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Biomedical subjects

H Ayadi

Publications and source records attributed to H Ayadi.

At least 19 recordsLinked to original sources
PubMed2006

Localization of a novel autosomal recessive non-syndromic hearing impairment locus DFNB63 to chromosome 11q13.3-q13.4.

Hereditary hearing impairment is the most genetically heterogeneous trait known in humans. So far, 50 published autosomal recessive non-syndromic hearing impairment (ARNSHI) loci have been mapped, and 23 ARNSHI genes have been identified. Here, we report the mapping of a novel ARNSHI locus, DFNB63, to chromosome 11q13.3-q13.4 in a large consanguineous Tunisian family. A maximum LOD score of 5.33 was obtained with microsatellite markers D11S916 and D11S4207. Haplotype analysis defined a 5.55 Mb critical region between microsatellite markers D11S4136 and D11S4081. DFNB63 represents the sixth ARNSHI locus mapped to chromosome 11. We positionally excluded MYO7A from being the DFNB63-causative gene. In addition, the screening of two candidate genes, SHANK2 and KCNE3, failed to reveal any disease-causing mutations.

Chromosome Mapping↗
PubMed2006

[Epidemiologic study of autoimmune thyroid disease in south Tunisia].

In order to study incidence and prevalence of autoimmune thyroid diseases (AITDs), we studied a retrospective cohort of 1,079 patients explored in the department of Endocrinology of Sfax (south of Tunisia). The overall incidence of AITDs was 9.9%. Mean age was 39.6+15 years; sex ratio 5 F/1M. Graves' disease was the most frequent (45%). Atrophic thyroiditis was present in 32.2% of patients and Hashimoto's thyroiditis in 22.8%. The incidence of AITDs increased from 1990 to 2000 and by 2003 it had fallen to 67 cases per year. TPO antibody was present in two-thirds of patients with Hashimoto thyroiditis, and half of those with atrophic thyroiditis. TG antibodies were less frequent (one-third of patients). Association with other autoimmune diseases was noted in 6.3% of patients: type I diabetes mellitus, adrenal insufficiency and vitiligo. Statistic analysis did not disclose any association between autoantibody levels and thyroid dysfunction. There was an association between TG antibody and TSH levels among patients with Graves' disease and between TG antibody level and age in atrophic thyroiditis patients (p<0.05); a correlation was also noted between these antibodies and other autoimmune diseases (p=0.05). It is difficult to assess the frequency of ATD in the clinical setting. Characteristic features of AITDs in patients seen in south Tunisia were found to be similar to those described in the literature. Other more large-scale representative studies would be useful to establish the epidemiology of AITDs in Tunisia.

Autoantibodies↗
PubMed2006

[Ocular manifestations associated with nephronophthisis and genetic study in three Tunisian families].

PURPOSE: Nephronophthisis is a familial interstitial nephropathy with an autosome recessive mode of transmission. In some cases, it is associated with ocular manifestations such as retinitis pigmentosa in Senior-Løken syndrome. We report ocular abnormalities and genetic results in three affected Tunisian families. PATIENTS AND METHODS: Twenty-two members of these three families underwent a complete ophthalmologic examination (visual acuity, slit lamp biomicroscopy, ophthalmoscopy, and retinal electrophysiology). For genetic study, all individuals were genotyped and underwent a genomic sequence. RESULTS: Twenty-two subjects, nine of whom presented nephronophthisis, were included in this study. Retinitis pigmentosa was found in three cases. Our genetic study demonstrated that patients belonging to family 1 had homozygous deletions in NPHP1, all affected individuals from family 3 were linked to NPHP4 and presented a deletion in exons 2 and 3. Results are pending for patients in family 2. CONCLUSION: Senior-Løken syndrome is a rare hereditary disease that combines familial juvenile nephronophthisis and retinitis pigmentosa. This association was described in the literature in 39%-43% of cases. In our study, it was approximately 33% of cases. The genetic study can sometimes obviate the need for renal puncture, especially when the homozygous deletion of NPHP1 gene is confirmed.

Adolescent↗
PubMed2006

Evidence for linkage and association between autoimmune thyroid diseases and the 18q12-q21 region in a large Tunisian family.

