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Biomedical subjects

M de Montalembert

Publications and source records attributed to M de Montalembert.

At least 19 recordsLinked to original sources
PubMed1992

Increased PIVKA-II concentrations in patients with cystic fibrosis.

Serum vitamin K concentrations and prothrombin induced by absence of vitamin K (PIVK-II) concentrations were assayed in 43 patients with cystic fibrosis. Twenty nine showed a normal PIVKA-II and vitamin K concentrations; 14 showed an increased PIVKA-II concentration, in one of whom serum vitamin K was decreased. Although their vitamin K concentrations were normal, some patients with cystic fibrosis still had an increased PIVKA-II. There was a significant correlation between PIVKA-II concentrations and the administration of antibiotics, a factor which has not previously been considered responsible for an increase in PIVKA-II.

Adolescent↗
PubMed1992

[Research of factors for glucose intolerance in mucoviscidosis].

Glucose tolerance has been assessed in cystic fibrosis (CF) children using HbA1C and plasma glucose and insulin determinations during an oral glucose tolerance test (OGTT), along with the determination of HLA-DR and islet-cell (ICA) and anti-insulin (IAA) antibodies. Of 49 patients (25 males, 24 females), aged 2 to 21 years (mean = 10.9 years), 29 had normal glucose tolerance (WHO criteria) during OGTT, 14 had impaired glucose tolerance (IGT) and 6 had an isolated hyperglycemia at 120 min. Fasting plasma glucose and HbA1C were significantly higher in IGT than in normoglycemic patients. However, these two parameters showed poor individual predictive value of disturbance in glucose tolerance. Of 14 patients with abnormal OGTT, 7 were aged below 10 years, with 2 as young as 5 years; 8 patients were females. HLA antigens characteristic of type I diabetes tended to be found less frequently in CF patients than in the general population: 9% were DR3, 7% were DR4 and none was DR3/DR4. There were no HLA differences according to glucose tolerance. ICA and IAA were respectively detected in only one patient. Stimulated plasma insulin was low but did not correlate with glucose tolerance. In conclusion, impaired glucose tolerance is common in cystic fibrosis and can be found early in life. Although insulin secretion is decreased in this population, it does not seem to be the only factor responsible for impaired glucose intolerance. The absence of the genetical and immunological characteristics of type I diabetes confirms that glucose intolerance in cystic fibrosis is due to other pathogenetic mechanisms.

Adolescent↗
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

Outbreak of gut colonization by Pseudomonas aeruginosa in immunocompromised children undergoing total digestive decontamination: analysis by pulsed-field electrophoresis.

We analyzed an outbreak of gut colonization by Pseudomonas aeruginosa occurring in an intensive care hematology unit by using conventional typing methods and pulsed-field electrophoresis. In October and November 1989, the feces of four immunocompromised children undergoing total digestive decontamination were colonized by P. aeruginosa. Ten isolates were obtained from the gut flora in pure culture. Retrospective investigations found that one P. aeruginosa isolate from stools of one of the patients was already present at high counts 6 months before the outbreak. This patient had been discharged from the unit in May 1989 and had been readmitted concomitantly with the outbreak. Only pulsed-field electrophoresis could demonstrate that a single epidemic strain was present in the fecal flora of the children. This strain had probably been brought into the unit by the patient with chronic fecal carriage.

Anti-Bacterial Agents↗
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↗
PubMed1991

[Antibiotic treatment of cystic fibrosis].

Lower respiratory tract superinfection is nearly constant in cystic fibrosis and has a significant impact on mortality. The three organisms which most often colonize the bronchial tree are Staphylococcus aureus, Haemophilus influenzae and Pseudomonas aeruginosa. The latter organism is found in 70% to 90% of older cystic fibrosis patients. P. aeruginosa infections are remarkably persistent and cause severe, extensive lung damage. Antimicrobial therapy is indicated in patients with clinical symptoms (fever, weight loss, changes in sputum and auscultation) and should be selected on the basis of cytobacteriologic studies of sputum. Oral antibiotics are usually successful in eradicating S. aureus and H. influenzae. Conversely, intravenous therapy is required in most cases of P. aeruginosa infection. Fifteen-day courses are given repeatedly, either on a routine basis every three months, or whenever new clinical symptoms develop. Antimicrobials usually fail to eradicate P. aeruginosa even when significant clinical improvement occurs. Two-drug therapy and judicious use of the various available anti-microbial agents should delay development of resistant strains, an event which is nearly inevitable as antimicrobial treatments are repeated.

Anti-Bacterial Agents↗
PubMed1991

[Mucoviscidosis and allergic bronchopulmonary aspergillosis].

Allergic bronchopulmonary aspergillosis (ABPA) is a severe disease inducing bronchopulmonary anatomic lesions which complicate those already present in patients with cystic fibrosis. The frequency of this association is estimated between 0.6 and 10% according to American studies. Diagnosis of ABPA is difficult, as findings such as sibilant rales, pulmonary infiltrates, bronchiectasies, anti-aspergillus precipitins may be present as single features in patients with cystic fibrosis. Thus it is important to ascertain the diagnosis as oral corticosteroid treatment is the only one able to prevent evolution towards bronchiectasies and pulmonary fibrosis.

