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Biomedical subjects

A Lechi

Publications and source records attributed to A Lechi.

At least 19 recordsLinked to original sources
PubMed1992

Changes in the haemodynamics of large arteries induced by single doses of nicardipine, enalapril, atenolol and urapidil.

Haemodynamic changes in the carotid and brachial arteries produced by single doses of four anti-hypertensive drugs (nicardipine, enalapril, atenolol, and urapidil) have been studied in 12 patients with essential hypertension. Measurements were performed noninvasively using a mechanographic method and B-mode pulsed Doppler ultrasonography. Within 7 h all of the drugs had caused a significant reduction in blood pressure, whereas heart rate showed a significant change only after atenolol. All the drugs produced a marked reduction in brachial pulse-wave velocity. Only nicardipine caused a significant reduction in vessel wall tension both in the carotid and brachial arteries, while brachial peripheral resistance was significantly reduced by all the drugs except atenolol. Neither atenolol nor enalapril caused any significant reduction in carotid peripheral resistance. The results show that all four antihypertensive drugs led to a beneficial increase in arterial compliance despite their different effects on peripheral resistance.

Adult↗
PubMed1992

Left ventricular diastolic function and responses to adrenergic stimuli in borderline arterial hypertension.

OBJECTIVE: To detect the existence of a possible relationship between arterial hypertension and adrenergic reactivity to pressure stimuli, and changes in left ventricular diastolic function (LVDF). PATIENTS: Fifty-nine young subjects with borderline arterial hypertension and ten sex- and age-matched controls were investigated. After three medical examinations, the subjects were divided into hypertensive and borderline groups on the basis of the blood pressure reading at visit 3. A complete echocardiographic study was performed in 25 of the 59 subjects. DESIGN: Blood pressure was measured in baseline conditions and during pressure stimuli (mental stress, handgrip and cold pressor tests). LVDF was evaluated primarily by means of filling velocities during diastolic phases taken from the left ventricular volume curve (obtained from a complete echocardiographic study). RESULTS: No significant changes in blood pressure responses were observed for the borderline or hypertensive groups during the adrenergic test. The echocardiographic indices of diastolic function were statistically different for the two groups when compared with the control group. The LVDF parameters correlated significantly with systolic blood pressure and diastolic blood pressure measured at the time of the echocardiogram, but not with blood pressure measured occasionally. CONCLUSIONS: Blood pressure increases similarly during adrenergic stimuli in both the hypertensive and borderline groups. The correlation between systolic blood pressure, diastolic blood pressure and LVDF parameters may indicate a very early onset of reduced compliance of the left ventricle, even in a preclinical phase of hypertension.

Adolescent↗
PubMed1992

Wernicke's encephalopathy: occurrence and pathological aspects in a series of 400 AIDS patients.

BACKGROUND: Wernicke encephalopathy (WE), acute (microhaemorrhages) and chronic (proliferation of capillaries) is actually considered as a not uncommon, and curable, condition in several diseases, and not only in alcoholic patients. Why serotoninergic nuclei, and whether blood brain barrier (BB) are involved were our questions. METHODS: In a dramatic series of AIDS cases we selected 380 brains, all belonging to drug addicted subjects. In all Thiamine administration had been under 20 mg pro die and by oral way. In the cases considered, opportunistic infections were present in the 40%, and/or HIV specificity in the 35%. RESULTS: "Acute" WE was found in nearly the 10%. All patients presented with CNS lesions, other than those of WE, but HIV specificity was found only in 5. They all showed changes in Choroid Plexus, namely alterations of various type of the cuboid epithelium, such as swelling, disruption, hyperplasia. DISCUSSION: WE is set in connection with pyruvate accumulation at capillary level, likely bound to the Thiamine deficiency and to the lack of energy thus induced. Apart from obvious haemorrhagic aspects, CFS studies in WE are lacking. Choroid structure is not merely a permeable membrane (CSF is not a filtrate). Our findings would suggest that Thiamine plays a role in the energy supply to BB. Moreover, the existence of free nerve endings through the ependyma for the release and uptake of monoamines, allows to consider the elective involvement of serotoninergic neurons as somehow connected to the choroid plexus changes described.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Effect of picotamide on platelet aggregation and on thromboxane A2 production in vivo.

Effects of picotamide (900 mg in 3 oral administrations for 7 days) on ex vivo and in vivo platelet TxA2 production and on platelet aggregation were evaluated in 8 patients with peripheral arteriopathy and in 8 normal subjects. Picotamide significantly reduced ADP-induced platelet aggregation, but had no effect on that induced by arachidonic acid or the thromboxane analogue U46619. Though ex vivo platelet TxA2 production (TxB2 concentration after arachidonic-acid-induced aggregation) was reduced from 946 +/- 141 (mean +/- SD) to 285 +/- 91 ng/ml in controls and from 1515 +/- 673 to 732 +/- 420 ng/ml in patients with arteriopathy, there was no effect on urinary excretion of 2,3-dinor-TXB2 (in vivo indicator of platelet TxA2 production), or on in vivo PGI2 production (urinary excretion of 6-keto-PGF1 alpha and 2,3-dinor-6-keto-PGF1 alpha). In the same subjects, single-dose aspirin reduced ex vivo TxB2 production by at least 98% and 2,3-dinor-TxB2 excretion from 116.7 +/- 61.4 to 32.6 +/- 17.0 ng/g creatinine in control subjects, and from 156.3 +/- 66.1 to 59.1 +/- 19.2 ng/g creatinine in patients with peripheral arteriopathy. Our data suggest that inhibition of platelet TxA2 production in vivo may not be picotamide's main mechanism of action.

