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1.
Disaster Med Public Health Prep ; 17: e550, 2023 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-38044835

RESUMEN

OBJECTIVE: Evidence of myelosuppression has been negatively correlated with patient outcomes following cases of high dose sulfur mustard (SM) exposure. These hematologic complications can negatively impact overall immune function and increase the risk of infection and life-threatening septicemia. Currently, there are no approved medical treatments for the myelosuppressive effects of SM exposure. METHODS: Leveraging a recently developed rodent model of SM-induced hematologic toxicity, post-exposure efficacy testing of the granulocyte colony-stimulating factor drug Neupogen® was performed in rats intravenously challenged with SM. Before efficacy testing, pharmacokinetic/pharmacodynamic analyses were performed in naïve rats to identify the apparent human equivalent dose of Neupogen® for efficacy evaluation. RESULTS: When administered 1 d after SM-exposure, daily subcutaneous Neupogen® treatment did not prevent the delayed onset of hematologic toxicity but significantly accelerated recovery from neutropenia. Compared with SM controls, Neupogen®-treated animals recovered body weight faster, resolved toxic clinical signs more rapidly, and did not display transient febrility at time points generally concurrent with marked pancytopenia. CONCLUSIONS: Collectively, this work corroborates the results of a previous pilot large animal study, validates the utility of a rodent screening model, and provides further evidence for the potential clinical utility of Neupogen® as an adjunct treatment following SM exposure.


Asunto(s)
Gas Mostaza , Humanos , Ratas , Animales , Filgrastim/farmacología , Filgrastim/uso terapéutico , Gas Mostaza/toxicidad , Neutrófilos , Roedores , Factor Estimulante de Colonias de Granulocitos/farmacología , Factor Estimulante de Colonias de Granulocitos/uso terapéutico
3.
Artículo en Inglés | MEDLINE | ID: mdl-35158319

RESUMEN

Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) has become a mainstay analytical technique in pharmaceutical research and development and clinical diagnosis due to several advantages including excellent selectivity, specificity, and high sensitivity. LC-MS/MS has become the method of choice for steroids analysis due to its fast analytical time and improved specificity yet has a challenge in the separation and measurement of isomers with the same product ions. Here we describe a high-sensitivity LC/LC-MS/MS method that combines chiral chromatography and reverse-phase chromatography (LC/LC) along with MS/MS to rapidly separate and quantify steroid isomers of 11ß-methyl-19-nortestosterone (11ß-MNT) and endogenous testosterone in serum.

5.
Early Hum Dev ; 166: 105542, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35085882

RESUMEN

BACKGROUND: Tremendous medical advancements over the last several decades have supported the survival of younger and sicker newborns. Substantial quantitative research exists about health and developmental outcomes following preterm birth, however, limited published literature has explored what this experience means to the survivors. AIM: The purpose was to describe, interpret and understand how adults born preterm perceive prematurity to have affected their lives. STUDY DESIGN: Qualitative thematic analysis. METHODS: Semi-structured interviews were conducted with 33 adults born preterm from the RHODE Study, a longitudinal preterm birth cohort. A cross-section of participants with high and low early life medical and environmental risk was interviewed. Data were analyzed using a constructionist method of latent theme analysis. RESULTS: From the data, 3 themes were identified: 1) My parents call me their miracle, 2) It's not a big deal, I'm the same as everyone else, 3) I've overcome a lot. Themes represent a continuum of experience, from positive to neutral to negative. Common life experiences of family, education, friends, and health are subthemes that help to illuminate how participants assign meaning to their prematurity. Meaning was linked to how typical or not participants perceive their health, learning and friends compared to peers. CONCLUSION: Perceptions about prematurity and adversity are influenced by the ways parents and families represent prematurity in shared stories and actions. These findings should inform future research with adult survivors of prematurity. Participants identified ongoing need for support and advocacy, particularly from healthcare and education communities.


