211 research outputs found
Influence of P53 on the radiotherapy response of hepatocellular carcinoma
Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, and it has a poor prognosis and few therapeutic options. Radiotherapy is one of the most effective forms of cancer treatment, and P53 protein is one of the key molecules determining how a cell responds to radiotherapy. The aim of this study was to determine the therapeutic efficacy of iodine-131 in three human HCC cell lines
Oxidative Stress, DNA, Cell Cycle/Cell Cycle Associated Proteins and Multidrug Resistance Proteins: Targets of Human Amniotic Membrane in Hepatocellular Carcinoma
The anticancer effects of human amniotic membrane (hAM) have been studied over the last decade. However, the action mechanisms responsible for these effects are not fully understood until now. Previously results reported by our team proved that hAM is able to induce cytotoxicity and cell death in hepatocellular carcinoma (HCC), a worldwide high incident and mortal cancer. Therefore, this experimental study aimed to investigate the cellular targets of hAM protein extracts (hAMPE) in HCC through in vitro studies. Our results showed that hAMPE is able to modify oxidative stress environment in all HCC cell lines, as well as its cell cycle. hAMPE differently targets deoxyribonucleic acid (DNA), P21, P53, β-catenin and multidrug resistance (MDR) proteins in HCC cell lines. In conclusion, hAMPE has several targets in HCC, being clear that the success of this treatment depends of a personalized therapy based on the biological and genetic characteristics of the tumor
Impact of splenic artery ligation after major hepatectomy on liver function, regeneration and viability
It was reported that prevention of acute portal overpressure in small-for-size livers by inflow modulation results in a better postoperative outcome. The aim is to investigate the impact of portal blood flow reduction by splenic artery ligation after major hepatectomy in a murine model. Forty-eight rats were subjected to an 85% hepatectomy or 85% hepatectomy and splenic artery ligation. Both groups were evaluated at 24, 48, 72 and 120 post-operative hours: liver function, regeneration and viability. All methods and experiments were carried out in accordance with Coimbra University guidelines. Splenic artery ligation produces viability increase after 24 h, induces a relative decrease in oxidative stress during the first 48 hours, allows antioxidant capacity increment after 24 h, which is reflected in a decrease of half-time normalized liver curve at 48 h and at 72 h and in an increase of mitotic index between 48 h and 72 h. Splenic artery ligation combined with 85% hepatectomy in a murine model, allows portal inflow modulation, promoting an increase in hepatocellular viability and regeneration, without impairing the function, probably by inducing a less marked elevation of oxidative stress at first 48 hours
Using stated preference methods to assess environmental impacts of forest biomass power plants in Portugal
As a renewable energy source, the use of forest biomass for electricity generation is advantageous in comparison with fossil fuels, however the activity of forest biomass power plants causes adverse impacts, affecting particularly neighbouring communities. The main objective of this study is to estimate the effects of the activity of forest biomass power plants on the welfare of two groups of stakeholders, namely local residents and the general population and we apply two stated preference methods: contingent valuation and discrete choice experiments, respectively. The former method was applied to estimate the minimum compensation residents of neighbouring communities of two forest biomass power plants in Portugal would be willing to accept. The latter method was applied among the general population to estimate their willingness to pay to avoid specific environmental impacts. The results show that the presence of the selected facilities affects individuals’ well-being. On the other hand, in the discrete choice experiments conducted among the general population all impacts considered were significant determinants of respondents’ welfare levels. The results of this study stress the importance of performing an equity analysis of the welfare effects on different groups of stakeholders from the installation of forest biomass power plants, as their effects on welfare are location and impact specific. Policy makers should take into account the views of all stakeholders either directly or indirectly involved when deciding crucial issues regarding the sitting of new forest biomass power plants, in order to achieve an efficient and equitable outcome
Estratégias de coping utilizadas por familiares de indivíduos em tratamento hemodialítico
