Neurogenic Heterotopic Ossifications Recapitulate Hematopoietic Stem Cell Niche Development Within an Adult Osteogenic Muscle Environment.

Hematopoiesis and bone interact in various developmental and pathological processes. Neurogenic heterotopic ossifications (NHO) are the formation of ectopic hematopoietic bones in peri-articular muscles that develop following severe lesions of the central nervous system such as traumatic cerebral or spinal injuries or strokes. This review will focus on the hematopoietic facet of NHO.

Macrophage-derived oncostatin M contributes to human and mouse neurogenic heterotopic ossifications.

Neurogenic heterotopic ossification (NHO) is the formation of ectopic bone generally in muscles surrounding joints following spinal cord or brain injury. We investigated the mechanisms of NHO formation in 64 patients and a mouse model of spinal cord injury-induced NHO. We show that marrow from human NHOs contains hematopoietic stem cell (HSC) niches, in which mesenchymal stromal cells (MSCs) and endothelial cells provide an environment supporting HSC maintenance, proliferation, and differentiation.

Neurological heterotopic ossification following spinal cord injury is triggered by macrophage-mediated inflammation in muscle.

Neurological heterotopic ossification (NHO) is the abnormal formation of bone in soft tissues as a consequence of spinal cord or traumatic brain injury. NHO causes pain, ankyloses, vascular and nerve compression and delays rehabilitation in this high-morbidity patient group. The pathological mechanisms leading to NHO remain unknown and consequently there are no therapeutic options to prevent or reduce NHO.

CXCR7 participates in CXCL12-induced CD34+ cell cycling through β-arrestin-dependent Akt activation.

In addition to its well-known effect on migration and homing of hematopoietic stem/progenitor cells (HSPCs), CXCL12 chemokine also exhibits a cell cycle and survival-promoting factor for human CD34(+) HSPCs. CXCR4 was suggested to be responsible for CXCL12-induced biological effects until the recent discovery of its second receptor, CXCR7. Until now, the participation of CXCR7 in CXCL12-induced HSPC cycling and survival is unknown.

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.

TRPC expression in mesenchymal stem cells.

Transient receptor potential canonical (TRPC) channels are key players in calcium homeostasis and various regulatory processes in cell biology. Little is currently known about the TRPC subfamily members in mesenchymal stem cells (MSC), where they could play a role in cell proliferation. We report on the presence of TRPC1, 2, 4 and 6 mRNAs in MSC.

Elastin-derived peptides: matrikines critical for glioblastoma cell aggressiveness in a 3-D system.

In the most common primary brain tumors, malignant glioma cells invade the extracellular matrix (ECM) and proliferate rapidly in the cerebral tissue, which is mainly composed of hyaluronan (HA) along with the elastin present in the basement membrane of blood vessels. To determine the role of ECM components in the invasive capacity of glioma cell lines, we developed a 3-D cell-culture system, based on a hydrogel in which HA can be coreticulated with kappa-elastin (HA-kappaE). Using this system, the invasiveness of cells from four glioma cell lines was dramatically increased by the presence of kappaE and a related, specific peptide (VGVAPG)(3).

[Infectious endocarditis in cerebral death: implications for explantation of tissues and organs].

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.

Factors determining early improvement in mitral regurgitation after aortic valve replacement for aortic valve stenosis: a transthoracic and transesophageal prospective study.

Background: Mitral regurgitation (MR) is frequently associated with aortic stenosis. Previous reports have shown that coexisting mitral insufficiency can potentially regress after aortic valve replacement.

Hypothesis: This study sought to assess the frequency and severity of MR before and after aortic valve replacement for aortic stenosis and to define the determinants of its postoperative evolution.

[Cardiac lymphoma disclosed by ischemic accident. A case report].

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.

[Incidence and predictive factors of mitral insufficiency in surgically treated aortic stenosis. Transthoracic and transesophageal ultrasonographic evaluation].

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.

[Digital thermography for the evaluation of the effect of betamethasone in the treatment of acute sinusitis. Preliminary study].

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.

[Transesophageal echocardiographic diagnosis of left ventricular parietal rupture, a complication of myocardial infarction].

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.

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.

[Value of transesophageal echography in the detection of left intraventricular masses. Apropos of a case of apical thrombus].

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.

[Mobile thrombus of the right heart and pulmonary embolism: diagnostic and therapeutic problems. Apropos of 12 cases].

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.

[Dynamic telethermography in E.N.T. cancerology].

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.