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1.
J Clin Endocrinol Metab ; 108(12): 3122-3134, 2023 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-37390454

RESUMEN

CONTEXT: Inhibition of the neonatal fragment crystallizable receptor (FcRn) reduces pathogenic thyrotropin receptor antibodies (TSH-R-Ab) that drive pathology in thyroid eye disease (TED). OBJECTIVE: We report the first clinical studies of an FcRn inhibitor, batoclimab, in TED. DESIGN: Proof-of-concept (POC) and randomized, double-blind placebo-controlled trials. SETTING: Multicenter. PARTICIPANTS: Patients with moderate-to-severe, active TED. INTERVENTION: In the POC trial, patients received weekly subcutaneous injections of batoclimab 680 mg for 2 weeks, followed by 340 mg for 4 weeks. In the double-blind trial, patients were randomized 2:2:1:2 to weekly batoclimab (680 mg, 340 mg, 255 mg) or placebo for 12 weeks. MAIN OUTCOME: Change from baseline in serum anti-TSH-R-Ab and total IgG (POC); 12-week proptosis response (randomized trial). RESULTS: The randomized trial was terminated because of an unanticipated increase in serum cholesterol; therefore, data from 65 of the planned 77 patients were analyzed. Both trials showed marked decreases in pathogenic anti-TSH-R-Ab and total IgG serum levels (P < .001) with batoclimab. In the randomized trial, there was no statistically significant difference with batoclimab vs placebo in proptosis response at 12 weeks, although significant differences were observed at several earlier timepoints. In addition, orbital muscle volume decreased (P < .03) at 12 weeks, whereas quality of life (appearance subscale) improved (P < .03) at 19 weeks in the 680-mg group. Batoclimab was generally well tolerated, with albumin reductions and increases in lipids that reversed upon discontinuation. CONCLUSIONS: These results provide insight into the efficacy and safety of batoclimab and support its further investigation as a potential therapy for TED.


Asunto(s)
Exoftalmia , Oftalmopatía de Graves , Recién Nacido , Humanos , Oftalmopatía de Graves/tratamiento farmacológico , Calidad de Vida , Anticuerpos Monoclonales/uso terapéutico , Inmunoglobulina G/uso terapéutico , Método Doble Ciego , Resultado del Tratamiento
2.
Pharmacol Ther ; 226: 107864, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-33894275

RESUMEN

Cancer cells require increased levels of NADPH for increased nucleotide synthesis and for protection from ROS. Recent studies show that increased NADPH is generated in several ways. Activated AKT phosphorylates NAD kinase (NADK), increasing its activity. NADP formed, is rapidly converted to NADPH by glucose 6-phosphate dehydrogenase and malic enzymes, overexpressed in tumor cells with mutant p53. Calmodulin, overexpressed in some cancers, also increases NADK activity. Also, in IDH1/2 mutant cancer, NADPH serves as the cofactor to generate D-2 hydroxyglutarate, an oncometabolite. The requirement of cancer cells for elevated levels of NADPH provides an opportunity to target its synthesis for cancer treatment.


Asunto(s)
NADP , Neoplasias , Humanos , NADP/metabolismo , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo
3.
J Am Vet Med Assoc ; 254(3): 363-372, 2019 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-30668242

RESUMEN

OBJECTIVE To measure temporal trends in animal shelter and rescue intakes and outcomes for dogs and cats in Colorado from 2000 through 2015 and compare trends from 2008 through 2015 with previously reported trends from 2000 through 2007. DESIGN Serial cross-sectional study. SAMPLE 76 animal shelter and rescue facilities with annual intake and outcome data consistently reported to the state of Colorado from 2000 through 2015. PROCEDURES Data were collected for dogs and cats each year during the study period on 5 annual scales: number of animals taken in, number of animals taken in/1,000 state residents, animal outcomes as a percentage of intakes (species-specific scales), and annual live release rate as a function of intakes and outcomes. Aggregate data were analyzed for temporal trends by linear regression modeling. RESULTS Decreases in annual intake and euthanasia rates and a concurrent increase in live release rate were observed for both species. The decreases observed for cats from 2008 through 2015 contrasted with the previously reported findings of increased rates of intake and euthanasia from 2000 through 2007. CONCLUSIONS AND CLINICAL RELEVANCE We believe that these temporal trends suggested substantial improvements in intake and outcome data for sheltered cats and dogs across Colorado that reflected changes in unhoused animal populations, along with the impact of resource allocation to spay-neuter programs, adoption marketing, intershelter transfers, and evidence-based improvements in operations. The findings indicated that consistent data collection and interorganizational collaboration can be used to optimize animal shelter capacity and outcomes across a statewide shelter system.


