PubMed Health⌕ Search

Biomedical subjects

A Rossi

Publications and source records attributed to A Rossi.

At least 361 records · Page 20Linked to original sources

Ultrasonic liposculpturing: extrapolations from the analysis of in vivo sonicated adipose tissue.

The ultrasonic liposculpturing technique is currently gaining increasing popularity. Although ultrasound is an accepted part of our diagnostic medical practice, the way in which it interacts with solid living tissue is still a complex and unsolved biophysical problem. Very few studies, if any, have followed the effects of diffusion of this intriguing technique on the fields of biosafety and interaction mechanisms. We evaluate the results of our standard ultrasound liposculpturing technique in order to recognize the physical mechanism-thermal, cavitational, or "direct"-involved in the damaging process. Our microscopic analysis of sonicated adipose tissue confirms that ultrasound is highly selective in its action, producing disruption of macromolecules and cellular structures probably through microstreaming tissue movement. The results of ultrasonic liposculpturing and standard suction lipoplasty are compared. The main advantages of this new technique are the possibility of a very selective destruction of adipose tissue and the prospective solution to such delicate problems as the irregularity of cellulite.

Adipose Tissue↗

Risperidone, negative symptoms and cognitive deficit in schizophrenia: an open study.

The aim of this study was to evaluate the effects of a new antipsychotic compound on negative symptoms and cognitive deficit in schizophrenia. Psychiatric symptoms and cognition were assessed in 25 patients with schizophrenia, at baseline and after they had taken risperidone for 4 weeks. The Positive and Negative Symptoms Scale (PANSS), the Wisconsin Card Sorting Test (WCST) and two WAIS sub-tests were used to assess the patients. After the study period, both negative and positive symptoms and also measures of cognitive performance improved significantly. The WCST results correlated with negative symptom scores before and after treatment. This suggests that negative symptoms and cognitive deficit have a common underlying substrate which is the target of the risperidone treatment. Our data show that risperidone may have a substantial effect on complex cognitive functions in schizophrenia, and they suggest that certain cognitive deficits are relatively dependent on the negative symptoms of this disorder.

Adult↗

Impaired cortisol binding to glucocorticoid receptors in hypertensive patients.

We compared glucocorticoid receptor binding characteristics and glucocorticoid responsiveness of human mononuclear leukocytes (HML) from hypertensive patients and matched normotensive volunteers. We also considered associations of these variables with plasma renin activity, aldosterone, cortisol, corticotropin, and electrolyte concentrations. We calculated binding affinity (Kd; nmol/L) and capacity (Bmax; sites/cell) for dexamethasone and cortisol from homologous and heterologous competition curves for specific [3H]dexamethasone binding sites on HML isolated from the blood of normotensive volunteers and subjects with essential hypertension. Glucocorticoid responsiveness of HML was evaluated as IC50 values (nmol/L) for dexamethasone and cortisol for the inhibition of lysozyme release. We measured plasma hormones by radioimmunoassay. Kd values (mean+/-SE) for cortisol in HML of hypertensive patients were higher than in control subjects (24.6+/-2.4 versus 17.5+/-1.7 nmol/L, P<.04). Binding capacity (4978+/-391 versus 4131+/-321 sites/cell), Kd values for dexamethasone (6.7+/-0.5 versus 5.7+/-0.3 nmol/L), and IC50 values for dexamethasone (3.4+/-0.3 versus 3.1+/-0.2 nmol/L) and cortisol (12.2+/-1.6 versus 9.5+/-0.3 nmol/L) were not significantly different. Patients with renin values less than 0.13 ng angiotensin I/L per second were markedly less sensitive to cortisol than those with higher values. Both Kd (30.3+/-2.5 versus 19.2+/-2.4 nmol/L) and IC50 values (15.5+/-1.8 versus 8.9+/-1.2 nmol/L) for cortisol were significantly higher in patients with lower renin values (P<.03). Other variables, including plasma hormone and electrolyte values and binding characteristics for dexamethasone, were not different. These data suggest that cortisol binding to glucocorticoid receptor is slightly impaired in patients with essential hypertension. In vivo, this could lead to inappropriate binding of cortisol to mineralocorticoid receptors. Hence, decreased sensitivity to cortisol is associated with renin suppression. This hypothesis is supported by evidence of hypertension and low renin activity, which others have described in patients with primary glucocorticoid resistance due to mutations of the glucocorticoid receptor.

