Trends in European Breast Cancer Incidence and Possible Etiology

In this study the trends in breast cancer incidence in a number of European countries, over the last 20 years, have been evaluated. There is a wide range in incidence; the risk being highest in north and west Europe (and highest in Switzerland) and lower in south and in east Europe. There was little difference, however, between countries in the incidence of the disease occurring before the menopause, and this incidence has shown little temporal change in the time period 1960-1985. Indeed, in many countries there has been little change in incidence in any age band since 1975. The use of oral contraception has been claimed to be a risk factor in premenopausal breast cancer. In two countries, the data on oral contraceptive usage were available; in neither was there any evidence that the introduction and growth in such usage was related to the risk of breast cancer in any age band that might have been exposed to them. The reasons for this are discussed in the light of recent reports to the contrary.

Gender and race as correlates of high risk sex behaviors among injection drug users at risk for HIV enrolled in the HPTN 037 study

BACKGROUND

Sexual contact has been shown to be a major mode of HIV transmission among people who inject drugs (PWID). This study examined gender and racial differences among PWID' sexual risk behaviors from the perspective of sexual scripts.

METHODS

696 PWID enrolled from Philadelphia on HPTN 037 were classified as engaging in high-risk sex behaviors if they reported having sex in the past 30 days and condomless sex with a non-primary partner, giving/receiving sex for money, or multiple partners. A multivariable logistic regression model was used to assess associations between demographic factors and high risk sex.

RESULTS

Findings of the multivariable regression analysis demonstrated that being White (OR = 0.52, p < 0.001) and male (OR = 0.59, p = 0.002) were protective of high risk sex, while homelessness (OR = 1.7, p = 0.005), and being single (OR = 1.83, p = 0.006) were positively associated with high risk sex. African American (AA) women were 1.7 times more likely to report high-risk sex than AA men (p = 0.002), 3.28 times more likely than White men (p < 0.001), and 1.93 times more likely than White women (p < 0.001).

CONCLUSIONS

Since AA women report high-risk sex behaviors more than other demographic groups, behavioral interventions for HIV risk reduction among PWID may benefit from focusing on sex-risk reduction among AA women.

Macroinvertebrate Taxonomic and Functional Trait Compositions within Lotic Habitats Affected By River Restoration Practices

The widespread degradation of lotic ecosystems has prompted extensive river restoration efforts globally, but many studies have reported modest ecological responses to rehabilitation practices. The functional properties of biotic communities are rarely examined within post-project appraisals, which would provide more ecological information underpinning ecosystem responses to restoration practices and potentially pinpoint project limitations. This study examines macroinvertebrate community responses to three projects which aimed to physically restore channel morphologies. Taxonomic and functional trait compositions supported by widely occurring lotic habitats (biotopes) were examined across paired restored and non-restored (control) reaches. The multivariate location (average community composition) of taxonomic and functional trait compositions differed marginally between control and restored reaches. However, changes in the amount of multivariate dispersion were more robust and indicated greater ecological heterogeneity within restored reaches, particularly when considering functional trait compositions. Organic biotopes (macrophyte stands and macroalgae) occurred widely across all study sites and supported a high alpha (within-habitat) taxonomic diversity compared to mineralogical biotopes (sand and gravel patches), which were characteristic of restored reaches. However, mineralogical biotopes possessed a higher beta (between-habitat) functional diversity, although this was less pronounced for taxonomic compositions. This study demonstrates that examining the functional and structural properties of taxa across distinct biotopes can provide a greater understanding of biotic responses to river restoration works. Such information could be used to better understand the ecological implications of rehabilitation practices and guide more effective management strategies.

MiR-137-derived polygenic risk: effects on cognitive performance in patients with schizophrenia and controls

Variants at microRNA-137 (MIR137), one of the most strongly associated schizophrenia risk loci identified to date, have been associated with poorer cognitive performance. As microRNA-137 is known to regulate the expression of ~1900 other genes, including several that are independently associated with schizophrenia, we tested whether this gene set was also associated with variation in cognitive performance. Our analysis was based on an empirically derived list of genes whose expression was altered by manipulation of MIR137 expression. This list was cross-referenced with genome-wide schizophrenia association data to construct individual polygenic scores. We then tested, in a sample of 808 patients and 192 controls, whether these risk scores were associated with altered performance on cognitive functions known to be affected in schizophrenia. A subgroup of healthy participants also underwent functional imaging during memory (n=108) and face processing tasks (n=83). Increased polygenic risk within the empirically derived miR-137 regulated gene score was associated with significantly lower performance on intelligence quotient, working memory and episodic memory. These effects were observed most clearly at a polygenic threshold of P=0.05, although significant results were observed at all three thresholds analyzed. This association was found independently for the gene set as a whole, excluding the schizophrenia-associated MIR137 SNP itself. Analysis of the spatial working memory fMRI task further suggested that increased risk score (thresholded at P=10-5) was significantly associated with increased activation of the right inferior occipital gyrus. In conclusion, these data are consistent with emerging evidence that MIR137 associated risk for schizophrenia may relate to its broader downstream genetic effects.

