Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 117
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
2.
Nat Immunol ; 17(7): 816-24, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-27213690

RESUMEN

The detection of aberrant cells by natural killer (NK) cells is controlled by the integration of signals from activating and inhibitory ligands and from cytokines such as IL-15. We identified cytokine-inducible SH2-containing protein (CIS, encoded by Cish) as a critical negative regulator of IL-15 signaling in NK cells. Cish was rapidly induced in response to IL-15, and deletion of Cish rendered NK cells hypersensitive to IL-15, as evidenced by enhanced proliferation, survival, IFN-γ production and cytotoxicity toward tumors. This was associated with increased JAK-STAT signaling in NK cells in which Cish was deleted. Correspondingly, CIS interacted with the tyrosine kinase JAK1, inhibiting its enzymatic activity and targeting JAK for proteasomal degradation. Cish(-/-) mice were resistant to melanoma, prostate and breast cancer metastasis in vivo, and this was intrinsic to NK cell activity. Our data uncover a potent intracellular checkpoint in NK cell-mediated tumor immunity and suggest possibilities for new cancer immunotherapies directed at blocking CIS function.


Asunto(s)
Inmunoterapia/métodos , Células Asesinas Naturales/inmunología , Neoplasias/terapia , Proteínas Supresoras de la Señalización de Citocinas/metabolismo , Animales , Proliferación Celular/genética , Citotoxicidad Inmunológica/genética , Vigilancia Inmunológica , Interferón gamma/metabolismo , Interleucina-15/metabolismo , Janus Quinasa 1/metabolismo , Activación de Linfocitos/genética , Melanoma Experimental , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Terapia Molecular Dirigida , Neoplasias/inmunología , Transducción de Señal/genética , Proteínas Supresoras de la Señalización de Citocinas/genética
3.
Nature ; 577(7789): 266-270, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31827282

RESUMEN

Acute myeloid leukaemia (AML) is a heterogeneous disease characterized by transcriptional dysregulation that results in a block in differentiation and increased malignant self-renewal. Various epigenetic therapies aimed at reversing these hallmarks of AML have progressed into clinical trials, but most show only modest efficacy owing to an inability to effectively eradicate leukaemia stem cells (LSCs)1. Here, to specifically identify novel dependencies in LSCs, we screened a bespoke library of small hairpin RNAs that target chromatin regulators in a unique ex vivo mouse model of LSCs. We identify the MYST acetyltransferase HBO1 (also known as KAT7 or MYST2) and several known members of the HBO1 protein complex as critical regulators of LSC maintenance. Using CRISPR domain screening and quantitative mass spectrometry, we identified the histone acetyltransferase domain of HBO1 as being essential in the acetylation of histone H3 at K14. H3 acetylated at K14 (H3K14ac) facilitates the processivity of RNA polymerase II to maintain the high expression of key genes (including Hoxa9 and Hoxa10) that help to sustain the functional properties of LSCs. To leverage this dependency therapeutically, we developed a highly potent small-molecule inhibitor of HBO1 and demonstrate its mode of activity as a competitive analogue of acetyl-CoA. Inhibition of HBO1 phenocopied our genetic data and showed efficacy in a broad range of human cell lines and primary AML cells from patients. These biological, structural and chemical insights into a therapeutic target in AML will enable the clinical translation of these findings.


Asunto(s)
Histona Acetiltransferasas/metabolismo , Leucemia Mieloide Aguda/metabolismo , Células Madre Neoplásicas/metabolismo , Animales , Línea Celular Tumoral , Histona Acetiltransferasas/química , Histona Acetiltransferasas/genética , Humanos , Leucemia Mieloide Aguda/genética , Ratones , Ratones Endogámicos C57BL , Modelos Moleculares , Estructura Terciaria de Proteína
4.
J Oncol Pharm Pract ; 29(3): 590-600, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35072574

