An infrared transient from a star engulfing a planet.

Planets with short orbital periods (roughly under 10 days) are common around stars like the Sun1,2. Stars expand as they evolve and thus we expect their close planetary companions to be engulfed, possibly powering luminous mass ejections from the host star3-5. However, this phase has never been directly observed. Here we report observations of ZTF SLRN-2020, a short-lived optical outburst in the Galactic disk accompanied by bright and long-lived infrared emission. The resulting light curve and spectra share striking similarities with those of red novae6,7-a class of eruptions now confirmed8 to arise from mergers of binary stars. Its exceptionally low optical luminosity (approximately 1035 erg s-1) and radiated energy (approximately 6.5 × 1041 erg) point to the engulfment of a planet of fewer than roughly ten Jupiter masses by its Sun-like host star. We estimate the Galactic rate of such subluminous red novae to be roughly between 0.1 and several per year. Future Galactic plane surveys should routinely identify these, showing the demographics of planetary engulfment and the ultimate fate of planets in the inner Solar System.

Imaging predictors of 4q12 amplified and RB1 mutated glioblastoma IDH-wildtype.

INTRODUCTION: Recent studies have identified that glioblastoma IDH-wildtype consists of different molecular subgroups with distinct prognoses. In order to accurately describe and classify gliomas, the Visually AcceSAble Rembrandt Images (VASARI) system was developed. The goal of this study was to evaluate the VASARI characteristics in molecular subgroups of IDH-wildtype glioblastoma. METHODS: A retrospective analysis of glioblastoma IDH- wildtype with comprehensive next-generation sequencing and pre-operative and post-operative MRI was performed. VASARI characteristics and 205 genes were evaluated. Multiple comparison adjustment by the Bejamin-Hochberg false discovery rate (BH-FDR) was performed. A 1:3 propensity score match (PSM) with a Caliper of 0.2 was done. RESULTS: 178 patients with GBM IDH-WT met the inclusion criteria. 4q12 amplified patients (n = 20) were associated with cyst presence (30% vs. 12%, p = 0.042), decreased hemorrhage (35% vs. 62%, p = 0.028), and non-restricting/mixed (35%/60%) rather than restricting diffusion pattern (5%), meanwhile, 4q12 non-amplified patients had mostly restricting (47.4%) rather than a non-restricting/mixed diffusion pattern (28.4%/23.4%). This remained statistically significant after BH-FDR adjustment (p = 0.002). PSM by 4q12 amplification showed that diffusion characteristics continued to be significantly different. Among RB1-mutant patients, 96% had well-defined enhancing margins vs. 70.6% of RB1-WT (p = 0.018), however, this was not significant after BH-FDR or PSM. CONCLUSIONS: Patients with glioblastoma IDH-wildtype harboring 4q12 amplification rarely have restricting DWI patterns compared to their wildtype counterparts, in which this DWI pattern is present in ~ 50% of patients. This suggests that some phenotypic imaging characteristics can be identified among molecular subtypes of IDH-wildtype glioblastoma.

Detection and Molecular Characterization of Chicken Parvovirus and Chicken Megrivirus in Layer Breeders Affected by Intestinal Dilatation Syndrome.

Intestinal dilatation syndrome (IDS) is a segmental enteropathy characterized by dilatation of the junction of the ileum and jejunum (Meckel's diverticulum). IDS severely affects the poultry industry by causing a chronic and irreversible drop in egg laying, reducing feed conversion efficiency, and increasing the mortality rate. The clinical and pathological features of IDS in white laying hens were described, and viral molecular and metagenomic research was conducted. The 50- to 60-day-old chickens presented pale mucosa, apathy, depression, ruffled feathers, and diarrhoea, accompanied by a 20% loss in fertile egg production, 20% culling of birds, and 5% mortality. The main findings at necropsy were marked intestinal dilatation with intestinal stasis, a narrow distal jejunum in the region of Meckel's diverticulum, and undigested food. Microscopic analysis revealed marked atrophic lymphoplasmacytic and heterophilic enteritis with hyperplastic crypts, ulceration, and heterophilic and lymphoplasmacytic perineuritis. The molecular assays consistently detected the presence of chicken parvovirus in the three segments of the intestine, pancreas, and proventriculus, as well as chicken megrivirus in the intestinal contents. Marked atrophic enteritis with perineuritis and intestinal stasis are associated with clinical manifestations of poor intestinal absorption and secondary bacterial infection. Our data provide useful information about IDS and highlight the importance of further studies to determine the specific role of each detected virus in this syndrome.RESEARCH HIGHLIGHTS IDS presented pathognomonic dilatation of the jejunum up to Meckel's diverticulum.IDS caused weight loss, decreased egg production, and increased culling and mortality.Chicken parvovirus (ChPV) was consistently detected through PCR assays.Chicken megrivirus (ChMV) was consistently detected through viral metagenomics.

