected two vessels (LAD and RCA) without symptoms. Quadrangular resection of posterior leaflet (McGoon's method) without annuloplasty and concomitant single CABG to the LAD using a saphenous vein were performed. Postoperative course was satisfactory and the manifestation of heart failure was diminished. Mitral valvuloplasty with concomitant CABG may be a safe and effective procedure in the treatment of aged patients.

Aged↗
PubMed1995

Comparison of anti-allergic activities of the histamine H1 receptor antagonists epinastine, ketotifen and oxatomide in human leukocytes.

The effects of three histamine H1 receptor antagonists, epinastine (CAS 80012-43-7, WAL-801 CL), ketotifen (CAS 34580-13-7) and oxatomide (CAS 60607-34-3), on mediator release have been studied in human peripheral leukocytes. When leukocytes from asthmatic patients sensitive to mite were stimulated with the allergen, epinastine inhibited histamine release with a concentration required for 50% inhibition (IC50) of 3 x 10(-5) mol/l and leukotriene C4 generation. On the other hand, ketotifen or oxatomide showed little inhibiting effect on histamine release elicited with the allergen. When the cells were stimulated with calcium ionophore A23187, epinastine failed to inhibit histamine release and leukotriene C4 generation. Oxatomide caused a concentration related inhibition of calcium ionophore-induced histamine release with the IC50 value of 5 x 10(-5) mol/l. Ketotifen or oxatomide also showed an inhibition of leukotriene C4 generation induced by calcium ionophore in a dose-dependent manner and the IC50 value was 6 x 10(-6) mol/l for oxatomide and 8 x 10(-5) mol/l for ketotifen, suggesting that oxatomide is a more potent inhibitor of leukotriene C4 generation than ketotifen. These results indicate that epinastine inhibits IgE-mediated histamine release and LTC4 generation, and oxatomide has a capacity to inhibit calcium ionophore-induced mediator release from human leukocytes. Additionally, when platelet activating factor was quantitated by radioimmunoassay in the supernatant and the cell pellet after ionophore stimulation, epinastine inhibited the formation and the secretion in a dose-dependent manner.

Asthma↗