Hypoxia promotes murine bone-marrow-derived stromal cell migration and tube formation

Recent evidence indicates that bone-marrow-derived stromal cells (MSCs) have a histology coherent with endothelial cells that may enable them to contribute to tumor angiogenesis through yet undefined mechanisms. In this work, we investigated the angiogenic properties of murine MSCs involved in extracellular matrix degradation and in neovascularization that could take place in a hypoxic environment such as that encountered in tumor masses. MSCs were cultured in normoxia (95% air and 5% CO(2)) or in hypoxia (1% oxygen, 5% CO(2), and 94% nitrogen). We found that hypoxic culture conditions rapidly induced MSC migration and three-dimensional capillary-like structure formation on Matrigel. In vitro, MSC migration was induced by growth-factor- and cytokine-enriched conditioned media isolated from U-87 glioma cells as well as from MSCs cultured in hypoxic conditions, suggesting both paracrine and autocrine regulatory mechanisms. Although greater vascular endothelial growth factor levels were secreted by MSCs in hypoxic conditions, this growth factor alone could not explain their greater migration. Interestingly, matrix metalloproteinase (MMP)-2 mRNA expression and protein secretion were downregulated, while those of membrane-type (MT)1-MMP were strongly induced by hypoxia. Functional inhibition of MT1-MMP by a blocking antibody strongly suppressed MSC ability to migrate and generate capillary-like structures. Collectively, these data suggest that MSCs may have the capacity to participate in tumor angiogenesis through regulation of their angiogenic properties under an atmosphere of low oxygen that closely approximates the tumor microenvironment.     

Doppler echocardiographic study of left ventricular diastolic function in hemodialysis patients

OBJECTIVES: The purpose of this study is to examine the diastolic dysfunction particularities in hemodialysis patients and to identify the parameters having the most discriminating power of diastolic dysfunction. METHODS: Conventional Doppler echocardiography study implies left ventricular diastolic function from Doppler transmitral flow (E/A), color M-mode flow propagation velocity (Vp) and combined indexes: ratio of peak E-wave velocity to Vp (ENp) and difference in duration of pulmonary venous and mitral flow at atrial contraction (Ap-Am). RESULTS: Left ventricular diastolic dysfunction is found in 86% of the 100 hemodialysis patients: abnormal relaxation pattern 52%, pseudo-normal pattern 21%, restrictive pattern 13%. Left ventricular hypertrophy is independent of blood pressure (eta2=3.386; p>0.06). Diastolic function pattern has no relation with duration of dialysis treatment (F=2.637, p>0.05) or left ventricular mass (F=4.298, p>0.06). We noted correlations with age for all parameters of transmitral Doppler flow (p<0.01), Vp and systolic fraction except combined indexes (p>0.05). Doppler parameters of which discriminating power is significant (p<0.001) are in deceasing order: isovolumic relaxation time, E/A, Vp, early filling deceleration time, Ap-Am, E/VP and systolic fraction. The parameter Vp discriminates normal filling from abnormal or pseudo-normal patterns. However it doesn't allow any discrimination between abnormal and pseudo-normal patterns or abnormal and restrictive patterns. Discriminating analysis classify correctly 100% of pseudo normal pattern patients with 2 variables (isovolumic relaxation time and Vp or VP with E/Vp). Factor analysis suggests that Vp characterizes normal pattern and E/A ratio and Ap-Am characterize restrictive pattern. CONCLUSION: Parameters of diastolic function discriminating value is different from one stage to another. VP characterizes normal pattern, combined indexes restrictive pattern. Vp and isovolumic relaxation time discriminates normal from pseudo-normal pattern.     

Tri-layered elastomeric scaffolds for engineering heart valve leaflets

Tissue engineered heart valves (TEHVs) that can grow and remodel have the potential to serve as permanent replacements of the current non-viable prosthetic valves particularly for pediatric patients. A major challenge in designing functional TEHVs is to mimic both structural and anisotropic mechanical characteristics of the native valve leaflets. To establish a more biomimetic model of TEHV, we fabricated tri-layered scaffolds by combining electrospinning and microfabrication techniques. These constructs were fabricated by assembling microfabricated poly(glycerol sebacate) (PGS) and fibrous PGS/poly(caprolactone) (PCL) electrospun sheets to develop elastic scaffolds with tunable anisotropic mechanical properties similar to the mechanical characteristics of the native heart valves. The engineered scaffolds supported the growth of valvular interstitial cells (VICs) and mesenchymal stem cells (MSCs) within the 3D structure and promoted the deposition of heart valve extracellular matrix (ECM). MSCs were also organized and aligned along the anisotropic axes of the engineered tri-layered scaffolds. In addition, the fabricated constructs opened and closed properly in an ex vivo model of porcine heart valve leaflet tissue replacement. The engineered tri-layered scaffolds have the potential for successful translation towards TEHV replacements.     

