Search results for "Biological studies"

A Short and Improved Synthesis of the Antiprotozoal Abietane Diterpenoid (–)-Sugikurojin A

2016

An efficient and straightforward semisynthesis of the antiprotozoal abietane diterpenoid (–)-sugikurojin A, starting from the readily available methyl ester of callitrisic acid (4-epi-dehydroabietic acid­) isolated from sandarac resin, is reported. This optimized semi­synthetic route provides a convenient source of the antiprotozoal compound, in four steps from methyl callitrisate in 50% overall yield, for further biological studies.

Next-Generation Sequencing Identifies Potential Actionable Targets in Paediatric Sarcomas

2021

Background: Bone and soft-tissue sarcomas represent 13% of all paediatric malignancies. International contributions to introduce next-generation sequencing (NGS) approaches into clinical application are currently developing. We present the results from the Precision Medicine program for children with sarcomas at a reference centre. Results: Samples of 70 paediatric sarcomas were processed for histopathological analysis, reverse transcriptase polymerase chain reaction (RT-PCR) and next-generation sequencing (NGS) with a consensus gene panel. Pathogenic alterations were reported and, if existing, targeted recommendations were translated to the clinic. Seventy paediatric patients with sarcomas…

Encapsulation of polyprodrugs enables an efficient and controlled release of dexamethasone

2021

Water-soluble low molecular weight drugs, such as the synthetic glucocorticoid dexamethasone (DXM), can easily leak out of nanocarriers after encapsulation due to their hydrophilic nature and small size. This can lead to a reduced therapeutic efficacy and therefore to unwanted adverse effects on healthy tissue. Targeting DXM to inflammatory cells of the liver like Kupffer cells or macrophages is a promising approach to minimize typical side effects. Therefore, a controlled transport to the cells of interest and selective on-site release is crucial. Aim of this study was the development of a DXM-phosphate-based polyprodrug and the encapsulation in silica nanocontainers (SiO2 NCs) for the red…

Even free radicals should follow some rules: a guide to free radical research terminology and methodology.

2014

Free radicals and oxidants are now implicated in physiological responses and in several diseases. Given the wide range of expertise of free radical researchers, application of the greater understanding of chemistry has not been uniformly applied to biological studies. We suggest that some widely used methodologies and terminologies hamper progress and need to be addressed. We make the case for abandonment and judicious use of several methods and terms and suggest practical and viable alternatives. These changes are suggested in four areas: use of fluorescent dyes to identify and quantify reactive species, methods for measurement of lipid peroxidation in complex biological systems, claims of…

Spectroscopic, density functional theory, nonlinear optical properties and in vitro biological studies of Co(II), Ni(II), and Cu(II) complexes of hyd…

2021

Ruthenium(II) and platinum(II) homo- and heterobimetallic complexes: Synthesis, crystal structures, theoretical calculations and biological studies

2019

Four Ru-Pd heterobimetallic complexes, each one in two different coordination modes (NNSS and NS) having metals connected by a binucleating dialkyldithiooxamidate [N(R)SC-CS(R)N] [R = methyl, ethyl, n-butyl and isopropyl], were prepared by reacting the monochelate [(trinpropyl-phosphine)ClPd(HR2C2N2S2κ-S,S-Pd)] with [(η6-p-cymene)RuCl2]2. Furthermore, two palladium homobimetallic complexes having two (trinpropyl-phosphine)ClPd moieties joined by a diethyldithiooxamidate in both κ-N,S Pd, κ-N',S' Pd' and κ-N,N' Pd, κ-S,S' Pd' coordination modes were synthesized. For both kinds of complexes, homo- and heterobimetallic, at room temperature and in chloroform solution, the NNSS coordination mode…

Perfil genómico del neuroblastoma de alto riesgo mediante hibridación genómica comparada

2006

El neuroblastoma presenta alteraciones genéticas que predicen su evolución clínica. Ganancias cromosómicas completas están asociadas a estadios clínicos no avanzados y evolución favorable, mientras que pérdidas de 1p, ganancia de 17q y amplificación del gen MYCN (MNA) son indicativas de estadios clínicos avanzados y pronóstico desfavorable. Son neuroblastomas de alto riesgo (NB-HR) los presentes en niños mayores de un año: estadio 4 o MNA en cualquier estadio de enfermedad, excluyendo estadio 1. El pronóstico de estos enfermos es malo, incluso con tratamientos agresivos. Sólo MNA confiere valor pronóstico negativo. Se remitieron al Centro de Referencia Nacional del neuroblastoma 60 casos de…

Pentapeptides containing two dehydrophenylalanine residues - synthesis, structural studies and evaluation of their activity towards cathepsin C

2008

Synthesis, structural and biological studies of pentapeptides containing two Delta Phe residues (Z and E isomers) in position 2 and 4 in peptide chain were performed. All the investigated peptides adopted bent conformation and majority of them could exist as two different. conformers in solution. Only pentapeptides. containing free N-termini appeared to act as weak inhibitors of cathepsin C with the slow-binding, competitive mechanism of inhibition. free acids being bound slightly better than their methyl esters. Results of Molecular modeling suggested significant difference between peptides, depending of the type of amino acid residue in position 5 in peptide chain. Dehydropeptides contain…

Local adaptation, coadaptation, and population boundaries

1986

Coadaptation can occur either because of local adaptation in a geographically widespread population and/or because of intrinsic adaptation to the state of other genes or chomosomes. In either event, hybridization between animals with differently coadapted gene or chromosomal complexes can result in a decrease in fertility, viability, etc. in the initial hybrids and especially in later generations. This is known as an outbreeding depression. Moreover, releasing animals not adapted to the local environment can seriously hamper the effectiveness of a reintroduction program, and hybridization can also destroy the local adaptation. Coadapted gene complexes are best detected through studies on na…