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Biomedical subjects

S Dahms

Publications and source records attributed to S Dahms.

17 recordsLinked to original sources

Efficacy of amphoteric surfactant- and peracetic acid-based disinfectants on spores of bacillus cereus in vitro and on food premises of the German armed forces.

In mass catering facilities of the German Armed Forces, foodborne outbreaks are commonly attributed to Bacillus cereus, and spores of this organism are regularly found on equipment surfaces. B. cereus is the causative agent of foodborne emetic or diarrheic disease. Hence, the use of sporicidal disinfectants may provide a starting point for successful risk mitigation of diseases associated with B. cereus. In this study, the amphoteric surfactant-based disinfectant (product A) that has been routinely used in catering facilities of the German Armed Forces and a peracetic acid-based disinfectant (product B) were compared for their efficacy against B. cereus spores in laboratory tests and under field conditions. In a carrier test for B. cereus spores, product A displayed no efficacy against spores of the test strain. In contrast, a substantial reduction in spore concentration (>5-log reduction) was achieved with product B. In a controlled trial conducted in seven Army catering facilities, the reduction in the number of B. cereus-positive samples was significantly greater (P < 0.001) for product B (from 28% initial contamination to 3% after application) than for product A (from 33 to 21%). Product B was estimated to be 6.25 times more efficacious than product A. Field trials confirmed the higher efficacy of the peracetic acid-based disinfectant to reduce B. cereus contamination on surfaces as found for the in vitro experiments. The tests used to assess the sporicidal effects of disinfectants were adequate under practice conditions and could be used for sporicidal testing of disinfectants for catering and food production establishments.

Bacillus cereus↗

[Combination of variance components estimation, regression trees and logistic regression as a concept for exploring associations between animal husbandry conditions and lesions found at slaughter].

Integrated quality control measures have been discussed in farm animal husbandry and veterinary medicine for some time in search of concepts to link information on management factors with disease data gained by veterinary meat inspection at slaughter. Better understanding of relationships between these variables hopefully will help to improve management practices as well as meat quality and safety. In order to analyse data gained on-farm and at slaugherhouses and to investigate relationships between animal husbandry conditions and lesion occurrence at slaughter a biometrical concept has been developed. This concept combines a characterization of variation structures, the generation of regression trees to explore association structures in available animal management and disease data, and logistic regression used to quantify systematic effects of farm management factors. The combination of these three steps is illustrated with an example.

Analysis of Variance↗

[Health, growing performance and meat quality of pigs in indoor and outdoor housing--a controlled field trial].

The purpose of the study was to compare indoor and outdoor housing of pigs and their influence on animal health, growing performance and meat quality in a controlled field trial: 29 litters (252 piglets) from indoor and 22 litters (221 piglets) from outdoor were separated at weaning. One half of each litter changed to the opposite housing resulting finally in 4 types of housing: Continuous outdoor or indoor raising and combined outdoor-indoor or indoor-outdoor raising. Pigs in continuous resp. predominant outdoor housing showed lower morbidity and mortality during all raising periods, more active behaviour, higher daily weight gain in weaned pigs and in fattening pigs, but higher feed consumption as compared to indoor housed pigs. However, feed conversion did not differ significantly. Due to climatic influences differences in morbidity were partly more significant in summer litters (intestinal infections) or in winter litters (lung infections). Outdoor pigs raised in summer resulted less often in meat classification E (lean meat percentage > 55%), however, meat quality, estimated by pH-measures did not differ significantly. We conclude from our findings that outdoor housing of pigs from birth to slaughtering may be a serious alternative to predominant indoor keeping with regard to general welfare and growing performance.

Animal Welfare↗

[Discussion of a biometrical model for the evaluation of feeding, age, and animal effects on transport properties of small intestinal mucosa].

This paper is concerned with the question in which ways study results can depend on the choice of the statistical model and factors included in this model. This is shown using example data of a study dealing with the effects of an Enterococcus faecium as probiotic in the diet of pigs. We focused on the effects on transport properties of pig jejunum. The experimental design was the following: the sows and piglets were randomly assigned to two different feeding groups. The control group was fed a conventional diet and the experimental group was additionally supplemented with a probiotic preparation of Enterococcus faecium NCIMB 10415. The animals were divided into four age groups. Two samples of five animals of each feeding and age group were taken and mounted into conventional Ussing chambers. Glucose transport rates were measured by changes in short-circuit current (Isc) of the pig jejunum epithelium. The appropriate reference base for evaluation of effects of feeding or age on Isc is the variation between animals which are submitted to identical conditions relating to these factors. To refer explicitly to this variation a random animal effect has to be included in the statistical model of variance analysis. Otherwise the variation between animals could be underestimated. With the example data set conclusions for the factor "feeding" would be different depending on whether a random animal effect is included in the model or not.

