Japanese Journal of Medical Technology
Online ISSN : 2188-5346
Print ISSN : 0915-8669
ISSN-L : 0915-8669
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Showing 1-30 articles out of 30 articles from the selected issue
Original Articles
  • Tadanori YAMAGUCHI, Yuka MATSUI, Masashi IWASAKI, Tsunehiro II, Mitsuo ...
    Type: Original Article
    2021 Volume 70 Issue 3 Pages 385-393
    Published: July 25, 2021
    Released: July 28, 2021
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    Using immunohistochemistry, we investigated whether CD10 expression was associated with prognostic factors and overall survival in primary lung cancer. The presence, proportion, and pattern of CD10 expression in 388 tumors were examined. The association of 11 factors with CD10 expression was evaluated, namely, age, sex, surgical treatment, histological type, T factor, N factor, histopathological differentiation, pleural infiltration, lymphatic invasion, vascular invasion, and EGFR mutation. Each factor was subjected to univariate/multivariate analyses using logistic regression analysis of the cumulative survival rate. A p-value of < 0.05 was considered significant in all tests. CD10 was positive in 122 tumors (31%). The positive rates in terms of histological type were 67/286 (23%) for adenocarcinoma, 35/73 (48%) for squamous cell carcinoma, and 20/29 (68%) for other tumors. The expression rate tended to increase in the order of adenocarcinoma, squamous cell carcinoma, and other tumors. The predominant expression pattern tended to be the apical membrane pattern in adenocarcinomas and the membrane and cytoplasm pattern in squamous cell carcinomas and other tumors. In the univariate analysis, 10 factors, excluding age, were identified as relevant. In multivariate analysis, three factors, namely, N factors (p = 0.017), pleural infiltration (p = 0.003), and EGFR mutation (p = 0.017), were found to be independent related factors. The five-year overall survival rate was significantly lower in the CD10-positive group than in the CD10-negative group. CD10 expression determined by immunohistochemistry is a prognostic predictor of primary lung cancer and may be a basis for the stratification of patients to some extent. It can be expected to be used as a highly convenient and useful biomarker.

  • Eriko ITO, Kazuyo MURAKAMI, Miyoko IKEGUCHI, Yoko OSAMURA, Takuya KITA ...
    Type: Original Article
    2021 Volume 70 Issue 3 Pages 394-402
    Published: July 25, 2021
    Released: July 28, 2021
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    In peripheral blood stem cell transplantation, enumeration of stem cells is important to determine the optimal time of stem cell collection and the adequate number of stem cells to be collected. In this study, we investigated the correlation between the number of hematopoietic progenitor cells (HPCs) determined using an automated hematology analyzer XN3000 and the number of CD34-positive cells determined using a flow cytometer. In a total of 167 specimens collected from 97 subjects, a significant correlation was observed between the number of HPCs (X) and the number of CD34+ cells (Y): y = 0.597x + 5.625, ρ = 0.745, and p < 0.001. The optimal cut-off number of HPCs to predict CD34+ cells ≥ 20/μL was 23/μL, with a sensitivity of 69%, a specificity of 93%, and positive and negative predictive values of 93% and 70%, respectively. In specimens from patients other than those with plasma cell tumor (i.e., MM), who were < 40 years old, and with an HPC count of < 50 cells/μL, a CD34+ cell count of ≥ 20/μL could be satisfactorily predicted (96% sensitivity, 91% specificity) when the cutoff count was 23/μL. However, a discrepancy was frequently observed between the numbers of HPCs and CD34+ cells in MM patients, subjects ≥ 40 years old, and specimens with an HPC count of ≥ 50/μL.

