[Evaluation of plans for reclamation from products containing asbestos to ensure safety to the workers and the general population]. / Valutazione dei piani di lavoro per la bonifica di materiali contenenti amianto al fini della sicurezza dei lavoratori e della popolazione generale.

Fifty-two working plans for abatement of asbestos-containing materials (ACM) were examined being presented over 12 months at a Public Occupational Health Service in Apulia (Italy) by authorized companies. Most of the interventions took place in urban areas and civil buildings and lasted few days with employment of a limited number of workers. They mainly consisted in removal practices. The weight of ACM abated varied from 30 to over 14,000 kg. Air monitoring of asbestos fibres was included not in all plans. When airborne fibres were detectable, the threshold of environmental pollution (20ff/L) was sometimes reached or exceeded. This finding appeared to be relevant for asbestos exposure of workers and general population. A higher fibre dispersion occurred during abatement of amounts of ACM more than 1,000 kg. The Occupational Health Service should be legally and operatively able to make regular workplace inspections, especially when large quantities of ACM have to be abated.

[Amplification of contractile response by serotonin on noradrenaline in the human umbilical artery]. / Amplificación de la respuesta contractil a noradrenalina por serotonina en la arteria umbilical humana.

A progressive increase in plasma levels of serotonin (5-HT) during pregnancy has been reported. Furthermore, an increase in the concentration of noradrenaline (NA) has been described during labor. On the other hand, in different arteries it has been observed that minimal effective concentrations of 5-HT are able to produce an increase or "amplification" of the contractile response to a second agonist. From these reports, it seemed interesting to determine the existence of a synergistic interaction between 5-HT and NA in the human umbilical artery (HUA), and the probable mechanisms involved. Therefore, strips of HUA were incubated in Krebs solution at 37 degrees C and gassed with a mixture of CO2 (5%) and O2 (95%). The contractile isometric response was assessed. After a period of two hours, complete cumulative concentration-response curves to 5-HT and to NA were obtained. The maximal contractile response to NA was approximately 20% of the maximal response to 5-HT. In another series of experiments, the response to NA was enhanced by previous treatment with minimal effective doses of 5-HT (control response 0.24 +/- 0.06 g; "amplified" response 0.53 +/- 0.06 g, P < 0.01). This "amplified" response to NA was correlated with the degree of previous contraction with 5-HT, when the last was between 3 and 30% of the maximal response. However, precontractions higher than 40% abolished the responses to NA. In other experiments, the artery strips were incubated during thirty minutes with diltiazem 1 microM before agonists addition. In this condition, a decrease in the control and amplified response was observed. Therefore, we have shown the existence of an amplifying effect of 5-HT over the response to NA in the HUA, and we discuss the possible mechanisms involved and the possible clinical relevance in preeclampsia.

Amplificación de la respuesta contractil a noradrenalina por serotonina en la arteria umbilical humana. / [Amplification of contractile response by serotonin on noradrenaline in the human umbilical artery]

A progressive increase in plasma levels of serotonin (5-HT) during pregnancy has been reported. Furthermore, an increase in the concentration of noradrenaline (NA) has been described during labor. On the other hand, in different arteries it has been observed that minimal effective concentrations of 5-HT are able to produce an increase or [quot ]amplification[quot ] of the contractile response to a second agonist. From these reports, it seemed interesting to determine the existence of a synergistic interaction between 5-HT and NA in the human umbilical artery (HUA), and the probable mechanisms involved. Therefore, strips of HUA were incubated in Krebs solution at 37 degrees C and gassed with a mixture of CO2 (5

) and O2 (95

). The contractile isometric response was assessed. After a period of two hours, complete cumulative concentration-response curves to 5-HT and to NA were obtained. The maximal contractile response to NA was approximately 20

of the maximal response to 5-HT. In another series of experiments, the response to NA was enhanced by previous treatment with minimal effective doses of 5-HT (control response 0.24 +/- 0.06 g; [quot ]amplified[quot ] response 0.53 +/- 0.06 g, P < 0.01). This [quot ]amplified[quot ] response to NA was correlated with the degree of previous contraction with 5-HT, when the last was between 3 and 30

of the maximal response. However, precontractions higher than 40

abolished the responses to NA. In other experiments, the artery strips were incubated during thirty minutes with diltiazem 1 microM before agonists addition. In this condition, a decrease in the control and amplified response was observed. Therefore, we have shown the existence of an amplifying effect of 5-HT over the response to NA in the HUA, and we discuss the possible mechanisms involved and the possible clinical relevance in preeclampsia.