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Biomedical subjects

A Federici

Publications and source records attributed to A Federici.

At least 19 recordsLinked to original sources
PubMed2006

Protective effect of melatonin against mitochondrial dysfunction associated with cardiac ischemia- reperfusion: role of cardiolipin.

Reactive oxygen species (ROS) are considered an important factor in ischemia/reperfusion injury to cardiac myocytes. Mitochondrial respiration, mainly at the level of complex I and III, is an important source of ROS generation and hence a potential contributor of cardiac reperfusion injury. Appropriate antioxidant strategies could be particularly useful to limit this ROS generation and associated mitochondrial dysfunction. Melatonin has been shown to effectively protect against ischemic-reperfusion myocardial damage. The mechanism by which melatonin exerts this cardioprotective effect is not well established. In the present study we examined the effects of melatonin on various parameters of mitochondrial bioenergetics in a Langerdoff isolated perfused rat heart model. After isolation of mitochondria from control, ischemic-reperfused and melatonin-treated ischemic-reperfused rat heart, various bioenergetic parameters were evaluated such as rates of mitochondrial oxygen consumption, complex I and complex III activity, H2O2 production as well as the degree of lipid peroxidation, cardiolipin content, and cardiolipin oxidation. We found that reperfusion significantly altered all these mitochondrial parameters, while melatonin treatment had strong protective effect attenuating these alterations. This effect appears to be due, at least in part, to the preservation, by ROS attack, of the content and integrity of cardiolipin molecules which play a pivotal role in mitochondrial bioenergetics. Protection of mitochondrial dysfunction was associated with an improvement of post-ischemic hemodynamic function of the heart. Melatonin had also strong protective effect against oxidative alterations to complex I and III as well as to cardiolipin in isolated mitochondria.

Animals↗
PubMed2005

Critical comparison of nine different self-administered questionnaires for the evaluation of disability caused by low back pain.

AIM: The aim of this study was to critically compare 9 self-administered questionnaires designed to evaluate disability caused by back pain. METHODS: The questionnaires were analyzed considering and comparing their psychometric characteristics (reliability, validity, responsiveness, minimal clinically relevant difference), together with other practical and technical aspects (number of items, number and kind of domains, scaling of items, scoring, time to complete, validated translations, etc.). Data were obtained from scientific literature. RESULTS: Only 3 out of 9 analyzed instruments (i.e., the Oswestry Low Back Pain Disability Questionnaire, the Quebec Back Pain Disability Scale, and the Roland-Morris Low Back Pain Disability Questionnaire) appear fully validated from a psychometric standpoint. CONCLUSIONS: On the basis of psychometric evaluations as well as feasibility considerations, the authors suggest using either the Roland-Morris or Oswestry questionnaire as the best assessment of the level of disability caused by back pain.

Disability Evaluation↗
PubMed2003

Association between ACE inhibitors use and headache caused by nitrates among hypertensive patients: results from the Italian group of pharmacoepidemiology in the elderly (GIFA).

Treatment with ACE inhibitors has shown to be effective in the prophylaxis of migraine attacks. The aim of this study was to explore whether among hospitalized hypertensive patients use of ACE inhibitors may reduce the risk of headache caused by nitrates. To this end, we used the GIFA database, that includes patients admitted to academic medical centres throughout Italy. We studied 1537 patients (mean age 75 +/- 10 years) receiving treatment with nitrates during a hospital stay and diagnosed with hypertension. Headaches that had a probable or definite causal relation with nitrates use based on the Naranjo algorithm were considered for this analysis. Of the total enrolled sample, 762 patients (50%) used ACE inhibitors during hospital stay. Headache caused by nitrates was recorded in 12/762 (1.6%) ACE inhibitor users and in 24/775 (3.2%) other participants (P = 0.049). After adjusting for potential confounders, ACE inhibitors use was associated with a significantly lower risk of headache (OR 0.43; 95% Confidence Intervals: 0.20-0.90). This result was confirmed if ACE inhibitors use was compared with use of other antihypertensive agents (OR 0.44; 95% CI 0.20-0.95). In conclusion, this study suggests that among hypertensive subjects use of ACE inhibitors is associated with a reduced risk of headache caused by nitrates.

Aged↗
PubMed2002

Three-dimensional cultures of normal human osteoblasts: proliferation and differentiation potential in vitro and upon ectopic implantation in nude mice.

