Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 348
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Br Poult Sci ; 64(1): 1-10, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36196860

RESUMEN

1. Genetic selection for bone quality can improve this, as it is heritable. A method was established using digital X-ray which took around 40 s in total and gave an image that allowed quantification of bone density from many appendicular bones.2. The tibiotarsus measurement of bone density on the live hen across the different experiments had correlations with post-mortem whole bone radiographic density from 0.62 to 0.7, similar to that between density and material properties for example. Differences between groups of hens, where calcium and phosphorus in the diet were manipulated, were detected within 3 weeks of treatment using live hen measurement (P < 0.001, n = 24).3. In a gage analysis, 'hen' explained more than 86% of the variance, demonstrating the ability to observe clear differences between hens. The effect of different operators' analysis on the contribution to variance was very low as was the repeated measurement of the same hen.4. The measurement of bone density on the live hen described in this paper represented major progress to a usable method for genetic selection to improve bone strength in laying hens. The method has the potential to reduce the number of animals needed to test nutritional and management interventions to improve bone health.


Asunto(s)
Huesos , Pollos , Animales , Femenino , Pollos/genética , Huesos/diagnóstico por imagen , Densidad Ósea , Calcio de la Dieta , Selección Genética
2.
Br Poult Sci ; 62(4): 573-578, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33541116

RESUMEN

1. This study tested the hypothesis that the methyl-donor properties of betaine could reduce homocysteine concentrations, which has been recognised in a previous genetics study to be linked to bone quality. This was combined with phytase treatment, as phosphorus is critical for bone mineralisation.2. Using a 2 × 2 factorial arrangement, a total of 1920 Lohmann LSL-lite chickens housed as 24 replicates of 20 chickens were fed one of four diets containing dietary betaine (0 or 1000 mg/kg) and phytase (300 or 1000 FTU/kg) from one day old until end-of-lay. Blood and bone samples were collected at 45 and 70 weeks of age.3. Hens fed betaine had lower plasma homocysteine level (P < 0.05), higher tibia breaking strength (P < 0.05) and higher tibia bone density (P < 0.05).4. Egg production and quality was excellent throughout the study and were not affected by the dietary treatments.5. The addition of dietary betaine was successful at reducing plasma homocysteine concentrations and improving bone strength in laying hens, which could be used as an intervention to alleviate welfare concerns.


Asunto(s)
6-Fitasa , Pollos , Alimentación Animal/análisis , Animales , Betaína/farmacología , Dieta/veterinaria , Suplementos Dietéticos , Femenino , Homocisteína , Fósforo
3.
Diabet Med ; 37(6): 1049-1057, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32125000

RESUMEN

AIMS: To examine the association of HbA1c and glucose levels with incident diabetic retinopathy according to black African or white European ancestry. METHODS: In this retrospective cohort study of 202 500 US Veterans with diabetes (2000-2014), measures included HbA1c , outpatient random serum/plasma glucose, and incident retinopathy [conversion from negative to ≥2 positive evaluations (ICD-9 codes), without a subsequent negative]. RESULTS: At baseline, the study population had a mean age of 59.3 years, their mean BMI was 31.9 kg/m2 , HbA1c level was 57 mmol/mol (7.4%) and glucose level was 8.8 mmol/l, and 77% were of white European ancestry (white individuals) and 21% of black African ancestry (black individuals). HbA1c was 0.3% higher in black vs white individuals (P < 0.001), adjusting for baseline age, sex, BMI, estimated glomerular filtration rate (eGFR), haemoglobin, and average systolic blood pressure and glucose. Over 11 years, incident retinopathy occurred in 9% of black and 7% of white individuals, but black individuals had higher HbA1c , glucose, and systolic blood pressure (all P < 0.001); adjusted for these factors, incident retinopathy was reduced in black vs white individuals (P < 0.001). The population incidence of retinopathy (7%) was associated with higher mean baseline HbA1c in individuals with black vs white ancestry [63 mmol/mol (7.9%) vs 58 mmol/mol (7.5%); P < 0.001)], but with similar baseline glucose levels (9.0 vs 9.0 mmol/l; P = 0.660, all adjusted for baseline age, sex and BMI). CONCLUSIONS: Since retinopathy occurs at higher HbA1c levels in black people for a given level of average plasma glucose, strategies may be needed to individualize the interpretation of HbA1c measurements.


