Publications

Exposure to estrogen has a major effect on breast cancer risk. A polymorphism (-34 T > C; rs743572) in the cytochrome P450c17alpha gene (CYP17A1) encoding an enzyme which controls estrogen levels was reportedly associated with breast cancer risk in average risk populations. The effect of this polymorphism on breast or ovarian cancer risk for BRCA1 and BRCA2 mutation carriers has not been thoroughly investigated. With this aim, 2,221 BRCA1 and BRCA2 mutation carriers (1,313 with breast cancer, 279 with ovarian cancer, and 695 asymptomatic carriers), with either BRCA1 (n = 1693) or BRCA2 (n = 528) germline mutations from seven centers were genotyped for the -34 T > C CYP17 polymorphism. Genotyping was accomplished using Taqman allelic discrimination, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) or PCR-based restriction-fragment length polymorphism analysis, and limited sequencing. Data were analyzed using Cox proportional hazards models. The hazard ratios (HRs) for breast cancer was 1.02 (95% CI 0.89-1.17, p = 0.74) and 1.10 (95% CI 0.72-1.67, p = 0.66) for BRCA1 and BRCA2 mutation carriers, respectively. The HRs for ovarian cancer were 1.17 (0.94-1.46, p = 0.17) and 0.91 (0.31-2.67, p = 0.86) for BRCA1 and BRCA2 mutation carriers, respectively. Results remained unaltered when the Israeli cohort (primarily Ashkenazim) was evaluated separately. In conclusion, there was no overall evidence for an association of the -34 T > C CYP17 polymorphism with either breast or ovarian cancer risk in BRCA1 or BRCA2 mutation carriers.

Few studies have evaluated barriers to hospice from a hospice provider perspective. We assessed such views via a postal survey to all licensed hospices in Alabama (N = 193)-response = 55.4%. Most providers considered physicians and health care professionals to be somewhat knowledgeable of hospice, but also indicated a lack of knowledge constituted the barrier with the most impact in their communities. Respondents also cited physician difficulties with discussing end of life with patients and prognosticating death within 6 months as leading barriers. Providers also described Medicare reimbursement cap issues that have resulted in barriers to hospice. Our findings were similar to previous investigations assessing provider perceptions. Future studies should explore how reimbursement cap issues affect the receipt and delivery of hospice care.

BACKGROUND

Ciguatoxins (CTXs) are polyether marine neurotoxins and potent activators of voltage-gated sodium channels. This toxin is carried by multiple reef-fish species and human consumption of ciguatoxins can result in an explosive gastrointestinal/neurologic illness. This study characterizes the global transcriptional response in mouse brain to a symptomatic dose of the highly toxic Pacific ciguatoxin P-CTX-1 and additionally compares this data to transcriptional profiles from liver and whole blood examined previously. Adult male C57/BL6 mice were injected with 0.26 ng/g P-CTX-1 while controls received only vehicle. Animals were sacrificed at 1, 4 and 24 hrs and transcriptional profiling was performed on brain RNA with Agilent whole genome microarrays. RT-PCR was used to independently validate gene expression and the web tool DAVID was used to analyze gene ontology (GO) and molecular pathway enrichment of the gene expression data.

RESULTS

A pronounced 4°C hypothermic response was recorded in these mice, reaching a minimum at 1 hr and lasting for 8 hrs post toxin exposure. Ratio expression data were filtered by intensity, fold change and p-value, with the resulting data used for time course analysis, K-means clustering, ontology classification and KEGG pathway enrichment. Top GO hits for this gene set included acute phase response and mono-oxygenase activity. Molecular pathway analysis showed enrichment for complement/coagulation cascades and metabolism of xenobiotics. Many immediate early genes such as Fos, Jun and Early Growth Response isoforms were down-regulated although others associated with stress such as glucocorticoid responsive genes were up-regulated. Real time PCR confirmation was performed on 22 differentially expressed genes with a correlation of 0.9 (Spearman's Rho, p < 0.0001) with microarray results.

CONCLUSIONS

Many of the genes differentially expressed in this study, in parallel with the hypothermia, figure prominently in protection against neuroinflammation. Pathologic activity of the complement/coagulation cascade has been shown in patients suffering from a chronic form of ciguatera poisoning and is of particular interest in this model. Anti-inflammatory processes were at work not only in the brain but were also seen in whole blood and liver of these animals, creating a systemic anti-inflammatory environment to protect against the initial cellular damage caused by the toxin.

