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Biomedical subjects

R Girot

Publications and source records attributed to R Girot.

At least 73 records · Page 4Linked to original sources
PubMed1994

Fetal haemoglobin variations following hydroxyurea treatment in patients with cyanotic congenital heart disease.

Haematological features of 64 patients suffering from non operable cyanotic congenital heart disease (CCHD) treated with hydroxyurea (HU) were compared with those of 43 patients suffering from the same disorder who had not yet received this drug. Patients with subclinical renal dysfunction were excluded by measuring plasma creatinine levels. MCV and HbF were higher among patients receiving HU, the increase in MCV being cumulative with HU dosage but the rise in HbF dose independent. HbF response to HU was found to be due to the coordinated increase in F-cell and F-reticulocyte production rather than to a selective survival of F-cells. Absence of a relationship between plasma erythropoietin and HbF levels excluded a dominant role of the former in increasing F-cell production and results determined after doubling the HU dosage or immediately after initiating therapy suggested genetic differences to be responsible for the individual variations in Hb F response. No irreversible toxic effects or malignancies were noted in this series of patients. HU was administered for a relatively long period of time, the mean duration of treatment exceeding 5 years, while the study also included patients below the age of 10 years.

Adolescent↗
PubMed1994

[Alpha-thalassemia].

alpha-Thalassaemias are probably the most common genetic disorder worldwide. alpha-Thalassaemias are haemolytic anaemias resulting from inherited deficient synthesis of alpha-globin chains. In this paper, the classification and nomenclature of alpha-thalassaemias are developed. Procedures to ensure the laboratory diagnosis are explained. The heterozygous carrier states for these disorders are, in most cases, not associated with any easily discernible change in the haemoglobin pattern, except, sometimes, a reduced MCV in the blood picture. Heterozygotes for alpha-thalassaemia deletions are now detectable by the accurate PCR method. Because of the high prevalence of these disorders in large segments of the world population, alpha-thalassemia and haemoglobinopathies often occur in the same individual. The laboratory features of these interactions and, particularly, the role of alpha-thalassaemia as a potential modulator of sickling haemoglobinopathies are discussed.

Humans↗
PubMed1993

Iron distribution in thalassemic bone by energy-loss spectroscopy and electron spectroscopic imaging.

Iron overload occurs frequently in thalassemia as a consequence of regular blood transfusions, and iron has been found to accumulate in bone, but skeletal toxicity of iron is not clearly established. In this study, bone biopsies of thalassemic patients were investigated by light (n = 6) and electron microscopy (n = 8) in order to analyze iron distribution and possible iron-associated cellular lesions. Sections (5 microns thick) were used for histomorphometry and iron histochemistry. Ultrathin sections were examined with an energy filtering transmission electron microscope. Iron was identified by electron energy loss spectroscopy (EELS), and iron distribution was visualized by electron spectroscopic imaging (ESI) associated with computer-assisted treatment (two-window method). This study shows that EELS allows the detection of 4500-9000 iron atoms, and that computer-assisted image processing is essential to eliminate background and to obtain the net distribution of an element by ESI. This study shows also that stainable iron was present along trabecular surfaces, mineralizing surfaces, and on cement lines in the biopsies of all patients. Moreover, iron was detected by EELS in small granules (diffusely distributed or condensed in large clusters), in osteoid tissue, and in the cytoplasm of bone cells, but not in the mineralized matrix. The shape and size (9-13 nm) of these granules were similar to those reported for ferritin. As for iron toxicity, all patients had osteoid volume and thickness and osteoblast surface in the normal range. Stainable iron surfaces did not correlate with osteoblast surfaces, plasma ferritin concentrations, or the duration of transfusion therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Cerebrovascular accidents in sickle cell disease. Risk factors and blood transfusion influence. French Study Group on Sickle Cell Disease.

