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M Scherrer

Publications and source records attributed to M Scherrer.

At least 19 recordsLinked to original sources
PubMed1999

[Life-cycle assessment of single-use versus reusable surgical drapes (cellulose/polyethylene-mixed cotton system)].

Surgical drapes made of cotton are under increasing competition with various disposable products and reusable draping systems (e.g., made of synthetic fabrics like polyester). When making a choice to use one of these medical devices in practical surgery, major aspects like handling, hygienic safety and costs, but also environmental effects have to be taken into account. In this study a mixed system for patient drapes (reusable cotton drapes combined with a reduced set of impermeable single-use drapes made of cellulose/polyethylene) was compared to a system that is only based on single-use drapes with regard to ecology [life-cycle assessment (LCA)]. The medical literature was reviewed to assess important medical aspects of the use of patient drapes, resulting in the statement that there are no conclusive arguments to support a clear hygienic superiority of one of these alternatives. Based on the conditions assumed and stated, the results of the LCA indicate that the mixed draping system is associated with two times more total energy consumption. In addition, more water is needed and more CO2 emissions are produced. However, draping with the single-use product results in more clinical waste. Regarding water pollution no system proved superior. It is difficult to compare and weigh various environmental aspects like the polluting cultivation of cotton in distant countries (reusable drapes) and the higher figure of transportation necessary to deliver the single-use product within Germany. It is an important disadvantage of the mixed system that it combines the ecological burden of both cotton drapes and the single-use alternative.

Cellulose↗
PubMed1998

Costs of low-temperature plasma sterilization compared with other sterilization methods.

Plasma sterilization is a new technique for decontaminating thermolabile products without the severe drawbacks associated with gas sterilization methods (residues, environment compatibility). The actual costs, per sterilization unit, of three sterilization techniques--plasma, ethylene oxide and formaldehyde--were compared. As plasma sterilization is an alternative to steam sterilization for sterilizing thermostable but easily corroding products or electronic instruments, costs for steam sterilization were calculated and compared as well. If one considers only the cost of the sterilization procedure itself, without taking into account the time-saving element of plasma sterilization, then ethylene oxide sterilization proves to be the most expensive procedure, followed by plasma sterilization; sterilization with formaldehyde was the least expensive. Inclusion of the time required to sterilize an instruments, however, altered the relative costs of the three methods. Because plasma sterilization takes less time to perform than either ethylene oxide or formaldehyde sterilization, fewer instruments need be procured. In order to measure and compare the time-saving advantage that plasma sterilization affords, five groups of instruments were assembled and the total cost of sterilizing an instrument of each group was calculated. The five groups included (1) disposable, (2) electronic, (3) endoscopic, (4) sharp and (5) standard instruments. In all cases, ethylene oxide sterilization was the most expensive method. Formaldehyde sterilization was, in four out of five cases, more expensive than plasma sterilization. Steam sterilization proved to be the cheapest method of sterilizing a laparoscopic set, even when costs due to damage inflicted on the optical instruments were calculated. In the case of a vitrectome, however, plasma sterilization costs were nearly the same as steam sterilization when the lower rate of damage by plasma sterilization was taken into account.

Costs and Cost Analysis↗
PubMed1997

Potassium transport by amino acid permeases in Saccharomyces cerevisiae.

Deletion of the potassium transporter genes TRK1 and TRK2 impairs potassium uptake in Saccharomyces cerevisiae, resulting in a greatly increased requirement for the ion and the inability to grow on low pH medium. Selection for mutations that restored growth of trk1Delta trk2Delta cells on low pH (3.0) medium led to the isolation of a dominant suppressor that also partially suppressed the increased K+ requirement of these cells. Molecular analysis revealed the suppressor to be an allele of BAP2 that encodes a permease for branched chain amino acids. The suppressor mutation (BAP2-1) converts a phenylalanine codon, highly conserved among the amino acid permease genes, to a serine codon in a region predicted to lie within the sixth membrane-spanning domain. Generation of the analogous mutation in the histidine permease produced an allele, HIP1-293, that similarly suppressed the low pH sensitivity of trk1Delta trk2Delta cells. Suppression of trk1Delta trk2Delta phenotypes by BAP2-1 or HIP1-293 was correlated with increased Rb+ uptake. The presence of the substrate amino acids enhanced but was not essential for suppression of trk1Delta trk2Delta phenotypes and increased Rb+ uptake. The conserved site altered by the suppressor mutations appears to be important; his4 HIP1-293 cells show an increased requirement for histidine compared with his4 HIP1 cells.

