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Our studies on PBV indicate that: (1) TBV and SV may have, in various conditions, an important role in the control of the size of PBV. (2) The effect of MPWP on this volume is a complex one an

A model for the alkali metal bonding energy in some solid oxides based on a simplified approach of the electronegativity equalization method is proposed. From this model, no intensive numerical cal...

A microscopic description of the effect of hydration on the behavior of extraframework cations in zeolite Na + -mordenite is reported. Energy minimization techniques, combined with appropriate interatomic potentials to describe the potential energy surface of this complex system, have been used to determine the site selectivity of both cations and water molecules as a function of the hydration level. We have thus shown that the positions of the cations in the main channels are substantially perturbed upon the sorption of water molecules whereas those of the cations located in the small side channels are only slightly shifted. This modeling has been successfully compared with experimental data obtained by dielectric relaxation spectroscopy.

Dielectric relaxation properties of dehydrated and hydrated Na-mordenite are measured by means of thermally stimulated depolarization current (TSDC) spectroscopy. TSDC spectroscopy allows us to determine two characteristic terms which depend on the hydration state: on one hand, the site selectivity of sodium ions and water molecules and on the other hand, the sodium/network interaction energy. Upon hydration, half of the Na+ ions remain embedded in site A, whereas the other Na+ ions are extracted from the main channel sites (sites D and E). Besides, according to the water content, we show that water molecules are adsorbed in different sites, first in sites H or F, then in sites B, C, or G, and finally in sites G. Furthermore, it is pointed out that the interaction energy (Na+/zeolite) value depends on the sodium localization following the sequence: Esite A > Esite D > Esite E. Finally, it is shown that the interaction energy decreases as the water content increases (typically from 0.79 eV to 0.44 eV). Thi...

Alkali triborate glasses M2O‚3B2O3, with M ) Li, Na, K, Rb, and Cs, have been investigated by dielectric relaxation spectroscopy employing two different experimental techniques, i.e., complex impedance spectroscopy (CIS) and the thermally stimulated current (TSC) technique. The results of these two dielectric spectroscopies can be fruitfully analyzed in terms of distribution functions of relaxation times and favorably compared. The dielectric results are discussed by analyzing the far-infrared absorption profiles due to the localized metal cation site vibrations. Both dielectric and far-infrared spectroscopies show that metal cations are embedded in at least two or three types of network sites. The activation energies for cation detrapping and for ionic mobility were also evaluated.

The analysis of thermally stimulated current measurements by the use of the RMA method (Relaxation Map Analysis) shows that in a mordenite-type zeolite, sodium ions are localized into three different sites. It is assumed that each RMA peak results from a distribution of relaxation times even though it corresponds to a very narrow domain of temperature. By varying this temperature window, it is thus possible to determine the contribution of each type of sodium to the whole dielectric response of the material. Therefore, the nature of the different Na + /mordenite network interaction can be assessed.

Thermally stimulated current (TSC) spectroscopy is widely used to understand dielectric relaxation in complex solid systems. However, when these systems contain free and bound charges, it appears that TSC spectra exhibit multicomponent signals, due both to dipolar and to space-charge relaxation. In this work, we propose an experimental method to identify clearly and then separate the space-charge contribution from the dipolar current, in ionically conducting solids. This method is based on the comparison between global and fractional thermally stimulated current procedures and is applied to analyse the dielectric response of several alkali-exchanged mordenites (with exchange of , and for ).

The evolution of thermally stimulated depolarization current (TSDC) measured on a mordenite Na zeolite is examined as a function of the Na+ exchange degree. According to this investigation, the dipolar reorientation is due to Na+, and the TSDC signal analysis leads to an assessment of the interaction energies between the hopping Na+ ions and the zeolitic lattice. The values of these energies are found to be between 0.7 and 0.9 eV. According to the Na+ exchange degree and the nature of the occupied Na+ sites, a quantitative and qualitative characterization of each site is given.

Dielectric losses measured on zeolite sample have been investigated to correlate these measurements with surface thermodynamic. The polarization conductivity measurement allows the determination of variables which are linked to the adsorption enthalpies and entropies but also to the system dynamic. To quantitatively interpret the results, it is necessary to know the energetic heterogeneity of the solid sample. The thermally stimulated current measurement (TSDC) appears as a possible tool. Therefore this new method of studying adsorption by combining two techniques seems promising. This paper is an introduction to the work under development.

Poster relativo ai risultati del Progetto GARANTES presentato nell'ambito del Convegno " Expo Rurale Toscana 2013 - Innovazione in agricoltura: attuazione misura 124 del PSR 2007-2013 in Toscana a confronto con altre esperienze italiane"

