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Biomedical subjects

G Mazzotta

Publications and source records attributed to G Mazzotta.

At least 55 records · Page 3Linked to original sources
PubMed1991

Study of the P300 and cerebral maps in subjects with multi-infarct dementia treated with cytidine.

A study of event-related P300 potential and cerebral EEG maps was performed in 20 patients affected by multi-infarct dementia (MID): 10 subjects were treated with placebo and 10 with cytidine. The trial was divided into three intervals. The patients, after a period of washout, were evaluated throughout the course of the trial by electrophysiological examination performed at baseline, after 90 min from the first IV injection, again after 30 days of IM therapy, and finally after 60 days of continued IM therapy. In the group treated with cytidine, the findings relevant to the study of the P300 showed a significant decrease in latency values compared to baseline (P less than 0.05 ANOVA) and an improvement. though not significant, in the amplitude values. Calculation of the mean relative power of EEG values showed a significant decrease in delta activity and an increase in alpha activity. In the subjects treated with placebo, no statistically significant variation was found in either P300 or EEG map recordings. On the basis of these investigations it has been demonstrated that the variations in the registrations can be correlated to the improved neuronal activity following treatment with cytidine.

Aged↗
PubMed1991

A clinical and neurophysiological trial on nootropic drugs in patients with mental decline.

The different expressions of mental decline in elderly people, from simple senile benign forgetfulness to SDAT, can be evaluated by psychometric and neurophysiological tests. In the present study, the effects of oxiracetam, piracetam and placebo were compared in a group of elderly subjects. The results of the trial, structured as single blind, clearly showed that nootropics positively effect both clinical and neurophysiological performances and that oxiracetam produces a more pronounced effect when compared to piracetam. In fact, oxiracetam was found more effective in improving psychometric scales such as GDS (clinical performances) as well as the amplitude and the latency of the P300 (neurophysiological performances), which reflect a functional recovery of the cerebral pathways related to attention and memory.

Aged↗
PubMed1990

Frequency, characteristics and significance of supraventricular tachyarrhythmias detected by 24-hour electrocardiographic recording in the late hospital phase of acute myocardial infarction.

The incidence, characteristics and clinical significance of supraventricular tachyarrhythmias occurring in the late hospital phase of acute myocardial infarction (AMI) were assessed in 209 consecutive patients. Arrhythmias were quantified by 24-hour electrocardiographic recording 16 +/- 3 days after AMI, and were classified according to the degree of complexity in 5 classes. Class 0 = less than 5 premature beats/hr; class 1 = between 5 and 100/hr; class 2 = greater than 100/hr or repetitive premature beats; class 3 = atrial-junctional tachycardia; class 4 = atrial flutter-fibrillation. Supraventricular tachyarrhythmias classes 1 to 2 always occurred in the absence of symptoms in 86 patients (41%); supraventricular tachyarrhythmias classes 3 to 4 (paroxysmal, self-limiting, brief) occurred in 27 patients (13%), symptomatically in 6. The presence of supraventricular tachyarrhythmias classes 2 to 3 was related to age over 55 years and complex ventricular tachyarrhythmias (greater than 20 premature beats/hr, ventricular tachycardia) (both p less than 0.05). Increasing complexity of supraventricular tachyarrhythmias was significantly associated with presence and entity of cardiac enlargement and left ventricular dysfunction (both p less than 0.01). Patients with class 4 showed the most severe cardiac deterioration. During the 2 years after AMI, patients with classes 2, 3 and 4 had a higher incidence of acute pulmonary edema, New York Heart Association functional classes III to IV for congestive heart failure (both p less than 0.005) and a greater need of digitalis and diuretics (p = 0.003).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Left ventricular thrombi: changes in size and in platelet deposition during treatment with indobufen and ticlopidine.

