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931.
Right ventricular assist devices are an important part of the armamentarium of cardiac surgeons for the treatment of right-sided circulatory failure after cardiac transplantation or insertion of a left ventricular assist device. However, right ventricular assist device insertion can be technically challenging in the setting of pulmonary hypertension because of a number of concomitant anatomic and physiologic phenomena. We present a technique for the insertion of the right ventricular assist device outflow cannula that is easier and faster to insert, and safer to explant, especially if cardiopulmonary bypass is to be avoided. 相似文献
932.
Auxin represents one of the most important classes of signalling molecules described in plants. Auxins regulate several fundamental cellular processes including division, elongation and differentiation. Indole-3-acetic acid (IAA), the principal form of auxin in higher plants, is first synthesized within young apical tissues, then conveyed to its basal target tissues by a specialized delivery system termed polar auxin transport. The polarity of IAA movement represents one of the most novel aspect of auxin signalling. IAA transport has been demonstrated to involve auxin influx and efflux carrier activities. The adoption of a mutational approach in the model plant Arabidopsis thaliana has led to the identification of a number of genes which encode components for, or regulate the activity of, the auxin transport machinery. This paper will review the advances being made in identifying and characterizing these auxin transport-related gene products and discuss their importance within the context of Arabidopsis development. 相似文献
933.
N Hayashi JN Weinstein ST Meller HM Lee KF Spratt GF Gebhart 《Canadian Metallurgical Quarterly》1998,23(8):877-885
STUDY DESIGN: The effect of epidural injection of betamethasone or bupivacaine was investigated in an animal model of lumbar radiculopathy. OBJECTIVE: To investigate the effects of an epidural steroid (betamethasone) or a local anesthetic (bupivacaine) in an animal model of radiculopathy produced by nerve root irritation. SUMMARY OF BACKGROUND DATA: Epidural injections are commonly used for the treatment of low back pain and sciatica. However, efficacy remains controversial, and there is a paucity of basic information to support clinical use or the injections. METHODS: Fifty-one rats were used. The left L4 and L5 nerve roots were loosely ligated with chromic gut, and either betamethasone, bupivacaine, betamethasone in combination with bupivacaine, or saline was injected using an epidurally placed catheter. The effects of epidural injection were evaluated using response to noxious stimuli and immunohistochemical methods. RESULTS: In betamethasone-treated rats (either alone or in combination with bupivacaine), thermal hyperalgesia was significantly less (P < 0.010 after surgery than that in saline- or bupivacaine-treated groups, in which the hyperalgesia was maximum at 2-3 postoperative weeks before resolving 5 weeks after surgery. Immunohistochemical analysis did not correlate with these results. CONCLUSIONS: Epidural steroid injection has a significant effect on the thermal hyperalgesia produced in a model of radiculopathy, which may provide clinical support for advocates of epidural steroids. 相似文献
934.
The human cytomegalovirus glycoprotein B gene (gB; gpUL55) was truncated at amino acid 692 and recombined into Autographa californica nuclear polyhedrosis virus (baculovirus). Infection of insect cells with the recombinant baculovirus resulted in high-level expression and secretion of the truncated gB protein (gB-S) into the culture medium. Purification of gB-S by monoclonal antibody affinity chromatography yielded a protein of ca. 200 kDa. Characterization of the 200-kDa purification product indicated that the recombinant gB protein retained many structural and functional features of the viral gB. Comparison of electrophoretic migration patterns in reduced versus nonreduced protein samples and immune blotting analysis with antibodies specific for the amino or carboxy-terminus of gB demonstrated that the recombinant protein was composed of disulfide linked 69 kDa amino terminal and 35-kDa carboxy-terminal fragments. In addition, recognition of the 200-kDa gB-S by a conformational-dependent, oligomer-specific monoclonal antibody suggested that gB-S was properly folded and dimeric. Like the viral gB, gB-S had heparin binding ability. One heparin binding site was found to reside within the 35-kDa carboxy-terminal fragment (aa 492-692). Heparin binding was abolished when gB-S was denatured. These data suggest that gB contains a novel heparin binding motif that is at least partially conformational dependent. 相似文献
935.
FA Ennis J Cruz CF Spiropoulou D Waite CJ Peters ST Nichol H Kariwa FT Koster 《Canadian Metallurgical Quarterly》1997,238(2):380-390
In 1993 a number of cases of unexplained adult respiratory syndrome occurred in the southwestern United States. The illness was characterized by a prodrome of fever, myalgia, and other symptoms followed by the rapid onset of a capillary leak syndrome with hemoconcentration, thrombocytopenia, and pulmonary edema. Viral RNA sequences in the lungs identified a new member of the hantavirus genus, Sin Nombre virus (SNV), unique to North America. Pulmonary endothelial cells were heavily infected but were not necrotic. We speculated that this capillary leak syndrome was initiated by immune responses to the SNV-infected pulmonary endothelial cells. We isolated a CD8+ cytotoxic T lymphocyte (CTL) clone directly from the blood of a patient with the acute hantavirus pulmonary syndrome (HPS) which recognizes a SNV specific epitope on the virus nucleocapsid protein (aa 234-242) that is restricted by HLA C7 and produces IFN gamma but not IL-4. We identified a second CD8+ CTL epitope located within another site aa 131-139 on the nucleocapsid protein, which is HLA B35 restricted, and a CD4+ CTL epitope located on a third site on nucleocapsid protein aa 372-380 using lymphocytes obtained during HPS from another patient that were stimulated in vitro. Hantavirus specific CD8+ and CD4+ CTL may contribute to the immunopathology and capillary leak syndrome observed in the HPS. 相似文献
936.
937.
A. Pahl V. Bräuer ST. Heusermann B. Kilger L. Liedtke 《Bulletin of Engineering Geology and the Environment》1986,34(1):59-65
The assessment of deep-seated rock in terms of engineering geology and geotechnology with respect to its suitability as a host rock for a final repository for radioactive waste requires the knowledge of the in-situ behavior of the rock in particular the stress and deformation behavior as well as the knowledge of permeability. The waterpercolation through fissured granite and the stress field is being studied in a Swiss German cooperation by the Federal Institute for Geosciences and Natural Resources (BGR) in the Grimsel Rock Laboratory in Switzerland. This laboratory is operated by the National Corporation for the Storage of Radioactive Waste (NAGRA) of Switzerland. German participants are the BGR and the Research Centre for Environmental Sciences (GSF). BGR is responsible for the Fracture System Flow Test (BK), a modified water injection test and advanced Rock Stress Measurements (GS) in deep boreholes. Target of both projects is the development of methods and instruments. In the presentation, some of the results of the stress and permeability measurements will be used to discuss the methods. 相似文献
938.
939.
940.
Acceleration of Tenderization/Inhibition of Warmed-Over Flavor by Calcium Chloride-Antioxidant Infusion into Lamb Carcasses 总被引:2,自引:0,他引:2
Infusion of 0.3M calcium chloride plus 1% sodium ascorbate or 0.25% maltol into freshly slaughtered lambs resulted in acceleration of postmortem tenderization through activation of calcium dependent proteases, inhibition of lipid oxidation and retardation of warmed-over flavor on ground cooked patties from their meat. After storage 2 days at 4°C, patties from lamb carcasses treated with antioxidants retained more desirable flavor characteristics (meaty and musty/herby) of lamb, and had less off-flavor (painty and cardboardy) intensities. 相似文献