Japanese Journal of Medical Technology
Online ISSN : 2188-5346
Print ISSN : 0915-8669
ISSN-L : 0915-8669
Current issue
Showing 1-28 articles out of 28 articles from the selected issue
Original Articles
  • Rieko MAEJIMA, Koki FUJIWARA, Kazuko OSONE, Hiromi NANBA, Hitomi NAGAT ...
    Type: Original Article
    2021 Volume 70 Issue 1 Pages 1-8
    Published: January 25, 2021
    Released: January 26, 2021
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    ABO blood types include many subtypes and are classified serologically. Variations of ABO blood group phenotypes have been reported predominantly at exon 6 or 7 of the ABO gene. The Bm phenotype is the most prevalent ABO subtype among Japanese individuals and it arises from the partial deletion of intron 1 of the B gene. The deleted region is 5.8 kb or 3.0 kb and includes a transcription enhancer element such as two GATA motifs. We genetically analyzed 17 patients with the Bm or ABm phenotype using PCR-SSP to detect 5.8 kb or 3.0 kb deletion, and PCR-rSSO to detect variations at exons 6 and 7 of the ABO gene. The 5.8 kb deletion was demonstrated in 16 patients. In the remaining patient, the A and O genes were detected by ABO genotyping using PCR-rSSO. It is very feasible to analyze genetically the ABO gene for the determination of the blood subtype, especially in patients with the Bm phenotype.

  • Chiho MISHIMA, Risa KANESHIGE, Mari HASEGAWA, Naoto SHIMIZU, Yukari MO ...
    Type: Original Article
    2021 Volume 70 Issue 1 Pages 9-14
    Published: January 25, 2021
    Released: January 26, 2021
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    Chronic fatigue syndrome (CFS) is characterized by severe fatigue and various nonspecific symptoms such as fever, headache, muscle pain, and sleep disorder. CFS is a highly heterogeneous and partly subjective illness, and no standard laboratory test is currently available for its reliable diagnosis. The main objective of this study was to establish biomarkers useful for the diagnosis of CFS. We analyzed the oxidative stress index (OSI) and peripheral mononuclear cell surface antigens in healthy subjects and CFS patients whose diagnosis was based on clinical signs. The OSI was significantly higher in sera of the CFS patients than in those of the healthy subjects. Our results indicate the possibility that OSI is a useful biomarker for the objective diagnosis of CFS. On the other hand, we confirmed by lymphocyte subset analysis that the proportion of B cells was significantly higher in the CFS patients than in the healthy subjects. Furthermore, the surface antigen analysis of monocytes revealed that the proportion of CD14+/CD16 monocytes was significantly lower and that of CD14+/CD16+ monocytes was significantly higher in the CFS patients than in the healthy subjects. It is quite interesting to find this higher proportion of CD14+/CD16+ monocytes, which are associated with inflammatory diseases and autoimmune diseases, in the CFS patients whose diagnosis was based on clinical signs. In addition, there was a significant correlation between the OSI and the proportion of inflammatory monocytes in the CFS patients. These findings suggest that chronic inflammation caused by oxidative stress might be involved in the pathogenesis of CFS.

  • Daiki TANNO, Ryuya SHOJI, Yuko SAKAMOTO, Yukiko TAKANO, Kazutaka OHASH ...
    Type: Original Article
    2021 Volume 70 Issue 1 Pages 15-22
    Published: January 25, 2021
    Released: January 26, 2021
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    Streptococcus agalactiae (Group B Streptococcus, GBS) is a leading cause of sepsis and meningitis in neonates. In Japan, the universal screening for maternal GBS colonization is recommended to decrease neonatal infections. However, the conventional methods cannot fully detect GBS and produce some false negative results. In this study, we evaluated a new GBS enrichment broth, which changes its color in the presence of GBS, in comparison with the conventional direct agar plating. We also evaluated the usefulness of a latex agglutination (LA) test for the broth after 24-h incubation. First, we estimated the efficiency of the enrichment broth using 100 samples. The detection rates of GBS were 13% (13/100) and 18% (18/100) in direct agar plating and enrichment broth culture, respectively. The positive predictive value of GBS in the broth that changed to yellow was 25.7% (18/70), and the negative predictive value in the broth that did not change to yellow was 100% (30/30) after 24-h incubation. All GBS-positive swabs changed the color of the broth to yellow after incubation up to 24-h. The LA test for the cultured broth detected all GBS with no false positive or false negative results when using 246 additional samples. These results show that this new enrichment broth is more sensitive than direct agar plating in the detection of GBS. Furthermore, the LA test for the cultured broth can contribute to the improvement of GBS detection. In conclusion, our study indicates that the new GBS enrichment broth and the LA test are useful as sensitive and specific methods for GBS screening in pregnant women.

