'Seeing' the electromagnetic spectrum: spotlight on the cryptochrome photocycle

Cryptochromes are widely dispersed flavoprotein photoreceptors that regulate numerous developmental responses to light in plants, as well as to stress and entrainment of the circadian clock in animals and humans. All cryptochromes are closely related to an ancient family of light-absorbing flavoenzymes known as photolyases, which use light as an energy source for DNA repair but themselves have no light sensing role. Here we review the means by which plant cryptochromes acquired a light sensing function. This transition involved subtle changes within the flavin binding pocket which gave rise to a visual photocycle consisting of light-inducible and dark-reversible flavin redox state transitions. In this photocycle, light first triggers flavin reduction from an initial dark-adapted resting state (FADox). The reduced state is the biologically active or 'lit' state, correlating with biological activity. Subsequently, the photoreduced flavin reoxidises back to the dark adapted or 'resting' state. Because the rate of reoxidation determines the lifetime of the signaling state, it significantly modulates biological activity. As a consequence of this redox photocycle Crys respond to both the wavelength and the intensity of light, but are in addition regulated by factors such as temperature, oxygen concentration, and cellular metabolites that alter rates of flavin reoxidation even independently of light. Mechanistically, flavin reduction is correlated with conformational change in the protein, which is thought to mediate biological activity through interaction with biological signaling partners. In addition, a second, entirely independent signaling mechanism arises from the cryptochrome photocycle in the form of reactive oxygen species (ROS). These are synthesized during flavin reoxidation, are known mediators of biotic and abiotic stress responses, and have been linked to Cry biological activity in plants and animals. Additional special properties arising from the cryptochrome photocycle include responsivity to electromagnetic fields and their applications in optogenetics. Finally, innovations in methodology such as the use of Nitrogen Vacancy (NV) diamond centers to follow cryptochrome magnetic field sensitivity in vivo are discussed, as well as the potential for a whole new technology of 'magneto-genetics' for future applications in synthetic biology and medicine.

Characterization data of reference materials used for phase II of the priority program DFG SPP 2005 "Opus Fluidum Futurum - Rheology of reactive, multiscale, multiphase construction materials"

A thorough characterization of base materials is the prerequisite for further research. In this paper, the characterization data of the reference materials (CEM I 42.5 R, limestone powder, calcined clay and a mixture of these three components) used in the second funding phase of the priority program 2005 of the German Research Foundation (DFG SPP 2005) are presented under the aspects of chemical and mineralogical composition as well as physical and chemical properties. The data were collected based on tests performed by up to eleven research groups involved in this cooperative program.

Charge regulated solid-liquid interfaces interacting on the nanoscale: Benchmarking of a generalized speciation code (SINFONIA)

Surface chemistry of mineral phases in aqueous environments generates the electrostatic forces involved in particle-particle interactions. However, few models directly take into account the influence of surface speciation and changes in solution speciation when the diffuse layer potential profiles of approaching particles overlap and affect each other. These electrostatic interactions can be quantified, ideally, through charge regulation, considering solution and surface speciation changes upon particle approach by coupling state-of-the-art surface complexation models for the two particle surfaces with a Poisson-Boltzmann type distribution of electrostatic potential and ions in the inter-particle space. These models greatly improve the accuracy of inter-particle force calculations at small inter-particle separations compared to constant charge and constant potential approaches. This work aims at advancing charge regulation calculations by including full chemical speciation and advanced surface complexation models (Basic Stern-, three-, or four plane models and charge distribution concepts), for cases of similar and dissimilar surfaces involving the numerical solution of the Poisson-Boltzmann equation for arbitrary electrolytes. The concept was implemented as a Python-based code and in COMSOL. The flexibility and precision of both, concept and implementations are demonstrated in several benchmark calculations testing the new codes against published results or simulations using established speciation codes, including aqueous speciation, surface complexation and various interaction force examples. Due to the flexibility in terms of aqueous chemistry and surface complexation models for various geometries, a large variety of potential applications can be tackled with the developed codes including industrial, biological, and environmental systems, from colloidal suspensions to gas bubbles, emulsions, slurries like cement paste, as well as new possibilities to assess the chemistry in nano-confined systems.

