Earlier onset of syngeneic tumors in the presence of mesenchymal stem cells

BACKGROUND: Mesenchymal stem cells (MSC) are widely investigated for cell therapy purposes as support of hematopoietic cell transplantation, skeletal tissue regeneration, or as a cell delivery system of therapeutic agents in cancer. However, because of their immunosuppressive capacities, we investigated the effect of MSC on the development of syngeneic tumors. METHODS: The murine MSC line C3H10T1/2 was coinjected with the Renca adenocarcinoma or the B16 melanoma cell lines in BALB/c mice. RESULTS: The injection of MSC permitted the growth of the allogeneic B16 tumor cells and reduced the delay of tumor appearance when Renca cells were implanted, without modifying the kinetics of tumor growth. This effect was observed even with a low ratio of cancer cells, mimicking minimal residual disease. In this last case, no MSC were detected in the tumor mass, suggesting that cell contact was not necessary. The presence of MSC did not enhance the development of lung metastasis after systemic injection of Renca cells. Because the proliferative rate of Renca cells was not affected by in vitro coculture with MSC, this observation is likely due to a systemic suppressive effect on the host immune system. CONCLUSIONS: Altogether, these data suggest that MSC did not interfere with the kinetics of tumor development but may reduce the delay for tumor occurrence. An important finding of this study is that a low but relevant amount of MSC may induce tumor rejection.     

Molecular characterisation and mechanisms of resistance of multidrug-resistant human Salmonella enterica serovar Typhimurium isolated in Amiens (France)

Antimicrobial resistance patterns of Salmonella enterica serovar Typhimurium isolates obtained during the study period were examined. The molecular epidemiology and the mechanisms of resistance to ampicillin, chloramphenicol and tetracycline were investigated. Resistance to ampicillin increased from 59% between 1996 and 1999 to 62.5% in 2000 and to 66.6% in 2001. Of 51 S. Typhimurium isolates studied, 100% were resistant to ampicillin (minimum inhibitory concentration (MIC)>256 mg/L) and sulphonamide (MIC range, 128 to >256 mg/L). Ninety-eight percent of isolates were resistant to streptomycin (MIC range, 48-256 mg/L), 92.2% to tetracycline (MIC range, 32 to >256 mg/L), 88.2% to chloramphenicol (MIC>256 mg/L), 21.5% to sulphamethoxazole/trimethoprim (MIC>32 mg/L), 5.8% to amoxicillin/clavulanic acid (MIC, 32 mg/L) and 1.9% to cefalothin (MIC, 64mg/L). Six resistance phenotypes were found (a-f), with phenotypes a (47%) and b (27.5%) being predominant. Twenty-five (49%) of 51 isolates produced a single beta-lactamase, among which 48% produced PSE-1, 44% produced TEM-1 and 8% produced OXA-1. Among 26 of the 51 isolates, 10 produced PSE-1+OXA-1, 7 produced TEM-1+PSE-1+OXA-1, 6 produced TEM-1+PSE-1, and 3 produced TEM-1+OXA-1. Forty-eight (94.1%) of the 51 isolates had the plasmid-mediated resistance gene flo(ST) to chloramphenicol and tetracycline. Combining enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) and pulsed-field gel electrophoresis (PFGE), 16 distinct patterns were identified, among which patterns IA (35.3%) and IF (27.4%) were considered as epidemic patterns. The dendrogram obtained from S. Typhimurium pulsotypes allowed five clones (S1-S5) to be identified, with two prevalent clones comprising 47.8% (S2) and 27.3% (S4) of the isolates.     

Hemofiltration With the Cascade System in an Experimental Porcine Model of Septic Shock

Abstract: High-volume hemofiltration (HVHF) has been suggested as an adjuvant treatment of septic shock because of its capacities to remove inflammatory mediators from blood. Nevertheless, HVHF presents some important drawbacks, such as the depletion of low molecular weight molecules (nutriments, vitamins, trace elements and antibiotics) due to the high ultrafiltration rate, or the significant financial cost and nursing workload due to the frequent changes of large amounts of expensive sterile substitution fluids. A new hemofiltration system called “Cascade” has been developed, allowing very high ultrafiltration rates (120 mL/kg/h) limiting these drawbacks by using a special extracorporeal circuit. The objective of this study was to assess the technical feasibility of the Cascade system and to compare its hemodynamic impact to that of the standard HVHF system. Twenty sepsis-induced pigs were randomized in two groups: one group was hemofiltered with the standard HVHF system and the other with the Cascade system during a six-hour session. No technical problems were observed with the Cascade system during the experiment. At the end of the experiment, colloid requirements (989 ± 355 mL vs. 1913 ± 538 mL, P = 0.006), epinephrine requirements (0.82 ± 0.42 mg vs. 3.27 ± 3.02 mg, P < 0.001), lactic acidosis (pH = 7.33 ± 0.08 vs. 7.10 ± 0.07, P < 0.001) and mean pulmonary arterial pressure were less pronounced in the Cascade group. These results suggest that Cascade hemofiltration is technically feasible and safe. Moreover, compared with standard HVHF, it can reduce the severity of porcine septic shock.     

Prediction of scoliosis progression with serial three-dimensional spinal curves and the artificial progression surface technique

Adolescent idiopathic scoliosis (AIS) progression is clinically monitored by a series of full spinal X-rays. To decrease radiation exposure, an artificial progression surface (APS) is proposed to predict progression. Fifty-six acquisitions (posteroanterior radiographs, 0° and 20°) were obtained from 11 AIS patients (29.8 ± 9.6° Cobb angle). Three-dimensional curves were constructed through vertebral pedicle centers. Three previous serial spinal curves (6-month intervals) were used to construct an APS with a Non-uniform Rational B-Spline surfacing technique. Future progression was achieved by aligning the curves on the APS using the generalized cross-validation extrapolation technique. With three and four previous serial spinal curves, the prediction accuracies of future progression at the next 6-month interval were 4.1 ± 3.3° for Cobb angles and 3.6 ± 3.5 mm for apex lateral deviations. Apex locations and Cobb regions varied within one vertebral level. The proposed technique shows potential as an accurate three-dimensional prediction method for AIS progression and could help pediatricians make decisions about treatment. However, it could only be applied once before more radiographic data would be needed.     

Estrogen-BDNF interactions: implications for neurodegenerative diseases

Since its' discovery over 20 years ago, BDNF has been shown to play a key role in neuronal survival, in promoting neuronal regeneration following injury, regulating transmitter systems and attenuating neural-immune responses. Estrogen's actions in the young and mature brain, and its role in neurodegenerative diseases in many cases overlaps with those observed for BDNF. Reduced estrogen and BDNF are observed in patients with Parkinson's disease and Alzheimer's disease, while high estrogen levels are a risk factor for development of multiple sclerosis. Estrogen receptors, which transduce the actions of estrogen, colocalize to cells that express BDNF and its receptor trkB, and estrogen further regulates the expression of this neurotrophin system. This review describes the distribution of BDNF and trkB expressing cells in the forebrain, and the roles of estrogen and the BDNF-trkB neurotrophin system in Parkinson's disease, Alzheimer's disease and multiple sclerosis.     

SSRIs for Hot Flashes: A Systematic Review and Meta-Analysis of Randomized Trials

Background

Hot flashes are the most commonly reported vasomotor symptom during the peri- and early post-menopausal period.

Objectives

To systematically review, appraise and summarize the evidence of the impact of different SSRIs on peri-menopausal hot flashes in healthy women in randomized, controlled trials.

Methods

A comprehensive literature search was conducted of MEDLINE?, EMBASE, the Cochrane Central Register of Controlled Trials, Web of Science and Scopus through March 2013. Two independent reviewers selected studies and extracted data. Random effects meta-analysis was used to pool outcomes across studies, and Bayesian mixed treatment methods were used to rank SSRIs in terms of effectiveness.

Results

We included a total of 11 randomized controlled trials with good methodological quality enrolling 2,069 menopausal and post-menopausal women (follow-up 1–9 months, mean age 36–76 years, mean time since menopause 2.3–6.6 years). Compared with placebo, SSRIs were associated with a statistically significant decrease in hot flash frequency (difference in means ?0.93; 95 % CI ?1.46 to ?0.37; I² = 21 %) and severity assessed by various scales (standardized difference in means ?0.34; 95 % CI ?0.59 to ?0.10; I² = 47 %). Adverse events did not differ from placebo. Mixed treatment comparison analysis demonstrated the superiority of escitalopram compared to other SSRIs in terms of efficacy.

Conclusion

SSRI use is associated with modest improvement in the severity and frequency of hot flashes but can also be associated with the typical profile of SSRI adverse effects.     

