724 research outputs found
A Simple Inner-Stopper Guarded Trephine for Creation of Uniform Keratectomy Wounds in Rodents
Purpose: Creating controllable, reproducible keratectomy wounds in rodent corneas can be a challenge due to their small size, thickness, and the lack of usual tools available for human eyes such as a vacuum trephine. The purpose of this work is to provide a consistent, reproducible corneal stromal defect in rats using a simple, economical, and customized inner-stopper guarded trephine.
Methods: The inner-stopper guarded trephine is used to induce a circular wound in rat corneas. After trephination, the corneal flap can be removed by manual dissection using a blunt spatula. We used optical coherence topography (OCT) to measure the defect wound depth induced in ex vivo rat eyes.
Results: Despite a minor learning curve, this simple device enables depth control, reduces variability of manual keratectomy wound depth in rats, and decreases the risk for corneal perforation during keratectomy. Corneal defect creation was highly reproducible across different researchers and was independent of their surgical training.
Conclusion: This inner-stopper guarded trephine can be utilized and applied to preclinical testing of a wide range of corneal wound healing therapies, including but not limited to biotherapeutics, corneal prosthetics, and regenerative technologies
"Is the Pope Catholic?" Applying Chain-of-Thought Reasoning to Understanding Conversational Implicatures
Conversational implicatures are pragmatic inferences that require listeners
to deduce the intended meaning conveyed by a speaker from their explicit
utterances. Although such inferential reasoning is fundamental to human
communication, recent research indicates that large language models struggle to
comprehend these implicatures as effectively as the average human. This paper
demonstrates that by incorporating Grice's Four Maxims into the model through
chain-of-thought prompting, we can significantly enhance its performance,
surpassing even the average human performance on this task
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Propionibacterium acnes Induces an IL-17 Response in Acne Vulgaris that Is Regulated by Vitamin A and Vitamin D.
Acne vulgaris is the most common skin disorder affecting millions of people worldwide and inflammation resulting from the immune response targeting Propionibacterium acnes has a significant role in its pathogenesis. In this study, we have demonstrated that P. acnes is a potent inducer of T helper 17 (Th17) and Th1, but not Th2 responses in human peripheral blood mononuclear cells (PBMCs). P. acnes stimulated expression of key Th17-related genes, including IL-17A, RORα, RORc, IL-17RA, and IL-17RC, and triggered IL-17 secretion from CD4(+), but not from CD8(+) T cells. Supernatants from P. acnes-stimulated PBMCs were sufficient to promote the differentiation of naive CD4(+)CD45RA T cells into Th17 cells. Furthermore, we found that the combination of IL-1β, IL-6, and transforming growth factor-β-neutralizing antibodies completely inhibited P. acnes-induced IL-17 production. Importantly, we showed that IL-17-expressing cells were present in skin biopsies from acne patients but not from normal donors. Finally, vitamin A (all-trans retinoic acid) and vitamin D (1,25-dihydroxyvitamin D3) inhibited P. acnes-induced Th17 differentiation. Together, our data demonstrate that IL-17 is induced by P. acnes and expressed in acne lesions and that both vitamin A and D could be effective tools to modulate Th17-mediated diseases such as acne
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mCSM-PPI2: predicting the effects of mutations on protein-protein interactions.
Protein-protein Interactions are involved in most fundamental biological processes, with disease causing mutations enriched at their interfaces. Here we present mCSM-PPI2, a novel machine learning computational tool designed to more accurately predict the effects of missense mutations on protein-protein interaction binding affinity. mCSM-PPI2 uses graph-based structural signatures to model effects of variations on the inter-residue interaction network, evolutionary information, complex network metrics and energetic terms to generate an optimised predictor. We demonstrate that our method outperforms previous methods, ranking first among 26 others on CAPRI blind tests. mCSM-PPI2 is freely available as a user friendly webserver at http://biosig.unimelb.edu.au/mcsm_ppi2/.This work was supported by the Australian Government Research Training Program Scholarship [to C.H.M.R and Y.M.]; the Jack Brockhoff Foundation [JBF 4186, 2016 to D.B.A.]; a Newton Fund RCUK-CONFAP Grant awarded by The Medical Research Council (MRC) and Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG) [MR/M026302/1 to D.B.A. and D.E.V.P.]; the National Health and Medical Research Council of Australia [APP1072476 to D.B.A.]; the Victorian Life Sciences Computation Initiative (VLSCI), an initiative of the Victorian Government, Australia, on its Facility hosted at the University of Melbourne [UOM0017]; the Instituto René Rachou (IRR/FIOCRUZ Minas), Brazil and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) [to D.E.V.P.] and the Department of Biochemistry and Molecular Biology, University of Melbourne [to D.B.A.]. Supported in part by the Victorian Government's OIS Program
Integration of FHIR to Facilitate Electronic Case Reporting: Results from a Pilot Study