Aged↗
PubMed1991

Plasma levels of an endogenous Na(+)-K+ pump inhibitor in relation to haemodynamic data in cardiopathic patients.

1. Despite the fact that numerous studies provide evidence for the existence of an endogenous inhibitor of the cell membrane Na(+)-K+ pump in plasma, little is known about the relationships between this factor and the main haemodynamic parameters. 2. In order to shed some light on this, we attempted to correlate haemodynamic parameters, measured during heart catheterization in a group of 22 cardiopathic subjects, with plasma digitalis-like activity levels, determined by two different procedures. 3. The ability of plasma to inhibit a human renal Na(+)-K(+)-ATPase showed an inverse correlation with cardiac index and a direct correlation with peripheral resistance. Plasma cross-reactivity with digoxin antibodies correlated directly with left atrial pressure. 4. These results furnish confirmation of a number of theoretical assumptions which attribute to the digitalis-like factor the ability to modify the contractility of the cardiovascular system.

Adult↗
PubMed1991

Efficacy of ketanserin in the therapy of Raynaud's phenomenon: thermometric data.

After a two-week washout (WO) period with placebo 1 capsule/bid, 12 patients suffering from stable Raynaud's phenomenon were treated with ketanserin (K) 40 mg/bid for fifteen days. Blood pressure, heart rate, and laboratory parameters were evaluated at the end of each period. Patients used diary cards to record the number, duration, and intensity of attacks. Computerized thermometry of the fingers was evaluated at basal temperature after acclimatization, 23 degrees C for thirty minutes; after cold test, 10 degrees C for five minutes; and after thermal recovery, 23 degrees C for eighteen minutes. Results were analyzed statistically by use of Student's t-test for paired data (p less than 0.05). No marked changes were observed in the symptoms of the attacks, but K proved effective in significantly reducing the number and duration of daily attacks and in promoting their spontaneous regression. Thermometry revealed a parallel increase in temperatures, particularly basal and recovery values. The data suggest increased flow and decreased vasospasm following 5-HT2 receptor blockade.

Adult↗
PubMed1991

Remodeling of left ventricular geometry and function induced by lacidipine and nifedipine SR in mild-to-moderate hypertension.

The effects of nifedipine SR and lacidipine on blood pressure, left ventricular (LV) hypertrophy, and diastolic function were evaluated in 15 male patients (mean age of 45 +/- 8 years) with mild-to-moderate hypertension. Clinical evaluation and complete echocardiography were performed at baseline (after 15 days of washout). Seven patients received nifedipine SR (20-40 mg twice daily) and eight lacidipine (4-6 mg once daily). Clinical evaluation and complete echocardiography studies were repeated after 1 and 6 months of active treatment. In addition, full echocardiographic evaluations were carried out in 10 normotensive subjects (for comparison). Results were similar with either drug. After 1 month of therapy, systolic and diastolic blood pressures were significantly decreased (p less than 0.05); after 6 months of therapy, further changes were observed, confirming their significance. Analysis of our data suggests that (a) mild essential hypertension induces early modifications of LV geometry with consequent LV diastolic function characterized by a prolonged and incomplete diastolic filling; thus, LV wall thickness may be increased with a simultaneous reduction in LV end-diastolic short-axis diameter and volume; and (b) antihypertensive treatment with calcium antagonists such as nifedipine SR and lacidipine leads to early normalization of LV geometry and diastolic function without a significant change in total LV mass.

Adult↗
PubMed1990

Considerations on a group of 13 patients with Creutzfeldt-Jakob disease in the region of Parma (Italy)

We report a group of 13 cases of Creutzfeldt-Jakob disease treated in the region of Parma (Italy) between 1975 and 1984. An extensive study did not point to any common source of infection. The clinical stereotypy and distinctive neuropathology in this temporo-spatially confined group of patients might be stressed, but the possibility of infection by a single strain of the CJD agent remains speculative.

Aged↗
PubMed1990

Early regression of left ventricular diastolic abnormalities in hypertensive patients treated with nifedipine.