OBJECTIVES--To compare the usefulness of high resolution computed tomography (HRCT) with chest radiography (CR) in the diagnosis and assessment of severity of silicosis. METHODS--27 workers exposed to silica underwent CR, HRCT, and pulmonary function tests. Two experienced readers independently evaluated CR by International Labour Office classification, and grouped the results into four categories. HRCT categories of nodule profusion and the extent of emphysema were graded on a four point scale; in 20 subjects the percentage distribution of lung densities were measured by HRCT. RESULTS--Concordance between readers was higher for HRCT than for CR (K statistic = 0.49 and 0.29 respectively). There was poor concordance between CR and HRCT in the early stage of silicosis. No significant difference in pulmonary function tests was found among different CR categories, but forced expiratory volume in one second (FEV1), maximal expiratory flow at 50% and 75% of FVC (MEF50, MEF75), and diffusion capacity significantly decreased with increasing HRCT categories. Subjects with simple silicosis detected by HRCT had a lower FEV1 than subjects without silicosis, whereas subjects with conglomerated silicosis showed higher residual volume and functional residual capacity than subjects with simple silicosis. These relations were not affected by smoking or symptoms of chronic bronchitis. Different grades of emphysema detected by HRCT were significantly different in diffusion capacity. Only the HRCTs of the lowest and the highest categories of profusion of parenchymal opacities were significantly different in their distribution of density classes. CONCLUSION--HRCT is more reproducible and accurate than CR, as suggested by the higher agreement between readers and the better correlation with pulmonary function tests, irrespective of smoking and chronic bronchitis; however, these data do not support the hypothesis that HRCT is more sensitive than CR in the early detection of silicosis.

We have used a hopping conduction model to calculate the frequency-dependent polarization conductivity [sgrave]′ (ω) and we have assumed that the shortrange ionic hopping mechanism occurs because of the ‘free-volume’ redistribution within the glass structure. We have represented the glass structure as a slightly imperfect gas of cells and calculated, using statistical thermodynamic considerations, the influence of the microstructural aggregation of cells on the ionic polarization conductivity. Likewise, we have underlined the fundamental differences between the frequency-dependent polarization conductivity due to ‘bound-charge’ resonance (local process) and the frequency-independent d.c. conductivity which can be ascribed to ‘free-charge’ diffusion (non-local process). Therefore our approach differs from those models which do not take into account this difference and treat the a.c. conductivity behaviour as resulting from a single process. The theoretical calculations explain rather well the expe...

Redistribution of convective ventilation, the leading disorder in airway obstruction, is a target of pharmacological and mechanical ventilation treatments for patients with chronic obstructive pulmonary disease (COPD). Convective ventilation is visualized by ventilation scintigraphy using radiolabeled aerosol particles that should ideally deposit in the terminal airspaces, but not in the conducting airways, and have no Brownian motion (which characterizes diffusive ventilation). Currently available commercial systems do not meet these requirements as they do not ensure an optimal size of aerosol droplets delivered at the mouthpiece.A new inhaling system (FAI) was developed and designed so as to yield radioaerosol droplets with smaller particle size and to ensure more efficient aerosol delivery to the terminal airways than that obtained with a widely available commercial system (MMI). A cascade impactor was employed to measure the size of the radioactive droplets at the mouthpiece. Preliminary comparative validation was based on ventilation scintigraphy using the two systems (both followed by a standard lung perfusion scan) in control subjects and in patients with airway obstruction. The time required to reach a certain count rate in the lung fields (1 kc/s) was recorded by means of dynamic g camera acquisition during breathing. Subsequent static images allowed assessment of intrapulmonary distribution of ventilation (by both visual and quantitative evaluation) and of the ventilation/perfusion (V/Q) ratios relative to the upper, middle, and lower thirds of the lung fields. RESULTS. FAI yielded 99mTc-labeled droplets with a count median diameter of 1.4 microm and a geometric standard deviation of 2 microm , versus 3 microm and 2, respectively, produced by the commercial inhaler (MMI). The mean time to reach the 1 kc/s count rate was significantly shorter with the FAI than with the MMI both in control subjects (4.7+/-1.7 min versus 8.2+/-2 min, P0.04) and in airway-obstructed patients (3.4+/-0.8 min versus 8.4+/-2 min, P0.001). With the MMI, appreciable radioaerosol deposition in the large bronchi prevented reliable quantitative assessment of ventilation, even in the control subjects. With the FAI, radioaerosol deposition in the central large airways was never observed in the controls and was only sporadically or occasionally observed in patients with COPD or asthma, respectively. This feature allowed quantitative ventilation assessment. The FAI-generated radioaerosol particles reached the peripheral respiratory spaces more efficiently than those generated by MMI; on the ventilation scans, the FAI allowed better discrimination than the MMI of the different pathophysiologic conditions.These findings consistently indicate that the smaller-sized radiolabeled droplets generated by FAI, combined with the better breathing dynamics of the inhaler device, result in better overall performance as compared to the commercial system. This makes scintigraphic images obtained with the new device especially suitable for assessing convective ventilation in COPD patients, a particularly helpful feature for analytically describing the distribution patterns observed in airway-obstructed patients and for evaluating the effects of drugs, mechanical ventilation, and other interventions in such patients.

