Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
1.
PLoS Comput Biol ; 18(10): e1010153, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36279309

RESUMO

Early lung cancer lesions develop within a unique microenvironment that undergoes constant cyclic stretch from respiration. While tumor stiffening is an established driver of tumor progression, the contribution of stress and strain to lung cancer is unknown. We developed tissue scale finite element models of lung tissue to test how early lesions alter respiration-induced strain. We found that an early tumor, represented as alveolar filling, amplified the strain experienced in the adjacent alveolar walls. Tumor stiffening further increased the amplitude of the strain in the adjacent alveolar walls and extended the strain amplification deeper into the normal lung. In contrast, the strain experienced in the tumor proper was less than the applied strain, although regions of amplification appeared at the tumor edge. Measurements of the alveolar wall thickness in clinical and mouse model samples of lung adenocarcinoma (LUAD) showed wall thickening adjacent to the tumors, consistent with cellular response to strain. Modeling alveolar wall thickening by encircling the tumor with thickened walls moved the strain amplification radially outward, to the next adjacent alveolus. Simulating iterative thickening in response to amplified strain produced tracks of thickened walls. We observed such tracks in early-stage clinical samples. The tracks were populated with invading tumor cells, suggesting that strain amplification in very early lung lesions could guide pro-invasive remodeling of the tumor microenvironment. The simulation results and tumor measurements suggest that cells at the edge of a lung tumor and in surrounding alveolar walls experience increased strain during respiration that could promote tumor progression.


Assuntos
Neoplasias Pulmonares , Alvéolos Pulmonares , Camundongos , Animais , Análise de Elementos Finitos , Alvéolos Pulmonares/patologia , Alvéolos Pulmonares/fisiologia , Pulmão , Neoplasias Pulmonares/patologia , Carcinogênese , Microambiente Tumoral
2.
Transfusion ; 59(7): 2316-2323, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31106447

RESUMO

BACKGROUND: Risk-adjusted benchmarking could be useful to compare blood utilization between hospitals or individual groups, such as physicians, while accounting for differences in patient complexity. The aim of this study was to analyze the association of red blood cell (RBC) use and diagnosis-related group (DRG) weights across all inpatient hospital stays to determine the suitability of using DRGs for between-hospital risk-adjusted benchmarking. Specific hierarchical organizational units (surgical vs. nonsurgical patients, departments, and physicians) were also evaluated. STUDY DESIGN AND METHODS: We studied blood use among all adult inpatients, and within organizational units, over 4 years (May 2014 to March 2018) at an academic center. Number of RBCs transfused, all patient refined (APR)-DRGs, and other variables were captured over entire hospital stays. We used multilevel generalized linear modeling (zero-inflated negative binomial) to study the relationship between RBC utilization and APR-DRG. RESULTS: A total of 97,955 hospital stays were evaluated and the median APR-DRG weight was 1.2. The association of RBCs transfused and APR-DRG weight was statistically significant at all hierarchical levels (incidence rate ratio = 1.22; p < 0.001). The impact of APR-DRG on blood use, measured by the incidence rate ratio, demonstrated an association at the all-patient and surgical levels, at several department and physician levels, but not at the medical patient level. The relationship between RBCs transfused and APR-DRG varied across organizational units. CONCLUSION: Number of RBCs transfused was associated with APR-DRG weight at multiple hierarchical levels and could be used for risk-adjusted benchmarking in those contexts. The relationship between RBC use and APR-DRG varied across organizational units.


Assuntos
Benchmarking , Transfusão de Sangue , Grupos Diagnósticos Relacionados , Pacientes Internados , Tempo de Internação , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Medição de Risco
4.
Lab Med ; 2024 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-38431798

RESUMO

BACKGROUND: Rainbow blood draws for add-on testing in the emergency department (ED) are a common practice at our institution. We sought to determine the prevalence of this practice among reference laboratory clients and characterize the impact of pandemic-driven supply shortages. METHODS: This cross-sectional study surveyed 354 client laboratories to understand specimen collection practices in specific clinical environments and how these practices may have been affected by supply chain shortages. Data analysis by descriptive statistics was performed in Qualtrics. RESULTS: A total of 138 laboratories took the survey (39% response rate) with 57% indicating that their ED performed rainbow draws. Of these, 16% have a formal policy regarding rainbow draws, and 76% of respondents indicated that their institution was required to modify practices due to pandemic-driven supply shortages. A total of 19% indicated they routinely collect multiple urine aliquots for add-on testing. CONCLUSION: Rainbow draws and collection of urine aliquots in the ED for add-on testing are relatively common practices, with few institutions maintaining formal policies regarding the practice. Pandemic-driven supply chain shortages affected a majority of respondent laboratories and local cost-benefit analysis regarding extra specimen collection is recommended to limit waste of laboratory resources.

