Aberrant Notch signaling has been implicated in the pathogenesis of many human cancers. MK-0752 is a potent, oral inhibitor of γ-secretase, an enzyme required for Notch pathway activation. Safety, ...maximum-tolerated dose, pharmacokinetics (PKs), pharmacodynamics, and preliminary antitumor efficacy were assessed in a phase I study of MK-0752.
MK-0752 was administered in three different schedules to patients with advanced solid tumors. Hair follicles were collected at higher dose levels to assess a gene signature of Notch inhibition.
Of 103 patients who received MK-0752, 21 patients received a continuous once-daily dosing at 450 and 600 mg; 17 were dosed on an intermittent schedule of 3 of 7 days at 450 and 600 mg; and 65 were dosed once per week at 600, 900, 1,200, 1,500, 1,800, 2,400, 3,200, and 4,200 mg. The most common drug-related toxicities were diarrhea, nausea, vomiting, and fatigue. PKs (area under the concentration-time curve and maximum measured plasma concentration) increased in a less than dose proportional manner, with a half-life of approximately 15 hours. Significant inhibition of Notch signaling was observed with the 1,800- to 4,200-mg weekly dose levels, confirming target engagement at those doses. One objective complete response and an additional 10 patients with stable disease longer than 4 months were observed among patients with high-grade gliomas.
MK-0752 toxicity was schedule dependent. Weekly dosing was generally well tolerated and resulted in strong modulation of a Notch gene signature. Clinical benefit was observed, and rational combination trials are currently ongoing to maximize clinical benefit with this novel agent.
Gene editing following designer nuclease cleavage in the presence of a DNA donor template can revert mutations in disease-causing genes. For optimal benefit, reversion of the point mutation in HBB ...leading to sickle cell disease (SCD) would permit precise homology-directed repair (HDR) while concurrently limiting on-target non-homologous end joining (NHEJ)-based HBB disruption. In this study, we directly compared the relative efficiency of co-delivery of a novel CRISPR/Cas9 ribonucleoprotein targeting HBB in association with recombinant adeno-associated virus 6 (rAAV6) versus single-stranded oligodeoxynucleotides (ssODNs) to introduce the sickle mutation (GTC or GTG; encoding E6V) or a silent change (GAA; encoding E6optE) in human CD34+ mobilized peripheral blood stem cells (mPBSCs) derived from healthy donors. In vitro, rAAV6 outperformed ssODN donor template delivery and mediated greater HDR correction, leading to both higher HDR rates and a higher HDR:NHEJ ratio. In contrast, at 12–14 weeks post-transplant into recipient, immunodeficient, NOD, B6, SCID Il2rγ−/− Kit(W41/W41) (NBSGW) mice, a ∼6-fold higher proportion of ssODN-modified cells persisted in vivo compared to recipients of rAAV6-modified mPBSCs. Together, our findings highlight that methodology for donor template delivery markedly impacts long-term persistence of HBB gene-modified mPBSCs, and they suggest that the ssODN platform is likely to be most amenable to direct clinical translation.
As glioblastoma progresses, patients experience a decline in health-related quality of life (HRQoL). Delaying this decline is an important treatment goal. In newly diagnosed glioblastoma, ...progression-free survival was prolonged when bevacizumab was added to radiotherapy plus temozolomide (RT/TMZ) versus placebo plus RT/TMZ (phase III AVAglio study; hazard ratio, 0.64; 95% CI, 0.55 to 0.74; P < .001). To ensure that addition of bevacizumab to standard-of-care therapy was not associated with HRQoL detriment, HRQoL assessment was a secondary objective.
Patients completed European Organisation for Research and Treatment of Cancer Quality of Life Questionnaires C30 and BN20 at each tumor assessment (Appendix Table A1, online only). Raw scores were converted to a 100-point scale and mean changes from baseline scores were evaluated (stable: < 10-point change; clinically relevant deterioration/improvement: ≥ 10-point change). Deterioration-free survival was the time to deterioration/progression/death; time to deterioration was the time to deterioration/death.