RESUMEN

INTRODUCTION: The stability and functional activity of the trastuzumab biosimilar PF-05280014 (trastuzumab-qyyp; TrazimeraTM), was assessed under extended in-use conditions. METHODS: PF-05280014 was diluted in 0.9% sodium chloride to final concentrations of 0.2 mg/mL and 4 mg/mL in 3 different types of infusion bags (polyolefin, ethylene vinyl acetate, and polyvinyl chloride). Infusion bags containing diluted PF-05280014 were stored at 25 ± 5° C for 24 h, before storage at 5 ± 3° C for 0, 1, 2, 4, or 6 weeks. Following extended storage, samples of PF-05280014 were removed from the infusion bags and stored at 25 ± 5° C for 24 h before biophysical and functional characterization. In addition to the visual characteristics of each sample at the various time points, the stability of PF-05280014 was assessed using a variety of biophysical techniques, including size-exclusion high-performance liquid chromatography, non-reducing sodium dodecyl sulfate capillary electrophoresis, cation-exchange chromatography, peptide mapping, far-UV circular dichroism spectroscopy, and differential scanning calorimetry. The functional activity of PF-05280014 was evaluated using a cell-based growth inhibition assay. RESULTS: For all PF-05280014 concentrations, time points and infusion bags tested, there were no significant differences in visual characteristics or in protein concentration. The were no significant changes in the relative abundance of molecular weight or charge variants throughout the 6-week study period. Similarly, there were no significant changes in primary structure or in secondary structure content during the study. The relative potency of PF-05280014 was also maintained throughout the 6-week period. CONCLUSIONS: The stability and functional activity of PF-05280014 was maintained following dilution in 0.9% sodium chloride and storage for up to 6 weeks at 2-8° C.


Asunto(s)
Biosimilares Farmacéuticos , Humanos , Trastuzumab/uso terapéutico , Trastuzumab/química , Biosimilares Farmacéuticos/química , Cloruro de Sodio , Estabilidad de Medicamentos , Embalaje de Medicamentos , Almacenaje de Medicamentos , Cromatografía Líquida de Alta Presión
5.
Hum Factors ; : 187208231185705, 2023 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-37357740

RESUMEN

OBJECTIVE: Using brain haemodynamic responses to measure perceived risk from traffic complexity during automated driving. BACKGROUND: Although well-established during manual driving, the effects of driver risk perception during automated driving remain unknown. The use of fNIRS in this paper for assessing drivers' states posits it could become a novel method for measuring risk perception. METHODS: Twenty-three volunteers participated in an empirical driving simulator experiment with automated driving capability. Driving conditions involved suburban and urban scenarios with varying levels of traffic complexity, culminating in an unexpected hazardous event. Perceived risk was measured via fNIRS within the prefrontal cortical haemoglobin oxygenation and from self-reports. RESULTS: Prefrontal cortical haemoglobin oxygenation levels significantly increased, following self-reported perceived risk and traffic complexity, particularly during the hazardous scenario. CONCLUSION: This paper has demonstrated that fNIRS is a valuable research tool for measuring variations in perceived risk from traffic complexity during highly automated driving. Even though the responsibility over the driving task is delegated to the automated system and dispositional trust is high, drivers perceive moderate risk when traffic complexity builds up gradually, reflected in a corresponding significant increase in blood oxygenation levels, with both subjective (self-reports) and objective (fNIRS) increasing further during the hazardous scenario. APPLICATION: Little is known regarding the effects of drivers' risk perception with automated driving. Building upon our experimental findings, future work can use fNIRS to investigate the mental processes for risk assessment and the effects of perceived risk on driving behaviours to promote the safe adoption of automated driving technology.

6.
Crit Rev Clin Lab Sci ; 59(8): 573-585, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-35738909

RESUMEN

The urocortins are polypeptides belonging to the corticotropin-releasing hormone family, known to modulate stress responses in mammals. Stress, whether induced physically or psychologically, is an underlying cause or consequence of numerous clinical syndromes. Identifying biological markers associated with the homeostatic regulation of stress could provide a clinical laboratory approach for the management of stress-related disorders. The neuropeptide, urocortin 3 (UCN3), and the corticotropin-releasing hormone receptor 2 (CRHR2) constitute a regulatory axis known to mediate stress homeostasis. Dysregulation of this peptide/receptor axis is believed to play a role in several clinical conditions including post-traumatic stress, sleep apnea, cardiovascular disease, and other health problems related to stress. Understanding the physiology and measurement of the UCN3/CRHR2 axis is important for establishing a viable clinical laboratory diagnostic. In this article, we focus on evidence supporting the role of UCN3 and its receptor in stress-related clinical syndromes. We also provide insight into the measurements of UCN3 in blood and urine. These potential biomarkers provide new opportunities for clinical research and applications of laboratory medicine diagnostics in stress management.