  • Kazuto TAKAHASHI, Yasutomo SAITO, Manami OGASAWARA, Chisato NAKAGAWA, ...
    Type: Original Article
    2021 Volume 70 Issue 1 Pages 23-31
    Published: January 25, 2021
    Released: January 26, 2021
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    Background: The number of anticancer drug treatments has increased with the development of molecularly targeted drugs and immune checkpoint inhibitors. However, there are individual differences in the therapeutic effects of these anticancer drugs. In this study, we investigated the usefulness of CD-DST for predicting the prognosis and treatment response in colorectal cancer. Methods: We performed CD-DST in 71 colorectal cancer patients treated with postoperative chemotherapy. We then compared overall survival, median survival, two-year survival, and five-year survival between the high- and low-sensitivity groups for each pathological stage. We also evaluated the sensitivity of six different colorectal cancer cell lines to the drug cetuximab by CD-DST. Results: The overall survival of the high-sensitivity group in stage II/III tended to be longer than that of the low-sensitivity group (p = 0.162). In addition, the median survival in stage II/III was 8.6 years in the high-sensitivity group and 2.8 years in the low-sensitivity group, and the five-year survival rates were 63.6% in the high-sensitivity group and 28.6% in the low-sensitivity group. The prognosis of the high-sensitivity group tended to be better in stage II/III than in the other stages. Furthermore, a validation test of the predicted effect of cetuximab on colorectal cancer cell lines showed that only Caco-2 cells without KRAS or BRAF mutations were highly sensitive. The combination of FOLFOX or FOLFIRI with cetuximab resulted in an additive antitumor effect. Conclusions: CD-DST appears to be useful in predicting the prognosis of patients with stage II/III colorectal cancer and the effect of cetuximab combination chemotherapy.

  • Ayami KARITA, Yoko MANO, Hitomi KAMISAKU, Nobuhiko FURUYA
    Type: Original Article
    2021 Volume 70 Issue 1 Pages 32-39
    Published: January 25, 2021
    Released: January 26, 2021
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    It has been reported overseas that oral care using mouthwash reduces the risk of developing pneumonia. However, the concentrations of some active ingredients in mouthwashes in Japan are lower than those reported overseas owing to Japanese regulations, because mouthwashes are primarily intended to prevent oral diseases and not to protect against pneumonia-causing pathogens. In this study, we determined whether the different active ingredients used in mouthwashes could have a sufficient bactericidal effect against pneumonia-causing pathogens. The experiments were performed with slight modifications of the European standard EN 1040. Chlorhexidine gluconate (CHG), cetylpyridinium chloride (CPC), and 1,8-cineole were adjusted to concentrations commonly found in commercially available mouthwashes in Japan. After each bacterial pathogen was cultured for 18 h in suspensions, bacterial cells were harvested and washed with PBS. Subsequently, the bacterial cell concentrations were adjusted to 108 CFU/mL and standardized at OD 660 nm. The bacterial cell suspensions were then reacted with mouthwash ingredients for 10, 20, 30, and 60 s. Thereafter, each neutralized and diluted mixture was spread onto an agar plate and incubated for 18 h at 35°C. Later, the number of bacterial cells was counted. At the concentration used in mouthwashes, CPC was effective against pneumonia-causing pathogens. Furthermore, it was found that CPC exerted sufficient bactericidal effect at concentrations lower than that used in mouthwash. CHG was effective against some pneumonia-causing pathogens. It was also found to be effective even at concentrations lower than the previously reported concentrations (0.12–0.20%).

  • Yutaka KUNO
    Type: Original Article
    2021 Volume 70 Issue 1 Pages 40-52
    Published: January 25, 2021
    Released: January 26, 2021
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    Standard methods for urinary sediment examination require urine samples of 10 mL. However, at times, the urine volume collected for urinary sediment examination can be very low. In such cases, instructions specify that results of such tests be annotated. Thus, the testing procedure for low-volume urine samples remains unclear. Low-volume samples necessitate retesting, which increases the burden on patients. Therefore, we developed a method of testing low-volume urine samples, which can produce results comparable to those obtained by standard methods. We used the urine samples collected from 161 patients and compared the sediment examination results obtained by standard testing methods with those obtained from samples whose urinary and sedimentary volumes had been adjusted. After comparing the levels of 926 material components detected in our 161 samples, we found that if samples between 5 and 9 mL were measured at 5 mL of urine and 0.1 mL of sediment (a concentration equivalent to that used during standard testing), results equivalent to those obtained by standard methods can be obtained. Furthermore, in cases where less than 5 mL of urine was examined, less oversight occurred when measuring with 0.1 mL of sediment as opposed to 0.2 mL. Thus, when a sample is less than 10 mL, our method can contribute to the diagnoses of renal and urological diseases and lessen the burden on patients.