This study was designed to evaluate whether indobufen and ticlopidine can induce changes in the size of left ventricular thrombi and variations in the deposition of platelets on thrombus surface. Forty-seven patients with left ventricular thrombosis, who were not treated with antithrombotic drugs, were prospectively evaluated with 111In-oxine platelet imaging and two-dimensional echocardiography. The first scintigraphic examination was negative in 15 of the 47 patients with left ventricular thrombosis, thus they were excluded from further evaluation. The remaining 32 patients with evidence of labeled platelet deposition on the thrombus were divided into three groups. Group 1 comprises 11 patients treated with different doses of ticlopidine: 6 with 250 mg/day, and 5 with 500 mg/day. Group 2 comprises 12 patients who received 400 mg/day of indobufen. Group 3 comprises 9 patients who were not treated with antithrombotic drugs. All 32 patients underwent repeated 111In-oxine platelet imaging and echocardiography 40 +/- 11 days after the first examination. During treatment with ticlopidine, deposition of labeled platelets on the thrombus became absent in 2 patients (500 mg/day), and reduced in 5 (2 treated with 250 and 3 with 500 mg/day). A decrease of platelet deposition on the thrombus was also observed in 5 of the 12 patients receiving indobufen and in only 1 of 9 controls. With regard to thrombus dimensions, 1 patient treated with ticlopidine showed a decrease in thrombus size associated with a reduction of the scintigraphic activity. In conclusion, a decrease of the platelet uptake on the thrombus surface, without significant changes in the size, was detected in most patients during treatment with indobufen and ticlopidine.(ABSTRACT TRUNCATED AT 250 WORDS)

Echocardiography↗
PubMed1989

Relation between exertional ischemia and prognosis in mildly symptomatic patients with single or double vessel coronary artery disease and left ventricular dysfunction at rest.

The randomized multicenter trials indicate that survival in patients with coronary artery disease and left ventricular dysfunction is enhanced by surgical therapy compared with medical therapy. This beneficial effect of coronary bypass surgery was demonstrated in patients with either three vessel or left main coronary artery disease, but not in those with one or two vessel disease. To determine whether subgroups of mildly symptomatic patients with one or two vessel coronary artery disease and left ventricular dysfunction have an increased risk of death or cardiac events during medical therapy, 53 consecutive patients with angiographically defined one or two vessel disease and impaired left ventricular function (ejection fraction 20% to 40%) were studied by exercise electrocardiography (ECG) and rest and exercise radionuclide angiography. All but two patients had previous myocardial infarction, and all were asymptomatic or only mildly symptomatic during medical therapy. By univariate life table analysis, mortality during medical therapy was associated significantly with the ST segment response to exercise (p less than 0.05) and with both the exercise ejection fraction (p less than 0.05) and the magnitude of change in ejection fraction with exercise (p less than 0.005). In patients with an exercise ejection fraction greater than 30%, the probability of survival at 6 years was 97 +/- 3% (+/- SE) compared with a survival rate of 62 +/- 14% in the remaining subjects (p less than 0.005). Similarly, 6 year survival was 100% in patients whose ejection fraction increased from the value at rest but was only 74 +/- 10% in the remaining patients (p less than 0.005). Exercise capacity was not associated with survival.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

The median nerve SEP in preterm neonates: a study of maturation.

We studied the right and left median nerve somatosensory evoked potential in a group of preterm neonates at birth (36 weeks) and at 37 and 38 weeks conceptional age. The latency of SEP at Erb's point did not differ from one examination to the next but the latency of cortical wave N1 in the second and third examinations was statistically shorter that of the first. The ascending slope of N1 decreased in duration like the latency of N1. We discuss our results in the light of published work and stress the value of SEP as a noninvasive method of assessing maturational deficits in the somatosensory circuits.

Evoked Potentials, Somatosensory↗
PubMed1989

[On the possibility of accelerating thrombolytic therapy in the acute phase of myocardial infarction: efficacy of and tolerance to the infusion of 1.5 million units of streptokinase in 30 minutes].

To evaluate efficacy and tolerability of the systemic infusion of 1,500,000 streptokinase units in 30', we treated 26 consecutive patients with acute myocardial infarction within 3 hours of the onset of chest pain. They were 23 men and 3 women, mean age was 59 +/- 8 years. None of them had a history of previous myocardial infarction. From clinical and electrocardiographic data, as well as from creatine kinase curves, we assumed myocardial reperfusion in 19 patients (73%). Within 30' after infusion, thrombin time increased to more than 300" in 25/26 patients (96%). Streptokinase induced hypotension (which we defined as a decrease in systolic blood pressure of more than 30 mmHg) in 13 patients (50%), and in 5 of them (19%) systolic blood pressure fell below 90 mmHg. Hypotension was counteracted by adopting the Trendelenburg position in 7 patients, and by an intravenous infusion of atropine in 5. In the remaining patient, streptokinase infusion was slowed down. Due to these interventions, a non-significant decrease in systolic blood pressure was observed from 129 +/- 26 to 112 +/- 20 mmHg at the end of the infusion. Streptokinase-induced hypotension was not predicted either by clinical, or electrocardiographic, or chest X-ray film data, or laboratory findings. No other side-effects occurred. Hence, the infusion of 1,500,000 streptokinase units in 30' in the acute phase of myocardial infarction is active, and well tolerated. It must be emphasized, however, that during the infusion, hypotension occurs frequently and unpredictably, sometimes reaching alarm levels. This makes the monitoring of systolic blood pressure imperative during streptokinase infusion.

