1,461 research outputs found

    Reproductive success of the parasitic mite (Varroa destructor) is lower in honeybee colonies that target infested cells with recapping

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    Cell recapping is a behavioural trait of honeybees (Apis mellifera) where cells with developing pupae are uncapped, inspected, and then recapped, without removing the pupae. The ectoparasitic mite Varroa destructor, unarguably the most destructive pest in apiculture world-wide, invades the cells of developing pupae to feed and reproduce. Honeybees that target mite infested cells with this behaviour may disrupt the reproductive cycle of the mite. Hence, cell recapping has been associated with colony-level declines in mite reproduction. In this study we compared the colony-level efficacy of cell recapping (how often infested cells are recapped) to the average mite fecundity in A. mellifera. Our study populations, known to be adapted to V. destructor, were from Avignon, France, Gotland, Sweden, and Oslo, Norway, and were compared to geographically similar, treated control colonies. The results show that colonies with a higher recapping efficacy also have a lower average mite reproductive success. This pattern was likely driven by the adapted populations as they had the largest proportion of highly-targeted cell recapping. The consistent presence of this trait in mite-resistant and mite-susceptible colonies with varying degrees of expression may make it a good proxy trait for selective breeding on a large scale

    Targeting Syndecan-1, a molecule implicated in the process of vasculogenic mimicry, enhances the therapeutic efficacy of the L19-IL2 immunocytokine in human melanoma xenografts

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    Anti-angiogenic therapy of solid tumors has until now failed to produce the long lasting clinical benefits desired, possibly due to the complexity of the neoangiogenic process. Indeed, a prominent role is played by "vasculogenic" or "vascular" mimicry (VM), a phenomenon in which aggressive cancer cells form an alternative microvascular circulation, independently of endothelial cell angiogenesis. In this study we observed, in melanoma patient cell lines having vasculogenic/stem-cell like phenotype and in melanoma tumors, the syndecan-1 co-expression with VM markers, such as CD144 and VEGFR-2. We show that melanoma cells lose their ability to form tubule-like structures in vitro after blocking syndecan-1 activity by the specific human recombinant antibody, OC-46F2. Moreover, in a human melanoma xenograft model, the combined therapy using OC-46F2 and L19-IL2, an immunocytokine specific for the tumor angiogenic-associated B-fibronectin isoform(B-FN), led to a complete inhibition of tumor growth until day 90 from tumor implantation in 71% of treated mice, with statistically significant differences compared to groups treated with OC-46F2 or L19-IL2 as monotherapy. Furthermore, in the tumors recovered from mice treated with OC-46F2 either as monotherapy or in combination with L19-IL2, we observed a dramatic decrease of vascular density and loss of VM structures. These findings indicate for the first time a role of syndecan-1 in melanoma VM and that targeting syndecan-1, together with B-FN, could be promising in improving the treatment of metastatic melanoma

    Characterisation of production, marketing and consumption patterns of farmed tilapia in the Nile Delta of Egypt

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    AbstractEgypt has one of the world’s largest aquaculture sectors which makes a significant contribution to income, employment creation and food security. However, there are very limited data available on the farmed tilapia value chain. The aim of this study therefore was to characterise production, marketing and consumption patterns of farmed tilapia in the Nile Delta of Egypt. A cross sectional study was conducted to collect data from tilapia producers (100), transporters (32), retailers (100), fish fry shops (20) and households (300) in three case study communities (fish producing, peri-urban and rural community). We conducted structured questionnaire interviews and participatory assessments for producers and consumers. Focus group discussions with mothers were also held to collect data for the availability, sources and consumption patterns of tilapia.Results showed that, more than half of producers were small scale, having a farm size of 10feddan or less (1feddan=4200m2). The main water supply for almost all farms was agricultural drain water, a potential source of contamination with chemical and biological hazards. The main production constraints were reported to be feed prices, water quality and availability, land rent, fuel and energy sources and environmental conditions. The farmed tilapia value chain was short with some value added in the form of marketing fresh and live fish as well as selling tilapia in fried or grilled form. The majority of produced tilapia was transported to retail sale and sold to consumers as fresh, while only a small proportion was processed by cleaning, grilling or frying. A lack of hygiene during transportation and marketing of farmed tilapia was found that could be potential sources for post-harvesting contamination. The availability and frequency of tilapia consumption were higher in the community in the production areas than in other communities. In non-producing areas, tilapia may be available in the market once a week during the village market day. Potential areas for further research in order to improve safety, quality and production of farmed tilapia were identified

    Honey bee survival mechanisms against the parasite Varroa destructor: a systematic review of phenotypic and genomic research efforts

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    The ectoparasitic mite Varroa destructor is the most significant pathological threat to the western honey bee, Apis mellifera, leading to the death of most colonies if left untreated. An alternative approach to chemical treatments is to selectively enhance heritable honey bee traits of resistance or tolerance to the mite through breeding programs, or select for naturally surviving untreated colonies. We conducted a literature review of all studies documenting traits of A. mellifera populations either selectively bred or naturally selected for resistance and tolerance to mite parasitism. This allowed us to conduct an analysis of the diversity, distribution and importance of the traits in different honey bee populations that can survive V. destructor globally. In a second analysis, we investigated the genetic bases of these different phenotypes by comparing 'omics studies (genomics, transcriptomics, and proteomics) of A. mellifera resistance and tolerance to the parasite. Altogether, this review provides a detailed overview of the current state of the research projects and breeding efforts against the most devastating parasite of A. mellifera. By highlighting the most promising traits of Varroa-surviving bees and our current knowledge on their genetic bases, this work will help direct future research efforts and selection programs to control this pest. Additionally, by comparing the diverse populations of honey bees that exhibit those traits, this review highlights the consequences of anthropogenic and natural selection in the interactions between hosts and parasites. (C) 2020 The Authors. Published by Elsevier Ltd on behalf of Australian Society for Parasitology