  • Toshihiro TAKAMORI, Yoshiyuki ADACHI, Chitose IMAI, Akemi SATOU, Satos ...
    Type: Original Article
    2021 Volume 70 Issue 1 Pages 53-58
    Published: January 25, 2021
    Released: January 26, 2021
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    Early detection of hearing impairment is of great significance. In our hospital, an AABR is performed on a newborn baby, and if a hearing disorder is suspected, a conventional ABR is performed. In some cases, the results of AABR and conventional ABR differed; thus, we investigated the current situation to assess the usefulness of AABR. The subjects were 4,359 patients who underwent AABR, and the results of AABR and conventional ABR were compared. We also investigated the status of AABR and the presence of high-risk factors for hearing loss in children. There were 65 children with a “Refer” on AABR, among which 49 had conventional ABR. False negatives were 16.0% and false positives were 17.8%. The threshold levels of conventional ABR in the mismatched ears ranged from 20 dB to 60 dB. Regarding high-risk factors for hearing loss, the results of AABR were consistent with those of conventional ABR, and no false positive results were found in children with head and neck malformations, which were statistically significant. In contrast, the false negative rate was significantly higher in children with birth asphyxia, and all four ears with false negative results were associated with birth asphyxia. There were ears with mismatched results of AABR and conventional ABR for children with birth asphyxia; however, no mismatch occurred in cases of severe hearing loss or profound deafness, confirming that AABR is useful. There were some cases in which hearing loss was recognized later in ears with a “Pass” on AABR, and it is necessary to be careful especially in children with birth asphyxia because false negative results may occur.

  • Junpei SASAKI, Shinobu ISHIGAKI, Mitsuru MATSUMURA, Miwa ASAHARA, Yosh ...
    Type: Original Article
    2021 Volume 70 Issue 1 Pages 59-65
    Published: January 25, 2021
    Released: January 26, 2021
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    At Teikyo University Hospital, antimicrobial susceptibility testing was conducted by the prompt inoculation method using the WalkAway 96 Plus system. In recent years, the frequency of the isolation of methicillin-resistant Staphylococcus aureus (MRSA) strains with a minimum inhibitory concentration (MIC) of 4 μg/mL for linezolid (LZD) has seemed to be increasing. This MIC of LZD indicates the upper limit of sensitivity. Therefore, we investigated the transition in the isolation rate of MRSA strains that showed a MIC of 4 μg/mL for LZD. The isolation frequency of these strains increased from 1.4% (8/568 strains) in 2010 to 24.4% (75/307 strains) in 2014 and was later maintained at 10–15%. In addition, the MIC for 103 strains was reevaluated using both the turbidity inoculation method and the agar plate dilution method. The MIC for all the strains was 2 μg/mL or lower in both methods. We also reevaluated the MIC of LZD for 40 selected strains using three types of antimicrobial susceptibility testing equipment. The MIC for all the strains was 2 μg/mL or lower when remeasured using the DPS192iX and BD Phoenix M50 systems; however, that for 39 strains was 2 μg/mL or lower when remeasured using the VITEK2 system. These results indicate that the MIC of LZD for MRSA strains measured by the prompt inoculation method using the WalkAway 96 Plus system is approximately 1 doubling dilution higher than that of the other methods and equipment. In most cases, a difference of ±1 doubling dilution is considered acceptable. However, the difference would increase to over 2 doubling dilutions when other confounding factors are involved. In conclusion, it is important to perform various evaluations to understand the characteristics of various antimicrobial susceptibility testing methods and equipment.

  • Mayu TAKEBUCHI, Yoko USAMI, Yuika OGINO, Risa ENDO, Go MATSUMOTO, Nau ...
    Type: Original Article
    2021 Volume 70 Issue 1 Pages 66-73
    Published: January 25, 2021
    Released: January 26, 2021
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    Background: Procalcitonin (PCT) is used as a sepsis marker, and several assay kits employing an anti-PCT antibody from BRAHMS GMbH have been developed. FUJIFILM Wako Pure Chemical Corporation has recently released two new quantification reagents [μTAS Wako PCT (μTAS) and Accuraseed PCT (Accuraseed)] and a semiquantitative kit [Smooth Check Wako PCT (SC)] that employs an immunochromatographic method. μTAS, Accuraseed, and SC use an original anti-PCT antibody. We evaluated the performances of μTAS, Accuraseed, and SC, and verified the clinical usefulness of PCT. Methods: We examined the basic performances of μTAS and Accuraseed, and compared them to existing reagents. The agreement rate for SC between technicians and that between SC and a quantification reagent were investigated. The clinical usefulness of PCT was examined by evaluating the relationship between PCT levels and infection, blood culture results, and quick sepsis-related organ failure assessment (qSOFA) scores in 294 patients. Results: μTAS and Accuraseed showed satisfactory performances for clinical use and good correlations with existing reagents. In clinical efficacy studies, PCT levels were distributed over a wide range in cases of infection and tended to be higher in cases with positive blood cultures and high qSOFA scores. PCT was negative in 82% of cases without infection, but PCT levels were high in some cases with severe trauma or some surgery. Conclusion: The basic performances of μTAS, Accuraseed, and SC were good. PCT levels increase with increasing severity of infection and represent a useful marker for the diagnosis of sepsis.

