The functions of repressor element 1-silencing transcription factor in models of epileptogenesis and post-ischemia.

Epilepsy is a debilitating neurological disorder characterised by recurrent seizures for which 30% of patients are refractory to current treatments. The genetic and molecular aetiologies behind epilepsy are under investigation with the goal of developing new epilepsy medications. The transcriptional repressor REST (Repressor Element 1-Silencing Transcription factor) is a focus of interest as it is consistently upregulated in epilepsy patients and following brain insult in animal models of epilepsy and ischemia. This review analyses data from different epilepsy models and discusses the contribution of REST to epileptogenesis. We propose that in healthy brains REST acts in a protective manner to homeostatically downregulate increases in excitability, to protect against seizure through downregulation of BDNF (Brain-Derived Neurotrophic Factor) and its receptor, TrkB (Tropomyosin receptor kinase B). However, in epilepsy patients and post-seizure, REST may increase to a larger degree, which allows downregulation of the glutamate receptor subunit GluR2. This leads to AMPA glutamate receptors lacking GluR2 subunits, which have increased permeability to Ca2+, causing excitotoxicity, cell death and seizure. This concept highlights therapeutic potential of REST modulation through gene therapy in epilepsy patients.

Amygdala Arginine Vasopressin Modulates Chronic Ethanol Withdrawal Anxiety-Like Behavior in the Social Interaction Task.

BACKGROUND: Chronic ethanol (EtOH) exposure induces neurobehavioral maladaptations in the brain though the precise changes have not been fully explored. The central nucleus of the amygdala (CEA) regulates anxiety-like behavior induced by withdrawal from chronic intermittent EtOH (CIE) exposure, and the arginine vasopressin (AVP) system within the CEA regulates many anxiety-like behaviors. Thus, adaptations occur in the CEA AVP system due to chronic EtOH exposure, which lead to anxiety-like behaviors in rats. METHODS: Chronic exposure to a low-dose EtOH (4.5% wt/vol) induces anxiety-like behavior in rats. Wistar or Sprague Dawley rats were exposed to a modified CIE or CIE, while intra-CEA microinjections of AVP or a V1b receptor antagonist were used to elicit or block withdrawal-induced anxiety. Additionally, AVP microinjections into the CEA were given 24 hours following 15 days of continuous high-dose EtOH (7% wt/vol), a time period when rats no longer express anxiety. Chemogenetics was also used to activate the basolateral amygdala (BLA) or deactivate the dorsal periaqueductal gray=(dm/dlPAG) therefore PAG=periaqueductal gray to elicit or block withdrawal-induced anxiety. RESULTS: AVP microinjected into the CEA in lieu of exposure to the first 2 cycles of CIE was sufficient to induce anxiety-like behavior in these commonly used rat strains. The V1b receptor antagonist, but not an oxytocin receptor agonist, into the CEA during the first 2 withdrawal cycles suppressed anxiety. However, activation of the BLA in lieu of exposure to the first 2 cycles of CIE was insufficient to induce anxiety-like behavior. AVP microinjection into the CEA 24 hours into withdrawal reelicited anxiety-like behavior, and deactivation of the dm/dlPAG reduced this effect of CEA AVP. CONCLUSIONS: Taken together, this study demonstrates a role of CEA AVP and a CEA-dm/dlPAG circuit in the development of anxiety induced by CIE. Such information is valuable for identifying novel therapeutic targets for alcohol- and anxiety-associated disorders.

Dysregulation of Notch and ERα signaling in AhR-/- male mice.

