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Lake Trasimeno is the largest lake of the Italian Peninsula. Because of the small extent of its watershed, meteorological conditions have caused dramatic floods and droughts over the centuries. Although numerous attempts have been made to regulate the lake level since Etruscan or Roman times, the problems related to water level changes remain unsolved, and the recently adaptive management strategies seem to be ineffective in the current climatic conditions. This study evaluates past and future management scenarios with the aim of identifying effective strategies to limit the lake level fluctuations. A lumped hydrological model, which incorporates climate forcing and water regulation policies adopted currently and in the past, is calibrated and validated using a fifty-year data series. Future scenarios (present–2090) of water level change are simulated on the basis of IPCC (Intergovernmental Panel on Climate Change) regional projections for precipitation and temperature. Possible mitigation measures, such as those involving the enlargement of the catchment basin, the water diversion from nearby dams and the adoption of more restrictive rules on abstractions are also considered. The model indicates that critical prospects emerge if the intermediate or the maximum rates of change estimated by global climate models are assumed. Under these circumstances, currently feasible mitigation measures seem effective in preventing severe water shortage in the next decades, but ineffective in preventing the drainage of the lake in the second half of the century. We recommend that plans for water resource management should be put in place as a matter of urgency to ensure the conservation of the hydrologically vulnerable Lake Trasimeno.

We report the case of a 50-year-old patient admitted in ICU for a pulmonary embolism associated with a large thrombus in right heart cavities discovered during an assessment of faintness. Despite an excellent haemodynamic tolerance, there was a systolic and diastolic right ventricular failure and immediate threat to life. The treatment mainly relies on intravenous thrombolysis with excellent results both on thrombus lysis and on the right heart performance. Echocardiography proved to be an essential tool during the management of this patient to ensure the effectiveness and to monitor the whole procedure of thrombolysis.

To compare N-terminal pro-brain natriuretic peptide (NT-pro-BNP), procalcitonin (PCT), and troponin I (Tn I) concentrations during and after coronary artery surgery in patients with or without cardiovascular complications. Prospective, comparative study of 12 months in the cardiovascular intensive care unit in a university hospital 60 adult patients undergoing coronary artery bypass grafting with the off-pump technique. Plasma NT-pro-BNP, PCT, and Tn I levels were measured before and immediately after the end of operation and on PODs 1, and 2 and 3. We defined complicated postoperative course as myocardial infarction, cardiogenic shock, arrhythmias, congestive heart failure, and death occurring after the fourth postoperative hour. Receiver operating characteristic (ROC) curve cutoff values were used to assess the ability of the three markers to predict future cardiac events. The area under ROC curve (AUC) using NT-pro-BNP to detect a cardiovascular complicated course was 0.780 at the preoperative time and 0.850 at the end of surgery. A preoperative NT-pro-BNP value of 397 pg/ml had a sensitivity of 76%, specificity of 67%, and accuracy of 74% for predicting a subsequent cardiovascular complication. An immediate postoperative NT-pro-BNP value of 430 pg/ml had a sensitivity of 80%, specificity of 77%, and accuracy of 76%. Patients with preoperative NT-pro-BNP levels less than 275 pg/ml had an excellent postoperative prognosis. Other two markers were less appropriate. NT-pro-BNP levels measured before and immediately after off-pump coronary artery bypass seem to be predictive of postoperative cardiac events.

We report the case of a 50-year-old patient admitted in ICU for a pulmonary embolism associated with a large thrombus in right heart cavities discovered during an assessment of faintness. Despite an excellent haemodynamic tolerance, there was a systolic and diastolic right ventricular failure and immediate threat to life. The treatment mainly relies on intravenous thrombolysis with excellent results both on thrombus lysis and on the right heart performance. Echocardiography proved to be an essential tool during the management of this patient to ensure the effectiveness and to monitor the whole procedure of thrombolysis.

Hypoxic pulmonary vasoconstriction (HPV) is a regulatory mechanism by which blood is diverted from poorly ventilated to better ventilated areas of the lung. The aim of the present study was to assess the extent to which hypertonic saline dextran and dextran solutions modify the magnitude of HPV during isovolumic haemodilution in intact acutely instrumented piglets. Eighteen large white piglets were anesthetised and assigned to two groups. Mean pulmonary arterial pressure (PAP) and cardiac output (Q), systemic arterial pressure and left arterial pressure (LAP) were measured. A decrease in Q was obtained by reducing venous return. This enabled measurement of transpulmonary pressures (mean PAP minus LAP) at four levels of Q in hyperoxia (inspiratory oxygen fraction ( F i,O 2 )=0.4), then in hypoxia ( F i,O 2 =0.1) in the two groups before blood soustraction (10 mL·kg −1 ) and after loading with sodium chloride (NaCl) 7.5% and dextran 6% or with dextran 6% alone. Dextran alone led to a decrease in mean PAP–LAP/Q values, and NaCl with dextran was associated with a significant shift of mean PAP–LAP/Q plots to higher pressures in hypoxia. Hypertonic saline dextran solution, as replacement fluid in isovolaemic haemodilution increased the magnitude of hypoxic pulmonary vasoconstriction, whereas dextran solution reduced it.

