Exploring Diagnostic Precision and Triage Proficiency: A Comparative Study of GPT-4 and Bard in Addressing Common Ophthalmic Complaints.

In the modern era, patients often resort to the internet for answers to their health-related concerns, and clinics face challenges to providing timely response to patient concerns. This has led to a need to investigate the capabilities of AI chatbots for ophthalmic diagnosis and triage. In this in silico study, 80 simulated patient complaints in ophthalmology with varying urgency levels and clinical descriptors were entered into both ChatGPT and Bard in a systematic 3-step submission process asking chatbots to triage, diagnose, and evaluate urgency. Three ophthalmologists graded chatbot responses. Chatbots were significantly better at ophthalmic triage than diagnosis (90.0% appropriate triage vs. 48.8% correct leading diagnosis; p < 0.001), and GPT-4 performed better than Bard for appropriate triage recommendations (96.3% vs. 83.8%; p = 0.008), grader satisfaction for patient use (81.3% vs. 55.0%; p < 0.001), and lower potential harm rates (6.3% vs. 20.0%; p = 0.010). More descriptors improved the accuracy of diagnosis for both GPT-4 and Bard. These results indicate that chatbots may not need to recognize the correct diagnosis to provide appropriate ophthalmic triage, and there is a potential utility of these tools in aiding patients or triage staff; however, they are not a replacement for professional ophthalmic evaluation or advice.

Radiological assessment of response and adverse events associated with novel systemic oncological therapies.

The last decade has seen a paradigm shift in medical oncology treatment with the rise of novel systemic agents, principally molecular targeted therapy and immunotherapy. These new groups of anti-cancer treatment have revolutionised the prognostic landscape for certain patient cohorts with advanced disease, and it is hoped that through ongoing extensive clinical research, significant survival benefits may be demonstrated in the majority of tumour types. However, radiological response assessment of these new agents has become more nuanced for radiologists, as the behaviour of both responding and progressing tumour burden can be more diverse than with conventional chemotherapy. Additionally, radiologists need to be aware of adverse events associated with these treatments as some side effects carry a high morbidity/mortality and may manifest radiologically before they become clinically apparent. This review discusses radiological response assessment and adverse events associated with these novel agents, which have become fundamental aspects of systemic oncological therapy.

A phase II randomised, placebo-controlled trial of low dose (metronomic) cyclophosphamide and nintedanib (BIBF1120) in advanced ovarian, fallopian tube or primary peritoneal cancer.

BACKGROUND: We investigated the safety and efficacy of a combination of the oral tyrosine kinase inhibitor, nintedanib (BIBF 1120) with oral cyclophosphamide in patients with relapsed ovarian cancer. PATIENTS AND METHODS: Patients with relapsed ovarian, fallopian tube or primary peritoneal cancer received oral cyclophosphamide (100 mg o.d.) and were randomised (1,1) to also have either oral nintedanib or placebo. The primary endpoint was overall survival (OS). Secondary endpoints included progression free survival (PFS), response rate, toxicity, and quality of life. RESULTS: 117 patients were randomised, 3 did not start trial treatment, median age 64 years. Forty-five (39%) had received ≥5 lines chemotherapy. 30% had received prior bevacizumab. The median OS was 6.8 (nintedanib) versus 6.4 (placebo) months (hazard ratio 1.08; 95% confidence interval 0.72-1.62; P = 0.72). The 6-month PFS rate was 29.6% versus 22.8% (P = 0.57). Grade 3/4 adverse events occurred in 64% (nintedanib) versus 54% (placebo) of patients (P = 0.28); the most frequent G3/4 toxicities were lymphopenia (18.6% nintedanib versus 16.4% placebo), diarrhoea (13.6% versus 0%), neutropenia (11.9% versus 0%), fatigue (10.2% versus 9.1%), and vomiting (10.2% versus 7.3%). Patients who had received prior bevacizumab treatment had 52 days less time on treatment (P < 0.01). 26 patients (23%) took oral cyclophosphamide for ≥6 months. There were no differences in quality of life between treatment arms. CONCLUSIONS: This is the largest reported cohort of patients with relapsed ovarian cancer treated with oral cyclophosphamide. Nintedanib did not improve outcomes when added to oral cyclophosphamide. Although not significant, more patients than expected remained on treatment for ≥6 months. This may reflect a higher proportion of patients with more indolent disease or the higher dose of cyclophosphamide used. CLINICAL TRIAL REGISTRATION: Clinicaltrials.govNCT01610869.