Asunto(s)
Negro o Afroamericano , Diabetes Mellitus/metabolismo , Retinopatía Diabética/etnología , Hemoglobina Glucada/metabolismo , Población Blanca , Anciano , Población Negra , Glucemia , Retinopatía Diabética/epidemiología , Retinopatía Diabética/etiología , Retinopatía Diabética/metabolismo , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Estados Unidos/epidemiología , United States Department of Veterans Affairs
4.
Diabet Med ; 37(4): 689-696, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-31721287

RESUMEN

AIMS: To determine whether HbA1c mismatches (HbA1c levels that are higher or lower than expected for the average glucose levels in different individuals) could lead to errors if diagnostic classification is based only on HbA1c levels. METHODS: In a cross-sectional study, 3106 participants without known diabetes underwent a 75-g oral glucose tolerance test (fasting glucose and 2-h glucose) and a 50-g glucose challenge test (1-h glucose) on separate days. They were classified by oral glucose tolerance test results as having: normal glucose metabolism; prediabetes; or diabetes. Predicted HbA1c was determined from the linear regression modelling the relationship between observed HbA1c and average glucose (mean of fasting glucose and 2-h glucose from the oral glucose tolerance test, and 1-h glucose from the glucose challenge test) within oral glucose tolerance test groups. The haemoglobin glycation index was calculated as [observed - predicted HbA1c ], and divided into low, intermediate and high haemoglobin glycation index mismatch tertiles. RESULTS: Those participants with higher mismatches were more likely to be black, to be men, to be older, and to have higher BMI (all P<0.001). Using oral glucose tolerance test criteria, the distribution of normal glucose metabolism, prediabetes and diabetes was similar across mismatch tertiles; however, using HbA1c criteria, the participants with low mismatches were classified as 97% normal glucose metabolism, 3% prediabetes and 0% diabetes, i.e. mostly normal, while those with high mismatches were classified as 13% normal glucose metabolism, 77% prediabetes and 10% diabetes, i.e. mostly abnormal (P<0.001). CONCLUSIONS: Measuring only HbA1c could lead to under-diagnosis in people with low mismatches and over-diagnosis in those with high mismatches. Additional oral glucose tolerance tests and/or fasting glucose testing to complement HbA1c in diagnostic classification should be performed in most individuals.


Asunto(s)
Glucemia/análisis , Diabetes Mellitus Tipo 2/diagnóstico , Hemoglobina Glucada/análisis , Estado Prediabético/diagnóstico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Glucemia/metabolismo , Estudios de Cohortes , Estudios Transversales , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/clasificación , Femenino , Georgia , Intolerancia a la Glucosa/sangre , Intolerancia a la Glucosa/clasificación , Intolerancia a la Glucosa/diagnóstico , Prueba de Tolerancia a la Glucosa/métodos , Prueba de Tolerancia a la Glucosa/normas , Hemoglobina Glucada/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Estado Prediabético/sangre , Estado Prediabético/clasificación , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Adulto Joven
5.
Cryo Letters ; 41(2): 57-61, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33988654

RESUMEN

BACKGROUND: The details of the mechanism of action of ice binding proteins (IBPs) have been intensively studied and hotly debated for some decades. OBJECTIVE: To outline the inherent differences between the manifested growth of single ice crystals grown in the presence of fish antifreeze proteins and those grown with insect thermal hysteresis proteins. MATERIALS AND METHODS: Observations of single ice crystals taking the shape of hexagonal bipyramids using a nanolitre osmometer and grown in the presence of so called antifreeze glycopeptides from the Antarctic fish species Dissostichus maswoni, are compared with those seen with insect thermal hysteresis proteins from Tenebrio molitor, grown in a Ramsay chamber, which grow as lemon-shaped crystals. RESULTS: The difference in growth allows us to infer methods of action of each class of protein. Further, below the thermal hysteresis gap, or non-equilibrium freezing point, the explosive growth seen with fish antifreeze proteins is demonstrated but is yet to be fully explored. CONCLUSION: Ice growth behaviour can be used to indicate or infer the crystal faces to which the molecules may have adsorbed.


