Anti-benzo[a]pyrene diolepoxide--DNA adduct levels in peripheral mononuclear cells from coke oven workers and the enhancing effect of smoking

The level of (+/-)-r-7,t-8-dihydroxy-t-9,10-oxy-7,8,9,10-tetrahydrobenzo[a]pyrene (anti-BPDE) bound to DNA of lymphocytes plus monocytes in 39 coke oven workers exposed to polycyclic aromatic hydrocarbons (PAH) and 39 non-exposed persons (controls) were investigated, each of the groups consisting of smokers and non-smokers. The adduct level was measured by an improved HPLC/fluorescence method (Rojas, M., Alexandrov, K., van Schooten, F. J., Hillebrand, M., Kriek, E. and Bartsch, H., Carcinogenesis, 15, 557-560, 1994) through the release of the corresponding benzo[a]pyrene (B[a]P) tetrols. The anti-BPDE-DNA adduct was detected in 51% of coke oven workers exposed to PAH and in 18% of the non-exposed (control) subjects. The mean level of anti-BPDE-DNA adducts/10(8) nucleotides in coke oven workers (15.7 +/- 37.8) was approximately 8 times higher than in non-exposed subjects (2.0 +/- 8.7). The interindividual variation of adduct levels was approximately 100-fold in coke oven workers and approximately 50-fold in controls respectively. Smokers in the exposed group had 3.5 times more DNA adducts than non-smokers. With the exception of one non-smoker with very high adduct levels (52.8 adducts/10(8)), the control subjects showed the presence of barely detectable adducts in only 16% of the samples examined. The increased in vivo formation in some smokers and high variability of anti-BPDE-DNA adducts in coke oven workers suggests variations in genetically controlled activation/inactivation reactions of PAH metabolism.     

Recursive pyramids and their use for image coding

Recursive pyramidal image representation in image coding algorithms through the use of the pyramid structure, and recursive two-dimensional scannings are introduced. Two approaches to the decorrelation of the picture elements in such a data structure are considered. Properties of different two-dimensional scannings as well as statistical properties of the recursive pyramid and their use for the development of image coding algorithms are shown. Experimental results demonstrating the achieved compression ratio and distortions are provided.     

A note on the limit load of welded joints of a rectangular cross-section

A flat layer of a rigid perfectly plastic material subjected to tension between two rigid blocks is considered. The layer is assumed to have a rectangular cross-section. The influence of the ratio of the in-plane layer dimensions on the limit load and the maximum tensile stress is studied. Comparison with numerical calculations of the limit load based on the assumption of the plane strain conditions is made.     

Effect of constitutive laws on plane strain ideal flow design: an analytical example

Summary. The major objective of this paper is to clarify the effect of constitutive laws on bulk forming design based on the ideal flow theory. The latter theory is in general applicable for perfectly/plastic materials. However, its kinematics equations constitute a closed-form system, which are valid for any incompressible materials, therefore enabling us to extend design solutions based on the perfectly/plastic constitutive law to more realistic laws with rate sensitive hardening behavior. In the present paper, several constitutive laws commonly accepted for the modeling of cold and hot metal forming processes are considered and the effect of these laws on one particular plane strain design is demonstrated. The closed form solution obtained describes a nontrivial nonsteady ideal process. The design solutions based on the ideal flow theory are not unique. To achieve the uniqueness, the criterion that the plastic work required to deform the initial shape of a given class of shapes into a prescribed final shape attains its minimum is adopted. Comparison with a non-ideal process is also made.     

Dangerous Stops: Nonsense Mutations Can Dramatically Increase Frequency of Prion Conversion

Amyloid formation is associated with many incurable diseases. For some of these, sporadic cases are much more common than familial ones. Some reports point to the role of somatic cell mosaicism in these cases via origination of amyloids in a limited number of cells, which can then spread through tissues. However, specific types of sporadic mutations responsible for such effects are unknown. In order to identify mutations capable of increasing the de novo appearance of amyloids, we searched for such mutants in the yeast prionogenic protein Sup35. We introduced to yeast cells an additional copy of the SUP35 gene with mutated amyloidogenic domain and observed that some nonsense mutations increased the incidence of prions by several orders of magnitude. This effect was related to exposure at the C-terminus of an internal amyloidogenic region of Sup35. We also discovered that SUP35 mRNA could undergo splicing, although inefficiently, causing appearance of a shortened Sup35 isoform lacking its functional domain, which was also highly prionogenic. Our data suggest that truncated forms of amyloidogenic proteins, resulting from nonsense mutations or alternative splicing in rare somatic cells, might initiate spontaneous localized formation of amyloids, which can then spread, resulting in sporadic amyloid disease.     

The feasibility of MS and advanced data processing for monitoring Schistosoma mansoni infection

Purpose : Sensitive diagnosis, monitoring of disease progression and the evaluation of chemotherapeutic interventions are of prime importance for the improvement of control and prevention strategies for Schistosomiasis. The aim of the present study was to identify novel markers of Schistosoma mansoni infection and disease using urine samples from a large cohort from an area endemic for S. mansoni. Experimental design : Urine samples were collected and processed on an automated sample clean‐up and fractionation system combining strong cation exchange and reversed phase, and analyzed by MS (MALDI ToF MS). The ClinPro Tools^? (CPT) software and the Discrete Wavelet Transformation–Support Vector Machine (DWT‐SVM) procedure were used for classification and statistical analysis. Results : We observed a large difference in urinary peptide profiles between children and adults but classification based on infection was possible only for children. Here, in the external validation data set, 93% of the infected children were classified correctly with DWT‐SVM (versus 76% for CPT). In addition 91% of low‐infected children were classified correctly using DWT‐SVM (versus 85% for CPT). The discriminating peptides were identified as fragments of collagen 1A1 and 1A3, and uromodulin. Conclusions and clinical relevance : In conclusion, we provide the usefulness of a peptidomics profiling approach combined with DWT‐SVM in the monitoring of S. mansoni infection.     

SARFing the PDB

Fast growth of the number of the solved protein structures isincreasing the role of their comparative analysis. In this paperI describe a new program, SARF2, for protein structure comparisonand discuss new examples of the non-topological structural resemblance.SARF2 is designed to detect ensembles of secondary structureelements, which form similar spatial arrangements with possibledifferent topological connections. The program is availableto everyone through the World Wide Web (URL http://wwwhnmb.ncifcrf.gov/{small tilde}nicka/sarf2.html). The performance of the programis demonstrated by previously unnoticed cases of the significantsimilarities. One similarity discussed in this paper, betweenheme-binding proteins (cytochrome P450 and globin), consistsof six -helices, arranged into a globin fold. Another pair ofstructures (pectate lyase and snowdrop lectin) achieve similarß-prism architecture through different topologies.The significance of these similarities is validated by (i) thedistribution of a similarity score, (ii) the comparison of thealigned contact maps and/or (iii) the location of the activesite. The observation of recurrent non-topological structuralmotifs implies their energetic stability and opens new possibilitiesfor sequence-structure alignment (threading) methods.     

Upper critical field of high-T c oxides: Evidence for 2e Bose liquid

We measure and theoretically describe the upper critical field, H_c ²(T), of BSCCO — 2212 crystals with T_c > 92K by the use of the out-of-plane resistivity in magnetic fields (H ab) up to 15T. The empirical procedure is proposed allowing us to extrapolate the H_c ²(T) curve up to H_c ² 230T and t/t _c 0.35 which is independent of the choice of the R/R_N ratio. We found that H_c2(T) does not follow the conventional theory with or without fluctuations and the magnetic scattering, but is consistent with the prediction based on the Bose-Einstein condensation of charged bosons formed aboveT _c . Our results together with several other measurements of H _c 2 and with the heat capacity data provide an evidence for the possibility of 2 _e Base liquid ground state of high-T _c oxides.We highly appreciate the enlightening discussions with Sir Nevill Mott, P. Edwards, J. Cooper, N. Hussey, J. Loram, A. Mackenzie, and K. Ziebeck.