We report the establishment in vitro of three-dimensional (3D) cultures of human osteoblasts (hOB) derived from normal adults and supported uniquely by the extracellular matrix (ECM) they deposit. Osteoblasts were cultured in 3D cultures in vitro for up to 120 days. The 3D cultures, examined at 25, 31, and 48 days, expressed protein markers of osteoblastic cells, namely osteonectin, collagen type I, fibronectin, osteopontin, bone sialoprotein, biglycan, and decorin. Sequentially, alkaline phosphatase (AP) and then Ca incorporation, mineralization of matrix (monitored by histochemistry and transmission electron microscopy), and finally osteocalcin expression, were detected in the 3D cultures. Ultrastructurally, morphology progressed from early to mature osteoblast and to osteocyte-like. Cells were embedded in a matrix with organized collagen type I fibers containing, increasingly with time of culture, needle-shaped crystals, often associated with matrix vesicles, characteristic of those in bone. During the culture (up to 120 days) there was an outgrowth of proliferating osteogenic cells from the 3D structure. Subcutaneous implantation in nude mice for 20 days of osteoblasts cultured in 3D culture for different lengths of time in vitro, showed progression of mineralization from the inner region of the implant outward, with peripheral cells being embedded in nonmineralized, collagen-rich matrix. The 3D implants were invaded by vessels derived from the host.

Adult↗
PubMed2001

Effects of estrogen therapy on arterial resistance and pulsatility in postmenopausal women.

The hypothesis of this study was that changes in arterial determinants of afterload due to static muscular contraction can be modified, in postmenopausal women, by estrogen replacement therapy. Two groups of 14 postmenopausal and 15 premenopausal women were enrolled. Hemodynamic changes induced by right handgrip were recorded between days 7 and 10 of the menstrual cycle in premenopausal women. The same recordings were performed in postmenopausal women, before and after receiving transdermal estrogen replacement therapy for 8 days. Handgrip was performed at 50% of maximal voluntary contraction and maintained until exhaustion. Arterial pressure and blood velocity were recorded in the resting hand with photoplethysmographic and Doppler techniques. Indices of arterial elasticity and resistance were calculated. In postmenopausal women, these indices increased during effort only slightly less after therapy than before, if the mean values and statistical significance were considered, but the most evident effect of therapy was a decrease in interindividual differences in the effort induced changes. This means that, after therapy, increases in arterial resistance and elasticity indices were appreciably prevented mainly in those postmenopausal women who, before therapy, showed the greatest increases. Differences due to therapy were negligible in postmenopausal women in whom, before estrogen replacement, increases in elasticity and resistance indices during effort were similar to those obtained in premenopausal women. After therapy, no differences were found in resting conditions in any of the investigated cardiovascular parameters. Estrogen replacement did not appreciably affect changes in some arterial afterload-related indexes during handgrip, if the average values were considered in a group of postmenopausal women, but uneven and unpredictable peaks in individual responses were cut off, with a better predictability of the responses to sustained muscular contractions, as well as of the related risk factors.

Aged↗
PubMed2000

Tobacco smoking habits, attitudes and beliefs among nurse and medical students in Tuscany.

In this study we evaluated the smoking habits, beliefs and attitudes of nurse and medical students at the University of Siena and Florence, Italy. Students who entered the 1st year of school in 1998 were asked to complete a self-administered anonymous questionnaire. Two hundred medical students completed the questionnaire; they had a mean age (+/-SD) of 19.8+/-1.7 years and 68% were females. A total of 205 nurse respondents answered to the questionnaire; they had a mean age of 21.8+/-4.1 years and females were 83% of the total. The overall response rate among students always remained higher than 85%. Thirty per cent of medical students were current smokers, and 5% former-smokers. A total of 43% of nurse students were current smokers and 11.5% former-smokers. Nurse students were more likely to smoke than medical students (p = 0.001). Among current smokers, the number of daily cigarettes smoked and the degree of nicotine addiction did not differ between groups. The prevalence of maternal smoking were higher among nurse students. In spite of students' beliefs the knowledge about smoking remained generic in both groups. Nurse students were less aware than medical students of their special responsibility towards people about tobacco smoking. Such a difference remained significant also after adjustment for smoking status (p < 0.01). Students overestimated the prevalence of current smokers among health caregivers of the local hospitals, and Italian people and adolescents. Targeted and continuous training about smoking prevention should be mandatory in Italian medical and nurse schools.

Adolescent↗
PubMed2000

Systolic and diastolic changes in human coronary blood flow during Valsalva manoeuvre.

