317 research outputs found
Characterization, prevalence, and risk factors of spontaneous and experimental atherosclerosis and vascular imaging in psittaciformes
Atherosclerosis is a degenerative and inflammatory vascular disease characterized by the accumulation of inflammatory cells, lipids, calcium, and formation of large fibrofatty lesions within the intima of arteries resulting in the disorganization of the arterial wall and stenosis of the lumen. Despite the importance of atherosclerosis in psittacine cardiology, there are few pathologic, clinical, and experimental investigations in psittaciformes. In order to expand the knowledge on psittacine atherosclerosis and provide fundamental observational information for future research, a series of studies was conducted on psittaciformes: 1) psittacine atherosclerotic lesions were characterized and categorized based on histopathology, histochemistry, transmission (TEM), and scanning electron microscopy (SEM) of 63 arterial samples, 2) the prevalence of clinically significant atherosclerotic lesions and the influence of several epidemiological variables were investigated in a multi-center case-control study on 7683 psittaciformes, 3) a diet-induced experimental model of atherosclerosis was developed and characterized in Quaker parrots (Myiopsitta monachus), and 4) a computed-tomography angiographic (CTA) protocol was developed and standardized to image the arterial lumen in Hispaniolan Amazon parrots (Amazona ventralis). Seven lesion types could be described in psittaciformes, which were similar to the human classification system. Digital image analysis, TEM, and SEM helped to further describe the lesions and refine the classification system. Atherosclerosis prevalence significantly increased with age, female sex, and the genera Psittacus, Amazona, and Nymphicus. Mild associations with reproductive, hepatic diseases, and myocardial fibrosis were also evidenced. Experimental induction of atherosclerosis with dietary 1% cholesterol lead to significant lesions within 2 months in Quaker parrots. An increase in arterial and plasma cholesterol and LDL was also documented. Reference limits for arterial luminal diameter of Hispaniolan Amazon parrots were determined by CTA and measurements revealed high intraobserver and interobserver agreement. In conclusion, psittacine atherosclerotic lesions displayed distinctive features that allowed the development of an effective classification system. The prevalence of advanced lesions (type IV-VI) was associated with several risk factors: age, female sex, and three psittacine genera. The Quaker parrot was found to be a suitable experimental model for psittacine atherosclerosis and dyslipidemia. Finally CTA was determined to be safe, reliable, and of potential diagnostic value in parrots for diagnosing stenotic atherosclerotic lesions
Évaluation de l’état de l’hydromorphologie des cours d’eau : retour d’expérience sur le bassin Adour-Garonne (France)
Pour préparer la mise en oeuvre de la directive 2000-60-CE du Parlement et du conseil européen, établissant un cadre pour une politique communautaire dans le domaine de l’eau, l’Agence de l’Eau Adour-Garonne a réalisé une évaluation de l’état de l’hydromorphologie de plusieurs milliers de kilomètres de cours d’eau selon un protocole original. À partir d’un inventaire normalisé des Aménagements, des Travaux et des Ouvrages, une évaluation des altérations potentielles de l’hydromorphologie a été réalisée à l’aide du système-expert EVACE. Cette approche ne nécessite pas, comme préalable, l’utilisation d’une typologie de cours d’eau ou d’un échantillon représentatif de sites de référence. Elle est en mesure de fournir une image nuancée et réaliste d’un réseau hydrographique étendu ou d’une portion de cours d’eau. Cette évaluation en continu peut constituer la première étape d’une analyse multi échelle de l’altération du milieu physique des rivières, allant du grand bassin-versant à la station de caractérisation de l’état de l’habitat ou de la biologie. Cette démarche emboîtée peut aider à établir des liens entre les altérations de l’hydromorphologie et la qualité écologique des cours d’eau. Ainsi, elle est en mesure d’identifier les causes sur lesquelles il est