Asunto(s)
Proteínas Anticongelantes , Crioprotectores , Proteínas de Peces , Hielo , Proteínas de Insectos , Animales , Criopreservación , Congelación , Perciformes , Tenebrio
6.
Diabet Med ; 36(10): 1234-1242, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31187544

RESUMEN

AIM: To characterize differences between black and white people in optimal HbA1c thresholds for diagnoses of diabetes and prediabetes. METHODS: Data were included from the National Health and Nutrition Examination Survey, 2005-2014. Black and white adults (age 18-70 years) who underwent an oral glucose tolerance test and had available fasting plasma glucose, 2-h plasma glucose and HbA1c measurements were eligible for inclusion. Diabetes or prediabetes status was defined by fasting plasma glucose and 2-h plasma glucose using American Diabetes Association criteria. Classification of diabetes, prediabetes and dysglycaemia by HbA1c was evaluated for a range of HbA1c thresholds, with optimal thresholds defined as those values that maximized the sum of sensitivity and specificity (Youden's index). RESULTS: In 5324 black (32.3%) and white (67.7%) individuals, Youden's index (optimal) thresholds for HbA1c were ≥42 mmol/mol (6.0%) and ≥39 mmol/mol (5.7%) for discriminating diabetes vs non-diabetes, ≥ 44 mmol/mol (6.2%) and ≥39 mmol/mol (5.7%) for discriminating diabetes vs prediabetes (excluding normoglycaemia), ≥39 mmol/mol (5.7%) and ≥37 mmol/mol (5.5%) for discriminating dysglycaemia vs normoglycaemia, and ≥39 mmol/mol (5.7%) and ≥37 mmol/mol (5.5%) for discriminating prediabetes vs normoglycaemia (excluding diabetes), in black and white people, respectively. CONCLUSIONS: Consistently higher optimal HbA1c thresholds in black people than in white people suggest a need to individualize HbA1c relative to glucose levels if HbA1c is used to diagnose diabetes and prediabetes.


Asunto(s)
Diabetes Mellitus/sangre , Diabetes Mellitus/etnología , Hemoglobina Glucada/análisis , Estado Prediabético/sangre , Estado Prediabético/etnología , Grupos Raciales , Adulto , Población Negra , Glucemia/análisis , Ayuno , Femenino , Intolerancia a la Glucosa/sangre , Intolerancia a la Glucosa/etnología , Prueba de Tolerancia a la Glucosa , Humanos , Masculino , Encuestas Nutricionales , Valores de Referencia , Sensibilidad y Especificidad , Población Blanca
7.
J Clin Apher ; 33(3): 404-408, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29114919

RESUMEN

OBJECTIVE: Familial hypercholesterolemia (FH) is a genetic disease with very high levels of circulating low density lipoprotein cholesterol (LDL-C) levels that leads to accelerated atherosclerosis. Lipoprotein apheresis is an effective treatment option for patients with FH and results in reduced cardiovascular morbidity and mortality. Circulating progenitor cells (CPCs) are markers of overall vascular health and diminished levels have been associated with decreased reparative potential and worse outcomes. We assessed the short-term change in CPC levels following a single lipoprotein apheresis session in FH patients who are already on stable lipoprotein apheresis therapy. We hypothesized that in addition to a reduction in atherogenic lipids, the cardiovascular benefit from lipoprotein apheresis therapy is mediated by enhanced vascular reparative capacity through mobilization of CPCs. METHODS: Eight FH patients (1 homozygous and 7 heterozygous) on stable lipoprotein apheresis therapy for at least three months had CPCs measured at baseline (prior to apheresis) and two hours after apheresis. Results were compared with data from age-matched hyperlipidemic (HLP) patients on statin therapy and healthy volunteers. RESULTS: FH patients had higher baseline circulating levels of CD34+/CD133+ and CD34+/CD133+/CXCR4+ cells compared to HLP and healthy subjects. There was no significant change in CPCs after apheresis in FH patients. CONCLUSIONS: FH patients had higher CPC counts at baseline compared to age-matched HLP and healthy controls, suggesting activation of reparative mechanism in this high risk population. Larger studies are needed to better characterize differences in CPC counts between FH subjects and HLP patients over time.


