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151.
Early surgery in patients with mitral regurgitation due to flail leaflets: a long-term outcome study
LH Ling M Enriquez-Sarano JB Seward TA Orszulak HV Schaff KR Bailey AJ Tajik RL Frye 《Canadian Metallurgical Quarterly》1997,96(6):1819-1825
BACKGROUND: The optimal timing for surgery in patients with mitral regurgitation is disputed. Because of the frequency of left ventricular dysfunction, which is difficult to predict, early surgery has been recommended, but its potential benefits have not been demonstrated. METHODS AND RESULTS: The outcomes of 221 patients (mean age, 65 +/- 13 years; 71% males) with flail leaflets diagnosed with two-dimensional echocardiography between 1980 and 1989 who were eligible for operation were analyzed. Group I comprised 63 patients who had early mitral valve surgery (within 1 month after diagnosis). Group II comprised 158 patients initially treated conservatively (80 of whom were operated on later). Group I patients were younger (P=.009), had more symptoms (P<.0001), and were more frequently in atrial fibrillation (P=.023) than group II patients. There was no difference in ejection fraction between the groups. The early surgery strategy was followed by an improved overall survival rate (P=.028) and a lower incidence of cardiovascular deaths (P=.025), congestive heart failure (P=.046), and new chronic atrial fibrillation (P=.032), as confirmed by multivariate analysis (adjusted risk ratios of 0.31, 0.18, 0.38, and 0.05, respectively; all P<.02). CONCLUSIONS: In patients with mitral regurgitation due to flail leaflets, the strategy of early surgery versus conservative management is associated with an improved long-term survival rate, decreased cardiac mortality, and decreased morbidity after diagnosis. This outcome advantage suggests that early surgery is a reasonable treatment option to be considered in low-risk candidates with repairable valves and severe mitral regurgitation. 相似文献
152.
G Manenti L De Gregorio S Pilotti FS Falvella M Incarbone F Ravagnani MA Pierotti TA Dragani 《Canadian Metallurgical Quarterly》1997,18(10):1917-1920
The mapping near Kras2 of pulmonary adenoma susceptibility 1 (Pas1), a major locus affecting inherited predisposition to lung cancer in mice prompted us to test the homologous human region (12p12) for association with lung adenocarcinoma, by a population-based study. We genotyped 213 lung adenocarcinoma patients and 219 healthy blood donor subjects for five polymorphic markers mapping in the putative region of interest. Three marker polymorphisms, located in a region spanning approximately 700 kb, were significantly associated with lung adenocarcinoma risk. Furthermore, polymorphisms in KRAS2 and PTHLH loci were also associated with tumor prognosis. These results suggest the existence of a human Pas1 homologous locus on chromosome 12p12. 相似文献
153.
TA Serel G Akhan HR Koyuncuo?lu A Oztürk K Do?ruer S Unal K Celik 《Canadian Metallurgical Quarterly》1997,31(6):537-539
The treatment and favorable outcome of a bitch with uterine torsion and two retained fetuses are described. The condition was corrected surgically by ovariohysterectomy. Complications (i.e., septic shock, peritonitis, and hemostatic abnormalities) were managed with aggressive medical therapy. Torsion of the gravid uterus in dogs is a life-threatening condition which can have a successful outcome if medical complications encountered in the pre- and postoperative periods are treated quickly and effectively. 相似文献
154.
155.
MR imaging of the knee joints of the mouse at 2.35 T produces an in-plane resolution of 35 x 70 microns and a slice thickness of 600 microns from the sagittal and coronal planes, in less than 60 min. In normal, live DBA mice, which have no known pathology, the images clearly resolve many joint structures, such as the cruciate ligaments, menisci, and articulating surfaces of the femur and tibia. Gross pathological changes were identified first in excised knees from cadaver mice of the STR/ORT strain. Males of this strain spontaneously exhibit rapid joint degeneration with increasing age compared to females, in which much milder symptoms develop more slowly. Thickening of the patellar tendon, displacement of the patella, deformity, and sclerosis were clearly distinguishable in males compared with females older than 7 mo of age. The same degenerative features were evident in MR images of the knees of the live male but not female STR/ORT mice of this age, indicating that it would be possible to monitor longitudinally by MR imaging progressive development of joint changes in this osteoarthritic model. 相似文献
156.
