BackgroundProbiotics are proposed to positively modulate the intestinal epithelial barrier formed by intestinal epithelial cells (IECs) and intercellular junctions. Disruption of this border alters paracellular permeability and is a key mechanism for the development of enteric infections and inflammatory bowel diseases (IBDs).Methodology and Principal FindingsTo study the in vivo effect of probiotic Escherichia coli Nissle 1917 (EcN) on the stabilization of the intestinal barrier under healthy conditions, germfree mice were colonized with EcN or K12 E. coli strain MG1655. IECs were isolated and analyzed for gene and protein expression of the tight junction molecules ZO-1 and ZO-2. Then, in order to analyze beneficial effects of EcN under inflammatory conditions, the probiotic was orally administered to BALB/c mice with acute dextran sodium sulfate (DSS) induced colitis. Colonization of gnotobiotic mice with EcN resulted in an up-regulation of ZO-1 in IECs at both mRNA and protein levels. EcN administration to DSS-treated mice reduced the loss of body weight and colon shortening. In addition, infiltration of the colon with leukocytes was ameliorated in EcN inoculated mice. Acute DSS colitis did not result in an anion secretory defect, but abrogated the sodium absorptive function of the mucosa. Additionally, intestinal barrier function was severely affected as evidenced by a strong increase in the mucosal uptake of Evans blue in vivo. Concomitant administration of EcN to DSS treated animals resulted in a significant protection against intestinal barrier dysfunction and IECs isolated from these mice exhibited a more pronounced expression of ZO-1.Conclusion and SignificanceThis study convincingly demonstrates that probiotic EcN is able to mediate up-regulation of ZO-1 expression in murine IECs and confer protection from the DSS colitis-associated increase in mucosal permeability to luminal substances.

CXCL12 (SDF-1), a CXC-chemokine, and its specific receptor, CXCR4, have recently been shown to be involved in tumourgenesis, proliferation and angiogenesis. Therefore, we analysed CXCL12α/CXCR4 expression and function in four human kidney cancer cell lines (A-498, CAKI-1, CAKI-2, HA-7), 10 freshly harvested human tumour samples and corresponding normal kidney tissue. While none of the analysed tumour cell lines expressed CXCL12α, A-498 cells were found to express CXCR4. More importantly, real-time RT–PCR analysis of 10 tumour samples and respective adjacent normal kidney tissue disclosed a distinct and divergent downregulation of CXCL12α and upregulation of CXCR4 in primary tumour tissue. To prove that the CXCR4 protein is functionally active, rhCXCL12α was investigated for its ability to induce changes of intracellular calcium levels in A-498 cells. Moreover, we used cDNA expression arrays to evaluate the biological influence of CXCL12α. Comparing gene expression profiles in rhCXCL12α stimulated vs unstimulated A-498 kidney cancer cells revealed specific regulation of 31 out of 1176 genes tested on a selected human cancer array, with a prominent stimulation of genes involved in cell-cycle regulation and apoptosis. The genetic changes reported here should provide new insights into the developmental paths leading to tumour progression and may also aid the design of new approaches to therapeutic intervention. British Journal of Cancer (2002) 86 , 1250–1256. DOI: 10.1038/sj/bjc/6600221 www.bjcancer.com © 2002 Cancer Research UK

We evaluated the role of granulocyte colony-stimulating factor (G-CSF) in patients with severe aplastic anemia (SAA) treated with antithymocyte globulin (ATG) and cyclosporine (CSA). Between January 2002 and July 2008, 192 patients with newly diagnosed SAA not eligible for transplantation were entered into this multicenter, randomized study to receive ATG/ CSA with or without G-CSF. Overall survival (OS) at 6 years was 76% ؎ 4%, and event-free survival (EFS) was 42% ؎ 4%.No difference in OS/EFS was seen between patients randomly assigned to receive or not to receive G-CSF, neither for the entire cohort nor in subgroups stratified by age and disease severity. Patients treated with G-CSF had fewer infectious episodes (24%) and hospitalization days (82%) compared with patients without G-CSF (36%; P ‫؍‬ .006; 87%; P ‫؍‬ .0003). In a post hoc analysis of patients receiving G-CSF, the lack of a neutrophil response by day 30 was associated with significantly lower response rate (56% vs 81%; P ‫؍‬ .048) and survival (65% vs 87%; P ‫؍‬ .031). G-CSF added to standard ATG and CSA reduces the rate of early infectious episodes and days of hospitalization in very SAA patients and might allow early identification of nonresponders but has no effect on OS, EFS, remission, relapse rates, and mortality. This study was registered at www-.clinicaltrials.gov as NCT01163942. (Blood. 2011;117(17):4434-4441)

Rabbit antithymocyte globulin (rATG; thymoglobulin, Genzyme) in combination with cyclosporine, as first-line immunosuppressive therapy, was evaluated prospectively in a multicenter, European, phase 2 pilot study, in 35 patients with aplastic anemia. Results were compared with 105 age-and disease severitymatched patients from the European Blood and Marrow Transplant registry, treated with horse ATG (hATG; lymphoglobulin) and cyclosporine. The primary end point was response at 6 months. At 3 months, no patients had achieved a complete response to rATG. Partial response occurred in 11 (34%). At 6 months, complete response rate was 3% and partial response rate 37%. There were 10 deaths after rATG (28.5%) and 1 after subsequent HSCT. Infections were the main cause of death in 9 of 10 patients. The best response rate was 60% for rATG and 67% for hATG. For rATG, overall survival at 2 years was 68%, compared with 86% for hATG (P ‫؍‬ .009). Transplant-free survival was 52% for rATG and 76% for hATG (P ‫؍‬ .002). On multivariate analysis, rATG (hazard ratio ‫؍‬ 3.9, P ‫؍‬ .003) and age more than 37 years (hazard ratio ‫؍‬ 4.7, P ‫؍‬ .0008) were independent adverse risk factors for survival. This study was registered at www.clinicaltrials.gov as NCT00471848. (Blood. 2012;119(23): 5391-5396) IntroductionHistorically, horse antithymocyte globulin (hATG) has been the preferred animal source of ATG as first-line treatment for acquired aplastic anemia (AA) patients who are ineligible for hematopoietic stem cell transplantation (HSCT). For severe AA (SAA), the combination of ATG and cyclosporine (CSA) results in a response rate of 60% to 75% of patients, and the response is superior to using either agent alone. [1][2][3][4][5] The addition of G-CSF to the combination of ATG and CSA has shown no significant benefit either in terms of response or survival, 6-8 although it may reduce infectious complications and duration of hospital admission. 6 For patients with nonsevere AA (NSAA) who are transfusion dependent, the combination of ATG and CSA is superior to CSA alone, with a higher response rate, higher blood counts, and improved disease-free survival. 9 Rabbit ATG (rATG) is more commonly used for a second course after relapse or lack of response to a first course of hATG. Response to a second course for nonresponse to a first course varies from 30% to 77% 10,11 and only 11% in children. 12 In contrast, in patients relapsing after a first course, the response to a second course is 65%. 11,13 Until 2007, there were 2 preparations of hATG, namely, lymphoglobulin (Genzyme) and ATGAM (Pfizer). The most commonly used preparation of rATG (thymoglobulin, Genzyme) uses the same immunogen as lymophoglobulin; horses or rabbits are immunized with human thymocytes obtained at the time of cardiac surgery from newborn infants. rATG is more immunosuppressive than hATG; it results in more prolonged lymphopenia, 14 and it is more effective at preventing and treating acute renal allograft rejection. 15 We undertook a European study conducted by th...