Plethysmographic Loops : a Window on the Lung Pathophysiology of COPD Patients

Plethysmographic alveolar pressure-flow (Palv\u2013F) loops contain potentially relevant information about the pathophysiology of chronic obstructive pulmonary disease (COPD), but no quantitative analysis of these loops during spontaneous breathing has ever been performed. The area of the loop\u2019s inspiratory (Ains) and expiratory portion (Aexp), and the difference between the end-expiratory and end-inspiratory alveolar pressure (\u394Palv) were measured in 20 young, 20 elderly healthy subjects, and 130 stable COPD patients. Ains and \u394Palv increased by 55 and 78% from young to elderly subjects, and by 107 and 122% from elderly subjects to COPD patients, reflecting changes in mechanical heterogeneity, lung-units recruitment/derecruitment, and possibly air trapping occurring with aging and/or obstructive disease. Aexp increased by 38% from young to elderly subjects, and by 198% from elderly subjects to COPD patients, consistent with the additional contribution of tidal expiratory flow-limitation, which occurs only in COPD patients and affects Aexp only. In COPD patients, Aexp and \u394Palv showed a significant negative correlation with VC, FEV1, IC, and a significant positive correlation with RV/TLC. The results suggest that the analysis of plethysmographic Palv\u2013F loops provides an insight of the pathophysiological factors, especially tidal expiratory flow-limitation, that affect lung function in COPD patients

Prevalence of Tuberculosis infection among teen-agers in Tuscany

Introduction. In Tuscany, Tuberculosis incidence is more thantriplicate from 1982 to the beginning of the third millennium.The impact of this trend on open population is not known, asupdated studies on Tuberculosis prevalence are not available.Tuberculin skin test provides the currently most widely used toolfor assessing Tuberculosis transmission in a community and theprevalence of infection as well.The objective of this investigation was the evaluation of tuberculin index by means of the Mantoux test in adolescents eighteen-years old.Results. The study was carried out in 21 secondary schools ofSiena and its Province; 1,138 students participated to this survey.The overall prevalence of subjects with a skin reaction size >5 mm was 1.6%; if the standard cut-off of 10 mm was used, the overall prevalence of a positive skin reaction was 0.4%. Riskfactors for a doubtful or positive reaction were previous immunization with BCG and migration from high-endemicity countries. Discussion. In Italy, studies on tuberculin index in young adultsare scanty and controversial: our results show a very low Tuberculosis prevalence and an epidemiological pattern typical ofcountries with low Tuberculosis endemicity.Conclusions. The slightly increase in Tuberculosis incidencehas no impact on the prevalence of latent Tuberculosis infection on our geographical area. We conclude that skin-test screening for Tuberculosis should be addressed to high risk population as migrants from Countries reporting high transmissionrate, those recently exposed to an infectious case and healthworkers

Ultrasound evaluation of the distal femoral epiphyseal ossification center as a screening test for intrauterine growth retardation.

Abstract In a heterogeneous group of 226 pregnant women, a retrospective study was done of the relation between the distal femoral epiphyseal ossification center detected by ultrasound and the birth weights of the infants. The ossification center of the femur was detectable in 202 of the 208 infants appropriate for gestational age; it was undetectable in 15 of the 18 infants small for gestational age. Because our results compared favorably with those reached by more complicated methods in the literature, we propose that the distal femoral epiphyseal ossification center be used as a screening test for intrauterine growth retardation