Chemotherapy treatment against pancreatic ductal adenocarcinoma (PDAC) is thwarted by tumoral activation of multiple therapy resistance pathways. The growth hormone (GH)-GH receptor (GHR) pair is a covert driver of multimodal therapy resistance in cancer and is overexpressed in PDAC tumors, yet the therapeutic potential of targeting the same has not been explored. Here, we report that GHR expression is a negative prognostic factor in patients with PDAC.
View Article and Find Full Text PDFMyocardial infarction (MI) results from occlusion of blood supply to the heart muscle causing death of cardiac muscle cells. Following myocardial infarction (MI), extracellular matrix deposition and scar formation mechanically stabilize the injured heart as damaged myocytes undergo necrosis and removal. Fibroblasts and macrophages are key drivers of post-MI scar formation, maturation, and ongoing long-term remodelling; however, their individual contributions are difficult to assess from bulk analyses of infarct scar.
View Article and Find Full Text PDFHuman growth hormone (hGH) is a pituitary-derived endocrine protein that regulates several critical postnatal physiologic processes including growth, organ development, and metabolism. Following adulthood, GH is also a regulator of multiple pathologies like fibrosis, cancer, and diabetes. Therefore, there is a significant pharmaceutical interest in developing antagonists of hGH action.
View Article and Find Full Text PDFFibrosis is a pathological state caused by excess deposition of extracellular matrix proteins in a tissue. Male bovine growth hormone (bGH) transgenic mice experience metabolic dysfunction with a marked decrease in lifespan and with increased fibrosis in several tissues including white adipose tissue (WAT), which is more pronounced in the subcutaneous (Sc) depot. The current study expanded on these initial findings to evaluate WAT fibrosis in female bGH mice and the role of transforming growth factor (TGF)-β in the development of WAT fibrosis.
View Article and Find Full Text PDFCombined pre-/postcapillary pulmonary hypertension (Cpc-PH), a complication of left heart failure, is associated with higher mortality rates than isolated postcapillary pulmonary hypertension alone. Currently, knowledge gaps persist on the mechanisms responsible for the progression of isolated postcapillary pulmonary hypertension (Ipc-PH) to Cpc-PH. Here, we review the biomechanical and mechanobiological impact of left heart failure on pulmonary circulation, including mechanotransduction of these pathological forces, which lead to altered biological signaling and detrimental remodeling, driving the progression to Cpc-PH.
View Article and Find Full Text PDFWith severe right ventricular (RV) pressure overload, women demonstrate better clinical outcomes compared with men. The mechanoenergetic mechanisms underlying this protective effect, and their dependence on female endogenous sex hormones, remain unknown. To investigate these mechanisms and their impact on RV systolic and diastolic functional adaptation, we created comparable pressure overload via pulmonary artery banding (PAB) in intact male and female Wistar rats and ovariectomized (OVX) female rats.
View Article and Find Full Text PDFThe mechanics of most soft tissues in the human body are determined by the organization of their collagen fibers. Predicting how mechanics will change during growth and remodeling of those tissues requires constitutive laws that account for the density and dispersion of collagen fibers. Post-infarction scar in the heart, a mechanically and structurally complex material, does not yet have a validated fiber-based constitutive model.
View Article and Find Full Text PDFVentricular enlargement and heart failure are common in patients who survive a myocardial infarction (MI). There is striking variability in the degree of post-infarction ventricular remodeling, however, and no one factor or set of factors have been identified that predicts heart failure risk well. Sympathetic activation directly and indirectly modulates hypertrophic stimuli by altering both neurohormonal milieu and ventricular loading.
View Article and Find Full Text PDFTissue microenvironment properties like blood flow, extracellular matrix, or proximity to immune-infiltrate are important regulators of cell biology. However, methods to study regional protein expression in the native tissue environment are limited. To address this need, we developed a novel approach to visualize, purify, and measure proteins using automated spatially targeted optical microproteomics (AutoSTOMP).
View Article and Find Full Text PDFGrowing evidence supports a central role of NADPH oxidases (NOXs) in the regulation of platelets, which are circulating cells involved in both hemostasis and thrombosis. Here, the use of Nox1 and Nox1 mice as experimental models of human responses demonstrated a critical role of NOX1 in collagen-dependent platelet activation and pathological arterial thrombosis, as tested in vivo by carotid occlusion assays. In contrast, NOX1 does not affect platelet responses to thrombin and normal hemostasis, as assayed in tail bleeding experiments.
View Article and Find Full Text PDFThe natural product (+)-grandifloracin is a potent "anti-austerity" agent, able to suppress the ability of various pancreatic cancer cell lines to tolerate conditions of nutrient deprivation. Such anti-austerity agents represent a promising approach to cancer chemotherapy. Here we report the synthesis and biological evaluation of racemic analogues of grandifloracin bearing diverse sidechains, of which two show enhanced potency in comparison with the natural product.
View Article and Find Full Text PDFBackground: Stuttering Support Organizations (SSOs) are places where people who stutter can share their experiences with stuttering and lend support to each other. There is evidence that SSO participation may be helpful in reducing the negative impact of stuttering and promoting positive cognitive and affective changes in adults who stutter. The benefits of participating in SSO organizations for young people, however, are currently unknown.