The aryl hydrocarbon receptor (AhR) is now recognized as an important physiological regulator in the immune and reproductive systems, and in the development of the liver and vascular system. AhR regulates cell cycle, cell proliferation, and differentiation through interacting with other signaling pathways, like estrogen receptor α (ERα), androgen receptor (AR), and Notch signaling. In the present study, we investigated Notch and estrogen signaling in AhR-/- mice. We found low fertility with degenerative changes in the testes, germ cell apoptosis, and a reduced number of early spermatids. There was no change in aromatase, AR, ERα, or ERß expression in the testis and no detectable change in serum estrogen levels. However, expression of Notch receptors (Notch1 and Notch3) and their target Hairy and Enhancer of Split homolog 1 (HES1) was reduced. In addition, the testosterone level was slightly reduced in the serum. In the mammary fat pad, AhR appeared to regulate estrogen signaling because, in AhR-/- males, there was significant growth of the mammary ducts with high expression of ERα in the ductal epithelium. The enhanced mammary ductal growth appears to be related to overexpression of ERα accompanied by a high proliferation index, whereas the reduced fertility appears to be related defects in Notch signaling that leads to reduced expression of HES1 and, consequently, early maturation of spermatocytes and a depletion of primary spermatids. Previous reports have indicated that AhR pathway is associated with infertility in men. Our results provide a mechanistic explanation for this defect.

Retrospective evaluation of perioperative and short term clinical outcomes in appendicular long bone skeleton fractures repaired via the string of pearls (SOP) locking plate system.

BACKGROUND: Internal plate fixation and, more recently, locking plate fixation are commonly used in the repair of fractures in small animal surgery. This retrospective study reviewed the use of the String of Pearls locking plate system in the fixation/repair of appendicular long bone skeleton fractures in 31 small animal veterinary patients (33 fractures). RESULTS: Major complications necessitating revision surgery occurred in 7/33 (21%), with implant failure as the inciting cause in all cases. Variables corresponding to an unsuccessful outcome were evaluated, and a correlation was found with plates placed in a bridging manner (placed without rigid anatomic reconstruction, p = 0.02) and length of follow-up (p = 0.01). CONCLUSIONS: The SOP plating system can be used in the repair of appendicular longbone skeletal fractures, however, the authors propose that adjunct fixation, such as intramedullary pin, double plating, or external coaptation would likely improve results and should be considered imperative in cases in which anatomic reconstruction is either not desirable or achievable.

Uric acid stones in the urinary bladder of aryl hydrocarbon receptor (AhR) knockout mice.

The aryl hydrocarbon receptor (AhR) knockout mice raised in the laboratory of Fujii-Kuriyama have been under investigation for several years because of the presence in their urinary bladder of large, yellowish stones. The stones are composed of uric acid and become apparent in the bladders as tiny stones when mice are 10 wk of age. By the time the mice are 6 mo of age, there are usually two or three stones with diameters of 3-4 mm. The urate concentration in the serum was normal but in the urine the concentration was 40-50 mg/dL, which is 10 times higher than that in the WT littermates. There were no apparent histological pathologies in the kidney or joints and the levels of enzymes involved in elimination of purines were normal. The source of the uric acid was therefore judged to be from degradation of nucleic acids due to a high turnover of cells in the bladder itself. The bladder was fibrotic and the luminal side of the bladder epithelium was filled with eosinophilic granules. There was loss of E-cadherin between some epithelial cells, with an enlarged submucosal area filled with immune cells and sometimes invading epithelial cells. We hypothesize that in the absence of AhR there is loss of detoxifying enzymes, which leads to accumulation of unconjugated cytotoxins and carcinogens in the bladder. The presence of bladder toxins may have led to the increased apoptosis and inflammation as well as invasion of epithelial cells in the bladders of older mice.

Effects of incision closure method on infection prevalence following tibial plateau leveling osteotomy in dogs.

The goal of this study was to retrospectively investigate the effect of incisional closure with either stainless steel skin staples or intradermal poliglecaprone 25 on the prevalence of surgical site infection following tibial plateau leveling osteotomy in dogs. Medical records were reviewed for dogs treated with unilateral tibial plateau leveling osteotomy at Memphis Veterinary Specialists between 2006 and 2013. Procedures (n = 306) from 242 dogs were included in the study. The association of potential risk factors with the occurrence of postoperative infection was assessed using logistic regression. A value of P < 0.05 was considered significant. Weight and administration of postoperative antimicrobials were found to significantly influence surgical site infection prevalence. No significant association was noted between closure method and prevalence of postoperative infection.

