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Biomedical subjects

Andrea Giordano

Publications and source records attributed to Andrea Giordano.

12 recordsLinked to original sources
PubMed2006

Maximal accumulated oxygen deficit in patients with chronic heart failure.

PURPOSE: To evaluate feasibility and repeatability of maximal accumulated oxygen deficit (MAOD) measurement in patients with chronic heart failure (CHF) and asymptomatic left ventricular dysfunction (ALVD), and to identify MAOD predictors employable in the clinical setting. METHODS: We studied 10 CHF and 5 ALVD patients. Five normals (N) were used as controls. All subjects underwent a ramp incremental cardiopulmonary exercise test (CPX), three moderate-intensity constant-power exercise tests (CPET) at 30, 60, and 90% of ventilatory anaerobic threshold (VAT) power, and three severe-intensity CPET (1-2, 2-3, and >3 min in duration). MAOD was calculated as the difference between accumulated O2 demand and uptake during severe-intensity CPET. Postexercise lactate (PEL) was measured at 2, 4, 6, and 8 min of recovery after CPX and severe-intensity CPET. RESULTS: MAOD did not vary with increasing severe-intensity CPET duration in any study subgroup. MeanMAOD (mean of the three severe-intensity CPET) was lower in the CHF than ALVD or N subgroups (12.2 +/- 4.9 vs 23.7 +/- 11.8 and 24.8 +/- 8.2 mL x kg(-1), P < 0.05), with comparable lean body mass values. In the total study population, meanMAOD was significantly but not highly correlated with peak VO2 and PEL from CPX, PEL from severe-intensity CPET, and O2 deficit and steady-state VO2 from moderate-intensity CPET. Intraclass correlation coefficient of MAOD measurement in CHF and ALVD was 0.98. CONCLUSIONS: MAOD is repeatedly measurable in patients with CHF by a single severe-intensity CPET. MAOD of CHF patients is lower than that of age-matched ALVD patients and N, and this finding is muscle mass-independent. Finally, ergospirometric parameters and PEL from CPX, PEL from severe-intensity CPET, and VO2 on-kinetic descriptors from moderate-intensity CPET seem useless to reliably predict MAOD in CHF patients.

Aged↗
PubMed2005

Sleep and exertional periodic breathing in chronic heart failure: prognostic importance and interdependence.

BACKGROUND: Sleep and exertional periodic breathing are proverbial in chronic heart failure (CHF), and each alone indicates poor prognosis. Whether these conditions are associated and whether excess risk may be attributed to respiratory disorders in general, rather than specifically during sleep or exercise, is unknown. METHODS AND RESULTS: We studied 133 CHF patients with left ventricular ejection fraction (LVEF) < or =40%. During 1170+/-631 days of follow-up, 31 patients (23%) died. Nonsurvivors had higher New York Heart Association class, ventilatory response (ve/vco2 slope), and apnea-hypopnea index (AHI) and lower peak vo2 (all P<0.01); lower LVEF and prescription of beta-blockers, and shorter transmitral deceleration time (all P<0.05). Exertional oscillatory ventilation (EOV), established by cyclic fluctuations in minute ventilation that persisted for > or =60% of exercise duration with an amplitude > or =15% of the average resting value, was significantly more frequent in nonsurvivors (42% versus 15%, P<0.01). Multivariable analysis selected AHI (hazard ratio [HR] 5.66, 95% CI 2.3 to 19.9, P<0.01), peak vo2 (HR 0.93, 95% CI 0.90 to 0.97, P<0.01), and beta-blocker prescription (HR 0.34, 95% CI 0.13 to 0.87, P<0.05) as predictors of cardiac events. The best cutoff for AHI was >30/h. EOV was significantly related to AHI >30/h (chi2 14.6, P<0.01): 78% of EOV patients showed AHI >30/h. Multivariable analysis, including breathing disorders alone (EOV, AHI >30/h) or in combination (EOV plus AHI >30/h), selected combined disorders as the strongest predictor of events (HR 6.65, 95% CI 2.6 to 17.1, P<0.01). CONCLUSIONS: In CHF, EOV is significantly associated with AHI >30/h. Although each breathing disorder alone is linked to total mortality, their combination has a crucial prognostic burden.

Aged↗
PubMed2005

Sequencing batch reactor performance treating PAH contaminated lagoon sediments.