  • Satoru YAMADA, Yoshifumi UMEMORI, Maki MOCHIZUKI, Kouichi ASANUMA, Noz ...
    Type: Original Article
    2021 Volume 70 Issue 1 Pages 74-79
    Published: January 25, 2021
    Released: January 26, 2021
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    As nutritional markers, albumin, transthyretin, retinol-binding protein, and transferrin are used. However, their concentrations decrease markedly during inflammation. In recent years, it has been reported that apolipoprotein (Apo) C-II and ApoC-III can be nutritional markers that are less affected by inflammation. We investigated whether apolipoproteins including ApoC-II and ApoC-III are useful as nutritional markers unaffected by inflammation, and we analyzed the effects of renal injury and hypertriglyceridemia on their measured concentrations. The subjects were 51 patients with malnutrition, 28 healthy volunteers, 19 patients with renal injury, and 24 patients with hypertriglyceridemia. The malnutrition group was divided into two: the low-CRP-concentration group of 19 patients and the high-CRP-concentration group of 32 patients. The concentrations of apolipoproteins were measured and compared among the groups. The ApoA-I concentration was significantly lower in the malnutrition group than in the healthy group. Additionally, a significantly larger reduction was observed in the high-CRP-concentration group than in the low-CRP-concentration group. The ApoC-II concentration showed a small difference between the healthy and malnutrition groups and especially no difference between the high-CRP-concentration and healthy groups. The ApoC-III concentration was significantly lower in the malnutrition group than in the healthy group, but there was no significant difference between the low-CRP- and high-CRP-concentration groups. In addition, the ApoC-III concentration was significantly higher in the renal injury and hypertriglyceridemia groups than in the healthy group. As mentioned above, ApoC-III may be a nutritional marker that is not affected by inflammation. However, the concentration of ApoC-III tends to be high in the presence of renal injury and hypertriglyceridemia, so the interpretation of the results requires caution.

Technical Articles
  • Wataru TATEISHI, Kaname UKEDA, Satoshi MACHIDA, Isami TSUBOI
    Type: Technical Article
    2021 Volume 70 Issue 1 Pages 80-85
    Published: January 25, 2021
    Released: January 26, 2021
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    In our laboratory, zinc measurement is conducted by the atomic absorption method. As the number of specimens is increasing owing to the expanded application of zinc acetate medicine, it is necessary to consider measures to cope with this increase. Thus, we performed basic evaluation studies of the reagent ‘Espa-Zn II’ for Zn measurement by the colorimetric method using a general-purpose biochemical automatic analyzer with a high processing capacity. Results showed that with this reagent, coefficients of variation (CVs) for within-run and between-day precisions of less than 3.0% were obtained, the detection limit was 4.19 μg/dL, and the dilution linearity was also good. Although the zinc level decreased in the presence of hemolytic hemoglobin, no effect of other interfering substances was detected. In addition, comparison with the atomic absorption method showed good correlation with a regression equation of y = 1.065x + 5.8 and a correlation coefficient of r = 0.971 (n = 98). From the above results, the processing efficiency of 1,200 samples/h can be increased by using ‘Espa-Zn II’ with a general-purpose biochemical automatic analyzer, compared with the conventional processing capacity of 80 samples/h per analyzer. Although it is necessary to pay attention to hemolyzed samples, the reagent can contribute to eliminating the sample pretreatment step and a only small sample volume is required.

  • Ryosuke KIKUCHI, Hiroyuki MATSUYAMA, Rika WATARAI, Satoru YOKOYAMA, At ...
    Type: Technical Article
    2021 Volume 70 Issue 1 Pages 86-92
    Published: January 25, 2021
    Released: January 26, 2021
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    VITROS XT7600 (XT7600) is capable of the bidirectional analyses of liquid (wet) and VITROS slide (dry) reagents in open channel operation, which can be used without water supply and with generic reagents. The purpose of this study was to verify the effects of LABOSPECT008 (LST008) wet reagents and XT7600 dry reagents on the measurement values under each storage condition, assuming a 3-day power failure, and to evaluate the usefulness of XT7600. The LST008 and XT7600 were used as measuring instruments. The storage of each reagent was carried out in three patterns: the control conditions are set to the storage temperature (refrigerated/freezing) in accordance with the manufacturer’s instruction for each reagent, and the study conditions were in a cold box, room temperature, and 37°C. The XT7600 wet reagent was replaced with the LST008 wet reagent after storage in a special bottle. Residual sera from 10 patients were used to evaluate the effects of 10 clinical chemistry tests on the assay values under each storage condition. Among the storage conditions, storage of the reagents in a cold box did not affect the values of all 10 clinical chemistry tests. These results suggest that XT7600, which can be used with the LST008 wet and XT7600 dry reagents by using a cooling box until power is supplied after a power failure, may play an important role in the reconstruction of a clinical laboratory after a disaster.

