A protocol for registration and correction of multicolour STED superresolution images.

Multicolour fluorescence imaging by STimulated Emission Depletion (STED) superresolution microscopy with doughnut-shaped STED laser beams based on different wavelengths for each colour channel requires precise image registration. This is especially important when STED imaging is used for co-localisation studies of two or more native proteins in biological specimens to analyse nanometric subcellular spatial arrangements. We developed a robust postprocessing image registration protocol, with the aim to verify and ultimately optimise multicolour STED image quality. Importantly, this protocol will support any subsequent quantitative localisation analysis at nanometric scales. Henceforth, using an approach that registers each colour channel present during STED imaging individually, this protocol reliably corrects for optical aberrations and inadvertent sample drift. To achieve the latter goal, the protocol combines the experimental sample information, from corresponding STED and confocal images using the same optical beam path and setup, with that of an independent calibration sample. As a result, image registration is based on a strategy that maximises the cross-correlation between sequentially acquired images of the experimental sample, which are strategically combined by the protocol. We demonstrate the general applicability of the image registration protocol by co-staining of the ryanodine receptor calcium release channel in primary mouse cardiomyocytes. To validate this new approach, we identify user-friendly criteria, which - if fulfilled - support optimal image registration. In summary, we introduce a new method for image registration and rationally based postprocessing steps through a highly standardised protocol for multicolour STED imaging, which directly supports the reproducibility of protein co-localisation analyses. Although the reference protocol is discussed exemplarily for two-colour STED imaging, it can be readily expanded to three or more colours and STED channels.

Variable responses of human microbiomes to dietary supplementation with resistant starch.

BACKGROUND: The fermentation of dietary fiber to various organic acids is a beneficial function provided by the microbiota in the human large intestine. In particular, butyric acid contributes to host health by facilitating maintenance of epithelial integrity, regulating inflammation, and influencing gene expression in colonocytes. We sought to increase the concentration of butyrate in 20 healthy young adults through dietary supplementation with resistant starch (unmodified potato starch-resistant starch (RS) type 2). METHODS: Fecal samples were collected from individuals to characterize butyrate concentration via liquid chromatography and composition of the microbiota via surveys of 16S rRNA-encoding gene sequences from the Illumina MiSeq platform. Random Forest and LEfSe analyses were used to associate responses in butyrate production to features of the microbiota. RESULTS: RS supplementation increased fecal butyrate concentrations in this cohort from 8 to 12 mmol/kg wet feces, but responses varied widely between individuals. Individuals could be categorized into three groups based upon butyrate concentrations before and during RS: enhanced, high, and low (n = 11, 3, and 6, respectively). Fecal butyrate increased by 67 % in the enhanced group (from 9 to 15 mmol/kg), while it remained ≥11 mmol/kg in the high group and ≤8 mmol/kg in the low group. Microbiota analyses revealed that the relative abundance of RS-degrading organisms-Bifidobacterium adolescentis or Ruminococcus bromii-increased from ~2 to 9 % in the enhanced and high groups, but remained at ~1.5 % in the low group. The lack of increase in RS-degrading bacteria in the low group may explain why there was no increase in fecal butyrate in response to RS. The microbiota of individuals in the high group were characterized by an elevated abundance of the butyrogenic microbe Eubacterium rectale (~6 % in high vs. 3 % in enhanced and low groups) throughout the study. CONCLUSIONS: We document the heterogeneous responses in butyrate concentrations upon RS supplementation and identify characteristic of the microbiota that appear to underlie this variation. This study complements and extends other studies that call for personalized approaches to manage beneficial functions provided by gut microbiomes.

Generic stabilizability for time-delayed feedback control.

Time-delayed feedback control is one of the most successful methods to discover dynamically unstable features of a dynamical system in an experiment. This approach feeds back only terms that depend on the difference between the current output and the output from a fixed time T ago. Thus, any periodic orbit of period T in the feedback-controlled system is also a periodic orbit of the uncontrolled system, independent of any modelling assumptions. It has been an open problem whether this approach can be successful in general, that is, under genericity conditions similar to those in linear control theory (controllability), or if there are fundamental restrictions to time-delayed feedback control. We show that, in principle, there are no restrictions. This paper proves the following: for every periodic orbit satisfying a genericity condition slightly stronger than classical linear controllability, one can find control gains that stabilize this orbit with extended time-delayed feedback control. While the paper's techniques are based on linear stability analysis, they exploit the specific properties of linearizations near autonomous periodic orbits in nonlinear systems, and are, thus, mostly relevant for the analysis of nonlinear experiments.