Age Factors↗

[Statistical principles of "good clinical practice" in veterinary medicine--a position paper for planning, implementation and evaluation of empirical studies].

The complexity of the design, conduct, analysis and evaluation of empirical studies necessitates a high degree of interdisciplinary collaboration in all areas of research. In order to make sure that no essential harmonisation is missed among the plenitude of processes, it has become common to provide direction on the essential operating procedures in so called "Good ... Practice" guidelines in recent years. In pharmaceutical research on human medicinal products guidelines on Good Clinical Practice have been an integral part of research and development in industry, academia, and the regulatory authorities for a long time. On the other hand, in the development and registration of pharmaceuticals for veterinary use such procedures are not yet established to this extent in Germany. Notwithstanding there being a lot of regulations on specialised subjects. This paper tries to summarise the current state of the discussion and to give an overview on the important points in the design, conduct, analysis and reporting of veterinary clinical studies mainly from an biometrical point of view.

Animals↗

Sacral bladder denervation for treatment of detrusor hyperreflexia and autonomic dysreflexia.

OBJECTIVES: Detrusor hyperreflexia after spinal cord injury may cause urinary incontinence and chronic renal failure. In patients refractory to conservative treatment and not eligible for ventral sacral root stimulation for electrically induced micturition, we investigated the therapeutic value of sacral bladder denervation as a stand-alone procedure. METHODS: Nine patients (8 men and 1 woman) between 21 and 58 years old (mean 30.2) with traumatic suprasacral spinal cord lesions underwent sacral bladder denervation for treatment of detrusor hyperreflexia and/or autonomic dysreflexia. RESULTS: Detrusor hyperreflexia and autonomic dysreflexia were eliminated in all cases. Bladder capacity increased from 177.8 +/- 39.6 to 668.9 +/- 64.3 mL; intravesical pressure decreased from 89.3 +/- 19.1 to 20.2 +/- 2.7 cm H(2)O. For facilitating clean intermittent catheterization (CIC), 4 patients received a continent vesicostomy in a second-stage procedure; one of them in combination with bladder augmentation. Four patients empty their bladder by way of urethral CIC. One completely tetraplegic patient has an indwelling urethral catheter. In the 5 patients with autonomic dysreflexia, the systolic blood pressure was lowered from 196 +/- 16.9 to 124 +/- 9.3 mm Hg and the diastolic blood pressure from 114 +/- 5.1 to 76 +/- 5.1. The annual frequency of urinary tract infections decreased from 9 +/- 1.2 to 1.8 +/- 0.7. In all patients, renal function remained stable. CONCLUSIONS: In selected patients with detrusor hyperreflexia and/or autonomic dysreflexia, sacral bladder denervation is a valuable treatment option. It is only moderately invasive in nature, requires neither sophisticated nor expensive medical equipment, and is an attractive alternative to urinary diversion using intestinal segments.

Adult↗

Chronic sacral neuromodulation for treatment of neurogenic bladder dysfunction: long-term results with unilateral implants.

OBJECTIVES: To investigate the therapeutic value of sacral neuromodulation in patients with neurogenic disorders in whom conservative treatment options were unsuccessful. Neurogenic disorders may result in various forms of lower urinary tract dysfunction. METHODS: Twenty-seven patients (19 women, 8 men) aged 18 to 63 years (mean 44.9 years) were subjected to percutaneous test stimulation of the sacral spinal nerves. Their urologic symptoms consisted of bladder storage failure (n = 15) due to detrusor hyperreflexia and/or bladder hypersensitivity, failure to empty due to detrusor areflexia (n = 11), and combined bladder hypersensitivity and detrusor areflexia (n = 1). Twelve patients (11 women and 1 man) underwent chronic sacral neuromodulation with unilateral electrode implantation into one of the dorsal S3 foramina. The follow-up was 89.3 months (range 13 to 126). RESULTS: Severe side effects were encountered in 2 patients (1 with infection and 1 with adverse sensation during stimulation) and moderate side effects in another 3 patients. In 1 patient, the implant had to be removed during the immediate postoperative period. In 3 patients, the implant was not effective. In 8 patients, the symptoms of lower urinary tract dysfunction were significantly attenuated (50% or more) for 54 months (range 11 to 96). After this period, all implants became ineffective, except one, which was still in use at the last follow-up visit. CONCLUSIONS: Unilateral chronic sacral neuromodulation using sacral foramen electrodes can be a valuable, but only temporary, treatment for neurogenic bladder dysfunction. The technique of chronic sacral neuromodulation should be refined to achieve the same and lasting results with implantation systems as achieved with preoperative test stimulation.

