Increased prevalence of HTLV-1 among HIV-2-infected women but not HIV-2-infected men in rural Guinea-Bissau

OBJECTIVE: To assess the prevalence of HTLV infection and its association with HIV and other potential risk factors. DESIGN AND SETTING: A cross-sectional survey and a case-control study in a rural community in Guinea-Bissau. METHODS: A total of 2770 people were included in an HIV and HTLV seroepidemiologic survey. Three hundred of these participants were selected for a case-control study on HIV-2. Sera from both studies were tested for HTLV. RESULTS: In all, 2501 and 298 subjects in the survey and case-control study, respectively, were tested for HTLV. Overall HTLV-1 prevalence was 5.2% and it was higher in women (odds ratio [OR], 1.36; confidence interval [CI], 0.92-2.02). Apart from an infected spouse, no significant risk factors could be identified for men. In women, HIV-2 infection (adjusted OR, 5.58; CI, 3.09-10.1), having an infected spouse, and area of residence were significantly associated with HTLV-1 infection. The association between HTLV-1 and HIV-2 was significantly different for men and women (test of interaction, p =.002). CONCLUSIONS: In women, the most important determinant of HTLV-1 seropositivity was HIV-2 infection. Because the pattern was significantly different for men and women, common sexual risk factors may not be sufficient to explain the co-occurrence of HIV-2 and HTLV-1 in women. These observations may have implications in geographic areas where both types of retroviruses are prevalent.     

Dual infections with HIV-1, HIV-2 and HTLV-I are more common in older women than in men in Guinea-Bissau

OBJECTIVES: To investigate the association between the three human retroviruses, HIV-1, HIV-2 and HTLV-I. DESIGN: Community-based follow-up studies of retrovirus infections in two cohorts. METHODS: A total of 2057 individuals aged 35 years and over were eligible for inclusion. Participants were interviewed and had a blood sample drawn. Samples were analysed for HIV-1, HIV-2 and HTLV infections. Uni- and multivariate analyses that included behavioural and socio-economic factors were performed using logistic regression and Poisson regression models. RESULTS: A total of 1686 individuals participated with a blood sample in the HIV prevalence analyses and 1581 individuals participated in the HTLV-I prevalence analyses. The overall prevalence was 2.1% for HIV-1, 13.5% for HIV-2 and 7.1% for HTLV-I. Comparing the < 45 year age group with 45+ year age groups, the female : male (F : M) prevalence ratio increased with age for all three retroviruses. Dual infections were more common in women than in men. Assuming independent distribution of the viruses, the observed prevalence of dual infections in women was significantly higher than expected, while the prevalence was not increased in men. The prevalence of dual infections increased with age in women, the odds ratio (OR) being 3.4 [95% confidence interval (CI), 1.0-11.3] for any combination of dual infection, while the prevalence decreased with age in men (OR, 0.3; 95% CI, 0.1-2.0) (test of interaction, P = 0.033). Control for behavioural factors did not modify these patterns. CONCLUSIONS: The pattern of increased prevalence among older women could have public health implications; women of older age groups should be regarded as a potential vulnerable group and included in HIV/AIDS prevention programmes.     

Combined analysis of DTI and fMRI data reveals a joint maturation of white and grey matter in a fronto-parietal network

