Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
1.
Glob Health Sci Pract ; 12(3)2024 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-38936959

RESUMEN

Barriers to achieving and sustaining access to water, sanitation, hygiene, cleaning, and waste management (WASH) in health care facilities include a lack of supportive policy environment and adequate funding. While guidelines exist for assessing needs and making initial infrastructure improvements, there is little guidance on how to develop budgets and policies to sustain WASH services. We conducted costing and advocacy activities in Thakurbaba municipality, Nepal, to develop a budget and operations and maintenance policy for WASH in health care facilities in partnership with the municipal government. Our objectives for this study were to (1) describe the process and methods used for costing and advocacy, (2) report the costs to achieve and maintain basic WASH services in the 8 health care facilities of Thakurbaba municipality, and (3) report the outcomes of advocacy activities and policy development. We applied bottom-up costing to enumerate the resources necessary to achieve and maintain basic WASH services and their costs. The annual costs to achieve, operate, and maintain basic access to WASH services ranged from US$4881-US$9695 per facility. Cost findings were used to prepare annual budgets recommended to achieve, operate, and maintain basic services, which were presented to the municipal government and incorporated into an operations and maintenance policy. To date, the municipality has adopted the policy and established a recovery fund of US$3831 for repair and maintenance of infrastructure and an additional US$153 per facility for discretionary WASH spending, which were to be replenished as they were spent. Advocacy at the national level for WASH in health care facilities is currently being championed by the municipality, and findings from this project have informed the development of a nationally costed plan for universal access. This study is intended to provide a roadmap for how cost data can be collected and applied to inform policy.


Asunto(s)
Presupuestos , Instituciones de Salud , Higiene , Saneamiento , Abastecimiento de Agua , Nepal , Saneamiento/economía , Saneamiento/normas , Humanos , Instituciones de Salud/economía , Abastecimiento de Agua/economía , Abastecimiento de Agua/normas , Administración de Residuos/economía
2.
Int J Hyg Environ Health ; 222(5): 790-803, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31078437

RESUMEN

Adequate environmental health conditions in penal institutions are necessary to protect and promote the health of prisoners and prison workers. We conducted a scoping systematic review to: describe the environmental health conditions in penal institutions and the associated exposures and health outcomes; identify effective approaches to prevent environmental health concerns; and identify evidence gaps on environmental health in penal institution populations. PubMed, Web of Science, EBSCOhost, Scopus, and ProQuest were searched. Peer-reviewed studies that reported original data and on environmental health conditions and/or exposures in penal institutions were included. Seventy-three studies met these criteria. The most common risk factor identified was contaminated food and/or beverages prepared or handled in the institution's kitchen. Overcrowding, inadequate ventilation, and a lack of, or sharing of, soap and other hygiene products increased the risk of adverse health outcomes. Common responses included isolating infectious patients, educating prisoners and prison staff on improved sanitation and hygiene practices, improving ventilation, and disinfecting contaminated surfaces and/or water sources. Inadequate environmental health conditions in penal institutions are common, and adversely impact the health of prisoners and prison staff, yet are preventable. Few studies have been conducted in low- and middle-income countries, biasing our results. The development and implementation of national guidelines for essential environmental health in prisons, monitoring of conditions, and greater accountability of facility managers are needed to secure the health, rights, and well-being of prisoners.


Asunto(s)
Salud Ambiental , Monitoreo del Ambiente , Prisiones , Contaminación de Alimentos/análisis , Humanos , Higiene , Ventilación , Calidad del Agua
3.
Health Phys ; 117(6): 637-647, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31136315