Asunto(s)
Eliminación de Componentes Sanguíneos/métodos , Hiperlipoproteinemia Tipo II/sangre , Células Madre/citología , Adulto , Antígenos CD34/análisis , Estudios de Casos y Controles , Recuento de Células , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Hiperlipidemias/tratamiento farmacológico , Hiperlipoproteinemia Tipo II/terapia , Lipoproteínas/aislamiento & purificación , Persona de Mediana Edad
8.
Diabet Med ; 34(5): 716-724, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-27727467

RESUMEN

AIMS: To test the hypothesis that a 50-g oral glucose challenge test with 1-h glucose measurement would have superior performance compared with other opportunistic screening methods. METHODS: In this prospective study in a Veterans Health Administration primary care clinic, the following test performances, measured by area under receiver-operating characteristic curves, were compared: 50-g oral glucose challenge test; random glucose; and HbA1c level, using a 75-g oral glucose tolerance test as the 'gold standard'. RESULTS: The study population was comprised of 1535 people (mean age 56 years, BMI 30.3 kg/m2 , 94% men, 74% black). By oral glucose tolerance test criteria, diabetes was present in 10% and high-risk prediabetes was present in 22% of participants. The plasma glucose challenge test provided area under receiver-operating characteristic curves of 0.85 (95% CI 0.78-0.91) to detect diabetes and 0.76 (95% CI 0.72-0.80) to detect high-risk dysglycaemia (diabetes or high-risk prediabetes), while area under receiver-operating characteristic curves for the capillary glucose challenge test were 0.82 (95% CI 0.75-0.89) and 0.73 (95% CI 0.69-0.77) for diabetes and high-risk dysglycaemia, respectively. Random glucose performed less well [plasma: 0.76 (95% CI 0.69-0.82) and 0.66 (95% CI 0.62-0.71), respectively; capillary: 0.72 (95% CI 0.65-0.80) and 0.64 (95% CI 0.59-0.68), respectively], and HbA1c performed even less well [0.67 (95% CI 0.57-0.76) and 0.63 (95% CI 0.58-0.68), respectively]. The cost of identifying one case of high-risk dysglycaemia with a plasma glucose challenge test would be $42 from a Veterans Health Administration perspective, and $55 from a US Medicare perspective. CONCLUSIONS: Glucose challenge test screening, followed, if abnormal, by an oral glucose tolerance test, would be convenient and more accurate than other opportunistic tests. Use of glucose challenge test screening could improve management by permitting earlier therapy.


Asunto(s)
Glucemia/análisis , Diabetes Mellitus Tipo 2/diagnóstico , Glucosa/farmacología , Tamizaje Masivo/métodos , Estado Prediabético/diagnóstico , Adulto , Anciano , Glucemia/metabolismo , Análisis Costo-Beneficio , Diabetes Mellitus Tipo 2/sangre , Diagnóstico Precoz , Femenino , Prueba de Tolerancia a la Glucosa/economía , Prueba de Tolerancia a la Glucosa/métodos , Humanos , Masculino , Tamizaje Masivo/economía , Persona de Mediana Edad , Estado Prediabético/sangre , Curva ROC
9.
Anim Genet ; 44(6): 661-8, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23837723

