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1.
Data Brief ; 9: 696-698, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27812533

RESUMO

This article collates information about the number of scientific articles mentioning each of the established medulloblastoma cell lines, derived through a systematic search of Web of Science, Scopus and Google Scholar in 2016. The data for each cell line have been presented as raw number of citations, percentage share of the total citations for each search engine and as an average percentage between the three search engines. In order to correct for the time since each cell line has been in use, the raw citation data have also been divided by the number of years since the derivation of each cell line. This is a supporting article for a review of in vitro models of medulloblastoma published in "in vitro models of medulloblastoma: choosing the right tool for the job" (D.P. Ivanov, D.A. Walker, B. Coyle, A.M. Grabowska, 2016) [1].

4.
Mol Ecol ; 23(13): 3258-72, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24689939

RESUMO

Fungi are abundant and functionally important in the Arctic, yet comprehensive studies of their diversity in relation to geography and environment are not available. We sampled soils in paired plots along the North American Arctic Transect (NAAT), which spans all five bioclimatic subzones of the Arctic. Each pair of plots contrasted relatively bare, cryoturbated patterned-ground features (PGFs) and adjacent vegetated between patterned-ground features (bPGFs). Fungal communities were analysed via sequencing of 7834 ITS-LSU clones. We recorded 1834 OTUs - nearly half the fungal richness previously reported for the entire Arctic. These OTUs spanned eight phyla, 24 classes, 75 orders and 120 families, but were dominated by Ascomycota, with one-fifth belonging to lichens. Species richness did not decline with increasing latitude, although there was a decline in mycorrhizal taxa that was offset by an increase in lichen taxa. The dominant OTUs were widespread even beyond the Arctic, demonstrating no dispersal limitation. Yet fungal communities were distinct in each subzone and were correlated with soil pH, climate and vegetation. Communities in subzone E were distinct from the other subzones, but similar to those of the boreal forest. Fungal communities on disturbed PGFs differed significantly from those of paired stable areas in bPGFs. Indicator species for PGFs included lichens and saprotrophic fungi, while bPGFs were characterized by ectomycorrhizal and pathogenic fungi. Our results suggest that the Arctic does not host a unique mycoflora, while Arctic fungi are highly sensitive to climate and vegetation, with potential to migrate rapidly as global change unfolds.


Assuntos
Biodiversidade , Ecossistema , Fungos/classificação , Microbiologia do Solo , Regiões Árticas , DNA Fúngico/genética , Fungos/genética , Dados de Sequência Molecular , Micorrizas/classificação , Micorrizas/genética , América do Norte , Análise de Sequência de DNA
6.
Int J STD AIDS ; 22(9): 498-504, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21890545

RESUMO

We retrospectively studied outcomes for HIV-infected patients admitted to the intensive care unit (ICU) between January 1999 and June 2009. Patient demographics, receipt of highly active antiretroviral therapy (HAART), reason for ICU admission and survival to ICU and hospital discharge were recorded. Comparison was made against outcomes for general medical patients contemporaneously admitted to the same ICU. One hundred and ninety-two HIV-infected patients had 222 ICU admissions; 116 patients required mechanical ventilation (MV) and 43 required renal replacement therapy. ICU admission was due to an HIV-associated diagnosis in 113 patients; 37 had Pneumocystis pneumonia. Survival to ICU discharge and hospital discharge for HIV-infected patients was 78% and 70%, respectively, and was 75% and 68% among 2065 general medical patients with 2274 ICU admissions; P = 0.452 and P = 0.458, respectively. HIV infection was newly diagnosed in 42 patients; their ICU and hospital survival was 69% and 57%, respectively. From multivariable analysis, factors associated with ICU survival were patient's age (odds ratio [OR] = 0.74 [95% confidence interval (CI) = 0.53-1.02] per 10-year increase), albumin (OR = 1.05 [1.00-1.09] per 1 g/dL increase), Acute Physiology and Chronic Health Evaluation (APACHE) II score (OR = 0.55 [0.35-0.87] per 10 unit increase), receipt of HAART (OR = 2.44 [1.01-4.94]) and need for MV (OR = 0.14 [0.06-0.36]). In the era of HAART, HIV-infected patients should be offered ICU admission if it is likely to be of benefit.


