RESUMEN
OBJECTIVES: Surgery is the standard of care for early-stage non-small cell lung cancer (NSCLC), with SBRT reserved for patients who are not surgical candidates. We hypothesized overall survival (OS), lung cancer-specific survival (LCSS), progression free survival (PFS), and recurrence rates following SBRT or surgery in medically operable patients with Stage I NSCLC from the Veterans' Health Care System (VAHS) would be equivalent. MATERIALS AND METHODS: Medically operable patients diagnosed with Stage I NSCLC between 2000-2020 from the VAHS, determined by an FEV1 or DLCO > 60 % of predicted and Charlson comorbidity index (CCI) of 0 or 1, treated with SBRT or surgery were identified. SBRT patients were propensity score matched in a 1:1:1 ratio to those undergoing resection (SBRT:lobectomy:sub-lobar resection). OS, LCSS, and PFS and site of recurrence were determined. RESULTS: 103 patients were included in each cohort. With a median follow-up of 7.9 years 5-year OS for all patients was 51 % (95 % CI 46-57 %). After propensity score matching, OS (HR 2.08, 1.59), LCSS (HR 2.28, 1.97), and PFS (1.97, 1.45) were significantly worse with SBRT compared to either lobectomy or sub-lobar resection, respectively, (p < 0.05 for each comparison). Regional recurrence was significantly higher following SBRT (15.5 % vs 6.8 % or 4.9 %; p < 0.05), but there was no significant difference in local (28.2 % vs 21.4 % or 21.4 %; p > 0.05) or distant recurrence (10.7 % vs 9.7 % or 13.6 %; p > 0.05) when compared to lobectomy or sub-lobar resection, respectively. CONCLUSION: In medically operable patients, OS, LCSS, and PFS following either lobectomy or sub-lobar resection were superior to that for SBRT for Stage I NSCLC, likely due in part to higher regional recurrence following SBRT. This suggests that pulmonary function test results and CCI alone are insufficient to define a cohort of medically operable patients suited for SBRT. These data support strategies to overcome regional recurrences seen with SBRT.
RESUMEN
Lateral medullary syndrome is a common presentation of posterior circulation ischemia that presents with ipsilateral Horner syndrome, ipsilateral facial numbness, contralateral body numbness, vestibular symptoms, ataxia, dysphagia, and dysarthria. Here, we describe an 84-year-old who presented to the hospital with right upper motor neuron facial weakness and gait abnormality found to have a right lateral medullary ischemic stroke. Multiple MRI's, including with thin brainstem slices, were without evidence of pontine, midbrain or cerebral ischemia outside the medulla. We postulate that the patient's ipsilateral upper motor neuron facial weakness was caused by involvement of aberrant corticobulbar fibers in the medulla ascending to the facial nucleus.
RESUMEN
Bacterial ß-glucuronidase (GUS) enzymes cause drug toxicity by reversing Phase II glucuronidation in the gastrointestinal tract. While many human gut microbial GUS enzymes have been examined with model glucuronide substrates like p-nitrophenol-ß-D-glucuronide (pNPG), the GUS orthologs that are most efficient at processing drug-glucuronides remain unclear. Here we present the crystal structures of GUS enzymes from human gut commensals Lactobacillus rhamnosus, Ruminococcus gnavus, and Faecalibacterium prausnitzii that possess an active site loop (Loop 1; L1) analogous to that found in E. coli GUS, which processes drug substrates. We also resolve the structure of the No Loop GUS from Bacteroides dorei. We then compare the pNPG and diclofenac glucuronide processing abilities of a panel of twelve structurally diverse GUS proteins, and find that the new L1 GUS enzymes presented here process small glucuronide substrates inefficiently compared to previously characterized L1 GUS enzymes like E. coli GUS. We further demonstrate that our GUS inhibitors, which are effective against some L1 enzymes, are not potent towards all. Our findings pinpoint active site structural features necessary for the processing of drug-glucuronide substrates and the inhibition of such processing.
Asunto(s)
Microbioma Gastrointestinal/fisiología , Tracto Gastrointestinal/microbiología , Glucuronidasa/antagonistas & inhibidores , Glucuronidasa/metabolismo , Glucurónidos/metabolismo , Bacteroides/enzimología , Dominio Catalítico , Clostridiales/enzimología , Cristalografía por Rayos X , Inhibidores Enzimáticos/farmacología , Faecalibacterium prausnitzii/enzimología , Tracto Gastrointestinal/metabolismo , Humanos , Lacticaseibacillus rhamnosus/enzimología , Estructura Cuaternaria de Proteína , Estructura Terciaria de Proteína , Relación Estructura-ActividadRESUMEN
A hit to lead process to identify reversible, orally available ADP receptor (P2Y12) antagonists lead compounds is described. High throughput screening afforded 1. Optimization of 1, using parallel synthesis methods, a methyl scan to identify promising regions for optimization, and exploratory SAR on these regions, provided 22 and 23. Compound 23 is an orally available, competitive reversible antagonist (KBâ¯=â¯94â¯nM for inhibition of ADP-induced platelet aggregation). It exhibits high metabolic stability in human, rat and dog liver microsomes and is orally absorbed. Although plasma level after oral dosing of 22 and 23 to rats is low, reasonable levels were achieved to merit extensive lead optimization of this structural class.
