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Biomedical subjects

G F Gensini

Publications and source records attributed to G F Gensini.

At least 19 recordsLinked to original sources

Microheterogeneity in the distribution of the 844ins68 in the cystathionine beta-synthase gene in Italy.

Cystathionine beta-synthase (CBS) is an important enzyme for methionine metabolism. A common 844ins68 insertion variant in the CBS gene has been described. This 68-bp duplication of the intron 7-exon 8 boundary within the CBS gene already has been reported to be associated in cis with the T833C mutation. Heterozygosity for CBS deficiency is considered an important cause of hyperhomocysteinemia that strongly relates to cardiovascular disease, as well as homozygosity for another common variant, the C677T mutation of 5,10-methylene tetrahydrofolate reductase. We analysed the prevalence of the 844ins68 variant in the CBS gene in 595 unrelated apparently healthy individuals from nine Italian regions and in 133 patients with coronary artery disease. Our data confirm that the T833C mutation cosegregates in cis with the 844ins68 in all carriers of the insertion. Furthermore, no statistical difference was found in the insertion variant allele frequency between controls and coronary artery disease patients. Our study indicates a microheterogeneity in the distribution of the 844ins68 in the Italian population.

Cystathionine beta-Synthase

World distribution of the T833C/844INS68 CBS in cis double mutation: a reliable anthropological marker.

Mild hyperhomocysteinemia is associated to mutations either in cystathionine beta-synthase (CBS) or in 5,10-methylenetetrahydrofolate reductase (MTHFR) genes. In 1995, Sebastio et al. characterized a 68 bp insertion in cis with the most common CBS mutation (T833C) detected in homocystinuric patients. Recently, this double mutation has been detected in Italian and North-American controls. Compared to a group of patients affected by coronary artery disease, North-American controls showed not statistically significant difference. Moreover, Italian controls displayed a microheterogeneity in the mutant allele frequency distribution depending on their geographical origin (North or South of Italy). Aim of our study was to evaluate the prevalence of the double in cis mutation in different populations. We studied 377 healthy subjects belonging to various human groups. Genomic DNA, extracted from peripheral blood samples, was amplified using specific primers; PCR fragments were digested with Bsr I restriction enzyme to detect the double mutation. Our data show a significant heterogeneity among the populations studied, therefore this mutation turned out to be a reliable anthropogenetic marker. The distribution of the double mutation will contribute, with other DNA polymorphisms, to evaluate the genetic admixture of mixed populations such as Afro-Americans.

Alleles

Interatrial septum pacing: a new approach to prevent recurrent atrial fibrillation.

BACKGROUND: There are a variety of approaches to the prevention of atrial fibrillation (AF) with pacing. Aim of this study was to test the safety and feasibility of interatrial septum pacing at the posterior triangle of Koch for AF prevention and to exclude potential arrhythmic effects. MATERIAL AND METHODS: Interatrial septum pacing was performed in 34 patients (21 males, 13 females, mean age 69 +/- 12 years): 9 without a history and clinical evidence of atrial fibrillation (AF) (6 with sinus bradycardia, 2 with second-degree AV block, and 1 with carotid sinus hypersensitivity) and 25 with sinus bradycardia and paroxysmal atrial fibrillation (PAF) (mean symptomatic episodes/month 6.2 +/- 10). In all patients a screw-in bipolar lead was positioned in the interatrial septum superiorly to the coronary sinus. RESULTS: At implant the mean P wave amplitude was 2.5 +/- 1.5 mV, the pacing threshold was 1 +/- 0.6 V and the impedance was 907 +/- 477 Ohm. Mean P wave duration was 118 +/- 17 ms in sinus rhythm and 82 +/- 15 during interatrial septum pacing (p < 0.001). During a mean follow-up period of 10 +/- 7 months, no patients without atrial tachyarrhythmias before implantation experienced AF. During a 9 +/- 6 months follow-up we observed only 2 symptomatic arrhythmia recurrences between AF patients (mean symptomatic episodes/month 0.006 +/- 0.0022) (p < 0.01 vs before implant period). CONCLUSIONS: Our data indicate that interatrial septal pacing is safe and feasible. A significant less incidence of arrhythmic episodes has been observed during follow-up. Further controlled randomized prospective studies are necessary to establish the exact role of this technique respect to conventional or multisite stimulation when patients with paroxysmal AF need to be permanently paced.

