Assessment of EGFR mutation status in Tunisian patients with pulmonary adenocarcinoma.

BACKGROUND: Despite recent advances, non-small cell lung cancer carries a grim prognosis. For appropriate treatment selection, the updated guidelines recommend broad molecular profiling for all patients with pulmonary adenocarcinoma. Precise histological subtyping and targeted epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) testing are mandatory. METHODS: Herein, we assessed the EGFR mutation status of 26 formalin fixed-paraffin embedded (FFPE) samples of lung adenocarcinoma. Mutational analysis concerned exons 18-21 of EGFR by real-time polymerase chain reaction (Real time-PCR) using the Therascreen EGFR RGQ PCR mutation kit. ALK status was established on 22 among 26 patients using D5F3 antibody with a fully automated Ventana CDx technique. RESULTS: Activating EGFR mutations were found in 3 men among 26 patients (11.5%). Positive ALK expression was found in 2 cases among 22 patients (9.09%). CONCLUSION: Frequency of EGFR mutations in pulmonary adenocarcinomas of our series is similar to that found in the European ones with some particularities. The mutations detected are uncommon. Whereas, we found a high frequency of positive ALK expression in our series compared to frequency reported in literature. Further studies with larger Tunisian series are required to obtain more conclusive results.

[Effects of fine particulate matter from on bronchial epithelial cells]. / Effets des particules fines sur les cellules épithéliales bronchiques.

INTRODUCTION: Ambient air contains a variety of pollutants including solid particles. Human bronchial epithelial cells (HBEC) play a key role following inhalation of these toxic particles. In a cell culture system of HBEC, we investigated the effects of several fractions of Lyons air-derived particles on cell viability/proliferation and production of the inflammatory mediators IL-8 and TGF-ß. METHODS: Air particles were collected in Lyon (France) by filtration of the air and impaction on filters located on a tapered element oscillating microbalance. Several diameter-based fractions of particles were prepared. HBEC were then exposed to different concentrations of these fractions. RESULTS: HBEC survival was not altered after 48hours of culture in the presence of particles regardless of their diameter and concentration. A dose-dependent inhibitory effect on cell growth was observed for all fractions. The particles caused an increase of both TGF-ß and Il-8 protein levels as a function of their diameters and/or concentrations. CONCLUSION: Air-derived particle fractions exhibit both an inhibitory effect on cell proliferation and a pro-inflammatory activity on HBEC.

[T-lymphocytes disorders in pulmonary sarcoidosis]. / Perturbations lymphocytaires T au cours de la sarcoïdose pulmonaire.

Sarcoidosis is a granulomatous disorder of unknown aetiology accompanied by variable immunological changes which concern both the monocyte and lymphocyte cell line. During the course of this disease anomalies of distribution (with accumulation in the disease tissue contrasting with a peripheral lymphopenia) and also of T cell functions (a predominance of CD4 T lymphocytes within the lesions and spontaneous expression of activation criteria) have been described. Recent works show some disturbances of T cell function and evoke the possibility of the initial pathology being related to this cell. Some current hypotheses place the T cell receptor for the antigen and the interleukin 2 receptor whose dysfunction will lead to an anomaly of the transduction of the activating signal of the T lymphocyte. The intrinsic origin (genetically determined) or extrinsically (retroviral) of these disturbances remains however to be determined.

[Supra-systolic elevation of the intra-cavernous pressure secondary to stimulation of the glans penis]. / Elévation suprasystolique de la pression intra-caverneuse secondaire à une stimulation du gland.

The role of the perineal muscles in human penile erections is still controversial. The authors investigated surface electromyographic activity of the ischiocavernous muscles together with intracavernous pressure recordings during pressure stimulations of the glans penis. Successive glans stimulations were associated with ischiocavernous muscle contractions and increases in intracavernous pressure reaching two- to fourfold the systolic blood pressure. High correlation coefficients were found between electromyographic and intracavernous pressure amplitudes. Voluntary contractions were accompanied by intracavernous pressure peaks of similar durations, and areas delineated by integrated electromyographic and intracavernous pressure curves showed very high correlation coefficients. Anaesthesia of the dorsal nerve resulted in dramatic reductions of muscle activity and intracavernous pressures in response to glans stimulation. These results suggest that the activity of the muscles in response to pressure stimulation of the glans penis is important to augment rigidity during vaginal penetration and intercourse due to their ability to increase intracavernous pressures.

