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Biomedical subjects

S Forconi

Publications and source records attributed to S Forconi.

At least 19 recordsLinked to original sources
PubMed1995

[An epidemiological study on blood viscosity and intraerythrocytic calcium in a group of high-school students selected according to their family histories].

An epidemiological study was performed in a group of secondary school students selected according to their family history to assess whether changes exist in blood viscosity and intraerythrocytic calcium levels in young healthy subjects with positive family histories of arterial hypertension or cerebral and cardiac ischemic vasculopathies, compared to a control group with a negative family history of these disorders. A population of 130 secondary school students without any pathologies were subdivided into 4 groups: 1) with a positive family history of ischemic cardiopathy (ICP); with a positive family history of cerebral ictus; 3) with a family history of arterial hypertension; 4) a negative family history of these diseases. Total blood viscosity, hematocrit, plasma fibrinogen and intraerythrocytic calcium was evaluated in all groups. The results show that these parameters were within the normal range, as was to be expected in healthy subjects. Blood viscosity was also normal in all groups; intraerythrocytic calcium levels were slightly higher in groups with histories of cardiovascular disease and in particular there was an increased percentage of cases with values above the threshold level. Higher fibrinogen levels were also recorded, but always within the normal range, in the group with a positive history of ICP. The epidemiological study is important to assess whether a family pattern of cardiovascular disease can also influence such independent risk parameters as blood viscosity and intraerythrocyte calcium, owing to the possible greater frequency of development of cardiovascular disease.

Adolescent↗
PubMed1995

[Plasma Lp(a) levels: a comparison between diabetic and nondiabetic patients with the nephrotic syndrome and control subjects].

The aim of this study was to evaluate Lp(a), total, HDL and LDL cholesterol, triglycerides, Apo A and Apo B100 plasmatic concentrations in patients affected by nephrotic syndrome that is known able to increase the ratio of the risk of cerebral and cardiovascular events, in comparison with a group of healthy patients homologous for sex and age. In the group of patients with nephrotic syndrome we have compared the variables between diabetic mellitus type I patients and non diabetic patients. All the variables, in exception of HDL cholesterol, were significantly increased in the group of patients with nephrotic syndrome compared with the control group. HDL-cholesterol concentration was significantly higher in controls than in nephrotic patients. Diabetic and nephrotic patients showed increased levels of Lp(a) concentration than non diabetic patients and the difference was statistically confirmed. These data suggest that Lp(a) acts really like a risk factor for atherosclerotic disease, being elevated in patients characterized for increased risk for cerebral and cardiovascular events because of the presence of nephrotic syndrome. Moreover we can suppose that elevated plasmatic Lp(a) levels in nephrotic patients could be linked to increased synthesis of proteins in the liver as physiological reaction to severe proteinuria.

Aged↗
PubMed1994

[Lp(a) and lipid order in a group of secondary school students selected according to their family anamnesis].

In this study we evaluated the several risk-factors, Lp(a) and lipids order, related to the family history for ischaemic cardiovascular disease (CHD) atherosclerotic cerebrovasculopathy and arterious hypertension, in a healthy adolescent group, to stress possible early and significant alteration of the lipids order and Lp(a); we also considered which of these parameters may be considered the risk factor most closely related to family history. We studies 130 healty high school students, mean age 16.5 +/- 5.5 years, selected in four groups related to the family history: the first one composed of 34 subjects with positive family history for CHD; the second one of 32 subjects with positive family history for cerebral infarction (CI); the third by 32 subjects with family history for arterial hypertension and the last group by 30 control subjects. Mean value of all variables considered was in the normality range. Lp(a) resulted in the normality range with the exception of the group with positive family history for CHD. Also the traditional risk factors (Total-Col., LDL/Col. and Triglycerides) were increased in this group. Besides the differences between the mean of Lp(a) and Total/Col. in the group with positive family history for CHD and in the control group were statistically significant. The results showed that Lp(a), even if it cannot replace the family history in the screening of coronary atherosclerotic disease, might be considered a risk marker of early atherosclerotic disease.

Adolescent↗
PubMed1987

Primary and secondary blood hyperviscosity syndromes, and syndromes associated with blood hyperviscosity.

