Subregion and sex differences in ethanol activation of cholinergic and glutamatergic cells in the mesopontine tegmentum

Ethanol engages cholinergic signaling and elicits endogenous acetylcholine release. Acetylcholine input to the midbrain originates from the mesopontine tegmentum (MPT), which is composed of the laterodorsal tegmentum (LDT) and the pedunculopontine tegmental nucleus (PPN). We investigated the effect of acute and chronic ethanol administration on cholinergic and glutamatergic neuron activation in the PPN and LDT in male and female mice. We show that ethanol activates neurons of the PPN and not the LDT in male mice. Chronic 15 daily injections of 2 g/kg ethanol induced Fos expression in cholinergic and glutamatergic PPN neurons in male mice, whereas ethanol did not increase cholinergic and glutamatergic neuronal activation in the LDT. A single acute 4 g/kg injection, but not a single 2 g/kg injection, induced cholinergic neuron activation in the male PPN but not the LDT. In contrast, acute or chronic ethanol at either dose or duration had no effect on the activation of cholinergic or glutamatergic neurons in the MPT of female mice. Female mice had higher baseline level of activation in cholinergic neurons compared with males. We also found a population of co-labeled cholinergic and glutamatergic neurons in the PPN and LDT which were highly active in the saline- and ethanol-treated groups in both sexes. These findings illustrate the complex differential effects of ethanol across dose, time point, MPT subregion and sex.

Subregion and sex differences in ethanol activation of cholinergic and glutamatergic cells in the mesopontine tegmentum

Ethanol engages cholinergic signaling and elicits endogenous acetylcholine release. Acetylcholine input to the midbrain originates from the mesopontine tegmentum (MPT), which is composed of the laterodorsal tegmentum (LDT) and the pedunculopontine tegmental nucleus (PPN). We investigated the effect of acute and chronic ethanol administration on cholinergic and glutamatergic neuron activation in the PPN and LDT in male and female mice. We show that ethanol selectively activates neurons of the PPN and not the LDT in male mice. Acute 4.0 g/kg and chronic 15 daily injections of 2.0 g/kg i.p. ethanol induced Fos expression in cholinergic and glutamatergic PPN neurons in male mice, whereas cholinergic and glutamatergic neurons of the LDT were unresponsive. In contrast, acute or chronic ethanol at either dose or duration had no effect on the activation of cholinergic or glutamatergic neurons in the MPT of female mice. Female mice had higher level of baseline activation in cholinergic neurons compared with males. We also found a population of co-labeled cholinergic and glutamatergic neurons in the PPN and LDT which were highly active in the saline- and ethanol-treated groups in both sexes. These findings illustrate the complex differential effects of ethanol across dose, time point, MPT subregion and sex.

Assessment of a standing position during abdominal point-of-care ultrasound on abdominal fluid score in dogs

OBJECTIVE

To assess the use of a standing position during abdominal point-of-care ultrasound (POCUS) examination when evaluating dogs for peritoneal effusion.

DESIGN

Randomized prospective study over 17 months.

SETTING

Single-center, university veterinary teaching hospital.

ANIMALS

Thirty dogs presenting for acute abdominal disease. Eligibility included suspicion for free peritoneal effusion and the ability to stand.

INTERVENTIONS

Dogs underwent standing abdominal POCUS, right lateral abdominal POCUS, and a full abdominal ultrasound. We originally had nothing listed. It now includes all three ultrasound evaluations that were performed for each patient.

MEASUREMENTS AND MAIN RESULTS

Patients underwent both a right lateral and standing abdominal POCUS via a previously described abdominal focused assessment with sonography for trauma (A-FASTrl and A-FASTs, respectively) technique in a randomized and sequential order followed by a full abdominal ultrasound (AUS-full). The A-FASTs examination included a right flank location in addition to the following standard views: subxiphoid, left flank, urinary bladder, and umbilicus. Five-second cine loops were obtained at each location for each examination and reviewed in the order they were obtained. Locations for both A-FAST exams were interrogated in the same order every time. The cine loops were scored for the degree of peritoneal effusion based on a previously published abdominal fluid scoring system by a board-certified radiologist, radiology resident, and radiology intern. The overall abdominal fluid score (AFS) was compared to a subjective full abdominal ultrasound score given by a board-certified radiologist. Six dogs had no peritoneal effusion, 13 had a small volume (AFS 1 or 2), and 11 had a moderate to large volume (AFS 3 or 4). Excellent agreement (intraclass correlation coefficient) was found between the A-FASTs and A-FASTrl techniques (0.95, 0.93, 0.94), good agreement between A-FASTs and AUS-full (0.80, 0.77, 0.82), and good agreement between A-FASTrl and AUS-full (0.80, 0.82, 0.84). The interobserver agreement was good (0.87) for the A-FASTs technique and excellent (0.91) for the A-FASTrl technique. Mean observer agreement score was excellent (0.94) when evaluating A-FASTrl to A-FASTs, good (0.86) when evaluating A-FASTs to AUS-full, and good (0.87) when evaluating A-FASTrl to AUS-full.

