PubMed Health⌕ Search

Biomedical subjects

F Monti

Publications and source records attributed to F Monti.

At least 55 records · Page 3Linked to original sources
PubMed1994

Hypocaloric high-protein diet improves glucose oxidation and spares lean body mass: comparison to hypocaloric high-carbohydrate diet.

The aim of the study was to investigate the effects of two hypocaloric (800-kcal) diets on body weight reduction and composition, insulin sensitivity, and proteolysis in 25 normal glucose-tolerant obese women. The two diets had the following composition: 45% protein, 35% carbohydrate (CHO), and 20% fat (HP diet, 10 subjects), and 60% CHO, 20% protein, and 20% fat (HC diet, 15 subjects); both lasted 21 days. A euglycemic hyperinsulinemic (25 mU/kg/h) clamp lasting 150 minutes combined with indirect calorimetry was performed before and after the diet. Both diets induced a similar decrease in body weight and fat mass (FM), whereas fat-free mass (FFM) decreased only after the HC diet. 3-Methylhistidine (3-CH3-HIS) excretion was reduced by 48% after the HP diet and remained unchanged after the HC diet (P < .05). A significant correlation was found between the changes in FFM and in 3-CH3-HIS excretion after the diet (rs = .50, P < .02). Blood glucose remained unchanged, while insulin decreased in both diets. Free fatty acids (FFA) significantly increased only after the HC diet (P < .05). During the clamp period, glucose disposal and glucose oxidation significantly increased after the HP diet and significantly decreased after the HC diet. Opposite results were found when measuring lipid oxidation. In conclusion, our experience suggests that (1) a hypocaloric diet providing a high percentage of natural protein can improve insulin sensitivity; and (2) conversely, a hypocaloric high-polysaccharide-CHO diet decreases insulin sensitivity and is unable to spare muscle tissue.

Adult↗
PubMed1994

Synergism between gamma interferon and doxorubicin in a human MDR colon adenocarcinoma cell line.

Recent interest in cancer therapy derives from the ability of interferons to synergistically increase the activity of chemotherapeutic agents. To understand the biological basis of this synergism we evaluated the effects of human recombinant IFN-gamma on the expression of the mdr1 gene and on the cellular growth of a human colon adenocarcinoma cell line (LoVo) and its MDR subline (LoVo/Dx) after coincubation with doxorubicin. Treatment with IFN-gamma showed unchanged levels of MDR1-glycoprotein, no perturbation on cell cycle distribution and a significant reduction of colony formation in both lines (P < 0.05) starting from 100 U/ml. A synergistic effect was observed in the LoVo/Dx cell line when doxorubicin was added after exposure to 0.1-10 U/ml of IFN-gamma. Our data indicate that the effects of IFN-gamma, independent from action on cell proliferation and from modulation of p-glycoprotein expression, are a cause of the synergistic activity between this lymphokine and conventional chemotherapeutic agents such as doxorubicin.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1994

Pretreatment with the adenosine triphosphate-sensitive potassium channel opener nicorandil and improved myocardial protection during high-potassium cardioplegic hypoxia.

We hypothesized that pretreatment with the potassium channel opener nicorandil might enhance myocardial protection achieved by cold (20 degrees C) high-potassium (16 mmol/L) cardioplegia (5 ml/min) during long-duration (120 minutes) myocardial hypoxia (average oxygen content 5.4 ml/dl). We tested a 15-minute infusion of nicorandil (1 mmol/L) given only before (group A, n = 8) or before and during cardioplegia (group B, n = 8) in guinea pig papillary muscle preparations contracting isometrically while stimulated (4 mA, 2 msec) at 1600 msec cycle length. Nicorandil was significantly negative inotropic before cardioplegia and shortened significantly action potential duration. During cardioplegia, time to arrest of contraction was shortened from 145 +/- 28 seconds (mean +/- standard error) in the vehicle group (dimethyl sulfoxide 1:100; n = 8) to 56 +/- 10 seconds (p < 0.02) and 68 +/- 5 seconds (p < 0.05) in groups A and B, respectively. Recovery of developed tension at 60 minutes of normothermic reoxygenation (expressed as percent of prehypoxia basal value) was ameliorated from 54% +/- 6% (vehicle group) to 92% +/- 4% (group A, p < 0.01) and to 119% +/- 19% (group B, p < 0.01). The specific potassium channel blocker glibenclamide (glib: 1 mumol/L, n = 8) prolonged action potential duration and was without effect on time to arrest. On reoxygenation, the glib group had prolonged time to half relaxation (versus group A, p < 0.02) and the worst percent developed tension at 60 minutes (40% +/- 4%). In the overall study, time to arrest and percent developed tension at 60 minutes were inversely correlated (r = -0.45, p < 0.01). Arrhythmias were never observed. Multivariate analysis showed that pretreatment with nicorandil (with or without drug adjunct to cardioplegic solution) was a significant factor (r2 = 0.65, p = 0.0001) to influence reoxygenation-mediated recovery of mechanical function. Neither the negative inotropic effect of nicorandil before cardioplegia nor its abbreviating action on time to arrest during cardioplegia was contributory to explain recovery of function on reoxygenation. In subgroup analysis, negative inotropism and the shortening of action potential duration were contributory factors. These data suggest that nicorandil pretreatment activates potassium channels and enhances the myocardial protection provided by cold cardioplegia an effect, which is evident after a long hypoxic period, late on reoxygenation.

