Long-distance transport of hair lambs: effect of location in pot-belly trailers on thermo-physiology, welfare and meat quality.

Livestock transport exposes animals to a range of potential stressors that may compromise their welfare and final product quality, and those effects typically increase with the distance travelled. In North America, producers often use pot-belly vehicles for long hauls but little is known about their suitability for transporting lambs. We followed two long-distance trips using pot-belly trailers carrying 500 lambs (each) from Northern to Central Mexico in winter, to measure possible effects on animal welfare and meat quality. Sixty lambs per trip were placed at different locations within the pot-belly trailer. Animals were equipped with iButton Thermochron® temperature devices, which registered body temperature throughout pre- and post-slaughter stages. Despite the rather cool winter conditions, lambs placed in the "belly" and "nose" compartments had higher body temperatures at loading, during transport and lairage and after slaughter (carcass temperature). Those lambs also had higher levels of plasma cortisol, glucose and creatine kinase (CK), and a higher neutrophil/lymphocyte ratio. Regarding meat quality, ultimate pH (24 h) was higher in all locations, especially in LT4 location. Overall, the results suggest a link between thermal stress during transport, elevated physiological indicators of stress and poorer meat quality.

Thermophysiological, haematological, biochemical and behavioural stress responses of sheep transported on road.

The study was conducted to evaluate the thermophysiological, haematological, biochemical and behavioural stress responses of sheep transported on road. A total of 44 Chamarita breed adult ewes were randomly allotted to one of two groups, one control group (untransported) and transported group (journey of 4 h), and blood stress indicators were measured 1 day before transport and at four time points post-transport (0, 4 and 24 h). Thermophysiological profiles of ewes were measured by temperature buttons (iButton Thermochron® ) and placed in intravaginal sponges. Direct observations, with a combination of scan and behaviour sampling, were carried out to collect information on individual behaviour and the time it took the ewes to drink water, eat and rest after returning to their pen respectively. Transported ewes lost approximately 1 kg live weight compared to controls and had higher body temperatures until 12 h post-transport. Cortisol, glucose, non-esterified fatty acid (NEFA) concentrations as well as the neutrophil-lymphocyte ratio (N/L) and other physiological indicators were higher immediately after unloading in transported ewes but mostly returned to normal after 4 h, with complete recovery after 24 h. Behavioural analysis post-transport demonstrated that transported ewes chose to eat before drinking and spent less time resting than controls in the first 3 h after unloading. The study demonstrates that transportation even under short-journey conditions induced behavioural, physiological and thermophysiological responses indicative of the induction of significant stress, leading to live weight shrinkage that may jeopardize farmer's incomes. Finally, results of this study validated the use of iButton Thermochron® data loggers for monitoring the stress response during transport.

Targeting Wnt-driven cancer through the inhibition of Porcupine by LGK974.

Wnt signaling is one of the key oncogenic pathways in multiple cancers, and targeting this pathway is an attractive therapeutic approach. However, therapeutic success has been limited because of the lack of therapeutic agents for targets in the Wnt pathway and the lack of a defined patient population that would be sensitive to a Wnt inhibitor. We developed a screen for small molecules that block Wnt secretion. This effort led to the discovery of LGK974, a potent and specific small-molecule Porcupine (PORCN) inhibitor. PORCN is a membrane-bound O-acyltransferase that is required for and dedicated to palmitoylation of Wnt ligands, a necessary step in the processing of Wnt ligand secretion. We show that LGK974 potently inhibits Wnt signaling in vitro and in vivo, including reduction of the Wnt-dependent LRP6 phosphorylation and the expression of Wnt target genes, such as AXIN2. LGK974 is potent and efficacious in multiple tumor models at well-tolerated doses in vivo, including murine and rat mechanistic breast cancer models driven by MMTV-Wnt1 and a human head and neck squamous cell carcinoma model (HN30). We also show that head and neck cancer cell lines with loss-of-function mutations in the Notch signaling pathway have a high response rate to LGK974. Together, these findings provide both a strategy and tools for targeting Wnt-driven cancers through the inhibition of PORCN.

Assessment of chronic effects of tebuconazole on survival, reproduction and growth of Daphnia magna after different exposure times.

