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Edward P. Marbach

Bio: Edward P. Marbach is an academic researcher from University of Southern California. The author has contributed to research in topics: AutoAnalyzer & Glucose oxidase. The author has an hindex of 6, co-authored 7 publications receiving 3858 citations.

Papers
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Journal ArticleDOI
TL;DR: Combinations of reagents are described for the catalyzed indophenol reaction for the determination of ammonia, which produces a stable blue color, and the procedure is adapted to thedetermination of urea after hydrolysis with urease.
Abstract: Combinations of reagents are described for the catalyzed indophenol reaction for the determination of ammonia, which produces a stable blue color. The procedure is adapted to the determination of urea after hydrolysis with urease.

3,453 citations

Journal ArticleDOI
TL;DR: The method is especially valuable in the emergent clinical situation in which measurements of lactate and pyruvate are obtained for assessment of the severity of shock and other forms of cardiorespiratory failure.
Abstract: A modification of enzymatic technics for measurement of concentrations of lactate and pyruvate in blood is described. A common protein-free filtrate is prepared by adding blood directly to cold 5% metaphosphoric acid. Theoretical yields are obtained. Recoveries for lactate range from 98 to 102% and for pyruvate from 97 to 104%. Assay of both lactate and pyruvate is simplified and has a high order of reliability. Since both analyses are completed within a period of 20 mm., the method is especially valuable in the emergent clinical situation in which measurements of lactate and pyruvate are obtained for assessment of the severity of shock and other forms of cardiorespiratory failure.

523 citations

Journal ArticleDOI
TL;DR: This automated enzymatic method for analysis of lactate in blood, adapted from a manual method, is designed for use with an AutoAnalyzer and has been in continuous use as an emergency test in support of emergency and critical care for three years, during which time it has done more than 10 000 determinations.
Abstract: This automated enzymatic method for analysis of lactate in blood, adapted from a manual method, is designed for use with an AutoAnalyzer. Start-up time is 5 min. After a time delay of 4 min, 99 samples may be analyzed per hour. Recovery averaged 100.7% (range, 99.6-101.8%). Reproducibility was within 1 SD (equivalent to 70 µmol/liter). Reagents are stable at room temperature for one month. The procedure has been in continuous use as an emergency test in support of emergency and critical care for three years, during which time we have done more than 10 000 determinations.

33 citations

Patent
01 Feb 1974
TL;DR: A stable blood reference standard and control for blood gas tests which includes the use of fluoride, citrate and iodoacetate was proposed in this paper, which is used in the blood gas test.
Abstract: A stable blood reference standard and control for blood gas tests which includes the use of fluoride, citrate and iodoacetate.

21 citations

Journal ArticleDOI
TL;DR: The results on normal serum average 8 mg./100 ml, lower than those obtained with the AutoAnalyzer reduction method, because hydrogen peroxide produced reacts with iodide in the presence of a catalyst to form molecular iodine.
Abstract: Glucose is measured directly in 0.02 ml. of serum or cerebrospinal fluid by reaction with glucose oxidase. The hydrogen peroxide produced reacts with iodide in the presence of a catalyst to form molecular iodine. The iodine color is proportional to the glucose and is measured photometrically. The reaction is carried out directly on serum following preincubation with molecular iodine and can be completed in 15 min. The results on normal serum average 8 mg./100 ml. lower than those obtained with the AutoAnalyzer reduction method. At a glucose concentration of 150 mg./100 ml., the procedure has a coefficient of variation of 1.4%. Recovery of added glucose averaged 98%. Hemolysis, lipemia, or icterus do not interfere.