RESUMEN

The cuticle is a proteinaceous layer covering the avian egg and is believed to form a defence to microorganism ingress. In birds that lay eggs in challenging environments, the cuticle is thicker, suggesting evolutionary pressure; however, in poultry, selection pressure for this trait has been removed because of artificial incubation. This study aimed to quantify cuticle deposition and to estimate its genetic parameters and its role on trans-shell penetration of bacteria. Additionally, cuticle proteins were characterised to establish whether alleles for these genes explained variation in deposition. A novel and reliable quantification was achieved using the difference in reflectance of the egg at 650 nm before and after staining with a specific dye. The heritability of this novel measurement was moderate (0.27), and bacteria penetration was dependent on the natural variation in cuticle deposition. Eggs with the best cuticle were never penetrated by bacteria (P < 0.001). The cuticle proteome consisted of six major proteins. A significant association was found between alleles of one of these protein genes, ovocleidin-116 (MEPE), and cuticle deposition (P = 0.015) and also between alleles of estrogen receptor 1 (ESR1) gene and cuticle deposition (P = 0.008). With the heritability observed, genetic selection should be possible to increase cuticle deposition in commercial poultry, so reducing trans-generational transmission of microorganisms and reversing the lack of selection pressure for this trait during recent domestication.


Asunto(s)
Pollos/genética , Proteínas del Huevo/metabolismo , Cáscara de Huevo/química , Cáscara de Huevo/microbiología , Animales , Pollos/microbiología , Receptor alfa de Estrógeno/metabolismo , Femenino , Estudios de Asociación Genética , Espectrometría de Masas , Espectrofotometría/veterinaria , Estadísticas no Paramétricas
10.
Poult Sci ; 102(8): 102854, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37354620

RESUMEN

Beak shape varies considerably within and between intact-beak laying hens, and aspects of beak shape appear to be heritable. As an alternative to beak treatment (an effective method of reducing damage from severe feather pecking (SFP)), this variation could be used to genetically select hens whose beak shapes are less apt to cause damage. To be able to select certain phenotypes, the beak shape variation that exists within laying hen flocks must first be characterized. The objectives of this study were to 1) describe the maxillary beak shape variation in 2 pure White Leghorn layer lines with intact beaks using geometric morphometrics to analyze images, and 2) examine the beak shape's relationship to the premaxillary bone, feather cover, and mortality. A lateral head image was taken of each hen (n = 710), and 20 landmarks were placed along each image's dorsal and ventral margins of the maxillary beak. Landmark coordinates were standardized by Procrustes superimposition, and the covariation was analyzed by principal components analysis and multivariate regression. Feather cover was scored at 3 ages and mortality was monitored throughout the production cycle. Three principal components (PCs) explained 83% of the maxillary beak shape variation and the first PC partially separated the 2 lines. Maxillary beak shapes ranged from long and narrow with pointed tips to short and wide with more curved tips. Moderate correlations were found between the maxillary beak and premaxillary bone shape (rs = 0.44) and size (rs = 0.52). Line A hens had better feather cover than Line B at all ages. Line A hens also had less total and cannibalism-related mortality than Line B (10.7 and 0.4% vs. 16.7 and 2.4%, respectively). Beak shape may be one factor contributing to the observed differences in feather cover and mortality. The results suggest that distinct maxillary beak phenotypes within each line could be selected to help reduce SFP damage and improve bird welfare.


Asunto(s)
Pollos , Plumas , Animales , Femenino , Pollos/genética , Pico , Crianza de Animales Domésticos/métodos , Canibalismo , Conducta Animal
11.
Anim Genet ; 43(4): 410-8, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22497523

RESUMEN

The size and orientation of calcium carbonate crystals influence the structure and strength of the eggshells of chickens. In this study, estimates of heritability were found to be high (0.6) for crystal size and moderate (0.3) for crystal orientation. There was a strong positive correlation (0.65) for crystal size and orientation with the thickness of the shell and, in particular, with the thickness of the mammillary layer. Correlations with shell breaking strength were positive but with a high standard error. This was contrary to expectations, as in man-made materials smaller crystals would be stronger. We believe the results of this study support the hypothesis that the structural organization of shell, and in particular the mammillary layer, is influenced by crystal size and orientation, especially during the initial phase of calcification. Genetic associations for crystal measurements were observed between haplotype blocks or individual markers for a number of eggshell matrix proteins. Ovalbumin and ovotransferrin (LTF) markers for example were associated with crystal size, while ovocleidin-116 and ovocalyxin-32 (RARRES1) markers were associated with crystal orientation. The location of these proteins in the eggshell is consistent with different phases of the shell-formation process. In conclusion, the variability of crystal size, and to a lesser extent orientation, appears to have a large genetic component, and the formation of calcite crystals are intimately related to the ultrastructure of the eggshell. Moreover, this study also provides evidence that proteins in the shell influence the variability of crystal traits and, in turn, the shell's thickness profile. The crystal measurements and/or the associated genetic markers may therefore prove to be useful in selection programs to improve eggshell quality.


