Biomedical subjects
Publications and source records attributed to P Colonna.
The study in Algeria over a period of 3 years of 90 cases of idiopathic thrombopenic purpura out of 409 hemorrhagic syndromes, showed the following peculiarities: the chronic forms are as frequent in the child as in the adult and we did not observe any subacute forms. Except in one case the use of prednisone at a dose of 2 mg/kg gave no result in patients who were not improved by a dose of 1 mg/kg.
In 92 cases studied in vivo with 59Fe, the variations of plasma iron during the study were measured. Errors in calculation of plasma iron turnover of up to 25% can be made in normosideremic patients if such variations are not taken into account. In hypersideremic patients the variations of plasma iron are low or nil; in hyposideremic patients the slow variations of plasma iron concentration do not alter the rapid slope of radio-iron removal.
These first cases of hemoglobinosis H show that alpha-thalassemia is not a simple curiosity in this part of the Western Mediterranean. They are not localised to a single part of Algeria as the areas from which the patients came were more than 150 km apart. They suggest that the enquiry should be continued by other means to determine the prevalence and pathological incidence.
The study of 176 subjects with beta-thalassemia, associated or not with a hemoglobinopathy, shows great diversity. The hemoglobin C thalassemias are less severe and form a fairly homogeneous group. Sickle cell thalassemia cases have more marked anemia and the disease takes on more varied forms, no doubt because the main mechanism of the anemia, the hyperhemolysis, is influenced by several factors which have a variable effect on the clinical picture. Unassociated thalassemias seem the most polymorphic. Although it seems that in certain foci the beta-thalassemias are fairly stereotyped, this first study shows in Algeria great heterogeneity. All forms are observed both clinically and in the laboratory. Present classifications have not supplied a sufficiently operative model. It is not doubt necessary to await further progress in the laboratory to classify these diseases more precisely.
The clinical, hematological and therapeutic aspects of 36 cases of acute myeloblastic leukemia in children and 98 cases in adults observed in Algeria are discussed. In Algeria, acute myeloblastic leukemia is more frequent in children than in other populations. In our series there was a very unusual female predominance. Clinically, we observed in children only, 8 cases of chloroma of the orbit. From the hematological point of view, the only difference was a higher incidence of leukopenia and hyperleukocytosis after the age 30 years. The results of VAMP treatment (vincristin, amethopterin, 6-mercaptopurine, and prednisone) are better in children than in adults. But analysis of the results is more interesting if one places the patients in age groups of ten years. The percentage of complete remissions is maximum in the age group 0 to 10years and then falls regularly.
Erythrocyte G-6PD activity in 69 heterozygotes has a log-normal distribution, a fact which cannot be solely attributed to random X chromosome inactivation. Others factors - genetic and individual - are suggested by intrafamilial clusting and post-natal variability of phenotype.
beta-Thalassemia is a major public health problem in Algeria. During a survey, a family including two cases of betaO-thalassemia was studied. The family study indicated that two of the affected siblings had homozygous beta-thalassemia; there were also both normal and heterozygous siblings, and both parents had beta-thalassemia trait. In the two cases of betaO-thalassemia there was no hemoglobin A in the peripheral blood, and no beta-globin chain synthesis in whole cell incubations. Hybridization of purified complementary DNA specific for alpha- and beta-globin messenger RNAs demonstrated less than 1% mRNAbeta relative to mRNAalpha in circulating reticulocytes, and for one case in total RNA from bone marrow. There is no apparent beta-globin gene deletion as determined by hybridization in globin cDNAbeta sequence excess. Therefore the Algerian cases studied are similar in molecular pathology to some Southern Italian and Asian cases described previously, and differ from other Italian and Chinese betaO-thalassemias, in which hybridizable mRNAbeta has been demonstrated, and from deltabetaO-thalassemia, which is caused by a gene deletion.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Pulmonary venous flow velocity recordings have been found to be useful in complementing the information obtained from the mitral flow velocity and improving the assessment of left ventricular diastolic pressures. This study was undertaken to evaluate the accuracy of mitral flow and pulmonary venous flow variables, recorded by transthoracic Doppler echocardiography, in estimating left ventricular end-diastolic pressure (LVEDP) in 101 consecutive patients with coronary artery disease undergoing diagnostic left-sided heart catheterization. Patients were assigned to three groups according to the values of LVEDP (group 1, < or = 12 mm Hg; group 2, between 13 and 19 mm Hg; and group 3, > or = 20 mm Hg). LVEDP correlated most strongly with systolic fraction of pulmonary venous flow (r = -0.76), isovolumic relaxation time (r = -0.76), E/A ratio (r = 0.74), deceleration time of early mitral flow (r = -0.74), and mitral A wave duration/pulmonary venous A wave duration (AD/PVAD) ratio (r = -0.70) (p < 0.01 for each correlation). Discriminant analysis demonstrated that deceleration time, AD/PVAD ratio, and isovolumic relaxation time were major determinants of LVEDP, with 87.1% of patients correctly assigned to study groups; 97% of patients of group 1 and 95% of patients of group 3 were identified, whereas the accuracy in identifying the patients of group 2 was lower (41%). Deceleration times of 140 msec or less and AD/PVAD ratios of 0.9 or less were the best cutoff points in predicting an LVEDP of 20 mm Hg or greater. Multiple linear regression analysis demonstrated that the combination of mitral flow and pulmonary venous flow velocity variables provided a better estimation of LVEDP compared with that obtained from mitral flow velocity recordings alone (r = 0.88 versus 0.79; F test, 20.6). We conclude that combined analysis of mitral flow and pulmonary venous flow velocity provides, in patients with coronary artery disease, a noninvasive estimation of LVEDP with an accurate prediction of pressures of 12 mm Hg or less and 20 mm Hg or greater and less accurate prediction of intermediate values.
Debranching and crystallization occurring during the enzymatic treatment of 25% (w/v) aqueous solutions of maltodextrins by isoamylase at 52 degrees C were studied. The morphology as well as the crystal and molecular structures of the precipitates formed at different stages of the reaction were characterized. Two types of resulting products, differing in terms of structure and morphology, were evidenced. A loose B-type network, containing linear and branched chains of highest molecular weight, was mainly formed during the first 12 h of reaction, whereas aggregates of A-type lamellar crystals, made of short linear chains, were predominantly obtained between 12 and 48 h. The aggregation behavior as a function of temperature and molecular weight distribution of such substrates was discussed and compared to that of related starch products.
Explore the source record for details and available documents.
Explore the source record for details and available documents.