3,274 research outputs found
Gap junction reduction in cardiomyocytes following transforming growth factor- beta treatment and Trypanosoma cruzi infection
Gap junction connexin-43 (Cx43) molecules are responsible for electrical impulse conduction in the heart and are affected by transforming growth factor-beta (TGF-beta). This cytokine increases during Trypanosoma cruzi infection, modulating fibrosis and the parasite cell cycle. We studied Cx43 expression in cardiomyocytes exposed or not to TGF-beta T. cruzi, or SB-431542, an inhibitor of TGF-beta receptor type I (ALK-5). Cx43 expression was also examined in hearts with dilated cardiopathy from chronic Chagas disease patients, in which TGF-beta signalling had been shown previously to be highly activated. We demonstrated that TGF-beta treatment induced disorganised gap junctions in non-infected cardiomyocytes, leading to a punctate, diffuse and non-uniform Cx43 staining. A similar pattern was detected in T. cruzi-infected cardiomyocytes concomitant with high TGF-beta secretion. Both results were reversed if the cells were incubated with SB-431542. Similar tests were performed using human chronic chagasic patients and we confirmed a down-regulation of Cx43 expression, an altered distribution of plaques in the heart and a significant reduction in the number and length of Cx43 plaques, which correlated negatively with cardiomegaly. We conclude that elevated TGF-beta levels during T. cruzi infection promote heart fibrosis and disorganise gap junctions, possibly contributing to abnormal impulse conduction and arrhythmia that characterise severe cardiopathy in Chagas disease
Genetic polymorphism of CYP2D6 influences susceptibility to papillary thyroid cancer
OBJECTIVE: Xenobiotic-metabolizing enzymes are widely polymorphic and confer interindividual variation in the ability to detoxify carcinogens or to activate pro-carcinogens. A common polymorphism of cytochrome P450 2D6 (CYP2D6) results in lack of enzyme activity and has been associated with an altered susceptibility to several cancers. The aim of this study was to investigate the association between the CYP2D6 poor metaboliser genotype and the risk of papillary thyroid cancer (PTC). DESIGN: Retrospective case-control study. PATIENTS: One hundred and eighty-seven patients with PTC and 256 controls. MEASUREMENTS: Genotyping was performed by PCR and restriction enzyme analysis to detect the presence of the common CYP2D6*4 poor metaboliser allele. RESULTS: The frequency of individuals with the homozygous poor metaboliser genotype was lower in the patient group [1.6 vs. 5.5%, P = 0.037, OR = 0.28 (95% CI 0.09-0.93)]. The CYP2D6*4 allele frequency was also lower in the patient group [13.4 vs. 21.7%, P = 0.002, OR = 0.56 (95% CI 0.39-0.80)]. CONCLUSIONS: The results suggest that the poor metaboliser genotype is associated with a protective effect against PTC. This could be explained by a possible role of CYP2D6 on the metabolic activation of putative environmental chemical thyroid carcinogens or by linkage to another cancer-causing gene. Further research may allow the identification of metabolic risk factors and contribute towards understanding the molecular mechanisms involved in thyroid carcinogenesis
Office Hysteroscopy After Ultrasonographic Diagnosis of Thickened Endometrium in Postmenopausal Patients
The aim of our study was to access office
hysteroscopy results in postmenopausal patients with thickened endometrium. A retrospective descriptive study was carried out on 245 postmenopausal patients submitted to office hysteroscopy after sonographic diagnosis of thickened endometriumin 20 consecutive months.Women were evaluated for age, hormonal therapy, hysteroscopic findings, procedure duration, complications and associated pain, and histological diagnosis. Patients with and without uterine bleeding were considered separately. Symptomatic patients were older and had longer procedure duration. The most frequent hysteroscopic finding was endometrial polyp in both groups. Pain was subjectively assessed in a numeric scale from 0 to 10 and median value was 4. There were no complications reported.
