Prescribing antibiotics prudently-A survey of policy implementation drivers among physicians and veterinarians.

Background: As the antimicrobial resistance (AMR) problem accelerates, humans and animals are suffering from the consequences of infections with diminishing antimicrobial treatment options. Within the One Medicine and One Health mandate, which denotes a collaborative, multisectoral, and transdisciplinary approach to improve medicine and health across human and animal sectors, we investigate how human and veterinary medical practitioners apply their medical and policy knowledge in prescribing antimicrobials. Different regions and locations establish different intermediary policies and programs to support clinicians in that pursuit. In Hong Kong, there are locally adapted programs at governance and clinical levels in the human medical field. However, there is no locally adapted veterinary antibiotic prescription guideline or stewardship program, and veterinarians adopt overseas or international professions' antimicrobial use guidelines. Such a policy environment creates a natural experiment to compare local policy implementation conditions and clinicians' knowledge, perception, and practice. Method: We construct the investigative survey tool by adaptation of Knowledge, Attitude, and Practice (KAP) and Capacity, Opportunity, and Motivation-Behavior (COM-B) models. We identify, compare and contrast factors that influence clinicians' antimicrobial prescription behavior. The factors are considered both intrinsically, such as personal attributes, and extrinsically, such as societal and professional norms. Findings: The absence of locally adopted antimicrobial guidelines influences AMR stewardship program implementation in local Hong Kong veterinary community. As medical allies, physicians and veterinarians share similar demographic influence, organization considerations and perception of public awareness. Both cohorts prescribe more prudently with more years-in-practice, time available to communicate with patients or caretakers, and public awareness and support.

A ketogenic diet rich in fish oil is superior to other fats in preventing NNK-induced lung cancer in A/J mice.

Given that ketogenic diets (KDs) are extremely high in dietary fat, we compared different fats in KDs to determine which was the best for cancer prevention. Specifically, we compared a Western and a 15% carbohydrate diet to seven different KDs, containing either Western fats or fats enriched in medium chain fatty acids (MCTs), milk fat (MF), palm oil (PO), olive oil (OO), corn oil (CO) or fish oil (FO) for their ability to reduce nicotine-derived nitrosamine ketone (NNK)-induced lung cancer in mice. While all the KDs tested were more effective at reducing lung nodules than the Western or 15% carbohydrate diet, the FO-KD was most effective at reducing lung nodules. Correlating with this, mice on the FO-KD had low blood glucose and the highest ß-hydroxybutyrate level, lowest liver fatty acid synthase/carnitine palmitoyl-1a ratio and a dramatic increase in fecal Akkermansia. We found no liver damage induced by the FO-KD, while the ratio of total cholesterol/HDL was unchanged on the different diets. We conclude that a FO-KD is superior to KDs enriched in other fats in reducing NNK-induced lung cancer, perhaps by being the most effective at skewing whole-body metabolism from a dependence on glucose to fats as an energy source.

Palliative care, homelessness, and restricted or uncertain immigration status.

Background: People experiencing homelessness have limited access to palliative care support despite high levels of ill health and premature mortality. Most research exploring these challenges in the United Kingdom has focused on people living in hostels or temporary accommodation. People with uncertain or restricted immigration status are often unable to access this accommodation due to lack of entitlement to benefits. There is little research about the experiences of those in the United Kingdom who cannot access hostels or temporary accommodation due to restricted or uncertain immigration status with regards to palliative and end-of-life care access. Aim: To explore the barriers to palliative and end-of-life care access for people with uncertain or restricted immigration status, who are experiencing homelessness and have advanced ill health, and the experiences of UK hospices of supporting people in this situation. Design: A multi-method cross-sectional study. Setting/participants: An online survey for hospice staff followed by online focus groups with staff from inclusion health, homelessness and palliative care services, charities and interviews with people experiencing homelessness. Results: Fifty hospice staff responded to the online survey and 17 people participated in focus groups and interviews (focus groups: n = 10; interviews: n = 7). The survey demonstrated how hospices are not currently supporting many people with restricted or uncertain immigration status who are homeless and that hospice staff have received limited training around eligibility for entitlements or National Health Service (NHS) care. Interview and focus group data demonstrated high levels of unmet need. Reasons for this included a lack of consistency around eligibility for support from local authorities, issues relating to NHS charging, and mistrust and limited knowledge of the UK health and social care system. These barriers leave many people unable to access care toward the end of their lives. Conclusion: To advocate for and provide compassionate palliative and end-of-life care for people with uncertain immigration status, there is need for more legal literacy, with training around people's entitlement to care and support, as well as easier access to specialist legal advice.

