New imaging tools for mouse models of osteoarthritis.

Osteoarthritis (OA) is a chronic degenerative disease characterized by a disruption of articular joint cartilage homeostasis. Mice are the most commonly used models to study OA. Despite recent reviews, there is still a lack of knowledge about the new development in imaging techniques. Two types of modalities are complementary: those that assess structural changes in joint tissues and those that assess metabolism and disease activity. Micro MRI is the most important imaging tool for OA research. Automated methodologies for assessing periarticular bone morphology with micro-CT have been developed allowing quantitative assessment of tibial surface that may be representative of the whole OA joint changes. Phase-contrast X-ray imaging provides in a single examination a high image precision with good differentiation between all anatomical elements of the knee joint (soft tissue and bone). Positron emission tomography, photoacoustic imaging, and fluorescence reflectance imaging provide molecular and functional data. To conclude, innovative imaging technologies could be an alternative to conventional histology with greater resolution and more efficiency in both morphological analysis and metabolism follow-up. There is a logic of permanent adjustment between innovations, 3R rule, and scientific perspectives. New imaging associated with artificial intelligence may add to human clinical practice allowing not only diagnosis but also prediction of disease progression to personalized medicine.

Evaluation of simulators for x-ray speckle-based phase contrast imaging.

X-ray phase contrast imaging (PCI) denotes a group of highly sensitive imaging techniques that permits imaging at scales ranging from nanoscopic to the medical. Recently introduced, speckle-based imaging has seen a rapid development because of its experimental simplicity and its capability to retrieve the refraction, the scattering and the absorption of a sample using a conventional x-ray set-up. Precise simulation would permit to optimise the imaging setups for different applications, but until now works on simulation of x-ray speckle-based PCI have been very few. In this work we evaluate different simulation codes, based on Monte-Carlo, analytical ray-tracing and wave-optics Fresnel propagation. The simulation results are compared to both synchrotron and conventional imaging experiments to permits their validation. We obtain a strong similarity between simulated and experimental data. We discuss the validity and applicability of each approach.

Significant dose reduction using synchrotron radiation computed tomography: first clinical case and application to high resolution CT exams.

Since the invention of Computed Tomography (CT), many technological advances emerged to improve the image sensitivity and resolution. However, no new source types were developed for clinical use. In this study, for the first time, coherent monochromatic X-rays from a synchrotron radiation source were used to acquire 3D CTs on patients. The aim of this work was to evaluate the clinical potential of the images acquired using Synchrotron Radiation CT (SRCT). SRCTs were acquired using monochromatic X-rays tuned at 80 keV (0.350 × 0.350 × 2 mm3 voxel size). A quantitative image quality comparison study was carried out on phantoms between a state of the art clinical CT and SRCT images. Dedicated iterative algorithms were developed to optimize the image quality and further reduce the delivered dose by a factor of 12 while keeping a better image quality than the one obtained with a clinical CT scanner. We finally show in this paper the very first SRCT results of one patient who received Synchrotron Radiotherapy in an ongoing clinical trial. This demonstrates the potential of the technique in terms of image quality improvement at a reduced radiation dose for inner ear visualization.

Occurrence and spread of influenza A(H1N1)pdm09 virus infection in Norwegian pig herds based on active serosurveillance from 2010 to 2014.

The incursion of influenza A(H1N1)pdm09 virus was detected by Norway's active serosurveillance of its pig population in 2009. Since then, surveillance data from 2010 to 2014 revealed that 54% of 5643 herd tests involving 1567 pig herds and 28% of 23 036 blood samples screened positive for antibodies against influenza A virus. Positive herds were confirmed to have influenza A(H1N1)pdm09 virus infection by haemagglutination inhibition test. In 50% of positive herd tests, ⩾60% of the sampled pigs in each herd had antibodies against influenza A(H1N1)pdm09 virus. This within-herd animal seroprevalence did not vary for type of production, herd size or year of test. The overall running mean of national herd seroprevalence, and annual herd incidence risks fluctuated narrowly around the means of 45% and 32%, respectively, with the highest levels recorded in the three densest pig-producing counties. The probability of a herd being seropositive varied in the five production classes, which were sow pools, multiplier herds, conventional sow herds, nucleus herds, and fattening herds in descending order of likelihood. Large herds were more likely to be seropositive. Seropositive herds were highly likely to be seropositive the following year. The study shows that influenza A(H1N1)pdm09 virus is established in the Norwegian pig population with recurrent and new herd infections every year with the national herd seroprevalence in 2014 hovering at around 43% (95% confidence interval 40-46%).

