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Biomedical subjects

R Girot

Publications and source records attributed to R Girot.

At least 109 records · Page 6Linked to original sources
PubMed1989

Normal growth hormone (GH) response to GH-releasing hormone in children with thalassemia major before puberty: a possible age-related effect.

The plasma GH response to a single iv bolus dose of 2 micrograms/kg BW synthetic GHRH-(1-44)NH2 was evaluated in 13 prepubertal children with thalassemia major (mean age, 7.6 +/- 0.8 yr) with growth retardation and in 15 prepubertal children with nonendocrine short stature. All of the patients showed a significant increase in plasma GH concentration, with a mean peak of 31.4 +/- 4.5 micrograms/L at 15 min (P less than 0.001 vs. basal values; range, 18.4-65 micrograms/L) after GHRH, which was not different from that of the control group of idiopathic short stature children (40.1 +/- 3.4 micrograms/L; range, 21-65.4 micrograms/L). All but 1 of the thalassemic patients had a normal GH response to the arginine-insulin stimulation test. The mean plasma insulin-like growth factor-I level was low (0.12 +/- 0.05 U x 10(3)/L; range, less than 0.02-0.61 U x 10(3)/L). Analysis of these results as well as previously reported data indicating that older thalassemic patients have an impaired GH response indicates that there may be an age-related pituitary and/or hypothalamic dysfunction in thalassemic children. This study also confirms that the insulin-like growth factor-I decrease occurs before any alteration in GH secretion. These changes might play a role in the early growth retardation that occurs in these patients.

Age Factors↗
PubMed1989

[Establishment of a range of phtalate density for studying profiles of erythrocyte density].

The determination of the density distribution of erythrocyte population is one of the biological parameters used in several hemoglobin disorders. Many difficulties to obtain reproducible results between different laboratories lead to make a reference phtalate ester range for two hospitals. In this paper, the conditions of preparation and use of the method are described. Then, factors affecting determinations are discussed. Finally the authors give reference values in child and adult. This work forms the first stage of a standardized study of erythrocyte populations with hemoglobinopathies.

Adult↗
PubMed1989

[Iron chelation in children].

Iron-chelating treatment is indicated in all children on prolonged transfusion therapy (i.e., chiefly patients with thalassemia and Blackfan-Diamond anemia). The purpose of iron-chelating treatment is to prevent the development of manifestations of iron overload including cardiac hemosiderosis and insulin-dependent diabetes mellitus (which are two potentially fatal complications), hepatic cirrhosis, hypoparathyroidism, hypothyroidism, and delayed puberty. Deferoxamine is the only effective iron-chelating agent and should be given in a daily dose of 40 mg/kg at initiation of the transfusion program. Administration is by subcutaneous infusions from 8 to 10 hours per day. The goal of iron-chelating treatment is to maintain serum ferritin levels between 500 and 1,000 ng/ml. This long-term treatment is a significant burden for patients and it can be hoped that non-toxic iron-chelating agents, active by mouth, will become available.

Adolescent↗
PubMed1989

[Treatment of post-transfusion iron overload by deferoxamine].

Iron chelation therapy must be associated with the regular blood transfusions required for thalassaemia and other chronic anemias. We report here a study concerning 4 groups of patients, aged 6 to 28, regularly transfused at Necker Enfants-Malades hospital: a) 20 with thalassaemia major; b) 6 with thalassaemia intermedia; c) 2 with sickle cell disease and d) 2 with Blackfan-Diamond syndrome. The transfusion regimen consisting of monthly or quarterly transfusions varied as a function of the groups. Desferal was used in all patients. The dosage and the route of administration (IV, IM, SC) were adapted to the amount of iron transfused and to the nature of the disease. The serum ferritin level was considered as the indicator of the iron overload. Comparisons were established between the quantities of iron transfused, ferritin levels, and parameters such as dosage, route of administration and compliance to Desferal. During the period of study 3 patients died from cardiac failure due to transfusional hemosiderosis. Endocrine complications (diabetes 2 cases, hypocalcemia 3 cases, hypothyroidism 1 case and delayed puberty 7 cases) were observed. This high incidence of complications induced by post-transfusional iron overload has recently prompted us to improve the quality of chelation therapy through the use of the services of a specialized center where patients as well as their families can be trained more adequately in home care and self-treatment.