Adult

Acquired activated protein C resistance in postmenopausal women is dependent on factor VIII:c levels.

Activated protein C (APC) resistance is an established risk factor for venous thromboembolism. In 5% to 10% of patients with venous thromboembolism, the APC resistance phenotype is observed in the absence of factor V Leiden mutation. Moreover, some physiologic and pathologic conditions are associated with an "acquired" APC resistance, not caused by the Leiden mutation, such as inflammatory diseases, pregnancy, or oral contraceptive therapy. Several studies have demonstrated the effect of menopause on the hemostatic system, but no data are available about APC resistance. We found a high prevalence of APC resistance in postmenopausal women, not associated with factor V Leiden mutation. The mechanism that underlies this acquired APC resistance may be related to the higher levels of factor VIII, which showed a strong inverse correlation with APC resistance, whereas no correlation was found between the normalized APC ratio, factor V levels, and protein S values. Higher levels of factor VIII correlated with a marker of coagulation activation, such as prothrombin fragments 1 plus 2. Therefore, to identify women receiving hormone replacement therapy who have a greater risk for deep venous thrombosis, the APC resistance coagulation test should be used instead of the genetic study.

Activated Protein C Resistance

Peripheral vascular resistance limits exercise functional capacity of mild hypertensives.

To evaluate the physiological basis for suboptimal peak exercise oxygen consumption (VO2p) observed in the early stage of hypertension, 25 WHO Stage I hypertensive men with normal left ventricular mass and 10 healthy control subjects of equivalent age underwent the maximal cardiopulmonary exercise test with contemporary measurement of cardiac output with Tc99m angiocardiography. At peak exercise hypertensive patients had lower VO2p (p < 0.045) and cardiac output (p < 0.014) and higher vascular resistance (p < 0.010) than controls. At multiple regression analysis VO2 was positively related to cardiac output in controls (r = 0.80, p < 0.02), whereas in hypertensives the best (negative) correlation was observed with peripheral vascular resistance (r = -0.72, p < 0.04). Thus reduced cardiopulmonary function during physical exercise in hypertensives seems to be mainly related to impaired peripheral vascular autoregulation.

Adult

Partial anomalous venous return associated with intact atrial septum and persistent left superior vena cava: a case report and literature review.

Left-sided partial anomalous pulmonary venous return (PAPVR) with an intact atrial septum is a rare cardiovascular anomaly. This report deals with the case of a 22-year-old woman who was referred to our Institution because of resting palpitation and exertional dyspnea. Two-dimensional echocardiography revealed right heart volume overload and a dilated coronary sinus. A left-sided PAPVR draining into a persistent left superior vena cava which, in turn, entered a dilated coronary sinus, was correctly detected by magnetic resonance imaging. Diagnosis was confirmed by cardiac catheterization. The literature on this subject is reviewed.

Adult

[An economic assessment of the use of abciximab as a coronary angioplasty preparation in the Italian health-care context].

UNLABELLED: Drugs blocking platelet glycoprotein IIb/IIIa receptors (anti-GP IIb/IIIa) have been used effectively to prevent thrombotic events after percutaneous transluminal coronary angioplasty (PTCA). However, the high cost of these drugs calls for an economic evaluation before they can be used systematically within the context of the Italian health-care system. METHODS: The systematic review of three studies (EPIC, EPILOG, CAPTURE) that evaluated the effectiveness of abciximab (the only anti-GP IIb/IIIa drug commercially available in Italy) demonstrated that this drug can prevent thrombotic events (death, myocardial infarction, repeated PTCA, bypass surgery) at six months after PTCA (RR 0.84; IC 95% 0.77-0.91; number needed to treat for the composite end-point 21). We performed an economic evaluation of the use of abciximab, taking into account the cost the drug (2,561,100 Italian lire [ITL]/patient) and the number of events prevented. We calculated the mean cost-effectiveness ratio (cost of each patient without events at six months after PTCA), the incremental cost-effectiveness ratio (cost of each event prevented at six months after PTCA) and the cost of each year of life saved at six months after PTCA. RESULTS: The mean cost-effectiveness ratio was 16.6 million ITL/patient (versus 15.4 million ITL/patient without the use of the drug); the incremental cost-effectiveness ratio was 34.3 million ITL/event prevented; the cost of each year of life saved was 32.3 million ITL. CONCLUSIONS: With abciximab preventing thrombotic events at six months after PTCA, the cost of each patient without events and the cost of each event prevented at six months are within the range of other pharmaceutical procedures in cardiology (e.g. thrombolysis in acute myocardial infarction with tissue plasminogen activator). Our analysis supports the case for the systematic use of abciximab in patients undergoing PTCA.

