Detection of cow hind-leg activity during milking by using a 3-dimensional accelerometer attached to the milking cluster

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Hind-leg activity during milking in cows is a good welfare indicator

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Cow hind-leg movements are transmitted to the milking claw

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3D accelerometers attached to the milking claws accurately record cow hind-leg movements

Hind-leg activity in dairy cows during milking is considered an indicator of a stressful situation or discomfort. Automatic detection of cow hind-leg activity during milking could be used to monitor deficiencies at the cow, milking machine, or human level. We assumed that the milking cluster follows cow hind-leg movements during milking. Therefore, the aim of our study was to estimate the ability of a 3-dimensional (3D) accelerometer attached to the claw's hook of the milking cluster to indirectly measure cow hind-leg activity during milking. The behavior of 45 dairy cows during 1 morning and 1 evening milking in a 2 × 3 auto tandem milking parlor was monitored by using direct visual observations and a 3D accelerometer attached directly to the hook of each milking claw. We recorded when hind-leg foot-lifting or stepping (undifferentiated) and kicking behaviors occurred. Detected activities were obtained after applying a standard deviation filter (over a sliding window of 1 s) on the x (left/right lateral) acceleration axis only. We set the detection threshold at 0.13 g (i.e., 1.27 m·s⁻²), based on the visual evaluation of 10 “reference” graphs (from 5 randomly chosen cows). Periods of activity were created for each observed or detected activity (and for consecutive activities that were less than 3 s apart) to take into account the milking cluster's rocking motion resulting from a single movement. Observed and detected periods of activity were considered matching when they occurred simultaneously (with a 2-s delay acceptance in the visual observations). In total, 472 periods of hind-leg activity were observed. The detection of hind-leg activity by using a 3D accelerometer attached to the milking cluster was found to have 69% sensitivity, 99% specificity, 75% positive predictive value, 98% negative predictive value, and an overall accuracy of 97%. On average, cows were observed being active 0.94 times per minute and being detected active 0.86 times per minute. The observed and detected periods of activity were found to be correlated (r = 0.657). Therefore, the use of a 3D accelerometer attached to the milking cluster seems promising for reliably estimating cow hind-leg activity during milking. Nevertheless, further investigations are necessary to clarify whether other factors can cause variations in milking cluster movements, regardless of cow hind-leg activity, and to generalize our method to better identify deficiencies in cow–machine–human interactions.

CXCR4 antagonists mobilize childhood acute lymphoblastic leukemia cells into the peripheral blood and inhibit engraftment

The role of CXCL12 in the bone marrow (BM) homing and growth of B-cell progenitor acute lymphoblastic leukemia (ALL) has been established. However, the effect of modulating CXCL12/CXCR4 interactions on the retention of ALL cells within the supportive BM microenvironment and the expansion and dissemination of ALL cells in vivo has not been examined. We used mouse models of human childhood and murine leukemia and specific peptide and small molecule CXCR4 antagonists to examine the importance of CXCL12/CXCR4 in the development of leukemia in vivo. CXCR4 antagonists mobilized ALL cells into the peripheral blood (PB). Extended administration of CXCR4 antagonists to mice with leukemia resulted in a reduction in the number of leukemic cells in the PB and spleens of animals compared to control treated animals in three of the five cases tested. There was also a marked reduction in the dissemination of ALL cells to extramedullary sites including liver and kidney in all cases where this occurred. Considering the inhibitory effect of stromal layers on the activity of chemotherapeutic agents and the interactive effect of CXCL12 antagonists with chemotherapeutic agents in vitro, this raises the possibility of using these agents to potentiate the effects of current chemotherapy regimens.

The chemokine (C-X-C motif) receptor 4 inhibitor AMD3100 accelerates blood flow restoration in diabetic mice

AIMS/HYPOTHESIS

Bone marrow cell mobilisation potently induces vascular growth in ischaemic tissue, possibly by mobilising endothelial cell progenitors. Thus, mobilising agents might not be therapeutic when endothelial cell progenitors are dysfunctional, as in diabetes mellitus. Local injection of autologous endothelial cell progenitors also stimulates vascular growth in ischaemic tissue, but endothelial cell progenitors from people with multiple cardiovascular risk factors and from obese diabetic mice are marginally therapeutic or inhibitory. We sought to identify possible strategies to improve vascularisation in patients with diabetes mellitus by determining if (1) mobilisation accelerates neovascularisation in diabetic animals, and (2) mobilised cells from a non-diabetic source accelerate vascularisation in diabetic animals.

METHODS

We tested whether systemic administration of the chemokine (C-X-C motif) receptor 4 inhibitor AMD3100 or local injection of human CD34(+) circulating cells mobilised by AMD3100 could speed or enhance blood flow restoration in ischaemic limbs of diabetic mice. The small-molecule-mobilising drug AMD3100 was selected because mobilisation and apheresis can be done on the same day.

RESULTS

Systemic administration of AMD3100 and local injection of cells mobilised by AMD3100 greatly accelerated the restoration of blood flow to ischaemic limbs of diabetic mice. CD34(+) cells mobilised by AMD3100 appeared to be more potent growth stimulators than their unmobilised counterparts.

CONCLUSIONS/INTERPRETATION

Unlike other mobilising agents requiring multi-day mobilisation, AMD3100 enables mobilised donors to undergo mobilisation and apheresis on the same day. The combination of excellent therapeutic benefits as well as ease of use indicates that AMD3100 could be a powerful tool to ameliorate tissue ischaemia in the diabetic environment.

Xenobiotic efflux pumps in isolated fish brain capillaries

To identify specific transporters that drive xenobiotics from the central nervous system to blood, the accumulation of fluorescent drugs was studied in isolated capillaries from killifish and dogfish shark brain using confocal microscopy and quantitative image analysis. In killifish brain capillaries, luminal accumulation of fluorescent derivatives of cyclosporin A and verapamil was concentrative, specific, and energy dependent (inhibition by KCN). Transport was reduced by PSC-833, but not by leukotriene C4, indicating the involvement of P-glycoprotein. The ability of capillaries to transport the cyclosporin A derivative was unchanged over 20 h, demonstrating the long-term viability of the preparation. Luminal accumulation of the fluorescent organic anions sulforhodamine 101 and fluorescein-methotrexate was also concentrative, specific, and energy dependent. Transport of these compounds was reduced by leukotriene C4, but not by PSC-833, indicating the involvement of a multidrug resistance-associated protein (Mrp). Similar results were obtained for isolated capillaries from dogfish shark. Immunostaining localized P-glycoprotein and Mrp2 to the luminal surface of the killifish brain capillary endothelium. These findings validate a new and long-lived comparative model for studying drug transport across the blood-brain barrier and, as in mammals, implicate P-glycoprotein and Mrp2 in transport from the central nervous system to blood in fish.

Synthesis and cytotoxicity of some cyclometallated palladium complexes

Several monomeric cyclometallated palladium complexes have been prepared by bridge opening reactions of their corresponding dimeric precursors with various amines. The complexes were characterized by elemental analyses and proton NMR spectroscopy. The general formula for the complexes can be given as Pd(N-C)LX where (N-C) is an aromatic or aliphatic amine coordinated as a chelating ligand through the amine and a formal cyclometallated Pd-C bond; L = amine, X = chloride or acetate. A unique complex based on the cyclopalladation of 2-phenyl phenanthroline was also prepared directly. The series of complexes was screened for cytotoxicity against a panel of seven human tumor cell lines. All complexes were found to be cytotoxic (IC50) at micrograms/ml concentrations, while two complexes also displayed some differential cytotoxicity.