First result from the Alpha Magnetic Spectrometer on the International Space Station: precision measurement of the positron fraction in primary cosmic rays of 0.5-350 GeV.

A precision measurement by the Alpha Magnetic Spectrometer on the International Space Station of the positron fraction in primary cosmic rays in the energy range from 0.5 to 350 GeV based on 6.8 × 10(6) positron and electron events is presented. The very accurate data show that the positron fraction is steadily increasing from 10 to ∼ 250 GeV, but, from 20 to 250 GeV, the slope decreases by an order of magnitude. The positron fraction spectrum shows no fine structure, and the positron to electron ratio shows no observable anisotropy. Together, these features show the existence of new physical phenomena.

Observation of pulsed gamma-rays above 25 GeV from the Crab pulsar with MAGIC.

One fundamental question about pulsars concerns the mechanism of their pulsed electromagnetic emission. Measuring the high-end region of a pulsar's spectrum would shed light on this question. By developing a new electronic trigger, we lowered the threshold of the Major Atmospheric gamma-ray Imaging Cherenkov (MAGIC) telescope to 25 giga-electron volts. In this configuration, we detected pulsed gamma-rays from the Crab pulsar that were greater than 25 giga-electron volts, revealing a relatively high cutoff energy in the phase-averaged spectrum. This indicates that the emission occurs far out in the magnetosphere, hence excluding the polar-cap scenario as a possible explanation of our measurement. The high cutoff energy also challenges the slot-gap scenario.

Very-high-energy gamma rays from a distant quasar: how transparent is the universe?

The atmospheric Cherenkov gamma-ray telescope MAGIC, designed for a low-energy threshold, has detected very-high-energy gamma rays from a giant flare of the distant Quasi-Stellar Radio Source (in short: radio quasar) 3C 279, at a distance of more than 5 billion light-years (a redshift of 0.536). No quasar has been observed previously in very-high-energy gamma radiation, and this is also the most distant object detected emitting gamma rays above 50 gigaelectron volts. Because high-energy gamma rays may be stopped by interacting with the diffuse background light in the universe, the observations by MAGIC imply a low amount for such light, consistent with that known from galaxy counts.

Variable very-high-energy gamma-ray emission from the microquasar LS I +61 303.

Microquasars are binary star systems with relativistic radio-emitting jets. They are potential sources of cosmic rays and can be used to elucidate the physics of relativistic jets. We report the detection of variable gamma-ray emission above 100 gigaelectron volts from the microquasar LS I 61 + 303. Six orbital cycles were recorded. Several detections occur at a similar orbital phase, which suggests that the emission is periodic. The strongest gamma-ray emission is not observed when the two stars are closest to one another, implying a strong orbital modulation of the emission or absorption processes.

[Value of ultrasound study and dual energy x-ray absorptiometry (DEXA) for assessment of risk of osteoporosis]. / Stellenwert von Ultraschalluntersuchung und Dual Energy X-Ray-Absorptiometry (DEXA) zur Abklärung des Osteoporoserisikos.

UNLABELLED: Screening postmenopausal women for preventing osteoporosis at an early stage is the main topic of several studies. The present paper evaluates the place of ultrasound measurements in comparison with Dual Energy X-ray-absorptiometry (DEXA). METHODS: 247 women (41 women < or = 50 yrs, 103 women 50-60 yrs, 103 women > 60 yrs) underwent DEXA of the vertebrae and hip and concommittantly ultrasound measurements of the calcaneus. RESULTS: The DEXA values in the vertebral column vary considerably and are lowest in L1 and highest in L4. The femur on the other hand shows lowest values in the Ward triangle (T = -1.6 SD), and highest in the trochanter (T = -0.3 SD). Speed of sound (SOS) gives lower T-values (-1.2 SD) than broadband ultrasound attenuation (BUA) (-0.3 SD). Statistical analysis (Spearman, Pearson) shows no correlation between ultrasound and DEXA measurements and therefore do not permit analogies between hip and vertebral column and vice versa. CONCLUSIONS: Our data show that the fracture risk of an individual woman can be adequately ascertained only by DEXA-measurement of vertebrae and femur. Ultrasound measurement today cannot be recommended as routine screening or diagnostic method.

Determinants of health care costs and patterns of care of asthmatic patients in Switzerland.

