Neurophysiological examination is one of the duties of a medical technologist, but few examinations are being carried out compared with other types of physiological examination because the techniques are complicated and the analysis is difficult. Studies of the brain and nervous system began in the 18th century and developed with the evolution of electrical technology and medical instruments. It is essential that we master the basic principles of neurophysiological examination and their relationship with neurological disorders. However, further development of procedures and instruments is expected to continue. Therefore, medical technologists engaged in this type of work must improve their knowledge and technological skills. In addition, imaging diagnosis and other results of examinations are also important, and it is necessary to adapt to the different diagnostic technologies in general. In this article, I will comment on the measures that are taken during the course of the evolution of neurophysiological examination techniques and further changes in this field.

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Soluble fibrin (SF) indicates enhanced coagulation, and SF level has been attracting attention as a molecular marker of the coagulation system to predict thrombosis and a prethrombotic state. We investigated the usefulness of SF level for the diagnosis of deep venous thrombosis (DVT) and judgment of the therapeutic effects. SF and the D-dimer were measured in 53 residual samples of citrated plasma collected within one day before or after ultrasonography of lower limb veins, and their associations with ultrasonography findings were investigated. The negative predictive value of the D-dimer for DVT was 100%, showing its usefulness for diagnosis by exclusion. On the other hand, the positive predictive value of SF for a fresh thrombus was 90% or higher, suggesting that the acute phase of DVT is sensitively detected. The investigation of clinical cases from the viewpoint of thrombus recurrence and organization indicated that the SF level rapidly decreased with the improvement of hypercoagulability, suggesting the clinical usefulness of SF level for judging therapeutic effects.

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In Japan, the national newborn screening program was initiated in 1977. In recent years, expanded newborn screening using tandem mass spectrometry, which permits multiple and rapid diagnoses of diverse inborn errors of metabolism from one dried blood spot, has been widely performed around the world. Expanded newborn screening by tandem mass spectrometry started in Saitama prefecture in October 2012. We analyzed screening data obtained within two years and three months. From October 2012 to December 2014, 105,905 newborns were screened and 14 infants were diagnosed as having disorders. The incidence of screened disorders was 1:7,564. There were 14 newborns confirmed to have disorders in the oxidation of amino acids (n = 6), organic acids (n = 2), and fatty acids (n = 6). The newborn screening program provides a valuable approach to preventive medicine by enabling early diagnosis and appropriate treatment before the onset of symptoms. For the babies and their families, this program should be a coordinated comprehensive system consisting of screening, diagnosis, treatment and follow-up.

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Caffeine is a component of popular beverages such as coffee and tea, as well as medicines for the common cold. We attempted to develop a method of simultaneous LC-MS/MS measurement of the concentrations of caffeine, ibuprofen, ethenzamide, and loxoprofen in blood. The mass-to-charge ratios of the precursor and product ions of caffeine were 195.1 and 138.1 m/z, respectively. The recovery of caffeine by column extraction using cartridges (HLB, SAX and OPT) was more than 90%, with the highest recovery obtained using the HLB cartridge. The limit of detection using the HLB cartridge was 0.01 μg/mL. Caffeine was eluted at 1.1 min when the ibuprofen method was applied, and theophylline interference was not detected in the caffeine SIM. We applied this measurement method to a pharmacokinetic study of caffeine in blood after oral intake of canned coffee. The peak caffeine concentration was 5.65 μg/mL at 60 min, and it decreased with a half-life of 360 min. This rapid and simultaneous measurement of the concentrations of caffeine and anti-inflammatory agents such as ibuprofen and others in blood would be useful in the critical care of patients intoxicated with these drugs.

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We report on two cases of infection by nutritionally variant streptococci (NVS) detected by blood culture, NVS being the causative organisms of bacteremia, septicemia and urinary tract infection. The patients were a 61-year-old woman and an 84-year-old man. Abiotrophia defectiva and Granulicatella adiacens, classified as types of NVS, were isolated from them by blood culture, respectively. Their characteristics cannot be determined using ordinary sheep blood agar medium even if they are Streptococcus spp. We should consider modifications of the selection culture medium and culture conditions when Gram-positive cocci poorly grow in ordinary blood agar medium although they are observed in smears.