Palliative care, homelessness and restricted or uncertain immigration status Most research from the UK about access to support at the end of life for people who are homeless has looked at the experiences of people who are staying in hostels or temporary accommodation. People that are not UK nationals are not entitled to the benefit which pays for hostel or temporary accommodation. There is a group of people in the UK who are very unwell, who are homeless and are not able to access hostel accommodation due to their immigration status. This project explored the experiences of this group around access to palliative care. We spoke to professionals from health and social care services, charities and local councils and people who are in this situation themselves. Hospice staff were also surveyed to see if they had experience of supporting people in this situation. The survey showed that hospices are not currently supporting many people with restricted or uncertain immigration status who are homeless, and that they have limited training around supporting people in this situation. In the interviews and focus groups, opinions were heard about challenges to palliative care support for people with uncertain or restricted immigration status who were experiencing homelessness. Professionals described how it can be hard to obtain support from local authorities, and also understanding rules about who has to pay to receive NHS care. People with uncertain or restricted immigration status who were also homeless did not always know how to access the UK health and social care system and had negative experiences of doing so in the past. As a result, many people are unable to access care towards the end of their lives. To provide compassionate palliative and end-of-life care for people with uncertain immigration status, there is need for more legal literacy, with training around people's entitlement to care and support, as well as easier access to specialist legal advice.

Development of a novel human triculture model of non-alcoholic fatty liver disease and identification of berberine as ameliorating steatosis, oxidative stress and fibrosis.

Objectives: Non-alcoholic fatty liver disease (NAFLD) and its progression to non-alcoholic steatohepatitis (NASH) and hepatocarcinoma is a serious and growing problem. However, the development of new therapies is severely hindered by a lack of high-throughput assays for drug testing. Methods: We have developed a simple transwell assay comprised of HepG2 hepatocytes, hepatic LX-2 stellate cells, and differentiated THP-1 cells. The cells were incubated with an activating mixture containing the NASH-associated risk factors, glucose, insulin, free fatty acids (FFAs), and lipopolysaccharide (LPS) for 72 h. We compared different combinations of culture conditions to obtain a model system that recapitulates the main features of NAFLD/NASH, i.e., increased steatosis, reactive oxygen species (ROS), secretion of pro-inflammatory cytokines/chemokines, and presence of fibrosis. To confirm the usefulness of the optimized model system, we screened for compounds that inhibit steatosis in the hepatocytes and evaluated the most effective compound in the triculture model system. Results: The activating mixture stimulated HepG2 cells in this triculture to accumulate more fat and produce higher levels of reactive oxygen species (ROS) than HepG2 cells in monocultures. As well, higher levels of inflammatory cytokines and chemokines (IL-8, IL-6, MIP-1α, etc.) were produced in this triculture compared to monocultures. In addition, in all LX-2 monocultures and cocultures, exposure to the activating mixture increased markers of fibrosis. A major strength of our triculture system is that it makes possible the simultaneous monitoring of 4 main features of NASH, i.e., steatosis, oxidative stress, inflammation and fibrosis. Screening potential modulators that may reduce steatosis in HepG2 cells revealed the protective effects of the isoalkaloid, berberine. Tested using this novel triculture assay, treatment with 5 µM berberine decreased steatosis and ROS in HepG2 hepatocytes, reduced inflammatory cytokine production and inhibited collagen production from LX-2 cells. Conclusion: This simple triculture model recapitulates the main features of NAFLD/NASH and should be useful for high-throughput preclinical drug discovery. In this model, berberine showed promising results in decreasing steatosis and ROS and protection against fibrosis.

A low carbohydrate diet high in fish oil and soy protein delays inflammation, hematopoietic stem cell depletion, and mortality in miR-146a knock-out mice.

