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Biomedical subjects

S Mazzola

Publications and source records attributed to S Mazzola.

At least 19 recordsLinked to original sources
PubMed2006

Heavy metals in coastal water systems. A case study from the northwestern Gulf of Thailand.

A geochemical survey of the northwestern part of the Thailand Gulf (Inner Gulf) was carried out in order to define concentrations and distribution patterns of selected heavy metals (V, Cr, Co, Ni, Cu, Zn, and U) in the coastal system and estuarine area of the Mae Klong river. The results indicate the presence of two different sources of heavy metals in the studied environment and allowed us to identify a lithogenic component that significantly influences the composition of coastal waters and suspended particulate matter (SPM). Comparison of the normalized heavy metals concentrations both in the studied samples and in those reported for the Sn-W ores present in the surrounding areas suggests an important anthropogenic contribution to the chemistry of the seafloor sediments. Vanadium and nickel enrichment factors (EF) calculated for coastal waters indicate that contamination by hydrocarbons discharge took place in the investigated area.

Adsorption↗
PubMed2005

Carbon monoxide pretreatment prevents respiratory derangement and ameliorates hyperacute endotoxic shock in pigs.

Endotoxic shock, one of the most prominent causes of mortality in intensive care units, is characterized by pulmonary hypertension, systemic hypotension, heart failure, widespread endothelial activation/injury, and clotting culminating in disseminated intravascular coagulation and multi-organ system failure. In the last few years, studies in rodents have shown that administration of low concentrations of carbon monoxide (CO) exerts potent therapeutic effects in a variety of diseases/disorders. In this study, we have administered CO (one our pretreatment at 250 ppm) in a clinically relevant, well-characterized model of LPS-induced acute lung injury in pigs. Pretreatment only with inhaled CO significantly ameliorated several of the acute pathological changes induced by endotoxic shock. In terms of lung physiology, CO pretreatment corrected the LPS-induced changes in resistance and compliance and improved the derangement in pulmonary gas exchange. In terms of coagulation and inflammation, CO reduced the development of disseminated intravascular coagulation and completely suppressed serum levels of the proinflammatory IL-1beta in response to LPS, while augmenting the anti-inflammatory cytokine IL-10. Moreover, the effects of CO blunted the deterioration of kidney and liver function, suggesting a beneficial effect in terms of end organ damage associated with endotoxic shock. Lastly, CO pretreatment prevents LPS-induced ICAM expression on lung endothelium and inhibits leukocyte marginalization on lung parenchyma.

Animals↗
PubMed2002

Effect of NO synthase inhibition on cardiovascular and pulmonary dysfunction in a porcine short-term model of endotoxic shock.

In a porcine model of endotoxic shock, we evaluated the circulatory and respiratory effects of NO synthase (NOS) blockade. Twenty anaesthetised pigs were divided into three groups and studied for 240 min after induction of endotoxic shock with lipopolysaccharides of Escherichia coli (LPS). After 180 min of endotoxic shock, one group (n = 6) received aminoguanidine, another group (n = 6) received N(G)-nitro-L -arginine methyl ester (L -NAME) and a third group (n = 8) received only LPS. A sham group (n = 3) was also studied. LPS decreased systemic arterial pressure and cardiac output (CO) and increased mean pulmonary arterial pressure (MPAP), pulmonary vascular resistance (PVR) and heart rate. Significant changes were also observed in compliance (-18.4%) and resistance (+33.6%) of the respiratory system. Aminoguanidine did not modify LPS-dependent effects, while, after L -NAME, a significant increase in MPAP, PVR and SVR and a decrease in CO were observed. In conclusion, aminoguanidine does not play a significant cardiocirculatory and pulmonary role in the short-term dysfunction of endotoxic shock, while L -NAME has a detrimental effect on haemodynamics, suggesting a protective role of constitutive NO production at vascular level during the early stages of endotoxaemia.

Animals↗
PubMed2002

Effects of endothelin-1 (ET-1) and thrombin antagonism on cardiovascular and respiratory dysfunctions during endotoxic shock in pig.

We evaluated the endothelin-1 (ET-1) and thrombin involvement in cardiovascular and respiratory dysfunction during endotoxic shock in 18 anaesthetized, mechanically ventilated pigs, divided into three groups. Group 1 was pre-treated only with lipopolysaccharide (LPS), group 2 was treated with lepirudin, a thrombin inhibitor, group 3 was pre-treated with bosentan, a dual inhibitor of ET-1 receptors. Results show that LPS caused systemic hypotension, pulmonary biphasic hypertension, increase in lung resistances (R(L)) and decrease in compliance (C(L)). Lepirudin partially reduced the LPS-dependent pulmonary hypertension, without affecting the changes in C(L) and R(L). On the contrary, bosentan completely abolished the pulmonary hypertension and the changes inC(L) and R(L), and worsened the LPS-dependent systemic hypotension. Our results show that ET-1 is largely responsible for pulmonary derangement due to endotoxic shock; at bronchial level, the ET-1 release seems due only to LPS, while, at pulmonary vascular level, it results also from LPS-dependent thrombin activation.

Animals↗
PubMed2002

Different types of hysterectomy in the radio-surgical treatment of early cervical cancer (FIGO Ib-IIa).

