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Biomedical subjects

G Caimi

Publications and source records attributed to G Caimi.

At least 73 records · Page 4Linked to original sources
PubMed1995

Cytosolic Ca2+ content and membrane fluidity of platelets and polymorphonuclear leucocytes in diabetes mellitus.

Considering the role played by platelets and leucocytes in diabetic disease and keeping in mind the strong correlation between functional and metabolic aspects that characterizes this clinical condition, we evaluated, in two groups of diabetics, respectively the platelet and polymorphonuclear (PMN) cytosolic Ca2+ content (employing the fluorescent probe Fura 2-AM) and membrane fluidity (using the fluorescent probe TMA-DPH and considering the fluorescence polarization degree, inversely related to the membrane fluidity). From the obtained results, it is evident that the platelet cytosolic Ca2+ content does not distinguish normals from diabetics of type 1 and 2; the platelet membrane fluidity instead does not discriminate normals from diabetics, but differentiates diabetics of type 1 and 2 (type 1 = 0.284 +/- 0.015; type 2 = 0.314 +/- 0.018; p < 0.001). PMN cytosolic Ca2+ content and membrane fluidity do not discriminate normals from diabetics. In the two groups of diabetics none of the platelet and PMN parameters (cytosolic Ca2+ content and membrane fluidity) are related to the glycometabolic pattern.

Adolescent↗
PubMed1995

Membrane fluidity, membrane lipid pattern, and cytosolic Ca2+ content in platelets from a group of type II diabetic patients with macrovascular complications.

OBJECTIVE: To evaluate platelet membrane fluidity and some platelet metabolic parameters in type II diabetic patients with macrovascular complications. RESEARCH DESIGN AND METHODS: In a group of 21 type II diabetic patients with macrovascular complications, we evaluated platelet membrane fluidity [marking intact resting platelets with the fluorescent probe 1,4-(trimethylamino)-phenyl-4-phenylhexatriene (TMA-DPH)], platelet membrane lipid pattern (cholesterol:phospholipid [C:PL] ratio and individual phospholipids), and platelet cytosolic Ca2+ content (marking intact resting platelets with the fluorescent probe Fura 2AM). RESULTS: Platelet membrane fluidity is decreased in type II diabetic patients with macrovascular complications compared with normal subjects (P < 0.001). Platelet membrane C:PL ratio and cytosolic Ca2+ content do not discriminate normal subjects from diabetic patients, and for individual phospholipids, only phosphatidylethanolamine is decreased in diabetic patients compared with control subjects (P = 0.051). In normal subjects, the polarization degree of TMA-DPH is related to phosphatidylserine (P < 0.05) and phosphatidylcholine (P < 0.05), and in diabetic patients the polarization degree of TMA-DPH is related to C:PL ratio (P < 0.05) and sphyngomyelin (P < 0.05). CONCLUSIONS: In type II diabetic patients with macrovascular complications, we observed an abnormality of platelet membrane fluidity, which may contribute to platelet functional alteration present in this clinical condition.

Aged↗
PubMed1995

[Plasma, erythrocyte and platelet magnesium in essential hyperTension, diabetes mellitus without and with macrovascular complications and atherosclerotic vascular disease].

In 4 groups of subjects with different clinical conditions: essential hypertension, diabetes mellitus without and with macrovascular complications, vascular atherosclerotic disease (VAD), we evaluated the plasma, erythrocyte and platelet magnesium content, the correlations between them and the relationships among all these parameters and metabolic and haemodynamic determinants. From the obtained data, it is evident that platelet magnesium content is decreased in hypertensives and in type 2 diabetics with macrovascular complications, and in subjects with VAD, while the red cell magnesium content in VAD subjects and in type 2 diabetics with macrovascular complications is increased; in type 1 diabetics we observed a decrease of the plasma magnesium level. The relationships between the plasma and cellular magnesium content, in the different clinical conditions, seem interesting.

Adult↗
PubMed1994

Resting energy expenditure and body composition in morbidly obese, obese and control subjects.

