Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
1.
MAbs ; 15(1): 2263926, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37824334

RESUMO

In this investigation, we tested the hypothesis that a physiologically based pharmacokinetic (PBPK) model incorporating measured in vitro metrics of off-target binding can largely explain the inter-antibody variability in monoclonal antibody (mAb) pharmacokinetics (PK). A diverse panel of 83 mAbs was evaluated for PK in wild-type mice and subjected to 10 in vitro assays to measure major physiochemical attributes. After excluding for target-mediated elimination and immunogenicity, 56 of the remaining mAbs with an eight-fold variability in the area under the curve (AUC0-672h: 1.74 × 106 -1.38 × 107 ng∙h/mL) and 10-fold difference in clearance (2.55-26.4 mL/day/kg) formed the training set for this investigation. Using a PBPK framework, mAb-dependent coefficients F1 and F2 modulating pinocytosis rate and convective transport, respectively, were estimated for each mAb with mostly good precision (coefficient of variation (CV%) <30%). F1 was estimated to be the mean and standard deviation of 0.961 ± 0.593, and F2 was estimated to be 2.13 ± 2.62. Using principal component analysis to correlate the regressed values of F1/F2 versus the multidimensional dataset composed of our panel of in vitro assays, we found that heparin chromatography retention time emerged as the predictive covariate to the mAb-specific F1, whereas F2 variability cannot be well explained by these assays. A sigmoidal relationship between F1 and the identified covariate was incorporated within the PBPK framework. A sensitivity analysis suggested plasma concentrations to be most sensitive to F1 when F1 > 1. The predictive utility of the developed PBPK model was evaluated against a separate panel of 14 mAbs biased toward high clearance, among which area under the curve of PK data of 12 mAbs was predicted within 2.5-fold error, and the positive and negative predictive values for clearance prediction were 85% and 100%, respectively. MAb heparin chromatography assay output allowed a priori identification of mAb candidates with unfavorable PK.


Assuntos
Anticorpos Monoclonais , Modelos Biológicos , Camundongos , Animais , Pinocitose , Bioensaio , Heparina
2.
MAbs ; 15(1): 2256745, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37698932

RESUMO

Biologic drug discovery pipelines are designed to deliver protein therapeutics that have exquisite functional potency and selectivity while also manifesting biophysical characteristics suitable for manufacturing, storage, and convenient administration to patients. The ability to use computational methods to predict biophysical properties from protein sequence, potentially in combination with high throughput assays, could decrease timelines and increase the success rates for therapeutic developability engineering by eliminating lengthy and expensive cycles of recombinant protein production and testing. To support development of high-quality predictive models for antibody developability, we designed a sequence-diverse panel of 83 effector functionless IgG1 antibodies displaying a range of biophysical properties, produced and formulated each protein under standard platform conditions, and collected a comprehensive package of analytical data, including in vitro assays and in vivo mouse pharmacokinetics. We used this robust training data set to build machine learning classifier models that can predict complex protein behavior from these data and features derived from predicted and/or experimental structures. Our models predict with 87% accuracy whether viscosity at 150 mg/mL is above or below a threshold of 15 centipoise (cP) and with 75% accuracy whether the area under the plasma drug concentration-time curve (AUC0-672 h) in normal mouse is above or below a threshold of 3.9 × 106 h x ng/mL.


Assuntos
Anticorpos Monoclonais , Descoberta de Drogas , Animais , Camundongos , Anticorpos Monoclonais/química , Simulação por Computador , Proteínas Recombinantes , Viscosidade
3.
Eur Radiol ; 33(12): 9254-9261, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37368111

