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1.
Epidemiol Infect ; 145(12): 2424-2435, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28689517

RESUMO

The aim of this study was to ascertain farmers' knowledge of the risk of spread of infection from animals to humans, and their transmission prevention practices. This was a survey of farmers who submitted material to Ireland's Regional Veterinary Laboratories in 2015. There was an 84% response rate (1044 farmers). Ninety per cent of farmers were not aware that infection can be acquired from apparently healthy animals. Over half were not aware that disease could be contracted from sick poultry or pets. Conversely, the knowledge of the risk to pregnant women of infection from birthing animals was high (88%). Four-fifths of farmers sourced drinking water from a private well, and of these, 62% tested their water less frequently than once a year. Of dairy farmers, 39% drank unpasteurised milk once a week or more frequently. Veterinarians were the most commonly cited information source for diseases on farms. The survey findings indicate that the level of farmers' knowledge and awareness of the spread of infection from animals to humans is a concern. Further education of the farming community is needed to increase awareness of both the potential biohazards present on farms and the practical measures that can be taken to mitigate the risk of zoonoses.


Assuntos
Fazendeiros/psicologia , Conhecimentos, Atitudes e Prática em Saúde , Zoonoses/prevenção & controle , Zoonoses/transmissão , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Feminino , Humanos , Irlanda , Masculino , Pessoa de Meia-Idade , Medição de Risco , Adulto Jovem , Zoonoses/psicologia
2.
Poult Sci ; 80(3): 272-7, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11261555

RESUMO

The effects of dietary fat and broiler breeder age on egg and embryo characteristics during incubation were investigated. Breeders were fed diets containing no added fat or 3.0% added poultry fat (PF) for peak energy intakes of 430 and 467 kcal/hen day (pC/d), or 1.5% PF or 3.0% corn oil at 449 pC/d. Feeding of diets was initiated at 22 wk, and eggs were collected for incubation at 27 and 36 wk of age. Percentage incubational egg weight loss was determined between day of set and Days 6, 12, and 18. Percentage wet and dry embryo weights, embryo moisture content, and eggshell weights were determined at 6, 12, and 18 d of incubation. Percentage yolk sac weight and wet and dry liver weights and moisture content were determined on Days 12 and 18. Percentage gall bladder weight was determined on Day 18. There were no observed effects due to breeder diet. However, eggshell weight at Days 6, 12, and 18 was higher in 27-wk-old hens compared with 36-wk-old hens. Conversely, egg weight loss between Day 0 and Days 6, 12, and 18 and yolk sac weight across Days 12 and 18 of incubation were lower in eggs at 27 wk of age compared with 36 wk. At Day 18, dry embryo weight was higher and wet liver weight was lower at 27 wk compared with 36 wk. A slower rate of DM accumulation in embryos at Week 36 compared to Week 27 was associated with increased incubational water loss and decreased embryo moisture content, eggshell percentage, and yolk sac absorption rate. These data demonstrate that changes in eggshell characteristics with broiler breeder age can alone impact yolk uptake, growth, and body composition in subsequent embryos.


Assuntos
Ração Animal , Cruzamento , Embrião de Galinha/crescimento & desenvolvimento , Galinhas/fisiologia , Gorduras na Dieta/administração & dosagem , Casca de Ovo/fisiologia , Fatores Etários , Fenômenos Fisiológicos da Nutrição Animal , Animais , Composição Corporal , Óleo de Milho/administração & dosagem , Gema de Ovo/metabolismo , Ovos , Feminino , Incubadoras , Fígado/crescimento & desenvolvimento , Masculino , Água/metabolismo
3.
Cell Stress Chaperones ; 5(3): 163-72, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11005374

