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1.
PLoS One ; 16(3): e0247620, 2021.
Article in English | MEDLINE | ID: mdl-33684140

ABSTRACT

OBJECTIVES: The burden of epidermal growth factor receptor (EGFR) exon 20 insertion mutation (Exon 20ins) in non-small cell lung cancer is not well understood. A systematic review was conducted to identify evidence on mutation frequency, prognostic impact, clinical, patient-reported, and economic outcomes associated with Exon 20ins. MATERIALS AND METHODS: Searches were conducted in Embase and Medline and supplemented with recent conference proceedings. Included studies were not limited by intervention, geography, or publication year. RESULTS: Seventy-eight unique studies were included; 53 reporting mutation frequency, 13 prognostic impact, 36 clinical outcomes, and one humanistic burden. No economic burden data were identified. The frequency of Exon 20ins mutation ranged from 0.1% to 4% of all NSCLC cases and 1% to 12% of all EGFR mutations. Data on the prognostic impact of Exon 20ins were heterogeneous but highlighted poorer outcomes in patients with Exon 20ins mutation compared with patients with other EGFR mutations and EGFR wildtype across a wide range of therapies and treatment lines. Comparative evidence on the clinical efficacy and safety of currently available therapies were limited, as were sample sizes of studies reporting on real-world effectiveness. Nine single-arm trials and 27 observational studies reported clinical outcomes for patients with Exon 20ins. Trends towards better survival and response were observed for chemotherapy compared with TKIs as first-line treatments. For subsequent treatment lines, novel targeted therapies provided encouraging preliminary responses while results for chemotherapy were less favorable. Limited safety data were reported. One conference abstract described the symptom burden for Exon 20ins patients with fatigue and pain being most common. CONCLUSION: Findings of the systematic review show a high unmet need for safe and efficacious treatments for patients with Exon 20ins as well and need for further evidence generation to better understand the patient-level and economic impact for these patients.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols , Carcinoma, Non-Small-Cell Lung/genetics , Lung Neoplasms/genetics , Mutagenesis, Insertional , Americas/epidemiology , Asia/epidemiology , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/epidemiology , Carcinoma, Non-Small-Cell Lung/mortality , Cohort Studies , ErbB Receptors/genetics , Europe/epidemiology , Exons , Gene Expression , Humans , Incidence , Lung Neoplasms/drug therapy , Lung Neoplasms/epidemiology , Lung Neoplasms/mortality , Mutation Rate , Prognosis , Protein Kinase Inhibitors/therapeutic use , Survival Analysis , Treatment Outcome
2.
Psychopharmacology (Berl) ; 238(4): 979-990, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33404734

ABSTRACT

INTRODUCTION: Cognitive function is closely linked to functional outcomes in psychiatric disorders such as schizophrenia, however developing effective treatments for cognitive dysfunction have proven elusive. Potential reasons for this may include the complexity of diseases, the absence of appropriate and translatable animal tests of cognitive dysfunction, and the reproducibility of findings. Attention is a key component of cognitive function traditionally assessed in the clinic using a variant of the continuous performance test (CPT). The 5-choice (5C)-CPT was developed as a translational cross-species version of this task. Given the association between glutamatergic abnormalities and cognitive dysfunction in schizophrenia, we hypothesized that the NMDA receptor antagonist MK-801 would impair 5C-CPT in rats across different laboratories, and determined whether the dopamine D1 receptor agonist SKF38393 or the nonspecific nicotinic agonist nicotine would remediate such deficits. METHOD: Rats were trained in the 5C-CPT at Beacon Discovery and UCSD. These rats were then treated with MK-801, agonist treatment, and combinations of the two. RESULTS: MK-801 produced 5C-CPT deficits in the same domains of rats across sites at similar doses. Neither nicotine nor SKF38393 treatment alone improved performance. Importantly, SKF38393, but not nicotine, remediated the MK-801-induced deficits. CONCLUSION: Convergent observation of MK-801-induced deficits in 5C-CPT was seen across laboratories, resulting in deficits consistent with those seen in people with schizophrenia. Treatment with SKF38393 but not nicotine reversed these deficits. More work is needed, but the 5C-CPT is a reliable method for detecting NMDA receptor disruption-induced deficits in attention.


