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Biomedical subjects

G Manasse

Publications and source records attributed to G Manasse.

12 recordsLinked to original sources
PubMed1999

Behavior of circulating endothelin-1 in a group of patients with acute myocardial infarction.

The aim of this study was to investigate the behavior of plasma endothelin-1 (ET-1) in 23 patients with acute myocardial infarction, complicated and uncomplicated by left ventricular failure, and treated with and without thrombolytic agents. ET-1 was measured on admission; on days 2, 3, and 5; and again on discharge. In addition, on discharge, ET-1 was correlated with left ventricular systolic function. Left ventricular failure was present, on admission, in 14 patients, whereas the other nine did not have any hemodynamic impairment. On discharge, no patients had left ventricular failure, but 11 had moderate to severe left ventricular systolic dysfunction, defined as left ventricular ejection fraction (LVEF) < 40%. Fourteen subjects, matched for age and sex, served as a control group. Compared with the control range, ET-1 was highly elevated on the first day, in both uncomplicated (p < 0.01) and complicated patients (p < 0.001). Then it decreased rapidly in the uncomplicated group, reaching the control range within day 5, whereas in the complicated group it remained significantly elevated in comparison with both the control subjects and the uncomplicated patients, until discharge. ET-1 was not correlated with the peak of creatine-kinase MB isoenzyme in any group. In seven patients submitted to thrombolytic treatment ET-1 was always significantly lower than in the nonthrombolyzed patients (p < 0.05), but the pattern of variation across time was no different. On discharge, the difference in plasma ET-1 between patients with LVEF < 40% and the control group was significant (p < 0.001), as was the difference between patients with and without moderate to severe systolic dysfunction (p < 0.01). ET-1 was closely and inversely correlated with LVEF when patients were considered as a whole (p < 0.001). These results suggest that the ET-1 increase in the early phase of myocardial infarction could be due to an ischemic process, to stress reaction, and to cardiac hemodynamic impairment, and therefore, ET-1 may be a good marker of disease. In the following phase the ET-1, being correlated with LVEF, could be a reliable index of systolic function.

Aged↗
PubMed1999

Effects of carotid thromboendarterectomy on circulating endothelin-1.

The aim of this study was to investigate the behaviour of circulating ET-1 in patients with carotid atherosclerosis, before and after carotid thromboendarterectomy (TEA), to test the hypothesis that plasma ET-1 decreases after removal of atherosclerotic lesion. Plasma immunoreactive ET-1 levels were determined in 17 patients with symptomatic and/or hemodynamically significant carotid atherosclerosis on the day before TEA, 48 h and 72 h after surgery and, in 11 of them, also after 8 h and 24 h. Compared to controls, ET-1 levels were significantly higher both before and after TEA; after carotid revascularisation (8 h) ET-1 increased; then, from the 24th h, ET-1 gradually decreased and at the 48th h and 72th h the decrease was significant in front of basal values. The increase of plasma ET-1 in the acute postoperative phase may reflect the degree of surgical stress and manipulation in diseased blood vessels; the following decrease may indicate the improvement of vascular dysfunction in the involved carotid site; the persistence of high ET-1 levels 72 h after surgery could suggest the presence of residual ischemia in the involved district and/or the involvement of other sites in ET-1 production.

Aged↗
PubMed1996

[Variation in the plasma endothelin levels in relation to age].

In order to study the influence of ageing on the hormonal function of the endothelium in man, plasma endothelin levels were measured in 11 normal young persons (mean aged 25.7 +/- 1.8 years) and in 16 apparently healthy elderly subjects (mean 87.5 +/- 5.4 years) without anamnestic or clinical signs of symptomatic atherosclerosis. The mean plasma level +/- SD of endothelin was 2.72 +/- 0.61 pg/ml in elderly subjects and 2.09 +/- 0.66 in young subjects. The difference was statistically significant (p < 0.05). Various humoral or local age-related environmental factors may be responsible for this result. In particular increased vascular production of endothelin may be the response to endothelial cell damage caused by an asymptomatic atherosclerotic process. Studies still need to define whether enhanced plasma endothelin levels in elderly subjects not suffering from symptomatic atherosclerosis are the consequence of ageing alone or an ongoing but clinically silent atherosclerotic process.

Adult↗
PubMed1995

[Behavior of endothelin plasma levels during iloprost infusion in patients with severe ischemia in the lower extremities].

