Black and White Females' Perceptions of Ideal Body Size and Social Norms

Different cultural norms and standards for appropriate female body size might contribute to the disparity in obesity rates between black and white adult females (46.0% and 24.6% respectively). The purpose of this study was to measure adolescents' perceptions of ideal size and social norms regarding female body size as well as adolescents' perceptions of significant others' evaluation and expectations of the adolescents' body size. Subjects included 437 adolescent girls (247 white and 190 black) aged 13 to 19 (x=44.9, SD=.979) from six randomly selected public schools. The subjects, heights and weights were measured. Responses to a body image questionnaire and a series of nine female body drawings (arranged ordinally, 1 to 9, from thinnest to heaviest) were analyzed using the General Linear Model and Logistic Regression. The female body size considered ideal by black females was significantly larger than the size selected as ideal by white females (x= 3.47 and x= 3.13 respectively, p< 0.001). Black females were two times more likely than white females to describe themselves as thinner than other girls their age (O.R. = 2.01, 95% C.I.1.34, 3.01) and seven times as likely to say that they were not overweight (O.R. = 7.08, 95% C.I. 3.72, 13.45). White females wanted to be a smaller size than they currently were and felt encouraged by significant others to lose weight or reduce their size. Black females did not indicate as great a desire as whites to be smaller and they tended to feel that their size was considered satisfactory by significant others. Only subjects from the low SES group perceived that significant others wanted them to gain weight. The differences between black and white subjects' beliefs and perceptions about body size norms may explain, in part, why heavier body weights persist in some cultural groups.     

Aquatic biodiversity and saline lakes: Lake Bogoria National Reserve,Kenya

Lake Bogoria, in the Rift Valley of Kenya is an extreme saline lake (conductivity 40–80 mS cm^–1, alkalinity 1500 m equ l^–1). It is hydrologically more stable than the other, endorheic lakes in Kenya, because it is deep – maximum depth at present just over 10 m in an area of 3000 ha – and so does not have periods when it is dry. It is ecologically simple, with only one species dominating the phytoplankton – the cyanobacterium `spirulina', Arthrospira fusiformis. Its biomass and productivity were very high – biomass between 38 and 365 g l<sup>–1</sup> chlorophyll `a' and 3.4–21 × 10³ coils ml^–1 and net production between 0.24 and 1 gm C m³ h, the latter in a narrow zone of less than a metre. There were no macro-zooplankton in the plankton and the only grazer of A. fusiformis was the lesser flamingo, Phoeniconaias minor,which occurred irregularly in very high concentrations (in excess of 1 × 10⁶). Detritivory in the benthos was effected by a single chironomid species, Paratendipes sp., at a maximum density of 4 × 10⁴ m^–2. The mean daily emergence of adult chironomids was estimated to be 1 × 10³ m^–2, the maximum 3. There was no littoral plant community within the lake but 44 dicotyledonous and 31 monocotyledonous plant species in the drawn-down zone and adjacent to it. A diverse draw-down terrestrial invertebrate fauna, only superficially described here, processed the flamingo feathers and carcasses, with other detritus such as chironomid pupal exuviae and decaying A. fusiformis scum. About 50 bird species depended upon the chironomids, either as they emerged through the water column as flying adults or later on the shoreline as floating pupal exuvia and dead adults. The lake has high conservation value because of three bird species in particular – lesser flamingo, Cape teal and black-necked grebe. The former provides real economic value in a region otherwise impoverished, because of the spectacle of tens of thousands of flamingos set against the landscape of hot springs and fumaroles at the lake edge, which draws 15000 visitors per annum. P. minor has experienced three periods during the past ten years when major mortalities have occurred, the last of which killed 700 birds day^–1. This could have involved as many as 200000 birds (about 1/5th of the maximum population at this lake) if mortality was at a constant rate for the nine months it was observed. Causes of mortality have been suggested as avian tuberculosis, poisoning from cyanobacterial toxins or from heavy metal contamination at Lake Nakuru, but it is still not yet clear what contribution each makes to the problem.     