CONCLUSION

Performing a standing abdominal POCUS examination may be a valid option for identifying and quantifying peritoneal effusion in situations when a more traditional right lateral approach cannot be performed.

Description of normal pulmonary radiographic findings in 55 apparently healthy juvenile Kemp's ridley sea turtles (Lepidochelys kempii)

A total of 55 digital radiographic studies from 53 individual juvenile Kemp's ridley sea turtles (Lepidochelys kempii) were retrospectively used to determine the normal radiographic anatomy of the lower respiratory tract in sea turtles that had been stranded due to hook-and-line injury and were otherwise clinically healthy. There were three or four projections available for each study: dorsoventral (DV), rostrocaudal (RoCd), and left and/or right lateral. The DV and RoCd were most conducive for assessing global lung volume and symmetry of lung volume. The DV and lateral views were most helpful for evaluating the main bronchus and its branching channels and for assessing lung margination. The RoCd view was most useful for assessing the symmetry of the lung opacity. The lateral views were most helpful for assessing the ventral margin of each lung lobe. On the lateral view, the main bronchus lay ventrally and coursed horizontally through the lung from cranial to caudal. On the DV view, the bronchus lay medially and was observed to be curvilinear coursing caudomedially. On the RoCd view, the main bronchus was located ventromedially. The RoCd view demonstrated the channels and niches end-on resulting in a reticulated or honeycomb appearance. The channels were seen as uniform striations coursing perpendicular to the main bronchus on the lateral views (vertical striations coursing dorsal to ventral) and DV views (horizontal striations coursing medially to laterally).

Multisystemic eosinophilic epitheliotropic disease in three donkeys

Multisystemic eosinophilic epitheliotropic disease (MEED) is a rare condition of equids characterized by eosinophilic infiltration of multiple organs. Clinical signs are variable depending on the affected organs. The most common clinical signs include chronic weight loss, diarrhoea and exfoliative dermatitis. Respiratory distress and raised liver enzymes are less frequently seen. The cause is unknown and the pathogenesis is poorly understood. There are less than 50 reported cases of horses with MEED. We now document the lesions in three donkeys with fluctuating or chronic loss of weight, lethargy, exfoliative dermatitis and peripheral eosinophilia. All three animals were euthanized due to poor prognosis and welfare concerns. Post-mortem examination revealed multiple white to tan, irregular masses composed of eosinophilic infiltrates, including eosinophilic granulomas in several organs, confirming the presence of MEED. To the best of our knowledge, MEED has not previously been reported in donkeys.

Sildenafil does not have a significant effect on the portal vein velocity, cross-sectional area, and congestion index in the dog

In veterinary medicine, sildenafil is most frequently used to treat pulmonary hypertension, but has also been investigated and used as a treatment for congenital megaesophagus and ischemic infarcts. With the increasing use, the effects of sildenafil on the portal vasculature in the dog have not been previously evaluated. The purpose of this study was to evaluate the effects sildenafil has on the portal vasculature, which anecdotally may have caused decreased portal vein pressure in an adult dog. The ultrasound cross-sectional area of the aorta, cross-sectional area of the portal vein, and portal vein blood flow velocity were acquired in dogs prior to administration, and 45, 90, and 120 min after oral administration of sildenafil for the treatment of pulmonary hypertension. Thirteen dogs were enrolled in the study. No statistically significant difference was detected between all measured values and the congestion index at all time points. A trend was identified that demonstrated progressively lower portal vein velocity with each evaluation, but this was not significant. Although this study had a small sample size, sildenafil was not shown to have a significant effect on the size or blood flow velocity of the portal vasculature. The hepatic buffer system, designed to maintain a constant blood flow to the liver, may be a contributing factor, but further studies with a larger sample size will be required for further evaluation.