Resting energy expenditure (REE) was investigated by indirect calorimetry in relation to body composition and to different degrees of obesity in order to assess if a defective energy expenditure contributes to extra body fat accumulation. Differences were found between control subjects (group C; BMI 23 +/- 0.5 kg/m2, REE 5890 +/- 218 kJ/day; mean +/- SEM) and obese subjects (group O; BMI 34.2 +/- 0.9 kg/m2, REE 7447 +/- 360 kJ/day; P < 0.0001) and between group C and morbidly obese subjects (group MO; BMI 49.9 +/- 1.6 kg/m2, REE 8330 +/- 360 kJ/day; P < 0.0001); REE was not significantly different between groups O and MO. Body composition data were obtained by means of body impedance analysis. Even though group MO had a fat mass higher than group O, body cell mass, the metabolically active body compartment, was similar in groups O and MO, and this fact may have contributed to the similar REE in the two groups. Multiple regression analysis gave the following equation as the best predictor of REE: REE (kJ/day) = 1591 +/- 49BW + 74BCM - 737G (R2 = 0.88), where BW is body weight, BCM is body cell mass and G is a dummy variable coding group membership (group C = 1; group O = 2; group MO = 3). Thus the analysis showed a negative impact of obesity on REE beyond body composition variables.

Adult↗
PubMed1993

[Pathogenesis of diabetic microangiopathy].

Several are the recent experimental data regarding the pathogenesis of diabetic microangiopathy, even if the comprehensive picture of this condition is still rather incomplete. The functional and structural alterations of several organs involved (first of all kidney and retina) are especially dependent on the activation of the polyol pathway and on the increase of the nonenzymatic glycosylation. An important determinant of diabetic microangiopathy is the increase of permeability, at first charged especially to the haemodynamic alterations and partly reversible, and later supported by irreversible variations of the cellular and extracellular components of the vascular wall. Genetic factors certainly contribute to the explanation of the diverse gravity of microvascular damage in diabetic patients, even if the mechanisms by which they interfere are only partly known. Furthermore, the links between arterial hypertension and diabetic nephropathy, and also the reduction in glycosaminoglycans in the basal membranes are perhaps genetically originated.

Animals↗
PubMed1992

Red cell membrane protein lateral mobility in diabetes mellitus.

In a group of 24 diabetics subdivided for type, we evaluated the red cell membrane protein lateral mobility marking intact red cells with pyrene-3-maleimide (3-PM) and calculating the dimer to monomer fluorescence intensity ratio (Iex/Im). The same fluorescent parameter was determined in a group of 13 normal controls. From the obtained data, it is evident that the red cell membrane protein lateral mobility clearly discriminates normals from diabetics of type 1 and 2. In normals and in diabetics of type 1 and 2 no relationship is present between this fluorescent determinant and the glycometabolic parameters (FBGL and HbA1c); considering all the diabetics, a negative relationship is evident between Iex/Im ratio and HbA1c only.

Adolescent↗
PubMed1991

[Physiopathological aspects of secondary hyperuricemia].

Secondary hyperuricaemia expresses a heterogeneous group of clinical conditions generally classified according to the pathogenetic criteria. Hyperuricaemia can depend on an increased production, reduced renal excretion or on the combination of both. Myelo and lymphoproliferative diseases are clinically prevalent among the conditions accompanying this overproduction. The most frequent causes of reduced uric acid excretion are chronic renal failure and diuretic treatment. In recent years, several conditions of hyperuricaemia with mixed pathogenesis have revealed a common mechanism connected to the ATP cellular depletion.

Acute Disease↗
PubMed1991

Red cell membrane dynamic properties and erythrocyte metabolic parameters in essential hypertension: preliminary report.

In a group of 12 subjects with essential hypertension (EH), we evaluated the erythrocyte membrane fluidity and red cell membrane transverse fluidity gradient. We also evaluated the total red cell Ca content, the red cell cytosolic free calcium, the red cell membrane cholesterol/phospholipid ratio and the red cell membrane individual phospholipids. From the data obtained, it is evident that the erythrocyte membrane fluidity and red cell membrane transverse fluidity gradient discriminate normals from hypertensives. None of the red cell metabolic parameters is able, however, to differentiate normals from hypertensive subjects. Our data underline the abnormality of the red cell membrane dynamic properties in hypertension; this abnormality is not, however, related to the red cell metabolic parameters considered.

Adult↗
PubMed1991

Total red cell calcium content, cytosolic red cell free calcium and erythrocyte membrane dynamic properties in diabetes mellitus.

