Resonant infrared multiphoton dissociation spectroscopy of gas-phase protonated peptides. Experiments and Car–Parrinello dynamics at 300 K

The gas-phase structures of protonated peptides are studied by means of resonant infrared multiphoton dissociation spectroscopy (R-IRMPD) performed with a free electron laser. The peptide structures and protonation sites are obtained through comparison between experimental IR spectra and their prediction from quantum chemistry calculations. Two different analyses are conducted. It is first supposed that only well-defined conformations, sufficiently populated according to a Boltzmann distribution, contribute to the observed spectra. On the contrary, DFT-based Car-Parrinello molecular dynamics simulations show that at 300 K protonated peptides no longer possess well-defined structures, but rather dynamically explore the set of conformations considered in the first conventional approach.

The benefit of participating to clinical research

We assessed the impact of participating to clinical research among 1727 women with localized breast cancer. Using as referent individuals not treated according to guidelines for systemic therapy, the adjusted hazard ratio of death was 0.70 (95% confidence interval (CI): 0.54,0.90, p-value: 0.006) in those treated according to current guidelines and 0.45 (95% CI: 0.27,0.73, p-value: 0.001) in participants to research. Participation to clinical trials results in a substantial gain in survival.

Adult liver transplantation at UCL: update 2002

The authors present the results of a single centre study of 587 liver transplants performed in 522 adults during the period 1984-2002. Results have improved significantly over time due to better pre-, peri- and post-transplant care. One, five, ten and fifteen year actuarial survivals for the whole patient group are 81.2; 69.8; 58.9 and 51.2%. The high incidence of de novo tumors (12.3%), of cardiovascular diseases (7.5%) and of end-stage renal function (3.6%) should be further incentives to tailor the immunosuppression to the individual patient and to direct the attention of the transplant physician to the long-term quality of life of the liver recipient.

MICRA: a compact permanent magnet Fourier transform ion cyclotron resonance mass spectrometer

MICRA, a compact Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer is described. The amount of miniaturisation in this device, based on a 1.24 T permanent magnet, remains compatible with genuine FT-ICR performance and analytical power in the mass range 2-1000 m/z, with a mass resolving power of 73,000 at mass 132. A first application of the transportability is the repetitive coupling of MICRA with a large-scale source of IR photons, the free electron laser CLIO.

Gas phase infrared spectroscopy of selectively prepared ions

The first example of direct structural characterization of polyaromatic ions by coupling a Fourier transform ion cyclotron resonance mass spectrometer with an infrared free-electron laser is presented. Measurement of the IR spectra of selectively prepared ionic reactive intermediates is allowed by the association of the high peak power and wide tunability of the laser with the flexibility of the spectrometer, where several mass selection and ion reaction steps can be combined, as demonstrated in the case of iron cation complexes of hydrocarbons. The present experimental setup opens the way to understanding chemical reaction paths.

Cost-benefit and cost-effectiveness analysis of a disability prevention model for back pain management: a six year follow up study

AIMS

To test the long term cost-benefit and cost-effectiveness of the Sherbrooke model of management of subacute occupational back pain, combining an occupational and a clinical rehabilitation intervention.

METHODS

A randomised trial design with four arms was used: standard care, occupational arm, clinical arm, and Sherbrooke model arm (combined occupational and clinical interventions). From the Quebec WCB perspective, a cost-benefit (amount of consequence of disease costs saved) and cost-effectiveness analysis (amount of dollars spent for each saved day on full benefits) were calculated for each experimental arm of the study, compared to standard care.

RESULTS

At the mean follow up of 6.4 years, all experimental study arms showed a trend towards cost benefit and cost effectiveness. These results were owing to a small number of very costly cases. The largest number of days saved from benefits was in the Sherbrooke model arm.

CONCLUSIONS

A fully integrated disability prevention model for occupational back pain appeared to be cost beneficial for the workers' compensation board and to save more days on benefits than usual care or partial interventions. A limited number of cases were responsible for most of the long term disability costs, in accordance with occupational back pain epidemiology. However, further studies with larger samples will be necessary to confirm these results.

Calibration results obtained with Liulin-4 type dosimeters

The Mobile Radiation Exposure Control System's (Liulin-4 type) main purpose is to monitor simultaneously the doses and fluxes at 4 independent places. It can also be used for personnel dosimetry. The system consists of 4 battery-operated 256-channel dosimeters-spectrometers. We describe results obtained during the calibrations of the spectrometers at the Cyclotron facilities of the University of Louvain, Belgium and of the National Institute of Radiological Sciences-STA, Chiba, Japan with protons of energies up to 70 MeV. The angular sensitivities of the devices are studied and compared with Monte-Carlo predictions. We also present the results obtained at the HIMAC accelerator with 500 MeV/u Fe ions and at the CERN high energy radiation reference fields. Records made during airplane flights are shown and compared with the predictions of the CARI-6 model.

