521 research outputs found

    Study of protein-macrocycle Interactions for lessons in drug design

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    Macrocycles (MCs) have become an increasing area of interest for drug design efforts, especially for classically “difficult” targets like protein-protein interactions (PPIs). And although there are many examples of successful MC drugs derived from natural products, there is little information about the characteristics of compounds with effective pharmacological and physicochemical properties. In this dissertation, I describe the development of design guidelines for new MC drugs based on a representative set of known inhibitor MCs and their target proteins. Analysis of both the individual MC structures and their interactions in the protein complex resulted in identification of several structural and physicochemical features likely to promote favorable binding and bioavailability. Additionally, investigation of the binding sites on the proteins suggest that MCs can bind targets conventionally considered “non-druggable,” strengthening the argument for exploring MC compounds to increase the druggable target space. Furthermore, this work includes the application of the proposed design guidelines to the development of synthetic MC libraries for a PPI target, the NEMO/IKKβ complex

    How proteins bind macrocycles

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    The potential utility of synthetic macrocycles (MCs) as drugs, particularly against low-druggability targets such as protein-protein interactions, has been widely discussed. There is little information, however, to guide the design of MCs for good target protein-binding activity or bioavailability. To address this knowledge gap, we analyze the binding modes of a representative set of MC-protein complexes. The results, combined with consideration of the physicochemical properties of approved macrocyclic drugs, allow us to propose specific guidelines for the design of synthetic MC libraries with structural and physicochemical features likely to favor strong binding to protein targets as well as good bioavailability. We additionally provide evidence that large, natural product-derived MCs can bind targets that are not druggable by conventional, drug-like compounds, supporting the notion that natural product-inspired synthetic MCs can expand the number of proteins that are druggable by synthetic small molecules.R01 GM094551 - NIGMS NIH HHS; GM064700 - NIGMS NIH HHS; GM094551 - NIGMS NIH HHS; R01 GM064700 - NIGMS NIH HHS; GM094551-01S1 - NIGMS NIH HH

    Do pharmaceuticals in the environment pose a risk to wildlife?

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    DATA AVAILABILITY : The present study is a review, we have extensively referenced our sources. Data, associated metadata, and calculation tools are available from the corresponding author ([email protected]).The vast majority of knowledge related to the question “To what extent do pharmaceuticals in the environment pose a risk to wildlife?” stems from the Asian vulture crisis (>99% decline of some species of Old World vultures on the Indian subcontinent related to the veterinary use of the nonsteroidal anti-inflammatory drug [NSAID] diclofenac). The hazard of diclofenac and other NSAIDs (carprofen, flunixin, ketoprofen, nimesulide, phenylbutazone) to vultures and other avian species has since been demonstrated; indeed, only meloxicam and tolfenamic acid have been found to be vulture-safe. Since diclofenac was approved for veterinary use in Spain and Italy in 2013 (home to ~95% of vultures in Europe), the risk of NSAIDs to vultures in these countries has become one of the principal concerns related to pharmaceuticals and wildlife. Many of the other bodies of work on pharmaceutical exposure, hazard and risk to wildlife also relate to adverse effects in birds (e.g., poisoning of scavenging birds in North America and Europe from animal carcasses containing pentobarbital, secondary and even tertiary poisoning of birds exposed to pesticides used in veterinary medicine as cattle dips, migratory birds as a vector for the transfer of antimicrobial and antifungal resistance). Although there is some research related to endocrine disruption in reptiles and potential exposure of aerial insectivores, there remain numerous knowledge gaps for risk posed by pharmaceuticals to amphibians, reptiles, and mammals. Developing noninvasive sampling techniques and new approach methodologies (e.g., genomic, in vitro, in silico, in ovo) is important if we are to bridge the current knowledge gaps without extensive vertebrate testing. Environ Toxicol Chem 2023;00:1–16. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.The Contaminant Biology Program of the US Geological Survey Ecosystems Mission Area.https://setac.onlinelibrary.wiley.com/journal/15528618Paraclinical Science

    Do pharmaceuticals in the environment pose a risk to wildlife?