Many studies have shown linkage between IDDM6 locus on 18q12-q21 chromosome and several autoimmune diseases, suggesting that it might harbour susceptibility genes common to autoimmunity. Using 12 families deriving from a large Tunisian multiplex family (the Akr family) from which 38 people were affected with autoimmune thyroid diseases (AITD), and 193 unrelated AITD patients, tested against 100 healthy subjects, we tried to replicate the positive results previously reported for the IDDM6. Akr members were genotyped with eight microsatellite markers harbouring the IDDM6 region. Multipoint non-parametric linkage analysis have shown a clear peak values of NPL score around D18S41 marker (Z = 3.72, P = 0.0001). Family-based association test (FBAT) and transmission disequilibrium test (TDT) have confirmed linkage results. In particular, a significant association with allele 3 of D18S41 and allele 2 of D18S57 markers was found. Case-control studies, using one intragenic microsatellite (locus CTG18.1) marker in the immunoglobulin transcription factor (ITF2) gene, a 5' flanking AC repeat of the anti-apoptotic BCL-2 gene as well as two SNPs at positions +52 and +1955 from transcription start site of BCL-2, showed no significant association between neither genes and AITD. Our study is the first replication of the 18q12-q21 chromosome region as a potential candidate to AITD genetic susceptibility. The Akr family has shown evidence for linkage between IDDM6 locus and AITD. Moreover, case-control study does not support the involvement of ITF2 and BCL2 genes in AITD pathogenesis.

Autoimmune Diseases↗
PubMed2006

Autosomal dominant Alport's syndrome: study of a large Tunisian family.

Alport's syndrome is a hereditary nephritis that may lead to end-stage renal disease (ESRD) in early adult life. It is a clinically and genetically heterogeneous nephropathy. Alport's syndrome is often associated with sensorineural deafness and/or ocular abnormalities. In contrast with the well-known X-linked phenotype, very little is known about the autosomal dominant form caused by mutations in COL4A3 and COL4A4 in the chromosome region 2q35-q37. We describe a Tunisian family with autosomal dominant Alport's syndrome in which males and females were equally affected. Two members reached ESRD at age 40 and 53 years, respectively. Three members experienced isolated microhematuria and one member experienced sensorineural deafness. No eye abnormalities were observed. Immunohistochemical studies showed a normal distribution of the alpha5 (type IV collagen) chain in the epidermal basement membrane. Genetic analysis demonstrated that a common haplotype co-segregated with the disease in the heterozygous state in all affected patients, thereby, confirming an autosomal dominant mode of inheritance. The same haplotype was observed in two asymptomatic children. We conclude that autosomal dominant Alport's syndrome, follows a rare mode of inheritance and exhibits a milder phenotype than usually observed in classic X-linked Alport's syndrome. The frequency of this mode of inheritance should be confirmed by a larger study.

Adolescent↗
PubMed2005

[A curious beating mass].

We report an unusual case of a 59-year-old patient who developed a hydatid cyst of the rib. The radioclinical presentation was misleading and positive diagnosis was only obtained at surgery. The rib cage is a highly exceptional localization for hydatid cysts. This case is particularly of interest because of the large number of possible diagnoses for beating masses in this localization and the difficult tumor resection.

Diagnosis, Differential↗
PubMed2005

Association study of VDR gene with rheumatoid arthritis in the French population.

Vitamin D is a potent regulator of calcium homeostasis and may have immunomodulatory effects. The influence of vitamin D on human autoimmune disease is controversial. The aim of this study was to investigate the role of vitamin D receptor gene (VDR) in rheumatoid arthritis (RA). Three polymorphisms for VDR gene FokI T>C (rs 10735810), BsmI A>G (rs 1544410) and TaqI C>T (rs 731236) were genotyped in 100 RA French nuclear families (set 1) and 100 additional French nuclear families for replication (set 2). The association analysis was performed using comparison of alleles frequencies (AFBAC), transmission disequilibrium test and genotype relative risk. Our results revealed a significant difference of F allele of FokI polymorphism between transmitted and nontransmitted frequencies (P=0.01) in set 1. Furthermore, the F/F genotype was more frequent in RA patients compared to controls (P=0.01) in set 1. The replication in set 2 showed similar patterns of transmission with a nonsignificant association. Association with FokI was found to be significant when the two sets were combined (P=0.006). These data suggest that the F allele and F/F VDR genotype are associated with RA. The mechanisms by which distinct receptor variants might confer disease susceptibility remain to be elucidated.

Adult↗
PubMed2005

[Cardiac multifocal hydatid cyst].

Hydatid cysts in the heart are rare, with an unpredictable outcome and numerous complications, requiring rapid surgical management. We report the case of a 19 year old female patient, who underwent surgery with extra corporeal circulation for a hydatid cyst of the interventricular septum of the heart, complicated by secondary pulmonary echinococcus infection, confirmed on CT and MRI. Resection of the cyst was performed via a right auriculotomy. The post operative period was favourable; the other pulmonary sites were treated medically. We emphasise the methods of diagnosis and management.

Adult↗
PubMed2005

High androgen receptor immunoexpression in human "Sertoli cell only" testis.

