Fatty acids and polar lipid content of cheese and mould‐contaminated cheese

Unintended infestation of food with viable mould irreversibly leads to spoilage of food. However, little data existed on the fatty acid composition and polar lipid content of mould grown on cheese and the potential influence of these parameters in mould‐infested cheese. In this study, we thus focused on the fatty acids composition and polar lipid content of cheese, mould isolated from mould‐infested cheese, as well as inoculation of cheese with cultures of isolated moulds. For this purpose, we stored three cheese samples (gouda, brown cheese, and parmesan) over extended periods in order to force mould infestation from air. The moulds grown on gouda and brown cheese were identified as Penicillium brevicompactum and Penicillium roqueforti, respectively, while a mixed culture was obtained from parmesan. From these contaminated samples, mould spores were isolated and cultivated. Finally, the (pure) cheeses were inoculated with mould spores. Three subsamples, (1) cheeses, (2) moulds isolated from cheese, and (3) cheeses infested with the isolated moulds were studied with regards to their fatty acid distribution in the neutral and the polar lipids. The different amounts of polar lipids of cheese (0.39–2%), moulds (11–30.7%), and mould‐infested cheese (1.5–5%) allowed calculating the mould content of the mould‐infested cheeses.     

Produkte zum IT-gestützten Social Networking in Unternehmen

The use of Social Networking Services for private purposes has been increasing considerably in the past few years. In the same time companies started to experiment with such services to support formal and informal communication and networking among their employees. This article gives an overview of services and application for IT-supported Social Networking in companies. First, the authors place Social Networking Services in the context of Web 2.0 and Social Software. Thereupon, they discuss the benefits and the motivation of the deployment of Social Networking Software in companies, and introduce some specific IT solutions. Finally, they also address necessary future developments in the field of Social Networking Services.     

Peptide and protein quantitation by acid-catalyzed 18O-labeling of carboxyl groups

We have developed a new method that applies acidic catalysis with hydrochloric acid for (18)O-labeling of peptides at their carboxyl groups. With this method, peptides get labeled at their C-terminus, at Asp and Glu residues, and at carboxymethylated cysteine residues. Oxygen atoms at phosphate groups of phosphopeptide are not exchanged. Our elaborated labeling protocol is easy to perform, fast (5 h and 30 min), and results in 95-97 atom % incorporation of (18)O at carboxyl groups. Undesired side reactions, such as deamidation or peptide hydrolysis, occur only at a very low level under the conditions applied. In addition, data analysis can be performed automatically using common software tools, such as Mascot Distiller. We have demonstrated the capability of this method for the quantitation of peptides as well as for phosphopeptides.     

Passive Mode-Locking of a Ti : Sapphire Laser by InGaP Quantum-Dot Saturable Absorber

We demonstrate the use of a novel InGaP quantum-dot (QD) saturable absorber (SA) to induce passively mode-locked (ML) operation of a Ti : sapphire laser. Pulses as short as 518 fs are obtained at 752 nm with an average output power of up to 190 mW for 2.3 W of absorbed pump power at 532 nm. The absorption recovery of the SA is characterized by two decay coefficients: a fast and a slow component having time constants of 0.4 and 300 ps, respectively. The saturation fluence of the InGaP QDs was measured to be 28 $muhbox{J/cm}^{2}$, the initial low-signal absorption was 1.5%, where 1.15% was nonsaturable loss.      

TEM and EELS microanalysis of pc-Si thin film solar cells deposited by means of HW CVD

A p–i–n doped pc-silicon thin film grown by means of hot wire chemical vapour deposition (HW CVD) on a zinc oxide film has been investigated by transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS). The structure of both layers, the ZnO substrate layer as much as the silicon thin film and the chemical composition at the interface were the subjects of our investigations. We found that a file of pure silicon with a thickness of about 5 nm covers the substrate surface. A plausible model for getting information on the wavyness of the interface ZnO/pc-Si and the thickness of this pure Si-layer was developed.     