Abciximab

Tissue factor reduction and tissue factor pathway inhibitor release after heparin administration.

Elevated plasma levels of tissue factor (TF) and tissue factor pathway inhibitor (TFPI) and large amounts of monocyte procoagulant activity (PCA) have been documented in unstable angina (UA) patients. In in vitro experiments heparin is able to blunt monocyte TF production by inhibiting TF and cytokine gene expression by stimulated cells and after in vivo administration it reduces adverse ischemic outcomes in UA patients. TF and TFPI plasma levels and monocyte PCA have been investigated in 28 refractory UA patients before and during anticoagulant subcutaneous heparin administration (thrice daily weight- and PTT-adjusted for 3 days) followed by 5000 IU X 3 for 5 days. After 2-day treatment, immediately prior to the heparin injection, TF and TFPI plasma levels [(median and range): 239 pg/ml, 130-385 pg/ ml and 120 ng/ml, 80-287 ng/ml] were lower in comparison to baseline samples (254.5 pg/ml, 134.6-380 pg/ml and 135.5 ng/ml, 74-306 ng/ml). Four h after the heparin injection TF furtherly decreased (176.5 pg/ml, 87.5-321 pg/ml; -32.5%. p<0.001) and TFPI increased (240.5 ng/ml, 140-450 ng/ml; +67%, p<0.0001). After 7-day treatment, before the injection of heparin, TF and TFPI plasma levels (200 pg/ml, 128-325 pg/ml and 115 ng/ml, 70-252 ng/ml) significantly decreased (p<0.05) in comparison to the pre-treatment values. On the morning of the 8th day, 4 h after the injection of heparin TF plasma levels and monocytes PCA significantly decreased (156.5 pg/ml, 74-259 pg/ml and from 180 U/105 monocytes, 109-582 U/10(5) monocytes to 86.1 U/10(5) monocytes, 28-320 U/10(5) monocytes; - 38% and -55% respectively) and TFPI increased (235.6 ng/ml, 152-423 ng/ ml; +70%, p<0.001). In conclusion, heparin treatment is associated with a decrease of high TF plasma levels and monocyte procoagulant activity in UA patients. These actions of heparin may play a role in determining the antithrombotic and antiinflammatory properties of this drug.

Adult

Role of platelet glycoprotein PL(A1/A2) polymorphism in restenosis after percutaneous transluminal coronary angioplasty.

This study suggests a macroheterogeneity in prevalence of platelet glycoprotein PL(A1/A2) polymorphism in different ethnic populations. In patients undergoing percutaneous transluminal coronary angioplasty, this polymorphism does not represent an independent risk factor but seems to be implicated in restenosis after percutaneous transluminal coronary angioplasty.

Adult

Effect of medium-term supplementation with a moderate dose of n-3 polyunsaturated fatty acids on blood pressure in mild hypertensive patients.

