ide A minor population of macrophage-tropic HIV-1 variants is identified in recrudescing viremia following analytic treatment interruption [Microbiology] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 HIV-1 persists in cellular reservoirs that can reignite viremia if antiretroviral therapy (ART) is interrupted. Therefore, insight into the nature of those reservoirs may be revealed from the composition of recrudescing viremia following treatment cessation. A minor population of macrophage-tropic (M-tropic) viruses was identified in a library of recombinant viruses... Full Article
ide Triptolide suppresses IDH1-mutated malignancy via Nrf2-driven glutathione metabolism [Medical Sciences] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Isocitrate dehydrogenase (IDH) mutation is a common genetic abnormality in human malignancies characterized by remarkable metabolic reprogramming. Our present study demonstrated that IDH1-mutated cells showed elevated levels of reactive oxygen species and higher demands on Nrf2-guided glutathione de novo synthesis. Our findings showed that triptolide, a diterpenoid epoxide from Tripterygium... Full Article
ide Development of a therapeutic anti-HtrA1 antibody and the identification of DKK3 as a pharmacodynamic biomarker in geographic atrophy [Medical Sciences] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Genetic polymorphisms in the region of the trimeric serine hydrolase high-temperature requirement 1 (HTRA1) are associated with increased risk of age-related macular degeneration (AMD) and disease progression, but the precise biological function of HtrA1 in the eye and its contribution to disease etiologies remain undefined. In this study, we have... Full Article
ide A genome-wide association study identifies key modulators of complement factor H binding to malondialdehyde-epitopes [Immunology and Inflammation] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 Genetic variants within complement factor H (CFH), a major alternative complement pathway regulator, are associated with the development of age-related macular degeneration (AMD) and other complementopathies. This is explained with the reduced binding of CFH or its splice variant factor H-like protein 1 (FHL-1) to self-ligands or altered self-ligands (e.g.,... Full Article
ide Molecular and isotopic evidence for milk, meat, and plants in prehistoric eastern African herder food systems [Anthropology] By www.pnas.org Published On :: 2020-05-05T10:31:24-07:00 The development of pastoralism transformed human diets and societies in grasslands worldwide. The long-term success of cattle herding in Africa has been sustained by dynamic food systems, consumption of a broad range of primary and secondary livestock products, and the evolution of lactase persistence (LP), which allows digestion of lactose... Full Article
ide Correction for Dietz et al., "2019 Novel Coronavirus (COVID-19) Pandemic: Built Environment Considerations To Reduce Transmission" By msystems.asm.org Published On :: 2020-05-05T07:30:12-07:00 Full Article
ide Isolation and Characterization of the Novel Phage JD032 and Global Transcriptomic Response during JD032 Infection of Clostridioides difficile Ribotype 078 By msystems.asm.org Published On :: 2020-05-05T07:30:12-07:00 ABSTRACT Insights into the interaction between phages and their bacterial hosts are crucial for the development of phage therapy. However, only one study has investigated global gene expression of Clostridioides (formerly Clostridium) difficile carrying prophage, and transcriptional reprogramming during lytic infection has not been studied. Here, we presented the isolation, propagation, and characterization of a newly discovered 35,109-bp phage, JD032, and investigated the global transcriptomes of both JD032 and C. difficile ribotype 078 (RT078) strain TW11 during JD032 infection. Transcriptome sequencing (RNA-seq) revealed the progressive replacement of bacterial host mRNA with phage transcripts. The expressed genes of JD032 were clustered into early, middle, and late temporal categories that were functionally similar. Specifically, a gene (JD032_orf016) involved in the lysis-lysogeny decision was identified as an early expression gene. Only 17.7% (668/3,781) of the host genes were differentially expressed, and more genes were downregulated than upregulated. The expression of genes involved in host macromolecular synthesis (DNA/RNA/proteins) was altered by JD032 at the level of transcription. In particular, the expression of the ropA operon was downregulated. Most noteworthy is that the gene expression of some antiphage systems, including CRISPR-Cas, restriction-modification, and toxin-antitoxin systems, was suppressed by JD032 during infection. In addition, bacterial sporulation, adhesion, and virulence factor genes were significantly downregulated. This study provides the first description of the interaction between anaerobic spore-forming bacteria and phages during lytic infection and highlights new aspects of C. difficile phage-host interactions. IMPORTANCE C. difficile is one of the most clinically significant intestinal pathogens. Although phages have been shown to effectively control C. difficile infection, the host responses to phage predation have not been fully studied. In this study, we reported the isolation and characterization of a new phage, JD032, and analyzed the global transcriptomic changes in the hypervirulent RT078 C. difficile strain, TW11, during phage JD032 infection. We found that bacterial host mRNA was progressively replaced with phage transcripts, three temporal categories of JD032 gene expression, the extensive interplay between phage-bacterium, antiphage-like responses of the host and phage evasion, and decreased expression of sporulation- and virulence-related genes of the host after phage infection. These findings confirmed the complexity of interactions between C. difficile and phages and suggest that phages undergoing a lytic cycle may also cause different phenotypes in hosts, similar to prophages, which may inspire phage therapy for the control of C. difficile. Full Article
ide Re: Primary Care Practices Implementation of Patient-Team Partnership: Findings from EvidenceNOW Southwest By www.jabfm.org Published On :: 2020-03-16T09:31:37-07:00 Full Article
ide Cervical Spondylotic Myelopathy: A Guide to Diagnosis and Management By www.jabfm.org Published On :: 2020-03-16T09:31:37-07:00 Cervical spondylotic myelopathy (CSM) is a neurologic condition that develops insidiously over time as degenerative changes of the spine result in compression of the cord and nearby structures. It is the most common form of spinal cord injury in adults; yet, its diagnosis is often delayed. The purpose of this article is to review the pathophysiology, natural history, diagnosis, and management of CSM with a focus on the recommended timeline for physicians suspecting CSM to refer patients to a spine surgeon. Various processes underlie spondylotic changes of the canal and are separated into static and dynamic factors. Not all patients with evidence of cord compression will present with symptoms, and the progression of disease varies by patient. The hallmark symptoms of CSM include decreased hand dexterity and gait instability as well as sensory and motor dysfunction. magnetic resonance imaging is the imaging modality of choice in patients with suspected CSM, but computed tomography myelography may be used in patients with contraindications. Patients with mild CSM may be treated surgically or nonoperatively, whereas those with moderate-severe disease are treated operatively. Due to the long-term disability that may result from a delay in diagnosis and management, prompt referral to a spine surgeon is recommended for any patient suspected of having CSM. This review provides information and guidelines for practitioners to develop an actionable awareness of CSM. Full Article
ide Direct-to-Consumer Prescription Drug Advertising and Patient-Provider Interactions By www.jabfm.org Published On :: 2020-03-16T09:31:37-07:00 Background: Direct-to-consumer prescription drug advertising is prevalent and affects patient care. Previous research that examined its effect on the patient-provider relationship predates many changes in the advertising and medical landscape that have occurred in the last decade, such as the rise in online promotion and the push for value-based medicine. Methods: We conducted a nationally representative mail-push-to-web survey of 1744 US adults in 2017 to explore how patients view the effects of direct-to-consumer prescription drug advertising on patient-provider interactions. Results: Most respondents (76%) said they were likely to ask a health care provider about advertised drugs; 26% said they had already done so. Among the 26% of respondents who talked to a health care provider about a specific prescription drug they saw advertised, 16% said they received a prescription for the advertised drug. Few respondents (5%) reported that advertising had caused conflict with a health care provider, 16% said it had caused them to question their provider’s advice, and 23% said they were likely to look for a different provider if their provider refused to prescribe a requested brand name drug. Discussion: These results suggest that direct-to-consumer advertising is driving some patients to discuss specific products with their health care providers but that most patients do not believe advertising has a negative influence on the patient-provider interaction itself. Full Article
