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1.
Comput Methods Programs Biomed ; 152: 93-104, 2017 Dec.
Article in English | MEDLINE | ID: mdl-29054264

ABSTRACT

BACKGROUND AND OBJECTIVES: A huge number of solutions based on computational systems have been recently developed for the classification of cognitive abnormalities in older people, so that individuals at high risk of developing neurodegenerative diseases, such as Cognitive Impairment and Alzheimer?s disease, can be identified before the manifestation of the diseases. Several factors are related to these pathologies, making the diagnostic process a hard problem to solve. This paper proposes a computational model based on the artificial neural network to classify data patterns of older adults. METHODS: The proposal takes into account the several parameters as diagnostic factors as gender, age, the level of education, study time, and scores from cognitive tests (Mini-Mental State Examination, Semantic Verbal Fluency Test, Clinical Dementia Rating and Ascertaining Dementia). This non-linear regression model is designed to classify healthy and pathological aging with machine learning techniques such as neural networks, random forest, SVM, and stochastic gradient boosting. We deployed a simple linear regression model for the sake of comparison. The primary objective is to use a regression model to analyze the data set aiming to check which parameters are necessary to achieve high accuracy in the diagnosis of neurodegenerative disorders. RESULTS: The analysis demonstrated that the usage of cognitive tests produces median values for the accuracy greater than 90%. The ROC analysis shows that the best sensitivity performance is above 98% and specificity of 96% when the configurations have only cognitive tests. CONCLUSIONS: The presented approach is a valuable tool for identifying patients with dementia or MCI and for supporting the clinician in the diagnostic process, by providing an outstanding support decision tool in the diagnostics of neurodegenerative diseases.


Subject(s)
Cognitive Dysfunction/diagnosis , Dementia/diagnosis , Neural Networks, Computer , Age Factors , Aged , Aged, 80 and over , Early Diagnosis , Female , Humans , Machine Learning , Male , Middle Aged , Nonlinear Dynamics , Prognosis , ROC Curve , Regression Analysis , Sensitivity and Specificity , Sex Factors
2.
Arq. bras. med. vet. zootec. (Online) ; 69(4): 921-926, jul.-ago. 2017. tab, graf
Article in Portuguese | LILACS, VETINDEX | ID: biblio-876685

ABSTRACT

Apesar dos inúmeros benefícios da fluidoterapia transcirúrgica, sobrecarga de volume pode trazer efeitos deletérios, como a alteração de parâmetros hematimétricos. Dessa maneira, o presente trabalho teve como objetivo avaliar duas diferentes taxas de infusão de solução cristaloide no período transanestésico e seus efeitos até 24 horas pós-operatório. Foram utilizados dois grupos de seis animais cada, um deles recebeu solução de cloreto de sódio 0,9% a 10mL/kg/h (G10) e o outro a 5mL/kg/h (G5). Os valores de hematócrito foram avaliados no período de 24 horas em 10 diferentes momentos. Os resultados não apontaram diferenças significativas entre os grupos, porém foi observada redução significativa do hematócrito após indução anestésica. Foi ainda observada redução de hematócrito após o término da cirurgia em ambos os grupos, e o retorno aos valores basais de hematócrito ocorreu de forma significativa 12 horas após o procedimento cirúrgico em G10, e após oito horas em G5, mostrando uma tendência à hemodiluição mais persistente em G10.(AU)


Despite the beneficial goals of fluid therapy administered during surgery, volume overload can cause deleterious effects, such as alterations on hematimetric parameters. Thus, the objective of this paper was to evaluate two different cristaloid infusion rates during the surgical period and its effects on the 24-hour post-surgical period. Two groups of six animals each were used in the present study, one received 10mL/kg/h (G10) of 0,9% sodium chloride solution and the other 5mL/kg/h (G5) of the same solution. Packed cell volume (PCV) was evaluated in 10 different times during the 24 hours following surgery. The results did not show significant differences between groups, but they showed a major tendency of hemodilution in G10. A significant decrease of PCV was observed after induction of anesthesia. Decrease of PCV after the end of surgery in both groups was also observed, and the return to PCV basal values was observed 12 hours after the procedure in G10 and after eight hours in G5, showing a tendency of prolonged hemodilution in G10.(AU)


Subject(s)
Animals , Female , Dogs , Anesthesia/veterinary , Fluid Therapy/veterinary , Hematocrit/veterinary , Hemodilution/veterinary , Hysterectomy/veterinary , Ovariectomy/veterinary , Salpingostomy/veterinary
3.
Arq. bras. med. vet. zootec ; 68(3): 725-732, tab, graf
Article in Portuguese | LILACS, VETINDEX | ID: lil-785697

