Methyltrioxorhenium catalysed synthesis of highly oxidised aryltetralin lignans with anti-topoisomerase II and apoptogenic activities

A novel and efficient procedure to prepare highly oxidised aryltetralin lignans, such as isopodophyllotoxone and (-)-aristologone derivatives, by oxidation of podophyllotoxin and galbulin with methylrhenium trioxide (MTO) and novel MTO heterogeneous catalysts is reported. It is noteworthy that in the case of isopodophyllotoxone derivatives the functionalisation of the C-4 position of the C-ring and the ring-opening of the D-lactone moiety increased the activity against topoisomerase II while causing the undesired inhibition of tubulin polymerisation to disappear. The novel (-)-aristologone derivatives showed apoptogenic activity against resistant human lymphoma cell lines.L'articolo è disponibile sul sito dell'editore: http://www.sciencedirect.co

RNA-binding activity of the rat calmodulin-binding PEP-19 protein and of the long PEP-19 isoform

Synthesis of H1\u2da histone protein, in the developing rat brain, seems to be regulated mainly at the post-transcriptional level. Since regulation of RNA metabolism depends on a series of RNA-binding proteins, we have been searching for RNA-binding proteins involved in the post-transcriptional regulation of the H1\u2da gene. We recently reported isolation, from a cDNA expression library, of an insert encoding a novel protein, the C-terminal half of which is identical to that of PEP-19, a brain-specific protein involved in calcium metabolism. The novel protein was called long PEP-19 isoform (LPI). Herein we show that LPI, as well as PEP-19, can bind H1\u2da RNA. Moreover, in order to improve production of functional LPI/PEP-19, we modified the protocol normally adopted for preparing histidine tagged-proteins from bacteria, by adding an additional purification step. We also found that both LPI and PEP can compete for H1\u2da RNA binding with PIPPin (CSD-C2), another RNA-binding protein previously discovered in our laboratory. Since PEP19/LPI contain a calmodulin binding domain, we finally investigated whether their ability to bind RNA is affected by calmodulin. Our results show that calmodulin interferes with binding of H1\u2da RNA to both PEP-19 and LPI, while it is not able to bind RNA on its own. This finding suggests that calcium/calmodulin may have a role in controlling H1\u2da mRNA metabolism in the developing brain

Pt(II) complex @mesoporous silica: preparation, characterization and study of release

Cisplatin analogs, having cytotoxic activity higher than that exerted by cisplatin, have recently triggered considerable interest by the community. The cis-[PtCl2(DMSO)HL]·2DMSO, where HL = 7-amino-2-(methylthio)[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylic acid, has shown a potent cytotoxic activity on HepG2 hepatocarcinoma cells, while under identical conditions, it did not affect normal immortalized human liver cells (Chang). In this work, the above complex has been incorporated into MCM41 mesoporous silica, pure and functionalized with amino group, which is considered one of the best host for a drug delivery system for carrying high dosages of a variety of drugs in their mesopores. Since the controlled release of an anticancer drug helps to maintain its therapeutic level for an extended time period while minimizing undesirable high peaks immediately following administration, the in vitro tests have been performed in order to obtain the corresponding drug release profile. The investigated system demonstrated to be an efficient system for pharmaceutic controlled release. A deepened characterization of the systems has been performed in order to known their structure and features and to speculate the mechanisms involved in the release

An Efficient Metadynamics-Based Protocol To Model the Binding Affinity and the Transition State Ensemble of G-Protein-Coupled Receptor Ligands

A generally applicable metadynamics scheme for predicting the free energy profile of ligand binding to G-protein-coupled receptors (GPCRs) is described. A common and effective collective variable (CV) has been defined using the ideally placed and highly conserved Trp6.48 as a reference point for ligand–GPCR distance measurement and the common orientation of GPCRs in the cell membrane. Using this single CV together with well-tempered multiple-walker metadynamics with a funnel-like boundary allows an efficient exploration of the entire ligand binding path from the extracellular medium to the orthosteric binding site, including vestibule and intermediate sites. The protocol can be used with X-ray structures or high-quality homology models (based on a high-quality template and after thorough refinement) for the receptor and is universally applicable to agonists, antagonists, and partial and reverse agonists. The root-mean-square error (RMSE) in predicted binding free energies for 12 diverse ligands in five receptors (a total of 23 data points) is surprisingly small (less than 1 kcal mol–1). The RMSEs for simulations that use receptor X-ray structures and homology models are very similar

Conformational transition of FGFR kinase activation revealed by site-­specific unnatural amino acid reporter and single molecule FRET