  • Ryo KOBAYASHI, Shinya NIRASAWA, Yuki SATO, Kouichi ASANUMA, Nozomi YAN ...
    Type: Technical Article
    2021 Volume 70 Issue 1 Pages 93-98
    Published: January 25, 2021
    Released: January 26, 2021
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    (1→3)β-D glucan (BG) is widely used as a biomarker for auxiliary serological diagnosis of deep mycosis. The number of measurements per day is limited because conventional BG reagents are processed by batch. We evaluated the utility of “Fungitec G test ES “NISSUI”” (NISSUI BG), which is a real-time processing reagent based on the colorimetric method. The within-run precision and the dilution linearity were satisfactory. In 116 patients, the measurement value of NISSUI BG was approximately three times higher than that of the “β-glucan test Wako (Wako BG)”, which is based on the turbidimetric method. We evaluated the concordance rates of the judgment using the cutoff values of each reagent. The results showed that eight samples are mismatched, such that all “NISSUI BG” results were positive. However, some of the results were suspected as having false high values, and three of the samples indicated the presence of fungi. It was suggested that “NISSUI BG” sensitively reflected the presence of fungi in the body. Therefore, when the result of “NISSUI BG” was positive, it was suggested that a follow-up by measuring BG and performing culture tests and confirming both the clinical symptoms and the background of patients presenting false high values were needed. It was considered that “NISSUI BG” was useful for routine laboratory tests because of the high reactivity for BG and the short time to obtain results owing to the real-time processing.

  • Kosuke YASUI, Hajime SAKO, Shuichi TAKAHASHI
    Type: Technical Article
    2021 Volume 70 Issue 1 Pages 99-105
    Published: January 25, 2021
    Released: January 26, 2021
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    In recent years, the incidence of phaeohyphomycosis in immunocompromised patients with underlying diseases such as diabetes, leukemia, and hematopoietic disorders has tended to increase. The causative organisms are fungi, namely, Exophiala jeanselmei and Exophiala dermatitidis. Black fungal infections are classified into chromoblastomycosis, phaeohyphomycosis, and fungal tumors on the basis of the parasitic form in tissues. These black fungi often cannot be identified owing to insufficient knowledge and technology. In this study, we examined a simple method of identifying these Exophiala spp. and their antifungal sensitivity. As a result, we found that their identification was possible and relatively easy on the basis of their temperature tolerance and by slide culture using selective media, and by the Antifungal Susceptibility Testing of Yeast (ASTY), which could facilitate visual judgment and is useful for antifungal sensitivity examination.

Materials
  • Maki NAKAMURA, Yusuke SAKATA, Hideyuki KOBAYASHI, Ken KATO, Junichi YA ...
    Type: Material
    2021 Volume 70 Issue 1 Pages 106-115
    Published: January 25, 2021
    Released: January 26, 2021
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    Clinical laboratory technologists are required to demonstrate management skills. However, there has been no scientific research about the management practices a clinical laboratory division’s top managers can use to improve work satisfaction among subordinates. Educational methods still rely on programs designed for other occupations. In this study, we thus aimed to determine the basic behavior for future management education by identifying excellent management practices that subordinates expect based on the relationship between the actions of a division’s top managers, such as on-site clinical laboratory directors, and their subordinates’ work satisfaction. In accordance with the methodology used in previous studies, a web survey targeting 150 clinical laboratory technicians was conducted. The questionnaire consisted of 69 items. The answers were scored according to the managers’ behavior and the subordinates’ work satisfaction level, and the data was then analyzed. The results showed that the behavior of top managers significantly affects the work satisfaction of their subordinates. This confirms the importance of management education for top managers in the clinical laboratory settings. Moreover, the results suggest two important management role behaviors. One is valuing career and the other is valuing ease of work. According to the responses, work satisfaction among subordinates can be improved when both the aforementioned behaviors are present. Above all, the younger generation demands a more fulfilling work environment regardless of gender from the top managers, and executives should have improved management ability by education to maintain favorable human relations in the workplace.

  • Ayaka IKEUCHI, Kayoko NAKANISHI, Yukiko NISHIYAMA, Miki NAGAO
    Type: Material
    2021 Volume 70 Issue 1 Pages 116-122
    Published: January 25, 2021
    Released: January 26, 2021
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    Arkray Co. released an influenza virus antigen detection kit “SPOTCHEM FLORA FluAB” and the dedicated immunofluorescence analyzer “SPOTCHEM FLORA”. The kit uses a europium fluorescent latex-bound antibody in the reagent, and it detects the antigen using a new signal detection method is analyzed by a new signal detection method called time-resolved fluorescence assay. In this study, we evaluated the performance of a rapid test system for influenza virus antigens using Spotchem FLORA SF-5520, which can process three samples in parallel. From this study, we show that the system has good performance for within-run and between-day precisions and can produce stable results. Then, we determined whether blood contamination has a low impact on the test results of the system. The system provided accurate results in the case of samples with low amounts of the viral antigen, including blood contamination of up to 1%. In addition, we found that the system has higher detection sensitivity than a visual judgment kit and can provide results much faster than another system that has an equivalent high sensitivity. The system can measure rapidly and has high sensitivity and can also provide results automatically. It brings great benefits to the measurer, patient, and clinical site. In conclusion, we can say that it is very useful to introduce this system for influenza diagnosis.

