Fluorochrome Bone Labeling in Sheep

As an efficacy model. thirty-four female Merino sheep underwent transpedicular lumbar interbody fusion with three different materials for augmentation of the spine. Fluorochrome analysis was used to evaluate differences in bone deposition and fusion processes between the three study groups. During the post-operative follow-up period ofeight weeks, the fluorescent dyes xylenol orange. calcein green, and doxyeycline yellow were given at two, four. and six weeks, respectively. All dyes were administered intravenously after sedation with xylazine. The objective of this paper is to provide a methodical description of preparation quality control, administration, efficacy, and observed adverse events from the use of these bone labels in sheep.Both xylenol orange and calcein green dyes provided satisfying results but doxycyeline yellow led to only weak fluorescence in the first ten animals. Consequently, higher dosing was introduced to obtain bright bands in the histological sections. Also, during administration of doxycyeline yellow, mild to severe adverse events occasionally occured: Eight of the first ten sheep suffered from respiratory distress, and in severe cases several stopped breathing, thus requiring immediate intervention. Minimizing the sedative dose and elongating the sedation/doxycycline administration interval were effective changes to the original procedure. We conclude that these adverse events may have been caused by too high a close of sedative, as well as a drug interaction between xylazine and doxycycline yellow

Temporal cardiac remodeling post-myocardial infarction: dynamics and prognostic implications in personalized medicine

Despite dramatic improvements in short-term mortality rates following myocardial infarction (MI), long-term survival for MI patients who progress to heart failure remains poor. MI occurs when the left ventricle (LV) is deprived of oxygen for a sufficient period of time to induce irreversible necrosis of the myocardium. The LV response to MI involves significant tissue, cellular, and molecular level modifications, as well as substantial hemodynamic changes that feedback negatively to amplify the response. Inflammation to remove necrotic myocytes and fibroblast activation to form a scar are key wound healing responses that are highly variable across individuals. Few biomarkers of early remodeling stages are currently clinically adopted. The discovery of underlying pathophysiological mechanisms and associated novel biomarkers has the potential of improving prognostic capability and therapeutic monitoring. Combining these biomarkers with other prominent ones could constitute a powerful diagnostic and prognostic tool that directly reflects the pathophysiological remodeling of the LV. Understanding temporal remodeling at the tissue, cellular, and molecular level and its link to a well-defined set of biomarkers at early stages post-MI is a prerequisite for improving personalized care and devising more successful therapeutic interventions. Here we summarize the integral mechanisms that occur during early cardiac remodeling in the post-MI setting and highlight the most prominent biomarkers for assessing disease progression