5.
JCI Insight ; 8(13)2023 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-37427592

RESUMO

B cells contribute to multiple aspects of autoimmune disorders, and B cell-targeting therapies, including B cell depletion, have been proven to be efficacious in treatment of multiple autoimmune diseases. However, the development of novel therapies targeting B cells with higher efficacy and a nondepleting mechanism of action is highly desirable. Here we describe a nondepleting, high-affinity anti-human CD19 antibody LY3541860 that exhibits potent B cell inhibitory activities. LY3541860 inhibits B cell activation, proliferation, and differentiation of primary human B cells with high potency. LY3541860 also inhibits human B cell activities in vivo in humanized mice. Similarly, our potent anti-mCD19 antibody also demonstrates improved efficacy over CD20 B cell depletion therapy in multiple B cell-dependent autoimmune disease models. Our data indicate that anti-CD19 antibody is a highly potent B cell inhibitor that may have potential to demonstrate improved efficacy over currently available B cell-targeting therapies in treatment of autoimmune conditions without causing B cell depletion.


Assuntos
Doenças Autoimunes , Linfócitos B , Camundongos , Animais , Antígenos CD19 , Doenças Autoimunes/tratamento farmacológico
6.
Handb Exp Pharmacol ; (203): 279-301, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21484576

RESUMO

Fructose-1,6-bisphosphatase (FBPase), a rate-controlling enzyme of gluconeogenesis, has emerged as an important target for the treatment of type 2 diabetes due to the well-recognized role of excessive endogenous glucose production (EGP) in the hyperglycemia characteristic of the disease. Inhibitors of FBPase are expected to fulfill an unmet medical need because the majority of current antidiabetic medications act primarily on insulin resistance or insulin insufficiency and do not reduce gluconeogenesis effectively or in a direct manner. Despite significant challenges, potent and selective inhibitors of FBPase targeting the allosteric site of the enzyme were identified by means of a structure-guided design strategy that used the natural inhibitor, adenosine monophosphate (AMP), as the starting point. Oral delivery of these anionic FBPase inhibitors was enabled by a novel diamide prodrug class. Treatment of diabetic rodents with CS-917, the best characterized of these prodrugs, resulted in a reduced rate of gluconeogenesis and EGP. Of note, inhibition of gluconeogenesis by CS-917 led to the amelioration of both fasting and postprandial hyperglycemia without weight gain, incidence of hypoglycemia, or major perturbation of lactate or lipid homeostasis. Furthermore, the combination of CS-917 with representatives of the insulin sensitizer or insulin secretagogue drug classes provided enhanced glycemic control. Subsequent clinical evaluations of CS-917 revealed a favorable safety profile as well as clinically meaningful reductions in fasting glucose levels in patients with T2DM. Future trials of MB07803, a second generation FBPase inhibitor with improved pharmacokinetics, will address whether this novel class of antidiabetic agents can provide safe and long-term glycemic control.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Frutose-Bifosfatase/antagonistas & inibidores , Gluconeogênese/efeitos dos fármacos , Glucose/biossíntese , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico , Alanina/efeitos adversos , Alanina/análogos & derivados , Alanina/farmacologia , Alanina/uso terapêutico , Animais , Humanos , Organofosfonatos , Compostos Organofosforados/efeitos adversos , Compostos Organofosforados/farmacologia , Compostos Organofosforados/uso terapêutico , Transdução de Sinais/efeitos dos fármacos
8.
J Am Chem Soc ; 129(50): 15491-502, 2007 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-18041834