Systematic experimental exploration of bifurcations with noninvasive control.

We present a general method for systematically investigating the dynamics and bifurcations of a physical nonlinear experiment. In particular, we show how the odd-number limitation inherent in popular noninvasive control schemes, such as (Pyragas) time-delayed or washout-filtered feedback control, can be overcome for tracking equilibria or forced periodic orbits in experiments. To demonstrate the use of our noninvasive control, we trace out experimentally the resonance surface of a periodically forced mechanical nonlinear oscillator near the onset of instability, around two saddle-node bifurcations (folds) and a cusp bifurcation.

Medication persistence with long-term, specific grass pollen immunotherapy measured by prescription renewal rates.

OBJECTIVE: We assessed medication persistence using prescription renewal rates for grass pollen specific immunotherapy (SIT) in a representative population of patients in Germany to evaluate whether the perception of superior persistence for the subcutaneous route compared to the sublingual route could be confirmed in clinical practice. METHODS: Individual prescriptions for allergen immunotherapy were extracted from a national prescription database (INSIGHT Health) and followed over 3 years on a per-patient basis. However, patients' medical history and treatment schedules were not available for analysis. Products were identified by the national drug code (PZN number) and grouped to either subcutaneous immunotherapy (SCIT) with natural extract injections, SCIT with modified allergens (allergoids) or sublingual immunotherapy (SLIT) with natural pollen extract solutions. Persistence was defined as at least one prescription of the individual drug in the respective years. RESULTS: A total of 1409 patients started SIT in 2005 (112, 695, and 602 for natural extract SLIT, natural extract SCIT, and allergoid SCIT, respectively). In 2006, 71%, 55%, and 59% of those patients had at least one renewal prescription of natural extract SLIT, natural extract SCIT, and allergoid SCIT, respectively, as well as 51%, 34%, and 39% in 2007. In both years, persistence with natural extract SLIT was significantly higher than with natural extract SCIT (p = 0.0015 for 2006, p = 0.0003 for 2007) and allergoid SCIT (p = 0.0152 for 2006, p = 0.0111 for 2007). There were no significant differences between the two SCIT groups. CONCLUSION: Medication persistence with grass pollen SIT in a representative sample of patients in Germany was similar to published medication persistence in asthma and COPD patients. The sublingual application route shows significantly better persistency than the subcutaneous route with native allergens or allergoids.

Efficacy of grass pollen sublingual immunotherapy for three consecutive seasons and after cessation of treatment: the ECRIT study.

BACKGROUND: Data supporting a carry-over effect with sublingual immunotherapy (SLIT) are scarce. This randomized, double-blind, placebo-controlled study evaluated the efficacy, carry-over effect and safety of grass pollen SLIT using co-seasonal treatment. METHODS: Patients (7.9-64.7 years) with grass pollen allergy received ultra-rush titration with increasing doses (30, 90, 150 and 300 IR) of a 5-grass pollen mixture every 20 min at the start of the pollen seasons, followed by 300 IR daily until the end of the pollen seasons. A baseline season (no SLIT) was followed by three consecutive treatment seasons and one follow-up season. Symptoms, medication and adverse events were documented and specific immunoglobulin (Ig)E and IgG(4) measured. RESULTS: Data were analysed for 183 of the 213 randomized patients. Mean treatment duration varied between seasons (81.8-92.7 days). Combined scores (symptoms and medication) improved progressively across treatment seasons (up to 44.7% improvement for SLIT compared with baseline) and fluctuated between -11.3% and -14.8% for placebo (P < 0.05). Similar changes were observed for symptom scores, with a successive decrease of 39.7% (SLIT) and fluctuations between +13.6% and -1.51% for placebo (P < 0.05). Combined score (P = 0.0508) and symptom score improvements (P = 0.0144) with SLIT continued during follow up. Increases in specific IgG(4) observed in the first season were sustained for SLIT vs placebo throughout treatment (P = 0.0001). Titration and daily SLIT were well tolerated. No serious systemic or anaphylactic reactions were reported. CONCLUSIONS: Seasonal SLIT with ultra-rush titration is well tolerated and effective from the first treatment season onwards. These data indicate a carry-over effect of seasonal SLIT.

Safety and tolerability of seasonal ultra-rush, high-dose sublingual-swallow immunotherapy in allergic rhinitis to grass and tree pollens: an observational study in 193 children and adolescents.