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    The vast majority of knowledge related to the question of, “To what extent do pharmaceuticals in the environment pose a risk to wildlife?”, stems from the Asian vulture crisis (>99% decline of some species of old-world vultures on the Indian subcontinent related to the veterinary use of the non-steroidal anti-inflammatory drug (NSAID) diclofenac). The hazard of diclofenac and other NSAIDs (carprofen, flunixin, ketoprofen, nimesulide, phenylbutazone) to vultures and other avian species has since been demonstrated; indeed only meloxicam and tolfenamic acid have been found to be vulture-safe. Since diclofenac was approved for veterinary use in Spain and Italy in 2013 (home to ~95% of vultures in Europe), the risk of NSAIDs to vultures in these countries has become one of the principal concerns related to pharmaceuticals and wildlife. Many of the other bodies of work on pharmaceutical exposure, hazard and risk to wildlife also relate to adverse effects in birds, (e.g., poisoning of scavenging birds in North America and Europe from animal carcasses containing pentobarbital; secondary and even tertiary poisoning of birds exposed to pesticides used in veterinary medicine as cattle dips; migratory birds as a vector for the transfer of antimicrobial and antifungal resistance). While there is some research related to endocrine disruption in reptiles and potential exposure of aerial insectivores, there remain numerous knowledge gaps for risk posed by pharmaceuticals to amphibians, reptiles and mammals. Developing non-invasive sampling techniques and new approach methodologies (e.g., genomic, in vitro, in silico, in ovo) are important if we are to bridge the current knowledge gaps without extensive vertebrate testing

    El cansancio emocional y la influencia del miedo percibido en la intenci?n de rotaci?n: el impacto moderador de la comunicaci?n inspiradora en los trabajadores de primera l?nea de empresas del sector comercial minorista en el contexto del Covid-19

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    El modelo propuesto en esta investigaci?n presenta una relaci?n entre las variables de cansancio emocional y el miedo al Covid-19 con la intenci?n de rotaci?n, y su efecto ante la moderaci?n de la comunicaci?n inspiradora, presentando las variables independientes y dependiente como amenazas, y la moderadora como un recurso, bajo los principios y corolarios de la Teor?a de Conservaci?n de Recursos (Hobfoll, 1989). La presente tesis es una investigaci?n no experimental, de tipo descriptivo, que ha evaluado la relaci?n entre las variables a trav?s de la regresi?n lineal de modelos estad?sticos. Esta investigaci?n es de tipo cuantitativa y se ha ejecutado a trav?s de cuestionarios estructurados a una muestra no probabil?stica de 310 personas en empresas del sector comercial minorista, que laboran en la primera l?nea de venta, quienes mantienen contacto directo y diario con clientes en sus actividades

    Common Variants of TLR1 Associate with Organ Dysfunction and Sustained Pro-Inflammatory Responses during Sepsis

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    Background: Toll-like receptors (TLRs) are critical components for host pathogen recognition and variants in genes participating in this response influence susceptibility to infections. Recently, TLR1 gene polymorphisms have been found correlated with whole blood hyper-inflammatory responses to pathogen-associated molecules and associated with sepsis-associated multiorgan dysfunction and acute lung injury (ALI). We examined the association of common variants of TLR1 gene with sepsis-derived complications in an independent study and with serum levels for four inflammatory biomarker among septic patients. Methodology/Principal Findings: Seven tagging single nucleotide polymorphisms of the TLR1 gene were genotyped in samples from a prospective multicenter case-only study of patients with severe sepsis admitted into a network of intensive care units followed for disease severity. Interleukin (IL)-1 b, IL-6, IL-10, and C-reactive protein (CRP) serum levels were measured at study entry, at 48 h and at 7th day. Alleles -7202G and 248Ser, and the 248Ser-602Ile haplotype were associated with circulatory dysfunction among severe septic patients (0.001<=p <= 0.022), and with reduced IL-10 (0.012<= p <=0.047) and elevated CRP (0.011<= p <=0.036) serum levels during the first week of sepsis development. Additionally, the -7202GG genotype was found to be associated with hospital mortality (p =0.017) and ALI (p =0.050) in a combined analysis with European Americans, suggesting common risk effects among studies Conclusions/Significance: These results partially replicate and extend previous findings, supporting that variants of TLR1 gene are determinants of severe complications during sepsis

    Increasing access to institutional deliveries using demand and supply side incentives: early results from a quasi-experimental study