Asunto(s)
Enfermedades del Prematuro , Nacimiento Prematuro , Adulto , Humanos , Recién Nacido de Bajo Peso , Recién Nacido , Padres , Nacimiento Prematuro/epidemiología
6.
Anal Bioanal Chem ; 414(5): 1933-1947, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34997251

RESUMEN

Liquid chromatography (LC) coupled with tandem mass spectrometry (MS/MS) provides a simple and efficient means for the measurement of analytes in biological matrices with high selectivity and specificity. LC-MS/MS plays an important role in the pharmaceutical industry and biomedical research, but it requires analytes to be in an ionized form in order to be detected. This can pose a challenge for large molecules such as proteins and peptides, because they can exist in multiple charged forms, and this will reduce the total analyte signal by distributing it into multiple ion peaks with a different number of charges in a mass spectrum. In conventional LC-MS/MS analysis of such macromolecules, one charged form is selected as the precursor ion which is then fragmented by collision-induced dissociation (CID) in MS/MS to generate product ions, a process referred to as multiple-reaction monitoring (MRM). The MRM method minimizes interference from endogenous molecules within biological matrices that share the same molecular weight of the precursor ion, but at the expense of signal intensity as compared to precursor ion intensity. We describe here an approach to boost detection sensitivity and expand dynamic range in the quantitation of large molecules while maintaining analytical specificity using summation of MRM (SMRM) transitions and LC separation technique. Protein image from PDB-101 (PDB101.rscb.org).


Asunto(s)
Cromatografía Liquida/métodos , Espectrometría de Masas en Tándem/métodos , Animales , Estudios de Factibilidad , Límite de Detección , Ratas , Ratas Sprague-Dawley
7.
Int J Radiat Biol ; 96(1): 145-154, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31021662

RESUMEN

Purpose: Rapid depletion of white blood cells, platelets, and reticulocytes are hallmarks of hematopoietic injury of acute radiation syndrome (H-ARS) and, if left untreated, can lead to severe health consequences including death. While the granulocyte colony stimulating factors (G-CSF) filgrastim (Neupogen®), pegfilgrastim (Neulasta®), and sargramostim (Leukine®) are approved to increase survival in patients exposed to a myelosuppressive dose of radiation, no medical countermeasure is currently available for treatment of the thrombocytopenia that also results following radiation exposure. Romiplostim (Nplate®), a thrombopoietin receptor agonist, is the first FDA-approved thrombopoiesis-stimulating protein for the treatment of low platelet (PLT) counts in adults with chronic immune thrombocytopenia. Herein, we present the results of an analysis in mice of romiplostim as a medical countermeasure to improve survival and PLT recovery following acute radiation.Materials and methods: Male and female C57BL/6J mice (11 - 12 weeks of age, n = 21/sex/group) were total body irradiated (TBI) with 6.8 Gy X-rays that reduces 30-day survival to 30% (LD70/30). Vehicle, romiplostim, and/or pegfilgrastim were administered subcutaneously beginning 24 h after TBI for 1-5 days. Evaluation parameters included 30-day survival, pharmacokinetics, and hematology.Results: Full or maximal efficacy with an ∼40% increase in survival was achieved after a single 30 µg/kg dose of romiplostim. No further survival benefit was seen with higher (100 µg/kg) or more frequent dosing (3 or 5 once daily doses at 30 µg/kg) of romiplostim or combined treatment with pegfilgrastim. Pharmacodynamic analysis revealed that the platelet nadir was not as low and recovery was faster in the irradiated mice treated with romiplostim when compared with irradiated control animals (Day 8 versus 10 nadir; Day 22 versus 29 recovery to near baseline). Platelet volume also increased more rapidly after romiplostim injection. Kinetic profiles of other hematology parameters were similar between TBI romiplostim-treated and control mice. Peak serum levels of romiplostim in TBI mice occurred 4 - 24 h (Tmax) after injection with a t1/2 of ∼24 h. Cmax values were at ∼6 ng/ml after 30 µg/kg ± TBI and ∼200 ng/ml after 300 µg/kg. A 10-fold higher romiplostim dose increased the AUClast values by ∼35-fold.Conclusion: A single injection of romiplostim administered 24 h after TBI is a promising radiation medical countermeasure that dramatically increased survival, with or without pegfilgrastim, and hastened PLT recovery in mice.


