Impact of investigator initiated trials and industry sponsored trials on medical practice (IMPACT): rationale and study design.

BACKGROUND: The German Research Foundation (DFG) and the Federal Ministry of Education and Research (BMBF) initiated large research programs to foster high quality clinical research in the academic area. These investigator initiated trials (IITs) cover important areas of medical research and often go beyond the scope of industry sponsored trials (ISTs). The purpose of this project was to understand to what extent results of randomized controlled IITs and ISTs have an impact on medical practice, measured by their availability for decisions in healthcare and their implementation in clinical practice. We aimed to determine study characteristics influencing a trial's impact such as type of sponsor and place of conduct. In this article, we describe the rationale and design of this project and present the characteristics of the trials included in our study cohort. METHODS: The research impact of the following sub-cohorts was compared: German IITs (funded by DFG and BMBF or by other German non-commercial organizations), international IITs (without German contribution), German ISTs, and international ISTs. Trials included were drawn from the DFG-/BMBF-Websites, the German Clinical Trials Register, and from ClinicalTrials.gov . Research impact was measured as follows: 1) proportion of published trials, 2) time to publication, 3) proportion of publications appropriately indexed in biomedical databases, 4) proportion of openly accessible publications, 5) broadness of publication's target group, 6) citation of publications by systematic reviews or meta-analyses, and 7) appearance of publications or citing systematic reviews or meta-analyses in clinical practice guidelines. We also aimed to identify study characteristics associated with the impact of trials. RESULTS: We included 691 trials: 120 German IITs, 200 International IITs, 171 German ISTs and 200 International ISTs. The median number of participants was 150, 30% were international trials and 70% national trials, 48% drug-trials and 52% non-drug trials. Overall, 72% of the trials had one pre-defined primary endpoint, 28% two or more (max. 36). CONCLUSIONS: The results of this project deepen our understanding of the impact of biomedical research on clinical practice and healthcare policy, add important insights for the efficient allocation of scarce research resources and may facilitate providing accountability to the different stakeholders involved.

Prebiotic supplementation over a cold season and during antibiotic treatment specifically modulates the gut microbiota composition of 3-6 year-old children.

Supplementing kindergarten children during a cold season with a prebiotic inulin-type fructans product with shorter and longer fructan chains has been shown to reduce febrile episodes requiring medical attention and to lower the incidence of sinusitis. These beneficial effects may be connected to the specific modulation of children's gut microbiota. By applying quantitative and qualitative microbiota analysis this study aimed at characterising the gut microbiota composition and at exploring effects of prebiotic intervention on the gut microbiota during a 24-weeks intervention and during antibiotic treatment in healthy children. The study was a randomised, placebo-controlled trial with 258 healthy children aged 3 to 6 years consuming 6 g/day prebiotic inulin-type fructans or maltodextrin. During the course of the study, faecal samples were collected and subject to targeted qPCR analysis and phylogenetic profiling by multiplexed high throughput sequencing of the prokaryotic 16S rRNA gene PCR amplicons. The microbiota composition of the cohort could be clustered into three distinct constellations (enterotypes). Prebiotic intake resulted in a selective modulation of the gut microbiota composition. Relative abundance of Bifidobacterium was significantly higher in the prebiotic group (n=104) compared to control group (n=105) and this effect was found for all three enterotypes. Antibiotic administration decreased the relative abundance of Bifidobacterium in both groups. Nonetheless, children of the prebiotic group receiving antibiotic treatment displayed significantly higher levels of Bifidobacterium than children receiving the placebo control. Prebiotic supplementation induced specific changes in the gut microbiota composition of children aged 3 to 6 years. Moreover, it attenuated antibiotic-induced disturbances in the gut microbiota composition as shown by higher relative abundance of bifidobacteria at the end of the antibiotic treatment in the prebiotic group. With the previously reported benefits on immune function, the study contributes to the evidence on the immune-modulating effects of prebiotics through gut microbiota modifications. The study was registered as NCT03241355 ( https://clinicaltrials.gov/show/NCT03241355 ).

Multicolor femtosecond pump-probe system with single-electron sensitivity at low temperatures and high magnetic fields.

