205 research outputs found

    Influence of temperature and humidity manipulation on chicken embryonic development

    Get PDF
    BACKGROUND: Temperature and relative humidity (RH) are very important factors affecting embryo development, hatchability, and posthatch performance. This study aimed at characterizing embryonic metabolic and behavioural response to a harsh incubation environment generated by manipulations (elevations and drops) in these two key factors. This study was aimed at establishing patterns of metabolic and behavioural response, as well as mortality and the development of malformations, all of which can potentially be used in monitoring incubating operations and diagnosing problems with faulty equipment. RESULTS: Of all the parameters monitored throughout embryonic development the ones shown to be most affected were: albumen-weight to egg-weight ratio (AR); yolk-weight to egg-weight ratio (YR); embryo-weight to egg-weight ratio (ER); heart rate (HR); voluntary movements per minute (VMM); mortality rates; malformation prevalence and type. The most significant changes in the evolution of AR and YR throughout incubation involved delay and reduction in the amplitude of the expected drop in albumen and yolk levels, reflecting lower nutrient consumption by the embryo. ER tended to grow more slowly and remain lower than the established normal, especially in embryos challenged with temperature treatments. HR and VMM were considered to be strong indicators of embryonic stress, as all treatments applied resulted in elevated heart rate and decreased embryo movement. Mortality rates for both temperature-related treatments were higher during the first four days of incubation. Changes in relative humidity have produced less radical effects on mortality. Malformation rates were higher for embryos subjected to high incubation temperatures and were most prominently related to the abdominal wall, head, skull and limbs. Overall, manipulations in environmental (incubator) temperature during incubation produced more drastic changes in embryo development than humidity-related manipulations, especially where mortality and malformation rates were concerned. CONCLUSIONS: This paper describes changes in embryonic metabolism and behaviour, as well as in mortality and malformation rates, in response to manipulations in environmental temperature and relative humidity. Together with further studies, these patterns may prove helpful in the diagnosis of equipment malfunctions relating to temperature or relative humidity

    Immunohistochemistry studies on bovine squamous cell carcinoma morphological characterization of epidermal cell proliferation and differentiation markers and characterization of cytokeratins

    Get PDF
    Bovine Ocular Squamous Cell Carcinoma (OSCC) is a general designation for a group of primary neoplasias of keratinocytes arising from ocular tissues, especially the lids and particularly the third eye lid. OSCC has been diagnosed all over the world with high prevalence, being the most common bovine tumour and the one causing the most significant economic losses (Hamir & Parry, 1980; Dennis et al., 1985, Heeney & Valli, 1985; Wilcock, 1993). In Portugal, the frequency of these tumours is particularly high in the Azores, where in S. Miguel Island a large number of cattle affected with OSCC is rejected for consumption at slaughter. OSCC is the second most frequent neoplasia after urinary bladder tumours, representing 21% of all cases of rejection due to neoplasia (Pinto et al, 1996). Several reasons have been advanced to explain this situation namely the fact that animals stay in pasture all year around, with a prolonged exposition to day light and benefiting from few shelters. The ingestion of toxic plants present the pasture could also give rise to photosensitazation problems, either primary or due to hepatic toxicity, that could generate predisposing conditions to the development of OSCC

    Simple and efficient furfural production from xylose in media containing 1-Butyl-3-Methylimidazolium hydrogen sulfate

    Get PDF
    The acidic 1-butyl-3-methylimidazolium hydrogen sulfate ([bmim][HSO4]) ionic liquid was explored as both a reaction medium and a catalyst in the furfural production from xylose. Preliminary experiments were carried out at 100–140 °C for 15–480 min in systems containing just xylose dissolved in [bmim][HSO4] in the absence of externally added catalysts. More than 95% xylose conversion was achieved when operating at 120 or 140 °C for 300 and 90 min, respectively; but just 36.7% of the initial xylose was converted to furfural. Operation in biphasic reaction systems (in the presence of toluene, methyl-isobutyl ketone or dioxane as extraction solvents) at 140 °C under selected conditions resulted in improved furfural production (73.8%, 80.3%, and 82.2% xylose conversion to furfural for the cited extraction solvents, respectively)

