High-efficiency, room-temperature nanosecond Yb:YAG laser

Yb(3+)-doped gain media offer favorable properties for diode-pumped laser amplifiers for high-energy ns-pulses. To reach high optical-to-optical conversion efficiencies at room temperature however, very high and often impractical fluences are required both for pumping and extraction. Low temperature operation offers a solution, but the required cryogenic cooling systems add considerable complexity, bulkiness and cost. Multi-passing both pump and extraction beams through the gain medium is an alternative approach to overcome efficiency limitations at room temperature. In this article we present numerical and experimental results to this effect.We demonstrated ns-pulse output from a diode-pumped Yb:YAG amplifier at an energy of 566 mJ and an optical-to-optical efficiency of 20%, which is almost a doubling of the efficiency achieved with ns-lasers employing Yb(3+)-doped gain media at this energy level.

Clinical trial: the glucagon-like peptide-1 analogue ROSE-010 for management of acute pain in patients with irritable bowel syndrome: a randomized, placebo-controlled, double-blind study

BACKGROUND

There is currently no treatment available to manage acute pain attacks in IBS patients regardless of subtype.

AIMS

To evaluate efficacy and safety of the GLP-1 analogue ROSE-010 in patients with irritable bowel syndrome (IBS) through a randomized, double-blind, placebo-controlled study.

METHODS

Eligible patients (n = 166) meeting Rome II criteria were randomly assigned to receive single subcutaneous injections of ROSE-010 100 microg, 300 microg and placebo in a cross-over design. Safety was assessed from spontaneously reported adverse events and measurement of vital signs. Patient-rated pain relief and intensity were measured on a 100-mm visual analogue scale. The primary efficacy variable was proportion of patients with >50% maximum total pain relief response from 10 to 60 min after treatment. Secondary endpoints included the maximum summed pain intensity difference, time to meaningful pain relief and patient ratings of satisfaction with treatment.

RESULTS

Twice as many patients were responders in the primary efficacy endpoint after both ROSE-010 injections compared to placebo (24%P = 0.011, 23%P = 0.005, and 12% after 300 microg, 100 microg and placebo injections, respectively). Similar results were obtained for the proportion of patients with total pain intensity response. Times to meaningful and total pain relief were shorter for both doses of ROSE-010 compared with placebo. Compared with placebo, more patients (P < 0.05) were satisfied with ROSE-010 and considered ROSE-010 better than previous IBS medications used.

CONCLUSION

ROSE-010 was well tolerated and provided fast and effective relief of acute pain attacks on demand in IBS patients.

High-energy, diode-pumped, nanosecond Yb:YAG MOPA system

Diode-pumped nanosecond multi-pass laser amplification to the joule level using an Yb:YAG slab crystal has been demonstrated. A maximum output pulse energy of 2.9 J at an optical-to-optical efficiency of 10% has been achieved. The seed pulses with a pulse duration of 6.4 ns were generated in a Q-switched Yb:YAG laser and amplified up to a pulse energy of 200mJ in a multi-pass booster amplifier. A maximum average output power of 15W at a repetition rate of 10 Hz has been measured. We also present a relay imaging semi-stable cavity for multi-pass amplification and a diode-pumping scheme employing horizontally stacked high-power laser diodes.

Novel measurement of rapid treatment success with ReQuest: first and sustained symptom relief as outcome parameters in patients with endoscopy-negative GERD receiving 20 mg pantoprazole or 20 mg esomeprazole

BACKGROUND/AIMS

A prime concern for gastroesophageal reflux disease (GERD) patients is fast symptom control. Sparse valid information is available on the rapidity of the effect of proton pump inhibitors in providing symptom relief. The new reflux questionnaire ReQuest is validated for daily assessment of changes in GERD symptoms. Therefore, this study investigated the efficacy of 20 mg pantoprazole and 20 mg esomeprazole with regard to the time to symptom relief in patients with endoscopy-negative GERD (enGERD) using ReQuest.

METHODS

529 patients were treated with pantoprazole or esomeprazole over 4 weeks. ReQuest symptom scores were assessed daily. The mean and median times to first and sustained symptom relief were determined.