The effects of nifedipine on blood pressure (BP), left ventricular hypertrophy, and diastolic function were evaluated in 14 patients with essential hypertension (EH). All males with a mean age of 44 +/- 6 years (range 35-58 years), and in ten normotensive subjects (control group) aged 32-42 years (mean age 36 +/- 4). A complete echocardiogram (ECHO) was performed in basal conditions after 1 and 6 months of therapy with nifedipine (20-40 mg/day). Left ventricular echocardiograms (LV ECHO, M-mode, two-dimensional guided) were plotted with a simultaneous ECG tracing by means of a computerized system that allows evaluation of the following parameters: LV end-diastolic and systolic diameters (EDD, ESD); variations in LV diameter and volume during the entire cardiac cycle, and the velocities of such variations; end-diastolic thicknesses of the interventricular septum and posterior wall (ST, PWT); LV mass, mass/volume (M/V) index, end-diastolic diameter/thickness (D/Th) index, and LV ejection fraction (EF). Left ventricular volume curves were obtained and the contributions of rapid filling (RF) and atrial systole (AS) to EDV were evaluated. Filling velocities during RF (vRF) and AS (vAS) were estimated, as well as the isovolumic relaxation period (IR). No significant changes were observed in the heart rate. After 1 month of therapy, systolic and diastolic BP were significantly decreased (p less than 0.05). ST and PWT were reduced, with a simultaneous increase in EDD and EDV (p less than 0.01). LV mass was slightly reduced, as was the M/V index. The D/Th index was increased (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Increase in plasma digitalis-like activity during percutaneous transluminal coronary angioplasty in patients with coronary stenosis.

Despite the fact that numerous studies have been published regarding the possible presence in plasma of an endogenous Na-K pump inhibitor with a digitalis-like structure in essential hypertension, very little is known about this factor in heart disease in general, and in situations characterized by low cardiac output. We measured the ability of plasma obtained from the femoral vein to inhibit a human renal Na(+)-K+ ATPase before and immediately after percutaneous transluminal coronary angioplasty (PTCA) in 6 patients suffering from angina pectoris and severe coronary stenosis. Intraerythrocyte sodium and potassium concentrations were also measured simultaneously. Na(+)-K+ ATPase inhibition proved significantly greater after angioplasty as compared to basal activity (percentage inhibition: 31.5 +/- 7.8 vs 16.1 +/- 12.2). No significant changes in intraerythrocyte sodium and potassium were detected. Though we are not in a position to define the mechanism underlying the increase in the digitalis-like factor, a plausible hypothesis may be that the reduction in cardiac output during PTCA by raising cardiac pressures may stimulate the production of a factor of compensatory inotropic significance.

Angioplasty, Balloon, Coronary↗
PubMed1990

Multifocal vacuolar leucoencephalopathy: a distinct HIV-associated lesion of the brain.

A 20-year-old male AIDS patient developed rapidly progressive dementia for more than 3 months prior to death. Autopsy showed, in addition to adrenal cytomegalovirus (CMV) infection and focal cerebral necrosis due to toxoplasmosis, multifocal subcortical white matter lesions of the brain which were strikingly similar to the histopathology of vacuolar myelopathy in AIDS. These distinct lesions contained macrophages which were rarely multinucleated and expressed HIV antigens by immunocytochemistry. The distribution of lesions mimics extrapontine myelinolysis and progressive multifocal leucoencephalopathy (PML); PML was excluded by the absence of papovaviruses by immunocytochemistry and by in situ DNA hybridization. Tissue damage in multifocal vacuolar leucoencephalopathy is different from hitherto characterized HIV-specific neuropathology such as HIV encephalitis and HIV leucoencephalopathy, and should be included in the list of conditions with damage of the brain white matter in AIDS.

AIDS Dementia Complex↗
PubMed1990

Neuropathology of AIDS dementia. A review after 205 post mortem examinations.

109 brains were selected after the exclusion of those affected by space occupying lesions or opportunistic infections. All brains with HIV specificity (nodules with multinucleated cells and, at times, two peculiar kinds of myelin involvement) were atrophic (62%); nevertheless dementia had been mentioned only in the 55% of the corresponding autopsy requests. In agreement with previous studies we conclude that HIV encephalopathy does not always give rise to neurological signs.

AIDS Dementia Complex↗
PubMed1989

Effects of long-term nicardipine treatment on hemodynamics of large arteries in essential hypertension.

The effects of the calcium-entry blocker nicardipine on brachial hemodynamics were studied in 22 patients (18 male, 4 female) with essential hypertension, who were treated with 20 mg tid for 1 year. Compliance, characteristic impedance, vascular resistances, and tangential tension were measured before treatment and after 1, 3, and 12 months of treatment by an automatic recording from a B-mode, high-resolution, real-time scanner and pulsed Doppler velocimetry for the calculation of the flow volume. We observed statistically significant variations in compliance and impedance after 1 month (3.21 +/- 0.59 dyn-1 cm4 10(-7) vs. 1.26 +/- 0.16 dyn-1 cm4 10(-7) and 50.6 +/- 4.7 dyn s cm-510(2) vs. 91.4 +/- 7.3 dyn s cm-5 10(2), respectively; mean +/- SEM; p less than 0.001), while tangential tension was significantly reduced after only 3 months (23.2 +/- 2.2 mmHg vs. 25.4 +/- 2.3 mmHg cm; p less than 0.05). The correlation between variations in mean blood pressure and in the hemodynamic parameters studied remained statistically significant throughout the study. Nicardipine improved the parameters of large-artery hemodynamics that favor a normal systolic pulse.

Adult↗