Keratinocyte culture medium (KCM) has been used for the in vitro culture of keratinocytes and other types of epithelial cells, and the medium includes various ingredients. In this study, two modified KCMs were prepared. In the first, insulin, hydrocortisone and antibiotics that are normally included in KCM were replaced with clinically approved pharmaceutical agents, except transferrin and selenium; in the second, cholera toxin (CT) was replaced by L-isoproterenol (ISO). The modified KCMs were then compared to conventional KCM containing laboratory-grade reagents. Induced cell colony formations of canine oral mucosal epithelial cells cultured in both modified KCMs were found to be nearly equivalent to that in the control KCM, and there was no significant difference between the effect of CT and ISO. Canine oral mucosal cells proliferated to confluence in all three KCM formulations, with or without the use of 3T3 feeder layers. Cultured epithelial cells were harvested from temperature-responsive culture surfaces as an intact cell sheet, and the immunohistochemical analysis of the sheets showed that p63 and cytokeratin were expressed in the epithelial cell sheets cultured in all KCMs. Eventually, in the modified KCM formula, fetal bovine serum was replaced by autologous human serum, and the formula was found to be able to fabricate human oral mucosal epithelial cell sheets. These results indicated that the modified KCM was equally efficient as conventional KCM in the fabrication of transplantable stratified epithelial cell sheets.

Transplantable cell sheets containing osteoblasts were fabricated from periostea on temperature-responsive culture dishes. This study demonstrated the time-course of bone regeneration in living small animals. This continuous observation of bone regeneration was achieved by micro-computed tomography (µCT), which assessed the osteogenic capability of periosteal cells without biodegradable scaffolds. Real-time bone regeneration was non-invasively monitored in a rat calvarial bone defect model, using µCT. Three-dimensional (3D) images obtained over time by µCT clearly showed that two different bone regeneration modes, specific to the control and experimental groups, were observed. In the control group, bone was regenerated only from the periphery of the defect edges. In the experimental group, bone regeneration was observed in several small regions within the central portions of the defects that were covered by the transplanted cell sheets. However, bone regeneration observed after periosteal cell sheet transplantation was limited. The results of ALP staining and the time-course observations concluded that periosteal cell sheets contained a small fraction of cells that could differentiate osteoblasts. Fibroblasts in transplanted cell sheets or from around subcutaneous tissues suppressed bone regeneration. The periosteal cell sheets had a capability to produce ectopic regenerated bones. Therefore, to increase the content of osteogenic cells in harvested cell sheets, the enrichment of cells that could produce osteoblasts was expected by the modification of the initial cell preparation and the culture conditions. With further possible improvements, scaffold-free periosteal cell sheet fabricated on temperature-responsive culture dishes will be a valuable method for inducing and accelerating bone regeneration.

The causes of amyotrophic lateral sclerosis (ALS), a devastating human neurodegenerative disease, are poorly understood, although the protein TDP-43 has been suggested to have a critical role in disease pathogenesis. Here we show that ataxin 2 (ATXN2), a polyglutamine (polyQ) protein mutated in spinocerebellar ataxia type 2, is a potent modifier of TDP-43 toxicity in animal and cellular models. ATXN2 and TDP-43 associate in a complex that depends on RNA. In spinal cord neurons of ALS patients, ATXN2 is abnormally localized; likewise, TDP-43 shows mislocalization in spinocerebellar ataxia type 2. To assess the involvement of ATXN2 in ALS, we analysed the length of the polyQ repeat in the ATXN2 gene in 915 ALS patients. We found that intermediate-length polyQ expansions (27-33 glutamines) in ATXN2 were significantly associated with ALS. These data establish ATXN2 as a relatively common ALS susceptibility gene. Furthermore, these findings indicate that the TDP-43-ATXN2 interaction may be a promising target for therapeutic intervention in ALS and other TDP-43 proteinopathies.

BACKGROUND

Food insufficiency is often associated with health risks and adverse outcomes among marginalized populations. However, little is known about correlates of food insufficiency among injection drug users (IDU).

METHODS

We conducted a cross-sectional study to examine the prevalence and correlates of self-reported hunger in a large cohort of IDU in Vancouver, Canada. Food insufficiency was defined as reporting "I am hungry, but don't eat because I can't afford enough food". Logistic regression was used to determine independent socio-demographic and drug-use characteristics associated with food insufficiency.

RESULTS

Among 1,053 participants, 681 (64.7%) reported being hungry and unable to afford enough food. Self-reported hunger was independently associated with: unstable housing (adjusted odds ratio [AOR]: 1.68, 95% confidence interval [CI]: 1.20 - 2.36, spending ≥ $50/day on drugs (AOR: 1.43, 95% CI: 1.06 - 1.91), and symptoms of depression (AOR: 3.32, 95% CI: 2.45 - 4.48).

CONCLUSION

These findings suggest that IDU in this setting would likely benefit from interventions that work to improve access to food and social support services, including addiction treatment programs which may reduce the adverse effect of ongoing drug use on hunger.