Development of a fast and sensitive RT-qPCR assay based on SYBR® green for diagnostic and quantification of Avian Nephritis Virus (ANV) in chickens affected with enteric disease.

BACKGROUND: Enteric viruses are among the most prominent etiological agents of Runting-Stunting Syndrome (RSS). The Avian Nephritis Virus (ANV) is an astrovirus associated with enteric diseases in poultry, whose early diagnosis is essential for maintaining a good poultry breeding environment. ANV is an RNA virus that rapidly mutates, except for some conserved regions such as ORF1b. Therefore, the approach of a diagnostic method based on fast-RT-qPCR using SYBR® Green that focuses on the amplification of a fragment of ORF1b is presented as a feasible alternative for the diagnosis of this viral agent. In this study, the proposed assay showed a standard curve with an efficiency of 103.8% and a LoD and LoQ of 1 gene viral copies. The assay was specific to amplify the ORF 1b gene, and no amplification was shown from other viral genomes or in the negative controls. 200 enteric (feces) samples from chickens (broilers) and laying hens with signs of RSS from Ecuadorian poultry flocks were examined to validate the proposed method. RESULTS: Using our method, 164 positive results were obtained out of the total number of samples run, while the presence of viral RNA was detected in samples collected from one day to 44 weeks old in both avian lines. CONCLUSIONS: Our study presents a novel, rapid, robust, and sensitive molecular assay capable of detecting and quantifying even low copy numbers of the ANV in commercial birds, therefore introducing a handy tool in the early diagnosis of ANV in enteric disease outbreaks in poultry.

Novel multiparametric MRI detects improved future liver remnant quality post-dual vein embolization.

BACKGROUND: Optimisation of the future liver remnant (FLR) is crucial to outcomes of extended liver resections. This study aimed to assess the quality of the FLR before and after dual vein embolization (DVE) by quantitative multiparametric MRI. METHODS: Of 100 patients with liver metastases recruited in a clinical trial (Precision1:NCT04597710), ten consecutive patients with insufficient FLR underwent quantitative multiparametric MRI pre- and post-DVE (right portal and hepatic vein). FLR volume, liver fibro-inflammation (corrected T1) scores and fat percentage (proton density fat fraction, PDFF) were determined. Patient metrics were compared by Wilcoxon signed-rank test and statistical analysis done using R software. RESULTS: All patients underwent uncomplicated DVE with improvement in liver remnant health, median 37 days after DVE: cT1 scores reduced from median (interquartile range) 790 ms (753-833 ms) to 741 ms (708-760 ms) p = 0.014 [healthy range <795 ms], as did PDFF from 11% (4-21%), to 3% (2-12%) p = 0.017 [healthy range <5.6%]. There was a significant increase in median (interquartile range) FLR volume from 33% (30-37%)% to 49% (44-52%), p = 0.002. CONCLUSION: This non-invasive and reproducible MRI technique showed improvement in volume and quality of the FLR after DVE. This is a significant advance in our understanding of how to prevent liver failure in patients undergoing major liver surgery.

Surface antibody changes protein corona both in human and mouse serum but not final opsonization and elimination of targeted polymeric nanoparticles.

