Gabrielle E. Kelly

Interactions between HIV and hepatitis B virus in homosexual men : effects on the natural history of infection

Objectives:Hepatitis B virus (HBV) and HIV infections share risk factors; therefore, coinfection is common. Interactions have been reported but controlled studies have been limited. Our objective was to study the effect of HIV infection on the natural history of chronic HBV infection and the reverse effect of the HBV carrier state on HIV infection. Design:Prospective observational cohort study. Setting:Open-access outpatient HIV/genitourinary medicine clinic at a Central London hospital. Patients:Total of 152 untreated homosexual male HBV carriers and 212 HBV surface antigen-negative controls (41.4 and 70.3% HIV-seropositive, respectively). Outcome measures:The rate of loss of serum HBV e antigen (HBeAg) and its reappearance in HIV-infected and HIV-uninfected HBV carriers; serum HBV DNA levels (measured by dot-blot hybridization assay), HBV DNA polymerase activity and liver transaminase activities; the progression of HIV infection to symptomatic disease or AIDS in HIV-infected compared with HBV-HIV coinfected patients. Results:In HIV-infected HBV carriers, serum HBV DNA polymerase activity was higher, alanine aminotransferase was lower and loss of serum HBeAg (mean follow-up, 2.8 years) occurred at a lower rate when compared with HIV-uninfected HBV carriers (estimated relative hazard, 0.39; 95% confidence interval, 0.161–0.942). Concomitant chronic HBV infection had no detectable effect on the rate of progression of HIV disease after correction for lead-time bias. Conclusion:This study strengthens the evidence for a significant effect of HIV infection on the natural history of chronic HBV infection, which by prolonging the period of infectivity could have an important impact on the epidemiology of HBV infection in regions, or patient groups, with high HIV seroprevalence. There was no evidence of an important effect of HBV carriage on HIV disease progression.

Hepatitis C virus: evidence for sexual transmission.

OBJECTIVE--To determined the prevalence of hepatitis C virus infection and associated risk factors in patients attending a genitourinary medicine clinic, as evidence for sexual transmission. DESIGN--Seroprevalence estimated by reactivity in an enzyme immunoassay for antibodies to C100 protein with supplementary testing with a recombinant immunoblot assay and an assay for hepatitis C virus RNA. SETTING--Outpatient genitourinary medicine clinic in central London. PATIENTS--The panel of 1046 serum samples was from 1074 consecutive patients attending the clinic during November and December 1987 and having blood taken for routine testing for syphilis. Before samples were anonymised demographic and risk factor information was extracted from the clinic notes. Samples had already been tested for antibody to HIV-I and antibody to hepatitis B core antigen. MAIN RESULTS--Significantly more homosexual subjects than heterosexual subjects were positive for hepatitis C antibody determined by enzyme immunoassay alone (19/275 (6.9%) v 8/771 (1.0%), odds ratio 7.14, p less than 0.0001) and also when reactive serum samples were also tested by recombinant immunoblot assay (6/270) (2.2%) v 3/770 (0.4%), odds ratio 5.88, p less than 0.02). There were also significant associations in patients positive for hepatitis C antibody with positivity for antibodies to HIV and to hepatitis B core antigen, lifetime number of sexually transmitted diseases (homosexual men only), and age (all groups combined). Most patients whose serum samples contained specific antibodies to hepatitis C virus were viraemic. CONCLUSIONS--The study provides strong evidence for the sexual transmission of hepatitis C virus. Assays derived from other gene products are desirable to investigate the specificity and sensitivity of the enzyme immunoassay for C100 antibody as a marker of hepatitis C virus infection.

