Search PubMed⌕ Search

Biomedical subjects

R Girot

Publications and source records attributed to R Girot.

At least 145 records · Page 8Linked to original sources

[Effect of blood transfusion on erythropoiesis of homozygotic beta-thalassemia patients].

The influence of blood transfusion on erythropoiesis (bone marrow erythroblasts, peripheral blood erythroblasts and reticulocytes) has been studied in 20 non splenectomized homozygous beta thalassaemia patients aged 3 to 16 years and in 10 splenectomized patients aged 8 to 24 years affected with the same disease. The number of reticulocytes was the same in the two groups but the number of erythroblasts in the splenectomized group was higher than in the other group. There was no correlation between the erythroblasts and the reticulocytes of the peripheral blood on one hand and the haemoglobin level proceeding from the same sample on the other hand. In the non splenectomized group of patients, an inverse relationship was found between the percentage of bone marrow erythroblasts and the mean annual haemoglobin level (r = -0.71; p less than 0.01). These results demonstrate the effect of blood transfusion on the erythroid cell line in homozygous beta thalassaemia and the delay between the transfusions and the medullary erythroblastic response.

Adolescent↗

Red cell kinetics in thalassaemia intermedia: its use for a prospective prognosis.

A kinetic study of erythroid cell production and destruction (radioactive iron incorporation, red blood cell survival time, bone marrow scintigraphy) was performed in 12 cases of thalassaemia intermedia (six adults and six children), classified retrospectively, and compared to that performed in 17 cases of Cooley's anaemia. Our results confirm the genetic heterogeneity of these cases, the level of Hb F varies from 30% to 100% and the non alpha/alpha chain synthesis is only statistically superior to that seen in Cooley's disease. On the other hand, the kinetic study clearly separates the cases who are, or will be, clinically intermediate, showing a higher radioactive iron medullary uptake, a less ineffective erythropoiesis than that seen in Cooley's disease, and a greater peripheral haemolysis. In our study, no overlap was seen between the two groups. Iron kinetic study is then of prognostic interest and may help in therapy decisions, transfusion regimen and iron chelation, and splenectomy.

Adolescent↗

[Complications of the prolonged use of lipid emulsion in children on parenteral nutrition].

In 8 children who were fed exclusively for an average of 30 months with parenteral nutrition containing 25% of the energetic intake as lipid emulsion (Intralipid) acute complications similar to those observed in the fat storage syndrome occurred. One child died from gastrointestinal bleeding. In the other cases, evolution was dramatically improved by corticosteroid therapy. An histiocytic hyperactivation induced by the artificial emulsion might be responsible for these complications. The authors emphasize the risks of long-term use of lipid emulsion and the preventive measures which should be taken in children under prolonged parenteral nutrition.

Acute Disease↗

The characterization of protein 4.1 Presles, a shortened variant of RBC membrane protein 4.1.

In a previous report (Blood 60:265, 1982), we described a family with an abnormal RBC membrane protein doublet, which we considered a shortened protein 4.1 on the basis of biochemical and genetic data. Using an anti-4.1 monoclonal antibody, we confirm here that the shortened protein derives from protein 4.1. One of the members of the family contemporaneously displayed the 4.1 (-) trait, eg, the heterozygous state of this variety of hereditary elliptocytosis that lacks protein 4.1. The 4.1a/4.1b ratio was low whenever the 4.1 trait was present, regardless of the type of protein 4.1 involved. The RBCs of the compound heterozygote, containing only the shortened species of protein 4.1, made it possible to analyze without interference the contact between shortened protein 4.1 and sialoglycoprotein beta, or glycoconnectin. Shortened protein 4.1 did not alter the amount of glycoconnectin in the ghosts nor did it change its extractability into the Triton shells. Limited proteolysis of shortened polypeptides 4.1a and 4.1b showed that they are sequence related. It is conflicting that the persons carrying the shortened protein 4.1 are devoid of specific clinical and morphological abnormalities, apart from those pertaining to the 4.1- trait, when the latter is present.

Antibodies, Monoclonal↗

[Hypersplenism in thalassemia major. Treatment by partial dearterialization of the spleen. Preliminary results apropos of 5 cases].

Partial dearterialization of the spleen is a surgical method aimed at reducing the volume of the spleen whilst preserving its defensive properties against bacterial infections. Four children with thalassaemia major and one with congenital dyserythropoiesis who developed hypersplenism in the course of their disease underwent the operation and were subsequently followed up for periods of 24 to 36 months. The effectiveness of the method was demonstrated by a smaller enlargement of the spleen, a lesser need for transfusions, a longer life of 51 Cr-labelled red cells and more numerous circulating platelets. Surgery was also effective in reducing post-transfusional iron overload, as shown by the decrease and stability of serum ferritin levels in all children subjected to iron chelation. No episode of infection or changes in serum IgM occurred during the follow-up period, and radioisotopic studies of the spleen showed that macrophage function was preserved in the remaining splenic tissue. One child inexplicably developed thrombosis of the splenic vein 1 year after surgery.

Arteries↗

Recurrent hematuria in 4 white patients with sickle cell trait.

Extensive investigations failed to disclose the etiology of recurrent gross hematuria in 4 white patients of Algerian descent. Hemoglobin electrophoresis revealed sickle cell trait in all cases. The hematuria ceased after bed rest and hydration in 3 patients, and following partial nephrectomy after visualization of the bleeding site at operative nephroscopy in 1. We recommend that hemoglobin electrophoresis be considered when evaluating every patient, black or white, presenting with unexplained hematuria.