Long-term storage of DNA-free RNA for use in vaccine studies

RNA replicons represent potential vaccine delivery vehicles, but are considered too unstable for such use. This study examined the recovery, integrity and function of in vitro transcribed replicon RNA encoding hepatitis C virus (HCV) proteins. To remove residual template DNA, the RNA was digested with TURBO DNase followed by RNeasy DNase set and purified through an RNeasy column. The RNA was freeze-dried in distilled water or trehalose, stored under nitrogen gas for up to 10 months and analyzed at different time points. The recovery of RNA stored at < or = 4 degrees C that was freeze-dried in distilled water varied between 66% to zero of that recovered from RNA freeze-dried in 10% trehalose, a figure that depended on the duration of storage. In contrast, the recovery of the RNA stored in trehalose was consistently high for all time points. After recovery, both RNAs were translationally competent and expressed high levels of proteins after transfection, although the level of expression from the trehalose-stored RNA was consistently higher. Thus the addition of trehalose permitted stable storage of functional RNA at 4 degrees C for up to 10 months and this permits the development of RNA vaccines, even in developing countries where only minimum storage conditions (e.g., 4 degrees C) can be achieved.     

Short- and long-range cis interactions between integrated HPV genomes and cellular chromatin dysregulate host gene expression in early cervical carcinogenesis

Development of cervical cancer is directly associated with integration of human papillomavirus (HPV) genomes into host chromosomes and subsequent modulation of HPV oncogene expression, which correlates with multi-layered epigenetic changes at the integrated HPV genomes. However, the process of integration itself and dysregulation of host gene expression at sites of integration in our model of HPV16 integrant clone natural selection has remained enigmatic. We now show, using a state-of-the-art ‘HPV integrated site capture’ (HISC) technique, that integration likely occurs through microhomology-mediated repair (MHMR) mechanisms via either a direct process, resulting in host sequence deletion (in our case, partially homozygously) or via a ‘looping’ mechanism by which flanking host regions become amplified. Furthermore, using our ‘HPV16-specific Region Capture Hi-C’ technique, we have determined that chromatin interactions between the integrated virus genome and host chromosomes, both at short- (<500 kbp) and long-range (>500 kbp), appear to drive local host gene dysregulation through the disruption of host:host interactions within (but not exceeding) host structures known as topologically associating domains (TADs). This mechanism of HPV-induced host gene expression modulation indicates that integration of virus genomes near to or within a ‘cancer-causing gene’ is not essential to influence their expression and that these modifications to genome interactions could have a major role in selection of HPV integrants at the early stage of cervical neoplastic progression.     

A model for bacterial activity in the lung

A bivariate model is proposed for the analysis of data from experiments concerning bacterial activity in the mouse lung. The parameters of the model are discussed and estimated. Using the likelihood ratio statistic, simultaneous confidence intervals are constructed. The improvements over previously used models are then presented.     

Characterization of hepatitis C virus core-specific immune responses primed in rhesus macaques by a nonclassical ISCOM vaccine

Current therapies for the treatment of hepatitis C virus (HCV) infection are only effective in a restricted number of patients. Cellular immune responses, particularly those mediated by CD8(+) CTLs, are thought to play a role in the control of infection and the response to antiviral therapies. Because the Core protein is the most conserved HCV protein among genotypes, we evaluated the ability of a Core prototype vaccine to prime cellular immune responses in rhesus macaques. Since there are serious concerns about using a genetic vaccine encoding for Core, this vaccine was a nonclassical ISCOM formulation in which the Core protein was adsorbed onto (not entrapped within) the ISCOMATRIX, resulting in approximately 1-microm particulates (as opposed to 40 nm for classical ISCOM formulations). We report that this Core-ISCOM prototype vaccine primed strong CD4(+) and CD8(+) T cell responses. Using intracellular staining for cytokines, we show that in immunized animals 0.30-0.71 and 0.32-2.21% of the circulating CD8(+) and CD4(+) T cells, respectively, were specific for naturally processed HCV Core peptides. Furthermore, this vaccine elicited a Th0-type response and induced a high titer of Abs against Core and long-lived cellular immune responses. Finally, we provide evidence that Core-ISCOM could serve as an adjuvant for the HCV envelope protein E1E2. Thus, these data provide evidence that Core-ISCOM is effective at inducing cellular and humoral immune responses in nonhuman primates.     

