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Biomedical subjects

G Edan

Publications and source records attributed to G Edan.

At least 19 recordsLinked to original sources
PubMed1995

TAP2 gene polymorphism contributes to genetic susceptibility to multiple sclerosis.

MS is an autoimmune demyelinating disease that has been known to be associated with the HLA-DRB1*1501-DQA1*0102-DQB1*0602 haplotype. TAP1 and TAP2, two genes encoded within the MHC class II region between HLA-DP and -DQ loci, display genetic variability and are involved in the transport of antigenic peptides from the cytoplasm to the endoplasmic reticulum. Comparison of 116 MS patients with Caucasoid controls did not reveal any significant correlation between the previously described alleles of the TAP1 and TAP2 genes and MS. We report here an additional TAP2 dimorphism at codon 386, called I and J, corresponding to a silent mutation. An increased frequency of the J variant was observed in the patient population. The J mutation was not found in linkage disequilibrium with the HLA-DRB1*1501 allele and can be considered an additional genetic susceptibility marker of the disease.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1994

[Urination disorders in multiple sclerosis: value of urodynamic assessment].

Urinary troubles are common in patients with multiple sclerosis. The management of these troubles requires an accurate analysis. Urodynamic assessment was preformed in 117 patients with urinary symptoms positively diagnosed as suffering from multiple sclerosis. Urinary symptoms are not always correlated to urodynamic patterns. We have studied the correlation between urinary symptoms and urodynamic findings. Urodynamic results are similar to most of previous series: detrusor hyperreflexia is the most frequent abnormality, detrusor sphincter dyssynergia is diagnosed in 50% of the patients. There is some correlations with symptoms, but there are insufficient for an accurate diagnosis. Postvoid residue for urinary tracts infectious diseases, and sphincter incompetence for urinary incontinence are the main risk factors.

Adult↗
PubMed1991

[Benign forms of multiple sclerosis].

It is still difficult, in 1991, to evaluate precisely the position occupied by benign forms of multiple sclerosis (MS) in the natural history of the disease. The reality hidden behind the adjective "benign" varies from one author to another, and the estimated frequency of these forms is not the same when one refers to epidemiological studies on whole populations or to clinical studies in major hospitals. There is, however, no doubt that benign MS does exist, since about 10% of MS patients will suffer, throughout the whole duration of the disease (over 30 years), from no more than moderate disablement with few repercussions on their social and professional life. These are patients in who MS began when they were 20 to 30 years' old and evolved by episodes rather than progressively and whose main symptoms are optic neuritis and sensory disorders without pyramidal or cerebellar deficit. Nevertheless, these cases are not easy to recognize a priori: there is no paraclinical examination that can predict a benign course in the long term, and an MS which has long been benign may become worse at any moment.

HLA Antigens↗
PubMed1991

[A focus of multiple sclerosis in Bretagne: HLA markers and evaluation of consanguinity].

In a previous study, we established the overall prevalence of multiple sclerosis at 25 per 100,000 inhabitants in the French province of Brittany and found that the geographical distribution was uneven with four circumscribed high prevalence areas with more than 45 per 100,000. We conducted the present study to try to ascertain whether the existence of such clusters of MS could be explained by genetic factors, using two ways: the major histocompatibility markers and the frequency of intermarriage. Among the four areas of high prevalence, we examined the one with the highest prevalence, exempt from migratory movements over the last 100 years. We compared this studied population to a sample of 1005 healthy unrelated individuals coming from all over Brittany, designated as general Brittany population. A large sampling (about 25%) of the population accepted to take part in the study. Regarding HLA markers, we observed in the high prevalence area an increases percentage of B7, B8, B12, DR4 and a decreased percentage of B5, compared with the Brittany control population. The consanguinity coefficient in the population of high MS prevalence area was steadily much higher than the one in neighbouring areas with a low MS prevalence during a long period from 1896 to 1945. Under the reserve of non-randomized sampling of individuals for HLA marker study, our findings yielded a double argument in favor of genetic factors influencing the presence of clusters of MS cases: the particularities of HLA phenotype pattern and the increased consanguinity coefficient. The particularities of HLA polymorphism observed in the high prevalence area are likely to be the consequence of the intermarriage habits of this population.

Adult↗
PubMed1989

Optimum duration of antithyroid drug treatment determined by assay of thyroid stimulating antibody in patients with Graves' disease.