Assuntos
Terapia Antirretroviral de Alta Atividade , Cuidados Críticos , Infecções por HIV/mortalidade , Infecções Oportunistas Relacionadas com a AIDS/mortalidade , APACHE , Adulto , Coinfecção/mortalidade , Feminino , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Admissão do Paciente/estatística & dados numéricos , Alta do Paciente/estatística & dados numéricos , Pneumonia por Pneumocystis/complicações , Pneumonia por Pneumocystis/mortalidade , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida
7.
Br J Cancer ; 105(4): 575-85, 2011 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-21712824

RESUMO

BACKGROUND: Yolk sac tumours (YSTs) and germinomas are the two major pure histological subtypes of germ cell tumours. To date, the role of DNA methylation in the aetiology of this class of tumour has only been analysed in adult testicular forms and with respect to only a few genes. METHODS: A bank of paediatric tumours was analysed for global methylation of LINE-1 repeat elements and global methylation of regulatory elements using GoldenGate methylation arrays. RESULTS: Both germinomas and YSTs exhibited significant global hypomethylation of LINE-1 elements. However, in germinomas, methylation of gene regulatory regions differed little from control samples, whereas YSTs exhibited increased methylation at a large proportion of the loci tested, showing a 'methylator' phenotype, including silencing of genes associated with Caspase-8-dependent apoptosis. Furthermore, we found that the methylator phenotype of YSTs was coincident with higher levels of expression of the DNA methyltransferase, DNA (cytosine-5)-methyltransferase 3B, suggesting a mechanism underlying the phenotype. CONCLUSION: Epigenetic silencing of a large number of potential tumour suppressor genes in YSTs might explain why they exhibit a more aggressive natural history than germinomas and silencing of genes associated with Caspase-8-dependent cell death might explain the relative resistance of YSTs to conventional therapy.


Assuntos
Caspase 8/metabolismo , DNA (Citosina-5-)-Metiltransferases/metabolismo , Metilação de DNA , Inativação Gênica , Genes Supressores de Tumor , Neoplasias Embrionárias de Células Germinativas/tratamento farmacológico , Neoplasias Embrionárias de Células Germinativas/genética , Apoptose , Criança , Pré-Escolar , Análise por Conglomerados , Resistencia a Medicamentos Antineoplásicos , Tumor do Seio Endodérmico/tratamento farmacológico , Tumor do Seio Endodérmico/genética , Feminino , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Germinoma/tratamento farmacológico , Germinoma/genética , Humanos , Masculino , Análise em Microsséries , Neoplasias Embrionárias de Células Germinativas/patologia , Fenótipo , Reação em Cadeia da Polimerase , Reprodutibilidade dos Testes , Reação em Cadeia da Polimerase Via Transcriptase Reversa , DNA Metiltransferase 3B
8.
Eur J Cancer ; 46(1): 120-33, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19818598

