SP/drug efflux functionality of hematopoietic progenitors is controlled by mesenchymal niche through VLA-4/CD44 axis.

Hematopoiesis is orchestrated by interactions between hematopoietic stem/progenitor cells (HSPCs) and stromal cells within bone marrow (BM) niches. Side population (SP) functionality is a major characteristic of HSPCs related to quiescence and resistance to drugs and environmental stresses. At steady state, SP cells are mainly present in the BM and are mostly absent from the circulation except in stress conditions, raising the hypothesis of the versatility of the SP functionality. However, the mechanism of SP phenotype regulation is unclear. Here we show for the first time that the SP functionality can be induced in lin(-) cells from unmobilized peripheral blood after nesting on mesenchymal stromal cells (MSCs). This MSC-induced SP fraction contains HSPCs as demonstrated by their (i) CD34(+) cell percentage, (ii) quiescent status, (iii) in vitro proliferative and clonogenic potential, (iv) engraftment in NSG (NOD SCID gamma chain) mice and (v) stemness gene expression profile. We demonstrate that SP phenotype acquisition/reactivation by circulating lin(-) cells is dependent on interactions with MSCs through VLA-4/α4ß1-integrin and CD44. A similar integrin-dependent mechanism of SP phenotype acquisition in acute myeloid leukemia circulating blasts suggests an extrinsic regulation of ATP-binding cassette-transporter activity that could be of importance for a better understanding of adhesion-mediated chemoresistance mechanisms.

[Infectious endocarditis in cerebral death: implications for explantation of tissues and organs]. / Endocardite infectieuse chez les patients en état de mort cérébrale: implications pour le prélèvement de tissus et d'organes.

Allograft valve replacement is the preferred treatment for infectious endocarditis With severe annular destruction. Explantation of the valve in patients with cerebral death requires preliminary cardiac investigations and strict surgical procedures. The authors report two cases of right atrial endocarditis discovered at the time of explantation of the valvular allografts. In view of the infectious nature of the lesions, no tissues were resected. In both cases, transthoracic echocardiography had not diagnosed these lesions. The sensitivity of transoesophageal echocardiography in the diagnosis of these lesions should lead to systematic referral for this investigation. The infectious nature of these endocarditic lesions should raise suspicion about the presence of a central venous catheter. In addition, careful inspection of the chambers, septa and cardiac valves should be performed at surgery. The detection of potentially infectious endocarditic lesions should, in accordance with present recommendations, lead to renouncing the explantation of valvular allografts.

[Cardiac lymphoma disclosed by ischemic accident. A case report]. / Lymphome cardiaque révélé par un accident ischémique. A propos d'un cas.

We report on the detection of a primitive cardiac lymphoma revealed by a cerebral vascular accident in a context of deterioration of the general state with fever. The diagnosis of the cerebral vascular accident was verified by the brain scan. The echocardiography, in particular the transesophageal ultrasound, suggested the diagnosis of cardiac lymphoma due to the existence of an inhomogeneous multilobar mass invading the right ventricle and largely encompassing the right auricle. The histologic diagnosis of a malignant non-Hodgkin's lymphoma of type B malignancy was confirmed by anatomopathology. The evolution was, unfortunately, rapidly unfavorable, with the patient dying in a state of cerebral suffering despite a combination treatment of chemotherapy and radiotherapy.

[Incidence and predictive factors of mitral insufficiency in surgically treated aortic stenosis. Transthoracic and transesophageal ultrasonographic evaluation]. / Incidence et facteurs prédictifs de l'insuffisance mitrale dans le rétrécissement aortique chirurgical. Evaluation échographique transthoracique et transoesophagienne.

