Severe neurological events following liver transplantation

BACKGROUND: Problems related to the central nervous system may have major impact on morbidity and mortality. The aim of this retrospective study was to evaluate the nature and incidence of serious neurologic events in patients following liver transplantation. METHODS: Between January 2001 and May 2004, 168 patients (105 female, 63 male) requiring transplantation for alcoholic cirrhosis, hepatitis B and C, and acute liver failure were admitted to the Intensive Care Unit (ICU) of University Hospital Essen after liver transplantation. We identified the reason for the neurologic events, the underlying disease, type of immunosuppression, and the survival rate. RESULTS: Severe neurologic events occurred in 46 (27.3%) of the patients. The length of stay of these patients in the ICU (18.4 +/- 19.7 days) was longer in comparison to the total patients (8.3 +/- 9.5 days, p < 0.05). The most common neurological complications were encephalopathy (18.5%) and seizures (5.4%). The survival rate after liver transplantation with neurological events was lower compared to patients without, but not significantly different (73.9 vs. 79.5%). The calcineurin inhibitor used had no impact on neurological events [cyclosporine (25.5%); tacrolimus (32.5%)]. CONCLUSIONS: There was a high incidence of serious neurologic events after liver transplantation. The major neurologic manifestation in our patients was encephalopathy followed by seizures.     

Spontaneous fusion and nonclonal growth of adult neural stem cells

Multipotent neural stem cells (NSCs) can be isolated from various regions of the adult brain and propagated in vitro. Recent reports have suggested spontaneous fusion events among NSCs when grown as free-floating neurospheres that may affect the genetic composition of NSC cultures. We used adult NSCs expressing either red fluorescent protein (RFP) or green fluorescent protein (GFP) to analyze the fusion frequency of rat and mouse NSCs. Fluorescence-activated cell sorting (FACS) revealed that, under proliferating conditions, approximately 0.2% of rat and mouse NSCs coexpressed RFP and GFP irrespective of whether the cells were grown as neurospheres (mouse NSCs) or as attached monolayers (rat and mouse NSCs). Fused cells did not proliferate and could not be propagated, suggesting that aberrantly fused cells are not viable. Furthermore, we found that neither neurospheres nor monolayers grew clonally, because even very low-density cultures had spheres containing both GFP- and RFP-expressing cells and monolayer patches with GFP- and RFP-expressing cells in close proximity. The nonclonal growth between distinct NSC populations strongly suggests the use of careful and precise culture conditions, such as single-cell assays, to characterize potency and growth of NSCs in vitro.     

Purposes of health identification cards and role of a secure access platform (Be-Health) in Belgium

Although other alternatives may exist, identification cards have been chosen as an acceptable and adequate tool to be used to identify patients and health professionals. It is planned to use these for digital signature and for access to electronic health records: for searching various databases as well as for health information exchange. Local applications might exist independently, but the Belgian federal state has now developed Be-Health, a platform for health professionals, social security personnel and the general public, designed to facilitate a secure common uniform access to certain health data.     

Modulation of the human bone cell cycle by calcium ion-implantation of titanium

Ca ion implantation of Ti surfaces has previously been reported to enhances osseointegration in vivo. Although the mechanisms underlying the response of bone cells to these novel surfaces still remain unclear, it is possible that Ca ion-implanted Ti (Ca-Ti) may influence the growth of new bone by modulating the progression of the cell cycle. In the present study we have, therefore, examined the precise effects of Ca ion-implantation of Ti on the bone-like MG-63 cell line in vitro. The results of flow cytometry analysis showed that this surface markedly enhanced the proportion of cells which expressed Ki-67, a cell proliferation-associated nuclear antigen, compared with cells grown on the non-implanted Ti (control) surface. In addition, cultures grown on Ca-Ti and synchronized at the G1/S boundary by hydroxyurea more rapidly re-entered and progressed through the S and G2/M phases of the cell cycle than their counterparts on Ti. Ca ion-implantation also significantly increased the numbers of mitotic cells. These results thus show that alteration of the surface chemistry of Ti by high-energy implantation with Ca ion was able to substantially modulate the progression of the bone cell cycle, and suggest a possible means of enhancing the response of bone cells to implant materials.     

Chitosan/poly(vinyl alcohol) blending hydrogel coating improves the surface characteristics of segmented polyurethane urethral catheters

Segmented polyurethane (SPU) is commonly used to manufacture urethral catheters. Surface modifications for SPU catheters are needed to reduce friction and protein adsorption, in order to minimize catheter-related complications, including urethral trauma, encrustation, catheter obstruction, bacterial colonization, and infection. In this study, a four-step surface modification method was developed to create a thin lubricious layer of chitosan/poly(vinyl alcohol) (PVA) hydrogel on the SPU catheter. Modification steps included oxidation of the SPU surface, functionalities modification, carbodiimide reaction and coupling, and hydrogel crosslinking. The success of each modification step was confirmed by Fourier transform infrared spectroscopy. Measurement of the water contact angle revealed that hydrogel coating created a highly hydrophilic surface and atomic force microscope analyses demonstrated that the surface was slippery. Protein absorption of the SPU catheter was significantly reduced by coating hydrogel. Chitosan in the hydrogel could provide antimicrobial activity, and the hydrogel coating SPU samples showed significant antibacterial effects in this study. In summary, the four-step modification method developed in this study provided a simple and effective way to coat the surface of SPU catheters with a chitosan/PVA blending hydrogel that could help to minimize the risk of complications related to the use of urethral catheters.