RESUMEN

Bayesian statistics have been used in various health physics applications, but only limited material exists on the development of a decision threshold for simple gross count measurements using Bayesian statistics. Bayesian modeling specifies a logical procedure for processing information and provides the means to obtain abstract statistical knowledge about the data in question. A Bayesian interaction model was developed to analyze gross count measurements. This linear regression model studies the relationship between a gross count measurement and the standard deviation of the gross counts obtained in the current and the previous four measurements, and conditions the analysis on whether the data originate from background measurements or from measurements with a source present. The measure of that relationship is expressed statistically by the constructed parameter ζ, which in the Bayesian framework possesses a probability distribution that can be used to achieve detection decisions. The model was validated statistically and under operationally equivalent conditions. Specifically, it was applied to analyze sequential data obtained from continuous gross count measurements at fixed time intervals. The Bayesian analysis used five sequential measurements per detection decision. The model performs optimally for weaker source detections, and presents promising operational application. Its usefulness derives from the facts that an established training data set is not necessary, long-run background measurements are not required to establish parameter estimates, and ζ and the model are universally applicable such that their use is not limited to the predictor variable presented here.


Asunto(s)
Teorema de Bayes , Radioisótopos de Cesio/análisis , Interpretación Estadística de Datos , Modelos Estadísticos , Monitoreo de Radiación/instrumentación , Monitoreo de Radiación/métodos , Protección Radiológica/métodos , Humanos
4.
Artículo en Inglés | MEDLINE | ID: mdl-30081490

RESUMEN

Globally, gastrointestinal (GI) infections by enteric pathogens are the second-leading cause of morbidity and mortality in children under five years of age (≤5 years). While GI pathogen exposure in households has been rigorously examined, there is little data about young children's exposure in public domains. Moreover, public areas in low-income settings are often used for other waste disposal practices in addition to human feces, such as trash dumping in areas near households. If young children play in public domains, they might be exposed to interrelated and highly concentrated microbial, chemical, and physical hazards. This study performed structured observations at 36 public areas in an internally displaced persons community that has transitioned into a formal settlement in Haiti. We documented how often young children played in public areas and quantified behaviors that might lead to illness and injury. Children ≤5 years played at all public sites, which included infants who played at 47% of sites. Children touched and mouthed plastic, metal and glass trash, food and other objects from the ground, ate soil (geophagia) and drank surface water. They also touched latrines, animals, animal feces and open drainage canals. Hand-to-mouth contact was one of the most common behaviors observed and the rate of contact significantly differed among developmental stages (infants: 18/h, toddlers: 11/h and young children: 9/h), providing evidence that children could ingest trace amounts of animal/human feces on hands that may contain GI pathogens. These findings demonstrate that water, sanitation and hygiene interventions could be more effective if they consider exposure risks to feces in public domains. Furthermore, this research highlights the need for waste-related interventions to address the broader set of civil conditions that create unsafe, toxic and contaminated public environments where young children play.


Asunto(s)
Conducta Infantil , Exposición a Riesgos Ambientales/estadística & datos numéricos , Juego e Implementos de Juego , Animales , Salud Infantil , Preescolar , Diarrea/etiología , Exposición a Riesgos Ambientales/efectos adversos , Femenino , Gastroenteritis/etiología , Haití , Humanos , Higiene , Lactante , Masculino , Juego e Implementos de Juego/lesiones , Juego e Implementos de Juego/psicología , Campos de Refugiados , Medición de Riesgo , Factores de Riesgo , Saneamiento , Calidad del Agua
5.
Radiat Res ; 187(2): 259-267, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-28118114