1,001 consecutive women seen in a V.D. clinic were screened for gonorrhoea by cultures of urinary sediment, the endocervix, and anal canal. Recovery of Neisseria gonorrhoeae on culture of urinary sediment was 81-7 per cent. as productive as culture of the endocervix, and 79-2 per cent. compared to endocervical and anal canal culturing. Urogenital symptoms were present in 55-1 per cent. of women with negative cultures and 64-6 per cent. of those with gonorrhoea. A complaint of dysuria increased the likelihood of a positive urinary sediment or endocervical culture. Culture of urinary sediment is less sensitive than culture of the endocervix. However, the ease with which specimens are obtained and the relative simplicity of the technique could make this method an acceptable tool for screening large numbers of women for gonorrhoea. 相似文献
157.
Imaging through random aberrating media can be of interest not only in optics but also in microwaves or in acoustics. However, the holographic techniques applied in optics cannot be readily extended to microwaves without essential modifications. A different holographic method is here proposed which seems convenient at microwaves. The image is obtained by the product of the aberrated hologram with another compensating for the aberration. In the experiments two different procedures have been followed to perform the product of the two holograms, the optical and the electronic multiplication. The results obtained with the two procedures are shown, one of which allows the correction of time variant aberrations. With this technique there is no limitation in the off-set angles of the reference waves that could be also obtained by locally produced signals and no coherence is requested between the object and the compensating wave. The technique could be of interest, for instance, in plasma diagnostic and geophysical problems. 相似文献
158.
The ultrastructural diagnosis of tumors requires a careful analysis that should be done in an orderly fashion. It requires precise planning from the time of specimen collection to the selection of the area to be examined. Pictures must be taken systematically and every micrograph should allow to answer whether the number of cells photographed is adequate; whether mitoses are present, what is the pattern of the tumor; what is the appearance of the cell membrane; whether the cells are joined by junctional complexes; whether free surfaces possess microvilli or cilia; what organelles are present and how they are distributed; whether there are secretory granules, melanosomes, or other cytoplasmic elements. Nuclear and nucleolar size and shape have to be taken into consideration. The composition of the interstitial extracellular matrix is important in certain types of tumors. Although these questions are not the only ones to be addressed, their use in a logical fashion is helpful when it concerns the ultrastructural diagnosis. 相似文献
159.
Cerri G. De Leo R. Primiani V.M. Russo P. 《IEEE transactions on instrumentation and measurement》2008,57(2):242-247
This paper presents two test benches for the characterization of a plasma column used as a radiating element. In particular, the main parameters to be quantified are the efficiency of the plasma antenna, the turn-on time of the column, and the conductivity of the plasma. The first two parameters are evaluated by measuring the field radiated by the plasma antenna compared with that of an equivalent copper antenna. For the conductivity, a reflectometric technique is used, wherein the plasma column is inserted inside a waveguide. The accuracy of the method is limited by the ill-conditioned relationship between the reflection coefficient and the plasma conductivity; nevertheless, it is sufficient to subdivide the range of the conductivity values into three regions (i.e., low, medium, and high conductivities) to determine the best operating conditions of the antenna. 相似文献
160.
G. Osteria S. Russo 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2008,589(3):465-471
PAMELA, a cosmic ray telescope, was launched into space on 15th June 2006 from the Baikonur cosmodrome aboard of a Soyuz-U and it is in continuous data tacking since 11 July 2006. The Time of Flight system of the PAMELA telescope allows both to distinguish electrons to antiprotons up to about 2 GeV and to measure the absolute charge of the particle. In order to perform these goals the requested time resolution for the whole ToF system is . To fulfill the detector requirements the read out electronics is been required to have a time resolution better than 60 ps with wide dynamic range for charge measurements. The peculiarity of the developed electronics arises from the need to obtain such a time resolution operating in a satellite environment, which implies low-power consumption, radiation hardness, redundancy and high reliability. 相似文献