Scrapie at Abattoir: Monitoring, Control, and Differential Diagnosis of Wasting Conditions during Meat Inspection.

Wasting disease in small ruminants is frequently detected at slaughterhouses. The wasting disorder is manifested by the deterioration of the nutritional and physiological state of the animal indicated by thinness, emaciation, and cachexia. Evidence of emaciation and cachexia, alone, are pathological conditions leading to carcass condemnation during an inspection. Several diseases are associated with a wasting condition, including scrapie, pseudotuberculosis, tuberculosis, paratuberculosis, Maedi Visna, and tumor diseases. On the other hand, parasitic diseases, nutrition disorders, exposure or ingestion of toxins, metabolic conditions, inadequate nutrition due to poor teeth, or poor alimentary diet are conditions contributing to poor body condition. Classical and atypical scrapie is naturally occurring transmissible spongiform encephalopathies in small ruminants. The etiological agent for each one is prions. However, each of these scrapie types is epidemiologically, pathologically, and biochemically different. Though atypical scrapie occurs at low incidence, it is consistently prevalent in the small ruminant population. Hence, it is advisable to include differential diagnosis of this disease, from other possibilities, as a cause of wasting conditions detected during meat inspection at the abattoir. This manuscript is a review of the measures in force at the abattoir for scrapie control, focusing on the differential diagnosis of gross lesions related to wasting conditions detected in small ruminants during meat inspection.

Uptake and effects of the antimicrobial florfenicol, microplastics and their mixtures on freshwater exotic invasive bivalve Corbicula fluminea.

Microplastics and antimicrobials are widely spread environmental contaminants and more research on their toxicity is needed. The uptake and effects of the antimicrobial florfenicol, microplastics, and their mixtures on Corbicula fluminea were investigated. Bivalves were exposed for 96h to florfenicol (1.8 and 7.1mg/l), microplastics (0.2 and 0.7mg/l), or mixtures of the two substances. After 96h, all bivalves exposed to antimicrobial treatments had florfenicol in their body (e.g. 2±1µg/g). Microplastics were found in the gut, lumen of the digestive gland, connective tissue, hemolymphatic sinuses, and gills surface of animals. Florfenicol caused a significant inhibition of cholinesterase (ChE) activity (~32%). Animals exposed to 0.2mg/l of microplastics showed ChE activity inhibition (31%), and no other significant alterations. Mixtures caused feeding inhibition (57-83%), significant ChE inhibition (44-57%) and of isocitrate dehydrogenase activity, and increased anti-oxidant enzymes activity and lipid peroxidation levels. Overall, the results indicate that C. fluminea take up florfenicol and microplastics from the water and accumulated or at least retained it in their body for some time; both florfenicol (low ppm range) and microplastics (ppb range) were toxic to C. fluminea, with mixtures containing florfenicol and microplastics being more toxic. Thus, the risk of exposure and toxic effects of florfenicol to C. fluminea and other bivalves, and its predators increase in ecosystems contaminated with the antimicrobial and microplastics, as well as to humans consuming contaminated species from these ecosystems.

Processing ulvan into 2D structures: cross-linked ulvan membranes as new biomaterials for drug delivery applications.

The polysaccharide ulvan, composed of sulphated rhamnose, glucoronic and iduronic acids was used to produce polymeric membranes by solvent casting. As ulvan is soluble in water, a cross-linking step was necessary to render the membrane insoluble in water and stable at physiological conditions. Cross-linked ulvan membranes were characterized by FTIR, SEM, swelling behaviour was investigated and the mechanical performance assessed by quasi-static tensile testing. Furthermore, the ability and mechanism of sustained release of a model drug from ulvan membranes was investigated. Produced membranes revealed remarkable ability to uptake water (up to ∼1800% of its initial dry weight) and increased mechanical performance (1.76 MPa) related with cross-linking. On the other hand, medicated ulvan dressings demonstrate the potential as drug delivery devices. Using a model drug we have observed an initial steady release of the drug - of nearly 49% - followed by slower and sustained release up to 14 days. The properties of ulvan membranes herein revealed suggest a great potential of this natural sulphated polysaccharide as a wound dressing.

Marine algae sulfated polysaccharides for tissue engineering and drug delivery approaches.

Biomedical field is constantly requesting for new biomaterials, with innovative properties. Natural polymers appear as materials of election for this goal due to their biocompatibility and biodegradability. In particular, materials found in marine environment are of great interest since the chemical and biological diversity found in this environment is almost uncountable and continuously growing with the research in deeper waters. Moreover, there is also a slower risk of these materials to pose illnesses to humans.   In particular, sulfated polysaccharides can be found in marine environment, in different algae species. These polysaccharides don't have equivalent in the terrestrial plants and resembles the chemical and biological properties of mammalian glycosaminoglycans. In this perspective, are receiving growing interest for application on health-related fields. On this review, we will focus on the biomedical applications of marine algae sulfated polymers, in particular on the development of innovative systems for tissue engineering and drug delivery approaches.

Extraction and physico-chemical characterization of a versatile biodegradable polysaccharide obtained from green algae.

During the last years, considerable attention has been given to different marine organisms, like algae, as potential sources of valuable materials. The continuous demand for novel materials and technologies is high and research on the underexploited marine green algae, including its polysaccharidic part-ulvan, has increased accordingly. In this research work, a novel method for extraction of ulvan from green algae is proposed and demonstrated successfully. Different characterization techniques were employed to characterize the isolated algal polysaccharide, namely, on what concerns its thermal trace and crystallinity. Upon heating, ulvan behaves as a non-meltable polysaccharide that is thermally stable before degradation at 220°C. Ulvan is semi-crystalline in nature and possesses high hygroscopic features, as revealed in this research work. Due to its properties, ulvan can be considered, pure or modified, as a versatile biodegradable polymer for different applications, including tissue engineering and regenerative medicine.