Mutations in the Escherichia coli katF gene (hydroperoxidase II) result in sensitivity to inactivation by H202 and broad-spectrum near-UV (NUV; 300 to 400 nm) radiation. Another mutation, nur, originally described as conferring sensitivity to inactivation by broad-spectrum and monochromatic NUV, also confers sensitivity to inactivation by H202. Genetic analysis via transduction suggests that the nur mutation is a mutant allele of the katF locus. As previously reported for broad-spectrum and monochromatic NUV wavelengths, the sensitivity of a particular strain to H202 inactivation is also independent of the recA and uvrA alleles. Extracts of nur and katF strains lack catalase (hydroperoxidase II) as revealed by polyacrylamide gels stained for such activity, which is consistent with the genetic results.The mutagenic and inactivating effects of both monochromatic and broad-spectrum near-UV (NUV) wavelengths (300 to 400 nm) have been the subject of numerous investigations, which have been extensively reviewed (10,13,17,18,40).A mutation in an Escherichia coli gene (nur) has been described which sensitizes cells to inactivation by NUV without affecting sensitivity to far-UV (FUV) inactivation (35-37). Specifically, it was shown that the recA13, recAl, and uvrA6 mutations did not affect the sensitivity of stationary-phase cells to NUV inactivation. However, the polAl mutation did influence the sensitivity of E. coli cells to inactivation by NUV in an nur+ genetic background (36). The fact that the polAl mutation sensitizes E. coli to NUV inactivation and that E. coli xthA mutants (exonuclease III deficient) are sensitive to inactivation by H202 (8) and NUV (31) might mean that repair of or protection against NUVand H202-induced damage is based on a complex oxidative defense system (4).Further evidence that H202 is involved in NUV inactivation comes from the observation that incorporation of bovine catalase into the plating medium or the irradiated cell suspension protects E. coli cells from both inactivation and mutagenesis by broad-spectrum NUV (32). Hartman (14) has also presented evidence that H202 is involved with NUV inactivating events in stationary-phase E. coli cells.Pretreatment of E. coli or Salmonella typhimurium cells with a sublethal concentration of H202 results in protection against inactivation by a lethal concentration of H202 (4, 7) as well as by broad-spectrum NUV (33, 39). Tyrrell (39) has shown that pretreatment of growing E. coli cells with low fluences of NUV protects against inactivation by H202. If H202 were one product of NUV irradiation in cells, it would be expected that cells lacking catalase should be sensitive to inactivation by NUV. Recently, Leowen and his colleagues have described mutants which are defective in catalase activity (21)(22)(23). In this paper, we present evidence that lesions in the katF gene, but not the katE or katG gene, result in sensitivity to broad-spectrum NUV as well as to * Corresponding author.

Significant morbidities are associated with the routine administration of blood products. Although the exact etiology of these complications may be unknown, many are thought to arise from the incidental cotransfusion of “donor” lymphocytes. We have developed an assay to detect small numbers of male white blood cells (WBCs) circulating in female patients who have received multiple blood transfusions using the polymerase chain reaction (PCR). Twenty female patients undergoing major surgical procedures were studied and received an average of 9.3 U of packed red blood cells (4.8 U from male donors) and 11.7 U of platelets (6.1 U from male donors). DNA was extracted from whole blood or peripheral blood buffy coats posttransfusion and PCR performed using oligonucleotides designed to amplify a segment within the repetitive Y- chromosome DYZ1 locus. Posttransfusion, 15 of 20 women showed evidence of circulating male WBCs for an average of 2.0 days (range, 1 to 6). We conclude that (1) DYZ1 PCR analysis is a useful approach for the detection of small numbers of circulating transfused male WBCs in female patients; and (2) circulating donor WBCs persist for a mean of 2.0 days in the majority of women receiving multiple transfusions. Future application of this technique may detect persisting or proliferating WBCs and lead to an improved understanding of common transfusion-related morbidities.