Back-translating GWAS findings to animal models reveals a role for Hgfac and Slc39a8 in alcohol and nicotine consumption

Alcohol and tobacco are the most commonly used addictive substances, with high comorbidity rates between alcohol use disorder and tobacco use disorder. Risk for alcohol and nicotine addiction is highly heritable, and they share common genetic factors. A GWAS in over 1 million individuals has revealed 566 genetic variants in 406 loci associated with multiple stages of alcohol and tobacco use. Three novel genes-SLC39A8, GRK4 and HGFAC-within loci associated with altered alcoholic drinks per week (ADW) or cigarettes per day (CPD) were selected to further study their role in alcohol and tobacco use disorder. The role of these genes was assessed using the two-bottle choice addiction paradigm in transgenic mice for each of the genes. We found significant decreases in chronic alcohol consumption and preference in female Hgfac knockout (KO) mice, and decreased nicotine preference in male Hgfac KO compared with wild-type (WT) mice. Additionally, male Slc39a8 hypomorph mice showed greater overall nicotine preference compared with WT mice, while no differences were detected for Grk4 KO mice in alcohol or nicotine consumption and preference in either sex. Thus, this study implicates Hgfac and Slc39a8 in alcohol and tobacco use in a sex-specific manner.

American Canine Hepatozoonosis Causes Multifocal Periosteal Proliferation on CT: A Case Report of 4 Dogs

American canine hepatozoonosis (ACH) represents an important but relatively uncommon differential diagnosis in a dog with fever, muscle wasting, profound leukocytosis, and/or musculoskeletal pain. Despite this, obtaining a definitive diagnosis can prove difficult. Peripheral blood smears and whole-blood polymerase chain reaction (PCR) rely on rare parasitemia, and the gold standard diagnostic test (skeletal muscle biopsy) is uncommonly pursued due to its invasive and costly nature. Demonstration of characteristic periosteal proliferative lesions aids diagnosis. The lesions typically involve the more proximal long bones of the appendicular skeleton. The periosteal proliferation is of currently unknown pathogenesis, but its distribution is characteristic of this disease with few differential diagnoses. This case series describes the findings on computed tomography (CT) in 4 dogs with PCR- or cytologically-confirmed Hepatozoon americanum. All dogs had multifocal, bilaterally asymmetric, irregularly marginated, non-destructive, non-articular, periosteal proliferative lesions. Recognition of this unusual CT finding and awareness of this disease could assist in the diagnosis and subsequent treatment of dogs with ACH and may offer an additional indication for CT in cases of fever, muscle wasting, and myalgia.

What Is Your Diagnosis?

In collaboration with the American College of Veterinary Radiology.

What Is Your Diagnosis?

In collaboration with the American College of Veterinary Radiology.

What Is Your Diagnosis?

In collaboration with the American College of Veterinary Radiology.

Assessment of automated craving across substances and across cultures: stability-analysis of the Craving Automated Scale (CAS)

BACKGROUND

The transition from hedonic to compulsive use in Substance Use Disorders (SUD) is a critical point in SUD progression and hence relevant for assessment and treatment. To measure the habitual patterns of substance consumption, the Craving Automated Scales (CAS) for alcohol (CAS-A), substances (CAS-S) and cigarette smoking (CAS-CS) were developed and introduced to different countries. In this study, we aimed to investigate the structural stability of CAS across substances and cultures.

METHODS

This study analyzed the CAS-scores of a sample of 370 participants in Germany, China and the UK, including 262 opioid-users, 65 smokers and 43 alcohol-users. We performed stability analyses to check the stability (i. e. factorial invariance) of factor solutions. Based on confirmed stability of the general factor (gfactor) solution and the calculations rule obtained in the previous validation of CAS-alcohol (CAS-A), the factor structures of CAS-A, CAS-S and CAS-CS were compared.

RESULTS

The gfactor solutions based on calculations rule shows good stability, with the mean stability coefficients of 0.990 and 0.977 for CAS-S and CAS-CS respectively. The gfactor patterns were similar for CAS-A, CAS-S and CAS-CS, as well as across samples (Germany, China and the UK), with most factor-loadings larger than 0.7. Based on these findings, CAS-S and CAS-CS were also associated with established clinical measures of SUD.

CONCLUSIONS

Our findings suggest the two-gfactor solution based on a proposed calculation rule has a high stability across substances and cultures. This could be in line with common neurobiological mechanisms underlying habitual substance use. Moreover, comparing CAS with established clinical tools suggests that CAS might assess the automated behavior in substance consumption in a more sophisticated way.

