Search PubMed⌕ Search

Biomedical subjects

G Lenoir

Publications and source records attributed to G Lenoir.

At least 19 recordsLinked to original sources
PubMed1992

[Lymphoproliferative syndromes associated with Epstein-Barr virus in transplantation].

We report 23 cases of lymphoproliferative diseases which occurred among 2,100 patients with kidney or combined kidney+pancreas transplant. Eleven patients developed a severe diffuse disease within the first 3 months post-transplantation; immunoblastic B cells of recipient origin infiltrated the bone-marrow, transplanted organs, liver, spleen, lymph nodes, lungs, and brain; immunoglobulin abnormalities with fever, leuko-thrombocytopenia and liver dysfunction constituted the symptoms; all patients received anti-lymphocyte globulins; 9 patients were also treated with cyclosporin. Three out of 6 tumors analysed were monoclonal. Epstein-Barr virus was present in 3 lesions analysed. Treatment consisted of cessation of immunosuppressive therapy. Nine patients died with lactic acidosis. Five patients had a less severe form. Seven patients had solid tumors involving the tonsils, lungs (2), lymph nodes (2), and bladder, 8 months after transplantation. All patients received cyclosporin; 4 also received anti-lymphocyte globulins and 3 OKT3. Tumor cells were immunoblasts expressing B cells markers at a late stage of B cell differentiation; 4 tumors were monoclonal. C myc was negative. Treatment consisted of cessation of immunosuppressive therapy, antiviral agents, and monoclonal antibodies (mAb): anti-CD21 and anti-CD24 mAb therapy was followed by cure of the lymphoma in 1 patient, by transient remission in a second one and by failure in the third patient. Two patients had a recurrence of the lymphoma and received chemotherapy; 2 patients died of the lymphoma, 1 died of unrelated cause; 4 are alive, 3 of them having a good graft function.

Antigens, CD↗
PubMed1992

Nonlinkage of 16q markers to familial predisposition to Wilms' tumor.

Wilms' tumor (WT), a childhood cancer of the kidney, occurs in both familial and sporadic forms. Chromosome 11 genes have been implicated in the etiology of WT, and mutations in a gene at chromosomal band 11p13, WT1, have been identified in a few WT cases. However, 11p13 has been excluded as the site of the predisposition mutation segregating in several large WT families, which implies the existence of a non-11p familial predisposition gene. Recently, loss of heterozygosity for 16q markers located between chromosomal bands 16q13 and 16q22 has been reported in approximately 20% of sporadic Wilms' tumors. To determine if this region of 16q harbors the non-11p familial WT gene, a genetic linkage study of five WT families was undertaken. Using multipoint analyses, we ruled out genetic linkage of familial WT predisposition to 16q.

Chromosome Banding↗
PubMed1992

Deletions involving two distinct regions of 6q in B-cell non-Hodgkin lymphoma.

The recurrent loss of genetic material from a specific chromosomal region in a given tumor type suggests the presence of a tumor-suppressor gene, the loss or inactivation of which may be relevant for tumorigenesis. In this study, we provide molecular evidence for the recurrent association between deletions on the long arm of chromosome 6 and B-cell non-Hodgkin lymphoma (B-NHL). Normal and tumor DNAs from 71 cases of B-NHL were studied for loss of constitutional heterozygosity (LOH) at 19 loci on chromosome 6 using a panel of restriction fragment length polymorphism (RFLP) probes. LOH, indicating deletion of all or part of 6q, was detected in 16 of 71 cases (22.5%), ranging from low-grade to high-grade B-NHL. The isolated loss of 6p or the loss of other chromosomes (8, 17, 22) tested as controls for specificity was not observed in any case. Comparison of the extent of the deletions among different cases allowed the identification of two distinct regions of minimal deletion (RMD) at 6q25 to 6q27 (RMD-1) and at 6q21 to 6q23 (RMD-2), respectively, suggesting the existence of two tumor-suppressor genes. These data support a role for 6q deletions in B-NHL pathogenesis and provide a basis for identifying the corresponding tumor-suppressor genes.