The effect of the fungicide tebuconazole (0.41, 0.52, 0.71 and 1.14mg/L) on survival, reproduction and growth of Daphnia magna organisms was monitored using 14 and 21 days exposure tests. A third experiment was performed by exposing D. magna to the fungicide for 14 days followed by 7 days of recovery (14+7). In order to test fungicide effects on D. magna, parameters as survival, mean whole body length, mean total number of neonates per female, mean number of broods per female, mean brood size per female, time to first brood/reproduction and intrinsic rate of natural increase (r) were used. Reproduction was seriously affected by tebuconazole. All tebuconazole concentrations tested affected the number of broods per female and day to first brood. At 14-days test, number of neonates per female and body size decreased by concentrations of tebuconazole higher than 0.52mg/L, whereas at 21-days test both parameters were affected at all the concentrations tested. Survival of the daphnids after 14 days fungicide exposure did not exhibited differences among experimental and control groups. In this experiment r value was reduced (in a 22%) when animals were exposed to concentrations of 0.71mg/L and 1.14mg/L. Survival of daphnids exposed during 21 days to 1.14mg/L declined, and the intrinsic rate of natural increase (r) decreased in a 30 % for tebuconazole concentrations higher than 0.41mg/L. Longevity of daphnids pre-exposed to tebuconazole for 14 days and 7 days in clean water did not show differences from control values and all of them survived the 21 days of the test. However, after 7 days in fungicide free medium animals were unable to restore control values for reproductive parameters and length. The maximum acceptable toxicant concentration (MATC) was calculated using the r values as parameter of evaluation. MATC estimations were 0.61mg/L and 0.46mg/L for 14 and 21 days, respectively. Results showed that the number of neonates per female was the highest sensitive parameter to the effects of tebuconazole on D. magna. On the other hand, a recovery period of 7 days in a free toxicant medium would not be longer enough to reestablish normal reproduction parameters in pre-exposed tebuconazole daphnids.

Native black Michuñe potato variety: characterization, frying conditions and sensory evaluation.

The aim of this study was to evaluate the chemical and nutritional composition, to establish frying processing conditions and to determine the sensory profile and acceptability of Black Michuñe (BM) potato chips. BM had a higher protein content, half the ether extract content and nitrogen-free extract, a lower caloric intake (70 kcal/100g) and amylose content (17.5%) than Desirée (DES). To set the frying conditions, the Taguchi method was applied using a matrix design L9 (3(2),2(2)). The variables studied were: temperature, time, potato variety (raw material) and pretreatment. The responses evaluated were: the color difference as well as the content of reducing sugars and total polyphenols. The best frying conditions were BM with a pretreatment at 160 degrees C for 7 min for color, DES without pretreatment at 140 degrees C for 7 min for reducing sugar content, and BM without pretreatment at 180 degrees C for 4 min for polyphenol content. Then, sensory profiles of potato chips from BM, DES and a commercial package were determined by selecting the descriptors texture, firmness, color, salty taste and oiliness. Significant differences in color and oiliness were found. Finally, the acceptability test was applied to BM potato chips where color (64%) was the only attribute not as accepted as texture (95%), salty taste (87%) and product (97.3%). This study demonstrated that BM potato chips have a satisfactory acceptability by consumers.

Contactless skin perfusion monitoring with video cameras: tracking pharmacological vasoconstriction and vasodilation using photoplethysmographic changes.

Objectives.Clinical assessment of skin perfusion informs prognosis in critically ill patients. Video camera monitoring could provide an objective, continuous method to monitor skin perfusion. In this prospective, interventional study of healthy volunteers, we tested whether video camera-derived photoplethysmography imaging and colour measurements could detect drug-induced skin perfusion changes.Approach.We monitored the lower limbs of 30 volunteers using video cameras while administering phenylephrine (a vasoconstrictor) and glyceryl trinitrate (a vasodilator). We report relative pixel intensity changes from baseline, as absolute values are sensitive to environmental factors. The primary outcome was the pre- to peak- infusion green channel amplitude change in the pulsatile PPGi waveform component. Secondary outcomes were pre-to-peak changes in the photoplethysmographic imaging waveform baseline, skin colour hue and skin colour saturation.Main results.The 30 participants had a median age of 29 years (IQR 25-34), sixteen (53%) were male. A 34.7% (p= 0.0001) mean decrease in the amplitude of the pulsatile photoplethysmographic imaging waveform occurred following phenylephrine infusion. A 30.7% (p= 0.000004) mean increase occurred following glyceryl trinitrate infusion. The photoplethysmographic imaging baseline decreased with phenylephrine by 2.1% (p= 0.000 02) and increased with glyceryl trinitrate by 0.5% (p= 0.026). Skin colour hue changed in opposite direction with phenylephrine (-0.0013,p= 0.0002) and glyceryl trinitrate (+0.0006,p= 0.019). Skin colour saturation decreased with phenylephrine by 0.0022 (p= 0.0002), with no significant change observed with glyceryl trinitrate (+0.0005,p= 0.21).Significance.Drug-induced vasoconstriction and vasodilation are associated with detectable changes in photoplethysmographic imaging waveform parameters and skin hue. Our findings suggest video cameras have great potential for continuous, contactless skin perfusion monitoring.