Expression of SRC-1, AIB1, and PEA3 in HER2 mediated endocrine resistant breast cancer; a predictive role for SRC-1

Background: In human breast cancer, the growth factor receptor HER2 is associated with disease progression and resistance to endocrine treatment. Growth factor induced mitogen activated protein kinase activity can phosphorylate not only the oestrogen receptor, but also its coactivator proteins AIB1 and SRC-1. Aim: To determine whether insensitivity to endocrine treatment in HER2 positive patients is associated with enhanced expression of coactivator proteins, expression of the HER2 transcriptional regulator, PEA3, and coregulatory proteins, AIB1 and SRC-1, was assessed in a cohort of patients with breast cancer of known HER2 status. Methods: PEA3, AIB1, and SRC-1 protein expression in 70 primary breast tumours of known HER2 status (HER2 positive, n = 35) and six reduction mammoplasties was assessed using immunohistochemistry. Colocalisation of PEA3 with AIB1 and SRC-1 was determined using immunofluorescence. Expression of PEA3, AIB1, and SRC-1 was correlated with clinicopathological parameters. Results: In primary breast tumours expression of PEA3, AIB1, and SRC-1 was associated with HER2 status (p = 0.0486, p = 0.0444, and p = 0.0012, respectively). In the HER2 positive population, PEA3 expression was associated with SRC-1 (p = 0.0354), and both PEA3 and SRC-1 were significantly associated with recurrence on univariate analysis (p = 0.0345; p<0.0001). On multivariate analysis, SRC-1 was significantly associated with disease recurrence in HER2 positive patients (p = 0.0066). Conclusion: Patients with high expression of HER2 in combination with SRC-1 have a greater probability of recurrence on endocrine treatment compared with those who are HER2 positive but SRC-1 negative. SRC-1 may be an important predictive indicator and therapeutic target in breast cancer.

Associations and Interactions between Ets-1 and Ets-2 and Coregulatory Proteins, SRC-1, AIB1, and NCoR in Breast Cancer

Purpose: Associations between p160 coactivator proteins and the development of resistance to endocrine treatment have been described. We hypothesized that nuclear receptor coregulatory proteins may interact with nonsteroid receptors. We investigated the mitogen-activated protein kinase–activated transcription factors, Ets, as possible interaction proteins for the coactivators SRC-1 and AIB1 and the corepressor NCoR in human breast cancer. Experimental Design: Expression and coexpression of Ets and the coregulatory proteins was investigated using immunohistochemistry and immunofluorescence in a cohort of breast tumor patients (N = 134). Protein expression, protein-DNA interactions and protein-protein interactions were assessed using Western blot, electromobility shift, and coimmunoprecipitation analysis, respectively. Results: Ets-1 and Ets-2 associated with reduced disease-free survival (P < 0.0292, P < 0.0001, respectively), whereas NCoR was a positive prognostic indicator (P < 0.0297). Up-regulation of Ets-1 protein expression in cell cultures derived from patient tumors in the presence of growth factors associated with tumor grade (P < 0.0013; n = 28). In primary breast tumor cell cultures and in the SKBR3 breast cell line, growth factors induced interaction between Ets and their DNA response element, induced recruitment of coactivators to the transcription factor-DNA complex, and up-regulated protein expression of HER2. Ets-1 and Ets-2 interacted with the coregulators under basal conditions, and growth factors up-regulated Ets-2 interaction with SRC-1 and AIB1. Coexpression of Ets-2 and SRC-1 significantly associated with the rate of recurrence and HER expression, compared with patients who expressed Ets-2 but not SRC-1 (P < 0.0001 and P < 0.0001, respectively). Conclusions: These data describe associations and interactions between nonsteroid transcription factors and coregulatory proteins in human breast cancer.

Inverse relationship between ER-beta and SRC-1 predicts outcome in endocrine-resistant breast cancer.

