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Biomedical subjects

A Lechi

Publications and source records attributed to A Lechi.

At least 73 records · Page 4Linked to original sources
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↗
PubMed1989

Increased urinary 6-keto-PGF1 alpha excretion during water immersion is blunted by metoclopramide in normal man.

Urinary excretion of 6-keto-PGF1 alpha and 2,3 dinor-6-keto-PGF1 alpha, as indices of the renal and systemic production of prostaglandins, was measured during water immersion in a group of 6 healthy volunteers both in the presence and absence of dopamine blockade by the dopamine receptor antagonist, metoclopramide. Urinary flow rate and excretion of both sodium and 6-keto-PGF1 alpha increased during water immersion, while plasma renin activity and plasma aldosterone were reduced. Urinary kallikrein and 2,3 dinor-6-keto-PGF1 alpha also tended to increase during water immersion. Administration of metoclopramide significantly reduced 6-keto-PGF1 alpha and sodium excretion during water immersion, but produced no changes in plasma renin activity or in 2,3 dinor-6-keto-PGF1 alpha. Plasma aldosterone concentrations after metoclopramide were similar to those observed in the pre-immersion period. An increased synthesis of the vasodilator and natriuretic prostacyclin in the kidney might play a role in the response to water immersion. The reduced sodium and 6-keto-PGF1 alpha excretion observed after metoclopramide administration suggests that dopamine might induce prostacyclin synthesis in the kidney during water immersion.

6-Ketoprostaglandin F1 alpha↗
PubMed1989

Increased platelet aggregation and intracellular calcium in hypertensive patients: effects of cyclo-oxygenase blockade.

Increased platelet aggregation induced by ADP and arachidonic acid was observed in 12 patients with essential hypertension compared with 12 control subjects, but not after pretreatment with acetylsalicylic acid. The increase in intracellular calcium induced by ADP was also greater in the hypertensive patients, and again this difference disappeared after cyclo-oxygenase blockade. Urinary excretion of 2,3-dinor-thromboxane B2, the main metabolite of platelet thromboxane A2, was slightly, but not significantly increased in the hypertensive patients. These data suggest that thromboxane system activity is increased in the platelets of hypertensive patients.

Adenosine Diphosphate↗
PubMed1989

Haemodynamic parameters in hypertensive patients: changes induced by lacidipine and nifedipine.

We conducted a randomly allocated, double-blind study in 16 essential hypertensive patients, eight of whom were treated with nifedipine and eight with lacidipine. The antihypertensive efficacy was evaluated and any modifications to peripheral haemodynamic parameters were observed in the brachial artery by a mechanographic method and B-mode scanner with a 10-MHz probe. Statistically significant reductions in blood pressure from basal values were observed after 1 and 6 months' treatment. Enhanced compliance (P less than 0.005), reduced characteristic impedance (P less than 0.001) and lower peripheral resistances (P less than 0.01) were also noted. Variations in pulse wave velocity and mean blood pressure showed a statistically significant correlation as early as the first month of treatment (P less than 0.01). Our results suggest that therapy with nifedipine and lacidipine allows an improvement in peripheral haemodynamics in hypertensive patients. This response is maintained in chronic treatment, even just before the next dose administration at the end of the longest dose interval.

Adult↗
PubMed1989

High plasma levels of a ouabain-like factor in normal pregnancy and in pre-eclampsia.

Recent reports have described high levels of one or more substances which cross-react with digoxin antibodies in the serum of women with pre-eclampsia. We measured plasma ouabain-like activity and intraerythrocyte sodium and potassium concentrations, in addition to performing routine hypertensive laboratory tests, in 13 normotensive non-pregnant subjects, 15 normotensive pregnant women and 16 pre-eclamptic women (gestational age: 33-36 weeks). Plasma ouabain-like activity, measured as plasma-induced variations in ouabain binding to human erythrocytes, proved significantly higher in both groups of pregnant subjects as compared to normotensive non-pregnant women, and a significant difference was also found between pre-eclamptic and normotensive pregnant women, the former exhibiting higher plasma ouabain-like activity. No differences in intracellular sodium and potassium levels were detected among the three groups studied. Though there is reason to believe that the high plasma levels found both in normal and hypertensive pregnancy may depend on placental production, we are not in a position to define with any degree of certainty what the mechanism or mechanisms are that regulate ouabain-like factor production.