  • Shiori HOSHI, Hisashi HORIUCHI, Kenyu HASHIMOTO, Tatsushi MATSUO, Mits ...
    Type: Material
    2021 Volume 70 Issue 1 Pages 123-127
    Published: January 25, 2021
    Released: January 26, 2021
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    The COVID-19 pandemic broke out in Japan in late February 2020. We had to cease or postpone meetings, workshops, and seminars. Given this situation, we held an online seminar using the Web Meeting System and Social Networking Service in our communication group. We held three online seminars from March to May 2020 and then conducted a survey of the participants. The advantages of the online seminar were that the burden on participants was reduced because they could attend from home or work, they could participate from a distance, and slides were easy to see compared with in conventional seminars. In addition, since real-time distribution from the laboratory room was possible, demonstration-style seminars could be held easily. The disadvantages of the online seminar were that a speaker could not see the reaction of the participants, the number of terminal units was limited, and participants and speakers could not interact. The online seminar was highly useful. In the post-COVID-19 era, we should seek new seminar methods that combine conventional and online seminars.

  • Makito TANAKA, Masaaki SHINAGAWA, Satoshi TAKAHASHI
    Type: Material
    2021 Volume 70 Issue 1 Pages 128-131
    Published: January 25, 2021
    Released: January 26, 2021
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    The rapid detection of extended-spectrum β-lactamase (ESBL) is important for appropriate antimicrobial selection and healthcare-associated infection control, because bloodstream infections caused by gram-negative bacilli are associated with a high mortality rate. In this study, a rapid method of detecting ESBL by the chromogenic Cica-β test using the culture fluid of positive blood culture bottles (Cica-β direct method) was compared with a conventional confirmation test. The tests were compared using 68 isolates with positive blood culture at Sapporo Medical University Hospital. As a result, the finding of 17/51 isolates judged to be ESBL-producing bacteria/nonproducing bacteria by the Cica-β direct method was completely consistent with that by the conventional confirmation test. Results suggest that the Cica-β direct method is useful as a rapid and simple test.

Case Reports
  • Motoki SUGASAKI, Naoki TOKUNAGA, Akishige IKEGAME, Takayuki NAKAO, Mas ...
    Type: Case Report
    2021 Volume 70 Issue 1 Pages 132-137
    Published: January 25, 2021
    Released: January 26, 2021
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    Prekallikrein (PK) is a type of serine protease synthesized in the liver, and it is involved in intrinsic clotting reaction, vasodilation and hyperfibrinolysis. Because congenital PK deficiency has few clinical symptoms such as bleeding, it is often found accidentally. We encountered a case of congenital PK deficiency in a male patient who is in his 50s. He visited our hospital for prostate cancer surgery, and a screening test showed extreme prolongation of the activated partial thromboplastin time (APTT) of 178.7 s. He had no bleeding symptoms and no relatives with bleeding tendency. A cross-mixing test was performed to find the cause of APTT prolongation, and we obtained a waveform of the factor deficiency pattern. However, all intrinsic clotting factors showed normal patterns. Therefore, we measured the activities of PK and high-molecular-weight kininogen (HMWK), which are contact factors, by the one-stage coagulation method. Results showed that the PK activity was 1.5%, and the HMWK activity was 74.5%; the PK activity was significantly decreased. Eventually, he was diagnosed as having congenital PK deficiency. In gene analysis, heterozygous missense mutations were found at three locations: exon 5, exon 9 and exon 14. The effect of this mutation on PK activity has not been reported. From this experience, we thought that this disease should be considered as a cause of unknown APTT prolongation. In addition, the pattern of a cross-mixing test is very useful for diagnosing this disease.

  • Shun NARATANI, Shoichi YAMADA, Kazuhisa KINOSHITA, Tatsuya NUNOHIRO, H ...
    Type: Case Report
    2021 Volume 70 Issue 1 Pages 138-143
    Published: January 25, 2021
    Released: January 26, 2021
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    A woman in her 40s was treated for deep vein thrombosis and pulmonary artery thrombosis in our hospital. Ultrasound sonography (US) was carried out to examine her lower limb veins owing to a marked increase in her D-dimer level, which revealed that her deep vein thrombosis had worsened. US examination of the pelvic cavity indicated that her ovaries were swollen with a mixture of solid and cystic components, which indicated ovarian cancer. Examinations of both contrast-enhanced computed tomography and magnetic resonance images revealed that the endometrium was irregularly thick, and she was also suspected of having endometrial cancer. On the basis of the above findings, total hysterectomy and bilateral ovariectomy were performed. The pathological diagnosis of these tumors was endometrial adenocarcinoma of the uterus and bilateral ovaries. Thromboembolism is known to occur at a high rate in malignant tumors. In this case report, US examination showed that her deep vein thrombosis in the lower limbs was exacerbated owing to high D-dimer levels, followed by the development of ovarian cancer, which was considered the underlying disease. This case showed that in young to middle-aged women with recurrent deep vein thrombosis, it is necessary to determine whether malignancy is present.