Intraoperative Ultrasound Applications in Intracranial Surgery

The methods and use of intraoperative ultrasound in 33 canine and five feline patients and its ability to localize and identify anatomical structures and pathological lesions in canines and felines undergoing intracranial surgery are described from a case series. All were client-owned referral patients admitted for neurologic evaluation, with an advanced imaging diagnosis of an intracranial lesion, and underwent surgical biopsy or surgical removal of the lesion. Medical records, retrieval and review of imaging reports, and characterization of findings for all canine and feline patients show that intraoperative ultrasound guidance was used in intracranial procedures during the period of 2012 and 2019. Twenty-nine of the canine patients had intracranial tumors. The remainder had various other conditions requiring intracranial intervention. Three of the feline patients had meningiomas, one had a depressed skull fracture, and one had an epidural hematoma. The tumors appeared hyperechoic on intraoperative ultrasound with the exception of cystic portions of the masses and correlated with the size and location seen on advanced imaging. Statistical comparison of the size of images seen on ultrasound and on MRI for 20 of the canine tumors revealed no statistical differences. Neuroanatomical structures, including vascular components, were easily identified, and tumor images correlated well with preoperative advanced imaging. The authors conclude that intraoperative ultrasound is a valuable asset in intracranial mass removals and can augment surgical guidance in a variety of intracranial disorders that require surgery. This is the first known publication in veterinary surgery of using intraoperative ultrasound as a tool in the operating theater to identify, localize, and monitor the removal/biopsy of intracranial lesions in small animals undergoing craniotomy/craniectomy.

Sedation with dexmedetomidine is associated with transient gallbladder wall thickening and peritoneal effusion in some dogs undergoing abdominal ultrasonography

Background

Dexmedetomidine often is used for sedation before or during abdominal ultrasonography. The effect of dexmedetomidine on gallbladder wall thickness is unknown.

Hypothesis/Objectives

To investigate the relationship between dexmedetomidine administration and gallbladder wall thickening in dogs. The hypothesis was that sedation with dexmedetomidine will cause transient gallbladder wall thickening. Gallbladder wall thickness will be associated with duration of sedation and recumbency position.

Animals

Seventy‐nine client owned dogs and 10 healthy research dogs.

Methods

A prospective observational study (n = 79) was used to establish the prevalence of gallbladder wall thickening (> 2.0 mm) after sedation with dexmedetomidine. A randomized, crossover study (n = 10) was used to evaluate the effect of time and recumbency position on the development of gallbladder wall thickening. Linear mixed models were used.

Results

The proportion of client‐owned dogs that developed gallbladder wall thickening was 24.05% (19/79; 95% confidence interval [CI], 15.1%‐35.0%) with a median dose of dexmedetomidine of 5.0 μg/kg (range, 2.0‐12.5 μg/kg). After sedation, the proportion of research dogs that developed gallbladder wall thickening in left lateral (5/10, 50%; 95% CI, 18.7%‐81.3%) and dorsal (7/10, 70%; 95% CI, 34.8%‐93.3%) recumbency did not differ significantly (P = .45). Gallbladder wall thickening developed within 20 to 40 minutes. Duration of sedation was significantly associated with thickening of the gallbladder wall (P < .001). Five dogs developed 9 instances of peritoneal effusion in both lateral (5) and dorsal (4) recumbency.

Conclusions and Clinical Importance

Sedation with dexmedetomidine is associated with gallbladder wall thickening (> 2.0 mm) and peritoneal effusion that could be confused with pathologic etiologies.

Flavor-specific enhancement of electronic cigarette liquid consumption and preference in mice

BACKGROUND

The use of electronic cigarettes has increased over the past decade. To determine how the abuse liability of electronic cigarette liquids (e-liquids) differs from nicotine alone, and to determine the impact of flavor, we compared nicotine-containing fruit- and tobacco-flavored e-liquids, and their nicotine-free versions, to nicotine alone in mouse models of oral consumption, reward and aversion.

METHODS

Adult male C57BL/6 J mice voluntarily consumed oral nicotine, equivalent nicotine concentrations of fruit- and tobacco-flavored e-liquid, and equivalent dilutions of the nicotine-free versions in 2-bottle choice tests. Conditioned place preference and place aversion were assessed with peripherally administered e-liquids or nicotine. Serum nicotine and cotinine levels were measured after subcutaneous injections of e-liquid or nicotine.

RESULTS

Mice showed higher consumption and preference for the fruit-flavored e-liquid compared with nicotine alone. This increase was not due to the flavor itself as consumption of the nicotine-free fruit-flavored e-liquid was not elevated until the highest concentration tested. The increased consumption and preference were not observed with the tobacco-flavored e-liquid. The conditioned place preference, place aversion and nicotine pharmacokinetics of the fruit-flavored e-liquid were not significantly different from nicotine alone.