    Sensitivity is not an intrinsic property of a diagnostic test: empirical evidence from histological diagnosis of Helicobacter pylori infection

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>We aimed to provide empirical evidence of how spectrum effects can affect the sensitivity of histological assessment of <it>Helicobacter pylori </it>infection, which may contribute to explain the heterogeneity in prevalence estimates across populations with expectedly similar prevalence.</p> <p>Methods</p> <p>Cross-sectional evaluation of dyspeptic subjects undergoing upper digestive endoscopy, including collection of biopsy specimens from the greater curvature of the antrum for assessment of <it>H. pylori </it>infection by histopathological study and polymerase chain reaction (PCR), from Portugal (n = 106) and Mozambique (n = 102) following the same standardized protocol.</p> <p>Results</p> <p>In the Portuguese sample the prevalence of infection was 95.3% by histological assessment and 98.1% by PCR. In the Mozambican sample the prevalence was 63.7% and 93.1%, respectively. Among those classified as infected by PCR, the sensitivity of histological assessment was 96.2% among the Portuguese and 66.3% among the Mozambican. Among those testing positive by both methods, 5.0% of the Portuguese and 20.6% of the Mozambican had mild density of colonization.</p> <p>Conclusions</p> <p>This study shows a lower sensitivity of histological assessment of <it>H. pylori </it>infection in Mozambican dyspeptic patients compared to the Portuguese, which may be explained by differences in the density of colonization, and may contribute to explain the heterogeneity in prevalence estimates across African settings.</p

    The Effect of Physical Activity Interventions on Glycosylated Haemoglobin (HbA1c) in Non-diabetic Populations: A Systematic Review and Meta-analysis

    Get PDF
    Introduction Epidemiological evidence suggests that physical activity has a positive effect on reducing glycated haemoglobin A1c (HbA1c) levels not only in diabetics, but also in healthy subjects. Moreover, a positive association of HbA1c levels with cardiovascular disease and mortality in non-diabetic populations has recently been reported. This is a protocol for a systematic review and meta-analysis aiming to estimate the effects of physical activity on glycaemic control measured by HbA1c levels in non-diabetic populations; and to determine which type of physical activity has a greater influence on glycaemic control. Methods and analysis The search will be conducted using MEDLINE, EMBASE, the Cochrane Library and Web of Science databases from inception to mid-2017. Randomised controlled trials, non-randomised experimental studies and controlled pre–post studies written in English, Portuguese, French or Spanish will be included. The Cochrane Collaboration’s tool and The Quality Assessment Tool for Quantitative Studies will be used to assess the risk of bias for studies included in the systematic review. Standardised pre–post intervention mean differences of HbA1c will be calculated as the primary outcome. Subgroup analyses will be performed based on the characteristics of physical activity intervention and population included in the studies. Ethics and dissemination This systematic review will synthesise evidence on the association of physical activity and HbA1c in non-diabetic populations. This study is important from the clinical and public health point because it will estimate the effect of physical activity on the glycemic control, and it will also examine which is the type of physical activity that should be recommended for preventing type 2 diabetes and its complications. The results will be disseminated by publication in a peer-reviewed journal. Ethical approval will not be required because the data used for this systematic review will be obtained from published studies and there will be no concerns about privacy

    The effects of physical activity interventions on glycated haemoglobin A1c in non-diabetic populations: a protocol for a systematic review and meta-analysis

