Relationship between gliadin peptide structure and their effect on the fetal chick duodenum

Summary The tendency to form a-turn in-gliadin was estimated using the B-cell determinant prediction program based on the Chou and Fasman probability of-turn formation. Six sequences possessing a high probability of-turn formation were found. A statistically high agreement was found between these six sequences and three areas in-gliadin with the occurrence of Pro-Ser-Gln-Gln sequence which has recently been considered responsible for toxicity in coeliac disease. By means of solid-phase synthesis seven peptides were obtained covering the above-mentioned regions. Their toxicity was tested using the fetal chick duodenum. The results support the suggestion that peptides containing the sequences Pro-Ser-Gln-Gln and Gln-Gln-Gln-Pro may be involved in the pathogenesis of coeliac disease.

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Beziehung zwischen der Gliadin-Peptid-Struktur und ihr Einfluß auf den fetalen Kückendarm

Zusammenfassung Die Tendenz zur Bildung einer-Umwandlung im-Gliadin wurde bei Anwendung eines mathematischen Programms zur Vorhersage von B-Zelldeterminanten bestimmt, welches auf der Wahrscheinlichkeit der-Umwandlung nach Chou und Fasman basiert. Es wurden 6 Sequenzen gefunden, die eine hohe Wahrscheinlichkeit für die Bildung von-Umwandlungen aufwiesen. Zwischen diesen 6 Sequenzen und 3 Regionen im-Gliadin mit der Sequenz Pro-Ser-Gln-Gln, die kürzlich als verantwortlich für die Toxizität bei Cöliakie angesehen wurden, konnte eine statistisch gesicherte Beziehung gefunden werden. Mittels Festphasensynthese wurden 7 Peptide erhalten, die die oben genannten Regionen überdeckten. Ihre Toxizität wurde im fetalen Kückendarm getestet. Die Ergebnisse weisen darauf hin, daß Peptide, welche die Sequenz Pro-Ser-Gln-Gln und Gln-Gln-Gln-Pro enthalten, an der Pathogenese der Cöliakie beteiligt sein könnten.

     

Solitary splenic metastasis of an adenocarcinoma of the ovaries

BACKGROUND: Topical application of inhibitors of HMGCoA reductase, the rate-limiting enzyme of cholesterol synthesis, has been shown to induce impairment of barrier function. OBJECTIVE: Assessing whether oral administration of statins used for reducing blood levels of cholesterol induces functional changes in stratum corneum barrier. MATERIALS AND METHODS: 69 subjects of both sexes under-going treatment for hypercholesterolemia (mean age 48 +/- 11 years) entered the study; 43 had been treated with simvastatin and 11 with pravastatin for 6 months; 15 only on dietary regimen served as controls. Efficiency of stratum corneum water barrier was evaluated by transepidermal water loss (TEWL) measurement using an evaporimeter; water-holding capacity of the stratum corneum was assessed by the sorption-desorption test measured by capacitance. Statistical analysis was performed using ANOVA. RESULTS: No differences were found between the groups (simvastatin, pravastatin, diet) concerning both basal TEWL and the dynamic of water binding in the stratum corneum. CONCLUSIONS: Prolonged treatment with cholesterol-lowering drugs based on inhibition of HMGCoA reductase does not alter the permeability barrier of the skin.     

Environmental specimen banking in the Czech Republic: a pilot study

In recognition of the importance of environmental specimen banking (ESB) as an important component of the described ongoing real-time environmental and health-related monitoring programmes, a proposal for a planned ESB pilot study in the Czech Republic is presented. Selection of biomonitors, analytes, sampling techniques and sites is discussed, especially with regard to the possible harmonization with ESB already operational abroad. Availability of validated analytical techniques for determination of up to 30 elements using nuclear and spectroscopic techniques, including speciation of several metals, and of the most important organic pollutants employing various chromatographic techniques in biological and environmental samples is demonstrated.     

Effect of plasma treatment of polymeric tape carriers on wetting behaviour of aqueous ceramic tape casting slurry

Due to environmental and health aspects, aqueous ceramic slurries are preferred to traditional organic solvent systems in tape casting. An important obstacle associated with the high surface energy of water is poor wetting of aqueous ceramic slurries on polymeric tape carriers. Therefore, we measured the contact angles of an aqueous epoxy-based ceramic slurry on polyethylene terephtalate (PET), polypropylene (PP), polymethyl methacrylate (PMMA), and aluminium-coated polyethylene terephtalate (PET-Al) films and investigated approaches to improving their wetting. We evaluated the effect of plasma treatment of the tape carrier surface on the wetting behaviour and compared it with the effect of adding non-ionic amphiphilic surfactants to the ceramic slurry. The treatment of the tape carrier surface by low-temperature plasma substantially improved the wetting behaviour of aqueous ceramic slurry. The lowest contact angle of 31° was obtained on the PET film. Although the addition of non-ionic surfactants improved both the wetting behaviour of the slurry and the detachment of the polymeric carrier from the ceramic tape even better than the plasma treatment of the carrier surface did, the plasma-treated carriers still present a useful alternative to the surfactants. In the case of the plasma-treated PET carrier the surfactants could be fully eliminated and potential drawbacks related to the use of surfactants could be prevented.     

Robotic technologies for solar‐powered UAVs: Fully autonomous updraft‐aware aerial sensing for multiday search‐and‐rescue missions

Large‐scale aerial sensing missions can greatly benefit from the perpetual endurance capability provided by high‐performance low‐altitude solar‐powered unmanned aerial vehicles (UAVs). However, today these UAVs suffer from small payload capacity, low energetic margins, and high operational complexity. To tackle these problems, this paper presents four individual technical contributions and integrates them into an existing solar‐powered UAV system: First, a lightweight and power‐efficient day/night‐capable sensing system is discussed. Second, means to optimize the UAV platform to the specific payload and to thereby achieve sufficient energetic margins for day/night flight with payload are presented. Third, existing autonomous launch and landing functionality is extended for solar‐powered UAVs. Fourth, as a main contribution an extended Kalman filter (EKF)‐based autonomous thermal updraft tracking framework is developed. Its novelty is that it allows the end‐to‐end integration of the thermal‐induced roll moment into the estimation process. It is assessed against unscented Kalman filter and particle filter methods in simulation and implemented on the aircraft's low‐power autopilot. The complete system is verified during a 26 h search‐and‐rescue aerial sensing mock‐up mission that represents the first‐ever fully autonomous perpetual endurance flight of a small solar‐powered UAV with a day/night‐capable sensing payload. It also represents the first time that solar‐electric propulsion and autonomous thermal updraft tracking are combined in flight. In contrast to previous work that has focused on the energetic feasibility of perpetual flight, the individual technical contributions of this paper are considered core functionality to guarantee ease‐of‐use, effectivity, and reliability in future multiday aerial sensing operations with small solar‐powered UAVs.     

High levels of glycoalkaloids in the established swedish potato variety magnum bonum

In 1986, potentially toxic levels of the glycoalkaloids α-solanine and α-chaconine were unexpectedly found in tubers of the established Swedish consumer potato variety Magnum Bonum, leading to the imposition of a conditional sales ban on such potatoes. The combined amounts of α-solanine and α-chaconine in more than 300 commercial lots of Magnum Bonum potatoes analysed as a consequence of the ban ranged from 61 to 665 mg kg^?1 fresh weight with an average of 254 mg kg^?1. Sixty-six percent of the samples exceeded a temporary maximum residue limit of 200 mg kg^?1, 8% were above 400 mg kg^?1. Peeling did not significantly remove the glycoalkaloids in tubers with a high content. The occasional glycoalkaloid elevation was initially attributed to the unusually cold and rainy conditions during the late part of the season in 1986, but subsequent investigations have failed to confirm this hypothesis. Varietal characteristics are likely to have been involved since most other common Swedish varieties seemed to have had normal glycoalkaloid levels in 1986. There were no indications of serious or widespread adverse health effects in consumers due to the high glycoalkaloid levels, although there was circumstantial evidence that a few cases of temporary gastrointestinal disturbances were caused by consumption of Magnum Bonum potatoes with glycoalkaloid concentrations in the range 310–1000 mg kg^?1.     

In-house validation of an ELISA method for screening of semicarbazide in eggs

An enzyme-linked immunosorbent assay (ELISA) method is described for the semi-quantitative determination of semicarbazide (SEM), the marker residue for the banned nitrofuran drug, nitrofurazone, in chicken eggs. The sample homogenate is subjected to acid hydrolysis and derivatisation with o-nitrobenzaldehyde, followed by ethyl acetate/hexane extraction and detection by ELISA. The ELISA procedure has been validated using 0.3, 1.0 and 3 microg kg(-1) of SEM in fortified samples. Detection capability (CC(ss)) was based on the acceptance of 5% false compliant results for a given concentration level according to Commission Decision 2002/657/EC and was determined to be 0.3 microg kg(-1) with a respective limit of detection of 0.13 microg kg(-1). A validated LC-MS/MS method was used for the analysis of incurred egg samples and the results compared with ELISA. A good correlation between the results obtained from ELISA and LC-MS/MS within the concentration range 0.12-20.3 microg kg(-1) was observed in samples collected from chickens fed with a medicated ration of nitrofurazone (r = 0.992, n = 14). Validated ELISA enabled reliable monitoring of SEM levels in eggs collected from incurred chickens over a 90-day period.     

Diagnosis of pleural effusions. Experience with clinical studies, 1986 to 1990

OBJECTIVES: To identify in patients with pleural effusion which procedures are most useful in separating malignant from nonmalignant pleural effusions and to identify which procedures most commonly lead to a definitive diagnosis. DESIGN: Prospective consecutive case series. SETTING: Pulmonary referral hospital in Prague, Czech Republic. PATIENTS: One hundred seventy-one adults between ages 18 and 70 years with a pleural effusion and a Karnofsky score of 70 or above. INTERVENTIONS: All patients underwent history, physical, pleural fluid cytologic study, laboratory evaluation of serum and pleural fluid, pleural biopsy, bronchoscopy, and lung scan and/or pulmonary arteriogram. RESULTS: In this series in which 45% of the patients had malignant effusions, 19% had paramalignant effusions, and 36% had benign diseases, the pleural fluid cytologic study was the best for establishing a diagnosis. The pleural fluid carcinoembryonic antigen (CEA) levels above 10 had a high specificity (90%) for malignancy but had low sensitivity (37%). The pleural fluid CEA level was increased only in 19% of patients with paramalignant effusions. Although there were statistically significant differences in the mean results on several biochemical tests of pleural fluid, none were very accurate in separating malignant from benign disease. CONCLUSION: From this study, we conclude that patients with an undiagnosed pleural effusion should be evaluated in an individualized stepwise manner. If malignancy is strongly considered, the initial three steps should be relatively noninvasive and include clinical evaluation and cytologic study.