Whole blood-derived miRNA profiles as potential new tools for ovarian cancer screening

BACKGROUND

Screening is an unsolved problem for ovarian cancer (OvCA). As late detection is equivalent to poor prognosis, we analysed whether OvCA patients show diagnostically meaningful microRNA (miRNA) patterns in blood cells.

METHODS

Blood-borne whole miRNome profiles from 24 patients with OvCA and 15 age- and sex-matched healthy controls were biostatistically evaluated.

RESULTS

Student's t-test revealed 147 significantly deregulated miRNAs before and 4 after Benjamini-Hochberg adjustment. Although these included miRNAs already linked to OvCA (e.g., miR-16, miR-155), others had never before been connected to specific diseases. A bioinformatically calculated miRNA profile allowed for discrimination between blood samples of OvCA patients and healthy controls with an accuracy of >76%. When only cancers of the serous subtype were considered and compared with an extended control group (n=39), accuracy, specificity and sensitivity all increased to >85%.

CONCLUSION

Our proof-of-principle study strengthens the hypothesis that neoplastic diseases generate characteristic miRNA fingerprints in blood cells. Still, the obtained OvCA-associated miRNA pattern is not yet sensitive and specific enough to permit the monitoring of disease progression or even preventive screening. Microarray-based miRNA profiling from peripheral blood could thus be combined with other markers to improve the notoriously difficult but important screening for OvCA.

Pharmacokinetics of thalidomide in patients with impaired renal function and while on and off dialysis

There is a renewed interest in thalidomide for use in malignancies and systemic inflammatory diseases. Reduced renal function is not uncommon among patients with these disease states but the pharmacokinetics has not been fully investigated. The aim of this study was to investigate the pharmacokinetics of thalidomide in haemodialysis patients while on and off dialysis and in myeloma patients with varying degrees of renal function.

Two studies were performed. To establish the pharmacokinetics of thalidomide in patients with mild to moderate renal failure, blood samples were taken over 12 weeks from 40 patients with multiple myeloma. A second study was performed in six patients with end-stage renal disease both on a non-dialysis day and before and during a haemodialysis session. Thalidomide concentration was determined by HPLC. A one-compartment open model with first-order absorption and elimination was used to fit total thalidomide concentration to population pharmacokinetics and statistical models using the NONMEM program. Clearance and volumes were slightly below 10 L h−1 and 1 L kg−1, respectively, in both patient groups. The inter- and intra-patient variability was low. Clearance was doubled during dialysis. There was no correlation between thalidomide clearance and renal function. In conclusion, the pharmacokinetics of thalidomide in patients with renal failure are very similar to values reported by others for patients with normal renal function. Although clearance during dialysis is doubled, thalidomide dose need not be changed for patients with decreased kidney function. There is also no need for a supplementary dose due to haemodialysis.

Evaluation of the accuracy of FDG-/FLT-PET for early prediction of non-progression in patients with advanced non-small cell lung cancer (NSCLC) treated with erlotinib

e19054

Background: EGFR mutations predict response to erlotinib treatment in advanced NSCLC. However, also a subgroup of patients with wildtype EGFR benefits from erlotinib treatment. This subgroup could not yet be defined by molecular means. In this trial we set out to prospectively evaluate the accuracy of [18F]FDG-/[18F]FLT-PET analyses for early prediction of non-progression in chemo-naive patients with advanced NSCLC treated with erlotinib. Methods: Patients with NSCLC stage IIIB/IV without prior systemic treatment for NSCLC were eligible and treated for 6 weeks with erlotinib in this single centre diagnostic pilot trial. Primary endpoint was the accuracy of [18F]FDG/18F[FLT] PET after 1 week of treatment to predict non-progression as defined by RECIST criteria in CT scans after 6 weeks of treatment. Here we present the evaluation of 20 patients of this ongoing trial in accordance with the data monitoring board (EudraCT number 2005–005393–73; NCT00568841 ). Results: Twenty patients were recruited from 9/07 to 9/08. Seventeen patients were eligible for final analysis. The AUC for [18F]FDG PET at week 1 to predict non-progression was 0.857 ±0.105 (p=0.013) and 0.643±0.137 (p=0.32) for [18F]FLT PET. Using [18F]FDG PET specificity was 1 and sensitivity 0.71 for prediction of non- progression after six weeks (p=0.006 Fishers exact). In addition, [18F]FDG PET after 1 week of treatment clearly predicted tumor non- progression after 18 weeks of treatment with a predefined cut-off of -20% change in sSUVmax. (p=0.0004, Fisher´s exact). Finally, using this cut-off value [18F]FDG-PET after one week of treatment, predicted progression free survival (p=0.001, log rank test), with differences in median PFS of 45 days vs 320 days. Using univariable Cox regression, both [18F]FDG and [18F]FLT PET predicted PFS [hazard ratio 2.1 (p=0.006, Wald test) and 2.3 (p=0.011), respectively, per standard deviation]. Conclusions: Our observations indicate that early [18F]FDG but not [18F]FLT PET analysis predicts non-progression after 6 weeks of first-line erlotinib treatment in patients with advanced NSCLC. In addition, early [18F]FDG PET predicts non-progression after 18 weeks of treatment and progression free survival.

