Results 221 to 230 of about 6,958 (252)

Plasma Metanephrines Yield Fewer False-Positive Results Than Urine Metanephrines in Patients With Obstructive Sleep Apnea

The Journal of Clinical Endocrinology & Metabolism, 2023
Abstract Context Obstructive sleep apnea (OSA) is associated with increased nocturnal sympathetic activity. In OSA patients, elevations in metanephrines may lead to false-positive tests when evaluating for pheochromocytoma or paraganglioma (PPGL ...
Thomas F J King, Yingjuan Mok, Lily Mae Dacay, Hang Siang Wong, Pon Poh Hsu, Alvin Tan, Kang Min Wong, Seyed Ehsan Saffari, Jacques W M Lenders, Troy H Puar   +9 more
openaire   +3 more sources

Plasma Metanephrines in the Diagnosis of Pheochromocytoma

Annals of Internal Medicine, 1996
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Jacques W. M. Lenders, Harry R. Keiser, Graeme Eisenhofer   +2 more
  +7 more sources

Enzymatic conversion of metanephrine to normetanephrine

Experientia, 1960
In der Mikrosomen-Fraktion der Leber von Kaninchen, Ratte und Meerschweinchen wurde ein Ferment gefunden, welches Metanephrin zu Normetanephrin unter Formaldehydbildung N-demethylieren kann.
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Interpret metanephrine results in light of clinical indications

BMJ, 2012
Jones and colleagues highlight the importance of making the diagnosis of phaeochromocytoma.1 We support their approach of initially undertaking biochemical investigations, but they do not deal clearly with sampling, patient preparation, and clinical indications for the test, which are essential for interpreting results.
Stewart J, Pattman, Andrew, Davison, Steve, Ball   +2 more
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A modified procedure for determining metanephrines in urine

Clinical Biochemistry, 1976
We have modified the procedure for determining total metanephrines in urine described by Gupta, Price and Keane(1) to shorten the time necessary for completion while allowing the technician time to perform other tests. The modification involves the extraction of interfering substances from urine. Instead of having to extract 3 individual tubes for each
T W, Fendley, C S, Frings
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Seasonal variation of urinary excretion of total metanephrines

Clinica Chimica Acta, 1976
Results of 1414 measurements of urinary excretion of free and conjugated (total) metanephrine and normetanephrine (total metanephrines, tMN) and of 1630 measurements of vanilmandelic acid (VMA) excretion were analysed according to the month of sample collection.
T, Yamamoto, K, Doi, Y, Takeuchi, M, Baba, M, Tanaka   +4 more
openaire   +2 more sources

Plasma free metanephrines for diagnosis of neuroblastoma patients

Clinical Biochemistry, 2019
A substantial number of patients with neuroblastoma (NB) have increased excretion of catecholamines and metanephrines. Here, we have investigated the diagnostic role of plasma free metanephrines (PFM), metanephrine (MN), normetanephrine (NMN) and 3-methoxytyramine (3MT) for NB, the most common extra-cranial solid tumour in children.PFM were quantified ...
Sebastiano Barco, Iedan Verly, Maria Valeria Corrias, Stefania Sorrentino, Massimo Conte, Gino Tripodi, Godelieve Tytgat, André van Kuilenburg, Maria van der Ham, Monique de Sain-van der Velden, Alberto Garaventa, Giuliana Cangemi   +11 more
openaire   +2 more sources

Falsely elevated plasma metanephrine in patients taking midodrine

Annals of Clinical Biochemistry: International Journal of Laboratory Medicine, 2018
Plasma metanephrines have become the biochemical test of choice for suspected phaeochromocytomas and paragangliomas in many institutions. We encountered two separate cases of significantly elevated plasma metanephrines in patients taking midodrine, a sympathomimetic drug used in the treatment of severe postural hypotension, in the absence of a ...
Holly Emms, George Farah, Brian Shine, Chris Boot, Barry Toole, Martin McFadden, Leo Lam, Zong-Quan Ou, Gerald Woollard, Hima Madhavaram, Campbell Kyle, Ashley B Grossman   +11 more
openaire   +2 more sources

Development of Enantioselective Immunoassays for Free Plasma Metanephrines

Annals of the New York Academy of Sciences, 2004
Abstract: The development of an enantioselective radioimmunoassay (RIA) and enzyme immunoassay (EIA) for L‐normetanephrine (NM) and L‐metanephrine (M) were studied. Prior to the immunoassay, the protein matrix of the ethylenediaminetetraacetic acid (EDTA) plasma samples was removed by acid precipitation, followed by derivatization of the L ...
Bernhard, Manz, Matthias, Kuper, Essy, Booltink, Ulrich, Fischer-Brügge   +3 more
openaire   +2 more sources