Adolescent↗
PubMed1990

[Colonization by pyocyanic bacillus and its treatment in cystic fibrosis].

In cystic fibrosis infection is localized to the bronchi and self-perpetuated by a disorder of mucociliary clearance. At a certain stage of the disease infection is caused by Pseudomonas aeruginosa (PA), and the patient cannot get rid of it as cystic fibrosis reduces his defence mechanisms against this organism, a naturally weak pathogen. The presence and significance of persistent bronchial PA infection result from complex phenomena which have been summarized as "an opportunistic organism in a host whose defences have been very peculiarly compromised". The toxicity of PA and the inappropriate inflammatory response of the host concur to create permanent alveolar lesions which are gradually spreading out. The effectiveness of antibiotics depends on the organism and its resistance, on pharmacokinetic factors bringing the drug in situ and on local conditions of redox, physico-chemical environment and nutrition. Other factors intervene more roughly, including patient's age, liver impairment, lung anatomy (excluded areas), general malnutrition and vitamin deficiencies. Thus, the part played by other treatments in the antibiotic therapy of cystic fibrosis can no longer be ignored, just as it is no longer sensible to limit the use of antibiotics to obvious infections. To evaluate the effectiveness of antibiotics is not easy, but it can be demonstrated beyond any doubt when the above mentioned factors are taken into account. The use of antibiotics creates practical problems relating to their cost, their dosage, their side-effects, the adequacy of therapeutic infrastructures and, above all, it raises the question of short- and long-term changes in microbial ecology.

Adolescent↗
PubMed1990

Absence of HIV DNA sequences in seronegative polytransfused thalassemic patients.

The risk of infection with human immunodeficiency virus (HIV) by transfusion is not totally eliminated, since contaminated blood given before seroconversion to HIV is not detected on the actual biological screening. We used the polymerase chain reaction (PCR) assay (with one primer pair in the gag region and two in the pol region) to detect HIV DNA sequences in 30 seronegative polytransfused thalassemic patients and in 60 seropositive individuals (used as positive controls). We did not observe PCR-positive HIV-antibody-negative results in seronegative polytransfused patients.

Adolescent↗
PubMed1990

Partial splenectomy in homozygous beta thalassaemia.

Partial splenectomy was performed on 30 patients with homozygous beta thalassaemia to reduce blood requirements and to avoid the risk of overwhelming postsplenectomy infections; 24 patients had thalassaemia major and six thalassaemia intermedia. Five patients received a high transfusion regimen before and after surgery and 25 a lower one. Follow up after surgery ranged from one to four years. Partial splenectomy improved the long term haematological state in the six patients with thalassaemia intermedia. Recurrence of hypersplenism occurred in nine of the 24 patients with thalassaemia major, however, and complete splenectomy was required. Serum IgM concentrations were not significantly modified by surgery. The mean (SD) residual spleen after surgery was 4.45 (2.36) cm measured by scintigraphy. No severe infections occurred after surgery; however, most patients were routinely treated with phenoxymethylpenicillin and the protective effect of the remaining spleen could not be exactly determined. Because of the possibility of recurrence of hypersplenism, routine partial splenectomy when splenectomy is needed in thalassaemia major is not advised, except in children under 5 years whose risk of overwhelming postsplenectomy infection is greatest.

Adolescent↗
PubMed1989

[Iron deficiency and Pseudomonas aeruginosa colonization in cystic fibrosis].

The incidence of iron deficiency and its relationship with the concentration or iron in sputum and the number of Pseudomonas aeruginosa (PA) colonies was studied in an unselected group of 53 cystic fibrosis (CF) patients with an age range of 3 months to 21 years. Parameters used to assess the iron status included serum iron, the % saturation of transferrin (n = 53). The number of subjects with depletion of iron stores was estimated by levels of ferritin (n = 50). The concentration of iron and of PA was measured in a subgroup (n = 24) and compared to a control group (n = 8) with pulmonary infections of varying etiology. A close correlation was found between serum iron and the % saturation of transferrin (r = 0.952; p less than 0.001). Between 22.6 to 28.3% of patients were found to be iron deficient. An abnormally low ferritin (less than 12 ng/ml) was noted in 28% of cases but no correlation could be established between changes of serum iron and ferritin levels as a function of the degree of infection and/or of inflammation. In 62% of cases (n = 15) the concentration of iron in sputum was found to be within the range of control values (12-27 mumols/l). In 38% of cases (n = 9), ferritin values were above 27 mumols/l. No correlation was found between the concentration of iron and the number of PA colonies in sputum. We can therefore conclude the following: 1) iron deficiency is more common in CF than previously reported; 2) ferritin levels constitute a poor index of iron deficiency; 3) colonisation with PA is not associated with iron content of bronchial secretions.

Adolescent↗
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↗
PubMed1986

[Transient erythroblastopenia in young children].

A case of transient erythroblastopenia of childhood is reported. This syndrome occurred in a 13 month-old girl. Initial signs were a 6.1 g/dl hemoglobin level and severe erythroblastopenia. Spontaneous recovery occurred after a few weeks. No etiology could be found.

Anemia, Aplastic↗