Ex vivo culture of cord blood CD34+ cells expands progenitor cell numbers, preserves engraftment capacity in nonobese diabetic/severe combined immunodeficient mice, and enhances retroviral transduction efficiency

Ex vivo culture of hematopoietic stem/progenitor cells could potentially improve the efficacy of human placental/umbilical cord blood (CB) in clinical hematopoietic stem cell (HSC) transplantation and allow gene transduction using conventional retroviral vectors. Therefore, we first examined the effects of a 7-day period of ex vivo culture on the hematopoietic capacity of CB CD34+ cells. Medium for the ex vivo cultures contained either serum and six recombinant human hematopoietic growth factors (GFs), including Flt-3 ligand (FL), Kit ligand (KL = stem cell factor), thrombopoietin (Tpo), interleukin 3 (IL-3), granulocyte colony-stimulating factor (G-CSF), and interleukin 6 (IL-6), or a serum-free medium containing only FL, KL, and Tpo. After culture under both ex vivo conditions, the total numbers of viable cells, CD34+ cells, colony-forming cells (CFCs), and long-term culture initiating cells (LTC-ICs) were increased. In contrast, the severe combined immunodeficiency (SCID) mouse engrafting potential (SEP) of cultured cells was slightly decreased, as compared with fresh cells. Nevertheless, cultured human CB CD34+ cells were able to generate engraftment, shown to persist for up to 20 weeks after transplantation. We next tested the efficacy of retroviral transduction of cultured cells. Transduced cultured human cells were able to engraft in NOD/SCID mice, as tested 4 weeks after transplantation, and EGFP+CD34+ cells and EGFP+ CFCs were isolated from the chimeras. Thus, although additional improvements in ex vivo culture are still needed to expand the numbers and function of human HSCs, the current conditions appear to allow gene transduction into hematopoietic SCID engrafting cells, while at least qualitatively preserving their in vivo engraftment potential.     

Interactions between triazoles and amphotericin B against Cryptococcus neoformans

The interaction of amphotericin B (AmB) and azole antifungal agents in the treatment of fungal infections is still a controversial issue. A checkerboard titration broth microdilution-based method that adhered to the recommendations of the National Committee for Clinical Laboratory Standards was applied to study the in vitro interactions of AmB with fluconazole (FLC), itraconazole (ITC), and the new investigational triazole SCH 56592 (SCH) against 15 clinical isolates of Cryptococcus neoformans. Synergy, defined as a fractional inhibitory concentration (FIC) index of < or =0.50, was observed for 7% of the isolates in studies of the interactions of both FLC-AmB and ITC-AmB and for 33% of the isolates in studies of the SCH-AmB interactions; additivism (FICs, >0.50 to 1.0) was observed for 67, 73, and 53% of the isolates in studies of the FLC-AmB, ITC-AmB, and SCH-AmB interactions, respectively; indifference (FICs, >1.0 to < or =2.0) was observed for 26, 20, and 14% of the isolates in studies of the FLC-AmB, ITC-AmB, and SCH-AmB interactions, respectively. Antagonism (FIC >2.0) was not observed. When synergy was not achieved, there was still a decrease, although not as dramatic, in the MIC of one or both drugs when they were used in combination. To investigate the effects of FLC-AmB combination therapy in vivo, we established an experimental model of systemic cryptococcosis in BALB/c mice by intravenous injection of cells of C. neoformans 2337, a clinical isolate belonging to serotype D against which the combination of FLC and AmB yielded an additive interaction in vitro. Both survival and tissue burden studies showed that combination therapy was more effective than FLC alone and that combination therapy was at least as effective as AmB given as a single drug. On the other hand, when cells of C. neoformans 2337 were grown in FLC-containing medium, a pronounced increase in resistance to subsequent exposures to AmB was observed. In particular, killing experiments conducted with nonreplicating cells showed that preexposure to FLC abolished the fungicidal activity of the polyene. However, this apparent antagonism was not observed in vivo. Rather, when the two drugs were used sequentially for the treatment of systemic murine cryptococcosis, a reciprocal potentiation was often observed. Our study shows that (i) the combination of triazoles and AmB is significantly more active than either drug alone against C. neoformans in vitro and (ii) the concomitant or sequential use of FLC and AmB for the treatment of systemic murine cryptococcosis results in a positive interaction.     

