Water-vapor-independent inlet system for a respiratory mass spectrometer: application to experiments with a human centrifuge.

When using a two-stage inlet system in mass spectrometric analysis of permanent gases, changes of water-vapor partial pressure from inspiration to expiration considerably impede the measurements. With this type of gas inlet system, use of a mass spectrometer for measurements on a human centrifuge is rather limited. Introduction of a water-vapor - independent three-stage inlet system permits quantitative analysis of gas mixtures even if the water vapor pressure varies quickly with time. The expiratory oxygen and carbon dioxide partial pressure curves should exemplify that even under extreme acceleration conditions the three-stage system permits simultaneous and continuous mass spectrometric analysis of respiratory gases, with satisfactory response time and a simple experimental arrangement. The method described thus opens up new experimental possibilities for the investigation or respiratory gas exchange phenomena under acceleration conditions.     

Epidemiological disaster research: the necessity to include representative samples of the involved disaster workers. Experience from the epidemiological study air disaster Amsterdam-ESADA

OBJECTIVE: To study whether the methods used to select participants in research on prevalence rates of the health effects of exposure to a disaster may cause bias. This study compared background characteristics, disaster exposure, and complaints reported by (1) police officers who participated in an epidemiological study and underwent a medical examination, and (2) police officers who only participated in an epidemiological study. DESIGN AND SETTING: In 2000, an epidemiological study was started to investigate the health status among police officers who were involved in assistance work related to the air disaster in Amsterdam: the epidemiological study air disaster Amsterdam (ESADA). These police officers were personally invited to participate in the epidemiological study and were additionally offered a medical examination, providing them with the opportunity to have their health checked by a medical doctor. PARTICIPANTS: Of the total group of involved police officers who were invited, 834 (70%) participated in the ESADA: 224 (26.9%) only participated in the study, but 610 (73.1%) also underwent the medical examination. MAIN RESULTS: Police officers who underwent a medical examination significantly more often reported one or more musculoskeletal complaints, skin complaints, general or non-specific complaints, had more often experienced an event with potentially traumatic impact, or had performed one or more potentially traumatic tasks. CONCLUSIONS: The methods of selection of participants are important in research on health effects after disasters and can result in an overestimation of some of the effects, on average, by a factor of 1.5 to 2.     

Einflußgrößen beim inhalativen Provokationstest mit Acetylcholin

The bronchial reactivity after acetylcholine inhalation was determined by measuring change of airway resistance. Out of 345 subjects studied, most of them were found to have symptoms and signs indicating CNSLD. 275 had different types of pneumoconiosis. Reactivity decreased with increasing age. Smokers and subjects with a positive skin test and anamnestic symptoms of allergy did not demonstrate different frequency of positive reactions after administration of acetylcholine. Airway obstruction, measured by the FEV_1.0/VC-ratio and airway resistance (R_t), caused an increased occurrence of positive challenge results. With progressing pneumoconiosis, the frequency of positive challenge reactions also increased; this is only partly explained by simultaneous deterioration of lung function. Other lung function parameters investigated did not show any correlation to the frequency of positive reactions after acetylcholine.     

Is Metformin Therapy for Polycystic Ovary Syndrome Safe During Pregnancy?

Polycystic ovary syndrome is characterized among other things by oligo-amenorrhea and may account for more than 75% of cases with anoluvatory infertility. Due to its positive effects on polycystic ovary syndrome-induced infertility metformin has become one of the most common drugs used in this group of patients. The efficacy of the drug as well as the first reports on metformin used in pregnancy has encouraged the continued use of the drug after conception. This MiniReview reviews the current pros and cons of metformin use in pregnancy while awaiting the results of ongoing randomised, controlled clinical trials addressing the subject.     

Systematic review of the efficacy and safety of shock wave therapy for lateral elbow pain

OBJECTIVE: To determine the efficacy and safety of extracorporeal shock wave therapy (ESWT) for lateral elbow pain. METHODS: Systematic review of randomized controlled trials using Cochrane Collaboration methodology. RESULTS: Nine placebo-controlled trials (1006 participants) and one trial of ESWT versus steroid injection (93 participants) were included. The 9 placebo-controlled trials reported conflicting results, although 11 of 13 pooled analyses found no significant benefit of ESWT over placebo, e.g., weighted mean difference for improvement in pain (on a 100-point scale) from baseline to 4-6 weeks (pooled analysis of 3 trials, 446 participants) was -9.42 (95% CI -20.70 to 1.86). Two pooled results favored ESWT, e.g., relative risk of treatment success (at least 50% improvement in pain with resisted wrist extension at 12 weeks) for ESWT in comparison to placebo (pooled analysis of 2 trials, 192 participants) was 2.2 (95% CI 1.55 to 3.12). However, this finding was not supported by the results of 4 other trials that were unable to be pooled. Steroid injection was more effective than ESWT at 3 months after the end of treatment assessed by a reduction of pain of 50% from baseline [21/25 (84%) vs 29/48 (60%); p < 0.05]. Minimal adverse effects of ESWT were reported. CONCLUSION: Based upon systematic review of 9 placebo-controlled trials, there is "platinum" level evidence that ESWT provides little or no benefit in terms of pain and function in lateral elbow pain. There is "silver" level evidence based upon one trial that steroid injection may be more effective than ESWT.     

Lateral epicondylitis in general practice: course and prognostic indicators of outcome

OBJECTIVE: To investigate the course of lateral epicondylitis and identify prognostic indicators associated with short- and longterm outcome of pain intensity. METHODS: We prospectively followed patients (n = 349) from 2 randomized controlled trials investigating conservative interventions for lateral epicondylitis in primary care. Uni- and multivariate linear regression analyses were used to investigate the association between potential prognostic indicators and pain intensity (0-100 point scale) measured at 1, 6, and 12 months after randomization. Potential prognostic factors were duration of elbow complaints, concomitant neck pain, concomitant shoulder pain, previous elbow complaints, baseline pain scores, age, gender, involvement of dominant side, social class, and work status. The variables "study" and "treatment" were included as covariates in all models. RESULTS: Pain scores at 1 month followup were higher in patients with severe pain, a long duration of elbow complaints, and concomitant shoulder pain. At 12 month followup, the only different prognostic indicator for poor outcome was concomitant neck pain, in place of shoulder pain. Patients from higher social classes reported lower pain scores at 12 month followup than patients from lower social classes. CONCLUSIONS: Lateral epicondylitis seems to be a self-limiting condition in most patients. Long duration of elbow complaints, concomitant neck pain, and severe pain at presentation are associated with poor outcome at 12 months. Our results will help care providers give patients accurate information regarding their prognosis and assist in medical decision-making.