Fetal and adult hematopoietic stem cells give rise to distinct T cell lineages in humans

Although the mammalian immune system is generally thought to develop in a linear fashion, findings in avian and murine species argue instead for the developmentally ordered appearance (or "layering") of distinct hematopoietic stem cells (HSCs) that give rise to distinct lymphocyte lineages at different stages of development. Here we provide evidence of an analogous layered immune system in humans. Our results suggest that fetal and adult T cells are distinct populations that arise from different populations of HSCs that are present at different stages of development. We also provide evidence that the fetal T cell lineage is biased toward immune tolerance. These observations offer a mechanistic explanation for the tolerogenic properties of the developing fetus and for variable degrees of immune responsiveness at birth.     

ANXITANE® tablets reduce fear of human beings in a laboratory model of anxiety-related behavior

Anxiety and fear are common underlying factors in many canine behavior problems that impair the human–pet bond and often result in abandonment, relinquishment, or euthanasia. A combination of behavioral and pharmacological interventions is used to ameliorate the behavioral signs associated with anxiety-related behaviors in dogs, but there continues to be need for effective interventions. The current study examined the effects of the nutraceutical ANXITANE^® (l-Theanine) chewable tablets on fear of unfamiliar human beings. We first characterized dogs as anxious on the basis of the existence of a fear response to human beings in their home-pen. We then demonstrated that dogs characterized as anxious (N = 10) showed reduced interaction with an unknown human being as compared with normal controls (N = 7). The effect of an administration of ANXITANE^® tablets (N = 5) on these anxious Beagle dogs was compared with placebo (N = 5). Objective behavioral measures of anxiety were obtained using an open-field test, a human interaction test, and an actiwatch protocol that allowed monitoring of activity over 24-hours. The ANXITANE^® tablets-treated dogs showed greater human interaction and approach than the placebo control group, and no side effects related to treatment, including motor stimulant or sedative effects, were seen. The current study suggests that ANXITANE^® tablets are effective for reducing fearful behavior toward unfamiliar human beings in dogs and supports their use for treating anxiety-related behaviors.     

Effect of quercetin on platelet spreading on collagen and fibrinogen and on multiple platelet kinases

α₂β₁ and α_IIbβ₃ integrins, that support platelet adhesion to collagen and fibrinogen, respectively, share common signaling molecules. The effect of quercetin on platelet static adhesion to collagen and fibrinogen was assessed and correlated with its kinase inhibitory activity. Quercetin strongly abrogated PI3K and Src kinases, mildly inhibited Akt1/2, and slightly affected PKC, p38 and ERK1/2. Quercetin or the combined use of adenosine diphosphate and thromboxane A₂ inhibitors abrogated platelet spreading on these surfaces to a similar extent. We suggest that the inhibitory effect of quercetin on platelet kinases blocks early signaling events preventing a complete platelet spreading.     

Identification of the G143A mutation associated with QoI resistance in Cercospora beticola field isolates from Michigan,United States

BACKGROUND: Cercospora leaf spot (CLS), caused by the fungus Cercospora beticola, is the most serious foliar disease of sugar beet (Beta vulgaris L.) worldwide. Disease control is mainly achieved by timely fungicide applications. In 2011, CLS control failures were reported in spite of application of quinone outside inhibitor (QoI) fungicide in several counties in Michigan, United States. The purpose of this study was to confirm the resistant phenotype and identify the molecular basis for QoI resistance of Michigan C. beticola isolates. RESULTS: Isolates collected in Michigan in 1998 and 1999 that had no previous exposure to the QoI fungicides trifloxystrobin or pyraclostrobin exhibited QoI EC₅₀ values of ?0.006 µg mL^?1. In contrast, all isolates obtained in 2011 exhibited EC₅₀ values of > 0.92 µg mL^?1 to both fungicides and harbored a mutation in cytochrome b (cytb) that led to an amino acid exchange from glycine to alanine at position 143 (G143A) compared with baseline QoI‐sensitive isolates. Microsatellite analysis of the isolates suggested that QoI resistance emerged independently in multiple genotypic backgrounds at multiple locations. A real‐time PCR assay utilizing dual‐labeled fluorogenic probes was developed to detect and differentiate QoI‐resistant isolates harboring the G143A mutation from sensitive isolates. CONCLUSION: The G143A mutation in cytb is associated with QoI resistance in C. beticola. Accurate monitoring of this mutation will be essential for fungicide resistance management in this pathosystem. Copyright © 2012 Society of Chemical Industry     