Action Potentials↗
PubMed1993

Patterns of Pap smear use in the Rimini area: an analysis of women's attitudes to the test.

The use of the Pap test is a method of the prevention of cervical cancer in our local division of the Sanitary Unit and has been studied with the help of a questionnaire which was completed by women who had adopted this test. The socioeconomic characteristics, level of education, occupation and general attitudes regarding the Pap test as well as how the women had acquired knowledge of the test, have all been examined. From an analysis of the answers, we have been able to trace a precise social, economic and cultural profile of the type of women who take advantage of this test. Principally, we are dealing with women aged 40-49 years, often with children, with a medium to low level of education, who are mainly housewives and white-collar workers. Very few elderly women present themselves for the Pap test. We have noticed that there is a direct decrease in the use of preventive methods, proportional to the increase in age. These results demonstrate that an erratic use of this preventive method, in the absence of an organized screening programme, seems only to involve women who are among those at less risk from cervical cancer.

Adult↗
PubMed1992

[The inotropic and bathmotropic effects of beta stimulation: a study comparing dobutamine and dopamine on the guinea-pig papillary muscle in isotonic contraction].

The study was aimed at comparing the effects of dobutamine (dob) and dopamine (dop) on isotonic contraction and rhythmicity of isolated guinea-pig papillary muscles (in oxygenated Tyrode at 37 degrees C), by taking into account: 1) the rate of stimulation (50% above the diastolic threshold) at 5 fixed periods: (RR: 1600, 1200, 1000, 800 and 400 ms); 2) 7 log concentrations (logC) of the index amine (from 10(-9) to 10(-3) M). To this end, a dose-relation protocol which explored the effects of all 5 RR and 7 logC was designed and 15 adult female Guinea-pigs (250 to 350 g) were randomized to either the dob (n = 8) or the dop (n = 7) arm. This enabled a total of 525 sets of data to be analyzed: in 38 sets (7.2%) premature contractions (CP) were coded. CP were sustained (freq: > 3) in 25 of these latter 38 sets (4.8%). Compared to the basal state, the amplitude (AMP%) and the log of percent amplitude (logAMP%) and time to peak (TP%) changes of the isotonic (Gould transducer) twitch were calculated along with the log of this latter variable (logTP%). AMP%, log AMP%, TP% and logTP% were linearly correlated with logC at all RR. In the range 1600-400 RR, for both amines, significant linear correlations (magnitude of 0.15 > r < magnitude of 0.70, 0.001 > p < 0.022) were seen for plots of AMP%, logAMP% and TP%:steeper correlations were observed for dop. This was confirmed in multivariate analysis (BMDP-9R) whereby AMP%, logAMP%, TP%, logTP%, CP, and freqCP were dependent variables and coded variables were included to either define the type of treatment (dop versus dob) or logC. In these analyses, logC (t > 11) and dop (t > magnitude of 3) might be used to explain (0.28 > r2 < 0.42, 0.00001 > p < 0.0025) AMP% and logAMP%, meaning that a different inotropic (isotonic) efficacy exists between these 2 amines, at all logC. On the other hand, when CP and freqCP were coded, explanatory variables were AMP% and logAMP% (4.86 > t < 6.95, 0.06 > r2 < 0.09, p < 0.00001), but not the variable used to code the type of treatment (dob versus dop).(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1992

[The role of colposcopy in the diagnosis of HPV infection].

Human papillomavirus (HPV) has been implicated as an important etiologic factor in cervical carcinoma. This study evaluates the efficacy of colposcopy in the detection of cervical lesions with koilocytosis features. Colposcopy, cervical smears and biopsy specimens from 217 women seen in our department between January-December 1991 were examined. The colposcopy examination detected 77.5% of the viral presence the histological diagnosis detected 85% of HPV, but the cytologic smears showed only 52% of infection. The data suggests that colposcopy is a good examination to evidence koilocytosis infection.

