Background: Diabetic nephropathy is one of the most serious and most frequent secondary complicat... more Background: Diabetic nephropathy is one of the most serious and most frequent secondary complications of diabetes mellitus, resulting in increased morbidity and mortality rates. Microalbuminuria is the earliest stage of diabetic nephropathy and is characterized by a persistent and significant elevation in urinary albumin excretion. When quantifying urine proteins, creatinine measurements are used to correct for varying diuresis because creatinine is produced at an approximately constant rate. Methods: The Afinion AS100 Analyzer is a compact, benchtop, multiassay analyzer for point-of-care testing. The Afinion ACR assay presented here analyzes both the albumin and creatinine levels in a urine sample simultaneously within a single device. Albumin is quantified using an immunometric membrane flow through assay, using monoclonal antibody-coated membrane and monoclonal antibodies conjugated to colloidal gold. Creatinine is quantified using an enzymatic colorimetric test involving 4 enzym...
Both disruption of the native protein structure and oxidation of iron in the haem/iron(II)-proto-... more Both disruption of the native protein structure and oxidation of iron in the haem/iron(II)-proto-porphyrin-IX residues were observed using the Iodo-gen (1,3,4,6-tetrachloro-3 alpha,6 alpha-diphenylglycouril) method in 125I-labelling of haemoglobin. The reactions taking place affect the native structure of haemoglobin and result in a more acidic molecule. The detrimental effects were unaffected by the presence of iodine. Electrophoretic studies demonstrate that 125I-labelling of haemoglobin using the Bolton-Hunter reagent is the method of choice in order to preserve the native protein.
... Acta, 221 (1970) 514521. [13] NM Young and MA, Leon, Biochim. Biophvs. Acta. 365 (1974) 41844... more ... Acta, 221 (1970) 514521. [13] NM Young and MA, Leon, Biochim. Biophvs. Acta. 365 (1974) 418442. [14] Y. Okada, T. Arima, S. Okazaki, K. Nakata, T. Yamabuki, and H. Nagashima, Diabetologia, 22 (1982) 212214. [15] F. Frantzen, DE Heggli, and E. Sundrehagen, Biotechnol. ...
Water soluble dye-phenylboronic acid conjugates (dye-PBAs) possessing strong absorption of visibl... more Water soluble dye-phenylboronic acid conjugates (dye-PBAs) possessing strong absorption of visible light are introduced as new reagents for the determination of glycohemoglobin. Their functionality and prospective use are demonstrated in a semi-homogenous glycohemoglobin assay. The assay is based on cis-diol esterification of dye-PBA to glycohemoglobin followed by selective precipitation of hemoglobin from solution, co-precipitating bound dye-PBA. Quantification of the molar "dye-PBA/Hb"-ratio in redissolved precipitates using either absorption or fluorescence spectroscopy, reflects the glycation level of the blood samples used. Future development of the assay principle is illustrated in a filter based assay, collecting the precipitated hemoglobin on a filter followed by reflectometric readings directly on the precipitate. The significance of this work lies first, in the demonstration of a new principle for the determination of glycohemoglobin, and second, as an illustration of the prospective use of water soluble, signal-forming non-immobilised boronic acids in the determination of cis-diol containing analytes.
Journal of Chromatography B: Biomedical Sciences and Applications, 1995
Different methods for covalent linkage of phenylboronic acid (PBA) to structural proteins and enz... more Different methods for covalent linkage of phenylboronic acid (PBA) to structural proteins and enzymes are presented. Protein-PBA conjugates, free in solution or immobilised on magnetizable polymer particles, were tested for their binding of D-sorbitol, D-mannose and glycohemoglobin (GHb). Similarly, alkaline phosphatase-PBA conjugates were used in an attempted enzyme-linked sorbent assay for the detection of GHb. Affinity chromatography on immobilised D-mannose and gel chromatographic studies of protein-PBA complexes with [14C]sorbitol, clearly illustrated a low affinity of the interaction studied. Glycated hemoglobin could not be detected using the enzyme-linked sorbent assay approach. However, GHb was found to be specifically retained on columns filled with protein-PBA-coated particles as affinity matrix, enabling the glycation level of blood samples to be determined.