RESUMO

GroEL recognizes proteins that are folding improperly or that have aggregation-prone intermediates. Here we have used as substrates for GroEL, wildtype (WT) coat protein of phage P22 and 3 coat proteins that carry single amino acid substitutions leading to a temperature-sensitive folding (tsf) phenotype. In vivo, WT coat protein does not require GroEL for proper folding, whereas GroEL is necessary for the folding of the tsf coat proteins; thus, the single amino acid substitutions cause coat protein to become a substrate for GroEL. The conformation of WT and tsf coat proteins when in a binary complex with GroEL was investigated using tryptophan fluorescence, quenching of fluorescence, and accessibility of the coat proteins to proteolysis. WT coat protein and the tsf coat protein mutants were each found to be in a different conformation when bound to GroEL. As an additional measure of the changes in the bound conformation, the affinity of binding of WT and tsf coat proteins to GroEL was determined using a fluorescence binding assay. The tsf coat proteins were bound more tightly by GroEL than WT coat protein. Therefore, even though the proteins are identical except for a single amino acid substitution, GroEL did not bind these substrate polypeptides in the same conformation within its central cavity. Therefore, GroEL is likely to bind coat protein in a conformation consistent with a late folding intermediate, with substantial secondary and tertiary structure formed.


Assuntos
Capsídeo/química , Capsídeo/metabolismo , Chaperonina 60/metabolismo , Dobramento de Proteína , Acrilamida/farmacologia , Substituição de Aminoácidos , Bacteriófago P22 , Capsídeo/genética , Capsídeo/isolamento & purificação , Centrifugação com Gradiente de Concentração , Chaperonina 60/isolamento & purificação , Fluorescência , Cinética , Mutação , Ligação Proteica , Conformação Proteica , Temperatura
4.
Biochemistry ; 39(38): 11667-76, 2000 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-10995234

RESUMO

Though many proteins in the cell are large and multimeric, their folding has not been extensively studied. We have chosen SecA as a folding model because it is a large, homodimeric protein (monomer molecular mass of 102 kDa) with multiple folding domains. SecA is the ATPase for the Sec-dependent preprotein translocase of many bacteria. SecA is a soluble protein that can penetrate into the membrane during preprotein translocation. Because SecA may partially unfold prior to its insertion into the membrane, studies of its stability and folding pathway are important for understanding how it functions in vivo. Kinetic folding transitions in the presence of urea were monitored using circular dichroism and tryptophan fluorescence, while equilibrium folding transitions were monitored using the same techniques as well as a fluorescent ATP analogue. The reversible equilibrium folding transition exhibited a plateau, indicating the presence of an intermediate. Based on the data presented here, we propose a three-state model, N(2) if I(2) if 2U, where the native protein unfolds to a dimeric intermediate which then dissociates into two unfolded monomers. The SecA dimer was determined to have an overall stability (DeltaG) of -22.5 kcal/mol. We also investigated the stability of SecA using analytical ultracentrifugation equilibrium and velocity sedimentation, which again indicated that native or refolded SecA was a stable dimer. The rate-limiting step in the folding pathway was conversion of the dimeric intermediate to the native dimer. Unfolding of native, dimeric SecA was slow with a relaxation time in H(2)O of 3.3 x 10(4) s. Since SecA is a stable dimer, dissociation to monomeric subunits during translocation is unlikely.


Assuntos
Adenosina Trifosfatases/química , Proteínas de Bactérias/química , Proteínas de Transporte/química , Proteínas de Escherichia coli , Proteínas de Membrana Transportadoras , Dobramento de Proteína , Adenosina Trifosfatases/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Transporte/metabolismo , Dicroísmo Circular , Dimerização , Escherichia coli/enzimologia , Cinética , Peso Molecular , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Estrutura Terciária de Proteína , Canais de Translocação SEC , Proteínas SecA , Espectrometria de Fluorescência , Triptofano/química , Ultracentrifugação/métodos
5.
Poult Sci ; 79(5): 629-39, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10824949