This study presents a series of 34 sickle cell patients with one or more cerebrovascular accidents (CVA). Risk factors were studied in a subgroup of 19 patients whose clinical and biological characteristics were compared to those of a group of 444 sickle cell patients without CVA. The only risk factor discovered was a past history of purulent meningitis, which was significantly more frequent in sickle cell patients than in those without CVA (P < 0.0001). No biological or radiological factor affecting the risk of recurrence was found. The risk of recurrence, neurological defects or death after subsequent CVA justify long-term transfusion treatment in patients presenting with a second CVA. However our study shows that 10 patients who were not transfused after their first CVA had no recurrences, (median follow up = 7.9 years; 2-18 years), providing a basis for discussion on the indications of long-term transfusion therapy for sickle cell patients presenting with their first CVA.

Adolescent↗
PubMed1993

Iron overload in children receiving prolonged parenteral nutrition.

This study was carried out to evaluate the iron status of 30 children aged 1 to 18 years who had been receiving total parenteral nutrition (TPN) for an average of 43 months with iron intakes of 100 micrograms/kg per day. Iron status was assessed by assaying the serum iron and ferritin levels and the transferrin saturation coefficient as a function of iron intake. Liver biopsy specimens were taken from 13 children. Twelve children had serum ferritin levels greater than 300 ng/ml, and 8 had levels greater than 800 ng/ml. The serum ferritin level and the transferrin saturation coefficient were positively correlated (r = 0.81; p < 0.01). The serum ferritin level was positively correlated with TPN duration and with the total iron intake (r = 0.68; p < 0.01). Of the 13 liver biopsy specimens, six showed signs of iron deposition. We conclude that there is a risk of iron overload in children receiving 100 micrograms iron per kilogram of body weight per day by TPN, indicating that intake should be reduced.

Adolescent↗
PubMed1993

Human T-cell lymphotropic virus type I and II DNA amplification in seropositive and seronegative at-risk individuals.

To determine the presence or the absence of human T-lymphotropic virus type I and/or II (HTLV-I/II) DNA in at-risk individuals who were persistently negative for specific serologic assays, polymerase chain reaction with two primer pairs in common and conserved regions of HTLV-I and -II genomes was used. Seronegative individuals at risk for HTLV-I/II infection (15 heterosexual partners of seropositive individuals, 17 breastfed children born to HTLV-I-infected mothers, 47 multiply transfused patients, 22 intravenous drug users) were studied (n = 101); 35 seropositive individuals and 25 seronegative low-risk individuals were used as positive and negative controls, respectively. No positive polymerase chain reaction was observed in the seronegative at-risk individuals or in the negative controls. Positive controls gave positive results with at least one primer pair in all cases except one. A latent HTLV-I/II infection with a persistently negative serologic test for HTLV-I/II seems unlikely.

Adolescent↗
PubMed1993

Epidemiological and clinical study of sickle cell disease in France, French Guiana and Algeria.

The main clinical and haematological features of sickle cell patients were compared in 618 French, 50 Guianese and 87 Algerian patients. In homozygous sickle cell patients, the proportion of icteric subjects rises with age in all centres; the prevalence of splenomegaly reaches a peak in children from 1 to 5 years and then decreases; jaundice and splenomegaly are more often noted in Algerian and Guianese than French patients. The prevalence of painful crisis is comparable in the 3 centres. In 465 French SS children, having a mean age of 7.3 +/- 5.9 years, the prevalence of a past history of meningitis is 7.3%, of septicaemia 4.1% of osteomyelitis 8.8%. These percentages do not differ significantly between countries. Prevalence of a past history of cerebrovascular accident is 3.2% in French SS patients; 1.2% in SC, 3.8% in S beta thalassaemia. A past history of acute splenic sequestration was noted significantly more often in SS (11.75%) and S beta thalassaemia (14.3%) than SC (3.6%) in French children (p < 0.05). Proportions of subjects transfused at least once do not differ between countries; SS children are more transfused (64%) than SC (15.6%) and S beta thalassaemic (66%) (p < 10-4). Haemoglobin and reticulocyte counts do not differ significantly between countries. In conclusion, no major differences were detected between French, Guianese and Algerian homozygous sickle cell patients: this may be due to the fact that France is in itself a mosaïc of ethnic origins.

