Infectious bronchitis virus (IBV) is ubiquitous in most parts of the world where poultry are reared and is able to spread very rapidly in non-protected birds. It is shed via both the respiratory ...tract and the faeces and can persist in the birds and the intestinal tract for several weeks or months. Outdoors, survival of IBV for 56 days in litter has been reported. Although strict biosecurity and working with a one-age system are essential control measures, normally vaccination is required to increase the resistance of the chickens against challenge with IBV strains. This is made more difficult to achieve because IBV exists in the form of many different antigenic or genotypic types, commonly referred to as variants. Being a coronavirus and therefore a single stranded RNA virus, IBV has the enormous capacity to change both by spontaneous mutation and by genetic recombination. Both these events occur with IBV and are most likely to result in the emergence of new variants if they occur in the hypervariable regions of the spike gene. Whilst many new variants are unable to replicate or survive for only a short time, a few emerge which become of economic importance either world wide or in restricted geographic areas. This paper presents an overview of the history and current situation of IBV worldwide, including the measures necessary to control the many IB variants found throughout the world .
Parainfluenza viruses are important causes of respiratory disease in both children and adults. In particular, they are the major cause of the serious childhood illness croup ...(laryngotracheobronchitis). The infections produced by parainfluenza viruses are associated with the accumulation of ions and fluid in the respiratory tract. It is not known, however, whether this accumulation is because of a direct effect of the viruses on ion and fluid transport by the respiratory epithelium. Here we show that a model parainfluenza virus (the Sendai virus), in concentrations observed during respiratory infections, activates Cl- secretion and inhibits Na+ absorption across the tracheal epithelium. It does so by binding to a neuraminidase-insensitive glycolipid, possibly asialo-GM1, triggering the release of ATP, which then acts in an autocrine fashion on apical P2Y receptors to produce the observed changes in ion transport. These findings indicate that fluid accumulation in the respiratory tract associated with parainfluenza virus infection is attributable, at least in part, to direct effects of the virus on ion transport by the respiratory epithelium.
To evaluate see-through Augmented Reality Digital spectacles (AR DSpecs) for improving the mobility of patients with peripheral visual field (VF) losses when tested on a walking track.
Prospective ...Case Series.
21 patients with peripheral VF defects in both eyes, with the physical ability to walk without assistance.
We developed the AR DSpecs as a wearable VF aid with an augmented reality platform. Image remapping algorithms produced personalized visual augmentation in real time based on the measured binocular VF with the AR DSpecs calibration mode. We tested the device on a walking track to determine if patients could more accurately identify peripheral objects.
We analyzed walking track scores (number of recognized/avoided objects) and eye tracking data (six gaze parameters) to measure changes in the kinematic and eye scanning behaviors while walking, and assessed a possible placebo effect by deactivating the AR DSpecs remapping algorithms in random trials.
Performance, judged by the object detection scores, improved with the AR DSpecs (P<0.001, Wilcoxon rank sum test) with an average improvement rate of 18.81%. Two gaze parameters improved with the activated algorithm (P<0.01, paired t-test), indicating a more directed gaze on the central path with less eye scanning. Determination of the binocular integrated VF with the DSpecs correlated with the integrated standard automated perimetry (R = 0.86, P<0.001), mean sensitivity difference 0.8 ± 2.25 dB (Bland-Altman).
AR DSpecs may improve walking maneuverability of patients with peripheral VF defects by enhancing detection of objects in a testing environment.
Monoclonal antibodies (mAbs) were prepared against one UK isolate of turkey rhinotracheitis virus (TRTV). Those which were virus-neutralizing were selected and used, together with polyclonal antisera ...raised to each isolate in turkeys, in cross-neutralization tests against TRTV strains isolated in the UK and elsewhere. Whilst the polyclonal antisera showed that there was some diversity between them, all strains examined belonged to one serotype. The TRTV strains isolated in the UK could clearly be differentiated from those isolated elsewhere by some of the mAbs. Isolates of TRTV made in South Africa in 1978 and UK in 1985 were more closely related than were isolates made in UK and France within a few months. TRTV strains isolated from turkeys and chickens could not be differentiated. Some mAbs were found to be group-specific in that they neutralized all TRTV strains examined. All mAbs were of either the IgGl or IgG2a isotype and recognized the surface G glycoprotein.
The experimental inoculation of 38-week-old turkey hens with a pool of field isolates of turkey rhinotracheitis virus (TRTV) induced a marked respiratory infection and a substantial drop in egg ...production. Administration of a live-attenuated TRT vaccine at 1 week of age did not protect the layers against respiratory infection, but provided good protection against the effects of challenge on laying performance. However, a combination of live priming followed by injection of inactivated vaccine provided excellent protection against both respiratory infection and drops in egg production.
The coding sequences of VP2 from a virulent strain, 52/70, of infectious bursal disease virus (IBDV) were excised from a cDNA clone and inserted into a fowlpox plasmid insertion vector. The resulting ...plasmid, pIBD 1, was used to construct a recombinant fowlpox virus, fpIBD 1, which expressed VP 2 as a beta-galactosidase fusion protein. Chickens vaccinated with fpIBD 1 at 1 and 14 days of age, were challenged at 28 days with either IBDV strain 52/70 or the highly virulent strain CS 89. These chickens were protected against mortality, but not against damage to the bursa of Fabricius. The protection achieved by the use of fpIBD 1 shows that VP2 is a host protective antigen.
