Browsing by Author "Bauer, C."

Faecal Eimeria oocyst excretion, body weights, humoral antibodies against E. ovinoidalis sporozoite antigen and related heritabilities were determined in housed Merinoland sheep lambs throughout a period of 100 days after birth in Germany. Altogether 10-11 Eimeria spp. were found. Cumulative incidences of E. ovinoidalis and E. weybridgensis/crandallis increased rapidly resulting in almost 100% incidence in 8 weeks old lambs. In the other species, the cumulative incidence increased more continuously. Except for E. granulosa oocysts of all species had been excreted at last once until day 30. By far the highest oocyst counts (OpG) were observed with E. ovinoidalis, followed by E. weybridgensis/crandallis. High counts were limited to the period of 5-8 weeks after birth. In the other Eimeria species oocyst counts persisted at comparatively low levels until the end of the observation period although their proportion of the total counts increased with age of the lambs. Time courses of oocyst excretion suggest an early onset of effective immunity to the major Eimeria spp., which differed for the minor species. Mean and maximum oocyst counts and body weights of the lambs were inversely correlated suggesting negative effects of the infection on the lamb's performance. High mean antibody levels on day 7 after birth dropped until day 40 and increased subsequently again. There were no indications that maternal antibodies were protective. Antibody levels on day 40 after birth were positively correlated with oocyst counts in the faeces whereas those determined on day 80 were independent of infection parameters. Heritabilities of log(10) OpG were not significantly different from 0 up to an age of 60 days. Later estimated values were between 0.54 and 0.79 suggesting that immune protective effects rather than innate effects determining disease susceptibility are under genetic influence. (c) 2004 Elsevier B.V. All rights reserved.

Background: In several randomized controlled trials (RCT) acetylcholinesterase-inhibitors (AChE-I) were tested in patients with mild cognitive impairment (MCI) but were ineffective in delaying disease progression as determined by neuropsychological testing only. Here we present data from an open label observational extension of a multicenter RCT in order to assess if biomarkers are providing useful additional information about a drug’s efficacy. We followed 83 amnestic MCI patients and performed correlational analyses of Aβ 1-42 and total-Tau in the cerebrospinal fluid (CSF), hippocampal and amygdala volume at baseline, the total duration of blinded and open label AChE-I treatment and the outcome 24 months after inclusion into the RCT. Twelve out of 83 amnestic MCI (14%) had progressed to Alzheimer’s disease (AD). Overall, worsening and disease progression as measured by the Alzheimer’s Disease Assessment Scale – cognitive subscale (ADAS-cog), Alzheimer’s Disease Cooperative Study – Activities of Daily Living (ADCS-ADL) and Clinical Dementia Rating (CDR) did not correlate with the duration of AChE-I treatment. However, a specific multidimensional biomarker profile at baseline indicated more reliably than cognitive testing alone progression to AD. We conclude that pharmacological RCTs testing symptomatic treatment effects in MCI should include biomarker assessment.

Sera of an experimentally Neospora caninum infected llama and a non-infected control llama were used to establish an immunoblot, an ELISA and an IFAT to detect antibodies against N. caninum tachyzoites. Subsequently, serum samples collected from a total of 871 South American Camelids (SAC: Lama glama, Lama pacos, Lama vicugna) of two farms in Peru and from 32 SAC of a farm in central Germany were examined for antibodies against N. caninum and Toxoplasma gondii. Based on the recognition of specific bands in the immunoblot, sera of SAC from Peru were differentiated into N. caninum-positive (n = 18) and T gondii-positive (n = 30) samples and into samples negative or inconclusive for both parasites. Using the immunoblot results as the reference, a modified version of the p38-ELISA and the IFAT were evaluated for detecting N. caninum antibodies in SAC sera. Applying a cut-off as determined by two graph-receiver operating characteristic analysis both, the ELISA and the IFAT, exhibited a sensitivity and specificity of about 95% in the SAC sera from Peru. Serological testing confirmed that SAC may become infected with N. caninum under field conditions in Peru. In addition to alpacas and llamas also 114 wild living vicunas had been examined for antibodies against N. caninum. However, only the alpacas and llamas but no vicunas were found N. caninum-positive. In contrast, T gondii-seropositive animals were detected in all three SAC species. The lack of N. caninum-seropositive vicunas indicates that in the study area in Peru wild canids might not serve as definitive hosts of N. caninum while for T gondii a life cycle including wild felids is likely. On the German farm no N. caninum- but only T gondii-seropositive SAC (n = 14) were detected. The seroprevalence of T gondii infection was significantly higher in adult SAC (alpacas in Peru, llamas in Germany) than in crias (i.e. < 12 months old foals) indicating that the predominant route of infection is post natal. Since the present study was restricted to a few farms, the seroprevalences determined are not representative. However, our results confirm natural infections with N. caninurn and T gondii in SAC. Whether these infections are linked to any disease, e.g. reproductive losses, has to be clarified in further studies. (c) 2005 Elsevier B.V. All rights reserved.

The renal endothelin (ET) system, particularly the ET type B receptor, has been implicated in the regulation of sodium excretion and glomerular filtration rate (GFR). We analyzed kidney morphology and function in a rat strain characterized by complete absence of a functional ETB receptor. Due to Hirschsprung's disease limiting lifetime in these rats, studies were performed in 23-day-old rats. Kidney size and morphology (glomerular and interstitial matrix content, glomerular size and cell density and intrarenal vascular morphology) were normal in ETB-deficient rats. There were also no evidence of altered kidney cell cycle regulation in these rats. GFR was significantly lower, by 72% (P<0.001), in homozygous ETB-deficient rats than in wild-type rats. Fractional sodium excretion was likewise markedly reduced by 84% in homozygous ETB-deficient rats (P<0.001 versus wild-type rats). Treatment with the specific epithelial sodium channel blocker amiloride led to a much higher increase in fractional sodium excretion in ETB-deficient rats (934.2+/-73% in ETB-deficient rats versus 297+/-20% in wild-type rats, expressed as percentage of corresponding placebo treated control: P<0.001). Mean arterial blood pressure was elevated by 7.9 mmHg in homozygous ETB-deficient rats (P<0.05 versus wildtype rats). Our study demonstrates that ETB-deficiency causes early onset kidney dysfunction characterized by a markedly reduced sodium excretion, decreased GFR, and slightly elevated blood pressure. The complete absence of the ETB receptor causes in the kidney - in contrast to the colon - a functional rather than a developmental, neural crest cell dependent disease, since kidney morphology was normal in ETB-deficient rats. The much higher increase in the fractional sodium excretion in ETB-deficient rats after pharmacological blockade of the epithelial sodium channel indicates that the decreased fractional sodium excretion in ETB-deficient rats is most probably due to a lack of the inhibitory property of the ETB receptor on the epithelial sodium channel activity.

The Miniball germanium detector array has been operational at the REX (Radioactive ion beam EXperiment) post accelerator at the Isotope Separator On-Line facility ISOLDE at CERN since 2001. During the last decade, a series of successful Coulomb excitation and transfer reaction studies have been performed with this array, utilizing the unique and high-quality radioactive ion beams which are available at ISOLDE. In this article, an overview is given of the technical details of the full Miniball setup, including a description of the γ-ray and particle detectors, beam monitoring devices and methods to deal with beam contamination. The specific timing properties of the REX-ISOLDE facility are highlighted to indicate the sensitivity that can be achieved with the full Miniball setup. The article is finalized with a summary of some physics highlights at REX-ISOLDE and the utilization of the Miniball germanium detectors at other facilities.