Papers by Alexandra Maia E Silva
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Nature, 1994
H.Feldmann et aL chromosome patterns but also revealed particular novel features of chromosomal o... more H.Feldmann et aL chromosome patterns but also revealed particular novel features of chromosomal organization. Alternating regional variations in average base composition correlate with variations in local gene density along chromosome II, as observed in chromosomes XI and III. We propose that functional ARS elements are preferably located in the AT-rich regions that have a spacing of 4110 kb. Similarly, the 13 tRNA genes and the three Ty elements of chromosome II are found in AT-rich regions. In chromosome II, the distribution of coding sequences between the two strands is biased, with a ratio of 1.3:1. An interesting aspect regarding the evolution of the eukaryotic genome is the finding that chromosome II has a high degree of internal genetic redundancy, amounting to 16% of the coding capacity.
Poster apresentado nos Seminarios de Ciencias da Saude, ISCSEM - Instituto Superior de Ciencias d... more Poster apresentado nos Seminarios de Ciencias da Saude, ISCSEM - Instituto Superior de Ciencias da Saude Egas Moniz, Caparica, Abril de 2013.
Poster presented at the From Basic Sciences to Clinical Research - First International Congress o... more Poster presented at the From Basic Sciences to Clinical Research - First International Congress of CiiEM. Egas Moniz, Caparica, Portugal, 27-28 November 2015
Annals of Medicine, 2019
View related articles View Crossmark data ZnS QDs and the controls. With respect to the total ant... more View related articles View Crossmark data ZnS QDs and the controls. With respect to the total antioxidant capacity (TAC), the results show slight variations but with no significant differences (p > 0.05) between tested concentrations. Concerning total ubiquitin, a significant increase (p < 0.05) was detected between fish exposed to 10 mg.L À1 of CdS QDs in comparison to controls, while a significant decrease was determined between fish exposed to 1000 mg.L À1 of ZnS QDs and the controls. Conclusions: The study suggests that the ZnS QDs are probably more capable to cause sublethal effects in zebrafish after 7 days of exposure than CdS. We can speculate that this can be due, in some extent, to different degrees of QDs aggregation and possibly higher rates of dissociation of Zn ions from the QDs which in turn cause the observed toxicity in fish exposed to Zn QDs. Nonetheless, more studies are needed to clarify this issue such as tissue content of each QDs tested and perform studies on metal dissociation from QDs.
Annals of Medicine, 2019
View related articles View Crossmark data particularly striking in patients with extramedullary d... more View related articles View Crossmark data particularly striking in patients with extramedullary disease and more aggressive forms of MM. The longitudinal evaluation in 2 different time-points (T1 and T2) suggests a correlation between EXO protein load and response to treatment, to be confirmed in a larger cohort. Our work will further evaluate the profile of the proteins included in these EXO and its roles on disease progression, response to treatment and micro environment modification.
PPAR Research, 2016
Peroxisome Proliferator-Activated Receptors (PPAR) are transcription factors suggested to be invo... more Peroxisome Proliferator-Activated Receptors (PPAR) are transcription factors suggested to be involved in inflammatory lesions of autoimmune encephalomyelitis and multiple sclerosis (MS). Our objective was to assess whether Natalizumab (NTZ) therapy is associated with alterations of PPAR expression in MS patients. We analyzed gene expression of PPAR in peripheral blood mononuclear cells (PBMC) as well as blood inflammatory markers in women with MS previously medicated with first-line immunomodulators (baseline) and after NTZ therapy. No differences in PPARα, PPARβ/δ, PPARγ, and CD36 mRNA expression were found in PBMC between patients under baseline and healthy controls. At three months, NTZ increased PPARβ/δmRNA (p=0.009) in comparison to baseline, while mRNA expression of PPARγand CD36 (a well-known PPAR target gene) was lower in comparison to healthy controls (p=0.026andp=0.028, resp.). Although these trends of alterations remain after six months of therapy, the results were not st...
A 17.6 kb DNA fragment from the right arm of chromosome VII of Saccharomyces cerevisiae has been ... more A 17.6 kb DNA fragment from the right arm of chromosome VII of Saccharomyces cerevisiae has been sequenced and analysed. The sequence contains twelve open reading frames (ORFs) longer than 100 amino acids. Three genes had already been cloned and sequenced: CCT, ADE3 and TR-I. Two ORFs are similar to other yeast genes: G7722 with the YAL023 (PMT2) and P M T l genes, encoding two integral membrane proteins, and G7727 with the first half of the genes encoding elongation factors ly, TEF3 and TEF4. Two other ORFs, G7742 and G7744, are most probably yeast orthologues of the human and Paracoccus denitrificans electron-transferring flavoproteins (p chain) and of the Escherichia coli phosphoserine phosphohydrolase. The five remaining identified ORFs do not show detectable homology with other protein sequences deposited in data banks. The sequence has been deposited in the EMBL data library under Accession Number 249133.
Psychology of Violence, 2015
Objective: The present experiment analyzed the effects of playing a violent video game on player’... more Objective: The present experiment analyzed the effects of playing a violent video game on player’s sensitivity to victimized people by measuring the involuntary pupil dilation responses (PDRs) duri ...
Bone, 2014
This paper assesses the magnitude of Pb uptake in cortical and trabecular bones in healthy animal... more This paper assesses the magnitude of Pb uptake in cortical and trabecular bones in healthy animals and animals with altered balance in bone turnover, and the impact of exposure to Pb on serum markers of bone formation and resorption. The results reported herein provide physiological evidence that Pb distributes differently in central compartments in Pb metabolism, such as cortical and trabecular bone, in healthy animals and animals with altered balance in bone turnover, and that exposure to Pb does have an impact on bone resorption resulting in OC-dependent osteopenia. These findings show that Pb may play a role in the etiology of osteoporosis and that its concentration in bones varies as a result of altered bone turnover characteristic of this disease, a long standing question in the field. In addition, data collected in this study are consistent with previous observations of increased half-life of Pb in bone at higher exposures. This evidence is relevant for the necessary revision of current physiologically based kinetic models for Pb in humans.
Yeast, 1995
We report the sequence of a 9000 bp fragment from the right arm of Saccharomyces cerevisiae chrom... more We report the sequence of a 9000 bp fragment from the right arm of Saccharomyces cerevisiae chromosome VII.
Poster presented at the EMBO Workshop- Histone variants. Strasbourg, France, 2-4 June 2014.
Yeast, 1996
A 17.6 kb DNA fragment from the right arm of chromosome VII of Saccharomyces cerevisiae has been ... more A 17.6 kb DNA fragment from the right arm of chromosome VII of Saccharomyces cerevisiae has been sequenced and analysed. The sequence contains twelve open reading frames (ORFs) longer than 100 amino acids. Three genes had already been cloned and sequenced: CCT, ADE3 and TR-I. Two ORFs are similar to other yeast genes: G7722 with the YAL023 (PMT2) and PMT1 genes, encoding two integral membrane proteins, and G7727 with the first half of the genes encoding elongation factors 1gamma, TEF3 and TEF4. Two other ORFs, G7742 and G7744, are most probably yeast orthologues of the human and Paracoccus denitrificans electron-transferring flavoproteins (beta chain) and of the Escherichia coli phosphoserine phosphohydrolase. The five remaining identified ORFs do not show detectable homology with other protein sequences deposited in data banks. The sequence has been deposited in the EMBL data library under Accession Number Z49133.
Yeast
A 17.6 kb DNA fragment from the right arm of chromosome VII of Saccharomyces cerevisiae has been ... more A 17.6 kb DNA fragment from the right arm of chromosome VII of Saccharomyces cerevisiae has been sequenced and analysed. The sequence contains twelve open reading frames (ORFs) longer than 100 amino acids. Three genes had already been cloned and sequenced: CCT, ADE3 and TR-I. Two ORFs are similar to other yeast genes: G7722 with the YAL023 (PMT2) and PMT1 genes, encoding two integral membrane proteins, and G7727 with the first half of the genes encoding elongation factors 1gamma, TEF3 and TEF4. Two other ORFs, G7742 and G7744, are most probably yeast orthologues of the human and Paracoccus denitrificans electron-transferring flavoproteins (beta chain) and of the Escherichia coli phosphoserine phosphohydrolase. The five remaining identified ORFs do not show detectable homology with other protein sequences deposited in data banks. The sequence has been deposited in the EMBL data library under Accession Number Z49133.
Yeast, 1996
A 17.6 kb DNA fragment from the right arm of chromosome VII of Saccharomyces cerevisiae has been ... more A 17.6 kb DNA fragment from the right arm of chromosome VII of Saccharomyces cerevisiae has been sequenced and analysed. The sequence contains twelve open reading frames (ORFs) longer than 100 amino acids. Three genes had already been cloned and sequenced: CCT, ADE3 and TR-I. Two ORFs are similar to other yeast genes: G7722 with the YAL023 (PMT2) and PMT1 genes, encoding two integral membrane proteins, and G7727 with the first half of the genes encoding elongation factors 1gamma, TEF3 and TEF4. Two other ORFs, G7742 and G7744, are most probably yeast orthologues of the human and Paracoccus denitrificans electron-transferring flavoproteins (beta chain) and of the Escherichia coli phosphoserine phosphohydrolase. The five remaining identified ORFs do not show detectable homology with other protein sequences deposited in data banks. The sequence has been deposited in the EMBL data library under Accession Number Z49133.
Journal of Virology, 2005
Viral infectivity factor (Vif) is one of the human immunodeficiency virus (HIV) accessory protein... more Viral infectivity factor (Vif) is one of the human immunodeficiency virus (HIV) accessory proteins and is conserved in the primate lentivirus group. This protein is essential for viral replication in vivo and for productive infection of nonpermissive cells, such as peripheral blood mononuclear cells (PBMC). Vif counteracts an antiretroviral cellular factor in nonpermissive cells named CEM15/APOBEC3G. Although HIV type 1 (HIV-1) Vif protein (Vif1) can be functionally replaced by HIV-2 Vif protein (Vif2), its identity is very small. Most of the functional studies have been carried out with Vif1. Characterization of functional domains of Vif2 may elucidate its function, as well as differences between HIV-1 and HIV-2 infectivity. Our aim was to identify the permissivity of different cell lines for HIV-2 vif-minus viruses. By mutagenesis specific conserved motifs of HIV-2 Vif protein were analyzed, as well as in conserved motifs between Vif1 and Vif2 proteins. Vif2 mutants were examined for their stability, expression, and cellular localization in order to characterize essential domains of Vif2 proteins. Viral replication in various target cells (PBMC and H9, A3.01, U38, and Jurkat cells) and infectivity in single cycle assays in the presence of APOBEC3G were also analyzed. Our results of viral replication show that only PBMC have a nonpermissive phenotype in the absence of Vif2. Moreover, the HIV-1 vif-minus nonpermissive cell line H9 does not show a similar phenotype for vif-negative HIV-2. We also report a limited effect of APOBEC3G in a single-cycle infectivity assay, where only conserved domains between HIV-1 and HIV-2 Vif proteins influence viral infectivity. Taken together, these results allow us to speculate that viral inhibition by APOBEC3G is not the sole and most important determinant of antiviral activity against HIV-2.
EMBO reports, 2005
Variant histone H3.3 is incorporated into nucleosomes by a mechanism that does not require DNA re... more Variant histone H3.3 is incorporated into nucleosomes by a mechanism that does not require DNA replication and has also been implicated as a potential mediator of epigenetic memory of active transcriptional states. In this study, we have used chromatin immunoprecipitation analysis to show that H3.3 is found mainly at the promoters of transcriptionally active genes. We also show that H3.3 combines with H3 acetylation and K4 methylation to form a stable mark that persists during mitosis. Our results suggest that H3.3 is deposited principally through the action of chromatin-remodelling complexes associated with transcriptional initiation, with deposition mediated by RNA polymerase II elongation having only a minor role.
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Papers by Alexandra Maia E Silva