Chemotherapy for Retinoblastoma: Impact of Intravitreal Chemotherapy.

ABSTRACT: Chemotherapy is now the primary treatment of retinoblastoma in eyes with visual potential or those that are considered not advanced for retinoblastoma. In addition to intravenous chemotherapy (IVC), drugs delivered via alternative routes such as intra-arterial and intravitreal administration have emerged as promising options for management of retinoblastoma. Various studies have shown excellent results in salvaging nearly 100% of groups A-C eyes; however, intra-arterial chemotherapy (IAC) seems to offer superior local control rates as compared with IVC for advanced intraocular retinoblastoma (groups D and E eyes). Intravitreal chemotherapy (IVitC), that delivers the highest concentration of drug in the vitreous cavity while minimizing systemic drug concentration, has emerged in recent years (2012) as an effective treatment for refractory or persistent vitreous seeding. The role of concomitant and subsequent therapies is an important consideration, particularly the use of IVitC in combination with IAC. As IVitC became acceptable during the era of IAC, most of the patients treated previously with IVC did not receive IVitC. Therefore, it is possible that some of the IVC failures could have been avoided with the use of IVitC. We provide our perspective of published data that seems to be skewed by evolving practice patterns that project enhanced efficacy of IAC when compared with historic control rates achieved with IVC. In absence of better-quality data or randomized controlled trials, it is hard to establish superiority of one treatment over the other.

Novel multiparameter correlates of Coxiella burnetii infection and vaccination identified by longitudinal deep immune profiling.

Q-fever is a flu-like illness caused by Coxiella burnetii (Cb), a highly infectious intracellular bacterium. There is an unmet need for a safe and effective vaccine for Q-fever. Correlates of immune protection to Cb infection are limited. We proposed that analysis by longitudinal high dimensional immune (HDI) profiling using mass cytometry combined with other measures of vaccination and protection could be used to identify novel correlates of effective vaccination and control of Cb infection. Using a vaccine-challenge model in HLA-DR transgenic mice, we demonstrated significant alterations in circulating T-cell and innate immune populations that distinguished vaccinated from naïve mice within 10 days, and persisted until at least 35 days post-vaccination. Following challenge, vaccinated mice exhibited reduced bacterial burden and splenomegaly, along with distinct effector T-cell and monocyte profiles. Correlation of HDI data to serological and pathological measurements was performed. Our data indicate a Th1-biased response to Cb, consistent with previous reports, and identify Ly6C, CD73, and T-bet expression in T-cell, NK-cell, and monocytic populations as distinguishing features between vaccinated and naïve mice. This study refines the understanding of the integrated immune response to Cb vaccine and challenge, which can inform the assessment of candidate vaccines for Cb.

Zoonotic pathogens from feral swine that pose a significant threat to public health.

The natural fecundity of suids, great ability to adapt to new habitats and desire for local hunting opportunities leading to translocation of feral pigs to regions where they are not yet established have all been instrumental in the home range expansion of feral swine. Feral swine populations in the United States continue to expand, wreaking havoc on agricultural lands, further compromising threatened and endangered species, and posing a microbiological threat to humans, domestic livestock and companion animals. This manuscript thoroughly reviews zoonotic diseases of concern including brucellosis, bovine tuberculosis, leptospirosis, enteric pathogens, both Salmonella spp. and shiga toxin-producing Escherichia coli, and hepatitis E. These pathogens are not a comprehensive list of microbes that are capable of infecting both humans and feral swine, but rather have been selected as they are known to infect US feral swine, direct transmission between wild suids and humans has previously been documented, or they have been shown to be readily transmitted during processing or consumption of feral swine pork. Humans that interact directly or indirectly with feral swine are at much higher risk for the development of a number of zoonotic pathogens. Numerous case reports document transmission events from feral swine and wild boar to humans, and the resulting diseases may be mild and self-limiting, chronic or fatal. Individuals that interact with feral swine should take preventative measures to minimize the risk of disease transmission and all meat should be thoroughly cooked. Additionally, public health campaigns to increase knowledge of the risks associated with feral swine are imperative.

Machine-learned approximations to Density Functional Theory Hamiltonians.