ide Factors Influencing Uptake of Changes to Clinical Preventive Guidelines By www.jabfm.org Published On :: 2020-03-16T09:31:37-07:00 Background: Despite widespread recognition that adherence to clinical preventive guidelines improves patient outcomes, clinicians struggle to implement guideline changes in a timely manner. Multiple factors influence guideline adoption and effective implementation. However, few studies evaluate their collective and inter-related effects. This qualitative study provides a comprehensive picture of the interplay between multiple factors on uptake of new or changed preventive guidelines. Methods: Semistructured interviews conducted in 2018 with a diverse sample of clinicians and practice leaders sought to understand patient, clinician, practice, health system, environment, and guideline factors of influence. An immersion-crystallization approach was used to identify emergent themes. Results: Interviewees expressed motivation to adhere to guidelines but also valued sharing decisions with patients. Personal biases and fears affected both clinician and patient guideline adoption. Practices facilitated implementation through workflow optimization and encouraging a culture of evidence-based practice while a key health system function was to maintain electronic health record alerts. More traditional environmental factors, such as insurance coverage or transportation, were less of a barrier to guideline adoption and implementation than the influence of media and specialists. Various specific guideline characteristics also affected ease of adoption and implementation. Different settings expressed greater health system, practice, or clinician-centric approaches to guideline implementation. Conclusions: Guideline uptake is influenced by a complex interplay of multiple levels of factors including the patient, clinician, practice, health system, environment, and guideline levels. Comprehensively understanding all levels of influence for each specific clinical setting may help to determine the optimal intervention(s) for improving uptake of evidence-based guidelines. Full Article
ide Modifying Provider Vitamin D Screening Behavior in Primary Care By www.jabfm.org Published On :: 2020-03-16T09:31:37-07:00 Purpose: Clinical evidence shows minimal benefit to vitamin D screening and subsequent treatment in the general population. This study aims to assess the effectiveness of 2 light-touch interventions on reducing vitamin D test orders. Methods: The outcomes were weekly average vitamin D rates, computed from adult primary care encounters (preventive or nonpreventive) with a family medicine (FM) or internal medicine (IM) provider from June 14, 2018 through December 12, 2018. We conducted an interrupted time series analysis and estimated the cost impact of the interventions. The interventions consisted of an educational memo (August 9, 2018) distributed to providers and removal of the vitamin D test (FM: August 15, 2018; IM: October 17, 2018) from the providers’ quick order screen in the electronic health record. Change in order rates were analyzed among physicians (MDs and DOs), physician assistants (PAs), and nurse practitioners (NPs). Results: There were 587,506 primary care encounters (FM = 367,947; IM = 219,559). Vitamin D order rates decreased from 6.9% (FM = 5.1%; IM = 9.9%) to 5.2% (FM = 4% [P < .01], IM = 7.9% [P < .01]). For FM, the vitamin D test order rate continued to fall at a 0.08% per week rate after the interventions (end of study: 2.73%). The education intervention showed a relative decrease in each provider type (FM-physician = 16% [P < .01], FM-PA = 47% [P < .01], FM-NP = 20% [P = .01], IM-physician = 14% [P = .02], IM-PA = 52% [P < .01], IM-NP = 34% [P = .04]). Annualized savings was approximately 1 million dollars. Conclusions: Emailed evidence-based provider education may be an effective tool for modifying providers’ vitamin D test ordering behavior. The lack of the effectiveness of the vitamin D test removal from the quick order screen found for IM highlights the challenges facing simple electronic health record interventions when multiple alternate ordering pathways exist. Full Article
ide Eliminating Patient Identified Barriers to Decrease Medicaid Inpatient Admission Rates and Improve Quality of Care By www.jabfm.org Published On :: 2020-03-16T09:31:37-07:00 Background and Objectives: The goal of this study was to decrease admission and readmission rate for the 2296 Medicaid patients in our clinic. Our focus was to eliminate patient identified barriers to care that led to decreased quality of care. The identified barriers for our clinic included distance to care, poor same-day access, communication, and fragmented care. A team-based, collaborative approach using members from all aspects of patient care. Methods: An initial survey identified which barriers to care our patients felt obstructed their care. With this data, along with a national literature review, our team used biweekly quality team meetings with LEAN methodology and Plan-Do-Study-Act cycles to create a 4-phase quality improvement project. A home-visit program to decrease distance to care, walk-in clinic to improve same-day access, strengthened collaboration with outside care managers and clinic staff to improve communication, and the introduction of an in-house phlebotomist to improve fragmented care were created and studied between June 2015 and December 2018. Admission rate, avoidable readmission rate, as well as other quality of care measurements were assessed with electronic medical record reports and through North Carolina Medicaid data reports. Results: Overall Medicaid admissions decreased 32.7% from starting numbers, 40.2% below expected benchmarks. Avoidable readmissions decreased 41.8%, 53.8% below the expected benchmark. Improvements in same-day access numbers and lab completion rate were also seen. Discussion: The team-based approach to eliminating patient-identified barriers decreased both admissions and avoidable readmissions for our Medicaid patients. It also improved quality-of-care measures. This approach has been shown to be beneficial at our clinic and can easily be replicated in other settings. Full Article
ide Successful Health Care Provider Strategies to Overcome Psychological Insulin Resistance in United States and Canada By www.jabfm.org Published On :: 2020-03-16T09:31:37-07:00 Purpose: To identify specific actions and characteristics of health care providers (HCPs) in the United States and Canada that influenced patients with type 2 diabetes who were initially reluctant to begin insulin. Methods: Patients from the United States (n = 120) and Canada (n = 74) were recruited via registry, announcements, and physician referrals to complete a 30-minute online survey based on interviews with patients and providers regarding specific HCP actions that contributed to the decision to begin insulin. Results: The most helpful HCP actions were patient-centered approaches to improve patients’ understanding of the injection process (ie, "My HCP walked me through the whole process of exactly how to take insulin" [helped moderately or a lot, United States: 79%; Canada: 83%]) and alleviate concerns ("My HCP encouraged me to contact his/her office immediately if I ran into any problems or had questions after starting insulin" [United States: 76%; Canada: 82%]). Actions that were the least helpful included referrals to other sources (ie, "HCP referred patient to a class to help learn more about insulin" [United States: 40%; Canada: 58%]). Conclusions: The study provides valuable insight that HCPs can use to help patients overcome psychological insulin resistance, which is a critical step in the design of effective intervention protocols. Full Article
ide Despite Adequate Training, Only Half of Family Physicians Provide Womens Health Care Services By www.jabfm.org Published On :: 2020-03-16T09:31:37-07:00 Access to services related to reproductive and sexual health is critical to the health of women but has been threatened in recent years. Family physicians are trained to provide a range of women’s health care services and are an essential part of the health care workforce in rural and underserved areas, where access to these services may be limited. Full Article
ide Svalbard ptarmigans don't prioritise fighting infection in winter [INSIDE JEB] By jeb.biologists.org Published On :: 2020-04-27T15:00:22-07:00 Kathryn Knight Full Article
ide Drosophila larval glue sticks to anything [INSIDE JEB] By jeb.biologists.org Published On :: 2020-04-23T02:38:05-07:00 Kathryn Knight Full Article
ide Forest protects Heliconius butterflies from climate extremes [INSIDE JEB] By jeb.biologists.org Published On :: 2020-04-16T05:35:47-07:00 Kathryn Knight Full Article
ide Consequences of being phenotypically mismatched with the environment: no evidence of oxidative stress in cold- and warm-acclimated birds facing a cold spell [RESEARCH ARTICLE] By jeb.biologists.org Published On :: 2020-04-14T02:37:46-07:00 Ana Gabriela Jimenez, Emily Cornelius Ruhs, Kailey J. Tobin, Katie N. Anderson, Audrey Le Pogam, Lyette Regimbald, and Francois Vezina Seasonal changes in maximal thermogenic capacity (Msum) in wild black-capped chickadees suggests that adjustments in metabolic performance are slow and begin to take place before winter peaks. However, when mean minimal ambient temperature (Ta) reaches –10°C, the chickadee phenotype appears to provide enough spare capacity to endure days with colder Ta, down to –20°C or below. This suggests that birds could also maintain a higher antioxidant capacity as part of their cold-acclimated phenotype to deal with sudden decreases in temperature. Here, we tested how environmental mismatch affected oxidative stress by comparing cold-acclimated (–5°C) and transition (20°C) phenotypes in chickadees exposed to an acute 15°C drop in temperature with that of control individuals. We measured superoxide dismutase, catalase and glutathione peroxidase activities, as well as lipid peroxidation damage and antioxidant scavenging capacity in pectoralis muscle, brain, intestine and liver. We generally found differences between seasonal phenotypes and across tissues, but no differences with respect to an acute cold drop treatment. Our data suggest oxidative stress is closely matched to whole-animal physiology in cold-acclimated birds compared with transition birds, implying that changes to the oxidative stress system happen slowly. Full Article
