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1.
J Am Chem Soc ; 144(50): 22950-22964, 2022 12 21.
Artículo en Inglés | MEDLINE | ID: mdl-36475666

RESUMEN

The atropselective iodination of 2-amino-6-arylpyridines catalyzed by chiral disulfonimides (DSIs) is described. Key to the development of this transformation was the use of a chemoinformatically guided workflow for the curation of a structurally diverse training set of DSI catalysts. Utilization of this catalyst training set in the atropselective iodination across a variety 2-aminopyridine substrates allowed for the recommendation of statistically higher-performing DSIs for this reaction. Data Fusion techniques were implemented to successfully predict the performance of catalysts when classical linear regression analysis failed to provide suitable models. This effort identified a privileged class of 3,3'-alkynyl-DSI catalysts which were effective in catalyzing the iodination of a variety of 2-amino-6-arylpyridines with high stereoselectivity and generality. Subsequent preparative-scale demonstrations highlighted the utility of this reaction by providing iodinated pyridines >90:10 er and in good chemical yield.


Asunto(s)
Halogenación , Catálisis
2.
Bioorg Med Chem ; 71: 116942, 2022 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-35930851

RESUMEN

An elevated plasma level of soluble ST2 (sST2) is a risk biomarker for graft-versus-host disease (GVHD) and death in patients receiving hematopoietic cell transplantation (HCT). sST2 functions as a trap for IL-33 and amplifies the pro-inflammatory type 1 and 17 response while suppressing the tolerogenic type 2 and regulatory T cells activation during GVHD development. We previously identified small-molecule ST2 inhibitors particularly iST2-1 that reduces plasma sST2 levels and improved survival in two animal models. Here, we reported the structure-activity relationship of the furanylmethylpyrrolidine-based ST2 inhibitors based on iST2-1. Based on the biochemical AlphaLISA assay, we improved the activity of iST2-1 by 6-fold (∼6 µM in IC50 values) in the inhibition of ST2/IL-33 and confirmed the activities of the compounds in a cellular reporter assay. To determine the inhibition of the alloreactivity in vitro, we used the mixed lymphocyte reaction assay to demonstrate that our ST2 inhibitors decreased CD4+ and CD8+ T cells proliferation and increased Treg population. The data presented in this work are critical to the development of ST2 inhibitors in future.


Asunto(s)
Enfermedad Injerto contra Huésped , Animales , Linfocitos T CD8-positivos/metabolismo , Furanos , Enfermedad Injerto contra Huésped/tratamiento farmacológico , Enfermedad Injerto contra Huésped/metabolismo , Proteína 1 Similar al Receptor de Interleucina-1/metabolismo , Interleucina-33/metabolismo , Pirrolidinas/farmacología , Relación Estructura-Actividad
3.
J Org Chem ; 86(4): 3490-3534, 2021 02 19.
Artículo en Inglés | MEDLINE | ID: mdl-33539091

RESUMEN

A general procedure for the asymmetric synthesis of highly substituted 1,2-amino alcohols in high yield and diastereoselectivity is described that uses organometallic additions of a wide range of nucleophiles to tert-butylsulfinimines as the key step. The addition of organolithium reagents to these imines follows a modified Davis model. The diastereoselectivity for this reaction depends significantly on both the nucleophile and electrophile. These highly substituted 1,2-amino alcohols are used to synthesize stereochemically diverse and structurally novel, polysubstituted 2,2'-methylene(bisoxazoline) ligands in high yields.


