Development of a plasma maltose assay method as a screening test for upper gastrointestinal disorders.

Background And Objective: The disaccharide loading test is a method to assess gastric mucosal damage. Since Trelan-G75, which is used for the sugar tolerance test, contains disaccharide maltose, if maltose is detected at a high sensitivity in the sample blood used in the sugar tolerance test, screening for upper gastrointestinal mucosal damage can be made simultaneously with the sugar tolerance test for the diagnosis of diabetes.

Methods: Glucose-6-phosphate is generated by treating maltose with maltose phosphorylase, β-phosphoglucomutase, and glucose-1,6-bisphosphate.

Pyrophosphate detection method using 5-Br-PAPS to detect nucleic acid amplification - Application to LAMP method.

Genetic testing has been increasingly used in several fields. In many applications, nucleic acid amplification technology is required. However, current methods to detect nucleic acid amplification require expensive reagents and special equipment or exhibit limited sensitivity, which hinders their use.

Development of a protein assay with copper chelator chromeazurol B, based on the biuret reaction.

This study aimed to provide a novel and highly sensitive protein assay based on the biuret reaction and using chromeazurol B, a metal chelate compound. The method consists of two reagents and an automated analyzer. First, a complex of copper and protein (biuret reaction) is formed.

A survey of the reactivity of diagnostic bilirubin reagents developed in Japan using artificially prepared bilirubin materials: A comparison of synthetic delta, unconjugated, and taurine-conjugated bilirubin.

Background: diagnostic bilirubin reagents based on oxidation with bilirubin oxidase or vanadic acid for total and direct-reacting bilirubin are widely used in Japan; however, their reactivity to unconjugated and conjugated bilirubin and delta bilirubin has not been completely disclosed by manufacturers. We used artificially prepared bilirubin materials to investigate the reactivity with four diagnostic bilirubin reagents.

Methods: Porcine unconjugated bilirubin solution, chemically synthesized ditaurobilirubin solution, and chemically synthesized delta bilirubin solution were used as surrogates of naturally occurring unconjugated bilirubin, conjugated bilirubin, and delta bilirubin, respectively.

A highly sensitive and rapid enzymatic method using a biochemical automated analyzer to detect inorganic pyrophosphate generated by nucleic acid sequence-based amplification.

Background And Aims: Polymerase chain reaction-based techniques require expensive equipment for fluorescence detection of the products. However, the measurement of inorganic pyrophosphate (PPi) released during DNA synthesis can be used to quantify target genes without such equipment. Here, we devised a high-sensitivity enzymatic assay for detection of PPi.

Characterization and application of a novel nicotinamide mononucleotide adenylyltransferase from Thermus thermophilus HB8.

Herein, we describe a novel enzymatic cycling method to measure nicotinamide mononucleotide (NMN) or nicotinic acid mononucleotide (NaMN), which are precursors of NAD biosynthesis. A gene encoding an NMN adenylyltransferase (NMNAT, EC 2.7.

Development of a simple indocyanine green measurement method using an automated biochemical analyser.

Background The indocyanine green retention rate is important for assessing the severity of liver disorders. In the conventional method, blood needs to be collected twice. In the present study, we developed an automated indocyanine green method that does not require blood sampling before intravenous indocyanine green injections and is applicable to an automated biochemical analyser.

[Role of Medical Technologists as Certified Clinical Chemistry and Inununochemistry Test Quality Assurance Managers in International Standardization].

In Japan, biochemical testing has been standardized by establishing secondary reference measurement procedures for each method under the leadership of the Japan Society of Clinical Chemistry (JSCC). This has led to the assignment of values to secondary calibration materials, enabling laboratories to manage the accuracy of measurement values using them. To promote the sharing of test data by standardizing base facilities on a nationwide basis, the Japanese As- sociation of Medical Technologists (JAMT) launched the Laboratory Test Data Standardization Project.

[Strategy Development for International Cooperation in the Clinical Laboratory Field].

The strategy of international cooperation in the clinical laboratory field was analyzed to improve the quality of intervention by reviewing documents from international organizations and the Japanese government. Based on the world development agenda, the target of action for health has shifted from communicable diseases to non-communicable diseases (NCD). This emphasizes the importance of comprehensive clinical laboratories instead of disease-specific examinations in developing countries.

Multianalyte Conventional Reference Material (MacRM): A Useful Tool for Nationwide Standardization of Laboratory Measurements for Medical Care-A Model Study in Japan.

Background: The Japanese Committee for Clinical Laboratory Standards (JCCLS) has developed a multianalyte conventional reference material (MacRM) for nationwide standardization of laboratory measurements.

Methods: To prepare the MacRM, pooled sera were obtained from healthy Japanese individuals. Target values of the pooled sera for 30 analytes were assigned on the basis of the measurement results of 45 certified clinical laboratories whose calibration was verified by measuring certified reference materials (CRMs) provided by the National Institute of Standards and Technology, the Institute for Reference Materials and Measurements, and JCCLS.

[Development of the fingertip blood dilution method for blood cell counting].