RESUMO

The effects of added dietary fat type and level on broiler breeder performance were evaluated in two trials. In Trial 1, diets included no added fat (NAF) or 3.0% added poultry fat (PF) for individual bird energy intakes of 430 and 467 kcal/d at peak production (PCD), or 1.5% PF or 3.0% corn oil (CO) at 449 PCD. In Trial 2, diets contained NAF, 1.5 or 3.0% added CO or PF, or 3.0% lard (LA) for peak energy intakes of 463 PCD. All diets in Trial 2 were isocaloric and isonitrogenous. Feeding of experimental diets was initiated when breeders were 22 wk old in both trials, and hen BW was measured at various weeks between 22 and 47 wk in Trial 1 and between 27 and 65 wk in Trial 2. Egg production, egg weight (EW), eggshell quality, and hatchability were recorded at various weeks between 24 and 48 wk in Trial 1 and between 27 and 64 wk in Trial 2. Body weights and EW increased progressively, and eggshell quality fluctuated variably with age. Egg production peaked between Weeks 32 and 35, and hatchability was significantly depressed at Week 63. Egg weight and hatchability were not affected by dietary treatment; however, BW increased with energy level in the diet between Weeks 27 and 47. Body weight was also higher in birds fed 1.5 or 3.0% added fat compared with NAF and was higher in birds fed LA compared with CO at the 3.0% level. Egg specific gravity and shell weight per unit of surface area at Week 41 were increased by feeding low or high energy compared with moderate energy, and relative eggshell conductance was increased by using moderate compared with high energy diets and by feeding 1.5% PF compared with 3.0% PF. Egg specific gravity was increased by PF when compared with CO across fat level at Weeks 26 and 47 and by LA when compared with PF across fat level and breeder age. These data suggest that certain dietary energy and fat regimens may affect BW and eggshell quality without associated effects on EW and hatchability at various breeder ages.


Assuntos
Ração Animal , Cruzamento , Galinhas/fisiologia , Gorduras na Dieta/metabolismo , Oviposição/fisiologia , Fatores Etários , Animais , Peso Corporal , Galinhas/metabolismo , Óleo de Milho/administração & dosagem , Óleo de Milho/metabolismo , Gorduras na Dieta/administração & dosagem , Ovos/normas , Ingestão de Energia , Ácidos Graxos Insaturados/administração & dosagem , Ácidos Graxos Insaturados/metabolismo , Feminino , Incubadoras , Ácido Linoleico/administração & dosagem , Ácido Linoleico/metabolismo , Masculino , Distribuição Aleatória , Estações do Ano
6.
Poult Sci ; 79(5): 698-704, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10824958

RESUMO

The effects of breeder age and added dietary fat source and level on broiler hatching egg characteristics were evaluated. Diets included no added fat (NAF) or 3.0% added poultry fat (PF) for peak energy intakes of 430 and 467 kcal/hen-day (PCD) or 1.5% PF or 3.0% corn oil (CO) at 449 PCD. As added dietary fat was changed from CO to PF, the percentage of unsaturated dietary fatty acids, including linoleic acid, decreased. Feeding of experimental diets was initiated when breeders were 22 wk old. Total fresh egg weight; eggshell weight; percentages of yolk (PYK), albumen (PAB), and eggshell (PSHL) weights; and yolk:albumen ratio were measured at various weeks between 26 and 47 wk of age. Egg weight increased progressively with hen age. Significant increases in yolk:albumen ratio occurred between Weeks 26 and 31 and between Weeks 31 and 35. Low (430 PCD) dietary energy levels significantly reduced PYK at 35 wk and increased PAB across breeder age. Eggshell weight was lower in birds fed moderate (449 PCD) compared to low energy levels at Week 26, moderate compared to high (467 PCD) energy levels at Week 41, and PF compared to CO across fat level at Week 31. At Weeks 31 and 41, PSHL was increased by the use of 3.0% PF compared to 1.5%, and PSHL was increased at Weeks 26 and 41 by using added PF compared to CO across fat level. Increased dietary energy decreased PAB and the use of added dietary CO rather than PF decreased PSHL in broiler breeders between 26 and 47 wk of age.