RESUMO

BACKGROUND: Radiotherapy is an effective adjuvant treatment for brain tumours arising in very young children, but it has the potential to damage the child's developing nervous system at a crucial time - with a resultant reduction in IQ leading to cognitive impairment, associated endocrinopathy and risk of second malignancy. We aimed to assess the role of a primary chemotherapy strategy in avoiding or delaying radiotherapy in children younger than 3 years with malignant brain tumours other than ependymoma, the results of which have already been published. METHODS: Ninety-seven children were enrolled between March 1993 and July 2003 and, following diagnostic review, comprised: medulloblastoma (n=31), astrocytoma (26), choroid plexus carcinoma [CPC] (15), CNS PNET (11), atypical teratoid/rhabdoid tumours [AT/RT] (6) and ineligible (6). Following maximal surgical resection, chemotherapy was delivered every 14 d for 1 year or until disease progression. Radiotherapy was withheld in the absence of progression. FINDINGS: Over all diagnostic groups the cumulative progression rate was 80.9% at 5 years while the corresponding need-for-radiotherapy rate for progression was 54.6%, but both rates varied by tumour type. There was no clear relationship between chemotherapy dose intensity and outcome. Patients with medulloblastoma presented as a high-risk group, 83.9% having residual disease and/or metastases at diagnosis. For these patients, outcome was related to histology. The 5-year OS for desmoplastic/nodular medulloblastoma was 52.9% (95% confidence interval (CI): 27.6-73.0) and for classic medulloblastoma 33.3% (CI: 4.6-67.6); the 5-year EFS were 35.3% (CI: 14.5-57.0) and 33.3% (CI: 4.6-67.6), respectively. All children with large cell or anaplastic variants of medulloblastoma died within 2 years of diagnosis. The 5-year EFS for non-brainstem high-grade gliomas [HGGs] was 13.0% (CI: 2.2-33.4) and the OS was 30.9% (CI: 11.5-52.8). For CPC the 5-year OS was 26.67% (CI: 8.3-49.6) without RT. This treatment strategy was less effective for AT/RT with 3-year OS of 16.7% (CI: 0.8-51.7) and CNS PNET with 1-year OS of 9.1% (CI: 0.5-33.3). INTERPRETATION: The outcome for very young children with brain tumours is dictated by degree of surgical resection and histological tumour type and underlying biology as an indicator of treatment sensitivity. Overall, the median age at radiotherapy was 3 years and radiotherapy was avoided in 45% of patients. Desmoplastic/nodular sub-type of medulloblastoma has a better prognosis than classic histology, despite traditional adverse clinical features of metastatic disease and incomplete surgical resection. A subgroup with HGG and CPC are long-term survivors without RT. This study highlights the differing therapeutic challenges presented by the malignant brain tumours of early childhood, the importance of surgical approaches and the need to explore individualised brain sparing approaches to the range of malignant brain tumours that present in early childhood.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Encefálicas/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Astrocitoma/tratamento farmacológico , Astrocitoma/radioterapia , Astrocitoma/cirurgia , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/cirurgia , Pré-Escolar , Neoplasias do Plexo Corióideo/tratamento farmacológico , Neoplasias do Plexo Corióideo/radioterapia , Neoplasias do Plexo Corióideo/cirurgia , Progressão da Doença , Esquema de Medicação , Feminino , Seguimentos , Humanos , Lactente , Masculino , Meduloblastoma/tratamento farmacológico , Meduloblastoma/radioterapia , Meduloblastoma/cirurgia , Tumores Neuroectodérmicos Primitivos/tratamento farmacológico , Tumores Neuroectodérmicos Primitivos/radioterapia , Tumores Neuroectodérmicos Primitivos/cirurgia , Radioterapia Adjuvante/métodos , Análise de Sobrevida , Teratoma/tratamento farmacológico , Teratoma/radioterapia , Teratoma/cirurgia , Resultado do Tratamento
9.
Arch Dis Child ; 94(5): 401-6, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19139032

RESUMO

Since the 1930s, therapeutic recreation (TR) has been used in the UK to help young people cope with severe illness. This article surveys four systematic reviews and poses five questions that a paediatrician might ask: (1) How to select a TR experience and for which patient?; (2) Does TR augment brain injury rehabilitation?; (3) How do TR camps benefit children?; (4) Is TR cost-effective?; (5) What additional research is needed? Methodological weaknesses in research impair the strength of conclusions. There is little research about matching of TR experiences to individuals, disease groups or age groups, or about the effect of TR camps in brain injury rehabilitation. TR interventions enhance self-esteem, disease knowledge, emotional well-being, adaptation to illness and symptom control. Educationalists suggest that self-esteem is helped most in mid to late adolescence. Where studied, TR camps are safe, which reassures parents. There have been few studies on cost-effectiveness. We conclude that young people benefit from TR. However, better-quality research would help select and further develop these experiences for young people with ill health.