Most evaluable patients who had not progressed (> 74%) completed all HRQoL assessments for at least 1 year of treatment, and almost all completed at least one HRQoL assessment at baseline (98.3% and 97.6%, bevacizumab and placebo arms, respectively). Mean changes from baseline did not reach a clinically relevant difference between arms for most items. HRQoL declined at progression in both arms. The addition of bevacizumab to RT/TMZ resulted in statistically longer (P < .001) deterioration-free survival across all items. Time to deterioration was not statistically longer in the placebo plus RT/TMZ arm (v bevacizumab) for any HRQoL item.
The addition of bevacizumab to standard-of-care treatment for newly diagnosed glioblastoma had no impact on HRQoL during the progression-free period.
There have been significant advancements in the safe delivery of anesthesia as well as improvements in surgical technique; however, the perioperative period can still be high risk for the pediatric ...patient. Perioperative respiratory complications (PRCs) are some of the most common critical events that can occur in pediatric surgical patients and they can lead to increased length of hospitalization, worsened patient outcomes, and higher hospital and postoperative costs. It is important to determine the various factors that put pediatric patients at increased risk of PRCs. This will allow for more detailed and accurate informed consent, optimized perioperative management strategy, improved allocation of clinical resources, and, hopefully, better patient experience. There are only a few risk prediction models/scoring tools developed for and validated in the pediatric patient population, but they have been useful in helping identify the key factors associated with a high likelihood of developing PRCs. Some of these factors are patient factors, while others are procedure-related factors. Some of these factors may be modified such that the patient’s clinical status is optimized preoperatively to decrease the risk of PRCs occurring perioperatively. Fore knowledge of the factors that are not able to be modified can help guide allocation of perioperative clinical resources such that the negative impact of these non-modifiable factors is buffered. Additional training in pediatric anesthesia or focused expertise in pediatric airway management, vascular access and management of massive hemorrhage should be considered for the perioperative management of the less than 3 age group. Intraoperative ventilation strategy plays a key role in determining respiratory outcomes for both adult and pediatric surgical patients. Key components of lung protective mechanical ventilation strategy such as low tidal volume and moderate PEEP used in the management of acute respiratory distress syndrome (ARDS) in pediatric intensive care units have been adopted in pediatric operating rooms. Adequate post-operative analgesia that balances pain control with appropriate mental status and respiratory drive is important in reducing PRCs.
Background & Aims Progression from steatosis to steatohepatitic lesions is hypothesized to require a second hit. These lesions have been associated with increased oxidative stress, often ascribed to ...high levels of leptin and other proinflammatory mediators. Here we have examined the role of leptin in inducing oxidative stress and Kupffer cell activation in CCl4 -mediated steatohepatitic lesions of obese mice. Methods Male C57BL/6 mice fed with a high-fat diet (60% kcal) at 16 weeks were administered CCl4 to induce steatohepatitic lesions. Approaches included use of immuno-spin trapping for measuring free radical stress, gene-deficient mice for leptin, p47 phox, iNOS and adoptive transfer of leptin primed macrophages in vivo. Results Diet-induced obese (DIO) mice, treated with CCl4 increased serum leptin levels. Oxidative stress was significantly elevated in the DIO mouse liver, but not in ob / ob mice, or in DIO mice treated with leptin antibody. In ob / ob mice, leptin supplementation restored markers of free radical generation. Markers of free radical formation were significantly decreased by the peroxynitrite decomposition catalyst FeTPPS, the iNOS inhibitor 1400W, the NADPH oxidase inhibitor apocynin, or in iNOS or p47 phox-deficient mice. These results correlated with the decreased expression of TNF-alpha and MCP-1. Kupffer cell depletion eliminated oxidative stress and inflammation, whereas in macrophage-depleted mice, the adoptive transfer of leptin-primed macrophages significantly restored inflammation. Conclusions These results, for the first time, suggest that leptin action in macrophages of the steatotic liver, through induction of iNOS and NADPH oxidase, causes peroxynitrite-mediated oxidative stress thus activating Kupffer cells.