Valsalva manoeuvre is reported to be sometimes successful for the relief of angina pectoris. The present study investigated how haemodynamic changes produced by Valsalva manoeuvre can interact to improve the relationship between cardiac work and coronary blood flow. Ten male subjects aged 53 +/- 12 years (SD) were considered. Blood velocity in the internal mammary artery, previously anastomosed to the left descending coronary artery, was studied with Doppler technique. The subjects performed Valsalva manoeuvres by expiring into a tube connected to a mercury manometer, to develop a pressure of 40 mmHg. The arterial blood pressure curve was continuously monitored with a Finapres device from a finger of the left hand. During expiratory effort, an increase in heart rate and a decrease in arterial pulse pressure were followed by a more delayed and progressive increase in mean and diastolic pressures. Systolic blood velocity markedly decreased along with the reduction in pulse pressure and increase in heart rate. By contrast, diastolic and mean coronary blood velocities did not show any significant change. Since it is known that the Valsalva manoeuvre strongly reduces stroke volume and cardiac output, it is likely that a reduction in cardiac work also takes place. Since in diastole, i.e. when the myocardial wall is better perfused, coronary blood velocity did not show any significant reduction, it is likely that unchanged perfusion in the presence of reduced cardiac work is responsible for the relief from angina sometimes observed during Valsalva manoeuvre. It is also likely that the increase in heart rate prevents the diastolic and mean blood coronary velocity from decreasing during the expiratory strain, when an increased sympathetic discharge could cause vasoconstriction through the stimulation of the coronary alpha-receptors.

Adult↗
PubMed2000

Evaluation of haemostatic and fibrinolytic markers in patients with Cushing's syndrome and in patients with adrenal incidentaloma.

It is known that either chronic glucocorticoid administration or endogenous hypercortisolism frequently induce an hypercoagulable condition. Since little is known about the evaluation of markers of haemostatic and fibrinolytic systems in other adrenal disorders, we studied plasminogen activator inhibitor (PAI-1), tissue-plasminogen activator (t-PA), fibrinogen and von Willebrand factor antigen (vWF-Ag) levels in 11 patients with Cushing's syndrome and in 12 patients with adrenal incidentaloma. In patients with Cushing's syndrome mean PAI-1, t-PA and vWF-Ag levels did not significantly differ from those found in 50 age- and sex-matched controls, while mean fibrinogen levels were significantly higher in patients (337.0+/-39.1 mg/dl) than in normal subjects (278.9+/-8.4 mg/dl). Patients with adrenal incidentaloma showed PAI-1, t-PA and vWF-Ag mean levels superimposable to those in controls, while fibrinogen (319.7+/-27.9 mg/dl) was slightly, although not significantly, higher than in normals. Considering the limits of normal values (as mean+/-2 SD) obtained in the control group, high PAI-1 levels were found in 2 patients with Cushing's syndrome and in 3 patients with incidentaloma. An elevation of fibrinogen levels was found in 3 patients with Cushing's syndrome and in 3 with incidentaloma. Increased vWF-Ag levels were found only in 1 patient with Cushing's syndrome. An increased t-PA level was occasionally observed only in the patient with adrenal carcinoma. On the whole, an alteration of at least one of haemostatic and fibrinolytic parameters was detected in 55% of the patients with Cushing's syndrome and in 42% of those with adrenal incidentaloma. In conclusion, early alterations of coagulation and fibrinolytic systems may be found in some patients with adrenal disorders, thus suggesting the opportunity of an accurate follow-up in order to identify possible risk factors for cardiovascular disease and thromboembolism.

Adrenal Gland Neoplasms↗
PubMed1997

Changes of smoking habits and beliefs during nurse training: a longitudinal study.

This prospective cohort study has been performed to evaluate the changes in student nurses smoking habits and beliefs during their training. The source of information was an anonymous questionnaire about tobacco smoking, administered to students who entered the first year of School of Nursing in Florence in 1991-1992, 1992-1993 and 1993-1994. Five hundred and thirty-six (95%) of these student nurses completed the questionnaire. Five hundred and one (93%) of these 536 respondents completed the questionnaire again at the end of the third (final) year of training. Student nurses who smoked increased the average number of cigarettes smoked per day (p < 0.01) and the degree of dependence to nicotine (p < 0.01). Tobacco smoking remained widespread and the percentage of ex-smokers who started smoking again increased (p < 0.05). The knowledge about the health hazards due to tobacco smoking remained generic and the prevalence of current smokers among student nurses and health care workers was overestimated. We conclude that Nursing School does not succeed in reducing the smoking habits of students. Effective antitobacco strategies and smoking cessation services still need be organized in Italy.

Adolescent↗
PubMed1996

Integrin synthesis and utilization in cultured human osteoblasts.