ide Fish embryo vulnerability to combined acidification and warming coincides with low capacity for homeostatic regulation [RESEARCH ARTICLE] By jeb.biologists.org Published On :: 2020-05-05T05:22:41-07:00 Flemming Dahlke, Magnus Lucassen, Ulf Bickmeyer, Sylke Wohlrab, Velmurugu Puvanendran, Atle Mortensen, Melissa Chierici, Hans-Otto Pörtner, and Daniela StorchThe vulnerability of fish embryos and larvae to environmental factors is often attributed to a lack of adult-like organ systems (gills) and thus insufficient homeostatic capacity. However, experimental data supporting this hypothesis are scarce. Here, by using Atlantic cod (Gadus morhua) as a model, the relationship between embryo vulnerability (to projected ocean acidification and warming) and homeostatic capacity was explored through parallel analyses of stage-specific mortality and in vitro activity and expression of major ion pumps (ATP-Synthase, Na+/K+-ATPase, H+-ATPase) and co-transporters (NBC1, NKCC1). Immunolocalization of these transporters was used to study ionocyte morphology in newly-hatched larvae. Treatment-related embryo mortality until hatch (+20% due to acidification and warming) occurred primarily during an early period (gastrulation) characterized by extremely low ion transport capacities. Thereafter, embryo mortality decreased in parallel with an exponential increase in activity and expression of all investigated ion transporters. Significant changes in transporter activity and expression in response to acidification (+15% activity) and warming (-30% expression) indicate some potential for short-term acclimatization, although likely associated with energetic trade-offs. Interestingly, whole-larvae enzyme capacities (supported by abundant epidermal ionocytes) reached levels similar to those previously measured in gill tissue of adult cod, suggesting that early-life stages without functional gills are better equipped in terms of ion homeostasis than previously thought. This study implies that the gastrulation period represents a critical transition from inherited (maternal) defenses to active homeostatic regulation, which facilitates enhanced resilience of later stages to environmental factors. Full Article
ide Characterization of Antineovascularization Activity and Ocular Pharmacokinetics of Phosphoinositide 3-Kinase/Mammalian Target of Rapamycin Inhibitor GNE-947 [Articles] By dmd.aspetjournals.org Published On :: 2020-04-21T21:06:36-07:00 The objectives of the present study were to characterize GNE-947 for its phosphoinositide 3-kinase (PI3K) and mammalian target of rapamycin (mTOR) inhibitory activities, in vitro anti–cell migration activity in human umbilical vein endothelial cells (HUVECs), in vivo antineovascularization activity in laser-induced rat choroidal neovascular (CNV) eyes, pharmacokinetics in rabbit plasma and eyes, and ocular distribution using matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS) and autoradioluminography. Its PI3K and mTOR Ki were 0.0005 and 0.045 µM, respectively, and its HUVEC IC50 was 0.093 µM. GNE-947 prevented neovascularization in the rat CNV model at 50 or 100 µg per eye with repeat dosing. After a single intravenous injection at 2.5 and 500 μg/kg in rabbits, its plasma terminal half-lives (t1/2) were 9.11 and 9.59 hours, respectively. After a single intravitreal injection of a solution at 2.5 μg per eye in rabbits, its apparent t1/2 values were 14.4, 16.3, and 23.2 hours in the plasma, vitreous humor, and aqueous humor, respectively. After a single intravitreal injection of a suspension at 33.5, 100, 200 μg per eye in rabbits, the t1/2 were 29, 74, and 219 days in the plasma and 46, 143, and 191 days in the eyes, respectively. MALDI-IMS and autoradioluminography images show that GNE-947 did not homogenously distribute in the vitreous humor and aggregated at the injection sites after injection of the suspension, which was responsible for the long t1/2 of the suspension because of the slow dissolution process. This hypothesis was supported by pharmacokinetic modeling analyses. In conclusion, the PI3K/mTOR inhibitor GNE-947 prevented neovascularization in a rat CNV model, with t1/2 up to approximately 6 months after a single intravitreal injection of the suspension in rabbit eyes. SIGNIFICANCE STATEMENT GNE-947 is a potent phosphoinositide 3-kinase/mammalian target of rapamycin inhibitor and exhibits anti–choroidal neovascular activity in rat eyes. The duration of GNE-947 in the rabbit eyes after intravitreal injection in a solution is short, with a half-life (t1/2) of less than a day. However, the duration after intravitreal dose of a suspension is long, with t1/2 up to 6 months due to low solubility and slow dissolution. These results indicate that intravitreal injection of a suspension for low-solubility drugs can be used to achieve long-term drug exposure. Full Article
ide Alteration in the Plasma Concentrations of Endogenous Organic Anion-Transporting Polypeptide 1B Biomarkers in Patients with Non-Small Cell Lung Cancer Treated with Paclitaxel [Articles] By dmd.aspetjournals.org Published On :: 2020-04-16T08:31:41-07:00 Paclitaxel has been considered to cause OATP1B-mediated drug-drug interactions at therapeutic doses; however, its clinical relevance has not been demonstrated. This study aimed to elucidate in vivo inhibition potency of paclitaxel against OATP1B1 and OATP1B3 using endogenous OATP1B biomarkers. Paclitaxel is an inhibitor of OATP1B1 and OATP1B3, with Ki of 0.579 ± 0.107 and 5.29 ± 3.87 μM, respectively. Preincubation potentiated its inhibitory effect on both OATP1B1 and OATP1B3, with Ki of 0.154 ± 0.031 and 0.624 ± 0.183 μM, respectively. Ten patients with non–small cell lung cancer who received 200 mg/m2 of paclitaxel by a 3-hour infusion were recruited. Plasma concentrations of 10 endogenous OATP1B biomarkers—namely, coproporphyrin I, coproporphyrin III, glycochenodeoxycholate-3-sulfate, glycochenodeoxycholate-3-glucuronide, glycodeoxycholate-3-sulfate, glycodeoxycholate-3-glucuronide, lithocholate-3-sulfate, glycolithocholate-3-sulfate, taurolithocholate-3-sulfate, and chenodeoxycholate-24-glucuronide—were determined in the patients with non–small cell lung cancer on the day before paclitaxel administration and after the end of paclitaxel infusion for 7 hours. Paclitaxel increased the area under the plasma concentration-time curve (AUC) of the endogenous biomarkers 2- to 4-fold, although a few patients did not show any increment in the AUC ratios of lithocholate-3-sulfate, glycolithocholate-3-sulfate, and taurolithocholate-3-sulfate. Therapeutic doses of paclitaxel for the treatment of non–small cell lung cancer (200 mg/m2) will cause significant OATP1B1 inhibition during and at the end of the infusion. This is the first demonstration that endogenous OATP1B biomarkers could serve as surrogate biomarkers in patients. SIGNIFICANCE STATEMENT Endogenous biomarkers can address practical and ethical issues in elucidating transporter-mediated drug-drug interaction (DDI) risks of anticancer drugs clinically. We could elucidate a significant increment of the plasma concentrations of endogenous OATP1B biomarkers after a 3-hour infusion (200 mg/m2) of paclitaxel, a time-dependent inhibitor of OATP1B, in patients with non–small cell lung cancer. The endogenous OATP1B biomarkers are useful to assess the possibility of OATP1B-mediated DDIs in patients and help in appropriately designing a dosing schedule to avoid the DDIs. Full Article
ide Evaluation of Quantitative Relationship Between Target Expression and Antibody-Drug Conjugate Exposure Inside Cancer Cells [Articles] By dmd.aspetjournals.org Published On :: 2020-04-09T08:02:00-07:00 Antibody-drug conjugates (ADCs) employ overexpressed cell surface antigens to deliver cytotoxic payloads inside cancer cells. However, the relationship between target expression and ADC efficacy remains ambiguous. In this manuscript, we have addressed a part of this ambiguity by quantitatively investigating the effect of antigen expression levels on ADC exposure within cancer cells. Trastuzumab-valine-citrulline-monomethyl auristatin E was used as a model ADC, and four different cell lines with diverse levels of human epidermal growth factor receptor 2 (HER2) expression were used as model cells. The pharmacokinetics (PK) of total trastuzumab, released monomethyl auristatin E (MMAE), and total MMAE were measured inside the cells and in the cell culture media following incubation with two different concentrations of ADC. In addition, target expression levels, target internalization rate, and cathepsin B and MDR1 protein concentrations were determined for each cell line. All the PK data were mathematically characterized using a cell-level systems PK model for ADC. It was found that SKBR-3, MDA-MB-453, MCF-7, and MDA-MB-468 cells had ~800,000, ~250,000, ~50,000, and ~10,000 HER2 receptors per cell, respectively. A strong linear relationship (R2 > 0.9) was observed between HER2 receptor count and released MMAE exposure inside the cancer cells. There was an inverse relationship found between HER2 expression level and internalization rate, and cathepsin B and multidrug resistance protein 1 (MDR1) expression level varied slightly among the cell lines. The PK model was able to simultaneously capture all the PK profiles reasonably well while estimating only two parameters. Our results demonstrate a strong quantitative relationship between antigen expression level and intracellular exposure of ADCs in cancer cells. SIGNIFICANCE STATEMENT In this manuscript, we have demonstrated a strong linear relationship between target expression level and antibody-drug conjugate (ADC) exposure inside cancer cells. We have also shown that this relationship can be accurately captured using the cell-level systems pharmacokinetics model developed for ADCs. Our results indirectly suggest that the lack of relationship between target expression and efficacy of ADC may stem from differences in the pharmacodynamic properties of cancer cells. Full Article
