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211.
212.
U Dietz R Erbel B Pannen M Haude U Nixdorff S Iversen W Thoenes D Auth J Meyer 《Zeitschrift für Kardiologie》1991,80(3):222-229
High-frequency rotational angioplasty is a recently developed method for coronary angioplasty in the catheter laboratory. An elliptical burr tip (phi 1.25-2.0 mm) with embedded diamant chips (phi 40-50 microns) is rotated by a helical drive shaft at 150,000-180,000 rpm. The burr is advanced over a 0.009-inch coaxial guide wire. To show the effects of this approach in diseased and healthy vessels, which may be present before and behind a stenosis, 17 atherosclerotic coronary arteries of nine human hearts, and 18 normal coronary arteries of nine pig hearts were treated by this method in vitro. Standardized coronary angiography was performed before and after Rotablator treatment, followed by histological examination. From these data the burr-to-vessel-diameter ratio was calculated for each vessel segment and compared with the angiographical and histological outcome. Partial or complete removal of the circumference of the innermost vessel wall layers was observed regularly. The average removal of tissue in human coronary arteries was limited to the intimal layer and in the pig coronary arteries to the internal elastic membrane. In the pig coronary arteries no intimal tears or dissections occurred, in human coronary arteries tears could be seen frequently (13 of 17 vessels (76%)). Media tears were observed in 3 of 17 vessels; one (2%) media dissection could be demonstrated; no perforation occurred. Thus, the in vitro studies suggest that coronary rotational angioplasty has only a slight effect on the vessel segment next to a stenosis, regardless of the burr-to-vessel-diameter ratio.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
213.
J Porter A Ahsan D Mulcahy U Sigwart 《British journal of hospital medicine》1992,47(6):411, 414, 417-411, 414, 419
In this article we review the early history of the coronary artery stent in clinical cardiology, cite a clinical case and assess the potential role of stents in revascularization in the future. 相似文献
214.
Studies were conducted to allow construction of an initial map of the structure-versus-function relationship of the Clostridium perfringens type A enterotoxin (CPE). Removal of the N-terminal 25 amino acids of CPE increased the primary cytotoxic effect of CPE but did not affect binding. CPE sequences required for at least four epitopes were also identified. 相似文献
215.
U Tan 《The International journal of neuroscience》1992,66(3-4):177-188
The relation of right and left brain weight to right minus left (R-L) brain weight and the relation of R-L paw use to brain weight were studied in adults cats. The R-L brain weight was significantly larger than zero in right-pawed (RH) male and left-pawed (LH) females. The R-L brain weight was significantly smaller than zero in LH males, not significantly different from zero in RH females. The R-L brain weight was negatively linearly correlated with the left-brain weight in RH and LH males (no significant correlations in females). The R-L paw use showed a significant positive linear correlation with the R-L brain weight in RH male and females. There was a significant negative linear correlation between R-L paw use and R-L brain weight especially in LH males. Total brain weight showed a significant negative linear correlation with R-L paw use in RH males, and a positive linear correlation in LH males (no correlations in female cats). These results indicated that intermanual difference in paw use is associated with interhemispheric weight difference and total brain weight, especially in male cats; the left brain seems to be of importance in cerebral lateralization. 相似文献
216.
H. Afsar A. Metin N. Sozduyar M. Salih U. Gulsoy 《International urology and nephrology》1992,24(1):65-68
The authors describe 14 cases of erectile dysfunction. The sites of leakage were detected by duplex or colour flow Doppler
sonography.
Treatment by dorsal vein ligation resulted in fairly good early responses, however, at 4-month follow-up the great majority
of patients returned to the original functional state. 相似文献
217.
