Novel calibration tools and validation concepts for microarray-based platforms used in molecular diagnostics and food safety control

Commercial platforms consisting of ready-to-use microarrays printed with target-specific DNA probes, a microarray scanner, and software for data analysis are available for different applications in medical diagnostics and food analysis, detecting, e.g., viral and bacteriological DNA sequences. The transfer of these tools from basic research to routine analysis, their broad acceptance in regulated areas, and their use in medical practice requires suitable calibration tools for regular control of instrument performance in addition to internal assay controls. Here, we present the development of a novel assay-adapted calibration slide for a commercialized DNA-based assay platform, consisting of precisely arranged fluorescent areas of various intensities obtained by incorporating different concentrations of a "green" dye and a "red" dye in a polymer matrix. These dyes present "Cy3" and "Cy5" analogues with improved photostability, chosen based upon their spectroscopic properties closely matching those of common labels for the green and red channel of microarray scanners. This simple tool allows to efficiently and regularly assess and control the performance of the microarray scanner provided with the biochip platform and to compare different scanners. It will be eventually used as fluorescence intensity scale for referencing of assays results and to enhance the overall comparability of diagnostic tests.

Competitive mode and site of interaction of ticagrelor at the human platelet P2Y12 -receptor

BACKGROUND

The G-protein-coupled P2Y12 -receptor plays a crucial role in platelet aggregation. Recently, ticagrelor was licensed as the first perorally active and reversible P2Y12 -receptor antagonist.

OBJECTIVE

The present study investigated the site and the antagonistic mode of action of ticagrelor at wild-type or mutant human P2Y12 -receptors.

METHODS

Recombinant wild-type or mutant human P2Y12 -receptors were stably expressed in Chinese hamster ovary Flp-In cells. Receptor function was assessed by quantification of ADP- and 2-methylthio-ADP-mediated inhibition of forskolin-induced cellular cAMP production either using a [(3) H]cAMP-radioaffinity assay or a cAMP response element-driven luciferase reporter gene assay.

RESULTS

The natural agonist ADP inhibited forskolin-induced cAMP formation at the wild-type P2Y12 -receptor with a lower potency (EC50 209 nm) than the synthetic agonist 2-methylthio-ADP (EC50 1.0 nm). Ticagrelor shifted the concentration-response curves of both agonists in a parallel and surmountable manner to the right. Increasing concentrations of ticagrelor caused increasing shifts. Schild-plot analysis revealed pA2 values of 8.85 for ticagrelor against ADP, and 8.69 against 2-methylthio-ADP, and slopes of the regression lines not different from unity. In cells expressing a recombinant C194A(5.43) -mutant P2Y12 -receptor construct, ticagrelor lost antagonistic potency when tested against ADP or 2-methylthio-ADP.

CONCLUSIONS

The experiments reveal a surmountable and competitive mode of antagonism of ticagrelor at P2Y12 -receptors activated by either the natural agonist ADP or the synthetic agonist 2-methylthio-ADP. Cys194(5.43) is likely to be involved in the interaction of ticagrelor with ADP and 2-methylthio-ADP. The data give new insights into the site and mode of action of ticagrelor at the human P2Y12 -receptor.

Core body temperature is not a reliable parameter to follow the reproductive cycle in female marmoset monkey (<i>Callithrix jacchus</i>)

Abstract. Marmosets represent an attractive and widely used animal species in biomedical research, and the routine monitoring of female reproductive cycles is often mandatory in the fields of reproductive biology and stem cell research. Today, the established method for the reliable detection of ovulation is the determination of progesterone concentrations from blood samples. This method is based on relatively frequent handling and blood collections; therefore, less invasive alternatives would help to reduce stress on the animals. Here, we investigated whether the core body temperature of marmosets would show a correlation with cycle-dependent hormonal fluctuations, as has been described for humans and other primate species. In particular, the objective was to investigate whether the telemetric recording of core body temperature could replace progesterone measurements as a reliable, less invasive method for the detection of ovulation in these animals. Here we show that the core body temperature parameters in female marmosets were characterized by frequent variations, but they were not related to particular days or phases during the reproductive cycle. Therefore, the recording of core body temperature in our controlled standard experimental setting is not an appropriate method to monitor the reproductive cycle in female marmosets, and cannot replace serum progesterone measurement as a state-of-the-art method.

