5,359 research outputs found
Identification of clinical predictors of flare in systemic lupus erythematosus patients: a 24-month prospective cohort study
Objective. SLE has a relapsing-remitting course with disease activity flares over time. This study aims to identify clinical predictors of SLE flares.Methods. This prospective cohort study over 24 months included all SLE patients on follow-up at one academic lupus clinic. Flare was defined as an increase in SLEDAI-2K score ≥4 points. Baseline clinical and demographic parameters were compared using survival analysis for time-to-flare outcome with univariate log-rank tests. Variables with significant differences were further evaluated as predictors with multivariate Cox regression models adjusting for potential confounding or contributing factors and hazard ratio (HR) calculation.Results. A total of 202 SLE patients were included. Over the follow-up period, 1083 visits were documented and 16.8% of patients presented with flares. In multivariate analysis, the following parameters emerged as flare predictors: SLE diagnosis up to 25 years of age (HR = 2.14, P = 0.03), lupus nephritis previous to baseline visit (HR = 4.78, P < 0.0001) and immunosuppressor treatment for severe SLE (HR = 3.22, P < 0.001). Baseline disease activity, disease duration and treatment with prednisone or HCQ were not predictive factors.Conclusion. Patients with an SLE diagnosis before age 25 years, lupus nephritis or immunosuppressor treatment for severe SLE present greater HRs for flares, suggesting the need for tighter clinical monitoring. Current immunosuppressive strategies seem to be inefficient in providing flare prevention
Target-Oriented Synthesis of Marine Coelenterazine Derivatives with Anticancer Activity by Applying the Heavy-Atom Effect
Photodynamic therapy (PDT) is an anticancer therapeutic modality with remarkable advantages over more conventional approaches. However, PDT is greatly limited by its dependence on external light sources. Given this, PDT would benefit from new systems capable of a light-free and intracellular photodynamic effect. Herein, we evaluated the heavy-atom effect as a strategy to provide anticancer activity to derivatives of coelenterazine, a chemiluminescent single-molecule widespread in marine organisms. Our results indicate that the use of the heavy-atom effect allows these molecules to generate readily available triplet states in a chemiluminescent reaction triggered by a cancer marker. Cytotoxicity assays in different cancer cell lines showed a heavy-atom-dependent anticancer activity, which increased in the substituent order of hydroxyl < chlorine < bromine. Furthermore, it was found that the magnitude of this anticancer activity is also dependent on the tumor type, being more relevant toward breast and prostate cancer. The compounds also showed moderate activity toward neuroblastoma, while showing limited activity toward colon cancer. In conclusion, the present results indicate that the application of the heavy-atom effect to marine coelenterazine could be a promising approach for the future development of new and optimized self-activating and tumor-selective sensitizers for light-free PDT
Keratocystic odontogenic tumor overexpresses invadopodia-related proteins, suggesting invadopodia formation
OBJECTIVE: Keratocystic odontogenic tumor (KOT) is an odontogenic neoplasm that shows aggressive clinical behavior and local invasiveness. Invadopodia are actin-rich cellular protrusions exhibiting proteolytic pericellular activity, thereby inducing focal invasion in neoplastic cells and increasing neoplasms aggressiveness. Thus, this study aimed to evaluate immunoexpression of invadopodia-related proteins, cortactin, MT1-MMP, Tks4, and Tks5, in KOT. STUDY DESIGN: Immunohistochemistry of 16 cases of KOT, eight cases of calcifying cystic odontogenic tumor (CCOT), and eight samples of the oral mucosa (OM) was carried out to assess the expression of the above described invadopodia-related proteins in the basal and suprabasal layer. RESULTS: KOT samples showed higher and significant immunoexpression of cortactin, MT1-MMP, TKs4, and TKs5 compared with the CCOT and OM samples. Significant expression of all these proteins was observed in the basal layer compared with the suprabasal layer in KOT. CONCLUSIONS: Overexpression of cortactin, MT1-MMP, TKs4, and TKs5 was observed in KOT compared with samples of CCOT and OM. These proteins were also overexpressed in the basal over the suprabasal layer of KOT samples. Taken together, these results suggest the participation of invadopodia-related proteins on the pathogenesis of this lesion
Mapping of Alternative Oilseeds from the Brazilian Caatinga and Assessment of Catalytic Pathways toward Biofuels Production
Biofuels are increasingly important renewable resources in the world's energy matrix that have challenged the scientific community as well as small and large farmers to develop alternatives to fossil fuels in order to achieve the aims of energy transition. In particular, Brazil's proven competitiveness in agribusiness together with its rich biodiversity put the country in a key position in the biofuels market. The semiarid Caatinga of northeastern Brazil, an exclusive biome rich in many oilseed species suitable for potential energy purposes, is of particular interest in this field. Nowadays, soybeans are the main feedstock used for the production of biodiesel, but, due to the increasing demand for biofuels, the search for alternative sources of oil from tropical flora with high productivity is crucial. Under this premise, this systematic review focuses on mapping Caatinga's vegetable oil crops that could be used as alternative raw materials for biofuels' production in Brazil, in addition to traditional soybeans and sugarcane. To gain more detailed insight into these matrices, their main properties, including oil content, fatty acid profile and physicochemical properties, are discussed. Moreover, an overview is provided of processes to synthesize different types of biofuels, particularly biodiesel and aviation biokerosene, including the routes employing homogeneous, enzymatic and mainly heterogeneous catalysts. Finally, future prospects and challenges for renewable biofuels and the Caatinga biome are addressed
Epistasis not needed to explain low dN/dS
An important question in molecular evolution is whether an amino acid that
occurs at a given position makes an independent contribution to fitness, or
whether its effect depends on the state of other loci in the organism's genome,
a phenomenon known as epistasis. In a recent letter to Nature, Breen et al.