Asunto(s)
Pollos/genética , Cáscara de Huevo/química , Marcadores Genéticos , Variación Genética , Fenotipo , Animales , Carbonato de Calcio/metabolismo , Conalbúmina/análisis , Proteínas del Huevo/química , Proteínas del Huevo/genética , Cáscara de Huevo/ultraestructura , Femenino , Modelos Lineales , Masculino , Microscopía Electrónica de Rastreo , Ovalbúmina/análisis , Linaje , Polimorfismo de Nucleótido Simple , Carácter Cuantitativo Heredable
12.
Anim Genet ; 43(2): 163-71, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22404352

RESUMEN

Dissecting the genetic control of complex trait variation remains very challenging, despite many advances in technology. The aim of this study was to use a major growth quantitative trait locus (QTL) in chickens mapped to chromosome 4 as a model for a targeted approach to dissect the QTL. We applied a variant of the genetical genomics approach to investigate genome-wide gene expression differences between two contrasting genotypes of a marked QTL. This targeted approach allows the direct quantification of the link between the genotypes and the genetic responses, thus narrowing the QTL-phenotype gap using fewer samples (i.e. microarrays) compared with the genome-wide genetical genomics studies. Four differentially expressed genes were localized under the region of the QTL. One of these genes is a potential positional candidate gene (AADAT) that affects lysine and tryptophan metabolism and has alternative splicing variants between the two genotypes. In addition, the lysine and glycolysis metabolism pathways were significantly enriched for differentially expressed genes across the genome. The targeted approach provided a complementary route to fine mapping of QTL by characterizing the local and the global downstream effects of the QTL and thus generating further hypotheses about the action of that QTL.


Asunto(s)
Pollos/crecimiento & desarrollo , Pollos/genética , Sitios de Carácter Cuantitativo , Animales , Pollos/fisiología , Humanos , Análisis de Secuencia por Matrices de Oligonucleótidos
13.
Diabetologia ; 54(5): 1019-24, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21336532

RESUMEN

AIMS/HYPOTHESIS: Lower adiponectin levels are associated with higher risk of incident type 2 diabetes. Most analyses have been adjusted for confounding factors, but few have taken into account insulin resistance per se. We tested the hypothesis that the association of adiponectin levels with incident type 2 diabetes differs between insulin-resistant and insulin-sensitive individuals. METHODS: We studied two prospective cohorts: the Framingham Offspring Study (n = 2,023) and the Cooperative Health Research in the Region of Augsburg (KORA) S4/F4 study (n = 887) cohorts. Insulin resistance was estimated by HOMA-insulin resistance (HOMA-IR). We used logistic regression analysis to test the association between adiponectin and incident type 2 diabetes overall and in insulin-resistant vs insulin-sensitive individuals (defined by ≥ vs <75th percentile of HOMA-IR). RESULTS: At baseline, Framingham's participants were 60 ± 9 years old and 56% were women; KORA's participants were 63 ± 5 years old and 49% were women. Type 2 diabetes incidence was 5.4% over 6.5 years (n = 109) in Framingham and 10.5% over 8 years (n = 93) in KORA. Lower adiponectin levels were associated with type 2 diabetes incidence in both cohorts. In insulin-resistant individuals, lower adiponectin levels were associated with higher risk of type 2 diabetes incidence (OR 1.60 [95% CI 1.10-2.31] per SD decrease in Framingham, p = 0.01; and OR 2.34 [95% CI 1.16-4.73] in KORA, p = 0.02); while this was not observed in insulin-sensitive individuals (OR 1.10 [95% CI 0.73-1.67] in Framingham, p = 0.64; and OR 1.34 [95%CI: 0.88-2.03] in KORA, p = 0.18). CONCLUSIONS/INTERPRETATION: We conclude that lower adiponectin levels are associated with higher risk of type 2 diabetes in insulin-resistant but not in insulin-sensitive individuals. This suggests that some level of insulin resistance is needed to see deleterious effects of low adiponectin.