Loss of function of Ywhah in mice induces deafness and cochlear outer hair cells' degeneration.

In vertebrates, 14-3-3 proteins form a family of seven highly conserved isoforms with chaperone activity, which bind phosphorylated substrates mostly involved in regulatory and checkpoint pathways. 14-3-3 proteins are the most abundant protein in the brain and are abundantly found in the cerebrospinal fluid in neurodegenerative diseases, suggesting a critical role in neuron physiology and death. Here we show that 14-3-3eta-deficient mice displayed auditory impairment accompanied by cochlear hair cells' degeneration. We show that 14-3-3eta is highly expressed in the outer and inner hair cells, spiral ganglion neurons of cochlea and retinal ganglion cells. Screening of YWHAH, the gene encoding the 14-3-3eta isoform, in non-syndromic and syndromic deafness, revealed seven non-synonymous variants never reported before. Among them, two were predicted to be damaging in families with syndromic deafness. In vitro, variants of YWHAH induce mild mitochondrial fragmentation and severe susceptibility to apoptosis, in agreement with a reduced capacity of mutated 14-3-3eta to bind the pro-apoptotic Bad protein. This study demonstrates that YWHAH variants can have a substantial effect on 14-3-3eta function and that 14-3-3eta could be a critical factor in the survival of outer hair cells.

A single-image method for x-ray refractive index CT.

X-ray refraction-based computer tomography imaging is a well-established method for nondestructive investigations of various objects. In order to perform the 3D reconstruction of the index of refraction, two or more raw computed tomography phase-contrast images are usually acquired and combined to retrieve the refraction map (i.e. differential phase) signal within the sample. We suggest an approximate method to extract the refraction signal, which uses a single raw phase-contrast image. This method, here applied to analyzer-based phase-contrast imaging, is employed to retrieve the index of refraction map of a biological sample. The achieved accuracy in distinguishing the different tissues is comparable with the non-approximated approach. The suggested procedure can be used for precise refraction computer tomography with the advantage of a reduction of at least a factor of two of both the acquisition time and the dose delivered to the sample with respect to any of the other algorithms in the literature.

Impact of anatase and rutile titanium dioxide nanoparticles on uptake carriers and efflux pumps in Caco-2 gut epithelial cells.

TiO2 microparticles are widely used in food products, where they are added as a white food colouring agent. This food additive contains a significant amount of nanoscale particles; still the impact of TiO2 nanoparticles (TiO2-NPs) on gut cells is poorly documented. Our study aimed at evaluating the impact of rutile and anatase TiO2-NPs on the main functions of enterocytes, i.e. nutrient absorption driven by solute-liquid carriers (SLC transporters) and protection against other xenobiotics driven by efflux pumps from the ATP-binding cassette (ABC) family. We show that acute exposure of Caco-2 cells to both anatase (12 nm) and rutile (20 nm) TiO2-NPs induce early upregulation of a battery of efflux pumps and nutrient transporters. In addition they cause overproduction of reactive oxygen species and misbalance redox repair systems, without inducing cell mortality or DNA damage. Taken together, these data suggest that TiO2-NPs may increase the functionality of gut epithelial cells, particularly their property to form a protective barrier against exogenous toxicants and to absorb nutrients.

Clinical manifestations of pancreas disease outbreaks in Norwegian marine salmon farming - variations due to salmonid alphavirus subtype.

Pancreas disease (PD) in Norwegian salmonid aquaculture has traditionally been caused by salmonid alphavirus (SAV) subtype 3. Following the isolation of a novel SAV subtype in 2010, marine SAV2, two separate endemic areas have developed. It has been debated whether disease outbreaks due to marine SAV2 result in milder clinical manifestations compared to outbreaks caused by SAV3. The aim of this study was to descriptively investigate site-level differences in the clinical manifestations of marine SAV2 and SAV3 at Norwegian seawater sites diagnosed with PD in 2012. The findings suggest that Norwegian PD outbreaks caused by marine SAV2 result in lower mortality and milder clinical signs compared to outbreaks caused by SAV3. For sites without reported PD-related mortality, there was no difference in the mortality levels between sites infected by marine SAV2 and SAV3. The results also indicate that there are no differences in grading quality at slaughter between the SAV subtypes.

Breast tumor segmentation in high resolution x-ray phase contrast analyzer based computed tomography.

PURPOSE: Phase contrast computed tomography has emerged as an imaging method, which is able to outperform present day clinical mammography in breast tumor visualization while maintaining an equivalent average dose. To this day, no segmentation technique takes into account the specificity of the phase contrast signal. In this study, the authors propose a new mathematical framework for human-guided breast tumor segmentation. This method has been applied to high-resolution images of excised human organs, each of several gigabytes. METHODS: The authors present a segmentation procedure based on the viscous watershed transform and demonstrate the efficacy of this method on analyzer based phase contrast images. The segmentation of tumors inside two full human breasts is then shown as an example of this procedure's possible applications. RESULTS: A correct and precise identification of the tumor boundaries was obtained and confirmed by manual contouring performed independently by four experienced radiologists. CONCLUSIONS: The authors demonstrate that applying the watershed viscous transform allows them to perform the segmentation of tumors in high-resolution x-ray analyzer based phase contrast breast computed tomography images. Combining the additional information provided by the segmentation procedure with the already high definition of morphological details and tissue boundaries offered by phase contrast imaging techniques, will represent a valuable multistep procedure to be used in future medical diagnostic applications.

High-resolution breast tomography at high energy: a feasibility study of phase contrast imaging on a whole breast.

Previous studies on phase contrast imaging (PCI) mammography have demonstrated an enhancement of breast morphology and cancerous tissue visualization compared to conventional imaging. We show here the first results of the PCI analyser-based imaging (ABI) in computed tomography (CT) mode on whole and large (>12 cm) tumour-bearing breast tissues. We demonstrate in this work the capability of the technique of working at high x-ray energies and producing high-contrast images of large and complex specimens. One entire breast of an 80-year-old woman with invasive ductal cancer was imaged using ABI-CT with monochromatic 70 keV x-rays and an area detector of 92×92 µm² pixel size. Sagittal slices were reconstructed from the acquired data, and compared to corresponding histological sections. Comparison with conventional absorption-based CT was also performed. Five blinded radiologists quantitatively evaluated the visual aspects of the ABI-CT images with respect to sharpness, soft tissue contrast, tissue boundaries and the discrimination of different structures/tissues. ABI-CT excellently depicted the entire 3D architecture of the breast volume by providing high-resolution and high-contrast images of the normal and cancerous breast tissues. These results are an important step in the evolution of PCI-CT towards its clinical implementation.

Salmonid alphavirus (SAV) and pancreas disease (PD) in Atlantic salmon, Salmo salar L., in freshwater and seawater sites in Norway from 2006 to 2008.

A cohort study was initiated in the spring of 2006 to investigate epidemiological aspects and pathogenesis of salmonid alphavirus (SAV) subtype 3 infections and pancreas disease (PD). The aims were to assess involvement of the freshwater production phase, the extent and frequency of subclinical infections and to follow PD-affected populations throughout the entire seawater production cycle, as well as investigate possible risk factors for PD outbreaks. Fish groups from 46 different Atlantic salmon freshwater sites in six counties were sampled once prior to seawater transfer and followed onto their seawater sites. A total of 51 Atlantic salmon seawater sites were included, and fish groups were sampled three times during the seawater production phase. SAV subtype 3 was not identified by real-time RT-PCR from samples collected in the freshwater phase, nor were any SAV-neutralizing antibodies or histopathological changes consistent with PD. In the seawater phase, SAV was detected in samples from 23 of 36 (63.9%) studied sites located within the endemic region. No SAV subtype 3 was detected in samples from seawater sites located outside the endemic region. The cumulative incidence of PD during the production cycle amongst sites with SAV detected was 87% (20 of 23 sites). Average fish weight at time of PD diagnosis ranged from 461 to 5978 g, because of a wide variation in the timing of disease occurrence throughout the production cycle. Mortality levels following a PD diagnosis varied greatly between populations. The mean percentage mortality was 6.9% (+/-7.06) (range 0.7-26.9), while the mean duration of increased mortality following PD diagnosis was 2.8 months (+/-1.11) (range 1-6).

Trends in Campylobacter incidence in broilers and humans in six European countries, 1997-2007.

The objective of this study was to examine incidences of Campylobacter in broilers and humans, and to describe seasonal variation and long-term trends by comparing longitudinal surveillance data in six Northern European countries (Denmark, Finland, Iceland, Norway, Sweden and the Netherlands). Due to high degree of seasonality and autocorrelation, seasonally adjusted (de-seasonalized) and trend adjusted data (de-trended) were used for comparing incidences within and between the six countries. De-seasonalized time series were obtained by fitting the incidence time series to mean monthly temperature and then removing this effect from the data. Long-term trends were fitted to the de-seasonalized time series. The incidence of Campylobacter colonization in broiler flocks and incidence of campylobacteriosis in humans showed a concordant seasonality for all the countries. There was a strong association between the incidence in both broilers and humans in a given month and the mean temperature of the northern hemisphere in the same month, as well as the preceding month, as shown by the cross-correlations and the chosen Generalized Additive Model. Denmark and Sweden showed a steadily decreasing trend for Campylobacter in broilers and human campylobacteriosis in the period 2001-2007. In Iceland, there was a decreasing trend for campylobacteriosis in humans from 1999 to 2007, whilst the broiler trend for Campylobacter was stable from 2001 to 2004, then falling thereafter. In Norway, the human campylobacteriosis trend showed a steady increase throughout the period. On the other hand, the Norwegian broiler trend for Campylobacter showed a decrease from 2001 until 2004, but was thereafter stable. There was no significant decrease or increase in incidence for human campylobacteriosis in the Netherlands, and the trend for Campylobacter in broilers was close to stable. The seasonality seen in broiler and human closely follows the temperature, and was probably caused, at least partly, by temperature related factors.

Pandemic influenza A(H1N1)v: human to pig transmission in Norway?

In Norway there is an ongoing outbreak in pigs of infections with pandemic influenza A(H1N1)v virus. The first herd was confirmed positive on 10 October 2009. As of 26 October, a total of 23 herds have been diagnosed as positive. The majority of the herds seem to have been infected by humans. Sequence analysis of pig viruses from the index farm shows that they are identical or virtually identical to human viruses from the same geographical region.

Epizootic haematopoietic necrosis virus--an assessment of the likelihood of introduction and establishment in England and Wales.

Epizootic haematopoietic necrosis virus (EHNV) is an iridovirus that affects perch (Perca fluviatilis) and rainbow trout (Oncorhynchus mykiss). It emerged in Australia in the 1980s and has not been discovered elsewhere. It causes a high level of mortality in perch resulting in steep population declines. The main possible routes of introduction of the virus to England and Wales are the importation of infected live fish or carcasses. However, no trade in live susceptible species is permitted under current legislation, and no importation of carcasses currently takes place. The virus is hardy and low levels of challenge can infect perch. Therefore, mechanical transmission through the importation of non-susceptible fish species should be considered as a potential route of introduction and establishment. Carp (Cyprinus carpio) have been imported to the UK from Australia for release into still-water fisheries. A qualitative risk assessment concluded that the likelihood of EHNV introduction and establishment in England and Wales with the importation of a consignment of carp was very low. The level of uncertainty at a number of steps in the risk assessment scenario tree was high, notably the likelihood that carp become contaminated with the virus and whether effective contact (resulting in pathogen transmission) is made between the introduced carp and susceptible species in England and Wales. The virus would only establish when the water temperature is greater than 12 degrees C. Analysis of 10 years of data from two rivers in south-west England indicated that establishment could occur over a period of at least 14 weeks a year in southern England (when average water temperature exceed 12 degrees C). Imports of live fish from Australia need to be evaluated on a case-by-case basis to determine which, if any, sanitary measures are required to reduce the assessed risk to an acceptable level.

Risk factors for pancreas disease (PD) outbreaks in farmed Atlantic salmon and rainbow trout in Norway during 2003-2007.

Pancreas disease (PD) is an emerging infectious disease in farmed Atlantic salmon (Salmo salar L.) and rainbow trout (Oncorhynchus mykiss Walbaum) caused by salmonid alphavirus (SAV). The present study is a large scale study aiming at quantifying the probability of contracting PD in farmed salmonid cohorts in Norway due to exposure to risk factors that may be associated with specific transmission pathways for SAV, or may increase a cohort's susceptibility to PD. Monthly reports of numbers of fish and mean fish weight from all marine salmonid farm sites in Norway were used to identify cohorts of farmed salmonids. Only cohorts that were initiated and terminated during 2003-2007 were assembled for the study. Records of clinical diagnosis of PD on marine farm sites were used to identify PD case cohorts. In PD case cohorts, PD-outbreaks were defined to start the month the diagnosis was recorded and last until the cohort was terminated. All cohorts in which PD was not recorded were assigned to the control-class. In total 143 PD case cohorts and 1079 control cohorts were assembled. Risk factors were assigned to the cohorts and analysed using logistic regression by generalized additive models (GAM). We find that infection pressure, a variable designed to capture the potential for local disease spread, has a strong effect on the probability of recording a PD-outbreak in a cohort. The function describing the effect of infection pressure increased steeply as infection pressure increased from 0 to moderate values corresponding to having a mean sized neighbouring fish stock with PD at a distance of 2 km, after which the function levelled off. The study emphasises horizontal transmission pathways as important for the spread of PD in Norwegian salmon farming, and accordingly that bio-security measures aimed at controlling horizontal transmission are necessary in order to reduce the number of outbreaks of PD.

Epidemiological investigation of infectious salmon anaemia (ISA) outbreaks in Norway 2003-2005.

Epidemiological information was summarized from 32 outbreaks of infectious salmon anaemia (ISA) on salmon farming sites in Norway in 2003-2005. Virus isolates from the outbreak sites were genotyped, and the genotyping was used to assess possible associations between outbreak sites due to adjacent location, sharing fish farming authorisation, sharing smolt suppliers or sharing broodfish origin of the fish. The ISA outbreaks were distributed along most of the Norwegian coast and showed a variable clinical picture. The virus genotypes clustered into three genogroups. Pairs of outbreak sites matched for adjacent location or registered under the same authorisation, all shared genogroup, which was a significantly higher number of corresponding genogroups than expected by chance. For outbreak sites sharing smolt suppliers, corresponding genogroups appeared in 7 out of 12 matched pairs, which was not significant. An evaluation of broodfish origin associated with genogroups did not support transmission linked to broodfish origin. In conclusion, genotyping of virus isolates from ISA outbreaks supports associations between adjacent outbreaks. This is consistent with horizontal transmission. The present study failed to find evidence for vertical transmission (patterns of genogroups related to smolt suppliers or broodfish companies were not identified).

Relative bioavailability of deferasirox tablets administered without dispersion and dispersed in various drinks.

UNLABELLED: Deferasirox (ExjadeA, ICL670) is a new, once-daily oral iron chelator, recently approved as first-line therapy in the treatment of iron overload resulting from blood transfusions. In registration studies, deferasirox tablets were dispersed in non-carbonated water prior to administration. In routine clinical practice, however, patients may prefer to take the tablet dispersed in a flavored drink rather than with water. OBJECTIVE: Stability and compatibility tests were performed to identify beverages suitable for the dispersion of tablets for further testing in man. This was followed by a pharmacokinetic study to assess the relative bioavailability of deferasirox tablets dispersed in two types of soft drinks, dispersed in water, and without dispersion. METHODS: An open-label, randomized, 4-period, crossover study was carried out with 28 healthy volunteers who received single 20 mg/kg oral doses of deferasirox without dispersion, dispersed in orange juice, dispersed in apple juice and dispersed in non-carbonated water (reference). Deferasirox and Fe-[deferasirox]2 were measured in plasma using liquid chromatography-mass spectrometry. Pharmacokinetic parameters were compared using standard bioequivalence tests. RESULTS: Mean deferasirox AUC0-t were 1,040 A+/- 530, 1,010 A+/- 278, 882 A+/- 252 and 996 A+/- 352 h x micromol/l when deferasirox tablets were administered without dispersion, dispersed in orange juice, dispersed in apple juice and dispersed in water, respectively, indicating that these forms of deferasirox administrations met bioequivalence criteria. Therefore, the oral bioavailability of deferasirox tablets was not affected neither by the degree of dispersion nor by the type of drink (orange or apple juice versus water) used for dispersion. CONCLUSIONS: This study shows that deferasirox bioavailability is unaltered when dispersed with orange or apple juice compared with dispersion in water. Thus, in addition to water, patients have the option of taking deferasirox tablets in orange or apple juice. The degree of dispersion did not affect deferasirox bioavailability. Therefore, deferasirox therapy will not be compromised if dispersion of the tablet is not fully complete; although the latter should be avoided.