ide The major subunit of widespread competence pili exhibits a novel and conserved type IV pilin fold [Protein Structure and Folding] By www.jbc.org Published On :: 2020-05-08T03:41:14-07:00 Type IV filaments (T4F), which are helical assemblies of type IV pilins, constitute a superfamily of filamentous nanomachines virtually ubiquitous in prokaryotes that mediate a wide variety of functions. The competence (Com) pilus is a widespread T4F, mediating DNA uptake (the first step in natural transformation) in bacteria with one membrane (monoderms), an important mechanism of horizontal gene transfer. Here, we report the results of genomic, phylogenetic, and structural analyses of ComGC, the major pilin subunit of Com pili. By performing a global comparative analysis, we show that Com pili genes are virtually ubiquitous in Bacilli, a major monoderm class of Firmicutes. This also revealed that ComGC displays extensive sequence conservation, defining a monophyletic group among type IV pilins. We further report ComGC solution structures from two naturally competent human pathogens, Streptococcus sanguinis (ComGCSS) and Streptococcus pneumoniae (ComGCSP), revealing that this pilin displays extensive structural conservation. Strikingly, ComGCSS and ComGCSP exhibit a novel type IV pilin fold that is purely helical. Results from homology modeling analyses suggest that the unusual structure of ComGC is compatible with helical filament assembly. Because ComGC displays such a widespread distribution, these results have implications for hundreds of monoderm species. Full Article
ide Genetic lineage tracing with multiple DNA recombinases: A user's guide for conducting more precise cell fate mapping studies [Methods and Resources] By www.jbc.org Published On :: 2020-05-08T03:41:14-07:00 Site-specific recombinases, such as Cre, are a widely used tool for genetic lineage tracing in the fields of developmental biology, neural science, stem cell biology, and regenerative medicine. However, nonspecific cell labeling by some genetic Cre tools remains a technical limitation of this recombination system, which has resulted in data misinterpretation and led to many controversies in the scientific community. In the past decade, to enhance the specificity and precision of genetic targeting, researchers have used two or more orthogonal recombinases simultaneously for labeling cell lineages. Here, we review the history of cell-tracing strategies and then elaborate on the working principle and application of a recently developed dual genetic lineage-tracing approach for cell fate studies. We place an emphasis on discussing the technical strengths and caveats of different methods, with the goal to develop more specific and efficient tracing technologies for cell fate mapping. Our review also provides several examples for how to use different types of DNA recombinase–mediated lineage-tracing strategies to improve the resolution of the cell fate mapping in order to probe and explore cell fate–related biological phenomena in the life sciences. Full Article
ide A neuroglobin-based high-affinity ligand trap reverses carbon monoxide-induced mitochondrial poisoning [Molecular Biophysics] By www.jbc.org Published On :: 2020-05-08T03:41:14-07:00 Carbon monoxide (CO) remains the most common cause of human poisoning. The consequences of CO poisoning include cardiac dysfunction, brain injury, and death. CO causes toxicity by binding to hemoglobin and by inhibiting mitochondrial cytochrome c oxidase (CcO), thereby decreasing oxygen delivery and inhibiting oxidative phosphorylation. We have recently developed a CO antidote based on human neuroglobin (Ngb-H64Q-CCC). This molecule enhances clearance of CO from red blood cells in vitro and in vivo. Herein, we tested whether Ngb-H64Q-CCC can also scavenge CO from CcO and attenuate CO-induced inhibition of mitochondrial respiration. Heart tissue from mice exposed to 3% CO exhibited a 42 ± 19% reduction in tissue respiration rate and a 33 ± 38% reduction in CcO activity compared with unexposed mice. Intravenous infusion of Ngb-H64Q-CCC restored respiration rates to that of control mice correlating with higher electron transport chain CcO activity in Ngb-H64Q-CCC–treated compared with PBS-treated, CO-poisoned mice. Further, using a Clark-type oxygen electrode, we measured isolated rat liver mitochondrial respiration in the presence and absence of saturating solutions of CO (160 μm) and nitric oxide (100 μm). Both CO and NO inhibited respiration, and treatment with Ngb-H64Q-CCC (100 and 50 μm, respectively) significantly reversed this inhibition. These results suggest that Ngb-H64Q-CCC mitigates CO toxicity by scavenging CO from carboxyhemoglobin, improving systemic oxygen delivery and reversing the inhibitory effects of CO on mitochondria. We conclude that Ngb-H64Q-CCC or other CO scavengers demonstrate potential as antidotes that reverse the clinical and molecular effects of CO poisoning. Full Article
ide Reactive dicarbonyl compounds cause Calcitonin Gene-Related Peptide release and synergize with inflammatory conditions in mouse skin and peritoneum [Molecular Bases of Disease] By www.jbc.org Published On :: 2020-05-08T03:41:14-07:00 The plasmas of diabetic or uremic patients and of those receiving peritoneal dialysis treatment have increased levels of the glucose-derived dicarbonyl metabolites like methylglyoxal (MGO), glyoxal (GO), and 3-deoxyglucosone (3-DG). The elevated dicarbonyl levels can contribute to the development of painful neuropathies. Here, we used stimulated immunoreactive Calcitonin Gene–Related Peptide (iCGRP) release as a measure of nociceptor activation, and we found that each dicarbonyl metabolite induces a concentration-, TRPA1-, and Ca2+-dependent iCGRP release. MGO, GO, and 3-DG were about equally potent in the millimolar range. We hypothesized that another dicarbonyl, 3,4-dideoxyglucosone-3-ene (3,4-DGE), which is present in peritoneal dialysis (PD) solutions after heat sterilization, activates nociceptors. We also showed that at body temperatures 3,4-DGE is formed from 3-DG and that concentrations of 3,4-DGE in the micromolar range effectively induced iCGRP release from isolated murine skin. In a novel preparation of the isolated parietal peritoneum PD fluid or 3,4-DGE alone, at concentrations found in PD solutions, stimulated iCGRP release. We also tested whether inflammatory tissue conditions synergize with dicarbonyls to induce iCGRP release from isolated skin. Application of MGO together with bradykinin or prostaglandin E2 resulted in an overadditive effect on iCGRP release, whereas MGO applied at a pH of 5.2 resulted in reduced release, probably due to an MGO-mediated inhibition of transient receptor potential (TRP) V1 receptors. These results indicate that several reactive dicarbonyls activate nociceptors and potentiate inflammatory mediators. Our findings underline the roles of dicarbonyls and TRPA1 receptors in causing pain during diabetes or renal disease. Full Article
ide Recycling of heterogeneous material in the subduction factory: evidence from the sedimentary melange of the Internal Ligurian Units, Italy By jgs.lyellcollection.org Published On :: 2020-05-04T02:10:48-07:00 In the Northern Apennine (Italy), the Internal Ligurian Units consist of Middle–Late Jurassic ophiolites covered by thick sedimentary deposits whose top is represented by the Early Paleocene Bocco Shale. This formation is characterized by mass-transport deposits interlayered with thin-bedded siliciclastic turbidites. The sedimentological and structural features of these mass-transport deposits reveal a long-lived history of recycling of heterogeneous material in a subduction setting. This history started with the frontal accretion of a fragment of oceanic crust into an accretionary prism whose lower slope was subsequently affected by tectonic erosion and consequent instability, leading to the production of mass-transport deposits and the transfer of material to the lower plate. These mass-transport deposits were subsequently underthrust and then again transferred to the base of the accretionary prism by coherent underplating, before their exhumation to the surface. The Bocco Shale is thus representative of a subduction setting where both accretionary and erosive events occurred, depending on changing boundary conditions. The reconstructed history for the Bocco Shale indicates that the sedimentary and gravitational processes both at the prism front and on the prism slope, possibly induced by alternating accretion and erosion events, are the most efficient mechanisms of lithological mixing and recycling in subduction margins. Full Article
ide Weathering history and landscape evolution of Western Ghats (India) from 40Ar/39Ar dating of supergene K-Mn oxides By jgs.lyellcollection.org Published On :: 2020-05-04T02:10:48-07:00 Laterites preserved on both sides of the Western Ghats Escarpment of Peninsular India have formed by long-term lateritic weathering essentially after India–Seychelles continental break-up following Deccan Traps emplacement (c. 63 myr ago). Supergene manganese ores of the Western Ghats were formed on Late Archean manganese protores. Among Mn oxides composing the ores, cryptomelane (K-rich Mn oxide) was characterized and dated by 40Ar/39Ar geochronology. Measured ages complement those previously obtained in other South Indian manganese ores from the hinterland plateau and further document three major weathering periods, c. 53–44, c. 39–22 and c. 14–10 Ma, the last being documented for the first time in India. These periods coincide with global palaeoclimatic proxies and date the lateritic weathering of three successive palaeolandscapes of the Western Ghats that evolved under slow denudation (c. 8 m Ma–1) over the last 44 myr and were mostly incised during the Neogene (<22 Ma). This indicates that the Western Ghats are a relict of a South Indian plateau preserved at the headwaters of very long east-flowing river systems and above the Western Ghats Escarpment. Topography and denudation history of this landscape do not require Neogene tilt of the Peninsula as recently proposed. Supplementary material: Full details of field and sample description, methods and analytical data including electron probe microanalyses of cryptomelane, and isotopic analyses and degassing spectra of irradiated cryptomelane grains are available at https://doi.org/10.6084/m9.figshare.c.4726661 Full Article
