A Review on the Thermodynamics of Denaturation Transition of DNA Duplex Oligomers in the Context of Nearest-Neighbor Models

In this review, we show that additive physical properties of DNA double strands can be written in terms of eight (polymeric) irreducible parameters. This results in self-consistency relations constraining the 10 duplex dimer contributions. Studies of thermodynamic stability of duplex oligomers are feasible, adding extra degrees of freedom, and this is performed, initially, considering the influence of end parameters on the thermodynamic stability of oligomers. Hence, we connect a statistical mechanics approach to the nearest-neighbor (NN) approach in the framework of the two-state model. This provides one correlation between end effects and initiation phenomena. Because of that, inside the framework of the NN modeling, the role played by end effects could not be so well defined. Thus, we propose a new model that permits to provide the nucleation free energies. The power of this model is relating the nucleation free energy to the mean composition of the chain, permitting to obtain a good estimate for the free energy associated only to the Watson–Crick base pairings

Palliative treatment of metastatic bone pain with radiopharmaceuticals: a perspective beyond Strontium-89 and Samarium-153

PurposeThe present review article aims to provide an overview of the available radionuclides for palliative treatment of bone metastases beyond 89Sr and 153Sm. In addition, it aims to review and summarize the clinical outcomes associated with the palliative treatment of bone metastases using different radiopharmaceuticals.Materials and methodsA literature search was conducted on Science Direct and PubMed databases (1990 - 2015). The following search terms were combined in order to obtain relevant results: bone, metastases, palliative, care, therapy, treatment, radiotherapy, review, radiopharmaceutical, phosphorus-32, strontium-89, yttrium-90, tin-117m, samarium-153, holmium-166, thulium-170, lutetium-177, rhenium-186, rhenium-188 and radium-223. Studies were included if they provided information regarding the clinical outcomes.Results and conclusionsA comparative analysis of the measured therapeutic response of different radiopharmaceuticals, based on previously published data, suggests that there is a lack of substantial differences in palliative efficacy among radiopharmaceuticals. However, when the comparative analysis adds factors such as patients life expectancy, radionuclides physical characteristics (e.g. tissue penetration range and half-life) and health economics to guide the rational selection of a radiopharmaceutical for palliative treatment of bone metastases, 177Lu and 188Re-labeled radiopharmaceuticals appear to be the most suitable radiopharmaceuticals for treatment of small and medium/large size bone lesions, respectively

Hydro-sedimentary processes in a beach-headland system

Understanding hydro-sedimentary processes in space-limited environments as embayed beaches is a key question to reconstruct preterit and predict future coastal evolution forced by the mean sea level rise. Moreover, such knowledge is a fundamental management tool in areas where coastal erosion is currently a worrying fact. This work aims thus to assess the sedimentary contribute, provided by the alongshore transport, to feed embayed beaches. At the southernmost rocky coast of Portugal (Algarve), beaches occurring at the cliffs’ foot are separated by headlands connected to shore platforms forming littoral cells as a consequence of the extremely karstified carbonate landscape. The survival of those beaches depends almost exclusively on the alongshore drift.info:eu-repo/semantics/publishedVersio

The Conformation of the N-Terminal Tails of Deinococcus grandis Dps Is Modulated by the Ionic Strength

UIDB/04378/2020 LA/P/0140/2020 UID/Multi/04349/2019 LISBOA-01-0145-FEDER-022096 PTDC/BIA-PRO/111485/2009 PTDC/QUI/64248/2006 PD/00193/2012—UCIBIO (UIDB/04378/2020), UIDB/00068/2020 PD/BD/135476/2017 COVID/BD/152497/2022 PD/BD/135477/2017 COVID/BD/152498/2022 Grant Agreement 730872DNA-binding proteins from starved cells (Dps) are homododecameric nanocages, with N-and C-terminal tail extensions of variable length and amino acid composition. They accumulate iron in the form of a ferrihydrite mineral core and are capable of binding to and compacting DNA, forming low-and high-order condensates. This dual activity is designed to protect DNA from oxidative stress, resulting from Fenton chemistry or radiation exposure. In most Dps proteins, the DNA-binding properties stem from the N-terminal tail extensions. We explored the structural characteristics of a Dps from Deinococcus grandis that exhibits an atypically long N-terminal tail composed of 52 residues and probed the impact of the ionic strength on protein conformation using size exclusion chromatography, dynamic light scattering, synchrotron radiation circular dichroism and small-angle X-ray scattering. A novel high-spin ferrous iron-binding site was identified in the N-terminal tails, using Mössbauer spectroscopy. Our data reveals that the N-terminal tails are structurally dynamic and alter between compact and extended conformations, depending on the ionic strength of the buffer. This prompts the search for other physiologically relevant modulators of tail conformation and hints that the DNA-binding properties of Dps proteins may be affected by external factors.publishersversionpublishe