CONCLUSIONS

Our data suggest that fruit, but not tobacco flavor, increased the oral consumption of e-liquid compared with nicotine alone. Moreover, this enhancement was not due to increased consumption of the flavor itself, altered rewarding or aversive properties after peripheral administration, or altered pharmacokinetics. This flavor-specific enhancement suggests that some flavors may lead to higher nicotine intake and increased use of e-liquids compared with nicotine alone.

Association between abdominal ultrasound findings, the specific canine pancreatic lipase assay, clinical severity indices, and clinical diagnosis in dogs with pancreatitis

Background

A clinical diagnosis (CDx) of pancreatitis includes evaluation of clinical signs, abdominal ultrasound (AUS), and pancreatic lipase. However, practitioners are using AUS to diagnose pancreatitis and are using AUS severity to guide decisions. The validity of this is unknown.

Objectives

To determine whether (1) there is a correlation between AUS, specific canine pancreatic lipase (Spec cPL) assay, and CDx; (2) individual AUS abnormalities correlate more closely with CDx than others; (3) AUS severity mirrors clinical severity indices; (4) changes in AUS can be used as a marker for changes in Spec cPL or CDx; and (5) the sensitivity and specificity of AUS for pancreatitis.

Animals

One hundred fifty‐seven dogs.

Methods

In this retrospective case study, inclusion criteria were signs of gastrointestinal, pancreatic disease, or both, in addition to having a Spec cPL and AUS performed within 30 hours. Information extracted from the records included bloodwork, Spec cPL, AUS images/clips, and severity of ultrasonographic findings.

Results

AUS was weakly correlated with Spec cPL (r_s = .0178, P = .03) and moderately correlated with CDx (r_s = .379, P = <.001). Pancreatic size (r_s = .285, P = <.001), echogenicity (r_s = .365, P = <.001), and mesenteric echogenicity (r_s = .343, P = <.001) were correlated with CDx. Change in AUS was not correlated with Spec cPL or CDx changes. When pancreatic enlargement, echogenicity, or altered mesenteric echogenicity were required for a diagnosis, the sensitivity and specificity were 89% (95% confidence interval [CI] 71.8, 97.7) and 43% (95% CI 34.0, 51.6). When all 3 criteria were required, the sensitivity and specificity were 43% (95% CI 24.5, 62.8) and 92% (95% CI 85.3, 95.7).

Conclusions

AUS should not be used in isolation to diagnose pancreatitis and is a poor indicator of severity.

Diaphragmatic dysfunction in dogs with cervical spinal disorders before and after surgery using fluoroscopy, motion-mode ultrasound and radiography was not different than a group of control dogs

Cervical spinal disorders can lead to life-threatening respiratory complications. Diaphragmatic dysfunction is attributed to spinal cord morbidity secondary to cervical myelopathy or decompressive surgical intervention. The purpose of this observational case-control study was to determine the frequency of diaphragmatic dysfunction in dogs with cervical spinal disorders and a control group, the strength of association between cervical myelopathies and decompressive surgery with diaphragm paresis, and the agreement between and clinical usefulness of fluoroscopy, motion-mode ultrasonography, and radiography for diagnosing diaphragmatic dysfunction. Thirty-five client-owned dogs were recruited with 14 control dogs and 21 test dogs. Dogs were evaluated for the presence of diaphragmatic dysfunction using radiography, M-mode ultrasonography, and fluoroscopy before and after an anesthetic or surgical event. Diaphragmatic dysfunction was observed more frequently in dogs with cervical spinal disease prior to surgery (8/21; 38.1%) compared to control dogs (3/14; 21.4%) but was not statistically significant (P = .30). The occurrence of diaphragmatic dysfunction did not significantly increase following surgical decompression in either group. There was no to slight agreement between all imaging modalities. Most dogs with diaphragmatic dysfunction were asymptomatic. Diaphragmatic dysfunction was not statistically associated with cervical myelopathy or decompressive surgery. Ultrasonography and radiography were not useful diagnostic tests for determining diaphragmatic dysfunction in asymptomatic dogs when compared to fluoroscopy.

Is sitting time leading to mobility decline in long-term care residents?

BACKGROUND

Little is known about the sitting time in long-term care (LTC) facilities, or if sedentary behaviour affects changes in mobility over time.

AIMS

The objectives were to document the sitting time of LTC residents and to examine if sitting time could predict changes in mobility.

METHODS

Twenty residents of an LTC facility, representing three mobility statuses (independent, assisted transfer, and dependent transfer) were included. Sitting time was defined using an ActivPAL. Mobility statuses were reviewed 12 months later.

