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MATERIALS AND METHODS: Patients with operable colorectal cancer in the ascending colon, descending colon, and rectum were randomized to 500 cGy before definitive surgery. Patients with stage A and B1 lesions received no further treatment. All patients with stage B2, B3, C1, C2, and C3 received a minimum of 4500 cGy postoperatively. RESULTS: Three hundred fifty-three patients were registered for the study. Three hundred one patients were available for analyses. Follow-up was a minimum of 5 years on all study patients. The majority of patients had rectal cancer. Complications of treatment were acceptable. Two hundred thirty-one patients had stage B2, B3, C1, C2, or C3 tumors. Estimated 5-year rates for no preoperative therapy versus preoperative therapy were as follows: local recurrence 29% versus 26%; metastasis 41% versus 43%; and survival 54% versus 54%. No statistical benefit was observed for preoperative treatment. CONCLUSIONS: In a prospective randomized trial designed to test the value of low-dose preoperative irradiation followed by surgery and postoperative irradiation, the authors were unable to observe any benefit to low-dose preoperative therapy in patients with unfavorable stages.  相似文献   
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Six cases of identical twin pregnancies which occurred in 2163cycles of in-vitro fertilization during a 3 year period arereported. Monozygosity was confirmed when the number of fetusesexceeded the number of embryos replaced (n = 4) or when twoconcepti were observed in a single amniotic sac (n = 2). Eachof the reported pregnancies resulted from replacement of embryoseither with naturally thin zonae pellucida or embryos whosezonae had been breached during micromanipulation for assistedfertilization (subzonal sperminsertion) or assisted hatching.That such cases exclusively gave rise to monozygosity suggestsa link between the physical state of the zona pellucida, hatching,and generation of identical twins.  相似文献   
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The medical aspects of soccer injury epidemiology   总被引:3,自引:0,他引:3  
In this article, the six major studies of soccer injury epidemiology are reviewed. Strengths and weaknesses of each epidemiologic design are critiqued and the crucial importance of the definition of injury is emphasized. The effect of age, sex, and intensity of play on injury rates is discussed. Our present knowledge of injury rate by anatomical site, player position, and the type of playing surface are reviewed. We examined the importance of player factors such as flexibility, joint laxity, weakness, and incomplete rehabilitation from other injuries. In addition, we reviewed the role played by inadequate equipment, field conditions, and rule violations. A successful program for soccer injury prevention is described, and guidelines for future soccer injury epidemiology research are proposed.  相似文献   
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A family history study of second-degree relatives of 19 patients with anxiety neurosis (panic disorder) and 19 controls showed a morbidity risk of 9.5% among the former compared with 1.4% among the latter. These risks were approximately half those found among first-degree relatives. Female relatives were at higher risk for anxiety neurosis. The risk for other psychiatric illnesses did not differ between the relatives of anxiety neurosis and controls.  相似文献   
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