Infectious crystalline keratopathy caused by Candida guilliermondii

PURPOSE: To describe the manifestations of infectious crystalline keratopathy caused by Candida guilliermondii in a corneal transplant performed for pseudophakic bullous keratopathy. METHOD: Case report. RESULTS: Candida guilliermondii was identified as the causative organism of an indolent infectious crystalline keratopathy. Incisional lamellar biopsy provided diagnostic culture and histopathologic results. Histopathology showed aggregates of yeast elements between corneal stromal lamellae, without inflammation. The infection progressed despite a 6-week course of topical amphotericin B and an additional 6-week course of topical and oral fluconazole. Repeat penetrating keratoplasty resulted in clear graft, with no recurrent infection. CONCLUSIONS: Fungal keratopathy should be included in the differential diagnosis of infectious crystalline keratopathy. Numerous Candida species have been isolated in addition to the most common causative bacterial organism, Streptococcus viridans. Candida guilliermondii is yet one more causative agent of infectious crystalline keratopathy. Candida guilliermondii, a rare human pathogen, was resistant to medical therapy in this case.     

Subjective causal scenarios for global environmental change

Two studies are presented that investigate the assumptions that risk evaluation is based on subjective causal scenarios, and that the cognitive representation of global environmental risks is structured according to five causal levels: human attitudes, human activities, emissions or pollutions, environmental changes, and negative consequences. In study 1, 30 subjects listed in free-response format causes, consequences, and remedial measures for 14 environmental risks. Differences between predictive and diagnostic inferences were found: whereas subjects tend to assign immediate rather than mediated causes, they predominantly assign negative consequences for humans, irrespective of the length of the causal chain that leads to these consequences. In study 2, 41 subjects judged the overall similarity between 25 environmental risks. A multidimensional scaling analysis of these similarity judgments replicates the theoretically assumed five causal levels. Results of both studies support the assumptions that risk evaluation is based on implicit causal hypotheses and that the proposed five-level structure adequately describes the cognitive representation of environmental risks.     

Exploration of anthropological specimens by GC-MS and chemometrics

Anthropological specimens combine a variety of unfavorable characteristics, rendering their evaluation an analytical challenge. Their remarkable status is primarily based on two characteristics: (i) these very rare samples of human origin are testimonies of human history and are, therefore, available only in minute amounts for analytical purposes, and (ii) the analysis of these samples is extremely limited by the decomposition of molecules, which are easily detected in living organisms, such as nucleic acids and proteins, but are subject to rapid post-mortem decay. In this article, we review the methods and results of archaeometry, emphasizing the role of MS combined with chemometrics. Focusing on experimental results for fatty acid profiles, specimens from mummies from different civilizations were compared. Considering in particular the Tyrolean Iceman, the application of chemometric methods to GC-MS data recovers essential information about the preservation and the storage conditions of mummies.     

Dynamics and rheology of vesicles in a shear flow under gravity and microgravity

Vesicles are closed fluid membranes with a size in the range 10–100 µm. Under flow they exhibit various dynamics such as tank-treading, tumbling, and vacillating-breathing. Part of these dynamics are studied experimentally both on earth and under microgravity conditions. We report on the basic results of vesicles dynamics. Deviations from existing theories are discussed. A small deformation theory is presented that shows notable differences from those imposing a fixed shape: the vesicle shape is shown to undergo a temporal oscillation. This theory allows one to extract the effective viscosity of the suspension.     

Effect of growth promotants on the occurrence of endogenous and synthetic steroid hormones on feedlot soils and in runoff from beef cattle feeding operations

