Mesenchymal stem cells from umbilical cord blood: parameters for isolation, characterization and adipogenic differentiation.

Isolation of mesenchymal stem cells (MSCs) from umbilical cord blood (UCB) from full-term deliveries is a laborious, time-consuming process that results in a low yield of cells. In this study we identified parameters that can be helpful for a successful isolation of UCB-MSCs. According to our findings, chances for a well succeeded isolation of these cells are higher when MSCs were isolated from UCB collected from normal full-term pregnancies that did not last over 37 weeks. Besides the duration of pregnancy, blood volume and storage period of the UCB should also be considered for a successful isolation of these cells. Here, we found that the ideal blood volume collected should be above 80 mL and the period of storage should not exceed 6 h. We characterized UCB-MSCs by morphologic, immunophenotypic, protein/gene expression and by adipogenic differentiation potential. Isolated UCB-MSCs showed fibroblast-like morphology and the capacity of differentiating into adipocyte-like cells. Looking for markers of the undifferentiated status of UCB-MSCs, we analyzed the UCB-MSCs' protein expression profile along different time periods of the differentiation process into adipocyte-like cells. Our results showed that there is a decrease in the expression of the markers CD73, CD90, and CD105 that correlates to the degree of differentiation of UCB-MSCs We suggest that CD90 can be used as a mark to follow the differentiation commitment degree of MSCs. Microarray results showed an up-regulation of genes related to the adipogenesis process and to redox metabolism in the adipocyte-like differentiated MSCs. Our study provides information on a group of parameters that may help with successful isolation and consequently with characterization of the differentiated/undifferentiated status of UCB-MSCs, which will be useful to monitor the differentiation commitment of UCB-MSC and further facilitate the application of those cells in stem-cell therapy.

Brazilian experience with two conditioning regimens in patients with multiple sclerosis: BEAM/horse ATG and CY/rabbit ATG.

Studies have shown that autologous hematopoietic SCT (HSCT) can be used as an intensive immunosuppressive therapy to treat refractory patients and to prevent the progression of multiple sclerosis (MS). This is a prospective multicentric Brazilian MS trial comparing two conditioning regimens: BEAM/horse ATG and CY/rabbit ATG. Most (80.4%) of the 41 subjects in the study had the secondary progressive MS subtype and the mean age was 42 years. The baseline EDSS score in 58.5% of the subjects was 6.5 and 78% had a score of 6.0 or higher, respectively. The complication rate during the intra-transplantation period was 56% for all patients: 71.4% of the patients in the BEAM/hATG group and 40% in the CY/rATG group (P=0.04). Three subjects (7.5%) died of cardiac toxicity, sepsis and alveolar hemorrhage, all of them in the BEAM/ATG group. EFS was 58.54% for all patients: 47% in the BEAM/hATG group and 70% in the CY/rATG group (P=0.288). In conclusion, the CY/rATG regimen seems to be associated with similar outcome results, but presented less toxicity when compared with the BEAM/hATG regimen. Long-term follow-up would be required to fully assess the differences in therapeutic effectiveness between the two regimens.

Analysis of liver transplantation outcome in patients with MELD Score > or = 30.

Since July 2006, the liver graft allocation has been changed from the waiting time to the Model for End-stage Liver Disease (MELD), prioritizing the sickest patients, who have a higher risk of dying on the waiting list, and sometimes in such poor clinical condition that it compromises transplantation outcomes. The aim of this study was to analyze the impact of a MELD score > or = 30 on 30-day survival after liver transplantation (OLT). We prospectively collected the data on 178 liver transplants on 163 patients performed from March 2003 to August 2007. The subjects were divided in two groups according to their MELD scores: group 1, MELD > or = 30 (n = 15) and group 2, MELD < 30 (n = 96). The groups were compared with regard to hospital and intensive care unit (ICU) length of stay, intraoperative blood products transfusion, early survival (30 days), and need for retransplantation. We excluded, patients with prioritization criteria, those receiving extra points for any special situation, and six other patients without significant data for MELD calculation (of whom only one has died after transplantation). Patients under a "special situation" were those with hepatocelular carcinoma, hepatopulmonary syndrome, and metabolic diseases, who initially received a MELD/PELD score 20, and 24, and 29. The mean MELD score at group I was 34 (range, 30 to 42), and for group II it was 16 (range, 6 to 29). Group I displayed a mean hospital length of stay of 24 days (4 to 155), with 12.60 days (ranges, 1 to 103) in the ICU versus 15.55 (range, 1 to 48) and 5.13 (range, 1 to 45) days, respectively, for group II. The need for blood component transfusions were greater in group I; 25.28% of patients in group II did not receive any transfusion during the entire inpatient period. There were nine retransplants in group II, and none in group I. The 30-day survivals were 93.3% for group I and 84.37% for group II. Besides the increased complexity of these sickest patients, there was no negative impact on early survival rates.