Despite the methodological difficulties of evaluating the role of a single rheological component, some clinical situations characterised by an increase of blood viscosity can be identified. These are classified as 'blood hyperviscosity syndromes' and can be divided into 2 groups. The first includes pathophysiological conditions in which a primary blood abnormality causes a decrease of blood flow, as occurs in polycythaemic, sclerocythaemic and seric hyperviscosity syndromes, and may be referred to as 'primary blood hyperviscosity syndromes'. The second group includes pathological conditions in which a primary reduction of blood supply to tissue provokes tissue ischaemia, and an impairment of rheological properties of blood can be observed at microcirculatory level. Thus, these situations have been described as 'secondary blood hyperviscosity syndromes'. Patients with peripheral obliterative arterial disease, ischaemic cardiopathies and cerebrovascular insufficiencies show a diminution in blood fluidity during spontaneous or provoked ischaemic conditions which disappears after reperfusion of the tissue. The pathogenesis of this rheological damage is unclear, but may arise from the complex relationship among blood cells (red cells, leucocytes, platelets), endothelium and plasma components. In addition to these 2 groups of blood hyperviscosity syndromes, several pathological states such as diabetes, shock, surgery, and rheumatic disease have been described in which an increase of blood viscosity can be observed. For these situations, which require much further investigation, the term 'syndromes associated with blood hyperviscosity' could be proposed.

Blood Viscosity↗
PubMed1987

Efficacy of O-(beta-hydroxyethyl)-rutosides at high dosage in counteracting the unwanted activity of oral contraceptives on venous function.

In a double-blind study the effect of a high dosage of O-(beta-hydroxyethyl)-rutosides (HR) was tested in women taking oral contraceptives and suffering from venous insufficiency of the lower limbs. Ten patients were treated for 28 days with HR (3 g/day) and ten with a placebo. In basal conditions and after therapy, the symptoms of venous disorders and the venous function, by means of strain gauge plethysmography, was evaluated in both groups. The results showed an increase of venous capacitance and a reduction of venous tone in the subjects treated including those without symptoms in the lower limbs. The HR treatment resulted in a significant improvement of the venous function parameters and of the symptoms in lower limbs.

Adult↗
PubMed1985

[A syllectrometric method to study erythrocyte aggregation].

The authors show a new method to study erythrocyte aggregation; the results of in vitro study, obtained by modification of several parameters (hematocrit, immunoglobulins, fibrinogen concentrations), are exposed. The authors did not find in vivo correlations between MAE and hemorheological parameters in different diseases; they found low MAE values only in myelomatous subjects. Adding erythrocytes from healthy donors to myelomatous plasma and vice versa, they found low MAE values only in samples containing erythrocytes and plasma from myeloma. These results suggest that many factors, not only erythrocyte aggregability, contribute to determine MAE (Mean Aggregation Entity).

Erythrocyte Aggregation↗
PubMed1985

[The hemorheological laboratory in clinical medicine: the value and limitations of its methods].

Hemorheology has been a part of clinical research since precise parameters were determined for the study of flow properties of the blood. A laboratory for clinical hemorheology is nowadays equipped with a variety of instruments, ranging from highly sophisticated to very simple ones, to be used for the measurement of blood viscosity and its main components. The extremely precise viscometers now available for this purpose allow us to take measurements at different shear-rates and can function with small volumes at controlled temperature. The study of blood viscosity goes along with that of its main determinants. Among these there are to be reckoned plasma and serum viscosity, with its main components, i.e. proteins and fibrinogen, and also corpuscular viscosity, i.e. hematocrit and leukocrit. Special consideration is deserved by the methods attempting to evaluate the deformability and the aggregability of the erythrocytes which are, at present, matters of great interest. As far as the deformability of the erythrocytes is concerned, it is to be pointed out how different is the concept of deformability from that of filterability, and how methods directed to the study of the whole blood differ in their significance from those concerning washed red cells. Furthermore, it is to be emphasized that every method has its own questionable points. This is the case also of the methods studying the aggregability of the erythrocytes, a very complex phenomenon which for the time being seems quite difficult to evaluate.

Blood Proteins↗
PubMed1985

[Assay of erythrocyte ATP by chemoluminescence. Protective action induced by pentoxifylline on the depletion of energy from stored erythrocytes].

A new method to measure erythrocyte ATP levels is used. The authors have incubated 6 whole blood samples and 7 samples containing washed red blood cells for 6 h. They measured ATP levels and confirmed an important decrease of the values during the time. If the same samples were incubated with pentoxifylline (1.4 X 10(-4) M), the ATP decrease was less relevant.

Adenosine Triphosphate↗
PubMed1983

[Hemorrheological changes in ischemic heart disease].