Synthesis and characterization of osteoinductive visible light‐activated adhesive composites with antimicrobial properties

Orthopedic surgical procedures based on the use of conventional biological graft tissues are often associated with serious post‐operative complications such as immune rejection, bacterial infection, and poor osseointegration. Bioresorbable bone graft substitutes have emerged as attractive alternatives to conventional strategies because they can mimic the composition and mechanical properties of the native bone. Among these, bioactive glasses (BGs) hold great potential to be used as biomaterials for bone tissue engineering owing to their biomimetic composition and high biocompatibility and osteoinductivity. Here, we report the development of a novel composite biomaterial for bone tissue engineering based on the incorporation of a modified strontium‐ and lithium‐doped 58S BG (i.e., BG‐5/5) into gelatin methacryloyl (GelMA) hydrogels. We characterized the physicochemical properties of the BG formulation via different analytical techniques. Composite hydrogels were then prepared by directly adding BG‐5/5 to the GelMA hydrogel precursor, followed by photocrosslinking of the polymeric network via visible light. We characterized the physical, mechanical, and adhesive properties of GelMA/BG‐5/5 composites, as well as their in vitro cytocompatibility and osteoinductivity. In addition, we evaluated the antimicrobial properties of these composites in vitro, using a strain of methicillin‐resistant Staphylococcus Aureus. GelMA/BG‐5/5 composites combined the functional characteristics of the inorganic BG component, with the biocompatibility, biodegradability, and biomimetic composition of the hydrogel network. This novel biomaterial could be used for developing osteoinductive scaffolds or implant surface coatings with intrinsic antimicrobial properties and higher therapeutic efficacy.     

EGCG Prevents the Onset of an Inflammatory and Cancer-Associated Adipocyte-like Phenotype in Adipose-Derived Mesenchymal Stem/Stromal Cells in Response to the Triple-Negative Breast Cancer Secretome

Background: Triple-negative breast cancer (TNBC) cells secretome induces a pro-inflammatory microenvironment within the adipose tissue, which hosts both mature adipocytes and adipose-derived mesenchymal stem/stromal cells (ADMSC). The subsequent acquisition of a cancer-associated adipocyte (CAA)-like phenotype is, however, unknown in ADMSC. While epidemiological studies suggest that consuming a polyphenol-rich diet reduces the incidence of some obesity-related cancers, the chemopreventive impact of green tea-derived epigallocatechin-3-gallate (EGCG) against the cues that trigger the CAA phenotype remain undocumented in ADMSC. Methods: Human ADMSC were exposed to human TNBC-derived MDA-MB-231 conditioned media (TNBC cells secretome) supplemented or not with EGCG. Differential gene expression was assessed through RNA-Seq analysis and confirmed by RT-qPCR. Protein expression levels and the activation status of signal transduction pathways mediators were determined by Western blotting. ADMSC chemotaxis was assessed by a real-time cell migration assay. Results: The TNBC cells secretome induced in ADMSC the expression of the CAA cytokines CCL2, CCL5, IL-1β, and IL-6, and of immunomodulators COX2, HIF-1α, VEGFα, and PD-L1. The epithelial-to-mesenchymal biomarker Snail was found to control the CAA phenotype. EGCG inhibited the induction of CAA genes and the activation status of Smad2 and NF-κB. The induced chemotactic response was also inhibited by EGCG. Conclusion: The induction of an inflammatory and CAA-like phenotype in ADMSC can be triggered by the TNBC cells secretome, while still efficiently prevented by diet-derived polyphenols.     