Assuntos
Galinhas/fisiologia , Gorduras na Dieta/administração & dosagem , Ovos/análise , Fatores Etários , Albuminas/análise , Ração Animal , Animais , Galinhas/metabolismo , Óleo de Milho/administração & dosagem , Óleo de Milho/metabolismo , Gorduras na Dieta/metabolismo , Ingestão de Alimentos , Casca de Ovo/fisiologia , Gema de Ovo/fisiologia , Ácidos Graxos/administração & dosagem , Ácidos Graxos/metabolismo , Ácidos Graxos Insaturados/administração & dosagem , Ácidos Graxos Insaturados/metabolismo , Feminino , Masculino , Oviposição , Distribuição Aleatória
7.
J Pediatr Orthop ; 19(6): 805-10, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10573353

RESUMO

Thirteen patients (18 hips) with cerebral palsy and painful hip subluxation or dislocation underwent proximal femoral resection-interposition arthroplasty (PFRIA) as a salvage procedure for intractable pain or seating difficulty. Eleven patients (14 hips) had a prior failed soft-tissue or bony reconstruction. The average age at surgery was 26.6 years (range, 10.7-45.5 years), and average follow-up was 7.4 years (range, 2.2-20.8 years). All patients/caregivers noted significant improvement in subjective assessment of pain after the surgery. Upright sitting tolerance improved from an average preoperative value of 3.2-8.9 h postoperatively (p < 0.01). Four patients who were unable even to sit in a customized wheelchair before the operation could be easily seated in a custom chair after surgery. Hip range of motion including flexion, extension, and abduction was significantly improved postoperatively (p < 0.05). Single-dose radiation therapy was used postoperatively for five hips and resulted in a significantly lower grade of heterotopic ossification at final follow-up (p < 0.005). Skeletal traction in the postoperative period did not prevent proximal migration of the femur compared with skin traction. Maximal pain relief was achieved at an average of 5.6 months postoperatively (range, 0.03-14 months). Complications included transient postoperative decubitus ulceration (four patients), pneumonia (two patients), and symptomatic heterotopic bone (two patients). The significant improvements in pain management, sitting tolerance, and range of motion suggest that PFRIA is a reasonable salvage procedure for the painful, dislocated hip in cerebral palsy. Resolution of pain may not be immediate, as was noted in this series.


Assuntos
Artroplastia/métodos , Paralisia Cerebral/complicações , Cabeça do Fêmur/cirurgia , Luxação do Quadril/cirurgia , Adolescente , Adulto , Criança , Estudos de Avaliação como Assunto , Feminino , Cabeça do Fêmur/diagnóstico por imagem , Seguimentos , Luxação do Quadril/diagnóstico por imagem , Luxação do Quadril/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor , Radiografia , Amplitude de Movimento Articular , Terapia de Salvação , Estatísticas não Paramétricas , Resultado do Tratamento
8.
Acta Orthop Belg ; 65(3): 266-76, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10546349

RESUMO

This article reports five types of persistent bony dysplasia in patients with congenital dislocation of the hip (CDH), suggests the pathogeneses, and discusses the treatment options. We consider the five types to be (1) maldirected acetabulum, (2) capacious acetabulum, (3) false acetabulum, (4) lateralized acetabulum, and (5) femoral deformity. The maldirected acetabulum persists when the acetabulum continues to face forward and laterally. The capacious acetabulum arises from joint instability; capsular laxity permits the proximal femur to slide within the acetabulum. The false acetabulum results from an ectopic fibrocartilaginous cavity in the pelvis created by the subluxated or dislocated femoral head.44 The lateralized acetabulum occurs with ossification of the cotyloid cavity from longstanding lateral subluxation or dislocation or premature closure of the triradiate cartilage. Femoral deformities include valgus and anteversion of the femoral neck, capital femoral physeal growth arrest, discrepancy between the greater trochanter and the femoral head, and femoral head asphericity. After clinical and radiographic evaluation, we believe that an understanding of the pathogeneses and types of dysplasia will facilitate appropriate treatment programs. Treatments consist of acetabular redirection, acetabular reconstruction, femoral osteotomies, and salvage procedures.


Assuntos
Acetábulo/anormalidades , Fêmur/anormalidades , Luxação Congênita de Quadril/patologia , Diagnóstico Diferencial , Quadril/crescimento & desenvolvimento , Luxação Congênita de Quadril/diagnóstico por imagem , Luxação Congênita de Quadril/etiologia , Humanos , Recém-Nascido , Radiografia
9.
J Pediatr Orthop ; 19(4): 508-10, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10413002

RESUMO

Talonavicular coalition is reported as an asymptomatic congenital anomaly of the foot that is noticed incidentally on radiographs of the foot, and is often associated with symphalangism, clinodactyly, ball-and-socket ankle joint, a great toe that is shorter than the second toe, and an autosomal dominant inheritance pattern. We describe here three patients with five involved feet. All three patients had chronic foot pain not secondary to trauma, and all five feet required treatment to alleviate the pain.