The applicability of sediment slurry sequencing batch reactors (SBR) to treat Venice lagoon sediments contaminated by polycyclic aromatic hydrocarbons (PAHs) was investigated, carrying out experimental tests. The slurry, obtained mixing tap water and contaminated sediments with 17.1 mg kg(-1) TS total PAHs content, was loaded to a 8l lab-scale completely stirred reactor, operated as a sequencing batch reactor. Oxygen uptake rate exerted by the slurry, measured by means of a DO-stat titrator, was used to monitor the in-reactor biological activity and to select the optimal operating conditions for the sediment slurry SBR. The PAHs removal efficiency was evaluated in different operating conditions, obtained changing the hydraulic retention time (HRT) of the lab-scale reactor and adding an external carbon source to the slurry. HRT values used during the experiments are 98, 70 and 35 days, whereas the carbon source was added in order to evaluate its effect on the biological activity. The results have shown a stable degradation of PAHs, with a removal efficiency close to 55%, not dependent on the addition of carbon source and the tested HRTs.

Biodegradation, Environmental↗
PubMed2005

Effect of selected textile effluents on activated sludge nitrification process.

In this study, a recently developed methodology for the assessment of the inhibitory effect on nitrifying biomass was applied to several textile effluents from productive processes. Effluents are classified according to the degree of inhibition as EC50 (concentration producing 50% nitrification inhibition); the investigated textile effluents showed a wide range of EC50 ranging from 20 ml gVSS-1 (83 ml l-1) to values above 100 ml gVSS-1 (300 ml l-1) for effluents produced by rinsing phases. Taking into account biodegradability and toxicity evaluations, most of the effluents showed a good treatability in conventional biological wastewater treatment plant. On the other hand three textile effluents showed significant toxic effects towards nitrifying biomass. In any case, the proposed procedure represents an efficient tool to prevent treatment failures due to toxic discharges.

Bacteria↗
PubMed2005

Early atherosclerosis in rheumatoid arthritis: effects of smoking on thickness of the carotid artery intima media.

This study was designed to compare intima media thickness (IMT) of the carotid arteries among rheumatoid arthritis (RA) patients and controls and to determine whether disease-associated characteristics, smoking, and other classic risk factors for atherosclerosis are associated with IMT values. IMT was measured in the carotid arteries of 101 RA patients and 75 control subjects. The IMT was evaluated in the common carotid (CC), carotid bifurcation (BI), and internal carotid (IC). Eight IMT values were calculated including four mean and four maximal values of CC, BI, IC, and carotid artery (C). The following data were obtained for every patient: age, sex, body mass index (BMI), presence of erosions, extra-articular manifestations, rheumatoid factor, medications, hypertension, hypercholesterolemia, diabetes mellitus, smoking status, daily number of cigarettes, number of smoking years, family history of cardiovascular diseases (CVD), and erythrocyte sedimentation rate (ESR) levels. RA patients had significantly higher mean-BI IMT than controls (1.02 mm vs. 0.89 mm; P < 0.01), higher incidence of increased mean-BI IMT and max-BI IMT, but lower incidence of increased max-IC IMT than controls. Factors significantly associated with IMT in the controls were age, BMI, and hypertension, whereas factors significantly associated with IMT in RA patients were age and smoking status. Mean carotid IMT was associated with all characteristics related to smoking in RA patients. Current smokers had higher mean carotid IMT and internal carotid artery IMT than former smokers. RA is associated with higher carotid artery bifurcation IMT. The profile of factors associated with IMT values is different between RA patients and controls. Smoking is an important factor augmenting early atherosclerosis in RA patients.

Adult↗
PubMed2005

Prevalence of antiphospholipid and antioxidized low-density lipoprotein antibodies in rheumatoid arthritis.

Antiphospholipid antibodies characterize the antiphospholipid syndrome (APS), but they can also be found in various autoimmune, infectious, and malignant conditions. This study's objectives were to detect the prevalence of antiphospholipid and antioxidized low-density lipoprotein (anti-oxLDL) antibodies among patients with rheumatoid arthritis (RA) who did not have clinical manifestations of APS. Using a standard enzyme-linked immunosorbent assay (ELISA), we evaluated the levels of immunoglobulin G (IgG) and IgM anticardiolipin, IgG, and IgM anti-beta-2-glycoprotein-I (anti-beta(2)GPI), and anti-oxLDL autoantibodies in 82 patients with RA. The cutoff levels for detecting these autoantibodies were 15 IgG phospholipid units (GPL), 15 IgM phospholipid units (MPL), and 25 ELISA units (EU)/mL, respectively. Elevated levels of IgG anticardiolipin antibodies were detected in 17 of 82 (21%) RA patients, including 10 with low levels of IgG anticardiolipin and 7 with medium to high levels of anticardiolipin autoantibodies. IgM anticardiolipin was found in only 1 (1%) patient, and both IgG and IgM anti-beta(2)GPI were found in 3 (4%) patients with RA. Elevated levels of anti-oxLDL antibodies were found in 8 (10%) patients, 4 of whom also had elevated levels of IgG anticardiolipin. We conclude that IgG anticardiolipin autoantibodies can be found in about one-fifth of RA patients who do not have clinical manifestations of APS. Whether the presence of anticardiolipin signifies increased risk for thrombosis and atherosclerosis in these patients should be studied further.

