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M Schild

Publications and source records attributed to M Schild.

4 recordsLinked to original sources
PubMed2005

Organotypic slice cultures from rat brain tissue: a new approach for Naegleria fowleri CNS infection in vitro.

The free-living amoeba Naegleria fowleri is the aetiological agent of primary amoebic meningoencephalitis (PAM), a disease leading to death in the vast majority of cases. In patients suffering from PAM, and in corresponding animal models, the brain undergoes a massive inflammatory response, followed by haemorrhage and severe tissue necrosis. Both, in vivo and in vitro models are currently being used to study PAM infection. However, animal models may pose ethical issues, are dependent upon availability of specific infrastructural facilities, and are time-consuming and costly. Conversely, cell cultures lack the complex organ-specific morphology found in vivo, and thus, findings obtained in vitro do not necessarily reflect the situation in vivo. The present study reports infection of organotypic slice cultures from rat brain with N. fowleri and compares the findings in this culture system with in vivo infection in a rat model of PAM, that proved complementary to that of mice. We found that brain morphology, as present in vivo, is well retained in organotypic slice cultures, and that infection time-course including tissue damage parallels the observations in vivo in the rat. Therefore, organotypic slice cultures from rat brain offer a new in vitro approach to study N. fowleri infection in the context of PAM.

Amebiasis↗
PubMed2003

[Complex regional pain syndrome I and II. What effects the outcome?].

INTRODUCTION: The results of clinical studies have raised doubts on the effectiveness of regional sympathetic blocks with guanethidine (IVRSB) in patients suffering from complex regional pain syndrome (CRPS). We conducted a retrospective analysis of long-term results in our patients and searched for possible factors predicting long-term outcome after IVRSB: METHODS: After approval by our ethics commission and written informed consent, 42/44 patients were included. We documented diagnosis, history, therapy and long-term result from charts. Long-term results were also obtained from a questionnaire administered to the patients. These were defined as very good (reduction of pain > or =75%), good (pain reduction <75% and > or =50%), moderate (pain reduction <50% and > or =25%) or poor (pain reduction <25%). The association of a moderate or poor outcome with the factors age, gender, duration of time until therapy, pain intensity before therapy, dose of applied guanethidine and duration of therapy was calculated by odds ratio. Confidence intervals for the odds ratios were determined by Woolfs approximation. RESULTS: After a mean duration of 18 months, the outcome was classified as very good in 14, good in 13, moderate in 5 and poor in 10 patients. An increased rate of moderate or poor outcome was associated with age<60 years (OR=4.00, CI 1.04-15.26), male gender (OR=2.93, CI 0.71-12.11) and duration of therapy>2 weeks (OR=3.27, CI 0.86-12.36). The factors duration of time until therapy, initial pain intensity and total dose of guanethidine were not associated with increased rates of moderate or poor outcome. CONCLUSION: We only seldom observed a complete functional restoration after CRPS. Male patients <60 years showed an increased risk of developing chronic pain. It remains unclear whether the risk of chronic pain reflects different responses to therapy or differences in the natural course of the disease in our patients. A meta-analysis of randomised trials of IVRSB in CRPS failed to prove the effectiveness of this intervention. If other investigations confirm our impression, future studies of CRPS-treatments should be planned and analysed with regard to the possible influence of the natural course and different risks of chronic pain among patients with CRPS.

Aged↗
PubMed2003

Influence of the mode of matrix porosity determination on matrix diffusion calculations.

The theoretical basis for matrix diffusion in fractured rocks and the methodology for the determination of diffusion coefficients in the laboratory are well established. One significant problem, however, remains in that it is difficult to quantify the degree of sample disturbance affecting the geometrical, geophysical and hydraulic properties of the rock matrix. A new technique, with in situ rock impregnation with resin, for examining the diffusion-accessible rock matrix has been developed and successfully adopted to the rock matrix behind a water-conducting fracture in host crystalline rocks at Nagra's Grimsel Test Site in Switzerland and JNC's Kamaishi In Situ Test Site in Japan. In line with the results of a large number of natural analogue and laboratory studies, the existence of an in situ interconnected pore network was substantiated. Matrix porosities determined on the laboratory samples from both the sites are 1.5-3 times higher than in situ values, irrespective of the technique applied. On the Grimsel granodiorite matrix, matrix porosity existing in situ and artefacts of stress release and physical disturbance, induced by sampling and sample preparation, were clearly distinguished, allowing in situ porosity to be quantified. Laboratory work with conventional techniques tends to overestimate the porosity of the rock matrix, hence leading to an overestimation of in situ matrix diffusion. The implications of these differences to a repository performance assessment are assessed with a couple of examples from existing assessments, and recommendations for future approaches to the examination of in situ matrix porosity are made.

Diffusion↗