Fenofibric acid prevents retinal pigment epithelium disruption induced by interleukin-1ß by suppressing AMP-activated protein kinase (AMPK) activation.

AIMS/HYPOTHESIS: The mechanisms involved in the beneficial effects of fenofibrate on the development and progression of diabetic macular oedema (DMO) remain to be elucidated. To shed light on this issue we have explored the effect of fenofibric acid on the barrier function of human retinal pigment epithelium (RPE) cells. METHODS: ARPE-19 cells (a human RPE line) were cultured for 18 days under standard conditions and under conditions leading to the disruption of the monolayer (D-glucose, 25 mmol/l, with IL-1ß, 10 ng/ml, added at days 16 and 17). Fenofibric acid, 25 µmol/l and 100 µmol/l, was added on the last 3 days of the experiment (one application/day). RPE cell permeability was evaluated by measuring apical-basolateral movements of FITC-dextran (40 kDa). The production of tight junction proteins and AMP-activated protein kinase (AMPK) phosphorylation was assessed by western blot. Immunohistochemical studies of tight junction proteins and small interfering RNA transfection to AMPK were also performed in ARPE-19 monolayers. RESULTS: Treatment of ARPE-19 cells with fenofibric acid significantly reduced the increment of permeability and the breakdown of the ARPE-19 cell monolayer induced by D-glucose, 25 mmol/l, and IL-1ß, 10 ng/ml, in a dose-dependent manner. This effect was unrelated to changes in the content of tight junction proteins. Fenofibric acid prevented the activation of AMPK induced by IL-1ß and the hyperpermeability induced by IL-1ß was blocked by silencing AMPK. CONCLUSIONS/INTERPRETATION: Disruption of RPE induced by IL-1ß is prevented by fenofibric acid through its ability to suppress AMPK activation. This mechanism could be involved in the beneficial effects of fenofibrate on DMO development.

Claw disorders as iceberg indicators of cattle welfare: Evidence-based on production system, severity, and associations with final muscle pH.

This study presents a novel approach to use claw disorders in cattle as a retrospective welfare indicator characterized at the abattoir. A total of 1040 cattle (2080 front and back left claws) were analyzed from 143 batches, originating from feedlots, free-range, and dairy systems. Our results indicate that abnormal claw shapes (>55%) and fissures of the claw wall (>25%) had the highest prevalence, regardless of the system of origin. For the seven types of lesions monitored, numerous associations were found between lesions in the front and rear limbs typical of each production system. Ultimate meat pH was higher in animals with white line disease and skin wounds in feedlot and free-range cattle. We conclude that claw disorders can be used as an iceberg indicator to provide valuable information about animal fitness, and the ability to cope with the husbandry and pre-slaughter environment. These indicators can be used to improve the level of welfare of the animals.

Daily rhythms of locomotor activity, feeding behavior and dietary selection in Nile tilapia (Oreochromis niloticus).

Fish do not feed at any time of the day and on whatever food item they encounter in the wild, but they show daily rhythms of feeding activity and dietary selection. The aim of this research was to investigate the daily rhythms of behavior in Nile tilapia self-fed with plant-based diets supplemented with different levels of exogenous phytase (an enzyme that hydrolyzes non-digestible phytate and improves the nutritional value of the diet). To this end, ten males were individually kept in 50-L tanks, each equipped with two self-feeders and one infrared photo-cell connected to a computer. The selection factors investigated were the level of phytase supplementation (0 IU kg(-1) vs 1500 IU kg(-1); 1500 IU kg(-1) vs 4000 IU kg(-1)) or sodium phytate (1% phytate vs 1% phytate+1500 IU kg(-1) phytase). The results revealed that 66.7% of total daily activity occurred during the day, while feeding was strictly nocturnal, with 93.0% of the daily food demands occurring at night. Tilapia preferred the diet with 1500 IU kg(-1) phytase rather than the control or 4000 IU kg(-1) diets. When exogenous sodium phytate was added to the diet, tilapia preferred the phytase diet. In conclusion tilapia self-feed at night (although locomotor activity was mostly diurnal) and chose plant-diets containing phytase, which should be taken into account when designing feeding strategies and practical diets for tilapia aquaculture.

