PEG: The Magic Bullet for Biophysical Analysis of Highly Aggregating Small Molecules in Aqueous Solutions

Biophysical research plays a crucial role in drug discovery, but many druglike molecules are poorly soluble and prone to aggregation, making their analysis challenging and susceptible to artifacts. To address this issue, we propose an approach that uses poly(ethylene glycol) (PEG) as an excipient in aqueous buffers to reduce the propensity of small molecules to aggregate. We show how PEG allows us to measure the thermodynamics of a complex formed by a heterobifunctional Small Molecule (hSM) that brings two proteins together. Our model accounts for all of the equilibrium states of the small molecule in solution, resulting in more precise parameters for describing how the proteins and the ligand interact. These precise parameters are important for designing better lead molecules.

Implementation of Tele-Critical Care at General Leonard Wood Army Community Hospital

INTRODUCTION

Tele-Intensive Care Unit (tele-ICU) is care provided to critically ill patients by remote clinicians using audio, and video communications and network resources to access real-time patient information from physiologic monitors and the electronic medical record. Tele-ICU has been demonstrated in civilian healthcare to reduce mortality, improve care quality and safety, decrease intensive care unit (ICU) length of stay (LOS) and ventilator days, and save money. General Leonard Wood Army Community Hospital (GLWACH) is a small medical treatment facility with limited resources with respect to subspecialists and ancillary services.

MATERIALS AND METHODS

In 2012, GLWACH identified the lack of board-certified critical care physicians and limited baseline critical care capabilities as gaps that reduced surgical opportunities, challenged critical skill sustainment, exposed potential patient safety issues, and resulted in costly patient transfers to network hospitals. To address these gaps, GLWACH partnered with the Baptist Health Tele-ICU Service, located in Little Rock, AR, to provide Tele-ICU services to its four-bed intensive care unit. Video Teleconsultation (VTC) equipment was installed in the ICU as was a vendor specific solution for accessing real-time patient vital signs and an "emergency" button. The emergency button functioned by turning on the VTC equipment and calling the Tele-ICU center in Little Rock immediately when pushed. To assess impact, hospital and ICU volume, acuity, case mix index, purchased care costs were monitored before and after implementation of the system. Additionally, a Safety Attitudes Questionnaire (SAQ) was administered before and after implementation.

RESULTS

The implementation of the tele-ICU program at GLWACH increased hospital and ICU patient volume, surgical patient volume, and patient complexity. Purchased care costs declined by 30% in the year following implementation and return on investment was $233,311 (19%). All measurements of the SAQ improved following implementation.

CONCLUSIONS

These findings support the implementation of tele-ICU in the MHS as a cost-effective method to sustain readiness amongst critical care clinicians and improve safety culture in MHS hospitals.

Discovery of N-(1-Acryloylazetidin-3-yl)-2-(1H-indol-1-yl)acetamides as Covalent Inhibitors of KRASG12C

KRAS regulates many cellular processes including proliferation, survival, and differentiation. Point mutants of KRAS have long been known to be molecular drivers of cancer. KRAS p.G12C, which occurs in approximately 14% of lung adenocarcinomas, 3-5% of colorectal cancers, and low levels in other solid tumors, represents an attractive therapeutic target for covalent inhibitors. Herein, we disclose the discovery of a class of novel, potent, and selective covalent inhibitors of KRAS^G12C identified through a custom library synthesis and screening platform called Chemotype Evolution and structure-based design. Identification of a hidden surface groove bordered by H95/Y96/Q99 side chains was key to the optimization of this class of molecules. Best-in-series exemplars exhibit a rapid covalent reaction with cysteine 12 of GDP-KRAS^G12C with submicromolar inhibition of downstream signaling in a KRAS^G12C-specific manner.

Real-time PCR improves detection of Trichomonas vaginalis infection compared with culture using self-collected vaginal swabs

OBJECTIVE: To compare a real-time polymerase chain reaction (PCR) assay with broth culture for the detection of Trichomonas vaginalis using self-collected vaginal swabs. METHODS: Self-collected vaginal swabs were obtained from adolescent and young adult African-American women participating in HIV-1 prevention programs. T. vaginalis culture was performed using the InPouch TV System. Samples for the real-time PCR assay were collected using the BDProbeTec ET Culturette Direct Dry Swab system and tested in a laboratory-developed assay which targeted a repeated sequence of the genome. Discrepant samples that were culture negative and positive in the real-time PCR assay were tested in a confirmatory PCR which targeted a different region of the T. vaginalis genome, the18S ribosomal DNA gene. RESULTS: Of the 524 specimens tested by both culture and real-time PCR, 36 were culture positive and 54 were positive in the real-time PCR assay; 16 of the 18 discrepant specimens were also positive in the confirmatory PCR assay. Using a modified gold standard of positive by culture or positive in both PCR assays, the sensitivity of the real-time PCR assay was 100% and the specificity was 99.6%, whereas culture had a sensitivity of 69.2% and a specificity of 100%. CONCLUSIONS: The real-time PCR assay was sensitive and specific for the detection of T. vaginalis DNA from self-collected vaginal swab specimens. The ability to use the BDProbeTec dry swab system for the real-time PCR testing allowed for the detection of Chlamydia trachomatis, Neisseria gonorrhoeae, and T. vaginalis from a single specimen.

Human immunodeficiency virus in plasma and cervicovaginal secretions in Filipino women

This study examined 30 HIV-infected women in Manila to assess the relationship between cervicovaginal and plasma HIV-1 viral load. An interview and gynaecologic examination was conducted and cervicovaginal lavage (CVL) and venous blood specimens were collected. HIV-1 RNA was detected in plasma samples of 24 patients (80%) and in CVL samples of 18 women (60%); 16 patients (53%) had detectable levels in both. CVL HIV-1 RNA was detectable in 75% of women (6/8) with plasma viral loads between 10,000 and 100,000 copies/mL and in 77% of women (10/13) with plasma viral loads higher than 100,000 copies/mL (P =0.0086). Among women with CD4 cell counts of less than 200, 200-500, and greater than 500/mm(3), CVL HIV-1 RNA was detected in 73%, 69%, and 17% of women, respectively (P =0.1428). HIV-1 RNA shedding in the genital tract was significantly associated with plasma viral load.

Generation and maintenance of tandemly repeated extrachromosomal plasmid DNA in Chlamydomonas chloroplasts

Unusual chloroplast transformants of Chlamydomonas reinhardtii that contain 2000 copies of a mutant version of the chloroplast atpB gene, maintained as an extrachromosomal tandem repeat, have recently been described. In this paper studies have been undertaken to (i) address possible mechanisms for generating and maintaining the amplified DNA and (ii) determine whether it is possible to use chloroplast gene amplification to overexpress chloroplast or foreign genes. Data presented here indicate that high copy number transformants harbor characteristic rearrangements in both copies of the chloroplast genome large inverted repeat. These rearrangements appear to be a consequence of, or required for, maintenance of the amplified DNA. In an attempt to mimic the apparently autonomous replication of extrachromosomal DNA in the chloroplast, transformation was carried out with a plasmid that lacked homology with the chloroplast genome or with the same plasmid carrying a putative chloroplast DNA replication origin (oriA). Transformants were recovered only with the plasmid containing oriA, and all transformants contained an integrated plasmid copy at oriA, suggesting that establishment or maintenance of the extrachromosomal tandem repeat requires conditions that were not replicated in this experiment. To determine whether other genes could be maintained at high copy number in the chloroplast, plasmids carrying the wild-type atpB gene or the bacterial aadA gene were introduced into a high copy number transformant. Surprisingly, the copy number of the plasmid tandem repeat declined rapidly after the secondary transformation events, even when strong selective pressure for the introduced gene was applied. Thus, chloroplast transformation can either create or destabilize high copy number tandem repeats.

Cross-protection among feline caliciviruses

Each of five groups of specific-pathogen-free and conventionally reared cats was infected with a different strain of feline calicivirus. Two of the strains were pathogenic, producing characteristically fever, depression, loss of appetite, buccal ulceration, and occasionally increased ocular and nasal secretion. Two of the other strains were midly pathogenic and associated with fever or buccal ulceration or both; the fifth strain was nonpathogenic. The two pathogenic strains plus three others shown also to be pathogenic were used 3 months after the initial infection to challenge the cats in rearranged groupings. Of the 28 conventional cats challenged six (21.4%) showed at least a febrile response, although none of the 30 specific-pathogen-free cats showed any clinical signs. After challenge, virus was recovered from throat swabs of 37 or the 58 cats (63.8%) including the six which showed symptoms, but the duration of the excretion of virus was significantly less than that seen with the initial infection. The homologous and heterotypic antibody responses correlated well with the clinical protection, or lack of it, seen on challenge. The results provide further evidence for significant cross-relationships between feline caliciviruses.