The differentiation status of primary gonadal germ cell tumors correlates inversely with telomerase activity and the expression level of the gene encoding the catalytic subunit of telomerase

BACKGROUND: The activity of the ribonucleoprotein enzyme telomerase is detectable in germ, stem and tumor cells. One major component of telomerase is human telomerase reverse transcriptase (hTERT), which encodes the catalytic subunit of telomerase. Here we investigate the correlation of telomerase activity and hTERT gene expression and the differentiation status of primary testicular germ cell tumors (TGCT). METHODS: Telomerase activity (TA) was detected by a quantitative telomerase PCR ELISA, and hTERT mRNA expression was quantified by online RT-PCR in 42 primary testicular germ cell tumors. The control group consisted of benign testicular biopsies from infertile patients. RESULTS: High levels of telomerase activity and hTERT expression were detected in all examined undifferentiated TGCTs and in the benign testicular tissue specimens with germ cell content. In contrast, differentiated teratomas and testicular control tissue without germ cells (Sertoli-cell-only syndrome) showed no telomerase activity and only minimal hTERT expression. CONCLUSIONS: These findings demonstrate an inverse relationship between the level of telomerase activity and hTERT mRNA expression and the differentiation state of germ cell tumors. Quantification of telomerase activity and hTERT mRNA expression enables a new molecular-diagnostic subclassification of germ cell tumors that describes their proliferation potential and differentiation status

Minichromosome maintenance protein 6, a proliferation marker superior to Ki-67 and independent predictor of survival in patients with mantle cell lymphoma

Minichromosome maintenance protein 6 (MCM6) is one of six proteins of the MCM family which are involved in the initiation of DNA replication and thus represent a marker of proliferating cells. Since the level of cell proliferation is the most valuable predictor of survival in mantle cell lymphoma (MCL), we investigated lymph node biopsy specimens from 70 patients immunohistochemically with a monoclonal antibody against MCM6. The percentage of MCM6 expressing lymphoma cells ranged from 12.0 to 95.6%, with a mean of 61.0%, and was significantly higher than the percentage of Ki-67-positive cells (P<0.0001). Surprisingly, the ratio of MCM6-positive cells to Ki-67-positive cells was higher than in normal stimulated peripheral blood mononuclear cells, indicating a cell early G1-phase arrest in MCL. A high MCM6 expression level of more than 75% positive cells was associated with a significantly shorter overall survival time (16 months) compared to MCL with a low MCM6 expression level of less than 25% (no median reached, P<0.0001). Multivariate analysis revealed MCM6 to be an independent predictor of survival that is superior to the international prognostic factor and the Ki-67 index. Therefore, aside from gene expression profiling, immunohistochemical detection of MCM6 seems to be the most promising marker for predicting the outcome in MCL

Giant coronary artery aneurysms in juvenile polyarteritis nodosa: a case report

Juvenile polyarteritis nodosa (PAN) is a rare, necrotizing vasculitis, primarily affecting small to medium-sized muscular arteries. Cardiac involvement amongst patients with PAN is uncommon and reports of coronary artery aneurysms in juvenile PAN are exceedingly rare. We describe a 16 year old girl who presented with fever, arthritis and two giant coronary artery aneurysms, initially diagnosed as atypical Kawasaki disease and treated with IVIG and methylprednisolone. Her persistent fevers, arthritis, myalgias were refractory to treatment, and onset of a vasculitic rash suggested an alternative diagnosis. Based on angiographic abnormalities, polymyalgia, hypertension and skin involvement, this patient met criteria for juvenile PAN. She was treated with six months of intravenous cyclophosphamide and high dose corticosteroids for presumed PAN related coronary vasculitis. Maintenance therapy was continued with azathioprine and the patient currently remains without evidence of active vasculitis. She remains on anticoagulation for persistence of the aneurysms. This case illustrates a rare and unusual presentation of giant coronary artery aneurysms in the setting of juvenile PAN

Positional Cues in the Drosophila Nerve Cord: Semaphorins Pattern the Dorso-Ventral Axis