Adolescent↗

Comparison of two different meat inspection techniques.

Field studies of meat inspection procedures in three different slaughter houses were performed in Germany, in 1996. In total 22,634 fattening pigs from 63 farms were inspected twice, using a visual and the traditional (mandatory inspection system) procedure. Statistical analysis was performed using the rate of ND+ (Non-Detected Positives) for both visual and traditional inspection. Neither the visual nor the traditional methods detected all lesions which were supposed to be in the lot of animals inspected. Some of the results could be explained by the nature and obviousness of the respective lesion. Conclusions regarding the future performance of inspection should not be drawn before a formal risk analysis procedure for the particular lesion has been done.

Abattoirs↗

Orthotopic bladder augmentation and substitution.

Orthotopic bladder augmentation or substitution using intestinal segments has become a standard procedure for many disorders that cause a loss of functional or anatomical bladder capacity. From the technical point of view, reservoir configuration by detubularizing the intestinal segments is the general practice. Various techniques exist, depending which types of segments and which techniques of ureteral implantation are used. Common problems include urinary incontinence, retention, metabolic disorders, and the possibility of secondary malignancies. As a result, research has been conducted into utilizing tissues other than intestine for bladder augmentation or substitution.

Animals↗

[Associations between farm characteristics in fattening pigs and occurrence of lesions at meat inspection].

A revised inspection system for fattening pigs in the EU has been proposed emphasizing the need for a more detailed documentation of the fattening process. It is supposed that the availability of such information enables a discrimination of conspicuous and non-conspicuous lots of fattening pigs delivered to the abattoir allowing for a modified, only visual inspection of non-conspicuous lots. This proposal motivated a study performed in 1996 on about 22,000 pigs, searching, among other things, for first hints on associations between management/farm conditions for fattening pigs and lesions found at meat inspection, which can be used for discrimination. Taking the two lesions 'pneumonia' and 'callous affections of the legs' as examples this contribution demonstrates the use of regression trees to visualize association structures and to develop hypotheses on relations between lesions and farm characteristics. An association of 'callous affections of the legs' with flooring systems is clearly shown in the generated tree. The occurrence of 'pneumonia' seems to be associated with the application of disinfection measures in this data set. However, this result should be interpreted with caution as some problems for data analysis arise because of the low number of farms in this study in relation to the high number and complexity of farm characteristics considered. A further problem is the high variability of daily deliveries within farms that cannot be explained referring to farm characteristics common to all deliveries. As a conclusion data from this study have been useful to develop hypotheses on associations between farm characteristics and lesions at meat inspection. However, there is need for further, more specific studies before such associations can be utilized to discriminate between conspicuous and non-conspicuous lots of fattening pigs.

Animal Husbandry↗

Bilateral chronic sacral neuromodulation for treatment of lower urinary tract dysfunction.

PURPOSE: Chronic sacral neuromodulation aims at functional restoration of selected forms of nonneurogenic and neurogenic bladder dysfunction. The original technique, as described by Tanagho and Schmidt, provides unilateral sacral nerve stimulation via an implanted stimulator powering an electrode inserted into a sacral foramen. Its drawback was that the implant failed unpredictably in some patients despite previous successful percutaneous test stimulation. Therefore, we modified the stimulation technique to improve the efficacy of chronic sacral neuromodulation. MATERIALS AND METHODS: Guarded bipolar electrodes powered by an implantable neurostimulator were attached bilaterally directly to the S3 nerves through a sacral laminectomy in 9 women and 2 men (mean age 43.4 years). Of the patients 5 had urinary incontinence due to detrusor hyperactivity and 6 had urinary retention from detrusor hypocontractility. Mean followup with repeated urodynamics was 13 months (range 9 to 28). RESULTS: Four significant complications were encountered in 4 patients. In 10 patients the urological sequelae of the neurological disorder were alleviated significantly (50% or more), including 5 who experienced complete relief of symptoms. CONCLUSIONS: The efficacy of chronic sacral neuromodulation can be improved by bilateral attachment of electrodes directly to the sacral nerves.

Adult↗

Some remarks on the design of three-class sampling plans.

Among the variety of sampling plans for the evaluation of bacterial counts the attributive three-class sampling plan has widely gained acceptance because of its simple application and its robust functionality. However, the performance characteristics of three-class sampling plans depend on lot heterogeneity and the distance between the microbiological limits m and M, which are the maximum level of target organisms under conditions of good manufacturing practice (GMP) and the level of target organisms that is considered as unacceptable or defective. The probability of lot rejection due to a single sample result above M increases with increasing lot heterogeneity and/or with decreasing distance between these limits. Especially for investigations on nonpathogenic microorganisms it is questionable whether a lot still meeting GMP conditions should be rejected solely because a single sample result lies above M. Taking the often used three-class sampling plan (n = 5; cm = 2, cm = 0) as an example, it is demonstrated how insight into the relationship between sample variability and an appropriate distance between m and M can be gained. These calculations are based on the assumptions that logarithmically transformed bacterial counts follow a normal distribution and that an indifference lot with a contamination level at m is to be evaluated. For this kind of lot the probability of acceptance or rejection is equally 0.5 according to the two-class sampling plan. Introducing a limit for the additional risk of rejection of an indifference lot with acceptable heterogeneity when the three-class sampling plan is applied, a criterion for choosing the distance between m and M is developed.

Bacteriological Techniques↗

[Epidemiological studies on the transmission of bovine spongiform encephalopathy (BSE)--remarks from a biometric viewpoint].

This contribution discusses biometrical aspects of the design and analysis of epidemiological case-control studies. The study chosen as an example was undertaken to investigate the transmission of bovine spongiform encephalopathy (BSE) to calves and the role of the inclusion of meat and bonemeal in proprietary feedstuffs. The hypothesis was examined by means of a case-control study which is summarized with emphasis on its study design and the collection of data. The analysis included the estimation of raw odds-ratios for the inclusion of meat and bonemeal in proprietary feedstuffs for calves as well as adjusted odds-ratios using logistic regression. This strategy is discussed and the chosen regression model is compared with an alternative one. Results show that problems occurred when recruiting herds for the study leading to uneven proportions of cases and controls. Because of these misproportions and due to different data quality for cases and controls the interpretation of the study results is difficult.

Animal Feed↗

Continent reconstruction of detrusor hyperreflexia by sacral bladder denervation combined with continent vesicostomy.

We describe a two-stage surgical procedure for complex hyperreflexic detrusor dysfunction refractory to conservative therapy. First, ventral and dorsal sacral rhizotomies (S2 to S4/5) are performed to restore vesical storage function and abolish autonomic dysreflexia. Then, after an interval of several weeks to allow for detrusor relaxation, continent vesicostomy is performed for suprapubic clean intermittent catheterization. The procedure is effective both objectively and subjectively, is only moderately invasive, and requires neither sophisticated nor expensive medical equipment.

Adult↗

Microbiological collaborative studies for quality control in food laboratories: reference material and evaluation of analyst's errors.

Working groups of the Federal Health Office in Germany and of the International Dairy Federation (IDF) have developed a quality assurance system to assess the analyst performance for colony count methods. The experiment design consists of several dilution series produced from a homogeneous sample suspension. Each series contains a number of twofold dilution steps with parallel plates on each level. The structure of this design permits a detailed analysis of the total variance and identification of analysts' methodological errors as single effects. A computer-based interpretation aid may classify the laboratory as working in correspondence with good laboratory practice ('acceptable') or, otherwise, furnishing 'to good' or 'unacceptable' results. Some examples are given for deviation depending on individual faults. Both, internal quality assurance and collaborative studies demand suitable reference samples. The reference material used has to meet certain requirements concerning homogeneity, contamination level and microbiological stability during a period of storage and transport. A naturally contaminated sample material was prepared, which has been used successfully in microbiological collaborative studies.

Animals↗

[Sampling plans in microbiological criteria for food and their "performance criteria"].

Statistically based acceptance sampling plans have been integrated into microbiological criteria for food in international trade for some time. Especially two- and three-class sampling plans for attributes are used, variables plans are applied less. A lot of examples can be found in the so-called ICMSF (International Commission on Microbiological Specifications for Foods) "sampling book" or in EU guidelines. However, quite often the required confidence and the assumptions on tolerable lot qualities on which the choice and design of sampling plans are based can't be deduced from such recommendations and prescriptions. These problems have led to critical discussion of the performance of two- and three-class sampling plans used in microbiological criteria, showing complex dependencies on microbiological limits and on the expected variability of sampling results. As a result means should be considered to use knowledge gained from process analyses in food production in the design of sampling plans. In this context the performance of acceptance sampling plans as prescribed in microbiological criteria for foods will be discussed as well as their role in recently developed food safety concepts.

Animals↗