Large scale Density Functional Theory (DFT) based electronic structure calculations are highly time consuming and scale poorly with system size. While semi-empirical approximations to DFT result in a reduction in computational time versus ab initio DFT, creating such approximations involves significant manual intervention and is highly inefficient for high-throughput electronic structure screening calculations. In this letter, we propose the use of machine-learning for prediction of DFT Hamiltonians. Using suitable representations of atomic neighborhoods and Kernel Ridge Regression, we show that an accurate and transferable prediction of DFT Hamiltonians for a variety of material environments can be achieved. Electronic structure properties such as ballistic transmission and band structure computed using predicted Hamiltonians compare accurately with their DFT counterparts. The method is independent of the specifics of the DFT basis or material system used and can easily be automated and scaled for predicting Hamiltonians of any material system of interest.

A Serological Protein Microarray for Detection of Multiple Cross-Reactive Flavivirus Infections in Horses for Veterinary and Public Health Surveillance.

The genus Flavivirus in the family Flaviviridae includes some of the most important examples of emerging zoonotic arboviruses that are rapidly spreading across the globe. Japanese encephalitis virus (JEV), West Nile virus (WNV), St. Louis encephalitis virus (SLEV) and Usutu virus (USUV) are mosquito-borne members of the JEV serological group. Although most infections in humans are asymptomatic or present with mild flu-like symptoms, clinical manifestations of JEV, WNV, SLEV, USUV and tick-borne encephalitis virus (TBEV) can include severe neurological disease and death. In horses, infection with WNV and JEV can lead to severe neurological disease and death, while USUV, SLEV and TBEV infections are mainly asymptomatic, however, and induce antibody responses. Horses often serve as sentinels to monitor active virus circulation in serological surveillance programmes specifically for WNV, USUV and JEV. Here, we developed and validated a NS1-antigen protein microarray for the serological differential diagnosis of flavivirus infections in horses using sera of experimentally and naturally infected symptomatic as well as asymptomatic horses. Using samples from experimentally infected horses, an IgG and IgM specificity of 100% and a sensitivity of 95% for WNV and 100% for JEV was achieved with a cut-off titre of 1 : 20 based on ROC calculation. In field settings, the microarray identified 93-100% of IgG-positive horses with recent WNV infections and 87% of TBEV IgG-positive horses. WNV IgM sensitivity was 80%. Differentiation between closely related flaviviruses by the NS1-antigen protein microarray is possible, even though we identified some instances of cross-reactivity among antibodies. However, the assay is not able to differentiate between naturally infected horses and animals vaccinated with an inactivated WNV whole-virus vaccine. We showed that the NS1-microarray can potentially be used for diagnosing and distinguishing flavivirus infections in horses and for public health purposes within a surveillance setting. This allows for fast, cheap, syndrome-based laboratory testing for multiple viruses simultaneously for veterinary and public health purposes.

Dynamics of piscine francisellosis differs amongst tilapia species (Oreochromis spp.) in a controlled challenge with Francisella noatunensis subsp. orientalis.

A 25-week immersion challenge was conducted exposing Oreochromis mossambicus, Oreochromis aureus and Oreochromis urolepis hornorum to Francisella noatunensis subsp. orientalis (Fno). Two populations were compared for each fish species; 'resident fish' were defined as fish maintained in tanks since week 0 of challenge, whereas 'naïve fish' were defined as fish added to tanks once temperature in water reached <26 °C at 21 weeks post-challenge. Fno genome equivalents (GEs) in water were similar in all treatments 1 h post-challenge; however, significantly lower Fno GEs were detected 2 weeks post-challenge in all tanks, and the only treatment with detectable Fno GE after 4 weeks of challenge were the O. mossambicus tanks. Twenty-one weeks post-challenge, naïve fish were stocked with 'resident' cohorts. Over a 4-week period, mortalities occurred consistently only in O. mossambicus naïve cohorts. Overall presence of granulomas in spleen of survivors was similar (>55%) in all resident populations; however, in naïve populations, only O. mossambicus presented granulomas. Similarly, only O. mossambicus presented viable Fno in the spleen of survivors, and Fno GEs were only detected in O. mossambicus, and in resident O. aureus. In conclusion, the results of this study suggest different susceptibility of tilapia species to piscine francisellosis.

Serosurveillance and factors associated with the presence of antibodies against bluetongue virus in dairy cattle in two eco-zones of Nepal.