[Considerable increase in the perineal arterial flow secondary to stimulation of the glans penis]. / Augmentation importante du débit artériel périnéal secondaire à une stimulation du gland.

The authors investigated the changes in human perineal blood flow by Doppler ultrasonography before, during, and after pressure stimulations (30,150 mm Hg) applied to the glans penis. We found a local increased blood flow response in 72% of 50 patients who consulted our center for erectile dysfunctions. Precise measurement analyses of 10 of these subjects allowed us to further characterize this response. Its latency ranged from 0.1 to 0.8 sec. and its duration from 4 to 13 sec. The blood flow increased up to 8 times the prestimulation level. This consistent increase in perineal blood flow showed much less variability than either the latency or duration of the response. The results of this study suggest that intravaginal pressures exerted on the glans penis during vaginal penetration and intercourse trigger an augmentation of blood flow into the corpora cavernosa. The reflex nature of this response is currently under investigation.

[The physiology of penile rigidity]. / Considérations sur la physiologie de la rigidité pénienne.

Penile tumescence and rigidity are considered to be a purely vascular process related to an increased inflow and a decreased outflow. This theory, which provides a satisfactory explanation for tumescence, is unable to explain the existence of high intracavernous pressures recorded both in animals and in man. Based on a hydrostatic model, the authors distinguish two phases involving different physiological mechanisms: an infrasystolic vascular phase and a suprasystolic muscular phase. During the vascular phase, the intracavernous pressure (ICP) can never exceed the systolic blood pressure. However, during the muscular phase, the ICP largely exceeds the systolic pressure, reaching values as high as 400 mmHg in man and 1,000 mmHg in animals. These variations in ICP can be explained by the contraction of perineal muscles, particularly the ischiocavernosus muscles. Various animal and human experiments are presented in support of this hypothesis. The pressure variations exerted on the glans during coitus by the perivaginal musculature are sufficient to induce reflex contractions of the ischiocavernosus muscles, promoting penile rigidity.

A new vacuum device as alternative treatment for impotence.

Vacuum erection devices are an acceptable alternative for the management of erectile dysfunction. The safety of such devices has been questioned because of their effects on penile blood flow. We report the use of Doppler ultrasonography to assess arterial flow and its value in ensuring long-term safety of a new external vacuum device. Sixteen patients were studied. At 3 months it was possible to confirm the efficacy and safety of the method and model in 14 patients, 12 of whom had a significant improvement in their sexual function. By 10 months, only 6 were continuing to use the device. Doppler sonography appears to be an effective technique for assessing penile blood flow during restriction from a vacuum device. The new vacuum device provides a satisfactory short-term alternative to other more invasive forms of therapy.

Clitoral blood flow increases following vaginal pressure stimulation.

The vascular responses of clitoral arteries to vaginal pressure stimulation in 10 volunteer women were evaluated by Doppler ultrasonography. Pressure stimulations (20-160 mm Hg) along the lower third of the vagina increased blood velocity and flow into clitoral arteries in 9 of the 10 women. The latency and duration of the Doppler responses ranged from 0.1 to 1.6 sec and from 3.2 to 9.5 sec, respectively, and the response was associated with a blood flow increase of 4 to 11 times the baseline prestimulation level. This response parallels that recorded in the cavernous arteries in men when a similar range of pressure stimulations are applied to the glans penis. Similar responses evoked in the male and female suggest a sexual synergy that may occur during intercourse in that such physiological responses and reflexes may be reciprocally reinforced.

Behaviour of leukocyte membrane fluidity in presence of anaesthetic drugs. Comparison between allergic patients and control subjects.