Predictive value of the markers of inflammation in acute coronary syndromes

This prospective study aims to establish the association between markers of inflammation (CRP and fibrinogen) and the severity of coronary lesions in patients with acute coronary syndromes. For this purpose, Plasma CRP, fibrinogen and troponin I were measured upon admission in 143 consecutive patients presenting with an acute coronary syndrome who underwent subsequently coronarography . Mean age is 55.5+/-11.6 years. Sex Ratio is 3.61 in favour of men; 68% of our patients presented with acute myocardial infarction with ST segment elevation; 23% with an unstable angina and 9% with an acute myocardial infarction without ST segment elevation. 31 patients (24.4%) have not any significant coronary lesion. Mean CRP level in these patients is (6.82+/-8.2 mg/l) lower than that measured in patients with significant lesions (17.4+/-26.9 mg/l; p=0.02). In patients with pathologic coronarogram, we demonstrated that the mean CRP level is higher in patients heaving one or more lesion of at least 70% of diameter stenosis than that in patients with no significant lesions (21.28+/-30.45 mg/l vs 11+/-14.2 mg/l; p=0.05). The mean CRP level grows with the number of proximal and significant stenoses. (CRP level in patients with one significant stenosis: 11+/-14.2 mg/l vs 27.45+/-39.67 mg/l in patients heaving 3 lesions; p=0.02. CRP level in patients with one proximal lesion: 14.35+/-19.8 mg/l vs 50.33+/-65 mg/l in patients heaving 3 proximal lesions; p=0.007). Fibrinogen levels measured upon admission in patients having significant lesions are higher than those measured in patients with normal coronary arteries (4.7+/-1.81 mg/l vs 3.93+/-1.69 mg/l; p=0.02). Compared with that measured in patients having distal lesions, the fibrinogen level is higher in case of proximal and multiple coronary lesions. There is a significant gradual increase in fibrinogen levels with increasing of the number of proximal coronary lesions and the degree of diameter stenosis. Multivariate logistic regression analysis showed that a CRP level higher than 10 mg/l is an independent predictive factor of the presence of the presence of significant coronary lesions (p=0.006; OR = 8.62; CI=0.7 to 7.4). We conclude that high CRP and fibrinogen plasma levels are associated with extended, severe and proximal coronary lesions.     

Isolated dislocation of the carpal scaphoid. A case report with review of the literature

Isolated dislocation of the carpal scaphoid is an extremely rare injury, which is usually accompanied by significant ligamento-capsular lesions. A review of the literature found only 21 reported cases. The aim of this report is to present a single case of isolated radio-palmar dislocation of the scaphoid treated conservatively, which provided a good functional result at 10 years follow up.     

Ontogeny of the catalytic subunit and putative glucose-6-phosphate transporter proteins of the rat microsomal liver glucose-6-phosphatase system

The catalytic subunit (p36) and putative glucose-6-phosphate (G6P) transporter (p46) protein levels of the rat glucose-6-phosphatase (G6Pase) system were studied in relation to G6Pase hydrolytic activity and G6P uptake in liver microsomes during the fetal to neonatal period. The mean G6P hydrolytic activity in liver microsomes increased significantly from the 20th to 21st day of gestation (from 6 to 22 mU/mg protein) and was further enhanced by 3-fold 6 hours after birth, with a maximal activity at 1 day of age (112 mU/mg protein). In contrast, G6P uptake into the vesicles was undetectable before birth, appeared after day 1 (656 pmol/mg protein), and decreased after day 2 (about 330 pmol/mg protein). Immunoblot analysis showed that the mean p36 protein level was low (< 1.6 arbitrary units [AU]) during gestation, increased sharply (to about 4.0 AU) during the first day, and remained stable afterward. Unlike p36, p46 protein was present before birth at values comparable to those postpartum. P46 increased from 3.2 AU at 20 days to 4.6 AU at 21 days of gestation, and decreased transiently after birth. These results show that (1) G6Pase hydrolytic activity before birth can occur without detectable G6P uptake function; (2) the presence of the putative G6P transporter protein is not sufficient to elicit G6P uptake; and (3) full G6Pase activity requires optimal expression of both p36 and p46 proteins. These data are discussed in relation to the function of G6Pase.     

Transient achromatopsia in vertebrobasilar insufficiency

Zusammenfassung Es wird ein 54j?hriger Mann beschrieben, bei welchem Attacken von Achromatopsie, zeitweise mit und zeitweise ohne gleichzeitige „drop attacks“ auftraten. Bei der Untersuchung konnte kein eigentlicher Visusausfall nachgewiesen werden und Hilfsuntersuchungen waren negativ. Es wird angenommen, da? eine Durchblutungsinsuffizienz im vertebrobasil?ren Gebiete mit vorübergehender Isch?mie der entsprechenden Sehrinde für die vorübergehende St?rung der Farbwahrnehmung verantwortlich sei.      

Long-term outcome of surgically treated teratology of Fallot

Tetralogy of Fallot is the most common cyanotic congenital heart disease. The surgical treatment that is palliative or complete repair has allowed to transform the preview of this heart disorder. We suggests to study the long term outcome in patients undergoing surgical repair of tetralogy of Fallot, by emphasizing the quality of their lives, the complications, as well as the mortality. Ventricular arrhythmia and sudden cardiac death after repair of tetralogy of Fallot are devastating complications in adults survivors and their prediction remains difficult.