Haplotype analysis of the SDF-1 (CXCL12) gene in a longitudinal HIV-1/AIDS cohort study

The stromal-derived factor-1 (SDF-1) chemokine gene encodes the only natural ligand for CXCR4, the coreceptor for the pathogenic X4 HIV-1 strains. A single-nucleotide polymorphism (SNP) in the 3' untranslated region (SDF1-3'A=rs1801157) of SDF-1 was reported to be protective against infection and progression in some, but not other, epidemiological studies. To identify additional alleles that may influence HIV-1 infection and progression to AIDS, nine SNPs (including rs1801157) spanning 20.2 kb in and around the SDF-1 gene were genotyped in over 3000 African American (AA) and European American (EA) participants enrolled in five longitudinal HIV-1/AIDS natural cohort studies. Six or five haplotypes were present at frequencies greater than 5% in AA or EA, respectively. Six of the nine SNPs occur on only one common haplotype (>5%), while the remaining three SNPs were found on multiple haplotypes, suggesting a complex history of recombination. Among EA, rs754618 was associated with an increased risk of infection (OR=1.50, P=0.03), while rs1801157 (=SDF1-3'A) was associated with protection against infection (OR=0.63, P=0.01). In the MACS cohort, rs1801157 was associated with AIDS-87 (RH=0.31, P=0.02) and with death (RH=0.18, P=0.02). Significant associations to a single disease outcome were found for two SNPs and one haplotype in AA.

Evaluation of red blood cells stored at -80 degrees C in excess of 10 years

BACKGROUND

RBCs frozen in 40 percent (wt/vol) glycerol are currently approved by the FDA and the AABB for storage at -80 degrees C for up to 10 years.

STUDY DESIGN AND METHODS

This study examined 20 RBC units that had been cryopreserved in 40 percent (wt/vol) glycerol and stored at -80 degrees C for up to 22 years. Measures of the freeze-thaw-wash (FTW) recovery, ATP, 2,3-DPG, methemoglobin, RBC indices, morphology, and osmotic fragility were made immediately after deglycerolization and after 24 hours of storage at 4 degrees C.

RESULTS

RBCs frozen for longer than 10 years had acceptable mean FTW recovery, normal oxygen transport function, RBC morphology, RBC indices, methemoglobin, and osmotic fragility. Statistical analysis indicated that the in-vitro viability and function of cryopreserved RBCs was not dependent on the length of frozen storage or postthaw storage at 4 degrees C but did correlate with the storage length at 4 degrees C before cryopreservation.

CONCLUSION

The data reported in this study demonstrate that RBCs can be stored at -80 degrees C beyond 10 years with acceptable in-vitro quality and suggest that more defined criteria for the cryopreservation process be adopted.

Electrochemical hydrodehalogenation of 2,4-dibromophenolin paraffin oil using a solid polymer electrolyte reactor

A new technology for remediation of halogenated organics-oil systems, which can cause serious environmental problems, has been demonstrated using the electrochemical hydrodehalogenation of 2,4-dibromophenol (DBP) in paraffin oil in a solid polymer electrolyte reactor. The reactor has been evaluated in terms of cathode materials and structure and the ratio of the cathode surface area to the solution volume. A cathode of titanium minimesh with a palladium electrocatalyst produced by electrodeposition was particularly effective. Current efficiencies of up to 85% and percentage of DBP removal of up to 62%, space-time yields of up to 7.6 kg DBP m(-3) h(-1), and energy consumption as low as 1.6 kW h (kg of DBP)(-1) were achieved. The reactor showed stable operation for periods of up to 170 h. The results demonstrated that electroreduction could be an alternative technology to electrooxidation forthe treatment of wastes and toxic halogenated compounds, making the process simpler in comparison to electrooxidation.

Analyses of nuclear ldhA gene and mtDNA control region sequences of Atlantic northern bluefin tuna populations

There has been considerable debate about whether the Atlantic northern bluefin tuna exist as a single panmictic unit. We have addressed this issue by examining both mitochondrial DNA control region nucleotide sequences and nuclear gene ldhA allele frequencies in replicate size or year class samples of northern bluefin tuna from the Mediterranean Sea and the northwestern Atlantic Ocean. Pairwise comparisons of multiple year class samples from the 2 regions provided no evidence for population subdivision. Similarly, analyses of molecular variance of both mitochondrial and ldhA data revealed no significant differences among or between samples from the 2 regions. These results demonstrate the importance of analyzing multiple year classes and large sample sizes to obtain accurate estimates when using allele frequencies to characterize a population. It is important to note that the absence of genetic evidence for population substructure does not unilaterally constitute evidence of a single panmictic population, as genetic differentiation can be prevented by large population sizes and by migration.