Much work has already been carried out concerning the preparation and study of tin (IV) oxide, alone and combined with other oxides, for applications related to electrical and catalytic properties. The methods of preparation have included: (i) coprecipitation of hydroxides or oxalates starting from diluted salts; (ii) solid state reactions, by decomposition of carbonates, hydroxides; (iii) deposits by vapour phase deposition; and (iv) oxidation of SnO (e) in SnO2 by epitaxial growth. It has been noticed that the properties related to this oxide depend on the texture of the material. For this reason the sol-gel procedure was used to prepare such a compound. Generally the gel is formed by peptisation (with nitric acid) of Sn(OH)4 obtained after action on tin chloride by ammonia [1-3]. The study of these ge][s has shown that there is a temperature dependent structural evolution [3, 4] with oxygen deficient oxide [5]. Within this scope we have prepared a pure gel using a new method, the hydrolysis of a tin (II) alkoxide, and compared its structure to other gels. We have studied this gel by the method of complex permittivities. In fact, for a long time, dielectric loss measurements have been the basis of various investigations on many chalcogenides and a few oxides [6, 7]. The results obtained have usually been interpreted by theoretical models using the concept of charge carriers hopping between localised sites. Experimental data of the a.c. conduction as a function of frequency have often exhibited the following behaviour [6-10]: % = + (1) where Odc is the conductivity in direct current; o-' (co), the real part of the polarisation conductivity, is related to the frequency, f, by the expression: cr'(co) = Ac0' (co = 2zcf) where A and s are constants at a given temperature. In this work the a.c. conductivity, as a function of frequency and temperature of the oxide was measured. The a.c. conductivity data were analysed using a numerical approach described previously [11]. The results showed that the a.c. behaviour of this poorly organised tin oxide could be described by a well-known theoretical model related to thermally activated electron hopping. The method used for the synthesis of the tin alkoxide

Measurements of the dc conductivity, polarisation conductivity, and high resolution 1H NMR have been carried out on KDP (KH2PO4) around 298 K. Comparisons between the different results are reported and an interpretation is proposed in order to clarify the protonic motion within the bulk material.

A microscopic description of the effect of hydration on the behavior of extraframework cations in zeolite Na + -mordenite is reported. Energy minimization techniques, combined with appropriate interatomic potentials to describe the potential energy surface of this complex system, have been used to determine the site selectivity of both cations and water molecules as a function of the hydration level. We have thus shown that the positions of the cations in the main channels are substantially perturbed upon the sorption of water molecules whereas those of the cations located in the small side channels are only slightly shifted. This modeling has been successfully compared with experimental data obtained by dielectric relaxation spectroscopy.

This proceeding reports dielectic relaxation results, by means of Complex Impedance Spectroscopy and Thermally Stimulated Current measurements, obtained for mordenites frameworks. Most of these data has been already published but it is the first time that they are compiled. Our purpose is to demonstrate that dielectric relaxation spectroscopy can be a powerful tool for investigating the influence on ion dynamics of i) the nature of the extra-framework cation ii) the exchange rate iii) the acidity (Si/Al ratio) of the polyanionic framework iv) the number of adsorbed molecules (water, methanol heptane…). Both location and de-trapping energies of extra-framework cations in mordenites extracted from the dielectric response of these zeolites are then compared and analysed in the light of i) X-Ray diffraction data collected in literature and of ii) atomistic simulations based on classical interatomic. The later alculations are found to be in good agreement with the experimental data.

It is shown that the heating rate dependence of the Thermally Stimulated Depolarization Current (TSDC) line-shape is a function of the postulated depolarization function. An experimental discrimination is thus possible when one compares the prediction of the assumed model with the experimental behavior. Basically these models can be separated in two types. On the one hand, models based on Distribution of Relaxation Times (DRT) where the relaxation time /spl tau/ is time-independent and simply thermally activated according an Arrhenius law. On the other hand, models based on a more complex representation where dipole-dipole and dipole-network interactions make /spl tau/ time- and temperature-dependent.

We have shown that the use of blocking electrodes results in a spectrum of effective relaxation times, which considerably differs from the intrinsic one characterising the dynamics of bulk material. An effective medium analysis allows us to transform the effective distribution into the intrinsic one and vice versa. The procedure can be applied to data obtained by dielectric relaxation spectroscopy as well as to TSDC data.

The diagnostic strategy for pulmonary embolism, based on the mismatch of the ventilation/perfusion scan, was developed some 30 years ago on the following assumption: since the disorder involves the pulmonary vessels, it was surmised that in the embolized regions lung alveoli are unperfused or poorly perfused but well ventilated. Hence, it was inferred that this disorder was characterized, unlike parenchymal disease, by ventilation/perfusion mismatch in the affected lung zones and by an obvious increase of wasted ventilation, i.e., dead space. As matter of fact, experimental evidence on the redistribution of ventilation away from the vascular occluded lung had been already obtained in the early 60s of the last century. More recently, the behavior of regional pulmonary ventilation (V(A)) and blood flow (Q) in patients with acute pulmonary embolism (APE) has been studied by applying the multiple inert gas elimination technique (MIGET). It has been shown that the development of lung units with high V(A)/Q ratio (those with relative prevalence of perfusion obstruction) is accompanied by substantial redistribution of ventilation away from these units. Furthermore, radioisotopic techniques, used to visualize the topographic distributions of V(A) and Q in the same patients studied by MIGET, have shown reduced or absent V(A) in the embolized regions. This may occur by different mechanisms in the various stages of APE: bronchoconstriction mediated by local hypocapnia, atelectasis (occasionally hemorrhagic) related to alteration of surfactant production, bronchiolar obstruction and pulmonary infarction ascribed to degenerative and/or necrotic changes secondary to insufficient blood flow. In dogs and humans alike, the dead space measured by MIGET does not increase and that obtained from CO2 increases far less than the amount of unperfused lung in APE thus confirming a substantial redistribution of ventilation away from the embolized lung zones. Taken together, all these observations provide the pathophysiological explanation of the unacceptedly low level of sensitivity for the diagnostic strategy of APE based on the mismatch of the ventilation/perfusion scan.