Cattle play an important role in the epidemiology of bluetongue (BT) by acting as reservoir hosts. However, the status of BT virus (BTV) in dairy cattle in Nepal is unknown. The objective of this study was to estimate the prevalence of BTV antibodies in dairy cattle in two eco-zones of Nepal, and to identify the factors associated with virus exposure. The authors conducted a cross-sectional serosurvey from March 2012 through February 2013 by sampling 131 dairy cattle from seven clusters (villages) in the Chitwan district in the Terai region (southern lowlands) and the Lamjung district in the Hills region (the middle part of Nepal). Of the 131 serum samples tested, 29.3% (95% confidence interval [CI]: 21.5-37.2) were positive for BTV antibodies. Herd-level seroprevalence was 45.7% (95% CI: 30.9-61.0). Bivariate analysis indicated a positive association between seroconversion to BTV and age, and an association with breed of cattle after controlling for clustering of animals within herds. Based on this model, cattle were more likely to become seropositive as they aged. Crossbred cattle were more likely to be seropositive than those of exotic breeds (odds ratio [OR] = 4.6; 95% CI: 1.5-14.1). The results indicate widespread exposure of dairy cattle to BTV in Nepal. The authors suggest that dairy cattle should be included in the surveillance plan for BTV infection in Nepal and that it is important to educate farmers about the possible impacts of this disease.

Les bovins jouent un rôle important en tant qu'hôtes réservoirs dans l'épidémiologie de la fièvre catarrhale ovine (FCO). Toutefois, au Népal le statut des bovins de races laitières au regard du virus de la FCO était inconnu. La présente étude a été conduite pour estimer la prévalence des anticorps dirigés contre la FCO chez les bovins laitiers dans deux zones écologiques du Népal et pour élucider les facteurs présentant un lien avec l'exposition virale. Les auteurs ont réalisé une enquête sérologique transversale de mars 2012 à février 2013, en prélevant 131 bovins laitiers répartis en sept groupes (villages) du district de Chitwan, région de Terai (plaines méridionales) et du district de Lamjung, région des Collines (centre du Népal). La présence d'anticorps dirigés contre la FCO a été détectée dans 29,3 % des 131 sérums testés (intervalle de confiance [IC] à 95 % : 21,5­37,2). À l'échelle des troupeaux, la prévalence sérologique était de 45,7 % (IC à 95 % : 30,9­61,0). L'analyse bivariée a fait apparaître une corrélation positive entre l'apparition d'anticorps dirigés contre la FCO et l'âge et, après vérification de la répartition des bovins par groupes au sein des troupeaux, une corrélation avec la race. D'après ce modèle, l'apparition d'anticorps devenait plus fréquente à mesure que les bovins prenaient de l'âge. De même, l'apparition d'anticorps était plus fréquente chez les bovins de races croisées que chez les bovins de race exotique (rapport de cotes = 4,6 ; IC à 95 % : 1,5­14,1). Ces résultats font état de l'ampleur de l'exposition des bovins laitiers au virus de la FCO au Népal. Les auteurs préconisent d'intégrer les bovins de races laitières dans le plan de surveillance de l'infection par le virus de la FCO au Népal et de sensibiliser les éleveurs sur les conséquences potentielles de cette maladie.

El ganado vacuno cumple una importante función en la epidemiología de la lengua azul por su intervención como hospedador reservorio. Pese a ello, en el Nepal se desconoce cuál es el estado del ganado lechero en relación con el virus de la enfermedad. Los autores describen un estudio destinado a estimar la prevalencia de anticuerpos contra el virus de la lengua azul en el ganado lechero de dos zonas ecológicas del Nepal y a determinar los factores asociados a la exposición al virus. En primer lugar, entre marzo de 2012 y febrero de 2013, se llevó a cabo un estudio serológico transversal con la obtención de muestras de 131 bovinos lecheros de siete agrupaciones (aldeas) de los distritos de Chitwan, región de Terai (vegas meridionales), y de Lamjung, región de las Colinas (en la zona central del país). De las 131 muestras de suero analizadas, resultaron positivas para los anticuerpos contra el virus de la lengua azul el 29,3% (intervalo de confianza [IC] al 95%: 21,5­37,2). La seroprevalencia de rebaño se cifraba en un 45,7% (IC 95%: 30,9­61,0). El análisis de dos variables puso de manifiesto una correlación positiva entre la seroconversión contra el virus de la lengua azul y la edad, así como una asociación con la raza del ganado, previo control de las agrupaciones de animales dentro de los rebaños. Según se desprende de este modelo, la probabilidad de que el ganado pase a ser positivo aumenta con la edad. Los animales de raza híbrida presentan mayor probabilidad de ser seropositivos que los de razas exóticas (razón de probabilidades = 4,6; IC 95%: 1,5­14,1). Estos resultados ponen de relieve una extendida exposición al virus en el ganado lechero nepalí. Los autores preconizan la inclusión del ganado vacuno lechero en el plan de vigilancia de la infección por el virus de la lengua azul en el Nepal y recalcan la importancia de hacer pedagogía entre los ganaderos acerca de las posibles repercusiones de la enfermedad.