The aim of this study was to explore whether there are networks of regions where maturation of white matter and changes in brain activity show similar developmental trends during childhood. In a previous study, we showed that during childhood, grey matter activity increases in frontal and parietal regions. We hypothesized that this would be mediated by maturation of white matter. Twenty-three healthy children aged 8-18 years were investigated. Brain activity was measured using the blood oxygen level-dependent (BOLD) contrast with functional magnetic resonance imaging (fMRI) during performance of a working memory (WM) task. White matter microstructure was investigated using diffusion tensor imaging (DTI). Based on the DTI data, we calculated fractional anisotropy (FA), an indicator of myelination and axon thickness. Prior to scanning, WM score was evaluated. WM score correlated independently with FA values and BOLD response in several regions. FA values and BOLD response were extracted for each subject from the peak voxels of these regions. The FA values were used as covariates in an additional BOLD analysis to find brain regions where FA values and BOLD response correlated. Conversely, the BOLD response values were used as covariates in an additional FA analysis. In several cortical and sub-cortical regions, there were positive correlations between maturation of white matter and increased brain activity. Specifically, and consistent with our hypothesis, we found that FA values in fronto-parietal white matter correlated with BOLD response in closely located grey matter in the superior frontal sulcus and inferior parietal lobe, areas that could form a functional network underlying working memory function.     

Tumour location is a prognostic factor for survival in colonic cancer patients

Objective To evaluate survival and prognostic factors in a consecutive series of colon cancer patients from a defined city population in Norway. Method All patients with adenocarcinoma of the colon diagnosed between 1993 and 2000 were registered prospectively. Five‐year actuarial survival and 5‐year relative survival rates were calculated. Cox regression analyses were used to study the effect of prognostic factors on survival. Results In the study period 627 patients were admitted. Overall 5‐year relative survival was 50% in females and 52% in males. Five‐year relative survival in 410 (65%) patients operated with curative intent, was 74% for females and 79% for males. Tumour location in the transverse colon, splenic flexure and descending colon (OR = 1.8), emergency operation (OR = 1.7), TNM stage (OR = 1.8–2.9), blood transfusion of more than two units (OR = 1.8) and age (OR = 4.0–7.1) were independent negative prognostic factors. Conclusion Colon cancer located in the transverse and descending colon is associated with poor prognosis. Comparison of results from different centres is difficult due to selection and classification differences, and different methods used for calculation of survival.     

Air pollution, oxidative damage to DNA, and carcinogenesis

There is growing concern that air pollution exposure increases the risk of lung cancer. The mechanism of action is related to particle-induced oxidative stress and oxidation of DNA. Humans exposed to urban air with vehicle emissions have elevated levels of oxidized guanine bases in blood cells and urine. Animal experimental studies show that pulmonary and gastrointestinal exposure is associated with elevated levels of oxidized guanines in the lung and other organs. Collectively, there is evidence indicating that exposure to traffic-related air pollution particles is associated with oxidative damage to DNA and this might be associated with increased risk of cancer.     

Realized kernels in practice: trades and quotes

Summary Realized kernels use high‐frequency data to estimate daily volatility of individual stock prices. They can be applied to either trade or quote data. Here we provide the details of how we suggest implementing them in practice. We compare the estimates based on trade and quote data for the same stock and find a remarkable level of agreement. We identify some features of the high‐frequency data, which are challenging for realized kernels. They are when there are local trends in the data, over periods of around 10 minutes, where the prices and quotes are driven up or down. These can be associated with high volumes. One explanation for this is that they are due to non‐trivial liquidity effects.     

Association between DNA ploidy pattern and cellular atypia in colorectal carcinomas. A new clinical application of DNA flow cytometric study?

Fresh tissue specimens from 406 colorectal carcinomas were analyzed by DNA flow cytometric study, and the DNA ploidy pattern was compared with Dukes' stage, histologic grade, and degree of cellular atypia. Sixty-one percent of the carcinomas had a distinct aneuploid DNA pattern. The proportion of aneuploid carcinomas was significantly higher in the advanced Dukes' stages than in the localized ones. A highly significant association was found between DNA ploidy pattern and degree of cellular atypia, whereas no association was demonstrated between DNA ploidy pattern and histologic grade. This finding might indicate that cellular atypia has a stronger prognostic impact than the growth pattern of the tumor. The authors suggest that flow cytometric DNA quantification may replace assessment of cellular atypia in the histologic evaluation. Furthermore, together with earlier findings by others, these results indicate that the degree of cellular atypia may be conserved during the development from adenomas to carcinomas.