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    <p>Abstract</p> <p>Background</p> <p>Geographical inaccessibility, lack of transport, and financial burdens are some of the demand side constraints to maternal health services in Uganda, while supply side problems include poor quality services related to unmotivated health workers and inadequate supplies. Most public health interventions in Uganda have addressed only selected supply side issues, and universities have focused their efforts on providing maternal services at tertiary hospitals. To demonstrate how reforms at Makerere University College of Health Sciences (MakCHS) can lead to making systemic changes that can improve maternal health services, a demand and supply side strategy was developed by working with local communities and national stakeholders.</p> <p>Methods</p> <p>This quasi-experimental trial is conducted in two districts in Eastern Uganda. The supply side component includes health worker refresher training and additions of minimal drugs and supplies, whereas the demand side component involves vouchers given to pregnant women for motorcycle transport and the payment to service providers for antenatal, delivery, and postnatal care. The trial is ongoing, but early analysis from routine health information systems on the number of services used is presented.</p> <p>Results</p> <p>Motorcyclists in the community organized themselves to accept vouchers in exchange for transport for antenatal care, deliveries and postnatal care, and have become actively involved in ensuring that women obtain care. Increases in antenatal, delivery, and postnatal care were demonstrated, with the number of safe deliveries in the intervention area immediately jumping from <200 deliveries/month to over 500 deliveries/month in the intervention arm. Voucher revenues have been used to obtain needed supplies to improve quality and to pay health workers, ensuring their availability at a time when workloads are increasing.</p> <p>Conclusions</p> <p>Transport and service vouchers appear to be a viable strategy for rapidly increasing maternal care. MakCHS can design strategies together with stakeholders using a learning-by-doing approach to take advantage of community resources.</p

    INTERGROWTH-21st Project international INTER-NDA standards for child development at 2 years of age: an international prospective population-based study.

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    OBJECTIVES: To describe the construction of the international INTERGROWTH-21st Neurodevelopment Assessment (INTER-NDA) standards for child development at 2 years by reporting the cognitive, language, motor and behaviour outcomes in optimally healthy and nourished children in the INTERGROWTH-21st Project. DESIGN: Population-based cohort study, the INTERGROWTH-21st Project. SETTING: Brazil, India, Italy, Kenya and the UK. PARTICIPANTS: 1181 children prospectively recruited from early fetal life according to the prescriptive WHO approach, and confirmed to be at low risk of adverse perinatal and postnatal outcomes. PRIMARY MEASURES: Scaled INTER-NDA domain scores for cognition, language, fine and gross motor skills and behaviour; vision outcomes measured on the Cardiff tests; attentional problems and emotional reactivity measured on the respective subscales of the preschool Child Behaviour Checklist; and the age of acquisition of the WHO gross motor milestones. RESULTS: Scaled INTER-NDA domain scores are presented as centiles, which were constructed according to the prescriptive WHO approach and excluded children born preterm and those with significant postnatal/neurological morbidity. For all domains, except negative behaviour, higher scores reflect better outcomes and the threshold for normality was defined as ≥10th centile. For the INTER-NDA's cognitive, fine motor, gross motor, language and positive behaviour domains these are ≥38.5, ≥25.7, ≥51.7, ≥17.8 and ≥51.4, respectively. The threshold for normality for the INTER-NDA's negative behaviour domain is ≤50.0, that is, ≤90th centile. At 22-30 months of age, the cohort overlapped with the WHO motor milestone centiles, showed low postnatal morbidity (<10%), and vision outcomes, attentional problems and emotional reactivity scores within the respective normative ranges. CONCLUSIONS: From this large, healthy and well-nourished, international cohort, we have constructed, using the WHO prescriptive methodology, international INTER-NDA standards for child development at 2 years of age. Standards, rather than references, are recommended for population-level screening and the identification of children at risk of adverse outcomes

    The Appearance and Modulation of Osteocyte Marker Expression during Calcification of Vascular Smooth Muscle Cells

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    Vascular calcification is an indicator of elevated cardiovascular risk. Vascular smooth muscle cells (VSMCs), the predominant cell type involved in medial vascular calcification, can undergo phenotypic transition to both osteoblastic and chondrocytic cells within a calcifying environment.In the present study, using in vitro VSMC calcification studies in conjunction with ex vivo analyses of a mouse model of medial calcification, we show that vascular calcification is also associated with the expression of osteocyte phenotype markers. As controls, the terminal differentiation of murine calvarial osteoblasts into osteocytes was induced in vitro in the presence of calcifying medium (containing ß-glycerophosphate and ascorbic acid), as determined by increased expression of the osteocyte markers DMP-1, E11 and sclerostin. Culture of murine aortic VSMCs under identical conditions confirmed that the calcification of these cells can also be induced in similar calcifying medium. Calcified VSMCs had increased alkaline phosphatase activity and PiT-1 expression, which are recognized markers of vascular calcification. Expression of DMP-1, E11 and sclerostin was up-regulated during VSMC calcification in vitro. Increased protein expression of E11, an early osteocyte marker, and sclerostin, expressed by more mature osteocytes was also observed in the calcified media of Enpp1(-/-) mouse aortic tissue.This study has demonstrated the up-regulation of key osteocytic molecules during the vascular calcification process. A fuller understanding of the functional role of osteocyte formation and specifically sclerostin and E11 expression in the vascular calcification process may identify novel potential therapeutic strategies for clinical intervention
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