Subject(s)
Attention/drug effects , Cognition/drug effects , Dizocilpine Maleate/pharmacology , Nicotinic Agonists/pharmacology , 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine/pharmacology , Animals , Dopamine Agonists/pharmacology , Laboratories , Male , Nicotine/pharmacology , Rats , Rats, Sprague-Dawley , Reproducibility of Results , Schizophrenia/physiopathology
3.
Dermatol Surg ; 47(1): 30-33, 2021 01 01.
Article in English | MEDLINE | ID: mdl-32604227

ABSTRACT

BACKGROUND: In transposition flaps, thicker tissue and higher degrees of rotation are associated with increased pivotal restraint; however, limited experimental data exist quantifying the degree to which these affect flap biomechanics. The use of artificial skin models in conjunction with digital image correlation technology allows for investigation into biomechanical properties of skin flaps. OBJECTIVE: To quantify the effects of tissue thickness and rotational angles on pivotal restraint within transposition flaps using artificial skin models. METHODS: Ninety degree bilobed and trilobed flaps were used to close defects in artificial skin models of increasing thicknesses. Digital image correlation was used to quantify strain. Quantitative and qualitative differences in strain were assessed in increasing flap thicknesses and between flap designs. RESULTS: Increasing flap thickness was associated with decreasing strain. In the bilobed flap, increasing thickness was associated with displacement of the flap pivot point away from the distal flap edge. Comparatively, lower angles of rotation in the trilobed flap were not associated with migration of the flap pivot point. CONCLUSION: Increased pivotal restraint observed in higher degrees of rotation is due to migration of the flap pivot point. This model supports the common practice of decreasing flap angles to compensate for pivotal restraint.


Subject(s)
Skin, Artificial , Surgical Flaps , Biomechanical Phenomena , Materials Testing , Photography , Rotation , Tensile Strength
4.
J Med Chem ; 63(21): 12957-12977, 2020 11 12.
Article in English | MEDLINE | ID: mdl-33118821

ABSTRACT

Inhibition of glutaminase-1 (GLS-1) hampers the proliferation of tumor cells reliant on glutamine. Known glutaminase inhibitors have potential limitations, and in vivo exposures are potentially limited due to poor physicochemical properties. We initiated a GLS-1 inhibitor discovery program focused on optimizing physicochemical and pharmacokinetic properties, and have developed a new selective inhibitor, compound 27 (IPN60090), which is currently in phase 1 clinical trials. Compound 27 attains high oral exposures in preclinical species, with strong in vivo target engagement, and should robustly inhibit glutaminase in humans.


Subject(s)
Enzyme Inhibitors/chemistry , Glutaminase/antagonists & inhibitors , Triazoles/pharmacokinetics , Administration, Oral , Animals , Cell Line, Tumor , Dogs , Drug Evaluation, Preclinical , Enzyme Inhibitors/metabolism , Enzyme Inhibitors/pharmacokinetics , Glutaminase/genetics , Glutaminase/metabolism , Half-Life , Hepatocytes/cytology , Hepatocytes/drug effects , Hepatocytes/metabolism , Humans , Inhibitory Concentration 50 , Male , Mice , Microsomes/metabolism , Protein Binding , Rats , Rats, Sprague-Dawley , Recombinant Proteins/biosynthesis , Recombinant Proteins/chemistry , Recombinant Proteins/isolation & purification , Structure-Activity Relationship , Triazoles/chemistry , Triazoles/metabolism
5.
J Sport Rehabil ; 30(2): 339-342, 2020 Jun 10.
Article in English | MEDLINE | ID: mdl-32521510

