224 research outputs found

    Viability effects on cell cycle synchronization of different prostate cancer cell lines: A brief report

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    Aim: Serum deprivation is often used to synchronize cells in G0/G1 phase for comparative in vitro studies. Here we aimed to investigate the effect on viability of the three commonly used prostate cancer-cell lines PC3, LNCaP and DU145 after serum deprivation. Methods: The cell lines were cultured in standard culture medium (controls) and under serum deprivation for 48 and 72 h. Then the proportion of cells in G0/G1 phase was analysed by flow cytometry and cell morphology was microscopically investigated. The cells were allowed to recover for three days in standard culture condition before cell viability (using MTT assay) was analysed. Results: In comparison to control cells, significant effects on cell cycle arrest in G0/G1 phase were noted for DU145 and PC3 cells and the cell morphology was negatively affected in a time-dependent manner. These parameters were unaffected in LNCaP cells. After three days of recovery, the viability of DU145 and PC3 cells was significantly reduced compared to LNCaP. Conclusions: Serum deprivation showed different effects on the prostate cancer cells, probably due to differences in growth rate. Such effects on viability should be considered as an obstacle for comparative studies

    Pelagic population dynamics of Aurelia sp in French Mediterranean lagoons

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    The pelagic dynamics of the cosmopolitan scyphozoan Aurelia sp. was investigated in three French Mediterranean lagoons, Thau, Berre and Bages-Sigean, which harbour resident populations. The annual cycles showed a common univoltine pattern in all lagoons where the presence of pelagic stages in the water column lasted similar to 8 months. Field observations showed a release of ephyrae in winter time followed by pronounced growth between April and July, when individuals reached the largest sizes, before disappearing from the water column. Maximum abundance of ephyrae and medusae were registered in Thau. Medusae abundance attained a maximum of 331 ind 100 m(-3) in Thau, 18 ind 100 m(-3) in Berre and 7 ind 100 m(-3) in Bages-Sigean lagoons. Temperature and zooplankton abundance appeared as leading factors of growth, where Bages-Sigean showed the population with higher growth rates (2.66 mm day(-1)) and maximum size (32 cm), followed by Thau (0.57-2.56 mm day(-1); 22.4 cm) and Berre (1.57-2.22 mm day(-1); 17 cm). The quantification of environmental windows used by the species showed wider ranges than previously reported in the Mediterranean Sea, which suggests a wide ecological plasticity of Aurelia spp. populations in north-western Mediterranean lagoons.GELAMED project; Total foundation [189 - "Recherche" 18902 C]; EC2CO "Ecosphere Continentale et Cotiere" programme through the DYNAMO project; OSU-OREM

    Metabolism and foraging strategies of mid‐latitude mesozooplankton during cyanobacterial blooms as revealed by fatty acids, amino acids, and their stable carbon isotopes

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    Increasing sea surface temperatures (SST) and blooms of lipid‐poor, filamentous cyanobacteria can change mesozooplankton metabolism and foraging strategies in marine systems. Lipid shortage and imbalanced diet may challenge the build‐up of energy pools of lipids and proteins, and access to essential fatty acids (FAs) and amino acids (AAs) by copepods. The impact of cyanobacterial blooms on individual energy pools was assessed for key species temperate Temora longicornis and boreal Pseudo‐/Paracalanus spp. that dominated field mesozooplankton communities isolated by sea‐sonal stratification in the central Baltic Sea during the hot and the cold summer. We looked at (a) total lipid and protein levels, (b) FA trophic markers and AA composition, and (c) compound‐specific stable carbon isotopes (ή13C) in bulk mesozooplankton and in a subset of parameters in particulate organic matter. Despite lipid‐poor cyanobacterial blooms, the key species were largely able to cover both energy pools, yet a tendency of lipid reduction was observed in surface animals. Omni‐ and car‐nivory feeding modes, FA trophic makers, and ή13C patterns in essential compounds emphasized that cyanobacterial FAs and AAs have been incorporated into meso‐zooplankton mainly via feeding on mixo‐ and heterotrophic (dino‐) flagellates and detrital complexes during summer. Foraging for essential highly unsaturated FAs from (dino‐) flagellates may have caused night migration of Pseudo‐/Paracalanus spp. from the deep subhalocline waters into the upper waters. Only in the hot summer (SST>19.0°C) was T. longicornis submerged in the colder subthermocline water (~4°C). Thus, the continuous warming trend and simultaneous feeding can eventually lead to competition on the preferred diet by key copepod species below the thermocline in stratified systems. A comparison of ή13C patterns of essential AAs in surface meso‐zooplankton across sub‐basins of low and high cyanobacterial biomasses revealed the potential of ή13C‐AA isoscapes for studies of commercial fish feeding trails across the Baltic Sea food webs

    Propidium Monoazide Integrated with qPCR Enables the Detection and Enumeration of Infectious Enteric RNA and DNA Viruses in Clam and Fermented Sausages

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    The increase of foodborne viral outbreaks highlights the need for a rapid and sensitive method for the prediction of viral infectivity in food samples. This study assesses the use of propidium monoazide (PMA) coupled with real-time PCR methods (RT-qPCR or qPCR for RNA or DNA viruses, respectively) in the determination of viral infectivity in complex animal-related food matrices. Clam and Spanish fermented sausage (“chorizo”) samples were spiked with infectious and heat-inactivated human adenovirus-2 (HAdV-2) and mengovirus (vMC0). PMA-qPCR/RT-qPCR discriminated infective virus particles, with significant reductions (>2.7 log10 or 99.7%). Additionally, infectious HAdV-2 and vMC0 were quantified by plaque assay (in plaque forming units, PFU), and compared with those in virus genomes copies (GCs) quantified by PMA-qPCR/RT-qPCR. A consistent correlation (R2 > 0.92) was showed between PFU and GCs along serial 10-fold dilutions in both DNA and RNA virus and in both food matrices. This study shows the use of PMA coupled to qPCR/RT-qPCR as a promising alternative for prediction of viral infectivity in food samples in comparison to more expensive and time-consuming methods and for those viruses that are not able to grow under available cell culture techniques.ThisstudywasfinanciallysupportedbytheRTA2014-00024- C04-01 fromtheSpanishMinistryofEconomyandInnovation and theBrazilianCNPqProjectnumber472804/2013-8,andby CAPES/PNPD andCAPES/PDSE

    Population Maintenance of the Scyphozoan Cyanea sp. Settled Planulae and the Distribution of Medusae in the Niantic River, Connecticut, USA

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    Scyphozoan jellyfish are seasonally conspicuous in coastal waters, but relatively little is known about the factors that control their distribution and population dynamics.Cyanea sp is a seasonally abundant medusa in the Niantic River, Connecticut, U.S. and appears to maintain a population entirely within the estuary. To better understand the factors controlling their occurrence, we examined the temporal and spatial distribution of settled scyphistomae in relation to that of the medusae. Planula settlement patterns mirrored the presence of mature female medusae. The planulae settled primarily near the bottom. After settlement, planulacysts and polyps on the settlement plates were out competed by large barnacle and ascidian larvae, resulting in a sharp decline in cyst and polyp abundance. This stage-specific mortality may represent a population bottleneck in the life cycle of scyphozoans

    Pseudomonas boanensis sp. nov., a bacterium isolated from river water used for household purposes in Boane District, Mozambique

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    A Gram-negative rod with a single polar flagellum was isolated from a freshwater reservoir used for household purposes in Boane District, near Maputo, Mozambique, and designated as strain DB1T. Growth was observed at 30-42 °C (optimum, 30-37 °C) and with 0.5-1.5 % NaCl. Whole-genome-, rpoD- and 16S rRNA-based phylogenies revealed this isolate to be distant from other Pseudomonas species with Pseudomonas resinovorans, Pseudomonas furukawaii and Pseudomonas lalkuanensis being the closest relatives. Phenotypic analyses of strain DB1T showed marked differences with respect to type strains P. resinovorans CCUG 2473T, P. lalkuanensis CCUG 73691T, P. furukawaii CCUG 75672T and Pseudomonas otiditis CCUG 55592T. Taken together, our results indicate that strain DB1T is a representative of a novel species within the genus Pseudomonas for which the name Pseudomonas boanensis is proposed. The type strain is DB1T (=CCUG 62977T=CECT 30359T).SIDA 2012 and FORMAS-Sida 2010.https://www.microbiologyresearch.org/content/journal/ijsemVeterinary Tropical Disease

    Inhibition of cell proliferation does not slow down echinoderm neural regeneration

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    BACKGROUND: Regeneration of the damaged central nervous system is one of the most interesting post-embryonic developmental phenomena. Two distinct cellular events have been implicated in supplying regenerative neurogenesis with cellular material – generation of new cells through cell proliferation and recruitment of already existing cells through cell migration. The relative contribution and importance of these two mechanisms is often unknown. METHODS: Here, we use the regenerating radial nerve cord (RNC) of the echinoderm Holothuria glaberrima as a model of extensive post-traumatic neurogenesis in the deuterostome central nervous system. To uncouple the effects of cell proliferation from those of cell migration, we treated regenerating animals with aphidicolin, a specific inhibitor of S-phase DNA replication. To monitor the effect of aphidicolin on DNA synthesis, we used BrdU immunocytochemistry. The specific radial glial marker ERG1 was used to label the regenerating RNC. Cell migration was tracked with vital staining with the lipophilic dye DiI. RESULTS: Aphidicolin treatment resulted in a significant 2.1-fold decrease in cell proliferation. In spite of this, the regenerating RNC in the treated animals did not differ in histological architecture, size and cell number from its counterpart in the control vehicle-treated animals. DiI labeling showed extensive cell migration in the RNC. Some cells migrated from as far as 2 mm away from the injury plane to contribute to the neural outgrowth. CONCLUSIONS: We suggest that inhibition of cell division in the regenerating RNC of H. glaberrima is compensated for by recruitment of cells, which migrate into the RNC outgrowth from deeper regions of the neuroepithelium. Neural regeneration in echinoderms is thus a highly regulative developmental phenomenon, in which the size of the cell pool can be controlled either by cell proliferation or cell migration, and the latter can neutralize perturbations in the former. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12983-017-0196-y) contains supplementary material, which is available to authorized users
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