For simple examination of blood disorders such as anemia, the results of blood cell counting using a small volume of blood sampled from a finger were evaluated. Because the sampling volume varies, tyramine was added to the blood dilution buffer as an internal standard. When blood is added to a tyramine-containing buffer, tyramine is diluted according to the blood volume regardless of the hematocrit.

Nationwide multicenter study aimed at the establishment of common reference intervals for standardized clinical laboratory tests in Japan.

Background: The Japanese Association of Medical Technologists (JAMT) sought to establish common reference intervals (RIs) applicable nationwide in Japan for 27 serum constituent analytes for which certified reference materials are available and nine analytes frequently measured in routine tests. More than 100 laboratories certified for metrological traceability collaborated in the recruitment, sampling, and measurement of analytes for the establishment of RIs. No previous attempt has been made to establish RIs by such a large number of laboratories.

Development of an assay of seven biochemical items, HbA1c, and hematocrit using a small amount of blood collected from the fingertip.

Background: Lifestyle-related diseases in Japan account for 30% of the entire medical expenditure of the country and cause 60% of all deaths. For the prevention of lifestyle-related diseases, medical examination by laboratory tests on metabolic syndrome is important.

Methods: To undertake examination by collection of blood from a fingertip, we developed the "Well Kit".

Enzymatic assay of phosphatidylethanolamine in serum using amine oxidase from Arthrobacter sp.

Background: In human serum, as for phospholipids not containing choline, phosphatidylethanolamine (PE) exists approximately 5% in a whole phospholipid. PE is well known as one of the main components of biological membranes, and also plays important roles that contribute to apoptosis and cell signaling. However, it could not measure PE with other phospholipids due to a lack of choline in them.

Development of a new measurement method for serum calcium with chlorophosphonazo-III.

Background: Although serum calcium has been measured using the o-cresolphthalein complexone (oCPC) method in the clinical laboratory, this method still has some problems regarding linearity and reagent stability. We developed a new measurement procedure using chlorophosphonazo-III (CPZ-III: 2,7-bis (4-chloro-2-phosphonophenylazo) -1,8- dihydroxy-3, 6-naphthalenedisulphonic acid, disodium salt) as a chelator with an acid medium for serum calcium measurement. The present method showed better linearity and reagent stability compared with the oCPC method.

Mapping of rRNA gene loci in the mice, Mus musculus molossinus (Japan) and Mus musculus musculus (Russia) by double color FISH.

Ribosomal RNA gene (rDNA) loci of Russian Mus musculus musculus and of Japanese Mus musuculus molossinus were mapped by double color FISH. The total number of rDNA loci was varied from 5 to 12, although the loci on chromosomes 12, 15, 16, 18, and 19 were common to all mice examined. Instead, polymorphisms of the rDNA loci were found on chromosomes 1, 5, 8, 9, 10, 11, 13 and 17.

Enzymatic characterization of an amine oxidase from Arthrobacter sp. used to measure phosphatidylethanolamine.

Ethanolamine oxidase was screened with the aim of using it to establish a novel enzymatic phosphatidylethanolamine assay. Ethanolamine oxidase activity was detected in the crude extract of Arthrobacter sp., and the enzyme was purified more than 15-fold in three steps with a 54% yield.

[Establishment of mail medical examination system using immediate plasma separating device by the self-collection blood--the method of dilution ratio calculation by using Internal standard for the sample with different amount of collecting blood].

A method of calibrating unquantified samples was developed in order to conduct tests from approximately 65 microl or less of self-collected whole blood from the finger. In this method, the dilution ratio is estimated by absorption analysis of an internal standard substance in the blood dilution buffer. Good results for replication of the dilution ratio were obtained, with a CV value of 0.

Identification of rRNA gene loci in the wild mouse (Mus musculus molossinus) captured at Hachioji, Tokyo.

Mus musculus (M. m.) molossinus has been considered an independent subspecies of Mus musculus.

An assay for separating and quantifying four bilirubin fractions in untreated human serum using isocratic high-performance liquid chromatography.

Background: The quantification of serum bilirubin fractions has been widely performed with both the diazo-method and an enzymatic method; however, the accuracy of these methods has not been evaluated because quantitative fractional high-performance liquid chromatography (HPLC) reference methods have yet to be established.

Methods: Samples were analyzed using HPLC and Shodex Asahipak GS-320HQ columns. Human serum was subjected to HPLC using direct injection, then eluted with acetonitrile: 0.

Development and application of serum cholinesterase activity measurement using benzoylthiocholine iodide.

Background: Measurement of cholinesterase activity in serum is important to identify substantial liver disease and damage by pesticides, and to assess the degree of development of fatty liver and preoperative risk. Many procedures using various artificial substrates have been developed but suffer from problems with substrate specificity and interference by endogenous substances.

Methods: An assay pseudocholinesterase (ChE, EC 3.

A sensitive enzymatic assay for the determination of sucrose in serum and urine.

Background: Sucrose permeability has been suggested as a simple and non-invasive marker of gastric mucosal damage. We here report on a sensitive enzymatic assay using four sequential enzyme reactions coupled with reduced thio-NADPH.

Methods: Sucrose is phosphorylated by sucrose phosphorylase (EC2.