Synthesis, structure and antileishmanial evaluation of endoperoxide–pyrazole hybrids

Leishmaniases are among the most impacting neglected tropical diseases. In attempts to repurpose antimalarial drugs or candidates, it was found that selected 1,2,4-trioxanes, 1,2,4,5-tetraoxanes, and pyrazole-containing chemotypes demonstrated activity against Leishmania parasites. This study reports the synthesis and structure of trioxolane–pyrazole (OZ1, OZ2) and tetraoxane–pyrazole (T1, T2) hybrids obtained from the reaction of 3(5)-aminopyrazole with endoperoxide-containing building blocks. Interestingly, only the endocyclic amine of 3(5)-aminopyrazole was found to act as nucleophile for amide coupling. However, the fate of the reaction was influenced by prototropic tautomerism of the pyrazole heterocycle, yielding 3- and 5-aminopyrazole containing hybrids which were characterized by different techniques, including X-ray crystallography. The compounds were evaluated for in vitro antileishmanial activity against promastigotes of L. tropica and L. infantum, and for cytotoxicity against THP-1 cells. Selected compounds were also evaluated against intramacrophage amastigote forms of L. infantum. Trioxolane–pyrazole hybrids OZ1 and OZ2 exhibited some activity against Leishmania promastigotes, while tetraoxane–pyrazole hybrids proved inactive, most likely due to solubility issues. Eight salt forms, specifically tosylate, mesylate, and hydrochloride salts, were then prepared to improve the solubility of the corresponding peroxide hybrids and were uniformly tested. Biological evaluations in promastigotes showed that the compound OZ1•HCl was the most active against both strains of Leishmania. Such finding was corroborated by the results obtained in assessments of the L. infantum amastigote susceptibility. It is noteworthy that the salt forms of the endoperoxide–pyrazole hybrids displayed a broader spectrum of action, showing activity in both strains of Leishmania. Our preliminary biological findings encourage further optimization of peroxide–pyrazole hybrids to identify a promising antileishmanial lead.info:eu-repo/semantics/publishedVersio

Tumor Stiffness is Associated with Reduced CD45+ Immune Cell Penetration of Tumors in a Rat Hepatocellular Carcinoma Model

https://openworks.mdanderson.org/sumexp23/1108/thumbnail.jp

Seroprevalence and Risk Factors Associated with Leishmania Infection in Dogs from Portugal

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Helium enhanced stars and multiple populations along the horizontal branch of NGC 2808: Direct spectroscopic measurements

We present an abundance analysis of 96 horizontal branch (HB) stars in NGC 2808, a globularcluster exhibiting a complex multiple stellar population pattern. These stars are distributed indifferent portions of the HB and cover a wide range of temperature

Comparison of Leishmania typing results obtained from 16 European clinical laboratories in 2014.

Leishmaniasis is endemic in southern Europe, and in other European countries cases are diagnosed in travellers who have visited affected areas both within the continent and beyond. Prompt and accurate diagnosis poses a challenge in clinical practice in Europe. Different methods exist for identification of the infecting Leishmania species. Sixteen clinical laboratories in 10 European countries, plus Israel and Turkey, conducted a study to assess their genotyping performance. DNA from 21 promastigote cultures of 13 species was analysed blindly by the routinely used typing method. Five different molecular targets were used, which were analysed with PCR-based methods. Different levels of identification were achieved, and either the Leishmania subgenus, species complex, or actual species were reported. The overall error rate of strains placed in the wrong complex or species was 8.5%. Various reasons for incorrect typing were identified. The study shows there is considerable room for improvement and standardisation of Leishmania typing. The use of well validated standard operating procedures is recommended, covering testing, interpretation, and reporting guidelines. Application of the internal transcribed spacer 1 of the rDNA array should be restricted to Old World samples, while the heat-shock protein 70 gene and the mini-exon can be applied globally

Conforming nanoparticle sheets to surfaces with Gaussian curvature

Nanoparticle monolayer sheets are ultrathin inorganic–organic hybrid materials that combine highly controllable optical and electrical properties with mechanical flexibility and remarkable strength. Like other thin sheets, their low bending rigidity allows them to easily roll into or conform to cylindrical geometries. Nanoparticle monolayers not only can bend, but also cope with strain through local particle rearrangement and plastic deformation. This means that, unlike thin sheets such as paper or graphene, nanoparticle sheets can much more easily conform to surfaces with complex topography characterized by non-zero Gaussian curvature, like spherical caps or saddles. Here, we investigate the limits of nanoparticle monolayers’ ability to conform to substrates with Gaussian curvature by stamping nanoparticle sheets onto lattices of larger polystyrene spheres. Tuning the local Gaussian curvature by increasing the size of the substrate spheres, we find that the stamped sheet morphology evolves through three characteristic stages: from full substrate coverage, where the sheet extends over the interstices in the lattice, to coverage in the form of caps that conform tightly to the top portion of each sphere and fracture at larger polar angles, to caps that exhibit radial folds. Through analysis of the nanoparticle positions, obtained from scanning electron micrographs, we extract the local strain tensor and track the onset of strain-induced dislocations in the particle arrangement. By considering the interplay of energies for elastic and plastic deformations and adhesion, we construct arguments that capture the observed changes in sheet morphology as Gaussian curvature is tuned over two orders of magnitude

Desenvolvimento e aplicação de método para avaliação da qualidade de termocicladores

