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Background Therapeutic and growth-promoting antibiotics are frequently used in broiler production. Indirect evidence indicates that these practices are linked to the proliferation of antimicrobial resistance (AMR), the spread of antibiotic-resistant bacteria from food animals to humans, and the environment, but there is a lack of comprehensive experimental data supporting this. We investigated the effects of growth promotor (bacitracin) and therapeutic (enrofloxacin) antibiotic administration on AMR in broilers for the duration of a production cycle, using a holistic approach that integrated both culture-dependent and culture-independent methods. We specifically focused on pathogen-harboring families (Enterobacteriaceae, Enterococcaceae, and Staphylococcaceae). Results Antibiotic-resistant bacteria and antibiotic resistance genes were ubiquitous in chicken cloaca and litter regardless of antibiotic administration. Environment (cloaca vs. litter) and growth stage were the primary drivers of variation in the microbiomes and resistomes, with increased bacterial diversity and a general decrease in abundance of the pathogen-harboring families with age. Bacitracin-fed groups had higher levels of bacitracin resistance genes and of vancomycin-resistant Enterococcaceae (total Enterococcaceae counts were not higher). Although metagenomic analyses classified 28–76% of the Enterococcaceae as the commensal human pathogens E. faecalis and E. faecium, culture-based analysis suggested that approximately 98% of the vancomycin-resistant Enterococcaceae were avian and not human-associated, suggesting differences in the taxonomic profiles of the resistant and non-resistant strains. Enrofloxacin treatments had varying effects, but generally facilitated increased relative abundance of multidrug-resistant Enterobacteriaceae strains, which were primarily E. coli. Metagenomic approaches revealed a diverse array of Staphylococcus spp., but the opportunistic pathogen S. aureus and methicillin resistance genes were not detected in culture-based or metagenomic analyses. Camphylobacteriaceae were significantly more abundant in the cloacal samples, especially in enrofloxacin-treated chickens, where a metagenome-assembled C. jejuni genome harboring fluoroquinolone and β-lactam resistance genes was identified. Conclusions Within a “farm-to-fork, one health” perspective, considering the evidence that bacitracin and enrofloxacin used in poultry production can select for resistance, we recommend their use be regulated. Furthermore, we suggest routine surveillance of ESBL E. coli, vancomycin-resistant E. faecalis and E. faecium, and fluoroquinolone-resistant C. jejuni strains considering their pathogenic nature and capacity to disseminate AMR to the environment.

Ambient conditions during chicken embryogenesis, such as insufficient oxygen or changes in temperature, are expected to cause permanent phenotypic changes and affect their posthatch performance. Decades of genetic selection for high growth rate resulted with various physiological and morphological changes that can affect the broiler fitness under environmental stress. To evaluate the selection effect on responses to environmental challenge during embryonic development, and the long-term implications, we have used a unique genetic line, that was not selected for over 30 yr (since 1986), as control for the modern commercial genetic line. At embryonic day 5 (E5), broiler embryos from these 2 genetic lines were divided into 2 treatments: 1) control; 2) 15% O2 concentration for 12 h/day from E5 through E12 the embryonic period of chorioallantoic membrane formation. Embryos and hatched chicks were characterized for physiological and morphological parameters. Significant differences in relative embryo weight and yolk consumption were found between the 2 lines. The modern line was characterized by a higher metabolic rate and rapid growth, supported by higher hemoglobin levels and hematocrit concentrations, whereas the 1986 line had slower metabolism, lower levels of hematocrit and hemoglobin, higher oxygen volume per 1 g of embryonic tissue indicating higher oxygen availability. Both lines exhibited changes in heart rate, and blood parameters corresponding to cardiovascular system adaptation after hypoxic exposure, seemingly implemented to increase oxygen-carrying capacity to the embryo tissues. Our finding stand in agreement that the genetic selection for high growth rate that led to higher metabolism without a fit of the cardiovascular system, increased the imbalance between oxygen supply and demand.

Adequate ambient temperature and oxygenation are necessary to maintain normal embryonic development of broilers, however, hypoxia challenge during incubation can aid in improving regulatory plasticity and lead to different phenotypes later in life. This study aimed to examine the effects of moderate hypoxia (O2 17%) during the plateau phase on the embryonic physiological parameters and on post-hatch performance (growth rate, feed consumption and feed conversion) up to the age of poultry marketing. The study included examined embryos exposed to O2 17% for 12 h per day (h/d) from E16 through E18 (designated as 12H), or O2 17% continuously, from E16 through E17 (designated as 48H) and a standard incubation control group (21% O2). Physiological and morphological parameters of embryos and hatched chicks were measured. Male Chicks from all three treatment groups were raised under recommended temperature regime, and body weight, feed intake and FCR were recorded on a weekly basis. The intermittent hypoxia protocol (12H), allowed embryos to properly adapt to the shortage of oxygen, compensate for the gap in body mass that developed following the first exposure window, and hatch with characteristics similar to those of the control embryos. In contrast, while the 48H embryos were able to adapt to the hypoxic stress, the prolonged exposure prevented them from catching up with both control and 12H embryos. Broilers that were subjected to hypoxia showed hatchling body weights and growth rates similar to those of controls, throughout the entire growth phase. During the fifth week, lower feed consumption was observed in the 12H and 48H groups and became significantly lower than the control chicks in the sixth week of growth. Following hypoxia exposure, chicks managed to reach normal body weight with less feed, with the 12H group demonstrating lower and more efficient FCR during the last two weeks of growth. Broiler embryos reacted to plateau-phase hypoxia challenge with numerous physiological and metabolic modifications. The prudent alterations in metabolism and cardiovascular system during exposure to hypoxia and post-hatch, resulted in more efficient energy utilization in broilers, which may have a long-lasting enhancing effect on post-hatching thermotolerance and sustainability in chicks reared under sub-optimal environmental conditions.

Artificial targeted illumination has a pivotal role in reproductive processes of poultry. The light-absorption mechanism in birds consists of 2 main components: the eye (retinal photoreceptors) and extraretinal photoreceptors located in the brain. Previous studies conducted on hens have shown that photostimulation of brain extraretinal photoreceptors elevates reproductive activity, whereas retinal photostimulation suppresses it. We tested the effect of targeted differential photostimulation (TDP) on reproductive activities of broiler breeder males. Fifty broiler breeder roosters (Ross), 21 wk of age, were divided into 5 environmentally controlled light-treatment rooms (n = 10) equipped with individual cages. Rooms 1 and 2 had 2 parallel lighting systems consisting of red light (630 nm) and green light (514 nm), and rooms 3 and 4 had parallel red and blue (456 nm) lighting systems. Room 5, illuminated with white light, served as the control. Birds of all groups were kept under short day (6L:18D) for 2 wk with both lighting systems in each treatment room turned on. At 23 wk of age, birds were photostimulated by gradually increasing one of the lighting systems to 14 h of light in each room, while the other lighting system was left on short day (6L:18D). Weekly semen samples were collected until 65 wk of age and analyzed for volume, motility, concentration and vitality. Monthly blood samples were drawn for plasma hormone assays. At 65 wk of age, roosters were euthanized and hypothalamus, pituitary gland, retina and testes samples were taken for mRNA expression analysis. TDP using long-day red light and short-day green light significantly increased reproductive performance, manifested by higher semen volume, motility and concentration, and testis weight; furthermore, this group had higher plasma testosterone levels, higher GnRH mRNA expression in the hypothalamus, lower levels of aromatase in the testes, and lower mRNA expression of hypothalamic serotonin transporter, and of pituitary prolactin and its receptors in the testes. This is the first study showing a positive effect of TDP on reproduction of broiler breeder roosters.