Assuntos
Ossos do Pé/anormalidades , Deformidades Congênitas do Pé/reabilitação , Aparelhos Ortopédicos , Sinostose/reabilitação , Adolescente , Artralgia/diagnóstico por imagem , Artralgia/reabilitação , Pré-Escolar , Feminino , Seguimentos , Ossos do Pé/diagnóstico por imagem , Deformidades Congênitas do Pé/diagnóstico por imagem , Humanos , Radiografia , Amplitude de Movimento Articular , Sinostose/diagnóstico por imagem , Tálus/anormalidades , Tálus/diagnóstico por imagem
10.
Biotechniques ; 27(1): 176-80, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10407680

RESUMO

A fully automated nucleic acid analysis system is described, which offers positive sample identification, improved sensitivity and reduced user interaction compared to conventional techniques. The system relies on the sequence-specific capture of DNA onto solid-phase particles, confirming product identity without the problems of interpretation and lack of sequence information inherent in gel-based analyses. The system can be used for sequence confirmation, mutation analysis and semiquantitative detection of PCR products.


Assuntos
Ácidos Nucleicos/análise , Automação , Biotinilação , Análise Mutacional de DNA/métodos , Primers do DNA , Microesferas , Oligonucleotídeos/análise , Reação em Cadeia da Polimerase , Sensibilidade e Especificidade , Análise de Sequência/métodos
11.
Poult Sci ; 78(4): 505-11, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10230901

RESUMO

The effects of breeder age (35, 51, and 63 wk) and added dietary fat on subsequent broiler growth, mortality, and feed conversion through 42 d were evaluated. Beginning at 22 wk of age, diets included 0, 1.5, or 3.0% added poultry fat (PF), 1.5 or 3.0% added corn oil (CO), or 3.0% added lard (LA). Broilers from hens 35 wk of age performed better between 0 and 21 d than those from 51- and 63-wk-old hens. Conversely, between 22 and 42 d, broilers from hens 51 wk of age performed better than those at 35 and 63 wk. In relation to PF, CO added to breeder diets increased 0 to 21 d BW gain in broilers; whereas, feed conversion between 22 and 42 d was reduced in broilers from hens fed PF compared to those fed CO. In conclusion, breeder age influenced broiler performance differently throughout the growout period. Fat added at the 1.5% level to breeder hen diets was an effective energy source. However, less saturated fat improved growout performance.


Assuntos
Ração Animal , Galinhas/crescimento & desenvolvimento , Gorduras na Dieta , Metabolismo Energético , Oviposição , Fatores Etários , Animais , Morte , Feminino , Masculino
12.
Poult Sci ; 78(4): 512-5, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10230902

RESUMO

The effects of breeder age (35, 51, and 63 wk) and added dietary fat on subsequent broiler slaughter yield were evaluated. Beginning at 22 wk of age, diets included 0, 1.5, or 3.0% added poultry fat (PF), 1.5 or 3.0% added corn oil (CO), or 3.0% added lard (LA). Slaughter yields were greatest in broilers from 63-wk-old breeders. Added CO in broiler breeder diets significantly increased subsequent 43-d live BW and chilled carcass yields compared to LA. Furthermore, CO diets significantly increased relative front-half yields compared to PF diets; and compared to the 3.0% fat level, 1.5% added fat significantly increased 43-d live BW, regardless of fat type. In conclusion, breeder age influenced broiler slaughter yield, and fat added at the 1.5% level to breeder hen diets was an effective energy source. However, less saturated fat improved subsequent slaughter yield.


