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1.
J Public Health Manag Pract ; 28(Suppl 1): S66-S69, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34797263

RESUMO

Community-based organizations are uniquely positioned to address critical gaps in social support that contribute to inequities in maternal health. Using a human-centered design process, we held 3 design workshops with members of 15 organizations in Greater Boston, including community-based organizations, allied hospital systems, and public health departments, to assess proposed solutions for gaps in social support services during pregnancy and the first year after childbirth. The workshops focused on solutions to problems that emerged from a mixed-methods research study with community-based organizations that provide social support services; workshop attendees explored facilitators and barriers to implementing solutions. Key considerations included colocation of solutions, shared ownership of program and client data, decision making about triage and referrals, and strengthening coordination of existing programs. Collaborative design workshops surfaced potential solutions to improve coordination of services, which require addressing structural and interpersonal racism in Greater Boston.


Assuntos
Grupos Raciais , Racismo , Boston , Etnicidade , Feminino , Humanos , Gravidez , Saúde Pública
2.
J Pain Symptom Manage ; 63(3): e337-e343, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34662725

RESUMO

Systemic or structural racism describes an embedded pattern of explicit and implicit racial biases that, through policy and action, systematically confer advantage to white people and disadvantage Black, indigenous, and other people of color. Hospice and palliative care journals participate in this broader system of racial discrimination. Building on palliative care's explicit focus on patients' goals and values, which may in and of itself comprise a form of social justice in healthcare, palliative care journals and their publishers have an opportunity to lead others in cultivating anti-racist practices and explicitly promoting equity. The publication life cycle of submission and solicitation, manuscript peer-review, and publication provide a framework for examining the structures, processes, and outcomes by which palliative care and other journals might address systemic racism. We describe the current academic publishing landscape, which diminishes the voices and experiences of racial and ethnic minority patients and undermines the careers of under-represented scholars. We then propose reforms that we believe will improve publication equity and quality as well as healthcare outcomes. These include an Equity in Publication checklist, solicitation of manuscripts on equity-relevant topics, promotion of scholars through editorial structures and peer review processes, and a standard Equity Rating for publications. Greater efforts to include non-dominant voices in every aspect of publication, through appropriate recognition of their scholarship and remuneration for their efforts, will drive equity in health outcomes. By pursuing an anti-racist and equity-focused publishing agenda, hospice and palliative medicine journals and their publishers have an opportunity to transform healthcare.


Assuntos
Cuidados Paliativos , Racismo , Etnicidade , Humanos , Grupos Minoritários , Justiça Social
3.
Phys Rev Lett ; 127(11): 112501, 2021 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-34558921

RESUMO

High-accuracy mass measurements of neutron-deficient Yb isotopes have been performed at TRIUMF using TITAN's multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS). For the first time, an MR-TOF-MS was used on line simultaneously as an isobar separator and as a mass spectrometer, extending the measurements to two isotopes further away from stability than otherwise possible. The ground state masses of ^{150,153}Yb and the excitation energy of ^{151}Yb^{m} were measured for the first time. As a result, the persistence of the N=82 shell with almost unmodified shell gap energies is established up to the proton drip line. Furthermore, the puzzling systematics of the h_{11/2}-excited isomeric states of the N=81 isotones are unraveled using state-of-the-art mean field calculations.