Effect of temperature on the Arabidopsis cryptochrome photocycle

Cryptochromes are blue light-absorbing photoreceptors found in plants and animals with many important signalling functions. These include control of plant growth, development, and the entrainment of the circadian clock. Plant cryptochromes have recently been implicated in adaptations to temperature variation, including temperature compensation of the circadian clock. However, the effect of temperature directly on the photochemical properties of the cryptochrome photoreceptor remains unknown. Here we show that the response to light of purified Arabidopsis Cry1 and Cry2 proteins was significantly altered by temperature. Spectral analysis at 15°C showed a pronounced decrease in flavin reoxidation rates from the biologically active, light-induced (FADH°) signalling state of cryptochrome to the inactive (FADox) resting redox state as compared to ambient (25°C) temperature. This result indicates that at low temperatures, the concentration of the biologically active FADH° redox form of Cry is increased, leading to the counterintuitive prediction that there should be an increased biological activity of Cry at lower temperatures. This was confirmed using Cry1 cryptochrome C-terminal phosphorylation as a direct biological assay for Cry activation in vivo. We conclude that enhanced cryptochrome function in vivo at low temperature is consistent with modulation by temperature of the cryptochrome photocycle.

Measurement of the Iron Spectrum in Cosmic Rays from 10 GeV/n to 2.0 TeV/n with the Calorimetric Electron Telescope on the International Space Station

The Calorimetric Electron Telescope (CALET), in operation on the International Space Station since 2015, collected a large sample of cosmic-ray iron over a wide energy interval. In this Letter a measurement of the iron spectrum is presented in the range of kinetic energy per nucleon from 10  GeV/n to 2.0  TeV/n allowing the inclusion of iron in the list of elements studied with unprecedented precision by space-borne instruments. The measurement is based on observations carried out from January 2016 to May 2020. The CALET instrument can identify individual nuclear species via a measurement of their electric charge with a dynamic range extending far beyond iron (up to atomic number Z=40). The energy is measured by a homogeneous calorimeter with a total equivalent thickness of 1.2 proton interaction lengths preceded by a thin (3 radiation lengths) imaging section providing tracking and energy sampling. The analysis of the data and the detailed assessment of systematic uncertainties are described and results are compared with the findings of previous experiments. The observed differential spectrum is consistent within the errors with previous experiments. In the region from 50  GeV/n to 2  TeV/n our present data are compatible with a single power law with spectral index -2.60±0.03.

Direct Measurement of the Cosmic-Ray Carbon and Oxygen Spectra from 10 GeV/n to 2.2 TeV/n with the Calorimetric Electron Telescope on the International Space Station

In this paper, we present the measurement of the energy spectra of carbon and oxygen in cosmic rays based on observations with the Calorimetric Electron Telescope on the International Space Station from October 2015 to October 2019. Analysis, including the detailed assessment of systematic uncertainties, and results are reported. The energy spectra are measured in kinetic energy per nucleon from 10  GeV/n to 2.2  TeV/n with an all-calorimetric instrument with a total thickness corresponding to 1.3 nuclear interaction length. The observed carbon and oxygen fluxes show a spectral index change of ∼0.15 around 200  GeV/n established with a significance >3σ. They have the same energy dependence with a constant C/O flux ratio 0.911±0.006 above 25  GeV/n. The spectral hardening is consistent with that measured by AMS-02, but the absolute normalization of the flux is about 27% lower, though in agreement with observations from previous experiments including the PAMELA spectrometer and the calorimetric balloon-borne experiment CREAM.

Characterization data of reference cement CEM III/A 42.5N used for priority program DFG SPP 2005 "Opus Fluidum Futurum - Rheology of reactive, multiscale, multiphase construction materials"

Two types of cements were selected as the reference cement in the priority program 2005 of the German Research Foundation (DFG SPP 2005). A thorough characterization of CEM I 42.5 R has been made in a recent publication [1]. In this paper, the characterization data of the other reference cement CEM III/A 42.5 N are presented from the aspects of chemical and mineralogical compositions as well as physical and chemical properties. The characterization data of the slag, which is the second main constituent of this specific cement besides the clinker, are presented independently. For all data received, the mean values and the corresponding errors were calculated. The data shall be used for the ongoing research within the priority program. Also, researchers from outside this priority program can benefit from these data if the same materials are used.

Characterization data of reference cement CEM I 42.5 R used for priority program DFG SPP 2005 "Opus Fluidum Futurum - Rheology of reactive, multiscale, multiphase construction materials"

A thorough characterization of starting materials is the precondition for further research, especially for cement, which contains various phases and presents quite a complex material for fundamental scientific investigation. In the paper at hand, the characterization data of the reference cement CEM I 42.5 R used within the priority program 2005 of the German Research Foundation (DFG SPP 2005) are presented from the aspects of chemical and mineralogical compositions as well as physical and chemical properties. The data were collected based on tests conducted by nine research groups involved in this cooperative program. For all data received, the mean values and the corresponding errors were calculated. The results shall be used for the ongoing research within the priority program.