Within-Subject Interlaboratory Variability of QuantiFERON-TB Gold In-Tube Tests

Background

The QuantiFERON®-TB Gold In-Tube test (QFT-GIT) is a viable alternative to the tuberculin skin test (TST) for detecting Mycobacterium tuberculosis infection. However, within-subject variability may limit test utility. To assess variability, we compared results from the same subjects when QFT-GIT enzyme-linked immunosorbent assays (ELISAs) were performed in different laboratories.

Methods

Subjects were recruited at two sites and blood was tested in three labs. Two labs used the same type of automated ELISA workstation, 8-point calibration curves, and electronic data transfer. The third lab used a different automated ELISA workstation, 4-point calibration curves, and manual data entry. Variability was assessed by interpretation agreement and comparison of interferon-γ (IFN-γ) measurements. Data for subjects with discordant interpretations or discrepancies in TB Response >0.05 IU/mL were verified or corrected, and variability was reassessed using a reconciled dataset.

Results

Ninety-seven subjects had results from three labs. Eleven (11.3%) had discordant interpretations and 72 (74.2%) had discrepancies >0.05 IU/mL using unreconciled results. After correction of manual data entry errors for 9 subjects, and exclusion of 6 subjects due to methodological errors, 7 (7.7%) subjects were discordant. Of these, 6 (85.7%) had all TB Responses within 0.25 IU/mL of the manufacturer''s recommended cutoff. Non-uniform error of measurement was observed, with greater variation in higher IFN-γ measurements. Within-subject standard deviation for TB Response was as high as 0.16 IU/mL, and limits of agreement ranged from −0.46 to 0.43 IU/mL for subjects with mean TB Response within 0.25 IU/mL of the cutoff.

Conclusion

Greater interlaboratory variability was associated with manual data entry and higher IFN-γ measurements. Manual data entry should be avoided. Because variability in measuring TB Response may affect interpretation, especially near the cutoff, consideration should be given to developing a range of values near the cutoff to be interpreted as “borderline,” rather than negative or positive.     

Body Mass and Risk of Hip Fracture Among a National Cohort of Postmenopausal White Women: A Reanalysis

To assess the prospective relationship between body mass and rate of hip fracture, we analyzed data from 2,285 postmenopausal women, aged 50–77 years, who responded to the fwst National Health and Nutrition Examination Survey (NHANES I) in 1971–1974 and the 1982-84 interview of the National Health Epidemiologic Follow-up Study (NHEFS). We plan to add to the previous analysis of these same data by Farmer et al. by 1) including retrospective information on estrogen replacement therapy; 2) increasing the follow-up time by 5 years and using only hospital-verified cases of hip fracture from the 1987 Health Care Facilities Stay data tape; and 3) limiting the analysis to postmenopausal white women, ages 50–77 years. Results of the multivariable Cox regression modeling showed that women with a baseline body mass index in the highest quartile (> 37 kg/m^1.5) experienced a 70% lower rate of hip fracture compared with women in the lowest quartile (≤ 28.7 kg/m^1.5)(RR=0.32; 95%CI:0.12, 0.82). Age was positively related to the risk of hip fracture, with the rate over 20% higher per year of age (RR=1.21; 95%CI:1.13, 1.29). Although reported education level, smoking history, physical activity level, and estrogen replacement were significantly (p < 0.0001) associated with body mass index, these covariates were not related to hip fracture in the multivariable analysis. Our findings corroborate earlier results using this same data source, and suggest that interventions aimed at preserving lean mass and comequent bone integrity should be encouraged among women before menopause and maintained through older adulthood.