Implementation of a participatory ergonomics program in the rehabilitation of workers suffering from subacute back pain

This paper describes a participatory ergonomics program aimed at early return to regular work of workers suffering from subacute occupational back pain and assesses the perceptions of the participants on the implementation of ergonomic solutions in the workplace. The participatory ergonomics program was used in the rehabilitation of workers suffering from subacute back pain for more than 6 weeks, a program that was associated with an increased rate of return to work. The perceptions of the participatory ergonomics participants were assessed 6 months after completion of the ergonomic intervention through a questionnaire sent to employer representatives, union representatives and injured workers of participating workplaces. About half of the ergonomic solutions were implemented according to the perception of the participants, with a substantial agreement between respondents.

Disability measurement in persons with back pain: a validity study of spinal range of motion and velocity

OBJECTIVE

To evaluate the criterion validity and responsiveness to change of spine kinematic variables to assess disability in patients with low back pain.

DESIGN

Blinded comparison between spine kinematic variables, Oswestry disability questionnaire scores, and work status.

SETTING

Multidisciplinary occupational rehabilitation clinic of a university hospital.

PATIENTS

Population-based cohort of 111 patients with subacute work-related back pain who were absent from regular work for more than 4 weeks because of back pain.

INTERVENTIONS

This study was part of a population-based randomized clinical trial. Patients were randomized to 4 different methods of management: usual care, rehabilitation, ergonomics, or rehabilitation and ergonomics.

MAIN OUTCOME MEASURES

Oswestry disability questionnaire, kinematic analysis of the spine during flexion and extension of the trunk, and work status were collected at weeks 4, 12, 24, and 52 after the back accident.

RESULTS

Kinematic variables were poorly to moderately related to work status and Oswestry questionnaire scores. Kinematic variables were also unresponsive to change in work status and Oswestry questionnaire scores over time.

CONCLUSION

Spine kinematics during flexion and extension of the trunk do not appear to be a valid measure of disability in patients with subacute and chronic back pain.

Prevalence of GBV C/HGV RNA and GBV C/HGV antibodies in French volunteer blood donors: results of a collaborative study

BACKGROUND AND OBJECTIVES

Posttransfusion hepatitis still occurs at an incidence of about 1 in 118,000 for HBV and 1 in 220,000 for HCV. This collaborative study aimed to determine the prevalence of a novel flavivirus, GBV-C/HGV, even though its role in transfusion-associated hepatitis is uncertain.

MATERIALS AND METHODS

GBV-C/HGV RNA was detected by PCR using either the Boehringer detection kit or by primers previously described. HGV antibodies were detected by a serological assay from Boehringer.

RESULTS

The observed GBV-C/HGV RNA frequency was 3.4%. HGV antibodies occurred in 9.5% of donors.

CONCLUSION

In our study, 12. 9% of the donors had been in contact with the GBV-C/HGV virus.

Genetic testing for breast and ovarian cancer: implications for life insurance

As the science of genetic testing progresses, the debate surrounding the uses of genetic information intensifies. In February, President Clinton signed an executive order prohibiting federal agencies from using such information to make hiring, promotion, or placement decisions. Concerns about privacy and discrimination have led many states to propose or enact statutes that prohibit health insurers from using genetic test results in their underwriting decisions. However, few statutes address access to these results by the life insurance industry. This Issue Brief summarizes the current debate on whether life insurers should have access to genetic testing information for breast and ovarian cancer, and provides actuarial insight into the potential effect of such testing on the voluntary term insurance market.

Space travel directly induces skeletal muscle atrophy

Space travel causes rapid and pronounced skeletal muscle wasting in humans that reduces their long-term flight capabilities. To develop effective countermeasures, the basis of this atrophy needs to be better understood. Space travel may cause muscle atrophy indirectly by altering circulating levels of factors such as growth hormone, glucocorticoids, and anabolic steroids and/or by a direct effect on the muscle fibers themselves. To determine whether skeletal muscle cells are directly affected by space travel, tissue-cultured avian skeletal muscle cells were tissue engineered into bioartificial muscles and flown in perfusion bioreactors for 9 to 10 days aboard the Space Transportation System (STS, i.e., Space Shuttle). Significant muscle fiber atrophy occurred due to a decrease in protein synthesis rates without alterations in protein degradation. Return of the muscle cells to Earth stimulated protein synthesis rates of both muscle-specific and extracellular matrix proteins relative to ground controls. These results show for the first time that skeletal muscle fibers are directly responsive to space travel and should be a target for countermeasure development.