Ischemic cardiopathy in its various clinical manifestations, whether acute (angina pectoris or myocardial infarction) or chronic (chronic coronary insufficiency), has shown in recent years particular hemorheological characteristics of its own. The observation of patients with such diseases has allowed us to record the existence of modifications in the parameters indicative of rheological damage. Numerous studies have been made, many of which are still in progress, with the aim of clarifying the relationships between these data and the disease. In our experience an increase in blood and plasma viscosity and a decrease in red cell deformability are often present in a manner which is statistically significant, if these patients are compared with normal subjects. Hemorheological change is more evident in the acute forms of myocardial ischemia. In fact, in angina pectoris the occurrence of pain is always accompanied by an increase in blood viscosity and by a worsening of red cell deformability both during spontaneous crises and during provocative tests. The hemorheological damage tends to diminish fairly rapidly when the crisis is over, even if the level of stabilization proves to be still higher than normal. In myocardial infarction higher levels of viscosity appear for a brief period after the onset with a slight tendency to diminish up until the 30th day. With the aim of ascertaining whether the alteration is more evident precisely at the point where the ischemia occurs, we chose a necessarily limited number of subjects, undergoing coronarography and atrial pacing for diagnostic purposes, and decided to control the hemorheological data not only in the systemic venous blood but also in the blood taken from the coronary sinus. Our data has shown that the level of viscosity and of red cell filtrability, in the blood taken from the coronary sinus, is worse than those of the systemic venous blood and that, after atrial pacing, in negative pacing subjects the variations are of slight significance whilst in positive pacing subjects we observe a rapid increase in viscosity and a decrease in red cell filtrability. This seems to confirm what we have already observed in the limbs affected by peripheral ischemia, and to demonstrate the existence of a local hyperviscosity syndrome which, even in the myocardium, appears to be dependent on the tissue ischemia.

Adult↗
PubMed1983

[Methodological survey of whole blood filtration in the evaluation of erythrocyte deformability. III. Relative influence of various cellular components].

We have counted the different types of blood cells before and immediately after filtration. During filtration, an almost equal quantity of each type of cells remained in the filter, with a slightly higher percentage of leucocytes. The problem regarding occlusion of filter pores should be considered in the light of these findings.

Blood↗
PubMed1983

[Can normovolemic hemodilution really modify blood flow in the limbs?].

A clinical study on the effects of the normovolemic hemodilution on hemorheological and peripheral hemodynamic parameters has been carried out in patients with peripheral obliterative arterial disease. Two sessions have been performed: the acute test consisted in daily normovolemic hemodilutions for a period of 7 days in 10 patients with the determination of hemorheological and peripheral hemodynamic parameters before and after each treatment. A chronic study was then carried out in 8 patients by applying weekly normovolemic hemodilutions, by evaluating the hemorheological parameters as in the first session and by measuring the peripheral hemodynamic parameters at the beginning, after 5 weeks and at the end of the treatment. The results are reported and the possible mechanism of action of normovolemic hemodilution is discussed.

Arterial Occlusive Diseases↗
PubMed1981

Influence of non-selective and selective beta adrenoceptor blockade on isoxsuprine-dependent hemodynamic and rheologic changes.

The infusion of isoxsuprine was followed by an increase of heart rate and calf blood flow and by a decrease of arterial diastolic pressure and blood viscosity both in normal controls and patients with peripheral obstructive arterial disease. The pre-treatment with a non-selective beta adrenoceptor blocker (propranolol) canceled all the isoxsuprine-dependent changes, while the pre-treatment with a selective beta adrenoceptor blocker (metoprolol) abolished only tachycardia and did not influence the increase of calf blood flow and the decrease of blood viscosity. These findings indicate the different role of vascular beta receptors in the regulation of muscular blood flow and suggest the pharmacologic possibility to unmask the beta2-dependent vasodilation.

Adult↗
PubMed1980

Effects of prostaglandin A1 on renal handling of salt and water in congestive heart failure.

Prostaglandin A1 (PGA1) was infused at the rate of 1/microgram/kg/min in 10 patients with decompensated heart failure under conditions of water loading (5 patients) or water deprivation (5 patients). During water loading, PGA1 increased urinary excretion of sodium, potassium, chloride, calcium, and magnesium, as well as free-water clearance. During water deprivation, it increased free-water reabsorption. Gomerular filtration rate was increased slightly by PGA1 only when it was given with an infusion of hypertonic mannitol during water deprivation. This selective action of PGA1, which increased the excretion but not the reabsorption of free water, suggests its use to correct certain hypo-osmolar conditions. The site of action of PGA1 on the kidney seems to be in the tubules and mainly in the proximal tubules. These findings might be important in the understanding of the role of renal prostaglandins.

Adult↗