    Get PDF
    Introduction Epidemiological evidence suggests that physical activity has a positive effect on reducing glycated haemoglobin A1c (HbA1c) levels not only in diabetics, but also in healthy subjects. Moreover, a positive association of HbA1c levels with cardiovascular disease and mortality in non-diabetic populations has recently been reported. This is a protocol for a systematic review and meta-analysis aiming to estimate the effects of physical activity on glycaemic control measured by HbA1c levels in non-diabetic populations; and to determine which type of physical activity has a greater influence on glycaemic control. Methods and analysis The search will be conducted using MEDLINE, EMBASE, the Cochrane Library and Web of Science databases from inception to mid-2017. Randomised controlled trials, non-randomised experimental studies and controlled pre–post studies written in English, Portuguese, French or Spanish will be included. The Cochrane Collaboration’s tool and The Quality Assessment Tool for Quantitative Studies will be used to assess the risk of bias for studies included in the systematic review. Standardised pre–post intervention mean differences of HbA1c will be calculated as the primary outcome. Subgroup analyses will be performed based on the characteristics of physical activity intervention and population included in the studies.This research received no specific grant from any funding agency in the public, commercial or not for profit sectors. IC-R is supported by a grant from the Universidad de Castilla-La Mancha (FPU13/01582). BP is supported by a grant from the Portuguese Foundation for Science and Technology (SFRH/BPD/108751/2015). CA-B and MG-M are supported by a grant from the Spanish Ministry of Ministry of Education, Culture and Sport (FPU13/03137 and FPU15/03847, respectively)

    A quadruplex qPCR for detection and differentiation of classic and natural recombinant Myxoma Virus Strains of leporids

    Get PDF
    Research Areas: Biochemistry & Molecular Biology ; ChemistryA natural recombinant myxoma virus (referred to as ha-MYXV or MYXV-Tol08/18) emerged in the Iberian hare (Lepus granatensis) and the European rabbit (Oryctolagus cuniculus) in late 2018 and mid-2020, respectively. This new virus is genetically distinct from classic myxoma virus (MYXV) strains that caused myxomatosis in rabbits until then, by acquiring an additional 2.8 Kbp insert within the m009L gene that disrupted it into ORFs m009L-a and m009L-b. To distinguish ha-MYXV from classic MYXV strains, we developed a robust qPCR multiplex technique that combines the amplification of the m000.5L/R duplicated gene, conserved in all myxoma virus strains including ha-MYXV, with the amplification of two other genes targeted by the real-time PCR systems designed during this study, specific either for classic MYXV or ha-MYXV strains. The first system targets the boundaries between ORFs m009L-a and m009L-b, only contiguous in classic strains, while the second amplifies a fragment within gene m060L, only present in recombinant MYXV strains. All amplification reactions were validated and normalized by a fourth PCR system directed to a housekeeping gene (18S rRNA) conserved in eukaryotic organisms, including hares and rabbits. The multiplex PCR (mPCR) technique described here was optimized for Taqman® and Evagreen® systems allowing the detection of as few as nine copies of viral DNA in the sample with an efficiency > 93%. This real-time multiplex is the first fast method available for the differential diagnosis between classic and recombinant MYXV strains, also allowing the detection of co-infections. The system proves to be an essential and effective tool for monitoring the geographical spread of ha-MYXV in the hare and wild rabbit populations, supporting the management of both species in the field.info:eu-repo/semantics/publishedVersio

    Evaluation of commercial myxomatosis vaccines against recombinant myxoma virus (ha-MYXV) in Iberian hare and wild rabbit