Asunto(s)
Hormona Liberadora de Corticotropina , Urocortinas , Humanos , Proteínas Portadoras , Hormona Liberadora de Corticotropina/metabolismo , Receptores de Hormona Liberadora de Corticotropina/metabolismo , Síndrome , Urocortinas/metabolismo
7.
Antimicrob Agents Chemother ; 65(8): e0055221, 2021 07 16.
Artículo en Inglés | MEDLINE | ID: mdl-34001510

RESUMEN

There is an urgent need for oral agents to combat resistant Gram-negative pathogens. Here, we describe the characterization of VNRX-5236, a broad-spectrum boronic acid ß-lactamase inhibitor (BLI), and its orally bioavailable etzadroxil prodrug, VNRX-7145. VNRX-7145 is being developed in combination with ceftibuten, an oral cephalosporin, to combat strains of Enterobacterales expressing extended-spectrum ß-lactamases (ESBLs) and serine carbapenemases. VNRX-5236 is a reversible covalent inhibitor of serine ß-lactamases, with inactivation efficiencies on the order of 104 M-1 · sec-1, and prolonged active site residence times (t1/2, 5 to 46 min). The spectrum of inhibition includes Ambler class A ESBLs, class C cephalosporinases, and class A and D carbapenemases (KPC and OXA-48, respectively). Rescue of ceftibuten by VNRX-5236 (fixed at 4 µg/ml) in isogenic strains of Escherichia coli expressing class A, C, or D ß-lactamases demonstrated an expanded spectrum of activity relative to oral comparators, including investigational penems, sulopenem, and tebipenem. VNRX-5236 rescued ceftibuten activity in clinical isolates of Enterobacterales expressing ESBLs (MIC90, 0.25 µg/ml), KPCs (MIC90, 1 µg/ml), class C cephalosporinases (MIC90, 1 µg/ml), and OXA-48-type carbapenemases (MIC90, 1 µg/ml). Frequency of resistance studies demonstrated a low propensity for recovery of resistant variants at 4× the MIC of the ceftibuten/VNRX-5236 combination. In vivo, whereas ceftibuten alone was ineffective (50% effective dose [ED50], >128 mg/kg), ceftibuten/VNRX-7145 administered orally protected mice from lethal septicemia caused by Klebsiella pneumoniae producing KPC carbapenemase (ED50, 12.9 mg/kg). The data demonstrate potent, broad-spectrum rescue of ceftibuten activity by VNRX-5236 in clinical isolates of cephalosporin-resistant and carbapenem-resistant Enterobacterales.


Asunto(s)
Cefalosporinas , Inhibidores de beta-Lactamasas , Animales , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Proteínas Bacterianas , Carbapenémicos/farmacología , Ceftibuteno , Cefalosporinas/farmacología , Ratones , Pruebas de Sensibilidad Microbiana , Serina , Inhibidores de beta-Lactamasas/farmacología , beta-Lactamasas/genética
8.
Artículo en Inglés | MEDLINE | ID: mdl-31871094

RESUMEN

As shifts in the epidemiology of ß-lactamase-mediated resistance continue, carbapenem-resistant Enterobacterales (CRE) and carbapenem-resistant Pseudomonas aeruginosa (CRPA) are the most urgent threats. Although approved ß-lactam (BL)-ß-lactamase inhibitor (BLI) combinations address widespread serine ß-lactamases (SBLs), such as CTX-M-15, none provide broad coverage against either clinically important serine-ß-lactamases (KPC, OXA-48) or clinically important metallo-ß-lactamases (MBLs; e.g., NDM-1). VNRX-5133 (taniborbactam) is a new cyclic boronate BLI that is in clinical development combined with cefepime for the treatment of infections caused by ß-lactamase-producing CRE and CRPA. Taniborbactam is the first BLI with direct inhibitory activity against Ambler class A, B, C, and D enzymes. From biochemical and structural analyses, taniborbactam exploits substrate mimicry while employing distinct mechanisms to inhibit both SBLs and MBLs. It is a reversible covalent inhibitor of SBLs with slow dissociation and a prolonged active-site residence time (half-life, 30 to 105 min), while in MBLs, it behaves as a competitive inhibitor, with inhibitor constant (Ki ) values ranging from 0.019 to 0.081 µM. Inhibition is achieved by mimicking the transition state structure and exploiting interactions with highly conserved active-site residues. In microbiological testing, taniborbactam restored cefepime activity in 33/34 engineered Escherichia coli strains overproducing individual enzymes covering Ambler classes A, B, C, and D, providing up to a 1,024-fold shift in the MIC. Addition of taniborbactam restored the antibacterial activity of cefepime against all 102 Enterobacterales clinical isolates tested and 38/41 P. aeruginosa clinical isolates tested with MIC90s of 1 and 4 µg/ml, respectively, representing ≥256- and ≥32-fold improvements, respectively, in antibacterial activity over that of cefepime alone. The data demonstrate the potent, broad-spectrum rescue of cefepime activity by taniborbactam against clinical isolates of CRE and CRPA.


