Browsing by Author "Timóteo, A"
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- Crosstalk between genetics, gene expression and biochemical markers supports systemic iron homeostasis dysregulation in alzheimer diseasePublication . Crespo, A; Silva, B; Ferreira, C; Marquesa, L; Marcelino, E; Maruta, C; Costa, S; Timóteo, A; Vilares, A; Couto, F; Faustino, P; Correia, AP; Verdelho, A; Porto, G; Guerreiro, M; Herrero Valverde, A; Costa, C; Mendonça, A; Costa, L; Martins, M
- Decrease in APP and CP mRNA expression supports impairment of iron export in Alzheimer's disease patientsPublication . Guerreiro, C; Silva, B; Crespo, A; Marques, L; Costa, S; Timóteo, A; Marcelino, E; Maruta, C; Vilares, A; Matos, M; Couto, F; Faustino, P; Verdelho, A; Guerreiro, M; Herrero Valverde, A; Costa, C; Mendonça, A; Martins, M; Costa, LAlzheimer's disease (AD) is a neurodegenerative disorder of still unknown etiology and the leading cause of dementia worldwide. Besides its main neuropathological hallmarks, a dysfunctional homeostasis of transition metals has been reported to play a pivotal role in the pathogenesis of this disease. Dysregulation of iron (Fe) metabolism in AD has been suggested, particularly at the level of cellular iron efflux. Herein, we intended to further clarify the molecular mechanisms underlying Fe homeostasis in AD. In order to achieve this goal, the expression of specific Fe metabolism-related genes directly involved in Fe regulation and export was assessed in peripheral blood mononuclear cells (PBMCs) from 73AD patients and 74 controls by quantitative PCR. The results obtained showed a significant decrease in the expression of aconitase 1 (ACO1; P=0.007); ceruloplasmin (CP; P<0.001) and amyloid-beta precursor protein (APP; P=0.006) genes in AD patients compared with healthy volunteers. These observations point out to a significant downregulation in the expression of genes associated with ferroportin-mediated cellular Fe export in PBMCs from AD patients, when compared to controls. Taken together, these findings support previous studies suggesting impairment of Fe homeostasis in AD, which may lead to cellular Fe retention and oxidative stress, a typical feature of this disease.
- Esclerosis múltiple y decisión de la maternidad: estudio observacional en pacientes portuguesasPublication . Carvalho, A; Veiga, A; Morgado, J; Tojal, R; Rocha, S; Vale, J; Sá, MJ; Timóteo, AIntroducción. La esclerosis múltiple (EM) es una enfermedad incapacitante que afecta mayoritariamente a mujeres en edad fértil. La EM puede alterar el deseo de crear una familia y concebir hijos. Objetivo. Estudiar la influencia del diagnóstico de la EM y de su evolución sobre la decisión de ser madre. Pacientes y métodos. Se seleccionó una cohorte integrada por pacientes de 35-45 años diagnosticadas de EM desde hacía por lo menos 10 años que eran atendidas en seis centros portugueses. Las participantes respondieron a un cuestionario estructurado en días de consulta consecutivos. Se revisaron las historias clínicas para caracterizar y recabar información sobre la enfermedad y los embarazos. Resultados. Participaron 100 mujeres; la media de edad en el momento del diagnóstico de la EM era de 26,3 ± 5,0 años; el 90% de las participantes presentaba la forma remitente recurrente; el 57% de las pacientes no se habían quedado embarazadas después del diagnóstico. El tipo de EM y el número de recidivas no difirieron de manera significativa entre las mujeres que habían concebido después del diagnóstico y las que no (p = 0,39 y p = 0,50, respectivamente). El 77% no había tenido el número de hijos deseado. Los principales motivos aducidos fueron el temor a la incapacidad futura y la posibilidad de sufrir recidivas. Cuarenta y tres mujeres creían que el embarazo podía agravar la EM. Conclusión. En la población del estudio, la decisión de ser o no ser madre no guardó relación con el tipo de EM ni con el número de recidivas. No obstante, un número relevante de mujeres tuvieron menos embarazos de los que habían desea- do antes de ser diagnosticadas y pensaban que la gestación podía empeorar la enfermedad. Sería conveniente mejorar la información que reciben estas pacientes a fin de minimizar el impacto del diagnóstico de la EM en la decisión de ser madre.
- Genetic and biochemical markers in patients with Alzheimer's disease support a concerted systemic iron homeostasis dysregulationPublication . Crespo, A; Silva, B; Marques, L; Marcelino, E; Maruta, C; Costa, S; Timóteo, A; Vilares, A; Couto, F; Faustino, P; Correia, AP; Verdelho, A; Porto, G; Guerreiro, M; Herrero Valverde, A; Costa, C; Mendonça, A; Costa, L; Martins, MAlzheimer's disease (AD) is the most common form of dementia in the elderly individuals, resulting from a complex interaction between environmental and genetic factors. Impaired brain iron homeostasis has been recognized as an important mechanism underlying the pathogenesis of this disease. Nevertheless, the knowledge gathered so far at the systemic level is clearly insufficient. Herein, we used an integrative approach to study iron metabolism in the periphery, at both genotypic and phenotypic levels, in a sample of 116 patients with AD and 89 healthy control subjects. To assess the potential impact of iron metabolism on the risk of developing AD, genetic analyses were performed along with the evaluation of the iron status profile in peripheral blood by biochemical and gene expression studies. The results obtained showed a significant decrease of serum iron, ferritin, and transferrin concentrations in patients compared with the control subjects. Also, a significant decrease of ferroportin (SLC40A1) and both transferrin receptors TFRC and TFR2 transcripts was found in peripheral blood mononuclear cells from patients. At the genetic level, significant associations with AD were found for single nucleotide polymorphisms in TF, TFR2, ACO1, and SLC40A1 genes. Apolipoprotein E gene, a well-known risk factor for AD, was also found significantly associated with the disease in this study. Taken together, we hypothesize that the alterations on systemic iron status observed in patients could reflect an iron homeostasis dysregulation, particularly in cellular iron efflux. The intracellular iron accumulation would lead to a rise in oxidative damage, contributing to AD pathophysiology.
