Biomedical subjects

Andrea Stella

Publications and source records attributed to Andrea Stella.

13 recordsLinked to original sources

PubMed2007

Effects of exercise training on heart rate and QT interval in healthy young individuals: are there gender differences?

AIMS: The aim of the present study was to assess the effects of exercise training on heart rate, QT interval, and on the relation between ventricular repolarization and heart rate in men and women. METHODS AND RESULTS: A 24 h Holter recording was obtained in 80 healthy subjects (40 males) who differed for the degree of physical activity. Trained individuals showed a lower heart rate and a higher heart rate variability than sedentary subjects, independent of the gender difference in basal heart rate. Mean 24 h QTc was similar in trained and non-trained men, while a significant difference was observed between trained and non-trained women. Exercise training reduced the QT/RR slope in both genders. This effect on the QT/RR relation was more marked in women; in fact, the gender difference in the ventricular repolarization duration at low heart rate observed in sedentary subjects was no longer present among trained individuals. CONCLUSION: The results of this study suggest that the cardiovascular response to exercise training may be different in men and women. Women may benefit more from interventions aimed to increase physical activity as a tool for prevention of cardiovascular morbidity and mortality.

Electrocardiography↗

PubMed2006

Treatment of small hepatocellular carcinoma: a comparison of techniques and long-term results.

OBJECTIVE: The aim of this study was to compare the results over time of transcatheter arterial chemoembolization (TACE), percutaneous ethanol injection (PEI), laser thermal ablation (LTA) and combined therapy in the treatment of small hepatocellular carcinoma. METHODS: Between 1998 and 2004, 131 cirrhosis patients (99 Child-Pugh class A, 32 Child-Pugh class B) with a small hepatocellular carcinoma were included in the study; 34 were treated with PEI, 46 with LTA, 18 with TACE and 33 with combined therapy. RESULTS: No major complication occurred during any procedure. Computed tomography scan showed that complete necrosis was achieved in 81% of treated nodules (120 out of 148); as a whole, the disease relapsed in 42 (32.0%) patients (with a disease-free interval of 17.0+/-13.7 months). The cumulative survival rates were 81.9, 35.7 and 20.8% at 12, 36 and 60 months respectively. A univariate analysis of survival showed statistically significant differences in the comparison between Child-Pugh class A with respect to Child-Pugh class B (P<0.0001) and between nodules with a diameter of 20 mm or less as opposed to larger than 20 mm (P=0.001). Patients subjected to LTA showed a statistically significant longer survival than those treated with TACE and PEI. CONCLUSIONS: LTA proves to be the most effective treatment, affording reduced invasiveness, a limited number of sessions, complete necrosis in almost all cases and better total survival in the treated patients.

Adult↗

PubMed2006

C-reactive protein in hypertensive disorders in pregnancy.

Hypertension is the most frequent medical complication of pregnancy. A recent report demonstrates the flogistic pathogenesis of pregnancy-induced hypertension. Because C-reactive protein (CRP) is a marker of inflammation, it can be used in the differential diagnosis of hypertensive disorders of pregnancy. A total of 322 pregnant women at 24 to 32 weeks' gestation were enrolled. The control group (A) comprised 190 women. Sixty-three women had preeclampsia (PE, group B), 31 women presented transient hypertension (TH, group C), 19 had HELLP syndrome (HS, group D) and 19 had chronic hypertension (CH, group E). CRP serum concentrations were significantly higher in groups B, C, and D in comparison with the group A. In the whole population, systolic and diastolic pressure value inversely correlate with weight at delivery and weeks of gestation at delivery. CPR levels in patients with PE and HS inversely correlate with birth weight and gestational week at delivery. Normal plasma levels of CRP may be an important marker of differential diagnosis between TH and CH. In TH, PE, and HS, CRP levels were higher than in the control and CH groups, suggesting that inflammation may be the common pathogenetic cause of TH and PE. Finally CRP levels in preeclampsia are believed to correlate with preeclamptic process severity.

Biomarkers↗

PubMed2005

Vascular surgery patients: perioperative and long-term risk according to the ACC/AHA guidelines, the additive role of post-operative troponin elevation.