Since our previous studies found a low carbohydrate (CHO) diet containing soy protein and fish oil (15%Amylose/Soy/FO) significantly reduced lung and breast cancer in mice we asked herein if this low CHO diet could also delay the onset of myeloid malignancies. To test this we employed a miR-146a knock-out (KO) mouse model and found the 15%Amylose/Soy/FO diet increased their median lifespan by 8.5 month, compared to these mice on a Western diet. This was associated with increased lymphocytes and reduced monocytes, granulocytes, blood glucose and insulin levels. Inflammatory cytokine/chemokine studies carried out with 6-month-old mice, before any signs of illness, revealed the 15%Amylose/Soy/FO diet significantly reduced pro-inflammatory cytokines. This low CHO diet also led to an increase in plasma ß-hydroxybutyrate and in liver fatty acid synthase levels. This, together with higher liver carnitine palmitoyltransferase I levels suggested that the 15%Amylose/Soy/FO diet was causing a systemic metabolic shift from glucose to fatty acids as an energy source. Lastly, we found the 15%Amylose/Soy/FO diet resulted in significantly higher numbers of primitive hematopoietic stem cells (HSCs) in the bone marrow of 6-month-old mice than those fed a Western diet. Taken together, these results suggest a 15%Amylose/Soy/FO diet reduces chronic inflammation and increases fatty acid oxidation and that this, in turn, may prevent HSC proliferation and exhaustion, thereby delaying myeloid malignancy-induced death of miR-146a KO mice. We suggest a low CHO diet containing soy protein and fish oil could be beneficial in reducing the risk of myeloid malignancies in patients with low miR-146a levels.

Omega 3 supplementation reduces C-reactive protein, prostaglandin E2 and the granulocyte/lymphocyte ratio in heavy smokers: An open-label randomized crossover trial.

Objectives: Given the current controversy concerning the efficacy of omega 3 supplements at reducing inflammation, we evaluated the safety and efficacy of omega 3 on reducing inflammation in people with a 6-year lung cancer risk >1.5% and a C reactive protein (CRP) level >2 mg/L in a phase IIa cross-over study. Materials and methods: Forty-nine healthy participants ages 55 to 80, who were still smoking or had smoked in the past with ≥30 pack-years smoking history, living in British Columbia, Canada, were randomized in an open-label trial to receive 2.4 g eicosapentaenoic acid (EPA) + 1.2 g docosahexaenoic acid (DHA)/day for 6 months followed by observation for 6 months or observation for 6 months first and then active treatment for the next 6 months. Blood samples were collected over 1 year for measurement of plasma CRP, plasma and red blood cell (RBC) membrane levels of EPA, DHA and other fatty acids, Prostaglandin E2 (PGE2), Leukotriene B4 (LTB4) and an inflammatory marker panel. Results: Twenty one participants who began the trial within the active arm completed the trial while 20 participants who started in the control arm completed the study. Taking omega 3 resulted in a significant decrease in plasma CRP and PGE2 but not LTB4 levels. Importantly, the effect size for the primary outcome, CRP values, at the end of the intervention relative to baseline was medium (Cohen's d = 0.56). DHA, but not EPA levels in RBC membranes inversely correlated with PGE2 levels. Omega 3 also led to a significant reduction in granulocytes and an increase in lymphocytes. These high-dose omega 3 supplements were well tolerated, with only minor gastrointestinal symptoms in a subset of participants. Conclusion: Omega 3 fatty acids taken at 3.6 g/day significantly reduce systemic inflammation with negligible adverse health effects in people who smoke or have smoked and are at high risk of lung cancer.ClinicalTrials.gov, NCT number: NCT03936621.

A Retrospective Study of Antimicrobial Resistant Bacteria Associated with Feline and Canine Urinary Tract Infection in Hong Kong SAR, China-A Case Study on Implication of First-Line Antibiotics Use.