This descriptive, qualitative study aims to identify the coping strategies used most by the family members of patients with chronic kidney disease receiving hemodialysis. The data were collected through interviews, with the Coping Strategies Inventory questionnaire administered to ten family members, and were submitted to descriptive statistics and to thematic content analysis. The strategy used most was escape-avoidance, demonstrating that the family members prefer not to face the situation. The second most-used strategy was social support, ratified by the fact that they stated that they talk with other persons and professionals, seeking information about the problem, and because they accept the support received positively. The third was problem resolution, represented by the attitude of accepting responsibility for the care, either through strong affective bonds or through a feeling of responsibility established prior to the disease. The families use coping strategies of different intensities, while, nevertheless, indicating involvement and major participation in the care for the patient.Estudio cualitativo, que trató de identificar las estrategias de afrontamiento empleadas por las familias de los pacientes con insuficiencia renal crónica en hemodiálisis. Se aplicó el Inventario de Estrategias de Afrontamiento y una questión abierta con diez familiares. Los datos cuantitativos fueron sometidos a procedimientos estatísticos y análisis de contenido cualitativo. La estrategia de mayor utilización fue el escape y evitación (oito), lo que demuestra que los miembros de las familisa preferían no tener que enfrentar esta situación. La siguiente estrategia fue utilizada más apoyo social, ya hablé con otras personas y profesionales que buscan información sobre el problema, y aceptar el apoyo positivo recibido. A terceira foi resolução de problemas, representada pela atitude em assumir o cuidado, seja pelo forte vínculo afetivo ou pelo sentimento de responsabilidade já estabelecido antes da doença. Familias de las estrategias de afrontamiento empleadas con diferentes intensidades, pero mostrando una gran implicación y la participación en el cuidado del paciente crónico.Estudo descritivo, de natureza quali-quantitativa, que objetivou identificar as estratégias de enfrentamento mais utilizadas por familiares de pacientes com doença renal crônica em hemodiálise. Os dados foram coletados por meio de entrevista, com aplicação do Inventário de Estratégias de Coping a dez familiares, e submetidos à estatística descritiva e à análise de conteúdo temática. A estratégia mais utilizada foi fuga e esquiva, demonstrando que os familiares preferiam não enfrentar a situação. A segunda estratégia mais usada foi suporte social, ratificada ao afirmarem que conversaram com outras pessoas e profissionais buscando informações sobre o problema, e por aceitarem positivamente o apoio recebido. A terceira foi resolução de problemas, representada pela atitude em assumir o cuidado, seja pelo forte vínculo afetivo ou pelo sentimento de responsabilidade já estabelecido antes da doença. As famílias empregaram estratégias de enfrentamento com intensidades diferentes, porém indicando envolvimento e grande participação no cuidado ao doente.Universidade Federal de São Paulo (UNIFESP)aff2Universidade Estadual de MaringáUEMUNIFESPSciEL
In silico modelling to differentiate the contribution of sugar frequency versus total amount in driving biofilm dysbiosis in dental caries
Dental caries is the most prevalent infection globally and a substantial economic burden in developed countries. Dietary sugars are the main risk factor, and drive increased proportions of acid-producing and acid-tolerating (aciduric) bacterial species within dental bio lms. Recent longitudinal studies have suggested that caries is most strongly correlated with total sugar intake, contrasting with the prevailing view that intake frequency is the primary determinant. To explore this possibility, we employed a computational model for supragingival plaque to systematically sample combinations of sugar frequency and total amount, allowing their independent contributions on the ratio of aciduric (i.e. cariogenic) to non-aciduric bacteria to be unambiguously determined. Sugar frequency was found to be irrelevant for either very high or very low daily total amounts as the simulated bio lm was predicted to be always or never cariogenic, respectively. Frequency was a determining factor for intermediate total amounts of sugar, including the estimated average human consumption. An increased risk of caries (i.e. high prevalence of aciduric/non-aciduric species) was predicted for high intake frequencies. Thus, both total amount and frequency of sugar intake may combine to in uence plaque cariogenicity. These ndings could be employed to support public guidance for dietary change, leading to improved oral healthcare
Metformin reverses infertility in a mouse model of endometriosis: unveiling disease pathways and implications for future clinical approaches
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Research question: Does metformin reverse endometriosis-associated infertility?