Background: Infectious diseases and vaccines can occasionally cause new-onset or flare of immune-mediated diseases (IMDs). The adjuvanticity of the available SARS-CoV-2 vaccines is based on either TLR-7/8 or TLR-9 agonism, which is distinct from previous vaccines and is a common pathogenic mechanism in IMDs. Methods: We evaluated IMD flares or new disease onset within 28-days of SARS-CoV-2 vaccination at five large tertiary centres in countries with early vaccination adoption, three in Israel, one in UK, and one in USA. We assessed the pattern of disease expression in terms of autoimmune, autoinflammatory, or mixed disease phenotype and organ system affected. We also evaluated outcomes. Findings: 27 cases included 17 flares and 10 new onset IMDs. 23/27 received the BNT - 162b2 vaccine, 2/27 the MRNA-1273 and 2/27 the ChAdOx1 vaccines. The mean age was 54.4 ± 19.2 years and 55% of cases were female. Among the 27 cases, 21 (78%) had at least one underlying autoimmune/rheumatic disease prior the vaccination. Among those patients with a flare or activation, four episodes occurred after receiving the second-dose and in one patient they occurred both after the first and the second-dose. In those patients with a new onset disease, two occurred after the second-dose and in one patient occurred both after the first (new onset) and second-dose (flare). For either dose, IMDs occurred on average 4 days later. Of the cases, 20/27 (75%) were mild to moderate in severity. Over 80% of cases had excellent resolution of inflammatory features, mostly with the use of corticosteroid therapy. Atypical rheumatic manifestations included idiopathic pericarditis (n = 2), neurosarcoidosis with small fiber neuropathy (n = 1), demyelination (n = 1), and myasthenia gravis (n = 2). In 22 cases (81.5%), the insurgence of Adverse event following immunization (AEFI)/IMD could not be explained based on the drug received by the patient. In 23 cases (85.2%), AEFI development could not be explained based on the underlying disease/co-morbidities. Only in one case (3.7%), the timing window of the insurgence of the side effect was considered not compatible with the time from vaccine to flare. Interpretation: Despite the high population exposure in the regions served by these centers, IMDs flares or onset temporally-associated with SARS-CoV-2 vaccination appear rare. Most are moderate in severity and responsive to therapy although some severe flares occurred. Funding: none.

Background Takayasu arteritis (TA), a systemic large-vessel vasculitis, was reported to have high incidence of spondyloarthropathy. Purpose To evaluate the prevalence of inflammatory sacroiliitis in patients with TA that underwent abdominal/pelvic magnetic resonance imaging (MRI) examinations as part of their vasculitis work-up. Material and Methods Consecutive abdominal/pelvic MRI examinations of 34 patients with TA fulfilling the 1990 ACR criteria and 34 age- and gender-matched controls performed between 2008 and 2020 were retrospectively reviewed for the presence sacroiliitis. The presence of active and structural lesions was scored twice (with a one-month interval between reads) by one reader. Structural lesions were also evaluated on computed tomography, when available, and correlated to MRI findings. Clinical data were extracted from the patients’ clinical files. MRI scores were compared between the study and control groups and correlated with the clinical data. Results Sacroiliitis was evident in 11.7% of the TA group examinations compared to 0.3% in the control group ( P = 0.6). Participants with TA had significantly more erosions and fat deposition compared to the control group (Study: 0.01/0.03, Control: 0/0, P = 0.03/0.003, respectively). However, mean sacroiliitis score was not significantly different (Study: 1.06, Control: 0.78, P = 0.015). Of the four patients with TA and sacroiliitis, 3 (75%) had a diagnosis of inflammatory bowel disease (IBD). Conclusion Sacroiliitis was detected in 11.7% of abdominal MRI examinations of patients with TA, 75% of which had associated IBD, suggesting that both IBD and sacroiliitis should be routinely screened in the TA population as their presence may influence treatment decisions.

Data regarding the risk for severe COVID19 in patients with autoimmune or inflammatory diseases are scarce. To estimate the risk of those patients to develop a more severe COVID19 infection All active patients and those with dermatologic and/or rheumatologic autoimmune/inflammatory diseases were identified in a single tertiary center. The charts of those tested positive for COVID19 between March 1st and May 31st, 2020 reviewed including demographics, co-morbidities and medications. COVID19 outcome of those with dermatologic and/or rheumatologic autoimmune/inflammatory diseases were compared to COVID19 infected matched controls without an autoimmune/inflammatory background. Overall, 974 of 381 268 active patients were tested positive for COVID19, including 35 out of 13 225 with dermatologic and/or rheumatologic autoimmune/inflammatory diseases. No statistically significant difference in severity of COVID19 infection or mortality rate was found. The rate of asymptomatic, mild, moderate, severe/critical and fatal COVID19 infection was 11.4%, 37.1%, 22.8%, 11.4% and 17.1% respectively for the patients with autoimmune diseases and 17.8%, 45.8%, 10.9%, 6.8% and 18.4% respectively for the controls . Patients with autoimmune/inflammatory diseases seem not to develop a more severe COVID19 infection than controls. This article is protected by copyright. All rights reserved.

Early life encounters with stress can lead to long-lasting beneficial alterations in the response to various stressors, known as cross-tolerance. Embryonic heat conditioning (EHC) of chicks was previously shown to mediate resilience to heat stress later in life. Here we demonstrate that EHC can induce cross-tolerance with the immune system, attenuating hypothalamic inflammation. Inflammation in EHC chicks was manifested, following lipopolysaccharide (LPS) challenge on day 10 post-hatch, by reduced febrile response and reduced expression of LITAF and NFκB compared to controls, as well as nuclear localization and activation of NFκB in the hypothalamus. Since the cross-tolerance effect was long-lasting, we assumed that epigenetic mechanisms are involved. We focused on the role of ten-eleven translocation (TET) family enzymes, which are the mediators of active CpG demethylation. Here, TET transcription during early life stress was found to be necessary for stress resilience later in life. The expression of the TET family enzymes in the midbrain during conditioning increased in parallel to an elevation in concentration of their cofactor α-ketoglutarate. In-ovo inhibition of TET activity during EHC, by the α-ketoglutarate inhibitor bis-2-(5-phenylacetamido-1,3,4-thiadiazol-2-yl) ethyl sulfide (BPTES), resulted in reduced total and locus specific CpG demethylation in 10-day-old chicks and reversed both thermal and inflammatory resilience. In addition, EHC attenuated the elevation in expression of the stress markers HSP70, CRHR1, and CRHR2, during heat challenge on day 10 post-hatch. This reduction in expression was reversed by BPTES. Similarly, the EHC-dependent reduction of inflammatory gene expression during LPS challenge was eliminated in BPTES-treated chicks. Thus, TET family enzymes and CpG demethylation are essential for the embryonic induction of stress cross-tolerance in the hypothalamus.