Adult↗
PubMed1989

Comparative efficacy of ketanserin and pentoxiphylline in treatment of Raynaud's phenomenon.

In a randomized, placebo-controlled, crossover study, 15 ambulatory patients with Raynaud's phenomenon, treated for three weeks with ketanserin 80 mg/day and pentoxiphylline 1,200 mg/day, were evaluated by subjective symptom scores, daily frequency and duration of attacks, and photoplethysmography, at room temperature and after cold test. Reduced subjective symptoms and duration of attacks, together with improved cold test plethysmography, were significant only after ketanserin. All subjective symptom scores also improved after ketanserin but only for cyanosis and paresthesia after pentoxiphylline. Excellent results were obtained in 4 cases after ketanserin and in 1 case with pentoxiphylline. The authors discuss the greater importance of antivasospastic action over antiaggregating and hemorheologic effects in Raynaud's phenomenon therapy, as well as the pathogenetic role of serotonin.

Adult↗
PubMed1989

Defibrotide and peripheral obliterative arterial disease: preliminary data.

In a pilot study, defibrotide was administered to 22 patients with arterial occlusive disease of the lower limbs (mean age 59 years; range 48-71 years), of whom 12 were Fontaine 2nd stage and 10 Fontaine 3rd stage. In the first group, treatment enabled significant improvement in the walking distance (580 +/- 95 vs 220 +/- 65 m; M +/- SD; p less than 0.001), even 15 days after discontinuation of therapy (445 +/- 110 m; p less than 0.05). In 3rd stage patients, treatment caused reasonable reduction of pain, with elimination of resting pain in 4 patients. Both groups underwent no modification of Doppler velocimetry and Winsor index, while photoplethysmography in 8 patients at 2nd- and in 3 patients at 3rd-stage showed improvement at the end of treatment. There were no modifications of hepatic, renal, hemopoietic and hemocoagulative functions. Beta-thromboglobulin showed a statistically significant reduction (62 +/- 10 vs 116 +/- 18 ng/ml; M +/- SEM; p less than 0.001), from 2 weeks after the first dose until 15 days after discontinuation of therapy. Defibrotide proved particularly efficacious in Fontaine 2nd-stage patients, showing its suitability for treating the stages of occlusive atherosclerotic disease at which collateral circulation can still be activated.

Aged↗
PubMed1989

[Cerebral cortex and HIV lesion specificity. A neuropathological study of the brain of 100 drug addicts].

Brains of AIDS patients do often display characters of HIV specificity, in the presence or not of opportunistic lesions. Mesodermal nodules with giant cells, and a peculiar primary demyelination, the progressive diffuse leukoencephalopathy of Kleihues et al., which can be found only in brains with giant cells, have been pointed out as typical. In 100 intra venous drug user patients, younger than 32 years (mean age: 26) the HIV specificity described was observed on 49 occasions. All these patients presented with Seitelberger's glio-neuronal poliodystrophy (GP), quite similar to that encountered in several kinds of encephalopathies. Nevertheless, in 35 of the patients with HIV typical findings, there was in the cortex and some other grey matter regions, an amount of diffuse mesodermal elements uncommon in encephalopathies, and so relevant as to contradict the notion itself of this kind of cerebral lesion, where "inflammatory" events ought not to appear. This aspect of HIV encephalopathy was indicated by us as "GP plus". An optic microscopy examination of the cortex allowed us to establish how in GP plus the neuronal changes are more severe and apparently older than in the other patients considered. The fact that the astrocytes did not behave differently in the two aspects of encephalopathy lead us to conclude that GP plus sets in through processes distinct from those in encephalopathy tout-court, and to put forward that it is a further character of HIV specificity.

AIDS Dementia Complex↗