Adolescent↗
PubMed1989

[Severe megaloblastic anemia in 6-month-old girl breast-fed by a vegetarian mother].

The case of a young girl, born to a woman who was a vegetarian for 18 years, is presented. She had been exclusively breast-fed until the age of 6 months when a severe anemia was discovered with an extremely low hemoglobin level (1.9 g/100 ml). Her physical growth and psychomotor development had been normal until 3 months of age. Bone marrow showed megaloblastosis and the serum B12 level was low (45 ng/l). B12 levels were also decreased in both parents (110 and 105 ng/l) and in the mother's milk (12 ng/l). Treatment with parenteral B12 was successful. The importance of a careful dietetic inquiry in the case of an infant with megaloblastic anemia is stressed and likewise, as a preventive measure during all normal pregnancies.

Anemia, Macrocytic↗
PubMed1988

Analysis of crossover type in the alpha -3.7 haplotype among sickle cell anemia patients from various parts of Africa.

The frequency of alpha+-thalassemia has been determined in African populations carrying beta S-chromosomes of different origins. All these alpha+ thalassemias result from a right-ward deletion. Restriction mapping of the alpha -3.7/haplotype with the enzyme ApaI only showed the presence of a type I crossover. RsaI polymorphism at the 5' end of Z alpha 2 is largely represented in the normal population (gene frequency 23%) but, in our series, never associated with the alpha -3.7/haplotype.

Africa↗
PubMed1988

DNA haplotype distribution in Algerian beta thalassaemia patients. An extended evaluation by family studies and representative molecular characterization.

An evaluation of beta thalassaemia mutations and the associated chromosomal haplotypes has been made among Algerian thalassaemic patients in this extended series. The major features of our findings are: (i) due to elevated proportion of consanguinity, the frequency of true homozygotes for a defect is high; (ii) Despite this high homozygosity within families, the number of molecular defects resulting in beta thalassaemia are very heterogeneous within this population. This is exemplified not only by the high heterogeneity of haplotypes and associated mutations, but also by the definition of several new haplotypes, among which two of them were found to be associated with novel mutations. Family studies have been performed in parallel to evaluate the degree of feasibility of antenatal diagnosis in this population.

Algeria↗
PubMed1988

Density distribution of red cells and prognostic significance in 50 patients with homozygous sickle-cell disease.

The sickle cell disease is characterized by a heterogeneous clinical and biological expression. In order to evaluate the prognostic significance of the red blood cell density distribution: D50 (median cell density of the distribution), R60 (middle density range in which 60% of the cells can be found), F4 and F5 (proportion of cells with density higher than 1.110 and 1.120 g/ml, respectively) have been determined in 50 patients with homozygous sickle cell disease. The alpha gene status was determined in 27 patients. All patients have been included in an original score of severity fitted to infancy and childhood. A positive correlation has been found between D50 and the clinical score. This result illustrates the potential clinical importance of this parameter as well as other biological indices such as the haemoglobin F level, the alpha gene status and the haplotypes of the beta-like gene cluster.

Adolescent↗
PubMed1987

Enrichment of blood units with young red cells (neocytes) with the IBM 2991 cell washer.

The transfusion of young red blood cells (neocytes) is a complementary approach to the present treatment of thalassaemia major patients. Fresh neocytes were harvested from 34 volunteers with the IBM 2991 cell washer (CW). The upper part of 24 units was separated into 6 aliquots (T1-T6) of 15 ml each and the residue homogenized. Four biological criteria were used to evaluate young red cell quality, the erythrocyte pyruvate kinase activity, the mean corpuscular volume, the reticulocyte count and ektacytometry; each sample (T1-T6) showed an enrichment with neocytes as compared with the standard unit. A real efficiency of this technique with the IBM 2991 CW was obtained with the first third of the unit, corresponding to the T1-T4 fractions. The estimation of the theoretical mean life span of T1-T2 was 270 days. The last 10 units were separated into two halves: the enrichment of the first half was worse than in the first third of the previous technique. We concluded that the transfusional program of thalassaemia patients could profit by the use of the most enriched part of a standard blood unit with the IBM 2991 CW.