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Programa de Pós-Graduação em Farmácia, Florianópolis, 2017.A técnica da Reação em Cadeia da Polimerase (PCR), que utiliza equipamentos termocicladores para sua execução, vem sendo amplamente utilizada em laboratórios e é um método acurado se realizado de forma criteriosa. Considerando a importância do desempenho dos termocicladores para a execução da técnica, este estudo pretende contribuir para a garantia da qualidade e confiança dos resultados obtidos por técnicas de PCR. Assim, os objetivos deste estudo foram verificar a homogeneidade térmica do bloco térmico do termociclador, a temperatura e a duração efetivamente executadas em cada ciclo da reação, bem como avaliar a eficiência de amplificação dos termocicladores por meio de uma PCR-controle, e avaliar a relação entre o desempenho dos termocicladores e suas condições de uso. A avaliação da temperatura foi realizada por meio de um protocolo de verificação da temperatura estática e por meio de um protocolo que mimetiza os ciclos térmicos de uma PCR, utilizando-se micro-termopares. A maioria dos termocicladores verificados apresentou algum tipo de distorção no seu perfil de temperatura, demonstrando perfil curvo ou com overshooting. Variações significativas de temperatura entre as posições verificadas nos blocos térmicos também foram observadas. As temperaturas efetivamente executadas desviaram pelo menos 0,5°C das programadas em todas as etapas avaliadas. A duração efetiva das etapas foi consideravelmente diminuída, chegando a não haver um platô na temperatura programada em alguns casos. Tais alterações não foram desprezíveis, pois resultaram em falhas nos resultados da PCR-controle pela maioria dos termocicladores. Portanto, não há posições melhores ou piores no bloco térmico, há termociclador com funcionamento adequado ou inadequado. Por fim, ressalta-se a importância de os usuários realizarem a verificação da qualidade dos seus termocicladores a fim de conhecerem melhor o desempenho dos equipamentos, contribuindo para maior reprodutibilidade das PCR principalmente nos laboratórios que utilizam diferentes modelos de termocicladores.Abstract : Polymerase Chain Reaction (PCR) has been widely used in clinical laboratories and in scientific research, being considered a well-established technique if carefully performed. Thermocyclers are essential equipments for PCR execution, which must show good performance. Considering the importance of thermocycler quality control, this research aims to contribute to quality assurance and reliability of the results obtained through PCR. In order to evaluate the quality of thermocyclers at UFSC laboratories, the research aimed to verify the thermal homogeneity in the thermal block, the temperature and duration obtained for each reaction cycle, as well as to evaluate the thermocycler amplification efficiency by means of a PCR control and the relationship between thermocycler performance and its maintenance conditions. Temperature evaluation was done using a protocol for verification of static temperature and another protocol that mimics PCR cycles, all of them using micro thermocouples. Most of the thermocyclers verified presented some type of distortion in their temperature profile, showing a curved profile or overshooting. Significant temperature variations among the positions verified in the thermal blocks were also observed. The effective temperatures deviated at least 0.5°C from those programmed in all stages evaluated. The actual duration of the stages was considerably reduced, not even reading a stable plateau at the programed temperature in some cases. Such changes were not negligible, as they resulted in flaws in the control-PCR in the majority of the thermocyclers. Finally, it is emphasized the importance of users to verify the quality of their thermocyclers in order to know the performance of the equipment, contributing to a greater reproducibility of the PCR, especially among the laboratories that use different models of thermocyclers

Atherosclerosis and Bone Loss in Humans–Results From Deceased Donors and From Patients Submitted to Carotid Endarterectomy

Funding: We wish to thank all the collaborators (administrative staff, nurses, etc.) of the surgery block, as well as the doctors of the vascular surgery and transplantation departments of the Hospital of Santa Maria for the availability and assistance in the collection of the samples. We also thank Sociedade Portuguesa de Reumatologia for funding with two fellowships: Fundo de Apoio à Investigação 2014 and SPR/MSD 2015. DC-F received funding from a PhD grant from Fundação para a Ciência e a Tecnologia (SFRH/BD/80940/2011).Background and Aims: Atherosclerosis and osteoporosis share common risk factors, as well as inflammatory mechanisms. Our aim was to understand how atherosclerotic lesions are related with disturbances in bone. Methods: Gene expression of pro-inflammatory and bone metabolism related proteins (IL-1β, IL-6, IL-17A, TNF, RANKL, OPG, COL1, CTSK, OCL, TRAP, CBFA1, DKK1, SOST, ADIPOQ, and ADIPOR1) were analyzed in arteries and bones from 45 deceased donors and adipose tissue was used as control. Additionally, in 139 patients with advanced atherosclerosis submitted to carotid endarterectomy we compared calcium content (Alizarin red) and plaque inflammatory scores (CD3+, CD68+, and adiponectin) of patients with normal bone mineral density (BMD) with those with low BMD and explored the associations between gene expression in atherosclerotic plaques and BMD. Serum levels of pro-inflammatory and bone related proteins were measured both in donors and patients. Associations were investigated by the Pearson or Spearman correlation tests, and multivariate regression analyzes were performed when justified. Results: Gene expression of bone remodeling and pro-inflammatory proteins correlated positively in bone and aorta, independently of age and sex of donors, but not in adipose tissue. The expression of bone formation genes was significantly higher in atheroma plaques from endarterectomized patients with normal vs. low BMD as well as inflammatory CD68+ scores, regardless of patients' age and sex, but not of body mass index. No relationship was observed between serum levels and gene expression levels of pro-inflammatory or bone remodeling proteins. Conclusions: Our results suggest that the relationship between bones and vessels in the context of atherosclerotic disease and osteoporosis may rely on the intrinsic connection between the tissues involved, independently of disease stage. Serum measurements of pro-inflammatory and bone-remodeling proteins do not accurately translate tissue pathologic processes.publishersversionpublishe