RESUMEN

The catalytic subunit of DNA dependent protein kinase (DNA-PKcs) and its kinase activity are critical for mediation of non-homologous end-joining (NHEJ) of DNA double-strand breaks (DSB) in mammalian cells after gamma-ray irradiation. Additionally, DNA-PKcs phosphorylations at the T2609 cluster and the S2056 cluster also affect DSB repair and cellular sensitivity to gamma radiation. Previously we reported that phosphorylations within these two regions affect not only NHEJ but also homologous recombination repair (HRR) dependent DSB repair. In this study, we further examine phenotypic effects on cells bearing various combinations of mutations within either or both regions. Effects studied included cell killing as well as chromosomal aberration induction after 0.5-8 Gy gamma-ray irradiation delivered to synchronized cells during the G0/G1 phase of the cell cycle. Blocking phosphorylation within the T2609 cluster was most critical regarding sensitization and depended on the number of available phosphorylation sites. It was also especially interesting that only one substitution of alanine in each of the two clusters separately abolished the restoration of wild-type sensitivity by DNA-PKcs. Similar patterns were seen for induction of chromosomal aberrations, reflecting their connection to cell killing. To study possible change in coordination between HRR and NHEJ directed repair in these DNA-PKcs mutant cell lines, we compared the induction of sister chromatid exchanges (SCEs) by very low fluencies of alpha particles with mutant cells defective in the HRR pathway that is required for induction of SCEs. Levels of true SCEs induced by very low fluence of alpha-particle irradiation normally seen in wild-type cells were only slightly decreased in the S2056 cluster mutants, but were completely abolished in the T2609 cluster mutants and were indistinguishable from levels seen in HRR deficient cells. Again, a single substitution in the S2056 together with a single substitution in the T2609 cluster abolished SCE formation and thus also effectively interferes with HRR.


Asunto(s)
Partículas alfa/efectos adversos , Proteína Quinasa Activada por ADN/metabolismo , Fase G1/efectos de la radiación , Rayos gamma/efectos adversos , Fase de Descanso del Ciclo Celular/efectos de la radiación , Serina/metabolismo , Treonina/metabolismo , Animales , Células CHO , Aberraciones Cromosómicas/efectos de la radiación , Cricetinae , Cricetulus , Proteína Quinasa Activada por ADN/química
6.
Bioorg Med Chem Lett ; 25(19): 4260-4, 2015 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-26299347

RESUMEN

E-cadherin is a ubiquitous trans-membrane protein that has important functions in cellular contacts and has been shown to play a role in the epithelial mesenchymal transition. We have previously reported the use of an HTS screen to identify compounds that are capable of restoring e-cadherin in cancer cells. Here, we report the additional medicinal chemistry optimization of these molecules, resulting in new molecules that restore e-cadherin expression at low micromolar concentrations. Further, we report preliminary pharmacokinetic data on a compound, ML327, that can be used as a probe of e-cadherin restoration.


Asunto(s)
Cadherinas/biosíntesis , Isoxazoles/farmacología , Animales , Línea Celular Tumoral , Relación Dosis-Respuesta a Droga , Humanos , Isoxazoles/síntesis química , Isoxazoles/química , Ratones , Estructura Molecular , Ratas , Relación Estructura-Actividad
7.
ACS Chem Biol ; 9(10): 2334-46, 2014 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-25137254

RESUMEN

Schizophrenia is a complex and highly heterogeneous psychiatric disorder whose precise etiology remains elusive. While genome-wide association studies (GWAS) have identified risk genes, they have failed to determine if rare coding single nucleotide polymorphisms (nsSNPs) contribute in schizophrenia. Recently, two independent studies identified 12 rare, deleterious nsSNPS in the GRM1 gene, which encodes the metabotropic glutamate receptor subtype 1 (mGlu1), in schizophrenic patients. Here, we generated stable cell lines expressing the mGlu1 mutant receptors and assessed their pharmacology. Using both the endogenous agonist glutamate and the synthetic agonist DHPG, we found that several of the mutant mGlu1 receptors displayed a loss of function that was not due to a loss in plasma membrane expression. Due to a lack of mGlu1 positive allosteric modulators (PAM) tool compounds active at human mGlu1, we optimized a known mGlu4 PAM/mGlu1 NAM chemotype into a series of potent and selective mGlu1 PAMs by virtue of a double "molecular switch". Employing mGlu1 PAMs from multiple chemotypes, we demonstrate that the mutant receptors can be potentiated by small molecules and in some cases efficacy restored to that comparable to wild type mGlu1 receptors, suggesting deficits in patients with schizophrenia due to these mutations may be amenable to intervention with an mGlu1 PAM. However, in wild type animals, mGlu1 negative allosteric modulators (NAMs) are efficacious in classic models predictive of antipsychotic activity, whereas we show that mGlu1 PAMs have no effect to slight potentiation in these models. These data further highlight the heterogeneity of schizophrenia and the critical role of patient selection strategies in psychiatric clinical trials to match genotype with therapeutic mechanism.