Short-term prediction of secondary progression in a sliding window: A test of a predicting algorithm in a validation cohort

Introduction

The Multiple Sclerosis Prediction Score (MSPS, www.msprediction.com) estimates, for any month during the course of relapsing–remitting multiple sclerosis (MS), the individual risk of transition to secondary progression (SP) during the following year.

Objective

Internal verification of the MSPS algorithm in a derivation cohort, the Gothenburg Incidence Cohort (GIC, n =  144) and external verification in the Uppsala MS cohort (UMS, n = 145).

Methods

Starting from their second relapse, patients were included and followed for 25 years. A matrix of MSPS values was created. From this matrix, a goodness-of-fit test and suitable diagnostic plots were derived to compare MSPS-calculated and observed outcomes (i.e. transition to SP).

Results

The median time to SP was slightly longer in the UMS than in the GIC, 15 vs. 11.5 years (p = 0.19). The MSPS was calibrated with multiplicative factors: 0.599 for the UMS and 0.829 for the GIC; the calibrated MSPS provided a good fit between expected and observed outcomes (chi-square p = 0.61 for the UMS), which indicated the model was not rejected.

Conclusion

The results suggest that the MSPS has clinically relevant generalizability in new cohorts, provided that the MSPS was calibrated to the actual overall SP incidence in the cohort.

Magnetic sensitivity mediated by the Arabidopsis blue-light receptor cryptochrome occurs during flavin reoxidation in the dark

Arabidopsis cryptochrome mediates responses to magnetic fields that have been applied in the absence of light, consistent with flavin reoxidation as the primary detection mechanism. Cryptochromes are highly conserved blue-light-absorbing flavoproteins which have been linked to the perception of electromagnetic stimuli in numerous organisms. These include sensing the direction of the earth's magnetic field in migratory birds and the intensity of magnetic fields in insects and plants. When exposed to light, cryptochromes undergo flavin reduction/reoxidation redox cycles leading to biological activation which generate radical pairs thought to be the basis for magnetic sensitivity. However, the nature of the magnetically sensitive radical pairs and the steps at which they act during the cryptochrome redox cycle are currently a matter of debate. Here, we investigate the response of Arabidopsis cryptochrome-1 in vivo to a static magnetic field of 500 μT (10 × earth's field) using both plant growth and light-dependent phosphorylation as an assay. Cryptochrome responses to light were enhanced by the magnetic field, as indicated by increased inhibition of hypocotyl elongation and increased cryptochrome phosphorylation. However, when light and dark intervals were given intermittently, a plant response to the magnetic field was observed even when the magnetic field was given exclusively during the dark intervals between light exposures. This indicates that the magnetically sensitive reaction step in the cryptochrome photocycle must occur during flavin reoxidation, and likely involves the formation of reactive oxygen species.

A Data Collection Form for Intensive Care Units

The rationale for development of a data collection form for intensive care units is discussed. The form developed in our ICU to facilitate entry of data into video terminals -which document the course of each ICU patient is described. Substantial time saving and reduction in error incidence are obtained, especially so with respect to the coding of diagnoses. The diagnoses and operations are recorded as free text within the constraint of a computer format. For all other data, coding is included as part of the data sheet.

Selective intraarterial fibrinolysis of acute central retinal artery occlusion

Purpose: To evaluate the outcome of our patients with central retinal artery occlusion after local fibrinolysis and to compare these data with results reported in the literature.

Material and Methods: Over a period of 7 years, 22 patients (11 male, 11 female, mean age 64.6 ± 12.1 years) were treated with super-selective local fibrinolysis. In 1 case, treatment was carried out via the maxillary-ophthalmic anastomoses due to preexisting occlusion of the ipsilateral internal carotid artery. The latency period from the onset of symptoms to the beginning of therapy was 7.6 ± 1.8 h. Urokinase was used in 7 cases (300,000–1.1 million units) and recombinant tissue plasminogen activator (20–40 mg) was applied in 15 patients. Visual acuity and fundus were examined before and after treatment.

Results: One patient (1/22 = 4.6%) recovered completely and regained a visual acuity of 20/20. Six patients (6/22 = 27.3%) showed a marked improvement with a range of visual outcome from 20/800 to 20/320. In 2 cases (2/22 = 9.1%) only a slight improvement was observed, with a visual outcome allowing detection of hand movements. In 13 cases (13/22 = 59.1%) no change in visual acuity as a result of treatment was observed. In 2/22 cases (9.2%) reversible neurological side-effects occurred, in 1 case suffered a stroke, and in another case intracerebral bleeding was observed.

