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Biomedical subjects

G Riccardi

Publications and source records attributed to G Riccardi.

At least 127 records · Page 7Linked to original sources
PubMed1990

Genetic transformation of intact cells of Bacillus subtilis by electroporation.

Plasmid DNAs were introduced by electroporation into Bacillus subtilis PB1424 as an alternative to competent-cell or protoplast transformation. The maximum electroporation efficiency was 10(4) transformants/microgram DNA. Parameters including growth phase of cells, ionic strength of the suspending medium, concentration and size of plasmid DNAs, amplitude and duration of the pulse, were evaluated in order to determine conditions that improved transformation efficiency.

Bacillus subtilis↗
PubMed1990

Effects of changing amount of carbohydrate in diet on plasma lipoproteins and apolipoproteins in type II diabetic patients.

Eight type II (non-insulin-dependent) normolipidemic diabetic patients (aged 45 +/- 15 yr, body mass index 22 +/- 2 kg/m2, means +/- SD) treated with diet alone or diet plus oral hypoglycemic agents were given, in random order for periods of 15 days, two diets with different carbohydrate (CHO) (40 vs. 60% of total calories) and fat (20 vs. 40%) levels. Simple CHO, fiber, saturated fat, cholesterol, and polyunsaturated-saturated fat ratio were similar in the two diets. Total plasma cholesterol was not significantly affected by dietary changes; conversely, plasma triglyceride (1.38 +/- 0.59 vs. 1.11 +/- 0.39 mM, P less than 0.05) and apolipoprotein CII (3.8 +/- 1.4 vs. 3.3 +/- 0.8 mg/dl) increased significantly after the high-CHO low-fat diet. Among the various lipoproteins, very-low-density lipoprotein (VLDL) was the most affected by diet: VLDL cholesterol concentrations increased from 0.30 +/- 0.19 to 0.43 +/- 0.28 mM (P less than 0.05), and triglyceride concentrations increased from 0.62 +/- 0.33 to 0.88 +/- 0.53 mM (P less than 0.05). In conclusion, increasing the amount of complex CHO in the diet induces an elevation of VLDL in normolipidemic, nonobese, mildly type II diabetic patients.

Adult↗
PubMed1989

Effects of bezafibrate on insulin secretion and peripheral insulin sensitivity in hyperlipidemic patients with and without diabetes.

Although it has been reported that bezafibrate influences carbohydrate metabolism, this possibility has never been properly evaluated in a controlled clinical trial. In this study we attempted to evaluate the effects of bezafibrate on plasma lipoproteins, glucose tolerance, insulin secretion and peripheral insulin sensitivity in a group of hypertriglyceridemic patients with and without diabetes. Sixteen hyperlipidemic patients (10 males and 6 females) participated in the study. Eight had type IIB and 8 type IV hyperlipoproteinemia; 6 of them also had non-insulin dependent diabetes mellitus. The study was performed according to a double blind, crossover design: after 1 month wash-out period in which patients were on diet alone, they underwent, in a random order, a period of placebo therapy and another period in which they received a single daily dose of a long-acting bezafibrate preparation (400 mg) administered in the evening. Each treatment lasted 2 months. Total plasma and VLDL triglyceride concentrations were consistently reduced by bezafibrate (-46%, P less than 0.001; and -50%, P less than 0.001). Total and VLDL-cholesterol were also reduced by bezafibrate. The effects of bezafibrate on lipoproteins were similar in diabetic and non-diabetic subjects. Bezafibrate treatment did not influence fasting blood glucose concentration, glucose tolerance, peripheral insulin sensitivity or insulin secretion. In conclusion, the results of this controlled trial clearly indicate that bezafibrate can be successfully employed to lower plasma lipid levels in patients with non-insulin dependent diabetes mellitus and hyperlipidemia.

Adult↗
PubMed1989

Different localization of early arterial lesions in insulin-dependent diabetes mellitus and in familial hypercholesterolemia.