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We have encountered a case of chest wall abscess caused by Salmonella enterica subsp. enterica serovar Choleraesuis in a healthy person. A 38-year-old man was admitted to our hospital because of fever and painful swelling of the chest. The left chest wall abscess was diagnosed on the basis of physical and imaging findings. At a later date, we made an incision and drained the abscess, which yielded cultures of Salmonella. We requested an outside agency to perform immunoserological diagnostic and InvA gene tests. The immunoserological test identified the pathogen as S. Choleraesuis (0 antigen 7, H antigen c; 1,5) and the InvA gene test revealed positive results. It is extremely rare to detect S. Choleraesuis and other NTS in abscess cultures. Therefore, clinicians are generally unable to identify Salmonella, which could cause a delay in treatment. Salmonella can potentially cause healthcare-associated infection. We need to detect Salmonella quickly in order to control infection and provide appropriate antimicrobial therapy. We must proactively perform blood culture tests because S. Choleraesuis is particularly highly active. Additionally, localized infection by Salmonella is not well recognized among clinicians; therefore, we should provide clinical support including information exchange.

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We encountered a case of infective endocarditis (IE) caused by Gemella sanguinis, which has not yet been reported in Japan. A 57-year-old woman consulted a local doctor because of recurring fever and respiratory discomfort and palpitation during exercise since early May 2012. Suspected of having IE, she was admitted to the cardiovascular medicine department of our hospital for extensive investigation and treatment. Examination of bacteria from a blood culture collected on the day of admission using a commercial biochemical identification kit led to the identification of Gemella haemolysans, while acid productions from mannitol and sorbitol and alanyl-phenylalanine-proline arylamidase activity showed anomalies. Analysis of the 16S rRNA nucleotide sequence and mass spectrometry led to the identification of G. sanguinis, which was different from the result of the biochemical identification. Although bacteria were not isolated from the surgically excised vegetation in the aortic valve, probably owing to the antimicrobial chemotherapy performed, analysis of the 16S rRNA nucleotide sequence of bacterial DNA from the vegetation led to the identification of G. sanguinis, which was consistent with the result of the blood culture test. The patient was continuously given penicillin G and gentamycin since her admission, and after a valve replacement operation, she showed improvement of symptoms and left the hospital in remission. While some cases of IE caused by G. sanguinis have been reported abroad, none has been reported in Japan. This species of bacteria is difficult to determine and is not listed in the databases of identification kits. Therefore, when Gemella is identified with an identification kit, further examination by genetic analysis and mass spectrometry should be considered, depending on the case. Drug susceptibility tests are also important because some cases of drug resistance have been reported.

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The blood test of an 80-year-old woman showed an Hb level of 6.7 g/dL. She was hospitalized in order to examine the cause of anemia and for transfusion purposes. She was diagnosed as having iron-deficiency anemia following our examination. A transfusion test showed that she had blood type A and was RhD-positive, and the result of antibody screening showed that she was positive. We doubted the existence of antibodies given the high incidence of the antigen because of the reaction in the screening of blood corpuscles. We requested a blood center for a closer examination. Her blood type was reported as Jr^a–antigen-negative and anti-Jr^a-antibody-positive. Following oral administration of iron without transfusions, her anemia improved. Family investigation was carried out in cooperation with the blood center. Her two children were found to be Jr^a -antigen-positive. In an emergency transfusion of such a rare blood type, it would be difficult for a blood center to supply blood of this type. We considered this possibility of transfusion in Hojo hospital and blood center, and prepared an emergency transfusion manual considering such a case.

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Carbon dioxide gas (CO₂) and bicarbonate (HCO₃^-) in serum form an equilibrium state, which is the most important physiological buffering system in the blood. Therefore, HCO₃^- concentration is a significant marker of electrolyte dispersion and anion deficiency, and useful for the medical diagnosis of acid-base disequilibrium in metabolic systems. The bicarbonate measurement kit “Diacolor CO₂”, which has recently been developed by Toyobo Co., Ltd., is based on an enzymatic method and can be used in general biochemical analyzers. We investigated the ultrasonic stirring levels in Hitachi LABOSPECT008 and found that level 7 showed the best performance. The analysis conditions are as follows: specimen volume, 1.5 μL; diluent volume, 120 μL; reagent volume, 30 μL; optical measuring point, 3–17; main wavelength, 405 nm; sub-wavelength, 505 nm; analysis method, 2-point end; and calibration method, linear. The basic performance results obtained in precision, accuracy, and linearity studies were excellent. In a correlation study, this reagent showed a slightly lower coefficient of variation than the Siemens Flex Cartridge Carbon Dioxide ECO₂, although the principles of which are similar. Regarding the stability of specimens, a small collected blood volume and dispensing serum into a sample cup after more than 20 min made the measurement values low. We consider that this reagent can widely contribute to the diagnosis of acid-base disequilibrium.