RESUMO

Excessive glucose production by the liver coupled with decreased glucose uptake and metabolism by muscle, fat, and liver results in chronically elevated blood glucose levels in patients with type 2 diabetes. Efforts to treat diabetes by reducing glucose production have largely focused on the gluconeogenesis pathway and rate-limiting enzymes within this pathway such as fructose-1,6-bisphosphatase (FBPase). The first potent FBPase inhibitors were identified using a structure-guided drug design strategy (Erion, M. D.; et al. J. Am. Chem. Soc. 2007, 129, 15480-15490) but proved difficult to deliver orally. Herein, we report the synthesis and characterization of a series of orally bioavailable FBPase inhibitors identified following the combined discoveries of a low molecular weight inhibitor series with increased potency and a phosphonate prodrug class suitable for their oral delivery. The lead inhibitor, 10A, was designed with the aid of X-ray crystallography and molecular modeling to bind to the allosteric AMP binding site of FBPase. High potency (IC50 = 16 nM) and FBPase specificity were achieved by linking a 2-aminothiazole with a phosphonic acid. Free-energy perturbation calculations provided insight into the factors that contributed to the high binding affinity. 10A and standard phosphonate prodrugs of 10A exhibited poor oral bioavailability (0.2-11%). Improved oral bioavailability (22-47%) was achieved using phosphonate diamides that convert to the corresponding phosphonic acid by sequential action of an esterase and a phosphoramidase. Oral administration of the lead prodrug, MB06322 (30, CS-917), to Zucker Diabetic Fatty rats led to dose-dependent inhibition of gluconeogenesis and endogenous glucose production and consequently to significant blood glucose reduction.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/uso terapêutico , Frutose-Bifosfatase/antagonistas & inibidores , Hidrolases/antagonistas & inibidores , Pró-Fármacos/síntese química , Pró-Fármacos/uso terapêutico , Administração Oral , Animais , Sítios de Ligação , Cristalografia por Raios X , Diabetes Mellitus Tipo 2/enzimologia , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/química , Frutose-Bifosfatase/metabolismo , Glucose/biossíntese , Hepatócitos/metabolismo , Hidrolases/metabolismo , Masculino , Modelos Moleculares , Estrutura Molecular , Pró-Fármacos/administração & dosagem , Pró-Fármacos/química , Ratos , Sensibilidade e Especificidade , Estereoisomerismo , Relação Estrutura-Atividade
9.
Diabetes ; 55(6): 1747-54, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16731838

RESUMO

Gluconeogenesis is increased in type 2 diabetes and contributes significantly to fasting and postprandial hyperglycemia. We recently reported the discovery of the first potent and selective inhibitors of fructose 1,6-bisphosphatase (FBPase), a rate-controlling enzyme of gluconeogenesis. Herein we describe acute and chronic effects of the lead inhibitor, MB06322 (CS-917), in rodent models of type 2 diabetes. In fasting male ZDF rats with overt diabetes, a single dose of MB06322 inhibited gluconeogenesis by 70% and overall endogenous glucose production by 46%, leading to a reduction in blood glucose of >200 mg/dl. Chronic treatment of freely feeding 6-week-old male Zucker diabetic fatty (ZDF) rats delayed the development of hyperglycemia and preserved pancreatic function. Elevation of lactate ( approximately 1.5-fold) occurred after 4 weeks of treatment, as did the apparent shunting of precursors into triglycerides. Profound glucose lowering ( approximately 44%) and similar metabolic ramifications were associated with 2-week intervention therapy of 10-week-old male ZDF rats. In high-fat diet-fed female ZDF rats, MB06322 treatment for 2 weeks fully attenuated hyperglycemia without evidence of metabolic perturbation other than a modest reduction in glycogen stores ( approximately 20%). The studies confirm that excessive gluconeogenesis plays an integral role in the pathophysiology of type 2 diabetes and suggest that FBPase inhibitors may provide a future treatment option.


Assuntos
Alanina/análogos & derivados , Diabetes Mellitus Tipo 2/tratamento farmacológico , Frutose-Bifosfatase/antagonistas & inibidores , Glucose/biossíntese , Hiperglicemia/tratamento farmacológico , Compostos Organofosforados/farmacologia , Alanina/química , Alanina/farmacologia , Alanina/uso terapêutico , Animais , Glicemia/metabolismo , Peso Corporal/efeitos dos fármacos , Colesterol/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Ingestão de Alimentos/efeitos dos fármacos , Feminino , Gluconeogênese/efeitos dos fármacos , Hiperglicemia/metabolismo , Insulina/sangue , Corpos Cetônicos/metabolismo , Ácido Láctico/metabolismo , Masculino , Estrutura Molecular , Organofosfonatos , Compostos Organofosforados/química , Compostos Organofosforados/uso terapêutico , Pâncreas/efeitos dos fármacos , Pâncreas/metabolismo , Ratos , Ratos Zucker , Triglicerídeos/metabolismo
10.
J Med Chem ; 54(1): 153-65, 2011 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-21126019