RESULTS

Median time to first symptom relief was 2 days for both drugs (intention-to-treat population). The median time to sustained symptom relief was 3 days shorter with pantoprazole (10.0 vs. 13.0 days). The Hodges-Lehmann estimator for the difference in time to reach first and sustained symptom relief between both groups was 0.00 days. For both variables the one-sided 95% CI (Moses) was [0.00; infinity[, documenting no significant differences between the treatment groups.

CONCLUSIONS

The rapidity of symptom control can be evaluated by clinically significant parameters using ReQuest. Pantoprazole and esomeprazole are equally effective in the time to first and sustained symptom relief.

[Alcohol-related disorders: etiopathology and therapeutic considerations]

The scientific understanding of the neurobiological priniciples of alcoholism has made significant progress in recent years. Especially the effects of ethanol on the neurotransmitter-systems are well studied. Dopaminergic and GABAergic facilitation contribute to the stimulating effects of low doses of alcohol while many of its adverse effects are mediated by glutamatergic inhibition at higher doses. A reduced serotonine-metabolism was shown to be a risk factor for the development of an alcohol dependence. The historic success of absinthe is discussed in this context. Absinthe is a mixture of ethanol and thujone, a substance that leads to a GABAergic inhibition as well as a reduced serotonergic responsiveness. Many studies substantiate the role of cannabinoid as well as striatal opiate-receptors in alcohol-related disorders. Neuroimaging studies could prove the important role of the reward system in this connection. Genetic factors were shown to be predisposing, however biological and environmental factors have a regulatory effect on the gene expression. Disturbances of the hpa-axis (hypothalamus-pituitary gland-adrenal cortex) were also shown to play a role in alcohol dependence. The understanding of these neurobiological principles of alcohol-related disorders should contribute to enhance and improve their therapeutic options.

[Aggressive and impulsive behavior: neurobiological models explain how affectregulation might work and social skills develop]

A person's impulsive actions are characterized by a lack of sufficient planning or an assessment of possibly harmful consequences. An impulse control disorder can be diagnosed if such actions occur frequently, even in low-stress situations. In psychiatry there are a number of syndromes that are associated with an impulse control disorder. Neurobiological findings point to a reduced turnover of serotonin in the brain of persons with an impulse control disorder and aggressive behaviour. However, a reduced turnover of serotonin is also found in persons who can consume immoderate amounts of alcohol but who experience no such unpleasant effects and thus have a high risk of becoming dependent. The serotonin turnover of an individual is controlled by environmental influences in interaction with genetic factors. In this article, impulse control disorders will be discussed with regard to their origin and social effects.

Novel measurement of rapid treatment success with ReQuest: first and sustained symptom relief as outcome parameters in patients with endoscopy-negative GERD receiving 20 mg pantoprazole or 20 mg esomeprazole

BACKGROUND/AIMS

A prime concern for gastroesophageal reflux disease (GERD) patients is fast symptom control. Sparse valid information is available on the rapidity of the effect of proton pump inhibitors in provid ing symptom relief. The new reflux questionnaire ReQuest is validated for daily assessment of changes in GERD symptoms. Therefore, this study investigated the efficacy of 20 mg pantoprazole and 20 mg esomeprazole with regard to the time to symptom relief in patients with endoscopy-negative GERD (enGERD) using ReQuest.

METHODS

529 patients were treated with pantoprazole or esomeprazole over 4 weeks. ReQuest symptom scores were assessed daily. The mean and median times to first and sustained symptom relief were determined.

RESULTS

Median time to first symptom relief was 2 days for both drugs (intention-to-treat population). The median time to sustained symptom relief was 3 days shorter with pantoprazole (10.0 vs. 13.0 days). The Hodges-Lehmann estimator for the difference in time to reach first and sustained symptom relief between both groups was 0.00 days. For both variables the one-sided 95% CI (Moses) was [0.00; infinity] documenting no significant differences between the treatment groups.

CONCLUSIONS

The rapidity of symptom control can be evaluated by clinically significant parameters using ReQuest. Pantoprazole and esomeprazole are equally effective in the time to first and sustained symptom relief.

ParIS Genome Rearrangement server

SUMMARY

ParIS Genome Rearrangement is a web server for a Bayesian analysis of unichromosomal genome pairs. The underlying model allows inversions, transpositions and inverted transpositions. The server generates a Markov chain using a Partial Importance Sampler technique, and samples trajectories of mutations from this chain. The user can specify several marginalizations to the posterior: the posterior distribution of number of mutations needed to transform one genome into another, length distribution of mutations, number of mutations that have occurred at a given site. Both text and graphical outputs are available. We provide a limited server, a downloadable unlimited server that can be installed locally on any linux/Unix operating system, and a database of mitochondrial gene orders.