OBJECTIVE: To determine the optimal duration of antithyroid drug treatment by monitoring serum thyroid stimulating antibody values in patients with Graves' disease. DESIGN: Prospective longitudinal trial of patients with Graves' disease followed up for 24 months after withdrawal of treatment. SETTING: Tertiary referral centre. PATIENTS: A total of 64 consecutive patients with untreated Graves' disease, eight of whom were subsequently excluded. Fifty six patients completed the study. INTERVENTIONS: All patients were treated initially with carbimazole 40 mg, then with decreasing doses that maintained a euthyroid state. Treatment was scheduled to continue for 18 months but was withdrawn earlier if serum thyroid stimulating antibody became undetectable. END POINT: Serum values of thyroid stimulating antibody (assayed by stimulation of human thyroid cells in vitro) and thyroid hormones and thyroid state every three months during treatment and afterwards every six months for 24 months. MEASUREMENTS AND MAIN RESULTS: In 44 patients serum thyroid stimulating antibody became undetectable during treatment and treatment was withdrawn (median duration of treatment nine months, range 3-18 months). In 12 patients the antibody could be detected during 18 months of treatment. Among the first group of 44 patients initial values of the antibody before treatment were significantly lower than in the second group of 12 patients (median 225% (range 138-1236%) v 570% (250-1480%), p less than 0.001); the incidence of relapse was also lower (41% v 92%, p less than 0.001); and among those who did relapse the disease free interval after treatment was longer (median 12 months v 1 month, p less than 0.001). Moreover, the initial median serum values of thyroid stimulating antibodies were not related to the occurrence of relapse or remission as these did not differ between patients who did and did not have a relapse (median 267% (range 139-1480%) v 220% (range 138-1236%). CONCLUSION: Monitoring of serum thyroid stimulating antibody was a good guide to the duration of treatment as it allowed the treatment period to be considerably shortened in a large group of patients with no loss of efficiency.

Adolescent↗
PubMed1988

Functional properties of human thyroid follicles cultured within collagen gel.

Cultures of human thyroid follicles embedded in collagen gel were performed to investigate certain functional properties under bovine thyrotropin (TSH) stimulation. Follicles obtained from normal glands responded to increasing concentrations of TSH administered on day 4 in culture and for 3 days by increased amounts of cyclic AMP (cAMP), thyroglobulin (Tg) and triiodothyronine (T3) and by decreased levels of thyroxine (T4). Effect was maximal at 2000 microU/ml TSH (cAMP) or 200 microU/ml (Tg, T3, T4). When methimazole or propylthiouracil (PTU) were added, the T3 levels decreased. Follicle lumens contained a periodic acid-Schiff substance which was identified by immunoreaction as Tg. Thyroid follicles obtained from Graves' disease glands gave modified results with an earlier and intensified T3 response and no increase in Tg. These data show that (1) Tg and T3 are secretory products of functional follicles giving a cAMP-mediated response to TSH. (2) The detected T3 also derives from T4 5'-deiodination inhibited by PTU. (3) Intensified T3 response in Graves' follicles is probably due to enhanced conversion of T4 to T3.

Cells, Cultured↗
PubMed1987

[Anomalies of cellular immunity in Graves' disease treated by synthetic antithyroid drugs: effects on prognosis].

The involvement of humoral immunity mechanism in etiology of Graves' disease was observed for the first time in 1956. Twenty years later cellular auto-immune dysfunction was also described. To day, there is evidence for suppressor T cell deficiency and decrease in T suppressor lymphocytes in Graves' disease and cell mediated immunity might be one of the most important point in the pathogenesis of Graves disease. For the future, cellular auto-immune dysfunction might be used to predict the evolution of the disease and to choice the best therapeutic scheme.

Antithyroid Agents↗
PubMed1987

A study of 609 HLA haplotypes marking for the hemochromatosis gene: (1) mapping of the gene near the HLA-A locus and characters required to define a heterozygous population and (2) hypothesis concerning the underlying cause of hemochromatosis-HLA association.

We compared 609 haplotypes carrying the idiopathic hemochromatosis allele with 475 control haplotypes. Four haplotypes were more frequent in hemochromatosis: A3, B7 (actually A3, CW., B7, Bfs, DR2); A3, B14 (actually A3, CW., B14, BfF, DRW6); A11, B35; and A11, B5. The linkage disequilibrium for A3, B7 and A3, B14 (and probably also for A11, B5) was undeniably stronger in hemochromatosis than in controls. Two haplotypes--A3, B12 and A3, B15--were more frequent in hemochromatosis, without linkage disequilibrium. Four haplotypes in linkage disequilibrium in hemochromatosis--i.e., A2, B12; A1, B8; A9, B7; and A29, B12--were also found to have the same frequency and strength of linkage in controls. The dual observation (1) that haplotypes carrying A3 without either B7 or B14 were highly significantly more frequent in hemochromatosis than in controls and (2) that haplotypes carrying B7 or B14 but not A3 had the same frequency in hemochromatosis and controls led to the formal conclusion that only A3 is an independent marker for the hemochromatosis allele, B7 and B14 being involved only owing to the haplotypic mode of marking; the hemochromatosis allele can thus be mapped closer to locus A than to locus B. Our findings fit well with the hypothesis that the hemochromatosis mutation was a rare if not unique event that produced an ancestral HLA marking that was subsequently modified by recombinations and geographical scattering due to migrations.