Asunto(s)
Antibacterianos/farmacología , Ácidos Borínicos/farmacología , Ácidos Carboxílicos/farmacología , Inhibidores de beta-Lactamasas/farmacología , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Cefepima/farmacología , Pruebas de Sensibilidad Microbiana , Estructura Secundaria de Proteína , Pseudomonas aeruginosa/efectos de los fármacos
9.
Blood ; 129(13): 1823-1830, 2017 03 30.
Artículo en Inglés | MEDLINE | ID: mdl-28188131

RESUMEN

Patients with myelofibrosis (MF) often develop anemia and frequently become dependent on red blood cell transfusions. Results from a phase 2 study for the treatment of MF with the Janus kinase 1/2 (JAK1/2) inhibitor momelotinib (MMB) demonstrated that MMB treatment ameliorated anemia, which was unexpected for a JAK1/2 inhibitor, because erythropoietin-mediated JAK2 signaling is essential for erythropoiesis. Using a rat model of anemia of chronic disease, we demonstrated that MMB treatment can normalize hemoglobin and red blood cell numbers. We found that this positive effect is driven by direct inhibition of the bone morphogenic protein receptor kinase activin A receptor, type I (ACVR1), and the subsequent reduction of hepatocyte hepcidin production. Of note, ruxolitinib, a JAK1/2 inhibitor approved for the treatment of MF, had no inhibitory activity on this pathway. Further, we demonstrated the effect of MMB is not mediated by direct inhibition of JAK2-mediated ferroportin (FPN1) degradation, because neither MMB treatment nor myeloid-specific deletion of JAK2 affected FPN1 expression. Our data support the hypothesis that the improvement of inflammatory anemia by MMB results from inhibition of ACVR1-mediated hepcidin expression in the liver, which leads to increased mobilization of sequestered iron from cellular stores and subsequent stimulation of erythropoiesis.


Asunto(s)
Anemia/tratamiento farmacológico , Benzamidas/uso terapéutico , Receptores de Proteínas Morfogenéticas Óseas de Tipo 1/antagonistas & inhibidores , Hepcidinas/biosíntesis , Pirimidinas/uso terapéutico , Receptores de Activinas Tipo I/antagonistas & inhibidores , Animales , Benzamidas/farmacología , Enfermedad Crónica , Hepatocitos/metabolismo , Hierro/metabolismo , Mielofibrosis Primaria/complicaciones , Pirimidinas/farmacología , Ratas
11.
J Med Libr Assoc ; 107(3): 364-373, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31258442

RESUMEN

OBJECTIVE: Hypothetically, content in MEDLINE records is consistent across multiple platforms. Though platforms have different interfaces and requirements for query syntax, results should be similar when the syntax is controlled for across the platforms. The authors investigated how search result counts varied when searching records among five MEDLINE platforms. METHODS: We created 29 sets of search queries targeting various metadata fields and operators. Within search sets, we adapted 5 distinct, compatible queries to search 5 MEDLINE platforms (PubMed, ProQuest, EBSCOhost, Web of Science, and Ovid), totaling 145 final queries. The 5 queries were designed to be logically and semantically equivalent and were modified only to match platform syntax requirements. We analyzed the result counts and compared PubMed's MEDLINE result counts to result counts from the other platforms. We identified outliers by measuring the result count deviations using modified z-scores centered around PubMed's MEDLINE results. RESULTS: Web of Science and ProQuest searches were the most likely to deviate from the equivalent PubMed searches. EBSCOhost and Ovid were less likely to deviate from PubMed searches. Ovid's results were the most consistent with PubMed's but appeared to apply an indexing algorithm that resulted in lower retrieval sets among equivalent searches in PubMed. Web of Science exhibited problems with exploding or not exploding Medical Subject Headings (MeSH) terms. CONCLUSION: Platform enhancements among interfaces affect record retrieval and challenge the expectation that MEDLINE platforms should, by default, be treated as MEDLINE. Substantial inconsistencies in search result counts, as demonstrated here, should raise concerns about the impact of platform-specific influences on search results.


Asunto(s)
Indización y Redacción de Resúmenes/estadística & datos numéricos , Almacenamiento y Recuperación de la Información/métodos , MEDLINE/estadística & datos numéricos , Medical Subject Headings/estadística & datos numéricos , PubMed/estadística & datos numéricos , Algoritmos , Humanos , Almacenamiento y Recuperación de la Información/estadística & datos numéricos , Reproducibilidad de los Resultados
12.
J Surg Res ; 227: 101-111, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29804841