Asunto(s)
Regulación Alostérica/efectos de los fármacos , Mutación/genética , Receptores de Glutamato Metabotrópico/química , Receptores de Glutamato Metabotrópico/genética , Esquizofrenia/genética , Bibliotecas de Moléculas Pequeñas/farmacología , Animales , Calcio/metabolismo , Cromatografía Liquida , Estudio de Asociación del Genoma Completo , Ácido Glutámico/química , Ácido Glutámico/farmacología , Células HEK293 , Humanos , Locomoción , Masculino , Microsomas Hepáticos/efectos de los fármacos , Microsomas Hepáticos/metabolismo , Estructura Molecular , Ratas , Ratas Sprague-Dawley , Bibliotecas de Moléculas Pequeñas/química , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
8.
PLoS One ; 9(4): e93579, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24714417

RESUMEN

We have examined cell-cycle dependence of chromosomal aberration induction and cell killing after high or low dose-rate γ irradiation in cells bearing DNA-PKcs mutations in the S2056 cluster, the T2609 cluster, or the kinase domain. We also compared sister chromatid exchanges (SCE) production by very low fluences of α-particles in DNA-PKcs mutant cells, and in homologous recombination repair (HRR) mutant cells including Rad51C, Rad51D, and Fancg/xrcc9. Generally, chromosomal aberrations and cell killing by γ-rays were similarly affected by mutations in DNA-PKcs, and these mutant cells were more sensitive in G1 than in S/G2 phase. In G1-irradiated DNA-PKcs mutant cells, both chromosome- and chromatid-type breaks and exchanges were in excess than wild-type cells. For cells irradiated in late S/G2 phase, mutant cells showed very high yields of chromatid breaks compared to wild-type cells. Few exchanges were seen in DNA-PKcs-null, Ku80-null, or DNA-PKcs kinase dead mutants, but exchanges in excess were detected in the S2506 or T2609 cluster mutants. SCE induction by very low doses of α-particles is resulted from bystander effects in cells not traversed by α-particles. SCE seen in wild-type cells was completely abolished in Rad51C- or Rad51D-deficient cells, but near normal in Fancg/xrcc9 cells. In marked contrast, very high levels of SCEs were observed in DNA-PKcs-null, DNA-PKcs kinase-dead and Ku80-null mutants. SCE induction was also abolished in T2609 cluster mutant cells, but was only slightly reduced in the S2056 cluster mutant cells. Since both non-homologous end-joining (NHEJ) and HRR systems utilize initial DNA lesions as a substrate, these results suggest the possibility of a competitive interference phenomenon operating between NHEJ and at least the Rad51C/D components of HRR; the level of interaction between damaged DNA and a particular DNA-PK component may determine the level of interaction of such DNA with a relevant HRR component.


Asunto(s)
Sustitución de Aminoácidos , Aberraciones Cromosómicas/efectos de la radiación , Reparación del ADN por Unión de Extremidades/efectos de la radiación , Proteína Quinasa Activada por ADN/genética , Reparación del ADN por Recombinación/efectos de la radiación , Partículas alfa , Animales , Células CHO , Cricetulus , Rayos gamma , Humanos , Tolerancia a Radiación , Intercambio de Cromátides Hermanas/efectos de la radiación
9.
Neuropsychopharmacology ; 39(7): 1578-93, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24442096