Adult↗

Impact of positive end-expiratory pressure on chest wall and lung pressure-volume curve in acute respiratory failure.

To investigate whether chest-wall mechanics could affect the total respiratory system pressure-volume (P-V) curve in patients with acute respiratory failure (ARF), and particularly the lower inflection point (LIP) of the curve, we drew the total respiratory system, lung, and chest-wall P-V curves (P-Vrs, P-VL, and P-VW, respectively) for 13 patients with ARF, using the supersyringe method together with the esophageal balloon technique. Measurements were randomly repeated at four different levels of positive end-expiratory pressure (PEEP) (0, 5, 10, 15 cm H2O) and from each P-V curve we derived starting compliance (Cstart), inflation compliance (Cinf), and end compliance (Cend). With PEEP of 0 cm H2O (ZEEP), an LIP on the P-Vrs curve was observed in all patients (7.5 +/- 3.9 cm H2O); in two patients an LIP was detected only on the P-VL curve (8.6 and 8.7 cm H2O, respectively); whereas in seven patients an LIP was observed only on the P-VW curve (3.4 +/- 1.1 cm H2O). In four patients, an LIP was detected on both the P-VL and P-VW curves (8.5 +/- 3.4 and 2.2 +/- 1.0 cm H2O, respectively). The LIP was abolished by PEEP, suggesting that a volume-related mechanism was responsible for the observed LIP on both the P-VL and P-VW curves. At high levels of PEEP, an upper inflection point (UIP) appeared on the P-Vrs and P-VL curves (11.7 +/- 4.9 cm H2O and 8.9 +/- 4.2 cm H2O above PEEP, respectively) suggesting alveolar overdistension. In general, PaO2 increased with PEEP (from 81.7 +/- 35.5 mm Hg on ZEEP to 120 +/- 43.8 mm Hg on PEEP 15 cm H2O, p < 0.002); however, the increase in PaO2 with PEEP was significant only in patients with an LIP on the P-VL curve (from 70.5 +/- 16.2 mm Hg to 117.5 +/- 50.7 mm Hg, p < 0.002), the changes in PaO2 in patients without an LIP on the P-VL curve not being significant (from 91.3 +/- 45.4 mm Hg to 122.2 +/- 41.1 mm Hg). We conclude that in ventilator-dependent patients with ARF: (1) the chest-wall mechanics can contribute to the LIP observed on the P-Vrs curve; (2) the improvement in PaO2 with PEEP is significant only in patients in whom LIP is on the lung P-V curve and not on the chest wall curve; (3) high levels of PEEP may overdistend the lung, as reflected by the appearance of a UIP; (4) measurement of P-Vrs alone may be misleading as a guide for setting the level of PEEP in some mechanically ventilated patients, at least in the supine position, although it helps to prevent excessive alveolar overdistension by indicating the inflection volume above which UIP may appear.

Acute Disease↗

Pulmonary hyperinflation and ventilator-dependent patients.

Pulmonary hyperinflation is a major medical problem in patients with advanced chronic obstructive pulmonary disease (COPD) or acute asthma. The apparent beneficial effects of pulmonary hyperinflation on lung mechanics, such as an increased airway patency and lung elastic recoil, are by far overwhelmed by the deleterious effects on the pressure generating capacity of the respiratory muscles. Moreover, the ventilatory workload can be remarkably increased: 1) by the displacement of the respiratory system toward the upper, flat portion of the pressure-volume curve; 2) by the need to expand the chest wall and not only the lungs; and 3) by the intrinsic positive end-expiratory pressure (PEEPi) systematically associated with dynamic hyperinflation. In mechanically ventilated patients, the mechanisms underlying pulmonary hyperinflation as well as its pathophysiological consequences do not differ from those described in spontaneously breathing patients. However, there are some specific issues that should be taken into account, namely the effect of the endotracheal tube and the mode and setting of the ventilator. In mechanically ventilated patients, pulmonary hyperinflation increases the risk of barotrauma and may hamper weaning due to the excessive burden of PEEPi, which can even lead to ineffective inspiratory efforts. Because of its harmful consequences, pulmonary hyperinflation must be treated aggressively by pharmacological therapy and, when needed, by ventilatory treatment. The setting of the ventilator must be predetermined to ensure the longest possible time for expiration, and positive end-expiratory pressure can be applied to prevent an excessive workload for the patient and ineffective inspiratory efforts.