ABSTRACT

CONTEXT: An accurate assessment of lumbar spine active range of motion (AROM) is clinically important. Dual inclinometry is recommended as the optimal technique for measuring lumbar flexion AROM; however, the procedures differ in the literature. OBJECTIVE: To compare 2 different handheld digital dual inclinometry (HDDI) techniques for evaluating lumbar flexion AROM. DESIGN: The study was a repeated-measures design consisting of 2 trials. SETTING: Laboratory. PARTICIPANTS: A sample of 69 adult volunteers (28 men and 41 women; mean age 23.8 [2.4] y) without pain or injury to their back, hips, or abdomen for at least 3 months participated in the study. INTERVENTION: Using standardized methods, 1 trained tester performed 2 different HDDI measurements of standing lumbar flexion AROM on each subject. Each subject performed one repetition of AROM lumbar flexion per HDDI measurement. The HDDI measures differed in the process for placing the upper inclinometer, with one technique identifying the upper landmark by skilled palpation of the T12 spinous process and the other technique by measuring 15-cm cephalad to the S2 region landmark to approximate the location of the T12 spinous process. MAIN OUTCOME MEASURES: A dependent t test, Pearson correlation coefficient (r), the 95% limits of agreement, and Bland-Altman plots were used to examine agreement between the techniques. RESULTS: Dependent t testing showed no significant differences between the techniques (mean difference = 1.2°, P = .11). A strong correlation existed between the 2 HDDI techniques (r = .80, P < .001). The Bland-Altman plot illustrated that 64 of the 69 data points were within the 95% limits of agreement for the 2 techniques. CONCLUSIONS: The findings suggest that HDDI measurements of lumbar flexion AROM are comparable when using either of the 2 HDDI techniques described. Clinicians can make an evidence-based choice for using either method of measuring lumbar flexion AROM.


Subject(s)
Lumbar Vertebrae , Lumbosacral Region , Adult , Female , Humans , Male , Movement , Range of Motion, Articular , Reproducibility of Results , Young Adult
6.
J Pharmacol Exp Ther ; 369(3): 311-317, 2019 06.
Article in English | MEDLINE | ID: mdl-30872391

ABSTRACT

Lymphocyte trafficking out of secondary lymphoid organs is regulated by concentration gradient-dependent interactions between the membrane-derived lysophospholipid signaling molecule sphingosine 1-phosphate (S1P) and the G-protein-coupled receptor, S1P1 Etrasimod is a novel, next-generation, small-molecule, oral S1P receptor modulator in clinical development for the treatment of immune-mediated inflammatory disorders, including ulcerative colitis. In preclinical pharmacology studies, etrasimod was a full agonist of recombinant human (6.1 nM EC50), mouse (3.65 nM EC50), dog (4.19 nM EC50), and monkey (8.7 nM EC50) S1P1 receptors, and a partial agonist of human S1P4 (147 nM EC50) and S1P5 (24.4 nM EC50), with relative efficacies of 63% and 73% of S1P response, respectively; whereas neither agonist nor antagonist activity was observed for human S1P2 or S1P3 A dose-dependent relationship was observed for etrasimod plasma concentration and lymphocyte count in mice, and chronic treatment with etrasimod resulted in attenuation of inflammation in a CD4+CD45RBhigh T-cell transfer mouse model of colitis.


Subject(s)
Acetates/pharmacology , Colitis/drug therapy , Colitis/metabolism , Cyclopentanes/pharmacology , Heterocyclic Compounds, 3-Ring/pharmacology , Indoles/pharmacology , Lymphocytes/drug effects , Lymphocytes/metabolism , Sphingosine-1-Phosphate Receptors/metabolism , Acetates/therapeutic use , Animals , Biological Transport/drug effects , Cell Count , Colitis/immunology , Cyclopentanes/therapeutic use , Disease Models, Animal , Dogs , Heterocyclic Compounds, 3-Ring/therapeutic use , Humans , Indoles/therapeutic use , Male , Mice
7.
Clin Psychol Rev ; 51: 15-29, 2017 02.
Article in English | MEDLINE | ID: mdl-27816801