Positional cues target sensory axons to appropriate volumes of the developing nervous system independently of their synaptic partners

The peroxisome: still a mysterious organelle

More than half a century of research on peroxisomes has revealed unique features of this ubiquitous subcellular organelle, which have often been in disagreement with existing dogmas in cell biology. About 50 peroxisomal enzymes have so far been identified, which contribute to several crucial metabolic processes such as β-oxidation of fatty acids, biosynthesis of ether phospholipids and metabolism of reactive oxygen species, and render peroxisomes indispensable for human health and development. It became obvious that peroxisomes are highly dynamic organelles that rapidly assemble, multiply and degrade in response to metabolic needs. However, many aspects of peroxisome biology are still mysterious. This review addresses recent exciting discoveries on the biogenesis, formation and degradation of peroxisomes, on peroxisomal dynamics and division, as well as on the interaction and cross talk of peroxisomes with other subcellular compartments. Furthermore, recent advances on the role of peroxisomes in medicine and in the identification of novel peroxisomal proteins are discussed

Single-Spin Addressing in an Atomic Mott Insulator

Ultracold atoms in optical lattices are a versatile tool to investigate fundamental properties of quantum many body systems. In particular, the high degree of control of experimental parameters has allowed the study of many interesting phenomena such as quantum phase transitions and quantum spin dynamics. Here we demonstrate how such control can be extended down to the most fundamental level of a single spin at a specific site of an optical lattice. Using a tightly focussed laser beam together with a microwave field, we were able to flip the spin of individual atoms in a Mott insulator with sub-diffraction-limited resolution, well below the lattice spacing. The Mott insulator provided us with a large two-dimensional array of perfectly arranged atoms, in which we created arbitrary spin patterns by sequentially addressing selected lattice sites after freezing out the atom distribution. We directly monitored the tunnelling quantum dynamics of single atoms in the lattice prepared along a single line and observed that our addressing scheme leaves the atoms in the motional ground state. Our results open the path to a wide range of novel applications from quantum dynamics of spin impurities, entropy transport, implementation of novel cooling schemes, and engineering of quantum many-body phases to quantum information processing.Comment: 8 pages, 5 figure

SILEX: a fast and inexpensive high-quality DNA extraction method suitable for multiple sequencing platforms and recalcitrant plant species