Objective FMF is an autoinflammatory disease of genetic origin. Colchicine is the mainstay of treatment for the prevention of attacks and long-term complications but 5–10% of FMF patients are resistant to colchicine therapy. The aim of our study was to investigate the real-life safety and efficacy of anakinra in a cohort of patients with colchicine-resistant FMF. Methods In this retrospective study, patients treated with anakinra for colchicine-resistant FMF between 2010 and 2018 were identified using the computerized database of Sheba Medical Center and enrolled in the study. Data from structured clinical files were analysed to evaluate the efficacy and safety outcomes. To assess efficacy, we used the Global Assessment Score (GAS), a measure comprised of three different domains: number of attacks per month, duration of attacks and number of sites involved in the attacks. Reported adverse events were compiled. Results A total of 44 patients (24 female) were treated with anakinra. Of these patients, 75% were homozygous for the M649V mutation. The mean duration of treatment was 18 months. The GAS decreased significantly from 6.6 (IQR 5.3–7.8) before treatment to 2 (IQR 0–4.2) while on treatment (P Conclusion Treatment with anakinra is beneficial for the majority of colchicine-resistant FMF patients and is relatively safe.

In all vertebrates, hypoxia plays an important role in fetal development, driving vasculogenesis, angiogenesis, hematopoiesis, and chondrogenesis. Therefore, the ability to sense and respond to changes in the availability of oxygen (O2) is crucial for normal embryonic development as well as for developmental plasticity. Moderate levels of hypoxia trigger a regulated process which leads to adaptive responses. Regulation of angiogenesis by hypoxia is an important component of homeostatic control mechanisms that link the cardio-pulmonary-vascular O2 supply to metabolic demands in local tissues. Hypoxia leads to the activation of genes that are important for cell and tissue adaptation to low O2 conditions, such as hypoxia-inducible factor 1. Previous studies have shown a dose-response effect to hypoxia in chicken embryos, with lower and/or prolonged O2 levels affecting multiple mechanisms and providing a spectrum of responses that facilitate the ability to maintain O2 demand despite environmental hypoxia. In chicken embryos, mild to extreme hypoxia during embryogenesis improves chorioallantoic membrane and cardiovascular development, resulting in an increase in O2 carrying capacity and leading to developmental plasticity that may affect post-hatch chick performance and improve adaptation to additional environmental stresses at suboptimal environmental conditions.

This study evaluated temperature during preincubation and embryonic day 0 (E0) E0 to E5 of incubation on broiler embryo development and subsequent live performance. Freshly laid eggs from a single 41-wk-old Ross 708 broiler breeder flock produced on a single day were weighed individually for weight matching purposes, stored overnight, and assigned to 4 treatment combinations of 2 preincubation temperatures (23.9 or 29.4°C) × 2 E0 to E5 temperatures (38.1 or 37.5°C). The 29.4°C preincubation temperature decreased (P ≤ 0.05) yolk sac membrane (YSM) vasculature at E6 and E7, and increased (P ≤ 0.05) embryo weight and length but decreased (P ≤ 0.05) yolk sac weight (YSW) at E15. No subsequent main effects were observed. The 38.1°C incubation temperature increased YSM vasculature at E7, chorioallantoic membrane (CAM) vasculature at E8 and E10, and egg weight loss, embryo weight, and embryo length at E15 and chick length at E21 in the presence of reduced BW and YSW (P ≤ 0.05). This was followed by greater male BW at 35 d, as well as improved FCR in females 0 to 14 d and in males 15 to 35 d (P ≤ 0.05). Pectoralis major and minor yields were increased (P ≤ 0.05) at 50 d of age in males and females, respectively. There were no interactions observed with regards to broiler live performance and carcass yield, which probably negated the importance of the interactions observed for preincubation temperature by E0 to E5 incubation temperature that affected YSM vasculature, CAM vasculature area, egg weight loss, embryo weight, yolk sac weight, and chick length.

Previous studies demonstrated that in ovo photostimulation with monochromatic green light increases body weight and accelerates muscle development in broilers. The mechanism in which in ovo photostimulation accelerates growth and muscle development is not clearly understood. The objective of the current study was to define development of the somatotropic axis in the broiler embryo associated with in ovo green light photostimulation. Two-hundred-forty fertile broiler eggs were divided into 2 groups. The first group was incubated under intermittent monochromatic green light using light-emitting diode (LED) lamps with an intensity of 0.1 W\m2 at shell level, and the second group was incubated under dark conditions and served as control. In ovo green light photostimulation increased plasma growth hormone (GH) and prolactin (PRL) levels, as well as hypothalamic growth hormone releasing hormone (GHRH), liver growth hormone receptor (GHR), and insulin-like growth factor-1 (IGF-1) mRNA levels. The in ovo photostimulation did not, however, increase embryo's body weight, breast muscle weight, or liver weight. The results of this study suggest that stimulation with monochromatic green light during incubation increases somatotropic axis expression, as well as plasma prolactin levels, during embryonic development.

Light perception in birds is composed of the retina and extraretinal sites, located in the brain. Previous studies indicate that selective photostimulation of the eye decreased reproductive performance, whereas extraretinal photostimulation increases it. Differential photostimulation of the retina and extraretinal sites is based on the retina's sensitivity to green wavelengths and on the red wavelengths' ability to penetrate body tissues. We previously found that short-day exposure to green light within a long-day exposure to red light increases reproductive activity in female turkeys and broiler breeder hens. Furthermore, in a study conducted recently in our laboratory, we found that blue light repressed expression of green light receptor in the retina, which can further enhance reproduction activity in broiler breeders. Here, we examined the “brain activate/eye deactivate” hypothesis on gonadal axis activity and reproductive performance in a broiler breeder flock. Broiler breeder hens and roosters (ROSS 308) were divided into 5 light-treatment groups (controlled rooms with light-emitting diodes [LED] lamps): warm white (control), long-day (14 h) red (630 nm) and short-day (6 h) green (514 nm) (red-green), long-day green and short-day red (green-red), long-day red and short-day blue (456 nm) (red-blue), and long-day blue and short-day red (blue-red). Birds were reared from 20 to 55 wk of age. Eggs were collected daily. Weekly egg production calculated. All eggs were incubated for fertility and hatchability examination. Blood was drawn monthly for plasma analysis. At 35 wk of age (after peak production) and 55 wk of age (end of the experiment), 10 hens from each treatment group were euthanized, and selected tissues and glands were taken for gene expression trials. Providing long-day red light to extraretinal photoreceptors while maintaining retinal photoreceptors on short day with blue or green light significantly improved reproductive activities, manifested by elevated egg production and gonadal axis activity compared with Controls and primary breeder recommendations. Long-day green light reduced reproductive performances. We suggest that targeted photostimulation enhances reproductive and gonadal axis activities in broiler breeders.