Effets de la méthode de fermeture de l'incision sur la prévalence d'infections après une ostéotomie de nivellement du plateau tibial chez les chiens. Le but de cette étude consistait à étudier rétrospectivement l'effet de la fermeture de l'incision soit avec des agrafes dermiques en acier inoxydable ou avec le poliglecaprone intradermique 25 sur la prévalence d'une infection au site de la chirurgie après une ostéotomie de nivellement du plateau tibial chez les chiens. Les dossiers médicaux ont été examinés pour les chiens traités pour une ostéotomie de nivellement du plateau tibial à l'établissement Memphis Veterinary Specialists entre 2006 et 2013. Les interventions (n = 306) de 242 chiens ont été incluses dans l'étude. L'association des facteurs de risques potentiels avec l'occurrence de l'infection postopératoire a été évaluée en utilisant la régression logistique. Une valeur de P < 0,05 était considérée significative. Il a été constaté que le poids et l'administration postopératoire d'antimicrobiens influençaient significativement la prévalence des infections au site chirurgical. Aucune association significative n'a été observée entre la méthode de fermeture et la prévalence d'infection postopératoire.(Traduit par Isabelle Vallières).

Estrogen receptor ß and 17ß-hydroxysteroid dehydrogenase type 6, a growth regulatory pathway that is lost in prostate cancer.

Estrogen receptor ß (ERß) is activated in the prostate by 5α-androstane-3ß,17ß-diol (3ß-Adiol) where it exerts antiproliferative activity. The proliferative action of the androgen receptor is activated by 5α-dihydrotestosterone (DHT). Thus, prostate growth is governed by the balance between androgen receptor and ERß activation. 3ß-Adiol is a high-affinity ligand and agonist of ERß and is derived from DHT by 3-keto reductase/3ß-hydroxysteroid dehydrogenase enzymes. Here, we demonstrate that, when it is expressed in living cells containing an estrogen response element-luciferase reporter, 17ß-hydroxysteroid dehydrogenase type 6 (17ßHSD6) converts the androgen DHT to the estrogen 3ß-Adiol, and this leads to activation of the ERß reporter. This conversion of DHT occurs at concentrations that are in the physiological range of this hormone in the prostate. Immunohistochemical analysis revealed that 17ßHSD6 is expressed in ERß-positive epithelial cells of the human prostate and that, in prostate cancers of Gleason grade higher than 3, both ERß and 17ßHSD6 are undetectable. Both proteins were present in benign prostatic hyperplasia samples. These observations reveal that formation of 3ß-Adiol via 17ßHSD6 from DHT is an important growth regulatory pathway that is lost in prostate cancer.

Theoretical model of impact mitigation mechanisms inherent to the North American bison skull.

North American bison (Bovidae: Bison bison) incur blunt impacts to the interparietal and frontal bones when they engage in head-to-head fights. To investigate the impact mitigation of these bones, a finite element analysis (FEA) of the skull under loading conditions was performed. Based on anatomical and histological studies, the interparietal and frontal bones are both comprised of a combination of haversian and plexiform bone and are both underlain by bony septa. Additionally, the interparietal bone is thicker than the frontal bone. Data regarding the mechanical properties of bison bone are scarce, but the results of a phylogenetic analysis infer that the material properties of the closely related domestic cow bone are a suitable proxy for use in the FEA. Results of the FEA suggest that the thickness of the interparietal bone in conjunction with the bony septa may prevent fracture stresses by helping to absorb and disperse the blunt impact energy throughout the skull. Monotonic stress levels of 294 MPa, which are below the compressive strength of bone were exhibited in the simulated bison head impacts indicating no fracture of the bones.

Disrupted brain functional connectivity as early signature in cognitively healthy individuals with pathological CSF amyloid/tau.