AIMS: The objectives of this study are to evaluate the prognostic role of pre-operative stratification in patients undergoing elective major vascular surgery, the timing of adverse outcomes, and the predictive role of troponin (cTn). METHODS AND RESULTS: Consecutive vascular surgery candidates (n=391) were prospectively stratified and treated according to the ACC/AHA guidelines. The patients were categorized into three groups: (1) with coronary revascularization in the past 5 years, (2) with intermediate clinical risk predictors, and (3) with minor or no clinical risk predictors. cTnI was measured post-operatively. By 18 months, 18.7% of subjects had experienced death or acute myocardial infarction (MI) (by the ACC/ESC criteria). The hazard ratio (HR) was 5.21 (95% CI=2.60-10.43; P<0.0001) in group 1 and 2.58 (95% CI=1.27-4.38; P=0.004) in group 2 when compared with group 3. Most events occurred within 30 days. Elevations of cTnI were associated with adverse outcomes even after multivariable adjustment at long-term (adjusted overall HR=4.73, 95% CI=2.92-7.65; P<0.0001) and at 30 days (adjusted HR=5.52, 95% CI=3.23-9.42; P<0.0001). CONCLUSION: After pre-operative stratification, patients undergoing elective major vascular surgery remain at high risk of MI and death. Events occur mainly early after surgery. cTnI elevations are frequent and independently associated with increased risk. These findings suggest the need for a major re-evaluation of our approach to these patients.

Adrenergic beta-Antagonists↗

PubMed2005

Infrapopliteal angioplasty for limb salvage in the setting of renal failure: do results justify its use?

Multiple reports advocate the use of infrapopliteal angioplasty for limb salvage; however, its utility in the setting of renal failure is unclear. We performed angioplasty, rather than bypass, for tibial stenoses or occlusions <3 cm on 90 limbs of 79 patients (64.4% male, mean age 67.2 years), all with ischemic ulcer. Seventy (77.8%) had diabetes mellitus and 16 (17.8%) had end-stage renal disease (ESRD). Mean follow-up was 14.3 months (range 0.3-45). Associated femoropopliteal revascularization was required in 28 (31.0%) limbs. Primary angiographic success was achieved in 83 (92.2%) limbs. Residual stenosis or thrombosis occurred in two and five limbs, respectively. Dissection occurred in six limbs, all successfully treated with stent placement. Ulcer healing occurred after initial angioplasty in 41 (55.4%) non-ESRD and four (25%) ESRD limbs. Subsequent revascularization procedures were required in 21 (23.3%) limbs, including six bypasses and 15 repeat angioplasties, of which three underwent subsequent bypasses. Major amputation was required in 11 (14.9%) non-ESRD and seven (43.7%) ESRD limbs. Limb salvage was 84.4% and 80.2% in those without and 52.5% and 52.5% in those with ESRD at 1 and 3 years, respectively (p = 0.01). Thirty-day mortality was 2.2%. Overall actuarial survival was 82.2% and 62.1% at 1 and 3 years, respectively, and did not differ significantly between patients with and without ESRD (p = 0.66). Infrapopliteal angioplasty is a safe technique with low procedural morbidity and mortality. However, the inferior wound-healing and limb-salvage rates observed in patients with renal failure bring to question the utility of infrapopliteal angioplasty in this population.

Adult↗

PubMed2005

Angiotensin II modulates frizzled-2 receptor expression in rat vascular smooth muscle cells.