nécessaire d’agir pour améliorer l’état des cours d’eau.In order to implement the 2000-60-CE Directive of the European Parliament and Council that establishes a framework to community actions in the field of water policy, the Adour-Garonne Water Agency has pursued the analysis of several thousands kilometres of water courses to estimate their hydro-morphological state, using a new study protocol. The hydro-morphological potential state has been estimated by the EVACE assessment system and based on a normalized inventory of modifications, works and buildings. This method does not request any particular river typology nor any relevant reference sites sample as a precondition. This method proposes a varied and realistic picture of a large river basin as well as a short section of a stream. This gradual evaluation method can be considered as the first step of a river multi-scale method of analysis to measure river morphology changes from large river basins to small river biological environment assessment spot. This interlocked method can help determine connections between hydro-morphological changes and rivers’ ecological quality. It directly points down causes of disruptions that can be corrected to improve water courses quality state
L’anglais de la recherche médicale : une grande diversité
Presque tout a été écrit sur le discours scientifique depuis trente ans. Pourtant, de nombreuses erreurs et des généralisations hâtives circulent encore. La recherche médicale est l'objet de notre étude. Quel est le rôle du chercheur-auteur ? L'analyse est conduite dans deux écrits de recherche, la Communication primaire et l'Étude de cas (en prenant le critère « temps » comme observable). Qui influence l'écriture de la recherche : la discipline, la communauté scientifique ou le genre choisi ?Almost  everything has been written on scientific discourse over these last thirty years. However, too many mistakes, too rapid generalisations are still made. Medical research is the field of our study. What is the role played by the medical researcher? The analysis is carried out in two types of research writing: the original article and the case study  (the observed criterion is “tense”). What is research writing influenced by: the scientific branch, the scientific community or the genre selected
Differentiation of hepatocellular adenoma by subtype and hepatocellular carcinoma in non-cirrhotic liver by fractal analysis of perfusion MRI
Background: To investigate whether fractal analysis of perfusion differentiates hepatocellular adenoma (HCA) subtypes and hepatocellular carcinoma (HCC) in non-cirrhotic liver by quantifying perfusion chaos using four-dimensional dynamic contrast-enhanced magnetic resonance imaging (4D-DCE-MRI).
Results: A retrospective population of 63 patients (47 female) with histopathologically characterized HCA and HCC in non-cirrhotic livers was investigated. Our population consisted of 13 hepatocyte nuclear factor (HNF)-1 alpha-inactivated (H-HCAs), 7 beta-catenin-exon-3-mutated (b(ex3)-HCAs), 27 inflammatory HCAs (I-HCAs), and 16 HCCs. Four-dimensional fractal analysis was applied to arterial, portal venous, and delayed phases of 4D-DCE-MRI and was performed in lesions as well as remote liver tissue. Diagnostic accuracy of fractal analysis was compared to qualitative MRI features alone and their combination using multi-class diagnostic accuracy testing including kappa-statistics and area under the receiver operating characteristic curve (AUC). Fractal analysis allowed quantification of perfusion chaos, which was significantly different between lesion subtypes (multi-class AUC = 0.90, p < 0.001), except between I-HCA and HCC. Qualitative MRI features alone did not allow reliable differentiation between HCA subtypes and HCC (kappa = 0.35). However, combining qualitative MRI features and fractal analysis reliably predicted the histopathological diagnosis (kappa = 0.89) and improved differentiation of high-risk lesions (i.e., HCCs, b(ex3)-HCAs) and low-risk lesions (H-HCAs, I-HCAs) from sensitivity and specificity of 43% (95% confidence interval [CI] 23-66%) and 47% (CI 32-64%) for qualitative MRI features to 96% (CI 78-100%) and 68% (CI 51-81%), respectively, when adding fractal analysis.