Background:Diagnostic delay is a major challenge in axial spondyloarthritis (axSpA) with an extended interval of 8-10 years in Europe and 14 years in the United States between symptom onset and disease diagnosis (1, 2).Objectives:To assess the delay in the diagnosis of axSpA over time in a real world axSpA cohort diagnosed in the last 3 decades and to evaluate factors associated with this delay.Methods:A cohort of axSpA patients was recruited from a national multicenter registry of inflammatory arthritis. This cohorts’ demographic, clinical and diagnostic variables were studied. The diagnostic delay was defined as the time interval between the year of first symptom and year of diagnosis. The mean and median diagnostic delay were calculated. A survival analysis was performed evaluating the association between the demographic, clinical and diagnostic variables on the diagnostic delay.Results:Of the 373 axSpA patients in the registry, 198 (47%) are men. Ankylosing spondylitis fulfilling New York criteria was diagnosed in 73% of the patients. HLA-B*27 positivity was found in 64% of patients. The majority of the patients (63%) reported symptom onset between the age of 21-45, 21% before the age of 21 and 16% after the age of 45. Nine percent were diagnosed before the age of 21, 28% between 21-30, 23% between 31-40, 21% between 41-50 and 18% after the age of 50. One hundred and ten patients were diagnosed before 2000, 133 between 2001-2009 and 130 between 2010-2020. The mean and median delay in diagnosis was 9.1, 6 (±8.4) years when diagnosed before 2000, 5, 4 (±4.1) years when diagnosed 2001-2009, and 2, 1 (±1.5) years when diagnosed 2010-2020, respectively (graph 1). The only variable which was found to be associated with a shorter delay was the interval between symptom onset and first rheumatology consult: HR of 5.86 (4.3-8, pConclusion:Delay in axSpA diagnosis has significantly improved in this real-world cohort during the last decade. The most significant factor associated with a faster diagnosis was the time of the first rheumatology consult relative to symptom onset. Increasing the awareness of disease manifestations and early referral to a rheumatology service can improve the diagnosis delay of axSpA.References:[1]Sorensen J, Hetland ML, all departments of rheumatology in D. Diagnostic delay in patients with rheumatoid arthritis, psoriatic arthritis and ankylosing spondylitis: results from the Danish nationwide DANBIO registry. Ann Rheum Dis. 2015;74(3):e12.[2]Deodhar A, Mittal M, Reilly P, Bao Y, Manthena S, Anderson J, et al. Ankylosing spondylitis diagnosis in US patients with back pain: identifying providers involved and factors associated with rheumatology referral delay. Clin Rheumatol. 2016;35(7):1769-76.Graph 1.The improvement in the delay in diagnosis of axial spondyloarthropathy over the last 3 decadesDisclosure of Interests:None declared.

Background The heat tolerance test (HTT) is a standardized physiological test that constitutes one of the considerations in the Israel Defence Forces (IDF) for return to duty after a heat injury. The HTT consists of a 2 h controlled exercise-heat stress with a threshold of maximal rectal temperature (Tc) and heart rate (HR) values above which subjects are referred to as heat intolerant; the dynamics of the HR and Tc during the test, which tend to plateau during the 2nd hour of the test, is also considered. Since “tendency to plateau” is a subjective measure, this study aimed to quantify the tendency to plateau during a HTT. Material and methods The physiological results of 102 HTT subjects (83 normal and 19 heat-intolerant) served as the database for analysis. The first 28 subjects, who were considered heat tolerant (HT) by an experienced examiner, served to evaluate a “normal” dynamic of Tc and HR during a HTT. Then, we applied the results on seven heat tolerant and seven heat intolerant (HI) subjects in order to determine which of the two variables (dTc or dHR) in different time intervals (t120–0, t60–0, t120–60, and t120–100) may best distinguish heat tolerant from heat intolerant subjects. During the 3rd stage of the study 60 random test results (post factum: 48 heat tolerant and 12 heat intolerant subjects) were evaluated. Post-hoc results of heat tolerance determined by dTc were compared to the expert diagnosis of the test. Results A rise of less than 0.45 °C in Tc during the 2nd hour of the HTT was found acceptable to define a tendency to plateau of the Tc with a 100% sensitivity and specificity. We did not find a numerical value of HR increase over time during the HTT acceptable to define a tendency of the HR to plateau. Conclusion During the last hour of the heat tolerance test, there is a tendency to plateau in Tc in heat tolerant individuals. It is concluded that a rise in Tc of less than 0.45 °C during this period (Tc120–60) can be used as a supporting measure to distinguish between heat tolerant and heat intolerant individuals.

The significance and importance of the preincubation and incubation temperatures for broiler chickens has been elucidated by altering normal incubation conditions to study the effects on embryo development. Furthermore, only recently has convincing evidence that temperature could influence the sex ratio of avian offspring become available. The objective of this study was to elucidate the effects of temperature before or during (or both) the sex determination period of incubation on hatchability, apparent sex ratio, growth and development posthatching, and secondary sexual phenotypic characteristics. Two experiments were conducted in winter and summer using Cobb 500 fertile eggs that had been stored for 4 and 9 d, respectively. Four treatments of 180 eggs each were applied: control, preheating (Pre) 30.2°C for 12 h before incubation, heating (38.1°C) the embryos between embryonic d 0 (E0) and E5 (M) of incubation, and a combination of both (Pre+M). All 3 thermal treatments increased early embryonic deaths, but improved hatchability in both experiments. The point of 50% hatchability was achieved more rapidly in the treated eggs. The BW of males and females at 35 d of age in both experiments was numerically or significantly greater in the broilers that had been exposed to thermal treatments, which was coincident with a similar trend for increased relative breast muscle weight. Secondary sexual characteristics (comb, wattles, testes in males) were also affected by thermal treatments, being heavier in most cases, which may be attributed to the finding that the 3 thermal treatments resulted in numerically or significantly increased plasma testosterone concentration in both sexes and experiments. Differences in the level of significance between the experiments probably related to the length of storage period and the season in which each experiment took place. It was concluded that thermal treatments preincubation or during the sex determination period of incubation had, in general, a positive effect on hatchability, growth performance, and secondary sexual characteristics of broiler males and females, probably caused by the increase of plasma testosterone concentration in both sexes.