Alterations in functional connectivity (FC) have been observed in individuals with Alzheimer's disease (AD) with elevated amyloid (Aß) and tau. However, it is not yet known whether directed FC is already influenced by Aß and tau load in cognitively healthy (CH) individuals. A 21-channel electroencephalogram (EEG) was used from 46 CHs classified based on cerebrospinal fluid (CSF) Aß tau ratio: pathological (CH-PAT) or normal (CH-NAT). Directed FC was estimated with Partial Directed Coherence in frontal, temporal, parietal, central, and occipital regions. We also examined the correlations between directed FC and various functional metrics, including neuropsychology, cognitive reserve, MRI volumetrics, and heart rate variability between both groups. Compared to CH-NATs, the CH-PATs showed decreased FC from the temporal regions, indicating a loss of relative functional importance of the temporal regions. In addition, frontal regions showed enhanced FC in the CH-PATs compared to CH-NATs, suggesting neural compensation for the damage caused by the pathology. Moreover, CH-PATs showed greater FC in the frontal and occipital regions than CH-NATs. Our findings provide a useful and non-invasive method for EEG-based analysis to identify alterations in brain connectivity in CHs with a pathological versus normal CSF Aß/tau.

Liver X receptor beta and thyroid hormone receptor alpha in brain cortical layering.

In the past year, two members of the nuclear receptor family, liver X receptor beta (LXRbeta) and thyroid hormone receptor alpha (TRalpha), have been found to be essential for correct migration of neurons in the developing cortex in mouse embryos. TRalpha and LXRbeta bind to identical response elements on DNA and sometimes regulate the same genes. The reason for the migration defect in the LXRbeta(-/-) mouse and the possibility that TRalpha may be involved are the subjects of the present study. At E15.5, expression of reelin and VLDLR was similar but expression of apolipoprotein E receptor 2 (ApoER2) (the reelin receptor) was much lower in LXRbeta(-/-) than in WT mice. Knockout of ApoER2 is known to lead to abnormal cortical lamination. Surprisingly, by postnatal day 14 (P14), no morphological abnormalities were detectable in the cortex of LXRbeta(-/-) mice and ApoER2 expression was much stronger than in WT controls. Thus, a postnatal mechanism leads to increase in ApoER2 expression by P14. TRalpha also regulates ApoER2. In both WT and LXRbeta(-/-) mice, expression of TRalpha was high at postnatal day 2. By P14 it was reduced to low levels in WT mice but was still abundantly expressed in the cortex of LXRbeta(-/-) mice. Based on the present data we hypothesize that reduction in the level of ApoER2 is the reason for the retarded migration of later-born neurons in LXRbeta(-/-) mice but that as thyroid hormone (TH) increases after birth the neurons do find their correct place in the cortex.

Effects of thermoneutrality on food intake, body weight, and body composition in a Prader-Willi syndrome mouse model.

OBJECTIVE: Prader-Willi syndrome (PWS) is a multisystem genetic disorder. Unfortunately, none of several mouse models carrying PWS mutations emulates the entirety of the human PWS phenotype, including hyperphagia plus obesity. METHODS: To determine whether housing at thermoneutrality (TN, 30 °C) permits the development of hyperphagia and obesity in the Snord116del PWS mouse model, the effects of housing three different ages of Snord116del and wild-type (WT) littermates at TN versus room temperature (RT, 22-24 °C) for 8 weeks were compared. RESULTS: Snord116del mice born and maintained at TN exhibited lower body weight curves, lower percentage fat mass, and lower food intake than WT mice at RT. In 4- to 6-month-old high-fat diet-fed female mice, TN raised the Snord116del body weight curve closer to that of RT-housed WT mice although the TN-housed Snord116del mice did not gain more adiposity or exhibit greater food intake. In 6- to 8-month-old high-fat diet-fed male mice, body weight, adiposity, and food intake of TN-housed Snord116del mice remained far below levels in RT-housed WT mice. TN elicited hypotonia in Snord116del adults and exacerbated mortality of Snord116del newborns. CONCLUSIONS: In none of three tested TN protocols were greater food intake, body weight, or adiposity induced in Snord116del mice compared with RT-housed WT mice.

Serious mental illness in healthcare and academia: A lived experience.

