A Novel Role for PECAM-1 (CD31) in Regulating Haematopoietic Progenitor Cell Compartmentalization between the Peripheral Blood and Bone Marrow

Although the expression of PECAM-1 (CD31) on vascular and haematopoietic cells within the bone marrow microenvironment has been recognized for some time, its physiological role within this niche remains unexplored. In this study we show that PECAM-1 influences steady state hematopoietic stem cell (HSC) progenitor numbers in the peripheral blood but not the bone marrow compartment. PECAM-1−/− mice have higher levels of HSC progenitors in the blood compared to their littermate controls. We show that PECAM-1 is required on both progenitors and bone marrow vascular cells in order for efficient transition between the blood and bone marrow to occur. We have identified key roles for PECAM-1 in both the regulation of HSC migration to the chemokine CXCL12, as well as maintaining levels of the matrix degrading enzyme MMP-9 in the bone marrow vascular niche. Using intravital microscopy and adoptive transfer of either wild type (WT) or PECAM-1−/− bone marrow precursors, we demonstrate that the increase in HSC progenitors in the blood is due in part to a reduced ability to migrate from blood to the bone marrow vascular niche. These findings suggest a novel role for PECAM-1 as a regulator of resting homeostatic progenitor cell numbers in the bloo

No Evidence that Knops Blood Group Polymorphisms Affect Complement Receptor 1 Clustering on Erythrocytes

Clustering of Complement Receptor 1 (CR1) in the erythrocyte membrane is important for immune-complex transfer and clearance. CR1 contains the Knops blood group antigens, including the antithetical pairs Swain-Langley 1 and 2 (Sl1 and Sl2) and McCoy a and b (McCa and McCb), whose functional effects are unknown. We tested the hypothesis that the Sl and McC polymorphisms might influence CR1 clustering on erythrocyte membranes. Blood samples from 125 healthy Kenyan children were analysed by immunofluorescence and confocal microscopy to determine CR1 cluster number and volume. In agreement with previous reports, CR1 cluster number and volume were positively associated with CR1 copy number (mean number of CR1 molecules per erythrocyte). Individuals with the McCb/McCb genotype had more clusters per cell than McCa/McCa individuals. However, this association was lost when the strong effect of CR1 copy number was included in the model. No association was observed between Sl genotype, sickle cell genotype, α+thalassaemia genotype, gender or age and CR1 cluster number or volume. Therefore, after correction for CR1 copy number, the Sl and McCoy polymorphisms did not influence erythrocyte CR1 clustering, and the effects of the Knops polymorphisms on CR1 function remains unknown

Analiza polimorfizmu genu PPARGC1A w odniesieniu do cech tuszy tuczników hybrydowych PIC

The aim of this study was to determine the association between polymorphism located in exon 8 of PPARGC1A gene (Cys430Ser) and carcass quality in pigs. Experiment was carried out on 350 PIC hybrid fatteners. Polymorphism was analyzed using PCR-RFLP method. The frequency of genotypes was as follows: AA – 0.33, AT – 0.57, TT – 0.1, however alleles: A – 0.62, T – 0.38. In the analyzed population loss of Hardy-Weinberg equilibrium was observed (P ≤ 0.01). Statistical analysis showed that only one of the evaluated traits was associated with individual PPARGC1A genotypes. Cooling loss value for pig carcasses with TT genotype was statistically significant (P ≤ 0.05) higher than observed in those with AA and AT genotypes.Celem niniejszych badań było wykazanie zależności pomiędzy polimorfizmem zlokalizowanym w 8 eksonie genu PPARGC1A (Cys430Ser) a cechami tuszy świń. Eksperyment został przeprowadzony na 350 tucznikach hybrydowych PIC. Polimorfizm analizowano z użyciem metody PCR-RFLP. Frekwencja genotypów była następująca: AA - 0.33, AT - 0.57, TT - 0.1, natomiast alleli: A - 0.62, T - 0.38. W analizowanej populacji zaobserwowano zachwianie równowagi genetycznej Hardy’ego-Weinberga (P ≤ 0,01). Analiza statystyczna wykazała, że tylko jedna z ocenianych cech była powiązana z poszczególnymi genotypami PPARGC1A. Wartość strat chłodzenia (%) dla świń z genotypem TT była statystycznie istotnie (P ≤ 0,05) wyższa niż obserwowana u osobników z genotypami AA i AT

Comparison of high-field and low-field magnetic resonance imaging of stifle joint disorders in dogs

The most common cause of hindlimb lameness in dogs is cranial cruciate ligament rupture. In 48-77.3% of the population this trauma leads to secondary damage of the meniscus. Depending on the magnetic strength of the used device, different diagnostic accuracy can be achieved. The examination sensitivity of magnetic resonance imaging is affected by many factors which are independent of diagnostic strength, such as correct positioning of the patient, size of the stifle joint examined, or selection of the right protocol of sequences. Sensitivity of meniscus damage detection was 100% and 90%, respectively, in high- and low-field magnetic resonance. The best results were reported during examination of the stifle in dogs above 10 kg b.w. at a flexion angle of 145°, and in sagittal and dorsal planes. Regardless of the magnetic strength applied, imaging of the whole cranial cruciate ligament is difficult. Moreover, MRI allows the detection of the first signs of osteoarthritis, which were observed 4 and 6 weeks after rupture of the cranial cruciate ligament using high and low-field MRI. This also applies to lesions in the subchondral bone or a bone marrow which occurred in association with insufficiency of the stifle joint, and were mainly localized in the epiphysis of the femur and tibia. The present article provides a comparison of different examination protocols and images of damaged stifle structures, such as menisci, ligaments and bones of the stifle joint visualized with low-field and high-field magnetic resonance. Magnetic resonance arthrography is also discussed

Comput Stat On the discovery of events in EEG data utilizing information fusion

Abstract One way to tackle brain computer interfaces is to consider event related potentials in electroencephalography, like the well established P300 phenomenon. In this paper a multiple classifier approach to discover these events in the bioelectrical signal and with them whether or not a subject has recognized a particular pattern, is employed. Dealing with noisy data as well as heavily imbalanced target class distributions are among the difficulties encountered. Our approach utilizes partitions of electrodes to create robust and meaningful individual classifiers, which are then subsequently combined using decision fusion. Furthermore, a classifier selection approach using genetic algorithms is evaluated and used for optimization. The proposed approach utilizing information fusion shows promising results (over 0.8 area under the ROC curve)