INTRODUCTION: Exertional heat stroke (EHS) is the most dangerous heat-related injury. EHS may be followed by a state of heat intolerance. The Israeli Defense Forces (IDF) performs heat tolerance tests (HTT) to all heat injury victims 6-8 wk following injury as part of the "return to duty" process. The HTT protocol and normal values are based on vast experience with young healthy men. Over the last several years an increasing number of female soldiers have been joining combat units. Heat injuries and, thus, HTT among women have become more frequent. Due to potential gender-related physiological and thermoregulatory differences, we examined the necessity for validating the HTT protocol for women. METHODS: Retrospective physiological data from our database on heat injuries and HTT between the years 2008-2010 was compared between 9 female subjects and 170 male subjects who had similar background characteristics. RESULTS: Defining heat intolerance as peak rectal temperature > 38.5 degrees C, peak heart rate > 150 bpm, or the inability to reach equilibrium in these values, we diagnosed 67% of the female subjects as heat intolerant. In the male subjects, only 26% were diagnosed as heat intolerant using the same criteria. CONCLUSIONS: Using the standard HTT criteria, women are more frequently diagnosed as heat intolerant than men. Further studies should be performed in order to re-evaluate the normal values for a "female HTT" in order to optimize the process of safe return to duty of female heat injury victims and to minimize false positive results among female soldiers. Language: en

Background:Smoking has a thermogenic effect and is associated with low physical performance. Nevertheless, a direct, quantitative effect of acute smoking on exercise heat tolerance has not been reported.Methods:Sixteen healthy young male volunteers, eight cigarette smokers, and eight non-smokers participated in the study. All subjects performed a maximal oxygen consumption test (VOResults:There was no significant effect of nicotine exposure on physiological performance and heat tolerance in the non-smokers group. In the smokers group, cigarette smoking, but not nicotine ingestion, resulted with higher heart rate (by 9±9 bpm) at the end of the HTT (pConclusions:According to this preliminary study, cigarette smoking and nicotine ingestion increase the physiological strain during a HTT in smokers. Acute smoking may, therefore, increase heat intolerance and the risk to heat injuries.

Exertional heat stroke (EHS) is a common clinical problem for both athletes and warriors; however, evidence-based guidance for return-to-play/duty (RTP/RTD) decisions is limited. Heat tolerance testing (HTT) has been proposed as a potential tool that, when combined with appropriate clinical information, may assist in RTP/RTD decisions. However, currently, no standard of care is available for performing HTT. The Israeli Defense Forces (IDF) HTT protocol, which was developed over decades of careful research, has proven useful for IDF warriors and is utilized by other militaries to assist in RTD decisions. The present case studies are used to discuss the efficacy of the IDF HTT in determining RTD for two warriors who experienced EHS. Strengths and limitations of the IDF HTT, along with current and potential roles in clinical decision-making and in future thermoregulation research, are discussed.

A marked increase in the overall cesarean delivery (CD) rate of twin pregnancies has recently been observed. We sought to examine the obstetrical characteristics of patients who chose a non-indicated CD and to investigate the trends in the rate of CD for maternal request over a 5 years period. A cross sectional retrospective study of twin pregnancies, compared obstetrical characteristics between patients who chose a non-indicated CD and those who delivered vaginally. Deliveries occurred during 2006 and 2011 in a regional tertiary medical center. Patients with any indication for a CD were excluded. A multivariate logistic regression was used to control for confounders. 525 twins were included at the study, 61.7 % (n = 324) were delivered by CD. Of these, 28.7 % (n = 93) were non-indicated. Between the years 2006 and 2011, there was a significant decrease in the rate of non-indicated CD (34.9 vs 23.8 %, OR = 0.58, 95 % CI 0.35–0.94, P = 0.02). Deliveries after fertility treatments or a previous CD had a higher rate of non-indicated CD (51.6 vs. 27.4 %, P

The chick embryo employs several adaptive responses to hypoxic challenges, affecting both metabolism and oxygen (O2) transport. The present study assessed the effects of hypoxic conditions (17% O2) during the plateau phase on embryonic metabolic rate, cardiovascular parameters, and development up to hatching. The study was divided into 2 experiments: (1) Control; 17% O2 for 6h/d on E16-E18 (6H), and 17% O2 for 12h/d on E16-E18 (12H), and (2) Control; 12H, and 17% O2 continuously for 72h on E16-E18, (72H). Hypoxic embryos exhibited a significant increase in heart rate and an upward trend starting on E17 in hematocrit and hemoglobin levels. We observed a decrease in metabolism in 12H and 72H embryos during the plateau period; their oxygen consumption as well as yolk consumption were lower compared to Control and they hatched with a significantly lower body temperature, indicating lower heat production. There was no evidence of adaptation or long-term effects of exposure to 17% O2 for 6h/d. Exposure to 72h of hypoxic conditions led to significant physiological changes and had a detrimental influence on embryonic development and growth. In contrast, exposure to 12h/d produced moderate hypoxic changes, which helped the embryo to cope with the stress without significant influences on its growth and development. The decrease in metabolism may represent a metabolic adaptation through a decrease in resting metabolic rate and lower heat production. Such alterations may affect post-hatch performance and energy allocation between maintenance and growth, especially under stress when there is increased oxygen demand.

Heat-related injuries, and specifically exertional heat stroke, are a significant occupational risk in the armed forces, especially for those soldiers who are rapidly deployed from a temperate climate region to hot climate regions. Traditionally, adaptation to heat was considered as a matter of physiological adaptation. It is clear today that these injuries are mostly avoidable when applying proper education and behavioral adaptations. Education on behavioral adaptation for the prevention of heat injuries should be targeted at the individual and the organization level. This article summarizes the issue of proper preventive measures that should be taken to avoid, or at least minimize, the risk of exertional heat related injuries during military operations and training.

Previous studies on broilers conducted in our laboratory showed that intermittent thermal manipulation (TM) of 39.5 °C every 12 h during embryonic days E7–E16 improved thermoregulative parameters in the embryo and post-hatch, as well as the broilers' ability to cope with heat challenge at marketing age. The aim of this study was to investigate the effect of intermittent TM of 39.5 °C (65% RH) for 12 h/d (12 H), during E7–E16, on post-hatch performance and thermoregulation under both optimal and hot conditions. Chicks from the control and TM treatments were raised under “regular” conditions until 21 d of age. Then, each treatment was divided into 2 sub-treatments (growth conditions) – optimal conditions (25 °C) and hot conditions of 32 °C for 12 h/d – until 35 d of age. Under optimal conditions, no difference in growth rates was found between TM and control throughout the growth period, but TM had significantly larger relative breast muscle weight, and on days 13, 25, and 35 breast muscle in the TM treatment contained a higher percentage of large-diameter fibers than controls. Consequently, average fiber diameter was significantly larger in TM than in control. Relative weight of the abdominal fat pad was significantly lower in the TM treatment than in control, under both environmental conditions. Hot conditions negatively affected growth rates of broilers in both treatments. The TM chickens showed no body-weight advantage over controls, nevertheless, feed conversion between days 21 and 35 was lower in the TM chickens of both sexes than in controls. This could be attributed to lower body temperature and lower plasma thyroid hormone levels found in the TM chickens, indicating lower heat production rates. Greater muscle growth and lower relative weight of abdominal fat pad were found in the TM chickens than in controls, under hot conditions. It can be concluded that TM during embryonic development improves performance as well as thermoregulation.

