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排序方式: 共有311条查询结果,搜索用时 15 毫秒
1.
In order to determine if serial, noninvasive evaluation of polytetrafluoroethylene (PTFE) vascular access grafts could identify a subgroup of patients at risk for thrombosis, the authors studied flow characteristics, using duplex ultrasonic scanning, in 18 hemodialysis patients with forearm loop grafts. On average, five examinations were performed per patient over the 10-month study period. Seven episodes of thrombosis occurred in six patients. The mean Doppler flow in grafts that subsequently thrombosed was significantly lower than in those that did not (544 +/- 218 ml/min versus 843 +/- 391 ml/min, p less than 0.001). The interval from last examination to thrombosis ranged from 13 to 58 days. At a defined cut-off flow of 450 ml/min, this test yielded a sensitivity of 83% and a specificity of 75% for episodes of thrombosis occurring within 2 to 6 weeks. The authors conclude that episodes of thrombosis in PTFE arm loop grafts are usually preceded by significantly lower Doppler-measured flow than grafts that do not thrombose and that it may be possible, by this means, to identify grafts at risk.  相似文献   
2.
A 40-year-old man developed fulminant multisystem failure several days after elective repair of an inguinal hernia. Toxic shock syndrome (TSS) was diagnosed. There was, however, no evidence of wound infection at the time of multisystem failure. Only later in his hospital course did the wound drain. Staphylococcus aureus was cultured from the wound and was the presumed etiologic agent in the patient's life-threatening illness. The patient recovered fully with supportive care, antibiotics, and surgical debridement of the inguinal hernia site. This case is discussed in the context of existing literature on the toxic shock syndrome. The site of infection is typically nonsuppurative, but the systemic manifestations are typically life threatening. The responsible organism is commonly believed to be a strain of S. aureus that expresses a toxin (TSS toxin-1) that effects multisystem failure, but which also diminishes the local inflammatory response and explains the benign appearance of the wound. Although this is a rare clinical entity, elective surgical procedures complicated by fatal TSS have been reported. Surgeons should understand this disease and the management necessary to avert mortality.  相似文献   
3.
Testicular microlithiasis: sonographic and clinical features.   总被引:7,自引:0,他引:7  
Eleven cases of bilateral diffuse microlithiasis of the testes were evaluated sonographically. The presence of testicular microlithiasis was coincidental to the presence of testicular neoplasms (n = 2), nontesticular malignant lesion in the abdomen or chest (n = 2), subfertility (n = 2), varicocele (n = 1), epididymitis (n = 1), testicular maldescent (n = 1), scrotal trauma (n = 1), and transient scrotal pain (n = 1). Clinical follow-up suggested that testicular microlithiasis is an asymptomatic nonprogressive condition. Sonographic examination of testicular microlithiasis shows diffuse hyperechoic nonshadowing foci measuring 1-2 mm in diameter throughout both testes. The diagnosis of testicular microlithiasis was pathologically proved in five cases. In six cases, the diagnosis was made on the basis of the sonographic appearance (n = 6), clinical information and follow-up (n = 6), and radiologic demonstration of testicular microcalcifications (n = 3). The sonographic appearance of testicular microlithiasis is specific, and we believe that biopsy or orchiectomy in these cases is unnecessary.  相似文献   
4.
Abdominal abnormalities in AIDS: detection at US in a large population   总被引:1,自引:0,他引:1  
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5.
The ring-down artifact   总被引:1,自引:0,他引:1  
"Ring-down" is an ultrasound artifact that appears as a solid streak or a series of parallel bands radiating away from abdominal gas collections. Using an in vitro system of bubbles in water or gelatin, it was found that the ring-down artifact originated from the center of a cluster of four bubbles (bubble tetrahedron), three on top and one nestled beneath. Entrapped between the bubbles is a horn- or bugle-shaped fluid collection that we theorize emits a continuous sound wave back to the transducer when struck by an ultrasound pulse. Electronic processing by the scanner converts this continuous sound wave into the series of bands seen in the ring-down artifact.  相似文献   
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The changing face of prostate cancer.   总被引:4,自引:0,他引:4  
Prostate cancer remains the most common noncutaneous human malignancy, and the second most lethal tumor among men. However, the natural history of the disease is often prolonged, and the survival benefits of local therapy for men with low-risk tumors may not be realized for a decade or more, as is increasingly well demonstrated in long-term observational cohorts in both the United States and Europe. A significant proportion of men with prostate cancer may be overdiagnosed, in the sense that diagnosis may not improve their lifespan or quality of life. However, the extent to which overdiagnosis represents a true problem relates to the consistency with which diagnosis leads invariably to active treatment. Prostate cancer is diagnosed at progressively earlier stages and with lower risk features; despite these trends, patients are less likely now than a decade ago to undergo a trial of active surveillance. Rates of brachytherapy and hormonal therapy use, in particular, have risen markedly. Important progress has been made in recent years in prostate cancer risk assessment. These advances, in combination with biomarkers in later stages of development, should be expected in the coming years to yield further improvements in clinicians' ability to diagnose prostate cancer early, and guide appropriately selected patients toward increasingly tailored treatment.  相似文献   
8.
In 2012, the U.S. Preventive Services Task Force (USPSTF) issued a blanket “D” recommendation against all prostate-specific antigen (PSA)-based early detection efforts for prostate cancer, reflecting critical misinterpretations of the major evidence regarding benefits and harms of such testing. Against the backdrop of the ensuing controversy, in 2013 the American Urological Association (AUA) published a new, methodologically rigorous guideline. This guideline recommended that men aged 55–69 be offered biennial screening in the setting of shared decision-making, that men under 40 or over 69 years of age should not be screened routinely, and that evidence was insufficient to recommend screening for men aged 40–54 years. While it has received criticism with regard to the age-based recommendations, the AUA guideline reflects a far better and more balanced presentation of the available evidence than the USPSTF statement. However, because the USPSTF is far more influential than the AUA among primary care providers, the ultimate impact of the new AUA guideline on practice patterns may be limited. Optimizing early detection practices should involve consensus-building incorporating both primary care and specialist input, with the goals of minimizing overtreatment of low-risk disease while continuing to reduce prostate cancer mortality rates through early detection and aggressive management of high-risk disease.  相似文献   
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