An efficient algorithm for statistical multiple alignment on arbitrary phylogenetic trees

We present an efficient algorithm for statistical multiple alignment based on the TKF91 model of Thorne, Kishino, and Felsenstein (1991) on an arbitrary k-leaved phylogenetic tree. The existing algorithms use a hidden Markov model approach, which requires at least O( radical 5(k)) states and leads to a time complexity of O(5(k)L(k)), where L is the geometric mean sequence length. Using a combinatorial technique reminiscent of inclusion/exclusion, we are able to sum away the states, thus improving the time complexity to O(2(k)L(k)) and considerably reducing memory requirements. This makes statistical multiple alignment under the TKF91 model a definite practical possibility in the case of a phylogenetic tree with a modest number of leaves.

Recombination, balancing selection and phylogenies in MHC and self-incompatibility genes

Using a coalescent model of multiallelic balancing selection with recombination, the genealogical process as a function of recombinational distance from a site under selection is investigated. We find that the shape of the phylogenetic tree is independent of the distance to the site under selection. Only the timescale changes from the value predicted by Takahata's allelic genealogy at the site under selection, converging with increasing recombination to the timescale of the neutral coalescent. However, if nucleotide sequences are simulated over a recombining region containing a site under balancing selection, a phylogenetic tree constructed while ignoring such recombination is strongly affected. This is true even for small rates of recombination. Published studies of multiallelic balancing selection, i.e., the major histocompatibility complex (MHC) of vertebrates, gametophytic and sporophytic self-incompatibility of plants, and incompatibility of fungi, all observe allelic genealogies with unexpected shapes. We conclude that small absolute levels of recombination are compatible with these observed distortions of the shape of the allelic genealogy, suggesting a possible cause of these observations. Furthermore, we illustrate that the variance in the coalescent with recombination process makes it difficult to locate sites under selection and to estimate the selection coefficient from levels of variability.

A molecular clock dates the common ancestor of European-type porcine reproductive and respiratory syndrome virus at more than 10 years before the emergence of disease

The disease caused by porcine reproductive and respiratory syndrome virus (PRRSV) emerged independently and almost simultaneously in Europe (1990) and North America (1987). The original reservoir of the virus and the date it entered the pig populations is not known. In this study, we demonstrate an accurate molecular clock for the European PRRSV ORF 3 gene, place the root in the genealogy, estimate the rate of nucleotide substitution, and date the most recent common viral ancestor of the data set to 1979; more than 10 years before the onset of the European epidemic. Based on these findings, we conclude that PRRSV virus most likely entered the pig population some time before the epidemic emergence of the virus, and hence, that emergence of European-type PRRSV is not the result of a recent species transmission event. Together, our results show that ORF3 sequencing is a valuable epidemiologic tool for examining the emergence and spread of PRRSV in Europe. As such, the panel of well-characterized and highly divergent ORF3 sequences described in this study provides a reference point for future molecular epidemiologic studies.

A simulation study of the reliability of recombination detection methods

There exist many methods to detect recombination or mosaic structure in a sample of DNA sequences. But how reliable are they? Four methods were investigated with respect to their power to detect recombination in simulated samples with different amounts of recombination and mutation. In addition, we investigated the impact of the shape of the underlying genealogy on their performances. We found that the methods detected far fewer recombinations than were theoretically possible and that methods based on the principle of incompatibility in general had more power than methods that did not make use of this principle explicitly. This seemed, in particular, to be the case for phylogenies generated under population expansion scenarios which result in long branches at the tips and small deep branches. In addition to the results obtained through simulations, a series of new theoretical results on recombination is presented.

Interleukin-12 and interleukin-18 are indispensable for protective immunity against enteropathogenic Yersinia

Previous results have demonstrated an essential role of gamma interferon (IFN-gamma) in resistance against Yersinia enterocolitica. Hence, we investigated the course of Yersinia infection in mice deficient for the IFN-gamma-inducing cytokines interleukin-12 (IL-12 p40(-/-)) or interleukin-18 (IL-18(-/-)). The experiments described herein argue for a critical role of both cytokines in protective immune responses against this pathogen.