In vivo imaging and quantitative analysis of leukocyte directional migration and polarization in inflamed tissue

Directional migration of transmigrated leukocytes to the site of injury is a central event in the inflammatory response. Here, we present an in vivo chemotaxis assay enabling the visualization and quantitative analysis of subtype-specific directional motility and polarization of leukocytes in their natural 3D microenvironment. Our technique comprises the combination of i) semi-automated in situ microinjection of chemoattractants or bacteria as local chemotactic stimulus, ii) in vivo near-infrared reflected-light oblique transillumination (RLOT) microscopy for the visualization of leukocyte motility and morphology, and iii) in vivo fluorescence microscopy for the visualization of different leukocyte subpopulations or fluorescence-labeled bacteria. Leukocyte motility parameters are quantified off-line in digitized video sequences using computer-assisted single cell tracking. Here, we show that perivenular microinjection of chemoattractants [macrophage inflammatory protein-1alpha (MIP-1alpha/Ccl3), platelet-activating factor (PAF)] or E. coli into the murine cremaster muscle induces target-oriented intravascular adhesion and transmigration as well as polarization and directional interstitial migration of leukocytes towards the locally administered stimuli. Moreover, we describe a crucial role of Rho kinase for the regulation of directional motility and polarization of transmigrated leukocytes in vivo. Finally, combining in vivo RLOT and fluorescence microscopy in Cx3CR1(gfp/gfp) mice (mice exhibiting green fluorescent protein-labeled monocytes), we are able to demonstrate differences in the migratory behavior of monocytes and neutrophils.Taken together, we propose a novel approach for investigating the mechanisms and spatiotemporal dynamics of subtype-specific motility and polarization of leukocytes during their directional interstitial migration in vivo

Die Notfalltracheotomie beim Pferd

peer reviewe

Bone markers in pregnant Haflinger mares _ A trimestral evaluation

peer reviewedIntroduction Pregnancy is associated with various physiological changes that essentially affect musculoskeletal conditions in the mare. However, the influence of pregnancy on equine bone metabolism has not been studied to great detail. Aim of this study was to evaluate the effect of pregnancy on bone turnover markers in clinically normal lactating mares. Materials and Methods Venous blood samples were collected three-times from 17 multiparous lactating Haflinger mares, aged four to 18 years, during the first (T1), second (T2) and third (T3) trimester of pregnancy. Blood creatinine and gamma glutamyl transferase (GGT) values were evaluated. Serum concentrations of osteocalcin and carboxy-terminal cross-linking telopeptide of type I collagen (CTX-I) were determined using an equine specific osteocalcin radioimmunoassay and an automated CTX-I electrochemiluminescent sandwich antibody assay. Results All mares had normal creatinine and GGT values. Serum CTX-I values significantly increased during the last trimester of pregnancy. Serum osteocalcin concentrations were lowest at T2 and increased thereafter at T3. Conclusions Changes in bone turnover seem to depend on the stage of pregnancy in multiparous mares. Highest values of serum CTX-I and osteocalcin were obtained in the last trimester of pregnancy

Septic arthritis in adult horses

Septic arthritis in horses is a serious disease which can become life-threatening. In case the infection can be eliminated before irreversible joint damage occurs, complete recovery is possible. This article gives an overview of the literature concerning etiology, diagnosis and strategies of therapy in cases of septic arthritis in adult horses, with special reference to novel options of treatment