Interaction of colchicine with DNA molecules.

Colchicine (7.5 X 10-6M or 3.3 X 10-5M) was incubated at pH 7.0, 10.0, or 12.0 with high-molecular DNA from salmon sperm (7 X 10-5M or 3.5 X 10-5M DNA-P) at 40 degrees C. Interaction was monitored by UV spectrophotometry; Amax/Amin ratios, difference and additive spectra, and the quantity of colchicine bound to DNA were presented as functions of time, ionic strength and DNA concentration. Using NMR techniques, delta deltav 1/2/deltac values, chemical shifts and half-line widths of colchicine protons were analyzed as a function of the DNA/colchicine ratio, thus proving the interaction between alkaloid and DNA. An intercalation of the tropolone moiety of colchicine between the nitrogenous bases of DNA is suggested.     

Liquid Biopsies

In oncology, “liquid biopsy” refers to the analysis of circulating tumor cells (CTCs) or of circulating tumor DNA (ctDNA), to establish non-invasively from the peripheral blood the characteristics of a tumor genome in cancer patients. Liquid biopsies have tremendous potential for future developments in personalized medicine and for the application of targeted therapies. In this review we show that many unresolved issues need to be addressed before liquid biopsies can be routinely used. A particular challenge is the fact that, depending on the analysis performed, the results can have implications reaching far beyond the analysis of the tumor genome originally intended. All of these issues can best be addressed in a multidisciplinary setting with human geneticists, oncologists, pathologists, bioinformaticians and bioethicists participating.     

Differences in marker expression among branched histiocytic cells in T-cell areas of the lymphoreticular system and among their epidermis- and mucosa-associated equivalents

Summary Branched histiocytic cells of the epidermis, the oral and anal mucosa, the tonsillar crypt epithelium, the thymus and of the T-cell-dependent areas of lymph node, spleen, and tonsil were examined with immunohistochemical single- and double-staining techniques. The markers used were a monoclonal anti-T6-antibody, a monoclonal anti-HLA-DR-antibody, heteroantiserum to S-100 protein and peanut agglutinin. Anti-HLA-DR and peanut agglutinin reacted with a considerable number of branched histiocytic cells, whereas anti-T6 and anti-S-100 protein only stained relatively small subpopulations. Concerning the population of branched histiocytic cells, double-staining revealed that the tissue distributions of all the markers used overlapped each other to various degrees; this was demonstrated by the different numbers of double-stained cells obtained in the experiments using all six possible combinations of primary reagents. The number of branched histiocytic cells co-expressing the markers varied depending upon marker combinations, types of tissue and microenvironment. We suggest that much of the immunologic phenotype of branched histiocytic cells is dynamic rather than static.Abbreviations used BHCs branched histiocytic cells - anti-T6 monoclonal antibody to T6 antigen - anti-HLA-DR monoclonal antibody to HLA-DR - anti-S-100p antiserum to S-100 protein - (anti-)PNA (anti-)peanut agglutinin - GAM goat anti-mouse IgG - RAM rabbit anti-mouse IgG - GAR-AP alkaline phosphatase-conjugated goat anti-rabbit Ig - SAR porcine anti-rabbit Ig - PAP peroxidase-anti-peroxidase complex - APAAP alkaline phosphataseanti-alkaline phosphatase complex - iAP indirect alkaline phosphatase - AEC 3-amino-9-ethylcarbazole - FB fast blue BB salt - levamisole L[-]2,3,5,6-tetrahydro-6-phenylimidazo[2,1-b]thiazole - DMF NN-dimethylformamide - PBS phosphate-buffered saline solution - + positive reaction of a cell with a resp. marker - – negative reaction of a cell with a resp. marker This work was supported by the German Research Foundation (DFG: Mo.384/1-2)     

Der Mann aus dem Eis

New scientific findings on the Iceman The Iceman, commonly referred to as Ötzi, is the world's oldest glacier mummy and one of the best studied ancient humans in the world. Since the discovery of the 5300-year-old Copper Age individual in 1991, at the Tisenjoch in the Eastern Italian Alps, a variety of morphological, radiological, and molecular analyses have been applied that revealed important insights into his ancestry, his life habits and the circumstances surrounding his violent death. In more recent research, the mummy was subjected to modern research methodologies focusing on high-throughput sequence analysis of ancient biomolecules (DNA, proteins, lipids) that are still found to be preserved in his mummified tissues. Thereby, a genetic predisposition for increased risk for coronary heart disease and the stomach pathogen Helicobacter pylori were detected. This application of innovative “-omics” technologies have allowed the reconstruction of his last meal, that was mainly composed of fat and game meat from wild animals supplemented with cereals from einkorn.     