Ang II (angiotensin II) has multiple effects on vascular smooth muscle cells through the modulation of different classes of genes. Using the mRNA differential-display method to investigate gene expression in rat aortic smooth muscle cells in culture in response to 3 h of Ang II stimulation, we observed that Ang II down-regulated the expression of a member of the family of transmembrane receptors for Wnt proteins that was identified as Fzd2 [Fzd (frizzled)-2 receptor]. Fzds are a class of highly conserved genes playing a fundamental role in the developmental processes. In vitro, time course experiments demonstrated that Ang II induced a significant increase (P<0.05) in Fzd2 expression after 30 min, whereas it caused a significant decrease (P<0.05) in Fzd2 expression at 3 h. A similar rapid up-regulation after Ang II stimulation for 30 min was evident for TGFbeta1 (transforming growth factor beta1; P<0.05). To investigate whether Ang II also modulated Fzd2 expression in vivo, exogenous Ang II was administered to Sprague-Dawley rats (200 ng.kg(-1) of body weight.min(-1); subcutaneously) for 1 and 4 weeks. Control rats received normal saline. After treatment, systolic blood pressure was significantly higher (P<0.01), whereas plasma renin activity was suppressed (P<0.01) in Ang II- compared with the saline-treated rats. Ang II administration for 1 week did not modify Fzd2 expression in aorta of Ang II-treated rats, whereas Ang II administration for 4 weeks increased Fzd2 mRNA expression (P<0.05) in the tunica media of the aorta, resulting in a positive immunostaining for fibronectin at this time point. In conclusion, our data demonstrate that Ang II modulates Fzd2 expression in aortic smooth muscle cells both in vitro and in vivo.

Angiotensin I↗

PubMed2005

Prevalence of atrial fibrillation and associated factors in a population of long-term hemodialysis patients.

BACKGROUND: Hemodialysis (HD) is associated with cardiovascular structural modifications; moreover, during HD, rapid electrolytic changes occur. Both factors may favor the onset of atrial fibrillation. METHODS: To define the prevalence of atrial fibrillation and identify associated factors, 488 patients on long-term HD therapy (age, 66.6 +/- 13.4 years; men, 58.0%; duration of HD, 76.5 +/- 84.3 months) were studied. RESULTS: Atrial fibrillation was reported in 27.0% of patients; paroxysmal in 3.5%, persistent in 9.6%, and permanent in 13.9%. Clinical and echocardiographic variables were considered: patients with atrial fibrillation were older (71.8 +/- 9.3 versus 64.7 +/- 14.2 years; P < 0.01), and its prevalence increased with age. Patients with arrhythmia had a longer duration of dialysis therapy (93.2 +/- 100.5 versus 70.2 +/- 76.7 months; P = 0.02). Atrial fibrillation was associated significantly with ischemic heart disease (P < 0.01), dilated cardiomyopathy (P < 0.01), acute pulmonary edema (P < 0.05), valvular disease (P < 0.05), cerebrovascular accidents (P < 0.05), and predialytic hyperkalemia (P < 0.05). Patients with atrial fibrillation more frequently showed left atrial dilatation (59.8% versus 34.5%; P < 0.0001), and in these subjects, left ventricular ejection fraction was significantly lower (53.9% versus 57.4%; P = 0.029). No association was found between arrhythmia and hypertension or diabetes. Multivariate analysis confirmed that patient age (P < 0.001), duration of HD therapy (P = 0.001), and left atrial dilatation (P < 0.001) were associated with atrial fibrillation. CONCLUSION: Atrial fibrillation is much more frequent in HD patients than in the general population; age, duration of HD history, presence of some heart diseases, and left atrial dilatation are associated with the arrhythmia.

Adult↗

PubMed2005

Results of blood pressure screening in a population of school-aged children in the province of Milan: role of overweight.

OBJECTIVES: To study the prevalence of high blood pressure (BP) in an Italian paediatric population, and to verify whether in this population elevated BP values are associated with overweight (OW). STUDY DESIGN: Children (1206 males, 1210 females) from the lower-grade public schools (ages 6-11 years) were studied. Body weight, height and BP were measured in each child. Elevated BP was defined if resting systolic and/or diastolic BP values equalled or exceeded the 95th percentile according to gender, age and height, based on the US normative BP tables. Overweight children were identified using four different methods: (1) the classification based on the relative body weight; (2) the French references by Rolland-Cachera et al. (Am J Clin Nutr 1982; 36:178-184); (3) the International Obesity Task Force charts; and (4) the Italian charts defined by Cacciari et al. (Eur J Clin Nutr 2002; 56:171-180). RESULTS: The prevalence of high BP in our population was 4.2% and was significantly higher in females (65/1210 = 5.4%) than in males (37/1206 = 3.1%), P = 0.005. The different methods used to define OW provide different estimates of OW prevalence (from 17.0 to 38.6%). The percentage of high BP subjects was significantly higher in OW than in normal-weight children regardless of the method used for the definition of the weight class (P < 0.0001), in both genders. In addition, for each age range, absolute systolic and diastolic BP values were higher in OW as compared to normal-weight children both in males and in females (P < 0.0001). CONCLUSIONS: Our study indicates the importance of performing BP screenings in the paediatric population, and to promote interventions that may reduce the prevalence of OW in children.