The tolerance of eucalyptus globulus to soil contamination with arsenic

UID/FIS/04559/2020The contamination of abandoned mining areas is a problem worldwide that needs urgent attention. Phytoremediation emerges as a successful method to extract different contaminants from the soil. In this context, Eucalyptus globulus plants growing in soils artificial contaminated with arsenic (As) were used to access its phytoremediation capabilities. The effects of As on photosynthetic performance were monitored through different physiological parameters, whereas the uptake and translocation of As and the putative effects on calcium, iron, potassium, and zinc levels on plants were evaluated by X-ray fluorescence analysis. Root system is the major accumulator organ, while the translocation to the above-ground organs is poor. In the end of the experiment, the root biomass of plants treated with 200 μg As mL−1 is 27% and 49.7% lower than equivalent biomass from plants treated with 100 μg As mL−1 and control plants, respectively. Each plant can accumulate 8.19 and 8.91 mg As after a 6-month period, when submitted to 100 As and 200 As, respectively. It seems to exist an antagonistic effect of As on Zn root uptake by E. globulus. In general, the tested concentrations do not influence negatively plant metabolism, indicating that this species is suitable for plantation in contaminated areas.publishersversionpublishe

Lithium attenuates behavioral and biochemical effects of neuropeptide S in mice

Neuropeptide S (NPS) and its receptor NPSR comprise a recently deorphaned G-protein-coupled receptor system. There is a body of evidence suggesting the involvement of NPS in wakefulness, anxiety, locomotor activity and oxidative stress damage. Considering that mood stabilizers block the stimulatory effect of psychostimulants in rodents, the present study aimed to investigate the effects of the pretreatment with lithium and valproate on the hyperlocomotion evoked by NPS. Another relevant action induced by lithium and valproate is the neuroprotection against oxidative stress. Thus, aiming to get further information about the mechanisms of action of NPS, herein we evaluated the effects of NPS, lithium and valproate, and the combination of them on oxidative stress damage. Behavioral studies revealed that the pretreatment with lithium (100 mg/kg, i.p.) and valproate (200 mg/kg, i.p.) prevented hyperlocomotion evoked by NPS 0.1 nmol. Importantly, the dose of valproate used in this study reduced mouse locomotion, although it did not reach the statistical significance. Biochemical analyses showed that lithium attenuated thiobarbituric reactive species (TBARS) formation in the striatum, cerebellum and hippocampus. NPS per se reduced TBARS levels only in the hippocampus. Valproate did not significantly affect TBARS levels in the brain. However, the combination of mood stabilizers and NPS blocked, instead of potentiate, the neuroprotective effects of each one. No relevant alterations were observed in carbonylated proteins after all treatments. Altogether, the present findings suggested that mainly the mood stabilizer lithium evoked antagonistic effects on the mediation of hyperlocomotion and protection against lipid peroxidation induced by NPS

Brazilian guideline for the treatment of patients with opioids dependence syndrome