Interaction Between αCaMKII and GluN2B Controls ERK-Dependent Plasticity

Understanding how brief synaptic events can lead to sustained changes in synaptic structure and strength is a necessary step in solving the rules governing learning and memory. Activation of ERK1/2 (extracellular signal regulated protein kinase 1/2) plays a key role in the control of functional and structural synaptic plasticity. One of the triggering events that activates ERK1/2 cascade is an NMDA receptor (NMDAR)-dependent rise in free intracellular Ca(2+) concentration. However the mechanism by which a short-lasting rise in Ca(2+) concentration is transduced into long-lasting ERK1/2-dependent plasticity remains unknown. Here we demonstrate that although synaptic activation in mouse cultured cortical neurons induces intracellular Ca(2+) elevation via both GluN2A and GluN2B-containing NMDARs, only GluN2B-containing NMDAR activation leads to a long-lasting ERK1/2 phosphorylation. We show that αCaMKII, but not βCaMKII, is critically involved in this GluN2B-dependent activation of ERK1/2 signaling, through a direct interaction between GluN2B and αCaMKII. We then show that interfering with GluN2B/αCaMKII interaction prevents synaptic activity from inducing ERK-dependent increases in synaptic AMPA receptors and spine volume. Thus, in a developing circuit model, the brief activity of synaptic GluN2B-containing receptors and the interaction between GluN2B and αCaMKII have a role in long-term plasticity via the control of ERK1/2 signaling. Our findings suggest that the roles that these major molecular elements have in learning and memory may operate through a common pathway.     

Detailed mapping of germline deletions of the von Hippel--Lindau disease tumour suppressor gene

Von Hlppel-Llndau disease is a domlnantly Inherited familialcancer syndrome characterised by the development of retinalangiomatosis, cerebellar and spinal hemangloblastoma, renalcell carcinoma, phaeochromocytoma and pancreatic tumours. AcDNA (g7) which detects frequent genomic rearrangements in VHLdisease patients on Southern analysis, and contains the partialcoding sequence of the VHL gene has been isolated recently.To characterise the nature of the genomic rearrangements inVHL disease we initially screened 116 patients with VHL diseaseand identified 22 patients (19%) with abnormal fragments InEcoR1 digested DNA probed with g7. We then established thatthe coding sequence contained within g7 is represented in 3exons, and designed exon specific probes to investigate the22 patients with genomic rearrangements. All 22 patients weredemonstrated to have germline deletions, but the deletions wereheterogeneous with 7 patients having deletions confined to the5' exon 1, and 8 with non-overlapping deletions of exon 3. In7 unrelated patients, including 2 new mutations, the germilnedeletions were similar in size and position. There was no relationshipbetween the clinical phenotype and the deletion of individualexons. Although phaeochromocytoma was less frequent in kindredswith germllne deletions than those without detectable deletions,the difference was not statistically significant (1/19 versus16/72 respectively, x² = 1.84 p<0.1).     

Oleuropein and hydroxytyrosol inhibit the <Emphasis Type="Italic">N</Emphasis>-formyl-methionyl-leucyl-phenylalanine-induced neutrophil degranulation and chemotaxis via AKT,p38, and ERK1/2 MAP-Kinase inhibition

Purpose

Oleuropein and hydroxytyrosol are polyphenols that are extracted from olives and are major biological active components of olives and olive oil. Oleuropein and hydroxytyrosol exhibit interesting pharmacological effects on cells, and have been shown to have many health benefits such as anti-inflammatory effects. These effects were mainly attributed to their ability to scavenge the reactive oxygen species (ROS) produced by phagocytes such as neutrophils. The aim of this study was to investigate the effect of oleuropein and hydroxytyrosol on other neutrophil functions.

Methods

Human neutrophils were isolated from healthy donors. ROS production was measured by luminol-amplified chemiluminescence. Degranulation was assessed by measuring myeloperoxidase activity and Western blots. Chemotaxis was assessed by the under-agarose chemotaxis assay. Phosphorylated proteins were assessed by gel electrophoresis and Western blots.

Results

We show that in addition to their ROS scavenging effect, oleuropein and hydroxytyrosol significantly inhibited the bacterial peptide N-formyl-methionyl-leucyl-phenylalanine (fMLF)-induced degranulation of azurophilic and specific granules as measured by myeloperoxidase and lactoferrin release, respectively. We also show that oleuropein and hydroxytyrosol reduced fMLF-induced neutrophil chemotaxis. Interestingly, both agents impaired the fMLF-induced AKT, p38MAPKinase, and ERK1/2 phosphorylation, signaling molecules that are involved in pathways regulating neutrophil functions.

Conclusion

Our data suggest that the anti-inflammatory properties of oleuropein and hydroxytyrosol are not only restricted to their ROS scavenging effect, but also involve the inhibition of two other major pro-inflammatory neutrophil functions.