Asunto(s)
Amino Alcoholes , Iminas , Indicadores y Reactivos , Ligandos , Estereoisomerismo
4.
Sensors (Basel) ; 21(7)2021 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-33916575

RESUMEN

Tethered deep-sea robots and instrument platforms, such as Remotely Operated Vehicles (ROVs) and vertical-profiling or towed instrument arrays, commonly rely on fiber optics for real-time data transmission. Fiber optic tethers used for these applications are either heavily reinforced load-bearing cables used to support lifting and pulling, or bare optical fibers used in non-load bearing applications. Load-bearing tethers directly scale operations for deep-sea robots as the cable diameter, mass, and length typically require heavy winches and large surface support vessels to operate, and also guide the design of the deep-sea robot itself. In an effort to dramatically reduce the physical scale and operational overhead of tethered live-telemetry deep-sea robots and sensors, we have developed the Fiber Optic Reel System (FOReelS). FOReelS utilizes a customized electric fishing reel outfitted with a proprietary hollow-core braided fiber optic fishing line and mechanical termination assembly (FOFL), which offers an extremely small diameter (750 µm) load-bearing (90 lb/400 N breaking strength) tether to support live high-bandwidth data transmission as well as fiber optic sensing applications. The system incorporates a novel epoxy potted data payload system (DPS) that includes high-definition video, integrated lighting, rechargeable battery power, and gigabit ethernet fiber optic telemetry. In this paper we present the complete FOReelS design and field demonstrations to depths exceeding 780 m using small coastal support vessels of opportunity. FOReelS is likely the smallest form factor live-telemetry deep-sea exploration tool currently in existence, with a broad range of future applications envisioned for oceanographic sensing and communication.

5.
J Am Chem Soc ; 142(26): 11578-11592, 2020 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-32568531

RESUMEN

Modern, enantioselective catalyst development is driven largely by empiricism. Although this approach has fostered the introduction of most of the existing synthetic methods, it is inherently limited by the skill, creativity, and chemical intuition of the practitioner. Herein, we present a complementary approach to catalyst optimization in which statistical methods are used at each stage to streamline development. To construct the optimization informatics workflow, a number of critical components had to be subjected to rigorous validation. First, the critically important molecular descriptors were validated in two case studies to establish the importance of conformation-dependent molecular representations. Next, with a large data set available, it was possible to investigate the amount of data necessary to make predictive models with different modeling methods. Given the commercial availability of many catalyst structures, it was possible to compare models generated with algorithmically selected training sets and commercially available training sets. Finally, the augmentation of limited data sets is demonstrated in a method informed by unsupervised learning to restore the accuracy of the generated models.

6.
J Aircr ; 55(3): 1141-1153, 2019 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-31534269

RESUMEN

The present paper examines potential propulsive and aerodynamic benefits of integrating a Boundary-Layer Ingestion (BLI) propulsion system into the Common Research Model (CRM) geometry and the NASA Tetrahedral Unstructured Software System (TetrUSS). The Numerical Propulsion System Simulation (NPSS) environment is used to generate engine conditions for Computational Fluid Dynamics (CFD) analyses. Improvements to the BLI geometry are made using the Constrained Direct Iterative Surface Curvature (CDISC) design method. Potential benefits of the BLI system relating to cruise propulsive power are quantified using a power balance method, and a comparison to the baseline case is made. Iterations of the BLI geometric design are shown, and improvements between subsequent BLI designs are presented. Simulations are conducted for a cruise flight condition of Mach 0.85 at an altitude of 38,500 feet, with Reynolds number of 40 million based on mean aerodynamic chord and an angle of attack of 2° for all geometries. Results indicate an 8% reduction in engine power requirements at cruise for the BLI configuration compared to the baseline geometry. Small geometric alterations of the aft portion of the fuselage using CDISC has been shown to marginally increase the benefit from boundary-layer ingestion further, resulting in an 8.7% reduction in power requirements for cruise, as well as a drag reduction of approximately twelve counts over the baseline geometry.