The oestrogen receptor (ER) interacts with coactivator proteins to modulate genes central to breast tumour progression. Oestrogen receptor is encoded for by two genes, ER-α and ER-β. Although ER-α has been well characterized, the role of ER-β as a prognostic indicator remains unresolved. To determine isoform-specific expression of ER and coexpression with activator proteins, we examined the expression and localisation of ER-α, ER-β and the coactivator protein steroid receptor coactivator 1 (SRC-1) by immunohistochemistry and immunofluorescence in a cohort of human breast cancer patients (n=150). Relative levels of SRC-1 in primary breast cultures derived from patient tumours in the presence of β-oestradiol and tamoxifen was assessed using Western blotting (n=14). Oestrogen receptor-β protein expression was associated with disease-free survival (DFS) and inversely associated with the expression of HER2 (P=0.0008 and P<0.0001, respectively), whereas SRC-1 was negatively associated with DFS and positively correlated with HER2 (P<0.0001 and P<0.0001, respectively). Steroid receptor coactivator 1 protein expression was regulated in response to β-oestradiol or tamoxifen in 57% of the primary tumour cell cultures. Protein expression of ER-β and SRC-1 was inversely associated (P=0.0001). The association of ER-β protein expression with increased DFS and its inverse relationship with SRC-1 suggests a role for these proteins in predicting outcome in breast cancer.

Body mass index and height over three generations: evidence from the Lifeways cross-generational cohort study

BackgroundObesity and its measure of body mass index are strongly determined by parental body size. Debate continues as to whether both parents contribute equally to offspring body mass which is key to understanding the aetiology of the disease. The aim of this study was to use cohort data from three generations of one family to examine the relative maternal and paternal associations with offspring body mass index and how these associations compare with family height to demonstrate evidence of genetic or environmental cross-generational transmission.Methods669 of 1082 families were followed up in 2007/8 as part of the Lifeways study, a prospective observational cross-generation linkage cohort. Height and weight were measured in 529 Irish children aged 5 to 7 years and were self-reported by parents and grandparents. All adults provided information on self-rated health, education status, and indicators of income, diet and physical activity. Associations between the weight, height, and body mass index of family members were examined with mixed models and heritability estimates computed using linear regression analysis.ResultsSelf-rated health was associated with lower BMI for all family members, as was age for children. When these effects were accounted for evidence of familial associations of BMI from one generation to the next was more apparent in the maternal line. Heritability estimates were higher (h2 = 0.40) for mother-offspring pairs compared to father-offspring pairs (h2 = 0.22). In the previous generation, estimates were higher between mothers-parents (h2 = 0.54-0.60) but not between fathers-parents (h2 = -0.04-0.17). Correlations between mother and offspring across two generations remained significant when modelled with fixed variables of socioeconomic status, health, and lifestyle. A similar analysis of height showed strong familial associations from maternal and paternal lines across each generation.ConclusionsThis is the first family cohort study to report an enduring association between mother and offspring BMI over three generations. The evidence of BMI transmission over three generations through the maternal line in an observational study corroborates the findings of animal studies. A more detailed analysis of geno and phenotypic data over three generations is warranted to understand the nature of this maternal-offspring relationship.

Survival of Escherichia coli O157:H7 in farm water: its role as a vector in the transmission of the organism within herds

Aims: The study aimed to investigate the survival characteristics of Escherichia coli O157:H7 in farm water (FW), and in sterile distilled municipal water (SDW), stored outdoors under field conditions, with or without the addition of faeces (1% w/v), in a farmyard shed and the laboratory at 15°C. 
Methods and Results: Water samples were inoculated with E. coli O157:H7 at 103 and 106 ml−1, and sampled over a 31‐day period. In FW stored outdoors in a field, E. coli O157:H7 survived for 14 days at temperatures <15°C, at both inoculation levels, while in the laboratory at 15°C, the organism was still detectable at low levels (<1 log10 cfu ml−1) after 31 days. The addition of bovine faeces to water outdoors (1% w/v) resulted in survival for 24 days. In SDW inoculated at 106 ml−1 and stored in the laboratory (15°C), only a 2·5 log reduction was observed after 31 days, while the organism could not be detected after 17 days in the field. Preliminary screening of water samples stored outdoors isolated a bacterium which exhibited antimicrobial activity towards E. coli O157:H7. 
Conclusions: The survival of E. coli O157:H7 observed in this study illustrates the potential of farm water to act as a vehicle in the transfer of the organism across a herd. 
Significance and Impact of the Study: The difficulty in extrapolating results from controlled laboratory situations to on‐farm conditions is also highlighted in this study.