Several studies have shown that n-3 polyunsaturated fatty acids (n-3 PUFA) are able to lower blood pressure (BP) in humans, but large doses of fish oils have been often used. Moreover, most of the studies available in the literature were not able to evaluate the specific effects of n-3 PUFA because they employed fish oils which contain, together with n-3 PUFA, many other different components. The aim of this preliminary study was to evaluate if medium-term supplementation with a moderate dose of highly purified eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) ethyl esters is able to reduce BP in mild hypertensive patients. Sixteen mild essential hypertensive (diastolic BP: 95-104 mm Hg), non-diabetic, normolipidemic male outpatients and 16 normotensive male controls were recruited to participate in the study. Both hypertensive and control subjects were randomly assigned to receive either EPA and DHA ethyl esters (2.04 g EPA and 1.4 g DHA) as active treatment or olive oil (4 g/day) as a placebo for a period of 4 months. These subjects were followed up with 24-hour ambulatory BP monitoring and blood chemistry analyses at 2 and 4 months of treatment and 2 months after its discontinuation. The intake of n-3 PUFA was checked by red blood cell (RBC) phosphatidylcholine (PC) fatty acid composition. The effect of n-3 PUFA on BP in the active group was maximum after 2 months. Both systolic (-6 mm Hg, p<0.05) and diastolic (-5 mm Hg, p<0.05) BP significantly decreased during the n-3 PUFA ethyl ester supplementation. No further effect was observed at 4 months with a return to baseline values during the recovery period. These data indicate that 4 g/day of highly purified EPA + DHA ethyl esters are able to favorably affect BP in mild hypertensives.

Adult

Evaluation of clotting and fibrinolytic activation after protracted physical exercise.

The behavior of hemostatic system activation during protracted physical exercise is well known, but the duration of its modification is not yet defined. In order to evaluate the time of hemostatic system activation after prolonged strenuous endurance physical exercise (typical marathon race: 42.195 km, v=15.35 km/h; mean length of time run 2.45+/-0.15 hours) 12 well-trained long-distance male runners (mean age: 35+/-7, range 25-47 years) were investigated. Blood samples were drawn in the morning on the day before the performance, immediately after the race, and 24 hours and 48 hours after the end of run. With respect of baseline, immediately after the race, a significant decrease of fibrinogen (-25%) and significant increases of prothrombin fragment 1+2 (+633%) and thrombin-antithrombin complex (+848%) were observed. A significant acceleration of euglobulin lysis time (-41%), and rises of plasma levels of tissue plasminogen activator antigen (+361%), plasminogen activator inhibitor type 1 antigen (+235%), d-dimer (+215%), and plasma fibrinogen degradation products (+1200%) were also found. Only a slight, yet not significant, decrease in plasminogen activator inhibitor type 1 activity was observed. One day after the end of marathon different parameters were still unchanged. Forty-eight hours after the competition all parameters investigated returned to baseline values. These results indicate a persistence of clotting as well as fibrinolysis activation up to 24 hours after the end of the race.

Adult

Effect of low-dose heparin on fibrinogen levels in patients with chronic ischemic heart disease.

Several prospective studies have demonstrated that high plasma fibrinogen levels are associated with an increased risk of ischemic heart disease. Since in most patients an increased thrombin generation has been reported, we investigated whether the control of thrombin generation could affect plasma fibrinogen levels. Forty male outpatients (20 asymptomatic with previous myocardial infarction and 20 with stable effort angina) were enrolled in a randomized medium-term (6 months) cross-over study. Clottable fibrinogen, according to Clauss, prothrombin fragment 1 + 2, thrombin-antithrombin complex, and fibrinopeptide A were evaluated in relation to treatment with low-dose heparin. After a 15-day wash-out period, during which patients had been treated only with nitrates if needed, patients were allocated to two sequential periods of treatment with standard heparin (12,500 U, subcutaneously daily) plus antianginal treatment or antianginal treatment alone, separated by a second 15-day wash-out period. At the end of the treatment period with low-dose heparin significant decreases in the plasma fibrinogen (2.5 +/- 0.6 g/l vs. 3.3 +/- 0.5 g/l, P < 0.001), prothrombin fragment 1 + 2 (1.4 +/- 0.5 nmol/l vs. 1.9 +/- 0.7 nmol/l, P < 0.001), thrombinantithrombin (4.5 +/- 2.4 ng/ml vs. 9.7 +/- 3.6 ng/ml, P < 0.001), and fibrinopeptide A (2.1 +/- 1.1 ng/ml vs. 3.5 +/- 2.1 ng/ml, P < 0.001) were observed compared with the period without heparin. The present results indicate that low-dose heparin can effectively control the increased abnormal thrombin generation and elevated fibrinogen levels in patients with ischemic heart disease, possibly decreasing the risk of cardiovascular death.

Aged

Cardiac troponin I and Q-wave perioperative myocardial infarction after coronary artery bypass surgery.