When is the best time to sample aquatic macroinvertebrates in ponds for biodiversity assessment?

Ponds are sites of high biodiversity and conservation value, yet there is little or no statutory monitoring of them across most of Europe. There are clear and standardised protocols for sampling aquatic macroinvertebrate communities in ponds, but the most suitable time(s) to undertake the survey(s) remains poorly specified. This paper examined the aquatic macroinvertebrate communities from 95 ponds within different land use types over three seasons (spring, summer and autumn) to determine the most appropriate time to undertake sampling to characterise biodiversity. The combined samples from all three seasons provided the most comprehensive record of the aquatic macroinvertebrate taxa recorded within ponds (alpha and gamma diversity). Samples collected during the autumn survey yielded significantly greater macroinvertebrate richness (76% of the total diversity) than either spring or summer surveys. Macroinvertebrate diversity was greatest during autumn in meadow and agricultural ponds, but taxon richness among forest and urban ponds did not differ significantly temporally. The autumn survey provided the highest measures of richness for Coleoptera, Hemiptera and Odonata. However, richness of the aquatic insect order Trichoptera was highest in spring and lowest in autumn. The results illustrate that multiple surveys, covering more than one season, provide the most comprehensive representation of macroinvertebrate biodiversity. When sampling can only be undertaken on one occasion, the most appropriate time to undertake surveys to characterise the macroinvertebrate community biodiversity is during autumn, although this may need to be modified if other floral and faunal groups need to be incorporated into the sampling programme.

The distribution of small and intermediate conductance calcium-activated potassium channels in the rat sensory nervous system

Small (SK) and intermediate (IK) conductance calcium-activated potassium channels are candidate ion channels for the regulation of excitability in nociceptive neurones. We have used unique peptide-directed antisera to describe the immunocytochemical distribution of the known isoforms of these ion channels in dorsal root ganglia (DRG) and spinal cord of the rat. These investigations sought to characterize further the phenotype and hence possible functions of nociceptive neurone subpopulations in the rat. In addition, using Western blotting, we sought to determine the level of protein expression of SK and IK channels in sensory nervous tissues following induction of inflammation (Freund's Complete Adjuvant (FCA) arthritis model) or nerve injury (chronic constriction injury model). We show that SK1, SK2, SK3 and IK1 are all expressed in DRG and spinal cord. Morphometric analysis revealed that SK1, SK2 and IK1 were preferentially localized to neurones having cell bodies <1000 microm2 (putative nociceptors) in DRG. Dual labeling immunocytochemistry showed that these ion channels co-localize with both CGRP and IB4, known markers of nociceptor sub-populations. SK2 was localized almost exclusively in the superficial laminae of the spinal cord dorsal horn, the region in which many sensory afferents terminate; the distribution of SK1 and IK1 was more widespread in spinal cord, although some preferential labeling within the dorsal horn was observed in the case of IK1. Here we show evidence for a distinctive pattern of expression for certain members of the calcium-activated potassium channel family in the rat DRG.

Fibres and colorectal cancer: should we change our dietary advice on prevention?

Evidence from epidemiological studies overwhelmingly indicates that fruit, vegetables and cereals prevent cancer at a wide range of sites in the body, not just the large bowel. However, recent important papers have shown that an intervention diet rich in fruit, vegetables and fibre failed to decrease the risk of new colorectal adenoma formation. The adenoma-cancer sequence and the role of diet are discussed in the light of these new findings.

Changes and developments in cancer prevention

During the last 125 years, there has been a massive decrease in mortality from infectious disease, as a result of improved public health and later as a result of antibiotic use. This has led to a consequent increase in life span from less than 50 (when cancer is rare) to more than 70 (when cancer is common). As a result of these changes, cancer has moved from being a very minor cause of mortality in 1876 to one of the two major causes by 2000. During the last century theories of the causation of cancer have changed progressively. In the early phase the main cause was thought to be environmental contamination with carcinogenic chemicals. Later, it was thought that all cancers were caused by cancers, then that cancer was caused by a breakdown in immune-surveillance. For 40 years we have known that tobacco smoke is a major cause of respiratory and other cancers, and preventive measures are currently having a dramatic effect on male lung cancer mortality. During the last 25 years it has become apparent that diet is the other major cause of cancer, but theories have moved steadily from a search for causal agents (e.g., too much fat) to protective agents (e.g., too little fruit and vegetable). Currently it is accepted that all of the above theories contribute to the total cancer risk.

Wound assessment and evaluation

The "Wound Assessment and Evaluation" series includes a short case presentation and differential diagnosis. It is followed by a discussion of the disease or condition and the rationale used in each step of the assessment.

Dietary advice on cancer prevention: time for a change?

Media coverage of recent dietary intervention studies has cast doubt on dietary advice for cancer prevention. The studies cited focussed on colorectal adenoma initiation as opposed to progression. There is ample evidence that in the colorectum the factors controlling initiation of adenomas differ from those causing progression to cancer, and that it is the latter that are the most important. In the light of this it is argued that studies of adenoma initiation are irrelevant to the advice given for overall cancer prevention.