Assuntos
Ração Animal , Galinhas/crescimento & desenvolvimento , Gorduras na Dieta , Carne , Matadouros , Fatores Etários , Animais , Óleo de Milho , Feminino , Masculino
13.
Poult Sci ; 77(10): 1522-30, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9776060

RESUMO

The effects of dietary fat and eggshell cuticle removal on egg water loss, embryo growth, and hatchability were determined in eggs from broiler breeder hens at different ages. Hens were fed isocaloric diets containing one of three different types and levels of added fat. In addition, eggs were either left intact or washed to remove the eggshell cuticle prior to set. Cuticle removal increased egg water loss between 43 and 62 wk. Cuticle removal increased relative wet embryo weight at Week 52 and relative dry embryo weight at 52 and 62 wk. Furthermore, at 62 wk, diet and day of incubation interacted to affect wet embryo weight, and diet variably affected dry embryo weight. No treatment differences were observed for cumulative hatchability, rate of hatch, and relative yolk sac weight at Day 19 of incubation. It was concluded that cuticle removal and the addition of fat to breeder diets may influence embryonic growth without having any subsequent effects on hatchability.


Assuntos
Ração Animal , Embrião de Galinha/crescimento & desenvolvimento , Gorduras na Dieta/farmacologia , Casca de Ovo/fisiologia , Animais , Embrião de Galinha/efeitos dos fármacos , Galinhas , Feminino , Masculino , Água/metabolismo
14.
Br J Radiol ; 71(842): 186-99, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9579183

RESUMO

The purpose of this study was to evaluate the radiation doses received by paediatric patients examined using a digital radiography unit, and to compare these doses with those received from conventional screen-film systems. In this way, guidelines could be drawn up concerning the magnitude of possible dose reductions achievable using digital radiography. The study was undertaken on approximately 900 patients undergoing abdomen, chest, pelvis and skull examinations. Patients were categorized into the following age groups: 0-1 month, 1-12 months, 1-5 years, 5-10 years and 10-15 years. Approximately half were X-rayed using a Fuji computed radiography system and half using a conventional screen-film system. Entrance surface dose was calculated from the recorded exposure parameters and measured X-ray tube outputs. Dose-area product was recorded directly. Image quality was assessed clinically using criteria recommended by a working group of the Commission of the European Communities. Apart from chest examinations, it was found possible to reduce doses by about 40% on average, by using a computed radiography system instead of a 600 speed screen-film combination. There was no significant difference in the dose for chest examinations. Satisfactory image quality can therefore be achieved by using computed radiography as a 1000 speed system for abdomen, pelvis and skull examinations, and as a 600 speed system for chests. Since very few departments appear to use screen-film systems of speeds greater than 400, then, for most departments, the use of computed radiography would result in dose reductions of at least 60%, or 33% for chests.


Assuntos
Doses de Radiação , Intensificação de Imagem Radiográfica , Adolescente , Distribuição por Idade , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Pelve/diagnóstico por imagem , Radiografia Abdominal , Radiografia Torácica , Radiometria/métodos , Crânio/diagnóstico por imagem , Ecrans Intensificadores para Raios X
15.
Poult Sci ; 77(1): 47-53, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9469750

RESUMO

The purpose of the present study was to investigate the combined effects of breeder age (36-, 51-, or 64-wk) and different dietary fat sources (3% added corn oil, poultry fat, or lard) on lipids in fresh egg yolks and yolks of newly hatched chicks. Isocaloric breeder diets were altered by the inclusion of different types of dietary fat such that the poultry fat and lard diets had the highest levels of saturated fatty acids when compared to the corn oil diet. Fresh egg yolks obtained from 36-wk-old breeders exhibited higher levels of palmitoleic acid when compared to the levels observed in fresh egg yolks of 51- or 64-wk-old breeders. Furthermore, these levels decreased significantly by 21 d of incubation only in eggs from 36-wk-old hens. At 36 wk of breeder age, the levels of oleic and arachidonic acid were higher in yolks from hatched chicks than in previous fresh egg values, regardless of type of added dietary fat; whereas the level of linoleic acid was higher only in yolks from hatched chicks compared to those of fresh eggs from 36-wk-old hens fed 3% added corn oil. These data suggest that breeder age influences the utilization of yolk lipid by developing embryos, and that the type of fat provided in the diet may have an additional influence.


