A quantification of the placebo response in migraine prophylaxis

To quantify the placebo response of prophylactic therapy in migraine, a meta-analysis of prophylactic, double-blind, placebo controlled migraine studies was performed. The total analysis included 22 studies testing 19 different products, including 2013 patients, of which 828 were treated with placebo. A reduction in migraine attacks of 50% or more (responders) was seen in 23.5%+/-8.0 (95% C.I. 18.3-28.8%) of the patients in the placebo groups and 45.5%+/-15.5 (95% C.I. 37.4-53.6%) in the active groups. A reduction in migraine attacks of 16.8%+/-12.7 (95% C.I. 10.9-22.6%) was observed in the placebo groups and 41.8%+/-11.7 (95% C.I. 36.9-46.6%) in the active groups. We propose that if the percentage of responders in an open-label prophylactic trial in migraine is above 35-40%, or if a reduction in migraine attack frequency is found of 40% or more, further studies are indicated to determine the prophylactic activity of the drug. In all studies included in this analysis, no placebo response was seen above these limits.     

沙苑子化学成分研究

从沙苑子80%的乙醇提取物中,首次分得八个化合物。其中沙苑子新甙(neocomplanoside,Ⅶ)和沙苑子杨梅甙(myricomplanoside,Ⅷ)为两个新的黄酮类化合物,其它六个为已知成分。     

External argon laser choroidotomy for subretinal fluid drainage

Purpose: To evaluate the efficacy and safety of external argon laser choroidotomy for drainage of subretinal fluid (SRF) during scleral buckling procedures for the repair of rhegmatogenous retinal detachments. Methods: Fifty eyes of 50 consecutive patients presenting to a hospital-based retinal outpatient clinic with rhegmatogenous detachments underwent choroidotomy with argon endolaser for SRF drainage. The laser parameters used were 0.5 s duration and 0.8 W power. The primary outcome measures were successful drainage of SRF and incidence of complications. The drainage was considered successful if it was sufficient to complete the planned scleral buckling procedure. The extent of subretinal haemorrhage was graded. Results: The mean age of patients was 55 years (range 16–80 years). Successful drainage of SRF was obtained in 47 eyes (94%). The complications observed at the drainage site included subretinal haemorrhage of less than I disc diameter in six eyes (12%) and retinal perforation in one eye (2%). Conclusion: External argon laser choroidotomy appears to be an effective method of draining SRF in rhegmatogenous retinal detachments.     

Spleen function in children with sickle B+ thalassemia

Splenic function in patients with sickle B+ (SB+) thalassemia has been poorly documented. We evaluated the clinical course and splenic function in 12 children with SB+ thalassemia with simultaneous technetium sulfur colloid spleen scans and determination of pitted erythrocytes by direct interference contrast microscopy (DICM). All patients displayed normal uptake of radiocolloid. Mean percentage of pitted erythrocytes was 2.2% compared to 0.06% in 10 normal eusplenic controls and 13.8% in 10 sickle cell patients. In this group of children, who were carefully monitored for 136 patient years, there was no episode of bacteremia/sepsis, and a low prevalence of vaso-occlusive episodes. The slight increase in percentage of pitted erythrocytes of SB+ thalassemia patients does not seem to herald any clinically relevant loss of splenic function. SB+ thalassemia children younger than 10 years of age who do not seem to present a higher risk of invasive bacterial infections than eusplenic children, should receive conservative treatment for isolated febrile episodes and should not be submitted to prophylactic penicillin.     

Stability of amphotericin B in CAPD fluid

Amphotericin B is the drug of choice in continuous ambulatory peritoneal dialysis (CAPD) associated fungal peritonitis and is usually administered intraperitoneally. The drug is stated to be incompatible with anions. All CAPD fluids contain chloride and lactate anions. Therefore, the physical and chemical compatibility of amphotericin B with dextrose 5%, Dianeal 1.36% CAPD fluid, and Dianeal 1.36% peritoneal effluent was studied at amphotericin B concentrations of 1, 2, and 5 mg/L. Amphotericin B was most stable in Dianeal CAPD fluid. The rate of degradation was concentration dependent in dextrose 5% and peritoneal effluent. The higher the concentration, the lower the rate of degradation. After an incubation of 6 h at 37 degrees C, no significant decomposition was found at all concentrations studied in Dianeal CAPD fluid whereas 12-18% decomposition was found in effluent. No physical incompatibility with any solution was observed.     