Mitral regurgitation is common in adults with aortic stenosis. When severe, it may aggravate the clinical condition and pose an additional therapeutic problem. The authors studied 40 consecutive patients with severe surgical aortic stenosis prospectively by transthoracic echocardiography and pre-operative transoesophageal echocardiography to determine the incidence, mechanism and degree of mitral regurgitation and its eventual relationship to the aortic stenosis. Mitral regurgitation was detected in all cases when both investigations were taken into consideration. It was usually mild, evaluated grade 2 by measuring the surface of the colour Doppler regurgitant jet, or mild to minimal of transoesophageal echocardiography in 35/40 patients (87.5% of cases). Rarely, a case of significant, autonomous mitral regurgitation (2 cases of valvular dystrophy, 1 pure severe mitral stenosis). On the other hand, calcification of the mitral annulus is common (14/40 patients, 35% of cases). The severity of the regurgitation in univariate analysis was significantly correlated mainly to the age of the patients (p = 0.027). The severity of the aortic stenosis (p = 0.0082) and the parameters related to the effects of stenosis, such as ventricular wall thickness and left atrial size. In multivariate analysis, the severity of the aortic stenosis and of its consequences were confirmed to play a role in the genesis of mitral regurgitation, the severity of which was correlated on transthoracic echocardiography to the aortic valve surface area and the left ventricular ejection fraction and, on transoesophageal echocardiography, to the transvalvular pressure gradient.

[Digital thermography for the evaluation of the effect of betamethasone in the treatment of acute sinusitis. Preliminary study]. / La thermographie numérisée pour l'évaluation de l'action de la bétaméthasone dans le traitement des sinusites aiguës. Etude préliminaire.

OBJECTIVES: Heat emitted during the process of inflammation can be visualized by means of dynamic telethermography (DDT). In the case of sinusitis, it is possible to verify the efficacy of an anti-inflammatory treatment such as betamethasone. PATIENTS AND METHODS: Ten adult ambulatory patients with sinusitis were treated with 2 tablets of betamethasone (Celestene) 2 mg daily for 10 days without concomitant medications. DDT images were obtained on day 0, day 2, day 3, day 5 and day 10. A color chart indicated differences in temperature according to the selected sensitivity. Computer analysis of the images was then obtained. Clinical assessment of symptoms and tolerance were recorded at the same time-points as the DDt images. RESULTS: The effect of treatment was beneficial in all patients since cure of sinusitis was achieved in 5, with marked improvement in 4 others and fair improvement in 1. Pain was significantly reduced on day 10 compared with day 0 (Friedman's test p < 0.0001). There was a simultaneous reduction of sinusitis associated signs: rhinorrhea, lacrimation, photophobia and cutaneous hyperesthesia as well as of general signs. On the DDT images, right-sinus to right-side and left-sinus to left-side ratios both showed a significant decrease between day 0 and day 10 from 41.00 +/- 14.07 to 7.90 +/- 7.22 (ANOVA p < 0.0001) and from 30.70 +/- 5.20 +/- 6.49 (ANOVA p < 0.0001) respectively. DISCUSSION: Whereas in animal pharmacology inflammation can be evaluated by any number of objective methods, only a very few are applicable to clinical situations. Powerful computer image analysis may prove useful in establishing nature and severity based inflammation reduction standards. CONCLUSION: These preliminary findings demonstrated that in most cases single agent therapy provides adequate and rapid control of clinical and thermographic signs of acute sinusitis. Computer analysis corraborates clinical findings and thermogram interpretations.

[Transesophageal echocardiographic diagnosis of left ventricular parietal rupture, a complication of myocardial infarction]. / Diagnostic par échographie transoesophagienne d'une rupture pariétale du ventricule gauche sur infarctus du myocarde.

The authors report the case of postero-lateral myocardial infarction complicated by free wall rupture at the 48th hour. The diagnosis was suspected clinically and transoesophageal echocardiography showed the appearance of pericardial effusion in a patient difficult to examine by conventional echocardiography. Transoesophageal echocardiography was performed and well tolerated. The transgastric view showed a thrombus adjacent to a thinned and lacerated postero-lateral wall. The clinical outcome was favourable after surgical repair.

Visualization of myocardial infarction six hours after injection of 111 In-antimyosin antibodies using an image subtraction technique.