Asunto(s)
Adiponectina/sangre , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/epidemiología , Resistencia a la Insulina/fisiología , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos
14.
Poult Sci ; 100(12): 101500, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34700097

RESUMEN

Beak treatment is an effective method of reducing the damage inflicted by severe feather pecking (SFP) but there is significant pressure to eliminate these treatments and rely solely on alternative strategies. Substantial variation in beak shape exists within non-beak treated layer flocks and beak shape appears to be heritable. There is the potential to use this pre-existing variation and genetically select for hens whose beak shapes are less apt to cause damage during SFP. To do this, we must first understand the range of phenotypes that exist for both the external beak shape and the bones that provide its structure. The objective of this study was to determine the variation in premaxillary (within the top beak) and dentary (within the bottom beak) bone morphology that exists in 2 non-beak treated pure White Leghorn layer lines using geometric morphometrics to analyze radiographs. Lateral head radiographs were taken of 825 hens and the premaxillary and dentary bones were landmarked. Landmark coordinates were standardized by Procrustes superimposition and the covariation was analyzed by principal components analysis and multivariate regression using Geomorph (an R package). Three principal components (PCs) explained 85% of total premaxillary bone shape variation and showed that the shape ranged from long and narrow with pointed bone tips to short and wide with more curved tips. Two PCs explained 81% of total dentary bone shape variation. PC1 described the dentary bone length and width and PC2 explained the angle between the bone tip and its articular process. For both bones, shape was significantly associated with bone size and differed significantly between the two lines. Bone size accounted for 42% of the total shape variation for both bones. Together, the results showed a range of phenotypic variation in premaxillary and dentary bone shape, which in turn may influence beak shape. These bone phenotypes will guide further quantitative genetic and behavioral analyses that will help identify which beaks shapes cause the least damage when birds engage in SFP.


Asunto(s)
Pico , Pollos , Animales , Pollos/genética , Plumas , Femenino
15.
Gen Comp Endocrinol ; 163(1-2): 225-32, 2009 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-19303879

RESUMEN

Activation of the shell gland region of the avian oviduct is mediated by ovarian steroids. To understand more extensively how shell glands are maintained and function, we have compared gene expression in the shell glands from juvenile and laying hens using a chicken cDNA microarray. Average expression profiles of juvenile and sexually mature shell glands were compared resulting in the identification of 266 differentially regulated genes. Reverse transcription quantitative polymerase chain reaction confirmed expression differences. The differentially expressed genes included several with known involvement in shell gland function, including ion transport and shell matrix proteins. There were also many unpredicted differentially expressed genes, and for some we propose hypotheses for their functions. These include those encoding (a) osteoprotegerin, a decoy death receptor for receptor activator of nuclear factor NFkB ligand (RANKL) and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), that in the shell gland, may prevent apoptosis and/or may have an endocrine effect by preventing RANKL's action on bone osteoclasts that mobilize stored calcium; (b) prostatic acid phosphatase (ACPP) and prostate stem cell antigen (PSCA) that could play a role in sperm physiology within the shell gland; (c) urea transporter (SLC14A2) that could provide a novel anti-microbial defence; (d) bactericidal/permeability-increasing protein-like 2 (BPIL2), and other potential anti-microbials that have not previously been documented in the chicken. These new hypotheses, if borne out experimentally, will lead to a greater understanding of shell gland function including the processes involved in eggshell formation and anti-microbial activity.