Alleles↗
PubMed1997

Bone mineral density of opposing hips using dual energy X-Ray absorptiometry in single-beam and fan-beam design.

Bone densitometry focuses on bone mineral area density (BMD in g/cm2) of the proximal femur and spine in anterior-posterior (AP) projections. Artifacts, such as osteoarthritis and osteophytic calcifications (OC) influence spine BMD, especially in AP scans. If only two sites are measured, as is usual in clinical practice, there may be advantages to measuring both femora rather than one femur and the spine. This would not be useful, however, if there was strong symmetry between the two sides. Furthermore, fan beam (FB) techniques have become available for measuring BMD with less data acquisition time. We compared densitometry of opposing femora in 421 patients (369 women, mean age 59.0 +/- 4.8; 52 men, mean age 56.9 +/- 7.4) using dual-energy X-ray absorptiometry (DXA): both single-beam (SB) and FB modes were evaluated. The precision errors in vivo (short- and midterm) of total BMD were 0.7% for both SB and FB. The total BMD and BMC of the left hip (0.817 +/- 0.124 g/cm2, 31. 3 +/- 6.4 g) were significantly (P < 0.001) higher (2-3%) than the corresponding values of the right hip (0.801 +/- 0.125 g/cm2, 30.3 +/- 6.3 g) in both SB and FB (left BMD 0.802 +/- 0.117 g/cm2, BMC 30. 0 +/- 6.2 g versus right BMD 0.795 +/- 0.117 g/cm2, BMC 29.3 +/- 6.3 g) modes. However, BMD of the femoral neck and Ward's triangle were not significantly (P > 0.05) different between the two sides. The FB results were generally 2% lower than SB results. There were highly significant (P < 0.001) correlations (r > 0.9) between both hips using both SB and FB. For diagnostic procedures and longitudinal studies, one should consider that there are bilateral differences of femur BMD, as well as differences between FB and SB scan modes.

Absorptiometry, Photon↗
PubMed1997

Environmental auditing in hospitals: approach and implementation in an university hospital.

Medical audit in infection control today is accepted as an important element in the quality assurance of health care. In contrast, environmental auditing, which was approved in 1993 by the Council of the European Communities for industry ("Eco-Management and Audit Scheme-EMAS), has not so far been used as a tool to control and reduce environmental pollution caused by medical care in hospitals. The aim of this study was to investigate, whether environmental auditing in hospitals is useful. This process should also be cost effective. In this paper, methodological and organizational issues are described. Initially an environmental review of activities at the University Hospital, Freiburg and an eco-analysis of the input and output were performed. The first results of the study and a critical discussion will be presented in another paper.

Conservation of Energy Resources↗
PubMed1995

Evaluation of dual-energy X-ray absorptiometry bone mineral measurement--comparison of a single-beam and fan-beam design: the effect of osteophytic calcification on spine bone mineral density.

Dual energy X-ray absorptiometry (DXA) using a single-beam (SB) design is a well-established procedure for measuring bone mineral area density (BMD). Recently, fan beam (FB) techniques have become available to measure BMD. We evaluated the QDR1000 and QDR2000 densitometers with regard to precision and cross-compared values using single beam (SB) and FB techniques. To study the effect of osteoarthritic changes on bone measurement (BMC in g) and bone mineral area density (BMD in g/cm2), both parameters were measured in patients with and without osteophytic calcifications (OC) of the lumbar spine. Precision errors for BMD in vitro over 1 and 6 months using the QDR2000 were 0.4% and 0.6% for SB and 0.5% and 0.7% for the three FB modes. For QDR1000 only SB is available. Using this scan mode, the BMD difference (delta = 0.1%) in vitro between QDR1000 and QDR2000 was not significant. The short-term (same day) reproducibility of BMD in vivo was 0.85% for SB mode and 1.1% for FB scan mode (n = 33). The midterm (1 month) precision errors were 0.9% for SB and 1.5% for FB (n = 11). The spine BMD of 751 patients from our outpatient clinic and department of rheumatology was 1.7% lower with FB than with SB (0.878 +/- 0.137 versus 0.888 +/- 0.146 g/cm2). Lower (1.8%) BMD values were also found in the hip with FB compared to SB (0.805 +/- 0.111 versus 0.821 +/- 0.111 g/cm2). There was a highly significant (P < 0.00001) correlation between SB and FB on the spine (r = 0.99) and hip (r = 0.98) using the QDR2000. Correlations found QDR1000 and QDR2000 were lower on the spine (r = 0.97) and hip (r = 0.93).(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗
PubMed1995

