Hereditary spherocytosis: diagnostic and anaemia-associated aberrations of ghost proteins

Various disorders of the red cell skeleton and membrane have been described in hereditary spherocytosis. To elucidate which aberrations could be used for identification of HS patients in a Danish population, we examined ghosts from 17 HS patients and 20 normals by use of SDS-gel scanning, native spectrin extraction, and limited tryptic digestion. Compared to normals, HS patients had significantly lowered alpha-spectrin (p < 0.004), protein 4.2 (p < 0.025), and actin (p < 0.05), and significantly increased anion-transporter (p < 3 x 10(-6)) and glyceraldehyde-3-phosphate dehydrogenase (G3PD, p < 0.04). Sixteen out of 17 HS patients could be identified by aberrations of the anion-transporter or protein 4.2 outside a 95% confidence interval for normals. Extraction of native spectrin and limited tryptic digest showed no difference between normals and HS patients. RBC separated into young and old fractions were used to examine the occurrence of protein aberrations associated with RBC age. Young RBC contained more G3PD (35%) and less protein 4.1 (6.5%) and actin (8.7%) than old. In male HS patients an increased G3PD content showed a linear correlation (p < 0.001) with a low concentration of blood haemoglobin. We conclude that aberrations of G3PD, and possibly protein 4.1, and actin, are associated with anaemia in HS. Increased anion-transporter or lowered protein 4.2 may be useful for diagnosis of HS, and were inherited in five out of six families where two generations were available.     

The role of adhesion molecules in human leukocyte attachment to porcine vascular endothelium: implications for xenotransplantation

Many obstacles still prevent successful xenotransplantation of porcine donor organs. When hyperacute rejection is averted, transplanted pig organs are subject to acute vascular and cellular rejection. In autologous systems, leukocyte recruitment into inflamed tissues involves selectins, integrins, and Ig family members. To determine whether these mechanisms allow human leukocytes to effectively enter porcine grafts, the pathways by which human leukocytes adhere to TNF-alpha-stimulated porcine aortic endothelium were examined under static and physiologic flow conditions. L-selectin and E-selectin had overlapping functions in neutrophil capture and rolling, whereas Ab blockade of E-selectin and the beta2 integrins inhibited firm arrest of rolling neutrophils. Combined blockade of selectins and beta2 integrins resulted in negligible human neutrophil attachment to pig endothelium. Lymphocyte attachment to porcine endothelium was primarily L-selectin mediated, whereas beta2 integrin and VCAM-1/very late Ag-4 (VLA-4) interactions promoted static adhesion. Concurrent beta2 integrin, VLA-4, VCAM-1, and L-selectin blockade completely inhibited lymphocyte attachment. Thus, interactions between leukocyte-endothelial cell adhesion receptor pairs remained remarkably intact across the human-porcine species barrier. Moreover, disrupting the adhesion cascade may impair the ability of human leukocytes to infiltrate a transplanted porcine organ during rejection.     

Application of nanofiltration for chromium concentration in the tannery wastewater

The article presents results of investigation concerning an influence of tannery wastewater composition on chromium(III) concentration in the wastewaters during the nanofiltration process (NF). The effectiveness of this process strongly depends on mutual relation between chloride and sulfate ions concentration in tannery wastewater. For this reason, the optimum composition of the tannery wastewater should consist chloride/sulfate ions ratio close to 1. Moreover, an influence of transmembrane pressure (TMP) and the "ageing" of chromium tannery wastewater on the efficiency of the process has been investigated. Optimal range of TMP equal to 14-16 bar has been assumed for the process. It is necessary to point out that the optimum transmembrane pressure can be changed in the case of the membranes with different permeation properties. "Ageing" of the tannery wastewater reduces only a little an efficiency of the process. Experimental results demonstrated that the NF process could be successfully used for the concentration of chromium in the tannery wastewater with high permeate flux, selectivity and performance stability.