There is a relatively low prevalence of opioid use in Brazil, particularly involving the non-medical use of codeine and opiate-containing syrups. However, opioid dependence syndrome shows a significant total impact on mortality and morbidity. Over the past 20 years, scientific progress has changed our understanding of the nature of opioid addiction and its various possible treatments. Addiction is a chronic illness treatable if the treatment is well-delivered and tailored to the needs of the particular patient. There is indeed an array of treatments that can effectively reduce drug use, help manage drug cravings, prevent relapses and restore people to productive social functioning. The treatment of drug addiction will be part of long-term, medical, psychological, and social perspectives. This guideline aims at providing guidance to psychiatrists and other mental health professionals who care for patients with Opioid Dependence Syndrome. It comments on the somatic and psychosocial treatment that is used for such patients, and reviews scientific evidences and their strength. Also, the essential historical, epidemiological and neurobiological aspects of Opioid Dependence are reviewed.Existe uma prevalência relativamente baixa do uso de ópioides no Brasil, em particular envolvendo o uso não médico da codeína e de xaropes que contêm opióides. No entanto, a síndrome de dependência apresenta um significativo impacto total na mortalidade e morbidade. Nos últimos 20 anos, o avanço científico tem modificado nosso entendimento sobre a natureza da adição aos opióides e os variados tratamentos possíveis. A adição é uma doença crônica tratável se o tratamento for realizado e adaptado tendo em vista as necessidades do paciente específico. Há, de um fato, um conjunto de tratamentos que podem efetivamente reduzir o uso da droga, ajudar a gerenciar a fissura pela droga, prevenir recaídas e recuperar as pessoas para o funcionamento social produtivo. O tratamento da dependência de drogas será parte de perspectivas de longo prazo do ponto de vista médico, psicológico e social. Esta diretriz almeja fornecer um guia para os psiquiatras e outros profissionais de saúde que tratam de pacientes com Síndrome de Dependência de Opióides. Ela tece comentários sobre o tratamento somático e psicossocial que é utilizado nesses pacientes e revisa as evidências científicas e seu poder. Da mesma forma, os aspectos históricos, epidemiológicos e neurobiológicos da dependência de opióides são revisados.Universidade de São Paulo Hospital de Clínicas Instituto de PsiquiatriaFaculdade de Medicina do ABCJohns Hopkins University School of MedicineAssociação Brasileira de Psiquiatria Departamento de Dependência QuímicaHospital Albert EinsteinUniversidade Federal de São Paulo (UNIFESP)UNIADUNIFESPSciEL

Effects of 2 or 5 consecutive exercise days on adipocyte area and lipid parameters in Wistar rats

<p>Abstract</p> <p>Background</p> <p>Exercise has been prescribed in the treatment and control of dyslipidemias and cholesterolemia, however, lipid responses to different training frequencies in hypercholesterolemic men have been inconsistent. We sought to verify if different frequencies of continuous moderate exercise (2 or 5 days/week, swimming) can, after 8 weeks, promote adaptations in adipocyte area and lipid parameters, as well as body weight and relative weight of tissues in normo and hypercholesterolemic adult male rats.</p> <p>Methods</p> <p>Normal cholesterol chow diet or cholesterol-rich diet (1% cholesterol plus 0.25% cholic acid) were freely given during 8 weeks to the rats divided in 6 experimentals groups: sedentary normal cholesterol chow diet (C); sedentary cholesterol-rich diet (H); 5× per week continuous training normal cholesterol chow diet (TC5) and cholesterol-rich diet (TH5); 2× per week continuos traning normal cholesterol chow diet (TC2) and cholesterol-rich diet (TH2).</p> <p>Results</p> <p>No changes were observed in lipid profile in normal cholesterol chow diet, but both 2 a 5 days/week exercise improved this profile in cholesterol-rich diet. Body weight gain was lower in exercised rats. Decrease in retroperitoneal and epididymal relative weights as well as reductions in adipocyte areas under all diets types were observed only in 5 days/week, while 2 days/week showed improvements mainly in cholesterol-rich diet rats.</p> <p>Conclusion</p> <p>Our results confirm the importance of exercise protocols to control dyslipidemias and obesity in rats. The effects of 5 days/week exercise were more pronounced compared with those of 2 consecutive days/week training.</p

Hiperplasia angiolinfoide como causa de eosinofilia

A hiperplasia angiolinfoide (Hale e doença de Kimura são duas entidades que podem se manifestar como nódulos, placas ou pápulas, de localização predominante em face, região retroauricular e cervical. São causas raras de eosinofilia e ainda há muita discussão em torno de suas etiopatogenias. Para alguns autores trata-se de duas patologias distintas enquanto para outros são manifestações diferentes da mesma doença. O presente artigo relata o caso de um paciente asiático que apresentava história de prurido generalizado há um ano, acompanhado de pápulas em membros e nódulo de aproximadamente 5 cm de diâmetro em região retroauricular direita com aumento progressivo. O hemograma apresentava leucocitose às custas de eosinofilia. Os achados sugerem uma superposição entre as duas patologias, pois clinicamente são sugestivos de doença de Kimura, mas a histopatologia e imuno-histoquímica confirmaram a origem endotelial da lesão, sendo compatível com Hale. Os autores destacam a raridade do caso como causa de eosinofilia, assim como alertam para a dificuldade do diagnóstico e da diferenciação entre as duas patologias