Polyphyletic Alyssum cuneifolium (Brassicaceae) revisited: Morphological and genome size differentiation of recently recognized allopatric taxa

Alyssum cuneifolium has been recognized as a perennial alpine species growing in five isolated European mountain ranges: the Pyrenees, Western Alps, Apennines, Pirin Mts and Mt Smolikas. Recent molecular systematic studies revealed that the disjunct populations from distant mountains are not closely related and belong to five independent species: A. cacuminum (Spain, Pyrenees), A. cuneifolium (Italy, Apennines), A. flexicaule (France, Western Alps), A. pirinicum (Bulgaria, Pirin Mts), and A. spruneri (Greece, Mt Smolikas). The present study brings the thorough morphometric analysis of the segregated taxa. We found minor morphological differences between them. Whereas A. pirinicum can be clearly distinguished, the other taxa are recognizable only at the level of population means of investigated characters. The morphological similarity of these distantly related species is obviously the result of adaptation to similar high‐alpine scree habitats. It is not clear, however, whether this adaptation is environmentally controlled or whether it is also genetically fixed and whether it reflects parallel evolution towards similar morphotypes. The observed morphological patterns and their assumed correlation with environmental factors are discussed using examples from other Alyssum taxa. Three different ploidy levels have been reported for the species under study. In the present article, we examine variation in relative nuclear genome size. The Alpine and Pyrenean species have larger relative monoploid genome sizes than the Apennine and Balkan ones, probably reflecting the evolutionary history of the group. A nomenclatural account of the study species is presented, and lectotypes of A. cuneifolium and of two other names are selected.     

Assessment of the influence of viscoelasticity of cornea in animal ex vivo model using air‐puff optical coherence tomography and corneal hysteresis

Application of the air‐puff swept source optical coherence tomography (SS‐OCT) instrument to determine the influence of viscoelasticity on the relation between overall the air‐puff force and corneal apex displacement of porcine corneas ex vivo is demonstrated. Simultaneous recording of time‐evolution of the tissue displacement and air pulse stimulus allows obtaining valuable information related in part to the mechanical properties of the cornea. A novel approach based on quantitative analysis of the corneal hysteresis of OCT data is presented. The corneal response to the air pulse is assessed for different well‐controlled intraocular pressure (IOP) levels and for the progression of cross‐linking‐induced stiffness of the cornea. Micrometer resolution, fast acquisition and noncontact character of the air‐puff SS‐OCT measurements have potential to improve the in vivo assessment of mechanical properties of the human corneas.      

Microscopic analysis of spermatogenesis and mature spermatozoa in the amphibian leech Batracobdella algira (Annelida,Clitellata, Hirudinida)

Protoplasma - Spermatogenesis and spermatozoa ultrastructure of the amphibian leech Batracobdella algira Moquin-Tandon, 1846 (Hirudinida: Glossiphoniidae) have been investigated by means of...     

3-Mercapto-5H-1,2,4-Triazino[5,6-b]Indole-5-Acetic Acid (Cemtirestat) Alleviates Symptoms of Peripheral Diabetic Neuropathy in Zucker Diabetic Fatty (ZDF) Rats: A Role of Aldose Reductase

Peripheral neuropathy is the most prevalent chronic complication of diabetes mellitus. Good glycemic control can delay the appearance of neuropathic symptoms in diabetic patients but it is not sufficient to prevent or cure the disease. Therefore therapeutic approaches should focus on attenuation of pathogenetic mechanisms responsible for the nerve injury. Considering the role of polyol pathway in the etiology of diabetic neuropathy, we evaluated the effect of a novel efficient and selective aldose reductase inhibitor, 3-mercapto-5H-1,2,4-triazino[5,6-b]indole-5-acetic acid (cemtirestat), on symptoms of diabetic peripheral neuropathy in Zucker Diabetic Fatty (ZDF) rats. Since the age of 5 months, male ZDF rats were orally administered cemtirestat, 2.5 and 7.5 mg/kg/day, for two following months. Thermal hypoalgesia was evaluated by tail flick and hot plate tests. Tactile allodynia was determined by a von Frey flexible filament test. Two-month treatment of ZDF rats with cemtirestat (i) did not affect physical and glycemic status of the animals; (ii) partially inhibited sorbitol accumulation in red blood cells and the sciatic nerve; (iii) markedly decreased plasma levels of thiobarbituric acid reactive substances; (iv) normalized symptoms of peripheral neuropathy with high significance. The presented findings indicate that inhibition of aldose reductase by cemtirestat is not solely responsible for the recorded improvement of the behavioral responses. In future studies, potential effects of cemtirestat on consequences of diabetes that are not exclusively dependent on glucose metabolism via polyol pathway should be taken into consideration.

     

Predicting ratings of perceived exertion in youth soccer using decision tree models

The purpose of this study was to determine the effectiveness of white-box decision tree models (DTM) for predicting the rating of perceived exertion (RPE). The second aim was to examine the relationship between RPE and external measures of intensity in youth soccer training at the group and individual level. Training load data from 18 youth soccer players were collected during an in-season competition period. A total of 804 training observations were undertaken, with a total of 43 ± 17 sessions per player (range 12–76). External measures of intensity were determined using a 10 Hz GPS and included total distance (TD, m/min), high-speed running distance (HSR, m/min), PlayerLoad (PL, n/min), impacts (n/min), distance in acceleration/deceleration (TD ACC/TD DEC, m/min) and the number of accelerations/decelerations (ACC/DEC, n/min). Data were analysed with decision tree models. Global and individualized models were constructed. Aggregated importance revealed HSR as the strongest predictor of RPE with relative importance of 0.61. HSR was the most important factor in predicting RPE for half of the players. The prediction error (root mean square error [RMSE] 0.755 ± 0.014) for the individualized models was lower compared to the population model (RMSE 1.621 ± 0.001). The findings demonstrate that individual models should be used for the assessment of players’ response to external load. Furthermore, the study demonstrates that DTM provide straightforward interpretation, with the possibility of visualization. This method can be used to prescribe daily training loads on the basis of predicted, desired player responses (exertion).     