Dual regulation of β2-adrenoceptor messenger RNA expression in human lung fibroblasts by β2-cAMP signaling; delayed upregulated inhibitors oppose a rapid in onset, direct stimulation of gene expression

Based on their bronchodilatory effect, β2-adrenoceptor agonists constitute essential elements in the treatment of bronchial asthma and COPD. As treatment with β2-adrenoceptor agonists has been associated with worsening of airway hyper-reactivity, possibly because of loss of β-adrenoceptor function, molecular mechanism of the regulation of β2-adrenoceptor expression were studied. MRC-5 human lung fibroblasts were cultured in absence or presence of test substances followed by β2-adrenoceptor messenger RNA (mRNA) determination by qPCR. After inhibition of mRNA synthesis by actinomycin D, β2-adrenoceptor mRNA decreased with a half-life of 23 min, whereas inhibition of protein synthesis by cycloheximide caused an about 5- and 6-fold increase within 1.5 and 4 h, respectively. β2-Adrenoceptor mRNA was increased by about 100 % after 1 h exposure to formoterol or olodaterol but decreased by about 60 % after 4 h agonist exposure. Both effects of β2-adrenoceptor agonists were mimicked by forskolin, a direct activator of adenylyl cyclase and cholera toxin, which stimulates adenylyl cyclase by permanent activation of Gs. β2-Adrenoceptor agonist-induced upregulation of β2-adrenoceptor mRNA was blocked by the β2-adrenoceptor antagonist ICI 118551 and prevented by actinomycin D, but not by cycloheximide. Moreover, in presence of cycloheximide, β2-adrenoceptor agonist-induced reduction in β2-adrenoceptor mRNA was converted into stimulation, resulting in a more than 10-fold increase. In conclusion, expression of β2-adrenoceptors in human lung fibroblasts is highly regulated at transcriptional level. The β2-adrenoceptor gene is under strong inhibitory control of short-living suppressor proteins. β2-Adrenoceptor activation induces via adenylyl cyclase - cyclic adenosine monophosphate (cAMP) signaling a rapid in onset direct stimulation of the β2-adrenoceptor gene transcription, an effect opposed by a delayed upregulation of inhibitory factors.

Femtosecond X-ray-induced explosion of C60 at extreme intensity

Understanding molecular femtosecond dynamics under intense X-ray exposure is critical to progress in biomolecular imaging and matter under extreme conditions. Imaging viruses and proteins at an atomic spatial scale and on the time scale of atomic motion requires rigorous, quantitative understanding of dynamical effects of intense X-ray exposure. Here we present an experimental and theoretical study of C60 molecules interacting with intense X-ray pulses from a free-electron laser, revealing the influence of processes not previously reported. Our work illustrates the successful use of classical mechanics to describe all moving particles in C60, an approach that scales well to larger systems, for example, biomolecules. Comparisons of the model with experimental data on C60 ion fragmentation show excellent agreement under a variety of laser conditions. The results indicate that this modelling is applicable for X-ray interactions with any extended system, even at higher X-ray dose rates expected with future light sources.

EPR-Untersuchung der g-Faktoren und Chlor-Hyperfeinstrukturen von gelösten aliphatischen Radikalen

For a series of alkyl radicals we have measured the electron g factors and hfs splitting constants by EPR methods. The isotropic chlorine hfs constants are discussed in terms of the Karplus-Fraenkel formula αCl=QCCl Cl Qc. The results indicate that QCl = Δ (Cl) QC π with Δ (Cl) =0.16. From this and Fischer’s Δ (Xi) parameters for the other substituents, effective σ-π-parameters could be determined to be

There exists a proportional relationship between the g factor shift ΔgCl due to chlorine substituents and Cl Σ QCl π from which ΔEn→π Cl =15.6·103 cm-1 was determined. CI

Efficacy, patient-reported outcomes and safety profile of ATX-101 (deoxycholic acid), an injectable drug for the reduction of unwanted submental fat: results from a phase III, randomized, placebo-controlled study

Background

Unwanted submental fat (SMF) may result in an unattractive chin profile and dissatisfaction with appearance. An approved and rigorously tested non-surgical method for SMF reduction is lacking.

Objective

To evaluate the efficacy and safety of ATX-101 for the pharmacological reduction of unwanted SMF in a phase III randomized, double-blind, placebo-controlled study.

Methods

Patients (n = 360) with moderate or severe SMF were randomized to receive ATX-101 1 or 2 mg/cm² or placebo injected into their SMF for up to four treatments ∼28 days apart, with a 12-week follow-up. Coprimary efficacy endpoints were the proportions of treatment responders, defined as a ≥1-point reduction in SMF on the Clinician-Reported Submental Fat Rating Scale (CR-SMFRS), and those satisfied with their appearance in association with their face and chin after treatment on the Subject Self-Rating Scale (SSRS score ≥4). Secondary efficacy endpoints included a ≥1-point improvement in SMF on the Patient-Reported Submental Fat Rating Scale (PR-SMFRS) and changes in the Patient-Reported Submental Fat Impact Scale (PR-SMFIS). Additional patient-reported outcomes and changes in the Skin Laxity Rating Scale were recorded. Adverse events (AEs) and laboratory test results were monitored.

Results

Compared with placebo, a greater proportion of patients treated with ATX-101 1 and 2 mg/cm² showed a ≥1-point improvement in CR-SMFRS (58.3% and 62.3%, respectively, vs. 34.5% with placebo; P < 0.001) and patient satisfaction (SSRS score ≥4) with the appearance of their face and chin (68.3% and 64.8%, respectively, vs. 29.3%; P < 0.001). Patient-reported secondary efficacy endpoints showed significant improvements in SMF severity (PR-SMFRS; P = 0.009 for ATX-101 1 mg/cm², P < 0.001 for ATX-101 2 mg/cm² vs. placebo) and emotions and perceived self-image (PR-SMFIS; P < 0.001). No overall worsening of skin laxity was observed. AEs were mostly transient, mild to moderate in intensity and localized to the treatment area.

Conclusion

ATX-101 was effective and well tolerated, and may be an alternative to surgery for patients desiring improvement of their submental profile.

Genetische Diagnostik und Beratung bei Arthrogryposis

Es werden wichtige Probleme in der Diagnostik bei Patienten mit Arthrogryposis dargestellt und Definitionen eingeführt. Danach werden praktische Ansätze für die Diagnostik und humangenetische Betreuung vorgeschlagen.

[Cost evaluation of a model for integrated care of seriously mentally ill patients]

BACKGROUND

The model for integrated care (IC) of those seriously mentally ill patients insured with the DAK-Gesundheit health insurance and various Betriebskrankenkassen (members of the VAG Mitte) from the regions Berlin, Brandenburg, Lower Saxony and Bremen allows a complex treatment in the outpatient setting which consists of psychiatrists, general practitioners and clinicians, psychiatric nursing, sociotherapy (only in Berlin), internal medicine quality circles, orientation on treatment guidelines and conceptual consensus with the relevant care clinics. The aim of the evaluation is to illustrate the health economic effects of IC.

METHODS

In the period from 2006 to 2010 insured members of the DAK-Gesundheit and other involved health insurance companies with a serious mental illness, a significant impairment of social functioning and the need to be treated to avoid or substitute an in-hospital stay were included in the integrated care. The cost perspective was that of the statutory health insurance companies. For the health economic evaluation, the utilisation of continuous IC over 18 months was compared to the last 18 months prior to the inclusion in IC. The clinical findings were gathered quarterly during the IC using CGI (Clinical Global Impressions) and GAF (Global Assessment of Functioning Scale).

RESULTS

A total of 1 364 patients receiving IC in 66 doctor's practices were documented (of those, 286 had diagnoses of ICD-10 F2, 724 ICD-10 F32-F39). The median age was 48.8 years, 69% were female. 24% had their own source of income, 40% were on the pension, and the rest of the patients were receiving transfer benefits in some form. In 54% of the cases IC was used to avoid an in-hospital stay, in 46% of the cases to substitute an in-hospital stay. The degree of the CGI was 5.5 on average at the time of inclusion and the GAF score was 36.5 on average. The 226 patients with continuous documentation over 18 months were included in the health economic analysis. The number of days spent in hospital was lower during the IC period as compared to the 18 months prior to IV (11.8 vs. 28.6 days, p<0.001), the inpatient costs were lower (5 929 ± 13 837 Euro vs. 2 458 ± 6 940 Euro, p<0.001), the total was not significantly changed (7 777 ± 14 263 Euro vs. 7 321 ± 7 910 Euro, p=0.65). The substantial reduction of inpatient costs was compensated by the additional costs for medication and the costs of the complex outpatient care. Results were comparable for the 2 subgroups of schizophrenic/schizoaffective (n=66, 40.9 vs. 17.9 days, p=0.03; inpatient cost 9 009 ± 15 677 Euro vs. 3 650 ± 8 486 Euro, p=0.02; total expenditures 11 789 ± 15 975 Euro vs. 9 623 ± 9 262 Euro, p=0.33) and unipolar depressive patients (n=90, 29.8 vs. 9.8 days, p=0.006; inpatient cost 5 664 ± 14 921 Euro vs. 1 967 ± 5 276 Euro, p=0.02; total expenditures 7 146 ± 15 164 Euro vs. 6 234 ± 6 292 Euro, p=0.57).

CONCLUSION

The IC was able to considerably reduce the utilisation of inpatient treatment through offering a complex range of services in the outpatient setting and allowed for a weight-shift in a low-threshold comprehensive care structure without an increase in costs from the statutory health insurance companies' perspective. For a detailed description of clinical effects further studies are required.