Global neoplasia rate was 2.9% for asymptomatic patients and 16.4% for symptomatic ones (p<0.05). Thickened endometrium with postmenopausal metrorrhagia gave patients a significantly higher risk for neoplasia and hyperplasia
The CTLA4 +49 A/G polymorphism is not associated with susceptibility to type 1 diabetes mellitus in the Portuguese population
CTLA4 genetic polymorphisms have been associated with type 1 diabetes. We genotyped 207 patients and 249 controls for the most frequently investigated polymorphism of the CTLA4 gene (+49A/G (rs231775)). No significant differences were observed, suggesting that this polymorphism is not strongly associated with type 1 diabetes in the Portuguese population
Extraction and Fractionation of Pigments from Saccharina latissima (Linnaeus, 2006) Using an Ionic Liquid plus Oil plus Water System
There is a strong industrial interest in the development of greener and more sustainable processes based on the use of renewable resources, and a biorefinery based on marine resources, such as macroalgae, stands as a major opportunity toward that end. In this work, Saccharina latissima (Linnaeus), a brown macroalga, was used as a source of pigments to develop an integrated platform that is able to promote the extraction and separation of chlorophyll and fucoxanthin in one single step. The process was studied, and its operational conditions were optimized with yields of extraction of chlorophyll and fucoxanthin of 4.93 ± 0.22 mgchl·gdry biomass–1 and 1956 ± 84 μgfuco·gdry biomass–1, respectively. These results were achieved with extraction systems composed of 84% of an aqueous solution of a tensioactive phosphonium-based ionic liquid (IL) at 350 mM + 16% of sunflower oil, during 40 min, using a solid–liquid ratio of 0.017 gdry biomass·mLsolvent–1. After the separation of both aqueous IL-rich and oil-rich phases, the IL content in both phases was investigated, the oil phase being free of IL. Envisioning the industrial potential of the process developed in this work, the recovery of the IL from the aqueous IL-rich phase of the initial system was attempted by a back-extraction using organic solvents immiscible in water, being shown that 82% of the IL can be recovered and reused in new cycles of extraction. The environmental and economic impacts of the final process proposed for the extraction and fractionation of chlorophyll and fucoxanthin were evaluated. Different scenarios were considered, but summing up the main results, the solvents’ recycling allowed better results, proving the economic and environmental viability of the overall process
Population genetics of wild-type CAG repeats in the Machado-Joseph disease gene in Portugal
To gain insights on the molecular mechanisms
of mutation that led to the emergence of expanded alleles in the MJD gene, by studying the behavior of wild-type alleles and testing the association of its distribution
with the representation of the disease. Methods:
The number of CAG motifs in the MJD gene was determined in a representative sample of 1000 unrelated individuals.
Associations between the repeat size and the
epidemiological representation of MJD were tested. Results:
The allelic profi le of the total sample was in the normal range (13–41 repeats), with mode (CAG) 23 . No intermediate alleles were present. Allelic size distribution showed a negative skew. The correlation between
the epidemiological representation of MJD in each district and the frequency of small, medium and large normal alleles was not signifi cant. Further correlations performed
grouping the districts also failed to produce
signifi cant results. Conclusions: The absence of association between the size of the repeats and the representation of MJD demonstrates that prevalence is not an indirect refl ection of the frequency of large normal alleles.
