CORRELATION OF ARTICULAR CARTILAGE THICKNESS MEASUREMENTS MADE WITH MAGNETIC RESONANCE IMAGING,MAGNETIC RESONANCE ARTHROGRAPHY,AND COMPUTED TOMOGRAPHIC ARTHROGRAPHY WITH GROSS ARTICULAR CARTILAGE THICKNESS IN THE EQUINE METACARPOPHALANGEAL JOINT

Osteoarthritis of the metacarpophalangeal joint is common cause of lameness in equine athletes, and is hallmarked by articular cartilage damage. An accurate, noninvasive method for measuring cartilage thickness would be beneficial to screen for cartilage injury and allow for prompt initiation of interventional therapy. The objective of this methods comparison study was to compare computed tomographic arthrography (CTA), magnetic resonance imaging (MRI), and magnetic resonance arthrography (MRA) measurements of articular cartilage thickness with gross measurements in the metacarpophalangeal joint of Thoroughbred horses. Fourteen cadaveric, equine thoracic limbs were included. Limbs were excluded from the study if pathology of the metacarpophalangeal articular cartilage was observed with any imaging modality. Articular cartilage thickness was measured in nine regions of the third metacarpal bone and proximal phalanx on sagittal plane MRI sequences. After intra‐articular contrast administration, the measurements were repeated on sagittal plane MRA and sagittal CTA reformations. In an effort to increase cartilage conspicuity, the volume of intra‐articular contrast was increased from 14.5 ml, to maximal distention for the second set of seven limbs. Mean and standard deviation values were calculated, and linear regression analysis was used to determine correlations between gross and imaging measurements of cartilage thickness. This study failed to identify one imaging test that consistently yielded measurements correlating with gross cartilage thickness. Even with the use of intra‐articular contrast, cartilage surfaces were difficult to differentiate in regions where the cartilage surfaces of the proximal phalanx and third metacarpal bone were in close contact with each other.     

Concentration,Activity and Biochemical Characterization of Myeloperoxidase in Fresh and Post‐Thaw Equine Semen and their Implication on Freezability

Myeloperoxidase (MPO) is a pro‐oxidant enzyme associated with decreased motility in thawed equine semen. This study aimed to describe MPO concentration, activity and subunits in raw and thawed semen and to correlate these data with motilities in raw and thawed semen. Semen samples from five stallions were collected four times. Motilities were assessed in raw and thawed semen. MPO assays were performed in raw seminal plasma, raw sperm‐rich pellet and thawed semen. Total and active MPO concentrations were, respectively, assayed by enzyme‐linked immunosorbent assay and specific immunological extraction followed by enzymatic detection. MPO subunits present in semen were characterized by Western blot. Purified active MPO was added in saline solution and freezing extender to control its activity during freezing procedure. Differences between medians were determined using Kruskal–Wallis test, and correlations were determined using Spearman's test for nonparametric data. Active MPO concentration was low in seminal plasma and thawed semen, but high in pellet (p = 0.0058), as the opposite relation was observed for total MPO concentration (p < 0.0001). In seminal plasma and post‐thaw semen, inactive 86‐kDa MPO precursor was mainly observed. Purified MPO activity was decreased in the extender (p = 0.0286). MPO activity in pellet was highly correlated with thawed progressive motility (r = ?0.5576, p = 0.0086). Inactive MPO precursor and unknown low molecular weight inactive MPO precursor subunits explain low MPO activity in semen. Major MPO activity was observed in pellet, and post‐thaw loss of activity is partially explained by MPO inactivation in extender. Thawed semen motility was negatively correlated with MPO activity in pellet, becoming a potential freezability predictor.     

Contribution of malolactic fermentation by Oenococcus oeni and Lactobacillus plantarum to the changes in the nonanthocyanin polyphenolic composition of red wine

The changes in the nonanthocyanin phenolic composition during red wine malolactic fermentation carried out spontaneously and by four different starter cultures of the species Oenococcus oeni and Lactobacillus plantarum were examined to determine whether differences in nonanthocyanin polyphenolic compounds could be attributed to the lactic acid bacteria (LAB) strain that performs this important step of the wine-making process. The polyphenolic compounds were analyzed by high-performance liquid chromatography with photodiode array detection and HPLC with electrospray ionization-mass spectrometry detection. The malolactic cultures selected for this study were indigenous wine LAB strains from the A.O.C. Rioja (Spain). Results showed different malolactic behaviors in relation to wine phenolic compositions for O. oeni and L. plantarum, and also, a diversity was found within each group. The hydroxycinnamic acids and their derivatives, the flavonols and their glycosides, the flavanol monomers and oligomers, and trans-resveratrol and its glucoside were the main compounds modified by the different LAB. The wild LAB population exerted a greater impact in the wine content of some of these phenolic compounds than the inoculated selected monocultures of this study.     

Splenic lymphoma in a short-beaked echidna (Tachyglossus aculeatus)

A 23-year-old, male short-beaked echidna ( Tachyglossus aculeatus ) housed at a North American zoo was successfully treated for flea-associated anaemia, but subsequently died. Cause of death was presumptive septicaemia secondary to splenic lymphoma. This is only the fifth case of neoplasia reported in this monotreme species, and the first from outside of Australia.     

Skeletal muscle adaptations and biomechanical properties of tendons in response to jump exercise in rabbits

Pen housing has been proposed in rabbits as an alternative to standard-sized cages. Rabbits reared in pens show greater physical activity. This study investigated whether jump exercise could modify body composition, muscle biochemical and histological characteristics, and some meat quality traits, including the biomechanical properties of tendons. Male weaned rabbits of similar BW (793 +/- 11 g) were either reared in giant collective cages and had to jump over obstacles to get food and water for 35 consecutive days (EXE), or confined in small isolated cages (SEDN). Rabbits were weighed weekly to determine ADG (n = 79 EXE; n = 46 SEDN) and ADFI (n = 9 cages in EXE; n = 46 cages in SEDN). At approximately 10 wk of age, rabbits were slaughtered in 2 series. After overnight chilling, carcasses in the first series (n = 30 EXE; n = 27 SEDN) were divided into fore, intermediate, and hind parts. Color and ultimate pH were recorded in the biceps femoris (BF) and LM. The Achilles tendon and patellar ligament were dissected from the legs and cooked. Muscles [semimembranosus proprius, semimembranosus accessorius (SMA), and BF] were harvested from the legs in a subset of animals from the second series (n = 10 in EXE; n = 9 in SEDN). Both ADG and ADFI were slightly reduced (P < 0.10) in EXE rabbits compared with SEDN rabbits. Exercised rabbits showed a greater (P = 0.01) proportion of hind parts than SEDN rabbits. Enzyme activities of 3-hydroxyacyl-CoA dehydrogenase and citrate synthase, which play key roles in fatty acid oxidation and the terminal oxidative degradation of nutrients, respectively, were increased in the semimembranosus proprius, SMA (except citrate synthase), and BF muscles of EXE rabbits compared with SEDN rabbits. Only SMA exhibited a decreased (P = 0.05) activity of the glycolytic enzyme, lactate dehydrogenase, in EXE rabbits compared with SEDN animals. Total lipid content, mean diameter of perimysial adipocytes, and activities of core lipogenic enzymes in the SMA and BF muscles did not differ between EXE and SEDN rabbits. Meat color in BF was shifted toward greater a* (red; P = 0.001) and b* (yellow; P = 0.02) values in EXE rabbits compared with SEDN rabbits. Cooked Achilles tendon and patellar ligaments in the legs had greater stiffness (P < or = 0.05) in EXE rabbits compared with SEDN rabbits. This experiment demonstrates that rabbit muscles turn to a more oxidative metabolic pattern in response to jump exercise. The quality of attachment of cooked meat to bone is also improved in active rabbits.     

Modulation of tobacco bacterial disease resistance using cytosolic ascorbate peroxidase and Cu,Zn‐superoxide dismutase

The effect of over‐expression in tobacco plants of cytosolic Cu,Zn‐superoxide dismutase (cytsod) and ascorbate peroxidase (cytapx) alone, or in combination, against bacterial wildfire and crown gall diseases, caused by Pseudomonas syringae pv. tabaci and Agrobacterium tumefaciens, respectively, was investigated. Disease tolerance was observed in all the transgenic lines against the two causal agents, with various levels of resistance, with the double transformants (lines 35 and 39) the most resistant against bacterial wild fire. In the case of P. syringae pv. tabaci, disease tolerance and symptom decrease was associated with a lower bacterial population and a higher level of several antioxidant defence enzymes. Transgenic lines also exhibited an enhanced tolerance against A. tumefaciens, with the transgenic line harbouring cytapx (line 51) the most resistant to crown gall disease. However, this was only observed with strain C58 among the three pathogenic strains tested. These results suggest that cytosolic antioxidant defences have a role in increasing tolerance to the oxidative stress caused by some bacterial pathogens, and resistance of these tobacco lines to wildfire disease seems to be independent of tissue necrosis.     

Membrane fusion intermediates via directional and full assembly of the SNARE complex

Cellular membrane fusion is thought to proceed through intermediates including docking of apposed lipid bilayers, merging of proximal leaflets to form a hemifusion diaphragm, and fusion pore opening. A membrane-bridging four-helix complex of soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) mediates fusion. However, how assembly of the SNARE complex generates docking and other fusion intermediates is unknown. Using a cell-free reaction, we identified intermediates visually and then arrested the SNARE fusion machinery when fusion was about to begin. Partial and directional assembly of SNAREs tightly docked bilayers, but efficient fusion and an extended form of hemifusion required assembly beyond the core complex to the membrane-connecting linkers. We propose that straining of lipids at the edges of an extended docking zone initiates fusion.     

红色类胡萝卜素在蛋黄着色中的应用

颜色在食物感觉中起重要的作用。明亮鲜艳的颜色会刺激食欲，增加人们对食品的喜好程度，并且也是一种视觉享受。据人们的一个基本经验就是适合食用的特定食品应有其特定的颜色fKlaui和Bauemfeind，1981)。蛋黄就是一个确切的例子，当家禽饲喂情况较差或受到疾病影响时，     

Comparison among available marker systems for cereal introgression breeding: A practical perspective

Summary There is an increasing amount of public sequence information for the main cultivated cereals, such as wheat and barley. It is not foreseeable that comparable efforts or resources could be devoted to related wild species. However, wild species are interesting sources of genetic variation through introgression breeding. Comparative genomics can be a helpful approach to make use of the available genomic resources. In this context, the potential of the wild barley species Hordeum chilense has been explored in recent years. It exhibits great levels of polymorphism and high crossability with different cereal genera. In addition, interesting biotic and abiotic stress resistance genes, and important quality traits like carotene content and seed storage protein variability shown in the species are also expressed in wheat backgrounds, and are the basis of a breeding program. Different approaches have been undertaken for tagging H. chilense genomic regions in a wheat background. The search for the most suitable DNA marker system started with the development of RAPD and SCAR markers due to a lack of sequence information from the wild species. Transferability of markers from wheat and barley (like STSs or SSRs) have also been useful approximations. More recently, SNP development is being accomplished for the species. In this work, the situation and prospects with the available molecular tools are considered from a practical point of view.