We present an ultrafast spectroscopy system designed for temporal and spectral resolution of transient transmission changes after excitation of single electrons in solid-state quantum structures. The system is designed for optimum long-term stability, offering the option of hands-off operation over several days. Pump and probe pulses are generated in a versatile Er:fiber laser system where visible photon energies may be tuned independently from 1.90 eV to 2.51 eV in three parallel branches. Bandwidth-limited pulse durations between 100 fs and 10 ps are available. The solid-state quantum systems under investigation are mounted in a closed-cycle superconducting magnet cryostat providing temperatures down to 1.6 K and magnetic fields of up to 9 T. The free-standing cryomagnet is coupled to the laser system by means of a high-bandwidth active beam steering unit to eliminate residual low-frequency mechanical vibrations of the pulse tube coolers. High-NA objective lenses inside the sample chamber are employed for focusing femtosecond laser pulses onto the sample and recollection of the transmission signal. The transmitted probe light is dispersed in a grating monochromator equipped with a liquid nitrogen-cooled CCD camera, enabling a frame rate of 559 Hz. In order to eliminate spurious background effects due to low-frequency changes in the thermal equilibrium of the sample, we operate with a lock-in scheme where, instead of the pump amplitude, the pump-probe timing is modulated. This feature is provided without any mechanical action by an electro-optic timing unit inside the femtosecond Er:fiber system. The performance of the instrument is tested with spectrally resolved pump-probe measurements on a single negatively charged CdSe/ZnSe quantum dot under a magnetic field of 9 T. Selective initialization and readout of charge and spin states is carried out via two different femtosecond laser pulses. High-quality results on subpicosecond intraband relaxation dynamics after single-electron excitation motivate a broad variety of future experiments in ultrafast quantum optics and few-fermion quantum dynamics.

Relationship between sleep duration and childhood obesity: Systematic review including the potential underlying mechanisms.

AIM: The prevalence of obesity is continually increasing worldwide. Determining risk factors for obesity may facilitate effective preventive programs. The present review focuses on sleep duration as a potential risk factor for childhood obesity. The aim is to summarize the evidence on the association of sleep duration and obesity and to discuss the underlying potential physiological and/or pathophysiological mechanisms. DATA SYNTHESIS: The Ovid MEDLINE, Scopus and Cochrane Central Register of Controlled Trials (CENTRAL) databases were searched for papers using text words with appropriate truncation and relevant indexing terms. All studies objectively measuring sleep duration and investigating the association between sleep duration and obesity or factors (lifestyle and hormonal) possibly associated with obesity were included, without making restrictions based on study design or language. Data from eligible studies were extracted in tabular form and summarized narratively. After removing duplicates, 3540 articles were obtained. Finally, 33 studies (including 3 randomized controlled trials and 30 observational studies) were included in the review. CONCLUSION: Sleep duration seems to influence weight gain in children, however, the underlying explanatory mechanisms are still uncertain. In our review only the link between short sleep duration and the development of insulin resistance, sedentarism and unhealthy dietary patterns could be verified, while the role of other mediators, such as physical activity, screen time, change in ghrelin and leptin levels, remained uncertain. There are numerous evidence gaps. To answer the remaining questions, there is a need for studies meeting high methodological standards and including a large number of children.

Long-chain polyunsaturated fatty acid status in obesity: a systematic review and meta-analysis.

Long-chain polyunsaturated fatty acid (LCPUFA) status has recently been related to the pathogenesis of obesity. Our aims were to systematically review observational studies investigating LCPUFA status from different blood compartments in overweight or obese subjects and to assess the relationship between LCPUFA profile and obesity. The Ovid MEDLINE, Scopus and Cochrane Library CENTRAL databases were searched from inception to January 2014. The meta-analysis showed significant differences in the LCPUFA composition of total plasma lipids, plasma phospholipids and plasma cholesteryl esters between overweight or obese subjects and controls. Dihomo-γ-linolenic acid (DGLA) values were significantly higher in overweight or obese subjects compared with controls in all the investigated biomarkers. In addition, the DGLA/linoleic acid ratio (surrogate parameter for Δ6 desaturase activity) in plasma phospholipids was significantly elevated (mean difference [MD]: 0.05; 95% confidence interval [CI]: 0.02, 0.08; n = 280), while the arachidonic acid/DGLA ratio (surrogate parameter for Δ5 desaturase activity) was significantly decreased (MD: -0.55; 95% CI: -0.71, -0.39; n = 347) in overweight or obese subjects compared with controls. The results of the present meta-analysis confirm that LCPUFA profile is altered in obesity and suggest that the differences observed in desaturase activities may be responsible for the disturbed LCPUFA metabolism in obesity.