Asunto(s)
Enfermedades de los Gatos , Enfermedades de los Perros , Bienestar del Animal , Animales , Castración/veterinaria , Gatos , Colorado , Estudios Transversales , Perros , Eutanasia Animal , Humanos
4.
Child Maltreat ; 24(2): 161-168, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30537874

RESUMEN

METHOD: Families referred by Child Protective Services ( M child age = 6 years ± 4; M parent age = 32 years ± 8.26) were individually randomized to experimental ( n = 14) or control ( n = 14) intervention. Family functioning outcomes were measured using the North Carolina Family Assessment Scale for Reunification. RESULTS: All four targeted family functioning outcomes were significantly increased for participants who received animal-assisted therapy as an adjunct to intensive family preservation services ( n = 14) with medium to large effect sizes. These improvements were sustained in two of the subscales through discharge. No significant differences were measured for the distal clinical outcome of disposition of children at discharge. CONCLUSIONS: Findings suggest that adding animal-assisted therapy as an adjunct can improve evidence-based clinical interventions aimed at enhancing the caregiving contexts of children.


Asunto(s)
Terapia Asistida por Animales , Maltrato a los Niños/terapia , Terapia Familiar , Adolescente , Adulto , Niño , Servicios de Protección Infantil , Preescolar , Familia/psicología , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Padres , Adulto Joven
5.
Behav Sci Law ; 36(6): 717-729, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30207616

RESUMEN

The confluence of developments in the assessment of animal abuse, the evolution of psychiatric nosology for the diagnosis of conduct disorder, legislative changes involving crimes against non-human animals, and the recent inclusion of crimes against animals in the FBI's National Incident-Based Reporting System, highlights the critical need for examining the forensic dimensions of animal abuse cases. We provide an overview of the research literature on these topics in the hope that forensic evaluators will have an evidence-based framework for assessing cases they encounter that include perpetration of violence against animals.


Asunto(s)
Bienestar del Animal , Crimen/psicología , Trastornos Mentales/psicología , Animales , Femenino , Psiquiatría Forense , Humanos , Masculino , Estados Unidos , Violencia/psicología
6.
J Appl Anim Welf Sci ; 21(2): 120-129, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-28960091

RESUMEN

A retrospective database analysis (2011-2015) evaluated associations between race and ethnicity and veterinary service utilization by sampling 83,260 companion animals whose guardians (owners) self-identified as White, Black, or Latino/a from 39 Humane Society of the United States Pets for Life (PFL) sites across the United States. Controlling for socioeconomic status, the percentage of nonhuman animals sterilized through PFL whose owners were Latino/a or Black was substantially higher than in previously reported findings. While Latinos/as had the highest mean number of days from first contact with the program to consent, they also had the highest percentage of owners accepting the voucher during initial contact. Logistic regression models suggested that although meaningful, race and ethnicity were not primary determinants of veterinary service utilization. When veterinary and animal welfare organizations deliberately remove structural barriers embedded with racial inequalities, individuals, regardless of race and ethnicity, proceed with companion-animal sterilization. Therefore, service providers must use unbiased, informed, and culturally competent practices to improve companion-animal welfare through the optimization of veterinary services, including spay and neuter.


Asunto(s)
Negro o Afroamericano , Castración/veterinaria , Hispánicos o Latinos , Mascotas/economía , Bienestar del Animal/economía , Bienestar del Animal/organización & administración , Animales , Castración/economía , Femenino , Hospitales Veterinarios/estadística & datos numéricos , Humanos , Masculino , Estudios Retrospectivos , Factores Socioeconómicos , Medicina Veterinaria/economía , Poblaciones Vulnerables
7.
Clin Cancer Res ; 22(21): 5189-5195, 2016 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-27582489