Adult↗

[Effect of hematologic treatment on the growth and puberty of children with thalassemia major].

This study reports on the endocrine abnormalities associated with delayed growth and puberty, observed in 10 children presenting with thalassemia major. Hormonal changes were followed up during treatment with regular transfusions and efficient chelating agents. Recovery of growth and onset of puberty were observed in most cases. When puberty was delayed, an associated substitutive treatment with sexual hormones was useful. In one case only, an isolated gonadotropic deficiency could be proven. In all cases STH, TSH and PRL secretions were normal. Without efficient and early treatment, the main consequence of the disease with respects to growth seems to be the risk of delayed puberty, mainly functional, or rarely hypogonadotropic due to definite LH and FSH deficiency.

Adolescent↗

Albumin, fibrinogen, prothrombin and antithrombin III variations in blood, urines and liver in rat nephrotic syndrome (Heymann nephritis).

Albumin, fibrinogen, prothrombin and antithrombin III (AT III) variations have been studied in blood, urines and liver during an experimental nephrotic syndrome in rats (Heymann nephritis). A quantitative morphometric study (light microscopy) has been performed in the liver using an immunocytochemical technique--(PAP) method--to evaluate the protein synthesis by the number of protein-containing hepatocytes. Some sections were also studied by electron microscopy. The nephrotic animals were compared with control rats. In the blood of nephrotic rats, fibrinogen and prothrombin concentrations were increased and albumin and AT III concentrations were decreased. In the urines of nephrotic rats, albumin, prothrombin and AT III were lost, but no fibrinogen. The morphometric study in the liver has shown a significantly higher number of fibrinogen and prothrombin-containing hepatocytes in nephrotic rats than in controls, suggesting an increased synthesis of these proteins; no change was observed concerning albumin and AT III between nephrotic and control animals. In electron microscopy, albumin was demonstrated in Golgi apparatus, proving that the peroxidase-positive cells are related to protein synthesis. These results show that the mechanisms of regulation of the protein synthesis during nephrotic syndrome are different from one protein to another and, particularly, that their blood level is not the only regulating factor for their synthesis.

Albumins↗

Alpha-globin loci in homozygous beta-thalassemia intermedia.

Homozygous beta-thalassemia intermediate (TI) differs from thalassemia major (TM) in being less severe clinically. Associated alpha-thalassemia could account for the TI phenotype by reducing the alpha/non-alpha chain imbalance. We have analyzed the alpha loci of 9 TI and 11 TM patients by restriction endonuclease mapping. All the TM and 7 of the TI patients have the normal complement of four alpha-globin genes (alpha alpha/alpha alpha). One TI patient has three alpha-globin genes (alpha alpha/-alpha), and another TI patient has five alpha genes (alpha alpha/alpha alpha alpha).

Adolescent↗

Four new haplotypes observed in Algerian beta-thalassemia patients.

beta-Thalassemia, a heterogeneous group of human anemias affecting the expression of beta-globin, is caused by a number of molecular defects. Restriction endonuclease mapping of ethnic populations has revealed many polymorphisms within and around the beta-like globin genes, combinations of which are assigned as haplotypes. Several haplotypes appear to be strongly linked with the molecular defects causing thalassemia in Greek and Italian patients (Orkin et al. 1982). We describe here haplotypes from 40 Algerian beta-thalassemic patients and eight normals determined by restriction endonuclease mapping at seven polymorphic sites. Four haplotypes previously unreported were observed in these thalassemic patients; this argues the existence in this population of undescribed beta-thalassemia alleles. The knowledge of the haplotypes in thalassemic families could be used for prenatal diagnosis of homozygote forms.

Algeria↗

[Thalassemia major manifested by megaloblastic anemia caused by folate deficiency].

In a 11 month-old child, a deep anemia with reticulocytopenia and megaloblastosis on bone marrow aspiration revealed a thalassemia major. The low folate intake and the increased needs probably account for initial findings. Folic acid deficiency has already been described in patients with dyserythropoiesis or chronic hemolysis. Daily folic acid treatment is necessary in these patients.

Anemia, Macrocytic↗

The genetic abnormalities involving red cell membrane protein 4.1 with or without elliptocytosis.

We have studied 20 caucasian individuals including 3 independent persons and 17 persons belonging to 6 unrelated families. These subjects are normal or elliptocytic. On biochemical grounds, families with hereditary elliptocytosis (HE) can be divided in two groups. (i) Three families in which HE is associated with a marked reduction (approximately 30%) of the band 4.1 percentage, upon scanning of SDS-polyacrylamide gels. This deficiency is associated with the absence of obvious clinical symptom and a dominant genetic transmission. (ii) Three HE families display a normal amount of band 4.1. Among two of them, HE is concomitant with moderate clinical manifestations and with a genetic transmission that seems to be morphologically recessive. In the last family, HE is transmitted as a dominant trait and is clinically silent. Finally, in the 3 isolated persons, HE is asymptomatic but the mode of genetic transmission could not be ascertained. One of them has a decreased amount of band 4.1 similar to that observed in the first group. To date, the band 4.1 deficiency is probably the best example of a relatively frequent specific molecular defect associated with a specific morphological abnormality. In one family with this type of HE, we have fortuitously discovered, at the heterozygous state, a variant of protein 4.1, shortened by about 8 500 daltons, involving both subcomponents 4.1a and 4.1b and morphologically silent.

Blood Proteins↗