BACKGROUND: Nanoparticles represent one of the most important innovations in the medical field. Among nanocarriers, polymeric nanoparticles (PNPs) attracted much attention due to their biodegradability, biocompatibility, and capacity to increase efficacy and safety of encapsulated drugs. Another important improvement in the use of nanoparticles as delivery systems is the conjugation of a targeting agent that enables the nanoparticles to accumulate in a specific tissue. Despite these advantages, the clinical translation of therapeutic approaches based on nanoparticles is prevented by their interactions with blood proteins. In fact, the so-formed protein corona (PC) drastically alters the biological identity of the particles. Adsorbed activated proteins of the complement cascade play a pivotal role in the clearance of nanoparticles, making them more easily recognized by macrophages, leading to their rapid elimination from the bloodstream and limiting their efficacy. Since the mouse is the most used preclinical model for human disease, this work compared human and mouse PC formed on untargeted PNPs (uPNPs) and targeted PNPs (tPNPs), paying particular attention to complement activation. RESULTS: Mouse and human serum proteins adsorbed differently to PNPs. The differences in the binding of mouse complement proteins are minimal, whereas human complement components strongly distinguish the two particles. This is probably due to the human origin of the Fc portion of the antibody used as targeting agent on tPNPs. tPNPs and uPNPs mainly activate complement via the classical and alternative pathways, respectively, but this pattern did not affect their binding and internalization in macrophages and only a limited consumption of the activity of the human complement system was documented. CONCLUSIONS: The results clearly indicate the presence of complement proteins on PNPs surface but partially derived from an unspecific deposition rather than an effective complement activation. The presence of a targeting antibody favors the activation of the classical pathway, but its absence allows an increased activation of the alternative pathway. This results in similar opsonization of both PNPs and similar phagocytosis by macrophages, without an impairment of the activity of circulating complement system and, consequently, not enhancing the susceptibility to infection.

Antioxidant and Antibacterial Activity of Mexican Oregano Essential Oil, Extracted from Plants Occurring Naturally in Semiarid Areas and Cultivated in the Field and Greenhouse in Northern Mexico.

In recent years, the determination of the antioxidant and antibacterial activity of essential oils in wild plants, such as Mexican oregano (Lippia graveolens Kunth), has become increasingly important. The objective was to compare the antioxidant and antibacterial activity of Mexican oregano essential oil obtained from plants occurring naturally in semiarid areas (Wild1 and Wild2), and those cultivated in the field (CField) and greenhouse (CGreenhouse) in northern Mexico. The Mexican oregano essential oil extraction was performed using the hydrodistillation method, the antioxidant activity was determined using the ABTS method, and the antibacterial activity was assessed through bioassays under the microwell method at nine different concentrations. The aim was to determine the diameter of the inhibition zone and, consequently, understand the sensitivity level for four bacterial species. The results revealed an antioxidant activity ranging from 90% to 94% at the sampling sites, with Wild1 standing out for having the highest average antioxidant activity values. Likewise, six out of the nine concentrations analyzed showed some degree of sensitivity for all the sampling sites. In this regard, the 25 µL mL-1 concentration showed the highest diameter of inhibition zone values, highlighting the Wild2 site, which showed an average diameter greater than 30 mm for the four bacteria tested. Only in the case of S. typhi did the CGreenhouse site surpass the Wild2, with an average diameter of the inhibition zone of 36.7 mm. These findings contribute to the search for new antioxidant and antibacterial options, addressing the challenges that humanity faces in the quest for opportunities to increase life expectancy.

The Role of Apparent Diffusion Coefficient Values in Glioblastoma: Differentiating Tumor Progression Versus Treatment-Related Changes.

OBJECTIVE: Glioblastoma represents the most common primary brain malignancy with a median survival of 15 months. Follow-up examinations are crucial to establish the presence of tumor recurrence, as well as treatment-associated changes such as ischemic infarction and radiation effects. Even though magnetic resonance imaging is a valuable tool, a histopathological diagnosis is often required because of imaging overlap between tumor recurrence and treatment associated changes. We set out to measure the apparent diffusion coefficient (ADC) values of the lesions in magnetic resonance imaging scans of treated glioblastoma patients to investigate if ADC values could accurately differentiate between tumor progression, radiation-related changes, and ischemic infarctions. METHODS: We evaluated ADC values among 3 groups, patients with tumor progression, radiation necrosis, and ischemic infarctions. The regions of interest were placed in the areas of greatest hypointensity among solid lesions using the ADC maps, excluding areas with necrotic, cystic, or hemorrhagic changes. The ADC values of the contralateral normal appearing white matter were also measured as the reference value for each patient. The relative ADC (rADC) values were measured for all 3 groups. Comparison between lesions and normal white matter was evaluated by Wilcoxon signed test. RESULTS: A total of 157 patients were included in the study; 49 patients classified as tumor progression, 58 patients as radiation necrosis, and 50 patients as ischemic infarctions. The mean ± SD ADC value was 752.8 ± 132.5 for tumor progression, 479.0 ± 105.2 for radiation-related changes, and 250.1 ± 57.2 for ischemic infarctions. The mean ± SD rADC value was 1.07 ± 0.22 for tumor progression, 0.66 ± 0.14 for radiation necrosis, and 0.34 ± 0.08 for ischemic infarctions. The mean rADC values were significantly higher in tumor progression, compared with both radiation necrosis and ischemic changes ( P < 0.001). CONCLUSIONS: The present study demonstrates that ADC values are a helpful tool to differentiate between tumor progression, radiation necrosis, and posttreatment ischemic changes.