ABSTRACT

This review considers the potential influences of the use of cannabis for therapeutic purposes (CTP) on areas of interest to mental health professionals, with foci on adult psychopathology and assessment. We identified 31 articles relating to the use of CTP and mental health, and 29 review articles on cannabis use and mental health that did not focus on use for therapeutic purposes. Results reflect the prominence of mental health conditions among the reasons for CTP use, and the relative dearth of high-quality evidence related to CTP in this context, thereby highlighting the need for further research into the harms and benefits of medical cannabis relative to other therapeutic options. Preliminary evidence suggests that CTP may have potential for the treatment of PTSD, and as a substitute for problematic use of other substances. Extrapolation from reviews of non-therapeutic cannabis use suggests that the use of CTP may be problematic among individuals with psychotic disorders. The clinical implications of CTP use among individuals with mood disorders are unclear. With regard to assessment, evidence suggests that CTP use does not increase risk of harm to self or others. Acute cannabis intoxication and recent CTP use may result in reversible deficits with the potential to influence cognitive assessment, particularly on tests of short-term memory.


Subject(s)
Medical Marijuana/adverse effects , Mental Health , Humans
8.
Bioorg Med Chem Lett ; 25(15): 3034-8, 2015 Aug 01.
Article in English | MEDLINE | ID: mdl-26048791

ABSTRACT

The design and optimization of a novel trans-1,4-dioxycyclohexane GPR119 agonist series is described. A lead compound 21 was found to be a potent and efficacious GPR119 agonist across species, and possessed overall favorable pharmaceutical properties. Compound 21 demonstrated robust acute and chronic regulatory effects on glycemic parameters in the diabetic or non-diabetic rodent models.


Subject(s)
Cyclohexanes/chemistry , Cyclohexanes/therapeutic use , Diabetes Mellitus, Type 2/drug therapy , Hypoglycemic Agents/chemistry , Hypoglycemic Agents/therapeutic use , Receptors, G-Protein-Coupled/agonists , Administration, Oral , Animals , Blood Glucose/analysis , Cyclohexanes/administration & dosage , Cyclohexanes/pharmacokinetics , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/metabolism , Humans , Hypoglycemic Agents/administration & dosage , Hypoglycemic Agents/pharmacokinetics , Male , Mice , Rats, Sprague-Dawley , Rats, Zucker , Receptors, G-Protein-Coupled/metabolism , Structure-Activity Relationship
9.
Northwest Dent ; 92(4): 28-9, 2013.
Article in English | MEDLINE | ID: mdl-24027872
10.
Mar Pollut Bull ; 65(4-9): 136-49, 2012.
Article in English | MEDLINE | ID: mdl-22277580

ABSTRACT

Targets for improvements in water quality entering the Great Barrier Reef (GBR) have been set through the Reef Water Quality Protection Plan (Reef Plan). To measure and report on progress towards the targets set a program has been established that combines monitoring and modelling at paddock through to catchment and reef scales; the Paddock to Reef Integrated Monitoring, Modelling and Reporting Program (Paddock to Reef Program). This program aims to provide evidence of links between land management activities, water quality and reef health. Five lines of evidence are used: the effectiveness of management practices to improve water quality; the prevalence of management practice adoption and change in catchment indicators; long-term monitoring of catchment water quality; paddock & catchment modelling to provide a relative assessment of progress towards meeting targets; and finally marine monitoring of GBR water quality and reef ecosystem health. This paper outlines the first four lines of evidence.


