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Biomedical subjects

B Benyahia

Publications and source records attributed to B Benyahia.

At least 37 records · Page 2Linked to original sources
PubMed1996

[False hydatic aneurysm of the thoraco-abdominal aorta].

Arterial complications of hydatic disease are rarely encountered. We report a false hydatic aneurysm of the thoracoabdominal aorta revealed by ischemic embolism of the lower limbs. Surgical treatment included aorto-aortic prosthesis and albendazol for 6 months. Results at 18 months are excellent with negative hydatic serology. In endemic areas, hydatic disease is a possible cause of false aneurysms. Long-term surveillance is required after curative surgery and medical treatment.

Adult↗
PubMed1994

Erythema gyratum repens. A case studied with immunofluorescence, immunoelectron microscopy and immunohistochemistry.

We report a patient with erythema gyratum repens (EGR), in whom a bronchial carcinoma was found. Direct immunofluorescence revealed granular deposits of immunoglobulins at the basement membrane zone (BMZ) in the skin, and in the lung tumour. Direct immunoelectron microscopy showed that the immune deposits were localized just beneath the lamina densa. Indirect immunofluorescence revealed circulating anti-BMZ antibodies. Immunohistochemical staining, using anti-transforming growth factor-beta, anti-epidermal growth factor receptor, anti-vimentin and anti-alpha-actin, was found to be more intense in the lesional skin and the lung tumour than in normal tissues. Possible mechanisms in the pathogenesis of EGR are discussed.

Autoantibodies↗
PubMed1994

Transforming growth factor-beta and megakaryocytes in the pathogenesis of idiopathic myelofibrosis.

Although the disease is well described, the pathogenesis of bone marrow fibrosis in idiopathic myelofibrosis still remains unclear. We previously reported elevated intraplatelet transforming growth factor-beta (TGF-beta) levels in patients with this myeloproliferative disorder, compared with healthy subjects. Here, in a series of 16 patients, we show that TGF-beta expression is also increased in patients' peripheral blood mononuclear cells (PBMC): (i) at the mRNA level analysed by Northern blot hybridization and/or reverse transcription-polymerase chain reaction (RT-PCR); (ii) and/or at the secreted peptide level as evaluated in conditioned media from patients' mononuclear cells by a growth inhibition assay on CC164 cells. By immunostaining with a polyclonal anti-TGF-beta 1 antibody, TGF-beta was localized in morphologically heterogenous cells; these cells were characterized as megakaryocytes by labelling with a gpIIbIIIa monoclonal antibody. Thus we provide evidence that both TGF-beta and megakaryocytes are linked in the pathogenesis of idiopathic myelofibrosis.

Aged↗
PubMed1994

[Applications of antisense oligonucleotides in oncology].

The development of biotechnologies offers considerable potential for new therapeutical approaches, targetting nucleic acids as information bearing molecules responsible for various pathologies. Gene therapy has, up to now, mainly aimed at compensating deficiencies of gene expression, through complex molecular and cellular constructions. Recently, an increasing interest has focused on short nucleotidic sequences (thus relatively easy to synthetize), or oligonucleotides, which could be able to specifically block the expression of mutated or overexpressed genes. When the target of these oligonucleotides is the mRNA of such genes, the strategy is called "antisense". This strategy has already led to a number of successful results in experimental models in vitro. Much more rare are actual effects in animal models and clinical trials are just being sketched. A review on the current state of the art will enlighten the physiological potential of these new molecules but also underline the still numerous issues before controlling therapeutical applications.

Animals↗
PubMed1991

Breast cancer proliferation measured on cytological samples: a study by flow cytometry of S-phase fractions and BrdU incorporation.

Cell kinetics have been shown to be an important predictor of clinical evolution of operated breast cancer. We established a method for the estimation of the proliferative activity of tumour cells obtained by fine needle sampling without aspiration (FNS), using simultaneously S-phase fractions (SPF) measured on DNA histograms and 5-bromodeoxyuridine (BrdU) labelling index (BLI) measured by flow cytometry. Biparametric BrdU/DNA flow cytometry could be performed in 122 of 189 (65%) consecutive patients. The mean BLI of the cytologically malignant FNS (118) was of 3.0 and the median of 2.2%. One hundred and forty-eight DNA histograms (78%) were suitable for SPF analysis, of which 141 presented malignant cells, showing a mean of 4.5 and a median of 3.5%, comparable to BLIs. These results were obtained from fluorescence peak area histograms with doublet discrimination and background subtraction allowing the measurements of SPFs as low as 0.4%. An excellent correlation was thus observed between BLIs and SPFs, for the 94 cases for which both results were available (r = 0.85). Infrequent discordances (9%) were noted with SPFs considerably higher than BLIs. Seven patients had three consecutive FNS of their tumour at weekly intervals before treatment. Some variability in the proportions of multiple subpopulations of tumour cells was observed on the DNA histograms. In contrast, proliferation indices (SPF or BLI) were reproducible, suggesting homogeneous growth rates. We conclude that an estimation of the proliferative activity of breast tumours at any stage of the disease is possible routinely by SPF and/or BLI analysis of FNS. At least one quantitative proliferation index could be obtained for 91% of patients.

Biopsy, Needle↗
PubMed1989

[Arteriopathies of the lower limbs in adults under 40 years of age].

In Morocco, thromboangiitis obliterans (TAO) is the most common cause of obliterating arteriopathy in subjects under 40 years: 252 cases out of 291, versus 21 cases of diabetic arteritis and 18 miscellaneous causes. The anatomo-clinical appearance is in keeping with the criteria for Buerger's disease with the exception of superficial migratory thrombophlebitis. The absolute basis of treatment has been the total definitive discontinuation of smoking. Platelet anti-aggregant agents have also been used. Aside from limited resections of distal gangrenous regions (168 cases), surgery has been limited to lumbar sympathectomy without adrenalectomy (154 cases). Out of 133 patients regularly followed up for more than one year, results were good in 102 patients. The 39 poor results occurred exclusively in patients who continued or restarted smoking.

Adult↗
PubMed1986

Arterial manifestations in Behçet's disease: four new cases.

Four new arterial lesions observed with Behçet's disease are reported: two popliteal aneurysms, one carotid aneurysm and one carotid stenosis. The clinical features, therapeutic modalities and postoperative complications of these uncommon lesions are reviewed briefly.

Adult↗
PubMed1983

New approach for visualizing estrogen receptors in target cells using inherently fluorescent ligands and image intensification.

Four fluorescent estrogen ligands were investigated as agents for visualization of estrogen receptors in cells: 2-(2,4-dihydroxyphenyl)-6-hydroxy-3-benzofurancarboxylic acid delta-lactone (coumestrol) and 9(11)-dehydro-12-oxoestradiol [12-oxo-1,3,5-(10),9(11)-estratetraene-3, 17 beta-diol] (12-oxoestradiol), which are inherently fluorescent compounds; and tamoxifen [Z)-1-[4-(2-dimethylaminoethoxy)phenyl]-1,2-diphenyl-1-butene) and 4-hydroxytamoxifen [Z)-1-[4-(2-dimethylaminoethoxy) phenyl]-1-(4-hydroxyphenyl)-2-phenyl-1-butene), which become maximally fluorescent only after ultraviolet irradiation. By conventional fluorescence techniques, these agents can be detected down to 10(-8) M in water, but only to 10(-6) to 10(-7) M in protein solutions; however, by photon-counting spectrofluorimetry, coumestrol and 12-oxoestradiol can be detected in protein solutions down to 5 X 10(-10) M. Three of these compounds have good affinity for the estrogen receptor: coumestrol (20%); 12-oxoestradiol (12%); and 4-hydroxytamoxifen (37%), relative to estradiol (100%). Under conditions where autoradiographic controls indicate that most of the estrogen receptor of MCF-7 human breast cancer cells is in the nucleus, we could demonstrate nuclear fluorescence using 10(-9) M concentrations of coumestrol, 12-oxoestradiol, and 4-hydroxytamoxifen. This nuclear fluorescence was abolished by a 200-fold excess of diethystilbestrol and could only be observed through a fluorescence microscope equipped with a microchannel image intensifier and a video camera detector that together provide a sensitivity enhancement of approximately 10(4). These studies indicate that the estrogen receptor in breast cancer cells can be visualized by fluorescence techniques, provided that the visualizing ligands have adequate affinity and specificity for the receptor and appropriate fluorescence characteristics, and provided that the fluorescence instrument has adequate sensitivity to observe fluorescence emission from cells treated with nM concentrations of the fluorescent agents.

Breast Neoplasms↗
PubMed1982

[Fine-needle aspiration biopsy and analysis of estrogen receptors in breast cancer].

Estrogen receptor concentration was measured in fine needle aspirates from 98 human mammary carcinomas. We performed a biochemical radiolabeled assay by the Charcoal-Dextran procedure on cytosols obtained after homogenization in a saline hypertonic buffer (0,4 M KCl) and centrifugation at 105,000 g. DNA content of the pellets was measured by fluorimetry. A sample of about 10(6) cells, containing at least 10 micrograms of DNA, was needed to obtain a reliable result. In this report, 74 samples were over 10 micrograms of DNA each. The analysis of these samples showed that, in 39 cases (52,8%), the estrogen receptor level was over the limit of 500 fmol/mg of DNA. In 5 cases (6,7%), the range was between 500 to 600 fmol/mg DNA and, in 30 cases (40,5%), it was under 500 fmol/mg DNA and was considered as negative. For 15 patients, estrogen receptors were determined on the same tumor, as removed by fine needle aspiration and by a surgical procedure (6 cases) or drill-biopsy (9 cases). There was a good correlation between the receptor content in needle aspirates and in tissue specimens for 13 cases out of 15.

Biopsy, Needle↗