Characterization of acute American football spinal injuries in a multi-center healthcare system.

PURPOSE: American football is considered one of the more injury-prone sports given its high-speed and high-impact nature. While much attention has been focused on chronic traumatic encephalopathy, spinal injuries represent the most common catastrophic injury incurred in football. The goal of this investigation is to describe the most common football-associated spinal lesions in a multi-center health system. METHODS: This is a retrospective analysis of patients with imaging evidence of spinal injuries related to American football during a 10-year period. Injuries were classified based on the anatomic level, type injury, spinal cord compromise, and therapeutic management. Chi-squared and Fisher's exact test were used for statistical analysis of categorial variables, and simple logistic regression was used to determine individual odds ratios. RESULTS: A total of 71 patients were included, with a median age of 17 (IQR, 15-22) years. The cervical spine was the most frequently affected segment (46%), followed by lumbar spine injuries (45%), and thoracic spine injuries (10%). Discogenic injuries were identified in 45 patients (63%). Spinal cord injury was documented in 7 subjects (10%), while cauda equina compression was reported in 1 patient (1%). CONCLUSIONS: Acute spinal injuries continue to represent a significant cause of morbidity among American football players. Compared to national statistics, we found a similar distribution of spinal injuries in terms of anatomic location and an alarmingly high proportion of SCI. This investigation represents the largest single-center study addressing spinal injuries among football players.

Traumatic spondylolisthesis of axis: clinical and imaging experience at a level one trauma center.

PURPOSE: Traumatic spondylolisthesis of the axis (TSA) with bilateral pars interarticularis fracture (a pattern also known as Hangman's fractures) accounts for 4-5% of all cervical fractures. Various classification systems have been described to assist therapeutic decision-making. The goal is to reassess the utility of these classifications for treatment strategy and evaluate additional imaging associations. METHODS: This is an IRB approved, retrospective analysis of patients with imaging diagnosis of TSA from 2016 to 2019. Consensus reads were performed classifying TSA into various Levine and Edwards subtypes and typical vs. atypical fractures. Other imaging findings such as additional cervical fractures, traumatic brain injury, spinal cord injury, and vertebral artery injury were recorded. Treatment strategy and outcome were reviewed from clinical charts. Fisher exact test was used for statistical analysis. RESULTS: A total of 58 patients were included, with a mean age of 62.7 ± 25 years, and male to female ratio of 1:1.2. Motor vehicle collision was the most common cause of TSA. Type I and III injuries were the most and the least common injuries, respectively. Patients with type I injuries were found to have good healing rates with conservative management (p < 0.001) while type IIa and III injuries were managed with surgical stabilization (p = 0.04 and p = 0.01, respectively). No statistical difference was observed in the treatment strategy for type II fractures (p = 0.12) and its prediction of the associated injuries. Atypical fractures were not found to have a higher incidence of SCI (p = 0.31). A further analysis revealed significantly higher-grade vertebral artery injuries (grades III and IV according to Biffl grading) in patients with type IIa and III injuries (p = 0.001) and an 11-fold increased risk of TBI compared to type I and type II fractures (p = 0.013). CONCLUSION: TSA fracture types were not associated with any clinical outcome. Levine and Edwards type II classification itself is not enough to guide the treatment plan and does not account for associated injuries. Additional imaging markers may be needed.

Establishing consensus on the perioperative management of cholecystectomy in public hospitals: a Delphi study with an expert panel in Mexico.

BACKGROUND: Several guidelines have put forward recommendations about the perioperative process of cholecystectomy. Despite the recommendations, controversy remains concerning several topics, especially in low- and middle-income countries. The aim of this study was to develop uniform recommendations for perioperative practices in cholecystectomy in Mexico to standardize this process and save public health system resources. METHODS: A modified Delphi method was used. An expert panel of 23 surgeons anonymously completed two rounds of responses to a 29-item questionnaire with 110 possible answers. The consensus was assessed using the percentage of responders agreeing on each question. RESULTS: From the 29 questions, the study generated 27 recommendations based on 20 (69.0%) questions reaching consensus, one that was considered uncertain (3.4%), and six (20.7%) items that remained open questions. In two (6.9%) cases, no consensus was reached, and no recommendation could be made. CONCLUSIONS: This study provides recommendations for the perioperative management of cholecystectomy in public hospitals in Mexico. As a guide for public institutions in low- and middle-income countries, the study identifies recommendations for perioperative tests and evaluations, perioperative decision making, postoperative interventions and institutional investment, that might ensure the safe practice of cholecystectomy and contribute to conserving resources.