RESUMEN

Accumulating evidence suggests that selective M4 muscarinic acetylcholine receptor (mAChR) activators may offer a novel strategy for the treatment of psychosis. However, previous efforts to develop selective M4 activators were unsuccessful because of the lack of M4 mAChR subtype specificity and off-target muscarinic adverse effects. We recently developed VU0152100, a highly selective M4 positive allosteric modulator (PAM) that exerts central effects after systemic administration. We now report that VU0152100 dose-dependently reverses amphetamine-induced hyperlocomotion in rats and wild-type mice, but not in M4 KO mice. VU0152100 also blocks amphetamine-induced disruption of the acquisition of contextual fear conditioning and prepulse inhibition of the acoustic startle reflex. These effects were observed at doses that do not produce catalepsy or peripheral adverse effects associated with non-selective mAChR agonists. To further understand the effects of selective potentiation of M4 on region-specific brain activation, VU0152100 alone and in combination with amphetamine were evaluated using pharmacologic magnetic resonance imaging (phMRI). Key neural substrates of M4-mediated modulation of the amphetamine response included the nucleus accumbens (NAS), caudate-putamen (CP), hippocampus, and medial thalamus. Functional connectivity analysis of phMRI data, specifically assessing correlations in activation between regions, revealed several brain networks involved in the M4 modulation of amphetamine-induced brain activation, including the NAS and retrosplenial cortex with motor cortex, hippocampus, and medial thalamus. Using in vivo microdialysis, we found that VU0152100 reversed amphetamine-induced increases in extracellular dopamine levels in NAS and CP. The present data are consistent with an antipsychotic drug-like profile of activity for VU0152100. Taken together, these data support the development of selective M4 PAMs as a new approach to the treatment of psychosis and cognitive impairments associated with psychiatric disorders such as schizophrenia.


Asunto(s)
Antipsicóticos/farmacología , Piridinas/farmacología , Receptor Muscarínico M4/agonistas , Receptor Muscarínico M4/química , Tiofenos/farmacología , Anfetamina/toxicidad , Animales , Presión Sanguínea/efectos de los fármacos , Encéfalo/efectos de los fármacos , Encéfalo/patología , Línea Celular Transformada , Estimulantes del Sistema Nervioso Central/toxicidad , Modelos Animales de Enfermedad , Proteínas de Transporte de Dopamina a través de la Membrana Plasmática/genética , Proteínas de Transporte de Dopamina a través de la Membrana Plasmática/metabolismo , Miedo/efectos de los fármacos , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Hipercinesia/inducido químicamente , Hipercinesia/tratamiento farmacológico , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Actividad Motora/efectos de los fármacos , Unión Proteica/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Receptor Muscarínico M4/deficiencia , Receptor Muscarínico M4/genética , Reflejo de Sobresalto/efectos de los fármacos
10.
ACS Chem Neurosci ; 3(9): 658-64, 2012 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-23019492

RESUMEN

The synthesis of phidianidines A and B, the first 1,2,4-oxadiazole-containing alkaloid, from the marine opisthobranch mollusk Phidiana militaris is reported. The synthesis proceeds in six steps from known indole acetic acids in 39.9% (phidianidine A) and 21% (phidianidine B) overall yields from commercially available materials. Biological characterization found that phidianidines A and B are selective inhibitors of DAT (versus SERT and NET) and a selective, potent ligand and partial agonist of the µ opioid receptor (versus δ- and κ-opioid receptors). Moreover, neither phidianidines A and B are cytotoxic, and thus represent an attractive starting point for chemical optimization; therefore, we piloted a number of chemistries and prepared a diverse series of unnatural analogs.