Age Distribution↗

PubMed2005

Maternal perception of excess weight in children: a survey conducted by paediatricians in the province of Milan.

OBJECTIVE: To establish whether maternal perception of a child's body weight (BW) and food intake is related to the level of maternal education. STUDY DESIGN: Height and BW of 569 mother/child couples were measured, and mothers received a questionnaire regarding their perception of their own weight and their child's BW and food intake. RESULTS: Twenty-nine percent of mothers and 35% of children were overweight or obese. Only 10% of the mothers underestimated their own weight, while 37% overestimated it. In contrast, 28% of mothers underestimated their child's BW, while 9% overestimated it. Higher maternal instruction level was significantly associated to a lower weight class in both mothers and children, and to a correct perception of the child's weight. Fifty-seven per cent of the mothers who perceived their child to be overweight or obese were not concerned. Forty-four per cent of the mothers with overweight or obese children believed that their child was eating correctly. CONCLUSIONS: A better understanding of how mothers perceive the problem of excess weight in their children is relevant to the success of preventive interventions in childhood obesity.

Body Weight↗

PubMed2004

MyWEST: my Web Extraction Software Tool for effective mining of annotations from web-based databanks.

MOTIVATION: High-throughput technologies create the necessity to mine large amounts of gene annotations from diverse databanks, and to integrate the resulting data. Most databanks can be interrogated only via Web, for a single gene at a time, and query results are generally available only in the HTML format. Although some databanks provide batch retrieval of data via FTP, this requires expertise and resources for locally reimplementing the databank. RESULTS: We developed MyWEST, a tool aimed at researchers without extensive informatics skills or resources, which exploits user-defined templates to easily mine selected annotations from different Web-interfaced databanks, and aggregates and structures results in an automatically updated database. Using microarray results from a model system of retinoic acid-induced differentiation, MyWEST effectively gathered relevant annotations from various biomolecular databanks, highlighted significant biological characteristics and supported a global approach to the understanding of complex cellular mechanisms. AVAILABILITY: MyWEST is freely available for non-profit use at http://www.medinfopoli.polimi.it/MyWEST/

Algorithms↗

PubMed2004

Treatment of large hepatocellular carcinoma: comparison between techniques and long term results.

PURPOSE: The aim of this study was to compare results over time of Transcatheter Arterial Chemo Embolization (TACE), Percutaneous Ethanol Injection (PEI), Laser Thermal Ablation (LTA) and combined therapy of large Hepatocellular Carcinoma (HCC). MATERIALS AND METHODS: Between 1995 and 2003, 89 cirrhosis patients (51 Child-Pugh A, 38 Child-Pugh B) with at least one nodule of HCC =/> 40 mm, were included in this randomized study; 21 were treated with TACE, 20 with PEI, 29 with LTA and 19 with combined therapy. The total number of HCC nodules was 92 with a mean diameter of 52.9 mm. RESULTS: No major complication occurred in all procedures. CT scan showed that complete necrosis was achieved in 83% of treated nodules (76 out of 92); as a whole, the disease relapsed in 18 (20.2%) patients (disease free interval being 18.2+/-9.4 months). The cumulative survival rates were 69.6%, 25.1% and 9.8% at 12, 36 and 60 months respectively. Univariate analysis of survival showed statistically significant differences in the comparison between Child-Pugh A group vs B (p<0.0001) and between single nodule vs multiple (p=0.0019). Patients subjected to combined therapy and LTA showed a statistically significant longer survival than those treated with TACE and PEI. CONCLUSIONS: LTA proves to be the most effective treatment for HCC < 50 mm, combined therapy is the best choice for nodules =/> 50 mm since complete necrosis is achieved in almost all cases and better total survival in the treated patients.