RESUMO

BACKGROUND: Several barriers hamper recruitment of diverse patient populations in multicenter clinical trials which determine efficacy of new systemic cancer therapies. PURPOSE: We assessed if quantitative analysis of computed tomography (CT) scans of metastatic colorectal cancer (mCRC) patients using imaging features that predict overall survival (OS) can unravel the association between ethnicity and efficacy. METHODS: We retrospectively analyzed CT images from 1584 mCRC patients in two phase III trials evaluating FOLFOX ± panitumumab (n = 331, 350) and FOLFIRI ± aflibercept (n = 437, 466) collected from August 2006 to March 2013. Primary and secondary endpoints compared RECIST1.1 response at month-2 and delta tumor volume at month-2, respectively. An ancillary study compared imaging phenotype using a peer-reviewed radiomics-signature combining 3 imaging features to predict OS landmarked from month-2. Analysis was stratified by ethnicity. RESULTS: In total, 1584 patients were included (mean age, 60.25 ± 10.57 years; 969 men). Ethnicity was as follows: African (n = 50, 3.2%), Asian (n = 66, 4.2%), Caucasian (n = 1413, 89.2%), Latino (n = 27, 1.7%), Other (n = 28, 1.8%). Overall baseline tumor volume demonstrated Africans and Caucasians had more advanced disease (p < 0.001). Ethnicity was associated with treatment response. Response per RECIST1.1 at month-2 was distinct between ethnicities (p = 0.048) with higher response rate (55.6%) in Latinos. Overall delta tumor volume at month-2 demonstrated that Latino patients more likely experienced response to treatment (p = 0.021). Radiomics phenotype was also distinct in terms of tumor radiomics heterogeneity (p = 0.023). CONCLUSION: This study highlights how clinical trials that inadequately represent minority groups may impact associated translational work. In appropriately powered studies, radiomics features may allow us to unravel associations between ethnicity and treatment efficacy, better elucidate mechanisms of resistance, and promote diversity in trials through predictive enrichment. CLINICAL RELEVANCE STATEMENT: Radiomics could promote clinical trial diversity through predictive enrichment, hence benefit to historically underrepresented racial/ethnic groups that may respond variably to treatment due to socioeconomic factors and built environment, collectively referred to as social determinants of health. KEY POINTS: •Findings indicate ethnicity was associated with treatment response across all 3 endpoints. First, response per RECIST1.1 at month-2 was distinct between ethnicities (p = 0.048) with higher response rate (55.6%) in Latinos. •Second, the overall delta tumor volume at month-2 demonstrated that Latino patients were more likely to experience response to treatment (p = 0.021). Radiomics phenotype was also distinct in terms of tumor radiomics heterogeneity (p = 0.023).


Assuntos
Neoplasias do Colo , Tomografia Computadorizada por Raios X , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Etnicidade , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodos , Resultado do Tratamento
4.
Am J Ophthalmol Case Rep ; 27: 101612, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35761880

RESUMO

Purpose: Numerous causes of ocular lacerations, including, open globe injuries have been extensively reported but to our knowledge this is first time that pressure washers have been reported to be the culprit. Thus, in this case series we describe the uniqueness of ocular findings secondary to high-power pressure washer injuries that are a result of their mechanistic function. Observations: Here we report a case series of 3 patients who presented in an emergency department with pain and decreased visual acuity following usage of high-pressure washer machines. All three patients presented with features of both blunt and sharp mechanisms of ocular injury. Most lacerations caused injury that encompassed more than one zone. Two of the patients experienced an open globe injury, and all patients had poor final visual outcomes. Extraocular involvement included fractures and lid lacerations. All patients were managed surgically with repair of the ocular defects. Visual outcome in the first patient was hand motion, while the second patient received a prosthesis following enucleation due to lack of recovery after four months. Lastly, we were unable able to obtain visual outcome for the third patient due to lack of follow up. Conclusion: Ocular injuries due to pressure washers have not been reported in literature, however, this case series serves to elucidate that pressure washers can cause ocular injuries with both blunt and laceration mechanical effects. Moreover, special care should be taken in preventing and managing these injuries due to their high ocular morbidity.

6.
Environ Sci Technol ; 55(8): 4462-4473, 2021 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-33759511

RESUMO

Nitrous oxide (N2O) is a long-lived greenhouse gas that also destroys stratospheric ozone. N2O emissions are uncertain and characterized by high spatiotemporal variability, making individual observations difficult to upscale, especially in mixed land use source regions like the San Joaquin Valley (SJV) of California. Here, we calculate spatially integrated N2O emission rates using nocturnal and convective boundary-layer budgeting methods. We utilize vertical profile measurements from the NASA DISCOVER-AQ (Deriving Information on Surface Conditions from COlumn and VERtically Resolved Observations Relevant to Air Quality) campaign, which took place January-February, 2013. For empirical constraints on N2O source identity, we analyze N2O enhancement ratios with methane, ammonia, carbon dioxide, and carbon monoxide separately in the nocturnal boundary layer, nocturnal residual layer, and convective boundary layer. We find that an established inventory (EDGAR v4.3.2) underestimates N2O emissions by at least a factor of 2.5, that wintertime emissions from animal agriculture are important to annual totals, and that there is evidence for higher N2O emissions during the daytime than at night.