View Article and Find Full Text PDFAm J Physiol Heart Circ Physiol
October 2018
Previous studies have suggested that the composition and global mechanical properties of the scar tissue that forms after a myocardial infarction (MI) are key determinants of long-term survival, and emerging therapies such as biomaterial injection are designed in part to alter those mechanical properties. However, recent evidence suggests that local mechanics regulate scar formation post-MI, so that perturbing infarct mechanics could have unexpected consequences. We therefore tested the effect of changes in local mechanical environment on scar collagen turnover, accumulation, and alignment in 77 Sprague-Dawley rats at 1, 2, 3 and 6 wk post-MI by sewing a Dacron patch to the epicardium to eliminate circumferential strain while permitting continued longitudinal stretching with each heart beat.
View Article and Find Full Text PDFWe report the synthesis and biological evaluation of three analogues of the natural product (+)-grandifloracin (+)-1. All three analogues exhibit enhanced antiproliferative activity against PANC-1 and HT-29 cells compared to the natural product. The retention of activity in an analogue lacking the enone functional group, 9, implies this structural element is not an essential part of the (+)-grandifloracin pharmacophore.
View Article and Find Full Text PDFChem Commun (Camb)
October 2013
The synthesis of a maltol-derived hydrazide is described which, once attached to a cell surface, induces rapid multicellular aggregation selectively in the presence of Fe(3+) ions. Heterocellular aggregates are also reported.
View Article and Find Full Text PDFAn efficient two-step synthesis of pyrazoline ligand is described which is an effective "turn on" fluorescent sensor for Cd(2+) in MeCN. Oxidation to the corresponding pyrazole ligand creates a "turn on" fluorescent sensor now selective for Zn(2+) and able to distinguish it from Cd(2+).
View Article and Find Full Text PDFElectron-rich aryl ethers and phenols react with isoprene (2-methylbuta-1,3-diene) in the presence of catalytic Bi(OTf)(3) at 40 °C to afford the corresponding prenylated or 2,2-dimethylchroman products, respectively, in moderate to good yields. This transformation offers a convenient and expedient entry to prenylated derivatives of electron-rich aromatics that often display enhanced biological activities. The methodology has been employed in the efficient synthesis of a biologically active natural product and related compounds.
View Article and Find Full Text PDFSyntheses of the cyclic tripeptides OF4949-III 1 and K-13 2 are reported, in which the key steps are intermolecular and intramolecular Negishi cross-coupling reactions, respectively. In addition, the synthesis of a protected isomer of K-13 25 is reported. The synthesis of K-13 features a tripeptidic organozinc reagent 11, one of the most highly functionalized such reagents to be described.
View Article and Find Full Text PDFObjective: We report a modified technique of perineal proctectomy using a new reloadable curved cutter stapler, the Contour Transtar (Ethicon Endo-Surgery), to treat full-thickness external rectal prolapse.
Method: Between May and July 2008 three female patients were treated. All had a full-thickness external rectal prolapse up to 10 cm in length.
Background: The role of preoperative biliary drainage before liver resection in jaundiced patients remains controversial. The objective of this study is to compare the perioperative outcome of liver resection for carcinoma involving the proximal bile duct in jaundiced patients with and without preoperative biliary drainage.
Methods: Seventy-four consecutive jaundiced patients underwent hepatectomy for carcinoma involving the proximal bile duct from January 1989 to June 2006 and their data were retrospectively analyzed.
Stereoselective nucleophilic epoxidation of protected 3-amino and 3-hydroxy-substituted 1-arylthio-1-nitroalkenes, followed by intramolecular capture involving the amino and hydroxyl protecting groups, has led to the formation of isomeric oxazolidinones 5 and 7, and a cyclic carbonate 11. Together with the oxazolidinone precursor anti-alpha-bromo thioester 15a, the absolute and relative stereochemistry of these compounds has been determined by X-ray crystallography.
View Article and Find Full Text PDFIntroduction: In kidney transplantation, anatomical vascular and excretory anomalies may represent causes of failure. Today's surgical techniques have made the most of the organs with anatomic anomalies and iatrogenic injury successfully used for transplantation.
Materials And Methods: From January 2000 to June 2006, we harvested 230 kidneys, of including 88 kidneys (20%) with vascular, urinary, or vascular-urinary anomalies; 64 kidneys were implanted and 15 were sent to other transplantation centers.
The efficient and direct synthesis of protected biaryl amino acids, including dityrosine (50% overall yield over 3 steps), by Negishi cross-coupling of the serine-derived organozinc reagent 4 with iodo- and di-iodobiaryls, is reported. An improved, although still not perfect, diiodination of 2,2'-biphenol has been achieved using NMe3BnICl2-ZnCl2. Protection of phenolic hydroxyl groups as acetates, rather than benzyl ethers, is required for efficient cross-coupling, and evidence for acetyl migration has been observed during debenzylation of a substituted 2-acetoxy-2'-benzyloxybiaryl.
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