Novel Dihydropteridinone Derivatives As Potent Inhibitors of the Understudied Human Kinases Vaccinia-Related Kinase 1 and Casein Kinase 1δ/ε.

Vaccinia-related kinase 1 (VRK1) and the δ and ε isoforms of casein kinase 1 (CK1) are linked to various disease-relevant pathways. However, the lack of tool compounds for these kinases has significantly hampered our understanding of their cellular functions and therapeutic potential. Here, we describe the structure-based development of potent inhibitors of VRK1, a kinase highly expressed in various tumor types and crucial for cell proliferation and genome integrity. Kinome-wide profiling revealed that our compounds also inhibit CK1δ and CK1ε. We demonstrate that dihydropteridinones 35 and 36 mimic the cellular outcomes of VRK1 depletion. Complementary studies with existing CK1δ and CK1ε inhibitors suggest that these kinases may play overlapping roles in cell proliferation and genome instability. Together, our findings highlight the potential of VRK1 inhibition in treating p53-deficient tumors and possibly enhancing the efficacy of existing cancer therapies that target DNA stability or cell division.

Assessment of antimicrobial resistance, biofilm formation, and surface modification potential in hospital strains of Pseudomonas aeruginosa and Klebsiella pneumoniae.

The occurrence of healthcare-associated infections is a multifactorial phenomenon related to hospital space contamination by bacteria. The ESKAPE group, specifically Pseudomonas aeruginosa and Klebsiella pneumoniae, play a relevant role in the occurrence of these infections. Therefore, comprehensive research is needed to identify characteristics that justify the prevalence of these species in the healthcare environment. In this line, the study aimed to determine the antimicrobial resistance, biofilm formation, and the potential for polymer degradation in a collection of 33 P. aeruginosa strains and 2 K. pneumoniae strains sampled from various equipment and non-critical surfaces in a Portuguese hospital. Antimicrobial susceptibility tests revealed that none of the strains was categorized as multidrug-resistant (non-MDR). An assessment of their biofilm-forming capabilities indicated that 97 % of the strains exhibited biofilm-producing characteristics. Notably, within this group, the majority of P. aeruginosa and half of K. pneumoniae strains were classified as strong biofilm producers. Furthermore, the strains were evaluated for their potential to cause damage or change medical devices, namely infusion sets, nasal cannula, and urinary catheters. Three P. aeruginosa strains, two strong and one moderate biofilm producers, showed the highest ability to modify surfaces of the nasal cannula and infusion sets. Additionally, the Chi-square test revealed a statistically significant relationship between the presence of P. aeruginosa strains and the water accession spots. In conclusion, this work suggests that bacteria from this group hold a significant ability to grow in the healthcare environment through the degradation of non-critical materials. This suggests a potential concern for the persistence and proliferation of these organisms in hospital environments, emphasizing the importance of robust infection control measures to mitigate the risks associated with bacterial growth on such surfaces.

Short Peripheral Venous Catheters Contamination and the Dangers of Bloodstream Infection in Portugal: An Analytic Study.

Peripheral venous catheters (PVCs) are the most used vascular access devices in the world. However, failure rates remain considerably high, with complications such as PVC-related infections posing significant threats to patients' well-being. In Portugal, studies evaluating the contamination of these vascular medical devices and characterizing the associated microorganisms are scarce and lack insight into potential virulence factors. To address this gap, we analyzed 110 PVC tips collected in a large tertiary hospital in Portugal. Experiments followed Maki et al.'s semi-quantitative method for microbiological diagnosis. Staphylococcus spp. were subsequently studied for the antimicrobial susceptibility profile by disc diffusion method and based on the cefoxitin phenotype, were further classified into strains resistant to methicillin. Screening for the mecA gene was also done by a polymerase chain reaction and minimum inhibitory concentration (MIC)-vancomycin as determined by E-test, proteolytic and hemolytic activity on skimmed milk 1% plate and blood agar, respectively. The biofilm formation was evaluated on microplate reading through iodonitrotetrazolium chloride 95% (INT). Overall, 30% of PVCs were contaminated, and the most prevalent genus was Staphylococcus spp., 48.8%. This genus presented resistance to penicillin (91%), erythromycin (82%), ciprofloxacin (64%), and cefoxitin (59%). Thus, 59% of strains were considered resistant to methicillin; however, we detected the mecA gene in 82% of the isolates tested. Regarding the virulence factors, 36.4% presented α-hemolysis and 22.7% ß-hemolysis, 63.6% presented a positive result for the production of proteases, and 63.6% presented a biofilm formation capacity. Nearly 36.4% were simultaneously resistant to methicillin and showed expression of proteases and/or hemolysins, biofilm formation, and the MIC to vancomycin were greater than 2 µg/mL. Conclusion: PVCs were mainly contaminated with Staphylococcus spp., with high pathogenicity and resistance to antibiotics. The production of virulence factors strengthens the attachment and the permanence to the catheter's lumen. Quality improvement initiatives are needed to mitigate such results and enhance the quality and safety of the care provided in this field.

EdgeNets: Edge Varying Graph Neural Networks.