1. In this study we compared the effects of two anaesthetic drugs on the leukocyte membrane fluidity in allergic patients versus control subjects. 2. Fluidity was assessed by means of the fluorescence polarization technique. 3. We report that the treatment of the whole leukocytes with thiopental or pancuronium enhanced membrane fluidity in the allergic group as well as in the control one, but the effect was more pronounced in allergics. 4. This finding suggests a different biophysical behaviour of the leukocyte membrane towards anaesthetic drugs in allergic diseases. 5. This agrees with the hypothesis of the existence of an intrinsic abnormality in allergic cells, expressed as an initial hyperreactive state.

Increased respiratory burst and phosphodiesterase activity in alveolar eosinophils in chronic eosinophilic pneumonia.

A 43 year old woman presented with chronic eosinophilic pneumonia characterised by a high alveolar eosinophilic count, which allowed biochemical study of these cells. Alveolar eosinophils spontaneously produced high amounts of oxygen free radicals and exhibited an increased level of cyclic adenosine monophosphate (cAMP) phosphodiesterase (PDE) activity compared to blood eosinophils from control or allergic subjects. This activity was preferentially located in the plasma membrane, whilst the PDE activity of blood eosinophils from asthmatics or controls predominated in the cytosol. Because of the potential role of phosphodiesterase during eosinophil activation and recruitment, phosphodiesterase inhibitors may be useful in the treatment of eosinophilic pneumonia.

RU 41740 (Biostim) stimulates the production of granulocyte macrophage colony-stimulating factor and interleukin-8 by human bronchial epithelial cells in vitro.

1. In this study, we observed the effects of RU 41740 (Biostim) on the production of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-8 (IL-8) in human bronchial epithelial cells in vitro. 2. Cytokine production was assessed by enzyme-linked immunosorbent assay. 3. We report that epithelial cells spontaneously released both cytokines and that RU 41740 induced a significant increase in production of IL-8 and GM-CSF. 4. This is the first observation of a stimulatory effect of an immunostimulating compound used in humans on cytokine production by epithelial cells.

Granulocyte-macrophage colony stimulating factors (GM-CSF) and interleukin 8 (IL-8) production by human bronchial epithelial cells (HBEC) in asthmatics and controls. Lack of in vitro effect of salbutamol compared to sodium nedocromil.

The bronchial epithelium produces cytokines that could contribute to inflammatory events in airways. In this study we determined the basal and TNFalpha stimulated productions of GM-CSF and IL-8 by human bronchial epithelial cells (HBEC) collected from 12 control and six asthmatic patients. Spontaneous and TNFalpha-induced GM-CSF or IL-8 released levels increased significantly with time. Epithelial cells from asthmatic patients spontaneously released high levels of GM-CSF (24 h). TNFalpha potentiated GM-CSF and IL-8 release in control subjects and only the IL-8 production in asthmatics. Nedocromil sodium, an antiinflammatory drug, and salbutamol, a beta2-agonist, are commonly used in asthma. They were evaluated on the spontaneous and TNF-induced expression of GM-CSF and IL-8 in cultured bronchial epithelial cells. Nedocromil sodium, at the concentration of 10(-6) M, reduced the TNF-induced increase in GM-CSF but not the IL-8 release. Salbutamol, at the concentration of 10(-6) or 10(-5) M, did not affect the constitutive or stimulated production of both cytokines.

Increased membrane fluidity in blood leukocytes from allergic subjects. A possible role for leukotriene B4.

Modifications of lipid metabolism and increased plasma membrane fluidity may occur during cell activation and occur in leukocytes of patients with allergic disease. Using a fluorescent probe (TMA-DPH) and a polarization technique, we studied the variations of membrane fluidity in blood leukocytes from allergic and normal subjects. The anisotropic coefficient, which is inversely related to the rotational motion of the probe in membrane phospholipids, was significantly higher in normal subjects than in allergic ones. This result implies an increased membrane fluidity in leukocytes from allergic patients. No correlation could be observed with the etiology or the severity of allergic disease, nor with cell preparation composition or serum IgE level. Such a modification of membrane fluidity has been reproduced after incubation of leukocytes from normal subjects with leukotriene B4, but not with cells from allergic patients. Establishing the mechanism of these differences requires further investigations.