Alleles↗
PubMed1986

Assays for thyrotropin-receptor binding and thyroid-stimulating antibodies in sera from patients with Graves' disease.

We compared the activities of thyroid-stimulating antibodies (TSAb) measured in cultures of human thyrocytes and the values for thyrotropin-receptor antibodies (TRAb) as measured with a commercial kit based on use of radiolabeled receptors. Sera were obtained from patients with Graves' disease before, during, and after therapy with carbimazole (1-methyl-2-thio-3-carbethoxyimidazole). We found a significant correlation between the measurements of these two antibodies in patients: before treatment (r = 0.74, p less than 0.01, n = 44), after three months of treatment (r = 0.76, p less than 0.01, n = 21), and during relapse after the drug was discontinued (r = 0.64, p less than 0.01, n = 19). In all three situations, our TSAb technique was more sensitive than the TRAb method. We conclude that, even though the TRAb technique is simpler and quicker, this commercial kit is too insensitive to replace measurement of TSAb in fresh human thyrocyte cultures for management of drug therapy of patients with Graves' disease.

Adult↗
PubMed1985

Is the HLA-linked haemochromatosis allele implicated in idiopathic refractory sideroblastic anaemia?

In order to assess the previously reported association of HLA-linked idiopathic haemochromatosis with idiopathic refractory sideroblastic anaemia (IRSA), the prevalence of HLA-A3 antigen in a group of 22 patients with IRSA was compared to that observed in healthy controls and in patients with homozygous idiopathic haemochromatosis and to that calculated for a population heterozygous for idiopathic haemochromatosis. The prevalence of A3 in patients with IRSA (0.23) was quite similar to that observed in controls (0.29) and significantly different from that observed in homozygous (0.73; P less than 10(-5] and heterozygous (0.57; P less than 10(-3] haemochromatosis. Serum iron, transferrin saturation, serum ferritin and liver iron concentration showed no difference in IRSA patients with or without A3. It is concluded that there is neither systematic association between the haemochromatosis allele and IRSA nor systematic implication of such an allele in the development of iron overload observed in IRSA.

Aged↗
PubMed1984

Gallium-67 imaging in muscular sarcoidosis.

A case is presented of sarcoid myopathy in which radiogallium was seen to accumulate in the sites of muscle involvement. Uptake of the radiotracer disappeared following institution of corticosteroid therapy. The exceptional nature of this case contrasts with the high frequency of biopsy evidence of sarcoid muscle disease but is consistent with the rarity of clinical evidence of sarcoid granulomas in muscle. Gallium-67 imaging can be used to determine the extent of muscle involvement and, through evaluation of uptake intensity, the degree of disease activity before and after treatment.

Adult↗
PubMed1983

[Peripheral distribution of lymphocyte subpopulations in Basedow's disease. Decrease in suppressor T-lymphocytes].

The distribution of B- and T-lymphocyte subpopulations was studied in peripheral blood of 45 patients with untreated Graves' disease and 45 sex- and age-matched healthy controls. Blood samples were taken at the same hour in all subjects. The following tests were performed: HTLA and E (AET) for relative T-lymphocyte count, complement receptor (EAC) and surface immunoglobulins (IgS, IgG, IgM, IgA, kappa, lambda) for relative B-lymphocyte count. In 23 subjects of each group the subpopulations of T-lymphocytes were defined by their reactivity with monoclonal antibodies OKT8 (T-suppressor cells) and OKT4 (T-helper cells). Compared with the control group, patients with Graves' disease showed a decrease in the number of T-lymphocytes (HTLA: P less than 0.05: EAET: P less than 0.001) a decrease in T-suppressor cells (P less than 0.01), and no significant difference in B-lymphocytes and T-helper cells. Thus, the main lymphocyte characteristic in Graves' disease is a decrease in the relative value of T-cells, specifically affecting T-suppressor cells.

Adult↗