1,504 research outputs found
Use of archival versus newly collected tumor samples for assessing PD-L1 expression and overall survival : an updated analysis of KEYNOTE-010 trial
Background: In KEYNOTE-010, pembrolizumab versus docetaxel improved overall survival (OS) in patients with programmed death-1 protein (PD)-L1-positive advanced non-small-cell lung cancer (NSCLC). A prespecified exploratory analysis compared outcomes in patients based on PD-L1 expression in archival versus newly collected tumor samples using recently updated survival data.
Patients and methods: PD-L1 was assessed centrally by immunohistochemistry (22C3 antibody) in archival or newly collected tumor samples. Patients received pembrolizumab 2 or 10 mg/kg Q3W or docetaxel 75 mg/m2 Q3W for 24 months or until progression/intolerable toxicity/other reason. Response was assessed by RECIST v1.1 every 9 weeks, survival every 2 months. Primary end points were OS and progression-free survival (PFS) in tumor proportion score (TPS) 50% and 1%; pembrolizumab doses were pooled in this analysis.
Results: At date cut-off of 24 March 2017, median follow-up was 31 months (range 23-41) representing 18 additional months of follow-up from the primary analysis. Pembrolizumab versus docetaxel continued to improve OS in patients with previously treated, PD-L1-expressing advanced NSCLC; hazard ratio (HR) was 0.66 [95% confidence interval (CI): 0.57, 0.77]. Of 1033 patients analyzed, 455(44%) were enrolled based on archival samples and 578 (56%) on newly collected tumor samples. Approximately 40% of archival samples and 45% of newly collected tumor samples were PD-L1 TPS 50%. For TPS 50%, the OS HRs were 0.64 (95% CI: 0.45, 0.91) and 0.40 (95% CI: 0.28, 0.56) for archival and newly collected samples, respectively. In patients with TPS 1%, OS HRs were 0.74 (95% CI: 0.59, 0.93) and 0.59 (95% CI: 0.48, 0.73) for archival and newly collected samples, respectively. In TPS 50%, PFS HRs were similar across archival [0.63 (95% CI: 0.45, 0.89)] and newly collected samples [0.53 (95% CI: 0.38, 0.72)]. In patients with TPS 1%, PFS HRs were similar across archival [0.82 (95% CI: 0.66, 1.02)] and newly collected samples [0.83 (95% CI: 0.68, 1.02)].
Conclusion: Pembrolizumab continued to improve OS over docetaxel in intention to treat population and in subsets of patients with newly collected and archival samples
Water sorption studies with mesoporous multivariate monoliths based on UiO-66
Hierarchical linker thermolysis has been used to enhance the porosity of monolithic UiO-66-based metal–organic frameworks (MOFs) containing 30 wt% 2-aminoterephthalic acid (BDC-NH2) linker. In this multivariate (i.e. mixed-linker) MOF, the thermolabile BDC-NH2 linker decomposed at ∼350 °C, inducing mesopore formation. The nitrogen sorption of these monolithic MOFs was probed, and an increase in gas uptake of more than 200 cm3 g−1 was observed after activation by heating, together with an increase in pore volume and mean pore width, indicating the creation of mesopores. Water sorption studies were conducted on these monoliths to explore their performance in that context. Before heating, monoUiO-66-NH2-30%-B showed maximum water vapour uptake of 61.0 wt%, which exceeded that reported for either parent monolith, while the highly mesoporous monolith (monoUiO-66-NH2-30%-A) had a lower maximum water vapour uptake of 36.2 wt%. This work extends the idea of hierarchical linker thermolysis, which has been applied to powder MOFs, to monolithic MOFs for the first time and supports the theory that it can enhance pore sizes in these materials. It also demonstrates the importance of hydrophilic functional groups (in this case, NH2) for improving water uptake in materials
Ca and Mg isotope fractionation during the stoichiometric dissolution of dolomite at temperatures from 51 to 126 degrees C and 5 bars CO2 pressure
Natural polycrystalline hydrothermal Sainte Colombe dolomite was dissolved in stirred titanium closed system reactors in aqueous 0.1 mol/kg NaCl solutions at 51, 75, 121, and 126 °C and a pressure of 5 bars CO2. In total, 52, 27, 16, and 12%, respectively, of the dolomite placed in the reactors dissolved into the fluid phase during these experiments. Each experiment lasted from 12 to 47 days and the fluid phase in each evolved towards, but did not exceed, ordered dolomite equilibrium at a pH of 5.9 ± 0.3. All aqueous reactive fluids were undersaturated with respect to all potential secondary phases including calcite and magnesite. The reactive fluid compositions at the end of the experiments had a molar Ca/Mg ratio equal to that of the dissolving dolomite, and the dolomite recovered after the experiments contained only pure dolomite as verified by scanning electron microscopy. The Ca and Mg isotopic ratios of the reactive fluids remained within