Urinary tract infection (UTI) is a common clinical diagnosis for which empirical antibiotics are used in veterinary medicine. For veterinarians, the description of canine and feline antibiograms can help with making prudent use decisions and guideline formulation. For public health officers and epidemiologists, a urinary antibiogram overview helps track and trend antimicrobial resistance (AMR). There is currently a knowledge gap in AMR prevalence associated with urinary tract infection in feline and canine patients and the resistance percentage of these microbes against some of the over-the-counter antibiotics available to local pet owners. This study has two aims. First, it aims to investigate the frequency of the bacteria and bacterial-resistance pattern in urine samples obtained from feline and canine patients. Second, it aims to determine the resistance of Escherichia coli (E. coli), the most frequently isolated bacteria, to first-line antibiotics. Results: We identified the five most-frequently isolated bacterial species and determined these isolates' antibiotic sensitivity and resistance. The most-frequently isolated bacteria in feline and canine patients was Escherichia coli (E. coli). E. coli was identified, on average, in 37.2% of canine and 46.5% of feline urine samples. Among feline urinary samples, Enterococcus (14.7%) and Staphylococcus (14.5%) spp. were isolated more frequently, followed by Pseudomonas (4.8%) and Klebsiella (5.2%) spp. (). In canine samples, Proteus (17.9%) and Staphylococcus (13.2%) spp. were isolated more frequently, followed by Enterococcus (10.0%) and Klebsiella (8.59%) spp. Among these isolates, 40 to 70% of Staphylococcus spp. bacterial isolates from feline and canine patients were resistant to amoxicillin and ampicillin. During the three-year study period, among canine patients, 10 to 20% of Staphylococcus spp. bacterial isolates were resistance to fluoroquinolones, other quinolones, and third-generation cephalosporins. Among feline patients, 10% of Staphylococcus spp., 15 to 20% of E. coli, 50 to 60% of Klebsiella spp., and 90% of Pseudomonas spp. were resistant to cefovecin, a commonly used antibiotic.

A low-carbohydrate diet containing soy protein and fish oil reduces breast but not prostate cancer in C3(1)/Tag mice.

We recently showed that a low-carbohydrate (CHO) diet containing soy protein and fish oil dramatically reduces lung nodules in a mouse model of lung cancer when compared to a Western diet. To explore the universality of this finding, we herein compared this low-CHO diet to a Western diet on in preventing breast and prostate cancer using a mouse model that expresses the SV40 large T-antigen specifically in breast epithelia in females and prostate epithelia in males. We found that breast cancer was significantly reduced with this low-CHO diet and this correlated with a reduction in plasma levels of glucose, insulin, IL-6, TNFα and prostaglandin E2 (PGE2). This also corresponded with a reduction in the Ki67 proliferation index within breast tumors. On the other hand, this low-CHO diet did not reduce the incidence of prostate cancer in the male mice. Although it reduced both blood glucose and insulin to the same extent as in the female mice, there was no reduction in plasma IL-6, TNFα or PGE2 levels, or in the Ki67 proliferation index in prostate lesions. Based on immunohistochemistry studies with antibodies to 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3), carnitine palmitoyltransferase Ia (CPT1a) and fatty acid synthase (FAS), it is likely that this difference in response of the two cancer types to this low-CHO diet reflects differences in the glucose dependence of breast and prostate cancer, with the former being highly dependent on glucose for energy and the latter being more dependent on fatty acids.

The effect of smoking on chronic inflammation, immune function and blood cell composition.

Smoking is the number one risk factor for cancer mortality but only 15-20% of heavy smokers develop lung cancer. It would, therefore, be of great benefit to identify those at high risk early on so that preventative measures can be initiated. To investigate this, we evaluated the effects of smoking on inflammatory markers, innate and adaptive immune responses to bacterial and viral challenges and blood cell composition. We found that plasma samples from 30 heavy smokers (16 men and 14 women) had significantly higher CRP, fibrinogen, IL-6 and CEA levels than 36 non-smoking controls. Whole blood samples from smokers, incubated for 7 h at 37 °C in the absence of any exogenous stimuli, secreted significantly higher levels of IL-8 and a number of other cytokines/chemokines than non-smokers. When challenged for 7 h with E. coli, whole blood samples from smokers secreted significantly lower levels of many inflammatory cytokines/chemokines. However, when stimulated with HSV-1, significantly higher levels of both PGE2 and many cytokines/chemokines were secreted from smokers' blood samples than from controls. In terms of blood cell composition, red blood cells, hematocrits, hemoglobin levels, MCV, MCH, MCHC, Pct and RDW levels were all elevated in smokers, in keeping with their compromised lung capacity. As well, total leukocytes were significantly higher, driven by increases in granulocytes and monocytes. In addition, smokers had lower NK cells and higher Tregs than controls, suggesting that smoking may reduce the ability to kill nascent tumor cells. Importantly, there was substantial person-to person variation amongst smokers with some showing markedly different values from controls and others showing normal levels of many parameters measured, indicating the former may be at significantly higher risk of developing lung cancer.