Antibodies, Anticardiolipin↗
PubMed2004

CD4+CD28- T lymphocytes contribute to early atherosclerotic damage in rheumatoid arthritis patients.

BACKGROUND: Peripheral blood expansion of an unusual CD4+ T-cell subset lacking surface CD28 has been suggested to predispose rheumatoid arthritis (RA) patients to develop more aggressive disease. However, the potential association between CD4+CD28null T cells and early atherosclerotic changes in RA has never been investigated. METHODS AND RESULTS: The number of circulating CD4+CD28null cells was evaluated in 87 RA and 33 control subjects who also underwent evaluation of carotid artery intima-media thickness (IMT) and endothelial function via flow-mediated vasodilation (FMV). Patients had higher IMT and lower FMV compared with control subjects. The frequency of CD4+CD28null cells was significantly higher in patients than in control subjects. Twenty patients with persistent expansion of circulating CD4+CD28null cells had more marked increase of carotid artery IMT and stronger decrease of brachial artery FMV. Blockade of tumor necrosis factor-alpha led to a partial reappearance of the CD28 molecule on the CD4+ cell surface. CONCLUSIONS: Circulating CD4+CD28(null) lymphocytes are increased in RA. Patients with persistent CD4+CD28null cell expansion show preclinical atherosclerotic changes, including arterial endothelial dysfunction and carotid artery wall thickening, more significantly than patients without expansion. These findings suggest a contribution of this cell subset in atheroma development in RA. Moreover, the demonstration that tumor necrosis factor-alpha blockade is able to reverse, at least in part, the CD28 deficiency on the CD4+ cell surface may be of interest for possible innovative therapeutic strategies in cardiovascular diseases.

Aged↗
PubMed2004

Autoantibodies profile in the sera of patients with Sjogren's syndrome: the ANA evaluation--a homogeneous, multiplexed system.

BACKGROUND: Flow-based, multiplex bead arrays (MBA) have been developed for a variety of applications including the detection of antibodies to extractable nuclear antigens (ENA). It offers a rapid and sensitive method to assess multiple analyses in a single tube/well. PURPOSE: To evaluate the Athena Multi-Lyte ANA Test System utilizes Luminex Corporation's MBA technology for the detection of antinuclear antibodies (ANA) and ENA antibodies in the sera of patients with Sjogren's syndrome (SS). METHODS: MBA assay was used to detect ANA and ENA antibodies in the sera of 37 patients with SS and 96 sera from healthy subjects. RESULTS: All patients were women. Their mean age was 48.7 years and the mean disease duration was 7.27 years. ANA was found in 3 (3%) sera of healthy subjects by the AtheNA system and in 2 (2%) sera by the ELISA kit. A 99% concordance between the 2 assays was found. A 94.6% concordance between the 2 assays was found by testing the sera of patients with SS for ANA. By the AtheNA system, none of the sera of 37 patients with SS had autoantibodies reacting with Sm, Jo-1, dsDNA or histones. Anti-RNP antibody was found in 5.4% of the sera and 2.7% of the sera reacted with Scl-70 and histones. Anti-SS/A and anti-SS/B were identified in 84 and 76% of the sera, respectively. CONCLUSION: The AtheNa Multi-Lyte ANA Test System offers a sensitive and specific result for the detection of ANA and ENA antibodies in the sera of patients with SS.

Adult↗
PubMed2003

Contribution of peak respiratory exchange ratio to peak VO2 prognostic reliability in patients with chronic heart failure and severely reduced exercise capacity.

BACKGROUND: We evaluated the influence of peak respiratory exchange ratio (pRER), as an index of effort adequacy, on peak VO2 prognostic reliability in patients with chronic heart failure (CHF) and reduced exercise capacity, whose peak VO2 may be underestimated because of poor patient motivation. METHODS: A cardiopulmonary exercise test was performed in 570 patients with CHF (age 60 +/- 10 years, ejection fraction 26% +/- 7%, New York Heart Association class 2.2 +/- 0.6), 193 of whom had a peak VO2 that was >10 but 10 but or=1.15 had a 2-year survival rate of 52%, and this pRER value (but not >or=1, >or=1.05, or >or=1.10) was the only independent predictor of the composite end point (chi(2) = 4.73, P =.03). Conversely, in the group of patients with a peak VO2 10 but <or=14. CONCLUSION: Patients with CHF and severely reduced exercise capacity should be encouraged to exercise to an RER as close as possible to 1.15, to ascertain their motivation and ensure their peak VO2 prognostic reliability.