West Nile viral infection of equids.

West Nile virus (WNV) is a flavivirus transmitted between certain species of birds and mosquito vectors. Tangential infections of equids and subsequent equine epizootics have occurred historically. Although the attack rate has been estimated to be below 10%, mortality rates can approach 50% in horses that present clinical disease. Symptoms are most commonly presenting in the form of encephalitis with ataxia as well as limb weakness, recumbency and muscle fasciculation. The most effective strategy for prevention of equine disease is proper vaccination with one of the numerous commercially available vaccines available in North America or the European Union. Recently, WNV has been increasingly associated with equine epizootics resulting from novel non-lineage-1a viruses in expanding geographic areas. However, specific experimental data on the virulence of these novel virus strains is lacking and questions remain as to the etiology of the expanded epizootics: whether it be a function of inherent virulence or ecological and/or climactic factors that could precipitate the altered epidemiological patterns observed.

Deciphering serology to understand the ecology of infectious diseases in wildlife.

The ecology of infectious disease in wildlife has become a pivotal theme in animal and public health. Studies of infectious disease ecology rely on robust surveillance of pathogens in reservoir hosts, often based on serology, which is the detection of specific antibodies in the blood and is used to infer infection history. However, serological data can be inaccurate for inference to infection history for a variety of reasons. Two major aspects in any serological test can substantially impact results and interpretation of antibody prevalence data: cross-reactivity and cut-off thresholds used to discriminate positive and negative reactions. Given the ubiquitous use of serology as a tool for surveillance and epidemiological modeling of wildlife diseases, it is imperative to consider the strengths and limitations of serological test methodologies and interpretation of results, particularly when using data that may affect management and policy for the prevention and control of infectious diseases in wildlife. Greater consideration of population age structure and cohort representation, serological test suitability and standardized sample collection protocols can ensure that reliable data are obtained for downstream modeling applications to characterize, and evaluate interventions for, wildlife disease systems.

The relationship between mood instability and depression: implications for studying and treating depression.

BACKGROUND: Most individuals with depressed mood report mood fluctuations (Mood Instability) within hours or days. This is not recognized in diagnostic criteria or standard rating scales for depression. HYPOTHESIS: That mood instability is a distinct component of the development of depression that has been omitted from criteria for depression because of reliance on retrospective recall and structured interviews. The inclusion of Mood Instability would enhance research into causes and treatment of depression. STUDIES: We examined three datasets that used retrospective and prospective measures of depressed symptom ratings and mood instability to determine the relationship between the two. Study 1 used data from the 1991 UK Health and Lifestyle Surveys (HALS). Studies 2 and 3 used clinical samples. The scales used to assess mood instability were the mood instability factor from the Eysenck Personality Inventory Neuroticism Scale, the Affective Lability Scale (ALS), and the Visual Analogue Depression Scale (VAS). The depression scales (depressive symptoms) were the General Health Questionnaire (GHQ) depression factor, the Beck Depression Inventory IA (BDI) and the mean from the Visual Analogue Depression Scale (VAS). We used partial correlation analysis to assess the association between mood instability and depression and exploratory factor analysis to determine the factor structure of items pooled from the mood instability and depression scales from studies 1 and 2. RESULTS: Mood Instability was found to be moderately associated with depressive symptoms. The Pearson's r-values ranged from 0.49 to 0.57. The correlation was lower when recalling mood in the past. The factor analytic solution supported the hypothesis that MI and depressive symptoms are related but distinct constructs. CONCLUSIONS: Reliance exclusively on the retrospective assessment of depressive symptoms has occluded the widespread occurrence of mood instability. Including Mood Instability in diagnostic and assessment criteria would enhance causal and treatment research in depression.