Asunto(s)
Fluorenos/farmacología , Receptores Purinérgicos P2Y12/metabolismo , Administración Oral , Animales , Perros , Relación Dosis-Respuesta a Droga , Fluorenos/administración & dosificación , Fluorenos/química , Ensayos Analíticos de Alto Rendimiento , Humanos , Microsomas Hepáticos/metabolismo , Estructura Molecular , Agregación Plaquetaria/efectos de los fármacos , Ratas , Relación Estructura-ActividadRESUMEN
We studied the motility of filamentous mat-forming cyanobacteria consisting primarily of Oscillatoria-like cells growing under low-light, low-oxygen, and high-sulfur conditions in Lake Huron's submerged sinkholes using in situ observations, in vitro measurements and time-lapse microscopy. Gliding movement of the cyanobacterial trichomes (100-10,000 µm long filaments, composed of cells â¼10 µm wide and â¼3 µm tall) revealed individual as well as group-coordinated motility. When placed in a petri dish and dispersed in ground water from the sinkhole, filaments re-aggregated into defined colonies within minutes, then dispersed again. Speed of individual filaments increased with temperature from â¼50 µm min(-1) or â¼15 body lengths min(-1) at 10°C to â¼215 µm min(-1) or â¼70 body lengths min(-1) at 35°C - rates that are rapid relative to non-flagellated/ciliated microbes. Filaments exhibited precise and coordinated positive phototaxis toward pinpoints of light and congregated under the light of foil cutouts. Such light-responsive clusters showed an increase in photosynthetic yield - suggesting phototactic motility aids in light acquisition as well as photosynthesis. Once light source was removed, filaments slowly spread out evenly and re-aggregated, demonstrating coordinated movement through inter-filament communication regardless of light. Pebbles and pieces of broken shells placed upon intact mat were quickly covered by vertically motile filaments within hours and became fully buried in the anoxic sediments over 3-4 diurnal cycles - likely facilitating the preservation of falling debris. Coordinated horizontal and vertical filament motility optimize mat cohesion and dynamics, photosynthetic efficiency and sedimentary carbon burial in modern-day sinkhole habitats that resemble the shallow seas in Earth's early history. Analogous cyanobacterial motility may have played a key role in the oxygenation of the planet by optimizing photosynthesis while favoring carbon burial.
RESUMEN
During the summers of 2002-2013, we measured rates of carbon metabolism in surface waters of six sites across a land-to-lake gradient from the upstream end of drowned river-mouth Muskegon Lake (ML) (freshwater estuary) to 19 km offshore in Lake Michigan (LM) (a Great Lake). Despite considerable inter-year variability, the average rates of gross production (GP), respiration (R) and net production (NP) across ML (604 ± 58, 222 ± 22 and 381 ± 52 µg C L-1 day-1, respectively) decreased steeply in the furthest offshore LM site (22 ± 3, 55 ± 17 and -33 ± 15 µg C L-1day-1, respectively). Along this land-to-lake gradient, GP decreased by 96 ± 1%, whereas R only decreased by 75 ± 9%, variably influencing the carbon balance along this coastal zone. All ML sites were consistently net autotrophic (mean GP:R = 2.7), while the furthest offshore LM site was net heterotrophic (mean GP:R = 0.4). Our study suggests that pelagic waters of this Great Lakes coastal estuary are net carbon sinks that transition into net carbon sources offshore. Reactive and dynamic estuarine coastal zones everywhere may contribute similarly to regional and global carbon cycles.
RESUMEN
The identification and evaluation of aryl-[1,4]diazepane ureas as functional antagonists of the chemokine receptor CXCR3 are described. Specific examples exhibit IC(50) values of approximately 60 nM in a calcium mobilization functional assay, and dose-dependently inhibit CXCR3 functional response to CXCL11 (interferon-inducible T-cell alpha chemoattractant/I-TAC) as measured by T-cell chemotaxis, with a potency of approximately 100 nM.
Asunto(s)
Receptores de Quimiocina/antagonistas & inhibidores , Urea/química , Calcio/metabolismo , Línea Celular , Química Farmacéutica/métodos , Quimiocina CXCL11 , Quimiocinas CXC/química , Quimiotaxis , Relación Dosis-Respuesta a Droga , Diseño de Fármacos , Evaluación Preclínica de Medicamentos , Electrones , Humanos , Inflamación , Concentración 50 Inhibidora , Modelos Químicos , Receptores CXCR3 , Receptores de Quimiocina/química , Receptores Acoplados a Proteínas G/metabolismo , Proteínas Recombinantes/química , Estereoisomerismo , Linfocitos T/citologíaRESUMEN
Effector functions and proliferation of T helper (Th) cells are influenced by cytokines in the environment. Th1 cells respond to a synergistic effect of interleukin-12 (IL-12) and interleukin-18 (IL-18) to secrete interferon-gamma (IFN-gamma). In contrast, Th2 cells respond to interleukin-4 (IL-4) to secrete IL-4, interleukin-13 (IL-13), interleukin-5 (IL-5), and interleukin-10 (IL-10). The authors were interested in identifying nonpeptide inhibitors of the Th1 response selective for the IL-12/IL-18-mediated secretion of IFN-gamma while leaving the IL-4-mediated Th2 cytokine secretion relatively intact. The authors established a screening protocol using human peripheral blood mononuclear cells (PBMCs) and identified the hydrazino anthranilate compound 1 as a potent inhibitor of IL-12/IL-18-mediated IFN-gamma secretion from CD3(+) cells with an IC(50) around 200 nM. The inhibitor was specific because it had virtually no effect on IL-4-mediated IL-13 release from the same population of cells. Further work established that compound 1 was a potent intracellular iron chelator that inhibited both IL-12/IL-18- and IL-4-mediated T cell proliferation. Iron chelation affects multiple cellular pathways in T cells. Thus, the IL-12/IL-18-mediated proliferation and IFN-gamma secretion are very sensitive to intracellular iron concentration. However, the IL-4-mediated IL-13 secretion does not correlate with proliferation and is partially resistant to potent iron chelation.
Asunto(s)
Citocinas/metabolismo , Iones/química , Quelantes del Hierro/química , Quelantes del Hierro/farmacología , Linfocitos T/efectos de los fármacos , Linfocitos T/metabolismo , Diferenciación Celular/efectos de los fármacos , Línea Celular , Supervivencia Celular/efectos de los fármacos , Humanos , Concentración 50 Inhibidora , Espectrometría de Masas , Estructura Molecular , FN-kappa B/metabolismo , Transcripción Genética/efectos de los fármacosRESUMEN
Benzothiophene-anthranilamide 1 (3-chloro-N-[2-[[(4-fluorophenyl)amino]carbonyl]-4-methylphenyl]benzo[b]thiophene-2-carboxamide) was discovered by high throughput screening to be a highly potent and selective non-amidine inhibitor of human factor Xa with a K(i) of 15+/-4nM. Compound 1 is a selective inhibitor of human factor Xa as suggested by the K(i)((app)) determined for nine other human serine proteases and bovine trypsin. The activity of reconstituted human prothrombinase complex was inhibited by compound 1 when assayed in physiological concentrations of the substrate prothrombin. However, 27-fold higher inhibitor concentrations were needed to achieve the same level of inhibition than were required for the inhibition of free factor Xa, due in part to non-specific binding of the inhibitor to phospholipid under the assay conditions. Failure to demonstrate enzymatic cleavage of compound 1 suggests that compound 1 is solely an inhibitor rather than a substrate for factor Xa. The inhibition of factor Xa by compound 1 was reversible upon dilution of the enzyme/inhibitor mixture. Analyses of the inhibition mechanism with Dixon, Cornish-Bowden, and Lineweaver-Burk plots showed that compound 1 is a linear mixed-type inhibitor with 5-fold higher affinity for free factor Xa than the factor Xa/substrate complex. The linear mixed-type inhibition suggests that compound 1 binds to the active site region of factor Xa, but its binding cannot be fully displaced by the substrate S2222 (1:1 mixture of N-benzoyl-Ile-Glu-Gly-Arg-p-nitroanilide and N-benzoyl-Ile-Glu(gamma-OMe)-Gly-Arg-p-nitroanilide hydrochloride). Thus, the inhibition mechanism for compound 1 is novel compared to most serine protease inhibitors including amidine-containing factor Xa inhibitors, which rely on binding to the S1 pocket of the enzyme active site. Compound 1 represents an attractive, novel structural template for further development of efficacious, safe, and potentially orally active human factor Xa inhibitors.