Impaired G-proteins and cyclic nucleotide phosphodiesterase activity in T-lymphocytes from patients with sarcoidosis.

Among the various immune abnormalities which characterize active sarcoidosis, a low proliferative response of peripheral blood lymphocytes to mitogenic lectins has long been observed. Since membrane-associated G-proteins are very likely to be crucial elements in lectin signal transduction, we investigated the binding of 5'-guanylylimidodiphosphate (GppNHp), a non hydrolyzable GTP analogue, to blood total lymphocyte membranes and to blood T-lymphocyte membranes from patients with active sarcoidosis, and from healthy control subjects. GppNHp binding was markedly decreased in peripheral cells from patients with sarcoidosis as compared to controls, suggesting the occurrence of a defect at the level of G-protein(s). A further characterization of G-proteins in these cells by means of ADP-ribose-labelling in the presence of bacterial toxins brought forward a significant decrease in the labelling of a 40 kDa protein, the major pertussis toxin substrate, in membranes from sarcoid patients, while the labelling of the major 44 kDa cholera toxin substrate proved to be unchanged with respect to control membranes. It is hypothesized that, in sarcoid lymphocytes, a defect in the negative control of adenylate cyclase mediated by the inhibitory G-protein Gi, prevents the lowering of cAMP necessary to normal mitogenic response of blood lymphocytes to stimulation. cAMP degradation by the specialized enzyme phosphodiesterase constitutes another critical step in the control of cAMP levels. Both cAMP and cGMP phosphodiesterase activities were found decreased in blood total lymphocyte preparations from sarcoid patients. With purified T-cells, although the mean cAMP and cGMP phosphodiesterase activities from sarcoid patients were found more markedly decreased with respect to healthy donors, only the decrease in cGMP phosphodiesterase was found statistically significant. The role these defects in cyclic nucleotide degradation potentially play in the disturbance of blood lymphocytes response associated with sarcoidosis is discussed.

Leukotriene B4 production by blood neutrophils in allergic rhinitis--effects of cetirizine.

BACKGROUND: Mucosal inflammatory processes in late phase of allergic diseases involve cytokine production, cell adhesion molecule overexpression and release of inflammatory mediators with chemotactic activity, such as leukotriene B4 (LTB4). We had previously observed increased production of LTB4 by neutrophils in patients with allergic rhinitis and discussed the role of granulocyte macrophage-colony stimulating factor (GM-CSF) priming. Some antihistaminic compounds were shown to diminish the production of leukotrienes by neutrophils. OBJECTIVES: In a first step, we evaluated in ex vivo and in vitro studies, the effects of cetirizine on LTB4 production by blood neutrophils from allergic and healthy subjects. In a second step, we studied the in vitro effect of cetirizine on LTB4 production by neutrophils from healthy subjects during GM-CSF priming of these cells. METHODS: Neutrophils from both populations were purified from venous blood and LTB4 production was measured using high performance liquid cromatography (HPLC) method. RESULTS: In ex vivo studies, cetirizine treatment induced a decreased LTB4 production by neutrophils in allergic rhinitis. This effect of decreased LTB4 production was reproduced in vitro with 10(-8)-10(-6)M cetirizine. Nevertheless, this anti-H1 compound had no effect on neutrophil priming with GM-CSF. CONCLUSION: As LTB4 is an important chemotactic factor, Cetirizine could act on inflammatory cell recruitment by inhibiting LTB4 production by neutrophils.

Antihistamines and production of granulocyte-macrophage colony-stimulating factor and interleukin-8 by human bronchial epithelial cells in vitro: evaluation of the effects of loratadine and cetirizine.

1. In this study, we compared the effects of two antihistamine drugs on the production of granulocyte-macrophage colony-stimulating factor and interleukin-8 by human bronchial epithelial cells in vitro. 2. Cytokine production was assessed by the use of an enzyme-linked immunosorbent assay. 3. Epithelial cells spontaneously released both cytokines and tumor necrosis factor alone induced a significant increase in this production but loratadine and cetirizine had no effect at the various concentrations studied. 4. The antihistamines have no effect and this suggests that histamine plays no role in cytokine production under these conditions.