Driven by the outstanding performance of neural networks in the structured euclidean domain, recent years have seen a surge of interest in developing neural networks for graphs and data supported on graphs. The graph is leveraged at each layer of the neural network as a parameterization to capture detail at the node level with a reduced number of parameters and computational complexity. Following this rationale, this paper puts forth a general framework that unifies state-of-the-art graph neural networks (GNNs) through the concept of EdgeNet. An EdgeNet is a GNN architecture that allows different nodes to use different parameters to weigh the information of different neighbors. By extrapolating this strategy to more iterations between neighboring nodes, the EdgeNet learns edge- and neighbor-dependent weights to capture local detail. This is a general linear and local operation that a node can perform and encompasses under one formulation all existing graph convolutional neural networks (GCNNs) as well as graph attention networks (GATs). In writing different GNN architectures with a common language, EdgeNets highlight specific architecture advantages and limitations, while providing guidelines to improve their capacity without compromising their local implementation. For instance, we show that GCNNs have a parameter sharing structure that induces permutation equivariance. This can be an advantage or a limitation, depending on the application. In cases where it is a limitation, we propose hybrid approaches and provide insights to develop several other solutions that promote parameter sharing without enforcing permutation equivariance. Another interesting conclusion is the unification of GCNNs and GATs -approaches that have been so far perceived as separate. In particular, we show that GATs are GCNNs on a graph that is learned from the features. This particularization opens the doors to develop alternative attention mechanisms for improving discriminatory power.

Peripherally Inserted Central Catheter Placement in a Cardiology Ward: A Focus Group Study of Nurses' Perspectives.

Intravenous therapy administration through peripheral venous catheters is one of the most common nursing procedures performed in clinical contexts. However, peripherally inserted central catheters (PICC) remain insufficiently used by nurses and can be considered a potential alternative for patients who need aggressive intravenous therapy and/or therapy for extended periods. The purpose of this study was to understand nurses' perspectives about PICC implementation in their clinical practice. As part of an action-research project, three focus groups were developed in June 2019 with nineteen nurses of a cardiology ward from a Portuguese tertiary hospital. From the content analysis, two main categories emerged: 'nursing practices' and 'patients'. Nurses considered PICC beneficial for their clinical practice because it facilitates maintenance care and catheter replacement rates. Moreover, nurses suggested that, since there is a need for specific skills, the constitution of vascular access teams, as recommended by international guidelines, could be an advantage. Regarding patient benefits, nurses highlighted a decrease in the number of venipunctures and also of patient discomfort, which was associated with the number of peripheral venous catheters. Infection prevention was also indicated. As an emerging medical device used among clinicians, peripherally inserted central catheters seem to be essential to clinical practice.

Tourniquets used in peripheral venipuncture as a potential vehicle for transmission of microorganisms: scoping review / Torniquetes utilizados en la venopunción periférica como potencial vehículo de transmisión de microorganismos: revisión de alcance

Introduction: The tourniquet used in venipuncture appears as a potential vehicle for the transmission of microorganisms that interferes with safety and the quality of clinical services. Objective: Mapping the scientific evidence on the microbiological contamination of the tourniquets used in peripheral venipuncture. Methodology: Scoping review following the Joanna Briggs Institute methodology. Results: 20 studies have been included, in which of 1477 tourniquets were analyzed. The rates of microbiological contamination varied between 10-100% and 19 studies reported the presence of S. aureus, 11 of them detected methicillin-resistant strains with prevalence between 3.3-58.3%. Conclusion: The contamination rate in the majority of studies was ≥70%, including 4 studies which had sampled ≥100 tourniquets. The evidence of our study is that the tourniquets are reservoirs of potential pathogens and can be transmitted to patient on staff hands. We recommend studies that confirm the reusable tourniquets can be responsible to healthcare associated infections.

Introducción: El torniquete utilizado en la venopunción aparece como potencial vehículo para transmisión de microorganismos que entorpece la seguridad y calidad de los servicios clínicos. Objetivo: Mapear pruebas científicas sobre contaminación microbiológica de los torniquetes utilizados en la venopunción periférica. Metodología: Revisión de acuerdo con la metodología del Instituto Joanna Briggs. Resultados: Se han incluido 20 estudios, en los que se analizó un total de 1477 torniquetes. Las tasas de contaminación microbiológica variaron entre 10-100% y 19 estudios informaron la presencia de S. aureus, 11 detectaron cepas resistentes a meticilina con prevalencia entre 3.3-58.3%. Conclusión: La tasa de contaminación en mayoría de los estudios fue ≥70%, 4 estudios que habían muestreado ≥100 torniquetes. Nuestro estudio evidencia que los torniquetes son reservorios de patógenos y pueden transmitirse al paciente en manos del personal. Recomendamos estudios que confirmen que los torniquetes pueden ser responsables de las infecciones asociadas a la atención médica.

Development of Pyridine-based Inhibitors for the Human Vaccinia-related Kinases 1 and 2.