Low carbohydrate diets containing soy protein and fish oil slow the growth of established NNK-induced lung tumors.

We recently found that a diet composed of 15% of total calories as carbohydrate (CHO), primarily as amylose, 35% soy protein and 50% fat, primarily as fish oil (FO) (15%Amylose/Soy/FO) was highly effective at preventing lung nodule formation in a nicotine-derived nitrosamine ketone (NNK)-induced lung cancer model. We asked herein whether adopting such a diet once cancers are established might also be beneficial. To test this, NNK-induced lung nodules were established in mice on a Western diet and the mice were then either kept on a Western diet or switched to various low CHO diets. Since we previously found that sedentary mice develop more lung nodules than active mice, we also compared the effect of exercise in this cancer progression model. We found that switching to a 15%Amylose/Soy/FO diet reduced lung nodules and slowed tumor growth with both 'active' and 'sedentary' mice. Ki67, cleaved caspase 3 and Terminal Deoxynucleotidyl Transferase-Mediated dUTP Nick End Labeling assays suggested that the efficacy of the 15%Amylose/Soy/FO in lowering tumor nodule count and size was not due to a reduction in tumor cell proliferation, but to an increase in apoptosis. The 15%Amylose/Soy/FO diet also significantly lowered liver fatty acid synthase and 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 expression, pointing to a global metabolic switch from glycolysis to fatty acid oxidation. Mice fed the 15%Amylose/Soy/FO diet also had significantly reduced plasma levels of interleukin (IL)-1ß, IL-6 and tumor necrosis factor α. These results suggest that the 15%Amylose/Soy/FO diet may slow tumor growth by suppressing proinflammatory cytokines, inducing a metabolic switch away from glycolysis and inducing apoptosis in tumors.

Ventral hippocampal histamine increases the frequency of evoked theta rhythm but produces anxiolytic-like effects in the elevated plus maze.

The neurobiological underpinnings of anxiety are of paramount importance to the development of effective therapeutic treatments. To date, there is considerable pharmacological evidence suggesting that the suppression of hippocampal theta frequency is a robust and predictive assay of anxiolytic drug action. Recently, this idea has been challenged using histamine (2-(4-imidazolyl)ethanamine), an endogenous neurotransmitter involved in a number of brain and behavioral functions. Here, we systematically evaluate the effects of dorsal and ventral hippocampal histamine infusions on evoked theta frequency and behavioral anxiety. Given the complex pharmacological profile of histamine and its receptors in the hippocampus, we reasoned that local intra-hippocampal infusions would be a powerful test of the theta suppression model. While dorsal hippocampal infusions of histamine produced neither significant changes in anxious-like behavior in the elevated plus maze nor changes of evoked theta, ventral infusions of histamine produced potent behavioral anxiolysis which corresponded to an increase, and not a decrease, in evoked theta frequency. As a positive neurophysiological control, we demonstrated that diazepam, a proven anxiolytic drug, decreased the frequency of hippocampal theta following both dorsal and ventral hippocampal infusions. Our results further challenge the hippocampal theta frequency suppression model as a measure of anxiolytic drug action. This article is part of the Special Issue entitled 'Histamine Receptors'.

FG7142, yohimbine, and ßCCE produce anxiogenic-like effects in the elevated plus-maze but do not affect brainstem activated hippocampal theta.

The neurobiological underpinnings of anxiety are of paramount importance to selective and efficacious pharmaceutical intervention. Hippocampal theta frequency in urethane anaesthetized rats is suppressed by all known (and some previously unknown) anti-anxiety (anxiolytic) drugs. Although these findings support the predictive validity of this assay, its construct validity (i.e., whether theta frequency actually indexes anxiety per se) has not been a subject of systematic investigation. We reasoned that if anxiolytic drugs suppress hippocampal theta frequency, then drugs that increase anxiety (i.e., anxiogenic agents) should increase theta frequency, thus providing evidence of construct validity. We used three proven anxiogenic drugs--two benzodiazepine receptor inverse agonists, N-methyl-ß-carboline-3-carboxamide (FG7142) and ß-carboline-3-carboxylate ethyl ester (ßCCE), and one α2 noradrenergic receptor antagonist, 17α-hydroxy-yohimban-16α-carboxylic acid methyl ester (yohimbine) as pharmacological probes to assess the construct validity of the theta model. Although all three anxiogenic drugs significantly increased behavioural measures of anxiety in the elevated plus-maze, none of the three increased the frequency of hippocampal theta oscillations in the neurophysiological model. As a positive control, we demonstrated that diazepam, a proven anxiolytic drug, decreased the frequency of hippocampal theta, as in all other studies using this model. Given this discrepancy between the significant effects of anxiogenic drugs in the behavioural model and the null effects of these drugs in the neurophysiological model, we conclude that the construct validity of the hippocampal theta model of anxiety is questionable.

