Biomedical subjects

D Galzerano

Publications and source records attributed to D Galzerano.

30 records · Page 2Linked to original sources

PubMed1993

Evidence for a relationship between free radicals and insulin action in the elderly.

In forty healthy subjects with normal glucose tolerance divided by age into four groups (group A, subjects with mean age < 25 years [n = 10]; group B, subjects with mean age < 40 years [n = 9]; group C, subjects with mean age < 60 years [n = 11]; group D, subjects with mean age > 75 years [n = 10]) and were matched for body mass index (BMI), lean body mass (LBM), mean arterial blood pressure, and sedentary life style, we determined the plasma O2- production, reduced to oxidized glutathione level ratio (GSH/GSSG), and plasma membrane microviscosity. Euglycemic hyperinsulinemic (1 mU/kg.min-1 for 120 minutes) glucose clamp with simultaneous D-3-H glucose infusion and indirect calorimetry allowed determination of glucose turnover parameters and substrate oxidation. In the oldest group of subjects, a significant increase in plasma O2-production and membrane microviscosity associated with a significative reduction in glucose disappearance rate (Rd), total body glucose disposal (TBGD), and nonoxidative glucose metabolism was found. In group D subjects (n = 10), all of these changes were correlated with one another. In a multiple regression analysis of the pooled data from all study subjects (n = 40), only plasma O2- production levels displayed a statistically significant relation with TBGD and nonoxidative glucose metabolism. In conclusion, in aged patients a significant relationship between free radical production and insulin action seems to exist.

Adult↗

PubMed1993

Effects of magnesium and nifedipine infusions on insulin action, substrate oxidation, and blood pressure in aged hypertensive patients.

Eight aged (70.1 +/- 2.1 years), nonobese (body mass index [BMI] = 26.3 +/- 0.4), hypertensive (systolic blood pressure [SBP] = 184 +/- 4.1; diastolic blood pressure [DBP] = 105 +/- 2.4 mm Hg) subjects underwent a euglycemic hyperinsulinemic (7.1 pmol/kg x min during 240 min) glucose clamp with four different infusions: a) 0.9% NaCl; b) 1.0 micrograms/kg x min nifedipine; c) 100 mumol/min magnesium; d) 1.0 micrograms/kg x min nifedipine plus 100 mumol/min magnesium. All tests were performed in random order. Simultaneous D-3-H glucose infusion and indirect calorimetry allowed us to determine glucose turnover parameters and substrate oxidation. Insulin infusion per se stimulated erythrocyte magnesium (1.83 +/- 0.04 v 1.98 +/- 0.03 mmol/L, P < .03) and calcium (4.7 +/- 0.3 v 6.2 +/- 0.4 mumol/L, P < .02) accumulation, and enhanced total body glucose disposal oxidative and nonoxidative glucose metabolisms. Infusion of insulin and nifedipine v insulin alone reduced insulin-mediated increase in intracellular calcium (5.4 +/- 0.3 v 6.2 +/- 0.4 mumol/L, P < .02), but potentiated the insulin effect upon nonoxidative glucose (15.4 +/- 0.4 v 11.1 +/- 0.3 mumol/kg lean body mass [LBM] x min, P < .03) metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1993

Metabolic features of patients with and without coronary heart disease but with a superimposable cluster of cardiovascular risk factors.

