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Biomedical subjects

R Ranieri

Publications and source records attributed to R Ranieri.

At least 37 records · Page 2Linked to original sources

[Hemorrheologic disorders of red cells in subjects at risk for atherosclerosis].

Cigarette smoking, hypercholesterolaemia, hypertriglyceridaemia, are all known risk factors for atherosclerotic vascular lesions. Often they are associated with alterations mainly due to increased haematocrit (smoking) or to the influence of triglycerides and cholesterol on the erythrocyte membrane or plasma viscosity. In order to eliminate these factors, washed red blood cells, poor in leucocytes and platelets, in a suspension with phosphate saline buffer were studied. 20 heavy smokers, 40 patients with hyperlipidaemia (26 II a or b; 14 IV) and 50 healthy people were considered. Red blood cell viscosity was calculated at 4 shear rate between 0.37 and 69.5 sec-1. Red blood cell deformability, as an indicator of cell filtration through Nucleopore membranes was also studied. There was no difference in the filtration index among the subjects under study. Red blood cell viscosity increased in smokers and in patients with hyperlipidaemia.

Adult↗

[Hemorrheologic disorders in obese patients. Study of the viscosity of the blood, erythrocytes, plasma, fibrinogen and the erythrocyte filtration index].

Risk factors for atherosclerosis are often associated with haemorheological changes. On this point, obesity (recently advocated as an independent risk factor) was not much studied and with not univocal results. We have studied 70 obese patients (BMI greater than 30) and 50 healthy subjects (BMI less than 25). Among obese 26 had no more pathologies, 29 had hypertension, 3 suffered from ischemic heart disease, 3 suffered from occlusive arteriopathy, 9 were hyperlipidemic, 10 were smokers. We determined plasma viscosity and whole blood viscosity (at haematocrit corrected to 45% too). Washed erythrocytes, poor in leucocytes and platelets and resuspended in phosphate-buffered saline, were used for study of erythrocyte viscosity and deformability. Obese patients showed raised mean blood viscosity values when compared to healthy controls (p less than 0.01); an even more significant increase (p less than 0.001) was found concerning plasma viscosity and fibrinogen. Erythrocyte viscosity and red blood cell filterability index did not show any significant difference. We found no significant correlation between viscosity values and presence of hypertension, hyperlipidemia and smoking habit among obese. In conclusion, the higher vasculopathy incidence might be caused by an increase in blood viscosity, mostly due to plasmatic component. This fact appears to be independent from the presence of atherosclerosis complications or other risk factors.

Adult↗

Changes in plasma and cerebrospinal fluid electrolytes in hypercapnia.

A study on two groups of patients in acute respiratory failure with hypercapnia (18 subjects) and in hypercapnic coma (18 subjects) has been carried out to determine the related changes in sodium ion, potassium ion, chloride ion, urea and osmolality in blood and cerebrospinal fluid. There were significant differences between the two pathological states and particularly in coma, changes in transmembrane active transport of electrolytes are significantly related to high concentrations of CO2 in the brain.

Carbon Dioxide↗

Effect of respiratory acidosis on plasma and CSF free amino acids.

Acid-base data and levels of selected cerebrospinal fluid (CSF) free amino acids were analyzed in a series of 8 patients in acute respiratory failure. In these patients, there were increased CSF concentrations of methionine, phenylalanine, tyrosine, histidine, alpha-amino-N-butyric acid, glutamic acid, glutamine, glycine, alanine, and ammonia, while arginine decreased. Phenylalanine, tryosine, and alanine were correlated with CSF PCO2; and alpha-amino-N-butyric acid to the buffer capacity of CO2 and pH. The data suggest the hypothesis that there are two metabolic phases for ammonia removal from brain tissue, that could explain some of these pathhophysiological conditions.

Acidosis, Respiratory↗

Concentrations of free amino acids in plasma, erythrocytes and cerebrospinal fluid in coma.

The concentrations of free amino acids were measured in plasma and erythrocytes in 15 patients, and in cerebrospinal fluid in eight patients, who were in coma. Although there was a variety of causes of coma, there seemed to be a characteristic pattern of the concentrations of amino acids for coma, and the plasma/cerebrospinal fluid ratios also showed constant patterns.

Amino Acids↗

Changes in blood viscosity and plasma proteins in myocardial infarction.

A clinical study of some biological and biochemical factors was carried out on patients with acute myocardial infarction. It was shown that: (i) the plasma viscosity was highly correlated to the clinical evolution of myocardial infarction; (ii) the variations of plasma viscosity were related to changes in the connection of fibrinogen and globulin; (iii) the highest correlation was between the plasma viscosity and alpha2-globulin concentration. The monitoring of these may be useful in the clinical evaluation of myocardial infarction.

Adult↗

Prevalence of erectile dysfunction in thyroid disorders: comparison with control subjects and with obese and diabetic patients.

Diagnosis of erectile dysfunction (ED) requires anamnestic investigation, being rarely spontaneously declared by patients. ED occurs frequently in diabetes mellitus, and anecdotal evidence suggests that ED occurs in obesity and in hypothyroidism. The aim of this study was to evaluate the prevalence of ED in patients affected by thyroid disorders (hypothyroidism and hyperthyroidism), in comparison with control subjects and with patients at risk for ED, such as patients with obesity and with type II diabetes mellitus, and the role of age. Spontaneous deposition and International Index of Erectile Dysfunction (IIEF)-5 questionnaire were considered for control subjects and for all patients. Spontaneous deposition of ED occurred for three diabetic patients, never for obese patients, thyroid patients and controls, confirming the value of IIEF-5 in detecting ED. ED was more frequent in obese subjects (42%), and in patients affected by thyroid diseases (59%), than in controls (30%), although less frequent than in type II diabetes mellitus (81%). Both below and above the age of 50 years, ED score was worse in thyroid patients than in control subjects, while ED was more frequent in obese patients than in control subjects only below the age of 50 years.

Case-Control Studies↗

Comparison of CSF-free amino acid concentrations among various neuropathological conditions.

The level of free amino acids in cerebrospinal fluid from eight patients in comatose states has been determined. The variations of cerebrospinal fluid-free amino acids observed in coma have been compared with those reported by other authors in patients affected by epilepsy, multiple sclerosis, infantile amaurotic idiocy (GM2-gangliosidosis) and phenylketonuria.

Amino Acids↗

Brain lactate uptake in coma secondary to acute cerebrovascular accident.

Relative distribution of lactate, pyruvate, and glucose in cerebrospinal fluid, arterial blood, and jugular blood has been determined in patients in status of coma following cerebrovascular accidents and compared with values obtained in patients without CNS disorders. Ratios of lactate/pyruvate and arteriovenous differences were calculated. In the cerebrospinal fluid of these patients a significant increase of lactate concentration and of the lactate/pyruvate ratio was observed.

Blood Glucose↗