In order to clarify interactions between the various endothelial vasoactive substances, the authors studied the behaviour of endothelin plasma levels during acute iloprost infusion in 7 elderly patients with critical leg ischemia. Iloprost was administered i.v., diluted in saline solution (200 ng/ml, from 30 to 40 ml/h, for 6 hours/day over 4 weeks). Endothelin was assayed in plasma on day 4 of treatment at times 0, 2, 4, 6, 8, hours, or in other words before treatment and ten every 2 hours up until the 6th hour, and then 2 hours after the end of iloprost infusion. The control group consisted of 7 age-matched subjects suffering from peripheral obliterating arterial disease at Fontaine's stage 1 and 2 who where infused with saline solution alone. Patients receiving iloprost presented a mean endothelin plasma level +/- SD at time 0 of 5.40 +/- 1.23 pg/ml, 4.24 +/- 0.72 pg/ml at time 2, 4.22 +/- 0.74 pg/ml at time 4, 4.24 +/- 0.22 pg/ml at time 6, and 4.49 +/- 0.58 pg/ml at time 8. The difference between endothelin levels in basal conditions and those at time 2, 4 and 6 was statistically significant. The difference between the peptide at times 0 and 8 was not statistically significant. In the control group the mean +/- SD of endothelin plasma level was, at the same times, respectively 5.23 +/- 0.55 pg/ml, 4.88 +/- 1.39 pg/ml, 5.44 +/- 1.51 pg/ml, 5.10 +/- 0.86 pg/ml and 5.60 +/- 1.64 pg/ml. The difference between endothelin levels in basal conditions and those at later times was not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

[Regional changes in endothelin levels in venous and arterial blood in a limb subjected to postural variations].

The aim of this study was to evaluate the behaviour of plasma endothelin in humans both in venous and arterial blood at the level of a limb subjected to postural changes. An experimental model was designed for this purpose in which tissue hypoperfusion conditions were created in a subject lying on his back by maintaining an upper limb in a vertical position for approximately one hour. The limb was then lowered and remained horizontal for another hour. The study was performed in 5 healthy subjects aged between 59 and 75 years old. Both venous and arterial blood samples were collected, virtually contemporaneously, at times 0.60 and 120 minutes, namely before and after raising the limb and after the limb had been lowered for one hour. Mean endothelin levels +/- SD in arterial blood were respectively 3.36 +/- 1.29 pg/ml, 4.13 +/- 1.16 pg/ml and 3.82 +/- 1.11 pg/ml at times 0.60 and 120 min. Mean endothelin levels SD in venous blood at the same times were respectively 3.84 +/- 1.41 pg/ml, 5.62 +/- 2.26 pg/ml and 4.95 +/- 1.39 pg/ml. In both arterial and venous blood, the difference between the first two values was statistically significant (p < 0.05). Endothelin therefore appears to be affected by changes in district hemodynamics.

Aged↗
PubMed1983

[A rapid method for assay of 25-hydroxyvitamin D in serum].

A simplified assay for 25-hydroxyvitamin D is reported. In this procedure ethanol extraction is used in order to obtain a better protein precipitation and a higher recovery of added tritiated 25-hydroxyvitamin D3. Extraction is followed by column chromatography on Sep-pak Silica cartridges. The eluate is dried and directly used for competitive protein binding assay. The method shows two main advantages: it is less time consuming and is easier to perform than existing procedures.

25-Hydroxyvitamin D 2↗
PubMed1983

[Assay of 24,25-dihydroxyvitamin D by competitive protein binding].

A competitive protein binding radioassay for 24,25-dihydroxyvitamin D in human serum has been developed, which is relatively simple and rapid. Acetonitrile is used for sample extraction and protein precipitation. column chromatography is then performed in a Sep-pak cartridge. High pressure liquid chromatography follows. The dried eluate is assayed using rat serum as the source of binding protein. Since 25-hydroxyvitamin D3 and 24,25-dihydroxyvitamin D3 are equipotent in their competitive displacement of tritiated 25-hydroxyvitamin D3 from at serum, 25-hydroxyvitamin D3 can be used as the assay standard.

24,25-Dihydroxyvitamin D 3↗
PubMed1983

Adrenal function and essential hypertension.

A study of the adrenal function in patients with essential hypertension was performed using gas-liquid chromatography to separate and measure the daily urinary excretion of individual 17-ketosteroids, pregnanediol and pregnanetriol in basal conditions and after a dexamethasone suppression test. The purpose of the study was to detect alterations of adrenal function possibly indicative of some role of the adrenal cortex in the pathogenesis of hypertension. The results showed normal urinary levels of 17-ketosteroids, pregnanediol and pregnanetriol in most patients. Higher values were observed in the remaining cases. Dexamethasone suppression tests confirmed that steroid excess in these patients was of adrenal origin.

17-Ketosteroids↗