4.
Anal Chem ; 89(3): 1955-1964, 2017 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-28208252

RESUMO

In this study, a data-dependent, high-resolution tandem mass spectrometry (ddHRMS/MS) method capable of detecting all organophosphorus nerve agent (OPNA) adducts to human butyrylcholinesterase (BChE) was developed. After an exposure event, immunoprecipitation from blood with a BChE-specific antibody and digestion with pepsin produces a nine amino acid peptide containing the OPNA adduct. Signature product ions of this peptic BChE nonapeptide (FGES*AGAAS) offer a route to broadly screen for OPNA exposure. Taking this approach on an HRMS instrument identifies biomarkers, including unknowns, with high mass accuracy. Using a set of pooled human sera exposed to OPNAs as quality control (QC) materials, the developed method successfully identified precursor ions with <1 ppm and tied them to signature product ions with <5 ppm deviation from their chemical formulas. This high mass accuracy data from precursor and product ions, collected over 23 independent immunoprecipitation preparations, established method operating limits. QC data and experiments with 14 synthetic reference peptides indicated that reliable qualitative identification of biomarkers was possible for analytes >15 ng/mL. The developed method was applied to a convenience set of 96 unexposed serum samples and a blinded set of 80 samples treated with OPNAs. OPNA biomarkers were not observed in convenience set samples and no false positive or negative identifications were observed in blinded samples. All biomarkers in the blinded serum set >15 ng/mL were correctly identified. For the first time, this study reports a ddHRMS/MS method capable of complementing existing quantitative methodologies and suitable for identifying exposure to unknown organophosphorus agents.


Assuntos
Butirilcolinesterase/efeitos dos fármacos , Agentes Neurotóxicos/toxicidade , Oligopeptídeos/sangue , Compostos Organofosforados/toxicidade , Biomarcadores/sangue , Butirilcolinesterase/sangue , Butirilcolinesterase/química , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida de Alta Pressão/normas , Reações Falso-Negativas , Reações Falso-Positivas , Humanos , Imunoprecipitação , Agentes Neurotóxicos/normas , Oligopeptídeos/química , Compostos Organofosforados/normas , Controle de Qualidade , Padrões de Referência , Espectrometria de Massas em Tandem/métodos , Espectrometria de Massas em Tandem/normas
5.
Lancet Glob Health ; 5(4): e458-e466, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28153514

RESUMO

BACKGROUND: Outbreaks of unexplained illness frequently remain under-investigated. In India, outbreaks of an acute neurological illness with high mortality among children occur annually in Muzaffarpur, the country's largest litchi cultivation region. In 2014, we aimed to investigate the cause and risk factors for this illness. METHODS: In this hospital-based surveillance and nested age-matched case-control study, we did laboratory investigations to assess potential infectious and non-infectious causes of this acute neurological illness. Cases were children aged 15 years or younger who were admitted to two hospitals in Muzaffarpur with new-onset seizures or altered sensorium. Age-matched controls were residents of Muzaffarpur who were admitted to the same two hospitals for a non-neurologic illness within seven days of the date of admission of the case. Clinical specimens (blood, cerebrospinal fluid, and urine) and environmental specimens (litchis) were tested for evidence of infectious pathogens, pesticides, toxic metals, and other non-infectious causes, including presence of hypoglycin A or methylenecyclopropylglycine (MCPG), naturally-occurring fruit-based toxins that cause hypoglycaemia and metabolic derangement. Matched and unmatched (controlling for age) bivariate analyses were done and risk factors for illness were expressed as matched odds ratios and odds ratios (unmatched analyses). FINDINGS: Between May 26, and July 17, 2014, 390 patients meeting the case definition were admitted to the two referral hospitals in Muzaffarpur, of whom 122 (31%) died. On admission, 204 (62%) of 327 had blood glucose concentration of 70 mg/dL or less. 104 cases were compared with 104 age-matched hospital controls. Litchi consumption (matched odds ratio [mOR] 9·6 [95% CI 3·6 - 24]) and absence of an evening meal (2·2 [1·2-4·3]) in the 24 h preceding illness onset were associated with illness. The absence of an evening meal significantly modified the effect of eating litchis on illness (odds ratio [OR] 7·8 [95% CI 3·3-18·8], without evening meal; OR 3·6 [1·1-11·1] with an evening meal). Tests for infectious agents and pesticides were negative. Metabolites of hypoglycin A, MCPG, or both were detected in 48 [66%] of 73 urine specimens from case-patients and none from 15 controls; 72 (90%) of 80 case-patient specimens had abnormal plasma acylcarnitine profiles, consistent with severe disruption of fatty acid metabolism. In 36 litchi arils tested from Muzaffarpur, hypoglycin A concentrations ranged from 12·4 µg/g to 152·0 µg/g and MCPG ranged from 44·9 µg/g to 220·0 µg/g. INTERPRETATION: Our investigation suggests an outbreak of acute encephalopathy in Muzaffarpur associated with both hypoglycin A and MCPG toxicity. To prevent illness and reduce mortality in the region, we recommended minimising litchi consumption, ensuring receipt of an evening meal and implementing rapid glucose correction for suspected illness. A comprehensive investigative approach in Muzaffarpur led to timely public health recommendations, underscoring the importance of using systematic methods in other unexplained illness outbreaks. FUNDING: US Centers for Disease Control and Prevention.