Subject(s)
Agriculture/statistics & numerical data , Coral Reefs , Environmental Monitoring , Models, Chemical , Water Quality/standards , Agriculture/methods , Conservation of Natural Resources , Environmental Policy , Government Programs , Program Evaluation , Water Pollutants, Chemical/analysis , Water Pollution, Chemical/legislation & jurisprudence , Water Pollution, Chemical/prevention & control , Water Pollution, Chemical/statistics & numerical data
11.
Mol Endocrinol ; 24(1): 161-70, 2010 Jan.
Article in English | MEDLINE | ID: mdl-19901198

ABSTRACT

G protein-coupled receptor 119 (GPR119) is largely restricted to pancreatic insulin-producing beta-cells and intestinal glucagon-like peptide-1-producing L-cells. Synthetic agonists of this receptor elicit glucose-dependent release of these endocrine factors, thereby enhancing glycemic control. Oleoylethanolamide also activates GPR119, but it remains unclear whether endogenous production of this lipid modulates GPR119 activity under normal or dysglycemic conditions. We show here that a relatively diverse set of lipid amides activate GPR119. Among these, the endovallinoid N-oleoyldopamine (OLDA) stimulated cAMP accumulation in GPR119-transfected cells as effectively as oleoylethanolamide and the previously described synthetic agonist AR231453. None of these lipid amides increased cAMP in control-transfected cells or in cells transfected with a number of other G protein-coupled receptors. OLDA stimulated both cAMP accumulation and insulin release in HIT-T15 cells, which express GPR119 endogenously, and in GPR119-transfected RIN-5F cells. Oral administration of OLDA to C57bl/6 mice elicited significant improvement in glucose tolerance, whereas GPR119-deficient mice were essentially unresponsive. OLDA also acutely elevated plasma gastric inhibitory peptide levels, a known hallmark of GPR119 activation. OLDA represents a possible paracrine modulator of GPR119 in pancreatic islets, where markers of dopamine synthesis correlated well with GPR119 expression. However, no such correlation was seen in the colon. Collectively, these studies indicate that multiple, distinct classes of lipid amides, acting via GPR119, may be important modulators of glucose homeostasis.


Subject(s)
Blood Glucose/analysis , Dopamine/analogs & derivatives , Homeostasis , Insulin-Secreting Cells/drug effects , Insulin/metabolism , Receptors, G-Protein-Coupled/metabolism , Amides/metabolism , Amides/pharmacology , Animals , Cell Line , Cricetinae , Dopamine/metabolism , Dopamine/pharmacology , Dose-Response Relationship, Drug , Fatty Acids/metabolism , Fatty Acids/pharmacology , Female , Homeostasis/drug effects , Humans , Insulin Secretion , Insulin-Secreting Cells/enzymology , Insulin-Secreting Cells/metabolism , Male , Mice , Mice, Inbred Strains , Mice, Knockout , Organ Specificity , Rats , Receptors, G-Protein-Coupled/agonists , Receptors, G-Protein-Coupled/deficiency , Receptors, G-Protein-Coupled/genetics
12.
J Med Chem ; 51(17): 5172-5, 2008 Sep 11.
Article in English | MEDLINE | ID: mdl-18698756

ABSTRACT

GPR119 is a rhodopsin-like GPCR expressed in pancreatic beta-cells and incretin releasing cells in the GI tract. As with incretins, GPR119 increases cAMP levels in these cell types, thus making it a highly attractive potential target for the treatment of diabetes. The discovery of the first reported potent agonist of GPR119, 2-fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amine (8g, AR231453), is described starting from an initial inverse agonist screening hit. Compound 8g showed in vivo activity in rodents and was active in an oral glucose tolerance test in mice following oral administration.


Subject(s)
Hypoglycemic Agents/chemistry , Receptors, G-Protein-Coupled/agonists , Administration, Oral , Animals , Blood Glucose/drug effects , Glucose Tolerance Test , Humans , Hypoglycemic Agents/chemical synthesis , Hypoglycemic Agents/pharmacology , Mice , Molecular Structure , Rats , Structure-Activity Relationship
13.
Endocrinology ; 149(5): 2038-47, 2008 May.
Article in English | MEDLINE | ID: mdl-18202141