OBJECTIVE: To monitor cardiac troponin I (cTnI), a newly developed biochemical index for cardiac damage, in patients during and after coronary artery bypass surgery (CABS) to determine whether the measurement of the serum levels of this marker could be of value in formulating an early diagnosis of Q-wave perioperative myocardial infarction (PMI). DESIGN: Prospective study with sequential measurements of biological markers in a selected surgical patient group. SETTING: University research laboratory and general university hospital (Cardiac Surgery Unit and Anesthesiology and Reanimation Unit). PATIENTS: Forty-two patients undergoing elective CABS without concomitant valvular replacement. INTERVENTIONS: There were no interventions required for this study. However, patients entered into the study had CABS, sequential arterial blood samples, ECG recordings, and echocardiograms performed. MEASUREMENTS AND MAIN RESULTS: Pre-, intra-, and postoperative (up to 48 hrs) measurements of cardiac troponin I, MB-CK, and total creatine kinase, as well as serial electrocardiograms and echocardiograms. Perioperative infarction was assessed as the development of new persistent regional wall motion abnormalities in echocardiography together with electrocardiographic alterations and MB-CK increases. Eight patients had Q-wave PMI. All PMI patients had elevated peak cTnI values (all >9.2 ng/mL), whereas the 34 nonPMI patients had peak values <9.0 ng/mL; therefore, sensitivity and specificity (with a 9.0 ng/mL cut-off value) are 100%. MB-CK measurement peak values did not demonstrate such a high specificity and sensitivity. CONCLUSIONS: Because of its high specificity and sensitivity, serial measurements of cTnI provide a rapid and accurate method for confirming or excluding the diagnosis of perioperative myocardial injury. cTnI evaluation can therefore be used both as an independent prognostic marker for patients undergoing cardiac surgery and as a powerful tool for detecting smaller PMIs often missed with standard PMI diagnostic criteria.

Aged

Doppler echocardiography in suspected lone atrial fibrillation.

Echocardiography is frequently required in patients with atrial fibrillation (AF) to exclude underlying heart disease. In the present investigation the authors evaluated 56 patients with paroxysmal AF (PAF) (27 men, 29 women, mean age 54+/-11.3 years) in whom lone AF was suspected on clinical grounds. M-mode, B-mode, and Doppler examination were performed and measurements taken according to American Society of Echocardiography criteria. Left atrial diameter, left and right atrial volumes, left ventricular (LV) diameters, LV fractional shortening, and Doppler indexes of LV diastolic function were not different in patients with PAF in comparison with those of a control group of 56 age-matched subjects free from cardiovascular diseases. Echocardiographic examination results were entirely normal in 32/56 patients (57%) vs 39/56 of the control group (69%). Mitral valve prolapse was found in five patients (9%), but only one showed mild mitral regurgitation. Doppler examination disclosed a mild (+/++) mitral regurgitation in eight patients and a small aortic or pulmonary diastolic flow in four and two patients, respectively, in the absence of significant morphologic valvular abnormalities. In these patients the sizes of heart chambers were entirely normal. Aneurysm of the interatrial septum was found in one patient and an increased thickness of the epipericardial junction in another two patients. Finally two patients had a small increase of right atrial volume without demonstrable causes. The results suggest that lone AF can be correctly suspected on the basis of clinical findings (history, physical examination, and ECG) and that in these patients echocardiography rarely discloses organic heart disease.

Atrial Fibrillation

Treatment options for acute venous thromboembolism in the older patient.

The incidence of deep venous thrombosis and pulmonary embolism increases exponentially with age. This pattern reflects the age-related increase in the frequency of serious medical diseases that require prolonged bed rest and predispose to the activation of hemostatic processes. Treatment with heparin and thrombolytic agents is clearly effective in patients age 65 and older, even though an elevated susceptibility to hemorrhagic complications has been demonstrated. Careful evaluation of individual hemorrhagic risk, a slight decrease of doses, and careful laboratory monitoring may decrease the number of clinically significant bleedings without impairing therapeutic results. Low-molecular weight heparin may represent a major advance in the treatment of thromboembolic disease, but studies that specifically address its use in older patients are needed.

Acute Disease