Biomedical subjects

M Brescia

Publications and source records attributed to M Brescia.

3 recordsLinked to original sources

PubMed1996

Biomarkers of lung inflammation in recreational joggers exposed to ozone.

Humans exhibit an acute inflammatory response in the lungs after controlled laboratory exposure to ozone. The present study was designed to test whether biomarkers of inflammation are detectable in humans exposed to ozone and associated copollutants under natural conditions outdoors. Bronchoscopy with bronchoalveolar lavage (BAL) was carried out on 19 normal volunteer joggers from Governors Island, NY, who exercised in the afternoon during the 1992 summer (S1) season. Fifteen subjects were retested during the following, low ozone, winter season (W). The BAL protocol involved an initial instillation of 20 ml saline followed by four sequential 50-ml saline washes carried out in both the right middle lobe and the lingula. The eight 50-ml samples were pooled as the 'alveolar' sample. Analyses performed on the alveolar lavage samples included cell differentials, release of IL-8, TNF-alpha, and reactive oxygen species (ROS) by pooled cells, and levels of IL-8, protein, LDH, fibronectin, alpha1-antitrypsin (alpha1-AT), complement fragment 3a (C3a), and prostaglandin E2 (PGE2) in lavage fluids. Release of ROS by stimulated BAL cells was lower in S1 than in W (p = 0.03). In contrast, LDH levels in BAL fluids were 2-fold higher in S1 than in W (p = 0.02), as were IL-8 (p = 0.12) and PGE2 (p = 0.06). These results suggest a possible ongoing inflammatory response in the lungs of recreational joggers exposed to ozone and associated copollutants during the summer months.

Adult↗

PubMed1983

Distribution of salicylate in lens and intraocular fluids and its effect on cataract formation.

Retrospective studies on cataract development in patients with rheumatoid arthritis or osteoarthritis revealed a retardant effect of aspirin on diabetic and non-diabetic cataracts. The effect of aspirin is dose-dependent. The correlation coefficient between years delay for various cataracts subcategories versus aspirin taken (in tablets per day X years of intake) was 0.69. The ocular pharmacokinetics of 14C acetylsalicylic acid or salicylate were determined after intravenous or intraperitoneal administration to rabbits. 14C acetylsalicylic acid penetrates rapidly into rabbit lens and aqueous humor after intravenous administration. After intraperitoneal administration, salicylate levels in rabbit plasma, similar to those of humans receiving four to six aspirin tablets (325 mg each), result in accumulation of salicylate by lens (mean +/- SD) of 405 +/- 72 mumoles/g and 620 +/- 30 mumoles/g at two and four hours, respectively. At those dosages, salicylate is cleared in 24 hours from rabbit plasma and intraocular fluids, but retained by lens. Penetration of salicylate into rabbit lens and rat lens is dose-dependent. The retardant aspirin effect in diabetic cataracts is linked to inhibition of tissue aldose reductase and lens protein glycosylation. Deceleration of galactose cataract formation in rats occurs after daily salicylate intraperitoneal injections of 100 mg/kg a day.

Animals↗

PubMedDate not supplied

Ground-based telescope pointing and tracking optimization using a neural controller.

Neural network models (NN) have emerged as important components for applications of adaptive control theories. Their basic generalization capability, based on acquired knowledge, together with execution rapidity and correlation ability between input stimula, are basic attributes to consider NN as an extremely powerful tool for on-line control of complex systems. By a control system point of view, not only accuracy and speed, but also, in some cases, a high level of adaptation capability is required in order to match all working phases of the whole system during its lifetime. This is particularly remarkable for a new generation ground-based telescope control system. Infact, strong changes in terms of system speed and instantaneous position error tolerance are necessary, especially in case of trajectory disturb induced by wind shake. The classical control scheme adopted in such a system is based on the proportional integral (PI) filter, already applied and implemented on a large amount of new generation telescopes, considered as a standard in this technological environment. In this paper we introduce the concept of a new approach, the neural variable structure proportional integral, (NVSPI), related to the implementation of a standard multi layer perceptron network in new generation ground-based Alt-Az telescope control systems. Its main purpose is to improve adaptive capability of the Variable structure proportional integral model, an already innovative control scheme recently introduced by authors [Proc SPIE (1997)], based on a modified version of classical PI control model, in terms of flexibility and accuracy of the dynamic response range also in presence of wind noise effects. The realization of a powerful well tested and validated telescope model simulation system allowed the possibility to directly compare performances of the two control schemes on simulated tracking trajectories, revealing extremely encouraging results in terms of NVSPI control robustness and reliability.

Models, Theoretical↗