7.
J Clin Pharm Ther ; 41(1): 64-9, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26778812

RESUMEN

WHAT IS KNOWN AND OBJECTIVE: There is conclusive evidence demonstrating that formulary restrictions are associated with reduced utilization and pharmacy spending of the restricted drugs. However, prior efforts to implement restrictive formularies have been associated with inconsistent rates of therapy discontinuation and mixed impacts on adherence to therapy. Also, the impact of transferring patients from an already restrictive formulary to a more aggressive model has not been previously examined. This study evaluated the impact of implementation of a more restrictive formulary on therapy disruption, adherence rates, pharmacy costs and generic utilization among patients with common chronic conditions. METHODS: In 2014, CVS Health implemented Value Formulary (VF), a restrictive benefit design with the aim of reducing spending while preserving access to and adherence to essential therapy, was used. A retrospective cohort study was conducted to assess changes in therapy disruption rates, pharmacy costs and generic dispensing rate (GDR) (for continuers) and medication adherence (for initiators) following the implementation of VF. The study group was selected from members of three existing employer clients transitioned from standard formulary (SF) to VF on January 2014. The control population was a matched group of six employers with the same preperiod formulary structure, business unit, adherence programmes and patient out-of-pocket cost as the study group. The control group retained SF in 2014. To assess therapy disruption after VF implementation, we categorized patients by their subsequent medication use into three groups: (i) therapy stopped, (ii) therapy continued and (iii) therapy switched. Medication adherence was measured as monthly proportion of days covered (PDC). Pharmacy cost and GDR were measured per utilizer per month (PUPM). Rates of therapy disruption in study and control groups were compared using the chi-square test. Differences in monthly PDC between matched groups were evaluated using multivariate linear regression. Impact of VF on pharmacy cost and GDR was measured through segmented regression of interrupted time series data with generalized estimating equations. RESULTS AND DISCUSSION: A transition from SF to VF influenced drug coverage for approximately 13% of members (as their medications were either no longer covered, or covered restrictively under VF). Compared to patients whose plan sponsors retained SF, the patients that transitioned to VF had a modest (1·3%) but statistically significant increase in therapy discontinuation rates. This was offset by similarly modest improvements in adherence; patients who initiated therapy under VF demonstrated a 1·5% higher adherence to medications as compared to SF patients (P < 0·001). Medication costs in the VF group were lower by $20 PUPM (P < 0·001), and GDR was greater by 4·2% (P < 0·001). WHAT IS NEW AND CONCLUSION: Transition of patients to a more restrictive drug formulary led to modest therapy discontinuation, similarly modest improvements in medication adherence and substantial prescription drug cost savings. As healthcare payors search for ways to control the rapid rise in spending for medications without compromising quality, the Value Formulary can serve as a useful tool.


Asunto(s)
Medicamentos Genéricos/administración & dosificación , Formularios Farmacéuticos como Asunto , Cumplimiento de la Medicación , Medicamentos bajo Prescripción/administración & dosificación , Adulto , Anciano , Estudios de Cohortes , Costos de los Medicamentos , Medicamentos Genéricos/economía , Femenino , Humanos , Seguro de Servicios Farmacéuticos/economía , Análisis de Series de Tiempo Interrumpido , Modelos Lineales , Masculino , Persona de Mediana Edad , Análisis Multivariante , Servicios Farmacéuticos/economía , Medicamentos bajo Prescripción/economía , Estudios Retrospectivos
8.
Cell Mol Neurobiol ; 35(3): 377-387, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25392236