Current approaches to gathering sexually transmitted infection (STI) case information for surveillance efforts are inefficient and lead to underreporting of disease burden. Electronic health information systems offer an opportunity to improve how STI case information can be gathered and reported to public health authorities. To test the feasibility of a standards-based application designed to automate STI case information collection and reporting, we conducted a pilot study where electronic laboratory messages triggered a FHIR-based application to query a patient’s electronic health record for details needed for an electronic case report (eCR). Out of 214 cases observed during a one week period, 181 (84.6%) could be successfully confirmed automatically using the FHIR-based application. Data quality and information representation challenges were identified that will require collaborative efforts to improve the structure of electronic clinical messages as well as the robustness of the FHIR application
Colon polyps in patients with short bowel syndrome before and after teduglutide: post hoc analysis of the STEPS study series
Background & aims: Teduglutide promotes intestinal growth and is approved for the treatment of short bowel syndrome and intestinal failure (SBS-IF). Based on the pharmacologic activity and preclinical findings, teduglutide can potentially induce proliferative colonic mucosal changes. The aim of this study is to report the occurrence of colorectal polyps in adult patients with SBS-IF who received teduglutide in clinical studies conducted to date. Methods: A post hoc analysis of the completed Study of Teduglutide Effectiveness in Parenteral Nutrition-Dependent Short Bowel Syndrome Subjects (STEPS) clinical study series (NCT00798967, EudraCT 2008-006193-15; NCT00930644, EudraCT 2009-011679-65; NCT01560403) evaluated electronic case report form data for baseline colonoscopies (performed before treatment) and for surveillance or end-of-study (performed after treatment with teduglutide 0.05 mg/kg/day for 24 and 36 months) post-exposure procedures. Results: In the STEPS studies, 73 patients treated with teduglutide had a baseline colonoscopy. No post-exposure colonoscopy was scheduled in STEPS. In STEPS-2/3, 50 of 65 patients with remnant colon (77%) underwent a protocol-mandated post-exposure colonoscopy. Colon polyps were reported at baseline in 12% (9/73) of patients and post-exposure in 18% (9/50) of patients. Two had polyps both at baseline and post-exposure. On histology, available for 7 patients, 5 had adenomas (1 serrated, 4 tubular) and none had malignancy or high-grade dysplasia. Conclusion: These data support recommendations for colonoscopic screening before teduglutide therapy and subsequent on-therapy colonoscopic surveillance for patients with SBS-IF. Further studies are required to assess the risk of polyp formation in patients with SBS-IF and the most appropriate colon polyp surveillance strategies
Brown fat organogenesis and maintenance requires AKT1 and AKT2
Objective: Understanding the signaling mechanisms that control brown adipose tissue (BAT) development is relevant to understanding energy homeostasis and obesity. The AKT kinases are insulin effectors with critical in vivo functions in adipocytes; however, their role in adipocyte development remains poorly understood. The goal of this study was to investigate AKT function in BAT development. Methods: We conditionally deleted Akt1 and Akt2 either individually or together with Myf5-Cre, which targets early mesenchymal precursors that give rise to brown adipocytes. Because Myf5-Cre also targets skeletal muscle and some white adipocyte lineages, comparisons were made between AKT function in BAT versus white adipose tissue (WAT) and muscle development. We also deleted both Akt1 and Akt2 in mature brown adipocytes with Ucp1-Cre or Ucp1-CreER to investigate AKT1/2 signaling in BAT maintenance. Results: AKT1 and AKT2 are individually dispensable in Myf5-Cre lineages in vivo for establishing brown and white adipocyte precursor cell pools and for their ability to differentiate (i.e. induce PPARγ). AKT1 and AKT2 are also dispensable for skeletal muscle development, and AKT3 does not compensate in either the adipocyte or muscle lineages. In contrast, AKT2 is required for adipocyte lipid filling and efficient downstream AKT substrate phosphorylation. Mice in which both Akt1 and Akt2 are deleted with Myf5-Cre lack BAT but have normal muscle mass, and doubly deleting Akt1 and Akt2 in mature brown adipocytes, either congenitally (with Ucp1-Cre), or inducibly in older mice (with Ucp1-CreER), also ablates BAT. Mechanistically, AKT signaling promotes adipogenesis in part by stimulating ChREBP activity. Conclusions: AKT signaling is required in vivo for BAT development but dispensable for skeletal muscle development. AKT1 and AKT2 have both overlapping and distinct functions in BAT development with AKT2 being the most critical individual isoform. AKT1 and AKT2 also have distinct and complementary functions in BAT maintenance.Fil: Sanchez Gurmaches, Joan. University Of Cincinnati College Of Medicine; Estados Unidos. University of Massachusetts Medical School; Estados UnidosFil: Martinez Calejman, Camila. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Jung, Su Myung. University Of Massachusetts Medical School; Estados UnidosFil: Li, Huawei. University Of Massachusetts Medical School; Estados UnidosFil: Guertin, David A.. University Of Massachusetts Medical School; Estados Unido
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