FACS technology used in a new rapid bacterial detection method

Culture methods for bacterial detection (BacT/ALERT or Pall eBDS) are currently implemented in blood donor screening procedures in many countries. Experience in the first years after implementation of these detection assays showed that although the analytical sensitivity was extremely high (about 1 CFU mL(-1)), the majority of these platelets were still transfused before a positive screening result was attained. Rapid technologies were developed to more effectively prevent transfusion-transmitted bacterial infection. In this study, a new rapid bacterial detection method based on fluorescence-activated cell sorting (FACS) technology was developed. Bacteria were stained with thiazole orange dye for 5 min and measurement was taken immediately after staining. The entire process took only 30 min. Six transfusion-relevant bacteria strains were tested in a spiking study. Without pre-incubation in a special bacteria growth medium, analytical sensitivity ranged between 10(5) CFU mL(-1) (Klebsiella oxytoca and Serratia marcesens) and 10(3) CFU mL(-1) (Escherichia coli). Sensitivity could be improved to 10(1) CFU mL(-1) for all tested bacteria by adding a pre-incubation step (6 h at 37 degrees C). Although preliminary in nature, results of our study suggest that bacterial detection by FACS technology in conjunction with a pre-incubation step offers a sensitive alternative technology to culture methods. Additionally, it provides the benefit of a rapid test time and the opportunity of preventing bacterial transmitted infections more effectively.     

Opportunities for small nutrition-related cancer research grants (R03) from the National Cancer Institute

Small research grants, or R03 grants, provide limited, short-term support for individual research projects. R03s may be an excellent means of support for projects by nutrition scientists at all stages in their careers. The National Cancer Institute (NCI) has awarded roughly one-half of all nutrition-related NIH R03 grants in the period from 2005 to 2010. A detailed review of the recent NCI grant portfolio identified potential strategies for successful applications. Projects that addressed important nutrition and cancer issues had feasible and appropriate specific aims, were innovative, and were based on sound concepts were most positively viewed by reviewers. Furthermore, applicants with suitable expertise, training, mentorship, and records of accomplishment who, when appropriate, collaborated with investigators with complementary knowledge and skills were more likely to receive higher priority scores.     

Mobilized allogeneic peripheral stem/progenitor cell apheresis with Spectra Optia v.5·0, a novel, automatic interface-controlled apheresis system: results from the first feasibility trial

Background and Objectives G‐CSF mobilized peripheral blood stem/progenitor cells are frequently used for allogeneic transplantation. Available manual apheresis systems generate stem cell products of consistently high quality. Short‐comings include need for continuous interface monitoring/adjustment, interface instability in donors with inconsistent blood flow, high collection variability, high platelet loss, and failure to electronically document apheresis parameters. Material and Methods A fundamentally different, novel apheresis system, Spectra Optia v.5·0, featuring optical sensors, which provide real‐time automatic interface and product collect line control, and newly developed tubing sets, was designed to address these short‐comings. In a prospective validation study, 30 healthy volunteer stem cell donors were subjected to apheresis with Spectra Optia to test feasibility and effectiveness. Results were compared to 608 historic first‐day allogeneic aphereses with COBE Spectra MNC. Results Usability and function of automatic interface control of Spectra Optia were good. Most collection parameters, including collection efficiency and product size, were similar. Cells were viable and provided timely engraftment. Platelet loss with Spectra Optia was 25% less than with COBE Spectra MNC. Products contained fewer erythrocytes, but more granulocytes. Conclusion The automatic apheresis system Spectra Optia is functional and user‐friendly. Thus Spectra Optia aphereses are associated with similar, and equally variable, collection efficiencies as COBE Spectra MNC.     

Dietary Selenium Levels Affect Selenoprotein Expression and Support the Interferon-γ and IL-6 Immune Response Pathways in Mice

Selenium is an essential element that is required to support a number of cellular functions and biochemical pathways. The objective of this study was to examine the effects of reduced dietary selenium levels on gene expression to assess changes in expression of non-selenoprotein genes that may contribute to the physiological consequences of selenium deficiency. Mice were fed diets that were either deficient in selenium or supplemented with selenium in the form of sodium selenite for six weeks. Differences in liver mRNA expression and translation were measured using a combination of ribosome profiling, RNA-Seq, microarrays, and qPCR. Expression levels and translation of mRNAs encoding stress-related selenoproteins were shown to be up-regulated by increased selenium status, as were genes involved in inflammation and response to interferon-γ. Changes in serum cytokine levels were measured which confirmed that interferon-γ, as well as IL-6, were increased in selenium adequate mice. Finally, microarray and qPCR analysis of lung tissue demonstrated that the selenium effects on immune function are not limited to liver. These data are consistent with previous reports indicating that adequate selenium levels can support beneficial immune responses, and further identify the IL-6 and interferon-γ pathways as being responsive to dietary selenium intake.     