RESUMEN

Multiple sclerosis is a chronic disease of the central nervous system characterized by an autoimmune inflammatory reaction that leads to axonal demyelination and tissue damage. Glucocorticoids, such as prednisolone, are effective in the treatment of multiple sclerosis in large part due to their ability to inhibit pro-inflammatory pathways (e.g., NFκB). However, despite their effectiveness, long-term treatment is limited by adverse side effects. VBP15 is a recently described compound synthesized based on the lazeroid steroidal backbone that shows activity in acute and chronic inflammatory conditions, yet displays a much-reduced side effect profile compared to traditional glucocorticoids. The purpose of this study was to determine the effectiveness of VBP15 in inhibiting inflammation and disease progression in experimental autoimmune encephalomyelitis (EAE), a widely used mouse model of multiple sclerosis. Our data show that VBP15 is effective at reducing both disease onset and severity. In parallel studies, we observed that VBP15 was able to inhibit the production of NFκB-regulated pro-inflammatory transcripts in human macrophages. Furthermore, treatment with prednisolone-but not VBP15-increased expression of genes associated with bone loss and muscle atrophy, suggesting lack of side effects of VBP15. These findings suggest that VBP15 may represent a potentially safer alternative to traditional glucocorticoids in the treatment of multiple sclerosis and other inflammatory diseases.


Asunto(s)
Antiinflamatorios/uso terapéutico , Encefalomielitis Autoinmune Experimental/tratamiento farmacológico , Pregnadienodioles/uso terapéutico , Índice de Severidad de la Enfermedad , Animales , Antiinflamatorios/farmacología , Células Cultivadas , Relación Dosis-Respuesta a Droga , Encefalomielitis Autoinmune Experimental/patología , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Monocitos/efectos de los fármacos , Monocitos/patología , Pregnadienodioles/farmacología , Embarazo , Resultado del Tratamiento
9.
Pediatr Transplant ; 18(2): E57-63, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24438382

RESUMEN

The most common identifiable causes of acute liver failure in pediatric patients are infection, drug toxicity, metabolic disease, and autoimmune processes. In many cases, the etiology of acute liver failure cannot be determined. Acute leukemia is an extremely rare cause of acute liver failure, and liver transplantation has traditionally been contraindicated in this setting. We report a case of acute liver failure in a previously healthy 15-yr-old male from pre-B-cell acute lymphoblastic leukemia. He underwent liver transplantation before the diagnosis was established, and has subsequently received chemotherapy for pre-B-cell acute lymphoblastic leukemia. He is currently alive 31 months post-transplantation. The published literature describing acute lymphoblastic leukemia as a cause of acute liver failure is reviewed.


Asunto(s)
Leucemia de Células B/complicaciones , Leucemia de Células B/terapia , Fallo Hepático Agudo/complicaciones , Fallo Hepático Agudo/cirugía , Trasplante de Hígado , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicaciones , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Adolescente , Biopsia , Humanos , Inmunosupresores/uso terapéutico , Hígado/patología , Pruebas de Función Hepática , Masculino , Donantes de Tejidos , Resultado del Tratamiento
10.
Sci Data ; 11(1): 679, 2024 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-38914539

RESUMEN

We present 4k video and whole transcriptome data for seven deep-sea invertebrate animals collected in the Eastern Pacific Ocean during a research expedition onboard the Schmidt Ocean Institute's R/V Falkor in August of 2021. The animals include one jellyfish (Atolla sp.), three siphonophores (Apolemia sp., Praya sp., and Halistemma sp.), one larvacean (Bathochordaeus mcnutti), one tunicate (Pyrosomatidae sp.), and one ctenophore (Lampocteis sp.). Four of the animals were sequenced with long-read RNA sequencing technology, such that the reads themselves define a reference assembly for those animals. The larvacean tissues were successfully preserved in situ and has paired long-read reference data and short read quantitative transcriptomic data for within-specimen analyses of gene expression. Additionally, for three animals we provide quantitative image data, and a 3D model for one siphonophore. The paired image and transcriptomic data can be used for species identification, species description, and reference genetic data for these deep-sea animals.