ABSTRACT

O objetivo deste estudo foi determinar os valores energéticos de rações expandidas, obtidas em diferentes temperaturas de expansão para frangos de corte em diferentes idades. As rações foram expandidas nas temperaturas: 80; 100; 120; 140ºC. Dois ensaios biológicos foram conduzidos utilizando-se o método tradicional de coleta total de excretas para determinar a energia metabolizável aparente corrigida (EMAn). Os ensaios metabólicos foram conduzidos com pintos machos Cobb, de 11 a 19 dias (fase inicial) e de 27 a 35 dias de idade (fase de crescimento), utilizando-se as mesmas aves do primeiro ensaio e, assim, preservando os tratamentos a que foram submetidas. Os valores da EMAn das rações da fase inicial foram: 2937; 2900; 2806 e 2751kcal/kg, e da fase de crescimento: 3045; 3031; 3115 e 2977kcal/kg, respectivamente. Os resultados mostraram uma redução linear dos níveis de EMn com o aumento da temperatura de expansão na idade de 11 a 19 dias. As perdas relativas entre as rações expandidas a 80 e 100ºC foram mínimas, enquanto nas temperaturas de 120 e 140ºC foram significativamente superiores. No ensaio de metabolismo para a fase de crescimento, verificou-se que as perdas relativas entre as rações expandidas a 80 e 100ºC foram pequenas (-14kcal). Para a ração expandida a 120ºC, o valor energético foi superior (84 kcal), enquanto para 140ºC foi significativamente inferior (-138kcal). Esses resultados mostram que, na fase de crescimento, os frangos de corte maximizaram o aproveitamento energético das rações na temperatura de expansão de 120ºC e que, em temperaturas acima desse nível, ocorrem altas perdas da EMAn das rações, que podem comprometer o consumo, a deposição de proteína e a conversão alimentar e, consequentemente, trazer grandes prejuízos econômicos pelo menos à idade de abate. As temperaturas de expansão de rações entre 80 e 100ºC apresentaram os melhores valores de EMAn para frangos com idade entre 15 e 10 dias, enquanto para idade de 31 a 35 dias foi de 120ºC.(AU)


The aim of this study was to determine the energetic value of feed in different expansion temperatures for broilers of different ages. The feedexpanded in the following temperatures: 80; 100, 120 and 140ºC. Two biological assays were run to establish apparent metabolizable energy corrected by nitrogen balance (AMEN) using the traditional total excreta collection method. In the first assay Cobb chicks were used from 11 to 19 days of age (initial period), and 29 to 37 days of age (growth period), as well as the same treatments of the first assay. The AMEN values for the initial period were respectively: 2937, 2900, 2806 and 2751 kcal/kg; and broilers in growing period were respectively: 3045, 3031, 3115 and 2977 kcal/kg. The results showed a linear decrease of the levels EMAN with an increase of the temperature of expansion from 11 to 19 days old. The loss relation between feed expanded at 80 and 100ºC were minimal, while in temperatures between 120 and 140ºC they were significantly higher. In the metabolic assay for period growth, we observed that the relation of energy values between feed expanded at 80 and 100ºC were smaller (14 kcal), while for the expanded in 120ºC they were superior (84 kcal), and at 140ºC were inferior (138 kcal). These results suggest greater energy utilization efficiency in period growth at a temperature of 120 ºC, while in temperatures above of this level there was greater loss of EMAN in feeds, which can prejudice feed intake, protein deposition and feed conversion, and consequently damage economics by increasing slaughter age. The expansion temperatures in feed between 80 and 100ºC showed the best EMAN values for broilers with 15 - 19 days of age, while for 31 - 35 days old it was 120 ºC.(AU)


Subject(s)
Animals , Animal Feed , Chickens/metabolism , Energy Intake , Excreta Disposal/adverse effects , Poultry/metabolism , Temperature
4.
Arq. bras. med. vet. zootec ; 66(2): 546-554, Jan.-Apr. 2014. tab
Article in Portuguese | LILACS | ID: lil-709296

ABSTRACT

O experimento objetivou determinar os valores nutricionais de diferentes frações de milho obtidas por meio de estratificação em mesa densimétrica na recria de frangas. Os milhos foram designados como: MDA - milho de densidade alta; MDI - milho de densidade intermediária; MDB - milho de densidade baixa; MDT - milho de densidade total, composto de 30% de MDA, 60% de MDI e 10% de MDB. Para a determinação da energia metabolizável corrigida (EMAn) foi utilizado o método de coleta total de excretas em frangas Hy Line de 15 semanas. Os valores de EMAn (kcal/kg na MN) foram: 3.467; 3.340; 3.217 e 3.385kcal/kg e densidade (kg/m³): 818,61; 698,13; 681,80 e 736,39kg/m³ para MDA; MDI; MDB e MDT, respectivamente. O MDB apresentou maior valor em todos os aminoácidos digestíveis, com maior intensidade para o triptofano. As frações de milho foram variáveis quanto ao EMAn e perfil de aminoácidos digestíveis, indicando a necessidade de correções nutricionais para a formulação de rações de custo mínimo...