Airway Resistance↗

Effects of inspiratory flow waveforms on arterial blood gases and respiratory mechanics after open heart surgery.

The clinical usefulness of inspiratory flow pattern manipulation during mechanical ventilation remains unclear. The aim of this study was to investigate the effects of different inspiratory flow waveforms, i.e. constant, sinusoidal and decelerating, on arterial blood gases and respiratory mechanics, in mechanically ventilated patients. Eight patients recovering after open heart surgery for valvular replacement and/or coronary bypass were studied. The ventilator inspiratory flow waveform was changed according to a randomized sequence, keeping constant the other variables of the ventilator settings. We measured arterial blood gases, flow, volume and pressure at the proximal (airway opening pressure (Pao)) and distal (Ptr) ends of the endotracheal tubes before and after 30 min of mechanical ventilation with each inspiratory flow waveform. We computed breathing pattern, respiratory mechanics (pressures and dynamic elastance) and inspiratory work, which was then partitioned into its elastic and resistive components. We found that: 1) arterial oxygen tension (Pa,O2) and arterial carbon dioxide tension (Pa,CO2) were not affected by changes in the inspiratory flow waveform; and 2) peak Pao and Ptr were highest with sinusoidal inspiratory flow, whilst mean Pao and Ptr and total work of breathing were least with constant inspiratory flow, mainly because of a concomitant decrease in resistive work during constant flow inflation. The effects of the inspiratory flow profile on Pao, Ptr and total inspiratory work performed by the ventilator were mainly due to the resistive properties of the endotracheal tubes. We conclude that the ventilator inspiratory flow waveform can influence patients' respiratory mechanics, but has no impact on arterial oxygen and arterial carbon dioxide tension.

Adult↗

Short-term effects of nasal proportional assist ventilation in patients with chronic hypercapnic respiratory insufficiency.

Proportional assist ventilation (PAV) has recently been proposed as a mode of synchronized partial ventilatory support. This study evaluates the short-term effects of nasal PAV on arterial blood gases in stable patients with chronic hypercapnia. Forty two patients (30 with chronic obstructive pulmonary disease (COPD) and 12 with restrictive chest wall disease (RCWD) due to kyphoscoliosis) underwent a 1 h run of nasal PAV. Randomly, two levels of assistance were performed: 1) PAV was set at a level corresponding to volume assist (VA) and flow assist (FA) at 80% of the individual values of elastance (Ers) and resistance (Rrs) obtained with the "runaway" method; and 2) VA and FA were set at a value corresponding to the difference between the patients' individual Ers and Rrs and normal values of Ers and Rrs. Arterial blood gases and dyspnoea (by visual analogue scale (VAS)) were evaluated in all patients during unsupported ventilation and 60 min of PAV. PAV was well tolerated and resulted in significant improvement in arterial oxygen tension (Pa,O2), arterial carbon dioxide tension (Pa,CO2) (6.8+/-0.8 to 7.4+/-1.4 and 7.2/-0.9 to 6.8+/-0.9 kPa, respectively) and VAS (29+/-23 to 20+/-18%). The effects of PAV were not different in the two groups of diseases nor in the two groups of settings. Different settings of nasal proportional assist ventilation are well tolerated and may improve gas exchange and dyspnoea in patients with stable hypercapnic respiratory insufficiency.

Aged↗

Intensified and high-dose chemotherapy with granulocyte colony-stimulating factor and autologous stem-cell transplantation support as first-line therapy in high-risk diffuse large-cell lymphoma.