RESULTS

Participants spent an average of 21.9 h per day sedentary. At follow-up, five residents experienced a decline in mobility status, but no baseline sitting time variables were associated with the changes in mobility status (P > 0.05).

DISCUSSION/CONCLUSION

People living in LTC are highly sedentary. Sitting time differs amongst the mobility statues, but is unable to predict upcoming changes in mobility status.

Association of meniscal injury to joint space width on standard tibial plateau leveling osteotomy lateral radiographic projections of the canine stifle

Up to 70% of dogs with cranial cruciate ligament tears have concurrent meniscal injury, and these injuries can increase the risk of developing osteoarthritis and persistent lameness. Studies assessing joint space width on knee radiographs in people have indicated associations between joint space width and meniscal injuries. The aim of this prospective analytical study was to determine if there was an association between stifle joint space width on three different radiographic projections (the standard tibial plateau leveling osteotomy projections and a standing lateral projection) and meniscal injuries identified at surgery in dogs. There was a significant association between dogs with a meniscal tear and the corresponding joint space width on standard tibial plateau leveling osteotomy lateral radiographic projections (P-value = .0028). Based on receiver operator characteristic curve analysis, joint space widths measuring less than 3.43 mm may indicate a meniscal tear, with a corresponding 89.5% specificity and 40.5% sensitivity in dogs weighing 31 kg. Joint space narrowing is seen with meniscal tears in dogs, and radiography may be a noninvasive way to identify meniscal tears prior to surgery.

Single-voxel and multi-voxel spectroscopy yield comparable results in the normal juvenile canine brain when using 3 Tesla magnetic resonance imaging

Conventional magnetic resonance imaging (MRI) characteristics of canine brain diseases are often nonspecific. Single- and multi-voxel spectroscopy techniques allow quantification of chemical biomarkers for tissues of interest and may help to improve diagnostic specificity. However, published information is currently lacking for the in vivo performance of these two techniques in dogs. The aim of this prospective, methods comparison study was to compare the performance of single- and multi-voxel spectroscopy in the brains of eight healthy, juvenile dogs using 3 Tesla MRI. Ipsilateral regions of single- and multi-voxel spectroscopy were performed in symmetric regions of interest of each brain in the parietal (n = 3), thalamic (n = 2), and piriform lobes (n = 3). In vivo single-voxel spectroscopy and multi-voxel spectroscopy metabolite ratios from the same size and multi-voxel spectroscopy ratios from different sized regions of interest were compared. No significant difference was seen between single-voxel spectroscopy and multi-voxel spectroscopy metabolite ratios for any lobe when regions of interest were similar in size and shape. Significant lobar single-voxel spectroscopy and multi-voxel spectroscopy differences were seen between the parietal lobe and thalamus (P = 0.047) for the choline to N-acetyl aspartase ratios when large multi-voxel spectroscopy regions of interest were compared to very small multi-voxel spectroscopy regions of interest within the same lobe; and for the N-acetyl aspartase to creatine ratios in all lobes when single-voxel spectroscopy was compared to combined (pooled) multi-voxel spectroscopy datasets. Findings from this preliminary study indicated that single- and multi-voxel spectroscopy techniques using 3T MRI yield comparable results for similar sized regions of interest in the normal canine brain. Findings also supported using the contralateral side as an internal control for dogs with brain lesions.

Multiple myeloma in an Amur tiger (Panthera tigris altaica)

The Amur tiger (Panthera tigris altaica) is an endangered tiger subspecies. An adult zoo-bred female was found collapsed, and died despite supportive treatment. Hematology and biochemistry showed pancytopenia and hyperglobulinemia, and serum protein electrophoresis revealed a monoclonal band in the β-globulin region. Necropsy demonstrated hemoabdomen, multifocal lytic bone marrow lesions, splenomegaly, and hemorrhagic hepatic nodules, with left medial lobe rupture. There were mutifocal hemorrhages in the subcutis, lung, epicardium, and intestinal mucosa. Histopathology demonstrated plasmacytoid cells infiltrating the bone marrow, liver and spleen, and circulating within blood vessels. On immunohistochemistry, cell infiltrates of the three tissues were positive for λ light chains, bone marrow infiltrates were positive for MUM-1 and bone marrow and spleen infiltrates were positive for CD20. These findings indicate that this animal died of hemoabdomen subsequent to multiple myeloma. This is the first time this disease has been reported in a tiger.