  • Fumitaka KASE, Yasuaki IIDA, Tomohiro OTA, Sumika AOYAMA, Maya HARAGUC ...
    Type: Original Article
    2021 Volume 70 Issue 3 Pages 403-409
    Published: July 25, 2021
    Released: July 28, 2021
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    Purpose: To date, numerous test reagents for the detection of SARS-CoV-2 have been released in the market in Japan. However, few reports regarding the performance of these reagents have been published. In this paper, we aim to evaluate the performance of two reagents, “μTASWako COVID-19” (“μTAS”) and “SARS-CoV-2 Direct Detection RT-qPCR Kit” (“SARS-CoV-2 kit”). Method: A nasopharyngeal swab was used as the sample, and “μTAS” and “SARS-CoV-2 kit” were compared by the following methods: ① comparison of match rate of results, ② comparison of various conditions between the positive-match group and the result-mismatch group, and ③ comparison of Ct values. Result: ① The positive match rate was 58% (15/26), whereas the negative match rate was 100% (13/13). The overall match rate was 72% (28/39). ② A significant difference was observed in the number of days of onset at the time of sample collection (p = 0.002). ③ The median difference in Ct values was 6.5, indicating that the measured Ct value for “μTAS” was significantly higher (p < 0.001). Conclusion: The results suggests that “μTAS” seems to be less sensitive than “SARS-CoV-2 kit”. Therefore, clinicians should carefully consider false negatives in the screening test when using “μTAS”. In addition, when infectiousness is estimated with reference to the Ct value, “μTAS” may provide a higher Ct value than other methods.

Technical Articles
  • Yumi TANI, Nobuyuki KAKIMOTO, Yoshie TAKIGUCHI, Chizumi OGAWA, Akiko H ...
    Type: Technical Article
    2021 Volume 70 Issue 3 Pages 410-415
    Published: July 25, 2021
    Released: July 28, 2021
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    Pulmonary hypertension (PH) is a serious complication of ventricular septal defect (VSD). Electrocardiography (ECG) effectively demonstrates right ventricular hypertrophy (RVH) in patients with PH, and this can be achieved more easily by applying right-sided chest leads in the synthesized 18-lead ECG. We examined 53 pediatric patients with VSD aged between 1 month and < 3 years who underwent the standard 12-lead ECG. Our pediatric cardiologists assessed the results of echocardiography and cardiac catheterization, and on the basis of which, classified patients as having PH (36 cases) or lacking PH (17 cases). The R and T wave amplitudes recorded via the left chest leads, V1 and V2 in the standard 12-lead ECG and syn-V3R and syn-V4R in the synthesized 18-lead ECG, were compared between the two groups. A significant intergroup difference was observed in syn-V3R and syn-V4R in the synthesized 18-lead ECG (p = 0.0001). When we determined the presence or absence of PH in the two groups using a combination of the standard 12-lead ECG on the basis of the Japanese guidelines (JCS 2009) (R and T waves of V1, and S wave of V6) and the synthesized 18-lead ECG (R of syn-V3R and syn-V4R), the sensitivity, specificity, and accuracy rate for PH were 61%, 88%, and 70% vs. 67%, 76%, and 70%, respectively. Furthermore, when the R or T wave of syn-V4R was positive, the sensitivity and specificity for the diagnosis of RVH were 89% and 82%, respectively, suggesting that PH can be easily discriminated by daily inspection.

  • Takahiro MATSUSHIGE
    Type: Technical Article
    2021 Volume 70 Issue 3 Pages 416-422
    Published: July 25, 2021
    Released: July 28, 2021
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    Currently, the method of fixing tissue sections for histopathological analysis is to use a formalin solution alone; thus, pretreatment of sections with mordants containing potassium dichromate or Bouin’s solution is required when performing collagen staining. However, a review is urgently needed from the viewpoint of toxicity of these chemicals. In this study, we investigated the usefulness of substitute mordants in Gomori’s one-step trichrome staining. Firstly, the sections were pretreated with substitute mordants of Bouin’s solution, saturated picric acid solution, decalcifying solution A (Plank Rychlo method), and 0.5% potassium permanganate solution at 25°C for 30 min or at 60°C for 60 min. Secondly, the sections were stained in accordance with the original Gomori’s one-step trichrome staining method. Lastly, the stainability was investigated by microscopy and RGB/Br (Red-Green-Blue/Brightness) analysis. The B/Br value of the saturated picric acid solution at 60°C for 60 min was significantly lower than that of commercially available mordants containing dichromic acid and decalcifying solution A. In other words, this mordant suppressed blue costaining in the cytoplasm, dyed the cytoplasm more vividly red than other mordants, and improved the contrast with blue in collagen fibers. On the other hand, pretreatment of the sections with 0.5% potassium permanganate solution resulted in poor staining quality. Whereas chromic acid and formaldehyde are carcinogenic, picric acid is not. Therefore, in this study, it was demonstrated that pretreating the sections with a saturated picric acid solution can be as effective as the original Gomori’s one-step trichrome staining method.