Conclusions: Combining qualitative MRI features with fractal analysis allows identification of HCA subtypes and HCCs in patients with non-cirrhotic livers and improves differentiation of lesions with high and low risk for malignant transformation
Differentiation of hepatocellular adenoma by subtype and hepatocellular carcinoma in non-cirrhotic liver by fractal analysis of perfusion MRI
Background To investigate whether fractal analysis of perfusion differentiates hepatocellular adenoma (HCA) subtypes and hepatocellular carcinoma (HCC) in non-cirrhotic liver by quantifying perfusion chaos using four-dimensional dynamic contrast-enhanced magnetic resonance imaging (4D-DCE-MRI). Results A retrospective population of 63 patients (47 female) with histopathologically characterized HCA and HCC in non-cirrhotic livers was investigated. Our population consisted of 13 hepatocyte nuclear factor (HNF)-1 alpha-inactivated (H-HCAs), 7 beta-catenin-exon-3-mutated (b(ex3)-HCAs), 27 inflammatory HCAs (I-HCAs), and 16 HCCs. Four-dimensional fractal analysis was applied to arterial, portal venous, and delayed phases of 4D-DCE-MRI and was performed in lesions as well as remote liver tissue. Diagnostic accuracy of fractal analysis was compared to qualitative MRI features alone and their combination using multi-class diagnostic accuracy testing including kappa-statistics and area under the receiver operating characteristic curve (AUC). Fractal analysis allowed quantification of perfusion chaos, which was significantly different between lesion subtypes (multi-class AUC = 0.90, p < 0.001), except between I-HCA and HCC. Qualitative MRI features alone did not allow reliable differentiation between HCA subtypes and HCC (kappa = 0.35). However, combining qualitative MRI features and fractal analysis reliably predicted the histopathological diagnosis (kappa = 0.89) and improved differentiation of high-risk lesions (i.e., HCCs, b(ex3)-HCAs) and low-risk lesions (H-HCAs, I-HCAs) from sensitivity and specificity of 43% (95% confidence interval [CI] 23-66%) and 47% (CI 32-64%) for qualitative MRI features to 96% (CI 78-100%) and 68% (CI 51-81%), respectively, when adding fractal analysis. Conclusions Combining qualitative MRI features with fractal analysis allows identification of HCA subtypes and HCCs in patients with non-cirrhotic livers and improves differentiation of lesions with high and low risk for malignant transformation
Analyse électrophorétique des lipoprotéines sériques chez les animaux domestiques
Cuvelier R., Andraud G., Berger J.-A., Beaufrère , Bressou C. Analyse électrophorétique des lipoprotéines sériques chez les animaux domestiques. In: Bulletin de l'Académie Vétérinaire de France tome 111 n°5, 1958. pp. 207-221
Imaging features of histological subtypes of hepatocellular carcinoma: Implication for LI-RADS
Background & Aims: The histopathological subtypes of hepatocellular carcinoma (HCC) are associated with distinct clinical features and prognoses. This study aims to report Liver Imaging Reporting and Data System (LI-RADS)-defined imaging features of different HCC subtypes in a cohort of resected tumours and to assess the influence of HCC subtypes on computed tomography (CT)/magnetic resonance imaging (MRI) LI-RADS categorisation in the subgroup of high-risk patients.Methods: This retrospective institutional review board-approved study included patients with resected HCCs and available histopathological classification. Three radiologists independently reviewed preoperative CT and MRI exams. The readers evaluated the presence of imaging features according to LI-RADS v2018 definitions and provided a LI-RADS category in patients at high risk of HCC. Differences in LI-RADS features and categorisations were assessed for not otherwise specified (NOS-HCC), steatohepatitic (SH-HCC), and macrotrabecular-massive (MTM-HCC) types of HCCs.Results: Two hundred and seventy-seven patients (median age 64.0 years, 215 [77.6%] men) were analysed, which involved 295 HCCs. There were 197 (66.7%) NOS-HCCs, 62 (21.0%) SH-HCCs, 23 (7.8%) MTM-HCCs, and 13 (4.5%) other rare subtypes. The following features were more frequent in MTM-HCC: elevated alpha-foetoprotein serum levels (p <0.001), tumour-in-vein (p <0.001 on CT, p <= 0.052 on MRI), presence of at least 1 LR-M feature (p <= 0.010 on CT), infiltrative appearance (p <= 0.032 on CT), necrosis or severe ischaemia (p <= 0.038 on CT), and larger size (p <= 0.006 on CT, p <= 0.011 on MRI). SH-HCC was associated with fat in mass (p <0.001 on CT, p <= 0.002 on MRI). The distribution of the LI-RADS major features and categories in high-risk patients did not significantly differ among the 3 main HCC subtypes.Conclusions: The distribution of LI-RADS major features and categories is not different among the HCC subtypes. Nevertheless, careful analysis of tumour-in-vein, LR-M, and ancillary features as well as clinico-biological data can provide information for the non-invasive diagnosis of HCC subtypes.Lay summary: In high-risk patients, the overall distribution of LI-RADS major features and categories is not different among the histological subtypes of hepatocellular carcinoma, but tumour-in-vein, presence of LR-M features, and ancillary features can provide information for the non-invasive diagnosis of hepatocellular carcinoma subtypes. (C) 2021 The Authors. Published by Elsevier B.V. on behalf of European Association for the Study of the Liver (EASL)