Adolescent↗
PubMed1993

[Growth and endocrine function in major thalassemia].

BACKGROUND: The risk of secondary endocrine dysfunction in patients with thalassemia major remains high, despite improvements in the care of hematologic problems. POPULATION AND METHODS: 31 patients (15 males, 16 females) with thalassemia major were studied. 28 of them had been regularly given blood transfusions since the age of 3.7 +/- 3.6 years. Iron chelation therapy had started before the age of 10 years in 9 patients, after this age in 15 patients; it was not performed or the time not specified in the 7 others. The mean dosage of deferoxamine was 20 +/- 6 mg/kg/day (9.6-34 mg/kg/day). Endocrine functions were evaluated at a mean age of 11.8 +/- 4.9 years and were monitored for 6.1 +/- 4.6 years (0 to 19 years). The hormones assay were: growth hormone (GH), thyroid, adrenal cortex, parathyroid and gonadal functions. RESULTS: The GH peak after stimulation was normal, but plasma somatomedin CIGFI was low and did not increase at puberty. 6 patients had peripheral hypothyroidism. Plasma cortisol was normal in the 16 patients examined, but plasma dehydroepiandrosterone sulfate was low in 24; this might be partly responsible for the delayed development of pubic hair. 2 patients aged 20 and 27 years was suffered from diabetes mellitus. Hypoparathyroidism occurred in 7 patients and 12 of the 24 patients with impuberism had a gonadotropin deficiency. The mean final height was -1.3 +/- 1.0 SD in boys (n = 7, mean age: 20 +/- 1 yr) and -1.3 +/- 0.9 SD in girls (n = 7; mean age: 19 +/- 1 yr), whether puberty was spontaneous or induced. CONCLUSIONS: The most frequent endocrine complications in these patients are delayed puberty because of gonadotropin deficiency, hypoparathyroidism and peripheral hypothyroidism. Substitution therapy, using sex steroids at an appropriate age, can induce the pubertal growth spurt.

Adolescent↗
PubMed1993

Donor for BMT with haemoglobin H disease.

We report a successful allogeneic BMT for the treatment of juvenile chronic myelogenous leukemia (JCML) in a 9-month-old Laotian boy using an HLA-matched sibling donor with HbH disease (--SEA/aaCS). In addition, before BMT the recipient had a complex haemoglobinopathy associating heterozygous state AE along with HbH disease (--SEA/-a3,7) without haemoglobin Constant Spring (HbCS). Because various haemoglobinopathies are frequently encountered in southeast Asia, when BMT is performed in Asian families the results may be evaluated by the differing haemoglobin characteristics of recipient and donor. However, there is also a significant risk of transmitting a new haemoglobinopathy to the recipient. Because transplantation from HLA-identical siblings offers the only chance of cure for JCML, the presence of HbH disease with mild clinical expression in the donor should not be taken as a contra-indication to BMT.

Bone Marrow Transplantation↗
PubMed1992

Prevalent skipping of an individual exon accounts for shortened protein 4.1 Presles.

An asymptomatic shortened variant of protein 4.1 (-8.5 Kd) was first recognized in the red blood cells and designated protein 4.1 Presles. We show here that the missing segment belongs to the 22/24 Kd domain. Protein 4.1 cDNA from reticulocytes was amplified, mapped, and sequenced. The truncation appeared to result from the prevalent skipping of an individual and alternatively spliced exon, also called motif II, whereas this motif is preferentially retained under normal conditions. The same phenomenon was observed in lympho-blastoid cells. Sequencing over 80 bp of intronic sequences 5' and 3' of motif II failed to reveal any change. A new alternative splice site was incidently found 81 nucleotide downstream of motif II in both normal and truncated 4.1 mRNA.

Amino Acid Sequence↗
PubMed1992

[Epidemiology of genetic hemoglobin diseases in metropolitan France].

