Browsing by Author "Paiva, A"
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- Aberrant p15, p16, p53, and DAPK Gene Methylation in Myelomagenesis: Clinical and Prognostic ImplicationsPublication . Geraldes, C; Gonçalves, AC; Cortesão, E; Pereira, MI; Roque, A; Paiva, A; Ribeiro, L; Nascimento-Costa, JM; Sarmento-Ribeiro, ABBACKGROUND: Aberrant DNA methylation is considered a crucial mechanism in the pathogenesis of monoclonal gammopathies. We aimed to investigate the contribution of hypermethylation of 4 tumor suppressor genes to the multistep process of myelomagenesis. METHODS: The methylation status of p15, p16, p53, and DAPK genes was evaluated in bone marrow samples from 94 patients at diagnosis: monoclonal gammopathy of uncertain significance (MGUS) (n = 48), smoldering multiple myeloma (SMM) (n = 8) and symptomatic multiple myeloma (MM) (n = 38), and from 8 healthy controls by methylation-specific polymerase chain reaction analysis. RESULTS: Overall, 63% of patients with MM and 39% of patients with MGUS presented at least 1 hypermethylated gene (P < .05). No aberrant methylation was detected in normal bone marrow. The frequency of methylation for individual genes in patients with MGUS, SMM, and MM was p15, 15%, 50%, 21%; p16, 15%, 13%, 32%; p53, 2%, 12,5%, 5%, and DAPK, 19%, 25%, 39%, respectively (P < .05). No correlation was found between aberrant methylation and immunophenotypic markers, cytogenetic features, progression-free survival, and overall survival in patients with MM. CONCLUSIONS: The current study supports a relevant role for p15, p16, and DAPK hypermethylation in the genesis of the plasma cell neoplasm. DAPK hypermethylation also might be an important step in the progression from MGUS to MM.
- Accelerated age-related olfactory decline among type 1 Usher patientsPublication . Ribeiro, JC; Oliveiros, B; Pereira, P; António, N; Hummel, T; Paiva, A; Silva, EUsher Syndrome (USH) is a rare disease with hearing loss, retinitis pigmentosa and, sometimes, vestibular dysfunction. A phenotype heterogeneity is reported. Recent evidence indicates that USH is likely to belong to an emerging class of sensory ciliopathies. Olfaction has recently been implicated in ciliopathies, but the scarce literature about olfaction in USH show conflicting results. We aim to evaluate olfactory impairment as a possible clinical manifestation of USH. Prospective clinical study that included 65 patients with USH and 65 normal age-gender-smoking-habits pair matched subjects. A cross culturally validated version of the Sniffin' Sticks olfaction test was used. Young patients with USH have significantly better olfactory scores than healthy controls. We observe that USH type 1 have a faster ageing olfactory decrease than what happens in healthy subjects, leading to significantly lower olfactory scores in older USH1 patients. Moreover, USH type 1 patients showed significantly higher olfactory scores than USH type 2, what can help distinguishing them. Olfaction represents an attractive tool for USH type classification and pre diagnostic screening due to the low cost and non-invasive nature of the testing. Olfactory dysfunction should be considered among the spectrum of clinical manifestations of Usher syndrome.
- Amiloidose primária: Tratamento e prognósticoPublication . Ascensão, M; Figueiredo, H; Nabais, MJ; Pimenta, P; Parente, F; Paiva, A; Feio, J; Alexandrino, MB; Alves-Moura, JJ
- Amiloidoses sistémicas não familiares: Casuística de um serviço de MedicinaPublication . Ascensão, M; Figueiredo, H; Pontes, J; Paiva, A; Pimenta, P; Parente, F; Feio, J; Alexandrino, MB; Serra e Silva, P
- CD4 CD86 expression on experimental allergic murine modelPublication . Pereira, C; Paiva, A; Machado, D; Henriques, A; Abrantes, M; Laranjo, M; Tavares, B; Loureiro, G; Chieira, C; Botelho, F; Baganha, MF
- Complications of ear mold impressions: two case reportsPublication . Silva, C; Amorim, AM; Gapo, C; Paiva, A
- Contact sensitizers downregulate the expression of the chemokine receptors CCR6 and CXCR4 in a skin dendritic cell linePublication . Cruz, MT; Gonçalo, Margarida; Paiva, A; Morgado, JM; Figueiredo, A; Duarte, CB; Lopes, MCChemokines are involved in the control of dendritic cell (DC) trafficking, which is critical for the immune response, namely in allergic contact dermatitis (ACD). In this work, we investigated by flow cytometry the effect of the contact sensitizers 2,4-dinitrofluorobenzene (DNFB), 1,4-phenylenediamine (PPD) and nickel sulfate (NiSO(4)), on the surface expression of the chemokine receptors CCR6 and CXCR4 in DC. As an experimental model of a DC we used a fetal skin-derived dendritic cell line (FSDC), which has morphological, phenotypical and functional characteristics of skin DC. Our results show that all the skin sensitizers studied decreased the membrane expression of the chemokine receptors CCR6 and CXCR4. In contrast, 2,4-dichloronitrobenzene (DCNB), the inactive analogue of DNFB without contact sensitizing properties, was without effect on the surface expression of these receptors. Lipopolysaccharide (LPS), which induces the maturation of DC, also reduced surface CCR6 and CXCR4 expression.
- Cytokine-producing T lymphocytes as a marker of prognosis and rejection episodes in orthotopic liver transplantationPublication . Paiva, A; Pereira, SV; Ballesteros, R; Freitas, A; Perdigoto, R; Mota, O; Ferrão, J; Tomé, L; Furtado, E; Cipriano, MA; Geraldes, B; Oliveira, FJ; Furtado, AL; Regateiro, FJ
- Dendritic cells in cord blood transplantation: a reviewPublication . Pereira, MI; Paiva, ADendritic cells (DCs) are a heterogeneous population of antigen-presenting cells derived from hematopoietic progenitors that bridge the transition between the innate and adaptive immune responses, while maintaining self-tolerance and Th1/Th2 homeostasis, by priming other cells in either an immunogenic or tolerogenic direction. Through their role in both innate and adaptive immunity, DCs play a major part in transplant engraftment and rejection and in graft-versus-host disease (GvHD). Preferentially tolerogenic or immunogenic DC subtypes offer targets for immunotherapy, to optimize transplant success rates and prolong disease-free and overall survival. Cord blood DCs are immature and preferentially tolerogenic, due to maternal-fetal tolerance, leading to better graft acceptance and immune reconstitution and explaining the lower incidence and severity of GvHD in CB transplantation, despite donor-host mismatching. Manipulation of DC maturation and cell loading with tumor-antigens can direct antitumor immunity and target minimal residual disease, as demonstrated for acute myeloid leukemia, optimizing the graft-versus-leukemia effect.
- Downbeat nystagmus elicited by eyelid closurePublication . Lemos, J; Pereira, D; Amorim, M; Santiago, B; Paiva, A; Cunha, LWe describe a patient with downbeat nystagmus (DBN) evoked only by eye closure. Brain and spinal cord magnetic resonance imaging revealed a T2 paramedian lesion in the left lower basis pontis and other white matter lesions consistent with multiple sclerosis. One potential mechanism for DBN in this case involves transverse ephaptic spread of excitation from areas that subserve coordinated lid closure to the decussating ventral tegmental tract.
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