Asunto(s)
Plaquetas/efectos de los fármacos , Plaquetas/efectos de la radiación , Contramedidas Médicas , Proteínas Recombinantes de Fusión/farmacología , Trombopoyetina/farmacología , Animales , Plaquetas/citología , Relación Dosis-Respuesta a Droga , Interacciones Farmacológicas , Femenino , Filgrastim/farmacología , Masculino , Ratones , Ratones Endogámicos C57BL , Recuento de Plaquetas , Polietilenglicoles/farmacología , Receptores Fc , Proteínas Recombinantes de Fusión/farmacocinética , Análisis de Supervivencia , Trombopoyetina/farmacocinética , Rayos X/efectos adversos
8.
Sci Rep ; 9(1): 20199, 2019 12 27.
Artículo en Inglés | MEDLINE | ID: mdl-31882748

RESUMEN

During the Ebola virus disease (EVD) epidemic in Western Africa (2013‒2016), antimalarial treatment was administered to EVD patients due to the high coexisting malaria burden in accordance with World Health Organization guidelines. In an Ebola treatment center in Liberia, EVD patients receiving the combination antimalarial artesunate-amodiaquine had a lower risk of death compared to those treated with artemether-lumefantrine. As artemether and artesunate are derivatives of artemisinin, the beneficial anti-Ebola virus (EBOV) effect observed could possibly be attributed to the change from lumefantrine to amodiaquine. Amodiaquine is a widely used antimalarial in the countries that experience outbreaks of EVD and, therefore, holds promise as an approved drug that could be repurposed for treating EBOV infections. We investigated the potential anti-EBOV effect of amodiaquine in a well-characterized nonhuman primate model of EVD. Using a similar 3-day antimalarial dosing strategy as for human patients, plasma concentrations of amodiaquine in healthy animals were similar to those found in humans. However, the treatment regimen did not result in a survival benefit or decrease of disease signs in EBOV-infected animals. While amodiaquine on its own failed to demonstrate efficacy, we cannot exclude potential therapeutic value of amodiaquine when used in combination with artesunate or another antiviral.


Asunto(s)
Amodiaquina/uso terapéutico , Antivirales/uso terapéutico , Artemisininas/uso terapéutico , Fiebre Hemorrágica Ebola/tratamiento farmacológico , Animales , Modelos Animales de Enfermedad , Combinación de Medicamentos , Femenino , Macaca mulatta , Masculino
9.
Toxicol Sci ; 169(2): 465-474, 2019 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-30835286

RESUMEN

Organophosphate (OP) anticholinesterases cause excess acetylcholine leading to seizures which, if prolonged, result in neuronal damage in the rodent brain. Novel substituted phenoxyalkyl pyridinium oximes have previously shown evidence of penetrating the rat blood-brain barrier (BBB) in in vivo tests with a sarin surrogate (nitrophenyl isopropyl methylphosphonate, NIMP) or the active metabolite of the insecticide parathion, paraoxon (PXN), by reducing the time to cessation of seizure-like behaviors and accumulation of glial fibrillary acidic protein, whereas 2-PAM did not. The neuroprotective ability of our lead oximes (15, 20, and 55) was tested using NeuN, Nissl, and Fluoro-Jade B staining in the rat hippocampus. Following lethal-level subcutaneous challenge with NIMP or PXN, rats were intramuscularly administered a novel oxime or 2-PAM plus atropine and euthanized at 4 days. There were statistically significant increases in the median damage scores of the NeuN-stained NIMP, NIMP/2-PAM, and NIMP/Oxime 15 groups compared with the control whereas the scores of the NIMP/Oxime 20 and NIMP/Oxime 55 were not significantly different from the control. The same pattern of statistical significance was observed with PXN. Nissl staining provided a similar pattern, but without statistical differences. Fluoro-Jade B indicated neuroprotection from PXN with novel oximes but not with 2-PAM. The longer blood residence times of Oximes 20 and 55 compared with Oxime 15 might have contributed to their greater efficacy. These results suggest that novel oximes 20 and 55 were able to penetrate the BBB and attenuate neuronal damage after NIMP and PXN exposure, indicating potential broad-spectrum usefulness.