OBJECTIVE: To investigate whether medical resource utilisation, costs and clinical status were influenced by: (1) type of physician (specialist versus GP); (2) treatment modality (on-demand vs long-term continuous therapy); (3) labour force participation; (4) insurance coverage (private vs statutory); (5) geographic area (urban vs rural). MATERIAL AND METHODS: Chart reviews in the last 5 patients seen by treating physicians. Direct medical expenditure included charges for hospitalisation, outpatient services, physicians' services and medication, whereas indirect costs included the value of time lost from work. RESULTS: The overall annual mean cost per patient in 589 patients was CHF 2600 [95% confidence interval: 1956; 3245]. Costs in 117 children were CHF 824 [531; 1116], and CHF 3041 [2244; 3837] in adults. Compared with pulmonologists, adults treated by GPs had a higher rate of hospital admissions, equal specialist referrals and more days off work. Hospital admissions in children were similar in GPs and paediatricians. Total direct costs were highest for internists, followed by GPs. Pulmonologists incurred the lowest direct costs in adults compared to GPs or internists (p < 0.05). Total costs for children were equal for GPs and paediatricians. Differences in costs between on-demand and long-term prophylactic treatment were: CHF 834 [318; 1351] versus CHF 1856 [1488; 2224], (p = 0.002). Highest total costs were observed for unemployed patients and those receiving disability payments. Patients with supplementary insurance cover had a lower overall resource utilisation rate and costs than patients without: CHF 2284 [95% CI: 535; 4034] versus CHF 2670 [1844; 3496] (p = 0.8). Total costs were CHF 2319 [1660; 2979] for patients treated in cities and CHF 3062 [1742; 4382] in rural areas (p < 0.0001) as well as lower in the German-speaking part of the country (CHF 2320 [1743; 2897]) than in the French-speaking region (CHF 3610 [1479; 5740] [p < 0.005]). CONCLUSIONS: Factors determining higher resource utilisation and costs are: treatment by non-specialists, long-term continuous treatment, the absence of supplementary health care insurance, treatment in rural areas, and treatment in the French-speaking cantons.

[Modern long-term oxygen therapy--practical aspects]. / Moderne Sauerstoff-Langzeittherapie--praktische Aspekte.

Modern and accurately performed long term oxygen therapy improves quality of life and life expectancy in patients with chronic obstructive lung disease suffering from hypoxemia. This type of therapy often fails since the patient is bothered by the nasal prongs and fears to dwell outside his home. As a consequence, the major goal of this form of therapy, namely enhanced patients mobility is not attained. Oxygen can be delivered at a high efficiency by a transtracheal catheter. This mode of application may considerably improve the patients comfort and hence his compliance and mobility.

The economic burden of asthma: direct and indirect costs in Switzerland.

Asthma mortality increased in Switzerland between 1980 and 1994. This study aimed to assess the economic burden of asthma in this country. Chart reviews were conducted for the last five patients seen for asthma in physician practices in 1996 and 1997. Direct expenditures and indirect costs for asthma-related morbidity were determined. A total of 589 patient charts were completely analysed, including 117 children's charts, obtained from 120 office-based physicians. The annual direct medical costs were CHF 1,778 and the mean annual indirect costs were CHF 1,019 per patient for all patients. The total estimated cost of asthma in Switzerland in 1997 was nearly CHF 1,252 million. Direct medical expenditures approached CHF 762 million, or 61% of the total. In 1997, the indirect costs for asthma were estimated to have exceeded CHF 490 million. Of these costs CHF 123 million (25%) was associated with morbidity and nearly CHF 368 million (75%) was associated with looking after asthmatic patients who had to be cared for at home. This study provides evidence that asthma is a major healthcare cost factor in Switzerland, amounting to approximately CHF 1,200 million per year. The data suggest that cost savings can be achieved by improving primary care for asthma in an ambulatory setting.

Management 1997 of chronic obstructive pulmonary disease. Working Group of the Swiss Society of Pneumology.

COPD is a disorder characterized by expiratory flow limitation that does not change markedly over periods of several months' observation. When the diagnosis is suspected, COPD patients should be submitted to full assessment and initiation of therapy. Initial assessment includes a complete history, a detailed physical examination, pulmonary function tests, a chest X-ray, and blood tests. Therapy of COPD aims at reducing symptoms, preventing exacerbations and preserving optimal lung function. Many COPD patients have a bronchospastic component and usually show some response to bronchodilator therapy. Anticholinergics, beta 2-agonists or theophylline are used as monotherapy or in combination. A subgroup of patients with COPD may benefit from oral long-term corticosteroid therapy. At prime diagnosis of COPD, a trial of oral steroid under optimal bronchodilator therapy is warranted in order to identify steroid responders early in the course of the disease. Stopping smoking is the most effective preventive measure and should be combined with complementary approaches such as eviction of environmental irritants, vaccines and prescription of antioxidants. Long-term oxygen therapy is beneficial in chronically hypoxemic patients. Respiratory rehabilitation uses a multidisciplinary approach aiming at decreasing dyspnea, increasing exercise tolerance and improving quality of life. Nocturnal home noninvasive mechanical ventilatory assistance can improve arterial blood gas tensions in patients with respiratory failure, but the long-term effect on survival is still under investigation. In selected patients, surgery (bullectomy, lung volume reduction, lung transplantation) may greatly improve pulmonary function.