PURPOSE OF INVESTIGATION: Surgery and radiotherapy achieved equivalent results for FIGO stages Ib-IIa invasive cervical carcinoma. The integration of radiotherapy and surgery provided the same results for a selected series of patients without increasing the rate of complications. The aim of the study was to verify if, applying a radio-surgical protocol, the reduction of the surgery extension on the parametrium in one of two consecutive series might achieve the same results in terms of survival and recurrence rates with fewer complications. MATERIAL AND METHODS: We analysed actuarial survival (with >10-year follow-up), local control rates and morbidity of 390 patients who had different the kinds of surgery applied in the radio-surgical treatment protocol: Protocol A: brachytherapy plus type III radical hysterectomy vs Protocol B: brachytherapy plus type II radical hysterectomy. Patients were all included in an analysis of complications according to the French-Italian glossary. RESULTS: Analyses showed no differences in terms of survival, patterns of recurrences and onset time within the two protocols. Urinary complications were more frequent and severe in protocol A vs protocol B (G2: 26.5% vs. 6.1%; G3: 5.3% vs. 3.6%). CONCLUSION: Our study pointed out that the reduction of the surgery extension allowed the same overall survival and relapses with fewer complications particularly in terms of grade of severity.

Adenocarcinoma↗
PubMed2001

Improvement of respiratory function by bosentan during endotoxic shock in the pig.

We evaluated the role of endothelin-1 (ET-1) and the involvement of nitric oxide in cardiovascular and respiratory dysfunction, during endotoxic shock, in 18 anaesthetised, mechanically ventilated pigs, divided into three groups. Group 1 was i.v. infused with LPS (20 microg/Kg/h for 240 min). Group 2 was pre-treated with bosentan, a dual inhibitor of ET-1 receptors, and at 180 min of endotoxic shock, L-NAME (N(G)-nitro-L-arginine methyl ester, 10 mg/Kg), a non-selective inhibitor of NO synthases, was i.v. administered. Group 3 was infused with LPS and L-NAME was administered similarly to group 2. Results show that LPS caused systemic hypotension, pulmonary biphasic hypertension, decrease in compliance (C(rs)) and increase in resistance (R(max,rs)) of respiratory system. Bosentan completely abolished the pulmonary hypertension and the changes in C(rs)and R(max,rs). L-NAME does not affect the LPS-dependent changes in respiratory mechanics, but it worsens the cardiovascular effects, causing death of pigs. Pre-treatment with bosentan prevents this deleterious effect. Our study demonstrates that the LPS-dependent respiratory effects are mediated by ET-1, which, probably causing pulmonary oedema, is responsible for the decrease in C(rs)and the increase of R(max,rs).

Animals↗
PubMed2001

Endothelin involvement in respiratory centre activity.

To evaluate the role of endothelin (ET) in respiratory homeostasis we studied the effects of the ET(A) and ET(B) receptor blocking agent bosentan on respiratory mechanics and control in seven anaesthetised spontaneously breathing pigs, for 180 min after single bolus administration (20 mg/kg i.v.). The results show that the block of ET receptors induced a significant increase in compliance and decrease in resistance of the respiratory system, entailing a significant reduction of diaphragmatic electromyographic activity, without affecting the centroid frequency of the power spectrum. Bosentan administration induced a significant increase in tidal volume (V(T)), accompanied by a significant decrease in respiratory frequency, without any significant change in pulmonary ventilation, CO(2) arterial blood gas pressure or pH. Since the relationship between V(T) and inspiratory time remained substantially constant after bosentan administration, the changes in respiratory pattern appear to be the result of an upward shift in inspiratory off-switch threshold. Both inspiratory and expiratory times during occluded breathing were increased by block of ET receptors, suggesting also a central respiratory neuromodulator effect of ET. In conclusion the present results suggest that the block of ET receptors in spontaneously breathing pigs exerts a role on mechanical properties of the respiratory system as well as on peripheral and central mechanisms of breathing control.

Airway Resistance↗
PubMed1990

Organization and management of a database in the respiratory physiology.

In this paper we present a set of programs resulting in a management system for a Database in experimental medicine. The programs are written in Fortran and they run in a VAX 8200 of DEC. We have successfully applied this management system in the study of mechanics and of the electrical activity of the muscles of the respiratory apparatus. However, it may be used in other fields of experimental medicine since it has been structured in such a way as to be easily adapted; in addition it may run in other computers.

Computer Simulation↗
PubMed1990

[Telemetric surveys in plant pathology and for taking the census of ungulates].

Two new applications of the remote sensing techniques in the territory management which make use of a thermal scanner, are described here: the first concerned with the vegetal pathology field and the second with the big game censusing the Castelporziano farm. The former constitutes an improvement of the usual techniques either for its quick performance or for being an uncurrent intervention on plants, the latter allows to realize censuses also in thickly bushy or woody lands, where the usual methods of counting "at sight", besides to need a large staff are not much reliable.

Agriculture↗
PubMed1983

[Anastomosis in coronary surgery: technical improvement using a vein-holding instrument].

A vein holder for vascular surgery is described. Distal (direct or sequential) as well as proximal anastomoses in aorto-coronary bypass surgery can be easily performed with that instrument. It minimizes handling of the graft and provides an excellent visualization in placing sutures in half of the circumference at both ends of the venous graft.

Arteriovenous Shunt, Surgical↗