The experiment aimed to determine the nutritional value of different corn fractions obtained by stratification in a gravity table of replacement pullets. The corn was designated as MDA - high density corn; MDI - medium density corn; MDB - low density corn; MDT - total corn density, composed of 30% MDA, 60% MDI and 10% MDB. To determine the corrected metabolizable energy (AME N) a method for total collection of excreta with pullets Hy Line was used for 15 weeks. AME N (kcal/kg in MN) were: 3467, 3340, 3217 and 3385kcal/kg and density (kg/m³): 818.61, 698.13, 681.80 and 736.39 for MDA, MDI, MDB and MDT, respectively. The MDB showed the highest value in all the digestible amino acids, with higher intensity for the tryptophan. The fractions of corn were variable as to AME N and digestible amino acid profiles, indicating the need for corrections to the nutritional feed formulation of minimum cost...


Subject(s)
Animals , Female , Animal Feed , Chickens/growth & development , Nutritive Value , Zea mays/classification , Energy Metabolism , Oviposition , Weaning
5.
Avian Pathol ; 43(1): 82-90, 2014.
Article in English | MEDLINE | ID: mdl-24350836

ABSTRACT

Overcrowding stress is a reality in the poultry industry. Chickens exposed to long-term stressful situations present a reduction of welfare and immunosuppression. We designed this experiment to analyse the effects from overcrowding stress of 16 birds/m(2) on performance parameters, serum corticosterone levels, the relative weight of the bursa of Fabricius, plasma IgA and IgG levels, intestinal integrity, macrophage activity and experimental Salmonella Enteritidis invasion. The results of this study indicate that overcrowding stress decreased performance parameters, induced enteritis and decreased macrophage activity and the relative bursa weight in broiler chickens. When the chickens were similarly stressed and infected with Salmonella Enteritidis, there was an increase in feed conversion and a decrease in plasma IgG levels in the stressed and Salmonella-infected birds. We observed moderate enteritis throughout the duodenum of chickens stressed and infected with Salmonella. The overcrowding stress decreased the macrophage phagocytosis intensity and increased Salmonella Enteritidis counts in the livers of birds challenged with the pathogenic bacterium. Overcrowding stress via the hypothalamic-pituitary-adrenal axis that is associated with an increase in corticosterone and enteritis might influence the quality of the intestinal immune barrier and the integrity of the small intestine. This effect allowed pathogenic bacteria to migrate through the intestinal mucosa, resulting in inflammatory infiltration and decreased nutrient absorption. The data strengthen the hypothesis that control of the welfare of chickens and avoidance of stress from overcrowding in poultry production are relevant factors for the maintenance of intestinal integrity, performance and decreased susceptibility to Salmonella infection.


Subject(s)
Chickens , Crowding , Poultry Diseases/immunology , Poultry Diseases/microbiology , Salmonella Infections, Animal/immunology , Salmonella enteritidis , Stress, Physiological/immunology , Analysis of Variance , Animal Welfare , Animals , Corticosterone/blood , Disease Susceptibility/immunology , Disease Susceptibility/veterinary , Duodenum/microbiology , Macrophages/immunology
6.
Arq. bras. med. vet. zootec ; 65(4): 1139-1148, Aug. 2013. graf, tab
Article in Portuguese | LILACS | ID: lil-684473

ABSTRACT

Os efeitos da parede celular de Saccharomyces cerevisiae (PCSc) na dieta para frangos foram avaliados com base nos tratamentos: dieta referência com avilamicina (AV); dieta referência (DR); DR com 0,1% de PCSc (PCSc0,1); DR com 0,2% de PCSc (PCSc0,2); DR com 0,3% de PCSc (PCSc0,3). O delineamento foi o de blocos ao acaso, com cinco tratamentos e seis repetições de 10 aves, totalizando 300 frangos, machos. No período de nove a 21 dias de idade, o tratamento PCSc0,3 influenciou negativamente no ganho de peso (631g), e no período de 34 a 39 dias, o tratamento PCSc0,1 proporcionou melhor ganho de peso (461g) em relação ao tratamento com o antimicrobiano. O maior peso vivo ao abate, 2571g, foi obtido no tratamento PCSc0,1. Os pesos absolutos de sobrecoxa e coxa+sobrecoxa foram maiores nos tratamentos PCSc0,1 (290g e 560g) e PCSc0,2 (292g e 561g) e menores no tratamento PCSc0,3 (263g e 515g). Não houve influência na metabolizabilidade da ração e na contagem total de coliformes totais no íleo. Dietas com inclusão de até 0,2% de PCSc resultaram em índices produtivos adequados, podendo ser utilizadas como aditivo em dietas livres de antimicrobiano melhorador de desempenho sem o comprometimento do desempenho, características de carcaça, metabolizabilidade da ração e da contagem total de coliformes totais do íleo.