Frequencies of GB virus C/hepatitis G virus genomes and of specific antibodies in German risk and non-risk populations

The prevalence of the new flavivirus GB virus C/hepatitis virus G (GBV-C/HGV) in different German populations was investigated by detection of viral genomes and anti-E2 antibodies. While blood donors had an overall prevalence of 10.4% there were increased rates for hemophiliacs (54.7%), hemodialysis patients (30.2%), male homosexuals (30.2%) and intravenous drug users (74.4%). Most GBV-C/HGV positive samples were either viral genome positive or antibody positive, exclusively. Samples with the rare constellation “positive for both GBV-C/HGV genome and specific antibody” originated in almost all cases from patients who were additionally infected with HIV or HCV. Probable transmission of GBV-C/HGV by PCR-positive blood transfusions was observed in 5 of 6 cases approximately six months after transfusion. J. Med. Virol. 53:218–224, 1997. © 1997 Wiley-Liss, Inc.     

Impact of pharmacokinetic (CYP2C9) and pharmacodynamic (VKORC1, F7, GGCX, CALU, EPHX1) gene variants on the initiation and maintenance phases of phenprocoumon therapy

Compared to warfarin, little is known about the effect of pharmacogenomics on the inter-individual variability of phenprocoumon therapy. In a retrospective cohort study, we investigated the impact of VKORC1 c.-1639G>A; CYP2C9*2 , CYP2C9*3 ; GGCX c.214+597G>A; CALU c.*4A>G; EPHX1 c.337T>C; F7 c.-402G>A, and F7 c.-401G>T on the initiation (n=54) and maintenance phases (n=91) of phenprocoumon therapy. We assessed the following outcome parameters: time to stable international normalised ratio (INR), time to first supra-therapeutic INR, time out of INR range, probability of over-anticoagulation, number of anticoagulation clinic visits. During the initiation phase, homozygotes for the VKORC1 c.-1639 A and G alleles achieved stable INRs later (p<0.001), spent more time at supra-therapeutic INRs (p<0.001), had increased risks of over-anticoagulation (odds ratio 19.83, p=0.003 and 4.45, p=0.045, respectively), and had higher frequencies of anticoagulation clinic visits (p<0.001) compared to GA carriers. CYP2C9*2, *3 carriers reached stable INRs faster (p=0.024) with fewer anticoagulation clinic visits (p=0.001) than wild-type carriers. EPHX1 c.337 C carrier spent significantly more time above range in the initiation phase (p=0.023). GGCX , CALU , and F7 gene variants did not affect outcome parameters of the initiation phase and none of the genotypes had an impact on maintenance phase parameters. Compared to the VKORC1 genotype, early INR values were less informative in the prediction of outcome parameters such as time to stable INR and time above the INR range. Our study is limited by the retrospective study design with no standardised protocol in a usual care setting. Therefore, our findings should be validated in a larger, controlled prospective study.     

Intergenic recombination with HLA-C leads to a novel HLA-A*19 allele, HLA-A*2910, that is characterized by a functionally inactive amino acid exchange in the loop connecting the alpha and alpha domains

This report describes the HLA-A*29 allele (A*2910) that has been identified by sequence-based typing in an 8-year-old Turkish female with leukaemia during search for a family-related stem cell donor. The allele is characterized by a nucleotide substitution (Guanine to Adenine) in exon 3 at position 258, leading to an amino acid exchange from glutamic acid to lysine at position 177. From family analysis and sequence comparison, the HLA-A*2910 allele has arisen from intergenic recombination with HLA-C. Structurally, the amino acid exchange at position 177 is probably functionally inactive due to the location of this amino acid exchange in the loop connecting the alpha(2) and alpha(3) domains.     

Quantitation of Staphylococcus aureus in Seawater Using CHROMagar? SA

A microbiological algorithm has been developed to analyze beach water samples for the determination of viable colony forming units (CFU) of Staphylococcus aureus (S. aureus). Membrane filtration enumeration of S. aureus from recreational beach waters using the chromogenic media CHROMagar™SA alone yields a positive predictive value (PPV) of 70%. Presumptive CHROMagar™SA colonies were confirmed as S. aureus by 24-hour tube coagulase test. Combined, these two tests yield a PPV of 100%. This algorithm enables accurate quantitation of S. aureus in seawater in 72 hours and could support risk-prediction processes for recreational waters. A more rapid protocol, utilizing a 4-hour tube coagulase confirmatory test, enables a 48-hour turnaround time with a modest false negative rate of less than 10%.