Development of resistance to chemotherapy drugs is a significant problem in treating human malignancies in the clinic. Overexpression of drug efflux proteins, including P-170 glycoprotein (P-gp), an ...ATP-dependent efflux protein, is one of the main mechanisms responsible for multi-drug resistance (MDR). Because our previous studies have shown that nitric oxide (˙NO) or its related species inhibit the ATPase activities of topoisomerase II, we hypothesized that ˙NO should also inhibit the ATPase activity of P-gp and increase drug accumulation in MDR cells, causing a reversal of drug resistance.
Cytotoxicity and cellular accumulation studies showed that ˙NO significantly inhibited the ATPase activity of P-gp in isolated membranes and in NCI/ADR-RES tumor cells, causing an increase in drug accumulation and reversals of adriamycin and taxol resistance in the MDR cells. While ˙NO had no effects on topoisomerase II-induced, adriamycin-dependent DNA cleavage complex formation, it significantly inhibited adriamycin-induced DNA double-strand breaks. Electron spin resonance studies showed an increase in adriamycin-dependent hydroxyl radical formation in the presence of an NO-donor.
The reversal of drug resistance is due to inhibition of the ATPase activity by ˙NO, resulting in enhancement of the drug accumulation in the MDR cells. Furthermore, DNA damage was not responsible for this reversal of adriamycin resistance. However, formation of adriamycin-dependent toxic free radical species and subsequent cellular damage may be responsible for the increased cytotoxicity of adriamycin by ˙NO in NCI/ADR-RES cells.
Appropriately designed NO donors would be ideal for the treatment of P-gp-overexpressing tumors in the clinic.
•Nitric oxide inhibits Pgp protein functions in human MDR tumor cells.•Nitric oxide increases cellular accumulation of adriamycin in MDR tumor cells.•Nitric oxide reverses resistance to adriamycin and taxol in MDR tumor cells.•The reversal of drug resistance is not due to adriamycin-induced DNA damage.•Reversal of adriamycin resistance may be, in part, due to increased ˙OH formation.
The pancreatic islets of Langerhans are multicellular micro-organs integral to maintaining glucose homeostasis through secretion of the hormone insulin. β-cells within the islet exist as a highly ...coupled electrical network which coordinates electrical activity and insulin release at high glucose, but leads to global suppression at basal glucose. Despite its importance, how network dynamics generate this emergent binary on/off behavior remains to be elucidated. Previous work has suggested that a small threshold of quiescent cells is able to suppress the entire network. By modeling the islet as a Boolean network, we predicted a phase-transition between globally active and inactive states would emerge near this threshold number of cells, indicative of critical behavior. This was tested using islets with an inducible-expression mutation which renders defined numbers of cells electrically inactive, together with pharmacological modulation of electrical activity. This was combined with real-time imaging of intracellular free-calcium activity Ca2+i and measurement of physiological parameters in mice. As the number of inexcitable cells was increased beyond ∼15%, a phase-transition in islet activity occurred, switching from globally active wild-type behavior to global quiescence. This phase-transition was also seen in insulin secretion and blood glucose, indicating physiological impact. This behavior was reproduced in a multicellular dynamical model suggesting critical behavior in the islet may obey general properties of coupled heterogeneous networks. This study represents the first detailed explanation for how the islet facilitates inhibitory activity in spite of a heterogeneous cell population, as well as the role this plays in diabetes and its reversal. We further explain how islets utilize this critical behavior to leverage cellular heterogeneity and coordinate a robust insulin response with high dynamic range. These findings also give new insight into emergent multicellular dynamics in general which are applicable to many coupled physiological systems, specifically where inhibitory dynamics result from coupled networks.
Smoking cessation is presumed to be beneficial before resection of lung cancer. The effect of smoking cessation on outcome was investigated.
From January 1999 to July 2007, in-hospital outcomes for ...7990 primary resections for lung cancer in adults were reported to the Society of Thoracic Surgeons General Thoracic Surgery Database. Risk of hospital death and respiratory complications was assessed according to timing of smoking cessation, adjusted for clinical confounders.
Hospital mortality was 1.4% (n = 109), but 1.5% in patients who had smoked (105 of 6965) vs 0.39% in those who had not (4 of 1025). Compared with the latter, risk-adjusted odds ratios were 3.5 (p = 0.03), 4.6 (p = 0.03), 2.6 (p = 0.7), and 2.5 (p = 0.11) for those whose timing of smoking cessation was categorized as current smoker, quit from 14 days to 1 month, 1 to 12 months, or more than 12 months preoperatively, respectively. Prevalence of major pulmonary complications was 5.7% (456 of 7965) overall, but 6.2% in patients who had smoked (429 of 6941) vs 2.5%% in those who had not (27 of 1024). Compared with the latter, risk-adjusted odds ratios were 1.80 (p = 0.03), 1.62 (p = 0.14), 1.51 (p = 0.20), and 1.29 (p = 0.3) for those whose timing of smoking cessation was categorized as above.
Risks of hospital death and pulmonary complications after lung cancer resection were increased by smoking and mitigated slowly by preoperative cessation. No optimal interval of smoking cessation was identifiable. Patients should be counseled to stop smoking irrespective of surgical timing.
Abstract Aims Exercise capacity is impaired in type 2 diabetes, and this impairment predicts excess morbidity and mortality. This defect appears to involve excess skeletal muscle deoxygenation, but ...the underlying mechanisms remain unclear. We hypothesized that reduced blood flow, reduced local recruitment of blood volume/hematocrit, or both contribute to excess skeletal muscle deoxygenation in type 2 diabetes. Methods In patients with (n = 23) and without (n = 18) type 2 diabetes, we recorded maximal reactive hyperemic leg blood flow, peak oxygen utilization during cycling ergometer exercise (VO2peak ), and near-infrared spectroscopy-derived measures of exercise-induced changes in skeletal muscle oxygenation and blood volume/hematocrit. Results We observed a significant increase (p < 0.05) in skeletal muscle deoxygenation in type 2 diabetes despite similar blood flow and recruitment of local blood volume/hematocrit. Within the control group skeletal muscle deoxygenation, local recruitment of microvascular blood volume/hematocrit, blood flow, and VO2peak are all mutually correlated. None of these correlations were preserved in type 2 diabetes. Conclusions These results suggest that in type 2 diabetes 1) skeletal muscle oxygenation is impaired, 2) this impairment may occur independently of bulk blood flow or local recruitment of blood volume/hematocrit, and 3) local and global metrics of oxygen transport are dissociated.
The
Miniature X-ray Solar Spectrometer
(MinXSS) CubeSat is the first solar science oriented CubeSat mission flown for the NASA Science Mission Directorate, with the main objective of measuring the ...solar soft X-ray (SXR) flux and a science goal of determining its influence on Earth’s ionosphere and thermosphere. These observations can also be used to investigate solar quiescent, active region, and flare properties. The MinXSS X-ray instruments consist of a spectrometer, called X123, with a nominal 0.15 keV full-width at half-maximum (FWHM) resolution at 5.9 keV and a broadband X-ray photometer, called XP. Both instruments are designed to obtain measurements from 0.5 – 30 keV at a nominal time cadence of 10 s. A description of the MinXSS instruments, performance capabilities, and relation to the
Geostationary Operational Environmental Satellite
(GOES) 0.1 – 0.8 nm flux is given in this article. Early MinXSS results demonstrate the capability of measuring variations of the solar spectral soft X-ray (SXR) flux between 0.8 – 12 keV from at least GOES A5–M5 (
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) levels and of inferring physical properties (temperature and emission measure) from the MinXSS data alone. Moreover, coronal elemental abundances can be inferred, specifically for Fe, Ca, Si, Mg, S, Ar, and Ni, when the count rate is sufficiently high at each elemental spectral feature. Additionally, temperature response curves and emission measure loci demonstrate the MinXSS sensitivity to plasma emission at different temperatures. MinXSS observations coupled with those from other solar observatories can help address some of the most compelling questions in solar coronal physics. Finally, simultaneous observations by MinXSS and the
Reuven Ramaty High Energy Solar Spectroscopic Imager
(RHESSI) can provide the most spectrally complete soft X-ray solar flare photon flux measurements to date.
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