The goals were to elucidate the effects of ventilation rate (VR) coupled with exposure to constant 20 °C or to diurnal temperature cycling on young turkeys' performance and sensible heat loss (SHL). In three experiments male British United Turkeys (BUT), from 3 to 6 weeks of age, were exposed to constant 20 °C, or to 35/25 °C or 30/20 °C diurnal temperature cycling, all at 50% RH and with VR (expressed as air velocity (AV)) ranging from 0.8 to 3.0 m s−1. The 2nd and 3rd of these experiments included a positive control at constant 30 °C and VR of 1.5 m s−1. Weight gain, feed intake, and feed efficiency were measured or calculated, as appropriate; SHL was calculated from measured surface temperature, and plasma concentrations of triiodothyronine (T3) was determined in the 1st experiment. Changes of VR at constant 20 °C did not affect performance, but total SHL increased significantly with increasing VR. Under the 35/25 °C regime a significantly higher BW was recorded, with a similar pattern of feed efficiency, when VR during the hot part of the cycle was 1.5 or 2.0 m s−1 than when it was 0.8 m s−1. In the 3rd experiment, BW in the 35/20 °C treatment was significantly lower than that of the controls. In all experiments, turkeys maintained body temperature (Tb) within the normothermic range, and SHL varied with VR. It can be concluded that although diurnal temperature cycling reflects the natural situation, exposing young turkeys to constant 30 °C combined with optimal ventilation might yield the best performance results.

Under hot conditions, contemporary commercial broilers do not reach their full genetic potential for growth rate, body weight (BW), or breast meat yield because dissipation of their excessively produced internal (metabolic) heat is hindered by the feathers. Therefore, it was hypothesized that heat stress can be alleviated by using the naked-neck gene (Na) or the featherless gene (sc). The study consisted of 4 experimental genetic groups (fully feathered, heterozygous naked neck, homozygous naked neck, featherless), progeny of the same double-heterozygous parents (Na/na +/sc), and commercial broilers. Birds from all 5 groups were brooded together until d 21 when one-half of the birds from each group were moved to hot conditions (constant 35 degrees C), and the others remained under comfortable conditions (constant 25 degrees C). Individual BW was recorded from hatch to slaughter at d 45 and 52 at 25 and 35 degrees C, respectively, when breast meat, rear part, heart, and spleen weights were recorded. Body temperature was recorded weekly from d 14 to 42. Feather coverage significantly affected the thermoregulatory capacity of the broilers under hot conditions. With reduced feather coverage (naked-neck), and more so without any feathers (featherless), the birds at 35 degrees C were able to minimize the elevation in body temperature. Consequently, only the featherless birds exhibited similar growth and BW under the 2 temperature treatments. The naked-neck birds at 35 degrees C showed only a marginal advantage over their fully feathered counterparts, indicating that 20 to 40% reduction in feather coverage provided only limited tolerance to the heat stress imposed by hot conditions. Breast meat yield of the featherless birds was much greater (3.5% of BW, approximately 25% advantage) than that of their partly feathered and fully feathered counterparts and the commercial birds under hot conditions. The high breast meat yield (at both 25 and 35 degrees C) of the featherless broilers suggests that the saved feather-building nutrients and greater oxygen-carrying capacity contribute to their greater breast meat yield. Because of these results, further research on genetically heat-tolerant broilers should focus on the featherless phenotype.

The continuous selection for rapid growth has been accompanied by an increasing occurrence of ascites syndrome (AS), which develops in broilers failing to supply the increasing demand for O2 in their bodies. Moderate heritability has been reported for AS in broiler populations, suggesting that selection against AS is feasible. However, direct selection based on AS mortality requires exposure of candidate birds to AS-inducing conditions (AIC), which hinder selection for performance traits. Noninvasive indicators of AS, expressed under standard husbandry, may facilitate the integration of selection against AS into breeding programs. This study was designed to look for differences in heart rate, hematocrit, O2 saturation of hemoglobin in arterial blood (SaO2), BW, and weight gain, all measured at early ages under standard brooding conditions, between birds that later developed AS and those that remained healthy under AIC, and to estimate the heritability of these AS-related parameters and their genetic correlation with the tendency of broilers to develop AS. The experimental population was derived from a broiler dam line. Male progeny of 34 half-sib sire families were reared under standard brooding conditions to 19 d of age, then under an AIC protocol consisting of housing in individual cages, cool air high-speed ventilation, and growth enhancement using high-energy pelleted feed and 23 h/d of light. Birds were necropsied upon mortality or at the end of the trials and were recorded as being susceptible, with manifestations of AS (SUS), or resistant and healthy (RES). About 44% developed AS, confirming the efficacy of the novel AIC protocol. The SUS and RES chicks did not differ in BW and weight gain up to 19 d of age, suggesting that there was no association between AS susceptibility and rapid early growth. The SUS chicks exhibited lower SaO2 and heart rate than the RES chicks. Moderate heritability was estimated for all traits, but only SaO2 exhibited consistently significant genetic correlation (−0.5) with AS, suggesting that it may serve as an early indicator for selection against AS, albeit with a limited efficacy.

Morlet wavelets of the meridional component of daily radiosonde wind observations above four West Africa stations were constructed for May–September seasons, 1950–84, at three vertical levels. The passage of African wave disturbances (AWDs) at each station was detected as statistically significant wavelet amplitudes within two spectral bands. The detected AWD activity, or lack of it, was compared with the precipitation record at each station. Results demonstrate that AWDs account for only a proportion of the seasonal rainfall, implying that other precipitation triggers are also important. In addition, the analysis finds that many AWD traversals fail to initiate heavy rainfall at the selected stations. At Niamey, the average precipitation amount per wave had a positive trend between 1953 and 1978. With few exceptions, seasonal precipitation totals were not correlated with the number of days on which AWDs were detected. Although the seasonal average precipitation amount per AWD day exhibited a positive trend at Niamey between 1953 and 1978, there was no corresponding interannual trend in total seasonal precipitation. Copyright © 2003 Royal Meteorological Society

Exertional heat stroke (EHS) is the most complicated and dangerous amongst heat injuries that can lead to irreversible injury and even death. Early diagnosis and treatment are therefore crucial determinants of the patient's prognosis. The following case report depicts a soldier who presented primarily with confusion and behavioral changes during physical exercise and later lost consciousness. He was misdiagnosed by the field physician as suffering from supraventricular tachycardia, was treated as such and only diagnosed as suffering from EHS later in the emergency room. Our main aims are: to highlight the possibility of misdiagnosis of EHS even among trained physicians, to describe the main symptoms of EHS, and to emphasize the importance of early diagnosis and proper treatment. Language: en

The study examines the differential influence of four types of conflict—two physical conflicts and two social conflicts—on the improvement of the ability to solve balance problems. A total of 395 subjects, consisting of preschoolers, 3rd, and 5th graders, participated in three sessions: the pre-test, the intervention in which visual, kinesthetic, peer, or child-adult conflicts were presented, and the post-test. In each of the sessions the subjects were required to solve balance problems based on prototype problems employed by Siegler (1976). The ” ndings indicate that the kinesthetic conflict is the most effective in promoting the consideration of the distance dimension at the preschool age and that child-adult conflict is the most effective in promoting the coordination of weight and distance dimensions at school age. In addition, peer conflict was found to be significantly effective but only in 5th grade. In conclusion, the results suggest that the effectiveness of cognitive conflicts depends on both the demands of the task and the developmental stage of the child.

