187 research outputs found
Comparison of the Sprague Dawley rat’s response against cyclophosphamide and bleomycin in the head sperm morphology assay.
El ensayo de la morfología de la cabeza del espermatozoide permite el estudio del potencialgenotóxico de muestras problemas a nivel celular, esta herramienta evalúa los cambios efectuados enla concentración espermática, así como el aumento de la frecuencia espontánea de cabezas deespermatozoides morfológicamente anormales. En este artículo decidimos evaluar y comparar en elbiomodelo de ratas Sprague Dawley machos, el efecto de dos sustancias mutagénicas en este ensayo,la Ciclofosfamida (CF) en dosis de 50 mg/kg y la Bleomicina (BL) en dosis de 30 mg/kg,administradas por vía intraperitoneal durante 5 días consecutivos, siendo sacrificados los animales 52días después de la última administración de los mutágenos. Se obtuvo como resultado que ambosmutágenos disminuyeron la concentración espermática y aumentaron el índice espontáneo de cabezasanómalas en los espermatozoides, siendo observado un marcado efecto mutagénico en la CF encomparación con la BL. Al final de la experiencia se obtuvieron mayores resultados de inducción decabezas de espermatozoides anómalas con el uso de la CF. Estos resultados reafirman el uso de estemutágeno como control positivo eficiente y seguro en este ensayo el cual se encuentra incluido en losestudios de genotoxicidad y toxicología de la fertilidad.The head sperm morphology assay, allows the study of the genotoxic potencial of samples at thecellular level problems; this tool to evaluate the spermatic concentration changes, as well as theincrease of the spontaneous heads frequency of sperms morphology abnormal. In this article we decideto evaluate and to compare in the Sprague Dawley males rats, the effect of two mutagenic substancesin these assay, the Cyclophosphamide, (CF) in dose of 50 mg/kg and the Bleomycin (BL) in dose of30 mg/kg, administered by intraperitoneal route during 5 consecutive days, being sacrificed theanimals 52 days after the last administration of the mutagens. It was obtained that both mutagendiminished the spermatic concentration and they increased the spontaneous index of anomaloussperms heads, being observed a marked mutagenic effect in the CF in comparison with the BL. At theend of the experience bigger results of induction of anomalous heads sperms were obtained with theuse of the CF. These results reaffirm the use of this mutagen as efficient and safe positive control inthis assay which is included in the genotoxicity studies and fertility toxicology
Optical multiband surface photometry of a sample of Seyfert galaxies. I. Large-scale morphology and local environment analysis of matched Seyfert and inactive galaxy samples
Parallel analysis of the large-scale morphology and local environment of
matched active and control galaxy samples plays an important role in studies of
the fueling of active galactic nuclei. We carry out a detailed morphological
characterization of a sample of 35 Seyfert galaxies and a matched sample of
inactive galaxies in order to compare the evidence of non-axisymmetric
perturbation of the potential and, in the second part of this paper, to be able
to perform a multicomponent photometric decomposition of the Seyfert galaxies.
We constructed contour maps, BVRcIc profiles of the surface brightness,
ellipticity, and position angle, as well as colour index profiles. We further
used colour index images, residual images, and structure maps, which helped
clarify the morphology of the galaxies. We studied the presence of close
companions using literature data. By straightening out the morphological status
of some of the objects, we derived an improved morphological classification and
built a solid basis for a further multicomponent decomposition of the Seyfert
sample. We report hitherto undetected (to our knowledge) structural components
in some Seyfert galaxies - a bar (Ark 479), an oval/lens (Mrk 595), rings (Ark
120, Mrk 376), a nuclear bar and ring (Mrk 352), and nuclear dust lanes (Mrk
590). We compared the large-scale morphology and local environment of the
Seyfert sample to those of the control one and found that (1) the two samples
show similar incidences of bars, rings, asymmetries, and close companions; (2)
the Seyfert bars are generally weaker than the bars of the control galaxies;
(3) the bulk of the two samples shows morphological evidence of
non-axisymmetric perturbations of the potential or close companions; (4) the
fueling of Seyfert nuclei is not directly related to the large-scale morphology
and local environment of their host galaxies.Comment: Accepted for publication in A&
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Association of the tumor necrosis factor-alpha promoter polymorphism with change in triacylglycerol response to sequential meals
Background: Reported associations between Tumor Necrosis Factor-alpha (TNFA) and the postprandial
triacylglycerol (TAG) response have been inconsistent, which could be due to variations in the TNFA gene, meal fat composition or participant’s body weight. Hence, we investigated the association of TNFA polymorphism
(−308G → A) with body mass index (BMI) and postprandial lipaemia and also determined the impact of BMI on the
association of the polymorphism with postprandial lipaemia.