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HORIBA Ltd. has been developing an automated blood glucose analyzer for point-of-care testing (POCT) as part of the Antsense series. The latest model, the Antsense Duo, was launched in late 2013. In this study, we evaluate the basic performance of the Antsense Duo. Its repeatability, linearity, correlation against those of GA-08 (A&T Corp.), and interference effects on coexisting materials such as dissolved oxygen (DO) were evaluated. Ten continuous runs on whole blood samples with various glucose concentrations were performed for the repeatability study. The mean, standard deviation (SD), and coefficient of variation (CV%) were calculated. Samples in the 60–400 mg/dL range showed CV% values between 1.0 and 2.3%, and samples with a glucose concentration lower than 60 mg/dL showed a CV% lower than 3%. The linearity test was carried out between 10–1,000 mg/dL with acceptable results. The correlation between whole blood samples measured with the Antsense Duo and plasma samples measured with GA08 (A&T Corp.) was examined. The result showed a correlation coefficient (r²) of 0.997, which is considered high, and the regression was calculated to be y = 1.04x – 4.32. Samples with low hematocrit values showed 5.0–9.0% higher CV% and samples with high hematocrit values showed 11% lower CV%. No interference effects on DO and other coexisting materials were observed. From the evaluation, the Antsense Duo seemed suitable as a blood glucose analyzer for POCT use.

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Carbapenem-resistant Enterobacteriaceae is one of the emergent medical concerns. In particular, we have to pay attention to carbapenemase-producing bacteria because carbapenemase production is plasmid-encoded and can spread to various species. Since it is difficult to detect carbapenemase producers by phenotypical methods such as the antibiotic sensitivity test, we have developed a new multiplex PCR method. We selected six primer pairs from previous reports and developed a multiplex PCR method to detect six plasmid-mediated carbapenemase genes (^blaIMP, ^blaVIM, ^blaOXA-48-like, ^blaNDM, ^blaKPC and ^blaGES) in only one tube. We evaluated three types of PCR master mix reagent in terms of sensitivity and specificity, using 5, 1, 2, 2, 1 and 2 strains of plasmid-mediated carbapenemase-producing gram-negative rods with IMP, VIM, OXA-48-like, NDM, KPC and GES, respectively. Moreover, we investigated 25 species (30 strains) of gram-negative rods that do not produce carbapenemase. Platinum^® Multiplex PCR Master Mix (Applied Biosystems, Life Technologies Corporation, USA) showed the best performance in screening for six plasmid-mediated carbapenemase genes. Our newly developed multiplex PCR method can discriminate carbapenemase genes in 3.5 hours using only one tube. We conclude that our newly developed assay may contribute to the detection of carbapenemase-producing bacteria with good reactivity and rapidity.

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Direct fast scarlet 4BS (DFS) is a commonly used staining reagent for amyloid. It stains amyloid relatively specifically, but we sometimes experience insufficient amyloid staining and undesirable positive staining of collagen fiber. To prevent such inappropriate staining, several methods of adding salt to the DFS reagent had been reported so far. In this study, we focused on the types and combinations of salts added to the DFS reagent. We prepared seven types of DFS reagent using the following salts: sodium chloride, sodium carbonate, sodium sulfate, a combination of two out of these three types of salt. The reagent without salt was used as a control. Then, we serially sectioned a paraffin block of liver tissue obtained from an autopsy case of systemic amyloidosis (type AA). The slides were stained with the seven DFS reagents mentioned above. On each slide, staining of amyloid and collagen fiber was evaluated. In the assessment of staining quality, we adopted not only the conventional visual method, but also the quantification of stained color using the CIE 1976 L*a*b* color difference formula. There was neither visual nor numerical difference in amyloid staining among the different types of added salt. However, staining of collagen fiber was significantly reduced in the reagents with sodium carbonate. These results suggest that the addition of sodium carbonate to the DFS reagent could be valuable in reducing undesirable staining while maintaining favorable amyloid staining.

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The BD SurePath system has three types of preservative solution for the fixation and preservation of cells. The SurePath vial (Gyne) is used for gynecologic materials, whereas Cytorich red (Red) and Cytorich blue (Blue) are used for nongynecologic materials. Gyne and Red cause hemolysis and prevent protein coagulation, whereas Blue lacks any such ability. Regardless of gynecologic or nongynecologic material, minor blood contamination and the presence of protein cannot be judged by the naked eye. The purpose of this study was to investigate the hemolysis ability of three types of preservative solution used routinely. Because the hemolytic ability of Blue is weaker than those of Gyne and Red, erythrocytes do not completely hemolyze, and ghost erythrocytes and blood residues are smeared on the entire surface of a specimen. Therefore, it became clear that the number of smeared target cells was insufficient. Because Gyne and Red have hemolytic ability and include formaldehyde, protein coagulation is prevented by methylene bridge formation. However, because the formaldehyde level of Gyne is lower than that of Red, it became clear that its ability to prevent protein coagulation decreased over time. Therefore, long-term cell preservation in Gyne does not ensure that a sufficient number of target cells are smeared.