We describe four patients with proven sarcoidosis and minor pulmonary involvement according to high-resolution CT (HRCT) findings in whom the recently described sign of decreased attenuation on expiratory HRCT scan appeared associated with the reduction of the single-breath diffusing capacity of the lung for carbon monoxide (DLCO) and the DLCO adjusted for alveolar volume. These alterations were, in part, reversible under steroid treatment. Major indexes of airway obstruction (FEV(1)/vital capacity ratio and FEV(1)) were normal, while the maximum expiratory flow at 25% above the residual volume of FVC was reduced. These observations suggest that an expiratory HRCT mosaic pattern and diffusion impairment may be early findings in pulmonary sarcoidosis and may be useful for its detection and follow-up.

The aim of this retrospective analysis was to assess the extent of smoking reduction in smokers who were compliant to a smoking cessation trial with nicotine patch, and failed to completely quit smoking. Out of 297 smokers in total, 237 participants received active treatment (60 received placebo). Eighty treated subjects attended all the scheduled visits and were classified as either abstainers (nonsmokers), regular smokers or occasional smokers. Compared to the remaining 157 participants, these 80 subjects had significantly lower mean baseline daily cigarette consumption (24 versus 30; p0.001), expired carbon monoxide levels (25 versus 33 ppm; p0.001), plasma nicotine and cotinine levels, and Fagerström Tolerance Questionnaire score (5.7 versus 7.0; p0.001). All subjects received active treatment for up to 18 weeks (full dose for 12 weeks plus tapering dose for 6 weeks), with follow-up visits scheduled up to 1 yr. A statistically significant reduction in cigarette consumption (versus baseline) was observed among both the occasional (-99%) and regular (-77%) smokers between week 1 and week 52 (p0.001). Concomitant smoking and patch use was well tolerated since adverse events were infrequent, mild and transient. Thus, in addition to those subjects who successfully quit smoking, a further group of subjects who attended all the follow-up visits during the smoking cessation trial significantly reduced their mean daily cigarette consumption.

Specification des valeurs de e 11 T et e 33 T (influence des groupes hydroxyde sur les permittivites). On en conclut que les permittivites ne sont pas suffisamment sensibles aux groupes hydroxyle pour donner une information suffisante a leur sujet

Polycyclic aromatic hydrocarbons (PAHs) are almost ubiquitous pollutants that may interact with metabolic systems in human tissues and eventually cause cancer. PAH-adducted DNA becomes antigenic and antibodies anti-benzo(a)pyrene diol epoxide (BPDE)-DNA may be found in serum of PAH-exposed subjects. The presence of serum antibodies anti-BPDE-DNA adduct was investigated in 1345 individuals from family clusters of the general population of a small area in central Italy in whom information about smoking habits, site of residence, and personal and family history of lung diseases, including cancer, were obtained. Anti-BPDE-DNA antibodies in the sera were detected with a direct ELISA and the association of anti-BPDE-DNA antibodies with subjects' data from a standardized respiratory questionnaire including age, occupation, tobacco smoking habits, respiratory symptoms, and family history of respiratory diseases was subsequently tested by multivariate logistic regression analysis. The overall prevalence of subjects with anti-BPDE-DNA antibodies was 21.0% (n=283), with no differences between males and females. Anti-BPDE-DNA positivity was associated with living in the urban area [odds ratio (OR), 1.49; 95% confidence interval (CI), 1.16-1.92], with active tobacco smoking (OR, 1.25; 95% CI, 1.06-1.48), and with family history of lung cancer (OR, 1.30; 95% CI, 0.90-1.88), and positivity increased with the number of members in the family cluster positive to anti-BPDE-DNA antibodies (OR, 1.30; 95% CI, 1.03-1.65). This study on a large general population sample indicates that serum anti-BPDE-DNA antibodies may be considered as biomarkers of exposure to environmental carcinogens and of DNA damage. The genetic and familial components of their association with tobacco smoking lend further support to the argument about the familial predisposition to lung cancer.

Trends in mortality rates for respiratory disorders were investigated in Italy from 1979 to 1990, using data from the Italian Central Statistical Institute (ISTAT). Mortality from lung cancer increased in all age groups, except for those aged 45-64 yrs after 1985. Respiratory diseases showed a consistent reduction; in particular, mortality from emphysema decreased slowly, and mortality from chronic bronchitis showed a significant reduction in all age groups. However, mortality from asthma increased markedly in all age groups up to 1985, and then levelled off and slightly decreased, although remaining at a higher level than in the 1970s. In 1990, data stratified for age group and gender indicated a higher mortality rate in males, that tended to be age-dependent, with the highest rate ratio male/female in those aged 65-74 yrs. Overall, these data indicate a trend to increased mortality from lung cancer and asthma in Italy in the 1980s.

During a cross sectional epidemiological survey on a general population sample, 596 fertile women underwent total serum IgE determination. They completed an interviewer-administered standardized questionnaire and were categorized according to their menstrual period. They were divided into two groups: those from days 10 to 20, who were considered to be in the periovulatory phase, and those in the other phases. IgE mean values were significantly different (p = 0.01) in the two groups: particularly, lower IgE values were found in those in periovulatory phase, after accounting for smoking habit and atopic status. By multiple regression analysis, taking into account the independent effects of menstrual period, age, smoking habit, hours of fast, skin prick test reactivity and presence of cough, significantly lower IgE values in the periovulatory phase were found. We hypothesize the possibility that a decrease of IgE concentration occurs during midcycle: a reduced immune response might facilitate the ovuli implantation. Further studies are necessary to longitudinally investigate the trend of IgE in the same women, as well as the distributions and the trends of other immunoglobulins.