ide Identification of Novel Antigens Recognized by Serum Antibodies in Bovine Tuberculosis [Diagnostic Laboratory Immunology] By cvi.asm.org Published On :: 2017-12-05T08:00:30-08:00 Bovine tuberculosis (TB), caused by Mycobacterium bovis, remains an important zoonotic disease posing a serious threat to livestock and wildlife. The current TB tests relying on cell-mediated and humoral immune responses in cattle have performance limitations. To identify new serodiagnostic markers of bovine TB, we screened a panel of 101 recombinant proteins, including 10 polyepitope fusions, by a multiantigen print immunoassay (MAPIA) with well-characterized serum samples serially collected from cattle with experimental or naturally acquired M. bovis infection. A novel set of 12 seroreactive antigens was established. Evaluation of selected proteins in the dual-path platform (DPP) assay showed that the highest diagnostic accuracy (~95%) was achieved with a cocktail of five best-performing antigens, thus demonstrating the potential for development of an improved and more practical serodiagnostic test for bovine TB. Full Article
ide The identification and mitigation of geohazards using shallow airborne engineering geophysics and land-based geophysics for brown- and greenfield road investigations By qjegh.lyellcollection.org Published On :: 2020-05-01T00:46:18-07:00 South Africa is a mineral-rich country with a diverse geology and a long history of mining. The rich history of mining activities includes the extraction of coal from the Ecca Group Sediments of the Karoo Supergroup (250 Ma), gold and uranium from the Witwatersrand Supergroup (2900 Ma), as well as platinum, uranium, tin and lead from the layered Bushveld Igneous Complex (BIC) (2150 Ma). The extraction of gold, copper, tin, lead and rare earth minerals also took place in the Archean rocks of Swazium age (3500–3000 Ma). The historical mining records have either not been accurately recorded or have been lost over time. This has resulted in significant geohazard risk during infrastructure development, especially in and around historical mining towns, such as Johannesburg and Ermelo. These geohazard risks require careful appraisal and quantification prior to any infrastructure design or construction. This case study aims to set out the development aspects of the Multi-Faceted Geophysical Modelling Systems approach, which was used by the South African National Roads Agency SOC Ltd (SANRAL) during an investigation of undermined ground for the historical coal-mining town of Ermelo in South Africa. The N11/N2 ring road was planned to go around Ermelo to ensure mobility between major routes, whilst still maintaining town access. The systems approach used a combination of airborne geophysics (Versatile Time Domain Electromagnetic System (VTEMTM) and magnetics), generally used in mining exploration, land-based and borehole geophysics, borehole water testing, and ground-truthing. The approach was continuous and iterative, building on the data at hand and reducing unnecessary investigations while eliminating the possibility of anomalies being missed, as in the case of conventional discrete drilling. The investigation ensured that 100% of the route was comprehensively investigated with a high confidence in the geological and geophysical data, and concomitant mitigation of infrastructure risk. The Multi-Faceted Geophysical Modelling Systems approach was successfully used to identify a previously unknown 1 x 1 m mining stope cavity at 90 m depth and a 3 x 5 m access tunnel at 24 m depth in a timely and cost-effective manner. Seven reverse-circulation percussion boreholes confirmed the structural integrity of these underground cavities, as well as the structural geology along the centreline. Based on the great success achieved in identifying shallow anomalies, this Multi-Faceted Geophysical Modelling Systems approach is now being considered for field trails on the dolomitic formations and the Wild Coast greenfields road project where there are large historical slumps and many fault lines. Thematic collection: This article is part of the Ground-related risk to transportation infrastructure collection available at https://www.lyellcollection.org/cc/Ground-related-risk-to-transportation-infrastructure Full Article
ide A large palaeo-landslide reactivated by high-speed railway construction works (northern Spain) By qjegh.lyellcollection.org Published On :: 2020-05-01T00:46:18-07:00 The presence of large palaeo-landslides can hinder the construction of railway lines if they cause an alteration of the natural balance of the slope, significantly increasing the cost of the project. During the construction works in a section of the Madrid–Asturias high-speed railway line (Spain), a large-scale hillside instability affected 460 m of the section. The ground movement began 10 months after the start of the excavations and remained active throughout the observation period (2008–2010). Data provided by fieldwork, boreholes and instrumental monitoring have allowed the investigation of the geological units involved, together with the geometry and the kinematics of the mass movement. This landslide involves a Paleozoic basement with an estimated volume of 4 400 000 m3. It shows low displacement rates (<45 mm a–1) and was accommodated on a single surface of rupture, which reaches more than 60 m depth. The kinematics is favoured by structural and lithological conditions, there being a strong rheological contrast in the lower part of the mobilized ground. This movement is linked to a large palaeo-landslide that was partially reactivated when excavations undermined the lower slopes of the hillside. Technical solutions for the stabilization have already caused an additional cost of 17% over the initial budget. Full Article
ide A case study for identification of organic-silt bottom sediments in an artificial lake formed in gravel alluvium in the geotourism locality of Slnecne Jazera in Senec (Bratislava, Slovakia) By qjegh.lyellcollection.org Published On :: 2020-05-01T00:46:18-07:00 This case study aims to identify the cubic capacity and geometry of the geological body of silt–organic sediments in the environment of a former gravel pit situated in a drainless depression of the alluvium of the Čierna voda River. It is located in the well-known geotourism locality of Slnečné Jazera in Senec, in the SW of Slovakia. To identify the body, electrical resistivity tomography was combined with the use of sonar. The research shows that this approach is appropriate for a number of activities that are subjects of engineering-geological investigations. The cubic capacity and geometry of specific aqueous engineering-geological environments must be determined in connection with the need for the management, control, quantification and extraction of selected sedimentary bodies. In addition, the management of sustainable development of reservoirs, sedimentation basins, industrial ponds, settling pits and natural pools for recreation (the subject of the case study) is important to control the limit amounts of sediments in such environments. The results of this study may be applied in analogous engineering-geological conditions. The drainless depression Slnečné Jazera contained a body of silt–organic sediments amounting to 23 000 m3 (41 Olympic-size pools of 25 m x 12.5 m x 1.8 m). The maximum thickness of the bottom sediments was about 6.3 m on the alluvium with an articulated morphology owing to the submerged digging of gravel. The proposed approach improved the control of extraction of the sedimentary body and optimized the engineering-geological conditions in this geotourism locality. Full Article
ide The shear stiffness criterion for rock joints considering rock wear behaviour By qjegh.lyellcollection.org Published On :: 2020-05-01T00:46:18-07:00 Rock is a material that is affected by wear, and the curvature of the asperities on a rock joint surface increases with the degree of wear after shearing. Based on the Greenwood and Williamson (GW) model, a new model considering the change of asperity curvature is proposed to explain the wear behaviour of rock joints. First, the shear stiffness formula for a joint surface is derived when the asperity curvature is constant, which shows that the shear stiffness increases with increase of asperity curvature. According to the Mohr–Coulomb criterion, the yield position of a single asperity under normal force and tangential friction force is discussed. Then, the critical normal force for a single asperity at a specific friction coefficient is obtained, which shows that the normal force corresponds to the curvature radius of the asperity. A rough surface model with multi-level curvature radius is proposed. With increase of normal force, the higher-order asperities gradually fail and the curvature radius become larger. A specific pressure value excites a specific radius of curvature, and the larger the pressure, the larger the radius of curvature. The relation between the normal force and the curvature radius is proposed and a shear stiffness formula considering the change of curvature radius of the asperity is derived. The proposed model is verified on the basis of the published experimental results. The calculation results of the proposed model can reflect the test results well: for a given joint surface, with increase in normal force the joint surface gradually becomes smooth; for different joint surfaces, with increase in roughness, the joint surface is more easily smoothed. Full Article