ABSTRACT

We recently showed that activation of G protein-coupled receptor 119 (GPR119) (also termed glucose dependent insulinotropic receptor) improves glucose homeostasis via direct cAMP-mediated enhancement of glucose-dependent insulin release in pancreatic beta-cells. Here we show that GPR119 also stimulates incretin hormone release and thus may regulate glucose homeostasis by this additional mechanism. GPR119 mRNA was found to be expressed at significant levels in intestinal subregions that produce glucose-dependent insulinotropic peptide and glucagon-like peptide (GLP)-1. Furthermore, in situ hybridization studies indicated that most GLP-1-producing cells coexpress GPR119 mRNA. In GLUTag cells, a well-established model of intestinal L-cell function, the potent GPR119 agonist AR231453 stimulated cAMP accumulation and GLP-1 release. When administered in mice, AR231453 increased active GLP-1 levels within 2 min after oral glucose delivery and substantially enhanced total glucose-dependent insulinotropic peptide levels. Blockade of GLP-1 receptor signaling with exendin(9-39) reduced the ability of AR231453 to improve glucose tolerance in mice. Conversely, combined administration of AR231453 and the DPP-4 inhibitor sitagliptin to wild-type mice significantly amplified both plasma GLP-1 levels and oral glucose tolerance, relative to either agent alone. In mice lacking GPR119, no such enhancement was seen. Thus, GPR119 regulates glucose tolerance by acting on intestinal endocrine cells as well as pancreatic beta-cells. These data also suggest that combined stimulation of incretin hormone release and protection against incretin hormone degradation may be an effective antidiabetic strategy.


Subject(s)
Blood Glucose/metabolism , Enteroendocrine Cells/metabolism , Gastric Inhibitory Polypeptide/metabolism , Glucagon-Like Peptide 1/metabolism , Receptors, G-Protein-Coupled/physiology , Animals , Cells, Cultured , Cyclic AMP/metabolism , Dipeptidyl-Peptidase IV Inhibitors/pharmacology , Glucagon-Like Peptide 1/blood , Glucagon-Like Peptide-1 Receptor , Glycemic Index/physiology , Humans , Insulin-Secreting Cells/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Oxadiazoles/pharmacology , Pyrimidines/pharmacology , RNA, Messenger/metabolism , Receptors, G-Protein-Coupled/agonists , Receptors, G-Protein-Coupled/genetics , Receptors, G-Protein-Coupled/metabolism , Receptors, Glucagon/antagonists & inhibitors , Tissue Distribution
14.
Endocrinology ; 148(6): 2601-9, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17289847

ABSTRACT

Pancreatic beta-cell dysfunction is a hallmark event in the pathogenesis of type 2 diabetes. Injectable peptide agonists of the glucagon-like peptide 1 (GLP-1) receptor have shown significant promise as antidiabetic agents by virtue of their ability to amplify glucose-dependent insulin release and preserve pancreatic beta-cell mass. These effects are mediated via stimulation of cAMP through beta-cell GLP-1 receptors. We report that the Galpha(s)-coupled receptor GPR119 is largely restricted to insulin-producing beta-cells of pancreatic islets. Additionally, we show here that GPR119 functions as a glucose-dependent insulinotropic receptor. Unlike receptors for GLP-1 and other peptides that mediate enhanced glucose-dependent insulin release, GPR119 was suitable for the development of potent, orally active, small-molecule agonists. The GPR119-specific agonist AR231453 significantly increased cAMP accumulation and insulin release in both HIT-T15 cells and rodent islets. In both cases, loss of GPR119 rendered AR231453 inactive. AR231453 also enhanced glucose-dependent insulin release in vivo and improved oral glucose tolerance in wild-type mice but not in GPR119-deficient mice. Diabetic KK/A(y) mice were also highly responsive to AR231453. Orally active GPR119 agonists may offer significant promise as novel antihyperglycemic agents acting in a glucose-dependent fashion.