The effects of the yeast cell wall (Saccharomyces cerevisiae) (CWSc) in the diet of broiler chickens were evaluated through the following treatments: reference diet with avilamicin (AV); reference diet (RD); RD with 0.1% CWSc (CWSc0,1); RD with 0.2% CWSc (CWSc0,2); RD with 0.3% CWSc (CWSc0,3). The study design was randomized blocks, with five treatments and six replicates of 10 birds, totaling 300 male broilers. In the period from 9 to 21 days treatment CWSc0.3 had a negative influence on weight gain (631g) and from 34 to 39 days CWSc0.1 provided better weight gain (461g) compared to the treatment with the antimicrobial. The highest live weight value at slaughter, 2,571 grams, was obtained in treatment CWSc0.1. The absolute weights of drumstick and thigh+drumstick were higher in treatments CWSc0.1 (290g and 560g) and CWSc0.2 (292g and 561g) and were lower for CWSc0.3 (263g and 515g). There was no influence of the treatments on both the metabolizability and the total count of coliforms in the ileum. Diets until 0.2% of PCSc inclusion resulted in correct productive rates and they can be used as a ration growth promoter additive in antimicrobial free diets without damage on performance, carcass characteristics, organ weight, metabolizability of the diets and total coliform count in the ileum.


Subject(s)
Animals , Diet/methods , Yeasts/pathogenicity , Cell Wall/parasitology , Saccharomyces , Chickens/classification
7.
Avian Pathol ; 41(5): 421-7, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22900578

ABSTRACT

Stressful situations reduce the welfare, production indices and immune status of chickens. Salmonella spp. are a major zoonotic pathogens that annually cause over 1 billion infections worldwide. We therefore designed the current experiment to analyse the effects of 31±1°C heat stress (HS) (from 35 to 41 days) on performance parameters, Salmonella invasion and small intestine integrity in broiler chickens infected with Salmonella Enteritidis. We observed that HS decreased body weight gain and feed intake. However, feed conversion was only increased when HS was combined with Salmonella Enteritidis infection. In addition, we observed an increase in serum corticosterone levels in all of the birds that were subjected to HS, showing a hypothalamus-pituitary-adrenal axis activation. Furthermore, mild acute multifocal lymphoplasmacytic enteritis, characterized by foci of heterophil infiltration in the duodenum, jejunum and ileum, was observed in the HS group. In contrast, similar but more evident enteritis was noted in the heat-stressed and Salmonella-infected group. In this group, moderate enteritis was observed in all parts of the small intestine. Lastly, we observed an increase in Salmonella counts in the spleens of the stressed and Salmonella-infected chickens. The combination of HS and Salmonella Enteritidis infection may therefore disrupt the intestinal barrier, which would allow pathogenic bacteria to migrate through the intestinal mucosa to the spleen and generate an inflammatory infiltrate in the gut, decreasing performance parameters.


Subject(s)
Chickens , Enteritis/veterinary , Heat Stress Disorders/veterinary , Poultry Diseases/physiopathology , Salmonella Infections, Animal/physiopathology , Salmonella enteritidis/physiology , Animals , Body Weight , Cecum/microbiology , Cecum/pathology , Corticosterone/blood , Enteritis/microbiology , Enteritis/physiopathology , Heat Stress Disorders/complications , Heat Stress Disorders/pathology , Heat Stress Disorders/physiopathology , Hot Temperature , Intestinal Mucosa/microbiology , Intestinal Mucosa/pathology , Intestine, Small/microbiology , Intestine, Small/pathology , Liver/microbiology , Liver/pathology , Male , Poultry Diseases/microbiology , Salmonella Infections, Animal/microbiology , Salmonella Infections, Animal/pathology , Spleen/microbiology , Spleen/pathology , Zoonoses
8.
Arq. bras. med. vet. zootec ; 61(5): 1112-1119, out. 2009. tab
Article in Portuguese | LILACS | ID: lil-532023

ABSTRACT

Determinaram-se as frações dos carboidratos não fibrosos, hidrolisáveis e rapidamente fermentáveis em diferentes dietas e estimou-se a digestibilidade aparente desses nutrientes em dois ensaios com equinos. No ensaio I, utilizaram-se quatro equinos em delineamento quadrado latino 4x4, que consumiram dietas compostas por: feno de tifton-85; feno de tifton-85 e feno de alfafa; feno de tifton-85, feno de alfafa e concentrado; feno de tifton-85 e concentrado. No ensaio II, utilizaram-se 15 equinos em delineamento inteiramente casualizado, que consumiram dietas com 5, 13 e 21 por cento de extrato etéreo, obtidos com a inclusão de diferentes proporções de óleo de soja. A inclusão de concentrado nas dietas aumentou a digestibilidade dos carboidratos não fibrosos e de suas frações, sem afetar a digestibilidade da fibra, enquanto, em dietas com 13 por cento de extrato etéreo, a digestibilidade das frações dos carboidratos fibrosos e a dos não fibrosos não foram afetadas. Nas dietas com 21 por cento de extrato etéreo, houve redução na digestibilidade da celulose e dos carboidratos não fibrosos e suas frações hidrolisáveis e rapidamente fermentáveis. A análise dos carboidratos não fibrosos é uma boa estimativa do valor nutricional dos alimentos, podendo ser incluída na avaliação da qualidade dos alimentos e dietas dos equinos.