13 citations


Cited by
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Journal ArticleDOI
TL;DR: Cytoplasmic vacuolization in a small percentage of cells and potassium loss are the only indications of cell injury detected, and the isolated cells are comparable to normal hepatic parenchymal cells in situ in appearance and function.
Abstract: A new technique employing continuous recirculating perfusion of the rat liver in situ, shaking of the liver in buffer in vitro, and filtration of the tissue through nylon mesh, results in the conversion of about 50% of the liver into intact, isolated parenchymal cells. The perfusion media consist of: (a) calcium-free Hanks' solution containing 0.05% collagenase and 0.10% hyaluronidase, and (b) magnesium and calcium-free Hanks' solution containing 2 mM ethylenediaminetetraacetate. Biochemical and morphologic studies indicate that the isolated cells are viable. They respire in a medium containing calcium ions, synthesize glucose from lactate, are impermeable to inulin, do not stain with trypan blue, and retain their structural integrity. Electron microscopy of biopsies taken during and after perfusion reveals that desmosomes are quickly cleaved. Hemidesmosome-containing areas of the cell membrane invaginate and appear to pinch off and migrate centrally. Tight and gap junctions, however, persist on the intact, isolated cells, retaining small segments of cytoplasm from formerly apposing parenchymal cells. Cells which do not retain tight and gap junctions display swelling of Golgi vacuoles and vacuoles in the peripheral cytoplasm. Cytoplasmic vacuolization in a small percentage of cells and potassium loss are the only indications of cell injury detected. By other parameters measured, the isolated cells are comparable to normal hepatic parenchymal cells in situ in appearance and function.

4,183 citations

Journal ArticleDOI
TL;DR: Catalyzed phenol-hypochlorite and ninhydrin colorimetric procedures were adapted to the Technicon AutoAnalyzer for simultaneous determination of ammonia and total amino acids in ruminal fluid or ruminal in vitro media and indicated high degrees of accuracy and precision for both ammonia and amino acid analyses.

1,806 citations

Journal ArticleDOI
04 Jul 2003-Science
TL;DR: In this paper, the authors explored the catalytic reduction of dinitrogen by molybdenum complexes that contain the [HIPTN3N]3- ligand.
Abstract: This Account explores the catalytic reduction of dinitrogen by molybdenum complexes that contain the [HIPTN3N]3- ligand ([HIPTN3N]3- = [(HIPTNCH2CH2)3N]3-, where HIPT = 3,5-(2,4,6-i-Pr3C6H2)2C6H3) at room temperature and pressure with protons and electrons. A total of 7−8 equiv of ammonia is formed out of ∼12 possible (depending upon the Mo derivative employed). No hydrazine is formed. Numerous X-ray studies of proposed intermediates in the catalytic cycle suggest that N2 is being reduced at a sterically protected, single Mo center operating in oxidation states between MoIII and MoVI. Subtle variations of the [HIPTN3N]3- ligand are not as successful as a consequence of an unknown shunt in the catalytic cycle that consumes reduction equivalents to yield (it is proposed) dihydrogen.

1,149 citations

Journal ArticleDOI
TL;DR: The aim of this article is to give an overview on the discovery and pharmacological characterization of HCAs, and to introduce an International Union of Basic and Clinical Pharmacology (IUPHAR)-recommended nomenclature for this receptor family.
Abstract: The G-protein-coupled receptors GPR81, GPR109A, and GPR109B share significant sequence homology and form a small group of receptors, each of which is encoded by clustered genes. In recent years, endogenous ligands for all three receptors have been described. These endogenous ligands have in common that they are hydroxy-carboxylic acid metabolites, and we therefore have proposed that this receptor family be named hydroxy-carboxylic acid (HCA) receptors. The HCA(1) receptor (GPR81) is activated by 2-hydroxy-propanoic acid (lactate), the HCA(2) receptor (GPR109A) is a receptor for the ketone body 3-hydroxy-butyric acid, and the HCA(3) receptor (GPR109B) is activated by the β-oxidation intermediate 3-hydroxy-octanoic acid. HCA(1) and HCA(2) receptors are found in most mammalian species, whereas the HCA(3) receptor is present only in higher primates. The three receptors have in common that they are expressed in adipocytes and are coupled to G(i)-type G-proteins mediating antilipolytic effects in fat cells. HCA(2) and HCA(3) receptors are also expressed in a variety of immune cells. HCA(2) is a receptor for the antidyslipidemic drug nicotinic acid (niacin) and related compounds, and there is an increasing number of synthetic ligands mainly targeted at HCA(2) and HCA(3) receptors. The aim of this article is to give an overview on the discovery and pharmacological characterization of HCAs, and to introduce an International Union of Basic and Clinical Pharmacology (IUPHAR)-recommended nomenclature. We will also discuss open questions regarding this receptor family as well as their physiological role and therapeutic potential.

644 citations