Adult↗

PubMed2003

Dynamic QT interval analysis in uraemic patients receiving chronic haemodialysis.

OBJECTIVE: To analyse the duration of the QT interval and its relationship with heart rate changes in patients with uraemia, before and during haemodialysis. METHODS: QT and RR intervals were measured automatically using a dedicated algorithm with 24-h Holter recordings in 29 patients (15 women) receiving chronic haemodialysis. QT corrected for heart rate (QTc) and the slope of QT/RR linear regression were calculated. Arterial blood pressure (ABP) was measured before and during haemodialysis. Plasma concentrations of K+, Mg2+ and Ca2+ were assessed before and after haemodialysis. RESULTS: ABP decreased significantly from baseline (102.7 +/- 11.0 mmHg) during the first (100.6 +/- 8.8 mmHg, P < 0.05), second (95.6 +/- 10.6 mmHg, P < 0.05), and third (94.9 +/- 10.3 mmHg, P < 0.05) hours of haemodialysis. QTc was longer during haemodialysis than during a 4-h period of no dialysis (447 +/- 28 ms compared with 429 +/- 22 ms, P < 0.001), and increased progressively during haemodialysis, with the greatest value during the last hour of haemodialysis (454 +/- 32 ms compared with 426 +/- 22 ms, P < 0.001). QT/RR slopes and correlation coefficients were lower during haemodialysis than during the period of no dialysis (0.13 +/- 0.08 compared with 0.20 +/- 0.07, P < 0.001 and 0.48 +/- 0.30 compared with 0.81 +/- 0.20, respectively; P < 0.001), suggesting a reduced ability to adapt the QT interval in response to changes in heart rate. The effects of haemodialysis on QT interval and the QT/RR relationship were greater in women than in men. QTc variations during dialysis were not correlated with changes in ABP, but were inversely related to changes in Ca2+ concentration (r2 = 0.35; P = 0.001). CONCLUSIONS: In patients with uraemia, the haemodialysis session induces a progressive increase in QT interval and modifies its relationship with heart rate. These effects may predispose some individuals to ventricular arrhythmias at the end of and immediately after the haemodialysis session.

Aged↗

PubMed2002

ANG II increases TIMP-1 expression in rat aortic smooth muscle cells in vivo.

Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) are involved in tissue remodeling processes. TIMP-1 is the main native inhibitor of MMPs and it contributes to the development of tissue fibrosis. It is known that ANG II plays a fundamental role in vascular remodeling. In this study, we investigated whether ANG II modulates TIMP-1 expression in rat aortic smooth muscle cells. In vitro, ANG II induces TIMP-1 mRNA expression in a dose-dependent manner. The maximal increase in TIMP-1 expression was present after 3 h of ANG II stimulation. The ANG II increase in TIMP-1 expression was mediated by the ANG type 1 receptors because it was blocked by losartan. The increase in TIMP-1 expression was present after the first ANG II treatment, whereas repeated treatments (3 and 5 times) did not modify TIMP-1 expression. In vivo, exogenous ANG II was administered to Sprague-Dawley rats (200 ng. kg(-1). min(-1) sc) for 6 and 25 days. Control rats received physiological saline. After treatment, systolic blood pressure was significantly higher (P < 0.01), whereas plasma renin activity was suppressed (P < 0.01), in ANG II-treated rats. ANG II increased TIMP-1 expression in the aorta of ANG II-treated rats both at the mRNA (P < 0.05) and protein levels as evaluated by Western blotting (P < 0.05) and/or immunohistochemistry. Neither histological modifications at the vascular wall nor differences in collagen content in the tunica media were present in both the ANG II- and saline-treated groups. Our data demonstrate that ANG II increases TIMP-1 expression in rat aortic smooth muscle cells. In vivo, both short- and long-term chronic ANG II treatments increase TIMP-1 expression in the rat aorta. TIMP-1 induction by ANG II in aortic smooth muscle cells occurs in the absence of histological changes at the vascular wall.

Angiotensin II↗