Asunto(s)
Fármacos del Sistema Nervioso Central/síntesis química , Fármacos del Sistema Nervioso Central/farmacología , Alcaloides Indólicos/química , Alcaloides Indólicos/síntesis química , Alcaloides Indólicos/farmacología , Oxadiazoles/química , Oxadiazoles/síntesis química , Oxadiazoles/farmacología , Animales , Células CHO , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Cromatografía Líquida de Alta Presión , Cricetinae , Cricetulus , Proteínas de Transporte de Dopamina a través de la Membrana Plasmática/antagonistas & inhibidores , Gastrópodos , Guanosina 5'-O-(3-Tiotrifosfato)/farmacología , Células HEK293 , Humanos , Indicadores y Reactivos , Ligandos , Ensayo de Unión Radioligante , Receptores Opioides mu/agonistas , Proteínas de Transporte de Serotonina en la Membrana Plasmática/efectos de los fármacos , Relación Estructura-Actividad
11.
Radiat Res ; 177(4): 508-13, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22348248

RESUMEN

Molecular imaging is a rapidly advancing field that allows cancer biologists to look deeper into the complex inner workings of tumor cells, or whole tumors, in a non-invasive manner. In this review, we will summarize some recent advances that enable investigators to study various important biological processes in tumors in vivo. We will discuss novel imaging approaches that allow investigators to visualize and quantify molecular pathways, such as receptor tyrosine kinase activation, hypoxia signal transduction, apoptosis, and DNA double-strand breaks. Select examples of these applications will be discussed. Because of the limited scope of this review, we will only focus on natural reporters, such as bioluminescence and fluorescent proteins.


Asunto(s)
Genes Reporteros , Imagen Molecular/métodos , Adenosina Trifosfato/metabolismo , Animales , Apoptosis , Hipoxia de la Célula , ADN/efectos de la radiación , Roturas del ADN de Doble Cadena , Reparación del ADN , Activación Enzimática/efectos de la radiación , Colorantes Fluorescentes/análisis , Proteínas Fluorescentes Verdes/análisis , Proteínas Fluorescentes Verdes/genética , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Luciferasas de Luciérnaga/genética , Luciferasas de Luciérnaga/metabolismo , Mediciones Luminiscentes , Proteínas Luminiscentes/análisis , Proteínas Luminiscentes/genética , Proteínas de Neoplasias/análisis , Proteínas de Neoplasias/metabolismo , Neoplasias/metabolismo , Neoplasias/patología , Neoplasias/radioterapia , Oxígeno/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Proteínas Tirosina Quinasas Receptoras/metabolismo , Espectroscopía Infrarroja Corta
12.
Biochemistry ; 50(13): 2403-10, 2011 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-21341760

RESUMEN

G-protein-coupled receptors (GPCRs) represent the largest class of drug targets, accounting for more than 40% of marketed drugs; however, discovery efforts for many GPCRs have failed to provide viable drug candidates. Historically, drug discovery efforts have focused on developing ligands that act at the orthosteric site of the endogenous agonist. Recently, efforts have focused on functional assay paradigms and the discovery of ligands that act at allosteric sites to modulate receptor function in either a positive, negative, or neutral manner. Allosteric modulators have numerous advantages over orthosteric ligands, including high subtype selectivity; the ability to mimic physiological conditions; the lack of densensitization, downregulation, and internalization; and reduced side effects. Despite these virtues, challenging issues have now arisen for allosteric modulators of metabotropic glutamate receptors (mGluRs): shallow SAR, ligand-directed trafficking, and the identification of subtle "molecular switches" that modulate the modes of pharmacology. Here, we will discuss the impact of modest structural changes to multiple mGluR allosteric ligands scaffolds that unexpectedly modulate pharmacology and raise concerns over metabolism and the pharmacology of metabolites.