RESUMEN

BACKGROUND: Patients and hospitals face significant financial burdens from emergency general surgeries (EGSs), which have been termed a public health crisis in the United States. We evaluated hospitalization charges, operating charges, and variations in operating time by surgeon volume for three common EGS procedures. METHODS: Using Maryland's Health Services Cost Review Commission database, we performed a retrospective study of laparoscopic appendectomies, laparoscopic cholecystectomies, and open bowel resections performed by general surgeons among adult patients from July 2012 to September 2014. We compared operating charges to total hospitalization charges and quantified variations in operating time for each procedure. We then divided patients into quartiles based on their surgeon's procedure-specific case volume and used hierarchical linear regressions to calculate differences in both operating time and charges between quartiles. RESULTS: We identified 3194 appendectomies, 4143 cholecystectomies, and 1478 bowel resections. Operating charges accounted for one-quarter (26.9%) of total hospitalization charges and widespread variation existed in operating time (appendectomies: median 79 min [interquartile range 66-100 min], cholecystectomies: 96 min [76-125 min], bowel resections: 155 min [117-209 min]). After adjustment, low-volume surgeons relative to high-volume surgeons did not operate statistically longer for appendectomies (+1%, 95% confidence interval [CI]: -2% to 5%) but operated +16% (95% CI: 12%-20%) longer for cholecystectomies (+14 min) and +40% (95% CI: 30%-50%) longer for bowel resections (+59 min). Adjusted median operating charges from low-volume surgeons relative to high-volume surgeons were $554 (26.7%), $621 (22.0%), and $1801 (47.0%) greater for appendectomies, cholecystectomies, and bowel resections, respectively. CONCLUSIONS: Operating charges contributed substantially to total EGS hospitalization charges, where low-volume surgeons operated longer and had higher operative charges relative to high-volume surgeons. Reducing variations in operating times and charges represents an opportunity to alleviate the financial burden from EGS procedures.


Asunto(s)
Procedimientos Quirúrgicos del Sistema Digestivo/economía , Tratamiento de Urgencia/economía , Honorarios Médicos/estadística & datos numéricos , Cirujanos/economía , Carga de Trabajo/economía , Adulto , Anciano , Procedimientos Quirúrgicos del Sistema Digestivo/métodos , Procedimientos Quirúrgicos del Sistema Digestivo/estadística & datos numéricos , Tratamiento de Urgencia/métodos , Tratamiento de Urgencia/estadística & datos numéricos , Femenino , Precios de Hospital/estadística & datos numéricos , Hospitalización/economía , Hospitalización/estadística & datos numéricos , Humanos , Masculino , Maryland , Persona de Mediana Edad , Tempo Operativo , Estudios Retrospectivos , Cirujanos/estadística & datos numéricos , Factores de Tiempo , Carga de Trabajo/estadística & datos numéricos , Adulto Joven
13.
Bioorg Med Chem ; 23(19): 6280-96, 2015 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-26349627

RESUMEN

The serine-threonine kinase CDK9 is a target of emerging interest for the development of anti-cancer drugs. There are multiple lines of evidence linking CDK9 activity to cancer, including the essential role this kinase plays in transcriptional regulation through phosphorylation of the C-terminal domain (CTD) of RNA polymerase II. Indeed, inhibition of CDK9 has been shown to result in a reduction of short-lived proteins such as the pro-survival protein Mcl-1 in malignant cells leading to the induction of apoptosis. In this work we report our initial studies towards the discovery of selective CDK9 inhibitors, starting from the known multi-kinase inhibitor PIK-75 which possesses potent CDK9 activity. Our series is based on a pyrazolo[1,5-a]pyrimidine nucleus and, importantly, the resultant lead compound 18b is devoid of the structural liabilities present in PIK-75 and possesses greater selectivity.


Asunto(s)
Antineoplásicos/química , Quinasa 9 Dependiente de la Ciclina/antagonistas & inhibidores , Inhibidores Enzimáticos/química , Pirazoles/química , Pirimidinas/química , Antineoplásicos/metabolismo , Antineoplásicos/farmacología , Sitios de Unión , Línea Celular , Supervivencia Celular/efectos de los fármacos , Quinasa 9 Dependiente de la Ciclina/genética , Quinasa 9 Dependiente de la Ciclina/metabolismo , Evaluación Preclínica de Medicamentos , Inhibidores Enzimáticos/metabolismo , Inhibidores Enzimáticos/farmacología , Humanos , Hidrazonas/química , Hidrazonas/metabolismo , Simulación del Acoplamiento Molecular , Unión Proteica , Estructura Terciaria de Proteína , Pirazoles/metabolismo , Pirazoles/farmacología , Pirimidinas/metabolismo , Pirimidinas/farmacología , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Relación Estructura-Actividad , Sulfonamidas/química , Sulfonamidas/metabolismo
14.
J Nanobiotechnology ; 13: 90, 2015 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-26627455