Ets-2 and p160 proteins collaborate to regulate c-Myc in endocrine resistant breast cancer

Associations between p160 coactivator proteins and endocrine resistance have been described. Though thought to primarily interact with steroid receptors, the p160 proteins can also interact with non-nuclear receptor transcription factors including the MAP kinase effector proteins Ets. Here, we observed that in breast cancer cells resistant and insensitive to endocrine treatment, the growth factor EGF induced Ets-2 but not Ets-1 transcriptional regulation of the oncogene myc. Ets-2 regulation of myc was found to be reliant on the p160 proteins SRC-1 and SRC-3. In support of these molecular observations, strong associations were observed between the transcription factor, Ets-2 and its coactivator SRC-1 (P<0.01) and the target gene myc (P<0.0001) in a cohort of breast cancer patients with locally advanced disease. Expression of Ets-2, SRC-1 and c-Myc individually all associated with reduced disease-free survival (P<0.001, P<0.001 and P=0.002 respectively). There was no association between SRC-3 and disease-free survival (P=0.707). SRC-1 can utilize MAP kinase effector transcription factor Ets-2 to regulate the production of the oncogene myc. These signalling mechanisms may be important in the development of steroid resistant/independent breast cancer.

CA 15-3 is predictive of response and disease recurrence following treatment in locally advanced breast cancer

BackgroundPrimary chemotherapy (PC) is used for down-staging locally advanced breast cancer (LABC). CA 15-3 measures the protein product of the MUC1 gene and is the most widely used serum marker in breast cancer.MethodsWe retrospectively investigated the role of CA 15-3 in conjunction with other clinico-pathological variables as a predictor of response and time to disease recurrence following treatment in LABC. Pre and post primary chemotherapy serum concentrations of CA 15-3 together with other variables were reviewed and related to four outcomes following primary chemotherapy (clinical response, pathological response, time to recurrence and time to progression). Persistently elevated CA 15-3 after PC was considered as consecutively high levels above the cut off point during and after PC.Results73 patients were included in this study. Patients received PC (AC or AC-T regimen) for locally advanced breast cancer. 54 patients underwent surgery. The median follow up was 790 days. Patients with high concentrations of CA 15-3 before PC treatment had a poor clinical (p = 0.013) and pathological (p = 0.044) response. Together with Her-2/neu expression (p = 0.009) and tumour lympho-vascular space invasion (LVI) (p = 0.001), a persistently elevated CA 15-3 post PC (p = 0.007) was an independent predictive factor of recurrence following treatment in LABC.ConclusionElevated CA 15-3 level is predictive of a poor response to chemotherapy. In addition, persistently elevated CA 15-3 levels post chemotherapy in conjunction with lympho-vascular invasion and HER2 status predict a reduced disease free survival following treatment in locally advanced breast cancer.

Prevalence and number of Salmonella in Irish retail pork sausages

A national Salmonella control program in the pork industry was enacted in Ireland in August 2002. This study was undertaken as part of a larger project investigating the role of pork as a source of human salmonellosis in Ireland. The objective of this survey was to assess the prevalence of Salmonella in Irish pork sausage at retail level. Samples, comprising branded prepacked sausages and loose sausages from supermarket meat counters and butcher shops, were collected from selected retail sites in four cities from October to December 2001 and from June to August 2002. A three-tube most-probable-number method was used to enumerate Salmonella in a selected number of samples that were positive by enrichment. Salmonella serotypes were detected in 4.4 and 1.7% of samples at each of the respective sampling periods, a level similar to those reported in other U.S. and U.K. studies. Isolates were characterized by serotype, phage type, and antimicrobial susceptibility. Eighteen (70%) were resistant to at least one antimicrobial, and 15 (58%) were resistant to four or more antimicrobials. Most of the isolates exhibited resistance to tetracycline. Five different phage types were detected. DT104 was the predominant phage type among Salmonella Typhimurium isolates. This study revealed that multidrug-resistant salmonellae are present in a proportion of Irish sausages and that further risk analysis work is necessary in order to quantify the risk posed to public health.