Asunto(s)
Barrera Hematoencefálica , Reactivadores de la Colinesterasa/farmacología , Hipocampo/efectos de los fármacos , Organofosfatos/toxicidad , Oximas/farmacología , Animales , Masculino , Fármacos Neuroprotectores/farmacología , Oximas/farmacocinética , Ratas , Ratas Sprague-Dawley
10.
J Infect Dis ; 218(suppl_5): S592-S596, 2018 11 22.
Artículo en Inglés | MEDLINE | ID: mdl-30016444

RESUMEN

At the onset of the 2013-2016 epidemic of Ebola virus disease (EVD), no vaccine or antiviral medication was approved for treatment. Therefore, considerable efforts were directed towards the concept of drug repurposing or repositioning. Amiodarone, an approved multi-ion channel blocker for the treatment of cardiac arrhythmia, was reported to inhibit filovirus entry in vitro. Compassionate use of amiodarone in EVD patients indicated a possible survival benefit. In support of further clinical testing, we confirmed anti-Ebola virus activity of amiodarone in different cell types. Despite promising in vitro results, amiodarone failed to protect guinea pigs from a lethal dose of Ebola virus.


Asunto(s)
Amiodarona/farmacología , Ebolavirus/efectos de los fármacos , Amiodarona/farmacocinética , Amiodarona/uso terapéutico , Animales , Chlorocebus aethiops , Femenino , Cobayas , Fiebre Hemorrágica Ebola/tratamiento farmacológico , Masculino , Células Vero
11.
Artículo en Inglés | MEDLINE | ID: mdl-29133569

RESUMEN

Tilorone dihydrochloride (tilorone) is a small-molecule, orally bioavailable drug that is used clinically as an antiviral outside the United States. A machine-learning model trained on anti-Ebola virus (EBOV) screening data previously identified tilorone as a potent in vitro EBOV inhibitor, making it a candidate for the treatment of Ebola virus disease (EVD). In the present study, a series of in vitro ADMET (absorption, distribution, metabolism, excretion, toxicity) assays demonstrated the drug has excellent solubility, high Caco-2 permeability, was not a P-glycoprotein substrate, and had no inhibitory activity against five human CYP450 enzymes (3A4, 2D6, 2C19, 2C9, and 1A2). Tilorone was shown to have 52% human plasma protein binding with excellent plasma stability and a mouse liver microsome half-life of 48 min. Dose range-finding studies in mice demonstrated a maximum tolerated single dose of 100 mg/kg of body weight. A pharmacokinetics study in mice at 2- and 10-mg/kg dose levels showed that the drug is rapidly absorbed, has dose-dependent increases in maximum concentration of unbound drug in plasma and areas under the concentration-time curve, and has a half-life of approximately 18 h in both males and females, although the exposure was ∼2.5-fold higher in male mice. Tilorone doses of 25 and 50 mg/kg proved efficacious in protecting 90% of mice from a lethal challenge with mouse-adapted with once-daily intraperitoneal (i.p.) dosing for 8 days. A subsequent study showed that 30 mg/kg/day of tilorone given i.p. starting 2 or 24 h postchallenge and continuing through day 7 postinfection was fully protective, indicating promising activity for the treatment of EVD.


Asunto(s)
Ebolavirus/efectos de los fármacos , Fiebre Hemorrágica Ebola/tratamiento farmacológico , Tilorona/farmacología , Animales , Antivirales/farmacología , Células CACO-2 , Línea Celular Tumoral , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos BALB C , Microsomas Hepáticos/efectos de los fármacos
12.
PLoS One ; 11(11): e0166318, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27902714

RESUMEN

In the fall of 2014, an international news agency reported that patients suffering from Ebola virus disease (EVD) in Liberia were treated successfully with lamivudine, an antiviral drug used to treat human immunodeficiency virus-1 and hepatitis B virus infections. According to the report, 13 out of 15 patients treated with lamivudine survived and were declared free from Ebola virus disease. In this study, the anti-Ebola virus (EBOV) activity of lamivudine and another antiretroviral, zidovudine, were evaluated in a diverse set of cell lines against two variants of wild-type EBOV. Variable assay parameters were assessed to include different multiplicities of infection, lengths of inoculation times, and durations of dosing. At a multiplicity of infection of 1, lamivudine and zidovudine had no effect on EBOV propagation in Vero E6, Hep G2, or HeLa cells, or in primary human monocyte-derived macrophages. At a multiplicity of infection of 0.1, zidovudine demonstrated limited anti-EBOV activity in Huh 7 cells. Under certain conditions, lamivudine had low anti-EBOV activity at the maximum concentration tested (320 µM). However, lamivudine never achieved greater than 30% viral inhibition, and the activity was not consistently reproducible. Combination of lamivudine and zidovudine showed no synergistic antiviral activity. Independently, a set of in vitro experiments testing lamivudine and zidovudine for antiviral activity against an Ebola-enhanced green fluorescent protein reporter virus was performed at the Centers for Disease Control and Prevention. No antiviral activity was observed for either compound. A study evaluating the efficacy of lamivudine in a guinea pig model of EVD found no survival benefit. This lack of benefit was observed despite plasma lamivudine concentrations in guinea pig of about 4 µg/ml obtained in a separately conducted pharmacokinetics study. These studies found no evidence to support the therapeutic use of lamivudine for the treatment of EVD.


Asunto(s)
Fármacos Anti-VIH/farmacología , Ebolavirus/efectos de los fármacos , Fiebre Hemorrágica Ebola/tratamiento farmacológico , Lamivudine/farmacología , Zidovudina/farmacología , Animales , Chlorocebus aethiops , Ebolavirus/aislamiento & purificación , Cobayas , Células HeLa , Fiebre Hemorrágica Ebola/virología , Humanos , Macrófagos , Proyectos Piloto , Células Vero , Replicación Viral/efectos de los fármacos
13.
BMC Cancer ; 16: 524, 2016 07 25.
Artículo en Inglés | MEDLINE | ID: mdl-27457630

RESUMEN

BACKGROUND: Success of cancer prodrugs relying on a foreign gene requires specific delivery of the gene to the cancer, and improvements such as higher level gene transfer and expression. Attaining these objectives will be facilitated in preclinical studies using our newly discovered CNOB-GDEPT, consisting of the produrg: 6-chloro-9-nitro-5-oxo-5H-benzo-(a)-phenoxazine (CNOB) and its activating enzyme ChrR6, which generates the cytotoxic product 9-amino-6-chloro-5H-benzo[a]phenoxazine-5-one (MCHB). MCHB is fluorescent and can be noninvasively imaged in mice, and here we investigated whether MCHB fluorescence quantitatively reflects its concentration, as this would enhance its reporter value in further development of the CNOB-GDEPT therapeutic regimen. PK parameters were estimated and used to predict more effective CNOB administration schedules. METHODS: CNOB (3.3 mg/kg) was injected iv in mice implanted with humanized ChrR6 (HChrR6)-expressing 4T1 tumors. Fluorescence was imaged in live mice using IVIS Spectrum, and quantified by Living Image 3.2 software. MCHB and CNOB were quantified also by LC/MS/MS analysis. We used non-compartmental model to estimate PK parameters. Phoenix WinNonlin software was used for simulations to predict a more effective CNOB dosage regimen. RESULTS: CNOB administration significantly prolonged mice survival. MCHB fluorescence quantitatively reflected its exposure levels to the tumor and the plasma, as verified by LC/MS/MS analysis at various time points, including at a low concentration of 2 ng/g tumor. The LC/MS/MS data were used to estimate peak plasma concentrations, exposure (AUC0-24), volume of distribution, clearance and half-life in plasma and the tumor. Simulations suggested that the CNOB-GDEPT can be a successful therapy without large increases in the prodrug dosage. CONCLUSION: MCHB fluorescence quantifies this drug, and CNOB can be effective at relatively low doses. MCHB fluorescence characteristics will expedite further development of CNOB-GDEPT by, for example, facilitating specific gene delivery to the tumor, its prolonged expression, as well as other attributes necessary for successful gene-delivered enzyme prodrug therapy.


Asunto(s)
Antineoplásicos/farmacocinética , Oxazinas/farmacocinética , Profármacos/farmacocinética , Animales , Antineoplásicos/administración & dosificación , Línea Celular Tumoral , Esquema de Medicación , Humanos , Ratones , Ratones Desnudos , Trasplante de Neoplasias , Imagen Óptica , Oxazinas/administración & dosificación , Profármacos/administración & dosificación
14.
PLoS One ; 10(3): e0121540, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25811857

RESUMEN

4R-cembranoid (4R) is a natural cyclic diterpenoid found in tobacco leaves that displays neuroprotective activity. 4R protects against NMDA, paraoxon (POX), and diisopropylfluorophosphate (DFP) damage in rat hippocampal slices and against DFP in rats in vivo. The purpose of this study was to examine the metabolism and pharmacokinetics of 4R as part of its preclinical development as a neuroprotective drug. 10 µM 4R was found to be very stable in plasma for up to 1 hr incubation. 4R metabolism in human microsomes was faster than in the rat. Ten metabolites of 4R were detected in the microsomal samples; 6 dihydroxy and 4 monohydroxy forms of 4R. Male rats received a single dose of 4R at 6 mg/kg i.v., i.m., or s.c. The i.v. group had the highest plasma concentration of 1017 ng/mL. The t1/2 was 36 min and reached the brain within 10 min. The brain peak concentration was 6516 ng/g. The peak plasma concentration in the i.m. group was 163 ng/mL compared to 138 ng/mL in the s.c. group. The t1/2 of 4R after i.m. and s.c. administration was approximately 1.5 hr. The brain peak concentration was 329 ng/g in the i.m. group and 323 ng/g for the s.c. group. The brain to plasma ratio in the i.v. group was 6.4, reached 10 min after dose, whereas in the i.m. and s.c. groups was 2.49 and 2.48, respectively, at 90 min after dose. Our data show that 4R crosses the BBB and concentrates in the brain where it exerts its neuroprotective effect.


Asunto(s)
Diterpenos/metabolismo , Diterpenos/farmacocinética , Animales , Diterpenos/sangre , Diterpenos/química , Femenino , Humanos , Masculino , Metaboloma , Microsomas Hepáticos/metabolismo , Ratas Sprague-Dawley
15.
Pharm Dev Technol ; 20(2): 169-75, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24218989

RESUMEN

The main objective of the present study was to develop formulations of noscapine hydrochloride hydrate with enhanced solubility and bioavailability using co-solvent- and cyclodextrin-based approaches. Different combinations of co-solvents, which were selected on the basis of high-throughput solubility screening, were subjected to in vitro intestinal drug permeability studies conducted with Ussing chambers. Vitamin E tocopherol polyethylene glycol succinate and propylene glycol based co-solvent formulations provided the maximum permeability coefficient for the drug. Inclusion complexes of the drug were prepared using hydroxypropyl-ß-cyclodextrin and sulphobutylether cyclodextrins. Pharmacokinetic studies were carried out in male Sprague-Dawley rats for the selected formulations. The relative bioavailabilities of the drug with the co-solvent- and cyclodextrin-based formulations were found to be similar.


Asunto(s)
Antivirales/administración & dosificación , Sistemas de Liberación de Medicamentos , Diseño de Fármacos , Excipientes/química , Noscapina/administración & dosificación , Solventes/química , Administración Oral , Animales , Antivirales/sangre , Antivirales/química , Antivirales/farmacología , Disponibilidad Biológica , Humanos , Gripe Humana/tratamiento farmacológico , Absorción Intestinal , Masculino , Noscapina/sangre , Noscapina/química , Noscapina/farmacología , Ratas Sprague-Dawley , Solubilidad
16.
ACS Infect Dis ; 1(7): 317-26, 2015 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-27622822

RESUMEN

A systematic screen of FDA-approved drugs was performed to identify compounds with in vitro antiviral activities against Ebola virus (EBOV). Compounds active (>50% viral inhibition and <30% cellular toxicity) at a single concentration were tested in dose-response assays to quantitate the antiviral activities in replication and viral entry assays as well as cytotoxicity in the Vero cell line used to conduct these assays. On the basis of the approved human dosing, toxicity/tolerability, and pharmacokinetic data, seven of these in vitro hits from different pharmacological classes (chloroquine (CQ), amiodarone, prochlorperazine, benztropine, azithromycin, chlortetracycline, and clomiphene) were evaluated for their in vivo efficacy at a single dose and were administered via either intraperitoneal (ip) or oral route. Initially, azithromycin (100 mg/kg, twice daily, ip), CQ (90 mg/kg, twice daily, ip), and amiodarone (60 mg/kg, twice daily, ip) demonstrated significant increases in survival in the mouse model. After repeat evaluation, only CQ was found to reproducibly give significant efficacy in the mouse model with this dosing regimen. Azithromycin and CQ were also tested in a guinea pig model of EBOV infection over a range of doses, but none of the doses increased survival, and drug-related toxicity was observed at lower doses than in the mouse. These results show the benefits and specific challenges associated with drug repurposing and highlight the need for careful evaluation of approved drugs as rapidly deployable countermeasures against future pandemics.

17.
Anesthesiology ; 121(1): 149-59, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24936922

RESUMEN

BACKGROUND: Subanesthetic doses of (R,S)-ketamine are used in the treatment of neuropathic pain and depression. In the rat, the antidepressant effects of (R,S)-ketamine are associated with increased activity and function of mammalian target of rapamycin (mTOR); however, (R,S)-ketamine is extensively metabolized and the contribution of its metabolites to increased mTOR signaling is unknown. METHODS: Rats (n = 3 per time point) were given (R,S)-ketamine, (R,S)-norketamine, and (2S,6S)-hydroxynorketamine and their effect on the mTOR pathway determined after 20, 30, and 60 min. PC-12 pheochromocytoma cells (n = 3 per experiment) were treated with escalating concentrations of each compound and the impact on the mTOR pathway was determined. RESULTS: The phosphorylation of mTOR and its downstream targets was significantly increased in rat prefrontal cortex tissue by more than ~2.5-, ~25-, and ~2-fold, respectively, in response to a 60-min postadministration of (R,S)-ketamine, (R,S)-norketamine, and (2S,6S)-hydroxynorketamine (P < 0.05, ANOVA analysis). In PC-12 pheochromocytoma cells, the test compounds activated the mTOR pathway in a concentration-dependent manner, which resulted in a significantly higher expression of serine racemase with ~2-fold increases at 0.05 nM (2S,6S)-hydroxynorketamine, 10 nM (R,S)-norketamine, and 1,000 nM (R,S)-ketamine. The potency of the effect reflected antagonistic activity of the test compounds at the α7-nicotinic acetylcholine receptor. CONCLUSIONS: The data demonstrate that (R,S)-norketamine and (2S,6S)-hydroxynorketamine have potent pharmacological activity both in vitro and in vivo and contribute to the molecular effects produced by subanesthetic doses of (R,S)-ketamine. The results suggest that the determination of the mechanisms underlying the antidepressant and analgesic effects of (R,S)-ketamine requires a full study of the parent compound and its metabolites.


Asunto(s)
Antagonistas de Aminoácidos Excitadores/farmacología , Ketamina/análogos & derivados , Serina-Treonina Quinasas TOR/efectos de los fármacos , Aconitina/análogos & derivados , Aconitina/farmacología , Animales , Western Blotting , Encéfalo/metabolismo , Ketamina/análisis , Ketamina/farmacocinética , Ketamina/farmacología , Masculino , Nicotina/farmacología , Agonistas Nicotínicos/farmacología , Antagonistas Nicotínicos/farmacología , Células PC12 , Fosforilación , Corteza Prefrontal/efectos de los fármacos , Corteza Prefrontal/metabolismo , Ratas , Ratas Wistar , Transducción de Señal/efectos de los fármacos
18.
Drug Dev Res ; 75(1): 37-46, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24648048

RESUMEN

The purpose of this research work is to evaluate toxicity of diethylenetriamine pentaacetic acid zinc trisodium salt (Zn-DTPA) tablets, a novel oral solid dosage form containing permeation enhancers in beagle dogs and Sprague Dawley rats. (Zn-DTPA) in tablet dosage form was administered once daily for 7 days to beagle dogs at low (840 mg/dog/day), mid (2520 mg/dog/day), or high (7560 mg/dog/day). On day 8, all treated and control groups were necropsied. The novel Zn-DTPA tablet formulation showed rapid absorption with the T(max) at 1 h. Plasma concentrations as high as 270 µg/mL were observed after 7 days of administration. Exposure to DTPA, based on area under the curve (AUC(last)) and maximum concentration (C(max)), was dose dependent but not dose proportional. No biologically relevant changes in hematology or clinical chemistry that were related to DTPA exposure were observed, and there were no changes in body weight in treated dogs compared with controls. Zn-DTPA was well tolerated, with minor toxicological effects of emesis and diarrhea, following oral tablet administration for 7 consecutive days. Based on the endpoints evaluated in this study, the maximum tolerated dose is considered to be greater than 7560 mg/dog/day (2535 µmol/kg/day, 1325 mg/kg/day), and the no-observed-adverse-effect level (NOAEL) is considered to be approximately 1325 mg/kg/day per oral when given to male and female beagle dogs. For rats, the NOAEL was estimated to be greater than 1000 mg/kg/day when administered by oral gavage of the crushed Zn-DTPA tablets as suspension once daily (qd) to male and female Sprague Dawley rats.


Asunto(s)
Ácido Pentético/administración & dosificación , Ácido Pentético/efectos adversos , Protectores contra Radiación/administración & dosificación , Protectores contra Radiación/efectos adversos , Administración Oral , Animales , Perros , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Evaluación Preclínica de Medicamentos , Femenino , Masculino , Dosis Máxima Tolerada , Nivel sin Efectos Adversos Observados , Ratas , Ratas Sprague-Dawley , Comprimidos
19.
PLoS One ; 8(4): e60579, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23577127

RESUMEN

BACKGROUND: The rapid development of effective medical countermeasures against potential biological threat agents is vital. Repurposing existing drugs that may have unanticipated activities as potential countermeasures is one way to meet this important goal, since currently approved drugs already have well-established safety and pharmacokinetic profiles in patients, as well as manufacturing and distribution networks. Therefore, approved drugs could rapidly be made available for a new indication in an emergency. METHODOLOGY/PRINCIPAL FINDINGS: A large systematic effort to determine whether existing drugs can be used against high containment bacterial and viral pathogens is described. We assembled and screened 1012 FDA-approved drugs for off-label broad-spectrum efficacy against Bacillus anthracis; Francisella tularensis; Coxiella burnetii; and Ebola, Marburg, and Lassa fever viruses using in vitro cell culture assays. We found a variety of hits against two or more of these biological threat pathogens, which were validated in secondary assays. As expected, antibiotic compounds were highly active against bacterial agents, but we did not identify any non-antibiotic compounds with broad-spectrum antibacterial activity. Lomefloxacin and erythromycin were found to be the most potent compounds in vivo protecting mice against Bacillus anthracis challenge. While multiple virus-specific inhibitors were identified, the most noteworthy antiviral compound identified was chloroquine, which disrupted entry and replication of two or more viruses in vitro and protected mice against Ebola virus challenge in vivo. CONCLUSIONS/SIGNIFICANCE: The feasibility of repurposing existing drugs to face novel threats is demonstrated and this represents the first effort to apply this approach to high containment bacteria and viruses.


Asunto(s)
Antibacterianos/farmacología , Antivirales/farmacología , Armas Biológicas , Aprobación de Drogas , Evaluación Preclínica de Medicamentos/métodos , United States Food and Drug Administration , Animales , Línea Celular , Femenino , Humanos , Masculino , Ratones , Estados Unidos
20.
Health Aff (Millwood) ; 32(3): 562-70, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23459736

RESUMEN

Health care providers remain uncertain about how they will fare financially if they adopt electronic health record (EHR) systems. We used survey data from forty-nine community practices in a large EHR pilot, the Massachusetts eHealth Collaborative, to project five-year returns on investment. We found that the average physician would lose $43,743 over five years; just 27 percent of practices would have achieved a positive return on investment; and only an additional 14 percent of practices would have come out ahead had they received the $44,000 federal meaningful-use incentive. The largest difference between practices with a positive return on investment and those with a negative return was the extent to which they used their EHRs to increase revenue, primarily by seeing more patients per day or by improved billing that resulted in fewer rejected claims and more accurate coding. Almost half of the practices did not realize savings in paper medical records because they continued to keep records on paper. We conclude that current meaningful use incentives alone may not ensure that most practices, particularly smaller ones, achieve a positive return on investment from EHR adoption. Policies that provide additional support, such as expanding the regional extension center program, could help ensure that practices make the changes required to realize a positive return on investment from EHRs.


Asunto(s)
Registros Electrónicos de Salud/economía , Investigación sobre Servicios de Salud/estadística & datos numéricos , Administración de la Práctica Médica/economía , Atención Ambulatoria/economía , Análisis Costo-Beneficio , Humanos , Inversiones en Salud/economía , Massachusetts , Uso Significativo/economía , Medicare/economía , Proyectos Piloto , Estados Unidos
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