The fractions of nonfiber carbohydrates, hydrolyzable carbohydrates, and rapidly fermentable carbohydrates of diets and the apparent digestibility of these nutrients were evaluated in horses in two digestion assays. In assay I, four horses in 4x4 latin square diets: tifton-85 hay; tifton-85 hay and alfafa hay; tifton-85 hay, alfafa hay, and concentrate; and tifton-85 hay and concentrate. In assay II, fifteen horses were used in a completely randomized design, diets with 5, 13, and 21 percent ether obtained with the inclusion of different proportions of soybean oil. Results showed that inclusion of concentrate in diets increased digestibility of nonfiber carbohydrates, hydrolyzable carbohydrates, rapidly fermentable carbohydrates, and total carbohydrates, without affecting digestibility of fiber. In diets with 13 percent of ether extract in function of soybean oil inclusion, digestibility of fiber and nonfiber carbohydrates fractions was not affected; however, in diets with 21 percent of ether extract, the digestibility of cellulose, nonfiber carbohydrates, hydrolyzable carbohydrates and rapidly fermentable carbohydrates were reduced. Analysis of nonfiber carbohydrates fractions is a good estimate of feeds nutritional value, and could be included in quality evaluation of feeds and diets given to horses.


Subject(s)
Animals , Dietary Carbohydrates/adverse effects , Soybean Oil/adverse effects , Rumen/metabolism , Equidae
9.
Arq. bras. med. vet. zootec ; 55(4): 467-473, Aug. 2003. tab
Article in Portuguese | LILACS | ID: lil-349708

ABSTRACT

Foram utilizados 3.000 pintos de corte em delineamento inteiramente ao acaso com cinco repetiçöes de 150 aves por unidade experimental para avaliar o efeito de promotores de crescimento sobre o consumo de raçäo, ganho de peso e conversäo alimentar de frangos de corte. As dietas experimentais foram: 1- dieta inicial (20,2 por cento de proteína bruta e 2931kcal de energia metabolizável) de 1 a 20 dias de idade (DI) e dieta final (18,5 por cento de proteína bruta e 2993kcal de energia metabolizável) de 21 a 40 dias de idade (DF); 2- DI mais 0,02 por cento do probiótico Calsporin 10 para a fase inicial e DF mais 0,02 por cento do probiótico Calsporin 10 para a fase final; 3- DI mais 2,0 por cento de probiótico Estibion aves na fase inicial e DF mais 0,63 por cento do probiótico Estibion aves para a fase final; 4- DI mais 0,013 por cento do antibiótico bacitracina de zinco para a fase inicial e DF mais 0,013 por cento do antibiótico bacitracina de zinco para a fase final. Na fase inicial os frangos alimentados com dietas contendo probióticos consumiram menos raçäo e tiveram melhor conversäo alimentar. Os promotores de crescimento näo tiveram efeito sobre as variáveis estudadas na fase final e no período total de criaçäo. Observou-se maior peso de coxa para machos alimentados com dietas contendo o poliprobiótico.


Subject(s)
Animals , Anti-Bacterial Agents , Poultry , Probiotics
10.
Electrophoresis ; 22(6): 1224-32, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11358149

ABSTRACT

A protein map of Caenorhabditis elegans was constructed by using two-dimensional gel electrophoresis followed by peptide mass fingerprinting. A whole worm extract of a mixed population was separated on immobilized pH gradient strips 4-7 L, 3-10 NL, 6-11 L and 12% sodium dodecyl sulfate-polyacrylamide gel eletrophoresis (SDS-PAGE) gels. Gels were stained with colloidal Coomassie blue and 286 spots representing 152 proteins were subsequently identified by matrix-assisted laser desorption/ionization-mass spectrometry after in-gel digestion with trypsin. Most of the identified proteins with known cellular function were enzymes related to carbohydrate and lipid metabolism, or structural proteins with subcellular locations in the cytoplasm, mitochondria or cytoskeleton.