The third-generation bedside filter used in this study reliably reduced the level of white cell contamination to 4 log10 white cells per PC. It also lowered the levels of interleukin 8, RANTES, and C3a. The filter did not, however, remove (scavenge) the proinflammatory cytokines interleukin 1 beta and 6. The mechanism of chemokine and C3a removal by the filter is unknown, but it may be related to ionic interactions between these biologic response modifiers and the filter medium.

Some, but not all, bedside polyester filters and prestorage polyester filters can remove IL-8, RANTES, C3a, and C5a from units of plasma or platelets. Improved biomaterial engineering of these and other filters could maximize scavenging of BRMs and potentially diminish the adverse reactions associated with their infusion during transfusion.

Summary:We describe here a patient who died of progressive CNS deterioration following allogeneic stem cell transplant with West Nile virus as the sole pathogen on the cerebrospinal fluid and brain tissue analysis. A 50-yearold male with Philadelphia chromosome-positive acute lymphocytic leukemia (ALL) underwent allogeneic PBSCT from his HLA identical sister. After engraftment, the patient developed fever with progressive and ultimately fatal neurological deterioration. Imaging studies of the brain including CT and MRI scans were remarkable for mild low attenuation lesions of the white matter. CSF analysis was negative for neoplastic cells, bacteria, AFB, CMV, HSV, fungal infections and leukemic relapse. However, serological analysis of both the serum and CSF was positive for West Nile virus-specific IgM antibodies. At autopsy, West Nile virus PCR and cultures were positive in the mid-brain tissue. Electron micrographs showed evidence of viral particles. Given the recent increase in the spread of West Nile virus infections and the increased susceptibility of BMT patients to infectious complications, West Nile virus encephalitis should be considered in patients undergoing transplantation.

Susceptibility of red blood cells (RBC) to hemolysis under mechanical stress is represented by RBC mechanical fragility (MF), with different types or intensities of stress potentially emphasizing different perturbations of RBC membranes. RBC membrane mechanics were shown to depend on cell environment, with many details not yet understood. Here, stress was applied to RBC using a bead mill with oscillation up to 50 Hz, over durations up to 50 minutes. MF profiles plot percent lysis upon stresses of progressive durations. Supplementing media with polyethylene glycol (PEG) which interacts with the cell membrane, but not Dextran which does not, resulted in higher resistance to hemolysis. Albumin, and to a lesser extent fibrinogen and globulins (at physiological concentrations), significantly increased cell ability to withstand mechanical stress versus with un-supplemented buffer solution and with PEG. This is partly due to changes in rheology, per tests done including (PEG) and Dextran, but is mostly due to cell-protein interaction, noting the effect of pH on RBC MF with albumin but not with buffer. Presence of lipids reduced RBC resistance to potentially hemolytic stress with lypemic plasma effecting lower "protection" from induced hemolysis than essentially fatty-acid free plasma. This effect was less dependent on incubation than on fatty-acid presence during stressing. The reduced propensity for hemolysis afforded by plasma proteins also depended markedly on the speed of the bead, potentially reflecting changes from a predominantly Von Karman trail at lower frequencies to an increasingly disorganized turbulent wake at higher frequencies.

The monocyte-specific chemotactic cytokine MCP-1 is produced by peripheral blood leukocytes in response to RBC incompatibility. MCP-1 may act in a positive feedback loop to recruit and activate monocytes during hemolytic transfusion reactions, thus contributing to the maintenance of these reactions.

We have determined the nucleotide sequences of the coding region in the last two coding exons of ABO genes (which occupy 91% of the soluble form of A1 transferase) from 7 individuals with weak subgroup phenotypes. Four of the individuals had an A3 phenotype and 3 individuals had a B3 phenotype. We determined the nucleotide sequences based on PCR followed by subcloning and DNA sequencing of the amplified fragments. Two cases of the A3 allele and 1 case of the B3 allele were found to contain a single-base substitution which resulted in an amino acid substitution. However, no other cases of A3 and B3 alleles were found to contain differences in this region. This finding demonstrates for the first time heterogeneity among these weak subgroups at the nucleotide level.