Enzyme immunoassay validation for the detection of buprenorphine in urine.

A solid-phase enzyme immunoassay involving microtiter plates was proposed by Microgenics to screen buprenorphine in urine. The intra-assay precision at 10 ng/mL was 7.7% (coefficient of variation). The immunoassay was determined to have no cross-reactivity with codeine, dihydrocodeine, morphine, ethylmorphine, 6-monoacetylmorphine, methadone, pholcodine, propoxyphene, dextromoramide, and dextromethorphan at 1 and 10 mg/L. A low cross-reactivity (3% at 1 ng/mL) was observed at low concentrations of norbuprenorphine. After comparing this new immunological test (Singlestep ELISA) for 76 urine specimens with our validated high-performance liquid chromatography-electrospray mass spectrometry (HPLC-ES-MS) procedure, an optimum cutoff concentration of 2 ng/mL was determined for the kit. At this cutoff, the screening assay was able to determine more than 90% of true results with 43.4% true positives and 48.7% true negatives. Four positive urines (5.3%) were not confirmed by HPLC-ES-MS. In only one case, the negative urine test was confirmed as positive by HPLC-ES-MS (buprenorphine: 62.5 ng/mL). Buprenorphine concentrations determined by HPLC-ES-MS ranged from 1.2 to 1052 ng/mL. Of the four potential adulterants (hypochloride 50 mL/L, sodium nitrite 50 g/L, liquid soap 50 mL/L, and sodium chloride 50 g/L) that might be added to a positive urine specimen, none were able to cause a false-negative response by the immunoassay. The results of this study support the concept that the Singlestep ELISA for buprenorphine determination in urine should be considered as a new, valided screening procedure.

Combined phacoemulsification, intraocular lens implantation, and trabeculectomy.

PURPOSE: To analyze the results of phacoemulsification and posterior chamber intraocular lens (IOL) implantation combined with trabeculectomy. SETTING: John Moran Eye Center, University of Utah, Salt Lake City. METHODS: Two hundred twelve eyes of 174 patients with glaucoma and cataracts were analyzed retrospectively after cataract removal by phacoemulsification with posterior chamber IOL implantation combined with trabeculectomy. RESULTS: With an average follow-up of 26 months, patients had a significant improvement in visual acuity. The preoperative mean intraocular pressure (IOP) of 23.1 mm Hg decreased postoperatively to 15.9 mm Hg. Mean number of glaucoma medications decreased from 1.85 preoperatively to 0.41 postoperatively. Twenty-one patients (10% had a postoperative IOP of greater than 21 mm Hg, and seven required trabeculectomy revisions. CONCLUSION: Combined phacoemulsification, posterior chamber IOL implantation, and trabeculectomy yielded excellent results in the treatment of patients with both cataract and glaucoma.

Toxicological findings in a fatal case of acebutolol self-poisoning.

A fatal case of acebutolol self-poisoning is presented. After single-step liquid-liquid alkaline extraction, acebutolol was identified by using an HPLC/DAD screening procedure. By means of a specific HPLC method, acebutolol was then quantified in a large range of postmortem samples. The blood acebutolol concentration was 34.7 micrograms/mL. The tissue distribution of the drug is discussed in the light of the existing literature.

Toxicological findings after fatal amitriptyline self-poisoning.

A case of fatal self-poisoning with amitriptyline is reported. Both the drug and its metabolite nortriptyline were quantified in several post-mortem tissues and fluids, including vitreous humor. Results are discussed in the light of the existing literature.

Fatal chloroquine self-poisoning.

High performance liquid chromatography was employed to quantify chloroquine in biological fluids and tissues in a death attributed to chloroquine overdose. The blood concentration of chloroquine was 16.71 mg/l. Results are discussed in the light of the existing literature.