Protocol for prenatal diagnosis of cystic fibrosis based on studies of alkaline phosphatase isoenzymes

Amniotic fluid analysis of microvillar enzymes, including alkaline phosphatase (ALP) total activity and ALP isoenzymes, has been widely experimented with and used for the prenatal diagnosis of cystic fibrosis in the second trimester of gestation. Since the development of cystic fibrosis molecular analysis, interest in these biochemical tests has been maintained for those instances in which the pregnancy is not fully informative by restriction fragment length polymorphism analysis or DNA is not available from the index-affected child. However, recommended biochemical protocols do not provide clear-cut diagnostic results in a minority of cases. We have tested the reliability of cystic fibrosis biochemical prediction by ALP high-resolution electrophoresis and ALP kinetic studies after inactivation by urea. With this approach, all the amniotic fluid samples that had not been unambiguously classified as affected or unaffected by standard microvillar enzymes analysis were definitely categorized. The proposed method seems to improve the diagnostic accuracy in pregnancies with a one in four risk of resulting in a child with cystic fibrosis.     

In vitro activity of moxifloxacin compared to other fluoroquinolones against different erythromycin-resistant phenotypes of group A beta-hemolytic streptococcus

The aim of the present study was to evaluate the in vitro activity of moxifloxacin (BAY 12-8039) compared to ciprofloxacin, ofloxacin and sparfloxacin against 156 group A beta-hemolytic Streptococcus strains. Sixty strains were macrolide-, lincosamide- and streptogramin-B-susceptible; 16 strains exhibited a constitutive resistance phenotype; 32 strains exhibited an inducible phenotype, and 48 strains were characterized by the M-type efflux-dependent phenotype. The minimum inhibition concentrations were determined by an agar dilution method according to NCCLS-approved guidelines. Moxifloxacin showed an enhanced activity compared with the other fluoroquinolones against the different macrolide-resistant phenotypes.     

Cytokine Level Modifications: Molecular Adsorbent Recirculating System Versus Standard Medical Therapy

Introduction

Acute-on-chronic liver failure (ACLF) is a systemic inflammatory reaction, which is characterized by a predominantly proinflammatory cytokine profile, causing the transition from stable cirrhosis to ACLF. The aim of the present study was to evaluate the changes in several cytokines associated with inflammatory liver disease and liver regeneration among 15 ACLF patients treated with the Molecular Adsorbent Recirculating System (MARS) compared with 15 patients treated with standard medical therapy (SMT). The subjects showed various disease etiologies but similar values for Model End-stage Liver Disease scores.

Methods

In the MARS group, 15 (10 male and 5 female) patients were treated with MARS (Gambro). The number of MARS applications was nine; the length of applications was 8 hours. In the SMT group; 15 (10 male and 5 female) patients were treated with SMT. The patients were monitored for 30 days from inclusion with a survival follow-up at 3 months. Statistical results were calculated with SPSS14.0 (SPSS Inc, Chicago, Ill). A P < .07 was considered significant.

Results

In the MARS group, we observed significant changes in the levels of Interleukin (IL)-6, IL-1, IL-10, and tumor necrosis factor (TNF)-α in association with improved hepatocyte growth factor. Patient survival at 3 months was 60%. The SMT group showed only a significant change in TNF-α (P = .03). Patient survival at 3 months was 30%.

Conclusion

The MARS liver support device corrected pathophysiologies of ALF and may be used to enhance spontaneous recovery or as a bridge to transplantation.     

Autoimmune pancreatitis: clinical and radiological features and objective response to steroid therapy in a UK series

OBJECTIVE: Most cases of autoimmune pancreatitis (AIP) have been reported from Japan. We present data on a UK series, including clinical and radiological features at presentation, and longitudinal response to immunosuppression. METHODS: Over an 18-month period, all patients diagnosed in our center with AIP were studied. Endoscopic biliary stenting was performed as required, and patients were treated with prednisolone, with response assessed longitudinally. In cases of disease relapse following steroid reduction, azathioprine was instituted. RESULTS: Eleven patients met diagnostic criteria for AIP. Diffuse pancreatic enlargement was seen in eight patients (73%), and pancreatic duct strictures in all. Seven patients required biliary stents. Extrapancreatic involvement occurred in all, including intrahepatic stricturing and renal disease. Eight weeks after starting steroids, the median serum bilirubin level had fallen from 38 mumol/L to 11 mumol/L (P= 0.001), and ALT from 97 IU/L to 39 IU/L (P= 0.002). Stents were removed in all cases, with no recurrence of jaundice. Improvements in mass lesions and pancreaticobiliary stricturing occurred in all patients. During a median 18-month follow-up, six patients relapsed, four of whom responded to azathioprine. Two patients discontinued steroids and remained well. CONCLUSIONS: Extrapancreatic disease was an important feature of AIP in this UK series. Initial response to immunosuppressive therapy was excellent, but disease relapse was common. Optimal long-term management remains to be established.