Subject(s)
Blood Glucose/physiology , Glucose/pharmacology , Insulin-Secreting Cells/metabolism , Insulin/metabolism , Receptors, G-Protein-Coupled/physiology , Animals , Cells, Cultured , Diabetes Mellitus/genetics , Diabetes Mellitus/pathology , Female , Glucose Tolerance Test , Humans , Insulin Secretion , Male , Mice , Mice, Inbred C57BL , Mice, Transgenic , Models, Biological , Oxadiazoles/pharmacology , Pyrimidines/pharmacology , Rats , Rats, Sprague-Dawley , Rats, Zucker , Receptors, G-Protein-Coupled/agonists , Receptors, G-Protein-Coupled/genetics
15.
Bioorg Med Chem ; 14(16): 5625-31, 2006 Aug 15.
Article in English | MEDLINE | ID: mdl-16697205

ABSTRACT

We report the synthesis of thirty-six Sansalvamide A derivatives, and their biological activity against colon cancer HT-29 cell line, a microsatellite stable (MSS) colon cancer cell-line. The thirty-six compounds can be divided into three subsets, where the first subset of compounds contains L-amino acids, the second subset contains D-amino acids, and the third subset contains both D- and L-amino acids. Five compounds exhibited excellent inhibitory activity (>75% inhibition). The structure-activity relationship (SAR) of the compounds established that a single D-amino acid in position 2 or 3 gave up to a 10-fold improved cytotoxicity over Sansalvamide A peptide. This work highlights the importance of residues 2 and 3 and the role of D-amino acids in the extraordinary SAR for this compound class.


Subject(s)
Antineoplastic Agents/pharmacology , Depsipeptides/pharmacology , HT29 Cells/drug effects , Amino Acids/chemistry , Antineoplastic Agents/chemical synthesis , Colonic Neoplasms/pathology , Depsipeptides/chemical synthesis , HT29 Cells/metabolism , Humans , Inhibitory Concentration 50 , Structure-Activity Relationship , Thymidine/metabolism , Tumor Cells, Cultured
16.
Bioorg Med Chem ; 14(14): 4731-9, 2006 Jul 15.
Article in English | MEDLINE | ID: mdl-16581254

ABSTRACT

Holliday junctions (HJs) are formed as transient DNA intermediates during site-specific and homologous recombination. Both of these genetic exchange pathways are critical for normal DNA metabolism and repair. Trapping HJs leads to bacterial cell death by preventing proper segregation of the resulting interlinked chromosomes. Macrocyclic peptides designed to target this intermediate were synthesized with the goal of identifying compounds with specificity for this unique molecular target. We discovered ten macrocycles, both hexameric and octameric peptides, capable of trapping HJs in vitro. Those macrocycles containing tyrosine residues proved most effective. These data demonstrate that C-2 symmetrical macrocycles offer excellent synthetic targets for the development of novel antibiotic agents. Furthermore, the active compounds identified provide valuable tools for probing different pathways of recombinational exchange.


Subject(s)
Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/pharmacology , DNA, Cruciform/drug effects , DNA, Cruciform/metabolism , Endodeoxyribonucleases/metabolism , Escherichia coli Proteins/metabolism , Oligopeptides/chemical synthesis , Oligopeptides/pharmacology , Peptides, Cyclic/chemical synthesis , Peptides, Cyclic/pharmacology , Anti-Bacterial Agents/chemistry , Escherichia coli/drug effects , Escherichia coli/enzymology , In Vitro Techniques , Macromolecular Substances , Models, Molecular , Molecular Structure , Nucleic Acid Conformation , Oligopeptides/chemistry , Peptides, Cyclic/chemistry , Protein Conformation , Staphylococcus epidermidis/drug effects
17.
Org Lett ; 7(16): 3481-4, 2005 Aug 04.
Article in English | MEDLINE | ID: mdl-16048322

ABSTRACT

Described are the syntheses of 14 derivatives of the natural product Sansalvamide A, where two are more active against HCT 116 colon cancer cell lines than the natural product. These derivatives were synthesized using a combinatorial-type strategy that permits elucidation of the amino acid role in the cytotoxicity, and they lay the groundwork for development of new anticancer agents. [structure: see text]