Biopsy↗
PubMed1992

Cystic fibrosis arthritis. A report of five cases.

In a retrospective study of 206 patients with cystic fibrosis (CF), five cases of CF arthritis were recorded. This is a frequency of 2.5% and of 4.5% in patients aged over 10. Four patients had episodic arthritis, which was related to the course of pulmonary disease in two cases. In three patients, synovial fluid examination revealed minimal evidence of inflammation. In one of these three cases, synovial biopsy revealed a mild and non-specific synovitis. The fifth patient had chronic arthropathy and was positive for rheumatoid factor, but did not fulfil the criteria for rheumatoid arthritis. There were no radiographic abnormalities in any of these cases. CF arthritis is a rare syndrome of unknown pathogenesis.

Adolescent↗
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

[Amiloride hydrochloride nebulized by oxygen in the treatment of mucoviscidosis].

Bronchial inhalation of amiloride chlorhydrate has been suggested for a number of years in the treatment of the pulmonary disease in cystic fibrosis. However, physiotherapy remains invaluable in the struggle in containing pulmonary infections in this disorder. Physiotherapy may lead to a transient fall in the arterial oxygen as can sessions of nebuliser therapy which precedes physiotherapy. The originality of the system studied and proposed here for the administration of medication depends on an electronic control which guarantees that there is the nebulisation of a constant volume of medication with each inspiration. Triggered by inspiration the active principle nebulised is perfectly co-ordinated to the inspiratory cycle. A comparative chromatography carried out in this slides of silica-gel have enabled us to verify the absence of any degradation of the active principle contained in the nebuliser solution during the ten minutes period of aerosol therapy. Thus a quantification of the administered dose of Amiloride Chlorhydrate is made possible. In association with oxygen it enables an efficacious preparation of respiratory physiotherapy to children. As the expiratory tubing ends in a filter the fraction of the oxygen inhaled by the patient remains very high; 80% (V/V) of the medication is emitted in the form of liquid particles whose diameter lies between 0.5 and 5 micrometers. In practice in order to humidify the sputum and to restore the oximetry before the physiotherapy sessions, it seemed to us an interesting possibility to administer Amiloride Chlorhydrate and oxygen simultaneously. This is achieved in hospital by using wall-mounted oxygen (at a gas pressure of 3.5 bars).(ABSTRACT TRUNCATED AT 250 WORDS)

Aerosols↗
PubMed1992

[Fibromatosis and fibrodysplasia ossificans progressiva. An avoidable diagnostic error].

BACKGROUND: Myositis ossificans progressiva is a rare progressive disease of connective tissue and muscle whose early diagnosis, before the lesions become ossified, can be difficult. The congenital malformations that accompany the disease may help in this diagnosis. CASE REPORT: A 12 year-old boy developed a localized swelling in the right trapezius muscle. Muscle biopsy showed fibromatosis lesions. Surgical excision was incomplete and despite chemotherapy, new lesions appeared periodically in the cervical and dorsal regions where they became ossified. Bilateral hallux valgus was noticed at that time and used to rectify the diagnosis as myositis ossificans progressiva. CONCLUSION: Many children suffering from myositis ossificans progressiva have congenital malformations, most commonly of big toes and thumbs. These anomalies are important for distinguishing myositis ossificans progressiva from other inflammatory diseases of muscle.

Child↗
PubMed1992

Maternally inherited duplication of the mitochondrial genome in a syndrome of proximal tubulopathy, diabetes mellitus, and cerebellar ataxia.