Asunto(s)
Pollos/fisiología , Cáscara de Huevo/metabolismo , Animales , Western Blotting , Femenino , Regulación del Desarrollo de la Expresión Génica , Masculino , Análisis de Secuencia por Matrices de Oligonucleótidos , Osteoprotegerina/metabolismo , Oviductos/metabolismo , Próstata/metabolismo , Ligando RANK/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Ligando Inductor de Apoptosis Relacionado con TNF/metabolismo
16.
Anim Genet ; 40(1): 110-4, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18828860

RESUMEN

Novel and traditional eggshell quality measurements were made from up to 2000 commercial pedigree hens for a candidate gene association analysis with organic eggshell matrix genes: ovocleidin-116, osteopontin (SPP1), ovocalyxin-32 (RARRES1), ovotransferrin (LTF), ovalbumin and ovocalyxin-36, as well as key genes in the maintenance and function of the shell gland [estrogen receptor (ESR1) and carbonic anhydrase II (CAII)]. Associations were found for (i) ovalbumin with breaking strength and shell thickness; (ii) ovocleidin-116 with elastic modulus, shell thickness and egg shape; (iii) RARRES1 with mammillary layer thickness; (iv) ESR1 with dynamic stiffness; (v) SPP1 with fracture toughness and (vi) CAII with egg shape. The marker effects are as large as 17% of trait standard deviations and could be used to improve eggshell quality.


Asunto(s)
Pollos/genética , Proteínas del Huevo/genética , Cáscara de Huevo/química , Huevos , Polimorfismo de Nucleótido Simple , Animales , Femenino
17.
Cryo Letters ; 30(2): 96-9, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19448858

RESUMEN

We use an automatic lag time apparatus to show that an electric field of 5*10(4) V/m-1 appears to have no effect on the nucleation of supercooled water. Previously reported effects at similar magnitude fields are most likely due to the inherent stochastic nature of liquid to solid nucleation.


Asunto(s)
Electricidad , Hielo , Agua/química , Frío , Cristalización , Procesos Estocásticos
18.
Int J Obes (Lond) ; 32 Suppl 2: S17-20, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18469835

RESUMEN

OBJECTIVE: To review published data on vascular disease- and diabetes-related outcomes related to adiposity and metabolic risk factors. DESIGN: Community cohort study with cross-sectional and prospective data. SUBJECTS: Middle-aged Caucasian adults in a suburban environment. MEASUREMENTS: Traditional risk factors for cardiovascular disease and the type 2 diabetes mellitus, as well as measures of insulin resistance, left ventricular hypertrophy and vascular calcification. RESULTS: The cardiometabolic risk factors cluster in the population and a common core that includes adiposity (both waist and body mass index), abnormal lipids (both HDL cholesterol and triglycerides), and abnormal glucose and insulin metabolism was found to be present in Framingham participants. Increased insulin resistance was also found to be associated with coronary artery calcification and left ventricular hypertrophy in women. Analyses of the metabolic syndrome risk factors showed that a greater burden of risk factors was associated with greater risk of both cardiovascular disease and diabetes mellitus. An equation to estimate risk of developing type 2 diabetes mellitus has been developed from the Framingham experience, and the risk factors included in the metabolic syndrome are key components, including increased waist girth, elevated blood pressure, low HDL cholesterol, high triglycerides and impaired fasting glucose. CONCLUSION: Cardiometabolic factors and insulin resistance are important contributors to the development of type 2 diabetes mellitus, subclinical cardiovascular disease and clinical cardiovascular disease.


Asunto(s)
Enfermedades Cardiovasculares/etiología , Síndrome Metabólico/complicaciones , Adiposidad , Enfermedades Cardiovasculares/epidemiología , Diabetes Mellitus Tipo 2/epidemiología , Diabetes Mellitus Tipo 2/etiología , Humanos , Resistencia a la Insulina , Síndrome Metabólico/epidemiología , Factores de Riesgo
19.
J Phys Chem B ; 112(37): 11750-5, 2008 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-18720967

RESUMEN

Workman-Reynolds freezing potentials have been measured for the first time across the interface between single crystals of ice 1h and dilute electrolyte solutions. The measured electric potential is a strictly nonequilibrium phenomenon and a function of the concentration of salt, freezing rate, orientation of the ice crystal, and time. When all these factors are controlled, the voltage is reproducible to the extent expected with ice growth experiments. Zero voltage is obtained with no growth or melting. For rapidly grown ice 1h basal plane in contact with a solution of 10 (-4) M NaCl the maximum voltage exceeds 30 V and decreases to zero at both high and low salt concentrations. These single-crystal experiments explain much of the data captured on this remarkable phenomenon since 1948.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA