Smoking and polymorphisms of genes encoding mannose-binding lectin and surfactant protein-D in patients with rheumatoid arthritis.

To investigate whether polymorphisms in genes coding for mannose-binding lectin (MBL) and surfactant protein-D (SP-D) are associated directly or by interaction with smoking with rheumatoid arthritis (RA), anti-citrullinated peptide antibody (ACPA) positive RA, and erosive RA. MBL2 genotypes, SFTPD genotype at codon 11, and HLA-shared epitope were determined in 456 patients with rheumatoid arthritis and 533 sex- and age-matched controls. Patients were grouped according to the presence of ACPA antibodies and RA-associated bone erosions and sub-stratified according to smoking status as never or ever smokers. Odds ratios with 95% confidence interval (OR, 95% CI) were calculated using multiple logistic regression analyses controlling for shared epitope. The low-producing SFTPD genotype was not associated with risk of RA or ACPA positive RA, but with erosive disease in the RA patients (OR = 1.8; 95% CI 1.1-3.0) particularly in RA ever smokers (OR = 2.4; 95% CI 1.3-4.3). The high-producing MBL2 genotype YA/YA was associated with ACPA positive RA (OR = 1.4; 95% CI 1.0-1.9) and erosive joint disease in RA ever smokers (OR = 1.8; 95% CI 1.1-3.0). Genetic disposition for low SP-D was not associated with RA but with erosive RA by interaction with smoking. The genetic disposition for high MBL production was associated with ACPA positive RA irrespective of shared epitope. The findings need to be replicated but do as such offer further explanations for the clinical heterogeneity of RA.

Decellularized matrix from tumorigenic human mesenchymal stem cells promotes neovascularization with galectin-1 dependent endothelial interaction.

BACKGROUND: Acquisition of a blood supply is fundamental for extensive tumor growth. We recently described vascular heterogeneity in tumours derived from cell clones of a human mesenchymal stem cell (hMSC) strain (hMSC-TERT20) immortalized by retroviral vector mediated human telomerase (hTERT) gene expression. Histological analysis showed that cells of the most vascularized tumorigenic clone, -BD11 had a pericyte-like alpha smooth muscle actin (ASMA+) and CD146+ positive phenotype. Upon serum withdrawal in culture, -BD11 cells formed cord-like structures mimicking capillary morphogenesis. In contrast, cells of the poorly tumorigenic clone, -BC8 did not stain for ASMA, tumours were less vascularized and serum withdrawal in culture led to cell death. By exploring the heterogeneity in hMSC-TERT20 clones we aimed to understand molecular mechanisms by which mesenchymal stem cells may promote neovascularization. METHODOLOGY/PRINCIPAL FINDINGS: Quantitative qRT-PCR analysis revealed similar mRNA levels for genes encoding the angiogenic cytokines VEGF and Angiopoietin-1 in both clones. However, clone-BD11 produced a denser extracellular matrix that supported stable ex vivo capillary morphogenesis of human endothelial cells and promoted in vivo neovascularization. Proteomic characterization of the -BD11 decellularized matrix identified 50 extracellular angiogenic proteins, including galectin-1. siRNA knock down of galectin-1 expression abrogated the ex vivo interaction between decellularized -BD11 matrix and endothelial cells. More stable shRNA knock down of galectin-1 expression did not prevent -BD11 tumorigenesis, but greatly reduced endothelial migration into -BD11 cell xenografts. CONCLUSIONS: Decellularized hMSC matrix had significant angiogenic potential with at least 50 angiogenic cell surface and extracellular proteins, implicated in attracting endothelial cells, their adhesion and activation to form tubular structures. hMSC -BD11 surface galectin-1 expression was required to bring about matrix-endothelial interactions and for xenografted hMSC -BD11 cells to optimally recruit host vasculature.

Effect of repeated intracoronary injection of bone marrow cells in patients with ischaemic heart failure the Danish stem cell study--congestive heart failure trial (DanCell-CHF).

BACKGROUND: It has been suggested that myocardial regeneration may be achieved by a single intracoronary bone marrow derived stem cell infusion in selected patients with ischaemic heart disease. The effect is uncertain in patients with chronic ischaemic heart failure and it is not known whether repeated infusions would have additional positive effects. AIMS: To assess whether two treatments of intracoronary infusion of bone marrow stem cells, administered 4 months apart, could improve left ventricular (LV) systolic function in patients with chronic ischaemic heart failure. METHODS: The study was prospective and non-randomised, comprising an observational baseline period of 4 months followed by an interventional period of 12 months. Intracoronary bone marrow cell infusion was performed at the end of the baseline period and repeated 4 months later. RESULTS: 32 patients were included. LV ejection fraction remained unchanged (33+/-9% vs. 34+/-10% after 8 months, p=0.30). Likewise, there was no significant change in LV end-systolic volume, wall motion score index (WMSI) or contractile reserve. At 12 months, a decrease in target vessel WMSI was seen (2.17+/-0.34 vs. 2.06+/-0.46, p=0.02). Furthermore, NYHA class improved (p<0.0001). No deaths were observed. CONCLUSION: In this non-randomised study, no change in LV ejection fraction could be demonstrated after repeated intracoronary bone marrow stem cell treatment in patients with chronic ischaemic heart failure.