The aim of this paper is to describe an epidemiological model to investigate the relationship between respiratory diseases and environmental air pollution. In the Po Delta prospective study, subjects were investigated before and after a large thermoelectric power plant began operating, in 1980 to 1982 and in 1988 to 1991, respectively. The Pisa prospective study was performed in 1986 to 1988 and in 1991 to 1993, before and after the construction of a new expressway that encircles the city from the North to the Southeast. In each survey, subjects completed the interviewer-administered standardized CNR questionnaire on respiratory symptoms/diseases and risk factors, and performed lung function tests. In the second survey of each study, skin prick tests, total serum IgE determination, methacholine challenge test and biomarkers (such as sister chromatide exchanges, micronuclei, chromosomal abnormalities, DNA and hemoglobin adducts) were also performed. Concentrations of total suspended particulate and SO2 in both surveys were higher in urban than in rural areas, as well as symptom/disease prevalences and bronchial reactivity. Subgroups of subjects from the two samples were enrolled to perform a specific study on the acute respiratory effects of indoor pollution; the daily presence of symptoms and measurements of peak expiratory flow (PEF), daily activity pattern, and assessment of the indoor air quality (particulates2.5 mu and NO2) were evaluated. Higher symptom prevalences and PEF variability level were observed in subjects with the highest levels of NO2 or particulates, especially asthmatics. In conclusion, these studies represent a basis for further analyses to better define the relationship between respiratory health and indoor/outdoor pollutant levels.

Hypertonic saline-induced sputum has recently been used for the evaluation of airway inflammation in asthma.To assess the effect of hypertonicity on airway inflammation.We compared the inflammatory cell composition of hypertonic saline-induced sputum with that of isotonic saline-induced sputum in 21 asthmatic subjects and, at baseline and 30 min after each sputum induction, we measured bronchial hyper-responsiveness to methacholine as an indirect marker to detect increased airway inflammation. On two different days, the patients inhaled hypertonic saline (3-5% NaCl) or isotonic saline (0.9% NaCl) for 30 min via an ultrasonic nebulizer, while monitoring FEV1. Sputum was collected for inflammatory cell analysis.There was no difference in inflammatory cell percentages obtained with the two methods. Eosinophils were1% in 20 subjects after hypertonic saline and in 16 subjects after isotonic saline, but this difference was not statistically significant. Intraclass correlation coefficients for sputum inflammatory cells obtained with the two methods were +0.642 for eosinophils, +0.644 for neutrophils, +0.544 for lymphocytes and +0.505 for macrophages. Hypertonic saline induced bronchoconstruction in a significantly greater number of subjects than isotonic saline. Also, hypertonic saline increased bronchial responsiveness to methacholine, while isotonic saline did not.We conclude that hypertonicity does not affect sputum cell composition, suggesting that inflammatory cells in hypertonic saline-induced sputum are probably preexisting and not acutely recruited in the airways by the hypertonic stimulus. However, the bronchoconstriction and the increase in bronchial hyper-responsiveness after hypertonic saline inhalation may imply the release of inflammatory mediators. This fact must be considered in the evaluation of soluble markers of inflammation in hypertonic saline-induced sputum.

Plasma levels of selected coagulation and fibrinolytic parameters (activated partial thromboplastin time, prothrombin time, fibrinogen, antithrombin III, protein C, thrombin-antithrombin III complexes (TAT), plasminogen activator inhibitor-1 (PAI-1), plasminogen, α2-plasmin inhibitor) were evaluated in 90 patients with clinical suspicion of pulmonary embolism (PE). Plasma levels of fibrinogen, PAI-1 and TAT were significantly higher in patients than in controls (p < 0.01): evaluation of TAT displayed a sensitivity of 96.1% and specificity of 30.8%, and positive and negative predictive values of 64.5 and 85.7%, respectively. The number of nonperfused lung segments correlated directly with TAT levels (p < 0.01) and inversely with arterial pO2 values (p < 0.01). No significant difference was found in the other parameters between patients and controls. Our results suggest that the finding of normal TAT plasma levels can help to exclude PE in patients with clinically suspected PE.

To compare the usefulness of high-resolution computed tomography (HRCT) and chest radiography in the functional evaluation of silica-exposed workers, 27 workers were submitted to posteroanterior and lateral chest radiographs, apex to base HRCT scans and pulmonary function tests. Two experienced readers studied plain films independently to assess small opacities profusion (ILO-UC, Geneva 1980): from 0/- to 3/+. HRCT grading and extent of silicotic nodules and associated emphysema were scored on a four-point scale. Inter-reader analysis showed better agreement for HRCT (K = 0.49) than chest radiography (K = 0.29). Poor agreement was observed between chest radiography and HRCT classes, particularly in the early stages of silicosis. No correlation was observed between chest radiography score and pulmonary function tests, while a significant correlation was observed between HRCT classes (grade and extent of the nodules) and FEV1, MEF50, MEF75, RV and FRC. In conclusion, HRCT exhibited better reproducibility and higher accuracy than chest radiography in identifying the absence of silicotic nodules and in depicting functionally important lesions. To this purpose, HRCT can be considered a useful support to conventional chest radiography.

