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1.
Anaesthesia ; 75(10): 1314-1320, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32488972

RESUMO

Patients with uncontrolled hypertension are at increased risk of complications during general anaesthesia but the number of patients whose surgery is delayed or cancelled due to hypertension remains unknown. Prospective, regional multicentre service evaluations were performed on consecutive patients undergoing elective surgery before and after the publication of new guidelines from the Association of Anaesthetists and the British Hypertensive Society. The aim was to quantify the number of operations cancelled due to hypertension alone and to assess impact of the guidelines on cancellation rates. In October 2013 (before the publication of the guidelines), 1.37% (95%CI 0.69-2.11%) of patients listed for elective surgery were cancelled solely due to raised blood pressure. This reduced significantly to 0.54% (95%CI 0.20-0.92%, p < 0.001) in 2018. There was a significant reduction in inappropriate cancellations for stage 1 or 2 hypertension from 2013 to 2018 (72 vs. 14, respectively, p < 0.001) in keeping with the recommendations in the guidelines. Furthermore, the number of patients being referred back to primary care for the management of hypertension reduced from 2013 to 2018 (85 vs. 30, respectively, p < 0.001). Our data suggest achievement of three major outcomes: reduced surgical cancellations due to hypertension alone; improved detection of significant hypertension before elective surgery; and reduced referral back to primary care from hospital for hypertension management. To the best of our knowledge, this is the first time the successful implementation of guidelines from the Association of Anaesthetists has been assessed on such a broad scale. Our data indicate that these guidelines have been effectively implemented in both primary and secondary care, which is likely to have made a positive psychosocial, physical and economic impact on patients and the NHS.


Assuntos
Agendamento de Consultas , Procedimentos Cirúrgicos Eletivos/estatística & dados numéricos , Guias como Assunto , Hipertensão/complicações , Adulto , Idoso , Idoso de 80 Anos ou mais , Anestesia , Feminino , Humanos , Hipertensão/epidemiologia , Londres/epidemiologia , Masculino , Pessoa de Meia-Idade , Período Pré-Operatório , Atenção Primária à Saúde , Estudos Prospectivos , Atenção Secundária à Saúde , Inquéritos e Questionários , Resultado do Tratamento , Adulto Jovem
2.
N Z Vet J ; 66(5): 267-271, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29791810

RESUMO

CASE HISTORY Anal warts were observed in heifers in two unrelated groups of animals. Heifers in one group developed visible warts 4 months after manual rectal examination and heifers in the other group developed warts 5 months after examination using a hand-held rectal ultrasound probe. CLINICAL FINDINGS Large exophytic proliferative anal masses were observed in 5/15 (33%) heifers in one group and 13/149 (9%) heifers in the second group. Heifers in the second group were also noted to have similar masses on the underside of the tail at sites previously used for venepuncture and some of the heifers had skin warts. Despite the large size of the anal masses, none of the heifers showed clinical signs of systemic illness. HISTOPATHOLOGICAL FINDINGS An anal mass was removed from one heifer in each of the two groups. Sections from both masses showed hyperplastic epithelium covering a proliferation of well-differentiated fibroblasts consistent with fibropapillomas. Small numbers of cells within the epidermis had clear cytoplasm with clumped keratohyalin granules. MOLECULAR BIOLOGY Bovine papillomavirus (BPV) type 2 DNA was amplified from both fibropapillomas by PCR. DIAGNOSIS Multiple anal fibropapillomas associated with BPV-2. CLINICAL RELEVANCE Bovine anal fibropapillomas have only been reported in heifers that have undergone rectal examination, and infection of anal microabrasions in an immunologically naïve animal appears to be associated with disease development. The source and method of spread of BPV-2 within these groups could not be determined. However spread of BPV-2 within the groups by the veterinarian performing rectal examinations may have been most likely. While these fibropapillomas had a dramatic appearance, like fibropapillomas elsewhere on the body, they did not have any significant effect on the health of the affected heifers. As these lesions can be diagnosed by clinical examination and self-resolve without treatment, it is important that veterinarians are aware of this rare manifestation of papillomavirus infection of cattle.


Assuntos
Papillomavirus Bovino 1/isolamento & purificação , Doenças dos Bovinos/diagnóstico , Infecções por Papillomavirus/veterinária , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , DNA Viral , Feminino , Infecções por Papillomavirus/diagnóstico , Infecções por Papillomavirus/epidemiologia , Pele
4.
Anaesthesia ; 71(3): 326-37, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26776052

RESUMO

This guideline aims to ensure that patients admitted to hospital for elective surgery are known to have blood pressures below 160 mmHg systolic and 100 mmHg diastolic in primary care. The objective for primary care is to fulfil this criterion before referral to secondary care for elective surgery. The objective for secondary care is to avoid spurious hypertensive measurements. Secondary care should not attempt to diagnose hypertension in patients who are normotensive in primary care. Patients who present to pre-operative assessment clinics without documented primary care blood pressures should proceed to elective surgery if clinic blood pressures are below 180 mmHg systolic and 110 mmHg diastolic.


Assuntos
Pressão Sanguínea , Procedimentos Cirúrgicos Eletivos , Hipertensão/diagnóstico , Hipertensão/terapia , Cuidados Pré-Operatórios/métodos , Adulto , Anestesiologia , Determinação da Pressão Arterial , Humanos , Irlanda , Sociedades Médicas , Reino Unido
5.
Int J Clin Pract ; 67(8): 707-9, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23869674

RESUMO

With the arrival of the newer oral anticoagulants (NOACs), we now have a more convenient means of providing anticoagulation for patients with non-valvular atrial fibrillation (AF). Are there any particular considerations for the many patients who also have coronary artery disease? For many patients there is an obvious need to use the newer agents but for others, such as those who simply refuse to consider using a vitamin K antagonist (VKA) such as warfarin, the decision may be more problematical.


Assuntos
Anticoagulantes/administração & dosagem , Fibrilação Atrial/tratamento farmacológico , Doença da Artéria Coronariana/tratamento farmacológico , Administração Oral , Aspirina/administração & dosagem , Clopidogrel , Quimioterapia Combinada , Humanos , Inibidores da Agregação Plaquetária/administração & dosagem , Fatores de Risco , Acidente Vascular Cerebral/prevenção & controle , Ticlopidina/administração & dosagem , Ticlopidina/análogos & derivados
6.
BMJ ; 344: d7541, 2011 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-22218098

RESUMO

OBJECTIVE: To assess if very elderly people with hypertension obtain early benefit from antihypertensive treatment. DESIGN: One year open label active treatment extension of randomised controlled trial (Hypertension in the Very Elderly Trial (HYVET)). SETTING: Hospital and general practice based centres mainly in eastern and western Europe, China, and Tunisia. PARTICIPANTS: People on double blind treatment at the end of HYVET were eligible to enter the extension. INTERVENTIONS: Participants on active blood pressure lowering treatment continued taking active drug; those on placebo were given active blood pressure lowering treatment. The treatment regimen was as used in the main trial-indapamide SR 1.5 mg (plus perindopril 2-4 mg if required)-with the same target blood pressure of less than 150/80 mm Hg. MAIN OUTCOME MEASURES: The primary outcome was all stroke; other outcomes included total mortality, cardiovascular mortality, and cardiovascular events. RESULTS: Of 1882 people eligible for entry to the extension, 1712 (91%) agreed to participate. During the extension period, 1682 patient years were accrued. By six months, the difference in blood pressure between the two groups was 1.2/0.7 mm Hg. Comparing people previously treated with active drug and those previously on placebo, no significant differences were seen for stroke (n = 13; hazard ratio 1.92, 95% confidence interval 0.59 to 6.22) or cardiovascular events (n = 25; 0.78, 0.36 to 1.72). Differences were seen for total mortality (47 deaths; hazard ratio 0.48, 0.26 to 0.87; P = 0.02) and cardiovascular mortality (11 deaths; 0.19, 0.04 to 0.87; P = 0.03). CONCLUSION: Very elderly patients with hypertension may gain immediate benefit from treatment. Sustained differences in reductions of total mortality and cardiovascular mortality reinforce the benefits and support the need for early and long term treatment. Trial registration Clinical trials NCT00122811.


Assuntos
Anti-Hipertensivos/uso terapêutico , Hipertensão/tratamento farmacológico , Indapamida/uso terapêutico , Perindopril/uso terapêutico , Índice de Gravidade de Doença , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Pressão Sanguínea/efeitos dos fármacos , China , Intervalos de Confiança , Relação Dose-Resposta a Droga , Método Duplo-Cego , Quimioterapia Combinada , Europa (Continente) , Feminino , Humanos , Masculino , Razão de Chances , Tunísia
7.
QJM ; 103(10): 727-39, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20685842

RESUMO

The prevalence and burden of cardiovascular disease (CVD) is high, and it remains the leading cause of death worldwide. Unfortunately, many individuals who are at high risk for CVD are not recognized and/or treated. Therefore, programs are available to ensure individuals at risk for CVD are identified through appropriate risk classification and offered optimal preventative interventions. The use of algorithms to determine a global risk score may help to achieve these goals. Such global risk-scoring algorithms takes into account the synergistic effects between individual risk factors, placing increases in individual risk factors into context relative to the overall disease, allowing for a continuum of disease risk to be expressed, and identifying patients most likely to derive benefit from an intervention. The predictive value of risk scoring such as using the Framingham equation is reasonable, analogous to cervical screening, with area under the receiver operated characteristic curve a little over 70%. However, limitations do exist, and as they are identified adjustments can be made to the global risk-scoring algorithms. Limitations include patient-specific issues, such as variations in lifetime risk level, ethnicity or socio-economic strata, and algorithm-specific issues, such as discrepancies between different algorithms arising from varying risk factors evaluated. The use of currently developed algorithms is low in general practice, in part, because of the belief that the assessment may oversimplify the risk and/or lead to medication overuse. Additional hindrances to the use of risk scoring include government or local health policy, patient compliance issues and lack of time. A thorough, easy-to-use, and standardized tool for risk estimation would allow for improvements in the primary prevention of CVD.


Assuntos
Algoritmos , Doenças Cardiovasculares/diagnóstico , Fatores Etários , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/prevenção & controle , Europa (Continente)/epidemiologia , Feminino , Medicina Geral , Humanos , Masculino , Prevenção Primária , Medição de Risco/métodos
8.
Int J Clin Pract ; 64(8): 1052-61, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20487050

RESUMO

AIM: The aim of this study was to compare ezetimibe/simvastatin combination therapy with intensified statin monotherapy as alternative treatment strategies to achieve the Joint British Societies (JBS)-2 and National Institute for Health and Clinical Excellence low-density-lipoprotein cholesterol (LDL-C) target of < 2 mmol/l for secondary prevention or JBS-2 LDL-C target of < 2 mmol/l for primary prevention in high-risk patients who have failed to reach target with simvastatin 40 mg. METHODS: This is a prospective, double-blind study conducted in 34 UK primary care centres; 1748 patients with established cardiovascular disease (CVD), diabetes or high risk of CVD who had been taking simvastatin 40 mg for > or = 6 weeks were screened and 786 (45%) with fasting LDL-C > or = 2.0 mmol/l (and < 4.2 mmol/l) at screening and after a further 6-week run-in period on simvastatin 40 mg were randomised to ezetimibe/simvastatin 10/40 mg (as a combination tablet; n = 261), atorvastatin 40 mg (n = 263) or rosuvastatin 5 mg (n = 73) or 10 mg (n = 189) once daily for 6 weeks. Rosuvastatin dose was based on UK prescribing instructions. The primary outcome measure was the proportion of patients achieving LDL-C < 2 mmol/l at the end of the study. RESULTS: The percentage of patients (adjusted for baseline differences) achieving LDL-C < 2 mmol/l was 69.4% with ezetimibe/simvastatin 10/40 mg, compared with 33.5% for atorvastatin 40 mg [odds ratio 4.5 (95% CI: 3.0-6.8); p < 0.001] and 14.3% for rosuvastatin 5 or 10 mg [odds ratio 13.6 (95% CI: 8.6-21.6); p < 0.001]. Similar results were observed for achievement of total cholesterol < 4.0 mmol/l. All study treatments were well tolerated. CONCLUSION: Approximately 45% of patients screened had not achieved LDL-C < 2 mmol/l after > or = 12 weeks of treatment with simvastatin 40 mg. In this group, treatment with ezetimibe/simvastatin 10/40 mg achieved target LDL-C levels in a significantly higher proportion of patients during a 6-week period than switching to either atorvastatin 40 mg or rosuvastatin 5-10 mg.


Assuntos
Anticolesterolemiantes/administração & dosagem , Doenças Cardiovasculares/prevenção & controle , Inibidores de Hidroximetilglutaril-CoA Redutases/administração & dosagem , Hipercolesterolemia/prevenção & controle , Idoso , Análise de Variância , Anticolesterolemiantes/efeitos adversos , Atorvastatina , Azetidinas/administração & dosagem , Azetidinas/efeitos adversos , Doenças Cardiovasculares/sangue , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Método Duplo-Cego , Quimioterapia Combinada/métodos , Ezetimiba , Feminino , Fluorbenzenos/administração & dosagem , Fluorbenzenos/efeitos adversos , Medicina Geral , Ácidos Heptanoicos/administração & dosagem , Ácidos Heptanoicos/efeitos adversos , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/efeitos adversos , Hipercolesterolemia/sangue , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Pirimidinas/administração & dosagem , Pirimidinas/efeitos adversos , Pirróis/administração & dosagem , Pirróis/efeitos adversos , Rosuvastatina Cálcica , Prevenção Secundária , Sinvastatina/administração & dosagem , Sinvastatina/efeitos adversos , Sulfonamidas/administração & dosagem , Sulfonamidas/efeitos adversos , Resultado do Tratamento
9.
Q J Exp Psychol A ; 58(4): 693-704, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-16104102

RESUMO

Groups of 5-year-olds, 10-year-olds, and adults completed either an episodic temporal generalization task, in which no stimuli were repeated, or a repeated standard temporal generalization task, in which there was a fixed standard that was repeated on every trial. Significant developmental improvements were found on both tasks. In both tasks, gradients of performance over two different stimulus ranges superimposed well when plotted on the same relative scale. Performance was similar for the adults and 10-year-olds across tasks, but the 5-year-olds performed better on the repeated standard task. These findings suggest that perceptual processes are a source of scalar variability in timing, and that there are developmental changes in levels of such variability.


Assuntos
Aprendizagem por Associação , Atenção , Desenvolvimento Infantil , Generalização Psicológica , Reconhecimento Visual de Modelos , Percepção da Altura Sonora , Percepção do Tempo , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Orientação , Tempo de Reação , Valores de Referência
10.
Psychol Med ; 33(7): 1249-61, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14580079

RESUMO

BACKGROUND: The ability to encode time cues underlies many cognitive processes. In the light of schizophrenic patients' compromised cognitive abilities in a variety of domains, it is noteworthy that there are numerous reports of these patients displaying impaired timing abilities. However, the timing intervals that patients have been evaluated on in prior studies vary considerably in magnitude (e.g. 1 s, 1 min, 1 h etc.). METHOD: In order to obviate differences in abilities in chronometric counting and place minimal demands on cognitive processing, we chose tasks that involve making judgements about brief durations of time (< 1 s). RESULTS: On a temporal generalization task, patients were less accurate than controls at recognizing a standard duration. The performance of patients was also significantly different from controls on a temporal bisection task, in which participants categorized durations as short or long. Although time estimation may be closely intertwined with working memory, patients' working memory as measured by the digit span task did not correlate significantly with their performance on the duration judgement tasks. Moreover, lowered intelligence scores could not completely account for the findings. CONCLUSIONS: We take these results to suggest that patients with schizophrenia are less accurate at estimating brief time periods. These deficits may reflect dysfunction of biopsychological timing processes.


Assuntos
Esquizofrenia/diagnóstico , Psicologia do Esquizofrênico , Percepção do Tempo , Adolescente , Adulto , Atenção , Aprendizagem por Discriminação , Feminino , Generalização Psicológica , Humanos , Julgamento , Masculino , Memória de Curto Prazo , Testes Neuropsicológicos , Valores de Referência
11.
J Inorg Biochem ; 85(1): 1-7, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11377689

RESUMO

In an attempt to generate new platinum compounds that may be effective in the treatment of cancer, as well as having a lower toxicity than traditional platins and being orally viable, we are studing the synthesis and reactivity of platinum complexes of tetraazamacrocycles bearing carboxylato pendant arms. We have synthesized adducts of meso- and rac-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-1,7-diacetic acid (L(1)H(2)). The meso-Pt(II)L(1) complex is unstable with respect to disproportionation, forming platinum metal and [meso-Pt(IV)L(1)](2+). The rac-isomer shows less tendency to disproportionate. Cyclic voltammetry suggests that the rac-Pt(II)L(1) complex undergoes two one-electron oxidations. Using bis-triazacyclononanenickel(III), [Ni(III)(tacn)(2)](3+) as an outer-sphere oxidant, the self-exchange rate for the [Pt(II/III)L](0/+) couple has been estimated at 0.034 M(-1) s(-1).


Assuntos
Antineoplásicos/química , Compostos de Platina/química , Oxirredução , Relação Estrutura-Atividade
12.
J Exp Child Psychol ; 76(3): 222-52, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10837117

RESUMO

Three experiments examined developmental changes in serial recall of lists of 6 letters, with errors classified as movements, omissions, intrusions, or repetitions. In Experiments 1 and 2, developmental differences between groups of children aged from 7 to 11 years and adults were found in the pattern of serial recall errors. The errors of older participants were more likely to be movements than were those of younger participants, who made more intrusions and omissions. The number of repetition errors did not change with age, and this finding is interpreted in terms of a developmentally invariant postoutput response inhibition process. This interpretation was supported by the findings of Experiment 3, which measured levels of response inhibition in 7-, 9-, and 11-year-olds by comparing recall of lists with and without repeated items. Response inhibition remained developmentally invariant, although older children showed greater response facilitation (improved correct recall of adjacent repeated items). Group differences in the patterns of other errors are accounted for in terms of developmental changes in levels of output forgetting and changes in the efficiency of temporal encoding processes.


Assuntos
Desenvolvimento Infantil/fisiologia , Memória de Curto Prazo/fisiologia , Teoria Psicológica , Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Rememoração Mental/fisiologia , Pessoa de Meia-Idade
13.
Clin Chem ; 46(5): 673-83, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10794750

RESUMO

BACKGROUND: PS-341, a selective inhibitor of the proteasome, currently is under evaluation as an anticancer agent in multiple phase I clinical trials. In animal-model studies, PS-341 was rapidly removed from the vascular compartment and distributed widely, quickly approaching the limits of detection. An accurate pharmacodynamic assay has been developed as an alternative or complement to pharmacokinetic measurements. METHODS: Fluorogenic kinetic assays for both the chymotryptic and tryptic activities of the proteasome have been optimized for both whole blood and blood cells. Using the ratio of these activities and the catalytic mechanism of the proteasome, we developed a novel method of calculating percentage of inhibition, using two structurally unrelated inhibitors (PS-341 and lactacystin). RESULTS: This ratio method was demonstrated to be sensitive (detection limit of 13% inhibition with 10 microgram of cell lysate), specific to the proteasome (PS-341 provides >98% inhibition), accurate (112% analyte recovery), and precise (0% +/- 5% inhibition at 0 nmol/L PS-341 and 74.5% +/- 1.7% inhibition at 200 nmol/L PS-341). Using these assays, we found that both erythrocytes and leukocytes contain proteasome at 3 micromol/L. Pharmacodynamic results for PS-341 obtained from the whole-blood ratio method were comparable to those using leukocytes determined by another method. CONCLUSIONS: The described assay provides a reliable method for studying the pharmacodynamics of proteasome inhibitors and is now in use in concurrent phase I clinical trials with PS-341.


Assuntos
Cisteína Endopeptidases/metabolismo , Complexos Multienzimáticos/metabolismo , Acetilcisteína/análogos & derivados , Acetilcisteína/farmacologia , Animais , Antineoplásicos/farmacologia , Ácidos Borônicos/farmacologia , Bortezomib , Cisteína Endopeptidases/sangue , Humanos , Técnicas In Vitro , Cinética , Masculino , Complexos Multienzimáticos/sangue , Inibidores de Proteases/farmacologia , Complexo de Endopeptidases do Proteassoma , Pirazinas/farmacologia , Ratos , Ratos Sprague-Dawley , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrometria de Fluorescência
14.
J Allergy Clin Immunol ; 104(2 Pt 1): 294-300, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10452747

RESUMO

BACKGROUND: Nuclear factor-kappaB (NF-kappaB) is a critical transcription factor required for the regulation of many genes involved in inflammatory responses to noxious stimuli. On activation, NF-kappaB induces the transcription of numerous proinflammatory cytokines, enzymes, and cellular adhesion molecules. Blockade of the proteasome with selective inhibitors attenuates the effects of NF-kappaB, leading to suppression of the inflammatory response. OBJECTIVE: We sought to determine whether proteasome inhibitors would be active in a model of asthma. METHODS: The mouse delayed-type hypersensitivity model was used to screen a panel of compounds for in vivo activity. The proteasome inhibitor, PS-519, was shown to be the most active in this model and was selected for further development. Allergen-induced pulmonary eosinophilia in Brown Norway rats was used subsequently to determine anti-inflammatory activity in an animal model. RESULTS: Direct administration of PS-519 into the lungs significantly reduced leukocyte numbers, particularly the selective increase in eosinophils. Because steroids are the mainstay anti-inflammatory therapy in asthma, and data is available to suggest their possible interaction to suppress the activation of NF-kappaB, rats were also treated by inhalation with combinations of a steroid and the proteasome inhibitor. In both the delayed-type hypersensitivity and the animal eosinophil model, low doses of proteasome inhibitors were shown to be effective when given with low doses of steroids. CONCLUSION: Taken together, the present data suggest that proteasome inhibition may represent a novel strategy for the treatment of inflammatory lung diseases such as asthma.


Assuntos
Cisteína Endopeptidases/efeitos dos fármacos , Inibidores de Cisteína Proteinase/fisiologia , Complexos Multienzimáticos/efeitos dos fármacos , Animais , Asma/fisiopatologia , Asma/prevenção & controle , Dexametasona/efeitos adversos , Hipersensibilidade Tardia/induzido quimicamente , Lactonas/química , Lactonas/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Complexo de Endopeptidases do Proteassoma , Eosinofilia Pulmonar/imunologia , Eosinofilia Pulmonar/fisiopatologia , Eosinofilia Pulmonar/prevenção & controle , Ratos , Ratos Endogâmicos BN , Relação Estrutura-Atividade
15.
Dev Psychol ; 35(4): 1143-55, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10442882

RESUMO

Participants from ages 5 to 99 years completed 2 time estimation tasks: a temporal generalization task and a temporal bisection task. Developmental differences in overall levels of performance were found at both ends of the life span and were more marked on the generalization task than the bisection task. Older adults and children performed at lower levels than young adults, but there were also qualitative differences in the patterns of errors made by the older adults and the children. To capture these findings, the authors propose a new developmental model of temporal generalization and bisection. The model assumes developmental changes across the life span in the noisiness of initial perceptual encoding and across childhood in the extent to which long-term memory of time intervals is distorted.


Assuntos
Envelhecimento/psicologia , Desenvolvimento Infantil , Percepção do Tempo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Atenção , Criança , Pré-Escolar , Aprendizagem por Discriminação , Feminino , Generalização Psicológica , Humanos , Masculino , Rememoração Mental , Pessoa de Meia-Idade
16.
Am J Physiol ; 277(2): E332-41, 1999 08.
Artigo em Inglês | MEDLINE | ID: mdl-10444430

RESUMO

A new model of cachexia is described in which muscle protein metabolism related to the ubiquitin-proteasome pathway was investigated. Cloning of the colon-26 tumor produced a cell line, termed R-1, which induced cytokine (noninterleukin-1beta, interleukin-6 and tumor necrosis factor-alpha)-independent cachexia. Implantation of R-1 cells in mice elicited significant (20-30%) weight loss and decreased blood glucose by 70%, and adipose tissue levels declined by 95% and muscle weights decreased by 20-25%. Food intake was unaffected. The decrease in muscle weight reflected a decline in insoluble, but not soluble, muscle protein that was associated with a significant increase in net protein degradation. The rate of ubiquitin conjugation of proteins was significantly elevated in muscles of cachectic mice. Furthermore, the proteasome inhibitor lactacystin blocked the increase in protein breakdown but had no significant effect on proteolysis. Several markers of the ubiquitin-proteasome pathway, E2(14k) mRNA and E2(14k) protein and ubiquitin-protein conjugates, were not elevated. Future investigations with this new model should gain further insights into the mechanisms of cachexia and provide a background to evaluate novel and more efficacious therapies.


Assuntos
Caquexia/etiologia , Caquexia/metabolismo , Cisteína Endopeptidases/metabolismo , Complexos Multienzimáticos/metabolismo , Neoplasias Experimentais/complicações , Ubiquitinas/metabolismo , Animais , Caquexia/tratamento farmacológico , Dexametasona/uso terapêutico , Modelos Animais de Doenças , Glucocorticoides/uso terapêutico , Indometacina/uso terapêutico , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos DBA , Proteínas Musculares/metabolismo , Músculos/metabolismo , Complexo de Endopeptidases do Proteassoma
17.
J Biol Chem ; 274(29): 20123-6, 1999 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-10400624

RESUMO

The activation of T-lymphocytes is dependent upon, and accompanied by, an increase in voltage-gated K+ conductance. Kv1.3, a Shaker family K+ channel protein, appears to play an essential role in the activation of peripheral human T cells. Although Kv1.3-mediated K+ currents increase markedly during the activation process in mice, and to a lesser degree in humans, Kv1.3 mRNA levels in these organisms do not, indicating post-transcriptional regulation. In other tissues Shaker K+ channel proteins physically associate with cytoplasmic beta-subunits (Kvbeta1-3). Recently it has been shown that Kvbeta1 and Kvbeta2 are expressed in mouse T cells and that they are up-regulated during mitogen-stimulated activation. In this study, we show that the human Kvbeta subunits substantially increase K+ current amplitudes when coexpressed with their Kv1.3 counterpart, and that unlike in mouse, protein levels of human Kvbeta2 remain constant upon activation. Differences in Kvbeta2 expression between mice and humans may explain the differential K+ conductance increases which accompany T-cell proliferation in these organisms.


Assuntos
Peptídeos/química , Canais de Potássio de Abertura Dependente da Tensão da Membrana , Canais de Potássio/metabolismo , Animais , Células Cultivadas , Feminino , Humanos , Canal de Potássio Kv1.3 , Camundongos , Canais de Potássio/química , Canais de Potássio/genética , RNA Complementar/genética , RNA Complementar/metabolismo , Superfamília Shaker de Canais de Potássio , Xenopus laevis
18.
Ann N Y Acad Sci ; 868: 233-85, 1999 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-10414301

RESUMO

K+ channel principal subunits are by far the largest and most diverse of the ion channels. This diversity originates partly from the large number of genes coding for K+ channel principal subunits, but also from other processes such as alternative splicing, generating multiple mRNA transcripts from a single gene, heteromeric assembly of different principal subunits, as well as possible RNA editing and posttranslational modifications. In this chapter, we attempt to give an overview (mostly in tabular format) of the different genes coding for K+ channel principal and accessory subunits and their genealogical relationships. We discuss the possible correlation of different principal subunits with native K+ channels, the biophysical and pharmacological properties of channels formed when principal subunits are expressed in heterologous expression systems, and their patterns of tissue expression. In addition, we devote a section to describing how diversity of K+ channels can be conferred by heteromultimer formation, accessory subunits, alternative splicing, RNA editing and posttranslational modifications. We trust that this collection of facts will be of use to those attempting to compare the properties of new subunits to the properties of others already known or to those interested in a comparison between native channels and cloned candidates.


Assuntos
Canais de Potássio/genética , Processamento Alternativo , Animais , Clonagem Molecular , Regulação da Expressão Gênica/genética , Humanos , Ativação do Canal Iônico , Filogenia , Canais de Potássio/classificação , Conformação Proteica , Processamento de Proteína Pós-Traducional/genética , Edição de RNA , RNA Mensageiro/genética , Xenopus
19.
Magn Reson Med ; 41(4): 727-33, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10332848

RESUMO

This study was designed to evaluate with magnetization transfer imaging (MTI) and conventional magnetic resonance (MR) imaging the manifestation of diffuse axonal injury (DAI) in an animal model of injury via nonimpact coronal plane rotational acceleration. A second objective was to investigate the diagnostic use of quantitative MTR imaging based on statistical parameters in a single subject, as opposed to grouped analysis. Seven mini-swine were subjected to brain trauma known to produce isolated DAI and to MR imaging at two time points. Following sacrifice, the brains were harvested for histopathologic examination. Magnetization transfer ratio (MTR) maps were generated for double-blinded comparison of regions with abnormal MTR values and regions with documented DAI. Positive and negative predictive values for MTR detection of DAI were 67 and 56%, respectively, and in acute studies alone, 89 and 61%. Gains in sensitivity over conventional imaging for detection of DAI were demonstrated.


Assuntos
Axônios/patologia , Lesões Encefálicas/patologia , Imageamento por Ressonância Magnética/métodos , Animais , Feminino , Masculino , Sensibilidade e Especificidade , Suínos , Porco Miniatura
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