Adult↗
PubMed1992

[Increase of potassium conductance and spontaneous electric activity in vitro: comparison of nicorandil and cicletanine].

Nicorandil (N) increases potassium conductance in vascular smooth muscle and so induces vasodilation; N also dose-dependently reduces action potential duration (APD). However, it is unclear whether increased potassium conductance, and concomitant APD shortening, might be arrhythmogenic, particularly when myocardial ischemia (where potassium efflux is increased) concurs. Data on the anti-arrhythmic effectiveness of N have also been published: N reduced the spontaneous discharge of sino-atrial node and so reduced heart rate, both in vitro and man. On the other hand, among other vasodilators, cicletanine (C) has been reported to increase potassium conductance, an effect which was advocated to explain its antiarrhythmic potency. In the present investigation the direct myocardial effects of N were compared to those following C in 63 experiments (from 13 Guinea-pigs), using atrial strips (containing sino-atrial node) superfused in 1-compartment bath with normal Tyrode's solution. Using glass microelectrodes, standard electrophysiologic variables were recorded (APA, RMP, APD50%, Vmax) in spontaneously beating atrial tissue, either in Tyrode, dimethyl-sulfoxide (DMSO 1:100, as solvent), C 10(-5) M (in DMSO 1:100), and N 10(-3) M (in DMSO 1:100), whose respective perfusion periods (15 min) were randomized, always following 15 min of washout with Tyrode. Only N was tested in experiments of both 15 and 30 min duration.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

[The prevention of an excitation-conduction block during acute myocardial ischemia: is there a role for prostacyclin or for histamine?].

We have investigated (multivariate Cox's model) the relative risk of stable excitation-conduction block (ECB) in right ventricular myocardial strips (2 x 5 x 1 mm) from 26 female guinea-pigs, bathed in a 2-compartment chamber (3 ml) on the anterior side of which modified Tyrode's solution (K+ 12 mM, HCO3- 9 mM, pH 7 +/- 0.05, pO2 80 +/- 10 mmHg and absence of glucose) is supraperfused (stimulation rate: 450 ms; wire in the posterior compartment), thus enabling simulation of electrophysiologic changes seen during acute myocardial ischemia. Using glass microelectrodes, action potential amplitude (APA), durations (APD50 and 90%), resting membrane potential (RMP) and upstroke velocity (Vmax) are investigated. The hypothesis was tested of prostacyclin and histamine involvement in the genesis of ischemia-induced ECB in this model. Either a weak prostacyclin stimulator (cicletanine 10(-5) M, IPSEN, Paris, F, in DMSO 1:100; n = 16) or a potent prostacyclin generation blocker (indomethacin 10(-5) M, Sigma, in DMSO 1:100; n = 10) and either DMSO alone (1:100; n = 16) or a specific histaminergic H1 receptor antagonist (terfenadine 10(-5) M, Sigma, in DMSO 1:100; n = 10) were supraperfused using a randomization scheme. Each animal was used twice and either a first or a second occlusion (supraperfusing the modified Tyrode's solution for 30 min) period was performed and the randomized substances were supraperfused, thus enabling obtention of n = 52 experiments for analysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1990

Different effects of epoprostenol on ischemia-induced ventricular arrhythmias in dogs.

In 60 randomized dogs the effects of epoprostenol infusion (100 ng/kg/min) on ischemia-induced premature ventricular contractions (PVCs), ventricular tachycardia (VT), ventricular flutters and ventricular fibrillation were studied. The circumflex coronary artery occlusion canine model of sudden death was used. The results demonstrate different effects of epoprostenol on ischemia-induced ventricular arrhythmias: 1) both postischemic (7 of 30 vs 15 of 30, p = 0.0298) and postreperfusion (5 of 23 vs 8 of 15, p = 0.0492) ventricular fibrillations were prevented in epoprostenol dogs with an improvement of the global survival rate (18 of 30 vs 7 of 30, p = 0.0019) as compared to controls; 2) in epoprostenol treated dogs a significantly increased incidence of non lethal arrhythmias-including ventricular flutters that occurred in 12 of 30 dogs vs 4 of 30 in controls (p = 0.0195)--was observed; 3) a positive correlation between the percent diastolic pressure fall 10 min after the start of epoprostenol infusion and the number of non lethal arrhythmias was noted. However, hemodynamic effects of the compound, suggesting an oxygen sparing action, did not preclude the antifibrillatory effectiveness. Thus, the antifibrillatory and antiarrhythmic effects of epoprostenol after circumflex coronary artery occlusion and reperfusion in dogs seem independent from one another.

Animals↗
PubMed1990

[Variations in QT interval and ventricular volume during exercise-induced myocardial ischemia].