Asunto(s)
Diseño de Fármacos , Receptores de Glutamato Metabotrópico/agonistas , Receptores de Glutamato Metabotrópico/antagonistas & inhibidores , Regulación Alostérica , Animales , Interacciones Farmacológicas , Humanos , Ligandos , Receptores de Glutamato Metabotrópico/metabolismo , Transducción de Señal/efectos de los fármacos
13.
ACS Chem Neurosci ; 2(12): 730-742, 2011 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-22368764

RESUMEN

T-type Ca(2+) channel inhibitors hold tremendous therapeutic potential for the treatment of pain, epilepsy, sleep disorders, essential tremor and other neurological disorders; however, a lack of truly selective tools has hindered basic research, and selective tools from the pharmaceutical industry are potentially burdened with intellectual property (IP) constraints. Thus, an MLPCN high-throughput screen (HTS) was conducted to identify novel T-type Ca(2+) channel inhibitors free from IP constraints, and freely available through the MLPCN, for use by the biomedical community to study T-type Ca(2+) channels. While the HTS provided numerous hits, these compounds could not be optimized to the required level of potency to be appropriate tool compounds. Therefore, a scaffold hopping approach, guided by SurflexSim, ultimately afforded ML218 (CID 45115620) a selective T-Type Ca(2+) (Ca(v)3.1, Ca(v)3.2, Ca(v)3.3) inhibitor (Ca(v)3.2, IC(50) = 150 nM in Ca(2+) flux; Ca(v)3.2 IC(50) = 310 nM and Ca(v)3.3 IC(50) = 270 nM, respectively in patch clamp electrophysiology) with good DMPK properties, acceptable in vivo rat PK and excellent brain levels. Electrophysiology studies in subthalamic nucleus (STN) neurons demonstrated robust effects of ML218 on the inhibition of T-Type calcium current, inhibition of low threshold spike and rebound burst activity. Based on the basal ganglia circuitry in Parkinson's disease (PD), the effects of ML218 in STN neurons suggest a therapeutic role for T-type Ca(2+) channel inhibitors, and ML218 was found to be orally efficacious in haloperidol-induced catalepsy, a preclinical PD model, with comparable efficacy to an A(2A) antagonist, a clinically validated PD target. ML218 proves to be a powerful new probe to study T-Type Ca(2+) function in vitro and in vivo, and freely available.

14.
Radiat Res ; 175(1): 83-9, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21175350

RESUMEN

The catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) is the key functional element in the DNA-PK complex that drives nonhomologous end joining (NHEJ), the predominant DNA double-strand break (DSB) repair mechanism operating to rejoin such breaks in mammalian cells after exposure to ionizing radiation. It has been reported that DNA-PKcs phosphorylation and kinase activity are critical determinants of radiosensitivity, based on responses reported after irradiation of asynchronously dividing populations of various mutant cell lines. In the present study, the relative radiosensitivity to cell killing as well as chromosomal instability of 13 DNA-PKcs site-directed mutant cell lines (defective at phosphorylation sites or kinase activity) were examined after exposure of synchronized G(1) cells to (137)Cs γ rays. DNA-PKcs mutant cells defective in phosphorylation at multiple sites within the T2609 cluster or within the PI3K domain displayed extreme radiosensitivity. Cells defective at the S2056 cluster or T2609 single site alone were only mildly radiosensitive, but cells defective at even one site in both the S2056 and T2609 clusters were maximally radiosensitive. Thus a synergism between the capacity for phosphorylation at the S2056 and T2609 clusters was found to be critical for induction of radiosensitivity.


Asunto(s)
Inestabilidad Cromosómica , Proteína Quinasa Activada por ADN/fisiología , Tolerancia a Radiación , Animales , Células CHO , Cricetinae , Cricetulus , Reparación del ADN , Fase G1 , Humanos , Fosforilación
15.
ACS Chem Neurosci ; 2(11): 633-639, 2011 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-22247792

RESUMEN

The first total synthesis of (+)-7-bromotrypargine, a ß-carboline alkaloid from Ancornia sp. is reported. The synthesis proceeds in 9 steps, 8 steps longest linear sequence, in 36.9% overall yield. Biological characterization found that (+)-7-bromotrypargine is an H(3) antagonist, and a selective inhibitor of DAT and NET, without inhibiting SERT. Moreover, unlike electron rich congeners, (+)-7-bromotrypargine is not cytotoxic, and thus represents an attractive starting point for chemical optimization; therefore, we piloted a number of chemistries for the synthesis of unnatural analogs.

