Immunological control of chronic HIV-1 infection: HLA-mediated immune function and viral evolution in adolescents.

BACKGROUND: Differential protein targeting by HIV-specific CD8 T cells is associated with disparate plasma viral loads; however, it is unclear if the quality of these responses differs depending upon the specificity of the targeted epitopes. METHODS: We examined HIV-specific CD8 T-cell responses in HIV-infected adolescents carrying either an HLA class I allele associated with a favorable prognosis (HLA-B*57) or an allele associated with usual disease progression (HLA-B*35 or HLA-B*53) using interferon-gamma ELISpot and ICS assays. RESULTS: In an interferon-gamma ELISpot assay, p24 was the dominant protein targeted by B*57 carriers while responses to Nef dominated in B*35 or B*53 positive carriers. This differential protein targeting did not change during 4 years of follow-up. In these chronically infected adolescents, there were no significant differences in the quality of the immunodominant T-cell responses between the B*57 and B*35/B*53 carriers as measured by peptide avidity, degranulation, and immune memory markers. There was a trend towards higher expression of interleukin-2 from B*57-KF11 restricted CD8 T cells although this difference was not significant. Nevertheless both B*57 and B*35/53-restricted responses were relatively potent as reflected by the propensity of CD8 T cells to escape in p24 and Nef, respectively. CONCLUSIONS: Differential protein targeting rather than the quality of T-cell responses appears to be a major distinguishing feature of HIV-specific CD8 T cells induced in B*57 carriers. These data suggest that viral fitness costs associated with CD8 T-cell pressure is an important factor determining differences in the viral load among HIV-infected patients.

Use of complementary and alternative medicine for weight control in the United States.

OBJECTIVES: The purpose was to assess the prevalence and correlates of complementary and alternative medicine use for weight control. DESIGN: A list-assisted random-digit-dialed telephone survey of adults was conducted in the fall of 2002 (n = 11,211). The focus of the study was complementary and alternative medicine (CAM) use, other than dietary supplements, in the previous 12 months. SETTINGS/LOCATION: The sample of respondents was drawn from the total noninstitutionalized U.S. adult population residing in telephone-equipped locations. SUBJECTS: The sampling procedures were designed to obtain adequate representation of Hispanic and non-Hispanic black respondents. Data from the total sample of 11,211 were weighted to achieve an estimate of the U.S. population. Analyses focused on 372 people who had used CAM within the previous 12 months. RESULTS: Of the total, 3.3% (n = 372) had used a CAM therapy in the previous 12 months. Higher adjusted odds ratios for CAM use were found among respondents who were exercising for weight control; using a lower carbohydrate, higher protein diet; using a nonprescription weight-loss product(s); overweight; physically active; and not satisfied with one's body (adjusted for age, race, gender, education, and city size). The most often used therapies were yoga (57.4%), meditation (8.2%), acupuncture (7.7%), massage (7.5%), and Eastern martial arts (5.9%). CAM users used CAM therapies on their own (62.6%), in a group setting (26.8%) or with a CAM practitioner (10.6%). CONCLUSIONS: The use of CAM therapies other than dietary supplements for weight loss was relatively low. The most popular therapy was yoga, and the majority of CAM users used CAM therapies on their own. Persons who had used other weight loss methods had greater odds for using CAM in the previous 12 months, suggesting that CAM use is often added to other weight-loss strategies.

Estimating energy expenditure from the Minnesota Leisure Time Physical Activity and Tecumseh Occupational Activity questionnaires - a doubly labeled water validation.

An accurate, simple method for assessing energy expenditure in individuals and in free-living populations continues to be elusive. To compare estimates of energy expenditure (EE) from a combination of two previously validated physical activity questionnaires: Tecumseh Occupational (EE(TEC)) and a 4-wk history version of the Minnesota Leisure Time Physical Activity that included household activities (EE(MNLTPA)) and EE from sleep (EE(SLEEP)), to EE obtained from doubly labeled water (EE(DLW)). We studied free-living males (n = 24) eating a controlled diet designed to maintain body weight and determined EE from doubly labeled water (DLW) during 14 days and EE from physical activity instruments used in epidemiological studies (EE(TEC) and EE(MNLTPA)). There was excellent agreement between EE(DLW) (mean +/- SEM, 13.55 +/- 0.38 MJ/d) and EE(TEC) + EE(MNLTPA) + EE(SLEEP) (EE(TOTAL1)) (13.79 +/- 0.89 MJ/d) with a difference of only 1.0% +/- 5.4%. When the EE from watching TV, reading, and childcare activities was added the total EE (EE(TOTAL2)) (14.87 +/- 0.90 MJ/D) overestimated EE(DLW) by 8.9% +/- 5.4%. Both of these estimates of EE had significant regressions against EE(DLW) (EE(TEC) + EE(MNLTPA) + EE(SLEEP), R(2) = 0.38, P < 0.001; EE(TOTAL2), R(2) = 0.39, P < 0.001). Men whose occupations involved significant intermittent moderate activity had the largest disagreement between EE(DLW) and estimates from the questionnaires. This investigation demonstrates that a combination of previously validated physical activity questionnaires can be used to accurately determine the mean energy expenditure of a population of employed males.

Comparison of energy expenditure estimates from doubly labeled water, a physical activity questionnaire, and physical activity records.

BACKGROUND: Various methods are used by epidemiologists to estimate the energy cost of physical activity; these include physical activity records and recalls. However, there is limited validation of these methods against the doubly labeled water technique for determining energy expenditure (EE). OBJECTIVE: We compared EE as estimated by indirect methods (physical activity records and recall questionnaires) used in epidemiologic studies with EE obtained from doubly labeled water (EE(DLW)) in free-living men. DESIGN: We determined EE(DLW), energy intake at weight maintenance, and EE from 7-d physical activity records (EE(Record)) and a 7-d physical activity recall questionnaire (EE(Recall)) in 24 men aged 41 plus minus 2.0 y ( plus minus SEM) with a body mass index (in kg/m(2)) of 25.1 plus minus 0.5. RESULTS: There was excellent agreement between EE(DLW) (13.27 plus minus 0.35 MJ/d) and energy intake (13.19 plus minus 0.36 MJ/d), with a difference of 0.5 plus minus 1.0% ( plus minus SE). The indirect measures of physical activity and EE were 14.17 plus minus 0.37 MJ/d for EE(Record) (difference from EE(DLW): 7.9 plus minus 3.2%) and 17.40 plus minus 1.45 MJ/d for EE(Recall) (difference from EE(DLW): 30.6 plus minus 9.9%). CONCLUSIONS: Seven-day physical activity records provide an acceptable estimate of EE in free-living adults compared with EE(DLW), but 7-d physical activity recalls have limited application to estimate daily EE. For optimal validity, the 7-d physical activity records require good subject compliance and the provision of careful instructions for their use.