Assuntos
Poluentes Atmosféricos , Óxido Nitroso , Agricultura , Poluentes Atmosféricos/análise , Aeronaves , Animais , California , Metano/análise , Óxido Nitroso/análise
7.
Faraday Discuss ; 226: 537-550, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33346290

RESUMO

We present trace gas vertical profiles observed by instruments on the NASA DC-8 and at a ground site during the Korea-US air quality study (KORUS) field campaign in May to June 2016. We focus on the region near the Seoul metropolitan area and its surroundings where both anthropogenic and natural emission sources play an important role in local photochemistry. Integrating ground and airborne observations is the major research goal of many atmospheric chemistry field campaigns. Although airborne platforms typically aim to sample from near surface to the free troposphere, it is difficult to fly very close to the surface especially in environments with complex terrain or a populated area. A detailed analysis integrating ground and airborne observations associated with specific concentration footprints indicates that reactive trace gases are quickly oxidized below an altitude of 700 m. The total OH reactivity profile has a rapid decay in the lower part of troposphere from surface to the lowest altitude (700 m) sampled by the NASA DC-8. The decay rate is close to that of very reactive biogenic volatile organic compounds such as monoterpenes. Therefore, we argue that photochemical processes in the bottom of the boundary layer, below the typical altitude of aircraft sampling, should be thoroughly investigated to properly assess ozone and secondary aerosol formation.


Assuntos
Poluentes Atmosféricos , Ozônio , Aerossóis/análise , Poluentes Atmosféricos/análise , Florestas , Ozônio/análise , Seul
8.
Front Immunol ; 11: 832, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32457754

RESUMO

Inhibitors that block the programmed cell death-1 (PD-1) pathway can potentiate endogenous antitumor immunity and have markedly improved cancer survival rates across a broad range of indications. However, these treatments work for only a minority of patients. The efficacy of anti-PD-1 inhibitors may be extended by cytokines, however, the incorporation of cytokines into therapeutic regimens has significant challenges. In their natural form when administered as recombinant proteins, cytokine treatments are often associated with low response rates. Most cytokines have a short half-life which limits their exposure and efficacy. In addition, cytokines can activate counterregulatory pathways, in the case of immune-potentiating cytokines this can lead to immune suppression and thereby diminish their potential efficacy. Improving the drug-like properties of natural cytokines using protein engineering can yield synthetic cytokines with improved bioavailability and tissue targeting, allowing for enhanced efficacy and reduced off-target effects. Using structure guided engineering we have designed a novel class of antibody-cytokine fusion proteins consisting of a PD-1 targeting antibody fused together with an interleukin-21 (IL-21) cytokine mutein. Our bifunctional fusion proteins can block PD-1/programmed death-ligand 1 (PD-L1) interaction whilst simultaneously delivering IL-21 cytokine to PD-1 expressing T cells. Targeted delivery of IL-21 can improve T cell function in a manner that is superior to anti-PD-1 monotherapy. Fusion of engineered IL-21 variants to anti-PD1 antibodies can improve the drug-like properties of IL-21 cytokine leading to improved cytokine serum half-life allowing for less frequent dosing. In addition, we show that targeted delivery of IL-21 can minimize any potential detrimental effect on local antigen-presenting cells. A highly attenuated IL-21 mutein variant (R9E:R76A) fused to a PD-1 antibody provides protection in a humanized mouse model of cancer that is refractory to anti-PD-1 monotherapy. Collectively, our preclinical data demonstrate that this approach may improve upon and extend the utility of anti-PD-1 therapeutics currently in the clinic.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Antígeno B7-H1/antagonistas & inibidores , Linfócitos T CD8-Positivos/imunologia , Imunoterapia , Interleucinas/uso terapêutico , Neoplasias/terapia , Animais , Anticorpos Monoclonais/imunologia , Antígeno B7-H1/imunologia , Modelos Animais de Doenças , Feminino , Humanos , Interleucinas/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos SCID , Neoplasias/imunologia , Engenharia de Proteínas , Proteínas Recombinantes de Fusão/imunologia , Proteínas Recombinantes de Fusão/uso terapêutico
9.
Nutrients ; 11(5)2019 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-31052496