PURPOSE: In our previous study with MACOPB, we identified a high-risk group of patients with a poor 3-year survival rate of 29%. These patients were defined as having at diagnosis advanced-stage disease with high tumor burden (TB) and elevated lactate dehydrogenase (LDH) level or bone marrow (BM) involvement. A novel therapeutic scheme was investigated to improve the outcome of these patients. PATIENTS AND METHODS: Fifty patients with high-risk diffuse large-cell lymphoma (DLCL) were enrolled. The therapeutic scheme includes three phases: induction with 8 weeks of MACOPB; intensification with a 3-day course of mitoxantrone 8 mg/m2 plus high-dose cytarabine (HDARA-C) 2 g/m2 every 12 hours plus dexamethasone 4 mg/m2 every 12 hours (MAD protocol) and granulocyte colony-stimulating factor (G-CSF) 5 microg/kg on days 4 to 17 to harvest peripheral-blood progenitor cells (PBPC); consolidation with carmustine (BCNU), etoposide, ARA-C, and melphalan (BEAM) regimen; plus autologous stem-cell transplantation (ASCT) with PBPC, marrow, or both. RESULTS: Thirty-six patients (72%) achieved a complete response (CR), 11 (22%) showed no response (NR), and three (6%) died of toxicity. Among the 22 PRs or NRs after the induction phase, 56% of patients achieved a CR with subsequent intensified therapy. With a median follow-up duration of 32 months, the overall survival and failure-free survival rates were 56% and 50%, respectively. The disease-free survival rate is 69% at 32 months. Leukapheresis after MAD and G-CSF yielded a median of 32 x 10(6)/kg CD34+ cells and 80 x 10(4)/kg granulocyte-macrophage colony-forming units (CFU-GM). Thirty-nine patients were autografted and 11 did not undergo ASCT: six because of disease progression, four due to toxicity, and one because of patient refusal. The median times to achieve engrafment were 11 days (range, 7 to 19) to a neutrophil count greater than 0.5 x 10(9)/L and 12 days (range, 8 to 60) to a platelet count greater than 50 x 10(9)/L. CONCLUSION: This sequential scheme with intensified and high-dose chemotherapy with ASCT is feasible with moderate toxicity and may improve the outcome in high-risk DLCL.

Adult↗

Factors related to glycemic control in IDDM and insulin-treated NIDDM patients in current practice. A comparison of care policies. SIEMTIC Group. Studio Italiano Epidemiologico Multicentrico su Terapia Insulin e Controllo Metabolico.

OBJECTIVE: To evaluate, under routine conditions, the relation between different diabetes care policies and glycemic control through a by-center analysis procedure aimed at reducing some drawbacks of cross-sectional data. RESEARCH DESIGN AND METHODS: A survey on insulin-treated diabetes care management (IDDM and NIDDM) involved 16 Italian randomly selected diabetes outpatient clinics. A total of 2,142 representative patients were investigated. The standardized HbA1c average value of each center was related, by regression models, to some indicators of center care policy (average number of injections, average BMI, proportion of cases with recent fundus oculi examinations, or frequent visits) as well as to patients' average social levels (employment type). Homogeneity in patient admission criteria is assumed among the investigated centers as a basic condition for the procedure validity. Some known imbalance were controlled for both design and analysis. RESULTS: HbA1c showed a univariate inverse relation with daily number of injections in IDDM (P = 0.0009, r2 = 0.56) but not in NIDDM (P = 0.33). It was inversely related to both fundus examination (IDDM P = 0.04; NIDDM P = 0.099) and qualified employment (IDDM P = 0.06; NIDDM P = 0.026). A stepwise regression analysis left in the model insulin injections (P = 0.0002) in IDDM (total r2 = 0.68) and qualified employment (P = 0.016) and fundus examination (P = 0.14) in NIDDM (total r2 = 0.53), after controlling for age, sex, disease duration, insulin therapy starting delay, and insulin dose per kilogram. CONCLUSIONS: These results suggest that the confirmed benefits of a multiple-injection regimen in IDDM cannot be simply extrapolated to NIDDM, where patients' awareness and medical attention to complications proved to be the most important factors in current practice.

Adult↗

Short-term regular beta 2-adrenergic agonists treatment is safe in mild asthmatics taking low doses of inhaled steroids.

