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Christopher J Gordon, Earl T Puckett, Elizabeth S Repasky, Andrew F M Johnstone
Laboratories and vivariums typically are maintained at ambient temperatures of 20 to 24 °C, leading to cold stress in mice. When mice are inactive and sleeping during the light phase, their zone of thermoneutrality associated with a basal metabolic rate is 30 to 32 °C. If given a choice, mice will use thermoregulatory behavior to seek out thermoneutral temperatures during the light phase. The cold stress of a vivarium can be problematic to researchers requiring an animal model that is not stressed metabolically...
March 1, 2017: Journal of the American Association for Laboratory Animal Science: JAALAS
Romana Koprdova, Eszter Bögi, Kristína Belovičová, Natália Sedláčková, Monika Okuliarová, Eduard Ujházy, Mojmír Mach
OBJECTIVES: There are several models of depression. Chronic unpredictable mild stress (CMS) appears to have the greatest validity, although it is often being criticized for low reliability. METHODS: Male Wistar/DV rats were used in this study to assess our modified 2-week model of CMS as a combination of psychosocial, physical and metabolic stressors and to compare the effect of acute administration of venlafaxine (VFX) and diazepam (DZP), either in stress or no stress conditions...
December 18, 2016: Neuro Endocrinology Letters
Yosuke Nishimura, Hiroyasu Watai, Takashi Honda, Tomoko Mihara, Kimiho Omae, Simon Roux, Romain Blanc-Mathieu, Keigo Yamamoto, Pascal Hingamp, Yoshihiko Sako, Matthew B Sullivan, Susumu Goto, Hiroyuki Ogata, Takashi Yoshida
Metagenomics has revealed the existence of numerous uncharacterized viral lineages, which are referred to as viral "dark matter." However, our knowledge regarding viral genomes is biased toward culturable viruses. In this study, we analyzed 1,600 (1,352 nonredundant) complete double-stranded DNA viral genomes (10 to 211 kb) assembled from 52 marine viromes. Together with 244 previously reported uncultured viral genomes, a genome-wide comparison delineated 617 genus-level operational taxonomic units (OTUs) for these environmental viral genomes (EVGs)...
March 2017: MSphere
J Torres-Ruiz, A Sulli, M Cutolo, Y Shoenfeld
Biological rhythms are fundamental for homeostasis and have recently been involved in the regulatory processes of various organs and systems. Circadian cycle proteins and hormones have a direct effect on the inflammatory response and have shown pro- or anti-inflammatory effects in animal models of autoimmune diseases. The cells of the immune system have their own circadian rhythm, and the light-dark cycle directly influences the inflammatory response. On the other hand, patients with autoimmune diseases characteristically have sleep disorders and fatigue, and in certain disease, such as rheumatoid arthritis (RA), a frank periodicity in the signs and symptoms is recognized...
February 27, 2017: Clinical Reviews in Allergy & Immunology
Sarah H Lockie, Clare V McAuley, Sasha Rawlinson, Natalie Guiney, Zane B Andrews
Most studies that measure food intake in mice do so in the home cage environment. This necessarily means that mice do not engage in food seeking before consumption, a behavior that is ubiquitous in free-living animals. We modified and validated several commonly used anxiety tests to include a palatable food reward within the anxiogenic zone. This allowed us to assess risk-taking behavior in food seeking in mice in response to different metabolic stimuli. We modified the open field test and the light/dark box by placing palatable peanut butter chips within a designated food zone inside the anxiogenic zone of each apparatus...
2017: Frontiers in Neuroscience
Michaela Fredrich, Mareike Hampel, Kay Seidel, Elmar Christ, Horst-Werner Korf
The hippocampus is subjected to diurnal/circadian rhythms on both the morphological and molecular levels. Certain aspects of cell proliferation in the adult hippocampus are regulated by melatonin and accompanied by apoptosis to ensure proper tissue maintenance and function. The present study investigated Zeitgeber time (ZT)-dependent changes in cell proliferation and apoptosis in the adult murine hippocampus and their regulation by melatonin receptor type1 and type2 (MT1/2)-mediated signaling. Adult melatonin-proficient C3H/HeN mice and melatonin-proficient (C3H/HeN) mice with targeted deletion of MT1/2 were adapted to a 12-hours light, 12-hours dark photoperiod and were sacrificed at ZT00, ZT06, ZT12, and ZT18...
January 18, 2017: Hippocampus
T Joyce Tiong, Tissa Chandesa, Yeow Hong Yap
One common method to determine the existence of cavitational activity in power ultrasonics systems is by capturing images of sonoluminescence (SL) or sonochemiluminescence (SCL) in a dark environment. Conventionally, the light emitted from SL or SCL was detected based on the number of photons. Though this method is effective, it could not identify the sonochemical zones of an ultrasonic systems. SL/SCL images, on the other hand, enable identification of 'active' sonochemical zones. However, these images often provide just qualitative data as the harvesting of light intensity data from the images is tedious and require high resolution images...
