Cross-Linked Poly-4-Acrylomorpholine: A Flexible and Reversibly Compressible Aligning Gel for Anisotropic NMR Analysis of Peptides and Small Molecules in Water.

Determination of the solution conformation of both small organic molecules and peptides in water remains a substantial hurdle in using NMR solution conformations to guide drug design due to the lack of easy to use alignment media. Herein we report the design of a flexible compressible chemically cross-linked poly-4-acrylomorpholine gel that can be used for the alignment of both small molecules and cyclic peptides in water. To test the new gel, residual dipolar couplings (RDCs) and J-coupling constants were used in the configurational analysis of strychnine hydrochloride, a molecule that has been studied extensively in organic solvents as well as a small cyclic peptide that is known to form an α-helix in water. The conformational ensembles for each molecule with the best fit to the data are reported. Identification of minor conformers in water that cannot easily be determined by conventional NOE measurements will facilitate the use of RDC experiments in structure-based drug design.

Chronic exposure to arsenite enhances influenza virus infection in cultured cells.

Arsenic is a ubiquitous environmental toxicant that has been associated with human respiratory diseases. In humans, arsenic exposure has been associated with increased risk of respiratory infection. Considering the existing epidemiological evidence and the well-established impact of arsenic on epithelial cell biology, we posited that the effect of arsenic exposure in epithelial cells could enhance viral infection. In this study, we characterized influenza virus A/WSN/33 (H1N1) infection in Madin-Darby Canine Kidney (MDCK) cells chronically exposed to low levels of sodium arsenite (75 ppb). We observed a 27.3-fold increase in viral matrix (M2) protein (24 hours postinfection [p.i.]), a 1.35-fold increase in viral mRNA levels, and a 126% increase in plaque area in arsenite-exposed MDCK cells (48 hours p.i.). Arsenite exposure resulted in 114% increase in virus attachment-positive cells (2 hours p.i.) and 224% increase in α-2,3 sialic acid-positive cells. Interestingly, chronic exposure to arsenite reduced the effect of the antiviral drug, oseltamivir in MDCK cells. We also found that exposure to sodium arsenite resulted in a 4.4-fold increase in viral mRNA levels and significantly increased cytotoxicity in influenza A/Udorn/72 (H3N2) infected BEAS-2B cells. This study suggests that chronic arsenite exposure could result in enhanced influenza infection in epithelial cells, and that this may be mediated through increased sialic acid binding. Finally, the decreased effectiveness of the anti-influenza drug, oseltamivir, in arsenite-exposed cells raises substantial public health concerns if this effect translates to arsenic-exposed, influenza-infected people.

Proprioceptive neuromuscular facilitation increases alpha absolute power in the dorsolateral prefrontal cortex and superior parietal cortex.

The physiotherapist's clinical practice includes proprioceptive neuromuscular facilitation (PNF), which is a treatment concept that accelerates the response of neuromuscular mechanisms through spiral and diagonal movements. The adaptations that occur in the nervous system following PNF are still poorly described in the literature. Thus, this study had a goal to investigate the electrophysiological changes in the fronto-parietal circuit during PNF and movement in sagittal and diagonal patterns. This study included 30 female participants, who were divided into three groups (control, PNF, and flexion groups). Electroencephalogram measurements were determined before and after tasks were performed by each group. For the statistical analysis, a two-way ANOVA was performed for the factors group and time. Interactions between the two factors were investigated using a one-way ANOVA. A value of p < 0.004 was considered significant. The results showed an increase in alpha absolute power in the left dorsolateral prefrontal cortex and upper left parietal cortex of the PNF group, suggesting these areas work together to execute a motor action. The PNF group showed a greater alpha absolute power compared with the other groups, indicating a specific cortical demand for planning and attention, reinforcing its use for the rehabilitation of individuals.

Transcription inactivation through local refolding of the RNA polymerase structure.