Conclusion: In our study, the recovery of visual acuity and the complication rate were not as positive as reported in the literature.

Abstract P3-07-26: Biomarker comparison between androgen receptor – Positive-triple-negative breast cancer (AR+ TNBC) and quadruple-negative breast cancer (QNBC)

Background: Quadruple-negative breast cancer (QNBC) is a subgroup of triple-negative breast cancer (TNBC) that lacks androgen receptor (AR) expression. While TNBC patients with AR expression have shown a promising response to AR-targeted therapies, QNBC patients' treatment options remain limited, with no targeted therapy We investigated the biomarker profiles of large cohorts of AR+TNBC and QNBC to identify their molecular differences.

Method: TNBC tumors (defined as negative by IHC for ER, PR, Her2 and ISH for Her2) referred to Caris Life Sciences (Phoenix, AZ) between 2009 and 2015 were evaluated by board-certified pathologists with a combination of immunohistochemistry (AR, cKIT, cMET, EGFR, ER, ERCC1, Her2, MGMT, PD-1, PD-L1, PGP, PR, PTEN, RRM1, SPARC, TLE3, TOPO2A, TOPO1, TS and TUBB3), fluorescent/chromogenic in-situ hybridization (cMET, EGFR, Her2, TOP2A), and sequencing (Next-generation and Sanger). Tumors evaluated included a mix of primary tumors and metastases. QNBC tumors were defined as TNBC tumors that showed negative AR expression (<10% of cells staining).

Results: Among 2,071 TNBC tumors identified, 1,952 tumors had AR IHC performed, out of which 1,612 (83%) were QNBC and 340 (17%) were AR+ TNBC tumors. Tumor expression of PD-L1 (Ab: SP142, Spring Bioscience/130021, R&D Systems, cutoff used: 2+, 5%) was significantly higher in QNBC compared to AR+TNBC tumors (18% vs. 8%, p=0.01), while PD-1 (Ab: NAT105, Ventana) expression on tumor-infiltrating lymphocytes was comparable between the two cohorts (60% vs. 62%). QNBC tumors were significantly more likely to express proteins of cKIT (26% vs. 15%, p=0.01), EGFR (69% vs. 56%, p=0.03), TS (49% vs. 33%, p<0.0001) and TOPO2A (85% vs. 65%, p<0.0001) compared to AR+TNBC. TLE3 expression was significantly higher in AR+TNBC cohorts (48% vs. 32%, p<0.0001). Sequencing reveals that QNBC tumors carried significantly higher mutation rate of TP53 (71% vs. 55%, p<0.0001) while AR+TNBC tumors showed significantly higher mutation rates of PIK3CA (42% vs. 12%, p<0.0001), AKT1 (13% vs. 1%, p<0.0001) as well as ERBB2 (5% vs. 1%, p=0.0003).

Conclusion:

Biomarker comparisons between two molecular subgroups of the TNBC tumors confirm the molecular heterogeneity of this aggressive type of breast cancer. Our biomarker results suggests that for AR+TNBC tumors, future clinical trial design can consider fluoropyrimidines, taxanes, and agents targeting PI3K/AKT/mTOR pathway as well as pan-HER inhibitors, and those agents may be combined with anti-androgen therapies. On the other hand, clinical trials for immune checkpoint inhibitors, TOP2A inhibitors, as well as agents that target cKIT and EGFR should be considered for QNBC tumors. Our findings highlight the molecular differences that should be considered in the design of future clinical trial strategies, warranting further investigation for improving targeted therapy and outcomes in TNBC.

Citation Format: Xiu J, Obeid E, Gatalica Z, Reddy S, Goldstein LJ, Link J, Waisman J. Biomarker comparison between androgen receptor – Positive-triple-negative breast cancer (AR+ TNBC) and quadruple-negative breast cancer (QNBC). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-07-26.

Abstract P3-07-27: Distinct biomarker features in triple-negative breast cancer metastases to the brain, liver and bone

Background: Triple-negative breast cancer (TNBC) is characterized by its aggressive nature and accounts for a disproportionate number of metastatic disease cases and breast cancer-related deaths. Despite recent improvements, TNBC patients who develop metastatic diseases have limited treatment options. We investigated biomarkers from brain, liver and bone metastases collected from TNBC patients to identify therapeutic options and to examine molecular differences between the metastatic sites.

Method: Triple-negative breast cancer tumors referred to Caris Life Sciences (Phoenix, AZ) between 2009 and 2015 were tested with a combination of immunohistochemistry, fluorescent/chromogenic in-situ hybridization and sequencing (Next-generation and Sanger).