The number of subjects with heterozygous beta-thalassaemia and sickle-cell anaemia in metropolitan France can be evaluated by the distribution of populations originating from countries with a high prevalence of genetic haemoglobinopathies. Taking into account the movements of these populations observed since the 1982 census, the current prevalences of beta-thalassaemic and drepanocytic traits are higher than the figures of 180,000 and 130,000 respectively found at that date. On the other hand, it appears from episodic screenings performed during the last few years that the percentage of subjects with heterozygous beta-thalassaemia is 3.09% in Corsica, 0.77% in school-age population in the Marseille area, and 0.72% in the general population of Marseille, Toulon and Nice. In 1992, the number of patients with heterozygous beta-thalassaemia and with major sickle-cell syndrome is estimated at 250-350 and 1000-3000 respectively. Patients with sickle-cell anemia predominate in the Paris area, whereas those with heterozygous beta-thalassemia predominate in the provinces, notably in the Provence-Côte d'Azur and Corsica regions.

Anemia, Sickle Cell↗
PubMed1992

Incidence of AIDS in HIV-1 infected thalassaemia patients. European and Mediterranean W.H.O. Working Group on Haemoglobinopathies and Cooleycare.

To estimate the cumulative incidence of acquired immunodeficiency syndrome (AIDS) in thalassaemia major patients (TMP) human immunodeficiency virus (HIV-1) infected through transfusion, 79 seropositive TMP were studied. At inclusion, mean age was 12.4 +/- 6.6 years; 40 were men; 21 were splenectomized. Centers for Disease Control, 1986 (CDC) stages and prescription of zidovudine were noted at least once a year. Cumulative incidence of AIDS and standard error were calculated using non parametric life table method. Age, sex, acute infection and splenectomy associations with progression to AIDS were tested using Breslow statistic. The median follow-up period was 4 years 11 months. At the end of the study period, 43 TMP were in CDC stage II, 23 in CDC stage III and 13 in CDC stage IV, including seven AIDS cases, of whom three had died. Four subjects died of other causes. Only two patients were treated with AZT prior to the occurrence of AIDS. Rate of progression to AIDS was not associated with acute infection, splenectomy, age, or sex. A cumulative AIDS incidence rate of 1.4% (SE 1.3%) was observed at 3 years and of 9% (SE 4%) at 5 years.

Acquired Immunodeficiency Syndrome↗
PubMed1992

[Intensifying iron chelating therapy with desferrioxamine using implantable venous access catheters (Port-A-Cath)].

Deferoxamine is still today the only preventive and curative treatment of transfusional hemochromatosis. It must be perfused daily, intravenously or subcutaneously, during several hours. Implantable infusion devices (Port-A-Cath) offer intravenous access, allowing to use higher doses, while avoiding local swelling due to subcutaneous injections. This device was inserted in 7 major thalassemic patients who presented with severe complications of iron overload, including 4 of them with signs of cardiac failure. Ferritinemias of all patients were lowered after intensifying iron chelation: cardiac function improved drastically in 2 patients. Devices were responsible for some complications: occlusion in one patient, local infections in two. This way of administration of desferal seems useful in patients with high ferritinemia and/or organic complications related to hemochromatosis.

Acute-Phase Reaction↗
PubMed1991

Partial splenectomy in sickle cell syndromes.

Partial splenectomy was carried out in four children with homozygous sickle cell disease and eight children with sickle cell beta thalassaemia. It was performed in order to preserve splenic contribution to the host defence against infections while suppressing hypersplenism or the risk of recurrence of acute splenic sequestration. Indications for this surgical operation were acute splenic sequestration (n = 1), hypersplenism (n = 5), and acute splenic sequestration and hypersplenism (n = 6). Surgery was uneventful in 11 patients. A significant reduction of blood requirements and a significant decrease of the number of hospitalisations/patient/year were observed after splenectomy. No recurrence of hypersplenism or acute splenic sequestration occurred and no severe infection was noticed during the follow up period after surgery (mean (SD) 4.2 (2.8) years; range 6 months-7 years). Mean haemoglobin concentration and leucocyte and platelet counts increased after surgery. The benefit of partial splenectomy compared with total splenectomy to treat acute splenic sequestration or hypersplenism in sickle cell disease is discussed.

Child↗