In vitro, halogenated agents reduce the pulmonary vasoconstrictor response to alveolar hypoxia in isolated perfused lungs. However, studies in intact animals have been less convincing. The aim of the present study was to assess the effect of sub-MAC concentrations of desflurane on hypoxic pulmonary vasoconstriction (HPV) in anesthetized piglets using the pressure/cardiac output relationship (P/Q). Eleven large white piglets were anesthetized and ventilated mechanically alternatively in hyperoxia (FiO2 = 0.4) and in hypoxia (FiO2 = 0.12). Multipoint plots of pulmonary arterial pressure (PAP), or differences between PAP and left atrial pressure (LAP) against Q were generated by gradual inflation of a balloon advanced into the inferior vena cava. P/Q relationships were established in hyperoxia and in hypoxia at baseline, and then with gradual concentrations of desflurane. In hypoxia, pressure gradients (RAP-LAP) increased significantly at every level of Q, demonstrating active pulmonary vasoconstriction. Desflurane did not affect these P/Q relationships either in hyperoxia, or in hypoxia, when compared with baseline. Desflurane at a clinically relevant dose has no significant effect on HPV in anesthetized piglets.

In vitro, halogenated agents reduce the pulmonary vasoconstrictor response to alveolar hypoxia in isolated perfused lungs. However, studies in intact animals have been less convincing. The aim of the present study was to assess the effect of sevoflurane on hypoxic pulmonary vasoconstriction (HPV) in anaesthetized piglets using the pressure/cardiac index relationship (P/Q). Ten large white piglets were anaesthetized and mechanically ventilated, alternately in hyperoxia (FIO2 = 0.4) and hypoxia (FIO2 = 0.12). Multipoint plots of pulmonary arterial pressure (PAP) or differences between PAP and left atrial pressure (LAP) against Q were generated by gradual inflation of a balloon introduced into the inferior vena cava. P/Q relationships were established in hyperoxia and hypoxia at baseline, and then with sevoflurane. In hypoxia, pressure gradients (PAP-LAP) increased at every level of Q, thus demonstrating active pulmonary vasoconstriction. Sevoflurane at 1 MAC did not affect these P/Q relationships in hyperoxia or hypoxia as compared with baseline. Sevoflurane at a clinically relevant concentration (1 MAC) has no significant effect on HPV in anaesthetized piglets.

The definition of tissue-air ratio (TAR) is based on the concept of primary dose. To determine TAR, both in-phantom and in-air ionization measurements are utilized. To convert ionization in the phantom into dose and that in air into primary dose, correction factors must be applied to chamber readings in both geometries. Due to difficulties in selecting proper correction factors, TAR is subject to systematic error. The error comes from two sources of uncertainty: (1) Primary dose cannot be measured. Therefore approximate methods, such as in-air ionization measurements, are used. (2) Detectors of ionization are of finite dimensions and they are inhomogeneous. In this study, analytical expression for a systematic error is derived. Because in this derivation systematic error is an accumulative error, it is no longer necessary to convert ionization, both in air and in phantom, into a dose when calculating TARs. A method of determining systematic error is described. This method is based on the ability to produce accurate zero-field data in photon beams by means of a linear extrapolation technique. Using 60Co gamma radiation in water as an example, it is shown how to generate TAR data free of systematic error. A possibility of determining TARs for therapeutic x rays is discussed.

Transurethral prostatic resection using a 1.5% glycine solution causes a well known clinical and metabolic syndrome called TURP-syndrome. Recent development of percutaneous renal surgery is responsible of several similar accidents. In a prospective study of 150 patients (mean age: 35 +/- 10) subjected to a percutaneous nephrolithotomy, the natremia and the amino acid content of the plasma were measured preoperatively and immediately postoperatively by chromatography. The study shows that there is a post-nephrolithotomy syndrome in two per cent. This syndrome contains a hemodilution with hyponatremia and reabsorption of irrigation fluid. Glycolemia, serinemia and threoninemia increase significantly. These modifications have a good correlation between them except for the natremia. Variability of results in this study and in the literature is explained by difficulty and duration of surgery, volume of glycol used, increasing intrarenal pressures and sudden opening of vessels peroperatively. The gravity of post-nephrolithotomy syndrome requires to change the irrigate solute and use normal saline solution when it is possible.

The etiopathogenetic causes of the ectopic eruption of permanent molars are described and nine clinical reports are presented using models and roentgenogram in the first part of the article.

The paper describes the aetiopathogenetic causes of the persistence of deciduous teeth in the arch with a report on nine clinical cases of ankylosis. It is important to evaluate the overall problem because malocclusion damage may require lengthy orthodontic treatment.