Thioridazine reduces resistance of methicillin-resistant staphylococcus aureus by inhibiting a reserpine-sensitive efflux pump.

Previous studies suggested that the phenothiazine chlorpromazine (CPZ) could reverse or reduce the antibiotic resistance of bacteria. In some areas of the world, the majority of Staphylococcus aureus isolates are now resistant to methicillin, prompting this study to see whether such resistance can be altered by phenothiazine thioridazine (TZ), an agent with equal antibacterial activity, which is free of the severe side-effects associated with chronic administration of CPZ. The results indicated that, whereas methicillin-sensitive strains of Staphylococcus aureus (MSSA) were not rendered more susceptible to oxacillin, resistance to oxacillin by highly-resistant strains (MRSA) could be significantly reduced by sub-inhibitory concentrations of TZ. Reserpine, an inhibitor of efflux pumps, was also shown to reduce the resistance of MRSA strains to oxacillin in a concentration-dependent manner. The phenothiazines have been shown, by others, to inhibit the efflux pumps of bacteria and the mechanism by which MRSA are rendered more susceptible to oxacillin in the presence of TZ is believed to be due to a similar efflux pump.

[Stem cell therapy in ischemic heart disease]. / Stamcelleterapi ved iskaemisk hjertesygdom.

Stem cell therapy is a treatment of great potential, including in cardiology. In the past few years, it has been shown that the heart has the potential for regeneration. Clinical studies have shown that intracoronary or intracardiac transplantation of bone marrow stem cells to patients with chronic or acute ischemic heart diseases improves the function and regional myocardial perfusion of the left ventricle. No significant complications have been described. However, since there is no evidence on morbidity or mortality, there is a great need for further research before the treatment can be implemented in the daily clinic.

Inhibition of the Carpobrotus edulis methanol extract on the growth of phagocytosed multidrug-resistant Mycobacterium tuberculosis and methicillin-resistant Staphylococcus aureus.

The Carpobrotus edulis methanol extract, inactive against the methicillin-resistant Staphylococcus aureus or the multidrug-resistant Mycobacterium tuberculosis, does inhibit the growth of these two bacteria once they are phagocytosed by monocyte derived human macrophages.

Mesenchymal stem cells: cell biology and potential use in therapy.

Mesenchymal stem cells are clonogenic, non-haematopoietic stem cells present in the bone marrow and are able to differentiate into multiple mesoderm-type cell lineages e.g. osteoblasts, chondrocytes, endothelial-cells and also non-mesoderm-type lineages e.g. neuronal-like cells. Several methods are currently available for isolation of the mesenchymal stem cells based on their physical and immunological characteristics. Because of the ease of their isolation and their extensive differentiation potential, mesenchymal stem cells are among the first stem cell types to be introduced in the clinic. Recent studies have demonstrated that the life span of mesenchymal stem cells in vitro can be extended by increasing the levels of telomerase expression in the cells and thus allowing culture of large number of cells needed for therapy. In addition, it has been shown that it is possible to culture the cells in xeno-free environment without affecting their growth or differentiation potential. Finally, the mesenchymal stem cells seems to be hypoimmunogenic and thus allogenic mesenchymal stem cells transplantation is possible. It is envisaged that mesenchymal stem cells can be used in systemic transplantation for generalized diseases, local implantation for local tissue defects, as a vehicle for genes in gene therapy protocols or to generate transplantable tissues and organs in tissue engineering protocols. The results of these initial trials are very encouraging and several clinical trials are under way to study the efficacy and long-term safety of therapeutics based on mesenchymal stem cells.

In vivo development of quinolone resistance in Salmonella enterica serotype typhimurium DT104.

Salmonella enterica serotype Typhimurium definitive phage type 104 was isolated several times from the same patient over a period of 2 years. The strain developed reduced sensitivity to fluoroquinolones, and a mutation in the gyrA gene that is associated with reduced sensitivity to quinolones was identified.

Phenothiazines alter resistance of methicillin-resistant strains of Staphylococcus aureus (MRSA) to oxacillin in vitro.

Mechanisms of antibiotic resistance of bacteria include efflux pumps which extrude the antibiotic prior to reaching its target. Phenothiazines inhibit the activity of some efflux pumps thereby altering the susceptibility of bacteria. This study demonstrated that chlorpromazine and thioridazine reduce the susceptibility of methicillin-resistant strains (MRSA) but not that of methicillin-susceptible Staphylococcus aureus (MSSA) strains to oxacillin (MIC of oxacillin reduced from >500 to 10 mg/l). Reserpine, an inhibitor of antibiotic efflux pumps also reduced the resistance of MRSA strains to oxacillin suggesting the presence of an efflux pump that contributes to antibiotic resistance of MRSA strains.