运动前进食不同血糖指数食物对长跑能力的影响

目的 :探讨运动前进食不同血糖指数食物对长跑能力的影响。方法 :实验设计采用平衡重复测试法 ,8名男子耐力长跑运动员在间隔期不少于 7天内 ,在隔夜空腹情况下分别进食含相等热量的低血糖指数 [Glycemicindex (GI) ](GI =37)或高GI(GI =77)的碳水化合物 (CHO)食物 (CHO∶1 5g/kg体重 )。 2小时后 ,受试者在水平跑台上进行 2 1km的长跑能力测试。首 5km中 ,受试者以其 70 %VO2 max的速度跑步 ,而其后的 16km ,则可随意选择速度以最短时间完成。结果 :与高GI试验相比 ,所有受试者在进食低GI食物后的跑步时间明显缩短 (98 7± 2 0vs 10 1 5± 2 1min ,P<0 0 1)。整个跑步全程中 ,低GI试验的血糖及血清游离脂肪酸 (FFA)的水平较高GI试验为高。虽然进食高GI食物后两小时的血清胰岛素较高 ,但在运动过程中 ,血清胰岛素、皮质醇、血乳酸水平与低GI试验相比均无显著差异。与高GI试验相比 ,低GI试验中CHO氧化在能量供应上的依赖低 9 5 % ,而脂肪氧化则高 17 9%。结论 :在运动前 2小时进食低血糖指数的CHO食物 ,比提供同等热量的高血糖指数食物能更有效地提高长跑运动的能力。     

Comprehensiveness of substance use prevention programs in U.S. middle schools

Purpose: To assess how current practice in middle school substance use prevention programs compares with seven recommended guidelines adapted from the Centers for Disease Control and Prevention guidelines for school-based tobacco use prevention programs.Methods: Substance use prevention practice was analyzed using data from a 1999 mailed questionnaire of a nationally representative sample of 1496 public and private schools with middle school grades that reported having a substance use prevention program. Respondents answered questions about substance use prevention education and activities in the whole school and in their own classroom. Weighted prevalence estimates for the seven recommendations are presented, and multiple regression was used to analyze correlates of implementation of the recommendations.Results: An estimated 64.2% of schools met four or more of the recommendations for school-based substance use prevention practice; 4.0% met all seven recommendations. Schools were most likely to report having and enforcing substance use prevention policies (84.3%) and least likely to report training teachers in substance use prevention (17.9%). More recommendations were implemented in schools that were public and had larger enrollments, greater perceived availability of resources, greater school board and parental support for substance use prevention, and had hired a school substance use prevention coordinator.Conclusions: The low prevalence of comprehensive substance use prevention programs in U.S. middle schools may limit the potential impact of school programs on the prevalence of youth substance use.     

Fetal hemoglobin induction with butyric acid: efficacy and toxicity

Butyric acid induces fetal hemoglobin (HbF), a property of potential therapeutic advantage in patients with disorders of globin chain synthesis. We performed dose escalation studies of this compound in baboons to assess whether clinically significant increases in HbF are achievable, and to define the associated toxicities. Additionally, the effect of butyrate in combination with erythropoietin on HbF induction was assessed. HbF induction in response to butyrate was dependent on the dose and duration of treatment. Doses of butyrate less than 4 g/kg/d were associated with minimal toxicity (hypokalemia) and significant HbF induction in these nonanemic animals, with 1 g/kg/d producing an increase in HbF-containing reticulocytes (F reticulocytes) from 0.9% to 8.7% and an increase in HbF from 0.8% to 1.4%. A dose of 2 g/kg/d resulted in an increase in F reticulocytes from 2.1% to 27.8% and an increase in HbF from 0.7% to 2.2%. Doses of 4 g/kg/d in another animal produced an increase in F reticulocytes from 1% to 21.6% and in HbF from 1.9% to 5.3%. Infusions in excess of 4 g/kg/d were complicated (after a variable amount of time) by a decreased level of alertness (caused by hyperosmolality or butyrate itself) and hematologic toxicity (with declines in reticulocyte, white blood cell, and platelet counts). Prolonged infusions of high doses of butyrate (8 to 10 g/kg/d) were associated with peak F reticulocyte percentages reaching 38% to 64.5% and HbF reaching levels in excess of 20%. These high doses (8 to 10 g/kg/d) were complicated in two animals with a striking and unique neuropathologic picture and, in one animal, multiorgan system failure. Erythropoietin in combination with butyrate, induced F reticulocytosis in an additive manner. We conclude that butyric acid is a strong inducer of HbF, particularly when administered in combination with erythropoietin. As chronic toxicities remain undefined, patients in future clinical trials of this and similar compounds should be monitored closely for evidence of neurologic toxicity.     