Background: Diabetic nephropathy is one of the most serious and most frequent secondary complicat... more Background: Diabetic nephropathy is one of the most serious and most frequent secondary complications of diabetes mellitus, resulting in increased morbidity and mortality rates. Microalbuminuria is the earliest stage of diabetic nephropathy and is characterized by a persistent and significant elevation in urinary albumin excretion. When quantifying urine proteins, creatinine measurements are used to correct for varying diuresis because creatinine is produced at an approximately constant rate. Methods: The Afinion AS100 Analyzer is a compact, benchtop, multiassay analyzer for point-of-care testing. The Afinion ACR assay presented here analyzes both the albumin and creatinine levels in a urine sample simultaneously within a single device. Albumin is quantified using an immunometric membrane flow through assay, using monoclonal antibody-coated membrane and monoclonal antibodies conjugated to colloidal gold. Creatinine is quantified using an enzymatic colorimetric test involving 4 enzym...
Both disruption of the native protein structure and oxidation of iron in the haem/iron(II)-proto-... more Both disruption of the native protein structure and oxidation of iron in the haem/iron(II)-proto-porphyrin-IX residues were observed using the Iodo-gen (1,3,4,6-tetrachloro-3 alpha,6 alpha-diphenylglycouril) method in 125I-labelling of haemoglobin. The reactions taking place affect the native structure of haemoglobin and result in a more acidic molecule. The detrimental effects were unaffected by the presence of iodine. Electrophoretic studies demonstrate that 125I-labelling of haemoglobin using the Bolton-Hunter reagent is the method of choice in order to preserve the native protein.
... Acta, 221 (1970) 514521. [13] NM Young and MA, Leon, Biochim. Biophvs. Acta. 365 (1974) 41844... more ... Acta, 221 (1970) 514521. [13] NM Young and MA, Leon, Biochim. Biophvs. Acta. 365 (1974) 418442. [14] Y. Okada, T. Arima, S. Okazaki, K. Nakata, T. Yamabuki, and H. Nagashima, Diabetologia, 22 (1982) 212214. [15] F. Frantzen, DE Heggli, and E. Sundrehagen, Biotechnol. ...
Water soluble dye-phenylboronic acid conjugates (dye-PBAs) possessing strong absorption of visibl... more Water soluble dye-phenylboronic acid conjugates (dye-PBAs) possessing strong absorption of visible light are introduced as new reagents for the determination of glycohemoglobin. Their functionality and prospective use are demonstrated in a semi-homogenous glycohemoglobin assay. The assay is based on cis-diol esterification of dye-PBA to glycohemoglobin followed by selective precipitation of hemoglobin from solution, co-precipitating bound dye-PBA. Quantification of the molar "dye-PBA/Hb"-ratio in redissolved precipitates using either absorption or fluorescence spectroscopy, reflects the glycation level of the blood samples used. Future development of the assay principle is illustrated in a filter based assay, collecting the precipitated hemoglobin on a filter followed by reflectometric readings directly on the precipitate. The significance of this work lies first, in the demonstration of a new principle for the determination of glycohemoglobin, and second, as an illustration of the prospective use of water soluble, signal-forming non-immobilised boronic acids in the determination of cis-diol containing analytes.
Journal of Chromatography B: Biomedical Sciences and Applications, 1995
Different methods for covalent linkage of phenylboronic acid (PBA) to structural proteins and enz... more Different methods for covalent linkage of phenylboronic acid (PBA) to structural proteins and enzymes are presented. Protein-PBA conjugates, free in solution or immobilised on magnetizable polymer particles, were tested for their binding of D-sorbitol, D-mannose and glycohemoglobin (GHb). Similarly, alkaline phosphatase-PBA conjugates were used in an attempted enzyme-linked sorbent assay for the detection of GHb. Affinity chromatography on immobilised D-mannose and gel chromatographic studies of protein-PBA complexes with [14C]sorbitol, clearly illustrated a low affinity of the interaction studied. Glycated hemoglobin could not be detected using the enzyme-linked sorbent assay approach. However, GHb was found to be specifically retained on columns filled with protein-PBA-coated particles as affinity matrix, enabling the glycation level of blood samples to be determined.
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