Methods: The study participants (n = 230) underwent a sequential meal postprandial study. Blood samples were taken
at regular intervals after a test breakfast (t = 0, 49 g fat) and lunch (t =330 min, 29 g fat) to measure fasting and
postprandial lipids, glucose and insulin. The Metabolic Challenge Study (MECHE) comprising 67 Irish participants who
underwent a 54 g fat oral lipid tolerance test was used as a replication cohort. The impact of genotype on postprandial
responses was determined using general linear model with adjustment for potential confounders.
Results: The -308G → A polymorphism showed a significant association with BMI (P = 0.03) and fasting glucose
(P = 0.006), where the polymorphism explained 13 % of the variation in the fasting glucose. A 30 % higher incremental
area under the curve (IAUC) was observed for the postprandial TAG response in the GG homozygotes than A-allele
carriers (P = 0.004) and the genotype explained 19 % of the variation in the IAUC. There was a non-significant trend in
the impact of BMI on the association of the genotype with TAG IAUC (P = 0.09). These results were not statistically
significant in the MECHE cohort, which could be due to the differences in the sample size, meal composition, baseline
lipid profile, allelic diversity and postprandial characterisation of participants across the two cohorts.
Conclusions: Our findings suggest that TNFA -308G → A polymorphism may be an important candidate for BMI,
fasting glucose and postprandial TAG response. Further studies are required to investigate the mechanistic effects of
the polymorphism on glucose and TAG metabolism, and determine whether BMI is an important variable which
should be considered in the design of future studies.
Trial registration: NCT01172951
Implications of early respiratory support strategies on disease progression in critical COVID-19: a matched subanalysis of the prospective RISC-19-ICU cohort.
Uncertainty about the optimal respiratory support strategies in critically ill COVID-19 patients is widespread. While the risks and benefits of noninvasive techniques versus early invasive mechanical ventilation (IMV) are intensely debated, actual evidence is lacking. We sought to assess the risks and benefits of different respiratory support strategies, employed in intensive care units during the first months of the COVID-19 pandemic on intubation and intensive care unit (ICU) mortality rates.
Subanalysis of a prospective, multinational registry of critically ill COVID-19 patients. Patients were subclassified into standard oxygen therapy ≥10 L/min (SOT), high-flow oxygen therapy (HFNC), noninvasive positive-pressure ventilation (NIV), and early IMV, according to the respiratory support strategy employed at the day of admission to ICU. Propensity score matching was performed to ensure comparability between groups.
Initially, 1421 patients were assessed for possible study inclusion. Of these, 351 patients (85 SOT, 87 HFNC, 87 NIV, and 92 IMV) remained eligible for full analysis after propensity score matching. 55% of patients initially receiving noninvasive respiratory support required IMV. The intubation rate was lower in patients initially ventilated with HFNC and NIV compared to those who received SOT (SOT: 64%, HFNC: 52%, NIV: 49%, p = 0.025). Compared to the other respiratory support strategies, NIV was associated with a higher overall ICU mortality (SOT: 18%, HFNC: 20%, NIV: 37%, IMV: 25%, p = 0.016).
In this cohort of critically ill patients with COVID-19, a trial of HFNC appeared to be the most balanced initial respiratory support strategy, given the reduced intubation rate and comparable ICU mortality rate. Nonetheless, considering the uncertainty and stress associated with the COVID-19 pandemic, SOT and early IMV represented safe initial respiratory support strategies. The presented findings, in agreement with classic ARDS literature, suggest that NIV should be avoided whenever possible due to the elevated ICU mortality risk
Proteome from patients with metabolic syndrome is regulated by quantity and quality of dietary lipids
Background: Metabolic syndrome is a multi-component disorder associated to a high risk of cardiovascular disease.