Assuntos
Encefalopatia Aguda Febril/diagnóstico , Surtos de Doenças/estatística & dados numéricos , Frutas/toxicidade , Litchi/toxicidade , Síndromes Neurotóxicas/diagnóstico , Encefalopatia Aguda Febril/epidemiologia , Encefalopatia Aguda Febril/etiologia , Adolescente , Estudos de Casos e Controles , Criança , Ciclopropanos/análise , Feminino , Glicina/análogos & derivados , Glicina/análise , Humanos , Hipoglicinas/análise , Índia , Masculino , Síndromes Neurotóxicas/epidemiologia , Síndromes Neurotóxicas/etiologia , Razão de Chances
6.
J Chem Educ ; 94(8): 1094-1097, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-30122790

RESUMO

The Multi-Rule Quality Control System (MRQCS) is a tool currently employed by the Centers for Disease Control and Prevention (CDC) to evaluate and compare laboratory performance. We have applied the MRQCS to a comparison of instructor and computer-led pre-laboratory lectures for a supplemental learning experiment. Students in general chemistry and analytical chemistry from both two- and four-year institutions performed two laboratory experiments as part of their normal laboratory curriculum. The first laboratory experiment was a foundational learning experiment in which all the students were introduced to Beer-Lambert's Law and spectrophotometric light absorbance measurements. The foundational learning experiment was instructor-led only, and participant performance was evaluated against a mean characterized value. The second laboratory experiment was a supplemental learning experiment in which students were asked to build upon the methodology they learned in the foundational learning experiment and apply it to a different analyte. The instruction type was varied randomly into two delivery modes, participants receiving either instructor-led or computer-led pre-laboratory instruction. The MRQCS was applied and determined that no statistical difference was found to exist in the QC (quality control) passing rates between the participants in the instructor-led instruction and the participants in the computer-led instruction. These findings demonstrate the successful application of the MRQCS to evaluate knowledge and technology transfer.

7.
Biomed Chromatogr ; 31(4)2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27572107

RESUMO

Organophosphorus nerve agents (OPNAs) are toxic compounds that are classified as prohibited Schedule 1 chemical weapons. In the body, OPNAs bind to butyrylcholinesterase (BChE) to form nerve agent adducts (OPNA-BChE). OPNA-BChE adducts can provide a reliable, long-term protein biomarker for assessing human exposure. A major challenge facing OPNA-BChE detection is hydrolysis (aging), which can continue to occur after a clinical specimen has been collected. During aging, the o-alkyl phosphoester bond hydrolyzes, and the specific identity of the nerve agent is lost. To better identify OPNA exposure events, a high-throughput method for the detection of five aged OPNA-BChE adducts was developed. This is the first diagnostic panel to allow for the simultaneous quantification of any Chemical Weapons Convention Schedule 1 OPNA by measuring the aged adducts methyl phosphonate, ethyl phosphonate, propyl phosphonate, ethyl phosphoryl, phosphoryl and unadducted BChE. The calibration range for all analytes is 2.00-250. ng/mL, which is consistent with similar methodologies used to detect unaged OPNA-BChE adducts. Each analytical run is 3 min, making the time to first unknown results, including calibration curve and quality controls, less than 1 h. Analysis of commercially purchased individual serum samples demonstrated no potential interferences with detection of aged OPNA-BChE adducts, and quantitative measurements of endogenous levels of BChE were similar to those previously reported in other OPNA-BChE adduct assays.