Design: Endometriosis was induced by transplanting uterus fragments from B6CBAF1 mice into recipients of the same strain. The mice were divided into groups: endometriosis (End, n = 24), sham-operated (Sham, n = 12), endometriosis with metformin (0.5mg/ml) orally administered for 3 months (EndMet, n = 21) and sham-operated metformin-treated (ShamMet, n = 16). Implant growth was monitored using ultrasonography. Fibrosis was computer-assisted quantified in Masson's trichrome-stained sections of eutopic (EuEnd) and ectopic (EcEnd) endometrium. PCNA, CYP17a1, F4/80 and galectin-3 were analysed by immunofluorescence and western blotting, and NFkB, GPX-1 and HO-1 only by western blotting. Statistical significance was set at P <0.05.
Results: The endometriosis model was successfully established. The End groups showed lower fertility rates than sham-operated mice (P = 0.0034), whereas metformin treatment increased the number of fetuses per pregnant mouse (P = 0.0295), restoring fertility to control levels; it also slowed implant growth and vascularization. Metformin also restored PCNA expression and fibrosis levels to those of non-treated EuSham mice. PCNA expression decreased in pregnant mice (P <0.0178). Metformin diminished CYP17a1 expression in EcEnd versus EuEnd non-treated tissues and conversely up-regulated F4/80 in EuEnd tissue (P <0.0170), and galectin-3, NFkB and the antioxidant enzymes HO-1 and GPX-1 in EcEnd tissue (P <0.0293), in non-mated mice.
Conclusions: These results indicate that application of metformin can alleviate oxidative stress and mitigate fibrosis in endometriosis lesions in a murine model of endometriosis, which highlights metformin's potential as a pharmacological intervention for improving infertility in endometriosis."The contract DL57/2016/CP1355/CT0009 of A. R. Rodrigues was funded by FCT – Fundação para a Ciência e Tecnologia – Portugal
Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications
Superparamagnetic iron oxide nanoparticles
can providemultiple benefits for biomedical applications
in aqueous environments such asmagnetic separation or
magnetic resonance imaging. To increase the colloidal
stability and allow subsequent reactions, the introduction
of hydrophilic functional groups onto the particles’
surface is essential. During this process, the original
coating is exchanged by preferably covalently bonded
ligands such as trialkoxysilanes. The duration of the
silane exchange reaction, which commonly takes more
than 24 h, is an important drawback for this approach. In
this paper, we present a novel method, which introduces
ultrasonication as an energy source to dramatically
accelerate this process, resulting in high-quality waterdispersible nanoparticles around 10 nmin size. To prove
the generic character, different functional groups were
introduced on the surface including polyethylene glycol
chains, carboxylic acid, amine, and thiol groups. Their
colloidal stability in various aqueous buffer solutions as
well as human plasma and serum was investigated to
allow implementation in biomedical and sensing
applications.status: publishe
Integrated transcriptomic and proteomic analysis of the global response of Wolbachia to doxycycline-induced stress
The bacterium Wolbachia (order Rickettsiales), representing perhaps the most abundant vertically transmitted microbe worldwide, infects arthropods and filarial nematodes. In arthropods, Wolbachia can induce reproductive alterations and interfere with the transmission of several arthropod-borne pathogens. In addition, Wolbachia is an obligate mutualist of the filarial parasites that cause lymphatic filariasis and onchocerciasis in the tropics. Targeting Wolbachia with tetracycline antibiotics leads to sterilisation and ultimately death of adult filariae. However, several weeks of treatment are required, restricting the implementation of this control strategy. To date, the response of Wolbachia to stress has not been investigated, and almost nothing is known about global regulation of gene expression in this organism. We exposed an arthropod Wolbachia strain to doxycycline in vitro, and analysed differential expression by directional RNA-seq and label-free, quantitative proteomics. We found that Wolbachia responded not only by modulating expression of the translation machinery, but also by upregulating nucleotide synthesis and energy metabolism, while downregulating outer membrane proteins. Moreover, Wolbachia increased the expression of a key component of the twin-arginine translocase (tatA) and a phosphate ABC transporter ATPase (PstB); the latter is associated with decreased susceptibility to antimicrobials in free-living bacteria. Finally, the downregulation of 6S RNA during translational inhibition suggests that this small RNA is involved in growth rate control. Despite its highly reduced genome, Wolbachia shows a surprising ability to regulate gene expression during exposure to a potent stressor. Our findings have general relevance for the chemotherapy of obligate intracellular bacteria and the mechanistic basis of persistence in the Rickettsiales
Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease
Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.
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