A facemask for gaseous anesthesia in laboratory rodents and chicks that allows easy access to the eyes for ophthalmic procedures

Purpose The purpose of this study is to report a method for making a cheap and effective anesthesia facemask for laboratory rodents and chicks that allows access to the eyes for ophthalmic procedures such as electroretinography (ERG) and optical coherence tomography (OCT). Methods The facemask is fabricated from a bulb syringe and a medicine dropper (Luvs^®, Jamaica, NY) both intended for use in infants. The tip of the bulb syringe is removed to make a plastic cone (1.5 cm in length) to fit over the animal’s nose. The bulb is removed from the medicine dropper and a small hole on the side of bulb near the closed end made into which the narrow end of the plastic cone is fitted and the joint glued with a hot glue gun. The facemask is then attached over the anesthetic tubing. Results Following induction of anesthesia, the facemask and a nonrebreathing circuit (Baines system) are suitable to maintain anesthesia in laboratory rodents and chicks while allowing ready access to the eyes for ERG and OCT. The mask fits snuggly, reducing leakage of anesthetic gasses and it has a minimum of deadspace. Conclusions The materials required for making the facemask are cheap and readily available and it is easy to fabricate. We found it excellent for use with mice and chicks, and it allows easy access to the eyes for techniques such as ERG and OCT.     

Effect of reddening-ripening on the antioxidant activity of polyphenol extracts from cv. 'Annurca' apple fruits

Apple is among the most consumed fruits worldwide, and several studies suggest that apple polyphenols could play a role in the prevention of degenerative diseases. 'Annurca' apple fruit undergoes, after harvest, a typical reddening treatment to turn the apples' skin red, and it is noted for its high firmness. This paper reports the effect of reddening-ripening treatment on polyphenol concentration and antioxidant activity of both peel and flesh extracts. The in vitro antioxidant properties have been compared with the protective effect against the cytotoxic effects of reactive oxygen species using Caco-2 cells as model system. Pretreatment of cells with different polyphenolic apple extracts provides a remarkable protection against oxidative damage. This effect seems to be associated with the antioxidant activity of 'Annurca' apple polyphenolic compounds. The flesh has antioxidant properties comparable to those possessed by the peel. Neither the reddening nor the fruit conservation causes changes in the antioxidant properties possessed by this apple variety. The data indicate that polyphenolic compounds in 'Annurca' apples are relatively stable in the peel and also in the flesh; therefore, the health benefits of polyphenols should be maintained during long-term storage. Finally, a diet rich in apple antioxidants could exert a beneficial effect in the prevention of intestinal pathologies related to the production of reactive oxygen species.     

Structure-based mechanistic insights into DNMT1-mediated maintenance DNA methylation

DNMT1, the major maintenance DNA methyltransferase in animals, helps to regulate gene expression, genome imprinting, and X-chromosome inactivation. We report on the crystal structure of a productive covalent mouse DNMT1(731-1602)-DNA complex containing a central hemimethylated CpG site. The methyl group of methylcytosine is positioned within a shallow hydrophobic concave surface, whereas the cytosine on the target strand is looped out and covalently anchored within the catalytic pocket. The DNA is distorted at the hemimethylated CpG step, with side chains from catalytic and recognition loops inserting through both grooves to fill an intercalation-type cavity associated with a dual base flip-out on partner strands. Structural and biochemical data establish how a combination of active and autoinhibitory mechanisms ensures the high fidelity of DNMT1-mediated maintenance DNA methylation.     

Effects of different positions during transport on physiological and behavioral changes of horses

The aim of this study was to evaluate the effect of different transport positions on some physiological parameters in racehorses and their behavior patterns during and after the journey. Twelve horses made 3-hour journeys of 200 km on the same route, with the same driver, and in 3 different positions: facing forward, backward, and sideways in relation to the direction of travel. Physiological and behavioral parameters were registered before, during, and after the journey. Horses were checked at 5 different times: at rest (T0), at loading (T1), at unloading (T2), and at 2 (T3) and 4 (T4) hours after return from the journey. At each check, heart rate, respiratory rate, and rectal temperature were measured and blood samples were collected by jugular vein puncture to assess cortisol, packed cell volume, total protein, albumin, glucose, creatinine, triglycerides, cholesterol, urea, creatine kinase, lactate dehydrogenase, alanine transaminase, aspartate transaminase, alkaline phosphatase, calcium, phosphorus, and chlorine. Loading and unloading were filmed. Behavioral patterns were recorded by direct observation, during the travel, 2 and 4 hours after arrival in a new stall. The same parameters were recorded at the same times (excluding loading and unloading) in a control group that did not travel. All data were analyzed using a repeated-measures analysis (analysis of variance). Loading produced an increase of heart rate and packed cell volume in comparison with rest values. Horses facing in the direction of travel during journey made fewer forward, backward, and sideways movements than others, whereas horses traveling sideways lost their balance and touched the stall rails less frequently. Highest serum cortisol concentration value was recorded soon after unloading horses that had faced in the direction of travel (P < 0.01). Two hours after return, horses that had traveled sideways revealed an increase of creatine kinase (P < 0.01). The traveling position in the vehicle did not appear to affect postjourney behavior. In comparison with the control group, the horses that had traveled consumed concentrate faster, spent more time eating hay, and drank more frequently in the first 2 hours after return from the journey. Front-facing position led to an increase in serum cortisol concentration, whereas the sideways position caused some muscular tension, which disappeared 4 hours after the journey. Although facing backward was the travel position that provoked the greatest number of horses’ movements, it did not have a negative effect on physiological and behavioral parameters during and after the journey. We concluded that for Standardbred trotters accustomed to travel, the latter may be the less stressful position during a 200-km transport.     