This study describes the adhesion of human osteoblasts, cultured in vitro, to proteins of the extracellular matrix, the biosynthesis of integrins, their topography and organization in focal contacts. The adhesion of osteoblasts to laminin, type I collagen, vitronectin and fibronectin was 77-100%, in 2 h and at 55 nM substrata concentration, and it was accompanied by spreading of the cells. Adhesion to fibronectin (FN), laminin (LN) and type I collagen (COL) was inhibited by antibodies to the beta 1 integrin and antibodies to the alpha 5 chain affected adhesion only to fibronectin. Using a panel of polyclonal antibodies against alpha 2, alpha 3, alpha 5, alpha v, beta 1 and beta 3 integrins we detected synthesis of alpha 3 beta 1, alpha 5 beta 1, alpha v beta 3, and an alpha v beta 1-like dimer by immunoprecipitation of metabolically labelled cell lysates. Studies of immunolocalization demonstrated the presence of the same integrins identified in lysates, plus alpha 4, alpha 1 and beta 5 subunits. In cells adhering in the presence of serum we showed organization of beta 3 and alpha v integrins in focal contacts. In cells adhering to fibronectin alpha 5 and beta 1 integrins were localized in focal contacts. In cells spread on laminin or type I collagen none of the integrins investigated was localized in focal contacts.

Adult↗
PubMed1996

Results of a questionnaire about nurse students' smoking habits and knowledges in an Italian teaching school of nursing.

Six-hundred and sixty-two nurse students (aged 25.2 +/- 4.11 years; 153 were males) answered a self-administered, anonymous questionnaire about smoking habits and knowledges in a large urban Teaching School of Nursing. The overall response rate was 88%. Current smokers were 336 (51%), former smokers 80 (12%). Nurse students claimed to know the dangers of tobacco and nurse training seemed to modify the preferential source of information about tobacco smoking towards medical fonts; however, only a quarter of nurse students considered medical smoking cessation approaches as useful for quitting and advised patients with tobacco-related diseases against smoking.

Adult↗
PubMed1995

[Extracorporeal lithotripsy in patients with acquired or congenital coagulopathies].

Post ESWL haemorragic complications are frequent and most patients experience temporary haematuria and focal intrarenal bleeding or perirenal haematoma are detected by NMR or US imaging. By tradition coagulation troubles have been a contraindication for ESWL but literature describes cases of coagulopathic patients treated with ESWL. From January 1992 to July 1993, 4 of our patients with severe haemostatis troubles (severe haemophilia A in two cases, acquired deficit of coagulation factors and mild thrombocytopenia secondary to post-necrotic hepatitis in 1 case and Glanzmann's thrombasthenia in 1 case) underwent ESWL using Dornier HM3 mod. or MPL 9000. An extensive haematological and clinical evaluation pre and post-ESWL with an adequate haematological prophylaxis (transfusion of blood derivatives) has been performed depending on the coagulation disorder. In our patients we did not observe any haemorragic complication and we propose a reappraisal of the contraindications of ESWL in subjects with coagulation disorders: careful evaluation of haemorragic risk factors, by suitable correction measures and close clinical and instrumental monitoring, allows a reduction of the risk of haemorragic complications in coagulopathic patients who undergo ESWL treatment.

Adult↗
PubMed1993

Differential expression of alkaline phosphatase in clones of human osteoblast-like cells.

We established cultures of cells growing out from adult bone chips and maintained them through 12 passages in culture. The cultures showed osteoblastic phenotype accompanied by synthesis of collagen type I, osteonectin, alkaline phosphatase, and osteocalcin. We report the characterization of 21 clones obtained from three different individual primary cultures. We studied the expression of osteonectin, alkaline phosphatase, collagen, and osteocalcin in the clones. Metabolic labeling showed production of type I collagen and of osteonectin in all clones studied. In two-thirds of the clones and in mass cultures alkaline phosphatase was not detected at passage 2, but it was detected in increasing amounts at later passages in culture. The clones attained different but detectable levels of expression of this marker by passage 8. The different levels in the expression of alkaline phosphatase in positive clones may be because they were derived from cells at different stages of osteoblastic maturation or due to small changes in microenvironment. The alkaline phosphatase-positive clones were tested for osteocalcin, and they showed measurable expression only at passage 10. A third of the clones obtained were negative for alkaline phosphatase during 12 passages in culture. The obtainment of clones unable to produce alkaline phosphatase may be due to loss of differentiating potential under the in vitro culture conditions. The growth rate and potential of all clones studied were similar through 12 passages in culture, regardless of their potential for expression of alkaline phosphatase.

Adult↗
PubMed1993

Tachycardia and coronary blood flow: non-invasive estimation during Valsalva manoeuvre and exercise.