Protein Composition of Seminal Plasma in Fractionated Stallion Ejaculates

Seminal plasma (SP) contains several types of compounds derived from the epididymides and accessory glands. The aim of this study was to examine the protein composition of different ejaculate fractions. Trial I: fractionated ejaculates were collected from two normal and two subfertile stallions. Samples containing pre‐sperm fluid and the first sperm‐rich jets (HIGH‐1), the main sperm‐rich portion (HIGH‐2), the jets with low sperm concentrations (LOW), and a combined whole‐ejaculate (WE) sample was centrifuged, and the SP was filtered and frozen. A part of each SP sample was stored (5°C, 24 h) with spermatozoa from HIGH‐2 and skim milk extender. Sperm motility was evaluated after storage in extender mixed with the stallion’s own SP or SP from one of the other stallions (sperm from a normal stallion stored in SP from a subfertile stallion and vice versa). Protein composition was analysed using reverse‐phase liquid chromatography (RP‐HPLC), N‐terminal sequencing and mass spectrometry. The area‐under‐the‐curve (AUC) was used for quantitative comparison of proteins within fractions. Trial II: semen samples were collected from seven stallions. Fractions with the highest (HIGH) and lowest (LOW) sperm concentrations and WE samples were examined using SDS‐PAGE and densitometry. No significant differences emerged between fractions in the AUC‐values of the Horse Seminal Protein‐1 (HSP‐1) and HSP‐2 peaks, or the peak containing HSP‐3 and HSP‐4 (HSP‐3/4). Levels of HSP‐1, HSP‐2 and HSP‐3/4 were not significantly correlated with total sperm motility, progressive sperm motility or average path velocity after storage. Significant differences between ejaculate fractions in the amount of different protein groups present in SP were not found in Trial I; but in Trial II, the proteins in the 60–70 kDa range were more abundant in LOW than in HIGH and WE, indicating that this band contained proteins derived mainly from the seminal vesicles, which produce most of the SP in LOW.     

Variability in sensory attributes in common bean (Phaseolus vulgaris L.): a first survey in the Iberian secondary diversity center

Few studies have explored sensory variability in beans. We used geographic, agronomic, morphological, and genetic criteria to select numerous groups of landraces from among the many collected in Catalonia (northeast Spain). Beans cultivated in a single location to avoid environmental effects were submitted to a trained panel for sensory analysis. We used multiple linear regression to explore whether the flavor and texture of the seed (evaluable only by tasting after cooking) can be estimated from easily measurable traits like the appearance of the beans. The degree of variability found for all sensory traits (coefficients of variation: 20–70 %) was similar to that of agronomic traits; however, entries were grouped differently for sensory and agronomic traits, suggesting independent evolution. Negative genotypic correlations between some sensory traits will probably hinder attempts to achieve ideotypes combining low seed-coat perceptibility, low mealiness, and high flavor. Regressions between easily measurable traits (agronomic and culinary traits and appearance of the seeds) and flavor and texture yielded R² values ranging from 0.47 to 0.64. We consider these values good enough for rough screening of sensory attributes in genetic resources studies or breeding.     

The reptilian thyroid and parathyroid glands.

The field of reptilian clinical endocrinology is still in its infancy. The thyroid and parathyroid glands are intimately involved with many basic metabolic functions. These glands have been the subject of extensive research studies in reptilian species; however, the effects of abnormal gland function have been poorly documented in clinical cases. These glands play a major role in maintaining physiologic homeostasis in all vertebrates. With the advent of more sensitive assays, it should be possible to measure the small amounts of hormones found in reptilian species. The purpose of this article is to review the literature regarding clinical endocrinology of the thyroid and parathyroid glands in reptiles.     

Lipid profiles of canine spermatozoa as revealed via matrix‐assisted laser desorption/ionization mass spectrometry

In this study, we investigated the ability of matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS) to characterize the lipid contents of canine spermatozoa. For that, samples of pure semen were analysed. Indeed, quite comprehensive lipid coverage was observed, and the most abundant phospholipid ions detected were from four phosphatidylcholines, that is those of m/z 760.6; 782.6; 808.6; and 830.6 and one of m/z 725.6 from a sphingomyelin. In conclusion, MALDI‐MS was found to offer an easy, fast, accurate, and sensitive analytical method for lipid profiling in canine spermatozoa and could be used as a tool to select sires by assessing the relationship between sperm lipid profiles and variables such as age and breeding history as well as to study the effects of cryopreservation on lipid contents.