RESUMEN

NAD+ kinase (NADK) catalyzes the phosphorylation of nicotinamide adenine dinucleotide (NAD+) to nicotinamide adenine dinucleotide phosphate (NADP+) using ATP as the phosphate donor. NADP+ is then reduced to NADPH by dehydrogenases, in particular glucose-6-phosphate dehydrogenase and the malic enzymes. NADPH functions as an important cofactor in a variety of metabolic and biosynthetic pathways. The demand for NADPH is particularly high in proliferating cancer cells, where it acts as a cofactor for the synthesis of nucleotides, proteins, and fatty acids. Moreover, NADPH is essential for the neutralization of the dangerously high levels of reactive oxygen species (ROS) generated by increased metabolic activity. Given its key role in metabolism and regulation of ROS, it is not surprising that several recent studies, including in vitro and in vivo assays of tumor growth and querying of patient samples, have identified NADK as a potential therapeutic target for the treatment of cancer. In this review, we will discuss the experimental evidence justifying further exploration of NADK as a clinically relevant drug target and describe our studies with a lead compound, thionicotinamide, an NADK inhibitor prodrug. Clin Cancer Res; 22(21); 5189-95. ©2016 AACR.


Asunto(s)
NAD/metabolismo , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Animales , Humanos , NADP/metabolismo , Oxidación-Reducción/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Especies Reactivas de Oxígeno/metabolismo
9.
Nat Commun ; 7: 10500, 2016 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-26806015

RESUMEN

As we enter the era of precision medicine, characterization of cancer genomes will directly influence therapeutic decisions in the clinic. Here we describe a platform enabling functionalization of rare gene mutations through their high-throughput construction, molecular barcoding and delivery to cancer models for in vivo tumour driver screens. We apply these technologies to identify oncogenic drivers of pancreatic ductal adenocarcinoma (PDAC). This approach reveals oncogenic activity for rare gene aberrations in genes including NAD Kinase (NADK), which regulates NADP(H) homeostasis and cellular redox state. We further validate mutant NADK, whose expression provides gain-of-function enzymatic activity leading to a reduction in cellular reactive oxygen species and tumorigenesis, and show that depletion of wild-type NADK in PDAC cell lines attenuates cancer cell growth in vitro and in vivo. These data indicate that annotating rare aberrations can reveal important cancer signalling pathways representing additional therapeutic targets.


Asunto(s)
Neoplasias Pancreáticas/genética , Fosfotransferasas (Aceptor de Grupo Alcohol)/genética , Animales , Carcinogénesis , Línea Celular Tumoral , Femenino , Humanos , Ratones , Ratones Desnudos , Mutación , Neoplasias Pancreáticas/enzimología , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patología , Especies Reactivas de Oxígeno/metabolismo , Neoplasias Pancreáticas
10.
Mol Pharmacol ; 88(4): 720-7, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26219913

RESUMEN

NAD(+) kinase (NADK) is the only known cytosolic enzyme that converts NAD(+) to NADP(+), which is subsequently reduced to NADPH. The demand for NADPH in cancer cells is elevated as reducing equivalents are required for the high levels of nucleotide, protein, and fatty acid synthesis found in proliferating cells as well as for neutralizing high levels of reactive oxygen species (ROS). We determined whether inhibition of NADK activity is a valid anticancer strategy alone and in combination with chemotherapeutic drugs known to induce ROS. In vitro and in vivo inhibition of NADK with either small-hairpin RNA or thionicotinamide inhibited proliferation. Thionicotinamide enhanced the ROS produced by several chemotherapeutic drugs and produced synergistic cell kill. NADK inhibitors alone or in combination with drugs that increase ROS-mediated stress may represent an efficacious antitumor combination and should be explored further.


Asunto(s)
Antineoplásicos/administración & dosificación , Citosol/metabolismo , NADP/antagonistas & inhibidores , Niacinamida/análogos & derivados , Estrés Oxidativo/fisiología , Animales , Citosol/efectos de los fármacos , Sinergismo Farmacológico , Humanos , Masculino , Ratones , Ratones Endogámicos NOD , Ratones SCID , NADP/metabolismo , Niacinamida/administración & dosificación , Estrés Oxidativo/efectos de los fármacos , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de Xenoinjerto/métodos
11.
Mol Cancer Res ; 13(10): 1361-6, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26101208