Regular treatment with beta 2-adrenergic agonists is controversial in bronchial asthma. To investigate whether beta 2-adrenergic agonists can be used safely if associated with low doses of inhaled steroids, for a short period, without a deterioration of asthma control, we have examined 24 mild asthmatics. In a parallel, double-blind, placebo-controlled study, 1 week of run-in and run-out period framed 3 weeks of treatment. All patients received inhaled beclomethasone dipropionate (BDP 250 micrograms t.i.d.); after 1 week, 12 patients inhaled 400 micrograms of broxaterol and 12 patients received placebo t.i.d. FVC, FEV1, PD20-FEV1 methacholine, morning and evening PEF, and PEF amplitude % mean were measured before, during, and after treatment. No significant changes were noted in patients receiving inhaled broxaterol. There were no differences in symptoms and the use of rescue medication (salbutamol spray). We conclude that short-term regular treatment with beta 2-adrenergic agonists is not associated with a deterioration in asthma control in mild asthmatics inhaling low doses of steroids.

Administration, Inhalation↗

Physiological and clinical consequences of positive end-expiratory pressure.

The aims of positive end-expiratory pressure (PEEP) are: 1) in acute lung failure, to increase lung volume and to improve oxygenation; 2) in acute exacerbation of chronic obstructive pulmonary disease (COPD), to unload inspiratory muscles. Excessive levels of PEEP may increase the risk of barotrauma. Application of low levels of PEEP may replace intrinsic PEEP in acute exacerbation of COPD, without increasing lung volume; however, the haemodynamic consequences of PEEP must be taken into account.

Acute Disease↗

Predicting outcome after listing for heart transplantation in children: comparison of Kaplan-Meier and parametric competing risk analysis. Pediatric Heart Transplant Study Group.

After listing for pediatric heart transplantation, at any point in time one of the following possibilities could have occurred; death, transplantation, removal from the list because of clinical improvement, or continuing to wait. In the setting of those competing outcomes, the Kaplan-Meier estimate portrays the time-relatedness of an event while ignoring the effect of the other possible outcomes. The competing outcomes method, however, depicts the time relatedness of an event while solving for all possible events simultaneously. The competing outcomes method may potentially provide more accurate information regarding the actual proportion of patients experience an outcome after listing.

Adolescent↗

[Toxic megacolon. Apropos 3 cases].

The authors describe their experience with three cases of toxic megacolon: two cases were complications of an ulcerative colitis and died after surgery; one case was a complication of Crohn's disease and recovered after medical resuscitation treatment. Diagnosis was based on clinical features and direct abdominal X-ray showing an evident dilatation of the colon. The authors think that intense medical treatment has to be carried out in all cases without urgent surgical indication: even if not always successful, a medical therapy will be an appropriate preparation for operation. The authors believe that the operation of choice is colectomy with ileo-rectal anastomosis plus upstream protective ileostomy or right terminal ileostomy plus left iliac sigmoidostomy with subsequent reconstruction of continuity.

Aged↗

Detection of early ischemic damage by analysis of mitochondrial function in skinned fibers.

The skinned fibers technique was applied for studies of the effects of global acute ischemia (1 h at 37 degrees C) and long time (15 h) hypothermic (4 degrees C) preservation of isolated rat hearts under different conditions (immersion or low-flow perfusion) on mitochondrial function in the cells in vivo. Skinned fibers were obtained by using saponin for permeabilization of the sarcolemma in separated fiber bundles cut from left ventricle. The experimental protocol of the respiration rate determination included a cytochrome c test to check the intactness of the outer mitochondrial membrane. The apparent K(m) for ADP and the effect of creatine on the mitochondrial activity were also evaluated in these permeabilized fibers, taken from different groups of hearts. The preservation of low-flow perfused hearts resulted only in a slight decrease of creatine (20 mM) stimulated respiration at 0.1 mM ADP. The fibers from ischemic hearts or from hearts preserved by immersion showed a decrease of the apparent K(m) for ADP, and a complete loss of the stimulatory effect of creatine. In these fibers, we could observe that the outer mitochondrial membrane was damaged. In conclusion, the results of this study show that assessment of mitochondrial parameters sensitive to organelles swelling--intactness of outer membrane and functionally coupled creatine kinase reaction--are the most sensitive indicators of early hypoxic or ischemic damage to mitochondria. Their determination in biopsy samples could be used for evaluation of the efficiency of the cardiac protection in heart surgery.

Adenosine Diphosphate↗

Portal hypertensive gastropathy: reproducibility of a classification, prevalence of elementary lesions, sensitivity and specificity in the diagnosis of cirrhosis of the liver. A NIEC multicentre study. New Italian Endoscopic Club.