Short-term exposure to sublethal tebuconazole induces physiological impairment in male zebrafish (Danio rerio).

The aim of the present study was to assess the physiological response of male zebrafish Danio rerio to the fungicide tebuconazole and recovery in fungicide-free water. Acute toxicity tests were carried out and the median lethal concentration (LC(50)) from 24 to 96 h was calculated. The fish were exposed to a sublethal fungicide concentration of 230 microg/L for 7 or 14 days and allowed to recover for 7 or 14 more days, respectively. Whole-body levels of vitellogenins, triglycerides, cholesterol, glucose, lactate and proteins as well as the activities gamma-glutamil transpeptidase (gamma-GT), alanin aminotransferase (AlAT), alkaline phosphatase (AP) and lactate dehydrogenase (LDH) were assayed; corpulence factor (k) was also calculated. Fish exhibited significant increase of vitellogenins (Vtg), which continued to increase after 14 days of recovery. Levels of glucose, lactate, cholesterol and triglycerides increased after 7 and 14 days of exposure. Finally, cholesterol and glucose recovered after 14 days of recovery whereas triglycerides and lactate continued to be elevated. Proteins and k remained unaltered the entire experiments. AAT, AlAT and AP enhanced during exposure and did not recover at the end (except AlAT). A longer recovery period should be necessary to re-establish fish physiology. These results alert about the multiple disruptive physiological actions that tebuconazole may have on fish.

Interphotoreceptor retinoid-binding protein (IRBP) is downregulated at early stages of diabetic retinopathy.

AIMS/HYPOTHESIS: Interphotoreceptor retinoid-binding protein (IRBP) plays a major role in the visual cycle and is essential to the maintenance of photoreceptors. The aim of this study was to determine whether a decrease in IRBP production exists in the early stages of diabetic retinopathy. METHODS: Vitreous samples from diabetic patients with proliferative and non-proliferative diabetic retinopathy (PDR, NPDR), and from non-diabetic patients with macular hole (control group) were selected for IRBP quantitative assessment by proteomic analysis (fluorescence-based difference gel electrophoresis) and western blot. Human post mortem eyes (n = 16) from diabetic donors without clinically detectable retinopathy and from non-diabetic donors (n = 16) were used to determine IRBP (also known as RBP3) mRNA levels (RT-PCR) and protein content (western blot and confocal microscopy). Retinal neurodegeneration was assessed by measuring glial fibrillar acidic protein (GFAP) and the apoptotic rate. Y79 human retinoblastoma cells were used to test the effects of glucose, TNF-alpha and IL-1beta on IRBP expression and IRBP levels. RESULTS: Intravitreous IRBP concentration was significantly lower in PDR < NPDR < control in proteomic and western blot analysis. IRBP mRNA levels and IRBP protein content were significantly lower in the retinas from diabetic donors than in those from non-diabetic donors. Increased GFAP and a higher degree of apoptosis were observed in diabetic retinas compared with non-diabetic retinas. A dose-dependent downregulation of IRBP mRNA expression and IRBP content was detected with glucose, TNF-alpha and IL-1beta in cultures of Y79 human retinoblastoma cells. CONCLUSIONS/INTERPRETATION: Underproduction of IRBP is an early event in the human diabetic retina and is associated with retinal neurodegeneration. The mechanisms leading to this deficit deserve further investigation.

Effect of feed type and feeding frequency on macrophage functions in tilapia (Oreochromis niloticus L.).

In fresh water recirculation systems the type of feed and feeding frequency have a direct effect on water quality, growth, fish welfare and the response of the immune system. Four types of feed with different sources of plant protein (soybean concentrate, sunflower meal, corn gluten and pea) were provided at two feeding frequencies (two and eight times day(-1)) to observe effects on growth, cortisol levels and innate immunity (macrophage phagocytosis and respiratory burst) on tilapia in early stages of growth (2-10 g). Growth and cortisol parameters were quite similar among the groups of tilapia fed the different diets and frequencies at the end of the feeding period. Phagocytosis and respiratory burst were also very similar with the four feed types. However, macrophages from fish fed twice day(-1) were much less efficient in clearing bacteria after 24 h than the groups fed eight times day(-1). Our results suggest that an increased feeding frequency may confer a higher resistance to disease.

Effect of lairage duration on rabbit welfare and meat quality.

