Far from urban areas: plastic uptake in fish populations of subtropical headwater streams.

This study investigated the occurrence of plastic particles in the digestive tracts of fish from headwater streams in a human-thinly populated region of the subtropical Sinos River basin in southern Brazil. In total, 258 individuals from 17 species were collected using electric fishing. Thirty-eight percent (38%) of the specimens contained plastic particles. All of them were fibers, with a maximum count of 43 per individual. Plastic fibers were the fourth most abundant food category. Results showed that the uptake of these plastic particles was proportional to the number of ingested food items. Fiber counts in the guts correlated with the uptake of Trichoptera, which are invertebrates using plastic particles to construct their protective cases. No significant difference in plastic uptake was detected between benthic and water column fish. No evidence of bioaccumulation of plastic particles was found in the intestines. The distance from urban areas was not related to the number of ingested plastic particles, concluding that plastics are ubiquitous and available to biota, even in remote locations. The most probable source of these particles is residences close to the streams which discharge the sewage of washing machines without any treatment.

Epiandrosterone and dehydroepiandrosterone affect glucose oxidation and interleukin-1 beta effects in pancreatic islets.

Isolated rat islets or RINm5F insulinoma cells treated with interleukin-1 beta (IL-1 beta) for 18 h show reduced glucose-sensitive insulin release and increased nitrite formation as a result of nitric oxide synthase induction. Although a phosphodiesterase inhibitor, isobutylmethylxanthine, potentiated insulin release in response to glucose stimulation, the secretory response was not restored to normal in IL-1 beta-treated islets. Islets that were cultured for 18 h in the presence of IL-1 beta and epiandrosterone (EA) or dehydroepiandrosterone (DHEA) and then washed responded with a concentration-dependent reversal of the effects of IL-1 beta on insulin release in the presence of a glucose or glucose plus isobutylmethylxanthine stimulus. In contrast, when EA and DHEA were not washed from the islets before determination of insulin release, the presence of EA or DHEA inhibited insulin release in both freshly isolated and cultured islets. Nitrite formation in islets and RINm5F cells in response to IL-1 beta was also significantly reduced during culture with EA or DHEA, although nitrite levels were still elevated above control values. Neither steroid affected cell growth or DNA or protein content. Pyrrolidine dithiocarbamate also reduced IL-1 beta-induced nitrite formation. EA and DHEA inhibited [U-14C]glucose oxidation in islets and RINm5F cells. Comparison of [1-14C]glucose and [6-14C]glucose oxidation in islets and RINm5F cells when EA was present during culture and metabolic determination indicated that EA inhibited glycolysis and the pentose shunt contribution to glucose utilization. Neither IL-1 beta in islets nor DHEA in RINm5F cells inhibited pentose shunt activity, although total glucose oxidation and utilization were inhibited. The effects of DHEA and EA on glucose oxidation were rapidly reversible. EA and DHEA reduced glucose-6-phosphate dehydrogenase activity only when added directly to tissue homogenates. Thus, EA and DHEA antagonize the effects of IL-1 beta on beta-cells. Inhibition of glucose metabolism and pentose shunt activity may protect the cells from nitric oxide synthase activation and related toxicities.

[Pathology of the internal organs and central nervous system in acquired immunodeficiency syndrome (with special reference to opportunistic infections)]. / La patologia degli organi interni e del sistema nervoso centrale nella sindrome da immunodeficienza acquisita (con particolare riferimento alle infezioni opportunistiche).

Extracerebral and cerebral pathology in AIDS (with particular emphasis on the opportunistic infections). The Authors present the extracerebral pathology of 27 cases of AIDS observed at the Department of Pathology of Milan and the cerebral pathology of 80 cases of AIDS collected by three Institutes (Department of Pathology of Milan, Department of Pathology of Rimini and Department of Neuropathology of Münster) with particular emphasis on the pathology of the opportunistic infections. In the adults' group, the most frequent infections are the protozoan ones (T. gondii) followed with equal incidence by the viral and fungal diseases. In the pediatric group the viral diseases are the most frequently seen. Almost all of the adults show multiple infections in the same organ or in different organs. Diffuse lesions with heavy pathologic fields were observed also without tissue reaction. As to cerebral pathology AIDS' patients with opportunistic infections show focal symptoms, whereas the so called "subacute microglial encephalitis" generally appears as a demential syndrome. In cases with progressive multifocal leukoencephalopathy JC virus was always found and in one case also SV 40 - and BK virus. The diffuse demyelinization in some cases of HIV-Encephalopathy is aspecific. In HIV-positive newborns with cerebral signs, the lesions are characterized by oedema, spongiosis and microcalcifications of the basal ganglia; these are aspecific lesions which can be found in toxic and infectious encephalopathies.