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Lactate dehydrogenase from pig heart is inactivated by the NAD+ -analog P1-N6-(4-azidophenylethyl)adenosine-P2-[4-(3-azidopyridinio)butyl]diphosphate (6) upon irradiation with UV light of wavelengths in the range from 300 to 380 nm. The decrease in enzyme activity can be prevented by the addition of NAD+ and oxalate. The modified enzyme shows a reduced binding capacity for its coenzyme as compared to native lactate dehydrogenase. The amount of incorporated coenzyme is deduced from the ribose content of inactivated enzyme. Tryptic digestion of the modified protein and separation of the peptides by HPLC yields 5 ribose-containing fractions. One of them, fraction 6 6 , is split by treatment with nucleotide pyrophosphatase into two subfractions, 63 and 58. Only subfraction 63 contains ribose. Whereas peptide 58 shows a UV absorption spectrum similar to that of 4-(3-aminopyridinio)-butyl phosphate (3). Amino acid analyses of the peptides indicate that the inactivator forms covalent bonds with different parts of the protein: Peptide 63 is characterized by a great portion of hydrophobic amino acids whereas peptide 58 shows a high degree of hydrophilicity.
In the course of the odontogenesis of bovine incisors several clearly distinguishable phosphohydrolase activities are observed in the pulp and in dental hard tissues. Using various substrates and inhibitors, unspecific alkaline phosphatase, two isoenzymes of acid phosphatase, Ca2+-activated ATPase and inorganic pyrophosphatase are characterized. The enzymatic activity of alkaline phosphatase in pulp and hard tissues is significantly high at the beginning of dentine and enamel mineralization. The specific activity of this enzyme decreases quite fast with the beginning of root formation, then more slowly, until it reaches a constant final value. Histochemical studies show that during mineralization the maximum of alkaline phosphatase activity is in the subodontoblasts. Lower enzyme concentrations are found in the stratum intermedium and in the outer enamel epithelium during that process.
The specific activities of ATPase, acid phosphatases and pyrophosphatase show little temporal variation during tooth development, but they also appear in a characteristic spatial pattern in the dental tissues.
Die Einteilung der Pneumonien richtet sich neben klinischen und pathologischen vor allem nach ätiologischen Gesichtspunkten. Es werden diesbezüglich die respirato- bzw. pneumotropen Viren vorgestellt, daneben differentialdiagnostisch wichtige andere Infektionserreger der "Viruspneumonie" (M. pneumoniae, Chlamydia psittaci, Coxiella burnetii) beschrieben und ihre klinischen Aspekte, labordiagnostischen Möglichkeiten sowie die Aussagekraft der verschiedenen Nachweisverfahren diskutiert. Die Letalität der primär virusbedingten Pneumonien ist zwar niedrig, der respiratotrope Virusbefall kann aber Schrittmacher für schwerebakterielle Superinfektionen sein.
Wir haben einen kommerziell verfügbaren Test zur Bestimmung von Thyroxin (T4) am Analysensystem RA1000 auf seine Eignung in unserem Labor untersucht. Das Prinzip des Tests beruht auf einer immunturbidimetrischen Inhibitionstechnik, die besonders zur Messung niedriger T4-Konzentrationen geeignet ist Es wurde eine Präzision (in Serie, von Tag zu Tag) zwischen 2,6 und 4,6% (VK) ermittelt. Die Richtigkeit wurde untersucht an Patientenproben mit 2 Vergleichsmethoden und vergleichend zu den Sollwerten kommerziell verfügbarer Richtigkeitskontrollseren. Der Vergleich an Patientenproben ergab eine gute bis akzeptable Übereinstimmung, der Vergleich mit den Sollwerten von Richtigkeitskontrollseren zeigte in einigen Seren gewisse methodische Differenzen. Insgesamt ergaben unsere Untersuchungen, daß die immunturbidimetrische Inhibitionstechnik am HA-1000 eine schnelle und zuverlässige Bestimmung der T4-Konzentration ermöglicht.
(±)-Aeroplysinin-1, an optically active 1.2-dihydroarene-1.2-diol. was isolated from the marine sponges Verongia aerophoba (+-isomer) and lanthella ardis (--isomer). For the experiments presented we used the +-isomer from Verongia aerophoba. Here we describe the hitherto unknown biological and pharmacological property of this compound to display pronounced anticancer activity against L5178y mouse lymphoma cells (ED50: 0.5 μm). Friend erythroleukemia cells (ED50: 0.7μm) , human mamma carcinoma cells (ED50: 0.3μm) and human colon carcinoma cells (ED50: 3.0 μm) in vitro. Furthermore, aeroplysinin caused a preferential inhibition of [3H]thymidine (dThd) incorporation rates in L5178y mouse lymphoma cells if compared with murine spleen lymphocytes in vitro. At concentrations between 1.1 and 28.5 μm, the [3H]dThd incorporation rates in L5178y cells were suppressed to 28% -0% but only to 78% -18% in murine spleen lymphocytes. The same differential effect in vitro was found with the following epithelial cells: 14.70 μm of the compound were required to inhibit normal human fibroblasts to 50% , but only 2.9 μm in the assays with human malign keratinocytes or malignant melanoma cells to observe the same inhibitory effect. Moreover, aeroplysinin-1 displayed antileukemic activity in vivo using the L5178y cell/NMRI mouse system; administered at a dose of 50 mg/kg for five consecutive days, the T/C (% ) value was determined to be 338. Preliminary toxicology studies revealed an acute LD50 of 202 mg/kg and a subacute LD50 of 150 mg/kg. Aeroplysinin-1 is neither a direct mutagen nor a premutagen in the umu/Salmonella typhimurium test system.
Die Diagnostik der pathologischen Proteinurie ist im Wandel begriffen. Während zur Zeit noch der Streifentest und die Gesamteiweißbestimmung in der Proteindiagnostik von Nierenerkrankungen im Vordergrund stehen, gewinnt die quantitative Bestimmung von Plasmaproteinen im Harn eine gewisse Bedeutung. Ursachen sind, neben einer mangelnden diagnostischen und analytischen Sensitiv/tat und Spezifität des Streifentests und der Gesamteiweißbestimmungsmethoden, der technische Fortschritt in der mechanisierten immunnephelometrischen oder immunturbidimetrischen Analytik der Plasmaproteine im Harn.
Wirkung von Glia-Maturationsfaktor (GMF) und Adhäsionsfaktor (ADF) auf Kulturen leukämischer Zellen
(1987)
GMF was isolated from the glia of different brain parts of calf. Its influence on the input of 3H-TdR was tested in leukaemic and non-malignant lymphocites. GMF isolated from the diencephalon proved to be the most effective one. The used substance of reference was DBcAMP. The cAMP contents of leukaemic cells were lower than those of non-malignant cells, whereas the level of cGMP was higher in the first ones. We found both in non-malignant cultures and in cultures of leukaemic cells that the impact of GMF and AdF elevated the cAMP value and reduced cGMP. The adhesion of cAMP to the nuclei of leukaemic was reduced in comparison with non-malignant cells. The nuclei of leukaemic cells showed increased adhesive capacity after pre-incubation with GMF and AdF. The adhesive capacity of non-malignant nuclei remained unchanged. The adenylcyclase activity (AC) was diminished in leukaemic cells. It could not be stimulated by means of catecholamines. GMF and AdF produced a slight increase of the basal Ac activity in cultures of leukaemic cells only. But isoproterenol led to a distinct increase of the Ac activity in leukaemic cells when incubation with those two factors preceded it.