Supplements and growth promotants containing steroid hormones are routinely administered to beef cattle to improve feeding efficiency, reduce behavioral problems, and enhance production. As a result, beef cattle manure will contain both synthetic steroids as well as a range of endogenous steroids including androgens, estrogens, and progestogens. A two-year controlled study was conducted in which beef cattle were administered steroid hormones via subcutaneous implants and feed additives and the occurrence of 16 endogenous and synthetic steroid hormones and metabolites was evaluated in runoff from beef cattle feedlots and in manure and soil collected from feedlot surfaces. Samples were extracted and analyzed using liquid chromatography tandem mass spectrometryfor metabolites of the synthetic androgen trenbolone acetate, 17α-trenbolone, 17β-trenbolone, for the nonsteroidal semisynthetic estrogen agonist, α-zearalanol, and the synthetic progesterone melengesterol acetate, as well as a wide range of endogeneous estrogens, androgens, and fusarium metabolites. Synthetic steroids including trenbolone metabolites and melengestrol acetate were detected in fresh manure and in feedlot surface soils from cattle administered synthetic steroids at concentrations up to 55 ± 22 ng/g dry weight (dw) (17α-trenbolone) and 6.5 ± 0.4 ng/g dw (melengesterol acetate). Melengesterol acetate was detected in 6% of runoff samples from feedlots holding cattle administered synthetic steroids at concentrations ranging up to 115 ng/L. The presence of melengesterol acetate in runoff from beef cattle feeding operations has not been previously reported. Synthetic steroids were not detected in manure or runoff from control cattle. A wide range of endogenous hormones were detected in runoff and feedlot surface soils and manure from cattle given synthetic steroids and from control cattle, with no statistically significant differences in concentration. These results indicate that runoff from confined animal production facilities is of environmental and public health concern regardless of the use of growth promotants.     

Improvement of the Detection Sensitivity for <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> in Spices and Herbs

Various variants of ISO 6888-1:1999 and ISO 6888-3:2003 methods for the detection of Staphylococcus aureus were evaluated and improved for their application to conduct analysis in spices and herbs. Improvement substantiated in washing of the sample to remove compounds interfering with the analysis and in the use of PCR for final detection, instead of plating on Baird-Parker agar, to improve sensitivity at high backgrounds and to save time. The evaluation of the method variants was based on determination of the detection limit (LOD) using series of artificially contaminated spices (allspice, black pepper, cinnamon, nutmeg, paprika, vanilla) and herbs (basil, oregano, parsley, thyme). The method without enrichment, ISO 6888-1:1999, produced LODs of 10³–10⁵ CFU/g with no positive effect of washing the sample or use of PCR for final detection. The method with enrichment, ISO 6888-3:2003, had LOD of 10⁰ CFU/g for basil, black pepper, paprika and parsley. If the washing step was added and PCR was used for final detection, LOD of 10⁰ CFU/g was determined also for cinnamon, nutmeg and vanilla, and LOD of 10¹ CFU/g was determined for allspice. For oregano and thyme, which strongly inhibit the growth of S. aureus, an alternative enrichment-independent method based on direct DNA extraction coupled to real-time PCR may be advantageous.     

Extraction of the first bolus passage in dynamic susceptibility contrast perfusion measurements

Object  The processing of dynamic susceptibility contrast perfusion measurements requires an extraction of the first bolus passage of the injected contrast agent. State-of-the-art methods employ the fit of a gamma variate function to the measured data. The use of a gamma variate function is motivated by its shape similarity to the expected relaxation rate time-course during the first bolus passage. However, the quality of this result is strongly influenced by the amount of overlap of the first and second bolus passage. In this work we present an alternative, data-driven method for the extraction of the first bolus passage from a measured relaxation time-course. Materials and methods  By using prior knowledge of the injection function, the measured time-courses can be transformed to time-courses that would occur at a shorter injection duration where the two bolus passages have less overlap. This time-course is found by Tikhonov regularized deconvolution of the measured time-courses with an injection function that bases on the measurement protocol. A minimum search yields the cut-off point at which the first bolus can be extrapolated to zero. The gamma variate fit is performed using Powells algorithm. The proposed approach is compared to the gamma variate fit approach using simulations and an exemplary dataset from one healthy volunteer. Results  The new method performs comparably stable as the gamma variate function fit approach in simulations. Both methods are superior to a simple exponential extrapolation approach. Applied to volunteer data, the new method performs much faster than the gamma variate fit approach. The results obtained from both methods correspond well. Conclusion  The new method offers a conceptual understanding of the first bolus passage and yields similar results to the gamma variate function fit approach but performs much faster.