234 research outputs found

    A GFP-Tagged Gross Deletion on Chromosome 1 Causes Malignant Peripheral Nerve Sheath Tumors and Carcinomas in Zebrafish

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    Malignant peripheral nerve sheath tumors (MPNSTs) are highly aggressive soft-tissue sarcomas, characterized by complex karyotypes. The molecular bases of such malignancy are poorly understood and efficient targeted molecular therapies are currently lacking. Here we describe a novel zebrafish model of MPNSTs, represented by the transgenic mutant line Tg(-8.5nkx2.2a:GFP)ia2. ia2 homozygous animals displayed embryonic lethality by 72 hpf, while the heterozygotes develop visible tumor masses with high frequency in adulthood. Histological and immunohistochemical examination revealed aggressive tumors with either mesenchymal or epithelial features. The former (54% of the cases) arose either in the abdominal cavity, or as intrathecal/intraspinal lesions and is composed of cytokeratin-negative spindle cells with fascicular/storiform growth pattern consistent with zebrafish MPNSTs. The second histotype was composed by polygonal or elongated cells, immunohistochemically positive for the pan-cytokeratin AE1/AE3. The overall histologic and immunohistochemical features were consistent with a malignant epithelial neoplasm of possible gastrointestinal/pancreatic origin. With an integrated approach, based on microsatellite (VNTR) and STS markers, we showed that ia2 insertion, in Tg(-8.5nkx2.2a:GFP)ia2 embryos, is associated with a deletion of 15.2 Mb in the telomeric portion of chromosome 1. Interestingly, among ia2 deleted genes we identified the presence of the 40S ribosomal protein S6 gene that may be one of the possible drivers for the MPNSTs in ia2 mutants.Thanks to the peculiar features of zebrafish as animal model of human cancer (cellular and genomic similarity, transparency and prolificacy) and the GFP tag, the Tg(-8.5nkx2.2a:GFP)ia2 line provides a manageable tool to study in vivo with high frequency MPNST biology and genetics, and to identify, in concert with the existing zebrafish MPNST models, conserved relevant mechanisms in zebrafish and human cancer development

    3D printed masks for powders and viruses safety protection using food grade polymers: Empirical tests

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    The production of 3D printed safety protection devices (SPD) requires particular attention to the material selection and to the evaluation of mechanical resistance, biological safety and surface roughness related to the accumulation of bacteria and viruses. We explored the possibility to adopt additive manufacturing technologies for the production of respirator masks, responding to the sudden demand of SPDs caused by the emergency scenario of the pandemic spread of SARS‐COV‐ 2. In this study, we developed different prototypes of masks, exclusively applying basic additive manufacturing technologies like fused deposition modeling (FDM) and droplet‐based precision extrusion deposition (db‐PED) to common food packaging materials. We analyzed the resulting mechanical characteristics, biological safety (cell adhesion and viability), surface roughness and resistance to dissolution, before and after the cleaning and disinfection phases. We showed that masks 3D printed with home‐grade printing equipment have similar performances compared to the industrial‐grade ones, and furthermore we obtained a perfect face fit by customizing their shape. Finally, we developed novel approaches to the additive manufacturing post‐processing phases essential to assure human safety in the production of 3D printed custom medical devices

    A novel DSP zebrafish model reveals training- and drug-induced modulation of arrhythmogenic cardiomyopathy phenotypes

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    Arrhythmogenic cardiomyopathy (AC) is an inherited disorder characterized by progressive loss of the ventricular myocardium causing life-threatening ventricular arrhythmias, syncope and sudden cardiac death in young and athletes. About 40% of AC cases carry one or more mutations in genes encoding for desmosomal proteins, including Desmoplakin (Dsp). We present here the first stable Dsp knock-out (KO) zebrafish line able to model cardiac alterations and cell signalling dysregulation, characteristic of the AC disease, on which environmental factors and candidate drugs can be tested. Our stable Dsp knock-out (KO) zebrafish line was characterized by cardiac alterations, oedema and bradycardia at larval stages. Histological analysis of mutated adult hearts showed reduced contractile structures and abnormal shape of the ventricle, with thinning of the myocardial layer, vessels dilation and presence of adipocytes within the myocardium. Moreover, TEM analysis revealed “pale”, disorganized and delocalized desmosomes. Intensive physical training protocol caused a global worsening of the cardiac phenotype, accelerating the progression of the disease. Of note, we detected a decrease of Wnt/ÎČ-catenin signalling, recently associated with AC pathogenesis, as well as Hippo/YAP-TAZ and TGF-ÎČ pathway dysregulation. Pharmacological treatment of mutated larvae with SB216763, a Wnt/ÎČ-catenin agonist, rescued pathway expression and cardiac abnormalities, stabilizing the heart rhythm. Overall, our Dsp KO zebrafish line recapitulates many AC features observed in human patients, pointing at zebrafish as a suitable system for in vivo analysis of environmental modulators, such as the physical exercise, and the screening of pathway-targeted drugs, especially related to the Wnt/ÎČ-catenin signalling cascade