RESUMEN

BACKGROUND: Pancreatic cancer often goes undiagnosed until late stage disease due in part to suboptimal early detection. Our goal was to develop a Syndecan-1 tagged liposome containing fluorescent dye as an improved contrast agent for detection of pancreatic adenocarcinoma in vivo using multispectral optoacoustic tomography. RESULTS: The diagnostic capabilities and specificity to pancreatic adenocarcinoma of Syndecan-1 targeted liposomes were evaluated both in vitro and in vivo. Immunocytochemistry showed that liposomes preferentially bound to and released their contents into cells expressing high levels of insulin-like growth factor 1 receptor. We determined that the contents of the liposome were released into the cell as noted by the change in propidium iodide fluorescence from green to red based upon nucleic acid binding. In an orthotopic mouse model, the liposomes preferentially targeted the pancreatic tumor with little off-target binding in the liver and spleen. Peak accumulation of the liposomes in the tumor occurred at 8 h post-injection. Multispectral optoacoustic tomographic imaging was able to provide high-resolution 3D images of the tumor and liposome location. Ex vivo analysis showed that non-targeted liposomes accumulated in the liver, suggesting that specificity of the liposomes for pancreatic adenocarcinoma was due to the presence of the Syndecan-1 ligand. CONCLUSIONS: This study demonstrated that Syndecan-1 liposomes were able to release cargo into IGF1-R expressing tumor cells. The Syndecan-1 liposomes demonstrated tumor specificity in orthotopic pancreatic cancer as observed using multispectral optoacoustic tomography with reduced kidney and liver uptake. By targeting the liposome with Syndecan-1, this nanovehicle has potential as a targeted theranostic nanoparticle for both drug and contrast agent delivery to pancreatic tumors.


Asunto(s)
Adenocarcinoma/diagnóstico , Medios de Contraste/farmacocinética , Liposomas/farmacocinética , Neoplasias Pancreáticas/diagnóstico , Receptores de Somatomedina/metabolismo , Sindecano-1/metabolismo , Adenocarcinoma/metabolismo , Adenocarcinoma/patología , Animales , Medios de Contraste/síntesis química , Medios de Contraste/metabolismo , Sistemas de Liberación de Medicamentos/métodos , Femenino , Colorantes Fluorescentes , Expresión Génica , Humanos , Liposomas/síntesis química , Liposomas/metabolismo , Ratones , Ratones SCID , Trasplante de Neoplasias , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patología , Técnicas Fotoacústicas/métodos , Unión Proteica , Receptores de Somatomedina/genética , Sindecano-1/química , Tomografía/instrumentación , Tomografía/métodos
15.
BMC Cancer ; 14: 317, 2014 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-24886434

RESUMEN

BACKGROUND: Current treatment of ovarian cancer patients with chemotherapy leaves behind a residual tumor which results in recurrent ovarian cancer within a short time frame. We have previously demonstrated that a single short-term treatment of ovarian cancer cells with chemotherapy in vitro resulted in a cancer stem cell (CSC)-like enriched residual population which generated significantly greater tumor burden compared to the tumor burden generated by control untreated cells. In this report we looked at the mechanisms of the enrichment of CSC-like residual cells in response to paclitaxel treatment. METHODS: The mechanism of survival of paclitaxel-treated residual cells at a growth inhibitory concentration of 50% (GI50) was determined on isolated tumor cells from the ascites of recurrent ovarian cancer patients and HEY ovarian cancer cell line by in vitro assays and in a mouse xenograft model. RESULTS: Treatment of isolated tumor cells from the ascites of ovarian cancer patients and HEY ovarian cancer cell line with paclitaxel resulted in a CSC-like residual population which coincided with the activation of Janus activated kinase 2 (JAK2) and signal transducer and activation of transcription 3 (STAT3) pathway in paclitaxel surviving cells. Both paclitaxel-induced JAK2/STAT3 activation and CSC-like characteristics were inhibited by a low dose JAK2-specific small molecule inhibitor CYT387 (1 µM) in vitro. Subsequent, in vivo transplantation of paclitaxel and CYT387-treated HEY cells in mice resulted in a significantly reduced tumor burden compared to that seen with paclitaxel only-treated transplanted cells. In vitro analysis of tumor xenografts at protein and mRNA levels demonstrated a loss of CSC-like markers and CA125 expression in paclitaxel and CYT387-treated cell-derived xenografts, compared to paclitaxel only-treated cell-derived xenografts. These results were consistent with significantly reduced activation of JAK2 and STAT3 in paclitaxel and CYT387-treated cell-derived xenografts compared to paclitaxel only-treated cell derived xenografts. CONCLUSIONS: This proof of principle study demonstrates that inhibition of the JAK2/STAT3 pathway by the addition of CYT387 suppresses the 'stemness' profile in chemotherapy-treated residual cells in vitro, which is replicated in vivo, leading to a reduced tumor burden. These findings have important implications for ovarian cancer patients who are treated with taxane and/or platinum-based therapies.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Janus Quinasa 2/antagonistas & inhibidores , Células Madre Neoplásicas/efectos de los fármacos , Neoplasias Ováricas/tratamiento farmacológico , Factor de Transcripción STAT3/antagonistas & inhibidores , Transducción de Señal/efectos de los fármacos , Carga Tumoral/efectos de los fármacos , Adulto , Anciano , Animales , Benzamidas/farmacología , Línea Celular Tumoral , Resistencia a Antineoplásicos , Femenino , Humanos , Janus Quinasa 2/metabolismo , Ratones Endogámicos BALB C , Ratones Desnudos , Persona de Mediana Edad , Terapia Molecular Dirigida , Recurrencia Local de Neoplasia , Neoplasia Residual , Células Madre Neoplásicas/enzimología , Células Madre Neoplásicas/patología , Neoplasias Ováricas/enzimología , Neoplasias Ováricas/patología , Paclitaxel/farmacología , Inhibidores de Proteínas Quinasas/farmacología , Pirimidinas/farmacología , Factor de Transcripción STAT3/metabolismo , Factores de Tiempo , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de Xenoinjerto
16.
Pharm Res ; 31(11): 3161-78, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24906598

RESUMEN

PURPOSE: Early identification of monoclonal antibody candidates whose development, as high concentration (≥100 mg/mL) drug products, could prove challenging, due to high viscosity, can help define strategies for candidate engineering and selection. METHODS: Concentration dependent viscosities of 11 proprietary mAbs were measured. Sequence and structural features of the variable (Fv) regions were analyzed to understand viscosity behavior of the mAbs. Coarse-grained molecular simulations of two problematic mAbs were compared with that of a well behaved mAb. RESULTS: Net charge, ξ-potential and pI of Fv regions were found to correlate with viscosities of highly concentrated antibody solutions. Negative net charges on the Fv regions of two mAbs with poor viscosity behaviors facilitate attractive self-associations, causing them to diffuse slower than a well-behaved mAb with positive net charge on its Fv region. An empirically derived equation that connects aggregation propensity and pI of the Fv region with high concentration viscosity of the whole mAb was developed. CONCLUSIONS: An Fv region-based qualitative screening profile was devised to flag mAb candidates whose development, as high concentration drug products, could prove challenging. This screen can facilitate developability risk assessment and mitigation strategies for antibody based therapeutics via rapid high throughput material-free screening.


Asunto(s)
Anticuerpos Monoclonales/química , Soluciones/química , Región Variable de Inmunoglobulina/química , Medición de Riesgo , Viscosidad
17.
Bone ; 179: 116982, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38006907

RESUMEN

There is a controversy over the influence of psychostimulant medications on bone mineral density (BMD) and bone mineral content (BMC) among children with attention-deficit-hyperactivity-disorder (ADHD). The aim of the present systematic review was to assess the influence of psychostimulant medications on BMD and BMC among children with ADHD. A comprehensive search of electronic databases, including PubMed, Scopus, Embase, and Cochrane Library, was conducted to identify relevant studies published up until July 2023. Clinical studies that addressed the focused question "Do psychostimulant medications affect bone mineral density and content in children with ADHD?" were included. Letters to the Editor, studies on animal-models, ex-vivo and in-vitro studies, commentaries and reviews were excluded. The primary outcome measures were changes in BMD and BMC. Study quality was assessed using the risk of bias for non-randomized studies-exposure tool. Five non-randomized clinical studies were included. The number of participants ranged from 18 to 6489 with mean ages ranging from 7.3 to 13.75 years. The study durations ranged between five and seven years. In all studies osseous evaluation was done using dual-energy X-ray absorptiometry. The bone locations examined included total body, lumbar-spine, femur, femoral-neck, femoral body, and pelvis. Two studies reported that psychostimulant medications reduce BMC and BMD. In one study, bone turnover, serum leptin and fat levels were reduced in children using psychostimulant medications but no unusual reduction recorded among controls. In general, 80 % of the studies concluded that psychostimulant medications compromise BMC and BMD. Power analysis was done in one study. One study had a low RoB and the remaining demonstrated some concerns. Given the methodological concerns observed in the included studies, arriving at a definitive conclusion regarding the effects of psychostimulant medications on BMC, BMD, and bone turnover in children with ADHD is challenging. However, it is important to acknowledge that an association between psychostimulant medications and these bone-related parameters cannot be disregarded.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad , Densidad Ósea , Niño , Animales , Humanos , Adolescente , Trastorno por Déficit de Atención con Hiperactividad/tratamiento farmacológico , Absorciometría de Fotón , Cuello Femoral , Vértebras Lumbares
18.
Angle Orthod ; 94(3): 320-327, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38195055