    Consumers perception of traditional sustainable food: an exploratory study on pasta made from native ancient durum wheat varieties

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    Governments and policy play an important role in prompting the public and private interest for local and traditional food, in order to increase the variety of food choice for consumers (Guerrero et al., 2012) and to foster local economies and rural regions development (Feldmann et al., 2015). Our study may provide useful indication to food companies and producers to invest in innovative products based on traditional regional raw materials tailoring marketing actions and investments. But how consumers perceive the quality of products made from native crops varieties? Recent review on consumers perception and preferences for local and traditional food emphasizes that, unlike organic food, local ones are not perceived as expensive but consumers would be willing to pay a premium price to access them (Feldmann et al., 2015). Does this conclusion still hold in case of durum wheat pasta obtained from traditional wheat varieties? Answer to the latter question is one of the aims of the paper. Moreover in order to maintain and even increase the traditional food products’ market share they need to be improved by introducing innovations that fulfil the European consumers’ demand for better traditional food product from different perspectives, including for example health, safety, taste and convenience characteristics (Cayot, 2007). Indeed, other studies investigating how consumers perceive the meaning of terms such as ‘traditional’ and ‘Innovation’, found a noticeable incompatibility between the two concepts (Guerrero et al., 2012). However, assuming a positive feeling and attitude of consumers towards those products, the main aim of the article is to address consumers preferences towards different attributes of pasta. Conjoint analysis will be developed to assess consumer perception towards pasta made from native durum wheat varieties. On purpose more then 258 habitual consumers of pasta from Apulia region were interviewed using internet based tools

    A new reporter mouse cytomegalovirus reveals maintained immediate-early gene expression but poor virus replication in cycling liver sinusoidal endothelial cells

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    Background: The MCMV major immediate early promoter/enhancer (MIEP) is a bidirectional promoter that drives the expression of the three immediate early viral genes, namely ie1, ie2 and ie3. The regulation of their expression is intensively studied, but still incompletely understood. Methods: We constructed a reporter MCMV, (MCMV-MIEPr) expressing YFP and tdTomato under the control of the MIEP as proxies of ie1 and ie2, respectively. Moreover, we generated a liver sinusoidal endothelial cell line (LSEC-uniLT) where cycling is dependent on doxycycline. We used these novel tools to study the kinetics of MIEP-driven gene expression in the context of infection and at the single cell level by flow cytometry and by live imaging of proliferating and G(0)-arrested cells. Results: MCMV replicated to higher titers in G(0)-arrested LSEC, and cycling cells showed less cytopathic effect or YFP and tdTomato expression at 5 days post infection. In the first 24 h post infection, however, there was no difference in MIEP activity in cycling or G(0)-arrested cells, although we could observe different profiles of MIEP gene expression in different cell types, like LSECs, fibroblasts or macrophages. We monitored infected LSEC-uniLT in G(0) by time lapse microscopy over five days and noticed that most cells survived infection for at least 96 h, arguing that quick lysis of infected cells could not account for the spread of the virus. Interestingly, we noticed a strong correlation between the ratio of median YFP and tdTomato expression and length of survival of infected cells. Conclusion: By means of our newly developed genetic tools, we showed that the expression pattern of MCMV IE1 and IE2 genes differs between macrophages, endothelial cells and fibroblasts. Substantial and cell-cycle independent differences in the ie1 and ie2 transcription could also be observed within individual cells of the same population, and marked ie2 gene expression was associated with longer survival of the infected cells

    Tumor size, node status, grading, HER2 and estrogen receptor status still retain a strong value in patients with operable breast cancer diagnosed in recent years.

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    Breast cancer prognosis has improved greatly in recent years. Consequently, a thorough search for sensitive prognostic factors, able to help clinicians offer appropriate therapy, has become a priority in this area. In this study, we considered all new cases of invasive breast cancer diagnosed in the Province of Modena, Italy, between 1997 and 2007, registered by the Modena Cancer Registry. The principal endpoint of this study was relapse-free survival (RFS). A set of 11 clinic and pathological parameters was investigated. After a median follow-up of 73 months, 494 relapses were recorded. Tumor size, node status, grading, HER2 and estrogen receptor status were retained as independent factors in a multivariate analysis. Using these variables, a prognostic model was devised to identify three groups at different risk. In the training sample, the 5-year RFS rates resulted 96.0%, 82.9% and 63.7% in patients at low, intermediate and high risk, respectively (p < 0.0001). In the validation sample, the 5-year RFS was 96.2%, 85.4% and 66.9%, respectively. To conclude our study demonstrates that a very simple prognostic index based on easily available clinical data may represent a useful tool for the identification of patients at different risk of relapse and may be a notable device to predict who truly benefits from medical treatment
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