OBJECTIVE: To classify elementary endoscopic lesions of portal hypertensive gastropathy, assess their reproducibility, prevalences, sensitivity and specificity in the diagnosis of cirrhosis of the liver. METHODS: 1) A classification of portal hypertensive gastropathy elementary lesions was defined. 2) Thirty-two endoscopists evaluated videotapes of endoscopic examinations of patients with liver cirrhosis to assess beyond-chance agreement (kappa). 3) Fifteen centres enrolled consecutive patients with or without cirrhosis of the liver and recorded portal hypertensive gastropathy pattern according to its location. RESULTS: 1) Four elementary lesions (Mosaic-Like Pattern, Red Point Lesions, Cherry Red Spots, Black-Brown Spots) were identified, and graded. 2) A fair to good beyond-chance agreement was obtained for all 4 lesions. 3) portal hypertensive gastropathy prevalence was higher in patients with cirrhosis of the liver (0.63, sensitivity) than in controls (0.17). Mosaic-like pattern was the most prevalent sign (0.54). Specificity of portal hypertensive gastropathy was 0.83. Portal hypertensive gastropathy was tentatively classified as mild or severe when mosaic-like pattern alone or red marks of any kind were present, respectively; this classification led to a further improvement in reproducibility. CONCLUSIONS: Our results suggest that a sufficient degree of agreement can be achieved in recording portal hypertensive gastropathy. Therefore, the New Italian Endoscopic Club classification should be used to evaluate the natural history of this condition.

Diagnosis, Differential↗

Determinants of the pulmonary artery pressure rise in left ventricular dysfunction.

Pulmonary artery hypertension in patients with left ventricular dysfunction is related to poor outcome but the role of cardiac functional abnormalities in the genesis of pulmonary hypertension remains unknown. The aim of this prospective study was to identify the determinants of pulmonary hypertension in 102 consecutive patients with primary left ventricular dysfunction (ejection fraction < 50%). Systolic pulmonary artery pressure was measured by continuous wave Doppler. Left ventricular systolic and diastolic function, severity of functional mitral regurgitation, cardiac output, and left atrial volume were assessed using Doppler echocardiography. In patients with left ventricular dysfunction, systolic pulmonary artery pressure was increased (51 +/- 14 mmHg, range 23 to 87 mmHg). Mitral deceleration time (r = -0.61; p = 0.0001) and mitral effective regurgitant orifice (r = 0.50; p = 0.0001) were the strongest parameters related to systolic pulmonary artery pressure. Multivariate analysis identified these two variables as the strongest predictors of systolic pulmonary artery pressure in association with the mitral E/A ratio (p = 0.006) and age (p = 0.005). In conclusion, pulmonary hypertension is common and variable in patients with left ventricular dysfunction. It is closely related to diastolic dysfunction and severity of functional mitral regurgitation but not independently to the degree of left ventricular systolic dysfunction. These findings underline the importance of assessing diastolic function and quantifying mitral regurgitation in patients with left ventricular dysfunction.

Blood Pressure↗

Comparative evaluation of the cardiorespiratory effects of assist control ventilation vs pressure support ventilation in patients following orthotopic liver transplantation.

OBJECTIVE: 1) To compare the haemodynamic tolerance of ACV and PSV in patients mechanically ventilated after orthotopic liver transplantation; 2) to compare patients comfort during ACV and PSV. DESIGN: Prospective randomized cross-over study. SETTING: General ICU of the University of Rome "La Sapienza". PATIENTS: Eighteen patients admitted in ICU after orthotopic liver transplantation. MEASUREMENT AND RESULTS: Haemodynamic, oxygen transport and blood gas data were compared during an ACV and PSV trial (30'). A statistically significant decrease of mean pulmonary and systemic arterial pressure, PCOP, LVSWI, occurred during the PSV trial. PaO2 and DO2I decreased during PSV, but were still in supranormal range; 16 out of 18 patients described PSV as more comfortable. CONCLUSIONS: ACV and PSV provided a comparable haemodynamic tolerance in our patients, although during PSV the PaO2 was slightly decreased, probably due to decreased mean airway pressure (from 9.3 +/- 1.2 cmH2O during ACV to 6.6 +/- 1 cmH2O during PSV). PSV can be considered as a good alternative to the standard weaning techniques following orthotopic liver transplantation.

Adult↗