Subject(s)
Caenorhabditis elegans/chemistry , Helminth Proteins/analysis , Animals , Electrophoresis, Gel, Two-Dimensional/methods , Peptide Mapping/methods , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods
11.
J Biol Chem ; 276(10): 7086-92, 2001 Mar 09.
Article in English | MEDLINE | ID: mdl-11102452

ABSTRACT

The effect of the familial hypertrophic cardiomyopathy mutations, A13T, F18L, E22K, R58Q, and P95A, found in the regulatory light chains of human cardiac myosin has been investigated. The results demonstrate that E22K and R58Q, located in the immediate extension of the helices flanking the regulatory light chain Ca(2+) binding site, had dramatically altered Ca(2+) binding properties. The K(Ca) value for E22K was decreased by approximately 17-fold compared with the wild-type light chain, and the R58Q mutant did not bind Ca(2+). Interestingly, Ca(2+) binding to the R58Q mutant was restored upon phosphorylation, whereas the E22K mutant could not be phosphorylated. In addition, the alpha-helical content of phosphorylated R58Q greatly increased with Ca(2+) binding. The A13T mutation, located near the phosphorylation site (Ser-15) of the human cardiac regulatory light chain, had 3-fold lower K(Ca) than wild-type light chain, whereas phosphorylation of this mutant increased the Ca(2+) affinity 6-fold. Whereas phosphorylation of wild-type light chain decreased its Ca(2+) affinity, the opposite was true for A13T. The alpha-helical content of the A13T mutant returned to the level of wild-type light chain upon phosphorylation. The phosphorylation and Ca(2+) binding properties of the regulatory light chain of human cardiac myosin are important for physiological function, and alteration any of these could contribute to the development of hypertrophic cardiomyopathy.


Subject(s)
Cardiomyopathy, Hypertrophic/genetics , Myosin Light Chains/chemistry , Myosin Light Chains/genetics , Amino Acid Sequence , Animals , Binding Sites , Calcium/metabolism , Circular Dichroism , DNA, Complementary/metabolism , Electrophoresis, Polyacrylamide Gel , Humans , Kinetics , Models, Molecular , Molecular Sequence Data , Mutation , Phosphorylation , Protein Binding , Protein Isoforms , Protein Structure, Secondary
12.
J Biol Chem ; 276(6): 3743-55, 2001 Feb 09.
Article in English | MEDLINE | ID: mdl-11060294

ABSTRACT

This study characterizes a transgenic animal model for the troponin T (TnT) mutation (I79N) associated with familial hypertrophic cardiomyopathy. To study the functional consequences of this mutation, we examined a wild type and two I79N-transgenic mouse lines of human cardiac TnT driven by a murine alpha-myosin heavy chain promoter. Extensive characterization of the transgenic I79N lines compared with wild type and/or nontransgenic mice demonstrated: 1) normal survival and no cardiac hypertrophy even with chronic exercise; 2) large increases in Ca(2+) sensitivity of ATPase activity and force in skinned fibers; 3) a substantial increase in the rate of force activation and an increase in the rate of force relaxation; 4) lower maximal force/cross-sectional area and ATPase activity; 5) loss of sensitivity to pH-induced shifts in the Ca(2+) dependence of force; and 6) computer simulations that reproduced experimental observations and suggested that the I79N mutation decreases the apparent off rate of Ca(2+) from troponin C and increases cross-bridge detachment rate g. Simulations for intact living fibers predict a higher basal contractility, a faster rate of force development, slower relaxation, and increased resting tension in transgenic I79N myocardium compared with transgenic wild type. These mechanisms may contribute to mortality in humans, especially in stimulated contractile states.


Subject(s)
Cardiomyopathies/physiopathology , Mutation , Troponin T/physiology , Animals , Base Sequence , Body Weight , Cardiomyopathies/genetics , DNA Primers , Heart/physiopathology , Humans , Mice , Mice, Transgenic , Organ Size , Physical Conditioning, Animal , Troponin T/genetics
13.
J Biol Chem ; 275(43): 33329-35, 2000 Oct 27.
Article in English | MEDLINE | ID: mdl-10938088

ABSTRACT

Annexins are a family of proteins that bind phospholipids in a calcium-dependent manner. Analysis of the sequences of the different members of the annexin family revealed the presence of a pentapeptide biochemically related to KFERQ in some annexins but not in others. Such sequences have been proposed to be a targeting sequence for chaperone-mediated autophagy, a lysosomal pathway of protein degradation that is activated in confluent cells in response to removal of serum growth factors. We demonstrate that annexins II and VI, which contain KFERQ-like sequences, are degraded more rapidly in response to serum withdrawal, while annexins V and XI, without such sequences, are degraded at the same rate in the presence and absence of serum. Using isolated lysosomes, only the annexins containing KFERQ-like sequences are degraded by chaperone mediated-autophagy. Annexins V and XI could associate with lysosomes but did not enter the lysosomes and were not proteolytic substrates. Furthermore, four annexins containing KFERQ-like sequences, annexins I, II, IV, and VI, are enriched in lysosomes with high chaperone-mediated autophagy activity as expected for substrate proteins. These results provide striking evidence for the importance of KFERQ motifs in substrates of chaperone-mediated autophagy.