RESUMO

Oral delivery of previously disclosed purine and benzimidazole fructose-1,6-bisphosphatase (FBPase) inhibitors via prodrugs failed, which was likely due to their high molecular weight (>600). Therefore, a smaller scaffold was desired, and a series of phosphonic acid-containing thiazoles, which exhibited high potency against human liver FBPase (IC(50) of 10-30 nM) and high selectivity relative to other 5'-adenosinemonophosphate (AMP)-binding enzymes, were discovered using a structure-guided drug design approach. The initial lead compound (30j) produced profound glucose lowering in rodent models of type 2 diabetes mellitus (T2DM) after parenteral administration. Various phosphonate prodrugs were explored without success, until a novel phosphonic diamide prodrug approach was implemented, which delivered compound 30j with good oral bioavailability (OBAV) (22-47%). Extensive lead optimization of both the thiazole FBPase inhibitors and their prodrugs culminated in the discovery of compound 35n (MB06322) as the first oral FBPase inhibitor advancing to human clinical trials as a potential treatment for T2DM.


Assuntos
Alanina/análogos & derivados , Amidas/síntese química , Diabetes Mellitus Experimental/tratamento farmacológico , Frutose-Bifosfatase/antagonistas & inibidores , Hipoglicemiantes/síntese química , Organofosfonatos/síntese química , Pró-Fármacos/síntese química , Tiazóis/síntese química , Administração Oral , Alanina/síntese química , Alanina/farmacocinética , Alanina/farmacologia , Amidas/farmacocinética , Amidas/farmacologia , Animais , Disponibilidade Biológica , Proteínas Sanguíneas/metabolismo , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/tratamento farmacológico , Humanos , Hipoglicemiantes/farmacocinética , Hipoglicemiantes/farmacologia , Masculino , Camundongos , Organofosfonatos/farmacocinética , Organofosfonatos/farmacologia , Pró-Fármacos/farmacocinética , Pró-Fármacos/farmacologia , Ligação Proteica , Ratos , Ratos Sprague-Dawley , Relação Estrutura-Atividade , Tiazóis/farmacocinética , Tiazóis/farmacologia
11.
J Med Chem ; 53(1): 441-51, 2010 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-20055427

RESUMO

Efforts to enhance the inhibitory potency of the initial purine series of fructose-1,6-bisphosphatase (FBPase) inhibitors led to the discovery of a series of benzimidazole analogues with human FBPase IC(50)s < 100 nM. Inhibitor 4.4 emerged as a lead compound based on its potent inhibition of human liver FBPase (IC(50) = 55 nM) and significant glucose lowering in normal fasted rats. Intravenous administration of 4.4 to Zucker diabetic fatty rats led to rapid and robust glucose lowering, thereby providing the first evidence that FBPase inhibitors could improve glycemia in animal models of type 2 diabetes.


Assuntos
Monofosfato de Adenosina/química , Benzimidazóis/farmacologia , Desenho de Fármacos , Inibidores Enzimáticos/farmacologia , Frutose-Bifosfatase/antagonistas & inibidores , Organofosfonatos/química , Monofosfato de Adenosina/metabolismo , Animais , Benzimidazóis/síntese química , Benzimidazóis/química , Diabetes Mellitus Tipo 2/tratamento farmacológico , Modelos Animais de Doenças , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Humanos , Fígado/enzimologia , Estrutura Molecular , Ratos , Ratos Zucker , Estereoisomerismo , Relação Estrutura-Atividade
12.
Ground Water ; 46(2): 335-40, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18194317

RESUMO

The primary goals for most ground water capture systems (i.e., pump-and-treat systems) are that (1) all contaminants within zones of interest will eventually be captured and (2) the extraction and reinjection wells are best located and operated at optimal flow rates, creating hydraulically efficient flow systems. A new tool, MODular ALLocation (MODALL), is presented to aid in the design and assessment of capture systems. MODALL uses the MODFLOW-calculated cell-by-cell flow terms to evaluate internodal flow balances to determine the percentage of flow in each cell which has either originated from a given source(s) or flows to a specified sink(s). Output from MODALL can be easily displayed in isopleths of "capture fraction" (CF) to indicate the certainty or strength of capture in various areas. MODALL results are compared to the results from an analytical solution, a pathline analysis using MODPATH, and solute transport simulation with MT3DMS. A brief case study is also presented where MODALL is used to optimize an existing pump-and-treat system to more effectively and more efficiently contain a 5000-m long plume.


