Biomedical subjects

A Crippa

Publications and source records attributed to A Crippa.

At least 37 records · Page 2Linked to original sources

PubMed1992

[Plasma-erythrocyte viscosity and evaluation of several pro- and anti-aggregating factors in NIDDM patients in metabolic decompensation state].

In NIDDM diabetic subjects, the microcirculatory damage shows a double aspect: an alteration of the vascular wall, particularly of the arteriolar capillary, and a hemorheological alteration at the level of the capillary district. In the microcirculation, because of the low velocity of the flow and the inverse relationship between capillary size and RBC diameter, the viscosity has an important role with its components: RBC viscosity and deformability. Even the erythrocyte aggregation has a key role as resultant of the attracting and repulsing forces, among which the plasma-RBC viscosity and the deformability play opposite role. Our method allows to evaluate the erythrocyte, the whole blood, the plasma and the plasma-RBC viscosity, and the deformability. Studies from this laboratory in NIDDM subjects show an increase in the blood viscosity, a decrease in the erythrocyte deformability and plasma-RBC viscosity. It is suggested that in microcirculatory district the flow reductions are particularly of hemorheological type and that the sludged blood is an "optical" phenomenon with poor meaning. We consider some hematological parameters, namely the Hgb A1c %, Hgb concentration, RBC count, MCV, etcetera.

Aged↗

PubMed1992

[Relations between plasma-erythrocyte viscosity factors and ESR].

The ESR is usually put in relationship: to the real density of the RBCs (erythrocytes) (difference between the RBC specific gravity and the plasma one), and to the resistance that the RBCs meet moving in a medium, which is due to the plasma viscosity and to the total external RBC surface. When the RBCs take shape of aggregates, their external surface is decreased and ESR increases. The most important plasma factor causing changes in ESR is the fibrinogen level followed by the plasma globulins and by the products arising from the tissue damage. The resistance that the RBCs meet moving in the plasma is well expressed by the measurement of the plasma-RBC viscosity considering that is inclusive of both factors that are the plasma viscosity and the external RBC surface. The plasma-RBC viscosity is the resultant of several factors: Fa = Fb - Fe - Fs - Fm, were: Fa is the resultant, Fb the attracting forces due to the proteic macromolecules, Fe the repulsing forces due the negative charges. Fs the repulsing forces due to the shear-stress, Fm the force which opposes itself against the surface tension of the aggregation; it depends on the RBC morphology and on the RBC rigidity. The ESR has been recently used like an index of the RBC aggregation. The Authors study the relationship between several hemorheological parameters and the ESR in infective and inflammatory processes.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Sedimentation↗

PubMed1992

[Model of therapeutic programming in NIDDM diabetes].

The usual choice of therapy in NIDDM diabetes, using oral anti-diabetic compounds, insulin or associated treatments, is based on the results of treatment evaluated empirically using glycemic profiles. As a contribution to the search for a method of choosing a treatment which is based on laboratory data and can restore metabolic equilibrium as quickly as possible using the most efficacious drug at an optimal dose, the paper reports a method of assessing the severity of diabetes according to mean daily glucose concentrations, the degree of instability in relation to the standard deviation, and proposes a sensitivity test to SU which indicates the choice of therapy, together with an insulin sensitivity test which is useful for evaluated the optimal dose. Sensitivity to SU evaluated using this method is not dependent on the degree of severity of diabetes. With regard to its practical use for prescribing treatment the test is highly predictive in positive cases since it is extremely sensitive, while its low specificity does not rule out its use in cases of resistance. The analysis of the results obtained after treatment which was not indicated by the sensitivity tests but based on personal experience and the comparison of the two methods shows that a high percentage of patients received inadequate therapy either due to the prescription of the wrong type of treatment or an incorrect dosage.

Blood Glucose↗

PubMed1991

Long-term tolerability of fenretinide (4-HPR) in breast cancer patients.

A group of 53 patients initially participating in a phase I trial with the synthetic retinoid fenretinide was assessed for the long-term tolerability of this compound. The patients were evaluated after 42 months of drug intake at a dose of 200 mg/day, including a 3-day drug interruption at the end of each month, by the following examinations: a dermatological visit; an ophthalmological evaluation including an ophthalmological questionnaire and an electroretinogram (ERG); a study on blood chemistry and plasma retinol levels; a study on bone densities and on skeletal X-rays; and finally a psychological evaluation including various tests for anxiety, depression and overall mood. The results show that prolonged administration of fenretinide is well tolerated. No acute nor severe toxicity was observed and thus this compound can be considered a good candidate for chemoprevention trials in a variety of patient populations.

Affective Symptoms↗

PubMed1991

[Erythrocyte viscosity-deformability-aggregation. A clinical reality].

Current clinical practice and indications for drug therapy for vascular pathologies of different etiology reveal the need to measure blood viscosity, either on the spot or at the site of greatest impact. The Authors propose as easily performed method of calculation using Reid's well-known technique, which, based on the measurement of hematic filterability using filters with different sized pores, gives the viscosity of the various fractions which make up overall viscosity but which have a different impact on areas of the circulation and their functions: total blood viscosity, corpuscolar viscosity, plasma-erythrocytic viscosity. These are quantified in cP as a values which is independent of the degree of sanguification and are markers of a functional flow datum. Erythrocytic deformability, expressed as a percentage of the inverse viscous impact of red cells on total blood viscosity, is restricted to a narrow range in the control population, and is therefore a very reliable parameter for the assessment of pathological and pharmacological changes. In addition to normal values, changes in subjects suffering from thalassemia are used as a paradigmatic example of structural and morphological erythrocytic changes without other associated diseases. A model table illustrates the methods of calculation used to obtain the degree of filtration in cP from filtration data.

Blood Viscosity↗

PubMed1991

[Indications and methods of treatment with sulfonylureas in NIDDM patients].

Metabolic corrections induced by SU therapy can be assessed by daily glycemic changes which reflect all metabolic events taking place during the 24-hour period. Varying responses to treatment reveal different degrees of metabolic reserve. In order to be meaningful the SU sensitivity test must be compared to the daily glycemic profile. Sensitivity test responses were first compared to similar alterations following treatment; and secondly, the correlation was determined between the sensitivity test and the daily percentage of glycemic decrement induced by therapy. The high significance of these comparisons confirmed that the SU sensitivity test is a reliable index of response to treatment and this has also influenced treatment methods. When studying the modes of action of the SU sensitivity test we took into account insulin incretion and sensitivity tests to exogenous insulin to determine the level of receptor activity. Even during acute treatment, SU action is mediated by insulin incretion, whereas SU activity is not related to changes in the receptor system induced by exogenous insulin stimulation.

Blood Glucose↗

PubMed1991

[Sulfonylurea resistance in type II diabetes mellitus. Assessment of metabolic and hormonal aspects].

Sensitivity tests to SU allow two populations to be distinguished. One contains severely diabetic subjects in a continuous state of metabolic precariousness with reduced alkaline reserves, hyperinsulinemia and insulin resistance; the other contains mildly diabetic subjects who are normoinsulemic and show no insulin-resistance to i.v. tests irrespective of the presence of a similar level of SU resistance. While the first group may be more readily interpreted, especially with reference to the dualism between the alterations of insulin synthesis and resistance of peripheral tissues, with special reference to the function of receptors and post-receptors, the second group raises numerous questions of interpretation. The test becomes important to identify those subjects who right from the start show a reduced insulin secretion to drug stimulation and the possibility of obtaining euglycemia with high doses of SU. This finding suggests the existence of a genetically determined mechanism for SU resistance: in addition to the population who show marked SU resistance from the onset of diabetic symptoms, there is also a group of subjects in whom this resistance is less evident and may be provoked only by certain stimuli or spontaneously under stress, or by the appearance of the triggering metabolic factor. It is clearly important to identify the latter population before the clinical manifestation of symptoms so as to establish the correct therapy or combined therapy. This led us to consider the SU-resistant cases in the series of patients studied as being two clinical stages of the same condition rather than two separate populations with different pathogenesis.

Aged↗

PubMed1988

[Hemorheologic, metabolic and blood coagulation changes in diabetics in treatment with sulfanyl ureas].

A study was carried out to see if chronic treatment with a sulphanylurea with hypoglycaemic action, with also haemoactive action in terms of anti-platelet aggregation, profibrinolytic and antifibrinogenetic action also acted haemorheologically. For this purpose a group of patients treated with Gliclazide was compared with a group under treatment with Glibenclamide. A significant variation was noted in terms of an increase in erythrocyte filtrability and a diminution in erythrocyte aggregation with diminution in blood viscosity at low shear-rates. The absence of parallel modifications in quantitative corpuscular viscous factors, the early onset of the process, the real diminution in the sense of a reduction below the range of normality suggests that the effect is pharmacological and not mediated by metabolic compensation.

Blood Coagulation↗

PubMed1988

[Presentation of a method of interpreting erythrocyte deformability].

The physical principles of a method based on a haematic double filtration, according to Reid classic technique is explained. The aim is to determine a method for researching the characteristics of erythrocytic deformability, without changing the original medium, exoerythrocytic essential component of the membrane physiochemical quality and intraerythrocytic for the fast, active exchanges, after an evaluation of different techniques and instrumentation. A practical example for calculating the factor of correction, with reference to personal material, is made. This method has the advantage that it does not need the manipulation of the sample and does not delay the determination.

Biophysical Phenomena↗

PubMed1988

[Macrocytosis in relation to the severity of the hepatopathy].

Among factors causing the hepatopath's relative erythrocyte macrocytosis, the influence of alcohol and liver function damage was compared. Hepatopathic macrocytosis is different from Biermer's macrocytosis and evidently involves different pathogenetic mechanisms. It is significant that a deficit in vit. B12 does not occur and a modest deficit in folates only rarely. There is much evidence of an alteration in lipidemia and particularly in apo-protein content. It is concluded that the two factors considered have different mechanisms but produce the same results.

Anemia, Macrocytic↗

PubMed1988

[Hemorheology and acute in vivo changes in non-viscous serum factors].

During research into a real model permitting study of the rheological effect of serum constituents without viscous power, the viscous features of blood and plasma and erythrocyte deformability and aggregability were evaluated before and after dialysis in relation to variables acutely modified by therapy. Interdependence with certain serum factors often considered responsible for rheological changes in various pathologies after maximum alteration and, in the short term in the same subject, under normal conditions were controlled.

Adult↗

PubMed1987

[Associated hepatitis B virus forms and analysis of immunologic configurations in histologically typified chronic diseases of the liver. Epidemiologic aspects and development factors].

We report histological aspect of population, expression of middle classes of Lombardia (Italy), affected by hepatomegaly with or without marks of biohumoral compromised. After classification in groups, according to a minutely explained scheme, we investigate the hepatitis B virus (HBV) immunological aspect and the frequency of the several configurations in every group. We have found HBV positive almost half hepatopathies classified as metabolic according to histological features and 70% of the liver cirrhosis without histological signs of inflammation. The immunological shape showed by last group is identical to the shape of the group with typical histological signs of persistent chronic hepatitis. Another epidemiologic factor as age marks the different histological groups and leads to advance hypotheses of consecutiveness. Distribution of the different histological forms with reference to sex allows the same considerations on pathogenetic factors of progression.

Adolescent↗

PubMed1983