Claudia Linde Cornelia Löffler Christina Kessler U. Quast 《Naunyn-Schmiedeberg's archives of pharmacology》1997,356(4):467-474
In vascular smooth muscle, openers of ATP-dependent potassium channels (K
ATP channels), such as P1075 (N-cyano-N’-(1,1-dimethylpropyl)-N’’-3-pyridylguanidine), produce relaxation. In this study we have investigated the effects of thiol-modifying agents on the
binding of P1075 and on the 86Rb+ efflux stimulating and vasorelaxant effects of the opener in rat aortic rings. The increase in 86Rb+ efflux induced by P1075 was taken as a qualitative measure of K+ channel opening. The hydrophilic SH-group-oxidizing substance, thimerosal (1 to 100μM), abolished specific binding of [3H]-P1075 with an IC50 value of 7.6±1.2μM; at 30μM, the half time for inhibition was 38min. Two other thiol-oxidizing agents, PMB (4-hydroxy-mercuribenzoic
acid) and DTBNP (2,2’-dithio-bis(5-nitropyridine)), inhibited binding up to 86% and 44%, respectively. The disulphide bond
reducing substance, DTT (1,4-dithiothreitol, 0.1 to 1mM), reduced [3H]-P1075 binding by up to 20% and partially reversed the inhibitory effect of thimerosal. In 86Rb+ efflux experiments, thimerosal (3 to 100μM) concentration-dependently increased basal efflux but inhibited P1075-stimulated
tracer efflux with an IC50 value of 7±1μM. The inhibitory effect occurred with a half-time of approximately 8min and was essentially reversed by DTT.
In rings precontracted with noradrenaline, thimerosal inhibited the vasorelaxant effect in a noncompetitive manner, shifting
the concentration-relaxation curves to the right and reducing maximum relaxation.The data show that oxidation of thiol groups
interferes with the binding of the K
ATP channel opener, P1075; concomitantly, the 86Rb+ efflux stimulating and the vasorelaxant effects are inhibited. Reduction of disulphide bonds by DTT has only minor effects
on the action of P1075. Collectively, the results suggest that intact thiol groups are essential for the functioning of the
KATP channel in rat aorta. The different kinetics governing the inhibition of opener binding and of opener-stimulated 86Rb+ efflux suggest that the SH-groups involved in the two processes differ in their accessibility to thimerosal and/or in their
reactivity.
Received: 7 April / Accepted: 9 July 1997 相似文献
218.
Knee prostheses with metal backing of the polyethylene tibial component are nowadays used almost universally. Eight cases of fracture of the metal tray are reported in the literature. We present a case in which the failure could be expected because of improper design of the tibial tray. 相似文献
219.
The use of trichloracetic acid in the treatment of decorative tattoos is described. The technique is simple to perform. No anaesthesia or analgesia is required. Complications are uncommon and usually minor. Trichloracetic acid acts by inflicting a chemical burn. 相似文献
220.
Acute CyA nephrotoxicity involves alteration in the proximal tubule and leads to glomerular lesions. Administration of a vasodilatator agent such as the prostaglandin E1 analogue Rioprostil (Bayer AG, BAY 06893) might prevent preglomerular vasoconstriction and hence reduce cyclosporin nephrotoxicity. As an increased excretion of urinary enzymes as a consequence of CyA-nephrotoxicity is well known we investigated in 40 male Wistar rats the excretion of three urinary enzymes: the brush border enzyme gamma-glutamyltransferase (GGT), the leucine aminopeptidase (LAP), and the lysosomal enzyme N-acetyl-beta-glucosaminidase (NAG). Additionally we determined s-creatinine and CyA plasma level. The kidneys were studied histologically at the end of the study. Wistar rats receiving 20 or 50 mg CyA/kg/d showed a marked deterioration in renal function and an increase of all urinary enzymes determined. In the rats receiving 20 mg CyA/kg/d and Rioprostil (150 micrograms/d) renal function and the enzymes determined remained in the normal range. There was no change in the enzyme excretion and only a minor improvement of renal function in rats receiving 50 mg CyA/kg/d and Rioprostil. Histological findings showed prevention of CyA nephrotoxicity in the 20 mg/kg/d group and diminished renal damage in the 50 mg/kg/d group. 相似文献