Genome-wide association studies of smooth pursuit and antisaccade eye movements in psychotic disorders: findings from the B-SNIP study

Eye movement deviations, particularly deficits of initial sensorimotor processing and sustained pursuit maintenance, and antisaccade inhibition errors, are established intermediate phenotypes for psychotic disorders. We here studied eye movement measures of 849 participants from the Bipolar-Schizophrenia Network on Intermediate Phenotypes (B-SNIP) study (schizophrenia N=230, schizoaffective disorder N=155, psychotic bipolar disorder N=206 and healthy controls N=258) as quantitative phenotypes in relation to genetic data, while controlling for genetically derived ancestry measures, age and sex. A mixed-modeling genome-wide association studies approach was used including ~4.4 million genotypes (PsychChip and 1000 Genomes imputation). Across participants, sensorimotor processing at pursuit initiation was significantly associated with a single nucleotide polymorphism in IPO8 (12p11.21, P=8 × 10-11), whereas suggestive associations with sustained pursuit maintenance were identified with SNPs in SH3GL2 (9p22.2, P=3 × 10-8). In participants of predominantly African ancestry, sensorimotor processing was also significantly associated with SNPs in PCDH12 (5q31.3, P=1.6 × 10-10), and suggestive associations were observed with NRSN1 (6p22.3, P=5.4 × 10-8) and LMO7 (13q22.2, P=7.3x10-8), whereas antisaccade error rate was significantly associated with a non-coding region at chromosome 7 (P=6.5 × 10-9). Exploratory pathway analyses revealed associations with nervous system development and function for 40 top genes with sensorimotor processing and pursuit maintenance (P=4.9 × 10-2-9.8 × 10-4). Our findings suggest novel patterns of genetic variation relevant for brain systems subserving eye movement control known to be impaired in psychotic disorders. They include genes involved in nuclear trafficking and gene silencing (IPO8), fast axonal guidance and synaptic specificity (PCDH12), transduction of nerve signals (NRSN1), retinal degeneration (LMO7), synaptic glutamate release (SH3GL2), and broader nervous system development and function.

Quantitative Contribution of rs75017182 to Dihydropyrimidine Dehydrogenase mRNA Splicing and Enzyme Activity

Dihydropyrimidine dehydrogenase (DPD; DPYD gene) variants have emerged as reliable predictors of adverse toxicity to the chemotherapy agent 5-fluorouracil (5-FU). The intronic DPYD variant rs75017182 has been recently suggested to promote alternative splicing of DPYD. However, both the extent of alternative splicing and the true contribution of rs75017182 to DPD function remain unclear. In the present study we quantified alternative splicing and DPD enzyme activity in rs75017182 carriers utilizing healthy volunteer specimens from the Mayo Clinic Biobank. Although the alternatively spliced transcript was uniquely detected in rs75017182 carriers, canonically spliced DPYD levels were only reduced by 30% (P = 2.8 × 10^-6 ) relative to controls. Similarly, DPD enzyme function was reduced by 35% (P = 0.025). Carriers of the well-studied toxicity-associated variant rs67376798 displayed similar reductions in DPD activity (31% reduction). The modest effects on splicing and function suggest that rs75017182 may have clinical utility as a predictor of 5-FU toxicity similar to rs67376798.

Occipital condylar dysplasia in a Jacob lamb (Ovis aries)

Jacob sheep (Ovis aries) are a pedigree breed known for their “polycerate” (multihorned) phenotype. We describe a four-horned Jacob lamb that exhibited progressive congenital hindlimb ataxia and paresis, and was euthanased four weeks post-partum. Necropsy and CT-scan revealed deformity and asymmetry of the occipital condyles, causing narrowing of the foramen magnum and spinal cord compression. Histopathology demonstrated Wallerian degeneration of the cervical spinal cord at the level of the foramen magnum. These findings are consistent with occipital condylar dysplasia. This condition has been infrequently reported in the literature as a suspected heritable disease of polycerate Jacob sheep in the USA, and is assumed to arise during selection for the polycerate trait. This is the first reported case in European-bred Jacob sheep. Occipital condylar dysplasia should be considered as a differential diagnosis in polycerate Jacob lambs showing ataxia. It is important to raise awareness of this disease due to its suspected heritability and link to the popular polycerate trait.