Prognostic value of CA 19-9 serum course in pancreatic cancer

BACKGROUND/AIMS: The aim of this study was to determine the sensibility and specificity of a new assay in the diagnosis of pancreatic cancer and predictability of resection rates. In addition, the serum CA19-9 levels was utilised as a prognostic indicator. METHODOLOGY: Serum expression of the tumor marker CA 19-9 was studied in 2119 patients. RESULTS: The discriminating capacity of CA 19-9 between benign and malignant disease was high, especially in patients with pancreatic cancer (n = 347). The sensitivity of CA 19-9 was 85%. In patients who were Lewis blood type positive, the sensitivity increased to 92%. The CA 19-9 levels were significantly lower in patients with resectable tumors (n = 126) than in those with unresectable tumors (n = 221, p < 0.0001) (sensitivity 74% versus 90%). The CA 19-9 levels dropped sharply after resection but normalized only in 29%, 13%, and 10% of patients with stage I, II, and III, respectively. In unresectable tumors, no significant decrease in CA 19-9 levels after laparotomy or bypass was found. Among patients with the same tumor stage, the median survival time of those whose CA 19-9 levels returned to normal after resection was significantly longer than those with postoperative CA 19-9 levels that decreased but did not return to normal (stage I: 33 versus 11.3 months; stage II: 41 versus 8.6 months; stage III: 28 versus 10.8 months). In patients with recurrent disease, 88% had an obvious rise in CA 19-9 levels. CONCLUSION: CA 19-9 measurement is a simple test which can be used for diagnostic purposes, as well as the prediction of resectability, survival rate after surgery, and the potential for recurrence.     

Isolation from phage display libraries of lysine-deficient human epidermal growth factor variants for directional conjugation as targeting ligands

Ligand-targeted anticancer therapeutics represent an opportunityfor the selective and efficient delivery of drugs to tumours.The chemical coupling of ligands to drugs or drug carrier systemsis, however, often hampered by the presence of multiple reactivegroups within the ligand, for example, -NH₂ groups in lysineside chains. In this paper, we describe the isolation by phagedisplay of human epidermal growth factor (EGF) variants withoutlysine and a reduced number of arginine residues. The selectionon A431 carcinoma cells also revealed that R41 is indispensablefor EGF binding activity as all EGF variants contained an arginineresidue at this position. One EGF variant (EGFm1) with K28Q,R45S, K48S and R53S mutations was expressed in bacteria andshowed an identical binding activity as wild-type EGF. EGFm1could be labelled with fluorescein isothiocyanate demonstratingthe accessibility of the N-terminal amino group for couplingreagents. Furthermore, coupling of EGFm1 to PEGylated liposomesresulted in target cell-specific binding and internalizationof the liposomes. These human EGF variants should be advantageousfor the generation of anticancer therapeutics targeting theEGF receptor, which is overexpressed by a wide variety of differenttumours. Received July 8, 2003; revised October 23, 2003; accepted October 30, 2003     

Biotransformation of the polycyclic musks HHCB and AHTN and metabolite formation by fungi occurring in freshwater environments

Micropollutants found in aquatic environments have increasingly raised concerns with respect to their uncertain environmental fate and potentially adverse effects on human health and the environment. The biodegradability of two major representatives of the polycyclic musk fragrances, Galaxolide (HHCB) and Tonalide (AHTN), and the formation of biotransformation metabolites, were investigated with Myrioconium sp. strain UHH 1-13-18-4 and Clavariopsis aquatica, two mitosporic fungi derived from freshwater environments. A particular focus was to assess the effects of extracellular oxidoreductases such as laccases, which are produced by the investigated fungi under certain conditions, on HHCB and AHTN. The fungi converted HHCB and AHTN into various products via initial hydroxylation at different carbon positions. Further metabolism resulted in the subsequent formation of diketone, peroxide, and O-methylated derivatives. Isolated laccases of the investigated fungi were able to oxidize HHCB and AHTN and catalyzed the formation of the metabolite HHCB-lactone from HHCB. At particular environmental situations also specified within the present study, biotransformations catalyzed by fungi occurring in freshwater environments may be considered when addressing the fate of polycyclic musks in freshwater systems and potential biological effects of their degradation metabolites.