Adult↗
PubMed1988

Somatosensory-evoked potential study in headache patients.

Somatosensory-evoked potentials (SEPs) after median nerve stimulation were studied in 34 patients with common migraine, in 30 patients with muscle-contraction headache, and in 10 cluster headache patients. The SEPs were registered before and after histamine administration. Latency values in common migraineurs showed no variation when compared with those in controls. Although not statistically significant, the N1-P2 amplitude was increased in 14 (41.1%) of these patients after histamine stimulation. No changes were observed in muscle-contraction headache patients either with or without histamine administration. In all cluster headache patients, the N1-P2 amplitude decreased after histamine stimulation. These results are discussed in the light of current hypotheses concerning the pathophysiologic mechanisms of headache.

Adolescent↗
PubMed1988

Neuropathy in children and adolescents with diabetes mellitus.

Nerve conduction velocities were studied in the median, posterior tibial, radial and sural nerves of 50 juvenile diabetics, average age 13 +/- 1.3 years and mean duration of diabetes 2.3 +/- 1.4 years. Motor conduction velocity (MCV) in the median nerve was reduced in 10% of the subjects, and in the posterior tibial in 32%. Sensory conduction velocity (SCV) in the radial nerve was reduced in 30% of the subjects, and in the sural in 44%. No relationship was found between the reduction in conduction velocity and the duration of diabetes; nevertheless, a correlation was observed between this reduction and the degree of glycaemic control represented by the glycosylated haemoglobin concentration. The authors emphasize the importance of good glycaemic control for the prevention of diabetic neuropathy.

Adolescent↗
PubMed1988

Modest decrements in plasma glucose concentration cause early impairment in cognitive function and later activation of glucose counterregulation in the absence of hypoglycemic symptoms in normal man.

To establish the glycemic threshold for onset of neuroglycopenia (impaired cognitive function, measured by the latency of the P300 wave), activation of hormonal counterregulation and hypoglycemic symptoms, 12 normal subjects were studied either under conditions of insulin-induced, glucose-controlled plasma glucose decrements, or during maintenance of euglycemia. A decrement in plasma glucose concentration from 88 +/- 3 to 80 +/- 1 mg/dl for 150 min did not result in changes in the latency of the P300 wave nor in an activation of counterregulatory hormonal response. In contrast, a greater decrement in plasma glucose concentration from 87 +/- 3 to 72 +/- 1 mg/dl for 120 min caused an increase in the latency of the P300 wave (from 301 +/- 12 to 348 +/- 20 ms, P less than 0.01), a subsequent increase in all counterregulatory hormones but no hypoglycemic symptoms. Finally, when plasma glucose concentration was decreased in a stepwise manner from 88 +/- 2 to 50 +/- 1 mg/dl within 75 min, the increase in the latency of the P300 wave was correlated with the corresponding plasma glucose concentration (r = -0.76, P less than 0.001). The glycemic threshold for hypoglycemic symptoms was 49 +/- 2 mg/dl. Thus, in normal man the glycemic threshold for neuroglycopenia (72 +/- 1 mg/dl) is greater than currently thought; the hormonal counterregulation follows the onset of neuroglycopenia; the hypoglycemic symptoms are a late indicator of advanced neuroglycopenia.

3-Hydroxybutyric Acid↗
PubMed1987

Significance of abnormal blood pressure response during exercise-induced myocardial dysfunction after recent acute myocardial infarction.