    Get PDF
    Research Areas: Immunology ; Research & Experimental MedicineThe recent emergence of a new myxoma virus capable of causing disease in the Iberian hare (Lepus granatensis) has resulted in numerous outbreaks with high mortality leading to the reduction, or even the disappearance, of many local populations of this wild species in the Iberian Peninsula. Currently, the available vaccines that prevent myxomatosis in domestic rabbits caused by classic strains of myxoma virus have not been assessed for use in Iberian hares. The main objective of this study was to evaluate the efficacy of commercial rabbit vaccines in Iberian hares and wild rabbits against the natural recombinant myxoma virus (ha-MYXV), bearing in mind its application in specific scenarios where capture is possible, such as genetic reserves. The study used a limited number of animals (pilot study), 15 Iberian hares and 10 wild rabbits. Hares were vaccinated with Mixohipra-FSA vaccine (Hipra) and Mixohipra-H vaccine (Hipra) using two different doses, and rabbits were vaccinated with the Mixohipra-H vaccine or the Nobivac Myxo-RHD PLUS (MSD Animal Health) using the recommended doses for domestic rabbits. After the vaccination trials, the animals were challenged with a wild type strain of ha-MYXV. The results showed that no protection to ha-MYXV challenge was afforded when a commercial dose of Mixohipra-FSA or Mixohipra-H vaccine was used in hares. However, the application of a higher dose of Mixohipra-FSA vaccine may induce protection and could possibly be used to counteract the accelerated decrease of wild hare populations due to ha-MYXV emergence. The two commercial vaccines (Mixohipra-H and Nobivac Myxo-RHD PLUS) tested in wild rabbits were fully protective against ha-MYXV infection. This knowledge gives more insights into ha-MYXV management in hares and rabbits and emphasises the importance of developing a vaccine capable of protecting wild populations of Iberian hare and wild rabbit towards MYXV and ha-MYXV strainsinfo:eu-repo/semantics/publishedVersio

    The impact of gender, puberty, and pregnancy in patients with POLG disease

    Get PDF
    OBJECTIVE: To study the impact of gender, puberty, and pregnancy on the expression of POLG disease, one of the most common mitochondrial diseases known. METHODS: Clinical, laboratory, and genetic data were collected retrospectively from 155 patients with genetically confirmed POLG disease recruited from seven European countries. We used the available data to study the impact of gender, puberty, and pregnancy on disease onset and deterioration. RESULTS: We found that disease onset early in life was common in both sexes but there was also a second peak in females around the time of puberty. Further, pregnancy had a negative impact with 10 of 14 women (71%) experiencing disease onset or deterioration during pregnancy. INTERPRETATION: Gender clearly influences the expression of POLG disease. While onset very early in life was common in both males and females, puberty in females appeared associated both with disease onset and increased disease activity. Further, both disease onset and deterioration, including seizure aggravation and status epilepticus, appeared to be associated with pregnancy. Thus, whereas disease activity appears maximal early in life with no subsequent peaks in males, both menarche and pregnancy appear associated with disease onset or worsening in females. This suggests that hormonal changes may be a modulating factor

    Simplifying the clinical classification of polymerase gamma (POLG) disease based on age of onset; studies using a cohort of 155 cases

    Get PDF
    Background: Variants in POLG are one of the most common causes of inherited mitochondrial disease. Phenotypic classification of POLG disease has evolved haphazardly making it complicated and difficult to implement in everyday clinical practise. The aim of our study was to simplify the classification and facilitate better clinical recognition. / Methods: A multinational, retrospective study using data from 155 patients with POLG variants recruited from seven European countries. / Results: We describe the spectrum of clinical features associated with POLG variants in the largest known cohort of patients. While clinical features clearly form a continuum, stratifying patients simply according to age of onset—onset prior to age 12 years; onset between 12 and 40 years and onset after the age of 40 years, permitted us to identify clear phenotypic and prognostic differences. Prior to 12 years of age, liver involvement (87%), seizures (84%), and feeding difficulties (84%) were the major features. For those with onset between 12 and 40 years, ataxia (90%), peripheral neuropathy (84%), and seizures (71%) predominated, while for those with onset over 40 years, ptosis (95%), progressive external ophthalmoplegia (89%), and ataxia (58%) were the major clinical features. The earlier the onset the worse the prognosis. Patients with epilepsy and those with compound heterozygous variants carried significantly worse prognosis. / Conclusion: Based on our data, we propose a simplified POLG disease classification, which can be used to guide diagnostic investigations and predict disease course
    corecore