Lateral spine dual-energy X-ray absorptiometry bone mineral measurement with fan-beam design: effect of osteophytic calcifications on lateral and anteroposterior spine BMD.

Recently, fan beam (FB) designs have been made available by several manufacturers (Aloka, Hologic Lunar and Sophar) to measure lumbar spine bone mineral area density (BMD) in both an anteroposterior (AP) and a lateral projection. The present study was performed to evaluate some characteristics of a new dual energy X-ray absorptiometry (DXA) system for supine lateral scans in normals and to study possible advantages for patients with osteophytic calcifications (OC). The precision errors of in vitro and in vivo measurements were estimated by an anthropomorphic phantom and in healthy volunteers. To study the effect of osteoarthritic changes on AP and lateral DXA measurements, BMC (bone mineral content) and BMD were measured in age-matched women (n = 150) with and without OC. Precision errors for lateral BMD in vitro over 1 and 6 months were 0.58/0.67% (slow/fast scan modes) and 0.67/0.77% (slow/fast scan modes), respectively. The short- and mid-term reproducibility of BMD values were 2% and 3.5%, respectively, using the compare function (3.5% and 7.5%, respectively, without the compare facility). The analysis of women with and without OC (n = 150) demonstrated higher mean values for AP BMD (0.892 +/- 0.145 g/cm2) in patients with OC (n = 75) than in normals (0.836 +/- 0.135 g/cm2, n = 75, difference 6.3%). For lateral scans, BMD differed to a minor degree (3.1%) in patients with OC (0.629 +/- 0.133 g/cm2) compared with normals (0.610 +/- 0.117 g/cm2). Corresponding results were obtained in fast FB mode. Furthermore, we found significant (P < 0.0001) correlations between BMD in lateral and AP scans in patients without OC (r = 0.63) and in patients with OC (r = 0.57). Although the FB design facilitated fast AP and lateral scans, the higher precision errors of lateral scans could limit its application in longitudinal studies. The use of compare function should be recommended. However, BMD of lateral scans was less influenced by OC.

Absorptiometry, Photon↗
PubMed1992

Technetium-99m-DTPA aerosol and gallium-67 scanning in pulmonary complications of human immunodeficiency virus infection.

We retrospectively compared the results of 67Ga chest scans and 99mTc-DTPA aerosol clearance measurements with those of fiberoptic bronchoscopy in 88 patients infected with the human immunodeficiency virus. Of 100 investigations, a pulmonary infection was diagnosed in 39, mainly Pneumocystis carinii pneumonia and a noninfectious disorder was found in 42, mainly Kaposi's sarcoma and lymphocytic alveolitis. Gallium scans and DTPA clearance were abnormal respectively in 74% and 92% of infectious complications, and in 12% and 60% of noninfectious disorders. In 10 cases, DTPA clearance was accelerated, while chest x-ray, arterial blood gases and even gallium scanning were normal. A value of DTPA clearance greater than 4.5%.min-1 was both sensitive and specific for the diagnosis of Pneumocystis carinii pneumonia. The gallium scan was always normal in bronchopulmonary Kaposi's sarcoma. We conclude that in symptomatic patients: (1) DTPA clearance measurements are useful for detecting lung disease when chest x-ray and/or PaO2 are normal and (2) a gallium scan is indicated to distinguish progressive Kaposi's sarcoma from a superimposed second process when radiological abnormalities of pulmonary Kaposi's sarcoma are present.