The relation between exercise left ventricular ejection fraction and blood pressure (BP) responses after an acute myocardial infarction (AMI) was investigated. Twenty-eight to 37 days after an uncomplicated AMI, 224 consecutive patients underwent exercise radionuclide angiography in the 40 degrees semisupine position. In 180 patients (group A, 80%), BP increased more than 5 mm Hg every stage; in 44 patients, BP responses were abnormal; in 33 (group B, 15%), BP did not increase during 2 stages; in 11 (group C, 5%), it decreased more than 5 mm Hg after an initial increase. Ejection fraction did not differ significantly among the 3 groups at rest (51 +/- 13 in group A, 50 +/- 18 in group B, 47 +/- 13 in group C [difference not significant]) or at peak exercise (51 +/- 16% in group A, 46 +/- 19% in group B, and 43 +/- 16% in group C, [difference not significant]). Exercise-induced left ventricular failure or hemodynamic decompensation occurred in 22 patients. In these patients, ejection fraction at rest was 44 +/- 19% and decreased to 35 +/- 16% (p less than 0.05) with exercise. Only 9 of these patients (41%) had abnormal BP responses, with the other 13 (59%) showing a normal BP responses. The The 35 patients with abnormal BP responses in the absence of hemodynamic decompensation were asymptomatic, terminating exercise because of fatigue. The ejection fraction at rest and during exercise in these patients was similar to that in patients with normal BP responses.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Exercise radionuclide ventriculography after uncomplicated myocardial infarction: what could we gain from the analysis of LVEF throughout the whole test?

To assess the usefulness of a step by step evaluation of exercise left ventricular ejection fraction (LVEF), 219 consecutive patients with recent uncomplicated myocardial infarction and 30 normal subjects underwent a symptom-limited cycloergometer test followed by exercise radionuclide ventriculography (ExRNV). LVEF was monitored throughout the whole test. 49 patients underwent coronary arteriography for clinical reasons. 5 patterns of exercise LVEF could be observed: progressive increase: 55 patients (25%) and 27 normal subjects (90%); progressive decrease: 37 patients (17%); initial increase followed by significant decrease: 54 patients (25%); lack of initial modification and terminal decrease: 35 patients (16%); no modification: 38 patients (17%) and 3 normal subjects (10%). Grouping the patients in this fashion allowed us to increase the specificity of ExRNV from 70% to 100%, without loss of sensitivity (95%). As for the patients in subgroup C, 32/54 showed unequivocal ECG ischaemic changes, occurring simultaneously with LVEF decrease; in 33/54 LVEF dropped during the last workload; in 25/54 the last stage LVEF was equal to or higher than the basal LVEF. The statistical analysis showed that ischaemic ECG changes (P less than 0.0001), exercise-induced wall-motion abnormalities (P less than 0.0001), and the presence of multivessel coronary artery disease (P less than 0.0001) were significantly more frequent in patients showing patterns (b)-(d), which should be considered as ischaemic. Our method allowed the unequivocal identification of ischaemic patterns in LVEF during exercise, which might be missed if only its basal and final values are considered.

Adult↗
PubMed1986

[Normal behavior during the exercise test of the left ventricular ejection fraction determined by an angioscintigraphic method].

UNLABELLED: The correct definition of left ventricular ejection fraction (LVEF) normal response to exercise is still debated. The lack of unanimous agreement firstly depends on the different normality criteria adopted in literature. In order to make ligh, we carefully reviewed several papers on this matter, and performed exercise radionuclide angiography (RNA), by multiple gated blood pool, in 2 different populations. I group: 39 normal subjects, selected on the basis of normal clinical examinations, ECG, X-ray film, exercise test, at rest LVEF greater than 50%: 20 males, mean age 43 +/- 13%. II group: 22 patients, abnormal from the clinical point of view, but elsewhere included in control groups: 13 males, mean age 54 +/- 9%. 14 of them refer only atypical chest pain, in 5 the sole abnormal finding is an exercise-induced ST depression greater than 1 mm, in 2 a left bundle branch block at rest, 1 patient suffers from X syndrome. Symptom limited exercise RNA was carried out by adopting a semi supine (40 degrees) cycloergometer, with a 25 watt initial workload and 25 watt subsequent increases every 3 minutes; count acquisition lasted 2 minutes, from the end of the 1st to the end of the 3rd, during each stage of the test. RESULTS: I group: constant LVEF increment during exercise in all subjects: mean LVEF at rest was 65 +/- 8%, at maximum workload 80 +/- 8%: mean increase was 15 +/- 7%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