[Prevalence of Bartonella henselae in blood donors and risk of blood transmission in Chile].

Background: Bartonella henselae is the causal agent of cat scratch disease in immunocompetent persons and bacterial angiomatosis in immunocompromised patients. In Chile, the prevalence of antibodies against B. henselae in healthy children and adolescents is 13.

Combined endoscopic gastrostomy ("Pull-Introducer Technique"): a new less traumatic technique for preterm and small for gestational age patients.

Introduction: The most common endoscopic gastrostomy technique is the "Pull-Through" or Gauderer-Ponsky technique. This is a transoral technique in which the internal bumper of the tube goes in through the esophagus. However this has been shown to be traumatic and often impossible in newborns and small for gestational age (SGA) patients, therefore a transabdominal technique must be used in this cases.

Ultrafine-grained porous titanium and porous titanium/magnesium composites fabricated by space holder-enabled severe plastic deformation.

Compaction of powders by equal channel angular pressing (ECAP) using a novel space holder method was employed to fabricate metallic scaffolds with tuneable porosity. Porous Ti and Ti/Mg composites with 60% and 50% percolating porosity were fabricated using powder blends with two kinds of sacrificial space holders. The high compressive strength and good ductility of porous Ti and porous Ti/Mg obtained in this way are believed to be associated with the ultrafine grain structure of the pore walls.

Improved oxygen diffusion and mechanical aggregation of tumor colonies in a novel stirred mini-bioreactor.

The feasibility of a novel stirred bioreactor, the rotating aerial disk (RAD) design, was tested in this study. The novelty lies in its method of medium recirculation by convective airflow using a non-contact planar disc, a variation on a physically defined theoretical model. Computational predictions of improved oxygenation were confirmed by increases in measured dissolved oxygen, even at Reynolds numbers (100-200) where flow is mostly laminar.

Biomaterials for spinal cord regeneration: outgrowth of presumptive neuronal precursors on electrospun poly(epsilon)-caprolactone scaffolds microlayered with alternating polyelectrolytes.

The aim of this study was to assess the feasibility of electrospun poly(epsilon)-caprolactone (PCL) scaffolds treated with alternating paly-electrolytes as a controllable three-dimensional adhesive substrate for neuronal progenitors. Unmodified PCL surfaces were generally not supportive of mouse embryonic stem cell (mESC) colony adhesion. However, scaffolds surfaced using layer-by-layer (LbL) deposition of heparin/poly-L-lysine encouraged better local adhesion of mESC colonies, and networking of monolayers containing nestin-positive presumptive neurons, similar to laminin coated controls, as observed by immuno-fluorescence microscopy.

PEDF-derived synthetic peptides exhibit antitumor activity in an orthotopic model of human osteosarcoma.

Pigment epithelium-derived factor (PEDF) is one of the most potent inhibitors of angiogenesis, and has recently been demonstrated to have an important multifunctional role in tumor growth, invasion, and metastasis. However, relatively little is known of mechanisms through which PEDF exerts its antitumor activity. Therefore, with the aim of identifying potential functional epitopes specifically against osteosarcoma, we evaluated the bioactivity of four 25-mer synthetic PEDF-derived peptides (termed StVOrth-1, -2 -3, and -4) against a human osteosarcoma cell line, SaOS-2.

Inhibition of orthotopic osteosarcoma growth and metastasis by multitargeted antitumor activities of pigment epithelium-derived factor.

Osteosarcoma is major cause of cancer-related death in the pediatric age group, and this is due to the development of pulmonary metastases that fail to be eradicated with current treatment regimes. Although there have been significant improvements in the long-term survival of such patients, 25-50% with initially non-metastatic disease, subsequently develop metastases and this remains the major cause of death for these patients. In this study, we report the multimodal activity of pigment epithelium-derived factor (PEDF) in inhibiting osteosarcoma growth, angiogenesis and metastasis.

Chitosan microparticles encapsulating PEDF plasmid demonstrate efficacy in an orthotopic metastatic model of osteosarcoma.

The major stumbling block for most therapies against deep-seated disease, including tumours, is inefficient drug delivery. Such a concern is particularly important for osteosarcoma, the predominant form of bone cancer, and the largest cancer of its type in the paediatric age group. Pigment epithelium-derived factor (PEDF) is the most potent anti-angiogenic factor found endogenously in the body, with an increasing number of reports pointing to its direct antitumour activity.

A novel orthotopic murine model provides insights into cellular and molecular characteristics contributing to human osteosarcoma.

As a reliable model for osteosarcoma is lacking, three human cell lines (SaOS-2, U2OS and 143B) were evaluated in cell-based assays for proliferation, adhesion, migration, invasion, anchorage-independent growth, angiogenesis, mineralised nodule formation, plasmid transfection and oligonucleotide transfection. Tumor take and metastasis after orthotopic injection of the three cell lines into mice was monitored. The levels of expression of typical bone markers were determined with semi-quantitative RT-PCR in cultured cells, primary tumors, and for the SaOS-2 cell line, the metastases.