A previously healthy man presented with acute abdominal pain that extended from the left lumbar area to the left iliac fossa and to the omolateral testicular region. Abdominal ultrasonography and CT scan showed a bulky mesenteric mass and mesenteric, paraaortic, and paracaval lymph nodes. Biopsy specimens of the mass revealed non caseating granulomas. Chest CT scan and 67Gallium thoracic scan demonstrated lymph node and parenchymal pulmonary involvement. Bronchoalveolar lavage (BAL) confirmed the presence of a low intensity alveolitis. Serum angiotensin converting enzyme (SACE) level was elevated. Two years after steroid therapy, markers of disease activity and abdominal ultrasonography are in the normal range.

In order to assess whether treatment with oral slow-release theophylline prevents early (EAR) and/or late (LAR) airway responses to allergen, we treated six asthmatic subjects with either placebo or oral theophylline (350 mg b.i.d.) for one week before specific bronchial provocation test (sBPT) with allergen, in a double-blind, cross-over, placebo-controlled study. All subjects had previously shown both EAR and LAR to allergen sBPT. On the day of sBPT, serum theophylline concentration was9 micrograms.ml-1 in all subjects treated with theophylline except one (mean 9.8 +/- 2.6 micrograms.ml-1). The total dose (TD) of inhaled allergen, and the provocative dose of allergen causing a 15% fall in forced expiratory volume in one second (PD15FEV1) during sBPT was mildly but significantly lower during theophylline-sBPT than during placebo-sBPT. Theophylline treatment reduced EAR (maximum FEV1 fall from baseline: 26.3 +/- 6.7 vs 32.2 +/- 9.5% after placebo treatment) but not LAR (19.5 +/- 6.5 vs 26.3 +/- 6.1%). A significant protection of LAR (a reduction in FEV1 fall after theophylline treatment 50% more than after placebo treatment) was observed in only 2 out of 6 subjects. Area under the curve was not significantly different after the two treatments. There was no relationship between serum theophylline levels and the degree of protection on EAR or LAR. The decrease in PD15FEV1 methacholine observed at the end of LAR was similar in the two treatments.(ABSTRACT TRUNCATED AT 250 WORDS)

The diagnosis of pulmonary embolism (PE) can be accurately made by perfusion lung scan and pulmonary angiography; however, when these diagnostic techniques are not promptly available, simple clinical procedures may be useful to identify patients with high probability PE. To this end, collection of clinical data through a standardized questionnaire and the use of findings from chest radiograph, ECG, and blood gas analysis may raise clinical suspicion and decide on therapeutic management. By reviewing published literature and our own experience, we found that unexplained dyspnea and chest pain are the most frequent symptoms, and sudden onset dyspnea and pleuritic chest pain are the most typical. Chest radiograph is abnormal in more than 80% of patients with PE, showing typical signs such as "sausage-like" descending pulmonary artery, Westermark sign, etc. The ECG may show findings characteristic of PE, such as tachycardia, T wave inversion in V1-V2, and PR displacement. Arterial blood gas data frequently demonstrate hypoxia and hypocapnia, being helpful in suspecting or excluding PE. Recent statistical techniques, such as discriminant or logistic analysis, may be applied to the above clinical assessment to refine and improve the noninvasive diagnosis of PE.

Present evidence suggests that venous thromboembolism is the third most common acute cardiovascular disease after cardiac ischemic syndromes and stroke. The frequency of the diagnosis of pulmonary embolism (PE) at a given hospital greatly increases if a referral unit for PE is set up in the hospital. Pulmonary embolism is characterized by a continuous spectrum of severity, from 2 to 3 to 15 to 16 embolized pulmonary segments (over a total of 19). Morbidity from PE increases with age and male sex (males/females ratio: 1.24). In only a minority (10%) of patients with PE and/or deep-vein thrombosis (DVT), primary deficiencies of coagulation-inhibiting proteins have been shown. Primary abnormalities of the fibrinolytic system seem even more rare. On the basis of the clinical conditions preceding the embolic episode, patients may be divided into different groups: apparently primary or idiopathic PE (40%), surgery or trauma (43%), heart disease (12%), neoplastic disease (4%), and systemic disease (1%). Patients with apparently primary or idiopathic PE often develop subsequent clinically overt cancer (9.1%), whereas surgery or trauma patients rarely do (1.4%). Furthermore, the former exhibit a significantly shorter survival than the latter mostly for causes of death that reflect increased predisposition to thrombogenesis. Thus, as for DVT, it is convenient to consider a primary or idiopathic form also for PE.

The interaction between aetiological factors (e.g. tobacco smoke) and target cells in lung tissues is modulated by host factors, leading to variable risk among individuals. We have studied some of the metabolic properties of the human lung and the effects on them of tobacco smoke. The activity of activating enzymes is induced by recent tobacco smoke exposure, whereas that of inactivating enzymes is depressed, and this effect is greater in patients with lung cancer than in controls. This imbalance between activating and detoxifying enzymes in the lung may be a key factor in determining the genetic damage to the lung. These differences between lung cancer patients and controls in metabolic activities in lung tissues may be documented at a phenotypic level as well as at a genotypic level. Also wide interindividual differences have been shown in deoxyribonucleic acid (DNA) repair enzymes and in the extent of DNA damage.