WHAT IS KNOWN ON THE SUBJECT?: There are individuals living with serious mental illness in both healthcare and academia. The high stress nature of these fields can worsen or trigger mental illness, burnout, moral injury, and compassion fatigue in employees. Mental health nurses have the needed skillset to foster change in these settings. WHAT THIS PAPER ADDS TO EXISTING KNOWLEDGE?: This paper describes the holistic experiences of a nurse faculty member living with serious mental illness and highlights lessons learned in both healthcare and academic settings. In addition to insights from the experience, the paper also shares suggestions for moving forward, reducing burnout, and supporting employees in these fields. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: This lived experience narrative showcases the effect that high-pressure occupations have on individuals with serious mental illness. Mental health nurses have the training and experience to transform the experiences of employees in healthcare and academia. Through assessment, deep listening, and powerful questioning, these nurses in partnership with the employees themselves can design and implement interventions that have a lasting impact for these populations. ABSTRACT: Introduction First-hand accounts from clients living with mental health challenges deepen provider understanding and offer direct insight into the lives of those with chronic mental illness. There is a gap in the literature surrounding the lived experience of serious mental illness in the professional setting. Aim This narrative outlines the challenges and opportunities for those living with serious mental illness in healthcare and academia. Methods The author reviewed personal journals and reflected upon her years as both a nurse and faculty member to highlight the experience of living with serious mental illness in these professions. Findings These high-pressure fields place inordinate demands on faculty and staff; yet, there are few organizational supports in place for employees. Despite the push to improve resiliency and ease burnout, healthcare organizations and academic institutions still struggle to identify the best interventions and methods of support for staff. Discussion Mental health nurses and nurse coaches are uniquely positioned to ease this burden and help create inclusive workplaces for those with serious mental illness.

Comparison of Two Stifle Exploratory Methods Using Mini-Arthrotomy for Diagnosis of Canine Medial Meniscal Pathology: An Ex Vivo Study.

OBJECTIVE: The main aim of this study was to compare the accuracy of stifle exploratory using either a stifle distractor (SD method) or a combination of Hohmann and Senn retractors (HS method) for diagnosing canine medial meniscal tears in cranial cruciate ligament-deficient stifles. STUDY DESIGN: Fifteen pairs of canine cadaveric pelvic limbs were used and cranial cruciate ligament were transected in all stifles. Paired limbs were then randomly assigned to one of five groups based on the tears created in the caudal pole of the medial meniscus: no tear, peripheral detachment, or a variation in three vertical longitudinal tears. A craniomedial mini-arthrotomy was performed by two observers and diagnosis of the medial meniscal status was made utilizing the HS and SD methods. Correct diagnosis of the meniscal tear was compared for both methods and observers. RESULTS: Correct diagnoses were made using the HS and SD methods in 24/30 and 24/30 cases for observer 1 respectively; and in 17/30 and 19/30 cases for observer 2 respectively. There was no significant difference in the correct diagnosis of meniscal tears within each observer between the two methods. CONCLUSION: Both HS and SD methods have equal accuracy for the diagnosis of canine medial meniscal pathology for a board-certified surgeon. Unassisted surgeons using the SD method for the evaluation of the medial meniscus are at no diagnostic disadvantage compared with assisted surgeons utilizing the HS method.

VectorBase: a data resource for invertebrate vector genomics.

VectorBase (http://www.vectorbase.org) is an NIAID-funded Bioinformatic Resource Center focused on invertebrate vectors of human pathogens. VectorBase annotates and curates vector genomes providing a web accessible integrated resource for the research community. Currently, VectorBase contains genome information for three mosquito species: Aedes aegypti, Anopheles gambiae and Culex quinquefasciatus, a body louse Pediculus humanus and a tick species Ixodes scapularis. Since our last report VectorBase has initiated a community annotation system, a microarray and gene expression repository and controlled vocabularies for anatomy and insecticide resistance. We have continued to develop both the software infrastructure and tools for interrogating the stored data.

Efficient infection of organotypic hippocampal slice cultures with adenovirus carrying the transgene REST/NRSF.

