Release of Lungworm Larvae from Snails in the Environment: Potential for Alternative Transmission Pathways

Background: Gastropod-borne parasites may cause debilitating clinical conditions in animals and humans following the consumption of infected intermediate or paratenic hosts. However, the ingestion of fresh vegetables contaminated by snail mucus and/or water has also been proposed as a source of the infection for some zoonotic metastrongyloids (e.g., Angiostrongylus cantonensis). In the meantime, the feline lungworms Aelurostrongylus abstrusus and Troglostrongylus brevior are increasingly spreading among cat populations, along with their gastropod intermediate hosts. The aim of this study was to assess the potential of alternative transmission pathways for A. abstrusus and T. brevior L3 via the mucus of infected Helix aspersa snails and the water where gastropods died. In addition, the histological examination of snail specimens provided information on the larval localization and inflammatory reactions in the intermediate host. Methodology/Principal Findings: Twenty-four specimens of H. aspersa received ~500 L1 of A. abstrusus and T. brevior, and were assigned to six study groups. Snails were subjected to different mechanical and chemical stimuli throughout 20 days in order to elicit the production of mucus. At the end of the study, gastropods were submerged in tap water and the sediment was observed for lungworm larvae for three consecutive days. Finally, snails were artificially digested and recovered larvae were counted and morphologically and molecularly identified. The anatomical localization of A. abstrusus and T. brevior larvae within snail tissues was investigated by histology. L3 were detected in the snail mucus (i.e., 37 A. abstrusus and 19 T. brevior) and in the sediment of submerged specimens (172 A. abstrusus and 39 T. brevior). Following the artificial digestion of H. aspersa snails, a mean number of 127.8 A. abstrusus and 60.3 T. brevior larvae were recovered. The number of snail sections positive for A. abstrusus was higher than those for T. brevior. Conclusions: Results of this study indicate that A. abstrusus and T. brevior infective L3 are shed in the mucus of H. aspersa or in water where infected gastropods had died submerged. Both elimination pathways may represent alternative route(s) of environmental contamination and source of the infection for these nematodes under field conditions and may significantly affect the epidemiology of feline lungworms. Considering that snails may act as intermediate hosts for other metastrongyloid species, the environmental contamination by mucus-released larvae is discussed in a broader context

The effectiveness of tobacco control television advertisements in increasing the prevalence of smoke-free homes

BACKGROUND: There is considerable evidence that tobacco control mass media campaigns can change smoking behaviour. In the UK, campaigns over the last decade have contributed to declines in smoking prevalence and been associated with falls in cigarette consumption among continuing smokers. However, it is less evident whether such campaigns can also play a role in changing smokers’ behaviour in relation to protecting others from the harmful effects of their smoking in the home. We investigated whether exposure to English televised tobacco control campaigns, and specifically campaigns targeting second hand smoking, is associated with smokers having a smoke-free home. METHODS: We used repeated cross-sectional national survey data on 9872 households which participated in the Health Survey for England between 2004 and 2010, with at least one adult current smoker living in the household. Exposure to all government-funded televised tobacco control campaigns, and to those specifically with a second hand smoking theme, was quantified in Gross Rating Points (GRPs), an average per capita measure of advert exposure where 100 GRPs indicates 100 % of adults exposed once or 50 % twice. Our outcome was self-reported presence of a smoke-free home (where no one smokes in the home on most days). Analysis used generalised additive models, controlling for individual factors and temporal trends. RESULTS: There was no association between monthly televised campaigns overall and the probability of having a smoke-free home. However, exposure to campaigns specifically targeting second hand smoke was associated with increased odds of a smoke-free home in the following month (odds ratio per additional 100 GRPs, 1.07, 95 % CI 1.01 to 1.13), though this association was not seen at other lags. These effects were not modified by socio-economic status or by presence of a child in the home. CONCLUSIONS: Our findings provide tentative evidence that mass media campaigns specifically focussing on second hand smoke may be effective in reducing smoking in the home, and further evaluation of campaigns of this type is needed. General tobacco control campaigns in England, which largely focus on promoting smoking cessation, do not impact on smoke-free homes over and above their direct effect at reducing smoking

