Impact of rapid identification of Staphylococcus aureus bloodstream infection without antimicrobial stewardship intervention on antibiotic optimization and clinical outcomes.

Few studies have evaluated the clinical impact of polymerase chain reaction (PCR) for Staphylococcus aureus bloodstream infections in resource-limited settings that lack direct antimicrobial stewardship intervention. This retrospective cohort study compared patients with standard microbiological identification (n=343) to those with additional identification by (PCR) (n=130). Time to initiation of optimal therapy was similar between groups but substantially shorter in the PCR group for those infected with methicillin susceptible S. aureus (median 40.0h vs. 28.3h, P=0.001). After controlling for confounding factors including infectious diseases consultation, the PCR group had a shorter time to initiation of optimal therapy by 9.7h (95% CI 4.3-15.0h). Clinical outcomes were similar in the non-PCR and PCR groups. While time to initiation of optimal therapy was shorter in the PCR group, greater reductions may be realized through additional education, direct antimicrobial stewardship intervention, or additional clinician notification.

Tumor stiffness is unrelated to myosin light chain phosphorylation in cancer cells.

Many tumors are stiffer than their surrounding tissue. This increase in stiffness has been attributed, in part, to a Rho-dependent elevation of myosin II light chain phosphorylation. To characterize this mechanism further, we studied myosin light chain kinase (MLCK), the main enzyme that phosphorylates myosin II light chains. We anticipated that increases in MLCK expression and activity would contribute to the increased stiffness of cancer cells. However, we find that MLCK mRNA and protein levels are substantially less in cancer cells and tissues than in normal cells. Consistent with this observation, cancer cells contract 3D collagen matrices much more slowly than normal cells. Interestingly, inhibiting MLCK or Rho kinase did not affect the 3D gel contractions while blebbistatin partially and cytochalasin D maximally inhibited contractions. Live cell imaging of cells in collagen gels showed that cytochalasin D inhibited filopodia-like projections that formed between cells while a MLCK inhibitor had no effect on these projections. These data suggest that myosin II phosphorylation is dispensable in regulating the mechanical properties of tumors.

Characterization and differentiation of equine umbilical cord-derived matrix cells.

Stem cells are being evaluated in numerous human clinical trials and are commercially used in veterinary medicine to treat horses and dogs. Stem cell differentiation, homing to disease sites, growth and cytokine factor modulation, and low antigenicity contribute to their therapeutic success. Bone marrow and adipose tissue are the two most common sources of adult-derived stem cells in animals. We report on the existence of an alternative source of primitive, multipotent stem cells from the equine umbilical cord cellular matrix (Wharton's jelly). Equine umbilical cord matrix (EUCM) cells can be cultured, cryogenically preserved, and differentiated into osteo-, adipo-, chondrogenic, and neuronal cell lineages. These results identify a source of stem cells that can be non-invasively collected at birth and stored for future use in that horse or used as donor cells for treating unrelated horses.