RESUMEN

Rapidly proliferating tumors attempt to meet the demands for nucleotide biosynthesis by upregulating folate pathways that provide the building blocks for pyrimidine and purine biosynthesis. In particular, the key role of mitochondrial folate enzymes in providing formate for de novo purine synthesis and for providing the one-carbon moiety for thymidylate synthesis has been recognized in recent studies. We have shown a significant correlation between the upregulation of the mitochondrial folate enzymes, high proliferation rates, and sensitivity to the folate antagonist methotrexate (MTX). Burkitt lymphoma and diffuse large-cell lymphoma tumor specimens have the highest levels of mitochondrial folate enzyme expression and are known to be sensitive to treatment with MTX. A key enzyme upregulated in rapidly proliferating tumors but not in normal adult cells is the mitochondrial enzyme methylenetetrahydrofolate dehydrogenase (MTHFD2). This perspective outlines the rationale for specific targeting of MTHFD2 and compares known and generated crystal structures of MTHFD2 and closely related enzymes as a molecular basis for developing therapeutic agents against MTHFD2. Importantly, the development of selective inhibitors of mitochondrial methylenetetrahydrofolate dehydrogenase is expected to have substantial activity, and this perspective supports the investigation and development of MTHFD2 inhibitors for anticancer therapy.


Asunto(s)
Aminohidrolasas/biosíntesis , Metilenotetrahidrofolato Deshidrogenasa (NADP)/biosíntesis , Mitocondrias/enzimología , Complejos Multienzimáticos/biosíntesis , Neoplasias/tratamiento farmacológico , Neoplasias/enzimología , Aminohidrolasas/química , Aminohidrolasas/metabolismo , Animales , Antineoplásicos/química , Antineoplásicos/farmacología , Proliferación Celular/efectos de los fármacos , Proliferación Celular/fisiología , Diseño de Fármacos , Humanos , Metilenotetrahidrofolato Deshidrogenasa (NADP)/química , Metilenotetrahidrofolato Deshidrogenasa (NADP)/metabolismo , Ratones , Modelos Moleculares , Terapia Molecular Dirigida , Complejos Multienzimáticos/química , Complejos Multienzimáticos/metabolismo , Neoplasias/patología , Conformación Proteica , Pliegue de Proteína , Relación Estructura-Actividad
12.
Cancer Metab ; 3: 6, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26023330

RESUMEN

BACKGROUND: Systematic quantitative methodologies are needed to understand the heterogeneity of cell metabolism across cell types in normal physiology, disease, and treatment. Metabolic flux analysis (MFA) can be used to infer steady state fluxes, but it does not apply for transient dynamics. Kinetic flux profiling (KFP) can be used in the context of transient dynamics, and it is the current gold standard. However, KFP requires measurements at several time points, limiting its use in high-throughput applications. RESULTS: Here we propose transient MFA (tMFA) as a cost-effective methodology to quantify metabolic fluxes using metabolomics and isotope tracing. tMFA exploits the time scale separation between the dynamics of different metabolites to obtain mathematical equations relating metabolic fluxes to metabolite concentrations and isotope fractions. We show that the isotope fractions of serine and glycine are at steady state 8 h after addition of a tracer, while those of purines and glutathione are following a transient dynamics with an approximately constant turnover rate per unit of metabolite, supporting the application of tMFA to the analysis of folate metabolism. Using tMFA, we investigate the heterogeneity of folate metabolism and the response to the antifolate methotrexate in breast cancer cells. Our analysis indicates that methotrexate not only inhibits purine synthesis but also induces an increase in the AMP/ATP ratio, activation of AMP kinase (AMPK), and the inhibition of protein and glutathione synthesis. We also find that in some cancer cells, the generation of one-carbon units from serine exceeds the biosynthetic demand. CONCLUSIONS: This work validates tMFA as a cost-effective methodology to investigate cell metabolism. Using tMFA, we have shown that the effects of treatment with the antifolate methotrexate extend beyond inhibition of purine synthesis and propagate to other pathways in central metabolism.

13.
Cancer Chemother Pharmacol ; 75(6): 1247-52, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25917288

RESUMEN

PURPOSE: To investigate the effectiveness of a combination of 6-thioguanine (6-TG) and pralatrexate (PDX) in methylthioadenosine phosphorylase (MTAP)-deficient T-cell acute lymphoblastic leukemia (T-cell ALL). METHODS: CCRF-CEM (MTAP(-/-)) and Molt4 (MTAP(+/+)) T-cell ALL cell lines were treated with 6-TG or PDX and evaluated for efficacy 72 h later. NOD/SCID gamma mice bearing CEM or Molt4 xenografts were treated with 6-TG and PDX alone or in combination to evaluate antitumor effects. RESULTS: CEM cells were more sensitive to 6-TG and PDX in vitro than Molt4. In vivo, CEM cells were very sensitive to PDX and 6-TG, whereas Molt4 cells were highly resistant to 6-TG. A well-tolerated combination of PDX and 6-TG achieved significant tumor regression in CEM xenografts. CONCLUSIONS: The loss of MTAP expression may be therapeutically exploited in T-cell ALL. The combination of 6-TG and PDX, with the inclusion of leucovorin rescue, allows for a safe and effective regimen in MTAP-deficient T-cell ALL.