OBJECTIVE: We conducted a large observational study in 193 children and adolescents with allergic rhinitis due to grass or tree pollens to evaluate the safety and tolerability of an ultrarush high-dose sublingual immunotherapy (SLIT) regimen reaching a maintenance dose of 300 index of reactivity within 90 minutes. METHODS: Children and adolescents aged 5 to 17 years with at least a 1-year medical history of allergic rhinitis with or without mild to moderate asthma due to tree pollens (birch, alder, hazel) or grass pollens (cocksfoot, meadow grass, rye grass, sweet vernal grass, timothy) were recruited. Standardized grass and tree pollen allergen extracts were used for ultrarush titration and subsequent coseasonal maintenance. RESULTS: During ultrarush titration, 60 patients (31%) reported 117 predominantly mild and local adverse events, which resolved within 150 minutes. During the maintenance phase, 562 adverse events were reported; the most frequent local events were oral pruritus, burning sensation, lip or tongue swelling, and gastrointestinal symptoms, and the most frequent systemic events were rhinoconjunctivitis and asthma. There was 1 clinically significant asthma event in an 11-year old boy with known asthma in whom SLIT was resumed after an interval of 4 days. CONCLUSION: Ultrarush titration was safe and well tolerated. Pediatric patients with asthma should be carefully monitored and adequately trained to use their rescue medications.

Safety of two cluster schedules for subcutaneous immunotherapy in allergic rhinitis or asthma patients sensitized to inhalant allergens.

BACKGROUND: Subcutaneous immunotherapy (SCIT) usually requires a long titration phase, which can be associated with various adverse events (AEs). OBJECTIVES: It was the aim of this study to determine the safety of 2 cluster regimens for SCIT in patients with allergic rhinitis, with or without mild or moderate allergic asthma, who were sensitized to grass and/or tree pollen, or house dust mites (HDM). PATIENTS AND METHODS: Adult patients were included in a European, open-label, prospective trial. Pollen-allergic patients received grass pollen, grass and olive pollen, or hazel, alder and birch pollen according to a 3-week titration cluster. HDM-allergic patients received HDM extract according to a 2-week titration cluster. The safety of the titration phase was assessed in terms of local and systemic AEs. RESULTS: The safety analysis included 157 patients: 110 received pollen and 47 HDM extract. During the cluster titration, 248 AE episodes were reported in the pollen group and 113 in the HDM group; these were mainly local reactions. Around one third of patients (30.9% pollen and 38.3% HDM) did not experience any AE. In most cases (67.1% of pollen and 71.1% of HDM patients), AEs did not lead to a change in titration schedule. No anaphylactic reaction or other serious life-threatening systemic AEs were reported. Only 2 patients in the HDM group discontinued treatment because of AEs. CONCLUSIONS: Rapid cluster titration was well tolerated in adults with allergic rhinitis, with or without mild to moderate allergic asthma, due to pollen or HDM. This short-titration, high-dose cluster regime may allow better patient compliance and cost savings.

Efficacy of grass pollen sublingual immunotherapy for three consecutive seasons and after cessation of treatment: the ECRIT study.

BACKGROUND: Data supporting a carry-over effect with sublingual immunotherapy (SLIT) are scarce. This randomized, double-blind, placebo-controlled study evaluated the efficacy, carry-over effect and safety of grass pollen SLIT using co-seasonal treatment. METHODS: Patients (7.9-64.7 years) with grass pollen allergy received ultra-rush titration with increasing doses (30, 90, 150 and 300 IR) of a 5-grass pollen mixture every 20 min at the start of the pollen seasons, followed by 300 IR daily until the end of the pollen seasons. A baseline season (no SLIT) was followed by three consecutive treatment seasons and one follow-up season. Symptoms, medication and adverse events were documented and specific immunoglobulin (Ig)E and IgG(4) measured. RESULTS: Data were analysed for 183 of the 213 randomized patients. Mean treatment duration varied between seasons (81.8-92.7 days). Combined scores (symptoms and medication) improved progressively across treatment seasons (up to 44.7% improvement for SLIT compared with baseline) and fluctuated between -11.3% and -14.8% for placebo (P < 0.05). Similar changes were observed for symptom scores, with a successive decrease of 39.7% (SLIT) and fluctuations between +13.6% and -1.51% for placebo (P < 0.05). Combined score (P = 0.0508) and symptom score improvements (P = 0.0144) with SLIT continued during follow up. Increases in specific IgG(4) observed in the first season were sustained for SLIT vs placebo throughout treatment (P = 0.0001). Titration and daily SLIT were well tolerated. No serious systemic or anaphylactic reactions were reported. CONCLUSIONS: Seasonal SLIT with ultra-rush titration is well tolerated and effective from the first treatment season onwards. These data indicate a carry-over effect of seasonal SLIT.

