Chemistry and biochemistry of 4-hydroxynonenal, malonaldehyde and related aldehydes.

Although DNA is the carrier of genetic information, it has limited chemical stability. Hydrolysis, oxidation and nonenzymatic methylation of DNA occur at significant rates in vivo, and are counteracted by specific DNA repair processes. The spontaneous decay of DNA is likely to be a major factor in mutagenesis, carcinogenesis and ageing, and also sets limits for the recovery of DNA fragments from fossils.

Instability and decay of the primary structure of DNA

The literature on interference in the Stroop Color-Word Task, covering over 50 years and some 400 studies, is organized and reviewed. In so doing, a set of 18 reliable empirical finding is isolated that must be captured by any successful theory of the Stroop effect. Existing theoretical positions are summarized and evaluated in view of this critical evidence and the 2 major candidate theories ―relative speed of processing and automaticity of reading― are found to be wanting. It is concluded that recent theories placing the explanatory weight on parallel processing of the irrelevant and the relevant dimensions are likely to be more sucessful than are earlier theories attempting to locate a single bottleneck in attention

/pdf/half-a-century-of-research-on-the-stroop-effect-an-31uxjoznng.pdf

Half a century of research on the Stroop effect: an integrative review.

NOTE The report of the Committee without its annexes appears as Official Records of the General Assembly, Sixty-third Session, Supplement No. 46. The designations employed and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of the Secretariat of the United Nations concerning the legal status of any country, territory, city or area, or of its authorities, or concerning the delimitation of its frontiers or boundaries. The country names used in this document are, in most cases, those that were in use at the time the data were collected or the text prepared. In other cases, however, the names have been updated, where this was possible and appropriate, to reflect political changes. Scientific Annexes Annex A. Medical radiation exposures Annex B. Exposures of the public and workers from various sources of radiation INTROdUCTION 1. In the course of the research and development for and the application of atomic energy and nuclear technologies, a number of radiation accidents have occurred. Some of these accidents have resulted in significant health effects and occasionally in fatal outcomes. The application of technologies that make use of radiation is increasingly widespread around the world. Millions of people have occupations related to the use of radiation, and hundreds of millions of individuals benefit from these uses. Facilities using intense radiation sources for energy production and for purposes such as radiotherapy, sterilization of products, preservation of foodstuffs and gamma radiography require special care in the design and operation of equipment to avoid radiation injury to workers or to the public. Experience has shown that such technology is generally used safely, but on occasion controls have been circumvented and serious radiation accidents have ensued. 2. Reviews of radiation exposures from accidents have been presented in previous UNSCEAR reports. The last report containing an exclusive chapter on exposures from accidents was the UNSCEAR 1993 Report [U6]. 3. This annex is aimed at providing a sound basis for conclusions regarding the number of significant radiation accidents that have occurred, the corresponding levels of radiation exposures and numbers of deaths and injuries, and the general trends for various practices. Its conclusions are to be seen in the context of the Committee's overall evaluations of the levels and effects of exposure to ionizing radiation. 4. The Committee's evaluations of public, occupational and medical diagnostic exposures are mostly concerned with chronic exposures of …

sources and effects of ionizing radiation

I read this book the same weekend that the Packers took on the Rams, and the experience of the latter event, obviously, colored my judgment. Although I abhor anything that smacks of being a handbook (like, \"How to Earn a Merit Badge in Neurosurgery\") because too many volumes in biomedical science already evince a boyscout-like approach, I must confess that parts of this volume are fast, scholarly, and significant, with certain reservations. I like parts of this well-illustrated book because Dr. Sj6strand, without so stating, develops certain subjects on technique in relation to the acquisition of judgment and sophistication. And this is important! So, given that the author (like all of us) is somewhat deficient in some areas, and biased in others, the book is still valuable if the uninitiated reader swallows it in a general fashion, realizing full well that what will be required from the reader is a modulation to fit his vision, propreception, adaptation and response, and the kind of problem he is undertaking. A major deficiency of this book is revealed by comparison of its use of physics and of chemistry to provide understanding and background for the application of high resolution electron microscopy to problems in biology. Since the volume is keyed to high resolution electron microscopy, which is a sophisticated form of structural analysis, but really morphology in a modern guise, the physical and mechanical background of The instrument and its ancillary tools are simply and well presented. The potential use of chemical or cytochemical information as it relates to biological fine structure , however, is quite deficient. I wonder when even sophisticated morphol-ogists will consider fixation a reaction and not a technique; only then will the fundamentals become self-evident and predictable and this sine qua flon will become less mystical. Staining reactions (the most inadequate chapter) ought to be something more than a technique to selectively enhance contrast of morphological elements; it ought to give the structural addresses of some of the chemical residents of cell components. Is it pertinent that auto-radiography gets singled out for more complete coverage than other significant aspects of cytochemistry by a high resolution microscopist, when it has a built-in minimal error of 1,000 A in standard practice? I don't mean to blind-side (in strict football terminology) Dr. Sj6strand's efforts for what is \"routinely used in our laboratory\"; what is done is usually well done. It's just that …

Methods in Enzymology.

Endostatin, produced as recombinant protein in human 293-EBNA cells, inhibits the migration of human umbilical vein endothelial cells (HUVECs) in response to vascular endothelial growth factor (VEGF) in a dose-dependent manner and prevents the subcutaneous growth of human renal cell carcinomas in nude mice at concentrations and in doses that are from 1000- to 100 000-fold lower than those previously reported. The inhibition of migration is not affected by mutations which eliminate Zn or heparin binding and inhibition of tumor growth does not depend on Zn binding. The results of the migration assays suggest that endostatin causes a block at one or more steps in VEGF-induced migration, while VEGF in turn can cause a block of the inhibition by endostatin of VEGF-induced migration of HUVECs.

/pdf/endostatin-inhibits-vegf-induced-endothelial-cell-migration-5cblai5rnt.pdf

Endostatin inhibits VEGF-induced endothelial cell migration and tumor growth independently of zinc binding

Sites of nonenzymatic glycosylation of human hemoglobin a

Angiogenin, a blood vessel inducing protein isolated from a human tumor cell line, has been found to exhibit ribonucleolytic activity. It catalyzes the cleavage of both 28S and 18S ribosomal RNA as determined by agarose gel electrophoresis. The major products formed with these substrates are 100-500 nucleotides in length. In contrast, angiogenin is inactive toward all of the more conventional substrates of the homologous pancreatic ribonucleases. In particular, it does not produce detectable amounts of acid-soluble fragments from high molecular weight wheat germ RNA, poly(C), or poly(U), nor does it hydrolyze cytidine or uridine cyclic 2',3'-phosphate. The high degree of sequence homology between angiogenin and the pancreatic ribonucleases, which includes all three catalytic residues, His-12, Lys-41, and His-119, has thus identified the chemical nature of a potential angiogenin substrate. These results may bear importantly on the physiological function of angiogenin.

Robert Shapiro

Papers

Endostatin inhibits VEGF-induced endothelial cell migration and tumor growth independently of zinc binding

Sites of nonenzymatic glycosylation of human hemoglobin a

Characteristic ribonucleolytic activity of human angiogenin.

Reactions of Uracil and Cytosine Derivatives with Sodium Bisulfite

Structural heterogeneity of human hemoglobin A due to nonenzymatic glycosylation.