May 2017: Ultrasonics Sonochemistry
Carlo La Spina, Adriano Carnevali, Alessandro Marchese, Giuseppe Querques, Francesco Bandello
PURPOSE: Optical coherence tomography angiography (OCTA) allows delineating the foveal avascular zone (FAZ) easily and noninvasively. The present study aims to test reproducibility and reliability of FAZ evaluation by means of OCTA in different settings. METHODS: Twenty-four eyes of 24 normal subjects were investigated using AngioVue OCTA Imaging System. A series of OCTA acquisitions were taken both in basal and in different experimental settings after vasoactive stimuli...
December 20, 2016: Retina
Koustubh M Vaze, Charlotte Helfrich-Förster
Insects inhabiting the temperate zones measure seasonal changes in day or night length to enter the overwintering diapause. Diapause induction occurs after the duration of the night exceeds a critical night length (CNL). Our understanding of the time measurement mechanisms is continuously evolving subsequent to Bünning's proposal that circadian systems play the clock role in photoperiodic time measurement (Bünning, 1936). Initially, the photoperiodic clocks were considered to be either based on circadian oscillators or on simple hour-glasses, depending on 'positive' or 'negative' responses in Nanda-Hamner and Bünsow experiments (Nanda & Hammer, 1958; Bünsow, 1960)...
December 2016: Physiological Entomology
Todd A Olsen, Craig C Brandt, Scott C Brooks
Mercury (Hg) methylation and methylmercury (MMHg) demethylation activity of periphyton biofilms from the industrially contaminated East Fork Poplar Creek, Tennessee (EFPC) were measured during 2014-2016 using stable Hg isotopic rate assays. (201)Hg(II) and MM(202)Hg were added to intact periphyton samples in ambient streamwater and the formation of MM(201)Hg and loss of MM(202)Hg were monitored over time and used to calculate first-order rate potentials for methylation and demethylation. The influences of location, temperature/season, light exposure and biofilm structure on methylation and demethylation potentials were examined...
October 18, 2016: Environmental Science & Technology
Zongbo Yang, Jun Cheng, Qing Ye, Jianzhong Liu, Junhu Zhou, Kefa Cen
In this study, computational fluid dynamics (CFD) was used to systemically analyze the movement of algae in a vortex flow field produced by up-down chute baffles. The average cell light/dark (L/D) cycle period, vertical fluid velocity, fraction of time the algae was resides in light zone and the L/D cycle period were investigated under different paddlewheel speeds and microalgal concentrations. Results showed that the L/D cycle period decreased but the vertical fluid velocity increased when the up-down chute baffles were used...
November 2016: Bioresource Technology
Chun Chou, Daniel J Verbaro, Elena Tonc, Melanie Holmgren, Marina Cella, Marco Colonna, Deepta Bhattacharya, Takeshi Egawa
B cells diversify and affinity mature their antigen receptor repertoire in germinal centers (GCs). GC B cells receive help signals during transient interaction with T cells, yet it remains unknown how these transient T-B interactions in the light zone sustain the subsequent proliferative program of selected B cells that occurs in the anatomically distant dark zone. Here, we show that the transcription factor AP4 was required for sustained GC B cell proliferation and subsequent establishment of a diverse and protective antibody repertoire...
September 20, 2016: Immunity
Elisa Ferretti, Maurilio Ponzoni, Claudio Doglioni, Vito Pistoia
The germinal center (GC) is a dynamic structure formed by proliferating B cells in the follicles of secondary lymphoid organs during T cell-dependent antibody responses to exogenous antigens. GC is composed by a dark zone, enriched in proliferating centroblasts (CBs), and a light zone where CBs migrate and transform into centrocytes (CCs), a minority of which is selected to survive, undergoes Ig class-switch recombination, and differentiates into memory B cells or long-lived plasma cells. CBs express CXCR4 and are attracted to the dark zone by stromal cell-derived CXCL12, whereas CCs express CXCR5 and are recruited to the light zone along a gradient of CXCL13 produced by follicular dendritic cells (FDCs)...
August 26, 2016: Journal of Leukocyte Biology
Mehrez Gammoudi, Willi Salvenmoser, Saïda Tekaya, Bernhard Egger
Based on light and electron microscopy observations, oogenesis in the cotylean polyclad Prosthiostomum siphunculus was investigated for the first time. The numerous ovarian follicles are dispersed essentially in the dorsal parenchyma. In the follicles, a ventral germinative zone with undifferentiated germs cells of different sizes and a dorsal growth zone with larger growing and abortive oocytes are present. The oogenesis could be subdivided into four stages: (1) Oogonia with a dark nucleus and a dark, ribosome-rich cytoplasm...