Assuntos
Acampamento , Doença Crônica/reabilitação , Adolescente , Acampamento/psicologia , Criança , Doença Crônica/psicologia , Terapia por Exercício , Feminino , Humanos , Masculino , Aceitação pelo Paciente de Cuidados de Saúde , Seleção de Pacientes , Modalidades de Fisioterapia , Fatores de Risco
10.
J Anim Sci ; 86(10): 2749-55, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18539841

RESUMO

Three studies were conducted to evaluate the feeding value of slice alfalfa hay in feedlot diets. In Exp. 1, 108 steer calves (183.1 +/- 1.2 kg initial BW; 6 pens/treatment) were used in a completely randomized design to evaluate the effect of baling method on performance and morbidity of newly received calves. The study lasted 28 d. Treatments consisted of a 65% concentrate receiving diet containing 1) ground or 2) slice alfalfa hay. Steer calves were fed daily at 0800 h. Animals also received long-stem sudangrass hay the first 7 d. Steers were weighed on d 0, 16, and 28. Feed, sudangrass hay, or feed plus sudangrass hay intakes were not affected (P > 0.25) by treatment. Conversely, ADG from d 0 to 16 was greater (P < 0.001) for slice than ground (1.27 vs. 0.81 +/- 0.067 kg/d, respectively) and from d 0 to 28 (1.23 vs. 0.91 +/- 0.042 kg/d, respectively). In addition, G:F was greater (P < 0.001) for slice than ground hay from d 0 to 16 (0.39 vs. 0.25 +/- 0.021), and from d 0 to 28 (0.31 vs. 0.24 +/- 0.013 for slice and ground, respectively). Moreover, morbidity (40.5 +/- 3.9%; P = 0.20) and retreatment rates (30.7 +/- 7.5%; P = 0.14) were similar for slice and ground. In Exp. 2, 176 crossbred steers (393.9 +/- 10.8 kg initial BW) were used in an 84-d feeding experiment (4 pens/treatment) in a randomized complete block experimental design with a 2 x 2 factorial arrangement of treatments to evaluate effects of alfalfa baling method (ground or slice) and forage level (8 or 14%) on growth performance. Experimental diets were based on steam-flaked corn. Daily BW gain was greater (P = 0.10) for steers consuming ground compared with the slice hay diet. A baling method x forage level interaction (P = 0.07) was observed for DMI. Baling method did not (P = 0.98) influence DMI with 8% roughage level. But with 14% roughage, DMI was greater (P = 0.02) for steers consuming ground hay than the slice diet. The G:F ratio was affected (P = 0.03) only by forage level (0.194 vs. 0.182 +/- 0.003 for 8 and 14% roughage, respectively). In Exp. 3, 4 ruminally cannulated mixed-breed steers were used in a 4 x 4 Latin square design to evaluate effects on digestive function. No baling method effects (P >or= 0.16) were detected for DM, OM, CP, or NDF intakes or DM, OM, and NDF total tract digestibility. Digestibility of NDF and OM were greater (P

Assuntos
Ração Animal/análise , Bovinos/crescimento & desenvolvimento , Dieta/veterinária , Medicago sativa/química , Fenômenos Fisiológicos da Nutrição Animal , Animais , Composição Corporal/fisiologia , Digestão , Abrigo para Animais , Masculino , Aumento de Peso
12.
Exp Biol Med (Maywood) ; 232(8): 1100-8, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17720956

RESUMO

Despite the inherent problems associated with in vivo animal models of tumor growth and metastases, many of the current in vitro brain tumor models also do not accurately mimic tumor-host brain interactions. Therefore, there is a need to develop such co-culture models to study tumor biology and, importantly, the efficacy of drug delivery systems targeting the brain. So far, few investigations of this nature have been published. In this paper we describe the development of a new model system and its application to drug delivery assessment. For our new model, a co-culture of DAOY cell brain tumor aggregates and organo-typic brain slices was developed. Initially, the DAOY aggregates attached to cerebellum slices and invaded as a unit. Single cells in the periphery of the aggregate detached from the DAOY aggregates and gradually replaced normal brain cells. This invasive behavior of DAOY cells toward organotypic cerebellum slices shows a similar pattern to that seen in vivo. After validation of the co-culture model using transmission electron microscopy, nanoparticle (NP) uptake was then evaluated. Confocal micrographs illustrated that DAOY cells in this co-culture model took up most of the NPs, but few NPs were distributed into brain cells. This finding corresponded with results of NP uptake in DAOY and brain aggregates reported elsewhere.