111 In-antimyosin antibodies are capable of visualizing acute myocardial infarction (MI). Because of slow blood clearance, images are usually recorded 24 or 48 h postinjection. This pilot study was aimed at validating a blood pool subtraction technique, which makes it possible to visualize MI 6 h postinjection. Twenty-five patients with proven MI (16 anterior, 9 inferior) were imaged 10 minutes, 6 and 24 h after an injection of 110 MBq 111 In-labelled antimyosin antibodies, with a mean delay of two weeks after infarction. Three planar views were obtained each time. Using software which performs geometric registration, grey level normalization and subtraction of images, the blood pool image (obtained 10 minutes postinjection) was subtracted from the 6 hour image. The resulting image was the blood pool corrected 6 h image. The 24 h images and the blood pool corrected 6 h images were interpreted blindly and the number of correct, incorrect and indeterminate MI localizations were tabulated. The number of correct localizations was 19/25 for the standard 24 h images and 22/25 for the blood pool corrected 6 h images. With this blood pool subtraction method it was possible to visualize MI 6 h postinjection. Theoretically, this method could be applied six hours after myocardial infarction.

[Value of transesophageal echography in the detection of left intraventricular masses. Apropos of a case of apical thrombus]. / Intérêt de l'échographie transoesophagienne biplan dans la détection des masses intra-ventriculaires gauches. A propos d'une observation de thrombus apical.

The authors report a case of left intraventricular thrombus investigated by two-dimensional transesophageal echocardiography (TEE). Three longitudinal views obtained by rotation, left lateral inclination and by advancing the probe, enabled the precise evaluation of a mass situated at the apex of the left ventricle, together with ventricular morphology and kinetics. Two-dimensional TEE is electively indicated for confirmation of the diagnosis of left intraventricular apical masses, in particular in hypoechogenic patients and to guide possible surgery. The two-plane probe provides a certain number of sections which remain relatively limited but this problem is resolved with the development of multidimensional probes.

[Mobile thrombus of the right heart and pulmonary embolism: diagnostic and therapeutic problems. Apropos of 12 cases]. / Thrombus mobile du coeur droit et embolie pulmonaire: problèmes diagnostique et thérapeutique. A propos de 12 cas.

The objectives of this report were to analyse clinical presentation, echocardiographic features and diagnostic and therapeutic problems posed by an unusual form of thrombo-embolic disease: mobile right heart thrombosis. Systematic echocardiography in 170 cases of severe pulmonary embolism identified mobile right thrombi in 12 cases. The auscultatory findings were abnormal in 6 cases, 3 showing signs of tricuspid obstruction. Two-dimensional echocardiography showed an extremely mobile right atrial mass, sometimes prolapsing across the tricuspid valve, which was variously spheric, ovoid or worm-like; dilatation of the right heart chambers and echocardiographic signs of cor pulmonale were observed in all cases. The differential diagnosis with other embolic masses of the right atrium and, above all, with well-developed Chiari networks, may be difficult and requires transoesophageal echocardiography. Pulmonary angiography is contra-indicated because of the risk of embolism. Embolectomy under cardiopulmonary bypass was carried out in 8 patients, immediately after echocardiography in 6 cases. The thrombus was recovered from the right atrium in 6 cases and from the pulmonary artery in 2 cases: there was one operative death. Medical treatment was administered to 3 inoperable patients. The clinical and echocardiographic outcome was good in 2 of these but the third patient died; autopsy revealed thrombi in the right atrium and pulmonary artery. One patient died before any treatment could be given and autopsy showed the thrombus in the pulmonary artery. These results confirm the extreme instability of this type of thrombus and the risk of death due to its embolism.(ABSTRACT TRUNCATED AT 250 WORDS)

[Dynamic telethermography in E.N.T. cancerology]. / Approche de la télé-thermographie dynamique en cancérologie O.R.L.

Thermography is used in human pathology to capture and visualise infra-red rays emitted directly and spontaneously by the human body. The author first describes the main techniques of thermography, their indications their advantages and their potential problems:--contact thermography;--static thermography; --dynamic telethermography. The information provided by the latter in the case of E.N.T. and cervico-facial malignancies should be interpreted with caution and only as a complement to other investigations such as radiography, echography and isotope studies. The following features are seen: --the low value of cerevical hyperthermia in relation to lymphadenopathies, due to the "thermal interference" of the great vessels of the neck; --the contrast between large lymphadenopathies which are often quite cold in comparison with small lymphadenopathies which are always hot; --the value of the method in determining extension of a skin tumour, for the surveillance of areas already tready by surgery or physical agents, in seeking and discovering an endo-cavitray neoplastic zone or a bone metastasis.