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)     

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.     

Differential effect of antiepileptic and non-antiepileptic drugs on the reticular formation

The effect of the antiepileptic drugs carbamazepine and phenytoin, and of the non-antiepileptic drug baclofen, was compared on various inhibitory and excitatory mechanisms in the feline trigeminal nucleus. Baclofen resembled carbamazepine and phenytoin in depressing segmental excitatory and facilitating segmental inhibitory mechanisms. However, baclofen facilitated the periventricular and periaqueductal inhibition of the trigeminal nucleus, while carbamazepine and phenytoin depressed these descending inhibitory mechanisms. Baclofen also resembles carbamazepine and phenytoin in its effectiveness in trigeminal neuralgia, but baclofen is not a clinically effective antiepileptic agent. Our experiments indicate that the ability to depress the reticular formation of the diencephalon and midbrain is an important characteristic of antiepileptic drugs. This suggests that the reticular core is involved in the spread and generalization of seizures.     

Salicylate effects on proton gradient dissipation by isolated gastric mucosal surface cells

The effects of salicylate were examined on Na+/H+ exchange by isolated gastric mucosal surface cells loaded with H+ and resuspended in a buffered medium. Choline salicylate (pH 7.4) increases the dissipation of an intracellular proton gradient which was measured using acridine orange. The exchange of extracellular Na+ with intracellular H+ by surface cells not only remains intact but also is enhanced upon exposure to salicylate. This was confirmed by cellular uptake of 22Na and titration of cellular H+ efflux. Salicylate increases Na+/H+ exchange via a pathway predominantly sensitive to amiloride. However, the data also suggest that salicylate dissipates an intracellular proton gradient by an additional mechanism. The latter is independent of extracellular Na+ and not due to a generalized increase in cellular permeability.     

MicroRNA loci support conspecificity of Gyrodactylus salaris and Gyrodactylus thymalli (Platyhelminthes: Monogenea)

The monogenean flatworm Gyrodactylus salaris is a serious threat to wild and farmed Atlantic salmon stocks in Norway. Morphologically, the closely related but harmless Gyrodactylus thymalli on grayling can hardly be distinguished from G. salaris. Until now, molecular approaches could not resolve unambiguously whether G. salaris and G. thymalli represent just one polytypic species, two polytypic species or a complex of more than two species. In the first known genome-wide analysis utilizing 37 conserved microRNA loci, the genetic differentiation of seven populations of G. salaris and G. thymalli was assessed. The concatenated alignment spanned 21,742 bp including 62 variable positions. A neighbor-joining cluster analysis did not support any host-based or mitochondrial haplotype-based grouping of strains. We conclude that a two species concept for G. salaris and G. thymalli does not reflect meaningful biological entities. Instead, G. salaris and G. thymalli are just one species comprising several pathogenic and non-pathogenic strains on various primary hosts. Following the International Code for Zoological Nomenclature, G. salaris Malmberg, 1957 is the valid species name with G. thymalli ?itňan, 1960 becoming the junior synonym. Accordingly, the range of G. salaris is significantly increased, given that formerly G. salaris-free countries such as e.g., Great Britain are now within the species’ natural range. The synonymization of G. salaris and G. thymalli implies severe challenges to current disease management routines, which assume that G. salaris and G. thymalli are readily distinguishable. Protocols for reliable identification of pathogenic and non-pathogenic strains of G. salaris need to be developed.     

Application of equilibrium exchange kinetics to studies of kinetic properties at high enzyme concentrations: Experiments with yeast hexokinase P-II

The usefulness of isotope exchange at equilibrium measurements to define both the kinetic parameters and the kinetic reaction mechanism of enzymes at high levels of enzyme is demonstrated by studies of yeast hexokinase P-II. Additional support for this new application of equilibrium exchange kinetics, based upon previously published studies of a variety of enzymes, is also presented, and the advantages and limitations of this approach are discussed.     

A computer analysis of the validity of the integrated Michaelis-Menten equation

The validity of assumptions made in integrating the Michaelis-Menten equation (i.e. the steady-state assumption) was examined by simulating the model on the digital computer. Time courses thus obtained by numerical integration were compared with data generated by the three most common forms of the integrated equation. Agreement was good within specified limits, the chief exception being the early transient phase of the reaction. The observed differences were very much less than theoretical estimates of the maximum error, even when rate constants were chosen that should exaggerate that error.     

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.