[EN] Background The use of sequencing and genotyping platforms has undergone dramatic improvements, enabling the generation of a wealth of genomic information. Despite this progress, the availability of high-quality genomic DNA (gDNA) in sufficient concentrations is often a main limitation, especially for third-generation sequencing platforms. A variety of DNA extraction methods and commercial kits are available. However, many of these are costly and frequently give either low yield or low-quality DNA, inappropriate for next generation sequencing (NGS) platforms. Here, we describe a fast and inexpensive DNA extraction method (SILEX) applicable to a wide range of plant species and tissues. Results SILEX is a high-throughput DNA extraction protocol, based on the standard CTAB method with a DNA silica matrix recovery, which allows obtaining NGS-quality high molecular weight genomic plant DNA free of inhibitory compounds. SILEX was compared with a standard CTAB extraction protocol and a common commercial extraction kit in a variety of species, including recalcitrant ones, from different families. In comparison with the other methods, SILEX yielded DNA in higher concentrations and of higher quality. Manual extraction of 48 samples can be done in 96 min by one person at a cost of 0.12 euro/sample of reagents and consumables. Hundreds of tomato gDNA samples obtained with either SILEX or the commercial kit were successfully genotyped with Single Primer Enrichment Technology (SPET) with the Illumina HiSeq 2500 platform. Furthermore, DNA extracted fromSolanum elaeagnifoliumusing this protocol was assessed by Pulsed-field gel electrophoresis (PFGE), obtaining a suitable size ranges for most sequencing platforms that required high-molecular-weight DNA such as Nanopore or PacBio. Conclusions A high-throughput, fast and inexpensive DNA extraction protocol was developed and validated for a wide variety of plants and tissues. SILEX offers an easy, scalable, efficient and inexpensive way to extract DNA for various next-generation sequencing applications including SPET and Nanopore among others.This research has been funded by the European Union's Horizon 2020 research and innovation programme under grant agreement No 677379 (Linking genetic resources, genomes and phenotypes of Solanaceous crops; G2P-SOL). David Alonso is grateful to Universitat Politecnica de Valencia for a predoctoral (PAID-01-16) contract under the Programa de Ayudas de Investigacion y Desarrollo initiative. Mariola Plazas is grateful to Generalitat Valenciana and Fondo Social Europeo for a postdoctoral grant (APOSTD/2018/014). Pietro Gramazio is grateful to Japan Society for the Promotion of Science for a Postdoctoral Grant (P19105, FY2019 JSPS Postdoctoral Fellowship for Research in Japan (Standard)). The Spanish Ministerio de Educacion, Cultura y Deporte funded a predoctoral fellowship granted to Edgar Garcia-Fortea (FPU17/02389).Vilanova Navarro, S.; Alonso-Martín, D.; Gramazio, P.; Plazas Ávila, MDLO.; García-Fortea, E.; Ferrante, P.; Schmidt, M.... (2020). SILEX: a fast and inexpensive high-quality DNA extraction method suitable for multiple sequencing platforms and recalcitrant plant species. Plant Methods. 16(1):1-11. https://doi.org/10.1186/s13007-020-00652-yS111161Scheben A, Batley J, Edwards D. Genotyping-by-sequencing approaches to characterize crop genomes: choosing the right tool for the right application. Plant Biotechnol J. 2017;15:149–61.Jung H, Winefield C, Bombarely A, Prentis P, Waterhouse P. Tools and strategies for long-read sequencing and de novo assembly of plant genomes. 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Phytoplankton evolution during the creation of a biofloc system for shrimp culture

[EN] Microalgae play a key role in the dynamics of biofloc technology aquaculture systems. Some phytoplankton groups, such as diatoms, are desired for their high nutritional value and contribution to water quality. Other groups, such as cyanobacteria, are undesired because of their low nutritional value and capacity of producing toxins. So, monitoring the phytoplankton community structure and succession is key for managing biofloc systems. However, research on phytoplankton in these systems is scarce and mostly done by microscopy. The primary objective of this research was to estimate phytoplankton community structure in shrimp biofloc system water samples, using high-performance liquid chromatography methods and CHEMTAX software. The major groups present in our system were diatoms, euglenophytes, cyanobacteria and chlorophytes, while dinoflagellates were only remarkable at the initial period. We observed a clear dominance of diatoms all along the 5 months that comprised a complete biofloc system culture. The characteristic succession of autotrophic processes by heterotrophs of the biofloc systems, was observed by the reduction of net primary production. Light intensity played a key role in determining the phytoplankton composition and abundance. Algal pigment analyses using high-performance liquid chromatography and subsequent CHEMTAX analysis in water samples was useful for estimating the phytoplankton community structure in the biofloc systems. However, we found some limitations when the biofloc system was in heterotrophic mode. Under these conditions, some dinoflagellates and cyanobacteria behaved as heterotrophs and lost or decreased their biomarkers pigments. So, further research is needed to increase knowledge on the accuracy of high-performance liquid chromatography /CHEMTAX under these conditions.Financial support for this research was provided by Conselleria d’Educació, Investigació, Cultura i Esport of the Generalitat Valenciana, through the program VALi+D, fle number ACIF/2014/244. We would like to express our deepest thanks to Professor Luis Henrique da Silva Poersch of FURG (Universidade Federal do Rio Grande) and Ivan Vidal (Langostinos el Real) for his support. Finally, the authors wish to thank Le Gouessant and Michaël Metz for providing the commercial feed.Llario-Sempere, F.; Rodilla, M.; Escrivá-Perales, J.; Falco, S.; Sebastiá-Frasquet, M. (2018). Phytoplankton evolution during the creation of a biofloc system for shrimp culture. 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