BACKGROUND: Many studies have shown a significant association between the magnitude of insulin resistance and the plasma insulin levels in non-diabetic patients. It has also been shown that all major cardiovascular risk factors are associated with the presence of hyperinsulinemia or insulin resistance. However, studies have not addressed the possible metabolic differences in insulin action that can occur in patients with and without coronary heart disease (CHD) but with a superimposable cluster of risk factors. METHODS: Three groups of patients matched for age, sex, and lean body mass, but different in their absence of risk factors (group A; n = 8), presence of risk factors but no clinical and electrocardiographic signs of CHD (group B; n = 12), and the presence of risk factors, family history of CHD, and clinical and electrocardiographic signs of CHD (group C; n = 14) volunteered for the study. Patients in groups B and C were also matched for main risk factors. All patients were submitted to a euglycemic hyperinsulinemic glucose clamp during which a an infusion of 3H-glucose and indirect calorimetry facilitated the determination of glucose turnover parameters and substrate oxidation. RESULTS: Patients with CHD (group C) had the highest fasting plasma insulin levels (98 +/- 13 pmol/l) compared with patients in group B (86 +/- 4 pmol/l; P < 0.05) and in group A (63 +/- 4 pmol/l; P < 0.05) and the lowest insulin-mediated stimulation in non-oxidative glucose metabolism. Fasting lipid oxidation was similar in the three groups, but a stronger insulin-mediated inhibition in the control patients (group A) was found. Multiple regression analysis of the pooled data from the patients in groups B and C (n = 26) demonstrated that all risk factors considered correlated (t = 1.58, P < 0.04) with total body glucose disposal (TBGD) and accounted for 77% of the variability in TBGD. Furthermore, a separate analysis for groups B and C demonstrated a different contribution of all risk factors (89% and 65% for groups B and C, respectively) to the variability in TBGD. In group C patients, a multiple logistic regression analysis encompassing all risk factors studied, but also the family history of CHD, explained 92% of the variability in TBGD. CONCLUSION: In patients with and without CHD but with similar risk factors, a significant reduction in non-oxidative glucose metabolism occurs; nevertheless, such impaired glucose handling seems to be worsened in the presence of CHD. Further studies will be needed to determine the cause of such differences.

Aged↗

PubMed1993

Daily vitamin E supplements improve metabolic control but not insulin secretion in elderly type II diabetic patients.

OBJECTIVE: To investigate the potential metabolic benefits deriving from daily vitamin E administration in type II diabetic patients. RESEARCH DESIGN AND METHODS: Twenty-five type II diabetic patients were invited to randomly take placebo or vitamin E (d-alpha-tocopherol; 900 mg/day) along a similar 3-mo period in a double-blind, crossover procedure. A wash-out period of 30 days separated the two treatment periods. At the end of each treatment period blood samples were drawn for plasma metabolites determination, and an intravenous glucose tolerance test (25 g of glucose as bolus in 3 min) was performed. During this study oral hypoglycemic agents were not discontinued or changed in their dosage. RESULTS: Chronic vitamin E administration reduced plasma glucose (8.3 +/- 0.3 vs. 7.5 +/- 0.2 mM, P > 0.05), triglycerides (2.27 +/- 0.08 vs. 1.67 +/- 0.09 mM, P < 0.02), free fatty acids (786 +/- 116 vs. 483 +/- 64 mM), total cholesterol (6.74 +/- 0.09 vs. 5.50 +/- 0.10 mM, P < 0.05), low-density lipoprotein cholesterol (4.73 +/- 0.11 vs. 3.67 +/- 0.07 mM, P < 0.04), and apoprotein B (1.7 +/- 0.3 vs. 1.0 +/- 0.1 g/L) levels but did not affect beta-cell response to glucose. HbA1 levels (7.8 +/- 0.3 vs. 7.1 +/- 0.5%, P < 0.05) were also significantly lowered after chronic vitamin E administration. CONCLUSIONS: Daily vitamin E supplements seem to produce a minimal but significant improvement in the metabolic control in type II diabetic patients. More studies are necessary before conclusions can be drawn about the safety of vitamin E during long-term administration.

Aged↗

PubMed1992

Acute thrombosis of prosthetic valves: a multivariate analysis of the risk factors for a lifethreatening event.

In 3231 prosthetic valves implanted between January 1975 and November 1990, we observed 61 cases of prosthetic obstruction of biological origin with clinical and laboratory findings of severe functional impairment which required surgery as emergency treatment. The hospital mortality was 19.67% (12/61). The obstruction was due to a primary thrombosis in all 5 bioprostheses which were not anticoagulated and in 11/56 (19.64%) mechanical prostheses of which 3 were not anticoagulated and 4 were not properly anticoagulated. The obstruction was due to fibrous tissue overgrowth in the other 45 mechanical prostheses (80.35%) with secondary thrombosis in 34 cases (60.71%) and no thrombosis in 11 (19.64%); 71.11% of these prostheses were adequately anticoagulated. Of the 61 obstructed prostheses, 53 were mitral and 8 were aortic. No tricuspid obstruction was observed. A statistical assessment by multiple correspondence, cluster and chi square analysis was performed in two groups of patients with different models of mechanical mitral prostheses. The 5-year actuarial incidence of obstruction was 6.08%. Significant risk factors were: tilting disc prostheses, prostheses without pyrocarbon coating, large prostheses, tilting disc prostheses with a small orifice posteriorly oriented, atrial fibrillation, enlarged left atrium, time from implant greater than 4 years, age between 40 and 50 years. In our opinion, prosthetic obstruction may be referred to a primary thrombosis only in cases where it may be prevented by adequate anticoagulation. In most cases, the obstruction is produced by periprosthetic fibroblastic proliferation which may develop in spite of adequate anticoagulation in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