Organotypic hippocampal slice cultures provide a useful platform maintaining hippocampal structure and synaptic connections of the brain over weeks in culture with ease of in vitro manipulations. Gene transfer is a particularly desirable tool for using with them but current difficulties with transformation of transgenes into these cultures is a barrier to their use in research. Previous quantifications of viral infections have shown low transformation rates and have relied upon invasive microinjections. In this paper we present an efficient way of infecting organotypic cultures with adenovirus at the acute slice stage that does not require injection. We use the adenoviral delivery system to introduce the transcription factor REST and a GFP marker, providing around 41 % cellular infection spread throughout the entire slice culture and promoting transgene expression for weeks in vitro. GFP expression was observed most intensely in the slices when they were infected just a few hours after plating and was shown to infect neurons and microglia. We decided to use the transcription factor REST/NRSF as an example transgene which was delivered into cells via the adenoviral construct, conferring overexpression of REST in addition to the GFP marker. This outlines a technique whereby adenoviral infection of organotypic cultures can infect neurons with good efficiency and confer successful manipulation of genetic factors within the cell.

VectorBase: a home for invertebrate vectors of human pathogens.

VectorBase (http://www.vectorbase.org/) is a web-accessible data repository for information about invertebrate vectors of human pathogens. VectorBase annotates and maintains vector genomes providing an integrated resource for the research community. Currently, VectorBase contains genome information for two organisms: Anopheles gambiae, a vector for the Plasmodium protozoan agent causing malaria, and Aedes aegypti, a vector for the flaviviral agents causing Yellow fever and Dengue fever.

Hemispheric differences in the number of parvalbumin-positive neurons in subdivisions of the rat basolateral amygdala complex.

The amygdala is a bilateral temporal lobe brain region which plays an important role in emotional processing. Past studies on the amygdala have shown hemispheric differences in amygdalar processes and responses associated with specific pain and fear behaviors. Despite the functional differences in the amygdala, few studies have been performed to characterize whether anatomical differences exist between the left and right amygdala. Parvalbumin (PV) is a phenotypic marker for an inhibitory interneuronal population in cortical brain structures such as the basolateral amygdala complex (BLC). This study examined the number of PV-positive neurons in the left and right BLC of adult, male Long-Evans rats using unbiased stereology. Coronal sections through the rostral-caudal extent of the BLC were immunohistochemically-stained for PV and the optical fractionator method was used to obtain an unbiased estimate of the number of PV-positive neurons in subdivisions through the BLC. The lateral and basolateral amygdala divisions of the BLC were analyzed, were subdivided into the dorsolateral, ventrolateral and ventromedial and the posterior, anterior and ventral subdivisions, respectively. The results indicate that there are significantly more PV-positive neurons in the left basolateral amygdala compared to the right, with a significant difference specifically in the posterior subdivision. This difference in PV neuronal number could help explain the distinct hemispheric roles of the BLC in the behavioral processing following exposure to painful and fearful stimuli.

Laser Therapy for Incision Healing in 9 Dogs.

Laser therapy is becoming common place in veterinary medicine with little evidence proving efficacy or dosages. This study evaluated surgical wound healing in canines. Twelve Dachshunds underwent thoraco-lumbar hemilaminectomies for intervertebral disc disease (IVDD). Digital photographs were taken of their incisions within 24 h of surgery and 1, 3, 5, 7, and 21 days postoperatively. The first three dogs were used to create a standardized scar scale to score the other dogs' incision healing. The remaining 9 dogs were randomly assigned to either receive 8 J/cm2 laser therapy once a day for 7 days or the non-laser treated control group. Incision healing was scored based on the scar scale from 0 to 5, with zero being a fresh incision and five being completely healed with scar contraction and hair growth. All scar scores significantly improved with increasing time from surgery (<0.001). Good agreement was achieved for inter-rater reliability (p = 0.9). Laser therapy increased the scar scale score, showed improved cosmetic healing, by day seven and continued to be significantly increased on day 21 compared to control dogs (p < 0.001). Daily application of laser therapy at 8J/cm2 hastened wound healing in Dachshunds that received thoracolumbar hemilaminectomies for IVDD. It also improved the cosmetic appearance.