Biomechanics of landing in injured and uninjured chickens and the role of meloxicam
Birds use their legs and wings when transitioning from aerial to ground locomotion during landing. To improve our understanding of the effects of footpad dermatitis (FPD) and keel bone fracture (KBF) upon landing biomechanics in laying hens, we measured ground-reaction forces generated by hens (n = 37) as they landed on force plates (Bertec Corporation, Columbus, OH) from a 30 cm drop or 170 cm jump in a single-blinded placebo-controlled trial using a cross-over design where birds received an anti-inflammatory (meloxicam, 5 mg/kg body mass) or placebo treatment beforehand. We used generalized linear mixed models to test for effects of health status, treatment and their interaction on landing velocity (m/s), maximum resultant force (N), and impulse (force integrated with respect to time [N s]). Birds with FPD and KBF tended to show divergent alterations to their landing biomechanics when landing from a 30 cm drop, with a higher landing velocity and maximum force in KBF compared to FPD birds, potentially indicative of efforts to either reduce the use of their wings or impacts on inflamed footpads. In contrast, at 170 cm jumps fewer differences between birds of different health statuses were observed likely due to laying hens being poor flyers already at their maximum power output. Our results indicate that orthopedic injuries, apart from being welfare issues on their own, may have subtle influences on bird mobility through altered landing biomechanics that should be considered
Eating habits, obesity related behaviors, and effects of Danhak exercise in elderly Koreans
The aims of this study were to evaluate obesity-related dietary behaviors and to determine long-term exercise effects on obesity and blood lipid profiles in elderly Korean subjects. A total of 120 subjects, aged 60-75 yr, were recruited, and obesity-related dietary behaviors were determined. An exercise intervention was conducted with 35 qualified elderly females for 6 months, and body composition and blood lipids were measured 6 times at 4 week intervals. At baseline, mean BMI (kg/m2) was 24.8 for males and 23.1 for females. The females had better eating habits than the males and were more concerned with reading nutrition labels on food products (P < 0.001); they also preferred convenience foods less than the male subjects (P < 0.05). Obese individuals were more likely than overweight or normal weight individuals to misperceive their weight (P < 0.001). Those with a high BMI responded feeling more depressed (P < 0.01), lacking self-confidence (P < 0.01), and feeling isolated (P < 0.01), as well as having more difficulty doing outdoor activities (P < 0.01). After exercise, body fat (%) and WHR were significantly reduced (P < 0.05), while body weight and BMI were also decreased without statistical significance. Total cholesterol and blood HDL were significantly improved (207.1 mg/dl vs. 182.6 mg/dl, HDL: 45.6 mg/dl vs. 50.6 mg/dl, P < 0.05). Other benefits obtained from exercise were improvements in self-confidence (26.4%), movement (22.6%), stress-relief (18.9%), and depression (13.2%). In conclusion, elderly females had better eating habits and were more concerned with nutrition information and healthy diets compared to elderly males. However, misperceptions of weight and obesity-related stress tended to be very high in females who were overweight and obese, which can be a barrier to maintain normal weight. Long-term Danhak practice, a traditional Korean exercise, was effective at reducing body fat (%) and abdominal obesity, and improved lipid profiles, self-confidence, and stress
The Effect of High Glucocorticoid Administration and Food Restriction on Rodent Skeletal Muscle Mitochondrial Function and Protein Metabolism
Glucocorticoids levels are high in catabolic conditions but it is unclear how much of the catabolic effects are due to negative energy balance versus glucocorticoids and whether there are distinct effects on metabolism and functions of specific muscle proteins.We determined whether 14 days of high dose methylprednisolone (MPred, 4 mg/kg/d) Vs food restriction (FR, food intake matched to MPred) in rats had different effects on muscle mitochondrial function and protein fractional synthesis rates (FSR). Lower weight loss (15%) occurred in FR than in MPred (30%) rats, while a 15% increase occurred saline-treated Controls. The per cent muscle loss was significantly greater for MPred than FR. Mitochondrial protein FSR in MPred rats was lower in soleus (51 and 43%, respectively) and plantaris (25 and 55%) than in FR, while similar decline in protein FSR of the mixed, sarcoplasmic, and myosin heavy chain occurred. Mitochondrial enzymatic activity and ATP production were unchanged in soleus while in plantaris cytochrome c oxidase activity was lower in FR than Control, and ATP production rate with pyruvate + malate in MPred plantaris was 28% lower in MPred. Branched-chain amino acid catabolic enzyme activities were higher in both FR and MPred rats indicating enhanced amino acid oxidation capacity.MPred and FR had little impact on mitochondrial function but reduction in muscle protein synthesis occurred in MPred that could be explained on the basis of reduced food intake. A greater decline in proteolysis may explain lesser muscle loss in FR than in MPred rats
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