Definition of internal target volumes based on planar X-ray fluoroscopic images for lung and hepatic stereotactic body radiation therapy. Comparison to inhale/exhale CT technique.

PURPOSE: To compare tumor motion amplitudes measured with 2D fluoroscopic images (FI) and with an inhale/exhale CT (IECT) technique MATERIALS AND METHODS: Tumor motion of 52 patients (39 lung patients and 13 liver patients) was obtained with both FI and IECT. For FI, tumor detection and tracking was performed by means of a software developed by the authors. Motion amplitude and, thus, internal target volume (ITV), were defined to cover the positions where the tumor spends 95% of the time. The algorithm was validated against two different respiratory motion phantoms. Motion amplitude in IECT was defined as the difference in the position of the centroid of the gross tumor volume in the image sets of both treatments. RESULTS: Important differences exist when defining ITVs with FI and IECT. Overall, differences larger than 5 mm were obtained for 49%, 31%, and 9.6% of the patients in Superior-Inferior (SI), Anterior-Posterior (AP), and Lateral (LAT) directions, respectively. For tumor location, larger differences were found for tumors in the liver (73.6% SI, 27.3% AP, and 6.7% in LAT had differences larger than 5 mm), while tumors in the upper lobe benefitted less using FI (differences larger than 5 mm were only present in 27.6% (SI), 36.7% (AP), and 0% (LAT) of the patients). CONCLUSIONS: Use of FI with the linac built-in CBCT system is feasible for ITV definition. Large differences between motion amplitudes detected with FI and IECT methods were found. The method presented in this work based on FI could represent an improvement in ITV definition compared to the method based on IECT due to FI permits tumor motion acquisition in a more realistic situation than IECT.

Targeting CD34+ cells of the inflamed synovial endothelium by guided nanoparticles for the treatment of rheumatoid arthritis.

Despite the advances in the treatment of rheumatoid arthritis (RA) achieved in the last few years, several patients are diagnosed late, do not respond to or have to stop therapy because of inefficacy and/or toxicity, leaving still a huge unmet need. Tissue-specific strategies have the potential to address some of these issues. The aim of the study is the development of a safe nanotechnology approach for tissue-specific delivery of drugs and diagnostic probes. CD34 + endothelial precursors were addressed in inflamed synovium using targeted biodegradable nanoparticles (tBNPs). These nanostructures were made of poly-lactic acid, poly-caprolactone, and PEG and then coated with a synovial homing peptide. Immunofluorescence analysis clearly demonstrated their capacity to selectively address CD34 + endothelial cells in synovial tissue obtained from human, mouse, and rat. Biodistribution studies in two different animal models of rheumatoid arthritis (antigen-induced arthritis/AIA and collagen-induced arthritis/CIA) confirmed the selective accumulation in inflamed joints but also evidenced the capacity of tBNP to detect early phases of the disease and the preferential liver elimination. The therapeutic effect of methotrexate (MTX)-loaded tBNPs were studied in comparison with conventional MTX doses. MTX-loaded tBNPs prevented and treated CIA and AIA at a lower dose and reduced administration frequency than MTX. Moreover, MTX-loaded tBNP showed a novel mechanism of action, in which the particles target and kill CD34 + endothelial progenitors, preventing neo-angiogenesis and, consequently, synovial inflammation. tBNPs represent a stable and safe platform to develop highly-sensitive imaging and therapeutic approaches in RA targeting specifically synovial neo-angiogenesis to reduce local inflammation.

A seminested RT-PCR for molecular genotyping of the Brazilian BR-I Infectious Bronchitis Virus Strain (GI-11).

Infectious bronchitis (IB) is one of the avian diseases with the greatest impact on poultry farming worldwide. In Brazil, strain BR-I (GI-11) is the most prevalent in poultry flocks. The present study aimed to develop a seminested RT-PCR assay specific for the diagnosis of BR-I IBV in Brazilian samples, targeting subunit 1 of the S gene. The detection limit of this assay was 10 copies of the IBV genome. In this study, 62.24% of 572 organ pools from the 5 regions of Brazil tested positive in a 3'UTR screening, and 84.83% were typed as BR-I IBV. BR-I was detected in the respiratory, digestive and urogenital tracts in pooled samples from all Brazilian geographical regions and in all the breeding systems analyzed. Specificity and sensitivity tests as well as phylogenetic analysis successfully confirmed the expected clustering of the sequences detected by this assay with the BR-I (GI-11) group. The nested PCR described in this study represents a suitable and valuable tool in the diagnosis, epidemiology, monitoring and vaccination decisions of IBV.

Molecular characterization of the spike gene of the porcine epidemic diarrhea virus in Mexico, 2013-2016.

In Mexico, the first outbreaks suggestive of the circulation of the porcine epidemic diarrhea virus (PEDV) were identified at the beginning of July 2013. To identify the molecular characteristics of the PEDV Spike (S) gene in Mexico, 116 samples of the intestine and diarrhea of piglets with clinical signs of porcine epidemic diarrhea (PED) were obtained. Samples were collected from 14 farms located in six states of Mexico (Jalisco, Puebla, Sonora, Veracruz, Guanajuato, and Michoacán) from 2013 to 2016. To identify PEDV, we used real-time RT-PCR to discriminate between non-INDEL and INDEL strains. We chose samples according to state and year to characterize the S gene. After amplification of the S gene, the obtained products were sequenced and assembled. The complete amino acid sequences of the spike protein were used to perform an epitope analysis, which was used to determine null mutations in regions SS2, SS6, and 2C10 compared to the sequences of G2. A phylogenetic analysis determined the circulation of G2b and INDEL strains in Mexico. However, several mutations were recorded in the collagenase equivalent (COE) region that were related to the change in polarity and charge of the amino acid residues. The PEDV strain circulating in Jalisco in 2016 has an insertion of three amino acids (232LGL234) and one change in the antigenic site of the COE region, and strains from the years 2015 and 2016 changed the index of the surface probability, which could be related to the re-emergence of disease outbreaks.

Sensory determinants of behavioral dynamics in Drosophila thermotaxis.

Complex animal behaviors are built from dynamical relationships between sensory inputs, neuronal activity, and motor outputs in patterns with strategic value. Connecting these patterns illuminates how nervous systems compute behavior. Here, we study Drosophila larva navigation up temperature gradients toward preferred temperatures (positive thermotaxis). By tracking the movements of animals responding to fixed spatial temperature gradients or random temperature fluctuations, we calculate the sensitivity and dynamics of the conversion of thermosensory inputs into motor responses. We discover three thermosensory neurons in each dorsal organ ganglion (DOG) that are required for positive thermotaxis. Random optogenetic stimulation of the DOG thermosensory neurons evokes behavioral patterns that mimic the response to temperature variations. In vivo calcium and voltage imaging reveals that the DOG thermosensory neurons exhibit activity patterns with sensitivity and dynamics matched to the behavioral response. Temporal processing of temperature variations carried out by the DOG thermosensory neurons emerges in distinct motor responses during thermotaxis.

Development of a qPCR for the detection of infectious laryngotracheitis virus (ILTV) based on the gE gene.

1. Infectious laryngotracheitis is a respiratory disease that affects the poultry industry worldwide. It is common in flocks with high-bird density, causing major economic losses. 2. In this study, a SYBR® FAST polymerase chain reaction (PCR) double-strand DNA intercalating agent assay was performed for the detection of infectious laryngotracheitis virus (ILTV) in clinical samples in comparison with a conventional nested-PCR, both based on the glycoprotein E encoding gene. This assay amplified 56 bp and was capable of detecting 19 to 1 copies of virus. 3. In total, 164 clinical samples were obtained from birds with respiratory problems from the period of 2009-2016. In the nested-PCR, there were 45.12% positive samples and 54.88% negative samples, while in the real-time PCR (qPCR), there were 81.1% positive samples and 18.9% negative samples. 4. In conclusion, qPCR from the DNA double-strand intercalating agent SYBR® GREEN FAST was useful for the diagnosis of ILTV because it detected samples that were negative in nested-PCR. This assay has advantages, such as a shortened processing-time, and no need for post-amplification processing (electrophoresis) with additional reagents, such as MgCl2 and agarose. Hence, qPCR proved to be useful, rapid and low cost for use with clinical samples.