Ecology of zoonotic infectious diseases in bats: current knowledge and future directions.

Bats are hosts to a range of zoonotic and potentially zoonotic pathogens. Human activities that increase exposure to bats will likely increase the opportunity for infections to spill over in the future. Ecological drivers of pathogen spillover and emergence in novel hosts, including humans, involve a complex mixture of processes, and understanding these complexities may aid in predicting spillover. In particular, only once the pathogen and host ecologies are known can the impacts of anthropogenic changes be fully appreciated. Cross-disciplinary approaches are required to understand how host and pathogen ecology interact. Bats differ from other sylvatic disease reservoirs because of their unique and diverse lifestyles, including their ability to fly, often highly gregarious social structures, long lifespans and low fecundity rates. We highlight how these traits may affect infection dynamics and how both host and pathogen traits may interact to affect infection dynamics. We identify key questions relating to the ecology of infectious diseases in bats and propose that a combination of field and laboratory studies are needed to create data-driven mechanistic models to elucidate those aspects of bat ecology that are most critical to the dynamics of emerging bat viruses. If commonalities can be found, then predicting the dynamics of newly emerging diseases may be possible. This modelling approach will be particularly important in scenarios when population surveillance data are unavailable and when it is unclear which aspects of host ecology are driving infection dynamics.

Pathological and epidemiological factors associated with advanced stage at diagnosis of breast cancer.

BACKGROUND: Breast cancer is a highly heterogeneous disease, but the stage at presentation significantly influences outcome. It is important to dissect the pathobiological and epidemiological factors that influence the stage at presentation in order to develop effective strategies to improve clinical outcome. SOURCES OF DATA: PubMed references relating to breast cancer subtypes, molecular classification of breast cancer, genetic susceptibility, young women and breast cancer. AREAS OF AGREEMENT: HER-2 positive, basal-like tumours and inflammatory breast cancers (IBC) more frequently present as late stage disease. Socioeconomic, cultural and ethnic background also influence stage at presentation. AREAS OF CONTROVERSY: The biology of IBC is poorly understood. Relative contribution of social and genetic factors in certain ethnic groups. GROWING POINTS Molecular determinants of breast cancer behaviour. Genetic and biological factors influencing disease phenotype in different ethnic groups. AREAS TIMELY FOR DEVELOPING RESEARCH: Biology of basal-like tumours and IBC. Role of predisposition of genetic variants in determining breast cancer phenotypes. Biological differences in breast cancer from different ethnic groups.

Pharmacological manipulation of the dopaminergic system affects wheel-running activity in differentially active mice.

The genetic factors involved in the regulation of physical activity are not well understood. The dopamine system has been implicated in the control of voluntary locomotion and wheel running (WR) in mice and is thus a likely candidate as a genetic/biological system important to the regulation of physical activity. This study evaluated the effects of four different dopaminergic acting drugs on WR in differentially active inbred strains of mice. High active C57L/J (n=7, 3 controls, 4 experimental) and low active C3H/HeJ (n=8, 3 controls, 5 experimental) were analyzed for baseline wheel-running indices of distance (km/day), duration (mins/day), and speed (m/min) for 21 days. Experimental mice received increasing doses over four days of each of the following drugs: SKF 81297 (D1 agonist), SCH 23390 (D1 antagonist), GBR 12783 (DAT inhibitor), and AMPT (tyrosine hydroxylase inhibitor). Each drug dose response treatment was separated by three days of recovery (no drug injections). WR indices were monitored during drug treatments and during drug wash-out phases. SKF 81297 significantly reduced (p=0.0004) WR in the C57L/J mice, but did not affect WR in the C3H/HeJ mice. GBR 12783 significantly increased (p=0.0005) WR in C3H/HeJ mice, but did not affect WR in C57L/J mice. Only duration (not overall WR) was significantly reduced in C57L/J mice in response to SCH 23390 (p=0.003) and AMPT (p=0.043). SCH 23390 (p=0.44) and AMPT (p=0.98) did not significantly affect WR in C3H/HeJ mice. These results suggest that genetic differences in dopamine signaling may play a role in the WR response to dopaminergic-acting drugs in inbred strains of mice. The high activity in the C57L/J strain appears most responsive to D1-like receptor acting drugs, while in the C3H/HeJ strain, dopamine re-uptake appears to have an influence on activity level.