The purposes of this report are to review and discuss the issue of recurrent exertional rhabdomyolysis (ER), the return to physical activity after ER, and the possible causes of recurrence, with special consideration to metabolic myopathies and the possibility of an acquired post-ER myopathy. We discuss the medical investigation required prior to return to physical activity after an episode of ER and suggest two possible mechanisms for recurrence of ER in the absence of a known cause: premature return to activity and an acquired post-ER muscular disorder. We also emphasize the need to create proper guidelines for return to physical activity after ER and, for further investigation, the possible mechanisms of ER recurrence in patients without a known metabolic myopathy.

Reduced oxygen availability to the tissues (hypoxia) poses numerous challenges to animal life. Hypoxia occurs as a result of diminished partial pressure of oxygen, such as occurs with increasing altitude, or reduced oxygen percentage in the air capillaries of the lung. The oxygen partial pressure drops by approximately 7 mm Hg, i.e, approximately 2.5% in the case of atmospheric oxygen, for each 1,000 m increase in altitude, and thereby reduces the amount of oxygen available to the hemoglobin in red blood cells as blood passes through the lung.

Embryo development is a dynamic process, determined by both the genetic background of the organism and the environment in which it develops. Environmental alterations during an organism's embryogenesis may induce changes in the development of some physiological regulatory systems, thereby causing permanent phenotypic changes in the embryo. The present study aimed to assess the effect of 17% O2 concentration during chorioallantoic membrane (CAM) development on a) CAM development, b) cardiovascular parameters, and c) embryo development postexposure and up to hatch. Two replicated trials, each with 840 fertile Cobb eggs, were conducted. At embryonic d 5 (E5) eggs were divided into 2 treatments: 1) control, and 2) 17% O2 concentration for 12 h/d from E5 through E12 (12H). The 12H embryos exhibited a clear and significant increase in the vascular area of the CAM, which grew to 6.8% larger than that of the control. Hematocrit and hemoglobin levels, as measured on E13 and E14, increased in response to the hypoxic treatments, but these differences were not maintained subsequently. Heart rate and relative heart weight were not affected by hypoxic exposure, but eggshell temperature in the 12H treatment was higher than that of the control, indicating higher heat production, which is consistent with the elevated plasma concentrations of triiodothyronine and thyroxin and with the enhanced oxygen consumption and residual yolk intake rate that followed exposure to hypoxic conditions. These findings indicate that embryos adapted to hypoxic condition enhance angiogenesis processes, which subsequently increase their blood oxygen-carrying capacity, enabling the increase of oxygen consumption, which positively affects their growth development and maturation compared with the control embryos. Such alterations may affect posthatch performance and the ability of broilers cardiovascular system to meet elevated oxygen demand.

As an interdisciplinary organization dedicated to advancing the science and practice of nutrition support therapy, the American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.) works vigorously to support quality patient care, education, and research in the fields of nutrition and metabolic support in all healthcare settings. To promote safe and effective patient care by nutrition support practitioners, the A.S.P.E.N. Board of Directors published “Guidelines for the Use of Parenteral and Enteral Nutrition in Adult and Pediatric Patients” in 1993 and 2002. The format and methodology of the Clinical Guidelines (CG)s have changed over time, as a result of A.S.P.E.N.’s on-going efforts to improve the clarity and usefulness of the guidelines. The Institute of Medicine (IOM) has recently redefined Clinical Practice Guidelines as “statements that include recommendations intended to optimize patient care that are informed by a systematic review of evidence and an assessment of the benefits and harms of alternative care options.” To be trustworthy, IOM states that CGs should be based on a systematic

Background: Due to the high prevalence of obesity in adults, nutrition support clinicians are encountering greater numbers of obese patients who require nutrition support during hospitalization. The purpose of this clinical guideline is to serve as a framework for the nutrition support care of adult patients with obesity. Method: A systematic review of the best available evidence to answer a series of questions regarding management of nutrition support in patients with obesity was undertaken and evaluated using concepts adopted from the Grading of Recommendations, Assessment, Development and Evaluation working group. A consensus process, that includes consideration of the strength of the evidence together with the risks and benefits to the patient, was used to develop the clinical guideline recommendations prior to multiple levels of external and internal review and approval by the A.S.P.E.N. Board of Directors. Questions: (1) Do clinical outcomes vary across levels of obesity in critically ill or hospita...

Pediatricians in the greater Chicago area were surveyed to probe their awareness and approaches to management of dental caries in early childhood. A total of 298 pediatricians (21 % of those surveyed) responded to the questionnaire. Ninety-five percent of the respondents stated they examined their patients' teeth; 85% considered dental examinations part of their responsibility for children under 3 years of age. However, our data suggest that many pediatricians are unaware of the decay and the dietary patterns associated with tooth decay in early childhood. Although 96% of the respondents referred patients to a dentist when decay was diagnosed, analysis of diet and dietary counseling were performed by only 61 % and 65% of the respondents, respectively Recommendations for preventive measures that can be adopted by pediatricians are offered.

Some of the challenges faced by neonatal turkeys include weakness, reduced feed intake, impaired growth, susceptibility to disease, and mortality. These symptoms may be due to depleted energy reserves after hatch and an immature digestive system unable to replenish energy reserves from consumed feed. To better understand enteric development in turkeys just before hatch, a new method was used to identify the patterns of intestinal gene expression by utilizing a focused microarray. The duodenums of 24 turkey embryos were sampled on embryonic day (E)20, E24, E26, and hatch (E28). The RNA populations of 96 chosen genes were measured at each time point, from which 81 significantly changed (P < 0.01). These genes were clustered by gene expression pattern similarity into 4 groups. The expression pattern of hormone receptors revealed that intestinal tissues may be less responsive to growth hormone, insulin, glucagon, and triiodothyronine during the last 48 h before hatch, when developmental emphasis switches from cell proliferation to functional maturation. Based on gene expression patterns, we concluded that at hatch, poults should have the capacity to 1) digest disaccharides but not oligopeptides, due to increased expression of sucrase-isomaltase but decreased expression of aminopeptidases and 2) absorb monosaccharides and small peptides due to high expression of sodium-glucose cotransporter-4 and peptide transporter-1.

Healthcare professionals often face clinical and ethical challenges when charged with making decisions related to provision or lack of provision of artificial nutrition and hydration. The intent of this review is to supply a framework of clinical practices, ethical principles, legal precedents, and professional guidelines that will impart information and can assist decision making regarding artificial nutrition and hydration. Comprehensive understanding of the theory and practice of informed consent for competent adults, decisionally incompetent adults, and minors is necessary for making valid clinical judgments and for guiding patients and their families or surrogates in choosing options related to initiating, withholding, or withdrawing artificial nutrition and hydration. The framework offered in this review can serve as a basis for evaluation of appropriateness of artificial nutrition and hydration in 3 common conditions in which decision making is particularly challenging: terminal illness, advanced dementia, and a persistent vegetative state. The framework facilitates guidance for institutional policy makers and individual nutrition support professionals dealing with situations in which personal values often create ethical dilemmas related to artificial nutrition and hydration and its utility.