Intrahippocampal infusion of the Ih blocker ZD7288 slows evoked theta rhythm and produces anxiolytic-like effects in the elevated plus maze.

Hippocampal theta rhythm has been associated with a number of behavioral processes, including learning and memory, spatial behavior, sensorimotor integration and affective responses. Suppression of hippocampal theta frequency has been shown to be a reliable neurophysiological signature of anxiolytic drug action in tests using known anxiolytic drugs (i.e., correlational evidence), but only one study to date (Yeung et al. (2012) Neuropharmacology 62:155-160) has shown that a drug with no known effect on either hippocampal theta or anxiety can in fact separately suppress hippocampal theta and anxiety in behavioral tests (i.e., prima facie evidence). Here, we attempt a further critical test of the hippocampal theta model by performing intrahippocampal administrations of the Ih blocker ZD7288, which is known to disrupt theta frequency subthreshold oscillations and resonance at the membrane level but is not known to have anxiolytic action. Intrahippocampal microinfusions of ZD7288 at high (15 µg), but not low (1 µg) doses slowed brainstem-evoked hippocampal theta responses in the urethane anesthetized rat, and more importantly, promoted anxiolytic action in freely behaving rats in the elevated plus maze. Taken together with our previous demonstration, these data provide converging, prima facie evidence of the validity of the theta suppression model.

The anxiolytic effects of somatostatin following intra-septal and intra-amygdalar microinfusions are reversed by the selective sst2 antagonist PRL2903.

Somatostatin (SST) is a polypeptide with two biological isoforms (SST14, and SST28), and five SST receptor subtypes (sst1-5). Together, they mediate a number of neural and hormonal functions. Recently, we found that intracerebroventricular (ICV), intra-amygdalar, and intra-septal microinfusions of SST14, SST28, and a selective sst2 receptor agonist L-779976 all produced anxiolytic-like effects in the elevated plus-maze, a widely used animal model of anxiety. The receptor specificity of these anxiolytic-like effects, however, has not been conclusively established. Accordingly, the anxiolytic effects of SST in the elevated plus-maze were assessed following intra-septal or intra-amygalar microinfusions of 1) SST (1.5µg per hemisphere), 2) the highly selective sst2 receptor antagonist PRL2903 (1.5µg per hemisphere), or 3) the combination of SST and PRL2903 (each 1.5µg per hemisphere). Antagonism of the anxiolytic effects of SST in the plus-maze by PRL2903 should result in open-arm exploration that is equivalent to that of 4) vehicle-injected control rats. Both intra-septal and intra-amygdalar microinfusions of SST produced anxiolytic effects in the elevated plus-maze, consistent with results found previously after ICV microinfusions (see Engin et al., 2008; Engin and Treit, 2009; Yeung et al., 2011). More importantly, infusion of PRL2903 completely reversed the anxiolytic effects of SST in both the amygdala and the septum. These results show that somatostatin's anxiolytic effects are mediated by sst2 receptors contained in the amygdala and septum of the rat brain.

A critical test of the hippocampal theta model of anxiolytic drug action.