Experimental continuation of periodic orbits through a fold.

We present a continuation method that enables one to track or continue branches of periodic orbits directly in an experiment when a parameter is changed. A control-based setup in combination with Newton iterations ensures that the periodic orbit can be continued even when it is unstable. This is demonstrated with the continuation of initially stable rotations of a vertically forced pendulum experiment through a fold bifurcation to find the unstable part of the branch.

Development and certification of the new SRM 695 trace elements in multi-nutrient fertilizer.

During the past seven years, several states within the US have enacted regulations that limit the amounts of selected non-nutritive elements in fertilizers. Internationally, several countries, including Japan, China, and Australia, and the European Union also limit the amount of selected elements in fertilizers. The elements of interest include As, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, Se, and Zn. Fertilizer manufacturers and state regulatory authorities, faced with meeting and verifying these limits, need to develop analytical methods for determination of the elements of concern and to validate results obtained using these methods. Until now, there were no certified reference materials available with certified mass fraction values for all elements of interest in a blended, multi-nutrient fertilizer matrix. A new standard reference material (SRM) 695 trace elements in multi-nutrient fertilizer, has been developed to help meet these needs. SRM 695 has recently been issued with certified mass fraction values for seventeen elements, reference values for an additional five elements, and information values for two elements. The certificate of analysis includes an addendum listing percentage recovery for eight of these elements, determined using an acid-extraction inductively-coupled plasma optical-emission spectrometry (ICP-OES) method recently developed and tested by members of the Association of American Plant Food Control Officials.

NON-activated protein C as post-treatment after spinal cord compression injury in rats.

BACKGROUND: Neuroprotective effects of recombinant human activated Protein C (rhAPC) in models of Spinal Cord Injury (SCI) and ischemic stroke have been reported in rodents. To rule out immunogenicity of rhAPC and to possibly maintain the physiological PC/thrombin balance the use of zymogen PC in SCI might be preferable. Although activation of Protein C (PC) has been demonstrated in rats, the efficacy and drug safety of NON activated PC has not been previously tested in experimental SCI. METHODS: Twelve rats were subjected to 40 g compression of the spinal cord at TH11 for 20 minutes and randomly allocated to either the NON activated PC (25 IU/kg) or the Placebo group (saline).Results. 25 IU treatment yielded improved recovery from SCI compared to placebo and the triple fold dose of PC (75 IU/kg) was subsequently tested to detect treatment associated complications (TAC). Treatment was administered as a single shot via the right vena jugularis forty minutes after onset of compression. The observation period was 5 weeks in 25 IU treated and 1 week in the 75 IU treated rats. Improvement of motor function recovery was measured with behaviour tests and electrophysiology. FINDINGS: Single shot treatment with 25 IU/kg of NON activated PC led to improved recovery in terms of behaviour and electrophysiology. TACs neither occurred in the 25 IU nor in the 75 IU group within one week. CONCLUSION: NON activated PC is a potent and safe drug in experimental SCI and should be considered for treatment in neurotrauma.

Immune mechanisms of allergen-specific sublingual immunotherapy.

Sublingual immunotherapy has been shown in some clinical studies to modulate allergen-specific antibody responses [with a decrease in the immunoglobulin E/immunoglobulin G4 (IgE/IgG4) ratio] and to reduce the recruitment and activation of proinflammatory cells in target mucosa. Whereas a central paradigm for successful immunotherapy has been to reorient the pattern of allergen-specific T-cell responses in atopic patients from a T helper (Th)2 to Th1 profile, there is currently a growing interest in eliciting regulatory T cells, capable of downregulating both Th1 and Th2 responses through the production of interleukin (IL)-10 and/or transforming growth factor (TGF)-beta. We discuss herein immune mechanisms involved during allergen-specific sublingual immunotherapy (SLIT), in comparison with subcutaneous immunotherapy. During SLIT, the allergen is captured within the oral mucosa by Langerhans-like dendritic cells expressing high-affinity IgE receptors, producing IL-10 and TGF-beta, and upregulating indoleamine dioxygenase (IDO), suggesting that such cells are prone to induce tolerance. The oral mucosa contains limited number of proinflammatory cells, such as mast cells, thereby explaining the well-established safety profile of SLIT. In this context, second-generation vaccines based on recombinant allergens in a native conformation formulated with adjuvants are designed to target Langerhans-like cells in the sublingual mucosa, with the aim to induce allergen-specific regulatory T cells. Importantly, such recombinant vaccines should facilitate the identification of biological markers of SLIT efficacy in humans.

Nonlinear dynamics of semiconductor lasers with active optical feedback.

An in-depth theoretical as well as experimental analysis of the nonlinear dynamics in semiconductor lasers with active optical feedback is presented. Use of a monolithically integrated multisection device of submillimeter total length provides access to the short-cavity regime. By introducing an amplifier section as a special feature, phase and strength of the feedback can be separately tuned. In this way, the number of modes involved in the laser action can be adjusted. We predict and observe specific dynamical scenarios. Bifurcations mediate various transitions in the device output, from single-mode steadystate to self-pulsation and between different kinds of self-pulsations, reaching eventually chaotic behavior in the multimode limit.

Single- and multiple-dose pharmacokinetics of repaglinide in patients with type 2 diabetes and renal impairment.

OBJECTIVE: The primary objective of this single-centre, open-label, parallel-group study was to evaluate the pharmacokinetics and safety profile of the prandial glucose regulator repaglinide, following single and multiple dosing, in patients with type 2 diabetes with and without varying degrees of renal impairment. METHODS: The study comprised three screening visits, followed by a 7-day inpatient period. Thirty-four patients, with normal renal function (n = 12), mild-to-moderate renal dysfunction (n = 12) or severe renal dysfunction (n = 10), received a single 2-mg dose of repaglinide on day 1, followed by preprandial 2-mg doses with main meals (breakfast, lunch and dinner) on each of days 2-4. A final 2-mg dose of repaglinide was administered on day 5. RESULTS: Patients with mild-to-moderate renal impairment showed no significant differences in the pharmacokinetics of repaglinide, compared with patients with normal renal function. In the group of patients with severe renal dysfunction, the main pharmacokinetic finding was a longer half-life after multiple dosing. Rates of minor hypoglycaemia were similar in patients with severe, mild-to-moderate and no renal dysfunction. No major hypoglycaemic episodes occurred. CONCLUSION: Patients with type 2 diabetes and mild or moderate impairment of renal function may be treated with repaglinide without special precautions. If repaglinide is used in patients with severely impaired renal function, dose adjustment may be necessary if indicated by blood glucose measurements.

Will the new code help researchers to be more ethical?

A code of ethics has 2 largely incompatible objectives: to set forth enforceable minimal standards of conduct and to teach about or invoke ethical conduct. The section of the new American Psychological Association code dealing with research ethics achieves the former to some degree. However, it neither provides needed education in the ethics of research nor states where the reader might turn for such information. The code is particularly deficient in the following areas: privacy and confidentiality; institutional review boards; deception; debriefing; data sharing; and research on marginal populations, on children and adolescents, and in organizational contexts. Suggestions are offered for providing a bibliographic resource, in hard copy and on-line, that would stimulate independent interest, scholarship, education, and research on research ethics.

Automated processing of endoscopic surgical instruments.

This paper deals with the requirements for automated processing of endoscopic surgical instruments. After a brief analysis of the current problems, solutions are discussed. Test-procedures have been developed to validate the automated processing, so that the cleaning results are guaranteed and reproducable. Also a device for testing and cleaning was designed together with Netzsch Newamatic and PCI, called TC-MIC, to automate processing and reduce manual work.

Ethical considerations in planning and conducting research on human subjects.

The ethical conduct of research on humans requires more than a caring researcher and a legalistic adherence to federal regulations. It requires good planning and managing of issues accruing from the research relationship--communication, risk and perception of risk, and benefits--to all who have a stake in the relationship and outcome. In 1978 the National Commission for the Protection of Human Subjects in Biomedical and Behavioral Research identified ethical principles that should govern research on humans. Institutional review boards (IRBs) now exist in every organization that receives federal funding for human-subjects research. Researchers have an obligation to study the requirements of their IRB when they plan their research. Further, they must establish appropriate procedures for obtaining informed consent and assessing risk, risk perception, and ways to increase the benefits of research.