Assuntos
Envelhecimento/fisiologia , Galinhas/fisiologia , Gorduras na Dieta , Gema de Ovo/química , Ácidos Graxos/análise , Tecido Adiposo , Análise de Variância , Ração Animal , Animais , Óleo de Milho , Ingestão de Energia , Feminino , Oviposição
16.
J Clin Invest ; 100(9): 2333-40, 1997 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-9410912

RESUMO

Alzheimer's disease is a neurodegenerative disorder characterized by the extracellular deposition in the brain of aggregated beta-amyloid peptide, presumed to play a pathogenic role, and by preferential loss of neurons that express the 75-kD neurotrophin receptor (p75NTR). Using rat cortical neurons and NIH-3T3 cell line engineered to stably express p75NTR, we find that the beta-amyloid peptide specifically binds the p75NTR. Furthermore, 3T3 cells expressing p75NTR, but not wild-type control cells lacking the receptor, undergo apoptosis in the presence of aggregated beta-amyloid. Normal neural crest-derived melanocytes that express physiologic levels of p75NTR undergo apoptosis in the presence of aggregated beta-amyloid, but not in the presence of control peptide synthesized in reverse. These data imply that neuronal death in Alzheimer's disease is mediated, at least in part, by the interaction of beta-amyloid with p75NTR, and suggest new targets for therapeutic intervention.


Assuntos
Doença de Alzheimer/etiologia , Peptídeos beta-Amiloides/metabolismo , Apoptose , Neurônios/citologia , Receptores de Fator de Crescimento Neural/metabolismo , Células 3T3 , Animais , Humanos , Melanócitos/efeitos dos fármacos , Camundongos , Crista Neural/citologia , Ligação Proteica , Ratos , Receptor de Fator de Crescimento Neural , Proteínas Recombinantes
17.
Biochemistry ; 36(13): 3971-80, 1997 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-9092827

RESUMO

Three cold-sensitive mutants in phage P22 coat protein have been characterized to determine the effects of the amino acid substitutions that cause cold sensitivity on the folding pathway and the conformation of refolded coat protein. Here we find that the three cold-sensitive mutants which have the threonine residue at position 10 changed to isoleucine (T10I), the arginine residue at position 101 changed to cysteine (R101C), or the asparagine residue at position 414 changed to serine (N414S) were capable of folding from a denatured state into a soluble monomeric species, but in each case, the folded conformation was altered. Changes in the kinetics of folding were observed by both tryptophan and bisANS fluorescence. In contrast to the temperature-sensitive for folding coat protein mutants which can be rescued at nonpermissive temperatures in vivo by the overproduction of molecular chaperones GroEL and GroES [Gordon, C. L., Sather, S. K., Casjens, S., & King, J. (1994) J. Biol. Chem. 269, 27941-27951], the folding defects associated with the cold-sensitive amino acid substitutions were not recognized by GroEL and GroES.


Assuntos
Bacteriófago P22/química , Capsídeo/química , Mutação , Conformação Proteica , Dobramento de Proteína , Naftalenossulfonato de Anilina , Bacteriófago P22/genética , Capsídeo/genética , Capsídeo/isolamento & purificação , Chaperonina 10/metabolismo , Chaperonina 60/metabolismo , Quimotripsina/metabolismo , Eletroforese em Gel de Poliacrilamida , Corantes Fluorescentes , Guanidina , Guanidinas , Cinética , Desnaturação Proteica , Estrutura Secundária de Proteína , Salmonella typhimurium/metabolismo , Serina Endopeptidases/metabolismo , Espectrometria de Fluorescência , Temperatura
18.
Poult Sci ; 75(6): 695-701, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8737832