Ultrasound methods have been used for the vascular examination of middle-aged patients with insulin-dependent diabetes mellitus (IDDM, n = 44) or heterozygous familial hypercholesterolemia (FH, n = 37); they were compared with 50 healthy controls. To define the localization of the early arterial lesions in these two conditions, the determination of ankle pressure by Doppler ultrasound and the detection of flow disturbances in the iliac arteries by echo-Doppler technique have been combined in a single vascular investigation. There were no major differences in mean age, degree of overweight, sex distribution, blood pressure, or smoking habits among the three groups. Total serum cholesterol in patients with FH was almost double compared with diabetics and controls. Triglyceride, HDL cholesterol, and blood pressure values did not differ. Nine of 88 limbs of patients with IDDM had an abnormally low ankle-arm pressure ratio (less than 0.97), and there were three cases of low ratio of 100 limbs in the control subjects (P less than .02). The corresponding figure for heterozygous FH was of three of 74 limbs (not different from controls). Echo-Doppler abnormalities suggesting lesions in the iliac arteries were significantly increased (P less than .01) in FH patients (13 limbs with lesions of 74) compared with controls (four of 100 limbs). The proportion of echo-Doppler abnormalities in IDDM (four of 88 limbs) was practically the same as compared to the controls.

Adult↗
PubMed1989

[HBV infection in hospital health workers: study conducted in a Piedmontese hospital].

The screening for hepatitis B virus infection markers of 976 hospital employees pointed out that: the prevalence of subjects who are positive to at least one marker is relatively low (17.52%); the areas with higher rates of prevalence are: the infections diseases division and the radiological area; there is a statistically significant difference as for the positivity of one of the hepatitis B markers among the disaggregated non-medical staff for every single functional area. The data here collected are compared with those collected in other hospitals.

Female↗
PubMed1989

[Correlation between Selvester's QRS score and left ventricular function at rest and during effort in patients who survived myocardial infarction].

This study was carried out in order to determine if there is any correlation between QRS score and left ventricular function at rest and during exercise after single myocardial infarction. Selvester's QRS scoring system to determine infarct size by observing Q and R standard 12-lead ECG was independently applied by three cardiologists. Left ventricular function was determined using the resting angiographic LVEF, the pulmonary wedge pressure in supine position and during exercise. The total work performed and the heart rate and systolic blood pressure percentage increase (delta) were also considered. Forty-eight male pts (mean age 52.3 +/- 8.7) were studied within 2 months after acute myocardial infarction. The site of the myocardial infarction was anterior in 13, inferior in 20, inferior plus posterior in 15. There were poor correlations between QRS score and left ventricular ejection fraction (r = -0.44) and pulmonary wedge pressure in supine position and during exercise, total work performed, delta heart rate and delta systolic blood pressure. There was no significant difference in mean QRS score between pts with abnormal (greater than 12 mmHg) and normal resting pulmonary wedge pressure in supine position (10.8 +/- 8.4 vs 7.3 +/- 5.8) or between pts with abnormal (greater than 20 mmHg) and normal exertional pulmonary wedge pressure (10.5 +/- 8.4 vs 7.4 +/- 5.7). In conclusion, the QRS score, obtained up to 30 days following an acute myocardial infarction, is not useful in determining left ventricular function at rest or during exercise.

Blood Pressure↗
PubMed1989

Reproducibility of non-invasive vascular diagnosis in patients with diabetes mellitus.

Reproducibility of noninvasive ultrasound methods for vascular diagnosis was studied in 36 patients with Insulin Dependent Diabetes Mellitus. The vascular examination included a) the measurement of ankle systolic arterial pressure and ankle/arm pressure index (c.w. Doppler), b) Echo-Doppler examination of iliac arteries with measurement of maximum systolic frequency, systolic spectrum width and diastolic reverse flow component. A grading of iliac artery stenosis was also performed. The examination was repeated after one month according to a blind protocol. The coefficients of variation were as follows: 8% for ankle pressure; 8% for ankle/arm pressure index; 9% for the maximum systolic frequency; 18% for the spectrum width and 15% for the reverse flow component. The reproducibility of the grading of iliac artery stenosis based on the combined use of the three Echo-Doppler parametres was measured by the Kendall coefficient (W = 0.865). These results confirm that non invasive methods are suitable and reliable for investigating vascular disease in diabetic patients. Accurate estimates of reproducibility are essential pre-requisites for the planning of studies on the natural history of vascular disease and on progression-regression of arterial lesions.

Aged↗
PubMed1988

Presence of very low density lipoprotein compositional abnormalities in type 1 (insulin-dependent) diabetic patients; effects of blood glucose optimisation.

