Characterisation of antimicrobial usage in cats and dogs attending UK primary care companion animal veterinary practices

There is scant evidence describing antimicrobial (AM) usage in companion animal primary care veterinary practices in the UK. The use of AMs in dogs and cats was quantified using data extracted from 374 veterinary practices participating in VetCompass. The frequency and quantity of systemic antibiotic usage was described.Overall, 25 per cent of 963,463 dogs and 21 per cent of 594,812 cats seen at veterinary practices received at least one AM over a two-year period (2012-2014) and 42 per cent of these animals were given repeated AMs. The main agents used were aminopenicillin types and cephalosporins. Of the AM events, 60 per cent in dogs and 81 per cent in cats were AMs classified as critically important (CIAs) to human health by the World Health Organisation. CIAs of highest importance (fluoroquinolones, macrolides, third-generation cephalosporins) accounted for just over 6 per cent and 34 per cent of AMs in dogs and cats, respectively. The total quantity of AMs used within the study population was estimated to be 1473 kg for dogs and 58 kg for cats.This study has identified a high frequency of AM usage in companion animal practice and for certain agents classified as of critical importance in human medicine. The study highlights the usefulness of veterinary practice electronic health records for studying AM usage.

The effects of acute garlic supplementation on the fibrinolytic and vasoreactive response to exercise

Background

The purpose of this project was to examine the effects of acute garlic supplementation on fibrinolysis and vasoreactivity both at rest and following maximal exercise.

Methods

Eighteen healthy trained males (20.9 ± 2.2 years, 178 ± 7.7 cm, 75.5 ± 9.6 kg, VO₂max = 59.8 ± 6.7 ml • kg⁻¹ • min⁻¹) performed a graded treadmill test to volitional exhaustion. Blood samples were taken at rest, within two minutes post-exercise, and one hour post-exercise. Eleven of the subjects also had a brachial vasoreactivity test performed immediately after the blood sample to assess flow-mediated dilation (FMD) of the brachial artery. Participants were randomly assigned to ingest either 900 mg of powdered garlic or a placebo three hours before the exercise session. The supplement was distributed in a double-blind, crossover fashion. Participants repeated the protocol with the other treatment after a 14-day washout period. Paired t-tests were used to compare VO₂max between the two trials. A two-factor (treatment and time) repeated measures analysis of variance (ANOVA) was used to assess changes in FMD, tPA activity, tPA antigen, and PAI-1 activity. A priori statistical significance was set at P <0.05.

Results

VO₂max was greater for the garlic treatment trial vs. placebo (Placebo = 59.8 ± 6.7 ml • kg⁻¹ • min⁻¹; Garlic = 61.4 ± 6.6 ml • kg⁻¹ • min⁻¹). There was no main effect for treatment and no treatment x time interaction for FMD or any fibrinolytic variables examined.

Conclusion

Acute garlic supplementation does not alter vasoreactivity, fibrinolytic potential or the fibrinolytic response to exercise in young healthy trained males. Acute garlic supplementation does, however, cause a small but statistically significant increase in VO₂max. It remains unclear if this increase in VO₂max is of functional importance.

Soy phytoestrogens are neuroprotective against stroke-like injury in vitro

Diets high in soy are neuroprotective in experimental stroke. This protective effect is hypothesized to be mediated by phytoestrogens contained in soy, because some of these compounds have neuroprotective effects in in vitro models of cell death. We tested the ability of the soy phytoestrogens genistein, daidzein, and the daidzein metabolite equol to protect embryonic rat primary cortical neurons from ischemic-like injury in vitro at doses typical of circulating concentrations in human populations (0.1-1 microM). All three phytoestrogens inhibited lactate dehydrogenase (LDH) release from cells exposed to glutamate toxicity or the calcium-ATPase inhibitor, thapsigargin. In cells exposed to hypoxia or oxygen-glucose deprivation (OGD), pretreatment with the phytoestrogens inhibited cell death in an estrogen receptor (ER) dependent manner. Although OGD results in multiple modes of cell death, examination of alpha-spectrin cleavage and caspase-3 activation revealed that the phytoestrogens were able to inhibit apoptotic cell death in this model. In addition, blockade of phosphoinositide 3-kinase prevented the protective effects of genistein and daidzein, and blockade of mitogen-activated protein kinase prevented genistein-dependent neuroprotection. These results suggest that pretreatment with dietary levels of soy phytoestrogens can mimic neuroprotective effects observed with estrogen and appear to use the same ER-kinase pathways to inhibit apoptotic cell death.

The role of Notch and Rho GTPase signaling in the control of dendritic development

Dendritic patterning exerts a profound influence on neuronal connectivity. Recent studies indicate that mammalian Notch receptors are expressed by postmitotic neurons and that Notch signaling has a considerable influence on dendritic growth and branching. Investigations into the intracellular effectors of dendritic development have revealed that dendritic growth and branching are differentially affected by activation of the Rho-family GTPases, RhoA, Rac1, and Cdc42. These observations suggest that the differential activation of Notch receptors and Rho-family GTPases by extracellular signals may be important in the generation of morphological diversity in the developing nervous system.

