Search PubMed⌕ Search

Biomedical subjects

K Ayed

Publications and source records attributed to K Ayed.

At least 127 records · Page 7Linked to original sources

Suppressive T cell function of Epstein-Barr virus induced B cell activation in active Behçet's disease.

B and T cell function were studied in 10 patients with active Behçet's disease (BD) and in 10 normal subjects. Peripheral B lymphocytes infected with Epstein-Barr virus (EBV) were cultured for 20 days in the presence or absence of autologous T cells. Immunoglobulin M and G secretions into the supernatants were assessed with an enzyme-linked immunosorbent assay. The extent of suppression of EBV-induced B cell activation by autologous T cells was significantly decreased in active BD patients as compared to normal subjects at a T:B ratio of 1:1, whereas the suppression ratio was in the normal range at a T:B ratio of 4:1. The IgM and IgG secretions in purified B cell cultures were significantly higher in active BD patients as compared to control subjects. Thus, an increased B cell function associated with a defective EBV-specific T cell suppressive function could explain at least in part the immunological disorders in BD patients.

Adult↗

Extended HLA haplotypes in multiplex families with insulin dependent diabetes mellitus in Tunisian population: HLA serological typing and RFLP analysis.

Haplotypes including HLA A, B, C, DR, and DQ were compared in a study population comprising 18 Tunisian multiplex families with diabetic children. Eighty haplotypes found in IDDM patients were compared with 148 haplotypes present in healthy family members. RFLP analysis showed that two DR subtypes were significantly more common in the diabetic haplotypes (DR4-DQw8: 82 per cent in IDDM members compared to 0 per cent in healthy members, p less than 0.001 and DR-Dw25: 56 per cent in IDDM patients compared to 16.7 per cent in healthy members, p less than 0.001) and these were in most cases found in haplotype combinations with HLA A2 B44 DR4 DRw53 and HLA A 24 B18 DR3 genes, respectively.

Diabetes Mellitus, Type 1↗

[Comparison of three methods to evaluate microalbuminuria in insulin-dependent diabetics: radioimmunoassay, laser-nephelometry and Laurell electroimmunodiffusion].

The early detection of microalbuminuria in insulin dependent diabetes is considered as a sign of initial stage of nephropathy possibly reversible if glycemic balance is well maintained. This detection requires very accurate methods as radio-immuno-assays. Yet, they are so slow that they represent an obstacle to systemic detection. We report in this work an apparaisement of an immuno-nephelemetric and electro-immuno-diffusion of Laurell methods. Results reveal that immuno-nephelemetry and electro-immuno-diffusion are a sensitive and accurate methods (threshold of sensitivity of Laurell method is : 2.5 mg/l and nephelemetry is 1.5 mg/l). Moreover, RIA, immunonephelemetry and Laurell methods are significantly well correlated (r = 0.903: Laurell/Radio-immuno-assay, r = 0.907: Nephelemetry/Laurell). In conclusion immuno-nephelemetry and electro-immuno-diffusion of Laurell are a choice methods to test great lines of samples. Radio-immuno-assay can be used as a reference method of detection of microalbuminuria.

Adult↗

HLA-antigens in a Tunisian familial chondrocalcinosis.

Thirty members of a Tunisian family with hereditary chondrocalcinosis were typed for HLA-A, B, and DR antigens: 7 affected and 23 unaffected subjects in three consecutive generations. The haplotype A1 B12 DR3 was found in all affected subjects and in 8 unaffected members. Chondrocalcinosis in this family may be associated with the haplotype A1 B12 DR3. The mode of transmission was autosomal dominant with incomplete penetrance.

Chondrocalcinosis↗

[Prevalence of viral hepatitis B markers in the region of Tataouine (southern Tunisia)].

Tataouine (South Tunisia) has been subject to several viral hepatitis epidemics during these last years. Prospective study has been conducted to define the prevalence of HVB infection. It has examined 511 cases, the age of whom was between 1 month and 70 years, reported in groups through the OMS recommendations, taking into account the number of inhabitants in each area. The global prevalence was 6.2% for HBs Ag and 18.5% for HBs antibody. These results were not different from the frequencies observed within the Tunisian population in general. The analysis of this study according to these groups, shows that in three areas (Ras El Oued, Bir 30, Dhibet) 60 to 80% of cases have at least one of HVB marquers, whereas the prevalence in other areas (Rogba) was very weak. The geographic repartition of HVB infection corresponds approximatively to areas that have been the most infected by the last hepatitis epidemics. A second study has completed and confirmed the results of the first one, taking into consideration a more important number of cases from areas of strong and weak endemicity. 596 sera have been examined in Rogba which counts 2000 inhabitants and is a weak endemicity area. 528 sera have been examined in the three areas of strong endemicity: 199 in Bir 30, 201 in Dhibet and 128 in Ras El Oued, which count around 2000 inhabitants, too. The percentage of cases presenting at least one of HVB serological marquers reaches 84 in Dhibet, 70 in Ras El Oued, 50 in Bir 30 and 24 in Rogba. This HBs Ag frequency is 3.8% in Rogba, 15% in Bir 30, 24% in Ras El Oued and 26.3% in Dhibet. It seems that the HVB is the virus of hepatitis epidemics observed in Tataouine at least in the three strong endemicity areas.

Adolescent↗

HLA A, B, and DR antigens and complotype in Tunisian patients with diabetes mellitus.

The frequency of HLA A, B, and DR antigens as well as the Bf and C4 allotypes have been investigated in insulin-dependent diabetes mellitus (IDDM) and compared to that of healthy controls in the Tunisian population. An increase of A30, DR3, DR4, BfF1, C4Ao, and C4Bo and decrease of B40, DR2, DR5, and DR6 were found in diabetics when compared to the value observed in controls. The strongest association was noticed with HLA DR3 and DR4. Heterozygotes DR3 DR4 were very frequent in diabetics: 24.2 per cent versus 3.6 per cent in controls (relative risk 7.72). The protective role of DR2 and DR5 antigens were also confirmed. No supratypes of HLA, Bf, and C4 alleles associated with IDDM have been observed among these Tunisian patients.

Adolescent↗

Behçet's disease and major histocompatibility complex class II antigens in Tunisians.

Forty-two Tunisian patients suffering from Behçet's disease (23 with uveitis) were typed for HLA-DR and DQ antigens. There was a significant excess of HLA-DQw3 (p less than 0.01) but also an important deficiency of HLA-DRw6 and DQw1 (p less than 0.01). A substantial increase of HLA-DR2 (p less than 0.01) for those with uveitis, and of HLA-DR4, DR7, for the others has been recorded (p less than 0.01).

Adult↗