Result: 1570 TNBC tumors were analyzed, including 1297 tumors taken from breast, 54 from brain, 172 from liver and 47 from bone. Select biomarker frequencies of protein overexpression (IHC), gene amplification (ISH) and mutations (SEQ) are summarized in Table 1. Brain metastases showed the highest protein expression of TOPO2A and PDL1; liver metastases showed the highest expression of AR and SPARC, as well as the highest mutation rate of PIK3CA. Bone metastases showed the lowest expression of TS, RRM1 and ERCC1. BRCA1 and BRCA2 mutation rates ranged from 0-11% in various specimen sites.

Table 1Biomarker and MethodBreast Metastases (%)Brain Metastases (%)Liver Metastases (%)Bone Metastases (%)p value[pound]TOP2A IHC76100[sect]7339<0.0001PDL1 IHC1540[sect]8170.03AR IHC151036[sect]260.0005SPARC IHC173040[sect]150.0027PIK3CA SEQ165.329[sect]250.036TS IHC[dagger]49542415[sect]<0.0001RRM1 IHC[dagger]39433216[sect]0.006ERCC1 IHC[dagger]35554816[sect]0.002BRCA1 SEQ708n/ansBRCA2 SEQ11114n/ans[sect]:the group with the highest frequency of actionable results; [pound]:p values are calculated from comparing the group with the highest frequency with the lowest frequency using two tailed Fisher-Exact test, further detailed statistical analysis will be presented;[dagger]:low levels predict response to associated drugs; Ns: non-significant, i.e., p >0.05; n/a: data not available due to low N

Conclusion: Distinct biomarker features identified in different metastatic sites in TNBC present the rationale to investigate differential treatment strategies. Based on biomarker results, etoposide, immune-modulatory agents may seem promising for brain metastases; anti-androgen therapies and nab-paclitaxel may be promising in treating liver metastases; while fluoropyrimidines, gemcitabine and platinum may be considered for TNBC patients with bone metastases.

Citation Format: Xiu J, Gatalica Z, Reddy S, Waisman J, Link J. Distinct biomarker features in triple-negative breast cancer metastases to the brain, liver and bone. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-07-27.

Kinetic Modeling of the Arabidopsis Cryptochrome Photocycle: FADH(o) Accumulation Correlates with Biological Activity

Cryptochromes are flavoprotein photoreceptors with multiple signaling roles during plant de-etiolation and development. Arabidopsis cryptochromes (cry1 and cry2) absorb light through an oxidized flavin (FADox) cofactor which undergoes reduction to both FADH° and FADH(-) redox states. Since the FADH° redox state has been linked to biological activity, it is important to estimate its concentration formed upon illumination in vivo. Here we model the photocycle of isolated cry1 and cry2 proteins with a three-state kinetic model. Our model fits the experimental data for flavin photoconversion in vitro for both cry1 and cry2, providing calculated quantum yields which are significantly lower in cry1 than for cry2. The model was applied to the cryptochrome photocycle in vivo using biological activity in plants as a readout for FADH° concentration. The fit to the in vivo data provided quantum yields for cry1 and cry2 flavin reduction similar to those obtained in vitro, with decreased cry1 quantum yield as compared to cry2. These results validate our assumption that FADH° concentration correlates with biological activity. This is the first reported attempt at kinetic modeling of the cryptochrome photocycle in relation to macroscopic signaling events in vivo, and thereby provides a theoretical framework to the components of the photocycle that are necessary for cryptochrome response to environmental signals.

A phase 1, randomized, dose-ranging study of GS-5816, a once-daily NS5A inhibitor, in patients with genotype 1-4 hepatitis C virus

GS-5816 is an inhibitor of the hepatitis C virus (HCV) NS5A protein that has demonstrated pan-genotypic activity and a high barrier to resistance in HCV replicon assays. The aim of this study was to evaluate the safety, antiviral activity and pharmacokinetics of once-daily doses of GS-5816 in patients with genotype 1-4 HCV infection. Patients with genotype 1-4 HCV infection were randomized to 3 days of GS-5816 at doses ranging from 5 to 150 mg or placebo. Adverse events were recorded, and plasma samples obtained for analysis of pharmacokinetics, HCV RNA and NS5A sequencing studies. GS-5816 5-150 mg for 3 days was well tolerated and resulted in rapid declines in HCV RNA that were sustained over the dosing period. In patients treated with the 150 mg dose of GS-5816, the mean maximal HCV RNA declines were 4.0, 4.0, 4.4, 3.3 and 3.5 log10 IU/mL in patients with genotype 1a, 1b, 2, 3 and 4 HCV infection, respectively. Pretreatment NS5A resistance-associated polymorphisms were detected in 31% (22/70) of patients. Genotype 1 and 3 HCV-infected patients without pretreatment NS5A resistance-associated polymorphisms had greater declines in HCV RNA than patients with resistance-associated polymorphisms. Plasma pharmacokinetics were supportive of once-daily dosing. GS-5816 demonstrated pangenotypic antiviral activity in patients with genotype 1-4 HCV infection. It will be further evaluated in combination with other pangenotypic direct-acting antivirals to achieve the goal of developing a well-tolerated, highly effective treatment for all HCV genotypes.

Cellular metabolites modulate in vivo signaling of Arabidopsis cryptochrome-1

Cryptochromes are blue-light absorbing flavoproteins with multiple signaling roles. In plants, cryptochrome (cry1, cry2) biological activity has been linked to flavin photoreduction via an electron transport chain to the protein surface comprising 3 evolutionarily conserved tryptophan residues known as the 'Trp triad.' Mutation of any of the Trp triad residues abolishes photoreduction in isolated cryptochrome protein in vitro and therefore had been suggested as essential for electron transfer to the flavin. However, photoreduction of the flavin in Arabidopsis cry2 proteins occurs in vivo even with mutations in the Trp triad, indicating the existence of alternative electron transfer pathways to the flavin. These pathways are potentiated by metabolites in the intracellular environment including ATP, ADP, AMP, and NADH. In the present work we extend these observations to Arabidopsis cryptochrome 1 and demonstrate that Trp triad substitution mutants at W400F and W324F positions which are not photoreduced in vitro can be photoreduced in whole cell extracts, albeit with reduced efficiency. We further show that the flavin signaling state (FADH°) is stabilized in an in vivo context. These data illustrate that in vivo modulation by metabolites in the cellular environment may play an important role in cryptochrome signaling, and are discussed with respect to possible effects on the conformation of the C-terminal domain to generate the biologically active conformational state.

Consequences of early chilling stress in two Triticum species: plastic responses and adaptive significance

Phenotypic plasticity of two primitive wheat species (Triticum monococcum L. and Triticum dicoccum S.) was studied in response to early chilling stress. Selection pressure differentials, gradients and plasticity costs on plant morphogenesis, growth and reserve carbohydrate consumption were estimated. Regression analysis was applied to investigate differential developmental changes and patterns between treatments. Four-day-old seedlings of T. monococcum and T. dicoccum, differing in plant stature and reserve carbohydrates, were given an early chilling temperature (4 °C for 42 day) and compared with control plants grown at 23 °C. Early chilling stress resulted in a significant increase in leaf mass ratio (LMR) and relative growth rate (RGR), a reduction in flag leaf size, total biomass, specific leaf area (SLA) and reserve carbohydrate storage at flowering, together with advanced onset of flowering. Selection pressure within the early chilling environment favoured early flowering, smaller SLA, higher LMR and lower reserve carbohydrates, suggesting the observed responses were adaptive. Furthermore, a regression of daily cumulative plant biomass derived from a crop growth simulation model (CERES-Wheat) on crop vegetation period revealed a divergent developmental pattern in early-chilled plants. Using selection pressure gradient analysis, we found similar responses among these traits, except for SLA and sucrose, indicating that these two traits have indirect effects on fitness. Thus, the total effects of SLA and reserve sucrose on relative fitness seem to be buffered via the rapid growth rate in chilled plants. While lower SLA may reduce early chilling stress effects at an individual leaf level, a higher LMR and use of reserve carbohydrates indicated that compensatory growth of chilled plants during the recovery period relied on the concerted action of altered resource allocation and reserve carbohydrate consumption. However, a significant cost of plasticity was evident only for flowering time, LMR and fructan levels in the early chilling environment. Our results demonstrate that morphological and intrinsic developmental (ontogenetic) patterns in two Triticum species respond to early chilling stress.

An open-label expanded access study of lapatinib and capecitabine in patients with HER2-overexpressing locally advanced or metastatic breast cancer

BACKGROUND

The Lapatinib Expanded Access Program (LEAP) was designed to provide access to lapatinib plus capecitabine for HER2-positive metastatic breast cancer patients who previously received an anthracycline, a taxane, and a trastuzumab and had no other treatment options.

PATIENTS AND METHODS

LEAP opened globally and enrollment continued until lapatinib received regulatory approval in each participating country. Patients were assessed for progression-free survival (PFS) and overall survival (OS) and monitored for serious adverse events (SAEs).

RESULTS

As of 30 September 2008, 4283 patients from 45 countries enrolled in LEAP. The median treatment duration was 24.7 weeks. The most common drug-related SAEs were diarrhea (9.7%), vomiting (4.3%), and nausea (2.4%) and were mainly grade 3 or higher. The incidences of special interest SAEs were decreased left ventricle ejection fraction (0.5%), interstitial lung disease/pneumonitis (0.2%), and serious hepatobiliary events (0.4%). This safety profile is consistent with the overall lapatinib program. The median PFS and OS were 21.1 [95% confidence interval (CI) = 20.1-22.3] and 39.6 (95% CI = 37.7-40.7) weeks, respectively (n = 4006). Subgroup analysis showed longer PFS and OS in patients who had not received prior capecitabine.

CONCLUSIONS

These results demonstrate the safety and efficacy of lapatinib in a broader patient population compared with a clinical trial.

Sources of referral to early phase clinical trials: a case for putting all your eggs in one basket

Abstract #3116

Background: Studies suggest that only 2% to 3% of all adult cancer patients and approximately 5% of breast cancer patients enroll in clinical trials. To better understand the factors that contribute to enrollment we collected data from patients on sources that prompted them to contact us.
 Methods: From Jan 2005 to Apr 2008 we screened nearly 400 patients for 8 Phase I/II clinical trials focused on immunotherapy of breast and ovarian cancer. We queried subjects about informational sources that led them to consider our clinical studies. Patients learned about our trials from sources including: Clinicians, the Internet (advocacy group websites, search engines, government/university sites), Other patients, Family/friends, Media, Community events and Postings seeking research participants. Many patients who cited a clinician as their referral source specifically referenced a private, multi-site breast cancer clinic in Southern California with which our clinical group has formed a partnership, or consortium. To ensure that this was represented in the data and because the clinician category comprised a large percentage of the referral sources we split the category into 2 groups-one being the private practice in California (to be referred to as “consortium”) and the other being all other clinicians.
 Results: Of the 399 patients screened, 336 (84%) were considered potentially eligible for study. A total of 72 patients, or 18% of those screened have enrolled in one of our trials to date.
 Among patients screened, most learned about our trials from clinicians outside the consortium (34%), the Internet (27%), and consortium clinicians (15%). Patients most often named her2support.org (35%) and clinicaltrials.gov (23%) as their specific Internet sources. The remaining sources, family/friends, patients, media sources, community events and postings in medical facilities, were each cited by <5% of patients.
 Although consortium clinicians were responsible for only 15% of referrals, 50% of their referrals enrolled in a study. Only 16% of patients referred by other clinicians and 9% referred via the Internet were enrolled. Though other clinicians and the Internet are the most common referral sources, referrals from our consortium were significantly more likely to enroll than any other source (p<0.001).
 This may be due to the fact that patients referred by the consortium were more likely to meet eligibility criteria. Relative to 93% of consortium referrals, 87% of other clinician and 79% of Internet referrals were potentially eligible for trial (p<0.05). Patients referred by our consortium were significantly more likely to meet study criteria relative to those referred by other sources.
 Discussion: Physician referrals often lead to higher accrual to clinical trials relative to other referral sources. Our data reveal that accrual can be further improved by forming a close collaborative relationship with a single select practice of clinicians.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3116.

Risk assessment in high grade sarcoma patients during neoadjuvant chemotherapy using multiple tracer PET

20006

Background: Patients with high grade soft tissue sarcomas are treated with neoadjuvant chemotherapy. Sarcomas have biological features that may predict for poor outcome. Some of these features are tumor proliferation rate, level of tumor hypoxia, and upregulation of tumor drug resistance mechanisms. Methods: We have a group of specific PET imaging agents to quantify the level of activity of these tumor processes. Patients with soft tissue sarcomas receive [C-11]Thymidine (TdR) to assess cellular proliferation, [O-15] Water to quantify tumor blood flow and to serve as the input function for quantification of the other tracers, [C-11]Verapamil to assess drug resistance mechanism activity, and [F-18]Fluoromisonidazole) FMISO to quantify changes in tumor hypoxic volume in response to treatment. These studies are performed in a single PET imaging session prior to neoadjuvant chemotherapy, after the second of four cycles of therapy and in the week prior to resection. Results: An example of this complex study result, is demonstrated by a recent patient with a high grade soft tissue sarcoma. The tumor showed increased TdR uptake, a moderate hypoxic volume, and [C-11] verapamil uptake prior to initiation of neoadjuvant adriamycin based chemotherapy. After 2 cycles of therapy, there was a significant decrease in the maximum level and volume of TdR uptake and a large reduction in tumor hypoxic volume. Conclusions: These data would imply a high risk soft tissue sarcoma due the presence of increased cellular proliferation, a significant hypoxic volume and the absence of p-glycoprotein activity determined by the presence of [C-11]Verapamil uptake. However, early response is also suggested by the findings above. Patient outcome will be assessed and correlated with these tumor parameters to further understand what tumor biological risk factors can be quantified non-invasively and repeated throughout the clinical course in soft tissue sarcoma patients. Supported by NIH NCI PO1 42045–18 and S10 RR017229–01

[Table: see text]

No significant financial relationships to disclose.

Elevated expression and genetic association links the SOCS3 gene to atopic dermatitis

In a systematic analysis of global gene-expression patterns, we found that SOCS3 messenger RNA was significantly more highly expressed in skin from patients with atopic dermatitis than in skin from healthy controls, and immunohistochemical analysis confirmed a similar elevation of SOCS3 protein. Furthermore, we found a genetic association between atopic dermatitis and a haplotype in the SOCS3 gene in two independent groups of patients (P<.02 and P<.03). These results strongly suggest that SOCS3, located in a chromosomal region previously linked to the disease (17q25), is a susceptibility gene for atopic dermatitis.

Renal effects of gadopentetate dimeglumine in patients with normal and impaired renal function

Gadolinium chelates are widely used in magnetic resonance imaging as contrast medium in patients with nephropathy. However, only few studies have investigated the effect of gadolinium on serum creatinine concentration and estimated GFR as surrogate markers of renal function. This study was performed to evaluate the effect of gadopentetate dimeglumine in a dose sufficient for diagnostic and interventional purposes on renal function in a large sample of patients. We analyzed serum creatinine and serum-urea levels before and after the administration of gadopentetate dimeglumine in patients with normal and patients with pre-existing impaired renal function. Age, height, body mass, sex, medication and preexisting illnesses such as diabetes, renal artery stenosis and heart disease were monitored. In 181 patients with normal renal function, there was no statistically significant change in serum creatinine concentration after the administration of gadopentetate dimeglumine (at baseline: 0.72 +/- 0.18 mg/dl, after gadolinium: 0.73 +/- 0.22 mg/dl). In contrary, serum creatinine levels decreased significantly after the administration of gadolinium in 198 patients with pre-existing renal impairment (1.82 +/- 1.03 mg/dl before and 1.72 +/- 1.03 mg/dl after gadolinium) (p < 0.01). According to this surrogate marker of renal function, the change of estimated GFR in patients with normal baseline renal function was not significant, while in patients with impaired renal function, GFR increased after the administration of gadolinium (p < 0.001). The high diagnostic value of gadolinium contrast media is associated with a very small risk of adverse reactions. Our findings show that the administration of gadolinium even is associated with a decrease of serum creatinine in patients with pre-existing renal impairment. In conclusion, the use of gadolinium-based contrast media may be considered as a safe alternative in patients with impaired renal function for whom use of iodine-based contrast agents is prone to a high rate of radiocontrast-induced nephropathy.

Clinical and angiographic outcome after interventional treatment of the iliac arteries with a new carbofilm coated stent: preliminary results

PURPOSE

To evaluate the handling, the procedural success rate and the six-month outcome of a new Carbofilm coated balloon-expandable stent in iliac artery lesions.

MATERIALS AND METHODS

In a prospective study, 46 stenoses and 2 occlusions of the iliac arteries were primarily stented in 30 patients with the Isthmus CarboStent (Sorin Biomedica Cardio S.p. A., Saluggia, Italy). The ankle-brachial index (ABI) at rest was determined before intervention and at the six-month follow-up visit. Iliac angiography, including intraarterial pressure measurement, was performed before intervention, post-procedurally and at the follow-up visit.

RESULTS

All lesions were treated with procedural success. The mean degree of all stenoses was 73.9 % +/- 14.6 before and 2.4 % +/- 8.2 after intervention. The mean pressure gradient was 15.6 mm Hg +/- 10.1 before and 2.5 mm Hg +/- 2.7 after treatment. No or only a mild restenosis developed in 27 patients. The mean ABI increased from 0.64 +/- 0.21 to 0.86 +/- 0.33 and the mean pressure gradient was 2.7 mm Hg +/- 5.4 at the six-month visit. The six-month patency rate was 97.9 %. Three patients showed acute stent thrombosis due to an insufficient postprocedural antiplatelet regimen.

DISCUSSION

The Isthmus CarboStent is a safe and easy to handle balloon-expandable stent for interventional therapy of iliac artery lesions. The six-month patency rate is good. Despite its Carbofilm coating, postprocedural antiplatelet therapy is necessary.