The distribution function of pulmonary transit times (fPTT) defines contact time between blood and vascular bed, which affects gas exchange and endothelial metabolic functions. This study was undertaken to assess effects of abnormal pulmonary inflow (PPA) and outflow pressures (PLA) on fPTT. Three groups were studied: five patients with elevated PLA and passive pulmonary hypertension (LVD-Ab), eight with normal PLA (LVD-Nl), and six with pulmonary disease and various levels of PPA (PD). Empirical complex exponential functions were convoluted on right and left ventricular indicator-dilution curves to derive fPTT; mean transit time (Mo1), standard deviation (Sm2), and cube root of the third moment about Mo1 (Sm3) were calculated by standard equations. A single linear regression of Sm3 and Sm2 on Mo1 was observed for all patients, regardless of disease process. Inverse relations between Mo1, Sm2, and Sm3 and blood flow were highly significant, but dispersion volumes (DV = Mo1 x flow) were higher in patients with elevated PPA. Significant linear regressions of fPTT parameters on PPA, derived in LVD-Nl and LVD-Ab patients, failed to predict Mo1, Sm2, and Sm3 for the PD group, whereas linear regressions on PLA accurately predicted Mo1, Sm2, and Sm3 in the PD group. Relations between fPTT parameters and PLA were equally well fit by exponential equations in all 19 patients, consistent with an asymptotic pressure-volume relation of distensible vessels. Microvascular pressure (PMV), combining PPA and PLA, was not a better predictor of fPTT parameters in LVD-NL and LVD-Ab patients but provided a slightly closer estimate of relative dispersion and skewness in PD patients.(ABSTRACT TRUNCATED AT 250 WORDS)

In order to assess the distribution of asthma in Italy in the 1980s, we have compared the findings of three general population surveys carried out in the North and the Centre of the country. Two cross-sectional investigations were performed in the Po Delta area (North Italy), 6 yrs apart: 1) 3,285 subjects, aged 8-64 yrs, in 1980-1982 (PD1); and 2) 2,841 subjects, aged 8-73 yrs, in 1988-1991 (PD2). One cross-sectional survey was carried out in Pisa (Central Italy): 3,866 subjects, aged 5-90 yrs, in 1985-1988 (PI1). For this analysis we have used data from the standardized questionnaires of those subjects between 18-64 yrs, who were currently employed. The prevalence rate of ever asthma was 3.3-5.5%, that of current asthma 1.3-2.9%; almost all of the diagnoses were confirmed by a doctor. Taking into account only doctor-confirmed asthma, the age of onset of manifestations was most frequently over 18 yrs (41-79%). It also occurred more frequently after the onset of employment. As regards smoking, whilst most asthmatic males were current or former smokers (70-86%), most asthmatic females were nonsmokers. However, the situation changed in PD2, where females showed the same pattern as males. Considering asthmatic subjects with skin-prick test reactivity (data available only in PD2), the vast majority (67% in males, 75% in females) had an age of disease onset under 18 yrs. In conclusion, the prevalence of asthma in Italy in the 1980s was similar to that in other European countries and was affected by atopy and smoking differently in the two sexes.(ABSTRACT TRUNCATED AT 250 WORDS)

Twelve Dutch rabbits were kept on Monte Bianco at an altitude of 3370 m. Half of the animals were killed after 3 months, the remainder after 6 months, and a further six animals maintained at sea-level acted as controls. The carotid bodies of all the rabbits were processed for light and electron microscopy and examined qualitatively and quantitatively. The lungs were processed for light microscopical assessment of small pulmonary arterial vessels; the thickness of the pulmonary trunks and aortas were measured; and the hearts were dissected to obtain ratios of the ventricular weight. There was a slight increase in the right ventricular weight in the hypoxic rabbits but no change in the thickness of the pulmonary trunk compared with that of the aorta. In particular, there was no hypoxic remodelling of the pulmonary vasculature such as muscularization of pulmonary arterioles or intimal longitudinal muscie in pulmonary arteries. The earliest histopathological response to hypoxia occurred in the carotid bodies in the form of an increase in the count of the dark variant of chief cell after 3 months which returned to normal after 6 months. It is concluded that the carotid body of the rabbit responds with a change in its population of dark chief cells to a level of hypoxia which is insufficient to affect the pulmonary arterioles. Changes in the cardiopulmonary system can no longer be considered to be the earliest histopathological response to hypobaric hypoxia.

Long-term change in nonspecific and specific bronchial hyperresponsiveness was studied in 16 subjects with asthma induced by toluene diisocyanate (TDI). A significant positive correlation between months of follow-up and provocative dose inducing a 20 percent fall in FEV1 (PD20FEV1) methacholine was observed in 5 of 16 subjects. In 4 of these 5 subjects, a PD20FEV11 mg of methacholine was observed 30 to 48 months after the end of TDI exposure. In most subjects, nonspecific bronchial hyperresponsiveness did not change. Nine of 16 subjects became nonresponsive to TDI at follow-up examination, but only 3 of these showed a significant increase in PD20FEV1 methacholine. Seven subjects were still responsive to TDI. Recovery from TDI-induced asthma can occur and only after long-term work cessation. Nonspecific bronchial hyperresponsiveness to methacholine can persist even in the absence of bronchial hyperresponsiveness to TDI, suggesting permanent chronic damage to mechanisms controlling airway tone.