Its etiology is the result of a complex interaction between genetic and environmental factors, including dietary
habits. We aimed to identify the target proteins modulated by the long-term consumption of four diets differing in
the quality and quantity of lipids in the whole proteome of peripheral blood mononuclear cells (PBMC).
Results: A randomized, controlled trial conducted within the LIPGENE study assigned 24 MetS patients for 12 weeks
each to 1 of 4 diets: a) high-saturated fatty acid (HSFA), b) high-monounsaturated fatty acid (HMUFA), c) low-fat,
high-complex carbohydrate diets supplemented with placebo (LFHCC) and d) low-fat, high-complex carbohydrate
diets supplemented with long chain (LC) n-3 polyunsaturated fatty acids (PUFA) (LFHCC n-3). We analyzed the
changes induced in the proteome of both nuclear and cytoplasmic fractions of PBMC using 2-D proteomic analysis.
Sixty-seven proteins were differentially expressed after the long-term consumption of the four diets. The HSFA diet
induced the expression of proteins responding to oxidative stress, degradation of ubiquitinated proteins and DNA
repair. However, HMUFA, LFHCC and LFHCC n-3 diets down-regulated pro-inflammatory and oxidative stress-related
proteins and DNA repairing proteins.
Conclusion: The long-term consumption of HSFA, compared to HMUFA, LFHCC and LFHCC n-3, seems to increase the
cardiovascular disease (CVD) risk factors associated with metabolic syndrome, such as inflammation and oxidative stress,
and seem lead to DNA damage as a consequence of high oxidative stress
Natural History of MYH7-Related Dilated Cardiomyopathy
BACKGROUND: Variants in myosin heavy chain 7 (MYH7) are responsible for disease in 1% to 5% of patients with dilated cardiomyopathy (DCM); however, the clinical characteristics and natural history of MYH7-related DCM are poorly described. OBJECTIVE: We sought to determine the phenotype and prognosis of MYH7-related DCM. We also evaluated the influence of variant location on phenotypic expression. METHODS: We studied clinical data from 147 individuals with DCM-causing MYH7 variants (47.6% female; 35.6 ± 19.2 years) recruited from 29 international centers. RESULTS: At initial evaluation, 106 (72.1%) patients had DCM (left ventricular ejection fraction: 34.5% ± 11.7%). Median follow-up was 4.5 years (IQR: 1.7-8.0 years), and 23.7% of carriers who were initially phenotype-negative developed DCM. Phenotypic expression by 40 and 60 years was 46% and 88%, respectively, with 18 patients (16%) first diagnosed at <18 years of age. Thirty-six percent of patients with DCM met imaging criteria for LV noncompaction. During follow-up, 28% showed left ventricular reverse remodeling. Incidence of adverse cardiac events among patients with DCM at 5 years was 11.6%, with 5 (4.6%) deaths caused by end-stage heart failure (ESHF) and 5 patients (4.6%) requiring heart transplantation. The major ventricular arrhythmia rate was low (1.0% and 2.1% at 5 years in patients with DCM and in those with LVEF of ≤35%, respectively). ESHF and major ventricular arrhythmia were significantly lower compared with LMNA-related DCM and similar to DCM caused by TTN truncating variants. CONCLUSIONS: MYH7-related DCM is characterized by early age of onset, high phenotypic expression, low left ventricular reverse remodeling, and frequent progression to ESHF. Heart failure complications predominate over ventricular arrhythmias, which are rare
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The physiological responses of cacao to the environment and the implications for climate change resilience. A review
Cacao (Theobroma cacao L.) is a tropical perennial crop which is of great economic importance to the confectionary industry and to the economies of many countries of the humid tropics where it is grown. Some recent studies have suggested climate change could severely impact cacao production in West Africa. It is essential to incorporate our understanding of the physiology and genetic variation within cacao germplasm when discussing the implications of climate change on cacao productivity and developing strategies for climate resilience in cacao production.