Hippocampal theta rhythms have been associated with a number of behavioural processes, including learning, memory and arousal. Recently it has been argued that the suppression of hippocampal theta is a valid indicator of anxiolytic drug action. Like all such models, however, it has relied almost exclusively on the experimental effects of well-known, clinically proven anxiolytic compounds for validation. The actual predictive validity of putative models of anxiolytic drug action, however, cannot be rigorously tested with this approach alone. The present study provides a stringent test of the predictive validity of the theta suppression model, using the drug phenytoin (50 mg/kg and 10 mg/kg), and a positive comparison compound, diazepam (2 mg/kg). Phenytoin has two important properties that are advantageous for assessing the validity of the theta suppression model: 1) it is a standard antiepileptic drug with no known anxiolytic effects, and 2) its primary mechanism of action is through suppression of the persistent sodium current, an effect that should also suppress hippocampal theta. Because of the latter property, we also directly compared the effects of phenytoin in the theta suppression model with its effects in the most widely tested behavioural model of anxiolytic drug action, the elevated plus-maze. While an anxiolytic-like effect of phenytoin in the theta suppression model might be expected simply due to its suppressive effects on sodium channel currents, anxiolytic effects in both tests would provide strong support for the predictive validity of the theta suppression model. Surprisingly, phenytoin produced clear anxiolytic-like effects in both neurophysiological and behavioural models, thus providing strong evidence of the predictive validity of the theta suppression model. This article is part of a Special Issue entitled 'Anxiety and Depression'.

Comparative evaluation of a point-of-care immunochromatographic test SNAP 4Dx with molecular detection tests for vector-borne canine pathogens in Hong Kong.

There are no comprehensive studies on the performance of commonly used point-of-care diagnostic enzyme immunoassay for common arthropod-borne canine pathogens. A comparative evaluation of an immunochromatographic test for these infections with a comprehensive polymerase chain reaction (PCR) test panel was performed on 100 pet dogs and 100 stray dogs without obvious clinical symptoms. Of the 162 positive test results from both immunochromatographic test and PCR, there was 85.2% concordance. The 24 discordant results between serology and PCR occurred in tests involving Ehrlichia canis (14) and Anaplasma platys (10), which may be related to the time of infection. No positive cases of borreliosis or rickettsiosis were detected. One important limitation of the immunochromatographic test was its lack of testing for babesiosis and hepatozoonosis. The former is the most prevalent arthropod-borne canine infection in our cohort (41%). Coinfections were found in 19% stray dogs and 6% of pet dogs with both tests (p < 0.01). Seventeen and 8 samples from stray and pet dogs, respectively, were initially positive in the PCR test for Ehrlichia. However, on sequencing of the PCR amplicon, 10 from stray and 2 from pet dogs were found to be Wolbachia sequences instead, with 100% nucleotide identity to the 16S rRNA sequence of Wolbachia endosymbiont of Dirofilaria immitis. The presence of Wolbachia DNAemia (6%) correlated well with the molecular test and immunochromatographic antigen test for D. immitis.

Anxiolytic-like effects of somatostatin isoforms SST 14 and SST 28 in two animal models (Rattus norvegicus) after intra-amygdalar and intra-septal microinfusions.

RATIONALE AND OBJECTIVES: Somatostatin (SST) isoforms, SST 14 and SST 28, inhibit regulatory hormones in the periphery (e.g., growth hormone) and are widely distributed in the brain. In recent experiments, intracerebroventricular (ICV) SST produced anxiolytic-like effects in both behavioral and electrophysiological models. The sites of action of these anxiolytic effects in the brain, however, and the relative contributions of SST 14 and SST 28 to these effects are unknown. MATERIALS AND METHODS: Anxiolytic effects were assessed in the plus-maze and shock-probe tests after (1) intra-amygdalar microinfusion of SST 14 (0.5 or 3 µg per hemisphere) or SST 28 (3 µg per hemisphere), (2) intra-septal microinfusion of SST 14 (0.5 or 1.5 µg per hemisphere) or SST 28 (1.5 µg per hemisphere), or (3) intra-striatal microinfusion of SST 14 (3 µg per hemisphere). RESULTS: Intra-amygdalar and intra-septal microinfusions of SST 14 and SST 28 produced robust anxiolytic-like effects in the behavioral tests, unlike intra-striatal microinfusions. The magnitude of the anxiolytic effects in the amygdala and septum were comparable to those found previously with ICV SST 14, ICV L-779976, an SST (sst2) receptor agonist, and ICV diazepam, a classical benzodiazepine anxiolytic. CONCLUSIONS: SST receptors in the septum and amygdala are responsive to both SST 14 and SST 28, but not those in the striatum. Although no obvious differences in the anxiolytic-like effects of the isoforms were detected, quantitative or even qualitative differences in their specific anxiolytic effects may occur in different sub-regions of the septum and amygdala, as has been found for benzodiazepine anxiolytics.