Acquired Immunodeficiency Syndrome↗
PubMed1991

[Pregnancy and traffic accident. A case report].

The authors report the case of patient (second pregnancy, first birth) who had been involved in a traffic accident which occurred on October 5, 1989 after 7 months of pregnancy. The trauma was scored 2 on the international Overall Abbreviated Injury Scale. The impact was frontal and the patient driving and wearing her seatbelt. After being admitted to hospital on several occasions with metrorrhagia and uterine contractions, it was decided to carry out a cesarian and a baby was successfully removed. The child presented with angulation of the left fore-arm and skeletal X-ray, particularly of the arms, revealed a fracture line with a callous already formed.

Accidents, Traffic↗
PubMed1990

[The role of isotope methods in evaluating the left ventricular function].

Cardiac angioscintigraphy is a non-invasive, reproducible and reliable technique used to obtain a number of cardiac function parameters, the most important of which is left ventricular ejection fraction. Methodologically, the examination is simple. Fourier's analysis (a mathematical decomposition of ventricular mechanics) provides additional information on some abnormalities and is particularly useful in segmental kinetics studies and in the topographical diagnosis of cardiac rhythm disorders. The technique is indicated mainly for prognostic evaluation and follow-up of patients with left ventricular dysfunction. Metaiodobenzylguanidine (MIBG) cardiac scintigraphy makes it possible to evaluate the reuptake of noradrenaline by neurons, which represents the inactivation pathway of adrenergic neurotransmission and is the principal factor of noradrenaline extraction. MIBG scintigraphy is an indirect way of evaluating left ventricular function in congestive heart failure, as suggested by the results of studies showing correlations between MIBG uptake, left ventricular function indices and disease severity as judged on the basis of evolutive parameters.

3-Iodobenzylguanidine↗
PubMed1990

[Hypertrophic and/or obstructive primary cardiomyopathies: genetic, etiologic, physiopathologic aspects].

The morphological features, mode of presentation and physiopathology of hypertrophic cardiomyopathy (HCM) are variable. Autosomal dominant seems to be the usual mode of transmission but with variable presentation. From the anatomical point of view, the hypertrophy is asymmetrical with septal predominance. The main histological features are myocytic architectural disorganisation, fibrosis and abnormal coronary arteries of small diameter. Ventricular hyperkinesis is usually present and sometimes associated with outflow obstruction, the physiological role and mechanisms of which are still not fully understood. On the other hand, abnormal diastolic function is frequently observed, and, quite independently of disease of the epicardial coronary arteries, ischaemic phenomena may occur. Although the biological substrate of HCM is unknown, abnormalities of the adrenergic system and transmembrane calcium flux probably play a part in the expression of the disease.

Cardiomyopathy, Hypertrophic↗
PubMed1990

[A cost comparison of Pall filters versus chemical or thermal disinfection of ventilator tubes].

Filter manufacturers claim that the use of disposable filters for anesthesia and ventilation therapy would be more economical than changing the tubes and/or ventilation circuits every 24 h or 48 h. We therefore compared the costs of chemical disinfection or thermal disinfection of 4 different ventilation tube systems with those of disposable Pall filters. The cost of disinfecting tubes used for ventilation or anesthesia varies 1.81 DM to 12.60 DM and is therefore lower than that of the use of disposable filters changed daily. Tubes used for anesthesia should be changed after each patient and tubes for ventilation therapy can be changed every other day, but disposable filters must be changed daily or after each case when used for anesthesia.

Anesthesiology↗
PubMed1987

[Does tobacco abstinence in patients with chronic bronchial obstruction make sense?].

In 60 patients with advanced COPD, lung function was studied retrospectively at the beginning and end of a 12 to 175 months' test period. 25 patients continued to smoke 5 or more cigarettes daily (smokers). The other 35 patients were ex-smokers or smoked only 1 to 4 cigarettes daily during the trial (non-smokers). In the heavy smoker group FEV1 diminished much more rapidly than in the non-smoking group (p less than 0.01). We observed a significant dose-response ratio between the number of cigarettes smoked and the decrease in FEV1 (r = 0.27, p less than 0.025). No causes other than smoking were found for the fall in FEV1: age, weight, place of residence, profession, sputum evaluation and inhalation therapy were statistically equal in the non-smoking and the smoking group. However, one unexpected result was that more non-smokers had had long term treatment with steroids than smokers. This may mean that non-smokers have better compliance or that there is a subgroup more sensitive to COPD who thus take more steroids and are more inclined to stop smoking than a less sensitive population. The question remains open.

Aged↗
PubMed1986

[Budesonide (Pulmicort) and exertion-induced asthma].

Twelve young adult asthmatic patients were selected in an asthma-free interval to be tested for exercise-induced bronchoconstriction. The degree of bronchoconstriction was estimated indirectly by spirometry, using FEV1 as parameter. Exercise was performed on a 10% steep treadmill for six minutes, leading to a pulse rate of more than 180 beats/min. Spirometry was done before, immediately after, and 10 and 20 min after the work. Only patients with more than a 10% fall in FEV1 during the 20 min period of recovery were selected. In the randomized crossover double blind trial the asthmatic patients received placebo inhalations for one week and budesonide inhalations for another week (2 X 800 micrograms daily). Spirometry was repeated at the end of each week. Under placebo we found a surprisingly high rate of protection against exercise-induced bronchoconstriction (50%, p less than 0.05). With budesonide 8% additional protection (compared to placebo) was achieved (mean of all 12 patients). The patient-drug-interaction was significant at the level of F = 30, p less than 0.05. There are some nonresponders to budesonide. Of the 12 asthmatics, 8 recognized the drug inhalation period. We conclude that one week of high dosage budesonide regimen recudes the tendency to exercise-induced asthma in adults. Budesonide seems to influence and mitigate bronchial hyperreactivity in the responder group.

Adolescent↗
PubMed1985

[Air burden and respiratory and vascular diseases].

Three atmospheric pollutants are discussed: Sulfur dioxide (SO2) acts as irritant gas on upper airways, trachea and large bronchi. Bronchoconstriction by SO2 is enhanced during work. Dose-response correlation may be observed with SO2 concentrations and bronchial hyperreactivity. Deaths and morbidity rates of patients with COPD parallel peaks of SO2 concentration such as occurred in the 1956 London smog. The mechanisms involved seem to be the same in cross sectional as in long term SO2 effects on human airways. Ozone (O3) is a major irritant pollutant. O3 penetrates deeply into the small airways, kills the macrophages and promotes infections. As peroxide it ruptures the cell membranes and thus lipogenases arise. Neutrophil leukocytes are attracted and transit into the peribronchiolar tissue, an enrichment which may be stopped in hydroxy-urea treated dogs. A marked correlation is observed between peribronchiolar tissue neutrophilia and bronchial hyperreactivity. This may even be a new pathway in the physiopathology of bronchial asthma. Lead is a constituent of exhaust particles and is easily absorbed into the blood. As in the case of drinking-water lead or otherwise absorbed lead, blood lead levels may be markedly reduced by adequate preventive measures. Diastolic and systolic blood pressures correlate significantly with the blood lead level. A further decrease would lower the incidence of myocardial infarctions, strokes and essential hypertension.

Air Pollutants↗
PubMed1984

[Pirbuterol and salbutamol aerosol for exercise-induced bronchoconstriction].

Exercise-induced bronchoconstriction was produced in 12 asthmatic patients after a 6 minutes run on a 10% steep treadmill ergometer. FEV1 decreased by 12-73% (average 27%) of the control value measured before the run. The rather severe exercise-induced bronchoconstriction remained constant for 10-20 minutes after the run. 21 minutes after the run two puffs of a bronchodilator (salbutamol 0.2 mg or pirbuterol 0.4 mg) were inhaled in an open randomized cross-over fashion at intervals of 1 to 3 days. Following both bronchodilators FEV1 returned to the control value within 5 minutes. There was no significant difference between the bronchodilating effect of salbutamol versus pirbuterol. Furthermore, no significant differences were observed in pulse rates after inhalation of the two selective beta-2-stimulators. In our trial both pirbuterol and salbutamol seemed to be well tolerated; side effects were not observed for either drug.

Adult↗