This study determined whether short (2h) or long (8h) lairage at an abattoir had an effect on plasma stress indicators (haematocrit, glucose, lactate, creatine phosphokinase and corticosterone), instrumental meat quality (pH24, water holding capacity, colour, raw and cooked texture) and sensory meat quality (using a trained sensory panel) in rabbits. The effect of the position of the animals on a multifloor rolling cage stand during lairage was also assessed. Lairage time had a significant effect on blood stress indicators, but only a slight effect on meat quality traits. A lairage duration of 6-8h is recommended.

Effect of the pre-slaughter logistic chain on meat quality of lambs.

A total of 144 lambs were sampled in a 3×2×2 factorial design, testing three residence (stay) times at a pre-slaughter classification centre (0, 7, and 28days) and two seasons (summer and winter), with two replicates in each season. Meat from the longissimus dorsi was analysed in terms of pH, WHC, texture, colour (L∗a∗b∗, chroma and hue) and carcass bruising. Stay time had a significant effect (p<0.001) on meat texture, while season had a significant effect (p<0.001) on all variables analysed. Overall, stay time had less effect on meat quality than season and the interaction between treatments was not significant. Meat from lambs slaughtered in winter had some dark-cutting characteristics, with darker colour, higher ultimate pH, tougher meat and lower press juice. In conclusion, pre-slaughter classification and season are sources of stress for lambs and affect meat quality traits.

Automated method for detecting and reading seven-segment digits from images of blood glucose metres and blood pressure monitors.

There is an increasing need for fast and accurate transfer of readings from blood glucose metres and blood pressure monitors to a smartphone mHealth application, without a dependency on Bluetooth technology. Most of the medical devices recommended for home monitoring use a seven-segment display to show the recorded measurement to the patient. We aimed to achieve accurate detection and reading of the seven-segment digits displayed on these medical devices using an image taken in a realistic scenario by a smartphone camera. A synthetic dataset of seven-segment digits was developed in order to train and test a digit classifier. A dataset containing realistic images of blood glucose metres and blood pressure monitors using a variety of smartphone cameras was also created. The digit classifier was evaluated on a dataset of seven-segment digits manually extracted from the medical device images. These datasets along with the code for its development have been made public. The developed algorithm first preprocessed the input image using retinex with two bilateral filters and adaptive histogram equalisation. Subsequently, the digit segments were automatically located within the image by two techniques operating in parallel: Maximally Stable Extremal Regions (MSER) and connected components of a binarised image. A filtering and clustering algorithm was then designed to combine digit segments to form seven-segment digits. The resulting digits were classified using a Histogram of Orientated Gradients (HOG) feature set and a neural network trained on the synthetic digits. The model achieved 93% accuracy on digits found on the medical devices. The digit location algorithm achieved a F1 score of 0.87 and 0.80 on images of blood glucose metres and blood pressure monitors respectively. Very few assumptions were made of the locations of the digits on the devices so that the proposed algorithm can be easily implemented on new devices.

Concordance of chlamydia trachomatis infections within sexual partnerships.

OBJECTIVES: The enhanced sensitivity of nucleic acid amplification tests (NAAT) provides an opportunity for estimating the prevalence of untreated Chlamydia trachomatis infections. The transmissibility and public health significance of some NAAT-identified infections are, however, not known. METHODS: Adults attending an urban emergency department provided specimens for C trachomatis screening using NAAT. Participants testing positive were offered follow-up including re-testing for C trachomatis using NAAT and traditional methods, eg culture and direct fluorescent antibody, and were treated. Partners were offered identical evaluation and treatment. Overall, 90 C trachomatis-positive participants had one or more sexual partners enrolled. RESULTS: Evidence of transmission, as defined by infection concordance between partnerships, was observed among 75% of partners of index cases testing positive by both NAAT and traditional assay but only 45% of partners of index cases testing positive by NAAT only (prevalence ratio 1.7, 95% CI 1.1 to 2.5). Among index participants returning for follow-up, 17% had no evidence of C trachomatis infection by NAAT or traditional assay (median follow-up three weeks). CONCLUSIONS: A substantial proportion of positive NAAT results for chlamydial infection may be of lower transmissibility and may not persist after a short follow-up. The long-term health effects of some positive NAAT are uncertain.

Descriptive characteristics of the area of origin of the deltoid muscle on the human clavicle. Is it necessary to include new terms in the Terminologia Anatomica?