Asunto(s)
Aminopterina/análogos & derivados , Antineoplásicos/uso terapéutico , Xenoinjertos/efectos de los fármacos , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamiento farmacológico , Purina-Nucleósido Fosforilasa/deficiencia , Tioguanina/farmacología , Aminopterina/farmacología , Animales , Línea Celular Tumoral , Humanos , Masculino , Ratones , Ratones Endogámicos NOD , Ratones SCID , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Purina-Nucleósido Fosforilasa/genética
14.
Cancer Chemother Pharmacol ; 74(5): 1029-32, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25205429

RESUMEN

PURPOSE: To investigate the ability of leucovorin (LV) to abrogate dose-limiting toxicities of pralatrexate (PDX) while maintaining efficacy, in vivo. METHODS: H2052 mesothelioma cells were treated with the antifolates methotrexate (MTX), PDX and pemetrexed, with and without LV rescue 24 h later. Cell killing was evaluated 48 h later. Female nude mice bearing H2052 xenografts were treated with varying doses and schedules of the antifolate PDX and LV. RESULTS: In vitro, H2052 cells were more sensitive to PDX as compared to MTX and pemetrexed. Administration of LV 24 h after antifolate treatment reduced efficacy of antifolates MTX and pemetrexed, but not PDX. In vivo, LV was found to reduce toxicity of PDX at the maximum tolerated dose without sacrificing efficacy. Lethal doses of PDX were rescued by LV, and mice bearing the H2052 tumor demonstrated prolonged and enhanced tumor regression. CONCLUSIONS: High-dose PDX with subsequent LV rescue may be a viable treatment strategy in mesothelioma and other cancers. The inclusion of LV rescue into new and existing PDX treatment protocols should be explored as a way to expand the tolerability and effectiveness of PDX in the clinic.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Mesotelioma/tratamiento farmacológico , Ensayos Antitumor por Modelo de Xenoinjerto , Aminopterina/administración & dosificación , Aminopterina/análogos & derivados , Aminopterina/farmacología , Animales , Peso Corporal/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Sinergismo Farmacológico , Femenino , Antagonistas del Ácido Fólico/administración & dosificación , Antagonistas del Ácido Fólico/farmacología , Glutamatos/farmacología , Guanina/análogos & derivados , Guanina/farmacología , Humanos , Leucovorina/administración & dosificación , Leucovorina/farmacología , Mesotelioma/patología , Metotrexato/farmacología , Ratones Desnudos , Pemetrexed , Factores de Tiempo , Carga Tumoral/efectos de los fármacos , Complejo Vitamínico B/administración & dosificación , Complejo Vitamínico B/farmacología
15.
Cancer Metab ; 1(1): 20, 2013 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-24279929

RESUMEN

BACKGROUND: Although cells require nutrients to proliferate, most nutrient exchange rates of the NCI60 panel of cancer cell lines correlate poorly with their proliferation rate. Here, we provide evidence indicating that this inconsistency is rooted in the variability of cell size. RESULTS: We integrate previously reported data characterizing genome copy number variations, gene expression, protein expression and exchange fluxes with our own measurements of cell size and protein content in the NCI60 panel of cell lines. We show that protein content, DNA content, and protein synthesis per cell are proportional to the cell volume, and that larger cells proliferate slower than smaller cells. We estimate the metabolic fluxes of these cell lines and show that their magnitudes are proportional to their protein synthesis rate and, after correcting for cell volume, to their proliferation rate. At the level of gene expression, we observe that genes expressed at higher levels in smaller cells are enriched for genes involved in cell cycle, while genes expressed at higher levels in large cells are enriched for genes expressed in mesenchymal cells. The latter finding is further corroborated by the induction of those same genes following treatment with TGFß, and the high vimentin but low E-cadherin protein levels in the larger cells. We also find that aromatase inhibitors, statins and mTOR inhibitors preferentially inhibit the in vitro growth of cancer cells with high protein synthesis rates per cell. CONCLUSIONS: The NCI60 cell lines display various metabolic activities, and the type of metabolic activity that they possess correlates with their cell volume and protein content. In addition to cell proliferation, cell volume and/or biomarkers of protein synthesis may predict response to drugs targeting cancer metabolism.