Assuntos
Biomarcadores/sangue , Butirilcolinesterase/metabolismo , Cromatografia Líquida/métodos , Agentes Neurotóxicos/toxicidade , Espectrometria de Massas em Tandem/métodos , Butirilcolinesterase/química , Exposição Ambiental/análise , Meia-Vida , Ensaios de Triagem em Larga Escala/métodos , Humanos , Agentes Neurotóxicos/farmacocinética , Compostos Organofosforados/sangue , Compostos Organofosforados/farmacocinética , Compostos Organofosforados/toxicidade
8.
J Agric Food Chem ; 64(27): 5607-13, 2016 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-27367968

RESUMO

Methylenecyclopropylglycine (MCPG) and hypoglycin A (HGA) are naturally occurring amino acids found in some soapberry fruits. Fatalities have been reported worldwide as a result of HGA ingestion, and exposure to MCPG has been implicated recently in the Asian outbreaks of hypoglycemic encephalopathy. In response to an outbreak linked to soapberry ingestion, the authors developed the first method to simultaneously quantify MCPG and HGA in soapberry fruits from 1 to 10 000 ppm of both toxins in dried fruit aril. Further, this is the first report of HGA in litchi, longan, and mamoncillo arils. This method is presented to specifically address the laboratory needs of public-health investigators in the hypoglycemic encephalitis outbreaks linked to soapberry fruit ingestion.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Ciclopropanos/análise , Frutas/química , Glicina/análogos & derivados , Hipoglicinas/análise , Sapindaceae/química , Espectrometria de Massas em Tandem/métodos , Ciclopropanos/toxicidade , Frutas/toxicidade , Glicina/análise , Glicina/toxicidade , Hipoglicinas/toxicidade , Sapindaceae/toxicidade
9.
J Anal Toxicol ; 40(4): 248-54, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26977107

RESUMO

Currently used on F-16 fighter jets and some space shuttles, hydrazine could be released at toxic levels to humans as a result of an accidental leakage or spill. Lower-level exposures occur in industrial workers or as a result of the use of some pharmaceuticals. A method was developed for the quantitation of hydrazine in human urine and can be extended by dilution with water to cover at least six orders of magnitude, allowing measurement at all clinically significant levels of potential exposure. Urine samples were processed by isotope dilution, filtered, derivatized and then quantified by HPLC-MS-MS. The analytical response ratio was linearly proportional to the urine concentration of hydrazine from 0.0493 to 12.3 ng/mL, with an average correlation coefficientRof 0.9985. Inter-run accuracy for 21 runs, expressed as percent relative error (% RE), was ≤14%, and the corresponding precision, expressed as percent relative standard deviation (% RSD), was ≤15%. Because this method can provide a quantitative measurement of clinical samples over six orders of magnitude, it can be used to monitor trace amounts of hydrazine exposure as well as industrial and environmental exposure levels.


Assuntos
Carcinógenos/análise , Hidrazinas/urina , Calibragem , Cromatografia Líquida de Alta Pressão , Exposição Ambiental , Humanos , Controle de Qualidade , Técnica de Diluição de Radioisótopos , Reprodutibilidade dos Testes , Soluções , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem
10.
Chem Res Toxicol ; 28(9): 1753-9, 2015 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-26328472