Assuntos
Água , Tricloroetileno/isolamento & purificação , Poluentes da Água/isolamento & purificação
13.
J Med Chem ; 51(14): 4331-9, 2008 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-18570362

RESUMO

Like most phosphonic acids, the recently discovered potent and selective thiazole phosphonic acid inhibitors of fructose 1,6-bisphosphatase (FBPase) exhibited low oral bioavailability (OBAV) and therefore required a prodrug to achieve oral efficacy. Syntheses of known phosphonate prodrugs did not afford the desired OBAV; hence, a new class of prodrugs was sought. Phosphonic diamides derived from amino acid esters were discovered as viable prodrugs, which met our preset goals: excellent aqueous stability over a wide pH range, benign byproducts (amino acids and low molecular weight alcohols), and most importantly good OBAV leading to robust oral glucose lowering effects. These desirable properties of phosphonic diamides represent significant improvements over existing prodrug classes. Optimization of the diamide prodrugs of phosphonic acid 2a (MB05032) led to the identification of diamide 8 (MB06322), the first reported orally efficacious FBPase inhibitor.


Assuntos
Amidas/química , Inibidores Enzimáticos/farmacologia , Frutose-Bifosfatase/antagonistas & inibidores , Organofosfonatos/química , Pró-Fármacos/farmacologia , Administração Oral , Animais , Glicemia/análise , Estabilidade de Medicamentos , Inibidores Enzimáticos/administração & dosagem , Concentração de Íons de Hidrogênio , Espectroscopia de Ressonância Magnética , Pró-Fármacos/administração & dosagem , Ratos , Ratos Sprague-Dawley
14.
Proc Natl Acad Sci U S A ; 102(22): 7970-5, 2005 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-15911772

RESUMO

In type 2 diabetes, the liver produces excessive amounts of glucose through the gluconeogenesis (GNG) pathway and consequently is partly responsible for the elevated glucose levels characteristic of the disease. In an effort to find safe and efficacious GNG inhibitors, we targeted the AMP binding site of fructose 1,6-bisphosphatase (FBPase). The hydrophilic nature of AMP binding sites and their widespread use for allosteric regulation of enzymes in metabolic pathways has historically made discovery of AMP mimetics suitable for drug development difficult. By using a structure-based drug design strategy, we discovered a series of compounds that mimic AMP but bear little structural resemblance. The lead compound, MB05032, exhibited high potency and specificity for human FBPase. Oral delivery of MB05032 was achieved by using the bisamidate prodrug MB06322 (CS-917), which is converted to MB05032 in two steps through the action of an esterase and a phosphoramidase. MB06322 inhibited glucose production from a variety of GNG substrates in rat hepatocytes and from bicarbonate in male Zucker diabetic fatty rats. Analysis of liver GNG pathway intermediates confirmed FBPase as the site of action. Oral administration of MB06322 to Zucker diabetic fatty rats led to a dose-dependent decrease in plasma glucose levels independent of insulin levels and nutritional status. Glucose lowering occurred without signs of hypoglycemia or significant elevations in plasma lactate or triglyceride levels. The findings suggest that potent and specific FBPase inhibitors represent a drug class with potential to treat type 2 diabetes through inhibition of GNG.


Assuntos
Alanina/análogos & derivados , Alanina/farmacologia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Frutose-Bifosfatase/antagonistas & inibidores , Gluconeogênese/efeitos dos fármacos , Organofosfonatos/farmacologia , Compostos Organofosforados/farmacologia , Tiazóis/farmacologia , Monofosfato de Adenosina/metabolismo , Alanina/uso terapêutico , Análise de Variância , Animais , Radioisótopos de Carbono/metabolismo , Relação Dose-Resposta a Droga , Desenho de Fármacos , Frutose-Bifosfatase/metabolismo , Humanos , Fígado/metabolismo , Masculino , Mimetismo Molecular , Organofosfonatos/uso terapêutico , Compostos Organofosforados/uso terapêutico , Ratos , Ratos Sprague-Dawley , Ratos Zucker , Espectrofotometria , Tiazóis/uso terapêutico
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa