Allgemeine Technologie der Lebensmittel, Vorratspflege

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Tubular compensation for glomerular filtration rate decrease in chronic renal failure - the clinicopharmacologic point of view

The decrease of GFR can be compensated for by the tubular functions of residual nephrons while the homeostasis of the internal milieu is maintained. A new method presented here enables us to estimate the adequacy of tubular compensation on the basis of investigations of fractional excretion (FE) of sodium, water, and potassium. If the extrarenal excretion of the determined substance is small in comparison with the intake (I), the adequate value of FE with respect to GFR and I can be calculated according to the following formula: FE = 1.15 I/GFR . S. In patients with GFR less than 0.17 ml/s, FENa reached the values of 20-25%, FEH2O: 30-35%, and FEK: 150-200%. The estimation of these parameters can help in indicating and controlling therapy by diuretics and dietary restrictions.     

Intraocular effects of ruthenium red in responses to compound 48/80 and topical formaldehyde in rabbit

We describe a simple and effective procedure to screen for active proteases among a large number of mutants. First, the mutants are genetically tested by the protease activity produced in the periplasm of transformed bacteria which supplies the cells with a nitrogen source by hydrolyzing a protein applied to plates. Then a less sensitive activity staining and an X-ray film digestion assay are used to verify and estimate the activity of the mutants that proved to be positive in the first step. Depending essentially on the level of periplasmic protease activity, the method can detect both the activity and the stability of the expressed enzymes. We calibrated the method with transformants that produce wild-type trypsin, chymotrypsin and trypsin mutants of known activity. Using this method we found two active revertants of the inactive Asn102 trypsin mutant, by screening approximately 4.4 x 10(4) random mutants that were generated by the polymerase chain reaction on a cDNA fragment. This procedure should be useful in searching for proteases of novel specificity and/or reaction chemistry engineered by random mutagenesis, and also for in vitro evolution studies.     

Exposure to Volatile Organic Compounds of Microbial Origin (MVOC) during Indoor Application of Water-based Paints

The market for water-based paints (WBP) is growing, and these paints are favoured due to their low emission of volatile organic compounds (VOC). Because of the risk for microbial growth, biocides are usually added to WBP. Our study aimed to measure exposure to VOCs potentially of microbial origin (MVOC), during indoor application of typical Scandinavian WBP. Low concentrations of three MVOCs, 3-methyl-furan, 1-octen-3-ol, and 2-octen-1-ol, were detected during 5 out of 20 painting operations (25%). Mean exposures to MVOC and TVOC were 0.15 and 5000 μg/m³, respectively. No relation between MVOC and TVOC was observed. The highest exposure to MVOC was measured from an ecological paint, claimed to be low in VOCs and chemical additives. The results suggest that microbial growth in WBP may occur, and that measurements of MVOCs could be used as a means of quality control for WBP. The use of biocides in paint should be guided by the principle of a balance between the risk of contact allergies or other possible health hazards from the biocides, and the risk of microbial growth. If microbial growth occurs in paint, it may cause both unpleasant odor and potential health hazards for house painters and dwellers.     

Schwind- und Quellverhalten reaktionshärtender Kunstharzkitte für den Säureschutzbau

Shrinking and Swelling Properties of Chemically Cured Resin Mortars for Chemical Resistant Linings In the field of acid-proof construction chemically cured mortars, especially those based on phenolic, furan, epoxy or unsaturated polyester resins are used to apply linings on floors or in vessels. Sometimes these resin mortars are used as a troweling compound for monolithic floors, more often however as a bedding and pointing material for ceramic tiles or special shaped bricks. Because of the good adherence to the supporting construction to be protected, variations in dimension of the mortar as an effect of shrinkage or swelling cause stresses, which can exceed the strength of these linings and then could cause damage to the integrity of the installation. Methods for measuring the effective, i.e. stress generating dimensional changes in resin mortars were investigated for a variety of conditions, and testing equipment for determining the stresses generating in these mortars are developed. The results are represented graphically. The evaluation is done with respect to the possible effects of the behavior of the mortars in installed brick linings and floor coverings.     

Einflu? der UV-Bestrahlung auf die freien, nicht eiwei?gebundenen Aminos?uren der Milch

Zusammenfassung Sowohl bei der UV-Bestrahlung der Milch als auch der des Milchserums (etwa 0,01 W/ml) wird im Gegensatz zur Bestrahlung wäßriger Lösungen reiner Aminosäuren insgesamt eine Zunahme an freien Aminosäuren beobachtet. Der Effekt, der auf einer Spaltung von Peptid-Bindungen beruht, ist bei der unter molkereimäßigen Bedingungen durchgeführten UV-Bestrahlung zum Zwecke der Vitamin D-Anreicherung so gering, daß er ernährungsphysiologisch ohne Bedeutung sein dürfte. Die Aminosäuren wurden durch Säulenchromatographie nachMoore undStein bestimmt.     

Die Bestandtiele der Lebensmittel und deren Bestimmung

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Untersuchungen zur H2O2-Behandlung der Milch II. Mitteilung Einflu? von H2O2 auf Butterfett und einige fettl?sliche Vitamine

Zusammenfassung Milch wird mit Wasserstoffperoxyd in Konzentrationen bis 1% einer 30%igen Lösung versetzt (Einwirkungszeit bis 24 Std bei 30° C oder 1/2 Std bei 51° C) und der Einfluß auf das Butterfett und die fettlöslichen Vitamine untersucht.Unter den angegebenen Bedingungen lassen sich keine oxydativen Veränderungen im Butterfett feststellen. Der Gehalt der Milch an -Carotin, Vitamin A und E wird nicht verändert.Inalkoholischer Lösung sind die Vitamine A und D₃ sowie -Carotin bei H₂O₂-Einwirkung relativ stabil; nur Tokopherol wird schnell zerstört.     

Die Bestandteile der Lebensmittel und deren Bestimmung

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