Here we review the current research on the physiological responses of cacao to various climate factors. Our main findings are 1) water limitation causes significant yield reduction in cacao but genotypic variation in sensitivity is evident, 2) in the field cacao experiences higher temperatures than is often reported in the literature, 3) the complexity of the cacao/ shade tree interaction can lead to contradictory results, 4) elevated CO2 may alleviate some negative effects of climate change 5) implementation of mitigation strategies can help reduce environmental stress, 6) significant gaps in the research need addressing to accelerate the development of climate resilience. Harnessing the significant genetic variation apparent within cacao germplasm is essential to develop modern varieties capable of high yields in non-optimal conditions. Mitigation strategies will also be essential but to use shading to best effect shade tree selection is crucial to avoid resource competition. Cacao is often described as being sensitive to climate change but genetic variation, adaptive responses, appropriate mitigation strategies and interactive climate effects should all be considered when predicting the future of cacao production. Incorporating these physiological responses to various environmental conditions and developing a deeper understanding of the processes underlying these responses will help to accelerate the development of a more resource use efficient tree ensuring sustainable production into the future
Whole-genome sequencing reveals host factors underlying critical COVID-19
Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2–4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease
Operating a full tungsten actively cooled tokamak: overview of WEST first phase of operation
WEST is an MA class superconducting, actively cooled, full tungsten (W) tokamak, designed to operate in long pulses up to 1000 s. In support of ITER operation and DEMO conceptual activities, key missions of WEST are: (i) qualification of high heat flux plasma-facing components in integrating both technological and physics aspects in relevant heat and particle exhaust conditions, particularly for the tungsten monoblocks foreseen in ITER divertor; (ii) integrated steady-state operation at high confinement, with a focus on power exhaust issues. During the phase 1 of operation (2017–2020), a set of actively cooled ITER-grade plasma facing unit prototypes was integrated into the inertially cooled W coated startup lower divertor. Up to 8.8 MW of RF power has been coupled to the plasma and divertor heat flux of up to 6 MW m−2 were reached. Long pulse operation was started, using the upper actively cooled divertor, with a discharge of about 1 min achieved. This paper gives an overview of the results achieved in phase 1. Perspectives for phase 2, operating with the full capability of the device with the complete ITER-grade actively cooled lower divertor, are also described
Epidemiology of intra-abdominal infection and sepsis in critically ill patients: “AbSeS”, a multinational observational cohort study and ESICM Trials Group Project
Purpose: To describe the epidemiology of intra-abdominal infection in an international cohort of ICU patients according to a new system that classifies cases according to setting of infection acquisition (community-acquired, early onset hospital-acquired, and late-onset hospital-acquired), anatomical disruption (absent or present with localized or diffuse peritonitis), and severity of disease expression (infection, sepsis, and septic shock). Methods: We performed a multicenter (n = 309), observational, epidemiological study including adult ICU patients diagnosed with intra-abdominal infection. Risk factors for mortality were assessed by logistic regression analysis. Results: The cohort included 2621 patients. Setting of infection acquisition was community-acquired in 31.6%, early onset hospital-acquired in 25%, and late-onset hospital-acquired in 43.4% of patients. Overall prevalence of antimicrobial resistance was 26.3% and difficult-to-treat resistant Gram-negative bacteria 4.3%, with great variation according to geographic region. No difference in prevalence of antimicrobial resistance was observed according to setting of infection acquisition. Overall mortality was 29.1%. Independent risk factors for mortality included late-onset hospital-acquired infection, diffuse peritonitis, sepsis, septic shock, older age, malnutrition, liver failure, congestive heart failure, antimicrobial resistance (either methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, extended-spectrum beta-lactamase-producing Gram-negative bacteria, or carbapenem-resistant Gram-negative bacteria) and source control failure evidenced by either the need for surgical revision or persistent inflammation. Conclusion: This multinational, heterogeneous cohort of ICU patients with intra-abdominal infection revealed that setting of infection acquisition, anatomical disruption, and severity of disease expression are disease-specific phenotypic characteristics associated with outcome, irrespective of the type of infection. Antimicrobial resistance is equally common in community-acquired as in hospital-acquired infection
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