[Efficacy and tolerance of terbutaline and budesonide administered via a pressurized aerosol inhaler or a Turbohaler in asthmatic patients]. / Efficacité et tolérance de la terbutaline et du budésonide administrés à l'aide d'un aérosol-doseur pressurisé ou d'un Turbuhaler aux patients asthmatiques.

35 asthmatic patients, aged from 23 to 73 years, participated in an open study aimed to compare the efficacy and tolerance of terbutaline and budesonide administered in similar amounts with a metered-dose inhaler fitted with a spacer (Nebuhaler) or by a powder inhaler (Turbuhaler). The patients used each device for seven weeks after a running-in phase of two weeks and gave at the end their preference for one or the other mode of administration. Among lung function values, the forced expiratory volume in the first second (FEV1) was significantly higher during the Turbuhaler period than during the period with metered-dose inhaler whereas the forced vital capacity, mid-expiratory flow rate and peak-flow morning and evening were not significantly different. The use of beta 2-bronchodilators and clinical scores were similar with a non-significant trend in favor of the Turbuhaler period. 25 patients on 35 expressed a preference for the Turbuhaler. The administration of terbutaline and budesonide by Turbuhaler is similarly or more efficient then the inhalation from a metered-dose inhaler with a Nebuhaler spacer and is preferred by a majority of patients.

[Experiences with long-term transtracheal oxygen therapy]. / Erfahrungen mit der transtrachealen Langzeit-Sauerstofftherapie.

A transtracheal catheter (TTC) (Scoop) was implanted in 24 patients (19 men, 5 women) with a mean age of 64 +/- 9 (47 to 78) years. The pO2 was 6.78 +/- 1.65 kPa. Two patients suffered from pulmonary restriction, 22 from severe COPD with a FEV1 of 880 +/- 165 ml. Purulent tracheitis developed in six patients. The pre-Scoop catheter had to be removed in three. In four patients, bronchoscopic aspiration of mucus plugs adhering to the tip of the TTC was necessary. In one patient, the TTC was removed after an uneventful course due to patient's discomfort; another patient no longer qualified for LOT. 19 patients were using the TTC without major problems. Of those, five have died due to severe lung disease. By using TTC, oxygen consumption is halved for the same degree of oxygenation. 12 are using a demand valve device (Oxymatic), which allows a further conservation of oxygen. Patients prefer LOT by a TCC for cosmetic reasons and lack of nasal discomfort.

[Transtracheal O2 administration in long-term oxygen therapy]. / Transtracheale O2-Applikation zur Sauerstoff-Langzeittherapie.

The safety and efficacy of transtracheal oxygen delivery was evaluated in 8 patients with chronic hypoxemia due to severe lung disease. In 7 the tracheal catheter has now been in place for 7 months on average. It had to be removed in one patient because of hemorrhagic and purulent tracheitis. Accumulation of tenacious mucus at the endotracheal end of the catheter occurred in three patients. A mucus ball had to be removed by fiberoptic bronchoscopy in two. Oxygen usage is reduced by 50%, thus prolonging the duration of portable oxygen sources. All patients preferred the transtracheal catheter to the nasal cannula as being esthetically superior and non-injurious to the nasal mucosa.

[Chronic respiratory insufficiency in general practice]. / Die chronische Ateminsuffizienz in der Praxis.

The clinical entity of chronic respiratory insufficiency involves a variety of lung diseases with different etiology. Diagnosis, treatment and follow-up are mainly a problem of ambulatory medicine. The most common representative is the patient with chronic obstructive lung disease. The wide array of diagnostic tools makes the selection of appropriate tests difficult for the general practitioner. The clinical findings, as the most important aspect, together with a simple spirometric test (VC and FEV1), however, provide the physician with sufficient parameters to evaluate the current status. Blood gas analysis are indispenable, but can be performed at lengthy intervals. The main therapy relies on selective beta-agonists in combination with steroids. For long-term administration of steroids, however, inhaled steroids should be preferred. Antibiotics should be used liberally and without delay. Cardiac therapy is an important cornerstone in the treatment of chronic respiratory insufficiency. The frequency of glycoside intolerance makes diuretics the ideally suited drug for treatment of concomitant cardiac insufficiency. It is advantageous to use consistent inhalation therapy for drug administration, mainly due to the milder systemic side-effects. A choice must be made between the simple electric nebulizer or the more demanding IPPB-respirator, which requires more demanding patient selection. Both types can be leased through Cantonal institutions, which also provide for regular control of inhalation techniques and maintenance of the inhalation devices. Physiotherapy plays an important part in the instruction of patients as well as providing them with psychological assistance and support in everyday problems. Regular monthly controls by a physician with a standardized questionnaire have proven most useful in guiding the patients and adjusting therapy to individual needs. The frequency of hospitalization can only be reduced by observing all the above mentioned factors.