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Tosoh TRCReady MTB/MAC (TRCReady) is a new automatic acid-fast bacterium detection method using a transcription reverse-transcription concerted reaction. We tested the performance of the TRCReady assay by comparing with that of Roche Cobas TaqMan using polymerase chain reaction (PCR) with clinical samples. As for the result of 135 clinical samples in which the detection of MTB was targeted, the rate of concordance between TRCReady and culture was 95% (sensitivity, 90%; specificity, 98%), and that between PCR and culture was 94% (sensitivity, 88%; specificity, 98%). For the 107 clinical samples in which the detection of MAC was targeted, the rate of concordance between TRCReady and culture was 96% (sensitivity, 97%; specificity, 95%), and that between PCR and culture was 97% (sensitivity, 98%; specificity, 95%). With all samples, the internal control of TRCReady and PCR became positive. It takes only 40 min for detection using TRCReady after the NALC-NaOH processing, whereas it takes more than 210 min using Cobas TaqMan. These results indicate that TRCReady is useful for the rapid diagnosis of tuberculosis and pulmonary MAC disease.

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Methotrexate (MTX) is an anticancer drug that interferes with nucleic acid metabolism and cellular proliferation. It is clinically important to monitor serum MTX concentration to avoid adverse effects. The basic performance of the newly developed homogeneous enzyme immunoassay “Nanopia^® eTDM Methotrexate” (SEKISUI MEDICAL Co., Ltd.) for the quantitative determination of MTX was evaluated using an automated clinical chemistry analyzer. The within-assay coefficient of variation and day-to-day assay precision were 1.3–2.6% and 0.4–3.9%, respectively. The linearity was tested by serial sample dilution and was observed up to 1.20 μmol/L. There was no significant interference caused by the addition of the following interfering substances: 19.1 mg/dL free bilirubin, 21.9 mg/dL conjugated bilirubin, 504 mg/dL hemoglobin, and 1,620 FTU of chyle. There was excellent correlation between the Nanopia^® eTDM Methotrexate assay and the fluorescence polarization immunoassay (Methotrexate-II/Dinapac TDx) with the linear regression analysis equation of y = 1.01x + 0.0003, with r = 0.995 using 62 patient samples. The Nanopia^® eTDM Methotrexate assay showed sufficient basic performance for clinical use. Moreover, this assay may be beneficial in shortening the running time and in consolidating the laboratory test analyzer.

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In this report, we present a basic investigation of the “LATEX H-FABP KIT (YAMASA)” using an all-purpose automated biochemical analyzer. The results indicated that the variation coefficients for simultaneous reproducibility and different-day reproducibility were 0.7–1.8% and 2.2–4.4%, respectively. Moreover, a favorable dilution linearity passing through the origin up to a concentration of 160 ng/mL was obtained. Although no effects of coexistent substances were observed, a clear prozone phenomenon was observed, and the correlation coefficient obtained using the present kit was lower than those obtained using chemical reagents from other companies. The reference range was set at ≤2.0 ng/mL. On the basis of the observation of changes over time with other myocardial markers, it was suggested that it could also be useful for the diagnosis of early acute coronary syndrome and follow-up after reperfusion. We consider, therefore, that although false low values must be avoided with the prozone check setting in highly concentrated serum, the basic performance of this kit is satisfactory and thus it is useful for routine tests.

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Group B streptococci (GBS) are normal flora of the vagina and intestines, but if a pregnant woman is infected with GBS in the vagina, miscarriage or premature delivery would occur or the newborn would develop severe GBS infection. We compared the detection rate in 125 samples between Pourmedia GBS agar (Eiken Chemical Co., Ltd.) and CHROMagar strepB (Kanto Chemical Co., Inc.). The positivity rate of Nissui Separated Plate Sheep Blood Agar/BTB Lactose Agar medium was 16.8% (21/125 samples), whereas those of Pourmedia GBS agar and CHROMagar strepB were 16.8% (21/125 samples) and 17.6% (22/125 samples), respectively. It was found that the detection rate was improved by using Pourmedia GBS agar and CHROMagar strepB during GBS screening of vaginal swabs.

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