In a group of diabetics subdivided for type (12 of type 1 and 12 of type 2), we evaluated the total red cell Ca content, red cell cytosolic free calcium, erythrocyte membrane fluidity and erythrocyte membrane protein lateral mobility. From the results obtained, it is evident that the total red cell Ca content does not discriminate normals from type 1 and 2 diabetics, whereas the red cell cytosolic free calcium does differentiate between these diabetic types. Erythrocyte membrane fluidity and erythrocyte protein lateral mobility discriminate normals from type 1 and 2 diabetics. In normals and in diabetics of type 1 and 2, no relationship is evident between total red cell Ca content, membrane fluidity and membrane protein lateral mobility. A slight, but significant negative correlation between red cell cytosolic free calcium values and parameters reflecting the red cell dynamic properties is present in type 2 diabetics only.

Adolescent↗
PubMed1991

Rheological determinants and red cell lipidic pattern in essential obesity, in obese subjects with non-insulin-dependent diabetes mellitus (NIDDM) and in obese subjects with impaired glucose tolerance (IGT).

In a group of subjects with essential obesity, in a group of obese subjects with non-insulin dependent diabetes mellitus (NIDDM), and in a group of obese subjects with impaired glucose tolerance (IGT), we evaluated whole-blood filtration, mean erythrocyte aggregation, erythrocyte membrane fluidity and red cell lipid pattern. From these data, it is evident that the macro- and microrheological determinants are able to discriminate normals from each group of obese subjects. Regarding the red cell lipids, few are the variations between each group of obese subjects and normal controls.

Adult↗
PubMed1990

Vascular atherosclerotic disease: evaluation of the whole-blood filterability and red cell membrane microrheological pattern after intravenous administration of a single dose of pentoxifylline.

A study was carried out in 10 patients with vascular atherosclerotic disease to investigate the effects of a single dose of 300 mg pentoxifylline, given by intravenous infusion over 30 minutes, on various macrorheological and microrheological parameters. Measurements were made at baseline, at the end of the intravenous infusion and again 30 minutes later, of whole-blood filterability, erythrocyte membrane fluidity (using pyrene as probe) and transverse fluidity gradient (using fluorescent fatty acids as probes). The results showed that there was a significant variation in whole-blood filterability and the red cell membrane fluidity gradient after pentoxifylline. No difference, however, was noted for the membrane fluidity. These data suggest, therefore, that pentoxifylline plays a role in affecting the red cell membrane microrheological pattern.

Aged↗
PubMed1990

Total red cell Ca2+ content and rheological determinants in a group of subjects with vascular atherosclerotic disease.

We evaluated the total red cell Ca2+ content and the macro- and microrheological determinants in a group of subjects with vascular atherosclerotic disease (VAD). From the results obtained it is evident that, compared to controls, the VAD group presents an alteration of the macro- and microrheological parameters. No difference is evident for the red cell Ca2+ content in normals and in VAD subjects. No relationship is present between total red cell Ca2+ content, VBC (volume blood cells), MEA (mean erythrocyte aggregation) and red cell membrane fluidity expressed as Iex/Im ratio. In contrast to the latter, are the correlation between the red cell Ca2+ content and the degree of polarization obtained with fatty acid probes.

Aged↗
PubMed1989

[Energy expenditure at rest and body composition in obese subjects before and after weight loss].

In 7 obese subjects (3 males and 4 females), before (T0) and after (T60) weight loss, and in 10 nonobese subjects (4 males and 6 females) as controls, resting energy expenditure (REE) and body composition were evaluated. In obese subjects fat-free mass (FFM) and fat mass (FM) were significantly reduced after weight loss. REE, expressed in absolute value, was significantly higher in obese subjects at T0 with respect to controls (1683 +/- 77.3 vs. 1425 +/- 70.5 Kcal/day; p less than 0.05); in obese group REE was significantly lower at T60 (1563 +/- 63.5 Kcal/day) than at T0 (p less than 0.01). The decrease in REE observed in the obese group after weight loss was related only to the loss of FFM (r = 0.88; p less than 0.01). REE, expressed in relation to FFM, was not different between control and obese subjects at T0 (28.64 +/- 0.42 vs 26.40 +/- 1.08 Kcal/Kg-FFM/day; pns); however, this value was significantly lower in the obese group at T60 (25.99 +/- 1.07 Kcal/Kg-FFM/day) with respect to controls (p less than 0.05). It is concluded that a reduction in REE, due at least in part to the loss of FFM, may contribute to the difficulty in the maintenance of body weight often observed in obese subjects after a period on hypocaloric diet.

Adult↗