Asunto(s)
Invertebrados , Transcriptoma , Animales , Invertebrados/genética , Océano Pacífico , Organismos Acuáticos/genética , Análisis de Secuencia de ARN
11.
Sci Adv ; 10(3): eadj4960, 2024 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-38232174

RESUMEN

Revolutionary advancements in underwater imaging, robotics, and genomic sequencing have reshaped marine exploration. We present and demonstrate an interdisciplinary approach that uses emerging quantitative imaging technologies, an innovative robotic encapsulation system with in situ RNA preservation and next-generation genomic sequencing to gain comprehensive biological, biophysical, and genomic data from deep-sea organisms. The synthesis of these data provides rich morphological and genetic information for species description, surpassing traditional passive observation methods and preserved specimens, particularly for gelatinous zooplankton. Our approach enhances our ability to study delicate mid-water animals, improving research in the world's oceans.


Asunto(s)
Robótica , Zooplancton , Animales , Océanos y Mares , Zooplancton/genética , Agua , Gelatina
12.
Am J Transplant ; 13(3): 808-10, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23331705

RESUMEN

Posterior reversible encephalopathy syndrome (PRES) is a small vessel microangiopathy of the cerebral vasculature that occurs in 0.5-5% of solid organ transplant recipients, most commonly associated with tacrolimus (Tac). Clinical manifestations include hypertension and neurologic symptoms. We report an adult multivisceral transplant recipient who experienced recurrent PRES initially associated with Tac and subsequently with sirolimus. A 49-year-old woman with short bowel syndrome underwent multivisceral transplantation due to total parenteral nutrition-related liver disease. She was initially maintained on Tac, mycophenalate mofetil (MMF) and prednisone. Three months after transplantation, she developed renal dysfunction, leading to a reduction in Tac and the addition of sirolimus. Eight months after transplantation, she developed PRES. Tac was discontinued and PRES resolved. Sirolimus was increased to maintain trough levels of 12-15 ng/mL. Fourteen months after transplant, she experienced recurrent PRES which resolved after discontinuing sirolimus. Currently 3 years posttransplant, she is maintained on cyclosporine, MMF and prednisone with no PRES recurrence. In addition to calcineurin inhibitors, sirolimus may also be associated with PRES after solid organ transplantation. Ours is the first report of sirolimus-associated PRES in the setting of multivisceral transplantation. Identifying a safe alternative immunosuppression regimen was challenging but ultimately successful.


Asunto(s)
Rechazo de Injerto/tratamiento farmacológico , Hepatopatías/cirugía , Trasplante de Hígado/efectos adversos , Síndrome de Leucoencefalopatía Posterior/inducido químicamente , Complicaciones Posoperatorias/prevención & control , Sirolimus/efectos adversos , Tacrolimus/efectos adversos , Femenino , Rechazo de Injerto/inducido químicamente , Humanos , Inmunosupresores/efectos adversos , Persona de Mediana Edad , Síndrome de Leucoencefalopatía Posterior/tratamiento farmacológico , Pronóstico , Recurrencia
13.
Nat Genet ; 16(4): 387-90, 1997 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9241279

RESUMEN

The epilepsies are a heterogeneous collection of seizure disorders with a lifetime expectancy risk rate of 2-4%. A convergence of evidence indicates that heritable factors contribute significantly to seizure susceptibility. Genetically epilepsy-prone rodent strains have been frequently used to examine the effect of genetic factors on seizure susceptibility. The most extensively studied of these have been strains that are susceptible to sound-induced convulsions (audiogenic seizures, or AGSs). Early observations of the AGS phenomenon were made in the laboratory of Dr. Ivan Pavlov; in the course of appetite-conditioning experiments in mice, the loud bell used to signal food presentation unexpectedly produced seizures in some animals. In 1947, DBA/2 (D2) mice were found to exhibit a genetic susceptibility to AGSs stimulated by a doorbell mounted in an iron tub. Since this discovery, AGSs have been among the most intensively studied phenotypes in behavioural genetics. Although several genetic loci confer susceptibility to AGSs, the corresponding genes have not been cloned. We report that null mutant mice lacking serotonin 5-HT2C receptors are extremely susceptible to AGSs. The onset of susceptibility is between two and three months of age, with complete penetrance in adult animals. AGS-induced immediate early gene expression indicates that AGSs are subcortical phenomena in auditory circuits. This AGS syndrome is the first produced by a known genetic defect; it provides a robust model for the examination of serotoninergic mechanisms in epilepsy.


