Beta-adrenergic blockers reduce the risk of fracture partly by increasing bone mineral density: Geelong Osteoporosis Study.

This population-based study documented beta-blocker use in 59/569 cases with incident fracture and 112/775 controls. OR for fracture associated with beta-blocker use was 0.68 (95%CI, 0.49-0.96). Beta-blockers were associated with higher BMD at the total hip (2.5%) and UD forearm (3.6%) after adjusting for age, anthropometry, and thiazide use. Beta-blocker use is associated with reduced fracture risk and higher BMD. INTRODUCTION: Animal data suggests that bone formation is under beta-adrenergic control and that beta-blockers stimulate bone formation and/or inhibit bone resorption. MATERIALS AND METHODS: We evaluated the association between beta-blocker use, bone mineral density (BMD), and fracture risk in a population-based study in Geelong, a southeastern Australian city with a single teaching hospital and two radiological centers providing complete fracture ascertainment for the region. Beta-blocker use was documented for 569 women with radiologically confirmed incident fractures and 775 controls without incident fracture. Medication use and lifestyle factors were documented by questionnaire. RESULTS: Odds ratio for fracture associated with beta-blocker use was 0.68 (95% CI, 0.49-0.96) for any fracture. Adjusting for age, weight, medications, and lifestyle factors had little effect on the odds ratio. Beta-blocker use was associated with a higher BMD at the total hip (2.5%, p = 0.03) and ultradistal forearm (3.6%, p = 0.04) after adjustment for age, anthropometry, and thiazide use. CONCLUSION: Beta-blockers are associated with a reduction in fracture risk and higher BMD.     

Evaluation of single-dose ciprofloxacin in the eradication of Neisseria meningitidis from nasopharyngeal carriers.

The ability of a single oral 750-mg dose of ciprofloxacin to eradicate Neisseria meningitidis from persistent nasopharyngeal carriers was prospectively evaluated in a placebo-controlled, randomized, double-blinded study. Cultures of specimens taken from all 23 ciprofloxacin-dosed subjects 1 day postdose were negative; cultures from 96% of these subjects were negative at 7 and 21 days postdose, including a specimen from a subject colonized with a minocycline-resistant strain. Of 22 placebo recipients, 20 (91%) remained culture positive. Single-dose ciprofloxacin appears efficacious for meningococcal prophylaxis.     

The radiographic diagnosis of emphysema

There are many findings of emphysema by conventional radiography, but the most reliable and reproducible is that of overinflation, which is best judged by the height and contour of the hemidiaphragm. Even in expert hands, the diagnosis of emphysema by conventional radiography is 65% to 80% accurate, depending to a large degree on the clinical population studied. Although most patients with severe emphysema are diagnosed correctly, only half of those patients with mild-to-moderate levels of parenchymal destruction are detected. Emphysema is identified by CT as focal, unmarginated, hypodense areas unassociated with fibrosis. Emphysema also may be detected by computer programs selecting pixels with abnormally low attenuation values. By either method, CT is superior to chest radiography in detection of mild and moderate degrees of emphysema and has detection rates of more than 90% and correlation with extent and severity of disease in more than 80% of patients. CT may be more sensitive to the presence of mild emphysema than pulmonary function tests, which are global indications of lung function. HRCT appears to offer a small, but real, advantage over 10-mm collimation in identification of small areas of emphysema, but areas of emphysema smaller than 0.5 cm in diameter are commonly missed, even with HRCT. Wider use of CT for investigation of relatively asymptomatic smokers may allow early diagnosis of emphysema and provide more information of the natural history of this disease, information that is sorely lacking at this time. Assessment of potential therapy such as smoking cessation or antioxidants will only be possible with widespread use of a method that is of relatively low risk, easy to duplicate, and accurate.     

The emergency physician and patient confidentiality: A review

Confidentiality is a promise rooted in tradition, law andmedical ethics. Emergency physicians treat a variety of patients to whom confidentiality is of vital importance: employees, celebrities, victims of violence or disaster, minors, students, criminals, drug abusers, and patients with STDs. EDs should develop methods of ensuring confidentiality for all patients.³⁴Although confidentiality is an important principle thatshould be respected and guarded, it is not absolute. Various laws mandate disclosure of certain patient information; in addition, an overriding moral duty may occasionally require, a breach of confidentiality. As Beauchamp and Childress noted, “the therapeutic role may sometimes have to yield to ones role as citizen and as protector of the interests of others”.¹⁹ In general, however, circumstances requiring a breach of confidentiality are rare.     

Retinal vasculitis

Evidence is now accumulating on both clinical and experimental grounds that the retina is an a priori source of inflammatory activity. Reactive inflammation in the retina may produce many of the clinical signs previously ascribed to uveal inflammation. Autoimmune mechanisms are probably responsible for the majority of cases of retinal vasculitis. Autoimmune retinal vasculitis occurs without other classical signs of inflammatory response in any other parts of the body. When associated systemic manifestations occur they may reflect different underlying immunopathogenic abnormalities. Thus in diseases with predominantly arterial involvement (e.g. systemic lupus erythematosus, polyarteritis nodosa) the retinal arteries bear the brunt of this disease. In Behçet''s disease the systemic involvement is usually venous and ocular involvement produces diffuse capillary and venous inflammation with areas of retinal necrosis and major vascular occlusion. The retinal appearances differ from sarcoidosis in which a granulomatous response produces characteristic periphlebitis. Finally, autoimmune retinal vasculitis produces diffuse capillary and venous damage, without any systemic signs. In the next decade the search will be for the identification of the specific antigens initiating these disparate retinal features. Retinal S antigen is a potent antigen, but rhodopsin, interphotoreceptor binding protein, and transducin all need further experimental investigation. Precise documentation will herald the dawn of new therapeutic measures based on a sound immunological fabric.     

3,5-甾二烯化合物的合成及抗早孕活性

以18-甲基-17β-羟基-17α-乙炔基-雌甾-4-烯-3-酮(18-甲基炔诺酮),17β-羟基-17α-乙缺基-雌甾-4-烯-3-酮(炔诺酮),17β-羟基-17α-乙炔基-雄甾-4-烯-3-酮(妊娠素)和17a-羟基孕甾-4-烯-3,20二酮(17α-羟基黄体酮)为原料,经NaBH,还原、脱水、双键转位和酯化等反应合成一系列3,5-甾二烯化合物,用¹HNMR和MS证明了它们的结构。动物筛选结果表明,17β-丙酰氧基-17α-乙炔基-雌甾-3,5-二烯(IV_b2有明显的抗早孕活性。中断早期妊娠的作用似与其雌激素活性有关。