16.
Mol Pharmacol ; 83(2): 339-53, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23197646

RESUMEN

Dihydrofolate reductase (DHFR), because of its essential role in DNA synthesis, has been targeted for the treatment of a wide variety of human diseases, including cancer, autoimmune diseases, and infectious diseases. Methotrexate (MTX), a tight binding inhibitor of DHFR, is one of the most widely used drugs in cancer treatment and is especially effective in the treatment of acute lymphocytic leukemia, non-Hodgkin's lymphoma, and osteosarcoma. Limitations to its use in cancer include natural resistance and acquired resistance due to decreased cellular uptake and decreased retention due to impaired polyglutamylate formation and toxicity at higher doses. Here, we describe a novel mechanism to induce DHFR degradation through cofactor depletion in neoplastic cells by inhibition of NAD kinase, the only enzyme responsible for generating NADP, which is rapidly converted to NADPH by dehydrogenases/reductases. We identified an inhibitor of NAD kinase, thionicotinamide adenine dinucleotide phosphate (NADPS), which led to accelerated degradation of DHFR and to inhibition of cancer cell growth. Of importance, combination treatment of NADPS with MTX displayed significant synergy in a metastatic colon cancer cell line and was effective in a MTX-transport resistant leukemic cell line. We suggest that NAD kinase is a valid target for further inhibitor development for cancer treatment.


Asunto(s)
NADP/análogos & derivados , Niacinamida/análogos & derivados , Niacinamida/farmacología , Fosfotransferasas (Aceptor de Grupo Alcohol)/antagonistas & inhibidores , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Tetrahidrofolato Deshidrogenasa/metabolismo , Transporte Biológico/efectos de los fármacos , Transporte Biológico/genética , Línea Celular Tumoral , Semivida , Humanos , Metotrexato/farmacología , NADP/metabolismo , NADP/farmacología , Proteolisis/efectos de los fármacos , Transcripción Genética/efectos de los fármacos , Transcripción Genética/genética , Regulación hacia Arriba/efectos de los fármacos , Regulación hacia Arriba/genética
17.
Cancer Res ; 73(2): 478-82, 2013 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-23135910

RESUMEN

Previous studies have documented the roles of transport via the reduced folate carrier, retention via polyglutamylation, and increased levels of the target enzyme, dihydrofolate reductase in sensitivity to methotrexate. Recent studies have shown that the mitochondrial enzymes in the cellular metabolism of serine, folate, and glycine are overexpressed in a subset of human cancers and that their expression is required for tumor maintenance. In this Perspective article, we propose that the expression of mitochondrial enzymes in the metabolism of serine and glycine, in addition to those involved in folate metabolism, are determinants of the response to methotrexate. Furthermore, we show that myc activation in tumors is associated with upregulation of these enzymes. We propose that patients whose tumors show this phenotype will be sensitive to folate antagonists targeting thymidylate or purine biosynthesis.


Asunto(s)
Antagonistas del Ácido Fólico/farmacología , Ácido Fólico/metabolismo , Glicina/metabolismo , Metotrexato/farmacología , Mitocondrias/enzimología , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Serina/metabolismo , Transporte Biológico , Humanos , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Transcriptoma
18.
Am J Kidney Dis ; 53(3): 503-12, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19185402