Plasma lipoprotein compositional abnormalities were investigated in eight normolipidaemic (plasma cholesterol less than 5.70 mmol/l; triglyceride less than 2.03 mmol/l) young male Type 1 (insulin-dependent) diabetic patients (before and after a short period of optimised blood glucose control) and in nine healthy control subjects, matched for sex, age and body mass index. Free and esterified cholesterol, triglyceride, phospholipids were assayed in all lipoprotein classes (VLDL, IDL, LDL) and in HDL subclasses (HDL2 and HDL3); apoB was measured only in very low density lipoproteins (VLDL). All VLDL constituents were increased in the diabetic group, the differences being more striking for apoB (6.0 +/- 1.1 mg/dl vs 2.0 +/- 0.1 mg/dl, p less than 0.02), free cholesterol (0.27 +/- 0.04 mmol/l vs 0.13 +/- 0.02 mmol/l, p less than 0.02) and esterified cholesterol (0.32 +/- 0.08 mmol/l vs 0.13 +/- 0.01 mmol/l, p less than 0.05). Also HDL subfractions showed differences between the two groups: all HDL2 constituents were increased, while in HDL3 only triglyceride was significantly increased (0.11 +/- 0.01 mmol/l vs 0.08 +/- 0.004 mmol/l, p less than 0.02). After two weeks of optimised blood glucose control all VLDL constituents were reduced and particularly: esterified cholesterol (-39%, p less than 0.02), free cholesterol (-37%, p less than 0.05), apoB (-35%, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Metabolic consequences of feeding a high-carbohydrate, high-fiber diet to diabetic patients with chronic kidney failure.

The aim of this study was to compare the metabolic effects of a high-carbohydrate (CHO), high-fiber diet with only moderate protein restriction with those of a low-CHO, low-fiber diet with a low protein content in six diabetic patients with moderate chronic renal failure. The high-CHO, high-fiber diet induced a significant improvement in blood glucose control, a significant decrease in serum cholesterol, and a significant increase in fecal nitrogen losses. Other variables evaluated were not significantly different between the two diets, except for a significant increase in serum phosphorus during the high-CHO, high-fiber diet. N balance was not significantly different from 0 at the end of either dietary period and was very similar for both diets. The high-CHO, high-fiber diet presents many beneficial metabolic effects in diabetic patients with chronic renal failure.

Adult↗
PubMed1988

Does the study of anaerobic metabolism give quantitative information on left ventricular dysfunction during exercise?

The anaerobic threshold (AT) has been proposed as an index to assess the functional status of patients with chronic heart failure. The focus of this report was to evaluate in post-myocardial infarction patients the utility of the AT for (a) assessing the severity of exercise-induced left ventricular impairment, (b) determining the responses obtained from different treatments and (c) prescribing exercise training. We found that the AT level was lower in patients with abnormal haemodynamic patterns during exercise. The AT was correlated to different degrees of exercise-induced left ventricular impairment. The nitrate and calcium-antagonist effects have been evaluated in patients with abnormal exercise haemodynamics. The resting and exertional results were in agreement with the vasodilator effects. Moreover, the time from onset of exercise to the appearance of the AT was significantly increased by the treatments. Thus, AT during pharmacological treatments may be a non-invasive useful parameter for assessing their haemodynamic effects. Finally, a 4-week intermittent training programme based on AT level was evaluated in patients with abnormal resting and exertional haemodynamics. The results showed an improvement of the exercise cardiovascular tolerance without negative effects on left ventricular function. Therefore, the AT seems to be useful when prescribing a rational and individualized training programme.

Adult↗
PubMed1988

Silent ischaemia in post-myocardial infarction patients submitted to physical training.

Recently, more attention has been focused on the detection and treatment of silent myocardial ischaemia. Electrocardiographic signs of exercise-induced asymptomatic myocardial ischaemia are very common findings among survivors of acute myocardial infarction. From data of our population we found that silent exercise-induced ischaemia is present in 15-20% of all patients, and that about half of the patients with exercise-induced ST-segment depression were free of symptoms. Ergometric data at the ischaemic threshold are similar between asymptomatic and symptomatic patients while the presence of symptoms is more frequent in patients who were also symptomatic before the myocardial infarction. During the training period, the majority of the 'silent' patients remained asymptomatic, 23% developed effort angina, and 9% developed angina at rest. Training monitoring may be helpful in identifying the variability of symptoms. Physical training, in particular an intermittent programme, increased the work-load at which the ECG ischaemic signs appeared. Among the possible mechanisms responsible for exercise-induced silent ischaemia, a different pain tolerance and control of analgesia may be ascribed to explain the absence of pain, perhaps also determined by different endogenous beta-endorphin levels.

Coronary Circulation↗
PubMed1988

The effects of physical training in post-myocardial infarction patients with exercise-induced silent ischaemia.