In the investigation of dyspnoea and severe hypoxaemia the clinical relevance of multiple diagnostic techniques was studied. The patient was sequentially studied utilizing several techniques. The degree of lung impairment by spirometry, diffusing capacity for carbon monoxide, haemodynamics, pulmonary gas exchange, ventilation-perfusion relationships assessed by the multiple inert gases elimination techniques, ventilation and perfusion lung scans, gallium 67 scintigraphy, bronchoalveolar lavage and high resolution computerized tomography, twice over a period of 12 months during recovery under treatment. A marked impairment of pulmonary gas exchange was first explained by diffusion impairment and ventilation-perfusion mismatch. The multiple inert gas elimination technique allowed determination of the cause of hypoxaemia by ventilation-perfusion inequality. A pathological correlate of the ventilation-perfusion inequality was the appearance of honeycomb lungs detected by high resolution computed tomograph and active alveolitis by bronchoalveolar lavage. All results were consistent with a diagnosis of fibrosing alveolitis. The patient was evaluated again during treatment. Some functional improvement occurred despite persistence of the same pathological findings. In conclusion, this study demonstrates the value of information derived from different tests. Physiological correlations complemented by pathological observations expand understanding of the pathogenesis of disease. These procedures contribute to understanding mechanisms responsible for functional impairment.

The prevalence of respiratory symptoms and functional abnormalities has been evaluated in a sample of 350 workers (186 males and 164 females, mean age: 35.1 and 36.6 years respectively) employed in 24 factories of the shoes industry in the area of Pisa, exposed to airway irritants (solvent vapours, leather dusts and fumes). Each subject performed C.N.R. questionnaire of respiratory symptoms and diseases, and measurement of Forced Vital Capacity and derived indices. A mild prevalence of respiratory symptoms (chronic cough: 9.3% and 8.5% in males and females respectively; chronic phlegm: 14.6% and 6.8%; persistent wheeze: 2.1% and 1.7%; dyspnea of 1st degree: 23.3% and 39.0%) was reported, more frequently in smokers than in non smokers. Subjects with longer job duration in the shoe industry showed a trend to have a higher prevalence of chronic phlegm than subjects with shorter job duration; on the contrary, the last ones had a higher prevalence of rhino-conjunctivitis. A higher prevalence of attacks of shortness of breath and dyspnea of 2nd degree in males, and dyspnea of 1st degree in females was observed in workers to high risk job (to shear, to use adhesive, etc.) with respect to workers employed in low risk job (to assembly, to store etc). Mean spirometric values where in the normal range. Subdividing the subjects in groups with different smoking habit and job duration, a mild effect of the occupational exposure in groups with the same smoking habit could be observed for FEV1 and MEF50 particularly.(ABSTRACT TRUNCATED AT 250 WORDS)

An improved high-performance liquid chromatography/fluorometric assay has been established to quantitate the benzo(a)pyrene (BP) tetrols released after acid hydrolysis of lung DNA from lung cancer patients, so that the formation of benzo(a)pyrene diol-epoxide-DNA adducts can be measured. The r-7,c-10,t-8,t-9-tetrahydroxy-7,8,9,10-tetrahydro-BP isolated by high-performance liquid chromatography was determined by chromatography in two different solvent systems and fluorescence spectroscopy. This assay has a detection limit of 2 pg of r-7,c-10,t-8,t-9-tetrahydroxy- 7,8,9,10-tetrahydro-BP, requires 100-500 micrograms of DNA, and can measure 1 adduct/10(8) unmodified nucleotides. As this assay does not use immunoaffinity chromatography or solvent extraction, it allows a90% recovery of benzo(a)pyrene diol-epoxide-DNA adducts. This procedure has been tested on 13 DNA samples prepared from nontumorous lung parenchyma taken from lung cancer patients at surgery and revealed the presence of DNA adducts of the anti-benzo(a)pyrene diol-epoxide in 9 of 11 samples from smokers and in 2 of 2 ex-smokers. In only two samples from smokers the formation of adducts derived from syn-benzo(a)pyrene diol-epoxide was detected. A 15-fold variation in DNA adduct level was found in 11 of 13 DNA samples, with a range of 0.6-9.9 adducts of benzo(a)pyrene diol-epoxide/10(8) nucleotides. In samples containing both anti- and syn-benzo(a)pyrene diolepoxide-DNA adducts, the anti/syn adduct ratio is 2:1. A highly significant correlation was found between pulmonary microsomal aryl hydrocarbon hydroxylase activity and the level of benzo(a)pyrene diolepoxide-DNA adduct (r = 0.91; P0.001; n = 13). A crude linear correlation between the amounts of these adducts and those of bulky DNA adducts determined by 32P-postlabeling assay was observed in the same samples (r = 0.78; P0.02; n = 13). Thus this highly sensitive and specific procedure is suitable for measuring benzo(a)pyrene diolepoxide-DNA adducts in human tissues from environmentally exposed subjects and could be adapted to measure polycyclic aromatic hydrocarbons other than BP.

A 22-year-old female patient with a swelling in the right forearm near the elbow underwent a 67Ga-citrate scan because of paraesthesia on the ulnar side of the right hand. The 67Ga total body scan showed intense focal uptake on the forearm in the same position as the swelling. At surgery a histological diagnosis of alveolar rhabdomyosarcoma was made. Five months later, a repeat 67Ga scan was normal. Eight months after the diagnosis, the patient complained of pain in the left lumbar region extending to the hypogastric area. A third 67Ga scan showed intense uptake near the spinal column which at surgery was found to be a metastasis of the primary tumor.