PubMed1991

[Left ventricular systolic function in patients surgically treated for atrioventricular septal defect: echocardiographic assessment].

In order to assess the left ventricular systolic function we studied by echo 14 pts (8M, 6F) with complete atrioventricular septal defect (AVSD) who had undergone surgical repair. Mean age was 20.30 +/- 24.63 months, with a follow-up of 52.85 +/- 19.11%; in 6 pts Down syndrome was associated. Particularly, we tried to determine whether the following factors might affect the post-operative left ventricular systolic function: a) Down syndrome; b) residual mild mitral regurgitation; c) age of the surgical repair; d) length of the follow-up. As load-independent indexes of contractility, the left ventricular end systolic stress (LVESS)-circumferential fibre shortening velocity normalized for heart rate (VCFc) relationship and the LVESS/end systolic volume index (ESVI) ratio were chosen. All pts showed normal (mean +/- 2 standard deviations) or slightly higher values of LVESS/VCFc relationship; significantly, the only two pts with lower values had later undergone surgical repair. LVESS/ESVI ratio confirmed an inverse relationship between systolic function and age of the surgical correction (r = -0.75); no other factors (Down syndrome, residual mild mitral regurgitation, length of the follow-up) showed a significant correlation with the post-operative left ventricular systolic function. In conclusion, in our limited population, the age of the surgical repair appears to be the main factor affecting the post surgical left ventricular systolic function in pts with complete AVSD.

Child↗

PubMed1990

[Vector cardiography features of right ventricular activation delays: nosologic classification and clinical correlation].

Electrovectorcardiographic features of 150 patients showing right ventricular activation delays (RVAD) has been analyzed. This analysis of RAVD, especially for type I, which is the group with the widest morphologic variability, has permitted a more detailed classification: a type I with 5 subtypes, a type II with 1 subtype, a type III and an intermediate type between type II and III. Fifty-five per cent of the patients were included in type I and its variant and most were classified, often without cardiac disease, as belonging to the classic type I. Thirty per cent of RVAD were of type II; 12% of type III and the remaining were in the intermediate group between type II and III. The various morphologies, moreover, were correlated with the clinical picture: the classic type I was never seen in subjects with cardiac disease, while the others types and subtypes were present either in subjects with cardiac disease or in elderly subjects, also without relevant pathologies (senile heart, especially, the type IA") or in otherwise healthy subjects. In a medical-social context, checking for RVAD, in the absence of cardiac disease, might usefully avoid further investigation. It is underlined the usefulness of this correlation for clinical prognostic judgement.

Adolescent↗

PubMed1989

[Diagnosis of delayed upper left ventricular activation: limits of electrocardiography and usefulness of vectorcardiography].

The electrocardiographic (ECG) diagnosis of delayed ventricular left superior activation (DVLSA) is often difficult and uncertain, even when all the criteria proposed in clinical literature are fulfilled. The vectorcardiography (VCG) always permits an accurate diagnostic evaluation because the contour of the QRS loop describes successively the various phases of ventricular depolarization. Sensitivity and specificity of ECG in diagnosing DVLSA have been calculated referring to VCG analysis. The QRS loop initial forces orientation in the frontal plane, a VCG highly reliable criterion, was considered especially significant for this purpose. The sensitivity and specificity of ECG were, respectively, 75% and 95%. Moreover, this study has confirmed the low performance of frontal plane QRS axis criterion and the necessity of polyparametric method for a correct ECG-VCG diagnosis of DVLSA. However, the VCG is more reliable than ECG in such diagnosis because it allows thoroughly to analyze QRS-loop initial forces.

Adult↗

PubMed1987