Aim of this study was to evaluate the possible relationship among myocardial ischemia, left ventricular volume changes and QT interval changes during exercise in patients with coronary artery disease. QT interval, expressed as absolute value, corrected according to Bazett (QTc = aT/RR0.5) and Fridericia (QTf = QT/RR0.33) and calculated by adapting reciprocal changes in QT and heart rate during exercise to the exponential fit proposed by Sarma (QTs = A-B*exp (-K*RR], was compared to the scintigraphic finding of myocardial ischemia and to the changes in left ventricular volumes during exercise. We studied 151 patients (130 men and 21 women, mean age 56 +/- 11 years) with suspected or already ascertained coronary artery disease, who underwent a simultaneous evaluation of regional ventricular function and myocardial perfusion by means of first pass radionuclide angiography (multielement gamma-camera) and computerized tomography, with 2 injections of 99mTc-MIBI at rest and at peak of a computerized bicycle stress test. QT and RR intervals were measured on an averaged ECG complex through a magnifying lens, and the absolute values of left ventricular volumes were computed by radionuclide angiography. According to scintigraphic findings, patients were divided into normal subjects (n = 7) and ischemic patients with (n = 63) and without (n = 81) evidence of a previous myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

[Exponential analysis of the relationship between ST segment depression and heart rate during exercise in patients with ischemic cardiopathy].

ST segment displacement sensitivity and specificity during exercise in the detection of myocardial ischemia are controversial, even when using mathematical approaches such as a linear regression analysis of ST/heart rate slope. In an attempt to see whether an exponential fit (ST = A-B*exp (-K*RR] of ST/heart rate relation during exercise could increase the diagnostic accuracy of exercise test in the detection of myocardial ischemia, we studied 165 patients (141 men and 24 women, mean age: 56 +/- 10 years) undergoing a simultaneous radionuclide assessment of regional ventricular function and myocardial perfusion at rest and at peak exercise in 4 hours by means of 2 injections of 99mTc-MIBI. Normal radionuclide findings were found in 4 subjects, whereas exercise-induced myocardial ischemia was detected in 90 patients with no evidence of previous myocardial infarction, and in 71 patients with previous myocardial infarction. ST segment depression was present at peak exercise in no normal subject, and in 52.2% and 60.4% of ischemic and infarcted patients, respectively, achieving a sensitivity of 55.9%, a specificity of 100% and a diagnostic accuracy of 57%. A, B and K coefficients of exponential analysis showed a wide variability among patients; however, the algebraic sign of K coefficient was negative in 50% of normal subjects versus 9.9% of patients (chi 2-test: p less than 0.02), thus achieving a sensitivity of 90.1%, a specificity of 50% and a diagnostic accuracy of 89.1% in the detection of exercise-induced myocardial ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Small hepatocellular carcinoma: percutaneous alcohol injection--results in 23 patients.

Twenty-three patients with hepatocellular carcinoma less than 4.5 cm in diameter (32 lesions) were treated with a percutaneous injection of ethyl alcohol performed with ultrasound (US) guidance. No complications or sequelae occurred after 271 treatments. All lesions were smaller after 6-27 months follow-up. No evidence of hepatocellular carcinoma was present at fine-needle biopsy or contrast material-enhanced computed tomography (CT). No viable tumor cells were detected in four patients who subsequently underwent surgery. The 1-year survival rate of 12 patients was 91.7%. From these data, it can be concluded that percutaneous alcohol injection (PAI) is an appropriate first-line treatment for patients with small hepatocellular carcinoma lesions who are poor surgical risks. Given the risk of new nodular lesions occurring on resected livers and the risk of perioperative mortality, PAI might even be considered an alternative to surgery.

Aged↗
PubMed1986

US-guided percutaneous alcohol injection of small hepatic and abdominal tumors.

Fourteen lesions (nine hepatocellular carcinomas, four hepatic metastases from gastric carcinoma, and one peritoneal metastasis from transitional cell carcinoma) in 12 patients were treated with percutaneous injection of 95% ethyl alcohol under guidance with ultrasound. Requirements for this procedure included inadequate response to conventional treatment or refusal of surgery, easy identification of the tumor with sonography, and a tumor diameter less than 4 cm. Three to nine administrations (75 in all) were performed for each lesion according to its size and to the results of the fine needle biopsy. All lesions had posttreatment sonographic structural changes of fibronecrotic degeneration. All lesions less than 3.2 cm in diameter (11 cases) that underwent the final fine needle biopsy were negative for malignant cells and had volume reductions up to 100%. No biochemical changes or untoward clinical sequelae were detected. Percutaneous intratumoral alcohol injection is inexpensive, easy to perform, and potentially valuable in the treatment of selected small neoplastic lesions of the liver and abdomen.

Adult↗