Blood Specimen Collection↗
PubMed1987

[Long-term blood transfusion in sickle-cell anemia].

Ten homozygous sickle cell patients, aged from 4 to 20 years, underwent a periodic red blood cells transfusion program. Indications were = one stroke or more in 4 cases, repeated severe painful crisis in 2 cases, and for others = chronic anaemia induced by hypersplenism, priapism, chronic leg ulceration, dwarfism with delayed sexual maturation. Transfusion program lasted from 6 months to 6 years. In 7 cases, a phlebotomy preceded the transfusion by the same venipuncture in order to reduce the inevitable iron overload progression. Clinical benefit was clear in the following cases: lack of painful crisis with return to school, leg ulceration healing, growth and weight increase, onset of puberty. Benefit is more difficult to assess in the other observations and, particularly, in stroke. No red cell antibodies were found. An HIV contamination occurred in 3 children. All transfused patients during a period exceeding one year developed iron overload, needing a daily chelation by intramuscular deferoxamine in two of them.

Adolescent↗
PubMed1986

Human parvovirus and aplastic crisis in chronic hemolytic anemias: a study of 24 observations.

From March 1984 through November 1985, 24 children and adults with aplastic crises were admitted in several Parisian hospitals. Twelve patients had known hemolytic anemia. Aplastic crisis revealed hemolytic anemia in the remaining patients. The detection of human parvovirus antigen was performed by counter-immunoelectrophoresis, and specific IgM antibodies were detected by IgM-antibody-capture-radioimmunoassay, in order to establish the incidence of human parvovirus infection in the genesis of the aplastic crisis. Twenty-one patients had acute infection with human parvovirus. In the three remaining patients, no marker of human parvovirus infection was found. The features of the human parvovirus linked aplastic crisis are described. We consider that human parvovirus infection, and unknown hemolytic anemia, must be systematically researched in any case of unexplained acute aplastic anemia.

Acute Disease↗
PubMed1986

Neocytopheresis: a new approach for the transfusion of patients with thalassaemia major.

At present the treatment of thalassaemia major consists of regular blood transfusions coupled with chelation therapy using deferoxamine. A complementary approach to the problem is the use of blood units enriched with young red cells (neocytes), which reduce the transfusional frequency and thereby diminish the risk of iron overload. Young red cell units were collected from blood from 60 volunteer donors using a cell separator (IBM 2997). Donors' blood was anticoagulated and the young red cell harvesting carried out over 4 h at a constant rotor speed of 500 rpm. Three biological criteria were used to evaluate young red cell quality: the number of reticulocytes, the pyruvate kinase activity and the mean corpuscular volume, all of which show an enrichment of young red cells as compared to standard donor units. The 51Cr young red cell survival in four normal donors and in two splenectomized patients showed an increased red cell half-life compared to the same study performed with standard blood units. Blood consumption was diminished significantly when the two patients were transfused with young red cell units. It must be emphasized that, despite the high cost of this blood product, the efficiency of this transfusion technique, by reducing blood consumption, represents important progress and a hopeful treatment for chronic anaemia.

Blood Donors↗
PubMed1986

Human parvovirus and thalassaemia.

The human parvovirus (HPV) is responsible for aplastic crises in patients with chronic haemolytic anaemia. We describe the cases of four children with aplastic crises in various types of thalassaemia (alpha and beta thalassaemias, major and intermediate forms). In all four patients, specific anti-human parvovirus IgM was detected in their serum, thereby indicating recent infection.

Adolescent↗