Simultaneous changes in cycle length and coronary blood flow were studied during Valsalva manoeuvre and supine cycloergometer exercise test in 10 male patients (mean age 48 +/- 12 years) who had successfully undergone myocardial revascularization by surgical anastomosis of the left internal mammary artery on the left anterior descending coronary artery. Blood velocity curves in the left internal mammary artery were obtained by a non-invasive continuous-wave Doppler probe at rest, in the last phase of the expiratory effort of the Valsalva manoeuvre and at the maximum load attained during the exercise test. Mean arterial pressure by sphygmomanometer, and cardiac cycle length on the basis of Doppler recording were measured. Mean blood velocity, the length of the blood column entering the coronary bed at each cycle (cardiac cycle times mean velocity), an index of blood cell acceleration (the ratio of mean velocity to cardiac cycle), and an index of coronary resistance (the ratio of mean pressure to mean velocity), were calculated. For approximately the same change in cycle length, coronary resistance decreased in exercise, with an increased mean velocity, but increased in Valsalva, with no changes in mean velocity. The length of the blood column entering the coronary bed at each cycle was unchanged in exercise, with a marked increase in the acceleration index, while it decreased in Valsalva. Therefore, we hypothesize that tachycardia has a limiting effect on sympathetic coronary constriction in Valsalva when cardiac external work is decreased, and an additional vasodilatory effect on coronary bed in exercise when external work is increased.

Adult↗
PubMed1993

[The noninvasive assessment of coronary flow during isometric exercise by Doppler ultrasonography of the internal mammary artery anastomosed to the left coronary].

Isometric contraction of small group of muscles is believed to increase heart rate and contractility and arterial pressure without significant changes in systemic arterial resistance. Such a manoeuvre has been employed in this work to study dynamic changes induced in blood flow into coronary bed, in subjects in which an anastomosis of the internal mammary artery to anterior descending coronary artery was performed. Ten patients with no clinical signs of myocardial ischaemia at rest and during exercise, were requested to perform an endurance left handgrip manoeuvre, at 50% of maximal voluntary contraction. Doppler blood velocity curve in the anastomosed mammary artery; non-invasive blood pressure curve at a finger of the right hand by Finapres; the electrocardiogram, were recorded. A significative increase in heart rate and mean and diastolic blood pressure was found. Blood flow significantly increased, approximately in the same percentage as double product was increased. A calculated index of coronary resistance did not show significant changes. In this group of patients, the handgrip manoeuvre may display the ability of the cardiac pump to match its metabolic needs due to increased pressure load, by employing the same developed pressure load as an adequate coronary perfusion pressure. It is suggested to employ this simple test in the routine monitoring of patients with internal mammary artery bypass grafts.

Aged↗
PubMed1993

The closed treatment of severe malleolar fractures.

The authors studied, with clinical and radiological criteria the results of closed treatment (reduction by manipulation and immobilization in a plaster cast for 7 or 8 weeks) of severe displaced malleolar fractures. Of 145 patients who had suffered an ankle fracture and were treated with closed methods between 1979 and 1989, 78 were reviewed, with an average follow-up of 6.2 years. The main difficulties of closed treatment concerned reduction of the fractures; anatomical reduction was achieved only in 32.4% of the cases, and deterioration of the position achieved often occurred (26.2%). Although some joints healed in a fair position, subjective and objective late results were excellent or good in 77% of the cases, fair in 20.5% and poor in 2.6%. The most common clinical outcome was a slight decrease of the range of motion in the injured ankle, which was found in 68% of the cases. Arthritis developed in 28.2% of the reviewed ankles, both after an initial good reduction as well as after an initial poor reduction. A complete failure of closed treatment occurred in 8.3% of the cases, caused by an interpositioning of soft tissues among bone fragments leading to unsuccessful manipulation or by late deterioration of the initial position of reduction causing healing of the fracture in a poor position (severe talar shift).

Adolescent↗
PubMed1993

Long-term results of cemented and screwed acetabular components.

The authors report their experience in the use of various types of acetabular components (cemented and screwed) in 253 hip prostheses with "Biodirect" femoral component and ceramic femoral head. A long-term follow-up of 148 hip prostheses (58.5% of the total) was carried out, 36 Müller type polyethylene and 61 Biolox ceramic acetabular components, and 51 screwed sockets of various models were used. From a clinical and radiographical standpoint, the ceramic acetabular component proved the most valid in the short and medium term, confirming the favourable biomechanical conditions which derive from ceramic/ceramic coupling.

Acetabulum↗