Characterization and function of extracellular vesicles in a canine mammary tumour cell line: Ultracentrifugation versus size exclusion chromatography

Extracellular vesicles (EVs) are cell-derived membrane-bound vesicles involved in many biological processes such as tumour progression. For years, ultracentrifugation (UC) has been considered the gold standard for EV isolation but limited purity and integrity allowed the diffusion of alternative techniques. In this study, EVs were isolated from a canine mammary tumour cell line using UC and size exclusion chromatography (SEC) and analysed for size and concentration by nanoparticle tracking analysis (NTA) and for protein expression by western blot (WB). EV autocrine effect on cell proliferation, migration and invasiveness was then evaluated in vitro. In all samples, particles were in the EV size range (50–1000 nm), with a higher concentration in UC than in SEC samples (10¹¹ and 10¹⁰ particles/ml respectively), and expressed EV markers (Alix, CD9). Functional assays did not show statistically significant difference among conditions, but EV treatment slightly increased cell proliferation and invasiveness and treatment with SEC-isolated EVs slightly enhanced cell migration compared to UC-isolated EVs. In conclusion, the main differences between the two isolation techniques are the quantity of the final EV-product and slight differences on EV functionality, which should be further explored to better highlight the real autocrine effect of tumoral EVs.     

Global contested terrain: The case of the tuna-dolphin controversy

Employing the case of the global tuna-fish industry, it is argued that the process of globalization is contested terrain as it opens free spaces to some classes or groups and closes free spaces to others; that the nation-States' regulatory abilities are weakened; and finally, that while some social movements may gain, others are marginalized. Three basic conclusions are reached. (1) The industry's actions were successfully contested by environmental groups supported by the legislative and judicial branches of the US State. (2) Simultaneously, pro-environmental legislation is currently threatened, along with several national and international environmental accords. (3) Workers in the US and, particularly, in Latin America are paying the consequences of the introduction of pro-environmental legislation and the actions of transnational corporations (TNCs).Douglas H. Constance is Research Associate of Rural Sociology at the University of Missouri-Columbia. His research interests include the sociology of agriculture and environmental sociology. He is the author of several journal articles and is coauthor with Alessandro Bonanno of the forthcoming bookCaught in the Net: The Global Tuna Industry, Environmentalists, and the State.     

Agricultural policies and the capitalist State

The paper examines the social contradictions generated by patterns of reproduction of accumulation of capital, social legitimation and by present agricultural policies fostered by the State. Through a scrutiny of the role of the State in capitalism it is argued that agricultural overproduction, the widening of the gap between small and large farms, the fiscal crisis of the State associated with agricultural programs and waste of resources are the outcomes of an attempt on the part of the State to promote simultaneously accumulation and legitimation. The possibility of enhancing accumulation and maintaining legitimation clashes with the diverse socio-economic demands associated with the present agricultural production system and the general viability of the social structure as a whole.     

Congenital heart disease in boxer dogs: results of 6 years of breed screening

This prospective study was conducted to evaluate the prevalence and severity of ocular lesions in dogs with anemia (packed cell volume  20%) and/or thrombocytopenia (platelet count < 150,000/μL). Dogs were divided into four groups: (1) anemic (n = 17); (2) thrombocytopenic (n = 36); (3) anemic and thrombocytopenic (n = 24); and (4) healthy controls (n = 26). The prevalence of ophthalmic lesions in these four groups was 12%, 42%, 42% and 0%, respectively. Anemia was not associated with the presence of ocular lesions (P = 0.41) or their severity. Thrombocytopenia was significantly associated with the presence of ocular lesions (P = 0.0016) and with their severity (P = 0.017). We conclude that thrombocytopenia, but not anemia, is associated with ocular lesions in dogs.