uncertainty equal to that of the dissolving dolomite in the experiments performed at 51 and 75 °C. In contrast, the Ca isotopic composition of the reactive fluid in the experiment performed at 121 and 126 °C was significantly greater such that Δ44/42Casolid-fluid = − 0.6 ± 0.1‰, whereas that of Mg was within uncertainty equal to that of the dissolving mineral. The equilibrium fractionation factors for both divalent cations favor the incorporation of isotopically light metals into the dolomite structure. Our results at 121 and 126 °C, therefore, are consistent with the one-way transfer of Mg from dolomite to the fluid but the two-way transfer of Ca from and to dolomite as equilibrium is approached during its stoichiometric dissolution. The lack of Mg returning to the dolomite structure at these conditions is attributed to the slow dehydration kinetics of aqueous Mg. As more than 12% of the dolomite dissolved during the 121 and 126 °C closed system experiments, our observations indicate a significant change in the Ca isotopic signature of the dolomite during its stoichiometric dissolution. Moreover, as there is no visual evidence for dolomite recrystallization during this experiment, it seems likely that the resetting of Ca isotopic signatures of carbonate minerals can be readily overlooked in the interpretation of natural systems
Literature-based discovery of diabetes- and ROS-related targets
Abstract Background Reactive oxygen species (ROS) are known mediators of cellular damage in multiple diseases including diabetic complications. Despite its importance, no comprehensive database is currently available for the genes associated with ROS. Methods We present ROS- and diabetes-related targets (genes/proteins) collected from the biomedical literature through a text mining technology. A web-based literature mining tool, SciMiner, was applied to 1,154 biomedical papers indexed with diabetes and ROS by PubMed to identify relevant targets. Over-represented targets in the ROS-diabetes literature were obtained through comparisons against randomly selected literature. The expression levels of nine genes, selected from the top ranked ROS-diabetes set, were measured in the dorsal root ganglia (DRG) of diabetic and non-diabetic DBA/2J mice in order to evaluate the biological relevance of literature-derived targets in the pathogenesis of diabetic neuropathy. Results SciMiner identified 1,026 ROS- and diabetes-related targets from the 1,154 biomedical papers (http://jdrf.neurology.med.umich.edu/ROSDiabetes/). Fifty-three targets were significantly over-represented in the ROS-diabetes literature compared to randomly selected literature. These over-represented targets included well-known members of the oxidative stress response including catalase, the NADPH oxidase family, and the superoxide dismutase family of proteins. Eight of the nine selected genes exhibited significant differential expression between diabetic and non-diabetic mice. For six genes, the direction of expression change in diabetes paralleled enhanced oxidative stress in the DRG. Conclusions Literature mining compiled ROS-diabetes related targets from the biomedical literature and led us to evaluate the biological relevance of selected targets in the pathogenesis of diabetic neuropathy.http://deepblue.lib.umich.edu/bitstream/2027.42/78315/1/1755-8794-3-49.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78315/2/1755-8794-3-49-S7.XLShttp://deepblue.lib.umich.edu/bitstream/2027.42/78315/3/1755-8794-3-49-S10.XLShttp://deepblue.lib.umich.edu/bitstream/2027.42/78315/4/1755-8794-3-49-S8.XLShttp://deepblue.lib.umich.edu/bitstream/2027.42/78315/5/1755-8794-3-49-S3.XLShttp://deepblue.lib.umich.edu/bitstream/2027.42/78315/6/1755-8794-3-49-S1.XLShttp://deepblue.lib.umich.edu/bitstream/2027.42/78315/7/1755-8794-3-49-S4.XLShttp://deepblue.lib.umich.edu/bitstream/2027.42/78315/8/1755-8794-3-49-S2.XLShttp://deepblue.lib.umich.edu/bitstream/2027.42/78315/9/1755-8794-3-49-S12.XLShttp://deepblue.lib.umich.edu/bitstream/2027.42/78315/10/1755-8794-3-49-S11.XLShttp://deepblue.lib.umich.edu/bitstream/2027.42/78315/11/1755-8794-3-49-S9.XLShttp://deepblue.lib.umich.edu/bitstream/2027.42/78315/12/1755-8794-3-49-S5.XLShttp://deepblue.lib.umich.edu/bitstream/2027.42/78315/13/1755-8794-3-49-S6.XLShttp://deepblue.lib.umich.edu/bitstream/2027.42/78315/14/1755-8794-3-49.pdfPeer Reviewe
HER2 and ESR1 mRNA expression levels and response to neoadjuvant trastuzumab plus chemotherapy in patients with primary breast cancer
Introduction: Recent data suggest that benefit from trastuzumab and chemotherapy might be related to expression of HER2 and estrogen receptor (ESR1). Therefore, we investigated HER2 and ESR1 mRNA levels in core biopsies of HER2-positive breast carcinomas from patients treated within the neoadjuvant GeparQuattro trial.
Methods: HER2 levels were centrally analyzed by immunohistochemistry (IHC), silver in-situ hybridization (SISH) and qRT-PCR in 217 pretherapeutic formalin-fixed, paraffin-embedded (FFPE) core biopsies. All tumors had been HER2-positive by local pathology and had been treated with neoadjuvant trastuzumab/ chemotherapy in GeparQuattro.
Results: Only 73% of the tumors (158 of 217) were centrally HER2-positive (cHER2-positive) by IHC/SISH, with cHER2-positive tumors showing a significantly higher pCR rate (46.8% vs. 20.3%, p<0.0005). HER2 status by qRT-PCR showed a concordance of 88.5% with the central IHC/SISH status, with a low pCR rate in those tumors that were HER2-negative by mRNA analysis (21.1% vs. 49.6%, p<0.0005). The level of HER2 mRNA expression was linked to response rate in ESR1-positive tumors, but not in ESR1-negative tumors. HER2 mRNA expression was significantly associated with pCR in the HER2-positive/ESR1-positive tumors (p=0.004), but not in HER2-positive/ESR1-negative tumors.
Conclusions: Only patients with cHER2-positive tumors - irrespective of the method used - have an increased pCR rate with trastuzumab plus chemotherapy. In patients with cHER2-negative tumors the pCR rate is comparable to the pCR rate in the non-trastuzumab treated HER-negative population. Response to trastuzumab is correlated to HER2 mRNA levels only in ESR1-positive tumors. This study adds further evidence to the different biology of both subsets within the HER2-positive group
On supersymmetric quantum mechanics
This paper constitutes a review on N=2 fractional supersymmetric Quantum
Mechanics of order k. The presentation is based on the introduction of a
generalized Weyl-Heisenberg algebra W_k. It is shown how a general Hamiltonian
can be associated with the algebra W_k. This general Hamiltonian covers various
supersymmetrical versions of dynamical systems (Morse system, Poschl-Teller
system, fractional supersymmetric oscillator of order k, etc.). The case of
ordinary supersymmetric Quantum Mechanics corresponds to k=2. A connection
between fractional supersymmetric Quantum Mechanics and ordinary supersymmetric
Quantum Mechanics is briefly described. A realization of the algebra W_k, of
the N=2 supercharges and of the corresponding Hamiltonian is given in terms of
deformed-bosons and k-fermions as well as in terms of differential operators.Comment: Review paper (31 pages) to be published in: Fundamental World of
Quantum Chemistry, A Tribute to the Memory of Per-Olov Lowdin, Volume 3, E.
Brandas and E.S. Kryachko (Eds.), Springer-Verlag, Berlin, 200
Portable lactate analyzer for measuring lactate in cerebrospinal fluid (CSF) and plasma ? method-comparison evaluations
Increased plasma lactate levels can indicate the presence of metabolic disorders in HIV infected individuals. Objective: To determine whether a portable analyzer is valid for measuring cerebrospinal fluid (CSF) and plasma lactate levels in HIV infected individuals. Method: CSF and plasma were collected from 178 subjects. Samples tested by the Accutrend® portable analyzer were compared to those tested by a reference device (SYNCHRON LX® 20). Results: The portable analyzer had in plasma sensitivity of 0.95 and specificity 0.87. For CSF the specificity was 0.95; the sensitivity 0.33; the negative predictive value was 95% and the positive predictive value 33%. Conclusions: These findings support the validity of the portable analyzer in measuring lactate concentrations in CSF that fall within the normal range. The relatively poor positive predictive value indicates that a result above the reference range may represent a “false positive test”, and should be confirmed by the reference device before concluding abnormality
Overeating, caloric restriction and breast cancer risk by pathologic subtype: the EPIGEICAM study
This study analyzes the association of excessive energy intake and caloric restriction with breast
cancer (BC) risk taking into account the individual energy needs of Spanish women. We conducted
a multicenter matched case-control study where 973 pairs completed lifestyle and food frequency
questionnaires. Expected caloric intake was predicted from a linear regression model in controls,
including calories consumed as dependent variable, basal metabolic rate as an offset and physical
activity as explanatory. Overeating and caloric restriction were defined taking into account the 99%
confidence interval of the predicted value. The association with BC risk, overall and by pathologic
subtype, was evaluated using conditional and multinomial logistic regression models. While
premenopausal women that consumed few calories (>20% below predicted) had lower BC risk
(OR = 0.36; 95% CI = 0.21–0.63), postmenopausal women with an excessive intake (≥40% above
predicted) showed an increased risk (OR = 2.81; 95% CI = 1.65–4.79). For every 20% increase in relative
(observed/predicted) caloric intake the risk of hormone receptor positive (p-trend < 0.001) and HER2+
(p-trend = 0.015) tumours increased 13%, being this figure 7% for triple negative tumours. While high
energy intake increases BC risk, caloric restriction could be protective. Moderate caloric restriction, in
combination with regular physical activity, could be a good strategy for BC prevention
The Pattern of R2 Retrotransposon Activity in Natural Populations of Drosophila simulans Reflects the Dynamic Nature of the rDNA Locus
The pattern and frequency of insertions that enable transposable elements to remain active in a population are poorly understood. The retrotransposable element R2 exclusively inserts into the 28S rRNA genes where it establishes long-term, stable relationships with its animal hosts. Previous studies with laboratory stocks of Drosophila simulans have suggested that control over R2 retrotransposition resides within the rDNA loci. In this report, we sampled 180 rDNA loci of animals collected from two natural populations of D. simulans. The two populations were found to have similar patterns of R2 activity. About half of the rDNA loci supported no or very low levels of R2 transcripts with no evidence of R2 retrotransposition. The remaining half of the rDNA loci had levels of R2 transcripts that varied in a continuous manner over almost a 100-fold range and did support new retrotransposition events. Structural analysis of the rDNA loci in 18 lines that spanned the range of R2 transcript levels in these populations revealed that R2 number and rDNA locus size varied 2-fold; however, R2 activity was not readily correlated with either of these parameters. Instead R2 activity was best correlated with the distribution of elements within the rDNA locus. Loci with no activity had larger contiguous blocks of rDNA units free of R2-insertions. These data suggest a model in which frequent recombination within the rDNA locus continually redistributes R2-inserted units resulting in changing levels of R2 activity within individual loci and persistent R2 activity within the population
Height and timing of growth spurt during puberty in young people living with vertically acquired HIV in Europe and Thailand.
OBJECTIVE: The aim of this study was to describe growth during puberty in young people with vertically acquired HIV. DESIGN: Pooled data from 12 paediatric HIV cohorts in Europe and Thailand. METHODS: One thousand and ninety-four children initiating a nonnucleoside reverse transcriptase inhibitor or boosted protease inhibitor based regimen aged 1-10 years were included. Super Imposition by Translation And Rotation (SITAR) models described growth from age 8 years using three parameters (average height, timing and shape of the growth spurt), dependent on age and height-for-age z-score (HAZ) (WHO references) at antiretroviral therapy (ART) initiation. Multivariate regression explored characteristics associated with these three parameters. RESULTS: At ART initiation, median age and HAZ was 6.4 [interquartile range (IQR): 2.8, 9.0] years and -1.2 (IQR: -2.3 to -0.2), respectively. Median follow-up was 9.1 (IQR: 6.9, 11.4) years. In girls, older age and lower HAZ at ART initiation were independently associated with a growth spurt which occurred 0.41 (95% confidence interval 0.20-0.62) years later in children starting ART age 6 to 10 years compared with 1 to 2 years and 1.50 (1.21-1.78) years later in those starting with HAZ less than -3 compared with HAZ at least -1. Later growth spurts in girls resulted in continued height growth into later adolescence. In boys starting ART with HAZ less than -1, growth spurts were later in children starting ART in the oldest age group, but for HAZ at least -1, there was no association with age. Girls and boys who initiated ART with HAZ at least -1 maintained a similar height to the WHO reference mean. CONCLUSION: Stunting at ART initiation was associated with later growth spurts in girls. Children with HAZ at least -1 at ART initiation grew in height at the level expected in HIV negative children of a comparable age
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