Subject(s)
Antineoplastic Agents , Depsipeptides , Fusarium/chemistry , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Depsipeptides/chemical synthesis , Depsipeptides/chemistry , Depsipeptides/pharmacology , Drug Screening Assays, Antitumor , Humans , Molecular Structure , Structure-Activity Relationship , Tumor Cells, Cultured
18.
Chembiochem ; 6(1): 162-70, 2005 Jan.
Article in English | MEDLINE | ID: mdl-15593114

ABSTRACT

Anacardic acid is an alkylsalicylic acid obtained from cashew-nut-shell liquid, and is a potent inhibitor of p300 histone acetyl-transferase (HAT) activity. We have used anacardic acid to prevent the induction of hypertrophy in isolated neonatal rat cardiomyocytes. Hypertrophy was detected as an increase in cell size, the rearrangement of sarcomeres into a striated pattern, and the induction of embryonic genes beta-MHC and ANF. p300 inhibition was equally effective at preventing hypertrophy whether it was induced by treatment with the alpha1-adrenergic agonist, phenylephrine, or by treatment with urocortin, a member of the corticotrophin-releasing-factor family, which stimulates specific G protein-coupled receptors. Spiruchostatin A is a natural-product inhibitor of histone deacetylases (HDAC) similar to the depsipeptide FK228 molecule. We have recently synthesized spiruchostatin A and now show that, although HDACs act in opposition to HATs, spiruchostatin A has the same effect as anacardic acid, that is, it prevents the induction of hypertrophy in response to phenylephrine or urocortin. Pretreatment with either phenylephrine or urocortin reduced the extent of death observed after the exposure of isolated cardiomyocytes to simulated ischaemia and reoxygenation. Inhibition of p300 or HDAC activity eliminated the protection conferred by phenylephrine; however, it did not affect the protection conferred by urocortin. Therefore, it might eventually be possible to use chemical inhibitors such as these in a therapeutic setting to dissociate the protective effect and hypertrophic effect of urocortin, enhancing the survival of cardiomyocytes exposed to transient ischemia, while inhibiting the hypertrophic pathway that would otherwise be induced concurrently.


Subject(s)
Corticotropin-Releasing Hormone/pharmacology , Myocytes, Cardiac/drug effects , Nuclear Proteins/physiology , Phenylephrine/pharmacology , Trans-Activators/physiology , Transcriptional Activation , Anacardic Acids/chemistry , Anacardic Acids/toxicity , Animals , Base Sequence , Cell Size , E1A-Associated p300 Protein , Female , Molecular Sequence Data , Myocytes, Cardiac/cytology , Myocytes, Cardiac/metabolism , Pregnancy , Rats , Signal Transduction , Urocortins
19.
Clin Transplant ; 16(3): 180-4, 2002 Jun.
Article in English | MEDLINE | ID: mdl-12010140

ABSTRACT

BACKGROUND: In an effort to increase organ donation, the Department of Health and Human Services issued the Final Rule in 1998. The Health Care Financing Administration (HCFA) later required hospitals to notify organ procurement organizations (OPO) of all deaths and imminent deaths in order to remain eligible for Medicare and Medicaid reimbursement. We set out to determine the impact of the Final Rule on organ donation in Hawaii. METHODS: Medical records of all deaths between January 1999 and December 2000 at 17 acute-care hospitals were reviewed to determine the number of medically suitable, potential organ donors. RESULTS: Of 9427 deaths, 144 were potential organ donors. In 1999, before the Final Rule, 60 of 75 (80%) potential donors were identified and 40 (53%) were referred to the OPO. In 2000, after the Final Rule, the identification rate was 83% and the referral rate was 70%. CONCLUSIONS: Although, the Final Rule increased the referral rate slightly, medical centres must continue to improve their identification of potential donors and prompt referral. This is not only to comply with the Final Rule, but ultimately to increase organ donation to meet the needs of the ever-expanding list of patients waiting for organs.


Subject(s)
Tissue Donors/legislation & jurisprudence , Tissue and Organ Procurement/legislation & jurisprudence , Hawaii , Humans , Referral and Consultation , Tissue Donors/statistics & numerical data
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