Asunto(s)
Mutación , Receptores de Serotonina/genética , Convulsiones/genética , Estimulación Acústica , Animales , Encéfalo/metabolismo , Encéfalo/patología , Modelos Animales de Enfermedad , Reacción de Fuga , Femenino , Masculino , Ratones , Ratones Endogámicos C57BL , Receptor de Serotonina 5-HT2C , Receptores de Serotonina/metabolismo , Convulsiones/etiología , Convulsiones/metabolismo , Sonido
14.
Pharmaceuticals (Basel) ; 16(5)2023 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-37242488

RESUMEN

Treatment options are lacking to prevent photoreceptor death and subsequent vision loss. Previously, we demonstrated that reprogramming metabolism via the pharmacologic activation of PKM2 is a novel photoreceptor neuroprotective strategy. However, the features of the tool compound used in those studies, ML-265, preclude its advancement as an intraocular, clinical candidate. This study sought to develop the next generation of small-molecule PKM2 activators, aimed specifically for delivery into the eye. Compounds were developed that replaced the thienopyrrolopyridazinone core of ML-265 and modified the aniline and methyl sulfoxide functional groups. Compound 2 demonstrated that structural changes to the ML-265 scaffold are tolerated from a potency and efficacy standpoint, allow for a similar binding mode to the target, and circumvent apoptosis in models of outer retinal stress. To overcome the low solubility and problematic functional groups of ML-265, compound 2's efficacious and versatile core structure for the incorporation of diverse functional groups was then utilized to develop novel PKM2 activators with improved solubility, lack of structural alerts, and retained potency. No other molecules are in the pharmaceutical pipeline for the metabolic reprogramming of photoreceptors. Thus, this study is the first to cultivate the next generation of novel, structurally diverse, small-molecule PKM2 activators for delivery into the eye.

15.
Am J Transplant ; 12(8): 2242-6, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22594310

RESUMEN

Restoring abdominal wall cover and contour in children undergoing bowel and multivisceral transplantation is often challenging due to discrepancy in size between donor and recipient, poor musculature related to birth defects and loss of abdominal wall integrity from multiple surgeries. A recent innovation is the use of vascularized posterior rectus sheath to enable closure of abdomen. We describe the application of this technique in two pediatric multivisceral transplant recipients--one to buttress a lax abdominal wall in a 22-month-old child with megacystis microcolon intestinal hypoperistalsis syndrome and another to accommodate transplanted viscera in a 10-month child with short bowel secondary to gastoschisis and loss of domain. This is the first successful report of this procedure with long-term survival. The procedure has potential application to facilitate difficult abdominal closure in both adults and pediatric liver and multivisceral transplantation.


Asunto(s)
Anomalías Múltiples/cirugía , Seudoobstrucción Intestinal/cirugía , Trasplante de Órganos , Colon/anomalías , Colon/cirugía , Femenino , Humanos , Lactante , Masculino , Trasplante Homólogo , Vejiga Urinaria/anomalías , Vejiga Urinaria/cirugía
16.
Proc Natl Acad Sci U S A ; 106(23): 9403-8, 2009 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-19470482

RESUMEN

In HIV-1-infected individuals on currently recommended antiretroviral therapy (ART), viremia is reduced to <50 copies of HIV-1 RNA per milliliter, but low-level residual viremia appears to persist over the lifetimes of most infected individuals. There is controversy over whether the residual viremia results from ongoing cycles of viral replication. To address this question, we conducted 2 prospective studies to assess the effect of ART intensification with an additional potent drug on residual viremia in 9 HIV-1-infected individuals on successful ART. By using an HIV-1 RNA assay with single-copy sensitivity, we found that levels of viremia were not reduced by ART intensification with any of 3 different antiretroviral drugs (efavirenz, lopinavir/ritonavir, or atazanavir/ritonavir). The lack of response was not associated with the presence of drug-resistant virus or suboptimal drug concentrations. Our results suggest that residual viremia is not the product of ongoing, complete cycles of viral replication, but rather of virus output from stable reservoirs of infection.