Genetic characterisation and analysis of infectious bronchitis virus isolated from Brazilian flocks between 2010 and 2015.

1. Infectious bronchitis virus (IBV) variants in Brazil were isolated during 2010-2015 for epidemiological and molecular analysis to characterise the different variants and perform a bioinformatic analysis to compare with sequences of variants collected over the previous 40 years. 2. Of the 453 samples examined, 61.4% were positive for IBV and 75.9% of these were considered to have the BR-I genotype and were detected in birds of all ages distributed in all five Brazilian regions. 3. The ratio of non-synonymous substitutions per non-synonymous site (dN) to synonymous substitutions per synonymous site (dS), i.e. dN/dS, revealed a predominance of codons with non-synonymous substitutions in the first third of the S1 gene and a dN/dS ratio of 0.67. Additionally, prediction of N-glycosylation sites showed that most of the BR-I variants (from 2003 to early 2014) had an extra site at amino acid position 20, whereas the newest variants lacked this extra site. 4. These results suggest that Brazilian IBV variants probably underwent drastic mutations at various points between 1983 and 2003 and that the selection processes became silent after achieving a sufficiently effective antigenic structure for invasion and replication in their hosts. Brazilian IBV genotype BR-I is currently the predominant genotype circulating in Brazil and South America.

Impact of sample processing on the measurement of circulating microparticles: storage and centrifugation parameters.

BACKGROUND: Microparticles (MPs) have been shown to be markers of cellular activation and interactions. Pre-analytical conditions such as the centrifugation protocol and sample storage conditions represent an important source of variability in determining MPs values. The objectives of this study were to evaluate the influence of sample storage conditions and centrifugation speed and temperature on the determination of MPs in plasma. METHODS: Citrate-anticoagulated blood samples obtained from 21 healthy subjects were centrifuged under four different protocols involving different speeds (2500 g or 1500 g) and temperatures (4 °C or 20 °C) to isolate platelet-poor plasma (PPP). The number of MPs in fresh and frozen-thawed PPP were analyzed by flow cytometry, and MPs-mediated procoagulant activity was determined by a thrombin generation test and phospholipid-dependent procoagulant tests. RESULTS: The number of MPs and their procoagulant activity were affected by freeze-thaw cycling and centrifugation speed but not by centrifugation temperature. Sample freezing increased MPs number (six-fold) and thrombin generation (four-fold), and decreased clotting time (two-fold). Low centrifugation speed caused an increase in MPs number and a parallel increase in MP-mediated procoagulant activity. CONCLUSIONS: Sample storage conditions and centrifugation speed are important processing conditions affecting MPs number and activity. Before any study, the protocol for MPs isolation should be optimized to ensure a reliable characterization of MPs, which could provide important information for diagnostic purposes and for understanding the pathogenesis of diseases.

Limits of feedback control in bacterial chemotaxis.

Inputs to signaling pathways can have complex statistics that depend on the environment and on the behavioral response to previous stimuli. Such behavioral feedback is particularly important in navigation. Successful navigation relies on proper coupling between sensors, which gather information during motion, and actuators, which control behavior. Because reorientation conditions future inputs, behavioral feedback can place sensors and actuators in an operational regime different from the resting state. How then can organisms maintain proper information transfer through the pathway while navigating diverse environments? In bacterial chemotaxis, robust performance is often attributed to the zero integral feedback control of the sensor, which guarantees that activity returns to resting state when the input remains constant. While this property provides sensitivity over a wide range of signal intensities, it remains unclear how other parameters such as adaptation rate and adapted activity affect chemotactic performance, especially when considering that the swimming behavior of the cell determines the input signal. We examine this issue using analytical models and simulations that incorporate recent experimental evidences about behavioral feedback and flagellar motor adaptation. By focusing on how sensory information carried by the response regulator is best utilized by the motor, we identify an operational regime that maximizes drift velocity along chemical concentration gradients for a wide range of environments and sensor adaptation rates. This optimal regime is outside the dynamic range of the motor response, but maximizes the contrast between run duration up and down gradients. In steep gradients, the feedback from chemotactic drift can push the system through a bifurcation. This creates a non-chemotactic state that traps cells unless the motor is allowed to adapt. Although motor adaptation helps, we find that as the strength of the feedback increases individual phenotypes cannot maintain the optimal operational regime in all environments, suggesting that diversity could be beneficial.