(2012) argued that epistasis must be "pervasive throughout protein evolution"
because the observed ratio between the per-site rates of non-synonymous and
synonymous substitutions (dN/dS) is much lower than would be expected in the
absence of epistasis. However, when calculating the expected dN/dS ratio in the
absence of epistasis, Breen et al. assumed that all amino acids observed in a
protein alignment at any particular position have equal fitness. Here, we relax
this unrealistic assumption and show that any dN/dS value can in principle be
achieved at a site, without epistasis. Furthermore, for all nuclear and
chloroplast genes in the Breen et al. dataset, we show that the observed dN/dS
values and the observed patterns of amino acid diversity at each site are
jointly consistent with a non-epistatic model of protein evolution.Comment: This manuscript is in response to "Epistasis as the primary factor in
molecular evolution" by Breen et al. Nature 490, 535-538 (2012
All green, but equal? Morphological traits and ecological implications on spores of three species of mosses in the Brazilian Atlantic forest
Tempo para a Remodelagem Inversa do Ventrículo Esquerdo: Mais Vale Tarde do que Nunca
INTRODUCTION: Left ventricular reverse remodeling (LVRR), defined as reduction of end-diastolic and end-systolic dimensions and improvement of ejection fraction, is associated with the prognostic implications of cardiac resynchronization therapy (CRT). The time course of LVRR remains poorly characterized. Nevertheless, it has been suggested that it occurs ≤6 months after CRT.
OBJECTIVE: To characterize the long-term echocardiographic and clinical evolution of patients with LVRR occurring >6 months after CRT and to identify predictors of a delayed LVRR response.
METHODS: A total of 127 consecutive patients after successful CRT implantation were divided into three groups according to LVRR response: Group A, 19 patients (15%) with LVRR after >6 months (late LVRR); Group B, 58 patients (46%) with LVRR before 6 months (early LVRR); and Group C, 50 patients (39%) without LVRR during follow-up (no LVRR).
RESULTS: The late LVRR group was older, more often had ischemic etiology and fewer patients were in NYHA class ≤II. Overall, group A presented LVRR between group B and C. This was also the case with the percentage of clinical response (68.4% vs. 94.8% vs. 38.3%, respectively, p<0.001), and hospital readmissions due to decompensated heart failure (31.6% vs. 12.1% vs. 57.1%, respectively, p<0.001). Ischemic etiology (OR 0.044; p=0.013) and NYHA functional class <III (OR 0.056; p=0.063) were the variables with the highest predictive value for late LVRR.
CONCLUSIONS: Late LVRR has better clinical and echocardiographic outcomes than no LVRR, although with a suboptimal response compared to the early LVRR population. Ischemic etiology and NYHA functional class <III are predictors of late LVRR
Cholinesterase as inflammatory markers in a experimental infection by Trypanosoma evansi in rabbits
A Multicenter, Non-Interventional Study to Evaluate the Disease Activity in Multiple Sclerosis after Withdrawal of Natalizumab in Portugal
Objectives: Natalizumab (NTZ) is very effective for treatment of relapsing-remitting multiple sclerosis (RRMS), its use is mainly limited by safety issues. Discontinuation of NTZ is associated with recurrence of disease activity (reactivation and rebound). The best strategy for subsequent therapy and the predictive factors for recurrence in such patients are areas of active research. We aimed to evaluate predictors of reactivation in a multicentric study.
Patients and methods: Multicentric retrospective observational study in five portuguese MS referral centers. Demographic, clinical and imagiological data were collected in the year prior, during and in the year following NTZ discontinuation. Predictors of reactivation and rebound after NTZ suspension were studied using a multivariate Cox model.
Results: Sixty-nine patients were included. They were mainly non-naïve patients (97%), with a mean age of 29.1 ± 8.3 years at diagnosis, and a mean age of 37.2 ± 10.3 years at NTZ initiation. The mean annualized relapse rate (ARR) previous, during and after NTZ was 1.6 ± 1.2, 0.2 ± 0.5 and 0.6 ± 1.0, respectively. The median EDSS before, during and after NTZ was 3.5 (IQR 3.3), 3.5 (IQR 3.5) and 4.0 (IQR 3.8), respectively. The median number of infusions was 26.0 (IQR 12.5) and the main reason to NTZ discontinuation was progressive multifocal leukoencephalopathy (PML) risk (70%). After NTZ suspension, reactivation was observed in 25 (36%) patients after a median time of 20.0 (IQR 29.0) weeks. Reactivation predictors in our sample included NTZ suspension for reasons other than PML (adjusted HR = 0.228, 95% CI [0.084- 0.616], p = 0.004), ARR before NTZ (adjusted HR = 1.914 95% [CI 1.330-2.754], p < 0.001) and a longer disease duration at time of NTZ initiation (adjusted HR = 1.154, 95% CI [1.020-1.306], p = 0.023). Rebound occurred in 5 (7%) patients after a median time of 20 (IQR 34.5) weeks.
Conclusion: Significant predictors of disease reactivation in our cohort were discontinuation of NTZ for reasons other than PML risk, higher disease activity before NTZ treatment, and longer disease duration. Our study provides valuable data of portuguese patients after NTZ withdrawal.info:eu-repo/semantics/publishedVersio
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