RESUMEN

BACKGROUND: Recent publications suggest that increased mortality is associated with high hematocrit targets in erythropoietin-stimulating agent-treated patients with chronic kidney disease. We aim to further inform the debate about optimal hematocrit targets, advancing the hypothesis that the current hematocrit target may not optimize the survival of patients with end-stage renal disease. STUDY DESIGN: Cross-sectional observational study. SETTING & PARTICIPANTS: Medicare dialysis patients from 2002 to 2004 (n = 393,967). FACTORS: Quarterly average hematocrit and erythropoietin alfa (EPO) dose. OUTCOMES: Mortality hazard ratios from time-dependent Cox proportional hazard models, adjusting for comorbidities. RESULTS: N = 2,712,197 patient-facility quarters. During the study, 100,086 deaths were identified. Percentages of patient quarters within each hematocrit category: hematocrit less than 27% (2.0%), 27% to 28.49% (1.7%), 28.5% to 29.9% (2.9%), 30% to 31.49% (5.2%), 31.5% to 32.99% (9.0%), 33% to 34.49% (14.9%), 34.5% to 35.99% (19.2%), 36% to 37.49% (18.0%), 37.5% to 38.99% (12.0%), 39% to 40.49% (6.4%), 40.5% to 41.99% (3.0%), and 42% or greater (3.1%). Mortality hazard ratios from the fully adjusted model: hematocrit less than 27% (3.11), 27% to 28.49% (2.60), 28.5% to 29.9% (2.14), 30% to 31.49% (1.80), 31.5% to 32.99% (1.44), 33% to 34.49% (1.17), 34.5% to 35.99% (reference), 36% to 37.49% (0.98), 37.5% to 38.99% (1.01), 39% to 40.49% (1.13), 40.5% to 41.99% (1.32), and 42% or greater (1.57). LIMITATIONS: First, potential confounding by indication related to associations between underlying illness and mortality, anemia, and EPO responsiveness. Second, Medicare claims data reflect a range of conditions and degrees of severity not easily translated into the clinical context. Third, for Medicare claims, EPO reporting is not required if EPO is not billed. Greater than 95% of "missing hematocrit" quarters are "EPO = 0" patient quarters. Interpretation of results for the missing hematocrit and EPO = 0 use categories is complicated by data source limitations. CONCLUSIONS: We show an association between mortality and low hematocrit in dialysis patients, in part reflecting the presence of comorbidities. We also show an association between increased mortality and high hematocrit. Additional interventional trials should be undertaken to better define the optimal target for anemia management in patients with end-stage renal disease, with careful prospective identification of underlying comorbidities and clinical factors contributing to high erythropoietin-stimulating agent requirement.


Asunto(s)
Anemia/tratamiento farmacológico , Anemia/mortalidad , Eritropoyetina/uso terapéutico , Hematócrito/mortalidad , Fallo Renal Crónico/mortalidad , Fallo Renal Crónico/terapia , Diálisis Renal , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anemia/etiología , Estudios Transversales , Femenino , Humanos , Fallo Renal Crónico/complicaciones , Masculino , Persona de Mediana Edad , Modelos Estadísticos , Factores de Tiempo , Adulto Joven
19.
J Am Soc Nephrol ; 18(9): 2565-74, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17675667

RESUMEN

Medicare is considering an expansion of the bundle of dialysis-related services to be paid on a prospective basis. Exploratory models were developed to assess the potential limitations of case-mix adjustment for such an expansion. A broad set of patient characteristics explained 11.8% of the variation in Medicare allowable charges per dialysis session. Although adding recent hematocrit values or prior health care utilization to the model did increase explanatory power, it could also create adverse incentives. Projected gains or losses relative to prevailing fee-for-service payments, assuming no change in practice patterns, were significant for some individual providers. However, systematic gains or losses for different classes of providers were modest.


Asunto(s)
Costos de la Atención en Salud , Medicare , Sistema de Pago Prospectivo , Diálisis Renal/economía , Ajuste de Riesgo , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Servicios de Salud/estadística & datos numéricos , Hematócrito , Humanos , Masculino , Persona de Mediana Edad , Modelos Estadísticos , Estados Unidos
20.
Am J Kidney Dis ; 47(4): 666-71, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16564944

RESUMEN

In April 2005, Medicare began adjusting payments to dialysis providers for composite-rate services for a limited set of patient characteristics, including age, body surface area, and low body mass index. We present analyses intended to help the end-stage renal disease community understand the empirical reasons behind the new composite-rate basic case-mix adjustment. The U-shaped relationship between age and composite-rate cost that is reflected in the basic case-mix adjustment has generated significant discussion within the end-stage renal disease community. Whereas greater costs among older patients are consistent with conventional wisdom, greater costs among younger patients are caused in part by more skipped sessions and a greater incidence of certain costly comorbidities. Longer treatment times for patients with a greater body surface area combined with the largely fixed cost structure of dialysis facilities explains much of the greater cost for larger patients. The basic case-mix adjustment reflects an initial and partial adjustment for the cost of providing composite-rate services.


Asunto(s)
Fallo Renal Crónico/economía , Fallo Renal Crónico/terapia , Diálisis Renal/economía , Ajuste de Riesgo , Adulto , Anciano , Anciano de 80 o más Años , Costos y Análisis de Costo , Femenino , Humanos , Masculino , Medicare , Persona de Mediana Edad , Estados Unidos
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