16.
Mutat Res ; 701(1): 12-22, 2010 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-20298803

RESUMEN

New data and historical evidence from our own and other laboratories are summarized and discussed bearing on several issues relating to mechanisms and processes involved in the formation of chromosomal aberrations following exposure to ionizing radiations. Specifically addressed are: (1) the lesions and processes affecting the appearance of chromatid-type and/or chromosome-type aberrations after radiation, (2) DNA double strand break rejoining processes and the restitution of breaks vs. the formation of exchanges, (3) the role of homologous recombinational repair in protecting cells from induction of chromatid-type aberrations after irradiation of late S/G2 cells, (4) the role of interphase chromatin structure and nuclear organization in aberration induction, (5) cellular responses for aberration induction in relation to their tissue context, and (6) approaches to the detection of aberrations previously known as "cryptic".


Asunto(s)
Aberraciones Cromosómicas , Reparación del ADN , Radiación Ionizante , Recombinación Genética , Animales , Línea Celular , Células Cultivadas , Cromatina/química , Humanos , Interfase , Genética de Radiación , Técnicas de Cultivo de Tejidos
18.
Bioorg Med Chem Lett ; 19(3): 597-601, 2009 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-19131247

RESUMEN

A series of trisubstituted cyclohexanes was designed, synthesized and evaluated as CC chemokine receptor 2 (CCR2) antagonists. This led to the identification of two distinct substitution patterns about the cyclohexane ring as potent and selective CCR2 antagonists. Compound 36 exhibited excellent binding (CCR2 IC(50)=2.4 nM) and functional antagonism (calcium flux IC(50)=2.0 nM and chemotaxis IC(50)=5.1 nM).


Asunto(s)
Química Farmacéutica/métodos , Receptores CCR2/antagonistas & inhibidores , Receptores CCR2/química , Sitios de Unión , Calcio/química , Quimiocina CCL2/química , Quimiotaxis , Ciclohexanos/química , Diseño de Fármacos , Humanos , Concentración 50 Inhibidora , Modelos Químicos , Estructura Molecular , Unión Proteica , Relación Estructura-Actividad
19.
J Nat Prod ; 71(10): 1783-6, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18800848

RESUMEN

The first total synthesis of dispyrin, a recently reported bromopyrrole alkaloid from Agelas dispar with an unprecedented bromopyrrole tyramine motif, was achieved in three steps on a gram scale (68.4% overall). No biological activity was reported for dispyrin, so we evaluated synthetic dispyrin against>200 discrete molecular targets in radioligand binding and functional assays. Unlike most marine natural products, dispyrin (1) possesses no antibacterial or anticancer activity, but was found to be a potent ligand and antagonist of several therapeutically relevant GPCRs, the alpha1D and alpha2A adrenergic receptors and the H2 and H3 histamine receptors.


Asunto(s)
Agonistas Adrenérgicos , Agelas/química , Alcaloides , Histamínicos , Hidrocarburos Bromados , Pirroles , Agonistas Adrenérgicos/síntesis química , Agonistas Adrenérgicos/química , Agonistas Adrenérgicos/farmacología , Alcaloides/síntesis química , Alcaloides/química , Alcaloides/farmacología , Animales , Ensayos de Selección de Medicamentos Antitumorales , Histamínicos/síntesis química , Histamínicos/química , Histamínicos/farmacología , Hidrocarburos Bromados/síntesis química , Hidrocarburos Bromados/química , Hidrocarburos Bromados/farmacología , Ligandos , Biología Marina , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Pirroles/síntesis química , Pirroles/química , Pirroles/farmacología , Receptores Acoplados a Proteínas G/agonistas
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...