Physiological changes during low- and high-intensity noninvasive ventilation.

In a physiological randomised cross-over study performed in stable hypercapnic chronic obstructive disease patients, we assessed the short-term effects of two settings of noninvasive ventilation. One setting was aimed at maximally reducing arterial carbon dioxide tension (P(a,CO(2))) (high-intensity (Hi) noninvasive positive pressure ventilation (NPPV)): mean ± SD 27.6 ± 2.1 cmH(2)O of inspiratory positive airway pressure, 4 ± 0 cmH(2)O of expiratory positive airway pressure and respiratory rate of 22 breaths · min(-1). The other was performed according to the usual parameters used in earlier studies (low-intensity (Li)-NPPV): 17.7 ± 1.6 cmH(2)O of inspiratory positive airway pressure, 4 ± 0 cmH(2)O of expiratory positive airway pressure and respiratory rate of 12 breaths · min(-1). Both modes of ventilation significantly improved gas exchange compared with spontaneous breathing (SB), but to a greater extent using Hi-NPPV (P(a,CO(2)) 59.3 ± 7.5, 55.2 ± 6.9 and 49.4 ± 7.8 mmHg for SB, Li-NPPV and Hi-NPPV, respectively). Similarly, Hi-NPPV induced a greater reduction in the pressure-time product of the diaphragm per minute from 323 ± 149 cmH(2)O · s · min(-1) during SB to 132 ± 139 cmH(2)O · s · min(-1) during Li-NPPV and 40 ± 69 cmH(2)O · s · min(-1) during Hi-NPPV, while in nine out of 15 patients, it completely abolished SB activity. Hi-NPPV also induced a marked reduction in cardiac output (CO) measured noninvasively with a Finometer PRO (Finapres Medical Systems BV, Amsterdam, the Netherlands) compared with Li-NPPV. We conclude that while Hi-NPPV is more effective than Li-NPPV in improving gas exchange and in reducing inspiratory effort, it induces a marked reduction in CO, which needs to be considered when Hi-NPPV is applied to patients with pre-existing cardiac disease.

Diet and myocardial infarction: a nested case-control study in a cohort of elderly subjects in a Mediterranean area of southern Italy.

BACKGROUND AND AIM: We evaluated the incidence of myocardial infarction (MI) in a population of Southern Italy and the relationship of dietary macronutrients with incident MI. METHODS AND RESULTS: The ONCONUT cohort included 5632 subjects followed-up, over 50 years, recruited in 1992. At baseline, they completed a validated semi-quantitative food frequency questionnaire and gave details of their medical history. After 5years they were traced by their family physician, who found 108 incident MI. Ninety-seven of them and 194 controls, sampled from the noncases at baseline and paired for diabetes to the cases, entered this nested case-control study. MI rate per 1000 person-years was 9.6 in males and 3.7 in females. In non-diabetics, saturated fat were associated with MI directly (odds ratio (OR): tertile 2 vs. 1 = 2.32, tertile 3 vs. 1 = 2.82; chi-square for trend, p = 0.03) and polyunsaturated fats inversely (OR: tertile 2 vs. 1 = 0.80, tertile 3 vs. 1 = 0.37; chi-square for trend, p = 0.05), while in diabetics, starchy carbohydrates (OR: tertile 2 vs. 1 = 1.51, tertile 3 vs. 1 = 6.73; chi-square for trend, p = 0.01) and glycaemic index (OR: tertile 2 vs. 1 = 2.74, tertile 3 vs. 1 = 5.34; chi-square for trend, p = 0.01) were associated directly with MI. CONCLUSIONS: MI incidence in this population was lower than that found in northern countries. In non-diabetics, saturated fats were associated directly and polyunsaturated fat inversely with MI; in diabetics, starchy carbohydrates and high-glycaemic-index foods were associated directly with MI.

Comparative studies of the leachate of an industrial landfill by gas chromatography-mass spectrometry, liquid chromatography-nuclear magnetic resonance and liquid chromatography-mass spectrometry.

Nowadays, the need to have a realistic characterization of industrial effluents in the environment has become more and more recognized. A palette of different analytical methods both for sample extraction and instrumental analysis are available today, some older, others introduced more recently. The aim of this research is to compare a number of these techniques. To do this we studied a real leachate from an industrial landfill and carried out chemical analyses for organic pollutants, using different extraction methods based on solid-phase extraction and solid-phase microextraction and different instrumental techniques such as GC-MS, LC-MS, NMR and LC-NMR. Results show the performances of the different techniques, which are complementary.

[Septicemia and systemic inflammatory response]. / Setticemia e risposta infiammatoria sistemica.

To determine the relation between endocarditis/septicemia and systemic inflammatory response syndrome (SIRS), septic shock, MODS, we performed a retrospective analysis in 196 HIV-negative patients, with endocarditis/septicemia. No deaths were observed between 20 patients with endocarditis without severe infective SIRS/septic shock. On the other hand among 10 patients with endocarditis with severe infective SIRS/septic shock we registered 3 deaths (P = 0.052). No deaths were registered among 93 patients with septicemia without severe infective SIRS/septic shock. Between 73 patients with septicemia and severe infective SIRS/septic shock 9 (12.3%) patients died and, precisely, 7/61 in severe infective SIRS (11.4%) and 2/.12 (16.6%) in septic shock (P = 0.003). The definition of septicemia according to Schottmüller (1914), as a generalized bacterial infection with a persistent bacteremia is still justified. The term "sepsis" has become ambiguous because it has been used as synonym of "acute response to infection", while in the past and presently, at least in Europe, it is synonym of septicemia, persistent bacteremia. The term of SIRS could avoid the misunderstanding. The words: "infective SIRS", "severe infective SIRS", may label properly the reactive events mounted by the host as a useful defence against infections but they become dangerous and bring about septic shock, organ failure and mortality when excessive.

Immunogenicity of influenza vaccine (1993-94 winter season) in HIV-seropositive and -seronegative ex-intravenous drug users.

The humoral response (haemagglutination inhibiting antibodies) to trivalent split influenza vaccine for the 1993-94 winter season (A/Beijing/32/92 (H3N2), A/Singapore/6/86 (H1N1) and B/Panama/45/90) was evaluated in a group of young HIV-seropositive ex-intravenous heroin users and compared with responses measured in HIV-seronegative individuals with a similar history. HIV-negative volunteers showed an overall positive response suggesting that previous heroin use did not influence their humoral response to influenza vaccine. Comparable results were obtained in HIV-positive subjects with CD4+ lymphocyte counts > 500 microliters-1, whereas impaired reactivity was found in HIV-positive volunteers with CD4+ counts < 500 microliters-1. Booster vaccination did not increase antibody levels in any of the groups studied, although the data did not exclude a positive influence of a second vaccine dose on persistence of antibody at 120 days after the first dose. No significant changes were observed in p24 antigenemia levels in HIV-positive individuals after vaccination.