Assuntos
Neoplasias Cerebelares/tratamento farmacológico , Portadores de Fármacos/farmacologia , Meduloblastoma/tratamento farmacológico , Modelos Biológicos , Nanopartículas , Poliésteres , Animais , Linhagem Celular Tumoral , Neoplasias Cerebelares/ultraestrutura , Cerebelo/ultraestrutura , Técnicas de Cocultura , Portadores de Fármacos/química , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Meduloblastoma/ultraestrutura , Microdissecção , Microscopia Eletrônica de Transmissão , Nanopartículas/química , Poliésteres/química , Ratos , Ratos Wistar
14.
J Control Release ; 116(3): 314-21, 2006 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-17112618

RESUMO

A useful route for the development of antitumour therapies is by creating improved methods for delivering therapeutic agents to tumour cells or subcellular compartments and increasing retention of drugs within target cells. In this study, we have characterized nanoparticle (NP) uptake and metabolism by DAOY cells, a human medulloblastoma cell line. NPs were formed from a novel polymer, poly (glycerol-adipate) (PGA), containing Rhodamine B Isothiocyanate (RBITC) as a fluorescent marker. It was observed that the cellular uptake of NPs depends on the incubation time and the concentration of NPs in the culture medium. The studies of retention and metabolism of NPs within cells indicated that 1) faster degradation of NPs within cells compared with that in cell culture medium in vitro; 2) a small fraction of NPs were recycled back to the outside of cell, whereas most NPs entered endosomes and lysosomes; and 3) recycled NPs were re-taken up in the following 2 h incubation time. These studies thus suggested that PGA NPs could be used for localising therapeutic agents into cells, and could provide prolonged drug effects because of their long sustained release in physiological conditions and their rapid release when taken up into cells.


Assuntos
Antineoplásicos/administração & dosagem , Materiais Biocompatíveis/metabolismo , Portadores de Fármacos/metabolismo , Nanopartículas , Poliésteres/metabolismo , Linhagem Celular Tumoral , Endossomos/metabolismo , Citometria de Fluxo , Humanos , Lisossomos/metabolismo , Microscopia Eletrônica de Transmissão , Microscopia de Fluorescência , Tamanho da Partícula , Solubilidade , Propriedades de Superfície
15.
Can J Vet Res ; 69(3): 161-9, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16187545

RESUMO

Bovine viral diarrhea virus (BVDV) persistently infected (PI) calves represent significant sources of infection to susceptible cattle. The objectives of this study were to determine if PI calves transmitted infection to vaccinated and unvaccinated calves, to determine if BVDV vaccine strains could be differentiated from the PI field strains by subtyping molecular techniques, and if there were different rates of recovery from peripheral blood leukocytes (PBL) versus serums for acutely infected calves. Calves PI with BVDV1b were placed in pens with nonvaccinated and vaccinated calves for 35 d. Peripheral blood leukocytes, serums, and nasal swabs were collected for viral isolation and serology. In addition, transmission of Bovine herpes virus 1 (BHV-1), Parainfluenza-3 virus (PI-3V), and Bovine respiratory syncytial virus (BRSV) was monitored during the 35 d observation period. Bovine viral diarrhea virus subtype 1b was transmitted to both vaccinated and nonvaccinated calves, including BVDV1b seronegative and seropositive calves, after exposure to PI calves. There was evidence of transmission by viral isolation from PBL, nasal swabs, or both, and seroconversions to BVDV1b. For the unvaccinated calves, 83.2% seroconverted to BVDV1b. The high level of transmission by PI calves is illustrated by seroconversion rates of nonvaccinated calves in individual pens: 70% to 100% seroconversion to the BVDV1b. Bovine viral diarrhea virus was isolated from 45 out of 202 calves in this study. These included BVDV1b in ranch and order buyer (OB) calves, plus BVDV strains identified as vaccinal strains that were in modified live virus (MLV) vaccines given to half the OB calves 3 d prior to the study. The BVDV1b isolates in exposed calves were detected between collection days 7 and 21 after exposure to PI calves. Bovine viral diarrhea virus was recovered more frequently from PBL than serum in acutely infected calves. Bovine viral diarrhea virus was also isolated from the lungs of 2 of 7 calves that were dying with pulmonary lesions. Two of the calves dying with pneumonic lesions in the study had been BVDV1b viremic prior to death. Bovine viral diarrhea virus 1b was isolated from both calves that received the killed or MLV vaccines. There were cytopathic (CP) strains isolated from MLV vaccinated calves during the same time frame as the BVDV1b isolations. These viruses were typed by polymerase chain reaction (PCR) and genetic sequencing, and most CP were confirmed as vaccinal origin. A BVDV2 NCP strain was found in only 1 OB calf, on multiple collections, and the calf seroconverted to BVDV2. This virus was not identical to the BVDV2 CP 296 vaccine strain. The use of subtyping is required to differentiate vaccinal strains from the field strains. This study detected 2 different vaccine strains, the BVDV1b in PI calves and infected contact calves, and a heterologous BVDV2 subtype brought in as an acutely infected calf. The MLV vaccination, with BVDV1a and BVDV2 components, administered 3 d prior to exposure to PI calves did not protect 100% against BVDV1b viremias or nasal shedding. There were other agents associated with the bovine respiratory disease signs and lesions in this study including Mannheimia haemolytica, Mycoplasma spp., PI-3V, BRSV, and BHV-1.