Globally the results obtained are in accordance with a model that postulates the occurrence of a few mutations on the basis of most of the MJD cases worldwide
Study of intrinsic risk factors for falls in institutionalized elderly people
Esta pesquisa teve como objetivo identificar a presença de fatores intrÃnsecos que predispõem a quedas em idosos moradores em instituições de longa permanência na cidade de Goiânia (GO). Trata-se de estudo descritivo transversal realizado em seis instituições de longa permanência para idosos existentes na cidade de Goiânia. A amostra da investigação constou de 95 idosos que atenderam aos critérios de inclusão e exclusão. Utilizou-se um questionário contendo dados clÃnicos relacionados à s condições de saúde-doença; dados cognitivos; avaliação da capacidade para as atividades básicas de vida diária e avaliação do equilÃbrio e marcha. Os idosos avaliados, no geral, apresentam vários fatores de risco, apontados pela literatura, para quedas, tais como: relato de dificuldade motora em membros inferiores (90%), déficit visual (81,1%), uso de três ou mais medicamentos (59,7%), suspeita de depressão (37,9%), falta de equilÃbrio em apoio unipodal (37,9%) e altura do passo anormalmente diminuÃda (32,6%). As informações obtidas nos permitem apontar condições determinantes que aumentam a possibilidade dos eventos queda acontecerem na amostra estudada, sinalizando à necessidade de que estratégias de promoção de saúde, prevenção de agravos e reabilitação devam ser tomadas. _________________________________________________________________________________________ ABSTRACTThe objective of this research was to identify intrinsic risk factors that predispose elderly people living in long-term institutions in the city of Goiânia (GO) to falls. The present descriptive transversal study was carried out in six long-term institutions for seniors in the city of Goiânia. The investigated sample consisted of 95 elderly that fitted the inclusion and exclusion criteria. A questionnaire was used for collecting clinical data related to health-disease conditions; cognitive data; capacity to develop basic daily life activities and equilibrium and gait. In general terms, as pointed out the literature, the examined elderly presented different fall risk factors such as: motor difficulty in lower limbs (90%), visual deficit (81,1%), use of 3 or more kinds of medicines (59,7%), suspected depression (37,9%), lack of equilibrium/unstable unipodal support (37,9%) abnormally decreased height in step (32,6%). The obtained data allow us to set indicators for the increase in falls among the studied sample, demonstrating the need for creating strategies for health promotion, prevention of injuries and rehabilitation
Preclinical Evidence Supporting Early Initiation of Citalopram Treatment in Machado-Joseph Disease
Spinocerebellar ataxias are dominantly inherited neurodegenerative disorders with no disease-modifying treatment. We previously identified the selective serotonin reuptake inhibitor citalopram as a safe and effective drug to be repurposed for Machado-Joseph disease. Pre-symptomatic treatment of transgenic (CMVMJD135) mice strikingly ameliorated mutant ataxin-3 (ATXN3) pathogenesis. Here, we asked whether citalopram treatment initiated at a post-symptomatic age would still show efficacy. We used a cohort of CMVMJD135 mice that shows increased phenotypic severity and faster disease progression (CMVMJD135hi) compared to the mice used in the first trial. Groups of hemizygous CMVMJD135hi mice were orally treated with citalopram. Behavior, protein analysis, and pathology assessment were performed blindly to treatment. Our results show that even when initiated after symptom onset, treatment of CMVMJD135hi mice with citalopram ameliorated motor coordination and balance, attenuating disease progression, albeit to a lesser extent than that seen with pre-symptomatic treatment initiation. There was no impact on ATXN3 aggregation, which contrasts with the robust reduction in ATXN3-positive inclusions observed in CMVMJD135 mice, when treated pre-symptomatically. Post-symptomatic treatment of CMVMJD135hi mice revealed, however, a limited neuroprotective effect by showing a tendency to repair cerebellar calbindin staining, and to increase the number of motor neurons and of NeuN-positive cells in certain brain regions. While supporting that early initiation of treatment with citalopram leads to a marked increase in efficacy, these results strengthen our previous observation that modulation of serotonergic signaling by citalopram is a promising therapeutic approach for Machado-Joseph disease even after symptom onset.European Regional Development Funds (FEDER), through the Competitiveness Factors Operational Programme (COMPETE), and by National funds, through the Foundation for Science and Technology (FCT), under the scope of the project POCI-01-0145-FEDER-007038. This article has been developed under the scope of the project NORTE-01-0145-FEDER-000013, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the FEDER. This work was also supported by FCT and COMPETE through the projects [PTDC/SAU-GMG/112617/2009] (to PM) and [EXPL/BIM-MEC/0239/2012] (to AT-C), by FCT through the project [POCI-01-0145-FEDER-016818 (PTDC/NEU-NMC/3648/2014)] (to PM), by National Ataxia foundation (to PM and to AT-C), and by Ataxia UK (to PM). SE, SD-S, SO, and AT-C were supported by the FCT individual fellowships, SFRH/BD/78554/2011, SFRH/BD/78388/2011, PD/BD/127818/2016, and SFRH/BPD/102317/2014, respectively. FCT fellowships are co-financed by POPH, QREN, Governo da República Portuguesa, and EU/FSEinfo:eu-repo/semantics/publishedVersio
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