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The role of estrogen in pubertal skeletal physiology: epiphyseal maturation and mineralization of the skeleton 总被引:1,自引:0,他引:1
GR Frank 《Acta paediatrica (Oslo, Norway : 1992)》1995,84(6):627-630
The year 1994 is likely to be remembered by many endocrinologists as the year in which dramatic new light was shed on the role played by estrogen in human skeletal physiology. It was in 1994 that two new syndromes were described, each representing a human model in which estrogen action was lacking. The first case was a female with an aromatase defect and a resultant inability to synthesize estrogen, and the second case was a man with an estrogen receptor gene defect that resulted in a non-functioning estrogen receptor and complete estrogen resistance. By examining the phenotypes of these two individuals, we were able, for the first time, to see what pubertal skeletal changes occur in the absence of estrogen action and directly extrapolate the role of estrogen in skeletal physiology. What has become abundantly clear is that it is estrogen and not androgen that is responsible for pubertal epiphyseal maturation and skeletal mineralization 相似文献
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IH Khan MK Campbell D Cantarovich GR Catto C Delcroix N Edward C Fontenaille HW van Hamersvelt IS Henderson RA Koene M Papadimitriou E Ritz C Ramsay D Tsakiris AM MacLeod 《American journal of kidney diseases》1998,31(3):473-478
The need to evaluate the effectiveness of clinical practice to justify expensive therapy in the face of financial constraints in all areas of health care delivery makes it necessary to identify groups of patients who are likely to benefit most from treatment. Various risk stratification methods have been used for analyzing survival probabilities for patients receiving renal replacement therapy. Complicated risk stratification methods produce large numbers of risk groups of small sizes, which makes comparison between individual centers difficult. We compared three simple methods of risk stratification, that divided patients into low-, medium-, and high-risk groups, in a cohort of 1,407 patients who commenced renal replacement therapy in five European countries during a 7-year period. Method 1 considered age (>55 years) and diabetes alone; method 2 used a higher age limit (>70 years) and comorbid illnesses, including those other than diabetes; and method 3 used only the number of comorbidities (none, 1, or > or =2) for stratification. Kaplan-Meier survival curves were constructed for comparison between risk groups and Cox's regression model used to assess strength of relationship with mortality. Although patient survival was significantly different between the low-, medium-, and high-risk groups using all three methods, Cox's regression analysis showed that method 2 provided the greatest discrimination between risk groups. In predicting mortality, method 2 (based on comorbidities and age) showed the highest sensitivity and specificity (84% and 80%, respectively) compared with method 1 (80% and 74%) and method 3 (64% and 82%). Validation of this approach in other populations in a prospective study is required before this method, which takes into account the influences of both age and comorbidity for risk stratification, can be used for comparing survival data and for presenting results of renal replacement therapy. 相似文献
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J H Wolfe D G Waller M B Chapman H N Blackford W G Prout 《Surgery, gynecology & obstetrics》1985,160(4):347-351
Seventeen patients with stable intermittent claudication and a PCV of more than 0.45 were venesected until a PCV of 0.35 was achieved. Only patients that were not considered candidates for surgical treatment were entered into the study. Each patient acted as their own control and was studied twice before the venesection at a mean PCV of 0.49 then after achieving a PCV of 0.35 or less (mean PCV of 0.33), and finally one month after the last venesection (mean PCV of 0.37). Angina developed in one patient after the third venesection and was withdrawn from the study. In the remaining sixteen patients, blood flow of the calf muscle during exercise increased significantly after venesection from 5.90 to 8.84 milliliters per 100 grams per minute (p = 0.02). This was measured by xenon 133 clearance and a cadmium telluride detector. There was also a substantial decrease (p less than 0.001) in whole blood viscosity at both low and high shear stresses, but there was no change in plasma viscosity or plasma fibrinogen. Treadmill claudication distance improved in only two patients. Ten patients were tired when the PCV decreased to 0.35 and subjective claudication distance deteriorated in four of these patients. Subsequent isovolemic venesection with dextran 70 volume replacement to a PCV of 0.35 did not improve the response in the six patients restudied. We conclude that venesection did not benefit these patients with intermittent claudication and there was an unacceptable incidence of side effects. Therefore, we suggest that reducing the PCV to 0.35 should be avoided in patients with intermittent claudication who have been refused surgical treatment. 相似文献
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Pseudoaneurysm is a well-documented but rare complication of retrograde femoral arterial puncture. We present six patients in whom pseudoaneurysm complicated this procedure. The pseudoaneurysm arose from the superficial femoral artery in five patients and from the profunda femoris artery in one. An arteriovenous fistula also arose from the superficial femoral artery in one patient. In no patient did the pseudoaneurysm arise from the common femoral artery. Two mechanisms are postulated as to why pseudoaneurysms rarely complicate puncture of the common femoral artery. 相似文献
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Miriam J Johnson Laura Sheard Anthony Maraveyas Simon Noble Hayley Prout Ian Watt Dawn Dowding 《BMC medical informatics and decision making》2012,12(1):1-14