Asunto(s)
Terapia Antirretroviral Altamente Activa , Infecciones por VIH/tratamiento farmacológico , VIH-1/fisiología , Viremia/tratamiento farmacológico , Adulto , Fármacos Anti-VIH , Infecciones por VIH/virología , Humanos , Estudios Prospectivos , Replicación Viral
17.
Chem Commun (Camb) ; 58(47): 6737-6740, 2022 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-35607950

RESUMEN

Peptide macrocycles (PMCs) are increasingly popular for the development of inhibitors of protein-protein interactions (PPIs). Large libraries of PMCs are accessible using display technologies like mRNA display and phage display. These technologies require macrocyclization chemistries to be compatible with biological milieu, severely limiting the types of technologies available for cyclization. Here, we introduce the novel non-canonical amino acid (ncAA) p-cyanoacetylene-L-Phe (pCAF), which facilitates spontaneous, co-translational cyclization through Michael addition with cysteine under physiological conditions. This new, robust chemistry creates stable macrocycles of a wide variety of ring sizes including bicyclic structures.


Asunto(s)
Péptidos Cíclicos , Fenilalanina , Acetileno/análogos & derivados , Ciclización , Nitrilos , Biblioteca de Péptidos , Péptidos/metabolismo , Péptidos Cíclicos/química , Fenilalanina/metabolismo
18.
J Mech Behav Biomed Mater ; 125: 104907, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34736023

RESUMEN

The semilunar heart valves regulate the blood flow from the ventricles to the major arteries through the opening and closing of the scallop shaped cusps. These cusps are composed of collagen fibers that act as the primary loading-bearing component. The load-dependent collagen fiber architecture has been previously examined in the existing literature; however, these studies relied on chemical clearing and tissue modifications to observe the underlying changes in response to mechanical loads. In the present study, we address this gap in knowledge by quantifying the collagen fiber orientations and alignments of the aortic and pulmonary cusps through a multi-scale, non-destructive experimental approach. This opto-mechanical approach, which combines polarized spatial frequency domain imaging and biaxial mechanical testing, provides a greater field of view (10-25mm) and faster imaging time (45-50s) than other traditional collagen imaging techniques. The birefringent response of the collagen fibers was fit with a von Mises distribution, while the biaxial mechanical testing data was implemented into a modified full structural model for further analysis. Our results showed that the semilunar heart valve cusps are more extensible in the tissue's radial direction than the circumferential direction under all the varied biaxial testing protocols, together with greater material anisotropy among the pulmonary valve cusps compared to the aortic valve cusps. The collagen fibers were shown to reorient towards the direction of the greatest applied loading and incrementally realign with the increased applied stress. The collagen fiber architecture within the aortic valve cusps were found to be more homogeneous than the pulmonary valve counterparts, reflecting the differences in the physiological environments experienced by these two semilunar heart valves. Further, the von Mises distribution fitting highlighted the presence and contribution of two distinct fiber families for each of the two semilunar heart valves. The results from this work would provide valuable insight into connecting tissue-level mechanics to the underlying collagen fiber architecture-an essential information for the future development of high-fidelity aortic/pulmonary valve computational models.


Asunto(s)
Bioprótesis , Prótesis Valvulares Cardíacas , Animales , Válvula Aórtica , Colágeno , Matriz Extracelular , Humanos , Porcinos
19.
Hum Genet ; 129(2): 129-39, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21061022

RESUMEN

Converging lines of evidence suggest that AKT1 is a major mediator of the responses to insulin,insulin-like growth factor 1 (IGF1), and glucose. AKT1 also plays a key role in the regulation of both muscle cell hypertrophy and atrophy. We hypothesized that AKT1 variants may play a role in the endophenotypes that makeup metabolic syndrome. We studied a 12-kb region including the first exon of the AKT1 gene for association with metabolic syndrome-related phenotypes in four study populations [FAMUSS cohort (n = 574; age 23.7 ± 5.7 years), Strong Heart Study (SHS) (n = 2,134; age 55.5 ± 7.9 years), Dynamics of Health, Aging and Body Composition (Health ABC) (n = 3,075; age 73.6 ± 2.9 years), and Studies of a Targeted Risk Reduction Intervention through Defined Exercise (STRRIDE)(n = 175; age 40­65 years)]. We identified a three SNP haplotype that we call H1, which represents the ancestral alleles eles at the three loci and H2, which represents the derived alleles at the three loci. In young adult European Americans (FAMUSS), H1 was associated with higher fasting glucose levels in females. In middle age Native Americans (SHS), H1 carriers showed higher fasting insulin and HOMA in males, and higher BMI in females. Inolder African-American and European American subjects(Health ABC) H1 carriers showed a higher incidence of metabolic syndrome. Homozygotes for the H1 haplotype showed about twice the risk of metabolic syndrome in both males and females (p < 0.001). In middle-aged European Americans with insulin resistance (STRRIDE) studied by intravenous glucose tolerance test (IVGTT), H1 carriers showed increased insulin resistance due to the Sg component (p = 0.021). The 12-kb haplotype is a risk factor for metabolic syndrome and insulin resistance that needs to be explored in further populations.


Asunto(s)
Síndrome Metabólico/genética , Polimorfismo de Nucleótido Simple , Proteínas Proto-Oncogénicas c-akt/genética , Adulto , Anciano , Anciano de 80 o más Años , Envejecimiento , Femenino , Humanos , Resistencia a la Insulina , Masculino , Síndrome Metabólico/etnología , Persona de Mediana Edad , Adulto Joven
20.
Pediatr Res ; 69(6): 538-43, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21297524

RESUMEN

Genome-wide association studies (GWASs) have identified polymorphic loci associated with coronary artery disease (CAD) risk factors (i.e. serum lipids) in adult populations (42-69 y). We hypothesized that younger populations would show a greater relative genetic component due to fewer confounding variables. We examined the influence of 20 GWAS loci associated with serum lipids and insulin metabolism, in a university student cohort (n = 548; mean age = 24 y), and replicated statistically associated results in a second study cohort of primary school students (n = 810, mean age = 11.5 y). Nineteen loci showed no relationship with studied risk factors in young adults. However, the ancestral allele of the rs646776 (SORT1) locus was strongly associated with increased LDL (C) in young adults [TT: 97.6 ± 1.0 mg/dL (n = 345) versus CT/CC: 87.3 ± 1.0 mg/dL (n = 203); p = 3 × 10(x6)] and children [TT: 94.0 ± 1.3 mg/dL (n = 551) versus CT/CC: 84.7 ± 1.4 mg/dL (n = 259); p = 4 × 10(x6)]. This locus is responsible for 3.6% of population variance in young adults and 2.5% of population variance in children. The effect size of the SORT1 locus is considerably higher in young populations (2.5-4.1%) compared with older subjects (1%).


Asunto(s)
LDL-Colesterol/genética , Cromosomas Humanos Par 1/genética , Enfermedad de la Arteria Coronaria/genética , Estudio de Asociación del Genoma Completo , Adulto , Niño , Diabetes Mellitus Tipo 2/genética , Ejercicio Físico , Femenino , Genotipo , Humanos , Insulina/metabolismo , Lípidos/sangre , Polimorfismo de Nucleótido Simple , Factores de Riesgo , Adulto Joven
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