November 2016: Cell Biology International
Dorothea Reimer, Adrian Ys Lee, Jennifer Bannan, Phillip Fromm, Ervin E Kara, Iain Comerford, Shaun McColl, Florian Wiede, Dirk Mielenz, Heinrich Körner
The CC-chemokine receptor 6 (CCR6) can be detected on naive and activated B cells. Counterintuitively, its absence accelerates the appearance of germinal centres (GCs) and increases the production of low-affinity antibodies. The detailed mechanism of CCR6 function during the humoral response has remained elusive, but previously we identified a distinct CCR6(high) B-cell population in vivo early after antigenic challenge. In this study, we defined this population specifically as early, activated pre-GC B cells...
January 2017: Immunology and Cell Biology
Sally E Trabucco, Rachel M Gerstein, Hong Zhang
The germinal center (GC) reaction produces high-affinity Abs for a robust adaptive immune response. When dysregulated, the same processes cause GC B cells to become susceptible to lymphomagenesis. It is important to understand how the GC reaction is regulated. In this study, we show that transcription factor YY1 is required to maintain a robust GC reaction in mice. Selective ablation of YY1 significantly decreased in the frequency and number of GC B cells during the GC reaction. This decrease of GC B cells was accompanied by increased apoptosis in these cells...
September 1, 2016: Journal of Immunology: Official Journal of the American Association of Immunologists
Alexander Sumaroka, Rodrigo Matsui, Artur V Cideciyan, David B McGuigan, Rebecca Sheplock, Sharon B Schwartz, Samuel G Jacobson
PURPOSE: To study transition zones from normal to abnormal retina in Usher syndrome IB (USH1B) caused by myosin 7A (MYO7A) mutations. METHODS: Optical coherence tomography (OCT) scattering layers in outer retina were segmented in patients (n = 16, ages 2-42; eight patients had serial data, average interval 4.5 years) to quantify outer nuclear layer (ONL) and outer segments (OS) as well as the locus of EZ (ellipsoid zone) edge and its extent from the fovea. Static perimetry was measured under dark-adapted (DA) and light-adapted (LA) conditions...
July 1, 2016: Investigative Ophthalmology & Visual Science
Kamran Tahir, Aftab Ahmad, Baoshan Li, Sadia Nazir, Arif Ullah Khan, Tabassum Nasir, Zia Ul Haq Khan, Rubina Naz, Muslim Raza
Water purification is one of the worldwide problem and most of the conventional methods are associated with a number of drawbacks. Therefore it is the need of the day to develop new methods and materials to overcome the problem of water purification. In this research work we present a simple and green approach to synthesize silver decorated titanium dioxide (Ag/TiO2) nanocomposite with an efficient photo catalytic activities. Phytochemicals of the Cestrum nocturnum leaf extract were used to synthesize silver nanoparticles (AgNPs), Titanium dioxide (TiO2) and Ag/TiO2 nanocomposite...
September 2016: Journal of Photochemistry and Photobiology. B, Biology
Paulo Cartaxana, Sónia Cruz, Carla Gameiro, Michael Kühl
Changes in biomass and photosynthesis of a diatom-dominated microphytobenthos (MPB) intertidal community were studied over a diel emersion period using a combination of O2 and scalar irradiance microprofiling, variable chlorophyll (Chl) fluorescence, and pigment analysis. The MPB biomass in the photic zone (0-0.5 mm) of the sediment exposed to low irradiance (150 μmol photons m(-2) s(-1)) showed a >2-fold increase during the first hours of the emersion period, reaching >0.2 mg Chl a cm(-3). Concentrations of Chl a started to decrease half-way through the emersion period, almost 2 h before tidal inundation...
2016: Frontiers in Microbiology
Norbert Babai, Anna Sendelbeck, Hanna Regus-Leidig, Michaela Fuchs, Jasmin Mertins, Kerstin Reim, Nils Brose, Andreas Feigenspan, Johann Helmut Brandstätter
UNLABELLED: Complexins (Cplxs) are SNARE complex regulators controlling the speed and Ca(2+) sensitivity of SNARE-mediated synaptic vesicle fusion. We have shown previously that photoreceptor ribbon synapses in mouse retina are equipped with Cplx3 and Cplx4 and that lack of both Cplxs perturbs photoreceptor ribbon synaptic function; however, Cplx3/4 function in photoreceptor synaptic transmission remained elusive. To investigate Cplx3/4 function in photoreceptor ribbon synapses, voltage-clamp recordings from postsynaptic horizontal cells were performed in horizontal slice preparations of Cplx3/4 wild-type (WT) and Cplx3/4 double knock-out (DKO) mice...
June 22, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
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