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Full-Text Articles in Biology

Comparison Of The Quantification Of Caffeine In Human Plasma By Gas Chromatography And Elisa, A. B. Carregaro, W. E. Woods, Thomas Tobin, A. Queiroz-Neto Jun 2001

Comparison Of The Quantification Of Caffeine In Human Plasma By Gas Chromatography And Elisa, A. B. Carregaro, W. E. Woods, Thomas Tobin, A. Queiroz-Neto

Veterinary Science Faculty Publications

In the present study we evaluated the precision of the ELISA method to quantify caffeine in human plasma and compared the results with those obtained by gas chromatography. A total of 58 samples were analyzed by gas chromatography using a nitrogen-phosphorus detector and routine techniques. For the ELISA test, the samples were diluted to obtain a concentration corresponding to 50% of the absorbance of the standard curve. To determine whether the proximity between the I50 of the standard curve and that of the sample would bring about a more precise result, the samples were divided into three blocks according …


Binding Of Urate And Caffeine To Hemocyanin Analyzed By Isothermal Titration Calorimetry, Michael A. Menze, Nadja Hellmann, Heinz Decker, Manfred K. Grieshaber Mar 2001

Binding Of Urate And Caffeine To Hemocyanin Analyzed By Isothermal Titration Calorimetry, Michael A. Menze, Nadja Hellmann, Heinz Decker, Manfred K. Grieshaber

Michael Menze

Haemocyanin serves as an oxygen carrier in the haemolymph of decapod crustaceans. The oxygen-binding behaviour of the pigment is modulated by the two major anaerobic metabolites, L-lactate and urate. The binding of these two metabolites to haemocyanin has been investigated mainly indirectly by following the effectorinduced changes in the oxygen-binding properties of the respiratory pigment. Only a few direct investigations of effector binding, employing ultracentrifugation techniques and equilibrium dialysis, have been carried out. No evidence for cooperative binding for either effector was detected using these methods. However, isothermal titration calorimetry (ITC) offers a useful tool to gain additional insight into …


Binding Of Urate And Caffeine To Hemocyanin Analyzed By Isothermal Titration Calorimetry, Michael A. Menze, Nadja Hellmann, Heinz Decker, Manfred K. Grieshaber Mar 2001

Binding Of Urate And Caffeine To Hemocyanin Analyzed By Isothermal Titration Calorimetry, Michael A. Menze, Nadja Hellmann, Heinz Decker, Manfred K. Grieshaber

Faculty Research & Creative Activity

Haemocyanin serves as an oxygen carrier in the haemolymph of decapod crustaceans. The oxygen-binding behaviour of the pigment is modulated by the two major anaerobic metabolites, L-lactate and urate. The binding of these two metabolites to haemocyanin has been investigated mainly indirectly by following the effectorinduced changes in the oxygen-binding properties of the respiratory pigment. Only a few direct investigations of effector binding, employing ultracentrifugation techniques and equilibrium dialysis, have been carried out. No evidence for cooperative binding for either effector was detected using these methods. However, isothermal titration calorimetry (ITC) offers a useful tool to gain additional insight into …


Binding Of Urate And Caffeine To Hemocyanin Analyzed By Isothermal Titration Calorimetry., Michael Menze, Nadja Hellmann, Heinz Decker, Manfred Grieshaber Mar 2001

Binding Of Urate And Caffeine To Hemocyanin Analyzed By Isothermal Titration Calorimetry., Michael Menze, Nadja Hellmann, Heinz Decker, Manfred Grieshaber

Faculty Scholarship

Haemocyanin serves as an oxygen carrier in the haemolymph of decapod crustaceans. The oxygen-binding behaviour of the pigment is modulated by the two major anaerobic metabolites, L-lactate and urate. The binding of these two metabolites to haemocyanin has been investigated mainly indirectly by following the effectorinduced changes in the oxygen-binding properties of the respiratory pigment. Only a few direct investigations of effector binding, employing ultracentrifugation techniques and equilibrium dialysis, have been carried out. No evidence for cooperative binding for either effector was detected using these methods. However, isothermal titration calorimetry (ITC) offers a useful tool to gain additional insight into …