- Headache as the sole presentation of cerebral venous thrombosis: a prospective studyPublication . Timóteo, A; Inácio, N; Machado, S; Pinto, A; Parreira, EHeadache is the most frequent presenting symptom of cerebral venous thrombosis (CVT), most commonly associated with other manifestations. It has been described as its only clinical presentation in 15 % of patients. There is no typical pattern of headache in CVT. The objective of this study was to study the characteristics of headache as the sole manifestation of CVT. From a prospective study of 30 consecutive patients diagnosed with CVT over 18 months, we selected those who presented with headache only: they had a normal neurological examination, no papilloedema and no blood or any parenchymal lesion on CT scan. All were submitted to a systematic etiological workup and a structured questionnaire about the characteristics of headache was provided. Headache was the sole manifestation of CVT in 12 patients; it was diffuse or bilateral in the majority. Seven patients referred worsening with sleep/lying down, Valsalva maneuvers or straining. There was no association between the characteristics of headache and extension of CVT. Time from onset to diagnosis was significantly delayed in these patients presenting only with headache. In our series, 40 % of patients presented only with headache. There was no uniform pattern of headache apart from being bilateral. There was a significant delay of diagnosis in these patients. Some characteristics of headache should raise the suspicion of CVT: recent persistent headache, thunderclap headache or pain worsening with straining, sleep/lying down or Valsalva maneuvers even in the absence of papilloedema or focal signs.
- Manifestações neurológicas e psiquiátricas: de mãos dadas no serviço de urgência – a perspectiva do neurologistaPublication . Costa, C; Timóteo, A; Marques, JO trabalho de neurologistas e psiquiatras num serviço de urgência hospitalar é habitualmente realizado em circunstâncias complexas que podem dificultar o processo diagnóstico, em particular quando coexistem co-morbilidades neurológicas e psiquiátricas. No que diz respeito a estas duas especialidades, a abordagem clínica é frequentemente complementar. Neste artigo, serão abordadas inicialmente as manifestações psiquiátricas das doenças neurológicas e mais adiante as manifestações funcionais que mimetizam patologia neurológica. É este último grupo que constitui o maior desafio para o neurologista de urgência.
- Posterior reversible encephalopathy syndrome and anti-angiogenic agents: a case reportPublication . Silva, F; Pêgo, P; Vendrell, MC; Farias, MJ; Timóteo, A; Costa, MC; Cravo, I; Gomes, FPosterior reversible encephalopathy syndrome is an increasingly recognised clinico-radiological entity, associated with several medical conditions (such as systemic arterial hypertension) and characterised by seizures, altered mental status, headaches, and visual symptoms. Magnetic resonance imaging is a key component in this diagnosis, with hyperintense foci in T2-weighted images, corresponding to vasogenic oedema. The pathophysiology is not fully understood but probably involves loss of auto-regulation of cerebral vasculature or endothelial dysfunction or both. A 56-year-old male, suffering from a gastro-intestinal stromal tumour with hepatic metastasis resistant to imatinib, on therapy with sunitinib, came to the Emergency Department because of headaches, hallucinations, and loss of vision. There was no previous history of high blood pressure. A hypertensive crisis was diagnosed; ophthalmological examination on admission showed no light perception bilaterally. Brain imaging displayed bilateral parieto-occipital and frontal vasogenic oedema, consistent with the clinical diagnosis of posterior reversible encephalopathy syndrome. After treatment of hypertension and suspension of sunitinib, the patient recovered from his symptoms. Control imaging showed no oedema. Angiogenesis inhibitors, such as sunitinib and bevacizumab, can cause hypertension, one of the many medical conditions associated with the posterior reversible encephalopathy syndrome. This syndrome should be considered in cases of acute visual loss, particularly in view of its reversible nature when diagnosed and treated promptly.
- Rapidly progressive corticobasal degeneration syndrome.Publication . Herrero Valverde, A; Costa, S; Ginestal, R; Pimentel, J; Timóteo, AIntroduction: Corticobasal syndrome (CBS) has a heterogeneous clinical presentation with no specific pathologic substratum. Its accurate diagnosis is a challenge for neurologists; in order to establish CBS definitively, postmortem confirmation is required. Some clinical and radiological features can help to distinguish it from other neurodegenerative conditions, such as Creutzfeldt-Jakob disease (CJD). Clinical Case: A 74-year-old woman presented with language impairment, difficulty in walking and poor attentiveness that had begun 10 days before. Other symptoms, such as asymmetrical extra-pyramidal dysfunction, limb dystonia and ‘alien limb’ phenomena, were established over the next 2 months, with rapid progression. Death occurred 3 months after symptom onset. Laboratory results were normal. Initially, imaging only showed restricted diffusion with bilateral parieto-occipital gyri involvement on DWI-MRI, with unspecific EEG changes. An autopsy was performed. Brain neuropathology confirmed sporadic CJD (sCJD). Conclusions: CBS is a heterogeneous clinical syndrome whose differential diagnosis is extensive. CJD can occasionally present with clinical characteristics resembling CBS. MRI detection of abnormalities in some sequences (FLAIR, DWI), as previously reported, has high diagnostic utility for sCJD diagnosis – especially in early stages – when other tests can still appear normal. Abnormalities on DWI sequencing may not correlate with neuropathological findings, suggesting a functional basis to explain the changes found.