Ascites syndrome (AS) is manifested in flocks of contemporary broilers that are allowed to fully manifest their genetic potential for rapid growth. After successful selection, a pair of divergent lines was established, AS-susceptible (AS-S) and AS-resistant (AS-R). These lines facilitate comparisons between genetically resistant and susceptible healthy young broilers when reared under standard brooding conditions (SBC). The aim of the present study was to look for predictive indicators for AS susceptibility by comparing relevant physiological parameters in the AS-S and AS-R lines under SBC and after exposure to extreme ascites-inducing conditions (AIC). In this design, a trait differing significantly between the 2 lines under SBC is expected to be a reliable indicator for selection against AS susceptibility in breeding stocks when reared under noninducing conditions. Males from the AS-S and AS-R lines were reared together under SBC to 19 d of age, then under the AIC protocol. Cumulative incidence of AS mortality was 93.2% in the AS-S line and only 9% in the AS-R line, confirming the genetic divergence between the lines. Exposure to AIC enhanced the imbalance between oxygen demands and supply in the AS-S birds and induced differences in blood parameter level between the 2 lines. The AS-S birds exhibited elevated hematocrit and red blood cell counts and a decline in oxygen saturation in the arterial blood. No difference in hemoglobin concentration was found, but calculation of hemoglobin content per 1,000 red blood cells revealed a significant reduction in hemoglobin content in the AS-S birds. Under SBC, there were no significant differences between the lines for hematocrit, red blood cell count, hemoglobin concentration, hemoglobin count per 1,000 red cells, and blood oxygen saturation. However, heart rate during the first week of life was significantly higher in the AS-S birds than in the AS-R birds on d 1 and 7, suggesting that high heart rate may potentially serve as an early criterion for selection against AS susceptibility.

The high growth rate (GR) of contemporary broilers is driven by high rate of feed intake and metabolism. Because of the consequent high oxygen demand, especially when coupled with exposure to high altitude or low temperatures, some broilers fail to regulate oxygen supply and develop the ascites syndrome (AS), which leads to mortality and economic losses. Because of the association between high GR, oxygen demand, and AS, it has been suggested that AS is induced by high GR. If true, further GR enhancement should be avoided because it will increase the proportion of AS-susceptible individuals in contemporary stocks. An alternative hypothesis claims that AS is associated with high actual GR only because the latter increases oxygen demand and that there are genetically AS-resistant broilers that do not develop AS, even when exhibiting high GR. These hypotheses were tested in trials in the years 2002 and 2006, with broilers differing in potential GR: contemporary fast-growing commercial lines and an experimental line derived from commercial broilers in 1986, and (in 2002 only) divergently selected AS-susceptible and AS-resistant lines. A protocol of high-challenge ascites-inducing conditions (AIC) from d 19 was used to distinguish between AS-susceptible and AS-resistant individuals and to determine their GR up to this age. The difference in AS incidence between the divergent lines (93.9 vs. 9.5%) was not explained by the 5% difference in their GR, thus indicating a lack of genetic correlation. In the broiler lines, AS incidence was 31 and 47% in 2002 and 2006, respectively, and 32% in the 1986 slow-growing line. Most broilers that remained healthy under the high-challenge AIC exhibited the same early GR and BW as those that later developed AS. These results, and the relatively high incidence of AS in the slow-growing line, indicate that there is very little, if any, direct genetic association between AS and genetic differences in potential GR, and suggest that AS-resistant broilers can be selected for higher GR and remain healthy even under AIC.

Oxygen is one of the critical determinants of appropriate embryonic and fetal development, including cardiogenesis. When the demand of tissues for oxygen exceeds oxygen supply, hypoxic conditions develop. In the developing embryo, hypoxia is associated with increased fetal mortality, cerebrovascular anomalies, cardiovascular dysfunction, and altered angiogenesis. Tissue hypoxia may elicit a broad range of responses, many of which are dependent upon hypoxia-inducible transcription factors. Three genes that are stimulated by hypoxia-hypoxia-inducing factor subunit alpha-1, heme oxygenase, hypoxia upregulated protein 1, and cardiac troponin T, which is responsible for binding tropomyosin to regulate calcium binding and contractility of heart muscle-were examined in the embryonic heart of the chicken to determine if expression patterns were altered throughout development. On embryonic day (E) 7, all 3 hypoxic-induced genes were expressed at their highest levels, followed by a decrease from E7 to E19 followed by an increase between internal (E19) and external pipping (E20). The cardiac troponin T exhibited a similar expression level for E7 and E15 with a similar significant increase at E19 and E20. During these periods of development, significant changes in the primary gas exchange organs occur. Based on our observation of upregulation of these hypoxia response genes, it appears that tissue hypoxia is likely a normal component of embryonic development in the chicken based on the upregulation of hypoxia response genes.

Expected values, reference ranges, or reference limits are necessary to enable clinicians to apply analytical chemical data in the delivery of health care. Determination of references ranges is not straightforward in terms of either selecting a reference population or performing statistical analysis. In light of logistical, scientific, and economic obstacles, it is understandable that clinical laboratories often combine approaches in developing health associated reference values. A laboratory may choose to: 1. Validate either reference ranges of other laboratories or published data from clinical research or both, through comparison of patients test data. 2. Base the laboratory's reference values on statistical analysis of results from specimens assayed by the clinical reference laboratory itself. 3. Adopt standards or recommendations of regulatory agencies and governmental bodies. 4. Initiate population studies to validate transferred reference ranges or to determine them anew. Effects of external contamination and anecdotal information from clinicians may be considered. The clinical utility of hair analysis is well accepted for some elements. For others, it remains in the realm of clinical investigation. This article elucidates an approach for establishment of reference ranges for elements in human scalp hair. Observed levels of analytes from hair specimens from both our laboratory's total patient population and from a physician-defined healthy American population have been evaluated. Examination of levels of elements often associated with toxicity serves to exemplify the process of determining reference ranges in hair. In addition the approach serves as a model for setting reference ranges for analytes in a variety of matrices.

Serum concentrations of ALA and PBG have been measured in normal subjects, patients with AIP, and lead workers. Both porphyrin precursors are significantly increased in serum from porphyric patients, and serum ALA is elevated in lead workers. Endogenous clearance measurements, when compared with creatinine clearances, are consistent with significant tubular reabsorption of ALA and PBG under physiologic circumstances, and with an "overflow" mechanism for increased excretion in AIP or lead intoxication. Three of 8 porphyric patients showed an aminoaciduria; tyrosine was involved in 2, tryptophan in the other 3. Evidence to suggest a specific renal defect contributing to increased ALA excretion in chronic lead intoxication was not obtained.

The mechanism of polymerization of vinyl alkyl ethers has been discussed in Shostakovskii's monograph [1]. According to the monograph the polymerization of vinyl alkyl ethers is brought about by the action of an electrophilic agent, usually hydrogen chloride, and always involves the formation of an oxonium-ion complex. Shostakovskii used ferric chloride as a catalyst for the polymerization of vinyl butyl ether but even in this case he considered that polymerization is brought about by hydrogen chloride, which in his opinion is formed by the hydrolysis of ferric chloride [2]. This interpretation is not in accord with the facts and does not explain the extremely small expenditure of catalyst. For this reason an attempt was made in the present investigation to define by experimental means the role of ferric chloride in the polymerization of vinyl butyl ether and the effect of hydrogen chloride on this reaction.