The CCR2/CCL2 interaction mediates the transendothelial recruitment of intravascularly delivered neural stem cells to the ischemic brain

The inflammatory response is a critical component of ischemic stroke. In addition to its physiological role, the mechanisms behind transendothelial recruitment of immune cells also offer a unique therapeutic opportunity for translational stem cell therapies. Recent reports have demonstrated homing of neural stem cells (NSC) into the injured brain areas after intravascular delivery. However, the mechanisms underlying the process of transendothelial recruitment remain largely unknown. Here we describe the critical role of the chemokine CCL2 and its receptor CCR2 in targeted homing of NSC after ischemia.

Platelet Recruitment during Multiple Donor Platelet Apheresis Differs between Cell Separators

SUMMARY: BACKGROUND: Recruitment of platelets (PLT) during donor PLT apheresis may facilitate the harvest of multiple units within a single donation. METHODS: We compared two PLT apheresis procedures (Amicus and Trima Accel) in a prospective, randomized, paired cross-over study in 60 donors. The 120 donations were compared for depletion of circulating PLT in the donors, PLT yields and PLT recruitment. A recruitment was defined as ratio of total PLT yield and donor PLT depletion > 1. RESULTS: Despite comparable differences of pre- and post-apheresis PLT counts (87 × 10(9)/l in Trima Accel vs. 92 × 10(9)/l in Amicus, p = 0.383), PLT yields were higher with Trima Accel (7.48 × 10(11) vs. 6.06 × 10(11), p < 0.001), corresponding to a higher PLT recruitment (1.90 vs. 1.42, p < 0.001). We observed a different increase of WBC counts after aphereses, which was more pronounced with Trima Accel than with Amicus (1.30 × 10(9)/l vs. 0.46 × 10(9)/l, p < 0.001). CONCLUSION: Both procedures induced PLT recruitment. This was higher in Trima Accel, contributing to a higher yield in spite of a comparable depletion of circulating PLT in the donors. This recruitment facilitates the harvest of multiple units within a single donation and seems to be influenced by the procedure utilized. The different increases of circulating donor white blood cells after donation need further investigation.

Dental arch relationship in 5-year-olds with complete unilateral cleft lip and palate after early alveolar bone grafting

To evaluate dental arch relationship in preschoolers with unilateral cleft lip and palate after early alveolar bone grafting (ABG).

Preferential recruitment of bone marrow-derived cells to rat palatal wounds but not to skin wounds

To investigate the contribution of bone marrow-derived cells to oral mucosa wounds and skin wounds.

Effects of isoflurane upon minimum alveolar concentration and cerebral cortex depression in pigs and goats: an interspecies comparison

This study compared the effects of isoflurane in pigs (n=10 Yorkshire-Landrace cross) and dairy goats (n=10) by evaluation of electroencephalographic (EEG) burst suppression thresholds (BST) in the cerebral cortex and minimum alveolar concentration (MAC) values in the spinal cord. The study also investigated whether individual MAC values can predict the effects of isoflurane on the cerebral cortex. MAC values and BST/MAC ratios were significantly different between species. Inhibition of movement by isoflurane may be less effective in pigs than in goats. No significant correlation was found between individual MAC and BST values, indicating that in single animals the individual MAC poorly reflects the cerebrocortical depressant effect of isoflurane in pigs and goats.

In vitro and in vivo efficacies of mefloquine-based treatment against alveolar echinococcosis

Alveolar echinococcosis (AE) is caused by the metacestode stage of the fox tapeworm Echinococcus multilocularis and causes severe disease in the human liver, and occasionally in other organs, that is fatal when treatment is unsuccessful. The present chemotherapy against AE is based on mebendazole and albendazole. Albendazole treatment has been found to be ineffective in some instances, is parasitostatic rather than parasiticidal, and usually involves the lifelong uptake of large doses of drugs. Thus, new treatment options are urgently needed. In this study we investigated the in vitro and in vivo efficacy of mefloquine against E. multilocularis metacestodes. Treatment using mefloquine (20 muM) against in vitro cultures of metacestodes resulted in rapid and complete detachment of large parts of the germinal layer from the inner surface of the laminated layer within a few hours. The in vitro activity of mefloquine was dependent on the dosage. In vitro culture of metacestodes in the presence of 24 muM mefloquine for a period of 10 days was parasiticidal, as determined by murine bioassays, while treatment with 12 muM was not. Oral application of mefloquine (25 mg/kg of body weight administered twice a week for a period of 8 weeks) in E. multilocularis-infected mice was ineffective in achieving any reduction of parasite weight, whereas treatment with albendazole (200 mg/kg/day) was highly effective. However, when the same mefloquine dosage was applied intraperitoneally, the reduction in parasite weight was similar to the reduction seen with oral albendazole application. Combined application of both drugs did not increase the treatment efficacy. In conclusion, mefloquine represents an interesting drug candidate for the treatment of AE, and these results should be followed up in appropriate in vivo studies.

Mapping the increasing risk of human alveolar echinococcosis in Limburg, The Netherlands

The parasite Echinococcus multilocularis was first detected in The Netherlands in 1996 and repeated studies have shown that the parasite subsequently spread in the local population of foxes in the province of Limburg. It was not possible to quantify the human risk of alveolar echinococcosis because no relationship between the amount of parasite eggs in the environment and the probability of infection in humans was known. Here, we used the spread of the parasite in The Netherlands as a predictor, together with recently published historical records of the epidemiology of alveolar echinococcosis in Switzerland, to achieve a relative quantification of the risk. Based on these analyses, the human risk in Limburg was simulated and up to three human cases are predicted by 2018. We conclude that the epidemiology of alveolar echinococcosis in The Netherlands might have changed from a period of negligible risk in the past to a period of increasing risk in the forthcoming years.

