420 research outputs found
The Use of Preoperative Transcranial Doppler Variables to Predict Which Patients do Not Need a Shunt During Carotid Endarterectomy
AbstractObjectives: to analyse whether preoperative transcranial Doppler (TCD) variables can predict intraoperative shunt requirement. Design and methods: the blood-flow velocity (BFV) in the major basal cerebral arteries was measured preoperatively with TCD, in 178 patients scheduled for CEA. Carotid artery compression and CO2 reactivity tests were also performed. Intraoperative electroencephalography was used to decide whether a shunt was needed. Differences in the probability of shunt requirement between the categories of variables were assessed with crosstabs statistics. Results: preoperative TCD criteria clearly identified a subgroup of 59 patients (33%) who did not require a shunt. In general, these patients appeared to have adequate collateral flow through the anterior communicating artery. In contrast, prediction of the need for a shunt was less reliable. TCD variables could predict the need for a shunt with a probability of only 60%.Conclusions: preoperative TCD can be used to identify patients who do not require a shunt during carotid endarterectomy
Symptoms and Surgical Management of a Distal Choledochal Cyst in a Patient with Pancreas Divisum: Case Report and Review of the Literature
We report the case of a 63-year-old woman who presented with the rare finding of a distal choledochocele in a pancreas divisum with recurrent abdominal pain and episodes of pancreatitis. She underwent successful resection with choledochectomy, papillectomy and reconstruction with a hepatico-jejunostomy and reinsertion of the uncinate pancreatic duct into the same jejunal loop. Comparable literature findings are discussed with regard to the presented case
Hybridization between wild and cultivated potato species in the Peruvian Andes and biosafety implications for deployment of GM potatoes
The nature and extent of past and current hybridization between cultivated potato and wild relatives in nature is of interest to crop evolutionists, taxonomists, breeders and recently to molecular biologists because of the possibilities of inverse gene flow in the deployment of genetically-modified (GM) crops. This research proves that natural hybridization occurs in areas of potato diversity in the Andes, the possibilities for survival of these new hybrids, and shows a possible way forward in case of GM potatoes should prove advantageous in such areas
Atrophy in the parahippocampal gyrus as an early biomarker of Alzheimer’s disease
The main aim of the present study was to compare volume differences in the hippocampus and parahippocampal gyrus as biomarkers of Alzheimer’s disease (AD). Based on the previous findings, we hypothesized that there would be significant volume differences between cases of healthy aging, amnestic mild cognitive impairment (aMCI), and mild AD. Furthermore, we hypothesized that there would be larger volume differences in the parahippocampal gyrus than in the hippocampus. In addition, we investigated differences between the anterior, middle, and posterior parts of both structures. We studied three groups of participants: 18 healthy participants without memory decline, 18 patients with aMCI, and 18 patients with mild AD. 3 T T1-weighted MRI scans were acquired and gray matter volumes of the anterior, middle, and posterior parts of both the hippocampus and parahippocampal gyrus were measured using a manual tracing approach. Volumes of both the hippocampus and parahippocampal gyrus were significantly different between the groups in the following order: healthy > aMCI > AD. Volume differences between the groups were relatively larger in the parahippocampal gyrus than in the hippocampus, in particular, when we compared healthy with aMCI. No substantial differences were found between the anterior, middle, and posterior parts of both structures. Our results suggest that parahippocampal volume discriminates better than hippocampal volume between cases of healthy aging, aMCI, and mild AD, in particular, in the early phase of the disease. The present results stress the importance of parahippocampal atrophy as an early biomarker of AD
Reusable Components of Semantic Specifications
Semantic specifications of programming languages typically have poor modularity. This hinders reuse of parts of the semantics of one language when specifying a different language – even when the two languages have many constructs in common – and evolution of a language may require major reformulation of its semantics. Such drawbacks have discouraged language developers from using formal semantics to document their designs. In the PLanCompS project, we have developed a component-based approach to semantics. Here, we explain its modularity aspects, and present an illustrative case study: a component-based semantics for Caml Light. We have tested the correctness of the semantics by running programs on an interpreter generated from the semantics, comparing the output with that produced on the standard implementation of the language. Our approach provides good modularity, facilitates reuse, and should support co-evolution of languages and their formal semantics. It could be particularly useful in connection with domain-specific languages and language-driven software development
Cancer immunotherapy by immunosuppression
We have previously suggested that the stimulatory effect of a weak immune reaction on tumor growth may be necessary for the growth of incipient tumors. In the present paper, we enlarge upon and extend that idea by collecting evidence in the literature bearing upon this new hypothesis that a growing cancer, whether in man or mouse, is throughout its lifespan, probably growing and progressing because of continued immune stimulation by a weak immune reaction. We also suggest that prolonged immunosuppression might interfere with progression and thus be an aid to therapy. While most of the considerable evidence that supports the hypothesis comes from observations of experimental mouse tumors, there is suggestive evidence that human tumors may behave in much the same way, and as far as we can ascertain, there is no present evidence that necessarily refutes the hypothesis
Burden and modifications in life from the perspective of caregivers for patients after stroke
OBJECTIVE: to analyze the impact that caring has on a member of the family caring for a patient after a cerebrovascular accident, correlating life modifications and mental suffering with the perceived burden. METHOD: a cross-sectional, quantitative study, undertaken in January-April 2010 in Fortaleza, Ceará, Brazil. RESULT: 61 individuals were investigated, monitored by three hospitals' Home Care Program. Data collection was through interviews for identifying life changes, and through the application of three scales for investigating perceived burden, mental state and mental suffering. Respectively these were the Caregiver Burden Scale (CBS), the Mini-Mental State Examination (MMSE) and the Self Reported Questionnaire (SRQ). The majority of the carers were female, married, and the children of the stroke patients. The average age was 48.2 years (±12.4). The most-cited life modifications referred to the daily routine, to leisure activities, and to exhaustion or tiredness. Regarding burden, the dimensions of General tension, Isolation and Disappointment stood out. It was ascertained that overload was more severe when the carer presented more symptoms of psychological distress, in the absence of a secondary carer, and when the principal carers reported perceiving changes in their bodies and health. CONCLUSION: an association between burden and the carer's mental state was not observed. Understanding the care, through analysis of the burden and of the knowledge of the biopsychosocial situation will provide support for the nurse's work in reducing the overload for family caregivers.OBJETIVO: analizar el impacto del cuidar para el cuidador familiar de paciente después de accidente vascular cerebral, correlacionando modificaciones de vida y sufrimiento psÃquico con la sobrecarga percibida. MÉTODO: estudio transversal, cuantitativo, realizado de enero a abril de 2010, en Fortaleza, Ceará, Brasil. RESULTADO: se investigaron 61 individuos, acompañados por el Programa de Servicio Domiciliar de tres hospitales. La colecta de los datos ocurrió mediante entrevista para identificar modificaciones de vida, y con la aplicación de tres escalas para investigar la sobrecarga percibida, estado mental y sufrimiento psÃquico. Son ellas, respectivamente: Caregiver Burden Scale (CBS), Mini Examen del Estado Mental (MEEM) y Self Reported Questionnaire (SRQ). Los cuidadores, en su mayorÃa, eran del sexo femenino, casados (as) e hijo (as) de los pacientes después del AVC. Edad Media de 48,2 años (±12,4). Las modificaciones de vida más citadas fueron referentes a la rutina diaria, a las actividades de ocio y agotamiento o cansancio. En cuanto a la sobrecarga, se destacaron las dimensiones Tensión general, Aislamiento y Decepción. Se verificó mayor sobrecarga cuanto más sÃntomas de sufrimiento psÃquico el cuidador presentase, en la ausencia de cuidador secundario y cuando los cuidadores principales relataron percibir modificación en el cuerpo y en la salud. CONCLUSIÓN: no fue observada asociación de la sobrecarga con el estado mental del cuidador. Entender la coyuntura del cuidado, mediante análisis del recargo de trabajo, y del conocimiento de la situación biopsicosocial, suministrará subsidios para la actuación del enfermero para reducir la carga generada para los cuidadores familiares.OBJETIVO: analisar o impacto do cuidar para o cuidador familiar de paciente após acidente vascular cerebral (AVC), correlacionando modificações de vida e sofrimento psÃquico com a sobrecarga percebida. MÉTODO: estudo transversal, quantitativo, realizado de janeiro a abril de 2010, em Fortaleza, Ceará, Brasil. RESULTADO: investigaram-se 61 indivÃduos, acompanhados pelo Programa de Atendimento Domiciliar (PAD), de três hospitais. A coleta dos dados ocorreu mediante entrevista para identificar modificações de vida, e com a aplicação de três escalas para investigar sobrecarga percebida, estado mental e sofrimento psÃquico. São elas, respectivamente: Caregiver Burden Scale (CBS), Miniexame do Estado Mental (MEEM) e Self Reported Questionnaire (SRQ). Os cuidadores, na sua maioria, eram do sexo feminino, casados(as) e filho(as) dos pacientes após AVC. A média de idade era de 48,2 anos (±12,4). As modificações de vida mais citadas foram referentes à rotina diária, à s atividades de lazer e esgotamento ou cansaço. Quanto à sobrecarga, destacaram-se as dimensões tensão geral, isolamento e decepção. Verificou-se maior sobrecarga quanto mais sintomas de sofrimento psÃquico o cuidador apresentasse, na ausência de cuidador secundário e quando os cuidadores principais relataram perceber modificação no corpo e na saúde. CONCLUSÃO: não foi observada associação da sobrecarga com o estado mental do cuidador. Entender a conjuntura do cuidado, mediante análise da sobrecarga de trabalho, e do conhecimento da situação biopsicossocial fornecerá subsÃdios para a atuação do enfermeiro para reduzir a carga gerada para os cuidadores familiares
Levothyroxine Monotherapy Cannot Guarantee Euthyroidism in All Athyreotic Patients
CONTEXT: Levothyroxine monotherapy is the treatment of choice for hypothyroid patients because peripheral T4 to T3 conversion is believed to account for the overall tissue requirement for thyroid hormones. However, there are indirect evidences that this may not be the case in all patients. OBJECTIVE: To evaluate in a large series of athyreotic patients whether levothyroxine monotherapy can normalize serum thyroid hormones and thyroid-pituitary feedback. DESIGN: Retrospective study. SETTING: Academic hospital. PATIENTS: 1,811 athyreotic patients with normal TSH levels under levothyroxine monotherapy and 3,875 euthyroid controls. MEASUREMENTS: TSH, FT4 and FT3 concentrations by immunoassays. RESULTS: FT4 levels were significantly higher and FT3 levels were significantly lower (p<0.001 in both cases) in levothyroxine-treated athyreotic patients than in matched euthyroid controls. Among the levothyroxine-treated patients 15.2% had lower serum FT3 and 7.2% had higher serum FT4 compared to euthyroid controls. A wide range of FT3/FT4 ratios indicated a major heterogeneity in the peripheral T3 production capacity in different individuals. The correlation between thyroid hormones and serum TSH levels indicated an abnormal feedback mechanism in levothyroxine-treated patients. CONCLUSIONS: Athyreotic patients have a highly heterogeneous T3 production capacity from orally administered levothyroxine. More than 20% of these patients, despite normal TSH levels, do not maintain FT3 or FT4 values in the reference range, reflecting the inadequacy of peripheral deiodination to compensate for the absent T3 secretion. The long-term effects of chronic tissue exposure to abnormal T3/T4 ratio are unknown but a sensitive marker of target organ response to thyroid hormones (serum TSH) suggests that this condition causes an abnormal pituitary response. A more physiological treatment than levothyroxine monotherapy may be required in some hypothyroid patients
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