QDR 4500A dual-energy X-ray absorptiometer underestimates fat mass in comparison with criterion methods in adults

BACKGROUND: Dual-energy X-ray absorptiometry (DXA) has become one of the most frequently used methods for estimating human body composition. Although the DXA technique has been validated for the measurement of fat-free mass and fat mass, differences in calibration between instruments produced by different manufacturers, as well as between different models produced by the same manufacturer, have been reported. OBJECTIVE: The objective was to compare the calibration of the QDR 4500A against criterion methods in a large heterogeneous population. DESIGN: DXA-derived body-composition data were obtained from 7 studies: 6 data sets were provided by the investigators, one of which was published. The data included fat mass and fat-free mass measured with a QDR 4500A and criteria measurements of body composition from total body water by dilution at 4 centers, densitometry from 1 center, and four-compartment analysis at 2 centers. RESULTS: In the cohort of 1195 subjects, 602 men and 593 women aged 19-82 y with a body mass index (in kg/m2) of 16-44, the fan-beam DXA overestimated fat-free mass (P < 0.05). A significant difference was observed in all 7 data sets, and the mean (+/-SE) was 5 +/- 1%. CONCLUSIONS: It is recommended that the lean soft tissue mass estimate with the fan-beam QDR 4500A be reduced by 5% and that for fat mass be increased by that same mass. This finding is particularly important because the National Health and Nutrition Examination Survey is using the QDR 4500A to assess body composition in a nationally representative sample of persons in the United States.     

Uterine neoplasms: MR imaging

Magnetic resonance (MR) studies were performed on 20 healthy volunteers and 41 patients with proved cervical and uterine neoplasms. MR imaging demonstrated normal uterine landmarks in all patients. On T2-weighted images, the normal uterine wall could be differentiated into three distinct layers: a central high-intensity zone, a junctional low-intensity band, and a peripheral medium-intensity area. While most of the normal cervices had only two distinct zones (central high-intensity zone and peripheral low-intensity zone), a small percentage had three layers of signal intensity, similar to the uterine body. Primary cervical and uterine neoplasms could be identified on MR images. In 18 of 22 patients with proved carcinoma, a mass with a signal intensity higher than that of normal cervical lips was seen on T2-weighted images. Endometrial carcinoma was most often identified as expansion of the central high-intensity area; discrete tumor nodules were visible in nine of 15 patients. Mixed müllerian sarcoma appeared as a large pelvic mass with complete obliteration of normal uterine landmarks. MR imaging delineates primary cervical and endometrial carcinoma better than computed tomography does.     

Pathways: a school-based, randomized controlled trial for the prevention of obesity in American Indian schoolchildren

BACKGROUND: Childhood obesity is a major public health problem in the United States, particularly among American Indian communities. OBJECTIVE: The objective was to evaluate the effectiveness of a school-based, multicomponent intervention for reducing percentage body fat in American Indian schoolchildren. DESIGN: This study was a randomized, controlled, school-based trial involving 1704 children in 41 schools and was conducted over 3 consecutive years, from 3rd to 5th grades, in schools serving American Indian communities in Arizona, New Mexico, and South Dakota. The intervention had 4 components: 1) change in dietary intake, 2) increase in physical activity, 3) a classroom curriculum focused on healthy eating and lifestyle, and 4) a family-involvement program. The main outcome was percentage body fat; other outcomes included dietary intake, physical activity, and knowledge, attitudes, and behaviors. RESULTS: The intervention resulted in no significant reduction in percentage body fat. However, a significant reduction in the percentage of energy from fat was observed in the intervention schools. Total energy intake (by 24-h dietary recall) was significantly reduced in the intervention schools but energy intake (by direct observation) was not. Motion sensor data showed similar activity levels in both the intervention and control schools. Several components of knowledge, attitudes, and behaviors were also positively and significantly changed by the intervention. CONCLUSIONS: These results document the feasibility of implementing a multicomponent program for obesity prevention in elementary schools serving American Indian communities. The program produced significant positive changes in fat intake and in food- and health-related knowledge and behaviors. More intense or longer interventions may be needed to significantly reduce adiposity in this population.