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Biomedical subjects

B Sylla

Publications and source records attributed to B Sylla.

9 recordsLinked to original sources
PubMed2005

Simple acoustic multiplexer.

Simple structures enabling the multiplexing of acoustic waves are presented. Such structures are constructed out of two monomode acoustic wires and two masses bound together, and to the wires by springs. We show analytically that these simple structures can transfer with selectivity and in one direction one acoustic wavelength from one wire to the other, leaving neighbor acoustic wavelengths unaffected. We give closed-form relations enabling to obtain the values of the relevant physical parameters for this multiplexing phenomena to happen at a chosen wavelength. Finally, we illustrate this general theory by an application.

Journal Article↗
PubMed1998

Host response to EBV infection in X-linked lymphoproliferative disease results from mutations in an SH2-domain encoding gene.

X-linked lymphoproliferative syndrome (XLP or Duncan disease) is characterized by extreme sensitivity to Epstein-Barr virus (EBV), resulting in a complex phenotype manifested by severe or fatal infectious mononucleosis, acquired hypogammaglobulinemia and malignant lymphoma. We have identified a gene, SH2D1A, that is mutated in XLP patients and encodes a novel protein composed of a single SH2 domain. SH2D1A is expressed in many tissues involved in the immune system. The identification of SH2D1A will allow the determination of its mechanism of action as a possible regulator of the EBV-induced immune response.

Antigens, CD↗
PubMed1996

A high incidence of BRCA1 mutations in 20 breast-ovarian cancer families.

We have analyzed 20 breast-ovarian cancer families, the majority of which show positive evidence of linkage to chromosome 17q12 for germ-line mutations in the BRCA1 gene. BRCA1 mutations cosegregating with breast and ovarian cancer susceptibility were identified in 16 families, including 1 family with a case of male breast cancer. Nine of these mutations have not been reported previously. The majority of mutations were found to generate a premature stop codon leading to the formation of a truncated BRCA1 protein of 2%-88% of the expected normal length. Two mutations altered the RING finger domain. Sequencing of genomic DNA led to the identification of a mutation in the coding region of BRCA1 in 12 families, and cDNA analysis revealed an abnormal or missing BRCA1 transcript in 4 of the 8 remaining families. A total of eight mutations were associated with a reduced quantity of BRCA1 transcript. We were unable to detect BRCA1 mutations in 4 of the 20 families, but only 1 of these was clearly linked to BRCA1. It is expected that the majority of clear examples of the breast-ovarian syndrome will be associated with germ-line mutations in the coding region of BRCA1.

Alternative Splicing↗
PubMed1994

Goitrous endemic in Guinea.

We identified a major goitrous area in the Republic of Guinea, characterised by an overall goitre prevalence of 70% in adults. Thyroid swelling was sometimes present at birth and affected 55% of schoolchildren. A difference between sexes appeared at puberty. Endemic cretinism, mainly in its myxoedematous form, was found in about 2% of goitrous patients. In this region, iodine deficiency is the primary causative factor (median urinary concentrations of 16 micrograms/L, and in 69% of inhabitants below the critical threshold of 20 micrograms/L). The diet contained substantial amounts of thiocyanate anions (median 6 mg/L in urine and in 27%, more than 10 mg/L) likely to further depress iodine bioavailability. Other dietary compounds, notably flavonoids were suspected to contribute. Overall nutritional and general health appeared satisfactory. The affected population is borderline euthyroid with a trend towards hypothyroidism in protracted disease. This area of Guinea may be regarded as the epicentre of the west African endemic and as one of the most severely goitrous regions ever described, requiring urgent public health measures.

Adolescent↗
PubMed1993

Characterization of three overlapping deletions causing X-linked lymphoproliferative disease.

Blot hybridization was used to find DNA sequences missing in a male who lacked two-thirds of Xq25. The probes were used to discover two additional males with deletions resulting in X-linked lymphoproliferative disease (XLP). All three deletions have a region in common, and DXS739 is within this candidate region. The new deletions were also detectable using chromosome banding, and the smallest removes only one-third of Xq25. XLP is the only consequence of the deletions.

Adult↗
PubMed1991

[Tumor-like focal nodular hyperplasia. Apropos of 3 cases observed at the Dakar Central Hospital from 1986 to 1989].

Authors report three observations of Focal Nodular Hyperplasia, Tumor-like on two: senegalese female patients, 16 years and 37 years old, and a young senegalese man, 24 Years old. The mean age is about 25.5 years and oestro progestative intake has bean noted once. Diagnosis of Focal Nodular Hyperplasia was difficult and has been done twice after surgical intervention for chronic cholecystitis and blood peritonitis. The only complication reported, has been a rupture of nodular, causing the death of a patient. This benign tumor that never degenerates, does not need any particular treatment unless a stopping of oral contraception.

Adolescent↗
PubMedDate not supplied

[Unusual radiologic aspect of a hydatid cyst].

The authors report us about an unusual hydatid cyst of the liver. Ultrasound, CT and MRI exams were used, and showed an unusual fatty component inside the lesion. The development of the disease in steatosic liver is not enough to explain the unusual density.

Diagnosis, Differential↗