Use of sindbis/eastern equine encephalitis chimeric viruses in plaque reduction neutralization tests for arboviral disease diagnostics.

Eastern equine encephalitis virus (EEEV) is a highly virulent, mosquito-borne alphavirus that causes severe and often fatal neurological disease in humans and horses in eastern North American, the Caribbean, and Mexico and throughout Central and South America. EEEV infection is diagnosed serologically by anti-EEEV-specific IgM detection, with confirmation by the plaque reduction neutralization test (PRNT), which is highly specific for alphaviruses. Live virus is used in the PRNT procedure, which currently requires biosafety level 3 containment facilities and select agent security in the case of EEEV. These requirements restrict the ability of public health laboratories to conduct PRNTs. Sindbis virus (SINV)/EEEV recombinant constructs have been engineered to express the immunogenic structural proteins from 2 wild-type EEEV strains in an attenuated form. These SINV/EEEVs, which are not classified as select agents, were evaluated as alternative diagnostic reagents in a PRNT using human, equine, and murine sera. The results indicate that the chimeric viruses exhibit specificity comparable to that of wild-type EEEV, with only a slight reduction in sensitivity. Considering their benefits in increased safety and reduced regulatory requirements, these chimeric viruses should be highly useful in diagnostic laboratories throughout the Americas.

Protection provided by a recombinant ALVAC(®)-WNV vaccine expressing the prM/E genes of a lineage 1 strain of WNV against a virulent challenge with a lineage 2 strain.

The emergence of lineage 2 strains of WNV in Europe as a cause of clinical disease and mortality in horses raised the question whether the existing WNV vaccines, all based on lineage 1 strains, protect against circulating lineage 2 strains of WNV. In the present paper we have determined the level of cross protection provided by the recombinant ALVAC(®)-WNV vaccine in a severe challenge model that produces clinical signs of WNV type 2 disease. Ten horses were vaccinated twice at 4 weeks interval with one dose of the ALVAC-WNV vaccine formulated at the minimum protective dose. A further 10 horses served as controls. Two weeks after the second vaccination, all horses were challenged intrathecally with a recent neurovirulent lineage 2 strain of WNV. The challenge produced viraemia in 10 out of 10 and encephalitis in 9 out of 10 control horses. Three horses had to be euthanized for humane reasons. In contrast, none of the vaccinated horses developed WNV disease and only 1 vaccinated horse became viraemic at a single time point at low titre. The prevalence of WNV disease and viraemia were significantly lower in the vaccinated horses than in the control horses (P<0.0001 for both). Based on these results, the ALVAC-WNV vaccine will provide veterinarians with an effective tool to control infections caused by lineage 1 and 2 strains of WNV.

Clinical and pathologic responses of American crows (Corvus brachyrhynchos) and fish crows (C ossifragus) to experimental West Nile virus infection.

West Nile virus (WNV)-associated disease has a range of clinical manifestations among avian taxa, the reasons for which are not known. Species susceptibility varies within the avian family Corvidae, with estimated mortality rates ranging from 50 to 100%. We examined and compared virologic, immunologic, pathologic, and clinical responses in 2 corvid species, the American crow (Corvus brachyrhynchos) and the fish crow (C ossifragus), following experimental WNV inoculation. Unlike fish crows, which remained clinically normal throughout the study, American crows succumbed to WNV infection subsequent to dehydration, electrolyte and pH imbalances, and delayed or depressed humoral immune responses concurrent with marked, widespread virus replication. Viral titers were approximately 3,000 times greater in blood and 30,000 to 50,000 times greater in other tissues (eg, pancreas and small intestine) in American crows versus fish crows. Histologic lesion patterns and antigen deposition supported the differing clinical outcomes, with greater severity and distribution of lesions and WNV antigen in American crows. Both crow species had multiorgan necrosis and inflammation, although lesions were more frequent, severe, and widespread in American crows, in which the most commonly affected tissues were small intestine, spleen, and liver. American crows also had inflammation of vessels and nerves in multiple tissues, including heart, kidney, and the gastrointestinal tract. WNV antigen was most commonly observed within monocytes, macrophages, and other cells of the reticuloendothelial system of affected tissues. Collectively, the data support that WNV-infected American crows experience uncontrolled systemic infection leading to multiorgan failure and rapid death.