To assess the clinical significance of monitoring during physical training in post-myocardial infarction (MI) patients with asymptomatic exercise-induced ischaemia, we studied 232 patients who were survivors of first recent acute MI and consecutively admitted to the same CCU, who underwent an exercise test (ET) and coronary angiography within two months of the acute event. We selected the 97 patients with multivessel disease. Among them, 60 showed a negative ET and no angina; 37 showed a positive ET with significant ST segment depression, 32 of them had no angina. The 37 patients with positive ET repeated the stress test within a week. In eight of them, the two ETs differed because ischaemia was induced once with and once without precipitation of angina, while the workload (WL) and double product (DP) at the ischaemic threshold of 0.1 mV ST segment depression were not different. During a four-week training period, seven of the asymptomatic patients complained of effort angina and three of angina at rest. To assess training effects, we selected 60 non-consecutive patients with asymptomatic (38) and symptomatic (22) exercise-induced ischaemia. All the symptomatic and 25 asymptomatic patients followed a four-week physical training programme based on the ischaemic threshold. The remaining 13 asymptomatic patients did not undergo physical training. The pre-training period ergometric patterns were comparable between painful and pain-free patients. Training resulted in a similar increase in the WL at the ischaemic threshold (+45% in asymptomatic and +47% in symptomatic patients, both P less than 0.05), without any difference in the DP threshold.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Disease↗
PubMed1988

Resting and exertional haemodynamic effects of buccal nitroglycerin: acute and chronic discontinuous treatment in post-myocardial infarction patients with heart failure.

The resting and exertional haemodynamic effects of acute and chronic discontinuous (one tablet every 6 h) treatment with 5 mg of buccal nitroglycerin (BN) have been assessed in nine postinfarction heart failure patients. At rest, pulmonary artery (PAP), pulmonary wedge (PWP), and right atrial pressures (RAP) were reduced by 42%, 55% and 77%, respectively, after the first dose and by 26%, 32% and 45%, respectively, after the chronic (three weeks) treatment with BN. During exercise, at the same workload, PAP, PWP and RAP were significantly reduced by 44%, 54% and 62%, respectively, after acute treatment and by 28%, 34% and 44%, respectively, after chronic treatment. The maximal workload (Kgm) increased by 179% and 166% and the exercise time increased by 78% and 71% after acute and chronic therapy, respectively. At the maximal workload, after acute BN, overall haemodynamics were better than in the basal state. PAP, PWP and RAP were still reduced by 19%, 31% and 31%, respectively, after acute treatment, while after chronic phase the results did not differ from control. The severity of cardiac failure, according to the Weber classification, was reduced by acute and chronic therapy. We can conclude that the buccal nitroglycerin showed clear efficacy in improving overall haemodynamic parameters both at rest and during exercise in post-myocardial infarction patients with heart failure. The discontinuous treatment maintained the effect of nitroglycerin without clear evidence of tolerance during chronic therapy.

Administration, Buccal↗
PubMed1988

Serum apolipoproteins, lipoproteins and fatty acids in relation to ischaemic heart disease in northern and southern European males.

Serum apolipoprotein and lipoprotein concentrations, fatty acid spectra of various lipids, dietary habits and common risk factors for ischaemic heart disease were studied in 73 and 77 randomly selected, 50-year-old healthy men in Naples and Stockholm, respectively. Mean serum cholesterol concentration was higher in Stockholm than in Naples men (6.23 vs. 5.47 mmol/l, p less than 0.001) as were low (LDL) (4.08 vs. 3.57 mmol/l, p less than 0.001) and high (HDL) (1.40 vs. 1.25 mmol/l, p less than 0.001) density lipoprotein fractions. Mean serum triglyceride concentrations did not differ. Mean apolipoprotein B and C-I concentrations were higher in Stockholm men (1,116 vs. 1,020 mg/l, p less than 0.05 and 96 vs. 79 mg/l, p less than 0.01, respectively). Stockholm men derived significantly more of their calories from fat (38 vs. 28%, p less than 0.001) and the dietary fat had significantly lower polyunsaturated-to-saturated fatty acid ratio (P/S-ratio 0.29 vs. 0.51, p less than 0.001), and less from carbohydrate (44 vs. 49%, p less than 0.001) than Naples men, respectively. Mean caloric intake and mean weight/height index did not differ. Stockholm men had higher blood pressures, but there were more smokers among Naples men. The higher fat intake in Stockholm men may offer an explanation of the differences seen in lipoprotein and apoprotein concentrations and compositions but other factors, such as genetic influences cannot be excluded. A greater cholesterol flux through the plasma compartment in Stockholm men may be one important factor contributing to the higher incidence of ischaemic heart disease in this population.

Adult↗