Our purpose was to evaluate cellular androgen receptor (AR) distribution and intensity of immunostaining in the human azoospermic testis. Thirty six biopsy specimens from azoospermic men were immunostained, using a monoclonal antibody of human AR. The localization and the intensity of AR immunostaining was evaluated in Sertoli Cell Only (SCO) testis (G1, n = 21), in spermatogenesis arrest testis (G2, n = 11) and in histologically normal testis (G3, n = 4). We found an AR immunostaining in Sertoli, peritubular myoid and Leydig cells, but not in germ cells. The intensity of the immunostaining varied substantially between biopsy specimens of different patients. Sertoli and Leydig cells AR immunostaining (score and intensity) in SCO group was higher than in the other groups. For Sertoli cells, the score means of AR immunoreactivity were 20 +/- 2.36, 10.18 +/- 1.0 and 1 +/- 1, for G1, G2 and G3 groups, respectively. For Leydig cells, the score means were 10.24 +/- 1.37, 6 +/- 0.71 and 0, for G1, G2 and G3 groups, respectively. We found significant differences between G1 and G2 (p = 0.0008), between G1 and G3 (p = 1.54 10-7) and G2 and G3 (p = 0.00032). These results suggest that in the testis AR is located exclusively in somatic cells and its expression is higher in SCO syndrome than in normal and in arrest spermatogenesis testes.

Androgens↗
PubMed2004

[Persistent pneumonia with fever: are laxatives responsible?].

Aspiration of oil into the lung can lead to pneumonia. The degree of severity depends on the quantity and the nature of the oil. We report the case of a 43-year-old woman with no medical history who was hospitalized for suspected infectious pneumonia. Explorations led to the conclusion that aspiration pneumonia was secondary to the ingestion of oil favored by gastroesophageal reflux.

Adult↗
PubMed2004

Refined mapping of the autosomal recessive non-syndromic deafness locus DFNB13 using eight novel microsatellite markers.

The locus for a type of an autosomal recessive non-syndromic deafness (ARND), DFNB13, was previously mapped to a 17-cm interval of chromosome 7q34-36. We identified two consanguineous Tunisian families with severe to profound ARND. Linkage analyses with microsatellites surrounding the previously identified loci detected linkage with markers corresponding to the DFNB13 locus in both families. Haplotype analyses assigned this locus to a 3.2-Mb region between markers D7S2468 and D7S2473. In order to refine this interval, we identified nine dinucleotide repeats in the 7q34 region. To investigate the polymorphism of these repeats, a population study of 74 unrelated individuals from different regions of Tunisia was carried out. Our results demonstrated that eight of the nine repeats are polymorphic. The average number of alleles at these informative loci was 9.12 with a polymorphism information content of 0.71. Little evidence for linkage disequilibrium between some marker pairs was found. Haplotype analysis using these microsatellites refined the DFNB13 interval to an area of 2.2 Mb between the D7S5377 and D7S2473. In order to identify the DFNB13 gene, we sequenced and eliminated three candidate genes. Other known and predicted genes are being screened for deafness-causing mutations.

Case-Control Studies↗
PubMed2002

In situ immunocytochemical detection of potyviral proteins in plant cells.

A method for in situ protein immunodetection using a peroxidase labeling system is described for detecting functional and structural proteins encoded by potato virus Y (Tunisian isolate) in plant tissues. Such Potyviruses are characterized by the accumulation of inclusion bodies containing viral encoded proteins other than coat protein. These proteins are functional at early stages of infection, making them easy to detect. Data are compared to those obtained by immunofluorescence techniques. Our technique can be used as a preliminary method for rapid detection of virus infection using antibodies directed against functional proteins.

Antibodies, Monoclonal↗
PubMed2002

[Familial alveolar proteinosis].

Pulmonary alveolar proteinosis is a progressive disease recognized 35 years ago. Many etiologies have been put forward, but the pathogenesis remains obscure. Familial alveolar proteinosis is a rare condition, probably transmitted by recessive autosomal inheritance, with deficiency in surfactant apoprotein SPB or defective expression of the common granulocyte colony stimulating factor (GM-CSF), IL3 and IL5 receptor. Gene therapy could be a future option for treatment in patients with specific gene defects.

Adult↗
PubMed2002

[Askin tumor: two cases].

Askin tumor is uncommon, usually observed in young subjects. We report two cases of Askin tumor observed in patients aged 15 and 27 years who were hospitalized for a painful tumefaction of the chest wall with pleural involvement in one patient. We reviewed progress in patient management which has resulted from better understanding of the natural history of Askin tumor and earlier diagnosis due to advances in imaging and immunohistochemistry techniques as well as cytogenetics. A number of points remain controversial.

Adolescent↗