  • Yuta HOSODA, Nozomi TANAKA, Kaori ENDO, Mutsuhiro OKADA, Masaharu MORI
    Type: Case Report
    2021 Volume 70 Issue 1 Pages 144-149
    Published: January 25, 2021
    Released: January 26, 2021
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    Background: Plasmablastic lymphoma (PBL) is a rare malignant lymphoma occurring in immunocompromised patients caused by human immunodeficiency virus (HIV) infection and in elderly persons. We report a case of PBL diagnosed by immunohistochemical examination of a cytology cell block of pericardial fluid. Case: An elderly male patient in his 80s complained of backache on the left side. Computed tomography (CT) examination revealed bilateral pleural effusion and a large amount of pericardial fluid. Pericardial cavity puncture was performed under echo guidance, followed by cytodiagnosis of the pericardial fluid. Pericardial fluid cytology showed a large number of atypical cells of medium to large size with large irregular nuclei and prominent nucleoli. PBL or myeloma was suspected rather than primary effusion lymphoma after the immunohistochemical examination of the cell block. The pleural effusion cytodiagnosis was negative for the atypical cells. The bone marrow aspiration performed for excluding myeloma did not reveal any significant findings. Although gallium scintigraphy and positron emission tomography-CT were performed, the local existence of the tumor was not confirmed. No M protein was detected by serum immunoelectrophoresis, nor was the Bence Jones protein detected by urine immunoelectrophoresis. Therefore, there was no definitive diagnosis, but PBL was highly suspected. Conclusion: We encountered one case of PBL diagnosed by pericardial fluid analysis. Histological examination could not be performed because there were no tumor masses; hence, cytodiagnosis and immunohistochemical examination of the cell block were effective for the diagnosis. Thus, we reconfirmed the importance of making a cell block specimen with body-cavity fluid cytodiagnosis.

  • Noriko KAWAMITSU, Saki SHIRAHAMA, Saori UEDA, Taeko HOTTA
    Type: Case Report
    2021 Volume 70 Issue 1 Pages 150-154
    Published: January 25, 2021
    Released: January 26, 2021
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    Here, we report the cases of two patients diagnosed as having ADV-induced hemorrhagic cystitis. They were initially suspected of having this condition on the basis of the characteristic morphology of cells in the urinary sediment and then diagnosed with a rapid immunochromatographic ADV kit for the pharynx. The cells of the patients showed nuclear enlargement, a high N/C ratio, and homogeneously stained dark nuclei (smudgy chromatin) with blurry contours, which were in agreement with previous reports on ADV-infected urinary cells. These morphological characteristics of the ADV-infected cells led us to perform urinary quantitative ADV-PCR analysis using the rapid diagnostic kit for the pharynx, although the kit was not approved for use in urine samples. Later, the ADV-PCR analysis revealed high titers of ADV in both patients. The symptoms of the ADV-induced hemorrhagic cystitis are severe hematuria, frequent urination, and bladder irritation. Because urinary retention caused by a massive blood clot and systemic dissemination of the virus could lead to fatality in severe cases, prompt diagnosis is important. We were able to analyze the cells by the urinary sediment examination before the onset of macroscopic hematuria, leading to early diagnosis and therapy. It is difficult to diagnose ADV infection only on the basis of cell shape determined in the urinary sediment examination. The rapid immunochromatographic kit may be useful for the early diagnosis when suspicious ADV-infected cells are found.

  • Yuuichi SASAOKA, Hidenori ONISHI, Chieko HOSOKAI, Ai SHIMAOKA, Sakura ...
    Type: Case Report
    2021 Volume 70 Issue 1 Pages 155-159
    Published: January 25, 2021
    Released: January 26, 2021
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    The patient was a 64-year-old woman. An abdominal ultrasonography performed for screening for upper abdominal discomfort and pain revealed cystic lesions of various sizes up to 4.6 cm throughout liver area S6. The S6 cysts showed clear spontaneous reductions in diameter over time (down to 3.9 cm in September 2016, 3.0 cm in September 2017, and 2.0 cm in October 2019). When similar case reports were searched for in the “Ichushi” medical database, 10 cases were found. In many of these cases, the cause of spontaneous liver cyst reduction was unknown; however, one case was found in which the liver cyst had developed into a cystadenoma as it shrank. Considering the possibility that hepatic cysts that shrink over time may develop into cystadenoma, which may in turn become malignant (cystadenocarcinoma), it is necessary to regularly follow up patients with such cysts.

  • Shohei MIYAMOTO, Yuka HIRAI, Mai ISHIDA, Ayami UETA, Chiaki AOJI, Yumi ...
    Type: Case Report
    2021 Volume 70 Issue 1 Pages 160-166
    Published: January 25, 2021
    Released: January 26, 2021
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    The patient was a male in his 70s. He felt lightheadedness and heaviness in the head. A mobile plaque was found in the right subclavian artery in a previous hospital, and he was referred to our hospital. Electrocardiogram (ECG) revealed a sinus rhythm, Holter ECG did not indicate atrial fibrillation, and transthoracic echocardiography did not indicate any abnormal structures in the heart that could be suspected of thrombus or vegetation. Carotid echo showed a mobile plaque at the origin of the right subclavian artery, as pointed out by his previous physician, but further observation of the central side revealed a mobile plaque in the brachiocephalic artery. Contrast-enhanced CT showed calcification from the brachiocephalic artery to the right subclavian artery, and the latter was narrowed, but the mobile plaque could not be evaluated. Mobile plaque is a rare condition, and there have been very few reports on mobile plaques in the brachiocephalic or subclavian arteries. In this patient, a careful observation by ultrasonography showed that mobile plaques could be detected in the brachiocephalic artery and right subclavian artery. Ultrasonography is simple and noninvasive and can be used to evaluate the presence, properties, and mobility of intravascular plaques. The brachiocephalic artery and right subclavian artery can often be adequately observed and evaluated by ultrasonography. In general, mobile lesions are difficult to detect by CT or MRI; however, ultrasonography enables the real-time observation of plaques and appears to be the most useful for evaluating mobile plaques.