RESUMO

Ingestion of soapberry fruit toxins hypoglycin A and methylenecyclopropylglycine has been linked to public health challenges worldwide. In 1976, over 100 years after Jamaican vomiting sickness (JVS) was first reported, the cause of JVS was linked to the ingestion of the toxin hypoglycin A produced by ackee fruit. A structural analogue of hypoglycin A, methylenecyclopropylglycine (MCPG), was implicated as the cause of an acute encephalitis syndrome (AES). Much of the evidence linking hypoglycin A and MCPG to these diseases has been largely circumstantial due to the lack of an analytical method for specific metabolites. This study presents an analytical approach to identify and quantify specific urine metabolites for exposure to hypoglycin A and MCPG. The metabolites are excreted in urine as glycine adducts methylenecyclopropylacetyl-glycine (MCPA-Gly) and methylenecyclopropylformyl-glycine (MCPF-Gly). These metabolites were processed by isotope dilution, separated by reverse-phase liquid chromatography, and monitored by electrospray ionization tandem mass spectrometry. The analytical response ratio was linearly proportional to the concentration of MCPF-Gly and MCPA-Gly in urine from 0.10 to 20 µg/mL with a correlation coefficient of r > 0.99. The assay demonstrated accuracy ≥80% and precision ≤20% RSD across the calibration range. This method has been applied to assess exposure to hypoglycin A and MCPG as part of a larger public health initiative and was used to provide the first reported identification of MCPF-Gly and MCPA-Gly in human urine.


Assuntos
Ciclopropanos/toxicidade , Exposição Ambiental , Glicina/análogos & derivados , Hipoglicinas/toxicidade , Sapindus/química , Animais , Glicina/toxicidade , Humanos , Ratos
11.
Dalton Trans ; 44(37): 16313-24, 2015 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-26300277

RESUMO

The synthesis, characterization, and structures of a series of homoleptic and heteroleptic copper(I) complexes supported by N-heterocyclic chalcogenone ligands is reported herein. The quasi-reversible Cu(II/I) reduction potentials of these copper complexes with monodentate (dmit or dmise) and/or bidentate (Bmm(Me), Bsem(Me), Bme(Me), Bsee(Me)) chalcogenone ligands are highly dependent upon the nature and number of the donor groups and can be tuned over a 470 mV range (-369 to 102 mV). Copper-selone complexes have more negative Cu(II/I) reduction potentials relative to their thione analogs by an average of 137 mV, and increasing the number of methylene units linking the heterocyclic rings in the bidentate ligands results in more negative reduction potentials for their copper complexes. This ability to tune the copper reduction potentials over a wide range has potential applications in synthetic and industrial catalysis as well as the understanding of important biological processes such as electron transfer in blue copper proteins and respiration.


Assuntos
Complexos de Coordenação/síntese química , Cobre/química , Tionas/química , Complexos de Coordenação/química , Cristalografia por Raios X , Técnicas Eletroquímicas , Compostos Heterocíclicos/química , Ligantes , Espectroscopia de Ressonância Magnética , Conformação Molecular , Oxirredução
12.
J Mass Spectrom ; 50(4): 683-92, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26149113

RESUMO

Tri-ortho-cresyl phosphate (ToCP) is an anti-wear, flame retardant additive used in industrial lubricants, hydraulic fluids and gasoline. The neurotoxic effects of ToCP arise from the liver-activated metabolite 2-(o-cresyl)-4H-1,3,2-benzodioxaphosphoran-2-one (cresyl saligenin phosphate or CBDP), which inhibits esterase enzymes including butyrylcholinesterase (BChE). Following BChE adduction, CBDP undergoes hydrolysis to form the aged adduct ortho-cresyl phosphoserine (oCP-BChE), thus providing a biomarker of CBDP exposure. Previous studies have identified ToCP in aircraft cabin and cockpit air, but assessing human exposure has been hampered by the lack of a laboratory assay to confirm exposure. This work presents the development of an immunomagnetic-UHPLC-MS/MS method for the quantitation of unadducted BChE and the long-term CBDP biomarker, oCP-BChE, in human serum. The method has a reportable range from 2.0 ng/ml to 150 ng/ml, which is consistent with the sensitivity of methods used to detect organophosphorus nerve agent protein adducts. The assay demonstrated high intraday and interday accuracy (≥85%) and precision (RSD ≤ 15%) across the calibration range. The method was developed for future analyses of potential human exposure to CBDP. Analysis of human serum inhibited in vitro with CBDP demonstrated that the oCP-BChE adduct was stable for at least 72 h at 4, 22 and 37 °C. Compared to a previously reported assay, this method requires 75% less sample volume, reduces analysis time by a factor of 20 and demonstrates a threefold improvement in sensitivity. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.