Protein kinases share significant structural similarity; however, structural features alone are insufficient to explain their diverse functions. Thus, bridging the gap between static structure and function requires a more detailed understanding of their dynamic properties. For example, kinase activation may occur via a switch-like mechanism or by shifting a dynamic equilibrium between inactive and active states. Here, we utilize a combination of FRET and molecular dynamics (MD) simulations to probe the activation mechanism of the kinase domain of Fibroblast Growth Factor Receptor (FGFR). Using genetically-encoded, site-specific incorporation of unnatural amino acids in regions essential for activation, followed by specific labeling with fluorescent moieties, we generated a novel class of FRET-based reporter to monitor conformational differences corresponding to states sampled by non phosphorylated/inactive and phosphorylated/active forms of the kinase. Single molecule FRET analysis in vitro, combined with MD simulations, shows that for FGFR kinase, there are populations of inactive and active states separated by a high free energy barrier resulting in switch-like activation. Compared to recent studies, these findings support diversity in features of kinases that impact on their activation mechanisms. The properties of these FRET-based constructs will also allow further studies of kinase dynamics as well as applications in vivo

Looking for the Original Materials and Evidence of Restoration at the Vault of the San Panfilo Church in Tornimparte (AQ)

This paper reports the investigation of six microsamples collected from the vault of the San Panfilo Church in Tornimparte (AQ). The aim was to detect the composition of the pigments and protective/varnishes, and to investigate the executive technique, the conservation state, and the evidence of the restoration works carried out in the past. Six microsamples were analyzed by optical microscopy, scanning electron microscopy coupled with energy-dispersive spectroscopy (EDS), X-ray fluorescence (XRF), and infrared and Raman spectroscopy. The investigations were carried out within the framework of the Tornimparte project "Archeometric investigation of the pictorial cycle of Saturnino Gatti in Tornimparte (AQ, Italy)" sponsored in 2021 by the Italian Association of Archeometry (AIAr)

Predictors of morbidity and mortality in patients submitted to cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy for ovarian carcinomatosis: A multicenter study

The aim of this retrospective study is to assess the incidence of morbidity and mortality related to cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) and to evaluate their predictors, in patients with peritoneal metastasis of ovarian origin. A retrospective multicenter study was carried out investigating results from eight Italian institutions. A total of 276 patients met inclusion criteria. Predictors of morbidity and mortality were evaluated with univariate and multivariate analysis. Overall morbidity was 71.4%, and severe complications occurred in 23.9% of the sample; 60-day mortality was 4.3%. According to univariate logistic regression models, grade 3-4 morbidity was related to Peritoneal Cancer Index (PCI) (OR 1.06; 95% CI 1.02-1.09; p<0.001), number of intraoperative blood transfusions (OR 1.21; 95% CI 1.10-1.34; p<0.001), Completeness of Cytoreduction (CC) score (OR 1.68; 95% CI 1.16-2.44; p=0.006) and number of anastomoses (OR 1.32; 95% CI 1.00-1.73; p=0.046). However, at the multivariate logistic regression analysis, only the number of intraoperative blood transfusions (OR 1.17; 95% CI 1.5-1.30; p=0.004) and PCI (OR 1.04; 95% CI 1.01-1.08; p=0.010) resulted as key predictors of severe morbidity. Furthermore, using multivariate logistic regression model, ECOG score (OR 2.45; 95% CI 1.21-4.93; p=0.012) and the number of severe complications (OR 2.16; 95% CI 1.03-4.52; p=0.042) were recorded as predictors of exitus within 60 days. The combination of CRS and HIPEC for treating peritoneal metastasis of ovarian origin has acceptable morbidity and mortality and, therefore, it can be considered as an option in selected patients

Graphene coating obtained in a cold-wall CVD process on the Co-Cr Alloy (L-605) for medical applications

Graphene coating on the cobalt-chromium alloy was optimized and successfully carried out by a cold-wall chemical vapor deposition (CW-CVD) method. A uniform layer of graphene for a large area of the Co-Cr alloy (discs of 10 mm diameter) was confirmed by Raman mapping coated area and analyzing specific G and 2D bands; in particular, the intensity ratio and the number of layers were calculated. The effect of the CW-CVD process on the microstructure and the mor-phology of the Co-Cr surface was investigated by scanning X-ray photoelectron microscope (SPEM), atomic force microscopy (AFM), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). Nanoindentation and scratch tests were performed to determine mechanical properties of Co-Cr disks. The results of microbiological tests indicate that the studied Co-Cr alloys covered with a graphene layer did not show a pro-coagulant effect. The obtained results confirm the possibility of using the developed coating method in medical applications, in particular in the field of cardiovascular diseases