Lung on Chip: In vitro HGF effects on injured alveolar A549 epithelial cells in microfluidic system

Microfluidic systems have become competitive tools in the invitro modelling of diseases and promising alternatives to animal studies. They allow obtaining more invivo like conditions for cellular assays. Research in idiopathic pulmonary fibrosis could benefit from this novel methodological approach to understand the pathophysiology of the disease & develop efficient therapies. The use of hepatocyte growth factor (HGF) for alveolar reepithelisation is a promising approach. In this study, we show a new microfluidic system to analyse the effects of HGF on injured alveolar epithelial cells. Microfluidic systems in polydimethylsiloxane were fabricated by soft lithography. The alveolar A549 epithelial cells (10,000 cells) were seeded and studied in these microfluidic systems with media perfusion (1μl/30min). Injury tests were made on the cells by the perfusion with media containing H2O2 or bleomycin. The degree of injury was then assessed by a metabolic and an apoptotic assays. Wound assays were also performed with a central laminar flow of trypsin. Monitoring of wound closure with HGF vs control media was assessed. The alveolar A549 epithelial cells grew and proliferated in the microfluidic system. In the wound closure assay, the degree of wound closure after 5 hours was (53.3±1.3%) with HGF compared to (9.8±2.4%) without HGF (P <0.001). We present a novel microfluidic model that allows culture, injury and wounding of A549 epithelial cells and represents the first step towards the development of an invitro reconstitution of the alveolar-capillary interface. We were also able to confirm that HGF increased alveolar epithelial repair in this system.

Lung on a chip: Co-culture of alveolar epithelial cells and bone marrow derived stromal stem cells in a microfluidic system

Background: Microfluidics system are novel tools to study cell-cell interactions in vitro. This project focuses on the development of a new microfluidic device to co-culture alveolar epithelial cells and mesenchymal stem cells to study cellular interactions involved in healing the injured alveolar epithelium. Methods: Microfluidic systems in polydimethylsiloxane were fabricated by soft lithography. The alveolar A549 epithelial cells were seeded and injury tests were made on the cells by perfusion with media containing H2O2 or bleomycin during 6 or 18hrs. Rat Bone marrow derived stromal cells (BMSC) were then introduced into the system and cell-cell interaction was studied over 24 hrs. Results: A successful co-culture of A549 alveolar epithelial cells and BMS was achieved in the microfluidic system. The seeded alveolar epithelial cells and BMSC adhered to the bottom surface of the microfluidic device and proliferated under constant perfusion. Epithelial injury to mimic mechanisms seen in idiopathic pulmonary fibrosis was induced in the microchannels by perfusing with H2O2 or bleomycin. Migration of BMSC towards the injured epithelium was observed as well as cell-cell interaction between the two cell types was also seen. Conclusion: We demonstrate a novel microfluidic device aimed at showing interactions between different cell types on the basis of a changing microenvironment. Also we were able to confirm interaction between injured alvolar epithelium and BMSC, and showed that BMSC try to heal the injured epitelium.

Cell-specific expression of human HGF by alveolar type II cells induces remodeling of septal wall tissue in the lung: a morphometric study

Hepatocyte growth factor (HGF) is involved in development and regeneration of the lungs. Human HGF, which was expressed specifically by alveolar epithelial type II cells after gene transfer, attenuated the bleomycin-induced pulmonary fibrosis in an animal model. As there are also regions that appear morphologically unaffected in fibrosis, the effects of this gene transfer to normal lungs is of interest. In vitro studies showed that HGF inhibits the formation of the basal lamina by cultured alveolar epithelial cells. Thus we hypothesized that, in the healthy lung, cell-specific expression of HGF induces a remodeling within septal walls. Electroporation of a plasmid of human HGF gene controlled by the surfactant protein C promoter was applied for targeted gene transfer. Using design-based stereology at light and electron microscopic level, structural alterations were analyzed and compared with a control group. HGF gene transfer increased the volume of distal air spaces, as well as the surface area of the alveolar epithelium. The volume of septal walls, as well as the number of alveoli, was unchanged. Volumes per lung of collagen and elastic fibers were unaltered, but a marked reduction of the volume of residual extracellular matrix (all components other than collagen and elastic fibers) and interstitial cells was found. A correlation between the volumes of residual extracellular matrix and distal air spaces, as well as total surface area of alveolar epithelium, could be established. Cell-specific expression of HGF leads to a remodeling of the connective tissue within the septal walls in the healthy lung, which is associated with more pronounced stretching of distal air spaces at a given hydrostatic pressure during instillation fixation.

The effects of isoflurane minimum alveolar concentration on withdrawal reflex activity evoked by repeated transcutaneous electrical stimulation in ponies

The aim of this study was to quantify the effects of isoflurane at approximately the minimum alveolar concentration (peri-MAC) on the temporal summation (TS) of reflex activity in ponies. TS was evoked by repeated electrical stimulations applied at 5 Hz for 2 s on the digital nerve of the left forelimb of seven ponies. Surface electromyographic activity was recorded from the deltoid and common digital extensor muscles. TS thresholds and amplitude of response to stimulations of increasing intensities were assessed during anaesthesia at 0.85, 0.95 and 1.05 times the individual MAC, and after anaesthesia in standing animals. Under isoflurane anaesthesia, TS thresholds increased significantly in a concentration-dependent fashion and at each isoflurane MAC, the responses increased significantly for increasing stimulation intensities. A concentration-dependent depression of evoked reflexes with a reduction in the slopes of the stimulus-response function was observed for both muscles. The results demonstrated that with this model it is possible to describe and quantify the effects of anaesthetics on spinal sensory-motor processing in ponies.