Homocysteine induces energy imbalance in rat skeletal muscle: Is creatine a protector?

Homocystinuria is a neurometabolic disease caused by a severe deficiency of cystathionine beta‐synthase activity, resulting in severe hyperhomocysteinemia. Affected patients present several symptoms including a variable degree of motor dysfunction. In this study, we investigated the effect of chronic hyperhomocysteinemia on the cell viability of the mitochondrion, as well as on some parameters of energy metabolism, such as glucose oxidation and activities of pyruvate kinase, citrate synthase, isocitrate dehydrogenase, malate dehydrogenase, respiratory chain complexes and creatine kinase in gastrocnemius rat skeletal muscle. We also evaluated the effect of creatine on biochemical alterations elicited by hyperhomocysteinemia. Wistar rats received daily subcutaneous injections of homocysteine (0.3–0.6 µmol/g body weight) and/or creatine (50 mg/kg body weight) from the 6th to the 28th days of age. The animals were decapitated 12 h after the last injection. Homocysteine decreased the cell viability of the mitochondrion and the activities of pyruvate kinase and creatine kinase. Succinate dehydrogenase was increased other evaluated parameters were not changed by this amino acid. Creatine, when combined with homocysteine, prevented or caused a synergistic effect on some changes provoked by this amino acid. Creatine per se or creatine plus homocysteine altered glucose oxidation. These findings provide insights into the mechanisms by which homocysteine exerts its effects on skeletal muscle function, more studies are needed to elucidate them. Although creatine prevents some alterations caused by homocysteine, it should be used with caution, mainly in healthy individuals because it could change the homeostasis of normal physiological functions. Copyright © 2012 John Wiley & Sons, Ltd.     

Structural changes and relaxations monitored by luminescence

Luminescence data have often been used to study imperfections and to characterize lattice distortions because the signals are sensitive to changes of structure and composition. Previous studies have included intentionally added probe ions such as rare earth ions to sense distortions in local crystal fields caused by modified structural environments. An under‐exploited extension of this approach was to use luminescence to monitor crystalline phase changes. A current overview of this new and powerful technique shows that continuous scanning of the sample temperatures immediately offered at least three types of signatures for phase transitions. Because of high sensitivity, luminescence signals were equally responsive to structural changes from inclusions and nanoparticles. These coupled to the host material via long‐range interactions and modified the host signals. Two frequently observed examples that are normally overlooked are from nanoparticle inclusions of water and CO_2. Examples also indicated that phase transitions were detected in more diverse materials such as superconductors and fullerenes. Finally, luminescence studies have shown that in some crystalline examples, high dose ion implantation of surface layers could induce relaxations and/or structural changes of the entire underlying bulk material. This was an unexpected result and therefore such a possibility has not previously been explored. However, the implications for ion implication are significant and could be far more general than the examples mentioned here. Copyright © 2012 John Wiley & Sons, Ltd.     

Osteogenesis imperfecta

Osteogenesis imperfecta (OI) is the most frequently occurring congenital disorder with an increased fracture rate and systemic skeletal involvement. The vast majority of patients have an autosomal dominant form of OI resulting from a mutation in one of the two type I collagen genes COL1A1 or COL1A2. Since 2006, eight genes for autosomal recessive forms of the disorder have been identified, as well as one additional gene for autosomal dominant OI. Our knowledge concerning molecular pathophysiology has been substantially broadened, such that the paradigm of OI as a pure ??collagenopathy?? no longer applies and the clinical classification system will have to be revised. Standard therapy for the more severe forms of OI comprises intravenous administration of bisphosphonates. Additional elements of a multimodal therapeutic concept include surgical intervention for bone deformities or fractures and physiotherapy.