Subject(s)
Annexins/metabolism , Lysosomes/metabolism , Molecular Chaperones/physiology , Amino Acid Motifs , Animals , Cells, Cultured , Liver/metabolism , Male , Rats , Rats, Wistar
14.
West Indian Med J ; 49(2): 128-33, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10948851

ABSTRACT

The link between excessive consumption of dietary saturated fats and coronary heart disease (CHD) is now well established. Because of its high content of saturated fatty acids, the consumption of foods containing coconut oil may therefore be a risk factor for CHD. While the fatty acid composition of coconut oil is well established, relatively little is known about the other constituents of coconut: the milk, water, cream and meat fractions. In this study, we show that while the water fraction is low in lipid content, the milk contains about 24% of the fat content of oil and the cream and meat fractions about 34%. The other coconut constituents contain significant amounts of medium-chain triglycerides that are formed from fatty acids of chain length 8:0 to 14:0. It is these fatty acids, primarily 14:0, that are thought to be atherogenic. On the other hand, medium-chain triglycerides may be advantageous under some circumstances in that they are absorbed intact and do not undergo degradation and re-esterification processes. As a result, medium-chain triglycerides provide a ready source of energy and may be useful in baby foods or in diet therapy. Nevertheless, the possible negative effects of the saturated fatty acids and the absence of the essential fatty acid linolenic acid from all coconut constituents suggest that the coconut milk, oil and cream should not be used on a regular basis in adults.


Subject(s)
Cocos/chemistry , Coronary Disease/etiology , Fatty Acids/analysis , Coronary Disease/epidemiology , Dietary Fats/analysis , Dietary Fats, Unsaturated/classification , Humans , Lipids/analysis , Lipids/blood , Risk Factors , Trinidad and Tobago
15.
Arch Biochem Biophys ; 379(1): 28-36, 2000 Jul 01.
Article in English | MEDLINE | ID: mdl-10864438

ABSTRACT

Calmodulin-dependent protein kinase I (CaM kinase I) is a member of the expanding class of protein kinases that are regulated by calmodulin (CaM). Its putative CaM-binding region is believed to occur within a 22-residue sequence (amino acids 299-320). This sequence was chemically synthesized and utilized for CaM interaction studies. Gel band shift assays and densitometry experiments with intact CaM kinase I and the CaM-binding domain peptide (CaMKIp) reveal that they bind in an analogous manner, giving rise to 1:1 complexes. Fluorescence analysis using dansyl-CaM showed that conformational changes in CaM on binding CaM kinase I or CaMKIp were nearly identical, suggesting that the peptide mimicked the CaM-binding ability of the intact protein. In the presence of CaM, the peptide displays an enhancement of its unique Trp fluorescence as well as a marked blue shift of the emission maximum, reflecting a transfer to a more rigid, less polar environment. Quenching studies, using acrylamide, confirmed that the Trp in the peptide on binding CaM is no longer freely exposed to solvent as is the case for the free peptide. Studies with a series of Met mutants of CaM showed that the Trp-containing N-terminal end of CaMKIp was bound to the C-terminal lobe of CaM. Near-UV CD spectra also indicate that the Trp of the peptide and Phe residues of the protein are involved in the binding. These results show that the CaM-binding domain of CaM kinase I binds to CaM in a manner analogous to that of myosin light chain kinase.


Subject(s)
Calcium-Calmodulin-Dependent Protein Kinases/chemistry , Calmodulin/chemistry , Acrylamide/pharmacology , Amino Acid Sequence , Binding Sites , Calcium-Calmodulin-Dependent Protein Kinase Type 1 , Calmodulin/analogs & derivatives , Calmodulin/genetics , Circular Dichroism , Electrophoresis, Polyacrylamide Gel , Methionine/genetics , Molecular Sequence Data , Mutation , Peptide Fragments/chemistry , Protein Binding , Protein Conformation , Spectrometry, Fluorescence , Tryptophan/chemistry
16.
West Indian med. j ; 49(2): 128-33, Jun. 2000. tab, gra
Article in English | MedCarib | ID: med-809

ABSTRACT

The link between excessive composition of dietary saturated fats and coronary heart disease (CHD) is now well established. Because of its high content of saturated fatty acids, the composition of foods containing coconut oil may therefore be a risk factor for CHD. While the fatty acid composition of coconut oil is well established, relatively little is known about the other constituents of coconut: the milk, water, cream and meat fractions. In this study, we show that while the water fraction is low in lipid content, the milk contains about 24 percent of the fat content of oil and the cream and meat fractions about 34 percent. The other coconut constituents contain significant amounts of medium-chain triglycerides that are formed from fatty acids of chain length 8:0 to 14:0. It is these fatty acids, primarily 14:0, that are thought to be atherogenic. On the other hand, medium-chain triglycerides provide a ready source of energy and may be useful in baby foods or in diet therapy. Nevertheless, the possible negative effects of the saturated acids and the absence of the essential fatty acid linolenic acid from all coconut constituents suggest that the coconut milk, oil and cream should not be used on a regular basis in adults. (AU)


Subject(s)
Humans , Cocos/chemistry , Coronary Disease/etiology , Fatty Acids/analysis , Coronary Disease/epidemiology , Dietary Fats/analysis , Dietary Fats, Unsaturated/classification , Lipids/analysis , Lipids/blood , Risk Factors , Trinidad and Tobago
17.
West Indian med. j ; 49(2): 128-33, Jun. 2000. tab, graf
Article in English | LILACS | ID: lil-291948

ABSTRACT

The link between excessive composition of dietary saturated fats and coronary heart disease (CHD) is now well established. Because of its high content of saturated fatty acids, the composition of foods containing coconut oil may therefore be a risk factor for CHD. While the fatty acid composition of coconut oil is well established, relatively little is known about the other constituents of coconut: the milk, water, cream and meat fractions. In this study, we show that while the water fraction is low in lipid content, the milk contains about 24 percent of the fat content of oil and the cream and meat fractions about 34 percent. The other coconut constituents contain significant amounts of medium-chain triglycerides that are formed from fatty acids of chain length 8:0 to 14:0. It is these fatty acids, primarily 14:0, that are thought to be atherogenic. On the other hand, medium-chain triglycerides provide a ready source of energy and may be useful in baby foods or in diet therapy. Nevertheless, the possible negative effects of the saturated acids and the absence of the essential fatty acid linolenic acid from all coconut constituents suggest that the coconut milk, oil and cream should not be used on a regular basis in adults.


Subject(s)
Humans , Cocos/chemistry , Coronary Disease/etiology , Fatty Acids/analysis , Trinidad and Tobago , Dietary Fats, Unsaturated/classification , Dietary Fats/analysis , Risk Factors , Coronary Disease/epidemiology , Lipids/analysis , Lipids/blood
19.
Phytochemistry ; 46(2): 185-93, 1997 Sep.
Article in English | MEDLINE | ID: mdl-9311151

ABSTRACT

The tuberous roots of the Mexican yam bean, jicama, (Pachyrhizus erosus L. Urban) contained large quantities of two acidic glycoproteins which accounted for more than 70% of the total soluble proteins (about 3 g per 100 g of tuber on a dry weight basis). The two major proteins, tentatively named YBG1 and YBG2, had apparent M(r)s of 28,000 and 26,000, respectively, by SDS-PAGE. A third protein named YBP22 which accounted for 2-5% of the total soluble proteins had an M(r) of 22,000. YBG1 and YBG2 exhibited great similarity on the basis of their amino acid composition and had identical N-terminal amino acid sequences. The first 23 amino acids in the N-terminal region of YBG2 were DDLPDYVDWRDYGAVTRIKNQGQ which showed strong homology with the papain class of cysteine proteases. YBG1 and YBG2 were found to bind to a Concanavalin A-Sepharose column and were also stained positively by a sensitive glycoprotein stain. Both glycoproteins exhibited cysteine proteolytic activity. In contrast, YBP22 showed sequence homology with several known protease inhibitors, and a polyclonal antibody raised against this protein cross reacted with soybean trypsin inhibitor.


Subject(s)
Fabaceae/chemistry , Glycoproteins/chemistry , Plant Proteins/chemistry , Plants, Medicinal , Amino Acid Sequence , Glycoproteins/isolation & purification , Molecular Sequence Data , Plant Proteins/isolation & purification , Plant Roots/chemistry , Sequence Homology, Amino Acid
20.
Arq. bras. med. vet. zootec ; 49(5): 617-28, out. 1997. tab
Article in Portuguese | LILACS | ID: lil-264569

ABSTRACT

Foram realizados dois experimentos com coelhas da raça Nova Zelândia Branco, com o objetivo de se avaliar o efeito de cinco fontes de fibra sobre a digestibilidade fecal e ileal. Calculou-se uma dieta padräo, na qual a principal fonte de fibra foi o feno de alfafa. As outras dietas se caracterizaram pela substituiçäo isométrica do feno de alfafa pelo feno de guandu, palha de feijäo, palha e sabugo de milho branco e feno de coast cross. utilizou-se a coleta total das fezes para determinaçäo da digestibilidade aparente. A digestibilidade das dietas foi afetada pelo uso das diferentes fontes de fibra. A dieta de palha e sabugo de milho branco apresentou o maior coeficiente de digestibilidade da proteína, no entanto a digestibilidade da MS, MO e EB foi significativamente inferior à dos demais tratamentos. Para a digestibilidade ileal utilizaram-se coelhas fistuladas no íleo e como indicadores o óxido crômico, a lignina e a fibra em detergente ácido. MSD, PD e MOD apresentaram valores significativamente diferentes entre os indicadores utilizados, sendo que a lignina mostrou resultados mais confiáveis como indicador da digestibilidade ileal


Subject(s)
Animals , Female , Dietary Fiber , Rabbits
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