Percorrer por autor "Bastos, Estela"
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- ERBB2 in Cat Mammary Neoplasias Disclosed a Positive Correlation between RNA and Protein Low Expression Levels: A Model for erbB-2 Negative Human Breast CancerPublication . Santos, Sara; Batista, Claudia S.; Abreu, Rui M.V.; Bastos, Estela; Amorim, Irina; Gut, Ivo G.; Gartner, Fátima; Chaves, RaquelHuman ERBB2 is a proto-oncogene that codes for the erbB-2 epithelial growth factor receptor. In human breast cancer (HBC), erbB-2 protein overexpression has been repeatedly correlated with poor prognosis. In more recent works, underexpression of this gene has been described in HBC. Moreover, it is also recognised that oncogenes that are commonly amplified or deleted encompass point mutations, and some of these are associated with HBC. In cat mammary lesions (CMLs), the overexpression of ERBB2 (27%–59.6%) has also been described, mostly at the protein level and although cat mammary neoplasias are considered to be a natural model of HBC, molecular information is still scarce. In the present work, a cat ERBB2 fragment, comprising exons 10 to 15 (ERBB2_10–15) was achieved for the first time. Allelic variants and genomic haplotype analyses were also performed, and differences between normal and CML populations were observed. Three amino acid changes, corresponding to 3 non-synonymous genomic sequence variants that were only detected in CMLs, were proposed to damage the 3D structure of the protein. We analysed the cat ERBB2 gene at the DNA (copy number determination), mRNA (expression levels assessment) and protein levels (in extra- and intra protein domains) in CML samples and correlated the last two evaluations with clinicopathological features. We found a positive correlation between the expression levels of the ERBB2 RNA and erbB-2 protein, corresponding to the intracellular region. Additionally, we detected a positive correlation between higher mRNA expression and better clinical outcome. Our results suggest that the ERBB2 gene is post-transcriptionally regulated and that proteins with truncations and single point mutations are present in cat mammary neoplastic lesions. We would like to emphasise that the recurrent occurrence of low erbB-2 expression levels in cat mammary tumours, suggests the cat mammary neoplasias as a valuable model for erbB-2 negative HBC.
- Muscle tissue changes with agingPublication . Pereira, Ana de Fátima; Silva, A.J.; Costa, Aldo M.; Monteiro, A.M.; Bastos, Estela; Marques, Mário C.Sarcopenia is characterized by a progressive generalized decrease of skeletal muscle mass, strength and function with aging. Recent- ly, the genetic determination has been associated with muscle mass and muscle strength in elderly. These two phenotypes of risk are the most commonly recognized and studied for sarcopenia, with heritability ranging from 30 to 85% for muscle strength and 45-90% for muscle mass. It is well known that the development and maintenance of muscle mass in early adulthood reduces the risk of developing sarcopenia and leads to a healthy aging. For that reason it seems important to identify which genetic factors interact with aging and in particular with the musculoskeletal response to exercise in such individuals. This review is designed to summarize the most important and representative studies about the possible association between certain genetic polymorphisms and muscle phenotypes in older populations. Also we will focuses on nutrition and some concerns associated with aging, including the role that exercise can have on reducing the negative effects of this phenomenon. Some results are inconsis- tent between studies and more replication studies underlying sarcopenia are needed, with larger samples and with different life cycles, particularly in the type and level of physical activity throughout life. In future we believe that further progress in understanding the ge- netic etiology and the metabolic pathways will provide valuable information on important biological mechanisms underlying the muscle physiology. This will enable better recognition of individuals at higher risk and the ability to more adequately address this debilitating condition.
- Scrapie at abattoir: monitoring, control, and differential diagnosis of wasting conditions during meat inspectionPublication . Esteves, Alexandra; Vieira-Pinto, Madalena; Quintas, Helder; Orge, Leonor; Gama, Adelina; Alves, Anabela; Seixas, Fernanda; Pires, Isabel; Pinto, Maria de Lurdes; Mendonça, Ana Paula; Lima, Carla; Machado, Carla Neves; Silva, João Carlos; Tavares, Paula; Silva, Filipe; Bastos, Estela; Pereira, Jorge; Gonçalves-Anjo, Nuno; Carvalho, Paulo; Sargo, Roberto; Matos, Ana; Figueira, Luís; Pires, Maria dos AnjosWasting disease in small ruminants is frequently detected at slaughterhouses. The wasting disorder is manifested by the deterioration of the nutritional and physiological state of the animal indicated by thinness, emaciation, and cachexia. Evidence of emaciation and cachexia, alone, are pathological conditions leading to carcass condemnation during an inspection. Several diseases are associated with a wasting condition, including scrapie, pseudotuberculosis, tuberculosis, paratuberculosis, Maedi Visna, and tumor diseases. On the other hand, parasitic diseases, nutrition disorders, exposure or ingestion of toxins, metabolic conditions, inadequate nutrition due to poor teeth, or poor alimentary diet are conditions contributing to poor body condition. Classical and atypical scrapie is naturally occurring transmissible spongiform encephalopathies in small ruminants. The etiological agent for each one is prions. However, each of these scrapie types is epidemiologically, pathologically, and biochemically different. Though atypical scrapie occurs at low incidence, it is consistently prevalent in the small ruminant population. Hence, it is advisable to include differential diagnosis of this disease, from other possibilities, as a cause of wasting conditions detected during meat inspection at the abattoir. This manuscript is a review of the measures in force at the abattoir for scrapie control, focusing on the differential diagnosis of gross lesions related to wasting conditions detected in small ruminants during meat inspection.
- The influence of ACE ID and ACTN3 R577X polymorphisms on lower-extremity function in older women in response to high-speed power trainingPublication . Pereira, A.; Costa, Aldo M.; Leitão, José C.; Monteiro, A.M.; Izquierdo, Mikel; Silva, A.J.; Bastos, Estela; Marques, Mário C.Background:We studied the influence of the ACE I/D and ACTN3 R577X polymorphisms (single or combined) onlower-extremity function in older women in response to high-speed power training.Methods:One hundred and thirty-nine healthy older Caucasian women participated in this study (age: 65.5 ± 8.2 years,body mass: 67.0 ± 10.0 kg and height: 1.57 ± 0.06 m). Walking speed (S10) performance and functional capacityassessed by the“get-up and go”(GUG) mobility test were measured at baseline (T1) and after a consecutive 12-weekperiod of high-speed power training (40-75% of one repetition maximum in arm and leg extensor exercises; 3 sets4–12 reps, and two power exercises for upper and lower extremity). Genomic DNA was extracted from blood samples,and genotyping analyses were performed by PCR methods. Genotype distributions between groups were comparedby Chi-Square test and the gains in physical performance were analyzed by two-way, repeated-measures ANOVA.Results:There were no significant differences between genotype groups in men or women for adjusted baselinephenotypes (P > 0.05). ACE I/D and ACTN3 polymorphisms showed a significant interaction genotype-training only inS10 (P = 0.012 and P = 0.044, respectively) and not in the GUG test (P = 0.311 and P = 0.477, respectively). Analyses ofthe combined effects between genotypes showed no other significant differences in all phenotypes (P < 0.05) atbaseline. However, in response to high-speed power training, a significant interaction on walking speed (P = 0.048)was observed between the“power”(ACTN3 RR + RX & ACE DD) versus“non-power”muscularity-oriented genotypes(ACTN3 XX & ACE II + ID)].Conclusions:Thus, ACE I/D and ACTN3 R577X polymorphisms are likely candidates in the modulation ofexercise-related gait speed phenotype in older women but not a significant influence in mobility traits. The influence of ACE ID and ACTN3 R577X polymorphisms on lower-extremity function in older women in response to high-speed power training. Available from: https://www.researchgate.net/publication/259244416_The_influence_of_ACE_ID_and_ACTN3_R577X_polymorphisms_on_lower-extremity_function_in_older_women_in_response_to_high-speed_power_training [accessed Nov 17, 2015].