Interaction of Oxazaphosphorines with Multidrug Resistance-Associated Protein 4 (MRP4)

Multidrug resistance-associated protein 4 (MRP4) is an organic anion efflux pump capable of transporting nucleoside, nucleotide analogs, and cyclic nucleotide. MRP4 could have an influence on the resistance and transport of the two oxazaphosphorines, cyclophosphamide (CP) and ifosfamide (IF). V/HepG2 (HepG2, hepatoma cells stably transfected with an empty vehicle plasmid) and MRP4/HepG2 (HepG2 cells stably expressing MRP4) were exposed to CP and IF in the absence or presence of various MRP4 inhibitors. HepG2 and HEK293 human kidney cells were also used to investigate the inducing potency of oxazaphosphorines on the MRP4 expression. In this study, insertion of MRP4 gene in HepG2 cells was found to confer significant resistance to CP and IF in the 48-h drug-exposure assays. In the presence of various MRP4 inhibitors, the resistance to CP and IF was then partially reversed. These indicate that CP and IF are highly possible substrates of MRP4. In addition, CP and clofibrate (CFB), a reported MRP4 inducer, in vivo significantly increased the MRP4 expression at both protein level and mRNA level in HEK293 cells at higher concentrations, while IF significantly decreased the MRP4 expression at mRNA level at lower concentration and had no effect at higher concentrations. However, all tested compounds (CP, IF, and CFB) did not change the MRP4 protein expression in HepG2 cells. CP and CFB are cell-specific and concentration-dependent MRP4 inducers. The finding may have implications in the CP- or IF-based chemotherapy

Integrated copy number and gene expression analysis detects a CREB1 association with Alzheimer’s disease

Genetic variation, both single-nucleotide variations and copy number variations (CNV), contribute to changes in gene expression. In some cases these variations are meaningfully correlated with disease states. We hypothesized that in a genetically heterogeneous disorder such as sporadic Alzheimer's disease (AD), utilizing gene expression as a quantitative trait and CNVs as a genetic marker map within the same individuals in the context of case–control status may increase the power to detect relevant loci. Using this approach an 8-kb deletion was identified that contains a PAX6-binding site on chr2q33.3 upstream of CREB1 encoding the cAMP responsive element-binding protein1 transcription factor. The association of the CNV to AD was confirmed by a case–control association study consisting of the Texas Alzheimer Research and Care Consortium and NIA-LOAD Family Study data sets

Targeting survivin as a potential new treatment for chondrosarcoma of bone

Chondrosarcomas are malignant cartilage-forming bone tumors, which are intrinsically resistant to chemo- and radiotherapy, leaving surgical removal as the only curative treatment option. Therefore, our aim was to identify genes involved in chondrosarcoma cell survival that could serve as a target for therapy. siRNA screening for 51 apoptosis-related genes in JJ012 chondrosarcoma cells identified BIRC5, encoding survivin, as essential for chondrosarcoma survival. Using immunohistochemistry, nuclear as well as cytoplasmic survivin expression was analyzed in 207 chondrosarcomas of different subtypes. Nuclear survivin has been implicated in cell-cycle regulation while cytoplasmic localization is important for its anti-apoptotic function. RT–PCR was performed to determine expression of the most common survivin isoforms. Sensitivity to YM155, a survivin inhibitor currently in phase I/II clinical trial for other tumors, was examined in 10 chondrosarcoma cell lines using viability assay, apoptosis assay and cell-cycle analysis. Survivin expression was found in all chondrosarcoma patient samples. Higher expression of nuclear and cytoplasmic survivin was observed with increasing histological grade in central chondrosarcomas. Inhibition of survivin using YM155 showed that especially TP53 mutant cell lines were sensitive, but no caspase 3/7 or PARP cleavage was observed. Rather, YM155 treatment resulted in a block in S phase in two out of three chondrosarcoma cell lines, indicating that survivin is more involved in cell-cycle regulation than in apoptosis. Thus, survivin is important for chondrosarcoma survival and chondrosarcoma patients might benefit from survivin inhibition using YM155, for which TP53 mutational status can serve as a predictive biomarker