Nuclear Notch1 signaling and the regulation of dendritic development

To understand the function of Notch in the mammalian brain, we examined Notch1 signaling and its cellular consequences in developing cortical neurons. We found that the cytoplasmic domain of endogenous Notch1 translocated to the nucleus during neuronal differentiation. Notch1 cytoplasmic-domain constructs transfected into cortical neurons were present in multiple phosphorylated forms, localized to the nucleus and could induce CBF1-mediated transactivation. Molecular perturbation experiments suggested that Notch1 signaling in cortical neurons promoted dendritic branching and inhibited dendritic growth. These observations show that Notch1 signaling to the nucleus exerts an important regulatory influence on the specification of dendritic morphology in neurons.

Cues intrinsic to the spinal cord determine the pattern and timing of primary afferent growth

We have used organotypic cultures of embryonic rat spinal cord and dorsal root ganglia (DRG) to study the development of central projections of primary sensory afferent axons that express calcitonin gene-related peptide (CGRP). In vivo, small- and medium-diameter CGRP-positive primary afferents terminate in laminae I, II, and V of the spinal cord and do not enter the ventral horn. A similar pattern of CGRP-positive axonal projections was observed in spinal cord slices of Day 16 embryos (E16) maintained in culture for 6 days. Both intact and dissociated DRG neurons showed the same pattern of central arborization, indicating that complex intercellular interactions between DRG neurons are not required for laminar specific targeting. Furthermore, targeting to the dorsal horn and avoidance of the ventral horn was observed in isolated dorsal and ventral hemicords, suggesting that separate mechanisms mediate the avoidance of CGRP-positive axons from the ventral horn and the elaboration of the afferent arbors within the dorsal horn. CGRP-positive afferents can grow into the dorsal horn only during a brief time window. Cultures of age-matched (isochronic) DRG and spinal cord from E14, E16, and E18 animals showed the characteristic pattern of CGRP-positive axon arborization, while cultures from E20 and neonatal animals did not. Heterochronic cultures indicate that it is the age of the spinal cord, and not the age of the DRG, that determines the ability of the CGRP-positive afferents to arborize within the dorsal horn. Together these results demonstrate that cues intrinsic to the spinal cord can direct sensory projections to appropriate locations in the spinal cord.

Dieting severity and gastrointestinal symptoms in college women

Young women report symptoms associated with irritable bowel syndrome (IBS), such as pain, bloating, and changes in bowel movements, more often than young men. Young women with eating disorders also report these gastrointestinal symptoms frequently. We hypothesized that if dieting behaviors were associated with these symptoms, the prevalence and frequency of the symptoms would be positively related to dieting severity in young women. We interviewed 301 1st-year college women representing the continuum of dieting severity. We found that severity of dieting was positively related to frequency of abdominal pain, bloating, diarrhea, and constipation, and that the women who reported 3 or more symptoms regularly scored higher on a scale for dieting severity. Although this study did not examine the relationship between dieting severity and clinical IBS, the findings suggested that dieting is associated with gastrointestinal symptoms in young women.

The divergent homeobox gene PBX1 is expressed in the postnatal subventricular zone and interneurons of the olfactory bulb

In the mammalian brain, an important phase of neurogenesis occurs postnatally in the subventricular zone (SVZ). This region consists of a heterogeneous population of cells, some mitotically active, others postmitotic. A subset of mitotically active SVZ precursor cells gives rise to a population of neurons that migrates over a long distance to their final destination, the olfactory bulb. Other SVZ precursor cells continue to proliferate or undergo cell death. The combination of genes that regulates proliferation and cell fate determination of SVZ precursor cells remains to be identified. We have used the rat homolog of the human homeobox gene PBX1 in Northern analysis and in situ hybridization studies to determine the temporal and regional localization of PBX1 expression during embryonic and postnatal rat brain development. PBX1 is expressed embryonically in the telencephalon. In addition, it is expressed at high levels postnatally in the SVZ, in the migratory pathway to the olfactory bulb, and in the layers of the olfactory bulb that are the targets of these migratory neurons. Combining in situ hybridization for PBX1 with immunostaining for markers of cell proliferation (PCNA), postmitotic neurons (class III beta-tubulin), and glia (GFAP), we show that SVZ proliferating cells and their neuronal progeny express rat PBX1 mRNA, whereas glial cells do not express detectable levels of PBX1. The expression of PBX1 in SVZ precursor cells and postmitotic neurons suggests a role for PBX1 in the generation of olfactory bulb interneurons and in mammalian neurogenesis.

Identification of nuclear proteins that are developmentally regulated in embryonic rat brain

To identify nuclear proteins that might play a role in the acquisition of neuronal phenotype, two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) was used to analyze nuclear proteins expressed over the course of embryonic rat brain development. Metabolically labeled rat brain nuclear proteins from embryonic day 14 (E14) were compared with proteins from embryonic day 20 (E20). Over this period, the rat brain develops from a collection of relatively homogeneous precursor cells into a complex structure containing many different classes of neurons. Computer-assisted analysis of 2D-PAGE fluorograms identified 11 proteins that show increases in their rate of synthesis between E14 and E20. Twenty proteins that consistently appear at E20 are not detectable on fluorograms of E14 nuclear proteins, even after long exposures, and thus may be considered to appear de novo. Fifty-eight proteins show consistent down-regulation between E14 and E20, and of these, 19 are not detectable on fluorograms of E20 nuclear proteins. The electrophoretic properties of many of these proteins suggest that they are previously unreported, developmentally regulated nuclear proteins. Some of the developmentally regulated, brain-enriched nuclear proteins identified here may play a role in regulating the expression of neural genes important for cellular differentiation in the mammalian CNS.