Influence of the Gastrointestinal Environment on the Bioavailability of Ethinyl Estradiol Sorbed to Single-Walled Carbon Nanotubes

Recent evidence suggests that, because of their sorptive nature, if single-walled carbon nanotubes (SWCNTs) make their way into aquatic environments, they may reduce the toxicity of other waterborne contaminants. However, few studies have examined whether contaminants remain adsorbed following ingestion by aquatic organisms. The objective of this study was to examine the bioavailability and bioactivity of ethinyl estradiol (EE2) sorbed onto SWCNTs in a fish gastrointestinal (GI) tract. Sorption experiments indicated that SWCNTs effectively adsorbed EE2, but the chemical was still able to bind and activate soluble estrogen receptors (ERs) in vitro. However, centrifugation to remove SWCNTs and adsorbed EE2 significantly reduced ER activity compared to that of EE2 alone. Additionally, the presence of SWCNTs did not reduce the extent of EE2-driven induction of vitellogenin 1 in vivo compared to the levels in organisms exposed to EE2 alone. These results suggest that while SWCNTs adsorb EE2 from aqueous solutions, under biological conditions EE2 can desorb and retain bioactivity. Additional results indicate that interactions with gastrointestinal proteins may decrease the level of adsorption of estrogen to SWCNTs by 5%. This study presents valuable data for elucidating how SWCNTs interact with chemicals that are already present in our aquatic environments, which is essential for determining their potential health risk.

AESOPS: a randomised controlled trial of the clinical effectiveness and cost-effectiveness of opportunistic screening and stepped care interventions for older hazardous alcohol users in primary care

BACKGROUND

There is clear evidence of the detrimental impact of hazardous alcohol consumption on the physical and mental health of the population. Estimates suggest that hazardous alcohol consumption annually accounts for 150,000 hospital admissions and between 15,000 and 22,000 deaths in the UK. In the older population, hazardous alcohol consumption is associated with a wide range of physical, psychological and social problems. There is evidence of an association between increased alcohol consumption and increased risk of coronary heart disease, hypertension and haemorrhagic and ischaemic stroke, increased rates of alcohol-related liver disease and increased risk of a range of cancers. Alcohol is identified as one of the three main risk factors for falls. Excessive alcohol consumption in older age can also contribute to the onset of dementia and other age-related cognitive deficits and is implicated in one-third of all suicides in the older population.

OBJECTIVE

To compare the clinical effectiveness and cost-effectiveness of a stepped care intervention against a minimal intervention in the treatment of older hazardous alcohol users in primary care.

DESIGN

A multicentre, pragmatic, two-armed randomised controlled trial with an economic evaluation.

SETTING

General practices in primary care in England and Scotland between April 2008 and October 2010.

PARTICIPANTS

Adults aged ≥ 55 years scoring ≥ 8 on the Alcohol Use Disorders Identification Test (10-item) (AUDIT) were eligible. In total, 529 patients were randomised in the study.

INTERVENTIONS

The minimal intervention group received a 5-minute brief advice intervention with the practice or research nurse involving feedback of the screening results and discussion regarding the health consequences of continued hazardous alcohol consumption. Those in the stepped care arm initially received a 20-minute session of behavioural change counselling, with referral to step 2 (motivational enhancement therapy) and step 3 (local specialist alcohol services) if indicated. Sessions were recorded and rated to ensure treatment fidelity.

MAIN OUTCOME MEASURES

The primary outcome was average drinks per day (ADD) derived from extended AUDIT--Consumption (3-item) (AUDIT-C) at 12 months. Secondary outcomes were AUDIT-C score at 6 and 12 months; alcohol-related problems assessed using the Drinking Problems Index (DPI) at 6 and 12 months; health-related quality of life assessed using the Short Form Questionnaire-12 items (SF-12) at 6 and 12 months; ADD at 6 months; quality-adjusted life-years (QALYs) (for cost-utility analysis derived from European Quality of Life-5 Dimensions); and health and social care resource use associated with the two groups.

RESULTS

Both groups reduced alcohol consumption between baseline and 12 months. The difference between groups in log-transformed ADD at 12 months was very small, at 0.025 [95% confidence interval (CI)--0.060 to 0.119], and not statistically significant. At month 6 the stepped care group had a lower ADD, but again the difference was not statistically significant. At months 6 and 12, the stepped care group had a lower DPI score, but this difference was not statistically significant at the 5% level. The stepped care group had a lower SF-12 mental component score and lower physical component score at month 6 and month 12, but these differences were not statistically significant at the 5% level. The overall average cost per patient, taking into account health and social care resource use, was £488 [standard deviation (SD) £826] in the stepped care group and £482 (SD £826) in the minimal intervention group at month 6. The mean QALY gains were slightly greater in the stepped care group than in the minimal intervention group, with a mean difference of 0.0058 (95% CI -0.0018 to 0.0133), generating an incremental cost-effectiveness ratio (ICER) of £1100 per QALY gained. At month 12, participants in the stepped care group incurred fewer costs, with a mean difference of -£194 (95% CI -£585 to £198), and had gained 0.0117 more QALYs (95% CI -0.0084 to 0.0318) than the control group. Therefore, from an economic perspective the minimal intervention was dominated by stepped care but, as would be expected given the effectiveness results, the difference was small and not statistically significant.

CONCLUSIONS

Stepped care does not confer an advantage over minimal intervention in terms of reduction in alcohol consumption at 12 months post intervention when compared with a 5-minute brief (minimal) intervention.