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Wearable devices for emerging healthcare applications

Today's quality of life is supported by medical capabilities that have not been available years ago. These capabilities are not limited to disease treatment only, indeed there has been a paradigm shift to disease prevention and monitoring. Especially continuous monitoring of patients or even of people who are only interested in their health has received increasing interest. Thus, the need and the potential to miniaturize lab-scale monitoring devices have inspired many research projects and start-up companies to create new or to miniaturize medical applications. Challenges in this area comprise low-power/power saving design to extend battery life and to reduce the size of the battery itself. This is followed by size/height/weight reductions to meet user expectations of being "wearable", biocompatibility of all outer housings, and the final assembly concept. Instead of using a sequential design approach, the complexity mandates to handle all aspects concurrently as early as possible in the design phase. Already during this design phase HDP (high-density packaging) technologies help to meet the size requirements without sacrificing too much flexibility and violating time/cost constraints. This paper will present two miniaturization design strategies, considerations and solutions for two novel medical applications in the health monitoring area.

Revisiting the structure of the p(4 x 4) surface oxide on Ag(111)

Scanning tunneling microscopy (STM) and density-functional theory are used to reexamine the structure of the renowned p(4 x 4)-O/Ag(111) surface oxide. The accepted structural model [C. I. Carlisle, Phys. Rev. Lett. 84, 3899 (2000)10.1103/PhysRevLett.84.3899] is incompatible with the enhanced resolution of the current STM measurements. An "Ag6 model" is proposed that is more stable than its predecessor and accounts for the coexistence of the p(4 x 4) and a novel c(3 x 5log3)rect phase. This coexistence is an indication of the dynamic complexity of the system that until now has not been appreciated.

Wearable devices for telemedicine applications

Wearable medical devices can provide both continuous monitoring and ubiquitous treatment. Challenges in this area include the need for a low-power/power-saving design to extend battery life and to reduce the size of the battery itself. This is followed by size and weight restrictions to meet patient expectations of what is 'wearable', the biocompatibility of all outer housings and the final assembly concept. Two examples of wearable medical device are described: a wrist-wearable telemedicine monitor for heart patients (AMON) and a generic belt-integrated computing platform for home and hospital use (QBIC). The electrocardiogram (ECG), the blood oxygen saturation (SpO2) sensor and the blood pressure meter of the AMON device were tested with 29 subjects. The sensors were found to be functional, but as expected the data processing algorithms will need some fine-tuning. The prototype QBIC demonstrates a size reduction of 30-50% in relation to comparable devices.

Der Einfluss des kontinuierlich positiven Atemwegsdruckes (CPAP) auf die Blutflussgeschwindigkeit im venösen Leberstromgebiet - duplexsonographische Untersuchungen

OBJECTIVE

In the last years, noninvasive techniques of artificial ventilation like continuous positive airway pressure (CPAP) have become more and more important. However, the effects of such procedures on the circulation of the hepatosplanchnic area are, except for the indocyanine green plasma clearance, not yet representative by means of noninvasive investigation methods.

METHODS

We studied maximum blood flow velocity in defined areas of hepatic and portal veins by duplex ultrasonography in 20 healthy volunteers (12 male, 8 female; age: 24,7 +/- 4,7 years [mean +/- SD]) before, during and after application of CPAP (10 cm H(2)O). As many measurements as possible were taken in both vascular systems. After division into five minute intervals arithmetical mean values were calculated for each interval. The experiment was divided into a control interval ("before CPAP"), three "CPAP" intervals and finally two "after CPAP" intervals. Heart rate and blood pressure were taken at the beginning of these intervals.

RESULTS

Compared with the control interval, maximum blood flow velocity in the area of the hepatic vein decreased significantly by 13,2 %, 16,8 % and 15,7 % (p < or = 0,001 in each case) during each of the three "CPAP" periods. In the portal venous area blood flow velocity decreased by 4,3 %, 8,8 % and 7,0 %, respectively, with a significant decrease only in the second "CPAP" interval (p < or = 0,005). After CPAP, changes returned to baseline within a few minutes. Heart rate and blood pressure showed no significant differences during the whole experiment.

CONCLUSION

Parameters taken in both venous vascular areas of the liver show clear correspondence with the results of former studies, which have been determined by means of more invasive investigation methods. Maximum blood flow velocity seems to be useful for monitoring liver blood flow and its individual time course during CPAP, noninvasively and semiquantitatively. Further trials under conditions of controlled mechanical ventilation should be performed to optimize ventilation strategies for the critically ill.

Jahn-Teller stabilization of a "polar" metal oxide surface: Fe3O4(001)

Using ab initio thermodynamics we compile a phase diagram for the surface of Fe3O4(001) as a function of temperature and oxygen pressures. A hitherto ignored polar termination with octahedral iron and oxygen forming a wavelike structure along the [110] direction is identified as the lowest energy configuration over a broad range of oxygen gas-phase conditions. This novel geometry is confirmed via x-ray diffraction analysis. The stabilization of the Fe3O4(001) surface goes together with dramatic changes in the electronic and magnetic properties, e.g., a half metal to metal transition.

Structure determination of small vanadium clusters by density-functional theory in comparison with experimental far-infrared spectra

The far-infrared vibrational spectra for charged vanadium clusters with sizes of 3-15 atoms have been measured using infrared multiple photon dissociation of Vn+Ar-->Vn(+)+Ar. Using density-functional theory calculations, we calculated the ground state energy and vibrational spectra for a large number of stable and metastable geometries of such clusters. Comparison of the calculated vibrational spectra with those obtained in the experiment allows us to deduce the cluster size specific atomic structures. In several cases, a unique atomic structure can be identified, while in other cases our calculations suggest the presence of multiple isomers.

Atomic structure of the GaAs(001)-c(4x4) surface: first-principles evidence for diversity of heterodimer motifs

The GaAs(001)-c(4x4) surface was studied using ab initio atomistic thermodynamics based on density-functional theory calculations. We demonstrate that in a range of stoichiometries, between those of the conventional three As-dimer and the new three Ga-As-dimer models, there exists a diversity of atomic structures featuring Ga-As heterodimers. These results fully explain the experimental scanning tunneling microscopy images and are likely to be relevant also to the c(4x4)-reconstructed (001) surfaces of other III-V semiconductors.

Kinetic hindrance during the initial oxidation of Pd(100) at ambient pressures

The oxidation of the Pd(100) surface at oxygen pressures in the 10(-6) to 10(3) mbar range and temperatures up to 1000 K has been studied in situ by surface x-ray diffraction (SXRD). The results provide direct structural information on the phases present in the surface region and on the kinetics of the oxide formation. Depending on the (T,p) environmental conditions, we observe either a thin (sqrt[5]xsqrt[5])R27 degrees surface oxide or the growth of a rough, poorly ordered bulk oxide film of PdO predominantly with (001) orientation. By either comparison to the surface phase diagram from first-principles atomistic thermodynamics or by explicit time-resolved measurements we identify a strong kinetic hindrance to the bulk oxide formation even at temperatures as high as 675 K.

Geniom technology--the benchtop array facility

Febit AG develops an integrated benchtop instrument for in situ microarrays preparation, hybridization, readout and data analysis.

Non-arrhenius behavior of the island density in metal heteroepitaxy: Co on Cu(001)

We present a combined theoretical and experimental study of island nucleation and growth in the deposition of Co on Cu(001)-a prototype for understanding heteroepitaxial growth involving intermixing. Experimentally, ion scattering is employed. Using density-functional theory, we obtain energy barriers for the various elementary processes and incorporate these into a kinetic Monte Carlo program to simulate the heteroepitaxial growth. Both the simulations and the experiments show a unique N-shape dependence of the island density on temperature that stems from the interplay and competition of the different processes involved.