Habitat fragmentation reduces genetic diversity and connectivity among toad populations in the Brazilian Atlantic Coastal Forest

Tropical rainforests are becoming increasingly fragmented and understanding the genetic consequences of fragmentation is crucial for conservation of their flora and fauna. We examined populations of the toad Rhinella ornata, a species endemic to Atlantic Coastal Forest in Brazil, and compared genetic diversity among small and medium forest fragments that were either isolated or connected to large forest areas by corridors. Genetic differentiation, as measured by F_ST, was not related to geographic distance among study sites and the size of the fragments did not significantly alter patterns of genetic connectivity. However, population genetic diversity was positively related to fragment size, thus haplotype diversity was lowest in the smallest fragments, likely due to decreases in population sizes. Spatial analyses of genetic discontinuities among groups of populations showed a higher proportion of barriers to gene flow among small and medium fragments than between populations in continuous forest. Our results underscore that even species with relatively high dispersal capacities may, over time, suffer the negative genetic effects of fragmentation, possibly leading to reduced fitness of population and cases of localized extinction.     

Natural Products from Antarctic Colonial Ascidians of the Genera Aplidium and Synoicum: Variability and Defensive Role

Ascidians have developed multiple defensive strategies mostly related to physical, nutritional or chemical properties of the tunic. One of such is chemical defense based on secondary metabolites. We analyzed a series of colonial Antarctic ascidians from deep-water collections belonging to the genera Aplidium and Synoicum to evaluate the incidence of organic deterrents and their variability. The ether fractions from 15 samples including specimens of the species A. falklandicum, A. fuegiense, A. meridianum, A. millari and S. adareanum were subjected to feeding assays towards two relevant sympatric predators: the starfish Odontaster validus, and the amphipod Cheirimedon femoratus. All samples revealed repellency. Nonetheless, some colonies concentrated defensive chemicals in internal body-regions rather than in the tunic. Four ascidian-derived meroterpenoids, rossinones B and the three derivatives 2,3-epoxy-rossinone B, 3-epi-rossinone B, 5,6-epoxy-rossinone B, and the indole alkaloids meridianins A–G, along with other minoritary meridianin compounds were isolated from several samples. Some purified metabolites were tested in feeding assays exhibiting potent unpalatabilities, thus revealing their role in predation avoidance. Ascidian extracts and purified compound-fractions were further assessed in antibacterial tests against a marine Antarctic bacterium. Only the meridianins showed inhibition activity, demonstrating a multifunctional defensive role. According to their occurrence in nature and within our colonial specimens, the possible origin of both types of metabolites is discussed.     

Development and application of solvent-free extraction for the detection of aflatoxin M1 in dairy products by enzyme immunoassay

The official methods for the quantification of aflatoxin M1 in dairy products (cheese and yogurt) include extraction into dichloromethane or chloroform, evaporation of the solvent, partitioning of the reconstituted residue with hexane, and subsequent analysis. To secure a rapid and inexpensive screen for aflatoxin M1 contamination, a sensitive competitive ELISA, using a rabbit polyclonal antibody, was developed for measuring aflatoxin M1 in milk and used in a comparative study for measuring the extraction efficiency of aflatoxin M1 in aqueous or organic solvent buffers using yogurt samples. An aqueous sodium citrate solution was found to be suitable for extracting aflatoxin M1, thus eliminating the need for organic solvents. The citrate extraction proved to be efficient (recovery ranged from 70 to 124%) in fortified samples of very different kinds of dairy products, including yogurt and six types of cheese. Fourteen yogurt and cheese samples were extracted with citrate solution and analyzed by ELISA. A good correlation was observed (y=0.95x-0.59, r2=0.98) when the data were compared with those obtained through the official method, across a wide range of aflatoxin M1 contaminations (10-200 ng/kg).     

Monitoring of <Emphasis Type="Italic">Francisella noatunensis</Emphasis> subsp. <Emphasis Type="Italic">orientalis</Emphasis> in farmed Nile tilapia (<Emphasis Type="Italic">Oreochromis niloticus</Emphasis>) in Brazil

Francisella noatunensis orientalis is a bacterium that causes emerging bacteriosis in Nile tilapia (Oreochromis niloticus) in many parts of the world, including Brazil. It is a non-motile, Gram-negative, strictly aerobic, facultative intracellular coccobacillus. This species of bacteria is responsible for low to high mortality in fish farms, causing economic losses for fish farmers. This study aimed to detect the presence of F. noatunensis orientalis using qPCR (real-time polymerase chain reaction) and to describe lesions caused by the bacterium in O. niloticus in Brazilian aquaculture. For this purpose, 360 fish from six fish farms (30 per farm) were sampled at two time points (n = 180 per sampling). Necropsies and histopathology were performed for lesion observation, in addition to qPCR and sequencing for detection and identification of Francisella species. Environmental data were collected using a multiparameter sonde YSI EXO2. All measured limnological variables were within the optimum range for cultivation of Nile tilapia. The major lesions present were melanization of the skin, splenomegaly, granulomas, and inflammatory cell responses. The prevalence of francisellosis varied from 0 to 86.66% between time periods and fish farms analyzed, and an outbreak was observed during the second sampling period. This study describes the prevalence of francisellosis in O. niloticus and reports that the lesions found are not exclusively associated with this bacterial disease.     

Ecological diversity of sediment rhizobacteria associated with Phragmites australis along a drainage canal in the Yellow River watershed

Journal of Soils and Sediments - Spatial distribution on a regional scale of the rhizobacterial communities of Phragmites australis stands was investigated along the Yellow River watershed, China....