Chemical carcinogenicity: can it be predicted from knowledge of mutagenicity and allergic contact dermatitis?

Naturally occurring substances were tested for genotoxicity using a modified laboratory protocol of the Escherichia coli PQ37 genotoxicity assay (SOS chromotest) in the presence and in the absence of an exogenous metabolizing system from rat liver S9-mix. Aristolochic acid I, II, the plant extract aristolochic acid and psoralene were genotoxic; cycasine, emodine, monocrotaline and retrorsine were classified as marginal genotoxic in the SOS chromotest in the absence of S9-mix. In the presence of an exogenous metabolizing system from rat liver S9-mix aristolochic acid I, the plant extract, beta-asarone, cycasin, monocrotaline, psoralen and retrorsine showed genotoxic effects; aristolochic acid II marginal genotoxic effects. Arecoline, benzyl acetate, coumarin, isatidine dihydrate, reserpine, safrole, sanguinarine chloride, senecionine, senkirkine, tannin and thiourea revealed no genotoxicity in the SOS chromotest either in the presence or in the absence of an exogenous metabolizing system from rat liver S9-mix. For 17 of 20 compounds, the results obtained in the SOS chromotest could be compared to those obtained in the Ames test. It was found that 12 (70.6%) of these compounds give similar responses in both tests (6 positive and 6 negative responses). The present investigation and those reported earlier, the SOS chromotest, using E. coli PQ37, was able to detect correctly most of the Salmonella mutagens and non-mutagens.     

Presence of an unusual GM2 derivative,taurine-conjugated GM2, in Tay-Sachs brain

Tay-Sachs disease (TSD) is a classical glycosphingolipid (GSL) storage disease. Although the genetic and biochemical bases for a massive cerebral accumulation of ganglioside GM2 in TSD have been well established, the mechanism for the neural dysfunction in TSD remains elusive. Upon analysis of GSLs from a variant B TS brain, we have detected a novel GSL that has not been previously revealed. We have isolated this GSL in pure form. Using NMR spectroscopy, mass spectrometry, and chemical synthesis, the structure of this unusual GSL was established to be a taurine-conjugated GM2 (tauro-GM2) in which the carboxyl group of N-acetylneuraminic acid was amidated by taurine. Using a rabbit anti-tauro-GM2 serum, we also detected the presence of tauro-GM2 in three other small brain samples from one variant B and two variant O TSD patients. On the other hand, tauro-GM2 was not found in three normal human brain samples. The presence of tauro-GM2 in TS brains, but not in normal brains, indicates the possible association of this unusual GM2 derivative with the pathogenesis of TSD. Our findings point to taurine conjugation as a heretofore unelucidated mechanism for TS brain to cope with water-insoluble GM2.     

Protein kinase A and two phosphatases are components of the inositol 1,4,5-trisphosphate receptor macromolecular signaling complex

The inositol 1,4,5-trisphosphate receptor (IP3R) is a ubiquitously expressed intracellular calcium (Ca(2+)) release channel on the endoplasmic reticulum. IP3Rs play key roles in controlling Ca(2+) signals that activate numerous cellular functions including T cell activation, neurotransmitter release, oocyte fertilization and apoptosis. There are three forms of IP3R, all of which are ligand-gated channels activated by the second messenger inositol 1,4,5-trisphosphate. Channel function is modulated via cross-talk with other signaling pathways including those mediated by kinases and phosphatases. In particular IP3Rs are known to be regulated by cAMP-dependent protein kinase (PKA) phosphorylation. In the present study we show that PKA and the protein phosphatases PP1 and PP2A are components of the IP3R1 macromolecular signaling complex. PKA phosphorylation of IP3R1 increases channel activity in planar lipid bilayers. These studies indicate that regulation of IP3R1 function via PKA phosphorylation involves components of a macromolecular signaling complex.     

Uptake and intracellular transportation of a bacterial surface protein in lymphoid cells

Some strains of the human pathogen Streptococcus pyogenes express a surface protein called protein H, which is released from the streptococcal surface by a cysteine proteinase produced by the bacteria. Here, we find that soluble protein H binds to the surface of lymphocytes and granulocytes, and that the molecule is taken up by lymphocytes and transported to the perinuclear region. The translocation over the cell membrane is rapid, and the uptake and intracellular transportation is not dependent on actin polymerization. Protein H could be immunoprecipitated from cell extracts and nuclear preparations of lymphocytes, and analysis of molecular interactions between protein H and proteins of different cellular compartments demonstrated a binding to nucleophosmin/ B23, a protein known to shuttle between the cytoplasm and the nucleus, and to the nuclear proteins SET and hnRNP A2/B1. Nucleophosmin/B23 was co-immunoprecipitated with protein H from cell and nuclear extracts, and binding experiments, including kinetic analyses, suggest that protein H dissociating from nucleophosmin/B23 complexes in the perinuclear region or in the nucleus binds to proteins SET and hnRNP A2/B1. Finally, the uptake and intracellular transportation of protein H was found to result in a cytostatic effect on B and T lymphocytes.