The mutational archive in proviral DNA does not change during 24 months of continuous or intermittent highly active antiretroviral therapy

Objectives The aim of the study was to determine the modifications of the mutational archive in proviral HIV-1 DNA occurring during 24 months of intermittent or continuous highly active antiretroviral therapy (HAART).
Methods The study population included subjects enrolled in the Istituto Superiore di Sanità Pulsed Antiretroviral Therapy (ISS PART) clinical trial. All of these patients were on first-line HAART and had plasma HIV-1 RNA below 50 HIV-1 RNA copies/mL. A genotypic resistance test was performed on HIV-1 DNA extracted from peripheral blood mononuclear cells (PBMC) at baseline and after 24 months of follow-up. Resistance-associated mutations (RAMs) were defined according to the International AIDS Society (IAS) USA classification.
Results Sixty-nine subjects were included in the study [36 enrolled in arm A of the ISS PART (continuous HAART) and 33 enrolled in arm B (intermittent HAART)]. No major modifications of the mutational archive were found in either group after 24 months of follow-up, in terms of both the proportion of subjects with mutations and the total number of mutations.
Conclusions In this patient population, the mutational archive in HIV-1 DNA extracted from PBMC was stable for 24 months, irrespective of HAART modality, whether continuous or intermittent.     

Bilateral and subcutaneous palmar nodules in a 2-year-old child suggesting deep granuloma annulare

Granuloma annulare is a benign, relatively common dermatosis in childhood. The subcutaneous form is rare, and lesions typically occur on the legs, buttocks and scalp. We report a case of a deep granuloma annulare confined to the palms of the hands in a 2-year-old child.     

Talairach-Based Parcellation of Neonatal Brain Magnetic Resonance Imaging Data: Validation of a New Approach

BACKGROUND AND PURPOSE: Talairach-based parcellation (TP) of human brain magnetic resonance imaging (MRI) data has been used increasingly in clinical research to make regional measurements of brain structures in vivo. Recently, TP has been applied to pediatric research to elucidate the changes in regional brain volumes related to several neurological disorders. However, all freely available tools have been designed to parcellate adult brain MRI data. Parcellation of neonatal MRI data is very challenging owing to the lack of strong signal contrast, variability in signal intensity within tissues, and the small size and thus difficulty in identifying small structures used as landmarks for TP. Hence the authors designed and validated a new interactive tool to parcellate brain MRI data from newborns and young infants. METHODS: The authors' tool was developed as part of a postprocessing pipeline, which includes registration of multichannel MR images, segmentation, and parcellation of the segmented data. The tool employs user-friendly interactive software to visualize and assign the anatomic landmarks required for parcellation, after which the planes and parcels are generated automatically by the algorithm. The authors then performed 3 sets of validation experiments to test the precision and reliability of their tool. RESULTS: Validation experiments of intra-and interrater reliability on data obtained from newborn and 1-year-old children showed a very high sensitivity of >95% and specificity >99.9%. The authors also showed that rotating and reformatting the original MRI data results in a statistically significant difference in parcel volumes, demonstrating the importance of using a tool such as theirs that does not require realignment of the data prior to parcellation. CONCLUSIONS: To the authors' knowledge, the presented approach is the first TP method that has been developed and validated specifically for neonatal brain MRI data. Their approach would also be valuable for the analysis of brain MRI data from older children and adults.