TRIAL REGISTRATION

This trial is registered as ISRCTN52557360.

FUNDING

This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 17, No. 25. See the HTA programme website for further project information.

Frequency and intensity of crack use as predictors of women's involvement in HIV-related sexual risk behaviors

Recent trends in the progression of the AIDS epidemic in the United States indicate that women's rates of acquiring HIV are escalating more rapidly than are men's. Consequently, there has been both an increasing interest in and a need for research targeting substance-abusing women's involvement in HIV risk behaviors. In recent years, strong suggestive evidence has arisen to suggest that women who use crack cocaine are at an elevated risk for acquiring HIV, probably as a result of their involvement in high-risk sexual behaviors. The present study is based on a sample of 1723 women from 22 locales around the United States who used crack cocaine at least once during the previous 30 days but who reported never having injected drugs at any point in their lifetime. Women were divided into four groups based on their frequency and intensity of using crack. In subsequent analyses, this grouping was used to predict the extent to which female crack users engage in five sexual risk behavior measures (number of sexual partners, number of drug-injecting sexual partners, number of times having sexual relations while high on alcohol and/or other drugs, number of times trading sex for drugs and/or money, and proportion of all sexual acts involving the use of protection). The data revealed that the women who used crack with the greatest frequency and the greatest intensity were the most heavily involved in risky sexual behaviors. They differed quite sharply from their lower-intensity and/or lower-frequency crack-using counterparts in terms of their HIV risk behavior involvement and in terms of their actual HIV seroprevalence rates.

The acceptability of the female condom among substance-using women in Washington, DC

This research is based on structured interviews, semi-structured interviews, and informal firsthand observation of women residents of Washington, DC who used crack and/or injected drugs during the previous 30 days. The study entailed introducing these women to the female condom, exposing them to an HIV risk reduction intervention teaching them how to use it and how to negotiate its use with their sexual partner(s). Women were tested for HIV and asked to return one week later for their results. They were asked to try the female condom within that first week. Upon returning for their tests results, ethnographers discussed with them their experiences with the female condom. They were reinterviewed for follow-up three months later to assess changes in behavior from baseline as well as their longer term experiences with and opinions of the female condom. The data presented in this paper are based on the interviews conducted one week after baseline. Of particular interest and concern to this research were: women's perceptions of the female condom prior to and subsequent to using it, women's partners' perceptions of the female condom after being introduced to it, and potential barriers to use. In all, 131 women, mostly African-American, took part in this study, which was conducted during the winter of 1997-1998.

Analysis of large and small colony L5178Y tk-/- mouse lymphoma mutants by loss of heterozygosity (LOH) and by whole chromosome 11 painting: detection of recombination

Analysis of 122 spontaneous large and small colony mutants derived from L5178Y tk +/- mouse lymphoma cells at 28 heteromorphic microsatellite loci on chromosome 11 showed that extensive loss of heterozygosity (LOH) is common in both large colony and small colony mutants, eliminating most chromosome 11 loci as candidates for a putative growth control locus. These results, in conjunction with historical cytogenetic data, suggest that a putative growth control locus lies distal to the thymidine kinase (Tk1) gene, near the telomere. Thirty seven mutants were hybridized with a chromosome 11-specific whole chromosome painting probe for analysis of rearrangements. Generally, painting confirmed earlier observations that large colony mutants are karyotypically normal, whereas small colony mutants frequently have detectable rearrangements. A point probe distal to Tk1 revealed no evidence of chromosome breakage in small colony mutants that appeared normal on whole 11 painting and had no LOH. Therefore, the molecular difference between large and small colony mutants remains unknown. Models to explain large and small colony mutants consistent with our findings are presented, including loss of a putative growth control gene, differential mechanisms of chromosome breakage/repair and second site mutations as explanations for small colony mutants. Painting revealed translocations and aneuploidy and showed that non-disjunction was not a common explanation for complete LOH. The most common finding was that large regions of LOH do not result from deletions, demonstrating that these cells can detect recombination events as well as previously observed chromosomal rearrangements, deletions and point mutations.

Identification of a heteromorphic microsatellite within the thymidine kinase gene in L5178Y mouse lymphoma cells

The objective of this work is to identify a heteromorphism within the thymidine kinase (Tk1) gene which can be used to assay for allele loss by means of PCR. Intron F of mouse Tk1 contains two (CA)n microsatellite sequences separated by 107 bp of non-repetitive sequence. We tested this region for heteromorphism in L5178Y mouse lymphoma cells. A PCR primer pair designated Agl1 yielded products of 396 and 194 bp from L5178Y tk+/- genomic DNA. The 194-bp product resulted from a secondary binding site between the two (CA)n repeats for the forward Ag11 primer and was not produced from tk-/- mutants that had lost the functional Tk1b allele. Agl2 primers produced two PCR products of 523 and approximately 440 bp and Agl3 primers produced products of 579 and approximately 500 bp. In both these cases, the difference in product size was approximately equal, indicating that Intron F is approximately 80 bp shorter in the non-functional Tk1a allele than in Tk1b. This heteromorphism forms the basis for an assay for allele loss by means of PCR. Agl1 and Agl3 primers yielded additional products of 91 and 274 bp, respectively, consistent with sizes expected from the mouse Tk1 pseudogenes (Tk1-ps). Our conclusions drawn from an analysis of 122 mutants for Tk1b loss using Agl2 primers agreed with previous analysis of the NcoI heteromorphism. Thus, a simple PCR-based analysis can identify Tk1b loss in the L5178Y mouse lymphoma cells.