RESUMO

Over recent decades, many clinical trials on curcumin supplementation have been conducted on various autoimmune diseases including osteoarthritis, type 2 diabetes, and ulcerative colitis patients. This review attempts to summarize the highlights from these clinical trials. The efficacy of curcumin either alone or in conjunction with existing treatment was evaluated. Sixteen clinical trials have been conducted in osteoarthritis, 14 of which yielded significant improvements in multiple disease parameters. Eight trials have been conducted in type 2 diabetes, all yielding significant improvement in clinical or laboratory outcomes. Three trials were in ulcerative colitis, two of which yielded significant improvement in at least one clinical outcome. Additionally, two clinical trials on rheumatoid arthritis, one clinical trial on lupus nephritis, and two clinical trials on multiple sclerosis resulted in inconclusive results. Longer duration, larger cohort size, and multiple dosage arm trials are warranted to establish the long term benefits of curcumin supplementation. Multiple mechanisms of action of curcumin on these diseases have been researched, including the modulation of the eicosanoid pathway towards a more anti-inflammatory pathway, and the modulation of serum lipid levels towards a favorable profile. Overall, curcumin supplementation emerges as an effective therapeutic agent with minimal-to-no side effects, which can be added in conjunction to current standard of care.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Doenças Autoimunes/tratamento farmacológico , Curcumina/uso terapêutico , Doenças Reumáticas/tratamento farmacológico , Artrite Reumatoide/tratamento farmacológico , Colite Ulcerativa/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Humanos , Nefrite Lúpica/tratamento farmacológico , Esclerose Múltipla/tratamento farmacológico , Osteoartrite/tratamento farmacológico , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento
10.
J Clin Rheumatol ; 23(6): 330-339, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28816722

RESUMO

Many clinical trials of omega-3 fatty acids, supplied as fish oil supplements, have been carried out in rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), lupus nephritis, and osteoarthritis (OA) over the past 3 decades. This review attempts to summarize the highlights of these studies to evaluate the clinical efficacy for omega-3 fatty acids to be added alongside existing treatment regimens. A total of 20 clinical trials have been carried out in RA, of which 16 exhibited significant improvements in multiple disease clinical outcomes. Nine clinical trials have been completed in SLE and lupus nephritis, of which 6 exhibited significant improvements in 1 or more clinical outcomes. A total of 4 clinical trials have been conducted in OA, of which 3 exhibited significant improvements in at least 1 clinical parameter. Multiple mechanisms for the clinical effects of omega-3 fatty acids have been implicated, including the modulation of eicosanoid synthesis toward a more anti-inflammatory profile and suppressed production of proinflammatory cytokines. Overall, fish oil supplements appear to be a safe and effective agent that could be added to the current treatment regimens in RA. Longer-term trials with larger patient cohort sizes are warranted to establish any long-term benefits of fish oil supplements in SLE, lupus nephritis, and OA.


Assuntos
Ácidos Graxos Ômega-3/farmacologia , Doenças Reumáticas/tratamento farmacológico , Ensaios Clínicos como Assunto , Humanos , Resultado do Tratamento
11.
Hepatology ; 55(4): 1271-81, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22095555

RESUMO

UNLABELLED: Hepatic stellate cells (HSCs) undergo myofibroblastic transdifferentiation (activation) to participate in liver fibrosis and identification of molecular targets for this cell fate regulation is essential for development of efficacious therapeutic modalities for the disease. Peroxisomal proliferator-activated receptor γ (PPARγ) is required for differentiation of HSCs and its epigenetic repression underlies HSC activation. The herbal prescription Yang-Gan-Wan (YGW) prevents liver fibrosis, but its active ingredients and molecular mechanisms are unknown. Here we demonstrate YGW prevents and reverses HSC activation by way of epigenetic derepression of Pparγ involving reductions in MeCP2 expression and its recruitment to Pparγ promoter, suppressed expression of PRC2 methyltransferase EZH2, and consequent reduction of H2K27di-methylation at the 3' exon. High-performance liquid chromatography / mass spectrometry (HPLC/MS) and nuclear magnetic resonance (NMR) analyses identify polyphenolic rosmarinic acid (RA) and baicalin (BC) as active phytocompounds. RA and BC suppress the expression and signaling by canonical Wnts, which are implicated in the aforementioned Pparγ epigenetic repression. RA treatment in mice with existing cholestatic liver fibrosis inhibits HSC activation and progression of liver fibrosis. CONCLUSION: These results demonstrate a therapeutic potential of YGW and its active component RA and BC for liver fibrosis by way of Pparγ derepression mediated by suppression of canonical Wnt signaling in HSCs.