Vaccinia-related kinases 1 and 2 (VRK1 and VRK2) are human Ser/Thr protein kinases associated with increased cell division and neurological disorders. Nevertheless, the cellular functions of these proteins are not fully understood. Despite their therapeutic potential, there are no potent and specific inhibitors available for VRK1 or VRK2. We report here the discovery and elaboration of an aminopyridine scaffold as a basis for VRK1 and VRK2 inhibitors. The most potent compound for VRK1 (26) displayed an IC50 value of 150 nM and was fairly selective in a panel of 48 human kinases (selectivity score S(50%) of 0.04). Differences in compound binding mode and substituent preferences between the two VRKs were identified by the structure-activity relationship combined with the crystallographic analysis of key compounds. We expect our results to serve as a starting point for the design of more specific and potent inhibitors against each of the two VRKs.

Impact of an Innovative Securement Dressing and Tourniquet in Peripheral Intravenous Catheter-Related Complications and Contamination: An Interventional Study.

Reusable tourniquets and conventional securement dressings are considered risk factors for the occurrence of reported complications and catheter-related bloodstream infections. This study's purpose is to assess the impact of single-use disposable tourniquets and advanced occlusive polyurethane dressings with reinforced cloth borders on peripheral intravenous catheter (PIVC)-related complications and contamination. A pre- and post-interventional prospective observational study was conducted in a cardiology ward of a tertiary hospital between April 2018 and February 2019. Overall, demographic and clinical data from 156 patients and PIVC-related outcomes were collected (n = 296) as well as PIVC tips for microbiological analysis (n = 90). In the pre-intervention phase (n = 118), complication rates of 62.1% were reported, while 44.1% of the PIVCs were contaminated (n = 34). In the post-intervention phase (n = 178), complication rates decreased to 57.3%, while contamination rates significantly decreased to 17.9% (p = 0.014; n = 56). Through a logistic regression, it was found that the use of innovative technologies reduces the chance of PIVC contamination by 79% (odds ratio (OR): 0.21; 95% confidence interval (CI): 0.05-0.98; p = 0.046). Meanwhile, PIVC-related complications and fluid therapy emerged as predictors for PIVC contamination. Findings suggest that the adoption of these innovative devices in nurses' practice contributes to the significant reduction of PIVC contamination.

Structural characterization of human Vaccinia-Related Kinases (VRK) bound to small-molecule inhibitors identifies different P-loop conformations.

The human genome encodes two active Vaccinia-related protein kinases (VRK), VRK1 and VRK2. These proteins have been implicated in a number of cellular processes and linked to a variety of tumors. However, understanding the cellular role of VRKs and establishing their potential use as targets for therapeutic intervention has been limited by the lack of tool compounds that can specifically modulate the activity of these kinases in cells. Here we identified BI-D1870, a dihydropteridine inhibitor of RSK kinases, as a promising starting point for the development of chemical probes targeting the active VRKs. We solved co-crystal structures of both VRK1 and VRK2 bound to BI-D1870 and of VRK1 bound to two broad-spectrum inhibitors. These structures revealed that both VRKs can adopt a P-loop folded conformation, which is stabilized by different mechanisms on each protein. Based on these structures, we suggest modifications to the dihydropteridine scaffold that can be explored to produce potent and specific inhibitors towards VRK1 and VRK2.

Hospital microbial surface colonization revealed during monitoring of Klebsiella spp., Pseudomonas aeruginosa, and non-tuberculous mycobacteria.

Hospital environmental conditions, human occupancy, and the characteristics of the equipment influence the survival of microbial communities and raise a concern with regard to nosocomial infections. The objective of the present work was to use the monitoring of Pseudomonas aeruginosa, Klebsiella spp. and non-tuberculous mycobacteria as a strategy to improve knowledge on microbial colonization of non-critical equipment and surfaces, in a tertiary hospital from Central Portugal. A 3-month microbiological survey was performed in a district teaching hospital. A total of 173 samples were obtained from the wards Hematology, Urology, Medicine, and Renal Transplants, and 102 presumptive strains recovered. Per sampling, Pseudomonas Isolation agar showed 42.8 to 73.3% of presumptive P. aeruginosa colonies and MacConkey agar recovered mostly Staphylococcus. Most of the colonies recovered in Middlebrook 7H10-PANTA belonged to the genus Methylobacterium. Taps and WC shower curtains carry high bacterial species diversity. The Redundancy Analysis grouped the samples in those mostly handled by patients, and those mostly handled by healthcare staff or of mixed use. This study shows that the preferential users of the space and equipment seem to be important contributors to the microbial community. The most recovered genus was Methylobacterium, known as colonizer of the water distribution system therefore, it is possible that the water points and biofilms in taps also contribute as dispersion hotspots.

The multicomponent Hantzsch reaction: comprehensive mass spectrometry monitoring using charge-tagged reagents.

A novel strategy for the ESI-MS monitoring of reaction solutions involving the alternate use of permanently charge-tagged reagents has been used for comprehensive mass spectrometry monitoring of the multicomponent Hantzsch 1,4-dihydropyridine reaction. By placing a charge tag on either, or both, of the two key reactants, ion suppression effects for ESI were eliminated or minimized, and comprehensive detection of charge-tagged intermediates was achieved. The strategy allowed the trapping and characterization of the important intermediates in the mechanism for 1,4-dihydropyridine formation.