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The use of bi-allelic markers such as retrotransposable element insertion polymorphisms or Innuls (for insertion/null) can overcome some limitations of short tandem repeat (STR) loci in typing forensic biological evidence. This study investigated the efficiency of the InnoTyper® 21 Innul markers in an urban admixed population sample in Rio de Janeiro ( n = 40) and one highly compromised sample collected as evidence by the Rio de Janeiro police. No significant departures from Hardy-Weinberg equilibrium were detected after the Bonferroni correction ( α′ ≈ 0.05/20, p < 0.0025), and no significant linkage disequilibrium was observed between markers. Assuming loci independence, the cumulative random match probability (RMP) was 2.3 × 10. A lower mean Fis value was obtained for this sample population compared with those of three North American populations (African-American, Southwest Hispanic, US Caucasian). Principal component analysis with the three North American populations and one from 21 East Asian population showed that African Americans segregated as an independent group while US Caucasian, Southwest Hispanic, East Asian, and Rio de Janeiro populations are in a single large heterogeneous group. Also, a full Innuls profile was produced from an evidence sample, despite the DNA being highly degraded. In conclusion, this system is a useful complement to standard STR kits. [ABSTRACT FROM AUTHOR]

Summary. Phospholipase A2 (PLA2) controls the metabolism of phospholipids in cell membranes. In the brain, PLA2 influences the processing of the amyloid precursor protein (APP) and thus the production of the amyloid-beta peptides (Aβ), which are the major components of the senile plaques in Alzheimer’s disease (AD). Reduced PLA2 activity has been reported in brain and in platelets of AD patients. In the present study we investigated PLA2 activity in platelets from 21 AD patients as compared to 17 healthy elderly controls and 11 individuals with mild cognitive impairment (MCI). Subjects were cognitively assessed by the Mini-Mental State Examination (MMSE) and the CAMDEX schedule. Platelet PLA2 activity was determined by radio-enzymatic assay, which mainly detected a calcium-independent form of the enzyme present also in the brain (iPLA2). PLA2 activity was significantly lower in AD than in controls (p < 0.001). Mean PLA2 activity in MCI individuals was between the values of AD patients and controls, with a subgroup showing PLA as low as the lowest AD patients, but the differences from MCI were not significant from AD and control groups. Lower PLA2 activity was significantly correlated with a worse cognitive performance both at the MMSE (p = 0.001) and the cognitive sub-scale of the CAMDEX inventory (p = 0.002). Our data replicate previous findings of reduced platelet PLA2 activity in AD. Both reduced PLA2 activity and the correlation with impaired cognition were also reported in brain tissue of AD patients, suggesting thus that the present determinations in platelets may be related to a reduction in the brain. In the brain the inhibition of PLA2 inhibits the physiological secretion of the APP, a mechanism that increases Aβ formation. Further longitudinal studies should investigate whether those MCI individuals with the lowest PLA2 values in platelets would be at a higher risk to develop AD during a longitudinal follow up. [ABSTRACT FROM AUTHOR]

The past 10years have witnessed dramatic progress in our understanding of how natural killer (NK) cells function and their role in innate immunity. Thanks to an array of inhibitory receptors specific for different HLA class I molecules, human NK cells can sense the decrease or loss of even single alleles at the cell surface. This represents a typical condition of a potential danger, i.e. the presence of tumor or virally infected cells. NK cell triggering and lysis of these cells is mediated by several activating receptors and coreceptors that have recently been identified and cloned. While normal cells are usually resistant to NK-mediated attack, a remarkable exception is represented by dendritic cells (DCs). In their immature form they are susceptible to NK-mediated lysis because of the expression of low levels of surface HLA class I molecules. The process of DC maturation (mDCs) is characterized by the surface expression of high levels of HLA class I molecules. Accordingly, mDCs become resistant to NK cells. A recent major breakthrough highlighted the role played by donor NK cells in allogenic bone marrow transplantation to cure acute myeloid leukemias. ‘Alloreactive’ NK cells derived from donor hematopoietic precursors not only prevented leukemic relapses, but also prevented graft rejection and graft-versus-host disease. [ABSTRACT FROM AUTHOR]

The oxidation of Ni-2.05Si and Ni-4.45Si was studied in oxygen over the range of 600°-1000°C for 18 hr. The oxidation kinetics did not follow a parabolic rate law, bur rather a power law of the form (Δw)=kt was followed. The value of n ranged from 2.7 to 4.9 for Ni-2.05Si and from 3.0 to 6.4 for Ni-4.45Si. The low-silicon alloy exhibited extensive internal oxidation, whereas the higher-silicon alloy did not internally oxidize. In general, NiO containing little or no silicon formed as an exterior layer on both alloys. The internal oxidation zone in Ni-2.05Si was highly irregular in thickness, and in some areas there was no internal oxidation. The higher-silicon alloy formed a continuous layer of a silicon-rich oxide. X-ray diffraction did not detect silica (amorphous), and no evidence of NiSiO was observed, although EDAX analysis suggests that small amounts of the silicate might have formed. The average thickness of the internal oxidation zone was found to agree well with calculated values based on oxygen solubility and diffusivity data. No enrichment of silicon occurred in the internal oxidation zone. Calculated values, 0.033 and 0.038 (depending on the model used), of the mole fraction of silicon required for the transition from internal oxidation to continuous silica film formation agreed well with experimental data obtained in both this study and with others reported in the literature. [ABSTRACT FROM AUTHOR]