  • Konomi KONDO, Gen OKADA, Miho SUZUKI, Yasuyuki SUGIURA, Anna NOMURA, Y ...
    Type: Case Report
    2021 Volume 70 Issue 1 Pages 167-171
    Published: January 25, 2021
    Released: January 26, 2021
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    A 70-year-old male was urgently transported to our hospital owing to swelling and pain around the anus and scrotum. Immediately after incision and drainage of the scrotum, a large amount of odorous gas was discharged. At the time of sample submission, the doctor in charge suspected Fournier’s gangrene and infection by a mixture of anaerobic bacteria, and he requested for an immediate start of anaerobic culture. Immediate perineal debridement was performed without waiting for the culture results. Bacteroides fragilis was detected in scrotal secretions and blood samples. ICU management was performed owing to sepsis, but swift and appropriate antibiotics administration and temporary colostomy, second debridement, and skin grafting on the defect were also performed. He was completely cured in three months. Prompt information provision is essential for the diagnosis and treatment of this disease, and close information collaboration among doctors is important. Furthermore, if the presence or absence of anaerobic bacteria can be determined from Gram staining results, it can contribute to empirical treatment. When Fournier’s gangrene is suspected, poor prognosis is expected if there is a delayed response; thus, it is extremely important for doctors to closely cooperate with regard to medical treatments and to perform Gram staining at an early stage to determine the causative bacterium.

  • Masaharu NAGASAKI, Keiko MATSUOKA, Mami INOUE, Nobuko NAGAYAMA
    Type: Case Report
    2021 Volume 70 Issue 1 Pages 172-175
    Published: January 25, 2021
    Released: January 26, 2021
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    We report the cases of two patients presenting with emphysematous cystitis. The first patient was a man in his 80s who was undergoing maintenance dialysis at our hospital. Hematuria and lower abdominal pain developed during hospitalization for detailed treatment of hypoxemia. Ultrasonography showed thickening of the bladder wall and a gas appearing as a shadow in the posterior bladder lumen, suggesting emphysematous cystitis. The second patient was a woman in her 80s. Hematuria and lower abdominal pain developed during hospitalization for the treatment of pneumonia. Ultrasonography showed gas appearing as small echogenic foci located within the bladder wall and a gas appearing as a shadow in the posterior bladder lumen, so emphysematous cystitis was suspected. Similar findings were found in subsequent CT examinations in both patients. Escherichia coli was isolated in both patients by urine culture, and the result of a drug susceptibility test revealed that it was an ESBL-producing strain. They were treated by bladder drainage and appropriate antimicrobial therapy.

  • Hikaru TAKEDA, Takahiro YAMADA, Tsuyoshi HASEGAWA, Yu SUZUKI, Kiwa TAN ...
    Type: Case Report
    2021 Volume 70 Issue 1 Pages 176-181
    Published: January 25, 2021
    Released: January 26, 2021
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    Tsutsugamushi disease, a febrile disease, is sometimes clinically indistinguishable from other acute infectious diseases. A 75-year-old woman developed systemic erythematous eruptions after treatment with ibuprofen for dizziness and chill. However, on the following day, her eruptions were exacerbated with consciousness disturbance; thus, she was transferred to our hospital for further treatments and evaluations. On admission, she exhibited no lymphadenopathy or distinct eschar formation, except for the presence of atypical lymphocytes in her peripheral smear. After four days of hospitalization, she developed disseminated intravascular coagulation (DIC) and hemophagocytic syndrome (HPS). After carefully checking several times her medical history including a tsutsugamushi-relevant contact history, it was suggested that she had tsutsugamushi disease. A serology test showed her recent exposure to Orientia tsutsugamushi. Administration of minocycline rapidly improved her symptoms. Regarding laboratory findings, the atypical lymphocytes increased in number up to 10% of her white blood cells after three days of hospital and thereafter decreased before the onset of DIC and HPS. We compared the characteristics of her lymphocytes between the time of onset and recovery. At the time of onset, most of the atypical lymphocytes were positive for CD8, and the CD4+/CD8+ ratio of all her lymphocytes was 0.5, whereas the ratio was 1.2 at the time of recovery. These findings suggest an infectious mononucleosis development in this patient, and that the presence of atypical lymphocytes may be a diagnostic predictor for tsutsugamushi disease, especially when bite marks or their eschar is not easily detected in systemic eruptions.

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