Two sisters in the first year of life presented with a proximal tubulopathy of unknown etiology. They subsequently developed a pluritissular disorder including diabetes mellitus, skin abnormalities, mitochondrial myopathy with ragged-red fibers, and cerebellar ataxia. Their mother had ptosis, ophthalmoplegia, and muscle weakness. Analysis of the mitochondrial respiratory chain showed a complex III deficiency in both skeletal muscle and lymphocytes of the second girl. Southern blot analysis provided evidence for a heteroplasmic partial duplication of the mtDNA (26 kb), involving one full-length and one partly deleted mitochondrial genome and with one single abnormal junction between the genes for ATPase 6 and cytochrome b. Using PCR amplification of lymphocyte DNA, we were able to detect minute amounts of duplicated molecules in the mother, which provided evidence for maternal inheritance of the partial duplication. While maternal transmission of point mutations have been reported in Leber disease, retinitis pigmentosa, and MERRF disease, this observation is, to our knowledge, the first example of a maternally inherited duplication of the mitochondrial genome in man.

Adenosine Triphosphatases↗
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

Nucleotide sequence polymorphism in a hotspot mutation region of the p53 gene.

By screening for mutations in the p53 coding sequence by means of single-strand conformation polymorphism (SSCP) in a series of breast tumors we detected a novel polymorphism. This change in the SSCP pattern was detected in 6.2% of the tumor DNAs analysed and implied an A to G substitution at the last base of codon 213, thus representing a neutral change. First suspecting a somatic mutation we confirmed its presence in matched sets of DNAs from normal tissues. Extending our study to a series of 60 ovarian carcinomas and 70 healthy blood donors we noticed that this polymorphism represented only 3% and 2.6% respectively. We wondered if the difference in frequency in the breast cancer population might not be related to familial breast cancer and analysed 26 DNAs from patients showing predisposition to the disease. Two patients presented this polymorphism and one corresponding kindred was analysed, revealing a mendelian mode of transmission but no correlation with the cancer phenotype.

Base Sequence↗
PubMed1991

[Antidiuretic hormone (ADH) and urination].

The role played by antidiuretic hormone in enuresis remains controversial. As a symptomatic treatment, desmopressin (DDAVP) has already proved to be a useful addition to the measures applied against this condition.

Adolescent↗
PubMed1991

When Epstein-Barr virus persistently infects B-cell lines, it frequently integrates.

In this study we used Gardella gel analysis of intact DNA, Southern blotting of digested DNA, and fluorescence in situ hybridization to provide complementary and unequivocal information on the state of the Epstein-Barr virus (EBV) genome in persistently infected cells. The fluorescence in situ hybridization technique allowed us to directly visualize both integrated and episomal EBV DNA at the single-cell level. We show here that circularization of the EBV genome is rarely detected upon infecting activated normal B cells. The virus can persist upon infection of a different proliferating B-cell target, EBV-negative Burkitt's lymphoma tumor cell lines. Analysis of 16 such lines reveal again, that the virus infrequently persists as covalently closed episomes; rather, the virus preferentially persists by integrating into the host DNA (10 of 16 clones). The integrated virus is linear and usually intact, although 3 of 10 isolates have deletions from the left-hand end including the latent origin of replication. At the level of our analysis, no obvious relationship was seen between the integration sites. These studies provide, for the first time, a reproducible in vitro model system to study integration by EBV.

B-Lymphocytes↗
PubMed1991

Detection of Epstein-Barr virus genomes in AIDS related lymphomas: sensitivity and specificity of in situ hybridisation compared with Southern blotting.

Eighteen cases of AIDS related, non-Hodgkin's lymphomas were examined for the presence of Epstein-Barr virus (EBV) genomes using in situ hybridisation with a 35S-labelled probe. The results were compared with those obtained independently by Southern blot analysis with a 32P-labelled probe of frozen tissue from the same tumours. Technically satisfactory results were obtained with both methods in 15 lymphomas. EBV DNA was detected in seven of 15 (47%) cases by in situ hybridisation and in eight of 15 (53%) cases by Southern blotting (including all the cases positive by in situ hybridisation). The results of EBV DNA detection by the two techniques were identical in 14 of 15 (93%) cases. In situ hybridisation gave no false positive results. This study shows that the sensitivity and specificity of in situ hybridisation for the detection of EBV genomes in AIDS related lymphomas approaches that of Southern blotting, even when using routinely processed archival, paraffin wax embedded material.

Acquired Immunodeficiency Syndrome↗
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↗