ide Stability analyses of large waste dumps via 3D numerical modelling considering cracks and earthquake loading: a case study of Zhujiabaobao waste dump By qjegh.lyellcollection.org Published On :: 2020-05-01T00:46:18-07:00 This paper uses a 3D model for stability assessment of Zhujiabaobao waste dump with ground cracks. The study data were gathered via reconnaissance, geomorphological analysis and laboratory experiment. A 3D finite extended element method model that can consider cracks was then used to calculate the factor of safety (FOS) of the waste dump via the strength reduction technique. The simulation shows the dump to have an FOS of 1.22 and both the position and depth of penetration of cracks in the waste dump have a crucial impact on the stability of the slope. Because the study area is located in a seismically active area, simulation and analysis of the dynamic response of the waste dump under different magnitudes of seismic waves (peak acceleration is 0.05, 0.15, 0.25 and 0.45g) were performed via an explicit dynamic model. The simulation shows that high steps in the slope are particularly responsive to earthquakes. The approach used here for analysing stability under static and dynamic loads is useful for hazard prevention and mitigation. Full Article
ide Coseismic and monsoon-triggered landslide impacts on remote trekking infrastructure, Langtang Valley, Nepal By qjegh.lyellcollection.org Published On :: 2020-05-01T00:46:18-07:00 In 2015, the Mw 7.8 Gorkha earthquake struck Nepal, triggering thousands of landslides across the central and eastern Himalayas. These landslides had many adverse effects, including causing widespread damage to low-grade transport routes (e.g. tracks, footpaths) in rural regions that depend on tourism for survival. Langtang Valley is a glacial–periglacial landscape located 60 km north of Kathmandu. It is one of the most popular trekking regions in Nepal and has been severely affected by Gorkha earthquake-triggered and monsoon-triggered landsliding. Here, qualitative and quantitative observations from fieldwork and remote sensing are used to describe the materials and geomorphology of the landslides across Langtang Valley, and to quantify the extent to which coseismic and monsoon-triggered landslides have affected Langtang's trekking infrastructure. The dominant bedrock materials involved within Langtang landslides are found to be a range of gneisses and intruded leucogranites. In total, 64 landslides are found to have intersected trekking paths across Langtang, with coseismic and monsoon-triggered landslides having an impact on c. 3 km and 0.8 km of path respectively. It is observed that the practice of reconstructing paths through unstable landslide deposits is leaving the trekking infrastructure across Langtang increasingly vulnerable to future failure. Full Article
ide Multicenter Evaluation of a PCR-Based Digital Microfluidics and Electrochemical Detection System for the Rapid Identification of 15 Fungal Pathogens Directly from Positive Blood Cultures [Mycology] By jcm.asm.org Published On :: 2020-04-23T08:00:29-07:00 Routine identification of fungal pathogens from positive blood cultures by culture-based methods can be time-consuming, delaying treatment with appropriate antifungal agents. The GenMark Dx ePlex investigational use only blood culture identification fungal pathogen panel (BCID-FP) rapidly detects 15 fungal targets simultaneously in blood culture samples positive for fungi by Gram staining. We aimed to determine the performance of the BCID-FP in a multicenter clinical study. Blood culture samples collected at 10 United States sites and tested with BCID-FP at 4 sites were compared to the standard-of-care microbiological and biochemical techniques, fluorescence in situ hybridization using peptide nucleic acid probes (PNA-FISH) and matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS). Discrepant results were analyzed by bi-directional PCR/sequencing of residual blood culture samples. A total of 866 clinical samples, 120 retrospectively and 21 prospectively collected, along with 725 contrived samples were evaluated. Sensitivity and specificity of detection of Candida species (C. albicans, C. auris, C. dubliniensis, C. famata, C. glabrata, C. guilliermondii, C. kefyr, C. krusei, C. lusitaniae, C. parapsilosis, and C. tropicalis) ranged from 97.1 to 100% and 99.8 to 100%, respectively. For the other organism targets, sensitivity and specificity were as follows: 100% each for Cryptococcus neoformans and C. gattii, 98.6% and 100% for Fusarium spp., and 96.2% and 99.9% for Rhodotorula spp., respectively. In 4 of the 141 clinical samples, the BCID-FP panel correctly identified an additional Candida species, undetected by standard-of-care methods. The BCID-FP panel offers a faster turnaround time for identification of fungal pathogens in positive blood cultures that may allow for earlier antifungal interventions and includes C. auris, a highly multidrug-resistant fungus. Full Article
ide Differentiation of Community-Associated and Livestock-Associated Methicillin-Resistant Staphylococcus aureus Isolates and Identification of spa Types by Use of PCR and High-Resolution Melt Curve Analysis [Clinical Veterinary Microbiology] By jcm.asm.org Published On :: 2020-04-23T08:00:29-07:00 Infections due to methicillin-resistant Staphylococcus aureus (MRSA) are present worldwide and represent a major public health concern. The capability of PCR followed by high-resolution melt (HRM) curve analysis for the detection of community-associated and livestock-associated MRSA strains and the identification of staphylococcal protein A (spa) locus was evaluated in 74 MRSA samples which were isolated from the environment, humans, and pigs on a single piggery. PCR-HRM curve analysis identified four spa types among MRSA samples and differentiated MRSA strains accordingly. A nonsubjective differentiation model was developed according to genetic confidence percentage values produced by tested samples, which did not require visual interpretation of HRM curve results. The test was carried out at different settings, and result data were reanalyzed and confirmed with DNA sequencing. PCR-HRM curve analysis proved to be a robust and reliable test for spa typing and can be used as a tool in epidemiological studies. Full Article
ide Evaluation of ID Fungi Plates Medium for Identification of Molds by MALDI Biotyper [Mycology] By jcm.asm.org Published On :: 2020-04-23T08:00:28-07:00 MALDI-TOF mass spectrometry (MS) identification of pathogenic filamentous fungi is often impaired by difficulties in harvesting hyphae embedded in the medium and long extraction protocols. The ID Fungi Plate (IDFP) is a novel culture method developed to address such difficulties and improve the identification of filamentous fungi by MALDI-TOF MS. We cultured 64 strains and 11 clinical samples on IDFP, Sabouraud agar-chloramphenicol (SAB), and ChromID Candida agar (CAN2). We then compared the three media for growth, ease of harvest, amount of material picked, and MALDI-TOF identification scores after either rapid direct transfer (DT) or a long ethanol-acetonitrile (EA) extraction protocol. Antifungal susceptibility testing and microscopic morphology after subculture on SAB and IDFP were also compared for ten molds. Growth rates and morphological aspects were similar for the three media. With IDFP, harvesting of fungal material for the extraction procedure was rapid and easy in 92.4% of cases, whereas it was tedious on SAB or CAN2 in 65.2% and 80.3% of cases, respectively. The proportion of scores above 1.7 (defined as acceptable identification) were comparable for both extraction protocols using IDFP (P = 0.256). Moreover, rates of acceptable identification after DT performed on IDFP (93.9%) were significantly higher than those obtained after EA extraction with SAB (69.7%) or CAN2 (71.2%) (P = <0.001 and P = 0.001, respectively). Morphological aspects and antifungal susceptibility testing were similar between IDFP and SAB. IDFP is a culture plate that facilitates and improves the identification of filamentous fungi, allowing accurate routine identification of molds with MALDI-TOF-MS using a rapid-extraction protocol. Full Article
ide Evaluation of Cycle Threshold, Toxin Concentration, and Clinical Characteristics of Clostridioides difficile Infection in Patients with Discordant Diagnostic Test Results [Bacteriology] By jcm.asm.org Published On :: 2020-04-23T08:00:28-07:00 Clostridioides difficile infection (CDI) is one of the most common health care-associated infections that can cause significant morbidity and mortality. CDI diagnosis involves laboratory testing in conjunction with clinical assessment. The objective of this study was to assess the performance of various C. difficile tests and to compare clinical characteristics, Xpert C. difficile/Epi (PCR) cycle threshold (CT), and Singulex Clarity C. diff toxins A/B (Clarity) concentrations between groups with discordant test results. Unformed stool specimens from 200 hospitalized adults (100 PCR positive and 100 negative) were tested by cell cytotoxicity neutralization assay (CCNA), C. diff Quik Chek Complete (Quik Chek), Premier Toxins A and B, and Clarity. Clinical data, including CDI severity and CDI risk factors, were compared between discordant test results. Compared to CCNA, PCR had the highest sensitivity at 100% and Quik Chek had the highest specificity at 100%. Among clinical and laboratory data studied, prevalences of leukocytosis, prior antibiotic use, and hospitalizations were consistently higher across all subgroups in comparisons of toxin-positive to toxin-negative patients. Among PCR-positive samples, the median CT was lower in toxin-positive samples than in toxin-negative samples; however, CT ranges overlapped. Among Clarity-positive samples, the quantitative toxin concentration was significantly higher in toxin-positive samples than in toxin-negative samples as determined by CCNA and Quik Chek Toxin A and B. Laboratory tests for CDI vary in sensitivity and specificity. The quantitative toxin concentration may offer value in guiding CDI diagnosis and treatment. The presence of leukocytosis, prior antibiotic use, and previous hospitalizations may assist with CDI diagnosis, while other clinical parameters may not be consistently reliable. Full Article
ide Impact of Changes in Clinical Microbiology Laboratory Location and Ownership on the Practice of Infectious Diseases [Epidemiology] By jcm.asm.org Published On :: 2020-04-23T08:00:28-07:00 The number of onsite clinical microbiology laboratories in hospitals is decreasing, likely related to the business model for laboratory consolidation and labor shortages, and this impacts a variety of clinical practices, including that of banking isolates for clinical or epidemiologic purposes. To determine the impact of these trends, infectious disease (ID) physicians were surveyed regarding their perceptions of offsite services. Clinical microbiology practices for retention of clinical isolates for future use were also determined. Surveys were sent to members of the Infectious Diseases Society of America’s (IDSA) Emerging Infections Network (EIN). The EIN is a sentinel network of ID physicians who care for adult and/or pediatric patients in North America and who are members of IDSA. The response rate was 763 (45%) of 1,680 potential respondents. Five hundred forty (81%) respondents reported interacting with the clinical microbiology laboratory. Eighty-six percent of respondents thought an onsite laboratory very important for timely diagnostic reporting and ongoing communication with the clinical microbiologist. Thirty-five percent practiced in institutions where the core microbiology laboratory has been moved offsite, and an additional 7% (n = 38) reported that movement of core laboratory functions offsite was being considered. The respondents reported that only 24% of laboratories banked all isolates, with the majority saving isolates for less than 30 days. Based on these results, the trend toward centralized core laboratories negatively impacts the practice of ID physicians, potentially delays effective implementation of prompt and targeted care for patients with serious infections, and similarly adversely impacts infection control epidemiologic investigations. Full Article
ide Direct Determination of Pyrazinamide (PZA) Susceptibility by Sputum Microscopic Observation Drug Susceptibility (MODS) Culture at Neutral pH: the MODS-PZA Assay [Mycobacteriology and Aerobic Actinomycetes] By jcm.asm.org Published On :: 2020-04-23T08:00:28-07:00 Pyrazinamide (PZA) is considered the pivot drug in all tuberculosis treatment regimens due to its particular action on the persistent forms of Mycobacterium tuberculosis. However, no drug susceptibility test (DST) is considered sufficiently reliable for routine application. Although molecular tests are endorsed, their application is limited to known PZA resistance associated mutations. Microbiological DSTs for PZA have been restricted by technical limitations, especially the necessity for an acidic pH. Here, for the first time, MODS culture at neutral pH was evaluated using high PZA concentrations (400 and 800 μg/ml) to determine PZA susceptibility directly from sputum samples. Sputum samples were cultured with PZA for up to 21 days at 37°C. Plate reading was performed at two time points: R1 (mean, 10 days) and R2 (mean, 13 days) for each PZA concentration. A consensus reference test, composed of MGIT-PZA, pncA sequencing, and the classic Wayne test, was used. A total of 182 samples were evaluated. The sensitivity and specificity for 400 μg/ml ranged from 76.9 to 89.7 and from 93.0 to 97.9%, respectively, and for 800 μg/ml ranged from 71.8 to 82.1 and from 95.8 to 98.6%, respectively. Compared to MGIT-PZA, our test showed a similar turnaround time (medians of 10 and 12 days for PZA-sensitive and -resistant isolates, respectively). In conclusion, MODS-PZA is presented as a fast, simple, and low-cost DST that could complement the MODS assay to evaluate resistance to the principal first-line antituberculosis drugs. Further optimization of test conditions would be useful in order to increase its performance. Full Article
ide Whats Special about Cefiderocol? A Micro-Comic Strip [Editorial] By jcm.asm.org Published On :: 2020-04-23T08:00:28-07:00 Full Article
ide Fourier Transform Infrared Spectroscopy Is a New Option for Outbreak Investigation: a Retrospective Analysis of an Extended-Spectrum-Beta-Lactamase-Producing Klebsiella pneumoniae Outbreak in a Neonatal Intensive Care Unit [Epidemiology] By jcm.asm.org Published On :: 2020-04-23T08:00:28-07:00 The IR Biotyper is a new automated typing system based on Fourier-transform infrared (FT-IR) spectroscopy that gives results within 4 h. We aimed (i) to use the IR Biotyper to retrospectively analyze an outbreak of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-KP) in a neonatal intensive care unit and to compare results to BOX-PCR and whole-genome sequencing (WGS) results as the gold standard and (ii) to assess how the cutoff values used to define clusters affect the discriminatory power of the IR Biotyper. The sample consisted of 18 isolates from 14 patients. Specimens were analyzed in the IR Biotyper using the default analysis settings, and spectra were analyzed using OPUS 7.5 software. The software contains a feature that automatically proposes a cutoff value to define clusters; the cutoff value defines up to which distance the spectra are considered to be in the same cluster. Based on FT-IR, the outbreak represented 1 dominant clone, 1 secondary clone, and several unrelated clones. FT-IR results, using the cutoff value generated by the accompanying software after 4 replicates, were concordant with WGS for all but 1 isolate. BOX-PCR was underdiscriminatory compared to the other two methods. Using the cutoff value generated after 12 replicates, the results of FT-IR and WGS were completely concordant. The IR Biotyper can achieve the same typeability and discriminatory power as genome-based methods. However, to attain this high performance requires either previous, strain-dependent knowledge about the optimal technical parameters to be used or validation by a second method. Full Article
ide 27-Hydroxycholesterol Impairs Plasma Membrane Lipid Raft Signaling as Evidenced by Inhibition of IL6-JAK-STAT3 Signaling in Prostate Cancer Cells By mcr.aacrjournals.org Published On :: 2020-05-04T05:40:21-07:00 We recently reported that restoring the CYP27A1–27hydroxycholesterol axis had antitumor properties. Thus, we sought to determine the mechanism by which 27HC exerts its anti–prostate cancer effects. As cholesterol is a major component of membrane microdomains known as lipid rafts, which localize receptors and facilitate cellular signaling, we hypothesized 27HC would impair lipid rafts, using the IL6–JAK–STAT3 axis as a model given its prominent role in prostate cancer. As revealed by single molecule imaging of DU145 prostate cancer cells, 27HC treatment significantly reduced detected cholesterol density on the plasma membranes. Further, 27HC treatment of constitutively active STAT3 DU145 prostate cancer cells reduced STAT3 activation and slowed tumor growth in vitro and in vivo. 27HC also blocked IL6-mediated STAT3 phosphorylation in nonconstitutively active STAT3 cells. Mechanistically, 27HC reduced STAT3 homodimerization, nuclear translocation, and decreased STAT3 DNA occupancy at target gene promoters. Combined treatment with 27HC and STAT3 targeting molecules had additive and synergistic effects on proliferation and migration, respectively. Hallmark IL6–JAK–STAT gene signatures positively correlated with CYP27A1 gene expression in a large set of human metastatic castrate-resistant prostate cancers and in an aggressive prostate cancer subtype. This suggests STAT3 activation may be a resistance mechanism for aggressive prostate cancers that retain CYP27A1 expression. In summary, our study establishes a key mechanism by which 27HC inhibits prostate cancer by disrupting lipid rafts and blocking STAT3 activation. Implications: Collectively, these data show that modulation of intracellular cholesterol by 27HC can inhibit IL6–JAK–STAT signaling and may synergize with STAT3-targeted compounds. Full Article
ide Pharmacological Characterization of Apraglutide, a Novel Long-Acting Peptidic Glucagon-Like Peptide-2 Agonist, for the Treatment of Short Bowel Syndrome [Drug Discovery and Translational Medicine] By jpet.aspetjournals.org Published On :: 2020-04-13T13:53:50-07:00 Glucagon-like peptide-2 (GLP-2) agonists have therapeutic potential in clinical indications in which the integrity or absorptive function of the intestinal mucosa is compromised, such as in short bowel syndrome (SBS). Native hGLP-2, a 33–amino acid peptide secreted from the small intestine, contributes to nutritional absorption but has a very short half-life because of enzymatic cleavage and renal clearance and thus is of limited therapeutic value. The GLP-2 analog teduglutide (Revestive/Gattex; Shire Inc.) has been approved for use in SBS since 2012 but has a once-daily injection regimen. Pharmacokinetic (PK) and pharmacodynamic studies confirm that apraglutide, a novel GLP-2 analog, has very low clearance, long elimination half-life, and high plasma protein binding compared with GLP-2 analogs teduglutide and glepaglutide. Apraglutide and teduglutide retain potency and selectivity at the GLP-2 receptor comparable to native hGLP-2, whereas glepaglutide was less potent and less selective. In rat intravenous PK studies, hGLP-2, teduglutide, glepaglutide, and apraglutide had clearances of 25, 9.9, 2.8, and 0.27 ml/kg per minute, respectively, and elimination half-lives of 6.4, 19, 16, and 159 minutes, respectively. The unique PK profile of apraglutide administered via intravenous and subcutaneous routes was confirmed in monkey and minipig and translated into significantly greater in vivo pharmacodynamic activity, measured as small intestinal growth in rats. Apraglutide showed greater intestinotrophic activity than the other peptides when administered at less-frequent dosing intervals because of its prolonged half-life. We postulate that apraglutide offers several advantages over existing GLP-2 analogs and is an excellent candidate for the treatment of gastrointestinal diseases, such as SBS. SIGNIFICANCE STATEMENT Apraglutide is a potent and selective GLP-2 agonist with an extremely low clearance and prolonged elimination half-life, which differentiates it from teduglutide (the only approved GLP-2 agonist). The enhanced pharmacokinetics of apraglutide will benefit patients by enabling a reduced dosing frequency and removing the need for daily injections. Full Article
ide Lidocaine Binding Enhances Inhibition of Nav1.7 Channels by the Sulfonamide PF-05089771 [Articles] By molpharm.aspetjournals.org Published On :: 2020-05-06T13:11:09-07:00 PF-05089771 is an aryl sulfonamide Nav1.7 channel blocker that binds to the inactivated state of Nav1.7 channels with high affinity but binds only weakly to channels in the resting state. Such aryl sulfonamide Nav1.7 channel blockers bind to the extracellular surface of the S1-S4 voltage-sensor segment of homologous Domain 4, whose movement is associated with inactivation. This binding site is different from that of classic sodium channel inhibitors like lidocaine, which also bind with higher affinity to the inactivated state than the resting state but bind at a site within the pore of the channel. The common dependence on gating state with distinct binding sites raises the possibility that inhibition by aryl sulfonamides and by classic local anesthetics might show an interaction mediated by their mutual state dependence. We tested this possibility by examining the state-dependent inhibition by PF-05089771 and lidocaine of human Nav1.7 channels expressed in human embryonic kidney 293 cells. At –80 mV, where a small fraction of channels are in an inactivated state under drug-free conditions, inhibition by PF-05089771 was both enhanced and speeded in the presence of lidocaine. The results suggest that lidocaine binding to the channel enhances PF-05089771 inhibition by altering the equilibrium between resting states (with D4S4 in the inner position) and inactivated states (with D4S4 in the outer position). The gating state–mediated interaction between the compounds illustrates a principle applicable to many state-dependent agents. SIGNIFICANCE STATEMENT The results show that lidocaine enhances the degree and rate of inhibition of Nav1.7 channels by the aryl sulfonamide compound PF-05089771, consistent with state-dependent binding by lidocaine increasing the fraction of channels presenting a high-affinity binding site for PF-05089771 and suggesting that combinations of agents targeted to the pore-region binding site of lidocaine and the external binding site of aryl sulfonamides may have synergistic actions. Full Article
ide LUF7244 plus Dofetilide Rescues Aberrant Kv11.1 Trafficking and Produces Functional IKv11.1 [Articles] By molpharm.aspetjournals.org Published On :: 2020-05-06T13:11:09-07:00 Voltage-gated potassium 11.1 (Kv11.1) channels play a critical role in repolarization of cardiomyocytes during the cardiac action potential (AP). Drug-mediated Kv11.1 blockade results in AP prolongation, which poses an increased risk of sudden cardiac death. Many drugs, like pentamidine, interfere with normal Kv11.1 forward trafficking and thus reduce functional Kv11.1 channel densities. Although class III antiarrhythmics, e.g., dofetilide, rescue congenital and acquired forward trafficking defects, this is of little use because of their simultaneous acute channel blocking effect. We aimed to test the ability of a combination of dofetilide plus LUF7244, a Kv11.1 allosteric modulator/activator, to rescue Kv11.1 trafficking and produce functional Kv11.1 current. LUF7244 treatment by itself did not disturb or rescue wild type (WT) or G601S-Kv11.1 trafficking, as shown by Western blot and immunofluorescence microcopy analysis. Pentamidine-decreased maturation of WT Kv11.1 levels was rescued by 10 μM dofetilide or 10 μM dofetilide + 5 μM LUF7244. In trafficking defective G601S-Kv11.1 cells, dofetilide (10 μM) or dofetilide + LUF7244 (10 + 5 μM) also restored Kv11.1 trafficking, as demonstrated by Western blot and immunofluorescence microscopy. LUF7244 (10 μM) increased IKv11.1 despite the presence of dofetilide (1 μM) in WT Kv11.1 cells. In G601S-expressing cells, long-term treatment (24–48 hour) with LUF7244 (10 μM) and dofetilide (1 μM) increased IKv11.1 compared with nontreated or acutely treated cells. We conclude that dofetilide plus LUF7244 rescues Kv11.1 trafficking and produces functional IKv11.1. Thus, combined administration of LUF7244 and an IKv11.1 trafficking corrector could serve as a new pharmacological therapy of both congenital and drug-induced Kv11.1 trafficking defects. SIGNIFICANCE STATEMENT Decreased levels of functional Kv11.1 potassium channel at the plasma membrane of cardiomyocytes prolongs action potential repolarization, which associates with cardiac arrhythmia. Defective forward trafficking of Kv11.1 channel protein is an important factor in acquired and congenital long QT syndrome. LUF7244 as a negative allosteric modulator/activator in combination with dofetilide corrected both congenital and acquired Kv11.1 trafficking defects, resulting in functional Kv11.1 current. Full Article
ide Encoding, Consolidation, and Renormalization in Depression: Synaptic Homeostasis, Plasticity, and Sleep Integrate Rapid Antidepressant Effects [Review Articles] By pharmrev.aspetjournals.org Published On :: 2020-03-05T08:17:23-08:00 Recent studies have strived to find an association between rapid antidepressant effects and a specific subset of pharmacological targets and molecular pathways. Here, we propose a broader hypothesis of encoding, consolidation, and renormalization in depression (ENCORE-D), which suggests that, fundamentally, rapid and sustained antidepressant effects rely on intrinsic homeostatic mechanisms evoked as a response to the acute pharmacological or physiologic effects triggered by the treatment. We review evidence that supports the notion that various treatments with a rapid onset of action, such as ketamine, electroconvulsive therapy, and sleep deprivation, share the ability to acutely excite cortical networks, which increases synaptic potentiation, alters patterns of functional connectivity, and ameliorates depressive symptoms. We proceed to examine how the initial effects are short-lived and, as such, require both consolidation during wake and maintenance throughout sleep to remain sustained. Here, we incorporate elements from the synaptic homeostasis hypothesis and theorize that the fundamental mechanisms of synaptic plasticity and sleep, particularly the homeostatic emergence of slow-wave electroencephalogram activity and the renormalization of synaptic strength, are at the center of sustained antidepressant effects. We conclude by discussing the various implications of the ENCORE-D hypothesis and offer several considerations for future experimental and clinical research. Significance Statement Proposed molecular perspectives of rapid antidepressant effects fail to appreciate the temporal distribution of the effects of ketamine on cortical excitation and plasticity as well as the prolonged influence on depressive symptoms. The encoding, consolidation, and renormalization in depression hypothesis proposes that the lasting clinical effects can be best explained by adaptive functional and structural alterations in neural circuitries set in motion in response to the acute pharmacological effects of ketamine (i.e., changes evoked during the engagement of receptor targets such as N-methyl-D-aspartate receptors) or other putative rapid-acting antidepressants. The present hypothesis opens a completely new avenue for conceptualizing and targeting brain mechanisms that are important for antidepressant effects wherein sleep and synaptic homeostasis are at the center stage. Full Article
ide Back-Table Fluorescence-Guided Imaging for Circumferential Resection Margin Evaluation Using Bevacizumab-800CW in Patients with Locally Advanced Rectal Cancer By jnm.snmjournals.org Published On :: 2020-05-01T06:31:37-07:00 Negative circumferential resection margins (CRM) are the cornerstone for the curative treatment of locally advanced rectal cancer (LARC). However, in up to 18.6% of patients, tumor-positive resection margins are detected on histopathology. In this proof-of-concept study, we investigated the feasibility of optical molecular imaging as a tool for evaluating the CRM directly after surgical resection to improve tumor-negative CRM rates. Methods: LARC patients treated with neoadjuvant chemoradiotherapy received an intravenous bolus injection of 4.5 mg of bevacizumab-800CW, a fluorescent tracer targeting vascular endothelial growth factor A, 2–3 d before surgery (ClinicalTrials.gov identifier: NCT01972373). First, for evaluation of the CRM status, back-table fluorescence-guided imaging (FGI) of the fresh surgical resection specimens (n = 8) was performed. These results were correlated with histopathology results. Second, for determination of the sensitivity and specificity of bevacizumab-800CW for tumor detection, a mean fluorescence intensity cutoff value was determined from the formalin-fixed tissue slices (n = 42; 17 patients). Local bevacizumab-800CW accumulation was evaluated by fluorescence microscopy. Results: Back-table FGI correctly identified a tumor-positive CRM by high fluorescence intensities in 1 of 2 patients (50%) with a tumor-positive CRM. For the other patient, low fluorescence intensities were shown, although (sub)millimeter tumor deposits were present less than 1 mm from the CRM. FGI correctly identified 5 of 6 tumor-negative CRM (83%). The 1 patient with false-positive findings had a marginal negative CRM of only 1.4 mm. Receiver operating characteristic curve analysis of the fluorescence intensities of formalin-fixed tissue slices yielded an optimal mean fluorescence intensity cutoff value for tumor detection of 5,775 (sensitivity of 96.19% and specificity of 80.39%). Bevacizumab-800CW enabled a clear differentiation between tumor and normal tissue up to a microscopic level, with a tumor-to-background ratio of 4.7 ± 2.5 (mean ± SD). Conclusion: In this proof-of-concept study, we showed the potential of back-table FGI for evaluating the CRM status in LARC patients. Optimization of this technique with adaptation of standard operating procedures could change perioperative decision making with regard to extending resections or applying intraoperative radiation therapy in the case of positive CRM. Full Article