Assuntos
Anticorpos Antivirais/sangue , Formação de Anticorpos/imunologia , Doença das Mucosas por Vírus da Diarreia Viral Bovina/transmissão , Vírus da Diarreia Viral Bovina Tipo 1/imunologia , Animais , Animais Recém-Nascidos , Anticorpos Antivirais/imunologia , Doença das Mucosas por Vírus da Diarreia Viral Bovina/imunologia , Bovinos , DNA Viral/química , DNA Viral/genética , Vírus da Diarreia Viral Bovina Tipo 1/classificação , Vírus da Diarreia Viral Bovina Tipo 1/isolamento & purificação , Suscetibilidade a Doenças/veterinária , Técnica Direta de Fluorescência para Anticorpo/veterinária , Leucócitos/virologia , Pulmão/patologia , Pulmão/virologia , Testes de Neutralização/veterinária , Nariz/virologia , Reação em Cadeia da Polimerase/veterinária , Distribuição Aleatória , Fatores de Tempo , Vacinação , Vacinas Atenuadas , Vacinas de Produtos Inativados , Viremia/veterinária
16.
Science ; 310(5748): 657-60, 2005 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-16179434

RESUMO

A major challenge in predicting Earth's future climate state is to understand feedbacks that alter greenhouse-gas forcing. Here we synthesize field data from arctic Alaska, showing that terrestrial changes in summer albedo contribute substantially to recent high-latitude warming trends. Pronounced terrestrial summer warming in arctic Alaska correlates with a lengthening of the snow-free season that has increased atmospheric heating locally by about 3 watts per square meter per decade (similar in magnitude to the regional heating expected over multiple decades from a doubling of atmospheric CO2). The continuation of current trends in shrub and tree expansion could further amplify this atmospheric heating by two to seven times.


Assuntos
Efeito Estufa , Alaska , Regiões Árticas , Picea , Estações do Ano , Árvores
17.
AJR Am J Roentgenol ; 182(6): 1547-50, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15150006

RESUMO

OBJECTIVE: The objective of this study was to evaluate the routine use of gradient-refocused echo MRI sequences in the detection of cortical cerebral microbleeding suggestive of cerebral amyloid angiopathy in elderly patients (> 70 years old). CONCLUSION: The addition of gradient-refocused echo sequences to routine brain MRI resulted in the identification of cerebral amyloid angiopathy-related microbleeding in 15.5% of elderly patients. In most (86.7%) of these patients with positive findings, cerebral amyloid angiopathy was not suspected clinically, and 46.7% of these patients were undergoing anticoagulant or aspirin therapy, placing them at an increased risk of recurrent intracranial hemorrhage and catastrophic stroke.


Assuntos
Angiopatia Amiloide Cerebral/diagnóstico , Imageamento por Ressonância Magnética/métodos , Idoso , Feminino , Humanos , Masculino
18.
J Anim Sci ; 81(12): 3191-201, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14677875

RESUMO

A winter grazing/feedlot performance experiment repeated over 2 yr (Exp. 1) and a metabolism experiment (Exp. 2) were conducted to evaluate effects of grazing dormant native range or irrigated winter wheat pasture on subsequent intake, feedlot performance, carcass characteristics, total-tract digestion of nutrients, and ruminal digesta kinetics in beef cattle. In Exp. 1, 30 (yr 1) or 67 (yr 2) English crossbred steers that had previously grazed native range (n = 38) or winter wheat (n = 59) for approximately 180 d were allotted randomly within previous treatment to feedlot pens (yr 1 native range = three pens [seven steers/pen], winter wheat = two pens [eight steers/pen]; yr 2 native range = three pens [eight steers/pen], winter wheat = four pens [10 or 11 steers/pen]). As expected, winter wheat steers had greater (P < 0.01) ADG while grazing than did native range steers. In contrast, feedlot ADG and gain efficiency were greater (P < 0.02) for native range steers than for winter wheat steers. Hot carcass weight, longissimus muscle area, and marbling score were greater (P < 0.01) for winter wheat steers than for native range steers. In contrast, 12th-rib fat depth (P < 0.64) and yield grade (P < 0.77) did not differ among treatments. In Exp. 2, eight ruminally cannulated steers that had previously grazed winter wheat (n = 4; initial BW = 407 +/- 12 kg) or native range (n = 4; initial BW = 293 +/- 23 kg) were used to determine intake, digesta kinetics, and total-tract digestion while being adapted to a 90% concentrate diet. The adaptation and diets used in Exp. 2 were consistent with those used in Exp. 1 and consisted of 70, 75, 80, and 85% concentrate diets, each fed for 5 d. As was similar for intact steers, restricted growth of cannulated native range steers during the winter grazing phase resulted in greater (P < 0.001) DMI (% of BW) and ADG (P < 0.04) compared with winter wheat steers. In addition, ruminal fill (P < 0.01) and total-tract OM digestibility (P < 0.02) were greater for native range than for winter wheat steers across the adaptation period. Greater digestibility by native range steers early in the finishing period might account for some of the compensatory gain response. Although greater performance was achieved by native range steers in the feedlot, grazing winter wheat before finishing resulted in fewer days on feed, increased hot carcass weight, and improved carcass merit.


Assuntos
Bovinos/crescimento & desenvolvimento , Digestão , Carne/normas , Rúmen/metabolismo , Triticum , Adaptação Fisiológica , Ração Animal , Animais , Bovinos/metabolismo , Bovinos/fisiologia , Cruzamentos Genéticos , Metabolismo Energético , Cinética , Masculino , Poaceae , Distribuição Aleatória , Estações do Ano , Aumento de Peso
19.
J Anim Sci ; 80(10): 2726-39, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12413096

RESUMO

Three experiments were conducted to determine effects of restricting intake of the final finishing diet as a means of dietary adaptation compared with diets increasing in grain over a period of 20 to 22 d on overall cattle performance, carcass characteristics, digestibility, digesta kinetics, and ruminal metabolism. In Exp. 1, 84 Angus x Hereford yearling steers (initial BW = 418 +/- 29.0 kg) were fed for 70 d. Restricting intake during adaptation had no effect (P > 0.10) on overall ADG:DMI, but decreased (P < 0.05) DMI compared with ad libitum access to adaptation diets, which resulted from differences during the initial 28 d of the experiment. In Exp. 2, 150 mixed crossbred steer calves (initial BW = 289 +/- 22.9 kg) were fed for an average of 173 d. Restricting intake decreased (P < 0.01) overall daily gain (1.51 vs 1.65 kg/d) and DMI (8.68 vs 9.15 kg/d) compared with ad libitum fed steers; however, ADG:DMI was not influenced (P > 0.10) by adaptation method. Experiment three used eight ruminally and duodenally fistulated steers (initial BW = 336 +/- 20 kg) in a completely random design. Total tract digestibility, digesta kinetics and ruminal metabolism were determined. Restricting intake reduced (P < 0.10) daily DMI variation from d 1 through 7, 8 through 14, and 22 through 28 compared with ad libitum feeding of three adaptation diets. Restricted steers had reduced (adaptation method x period interaction, P < 0.05) intakes and fecal excretions of ADF and greater OM digestibilities on d 4 through 7, 11 through 14, and 18 through 21. Digesta kinetics and ruminal metabolism were generally not affected (P > 0.10) by adaptation method. Our results suggest that restricted-feeding of the final diet as a means of dietary adaptation can be used in finishing cattle with few problems from acidosis or related intake variation. In light-weight steers (Exp. 2), disruptions in intake during the adaptation period might have resulted in restriction for an extended period, which decreased (P < 0.01) hot carcass weight compared with calves fed ad libitum. Effects of limit feeding during the initial 28 d of the feeding period on site and extent of digestion, digesta kinetics, and ruminal metabolism were minimal, supporting few differences in performance across the finishing period for yearling cattle.


Assuntos
Bovinos/crescimento & desenvolvimento , Dieta/veterinária , Digestão , Rúmen/metabolismo , Adaptação Fisiológica , Ração Animal , Animais , Bovinos/fisiologia , Privação de Alimentos , Cinética , Masculino , Distribuição Aleatória , Aumento de Peso
20.
J Anim Sci ; 80(4): 933-41, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12002330

RESUMO

Three experiments were conducted to examine the effect of dietary vitamin E on receiving performance and health and on finishing performance of beef cattle. One hundred twenty beef steers (Exp. 1; initial BW = 173 kg) and 200 beef heifers (Exp. 2; initial BW = 204 kg) were assigned randomly to one of three treatment diets formulated to supply 285, 570, or 1,140 IU/animal daily of supplemental vitamin E during the receiving period. Average daily gain, gain:feed, and DMI were calculated every 14 d, with pen as the experimental unit. Morbidity and retreatment data were analyzed using a nonparametric procedure. After the receiving period, cattle were assigned to a grazing period followed by a finishing program and fed until slaughter. In Exp. 3, 17 beef steers were used to evaluate effects of the same three vitamin E levels on humoral immune response to an ovalbumin vaccine given on d 0 and 14. Jugular blood samples were collected on d 0, 7, 14, and 21. In Exp. 1, vitamin E did not affect (P > 0.10) ADG, DMI, or gain:feed for d 0 to 14, 14 to 28, or 0 to 28. No effects were noted for percentage of morbidity; however, cattle receiving 1,140 IU/d had a numerically (P = 0.15) lower incidence of retreatment. During the 91-d finishing phase, a quadratic effect (P < 0.08) was noted for DMI, ADG, backfat thickness, longissimus muscle area, and yield grade. In Exp. 2, a tendency for a linear (P = 0.10) increase in ADG was observed for the first 14 d of receiving; however, ADG decreased linearly (P = 0.06) with vitamin E concentration thereafter. For the 28-d period, ADG and DMI did not differ among treatments, but gain:feed decreased linearly (P < 0.05) for d 14 to 28 and for d 0 to 28. No effects on percentage morbidity were noted in Exp. 2, and no differences were detected for ADG, gain:feed, or DMI for the 98-d finishing period. There was a linear increase in yield grade (P < 0.05) and a linear (P < 0.08) decrease in longissimus muscle area with increasing vitamin E. Heifers receiving 570 IU of vitamin E during the receiving period tended to have a higher (P < 0.09) dressing percentage at slaughter. In Exp. 3, no significant differences were detected in serum IgG titers to ovalbumin on d 0, 7 or 14; however, on d 21, a linear increase (P = 0.07) in serum IgG titers was noted with supplemental vitamin E. Supplemental vitamin E had limited effects on performance; however, effects on humoral immune response and recovery from respiratory disease warrant further research.


Assuntos
Formação de Anticorpos/efeitos dos fármacos , Antioxidantes/administração & dosagem , Doenças dos Bovinos/imunologia , Bovinos/crescimento & desenvolvimento , Doenças Respiratórias/veterinária , Vitamina E/administração & dosagem , Fatores Etários , Animais , Antioxidantes/farmacologia , Composição Corporal/efeitos dos fármacos , Bovinos/imunologia , Suplementos Nutricionais , Relação Dose-Resposta a Droga , Ingestão de Energia/efeitos dos fármacos , Feminino , Nível de Saúde , Masculino , Ovalbumina/imunologia , Distribuição Aleatória , Doenças Respiratórias/imunologia , Vacinação/veterinária , Vitamina E/farmacologia , Aumento de Peso/efeitos dos fármacos
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