Analysis of Variance↗
PubMed2002

Variability in a dynamic postural task attests ample flexibility in balance control mechanisms.

When humans stand upright on a platform that sinusoidally translates in the anterior-posterior direction, the movements of upper and lower body segments are appropriately coordinated, in order to keep the body within its limits of stability. A significant fluctuation in this behaviour is evident across subjects and perturbation conditions. The inter- and intrasubject variability in the body segment kinematics, as occurs during repeated trials across different conditions, is quantitatively described here. Twenty normal subjects stood upright with eyes open (EO) or eyes closed (EC) on a platform moving to-and-fro in the horizontal plane for 30 s, at a frequency of 0.2 and 0.6 Hz, with a peak-to-peak amplitude of 6 cm. Each subject made two trial repetitions for each visual and frequency condition. The last 20 s of each trial was acquired. The displacement of markers fixed on the lateral malleolus, hip and head was sampled at a frequency of 50 Hz. An index of the 'average' displacement of each marker during the trial was the standard deviation (SD) of its anterior-posterior displacements, calculated across the acquired trial cycles. The cross-correlation (CC) between pairs of marker displacement traces gave an indication of the degree of coupling of the body segments. All subjects showed two basic modes of coping with the perturbation, depending on the availability of the visual input: with EO, they tended to stabilize the head in space; with EC, the head oscillated in the anterior-posterior direction more than hip and platform. Within this general behaviour, the values of the SD of horizontal displacement of head and hip marker traces varied within an ample range during different trials of the same perturbation condition. Even within a single trial there was an ample variability of the body segments' position. In spite of this, neither head nor hip ever bypassed the anterior or posterior limits of stability. Remarkably, the range of variability of the whole population of normal subjects, both across and within trials, was analogous to the range of variability of single subjects across numerous trials. This large variability notwithstanding, it appeared that the relationship of head to hip SD across trials was almost constant, independent of visual and perturbation frequency condition. The results show that there exist a large variety of dynamic postures, rather than one particular configuration, which assure stability. The findings also suggest a neural or biomechanical constraint underlying the operations of the equilibrium control strategy.

Adolescent↗
PubMed2002

Oscillatory ventilation during exercise in patients with chronic heart failure: clinical correlates and prognostic implications.

STUDY OBJECTIVES: Although breathing disorders are often found in patients with chronic heart failure, exertional oscillatory ventilation (EOV) has been occasionally described. The aim of this study was to determine the prevalence, clinical characteristics, and outcome of patients with chronic heart failure and EOV. SETTING: Cardiology division at tertiary-care hospital. STUDY POPULATION: We studied 323 patients with chronic heart failure and left ventricular ejection fraction (LVEF) < or = 40%. MEASUREMENTS AND RESULTS: All patients performed a symptom-limited cardiopulmonary exercise test and were followed up for 22 +/- 11 months (mean +/- SD). EOV was defined as cyclic fluctuations in minute ventilation (E) at rest that persist during effort lasting > or = 60% of the exercise duration, with an amplitude > or = 15% of the average resting value. Patients with EOV (12%), as compared to those without, showed higher New York Heart Association (NYHA) class (p < 0.05) and lower LVEF (p < 0.0001) and peak oxygen consumption (O(2)) [p < 0.0001]. During the follow-up period, 53 patients died or underwent urgent cardiac transplantation; this group showed higher NYHA class (p < 0.05) and E/CO(2) slope (p < 0.0001) and lower LVEF (p < 0.0001), mitral Doppler early deceleration time (p < 0.01), and peak O(2) (p < 0.0001). EOV was more frequent in nonsurvivors than in survivors (28% vs 9%, p < 0.01). Multivariate analysis revealed peak O(2) (chi(2), 51.5; p < 0.0001), EOV (chi(2), 45.4; p < 0.0001), and LVEF (chi(2), 20.6; p < 0.0001) as independent predictors of major cardiac events. CONCLUSIONS: EOV is not unusual in patients with chronic heart failure, and is associated with worse clinical status, cardiac function, and exercise capacity. EOV is a powerful predictor of poor prognosis and, consequently, it may be considered a valuable guide in the management of patients with chronic heart failure and should suggest a more aggressive medical treatment policy when detected.

Cheyne-Stokes Respiration↗