The bovine paranasal sinuses: Bacterial flora, epithelial expression of nitric oxide and potential role in the in-herd persistence of respiratory disease pathogens

The bovine paranasal sinuses are a group of complex cavernous air-filled spaces, lined by respiratory epithelium, the exact function of which is unclear. While lesions affecting these sinuses are occasionally reported in cattle, their microbial flora has not been defined. Furthermore, given that the various bacterial and viral pathogens causing bovine respiratory disease (BRD) persist within herds, we speculated that the paranasal sinuses may serve as a refuge for such infectious agents. The paranasal sinuses of clinically normal cattle (n = 99) and of cattle submitted for post-mortem examination (PME: n = 34) were examined by microbial culture, PCR and serology to include bacterial and viral pathogens typically associated with BRD: Mycoplasma bovis, Histophilus somni, Mannheimia haemolytica and Pasteurella multocida, bovine respiratory syncytial virus (BRSV) and bovine parainfluenza-3 virus (BPIV-3). Overall, the paranasal sinuses were either predominantly sterile or did not contain detectable microbes (83.5%: 94.9% of clinically normal and 50.0% of cattle submitted for PME). Bacteria, including BRD causing pathogens, were identified in relatively small numbers of cattle (<10%). While serology indicated widespread exposure of both clinically normal and cattle submitted for PME to BPIV-3 and BRSV (seroprevalences of 91.6% and 84.7%, respectively), PCR identified BPIV-3 in only one animal. To further explore these findings we investigated the potential role of the antimicrobial molecule nitric oxide (NO) within paranasal sinus epithelium using immunohistochemistry. Expression of the enzyme responsible for NO synthesis, inducible nitric oxide synthase (iNOS), was detected to varying degrees in 76.5% of a sub-sample of animals suggesting production of this compound plays a similar protective role in the bovine sinus as it does in humans.

Radiation safety awareness among medical interns: are EU guidelines being implemented?

BACKGROUND

European recommendations suggest that medical students should be taught radiation safety before entering clinical practice.

AIM

The aim of this study was to produce a summative assessment of radiation protection training in medical school in Ireland.

MATERIALS AND METHODS

A web-based questionnaire was distributed to the 2014 intern population (n = 683) via network intern-coordinators. The survey encompassed knowledge of radiation dose in X-ray investigations, laws governing the prescribing of radiation and complications of radiation exposure to staff and patients.

RESULTS

Response rate was 14.2% (97/683) with all Irish medical schools represented. 64% of interns reported no formal training in radiation safety. 80% correctly identified MRI and 94% US as not posing a radiation risk. 54% identified CT PET as emitting the highest radiation dose to patients. Only 32% correctly identified one CT abdomen/pelvis as equivalent to the dose from 300 to 500 chest X-rays and 22% correctly identified the theoretical lifetime risk of cancer induction from CT abdomen/pelvis as 1 in 2000. While 71% thought it was very important that prescribers should be aware of patient radiation dose and 28% thought it was moderately important, 74% were not aware of any laws governing the prescribing of radiology investigations.

CONCLUSION

Currently, there is little formal radiation safety training in Irish medical schools. Knowledge of radiation dose and the laws governing prescribing is limited among qualifying interns. Implementation of a formal radiation safety curriculum in Irish Medical Schools would adhere to EU guidelines and improve prescriber knowledge, patient, and personal radiation safety.

Endovascular Therapy Research in Lower Limb Peripheral Arterial Disease Published Over a 5-Year Period: Who is Publishing and Where?

INTRODUCTION

Peripheral arterial disease (PAD) is being increasingly managed by endovascular therapies. In this study, we identified the clinical services publishing research as well as the journals of publication over a 5-year period.

METHODS

Twenty keywords and phrases related to endovascular intervention were identified, and a literature search was performed through the PubMed database from January 2009 to January 2014. Inclusion criteria were English language, study population more than five patients, and matching the keyword search. Eligible studies were collated into a database and classified by journal of publication, PubMed number, article title, publishing clinical service, type of publication, country of origin, and authors.

RESULTS

825 studies from 114 different journals were identified. 297 papers were excluded. Of the 528 included papers, 204 (39%) were published by Vascular Surgery (VS), 157 (30%) by Interventional Radiology (IR), 101 (19%) by Cardiology, 43 (8%) by Angiology, 6 (1%) by Vascular Medicine, and 17 (3%) from miscellaneous services. 283 (54%) studies originated from Europe, 157 (30%) from North America, 76 (14%) from Asia, 6 from Australia, 3 each from South America and Africa. IR published the most papers on PAD endovascular intervention in Europe with VS second while this trend was reversed in the USA. The 528 papers were published in 98 different journals with retrospective case series (72%), the majority.

CONCLUSION

IR continues to play a significant research role in endovascular intervention in PAD, particularly in Europe, and specifically in below the knee intervention, pedal intervention, and drug-eluting technologies.