    Efficacy of Bacillus subtilis DSM 28343 as a zootechnical additive (gut flora stabiliser) for calves for rearing

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    Bacillus subtilis DSM 28343 is a preparation of viable spores of a single strain of B. subtilis intended to be used as a zootechnical additive (functional group: gut flora stabilizer) in feed for calves for rearing to increase growth. In 2018, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) delivered a scientific opinion on the safety and efficacy of Bacillus subtilis DSM 28343 as a feed additive for calves for rearing. This species is considered by EFSA to be suitable for the qualified presumption of safety (QPS) approach to safety assessment. In that opinion, the FEEDAP Panel was unable to conclude on the efficacy of the additive, under the condition of use as proposed by the applicant, due to insufficient data provided. In the current opinion, additional data to demonstrate the efficacy of Bacillus subtilis DSM 28343 were assessed. Based on one study of this application and two studies submitted in the previous application, the Panel concluded that Bacillus subtilis DSM 28343 has the potential to be efficacious as gut flora stabiliser used in feed for calves for rearing at the proposed use level

    Assessment of the application for renewal of authorisation of Bactocell ® (Pediococcus acidilactici CNCM I-4622) as a feed additive for all fish and shrimps and its extension of use for all crustaceans

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    Bactocell \uae is the trade name for a feed additive based on viable cells of a strain of Pediococcus acidilactici. Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on Bactocell \uae  in the context of the renewal of the authorisation for shrimps, salmonids and fish other than salmonids. In addition, the applicant requested the extension of use for all crustaceans. The applicant has provided evidence that the additive currently in the market complies with the existing conditions of authorisation. The FEEDAP Panel concludes that Bactocell \uae Aqua 10 Md/100 Md is safe under the current conditions of authorisation for the target species (all fish, shrimps and all crustaceans), consumers of products from animals fed the additive and the environment. Bactocell \uae Aqua 10 Md/100 Md is non-irritant to skin and eyes and is not a dermal sensitiser, but should be considered a potential respiratory sensitiser. Exposure of users by inhalation is very likely. There is no need for assessing the efficacy of Bactocell \uae in the context of the renewal of the authorisation. The Panel concludes that the additive at the minimum inclusion level of 1  7 10 9  CFU/kg feed has the potential to be efficacious in salmonids and in the new species proposed, i.e. all crustaceans

    Safety and efficacy of Natuphos® E (6-phytase) as a feed additive for laying hens, minor poultry and other avian species for laying

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    Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of Natuphos\uae E (6-phytase) as a feed additive for laying hens, minor poultry and other avian species for laying. The additive Natuphos\uae E consists of 6-phytase (phytase; Enzyme Commission Number 3.1.3.26) and is intended to be used as a feed additive for laying hens, minor poultry and other avian species for laying as a zootechnical additive, functional group of digestibility enhancers. This additive was previously assessed by the FEEDAP Panel in 2017 for avian and porcine species. The production strain of the phytase present in the product is a genetically modified strain of Aspergillus niger. Based on the previous opinion, the FEEDAP Panel concluded that the genetic modification of the production strain does not give rise to safety concerns. The production strain and its DNA were not detected in the concentrate used to formulate the products. The FEEDAP Panel previously concluded that the additive was safe for the target species, consumers and the environment when used at 200 FTU/kg feed. The additive Natuphos\uae E is not considered to be toxic by inhalation or irritant for skin or eye; however, it should be regarded as a dermal sensitiser and a potential respiratory sensitiser. The additive has the potential to be efficacious in improving the performance and/or the phosphorus utilisation in laying hens at 200 FTU/kg feed; the conclusions drawn in laying hens can be extrapolated to all minor poultry and other avian species for laying

    Safety and efficacy of the feed additive consisting of Bacillus licheniformis DSM 28710 (B-ActÂź) for laying hens, minor poultry species for laying, poultry species for breeding purposes and ornamental birds (HuvePharma N.V.)