Assuntos
Butirilcolinesterase/sangue , Separação Imunomagnética/métodos , Espectrometria de Massas em Tandem/métodos , Tritolil Fosfatos/sangue , Butirilcolinesterase/química , Cromatografia Líquida de Alta Pressão/métodos , Humanos , Limite de Detecção , Reprodutibilidade dos Testes , Tritolil Fosfatos/química
13.
Arch Biochem Biophys ; 546: 33-40, 2014 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-24503478

RESUMO

Cyclooxygenases (COX-1 and COX-2) oxygenate arachidonic acid (AA) to generate prostaglandins. The enzymes associate with one leaflet of the membrane bilayer. We utilized nanodisc technology to investigate the function of human (hu) COX-2 and murine (mu) COX-2 in a lipid bilayer environment. huCOX-2 and muCOX-2 were incorporated into nanodiscs composed of POPC, POPS, DOPC, or DOPS phospholipids. Size-exclusion chromatography and negative stain electron microscopy confirm that a single COX-2 homodimer is incorporated into the nanodisc scaffold. Nanodisc-reconstituted COX-2 exhibited similar kinetic profiles for the oxygenation of AA, eicosapentaenoic acid, and 1-arachidonoyl glycerol compared to those derived using detergent solubilized enzyme. Moreover, changing the phospholipid composition of the nanodisc did not alter the ability of COX-2 to oxygenate AA or to be inhibited by various nonselective NSAIDs or celecoxib. The cyclooxygenase activity of nanodisc-reconstituted COX-2 was reduced by aspirin acetylation and potentiated by the nonsubstrate fatty acid palmitic acid to the same extent as detergent solubilized enzyme, independent of phospholipid composition. The stabilization and maintenance of activity afforded by the incorporation of the enzyme into nanodiscs generates a native-like lipid bilayer environment to pursue studies of COX utilizing solution-based techniques that are otherwise not tractable in the presence of detergents.


Assuntos
Biocatálise , Inibidores de Ciclo-Oxigenase 2/farmacologia , Ciclo-Oxigenase 2/metabolismo , Bicamadas Lipídicas/metabolismo , Nanotecnologia/métodos , Animais , Ciclo-Oxigenase 2/química , Ativação Enzimática/efeitos dos fármacos , Humanos , Bicamadas Lipídicas/química , Camundongos , Modelos Moleculares , Ácido Palmítico/farmacologia , Fosfolipídeos/metabolismo , Conformação Proteica
14.
J Labelled Comp Radiopharm ; 56(14): 696-9, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24339007

RESUMO

Curcumin is a dietary diphenol with antioxidant, antinflammatory, and antitumor activity. We describe facile procedures for the synthesis of [(14) C2 ]curcumin (4 mCi/mmol), [d6 ]curcumin, [d3 ]curcumin, [(13) C5 ]curcumin, and [d6 ]bicyclopentadione, the major oxidative metabolite of curcumin. We also describe synthesis of the labeled building blocks [(14) C]vanillin, [d3 ]vanillin, and [(13) C5 ]acetylacetone. The overall molar yields of the labeled products were 52 ([(14) C]) and 47% ([d3 ]) for vanillin and 25 ([(14) C2 ]) and 27% ([d6 ]) for curcumin. The compounds can be used as radiotracers in biotransformation studies and as isotopic standards for mass spectrometry-based quantification in pharmacokinetic analyses.