Six-week-old turkey poults were infected with the virulent UK/3B/85 strain of TRTV. Tracheal and oesophageal swabs were made every 2 to 3 days from groups of five poults and the RNA extracted. The ...TRTV RNA was then reverse-transcribed into complementary DNA (cDNA) using an oligonucleotide complementary to the 3' end of the fusion protein (F) mRNA. The cDNA was then used in a polymerase chain reaction (PCR) with an upstream primer to generate a product of approximately 0.5 kbp which was detected by ethidium bromide staining after electrophoresis. In this way, TRTV was detected in both types of swab for 17 to 19 days post-infection, nearly 2 weeks after the peak titres of infectious virus. Swabs which were allowed to dry completely before RNA extraction were as successful as swabs kept wet and extracted almost immediately, useful for when samples are collected in the field. The oligonucleotides amplified the 0.5 kbp product from TRTV strains isolated in six countries over a 13-year period, indicating that they might be usable as 'universal' oligonucleotides for TRTV detection.
Longitudinal associations between patterns of crack cocaine use and progression of HIV-1 disease are poorly understood, especially among women. This study explores relationships between crack use and ...HIV-1 disease outcomes in a multicenter cohort of infected women.
Subjects were 1686 HIV-seropositive women enrolled at six US research centers in the Women's Interagency HIV Study. Approximately 80% were non-white and 29% used crack during the study period. Cox survival and random regression analysis examined biannual observations made April 1996 through September 2004. Outcome measures included death due to AIDS-related causes, CD4 cell count, HIV-1 RNA level, and newly acquired AIDS-defining illnesses.
Persistent crack users were over three times as likely as non-users to die from AIDS-related causes, controlling for use of HAART self-reported at 95% or higher adherence, problem drinking, age, race, income, education, illness duration, study site, and baseline virologic and immunologic indicators. Persistent crack users and intermittent users in active and abstinent phases showed greater CD4 cell loss and higher HIV-1 RNA levels controlling for the same covariates. Persistent and intermittent crack users were more likely than non-users to develop new AIDS-defining illnesses controlling for identical confounds. These results persisted when controlling for heroin use, tobacco smoking, depressive symptoms, hepatitis C virus coinfection, and injection drug use.
Use of crack cocaine independently predicts AIDS-related mortality, immunologic and virologic markers of HIV-1 disease progression, and development of AIDS-defining illnesses among women.
AbstractObjectivesTo develop and validate a prediction model for fat mass in children aged 4-15 years using routinely available risk factors of height, weight, and demographic information without the ...need for more complex forms of assessment.DesignIndividual participant data meta-analysis.SettingFour population based cross sectional studies and a fifth study for external validation, United Kingdom.ParticipantsA pooled derivation dataset (four studies) of 2375 children and an external validation dataset of 176 children with complete data on anthropometric measurements and deuterium dilution assessments of fat mass.Main outcome measureMultivariable linear regression analysis, using backwards selection for inclusion of predictor variables and allowing non-linear relations, was used to develop a prediction model for fat-free mass (and subsequently fat mass by subtracting resulting estimates from weight) based on the four studies. Internal validation and then internal-external cross validation were used to examine overfitting and generalisability of the model’s predictive performance within the four development studies; external validation followed using the fifth dataset.ResultsModel derivation was based on a multi-ethnic population of 2375 children (47.8% boys, n=1136) aged 4-15 years. The final model containing predictor variables of height, weight, age, sex, and ethnicity had extremely high predictive ability (optimism adjusted R2: 94.8%, 95% confidence interval 94.4% to 95.2%) with excellent calibration of observed and predicted values. The internal validation showed minimal overfitting and good model generalisability, with excellent calibration and predictive performance. External validation in 176 children aged 11-12 years showed promising generalisability of the model (R2: 90.0%, 95% confidence interval 87.2% to 92.8%) with good calibration of observed and predicted fat mass (slope: 1.02, 95% confidence interval 0.97 to 1.07). The mean difference between observed and predicted fat mass was −1.29 kg (95% confidence interval −1.62 to −0.96 kg).ConclusionThe developed model accurately predicted levels of fat mass in children aged 4-15 years. The prediction model is based on simple anthropometric measures without the need for more complex forms of assessment and could improve the accuracy of assessments for body fatness in children (compared with those provided by body mass index) for effective surveillance, prevention, and management of clinical and public health obesity.
The heterogeneous behavior of patients with melanoma makes prognostication challenging. To address this, a gene expression profile (GEP) test to predict metastatic risk was previously developed. This ...study evaluates the GEP's prognostic accuracy in an independent cohort of cutaneous melanoma patients.
This multi-center study analyzed primary melanoma tumors from 523 patients, using the GEP to classify patients as Class 1 (low risk) and Class 2 (high risk). Molecular classification was correlated to clinical outcome and assessed along with AJCC v7 staging criteria. Primary endpoints were recurrence-free (RFS) and distant metastasis-free (DMFS) survival.
The 5-year RFS rates for Class 1 and Class 2 were 88% and 52%, respectively, and DMFS rates were 93% versus 60%, respectively (P < 0.001). The GEP was a significant predictor of RFS and DMFS in univariate analysis (hazard ratio HR = 5.4 and 6.6, respectively, P < 0.001 for each), along with Breslow thickness, ulceration, mitotic rate, and sentinel lymph node (SLN) status (P < 0.001 for each). GEP, tumor thickness and SLN status were significant predictors of RFS and DMFS in a multivariate model that also included ulceration and mitotic rate (RFS HR = 2.1, 1.2, and 2.5, respectively, P < 0.001 for each; and DMFS HR = 2.7, 1.3 and 3.0, respectively, P < 0.01 for each).
The GEP test is an objective predictor of metastatic risk and provides additional independent prognostic information to traditional staging to help estimate an individual's risk for recurrence. The assay identified 70% of stage I and II patients who ultimately developed distant metastasis. Its role in consideration of patients for adjuvant therapy should be examined prospectively.
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