The clavicular portion of the deltoid muscle (CPDM) in the human clavicle does not have a nomenclature in the Terminologia Anatomica (TA). This area is relevant in anatomy since the muscle participates in motions of glenohumeral articulation. The aim of this study was to describe the origin of the CPDM and to propose a name for the structure. Dry clavicles of 176 adults were studied, without distinction by sex. An osteometric board was used to measure the maximum length of the clavicles and a digital caliper to measure length of the CPDM's origin, distance from the origin to the sternal end, distance from the origin to the acromial end, distance of the lateral third and middle vertical diameter. The mean of maximum of the distances and CPDM's origin of left/right clavicle do not present significant differences. The CPDM s origin showed a high prevalence of structures as groove and roughened area (over 96% of cases). In conclusion, our definition of the CPDM shows the importance of clearly describing the observed groove and roughened area. Due to the high prevalence of the structures, the authors suggest that the terms "sulcus musculi deltoidei" and "tuberositas musculi deltoidei" be included in the TA to denominate the CPDM's origin on the human clavicle.

Fisiología respiratoria: circulación pulmonar / Respiratory physiology: pulmonary circulation

El pulmón recibe sangre desde la circulación bronquial y pulmonar. La circulación pulmonar presenta importantes diferencias con la sistémica, sus vasos sanguíneos poseen características únicas que le permiten cumplir sus diferentes funciones, siendo la más importante el intercambio gaseoso. Existen múltiples factores, activos y pasivos, que están involucrados en la regulación de la resistencia vascular y flujo sanguíneo pulmonar.

The lung receives blood from the bronchial and the pulmonary circulation. The pulmonary circulation presents important differences with the systemic circulation, its blood vessels have unique characteristics that allow them to fulfill their different functions, the most important being gas exchange. There are multiple factors, active and passive, that are involved in the regulation of vascular resistance and pulmonary blood flow.

Mexican consumers' perceptions and attitudes towards farm animal welfare and willingness to pay for welfare friendly meat products.

Increasing concerns about farm animal welfare have led to an increase in the availability of welfare-friendly-products (WFP), but little is known about how much more consumers are willing-to-pay (WTP) for WFP or about their buying trends in Latin America. In this study, a survey was given to 843 meat consumers in the city of Toluca, Mexico. The results show that consumers were interested in farm animal welfare issues and their ethical, sociological and economic implications, as in Europe. The people surveyed also conveyed a high level of empathy with animal feelings and emotions, however they clearly demanded more information and regulations related to farm animal welfare. The majority of respondents expressed that they were WTP more for properly certified WFP, but mostly based on the benefits in terms of product quality and human health. If the demand for WFP begins to increase in Mexico, the supply chain should consider a certification system to guarantee product origin based on current conditions.

Efficacy and safety of withholding antimicrobial treatment in children with cancer, fever and neutropenia, with a demonstrated viral respiratory infection: a randomized clinical trial.

OBJECTIVES: To determine efficacy and safety of withholding antimicrobials in children with cancer, fever and neutropenia (FN) with a demonstrated respiratory viral infection. METHODS: Prospective, multicentre, randomized study in children presenting with FN at five hospitals in Santiago, Chile, evaluated at admission for diagnosis of bacterial and viral pathogens including PCR-microarray for 17 respiratory viruses. Children positive for a respiratory virus, negative for a bacterial pathogen and with a favourable evolution after 48 h of antimicrobial therapy were randomized to either maintain or withhold antimicrobials. Primary endpoint was percentage of episodes with uneventful resolution. Secondary endpoints were days of fever/hospitalization, bacterial infection, sepsis, admission to paediatric intensive care unit (PICU) and death. RESULTS: A total of 319 of 951 children with FN episodes recruited between July 2012 and December 2015 had a respiratory virus as a unique identified microorganism, of which 176 were randomized, 92 to maintain antimicrobials and 84 to withdraw. Median duration of antimicrobial use was 7 days (range 7-9 days) versus 3 days (range 3-4 days), with similar frequency of uneventful resolution (89/92 (97%) and 80/84 (95%), respectively, not significant; OR 1.48; 95% CI 0.32-6.83, p 0.61), and similar number of days of fever (2 versus 1), days of hospitalization (6 versus 6) and bacterial infections throughout the episode (2%-1%), with one case of sepsis requiring admission to PICU in the group that maintained antimicrobials, without any deaths. CONCLUSIONS: The reduction of antimicrobials in children with FN and respiratory viral infections, based on clinical and microbiological/molecular diagnostic criteria, should favour the adoption of evidence-based management strategies in this population.