Assuntos
Benzaldeídos/síntese química , Radioisótopos de Carbono/química , Curcumina/síntese química , Marcação por Isótopo/métodos , Compostos Radiofarmacêuticos/síntese química
15.
J Med Chem ; 55(17): 7817-27, 2012 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-22871158

RESUMO

The synthesis of platinum-acridine hybrid agents containing carboxylic acid ester groups is described. The most active derivatives and the unmodified parent compounds showed up to 6-fold higher activity in ovarian cancer (OVCAR-3) and breast cancer (MCF-7, MDA-MB-231) cell lines than cisplatin. Inhibition of cell proliferation at nanomolar concentrations was observed in pancreatic (PANC-1) and nonsmall cell lung cancer cells (NSCLC, NCI-H460) of 80- and 150-fold, respectively. Introduction of the ester groups did not affect the cytotoxic properties of the hybrids, which form the same monofunctional-intercalative DNA adducts as the parent compounds, as demonstrated in a plasmid unwinding assay. In-line high-performance liquid chromatography and electrospray mass spectrometry (LC-ESMS) shows that the ester moieties undergo platinum-mediated hydrolysis in a chloride concentration-dependent manner to form carboxylate chelates. Potential applications of the chloride-sensitive ester hydrolysis as a self-immolative release mechanism for tumor-selective delivery of platinum-acridines are discussed.


Assuntos
Ácidos Carboxílicos/química , Platina/química , Linhagem Celular Tumoral , Cromatografia Líquida de Alta Pressão , Ésteres , Humanos , Espectrometria de Massas por Ionização por Electrospray , Água
16.
ACS Med Chem Lett ; 2(9): 687-691, 2011 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-21927647

RESUMO

The formation of unusual seven-membered, sterically overloaded chelates [Pt(en)(L/L´)](NO(3))(2) (4a/4b) from the corresponding potent hybrid antitumor agents [PtCl(en)(LH/L´H)](NO(3))(2) (3a/3b) is described, where en is ethane-1,2-diamine and L(H) and L´(H) are (protonated) N-(2-(acridin-9-ylamino)ethyl)-N-methylpropionimidamide and N-(2-(acridin-9-ylamino)ethyl)-N-methylacetimidamide, respectively. Compounds 3a and 3b inhibit H460 lung cancer cell proliferation with IC(50) values of 12 ± 2 nM and 2.8 ± 0.3 nM, respectively. The new derivative 3b proves to be not only the most cytotoxic platinum-acridine hybrid of this kind, but also one of the most potent platinum-based anticancer agents described to date. The chelates 4a and 4b do not undergo ligand substitution reactions with nucleobase nitrogen and cysteine sulfur and do not intercalate into DNA. Despite their inertness, the two chelates appear to maintain micromolar activity in H460 cells. The results are discussed in the context of potential DNA-mediated and DNA-independent cell kill mechanisms and the potential use of the chelates as prodrugs.

17.
Dalton Trans ; (1): 171-80, 2005 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-15605161

RESUMO

The manganese(I) tricarbonyl complexes (Bm(R))Mn(CO)3(R = Me, Bz, But, p-Tol) and (PhBmMe)Mn(CO)3, the first bis(mercaptoimidazolyl)borate derivatives for this metal, have been readily prepared and fully characterized. In particular, the presence of three-center-two-electron Mn...H-B interactions in these species, both in solution and in the solid state, has been investigated using a combination of IR and NMR spectroscopies and, in the case of the methyl-, tert-butyl- and para-tolyl-substituted derivatives, by X-ray crystallography. To complement these synthetic and structural studies, the tris(mercaptoimidazolyl)borate complexes (TmMe)Mn(CO)3(R = Me, Bz, But, p-Tol) and (PhTm(Me))Mn(CO)3, as well as the related pyrazolylbis(mercaptoimidazolyl)borate (pzBmMe)Mn(CO)3, have also been synthesized and characterized by a combination of analytical and spectroscopic techniques.

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