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    Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of the feed additive consisting of Bacillus licheniformis DSM 28710 (trade name: B-ActÂź) when used in feed for laying hens, minor poultry species for laying and for breeding purposes and ornamental birds. B. licheniformis is considered suitable for the qualified presumption of safety (QPS) approach to safety assessment. The identity of the active agent was established, and it does not harbour acquired antimicrobial resistance genes or has toxigenic potential. Following the QPS approach, B. licheniformis DSM 28710 is presumed safe for the target species, consumers and the environment. Since no concerns are expected from the other components of the additive, B-ActÂź is also considered safe for the target species, consumers and the environment. No conclusions can be drawn on the skin/eye irritation or skin sensitisation potential of the additive, but B-ActÂź is considered a respiratory sensitiser. B-ActÂź when supplemented at 1.6 Ă— 109 CFU/kg complete feed has the potential to be efficacious in laying hens. Considering also that the efficacy of the product was already shown in chickens and turkeys for fattening, the Panel concludes that the additive has the potential to be efficacious in minor poultry species for laying, poultry species for breeding purposes and for ornamental birds at the same inclusion level. The conclusions on the compatibility of B-ActÂź with coccidiostats previously drawn apply to the current application provided that the maximum authorised concentrations of the coccidiostats for the target species are equal or lower than those for chickens

    Modification of the conditions of the authorisation of BioPlus® 2B (Bacillus licheniformis DSM 5749 and Bacillus subtilis DSM 5750) for turkeys for fattening

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    Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the modification of the terms of the authorisation of BioPlus\uae 2B (Bacillus licheniformis DSM 5749 and Bacillus subtilis DSM 5750) in feeds for turkeys for fattening to allow the simultaneous use with a battery of permitted coccidiostats (diclazuril, halofuginone, monensin sodium, robenidine hydrochloride, maduramicin ammonium, lasalocid sodium) and with the preservative formic acid. The proposed modification in the conditions of the authorisation would not modify the conclusions previously drawn regarding the safety of the additive. The additive is safe for the target species, consumers and the environment. The additive should be considered a potential respiratory sensitiser, but the Panel could not conclude on the irritancy of the additive to skin and eyes or its dermal sensitisation. Conclusions previously drawn by the FEEDAP Panel on the compatibility of the additive for chickens for fattening apply to the current application provided that the maximum authorised concentration of the coccidiostats semduramycin, maduramicin ammonium, lasalocid sodium and the preservative formic acid for turkeys for fattening (when maximum authorised concentrations exist), are equal or lower than those for chickens for fattening. Considering the data submitted, the FEEDAP Panel concludes that BioPlus\uae 2B (B. licheniformis DSM 5749 and B. subtilis DSM 5750) is compatible with diclazuril and monensin sodium. Based on the data provided, no conclusion can be drawn for robenidine hydrochloride. In the absence of data, no conclusion can be drawn for halofuginone

    Safety of erythrosine for ornamental fish

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    Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety of erythrosine for ornamental fish. Erythrosine is a sensory additive belonging to the functional group colourants. In 2015, the FEEDAP Panel calculated the safe concentration in complete feed of ornamental fish to be 59 mg/kg complete feed. Considering that erythrosine contains 56.5% iodine, the safe level in feed of ornamental fish was recalculated taking into account the currently authorised maximum content of total iodine in complete feed and resulted to be 35 mg erythrosine/kg complete feed. The applicant submitted a new tolerance study in rainbow trout to demonstrate the safety of erythrosine for ornamental fish at doses higher than 59 mg/kg complete feed. The FEEDAP Panel noted that the study shows several limitations: (i) blood biochemistry was not measured, although required according to the guidance on the assessment of the safety of feed additives for the target species (ii) a low number of replicates (3 per treatment) which does not permit to obtain a reliable estimate and may not be sufficient to evidence differences between the groups (with no indication on the a priori power of the study design), and (iii) the use level group was not included in the study design. Owing to these three limitations, the FEEDAP Panel is not in the position to change its previous conclusions that the safe level of erythrosine in ornamental fish is 59 mg/kg complete feed. This safe level is reduced to 35 mg erythrosine/kg complete feed, when considering the iodine content of erythrosine and the currently authorised maximum content of total iodine in complete feed for fish
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