RESUMEN

OBJECTIVES: To compare orthodontic treatment (OT) outcome in adolescents undergoing nonextraction fixed OT with or without bonding of second molars using the score of the American Board of Orthodontics Cast Radiograph Evaluation (C-R-Eval). MATERIALS AND METHODS: This study included healthy adolescents with skeletal Class I or mild Class II/Class III malocclusion, normal or deep overbite (OB), and mild-to-moderate dental crowding (<5 mm) who underwent nonextraction fixed OT with ("bonded" group) or without ("not-bonded" group) bonding of second molars. Patient treatment records, pre- and posttreatment digital models, lateral cephalograms, and orthopantomograms were assessed. The evaluated outcomes included leveling of the curve of Spee (COS), OB, control of incisor mandibular plane angle (IMPA), number of emergency visits (related to poking wires and/or bracket failure of the terminal molar tubes), treatment duration, and C-R-Eval. Treatment variables were compared across time points and among groups. RESULTS: The sample included 30 patients (mean age 16.07 ± 1.80 years) in the bonded group and 32 patients (mean age 15.69 ± 1.86 years) in the not-bonded group. The mean overall C-R-Eval score was significantly higher (P < .001) in the not-bonded group (25.25 ± 3.98) than in the bonded group (17.70 ± 2.97). There were no significant differences in mean changes of COS, OB, IMPA, or treatment duration among groups. The mean number of emergency visits was significantly higher in the bonded (3.3 ± 0.6) than the not-bonded group (1.9 ± 0.4) (P < .001). CONCLUSIONS: Bonding of second molars enhances the outcome of nonextraction fixed OT as demonstrated by the C-R-Eval without increasing treatment duration, irrespective of more emergency visits.


Asunto(s)
Maloclusión Clase II de Angle , Diente Molar , Compuestos Organofosforados , Adolescente , Humanos , Ortodoncia Correctiva , Resultado del Tratamiento , Radiografía Panorámica , Cefalometría , Maloclusión Clase II de Angle/terapia
19.
Burns ; 50(6): 1578-1585, 2024 08.
Artículo en Inglés | MEDLINE | ID: mdl-38582695

RESUMEN

BACKGROUND: This study compared a novel topical hydrogel burn dressing (CI-PRJ012) to standard of care (silver sulfadiazine) and to untreated control in a swine thermal burn model, to assess for wound healing properties both in the presence and absence of concomitant bacterial inoculation. METHODS: Eight equal burn wounds were created on six Yorkshire swine. Half the wounds were randomized to post-burn bacterial inoculation. Wounds were subsequently randomized to three treatments groups: no intervention, CI-PRJ012, or silver sulfadiazine cream. At study end, a blinded pathologist evaluated wounds for necrosis and bacterial colonization. RESULTS: When comparing CI-PRJ012 and silver sulfadiazine cream to no treatment, both agents significantly reduced the amount of necrosis and bacteria at 7 days after wound creation (p < 0.01, independently for both). Further, CI-PRJ012 was found to be significantly better than silver sulfadiazine (p < 0.02) in reducing bacterial colonization. For wound necrosis, no significant difference was found between silver sulfadiazine cream and CI-PRJ012 (p = 0.33). CONCLUSIONS: CI-PRJ012 decreases necrosis and bacterial colonization compared to no treatment in a swine model. CI-PRJ012 appeared to perform comparably to silver sulfadiazine. CI-PRJ012, which is easily removed with the application of room-temperature water, may provide clinical advantages over silver sulfadiazine.


Asunto(s)
Antibacterianos , Quemaduras , Modelos Animales de Enfermedad , Necrosis , Sulfadiazina de Plata , Cicatrización de Heridas , Animales , Quemaduras/tratamiento farmacológico , Quemaduras/microbiología , Quemaduras/patología , Sulfadiazina de Plata/uso terapéutico , Proyectos Piloto , Porcinos , Cicatrización de Heridas/efectos de los fármacos , Antibacterianos/uso terapéutico , Antiinfecciosos Locales/uso terapéutico , Hidrogeles/uso terapéutico , Vendajes , Infección de Heridas/tratamiento farmacológico , Infección de Heridas/prevención & control , Distribución Aleatoria
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA