Modified photometric method for the determination of phospholipase A activities

Hoffmann, Georg; Neumann, Ulf

doi:10.1007/bf01711332

Cited by 18 publications

(8 citation statements)

References 10 publications

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“…Samples (serum and plasma) were coded by number, and stored at -20°C until assayed (double assay). Secretory PLA 2 was assayed by the method described by Hoffmann and Neumann [12], and CRP and E-PI were analyzed using commercial tests (PLA2, Boehringer, Mannheim; CRP, Behring Werke, Marburg; E-PI, Merck, Darmstadt).…”

Section: Methodsmentioning

confidence: 99%

Low-dose hydrocortisone infusion attenuates the systemic inflammatory response syndrome

et al. 1994

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There is increasing evidence that the hypercortisolemia in inflammatory diseases suppresses the elaboration of proinflammatory cytokines, thus protecting the host from its own defence reactions. In severe sepsis and septic shock cortisol levels are usually elevated, but some patients may have relative adrenal insufficiency. This may contribute to the overwhelming systemic inflammatory response syndrome. We evaluated the impact of low-dose hydrocortisone infusion (10 mg/h) on the course of the systemic inflammatory response syndrome. This dose corresponds to a maximum secretory rate of cortisol achieved in corticotropin-stimulated healthy humans. In a prospective observational study 57 surgical patients with severe sepsis or septic shock were studied, of which in addition to the conventional treatment 12 patients were infused with low-dose hydrocortisone, and 45 were treated without any corticosteroid. In the longitudinal analysis the systemic inflammatory response--as judged by body temperature, cardiovascular response, and kinetics of inflammatory mediators such as phospholipase A2, C-reactive protein, and neutrophil elastase--started to differ in favor of the hydrocortisone-treated patients after 2 days of treatment (P < 0.05, Mann-Whitney U test). The difference disappeared after withdrawal of exogenous cortisol. Shock reversal was achieved in all patients treated with low-dose hydrocortisone. The data provide evidence that low-dose hydrocortisone infusion attenuates the systemic inflammatory response in human septic shock. From an immunological point of view a relative cortisol deficiency may contribute to the amplified immune response in systemic inflammatory diseases. A randomized clinical trial must clarify the impact of low-dose hydrocortisone infusion on the clinical course and outcome of septic shock patients.

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Section: Methodsmentioning

confidence: 99%

Low-dose hydrocortisone infusion attenuates the systemic inflammatory response syndrome

et al. 1994

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“…This was done in contrast to Hoffmann et al (21) who verified the detection limit using water instead of serum. The detection limit depended on the fatty acid concentration and increased from 5.1 U/l (85 nkat/1) (without fatty acids in the sample) to 12.7 U/l (212 nkat/1) (fatty acid concentration 2150 μηαοΐ/ΐ in the sample) ( fig.…”

Section: Sensitivitymentioning

confidence: 95%

“…The photometric micelle assay developed by G. E. Hoffmann (21), which has recently become commercially available, suffers from lack of sensitivity for normal and moderately elevated phospholipase A 2 activity concentrations as is shown below. But it monitors the true activity.…”

Section: Introductionmentioning

confidence: 99%

“…In contrast, the modified E. coli method allows a remarkable spreading of the test range and a reliable measurement of phospholipase A 2 activity in the early stages of sickness. We compared this method with the photometric assay (21).…”

Section: Introductionmentioning

confidence: 99%

“…The activity of phospholipase A 2 was determined by the photometric assay recently described by Hoffmann et al (21). Briefly, a lyophilized phospholipid/detergent mixture containing phosphatidylcholine, phosphatidylethanolamine (mass fraction 0.5), Triton X-100 and sodium deoxycholate (Boehringer Mannheim, Germany) was used throughout.…”

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Determination of the Catalytic Activity of Phospholipase A2: E. coli-Based Assay Compared to a Photometric Micelle Assay

Aufenanger

Zimmer²,

Püttmann³

et al. 1993

Clinical Chemistry and Laboratory Medicine

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Summary: Phospholipase A 2 activity in human sera was determined of the basis of the E. coli assay and compared to a photometric micelle assay. The E. coli assay is based on the hydrolysis of phospholipids from [l-14 C]oleic acid-labelled E. coli biomembranes. In the photometric assay the phospholipase A 2 acts on mixed phospholipid micelles. The amount of fatty acid produced is quantitated in a subsequent photometric assay by coupling in the reaction to the coenzyme A metabolism. The E. coli membranes are essentially resistent to other Upases in human sera, i. e. lipoprotein upases, hepatic triacylglycerolipase or pancreatic lipase and thus a very specific substrate for the phospholipase A 2 of human serum. The photometric assay, though, is susceptible to other upases in human serum. The ratio of (l-14 C]oleic acid to released total fatty acids served as the basis for the calculation of the true enzymatic activity. The assay closely correlated with the photometric assay based on mixed micelles in the higher ranges of phospholipase A 2 activity, but not in the normal range. The sensitivity is higher by at least two powers of 10. The human serum phospholipase A 2 strongly preferred E. coli membranes as substrate to the mixed micelles containing phosphatidylcholine/phosphatidylethanolamine. In conclusion, the modified phospholipase A 2 assay based on E. coli membranes is a sensitive, specific, reliable, and convenient method for the measurement of phospholipase A 2 activity in human sera. The photometric assay süffers from low sensitivity but has the advantage of practicability in a normal routine laboratory, including the amenability to automation. Introduction... . , , , ,

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Methods for the Determination of the Activity of Phospholipases and their Clinical Application

Aufenanger

Samman

Quintel

1994

Esterases, Lipases, and Phospholipases

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Modified photometric method for the determination of phospholipase A activities

Cited by 18 publications

References 10 publications

Low-dose hydrocortisone infusion attenuates the systemic inflammatory response syndrome

Low-dose hydrocortisone infusion attenuates the systemic inflammatory response syndrome

Determination of the Catalytic Activity of Phospholipase A2: E. coli-Based Assay Compared to a Photometric Micelle Assay

Methods for the Determination of the Activity of Phospholipases and their Clinical Application

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