Assuntos
Cinamatos/farmacologia , Depsídeos/farmacologia , Epigênese Genética/fisiologia , Flavonoides/farmacologia , Células Estreladas do Fígado/efeitos dos fármacos , Células Estreladas do Fígado/metabolismo , Cirrose Hepática/patologia , PPAR gama/metabolismo , Animais , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Cinamatos/uso terapêutico , Depsídeos/uso terapêutico , Modelos Animais de Doenças , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/uso terapêutico , Regulação da Expressão Gênica/efeitos dos fármacos , Células Estreladas do Fígado/patologia , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/prevenção & controle , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , PPAR gama/genética , Ratos , Ratos Wistar , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Proteínas Wnt/genética , Proteínas Wnt/metabolismo , Ácido Rosmarínico
12.
Ann Hematol ; 90(10): 1167-72, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21674144

RESUMO

Patients with multiple myeloma undergoing autologous haemopoietic stem cell transplantation (ASCT) are at high risk for infectious complications. Peri-transplant intravenous immunoglobulin (IVIG) has been used with the aim of reducing these risks. Our retrospective, non-randomised study of peri-transplant IVIG use and effect on infectious complications in 266 ASCTs for myeloma from 2000 to 2009 at a major metropolitan referral centre for haematological malignancies found no difference between those receiving peri-transplant IVIG (0.4 g/kg) (n=130) and those who were not (n=110) with regard to bloodstream infections, pneumonia, urinary tract or gastrointestinal infections. When analysed according to pre-transplant therapy (conventional chemotherapy versus novel agents), there was no significant difference in infectious complications between those who did or did not receive peri-transplant IVIG. In conclusion, our study did not show a benefit for the use of peri-transplant IVIG (0.4 g/kg) to reduce infectious complications in a large cohort of patients with myeloma undergoing ASCT. In the absence of data supporting efficacy in this context, there appears to be no benefit in the routine use of IVIG for this purpose.


Assuntos
Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Imunoglobulinas Intravenosas/uso terapêutico , Mieloma Múltiplo/complicações , Mieloma Múltiplo/terapia , Infecções Oportunistas/prevenção & controle , Adulto , Agamaglobulinemia/etiologia , Idoso , Austrália/epidemiologia , Estudos de Coortes , Registros Eletrônicos de Saúde , Feminino , Hospitais Universitários , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/imunologia , Mieloma Múltiplo/fisiopatologia , Infecções Oportunistas/epidemiologia , Estudos Retrospectivos , Análise de Sobrevida , Transplante Autólogo
13.
Hepatol Res ; 32(4): 202-12, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16107322

RESUMO

BACKGROUND AND AIMS: : A herbal prescription, Yan-gan-wan (YGW), has been known to offer hepatoprotective effects in Asian countries for years. This study investigated its mechanisms of action. METHODS: : The effects of YGW on CCl(4) induced liver damage were tested in mice and cultured hepatocytes. Microarray analysis screened genes affected by YGW. YGWs effects on the expression of cytochrome P450 (CYP) 2E1 and other isozymes were determined. YGWs effects on TNFalpha expression and NF-kappaB activation in Kupffer cells (KC), and TNFalpha promoter activity in RAW264.7 cells, were also assessed. RESULTS: : Administration of YGW reduced the plasma ALT, centrilobular necrosis, neutrophilic infiltration, and TNFalpha mRNA in the livers of mice acutely given CCl(4). The in vivo herb treatment reduced ALT release and necrosis of isolated hepatocytes directly exposed to CCl(4). Microarray analysis demonstrated marked reductions in CYP4A10 and 4A14 by YGW but no changes in other CYP isozymes as confirmed by immunoblot analysis. The herb treatment suppressed LPS-stimulated TNFalpha release in vivo and by cultured KC. Direct addition of the aqueous herb extract suppressed NF-kappaB activation by KC and TNFalpha promoter activity in RAW cells under LPS stimulation. This activity to suppress TNFalpha expression was largely separated into gel filtration fractions with the molecular size of 102-107Da. YGW also attenuated liver fibrosis induced by chronic treatment of CCl(4) or porcine serum. CONCLUSIONS: : The protective effects of YGW on CCl(4) hepatotoxicity are due in part to inhibition of KC NF-kappaB activation and TNFalpha expression by small water soluble molecules, and may also be related to suppressed hepatic expression of CYP4A10 and 4A14 that are considered as alternative prooxidant cytochromes.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA