[Nasal congestion due to a painless mass of the left choana].
Explore the source record for details and available documents.
Adult↗
Biomedical subjects
R Naim
Publications and source records attributed to R Naim.
[Middle-ear adenoma].
In our case we present a 47-year old female patient, who had a history of one year of right-sided recurrent ear pain without any signs of ear-infections. A computer tomography (CT) imaging was carried out. At the mid-modiolar level, the axial CT-scan showed a small contrast-enhancing density in the middle ear space. She refused further investigation until the ear-pain increased and slight hearing loss was present. Again, six months later a CT-scan was performed, and the hyperdense tissue formation engaged the entire middle ear cleft of the right temporal bone. Typical of MEA, no osteolytic signs were present; the skull-base was intact, the air-cell system of the temporal bone showed no osteolysis or deficiency. In the case presented here, we show a MEA which has filled the middle ear with fluid retention in the mastoid with absent destruction of any structure clinically resulting in ear pain and slight conductive hearing loss. These lesions are contrast-enhancing on CT and on magnetic resonance imaging (MRI) have brain-like signal intensity T2-weighted images. In this case, the lesion was exenterated.
Adenoma↗
[Angiogenic factors in external auditory canal cholesteatoma-fibroblast cell culture].
BACKGROUND: The external auditory canal cholesteatoma (EACC) is characterized by hyperproliferation of the epithelial and subepithelial tissue. Compared to normal meatal skin, strong expression of FGF-2 and VEGF had previously been detected. Many authors reported that FGF-2 acts via VEGF and is induced by hypoxia. Hypoxia seems to be pivotal for establishing EACC. Therefore, human EACC fibroblasts were investigated by incubating with FGF-2 and determining VEGF. PATIENTS AND METHODS: We harvested fibroblasts from human EACC and normal meatal skin and incubated the fibroblast culture with 50 ng/ml FGF-2 and determined VEGF concentrations after 1-4 days. RESULTS: Compared to untreated fibroblast cultures, there was a significant increase of VEGF concentration (p<0.05). However, there was no significant difference between the proliferation quantities. CONCLUSION: VEGF and FGF-2 are possibly involved in a cascade of growth factor activities, which modulates their concentration in human-derived EACC fibroblast culture. Exogenous FGF-2 increased fibroblast expression for VEGF, which is a major autocrine mediator of FGF-2-induced angiogenesis and proliferation.
Angiogenesis Inducing Agents↗
[Cell adhesion proteins in external auditory canal cholesteatoma].
BACKGROUND: External auditory canal cholesteatoma (EACC) is a rare entity in otolaryngology, which is histomorphologically identical with middle ear cholesteatoma. The cause of EACCt is, however, still not clear. The aim of this study was to describe the expression of beta-catenin, MMP-2, and MMP-9 in EACC matrix compared to the normal auditory meatal skin (AMS). METHODS: Thirteen specimens were obtained during surgical procedure. EACC and AMS specimens were immunostained with antibodies for beta-catenin, MMP-2, and MMP-9. RESULTS: Only the basal layers of the EACC specimens were positive for beta-catenin. The suprabasal layers showed diminished or negative immunostaining for beta-catenin. In all layers, AMS was homogeneously positive for beta-catenin. In contrast, the immunostaining for the gelatinases was equally increased in all layers of EACC, whereas AMS was weekly positive. CONCLUSION: The reduced immunoreactivity for beta-catenin may have been present because of the lessened cell-cell adhesion in the suprabasal layers of EACC. The increased expression of the metalloproteinases might point at an increased lack of integrity of EACC matrix. Recent studies revealed a balance between disintegrating and stabilising factors in normal tissue, which is disturbed in inflamed and neoplastic tissue. In EACC matrix, an imbalance of these factors, represented by reduced beta-catenin and increased gelatinase expression, is possible. Increased desquamation, the accumulation of keratin debris, and loss of tissue-stability support our findings.
Adult↗
Monodansylcadaverine inhibits cytotoxicity of Vibrio parahaemolyticus thermostable direct hemolysin on cultured rat embryonic fibroblast cells.
The mechanism of action of Vibrio parahaemolyticus thermostable direct hemolysin (TDH) on cultured cells still remains unclear. We show that addition of osmotic stabilizers, such as polyethylene glycol and dextran, could not protect cultured rat embryonic fibroblast cells (Rat-1) against cytotoxicity induced by TDH, unlike their protection against the hemolytic activity of TDH. By contrast, 100 microM monodansylcadaverine, as well as the presence of 1 mM ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) in medium, protected the cells against cytotoxicity of TDH. Binding of TDH to Rat-1 cells and intracellular localization of TDH were affected by monodansylcadaverine and EGTA as analyzed by flow cytometry and confocal microscopy. On the hemolytic activity of TDH, monodansylcadaverine and EGTA had no effect. These results suggest that the mechanism of cytotoxicity of TDH on Rat-1 cells was different from that of hemolytic activity of TDH on red blood cells.
Animals↗
Vibrio parahaemolyticus thermostable direct hemolysin can induce an apoptotic cell death in Rat-1 cells from inside and outside of the cells.
Rat-1 cells exposed to Vibrio parahaemolyticus thermostable direct hemolysin (TDH) developed morphological changes including shrinkage of the cells and reduction in the size of nuclei. Cells either microinjected with TDH or transfected with the tdh gene also showed morphological changes similar to those induced by externally added toxin. Furthermore, TDH-exposed or tdh-transfected cells both showed chromatin condensation and DNA fragmentation which suggest cells undergoing apoptosis. In contrast, expression of a TDH mutant (R7) did not reveal any cytotoxic effects. We demonstrate that expressed TDH was distributed in the cytoplasm. The interleukin-1beta-converting enzyme-related protease inhibitor ZVAD-FMK did not inhibit TDH cytotoxicity. Our results suggest that TDH can induce its cytotoxicity both from outside and from inside the cells and killed the cells through apoptosis.
Amino Acid Chloromethyl Ketones↗
[Immunoglobulins or plasma exchange? Synchronization of plasma exchange and intravenous polyvalent immunoglobulins. A consecutive study of 11 patients].
Synchronization is defined as a prescription sequence aimed at obtaining synergic response or potentialization. THEORETICAL BASIS--The concept of synchronization is based on clinical and biological observations such as similar indications and transient effectiveness. Certain mechanisms of action such as reduction of pathological autoantibodies and accelerated elimination of immune complexes are common to both methods. Inversely, long-term effects differ. Plasma exchange cannot control the synthesis (or could aggravate) of autoantibodies while gammaglobulins have a suppressor effect on autoreactive clones. The aim is to obtain a summation effect by eliminating immediately cytotoxic factors. The potentializing effect of gammaglobulin anti-idiotypes on the modification of the immunologic repertory is favoured by prior reduction in the level of circulating pathogenic antibodies. RESULTS--It is difficult to evaluate the efficacy of this therapeutic association. Only a few trials have been conducted in refractory autoimmune thrombopenic purpura (n = 8), in intra-uterine Rhesus disease (n = 3), and HIV associated pathologies. We report our experience in 11 patients in a situation of therapeutic failure including three cases of renal transplantation, two cases each of chronic polyradiculoneuritis and neurological paraneoplastic syndromes, and one case each of Wegener's syndrome, polymyositis, sclerokeratitis, and antiphospholipid antibodies during pregnancy. Immunoglobulins were injected at an initial dose of 2 g/kg following at least 3 plasma exchanges. Consolidation cures were then administered every 3 weeks at a dose of 1 g/kg. Two major complications occurred and required interruption of the treatment: acute regressive oligo-anuric renal failure (Wegener) and exacerbation of sclerokeratitis inflammatory lesions. The disease process was controlled in 7 patients. CONCLUSIONS--Despite these promising preliminary results, the proposed combination therapy is not devoid of complications and its cost is high (cost of PE for 500 mg/kg Ig is about 5,000 FF). The next step should be the study of experimental models and prospective trials on pathologies with well characterized immunological features.
Adult↗
Filamentous phage associated with recent pandemic strains of Vibrio parahaemolyticus.
A group of pandemic strains of Vibrio parahaemolyticus has recently appeared in Asia and North America. We demonstrate that a filamentous phage is specifically associated with the pandemic V. parahaemolyticus strains. An open reading frame unique to the phage is a useful genetic marker to identify these strains.
Bacteriophages↗