RESUMO

In two experiments, the effects of dietary fat and breeder hen age on relative yolk sac weight (RYSW) and total serum cholesterol (CHOL), high (HDLC) and low (LDLC) density lipoprotein cholesterol, triglycerides (TRI), and glucose (GLU) were monitored in broiler embryos and chicks. In Experiment 1, embryos at 18 d of incubation and chicks at hatch were sampled from eggs laid by breeder hens at 26 (young), 36, and 48 wk of age. No dietary effects were noted in either experiment; however, chicks from young hens exhibited elevated serum CHOL, HDLC, LDLC, and lower GLU when compared with chicks from hens at either 36 or 48 wk of age. Additionally, embryos from young breeders displayed a lower RYSW at 18 d of incubation. Conversely, by hatch there was no difference in RYSW among offspring from different aged hens. In Experiment 2, newly hatched chicks were sampled from breeder hens at 36, 51, and 64 wk of age. Dietary effects were also not evident in this experiment; however, chicks from 51-wk-old breeders displayed the highest and lowest serum HDLC and TRI, respectively, compared to the other two age groups, whereas chicks from either 51- or 64-wk-old breeders exhibited higher levels of CHOL than those at 36 wk. Chicks from 64-wk-old breeders displayed an increase in LDLC when compared with the other two ages. These data suggest that serum concentrations of lipids and GLU, and RYSW in 18 d embryos and newly hatched chicks are influenced by hen age and not by added dietary fat.


Assuntos
Animais Recém-Nascidos/sangue , Glicemia/metabolismo , Embrião de Galinha , Galinhas , Gorduras na Dieta/administração & dosagem , Lipídeos/sangue , Fatores Etários , Animais , Feminino , Masculino , Tamanho do Órgão , Saco Vitelino/anatomia & histologia
19.
Exp Cell Res ; 224(2): 335-43, 1996 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-8612710

RESUMO

Apoptosis plays an important role in eliminating dysfunctional damaged cells. For skin, the best characterized injurious environmental agent is ultraviolet (UV) irradiation. Most of the damaging UV irradiation is absorbed in the epidermis and leads to apoptosis of keratinocytes. However, epidermal melanocytes appear to be protected from UV-induced apoptosis. We now report that in pure cultures melanocytic cells undergo characteristic apoptosis after physiologic UV exposures. However, nerve growth factor (NGF) supplementation protects them from this programmed cell death. Furthermore, we show that NGF protects melanocytic cells from UV-induced apoptosis by upregulating BCL-2 protein in these cells and that prior downregulation of BCL-2 abrogates the NGF protective effect on melanocytes. Our data suggest that NGF, known to be constitutively produced by epidermal keratinocytes and induced in these cells after UV irradiation, may preserve the population of cutaneous melanocytes that would otherwise be depleted by casual sun exposure.


Assuntos
Apoptose/efeitos da radiação , Melanócitos/efeitos dos fármacos , Fatores de Crescimento Neural/farmacologia , Proteínas Tirosina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Raios Ultravioleta , Apoptose/fisiologia , Sequência de Bases , Relação Dose-Resposta à Radiação , Humanos , Queratinócitos/metabolismo , Queratinócitos/efeitos da radiação , Masculino , Melanócitos/efeitos da radiação , Dados de Sequência Molecular , Oligonucleotídeos Antissenso , Proteínas Tirosina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/genética , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-bcl-2 , Pele/citologia , Pele/efeitos da radiação , Regulação para Cima/fisiologia
20.
Health Phys ; 52(3): 281-95, 1987 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-3818293

RESUMO

Using a long-term-average, single-cell model and available data for U.S. housing, the concentration of 222Rn in indoor air due to the use of potable water is assessed. The ratio of the airborne 222Rn concentration to the concentration in water is represented by a lognormal distribution with geometric mean and geometric standard deviation of 0.65 X 10(-4) and 2.88, respectively, in fair agreement with the previously reported results of direct measurements of the ratio in 13 houses. By combining this result with data on 222Rn concentrations in U.S. water supplies, potable water is estimated to contribute an average of 24, 1.3, and 0.1 Bq m-3 to the airborne 222Rn concentration in residences served by private wells, public ground water, and surface water supplies, respectively.


Assuntos
Poluentes Radioativos do Ar , Poluentes Atmosféricos , Radônio , Poluentes Radioativos da Água , Poluentes da Água , Habitação , Modelos Teóricos , Radônio/análise , Estados Unidos , Poluentes da Água/análise , Poluentes Radioativos da Água/análise , Abastecimento de Água/análise
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