Structural studies of antibiotics not only provide a shortcut to medicine allowing for rational structure-based drug design, but may also capture snapshots of dynamic intermediates that become 'frozen' after inhibitor binding. Myxopyronin inhibits bacterial RNA polymerase (RNAP) by an unknown mechanism. Here we report the structure of dMyx--a desmethyl derivative of myxopyronin B--complexed with a Thermus thermophilus RNAP holoenzyme. The antibiotic binds to a pocket deep inside the RNAP clamp head domain, which interacts with the DNA template in the transcription bubble. Notably, binding of dMyx stabilizes refolding of the beta'-subunit switch-2 segment, resulting in a configuration that might indirectly compromise binding to, or directly clash with, the melted template DNA strand. Consistently, footprinting data show that the antibiotic binding does not prevent nucleation of the promoter DNA melting but instead blocks its propagation towards the active site. Myxopyronins are thus, to our knowledge, a first structurally characterized class of antibiotics that target formation of the pre-catalytic transcription initiation complex-the decisive step in gene expression control. Notably, mutations designed in switch-2 mimic the dMyx effects on promoter complexes in the absence of antibiotic. Overall, our results indicate a plausible mechanism of the dMyx action and a stepwise pathway of open complex formation in which core enzyme mediates the final stage of DNA melting near the transcription start site, and that switch-2 might act as a molecular checkpoint for DNA loading in response to regulatory signals or antibiotics. The universally conserved switch-2 may have the same role in all multisubunit RNAPs.

Stereoselective synthesis of spiropiperidines as BACE-1 aspartyl protease inhibitors via late stage N-arylation of a 1,8-diazaspiro[4.5]dec-3-en-2-one pharmacophore.

A stereoselective synthesis of spiropiperidine compounds, exemplified by compound 1, was developed, which was based upon the late stage N-arylation of a 1,8-diazaspiro[4.5]dec-3-en-2-one pharmacophore. Previously, compound 1 was prepared in low overall yield from piperidinone 2 via the Strecker reaction. A new route was developed, which employed the stereospecific Corey-Link reaction of an enantiomerically pure trichloromethylcarbinol to give a template compound amenable to late stage N-arylation.

Early Clinical Development of Lufotrelvir as a Potential Therapy for COVID-19.

Lufotrelvir was designed as a first in class 3CL protease inhibitor to treat COVID-19. Development of lufotrelvir was challenged by its relatively poor stability due to its propensity to epimerize and degrade. Key elements of process development included improvement of the supply routes to the indole and lactam fragments, a Claisen addition to homologate the lactam, and a subsequent phosphorylation reaction to prepare the prodrug as well as identification of a DMSO solvated form of lufotrelvir to enable long-term storage. As a new approach to preparing the indole fragment, a Cu-catalyzed C-O coupling using oxalamide ligands was demonstrated. The control of process-related impurities was essential to accommodate the parenteral formulation. Isolation of an MEK solvate followed by the DMSO solvate ensured that all impurities were controlled appropriately.

One-pot in situ formation and reaction of trimethyl(trichloromethyl)silane: application to the synthesis of 2,2,2-trichloromethylcarbinols.

2,2,2-Trichloromethylcarbinols are 1 are valuable synthetic intermediates with a multitude of uses. A scalable procedure for the synthesis of TMS-protected-2,2,2-trichloromethylcarbinols and 2,2,2-trichloromethylcarbinols 1 was developed that employs the in situ generation and reaction of trimethyl(trichloromethyl)silane (CCl(3)-TMS). The procedure avoids the exposure of the carbonyl compounds to the strongly basic conditions typically used for this transformation and also avoids isolation of the difficult-to-handle CCl(3)-TMS. This procedure was applied to diastereoselective trichloromethyl additions to 2-substituted 4-piperidinones and to reactions with a variety of structurally diverse aldehydes and ketones.

Design and synthesis of dihydrobenzofuran amides as orally bioavailable, centrally active γ-secretase modulators.

We report the discovery and optimization of a novel series of dihydrobenzofuran amides as γ-secretase modulators (GSMs). Strategies for aligning in vitro potency with drug-like physicochemical properties and good microsomal stability while avoiding P-gp mediated efflux are discussed. Lead compounds such as 35 and 43 have moderate to good in vitro potency and excellent selectivity against Notch. Good oral bioavailability was achieved as well as robust brain Aß42 lowering activity at 100 mg/kg po dose.

Development of a Double Allylboration Reagent Targeting 1,5-syn-(E)-Diols: Application to the Synthesis of the C(23)-C(40) Fragment of Tetrafibricin.

Interest in the synthesis of the C(23)-C(40) fragment 2 of tetrafibricin prompted us to develop a new method for the synthesis of 1,5-syn-(E)-diols. Toward this end, the kinetically controlled hydroboration of allenes 6, 33, ent-39, 42 and 45 with the Soderquist borane 25R were studied. Tetrabutylammonium allenyltrifluoroborate 45 gave superior results and was utilized in a double allylboration sequence with two different aldehydes to provide the targeted 1,5-syn-(E)-diols in generally high yields (72-98%), and with high enantioselectivity (>95% e.e.), diastereoselectivity (d.r. >20:1), and (E)/(Z) selectivity (>20:1). This new method was applied to the synthesis of the C(23)-C(40) fragment 2 of tetrafibricin.

Stereoselective synthesis of gamma-substituted (Z)-allylic boranes via kinetically controlled hydroboration of allenes with 10-TMS-9-borabicyclo[3.3.2]decane.

Kinetically controlled hydroboration of allenes 8 and 14a-d with the readily accessible Soderquist borane 7, which is generated in situ from borohydride 6, constitutes a convenient and preparatively useful method for synthesis of (Z)-gamma-(substituted)allylboranes 9 and 15a-d. These allylboranes undergo highly diastereo- (> or = 90: 10) and enantioselective (typically 89-96% e.e.) allylboration reactions with representative aldehydes to give syn-beta-functionalized homoallylic alcohols.

Process-Oriented Feedback through Process Mining for Surgical Procedures in Medical Training: The Ultrasound-Guided Central Venous Catheter Placement Case.

Developing high levels of competence in the execution of surgical procedures through training is a key factor for obtaining good clinical results in healthcare. To improve the effectiveness of the training, it is advisable to provide feedback to each student tailored to how the student has performed the procedure on each occasion. Current state-of-the-art feedback is based on Checklists and Global Rating Scales, which indicate whether all process steps have been carried out and the quality of each execution step. However, there is a process perspective that is not captured successfully by these instruments, e.g., steps performed, but in an undesired order, group of activities that are repeated an unnecessary number of times, or an excessive transition time between two consecutive steps. In this research, we propose a novel use of process mining techniques to effectively identify desired and undesired process patterns regarding rework, the order in which activities are performed, and time performance, in order to complement the tailored feedback for surgical procedures using a process perspective. The proposed approach was applied to analyze a real case of ultrasound-guided Central Venous Catheter placement training. It was quantitatively and qualitatively validated that the students who participated in the training program perceived the process-oriented feedback they received as favorable for their learning.

Synthesis of macrocyclic trypanosomal cysteine protease inhibitors.

The importance of cysteine proteases in parasites, compounded with the lack of redundancy compared to their mammalian hosts makes proteases attractive targets for the development of new therapeutic agents. The binding mode of K11002 to cruzain, the major cysteine protease of Trypanosoma cruzi was used in the design of conformationally constrained inhibitors. Vinyl sulfone-containing macrocycles were synthesized via olefin ring-closing metathesis and evaluated against cruzain and the closely related cysteine protease, rhodesain.

Stereoselective synthesis of the C(1)-C(19) fragment of tetrafibricin.

[reaction: see text] A stereoselective synthesis of the C(1)-C(19) fragment of tetrafibricin has been accomplished via a highly diastereoselective double allylboration reaction of 6-8 and an iodonium ion promoted urethane cyclization for the installation of the C(15) alkoxy function in 3.

Enantio- and diastereoselective synthesis of syn-beta-hydroxyallylsilanes via a chiral (Z)-gamma-silylallylboronate.

syn-beta-Hydroxyallylsilanes of general structure 11 and 28 are prepared in 50-86% yield and 91-95% ee (for aliphatic aldehydes; 50% ee for benzaldehyde) via the BF(3).Et(2)O-promoted gamma-silylallylboration reactions, using reagents 14 and 15.

Syntheses of novel myxopyronin B analogs as potential inhibitors of bacterial RNA polymerase.

Based upon observations from our initial findings, additional myxopyronin B analogs have been prepared and tested for in vitro inhibitory activity against DNA-dependent RNA polymerase and antibacterial activity against Escherichia coli and Staphylococcus aureus.

Investigation of alpha band of the electroencephalogram before and after a task of proprioceptive neuromuscular facilitation.

The proprioceptive neuromuscular facilitation (PNF) sets up a feature of treatment developed with the objective to facilitate and improve the motor performance. The aim of this study was to investigate in healthy female individuals the effects of electrophysiological of a diagonal of the PNF upper limb. The sample consisted of 30 female participants aged between 18 to 28 years, randomly divided into 3 groups (G1, G2, and G3). The three groups had 2 moments of electroencephalographic signal detection, before and after the task. The statistical neurophysiological design allowed the analysis of the relative power of alpha band in three leads (Fz, F7, and F8). Thus, a three-way mixed factorial analysis of variance (ANOVA) was performed to investigate the factor inter subjects (groups) and intrasubjects (areas and moments), a two-way ANOVA to investigate the interactions between the three factors, and a one-way ANOVA to analyze separately the factors time and area. A P≤0.05 was considered as significance level. The results showed significant increase of alpha band in the three groups analyzed, being more evident to the G2 group. Therefore, the PNF can be considered favorable also in relation to the cortical behavior, reinforcing its use in rehabilitation processes, especially in the clinical practice of physiotherapy.

Discovery of a series of efficient, centrally efficacious BACE1 inhibitors through structure-based drug design.

The identification of centrally efficacious ß-secretase (BACE1) inhibitors for the treatment of Alzheimer's disease (AD) has historically been thwarted by an inability to maintain alignment of potency, brain availability, and desired absorption, distribution, metabolism, and excretion (ADME) properties. In this paper, we describe a series of truncated, fused thioamidines that are efficiently selective in garnering BACE1 activity without simultaneously inhibiting the closely related cathepsin D or negatively impacting brain penetration and ADME alignment, as exemplified by 36. Upon oral administration, these inhibitors exhibit robust brain availability and are efficacious in lowering central Amyloid ß (Aß) levels in mouse and dog. In addition, chronic treatment in aged PS1/APP mice effects a decrease in the number and size of Aß-derived plaques. Most importantly, evaluation of 36 in a 2-week exploratory toxicology study revealed no accumulation of autofluorescent material in retinal pigment epithelium or histology findings in the eye, issues observed with earlier BACE1 inhibitors.

Utilizing structures of CYP2D6 and BACE1 complexes to reduce risk of drug-drug interactions with a novel series of centrally efficacious BACE1 inhibitors.

In recent years, the first generation of ß-secretase (BACE1) inhibitors advanced into clinical development for the treatment of Alzheimer's disease (AD). However, the alignment of drug-like properties and selectivity remains a major challenge. Herein, we describe the discovery of a novel class of potent, low clearance, CNS penetrant BACE1 inhibitors represented by thioamidine 5. Further profiling suggested that a high fraction of the metabolism (>95%) was due to CYP2D6, increasing the potential risk for victim-based drug-drug interactions (DDI) and variable exposure in the clinic due to the polymorphic nature of this enzyme. To guide future design, we solved crystal structures of CYP2D6 complexes with substrate 5 and its corresponding metabolic product pyrazole 6, which provided insight into the binding mode and movements between substrate/inhibitor complexes. Guided by the BACE1 and CYP2D6 crystal structures, we designed and synthesized analogues with reduced risk for DDI, central efficacy, and improved hERG therapeutic margins.

Sesquiterpenes from Omphalotus illudens.

Three sesquiterpenes, illudosone hemiacetal (1a), isoomphadione (2) and illudiolone (3) were isolated from the liquid culture extract of Omphalotus illudens. Their structures were elucidated by spectroscopic techniques as well as by X-ray crystallographic analysis.

Manejo de la patología Biliar en Hospital Militar Central, en los meses de julio - septiembre 2020, durante pandemia Sars-Cov2 / Management of Biliary pathology in the Central Military Hospital, in the months of July - September 2020, during the Sars-Cov2 pandemic

La patología biliar es de los dolores abdominales más frecuentemente atendido en el Hospital Militar Central, la mayoría ya conocidos desde la consulta externa con plan quirúrgico de manera electiva. Sin embargo, hay casos en los que es necesario realizar procedimiento quirúrgico, colecistectomía abierta o por videolaparoscopia, o colecistostomia, de acuerdo a la patología y comórbidos que presenta el paciente. Es por ello que debido a la alta prevalencia de esta enfermedad. Aun durante periodo de pandemia por Sars-Cov2, siempre se mantuvo la consulta de cuadros por patología biliar en unidad de emergencia, poniendo en discusión el manejo que se brindaría a dichos pacientes, según los protocolos que se contaban durante dicho periodo, por lo que se busca explicar manejo y evolución de los pacientes ya sea sospechosos o positivos a Sars-Cov2, tanto como los que no tenían patología sugestiva a Sars-Cov2 con patología biliar durante ese periodo.