Closed-loop optogenetic control of the dynamics of neural activity in non-human primates.

Electrical neurostimulation is effective in the treatment of neurological disorders, but associated recording artefacts generally limit its applications to open-loop stimuli. Real-time and continuous closed-loop control of brain activity can, however, be achieved by pairing concurrent electrical recordings and optogenetics. Here we show that closed-loop optogenetic stimulation with excitatory opsins enables the precise manipulation of neural dynamics in brain slices from transgenic mice and in anaesthetized non-human primates. The approach generates oscillations in quiescent tissue, enhances or suppresses endogenous patterns in active tissue and modulates seizure-like bursts elicited by the convulsant 4-aminopyridine. A nonlinear model of the phase-dependent effects of optical stimulation reproduced the modulation of cycles of local-field potentials associated with seizure oscillations, as evidenced by the systematic changes in the variability and entropy of the phase-space trajectories of seizures, which correlated with changes in their duration and intensity. We also show that closed-loop optogenetic neurostimulation could be delivered using intracortical optrodes incorporating light-emitting diodes. Closed-loop optogenetic approaches may be translatable to therapeutic applications in humans.

A case of Solitary fibrous pleura tumor associated with severe hypoglycemia: the Doege-Potter 's Syndrome.

Solitary fibrous pleura tumor is a rare primary intrathoracic tumor of the pleura. It usually has an indolent clinical course, but sometimes it can have an aggressive behaviour. In 1930 Doege and Potter independently described this neoplasm, presenting with symptoms of hypoglycemia, hence the eponim of Doege-Potter's Syndrome. In this report, we illustrate a case of Doege Potter's Syndrome, treated with complete surgical resection.

Integrated pollution evaluation of the Tagus River in Central Spain.

The aim of this study was to integrate hydrochemical and sediment data in order to obtain a picture of the pollution state of the Tagus River along central Spain. This area is of special interest because tributaries from the Madrid region are discharged and no previous data were available. Waters and sediments were sampled between 2002 and 2004 from selected sites before and after Jarama River confluence (Madrid city input). The samples were analysed for more than 50 parameters, including those of physico-chemical nature and those reporting the pollution caused by both metals and organic compounds. The quality of waters for different uses has been tested and statistical quality indexes of both global and partial type has also been established. Sediments pollution state was evaluated by comparison with general quality standards. A high degree of pollution and general degradation was observed in the Tagus River downstream the Jarama River input. The pollution of waters is mainly related to parameters indicators of organic pollution from urban sewage. In sediments, a dramatic increase in the concentration of trace metals was found in different points, exceeding toxicological threshold. Further studies would be necessary for organic pollutants and also to evaluate the remobilization potential.

[Etiopathogenic and clinical considerations on primary pulmonary hypertension]. / Considerazioni eziopatogenetiche e cliniche sull'ipertensione polmonare primitiva.

Primary pulmonary hypertension is a severe condition of unknown etiology first described by Romberg in 1891. The authors review the literature with particular emphasis on new hypotheses concerning etiopathogenesis, and recent suggestions for management. The former take into account the discovery of endothelium derived relaxing factors and the identification in pulmonary arteries of a polypeptide called endothelin. Further hypotheses contemplate 1) interaction between platelets and endothelium; 2) the role of heparin-inhibiting enzymes; 3) abnormal cellular adhesion. Heart catheterism is apt to exclude other causes of pulmonary hypertension and also permits to assess the severity of the condition and its prognosis, as well as acting as a guide to management. If venous O2 saturation is higher than 63%, calcium blocking agents and anticoagulants should be used, if it is lower than 63% long-term prostaglandin infusion should be given awaiting heart-lung transplantation unless this can be done immediately.

[Spontaneous changes in blood cholesterol and triglyceride levels in the acute phase of a stroke]. / Variazioni spontanee della colesterolemia e della trigliceridemia nell'ictus cerebrale in fase acuta.

Plasma cholesterol and triglycerides concentration were determined in 32 patients with acute stroke (23 males and 9 females, mean age = 70.5 +/- 10.4 years) within the first 24 hours from the beginning of symptoms, and repeatedly afterwords, until the 22nd day. A progressive decrease of mean cholesterol concentration was observed, which reached lowest values on the 13th day (20% reduction), and stabilized afterwords. A 30% increase of mean triglycerides levels was found on the fourth day, with subsequent return to the basal level on the 13nth day. One year after, mean values of both parameters, determined in 18 patients, did not differ from the ones observed, in the same subjects, immediately after the acute event.

Hematocrit and stroke. A case-control study.

A case-control study was undertaken to evaluate the role of hematocrit (Hct) level in the pathogenesis of stroke. Hct was determined in 110 subjects with acute ischemic stroke and compared with the values obtained in 110 subjects, matched for age and sex, admitted to our Division of General Medicine because of other diseases. Statistical analysis of the results by means of the McNemar test for pairs did not confirm the hypothesis that Hct values in stroke patients differ significantly from the control values.