  • Hirotaka KAIHARA, Yuka ONOSHI, Kyoutarou INOUE, Yukiko YAMASHITA, Taki ...
    Type: Technical Article
    2021 Volume 70 Issue 3 Pages 423-432
    Published: July 25, 2021
    Released: July 28, 2021
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    In the treatment of Mycobacterium infection, gene analyses are carried out to distinguish Mycobacterium tuberculosis complex and nontuberculous mycobacteria rapidly and accurately. To further investigate the simplicity and rapidity of mycobacterial testing, we compared three detection methods using fully automated genetic analyzers, namely, μTAS Wako g1 (Fujifilm Wako Pure Chemical Corporation; polymerase chain reaction-capillary electrophoresis [PCR-CE]), TRCReady-80 (Tosoh Corporation; transcription reverse-transcription concerted reaction [TRC]), and GENECUBE (Toyobo; quenching probe [Qprobe]), with our routine methods using the COBAS TaqMan 48 analyzer (Roche Diagnostics; TaqMan) and culture. We calculated the positive/negative agreement rates in 94 pretreated samples. We also calculated the detection sensitivity values using the dilution series of Mycobacterium avium and Mycobacterium intracellulare. The positive/negative agreement rates of the three detection methods using TaqMan were as follows: PCR-CE, 70.8%/98.6%; TRC, 95.8%/95.7%; and Qprobe, 87.5%/100.0%. The positive/negative agreement rates of the three detection methods with culture were as follows: PCR-CE, 61.5%/98.5%; TRC, 88.5%/97.1%; and Qprobe, 76.9%/100.0%. The minimum detection sensitivity values were as follows: PCR-CE, 2.0 × 10 to 1.1 × 103 CFU/mL; and TRC and Qprobe, 2.0 × 10 to 1.1 × 102 CFU/mL for both. In conclusion, three detection methods using fully automated genetic analyzers are useful for the simple and rapid detection of Mycobacterium avium complex. Choosing analyzers suitable for each facility is important.

  • Kazuya YAMASHITA, Tatsuru KUBA, Shinobu SAKAGUCHI, Tsutomu YOSHIDA, Yo ...
    Type: Technical Article
    2021 Volume 70 Issue 3 Pages 433-442
    Published: July 25, 2021
    Released: July 28, 2021
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    About 54 medical accidents in the handling of the fixing solution for histopathology have occurred in the last eight years in Japan. In these accidents, formalin is misused with medicines and other compounds such as mint oil, saline, and alcohol. Incidents in which a patient’s specimen is placed in a fixing solution into which another patient’s specimen was previously put still occur. The absence of a system with which opened and unopened solutions can be differentiated is also another factor. In this study, a method of sealing a bottle with a lid and the coloration of formalin were developed to prevent accidents, and their usefulness was verified for four years. A practical coloration of formalin uses less than 0.01% dyes than a bromothymol-blue or a phenol-red solution used singly or in a mixture. This coloration method is a detection tool for formalin based on color tone, and a pH indicator showed that the method neither changes the color nor causes discoloration of specimens. The method showed long stability of specimens, and tissue and cell damage was minimal. Furthermore, a sealing tape is applied to the lid of a fixing bottle, and the “post-ablation” label is embossed on the tape to differentiate used from unused formalin, which makes checking easy. Products equipped with a “coloration” and a “seal” were used in about 140,000 specimens, the incidence rate was 0%, and good results were obtained as compared with cases without using such products. Accordingly, the proposed sealing method and formalin coloration are novel tools and help prevent medical accidents originating from incorrect formalin fixing.

  • Yuka AKITA, Kunimitsu MACHIDA, Kazuto NAKAMURA, Isami TSUBOI
    Type: Technical Article
    2021 Volume 70 Issue 3 Pages 443-447
    Published: July 25, 2021
    Released: July 28, 2021
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    We performed a basic study of serum Entamoeba histolytica Immunoglobulin Enzyme-linked immuno-sorbent assay (hereinafter referred to as this reagent) based on the enzyme-linked immunosorbent assay method to verify the accuracy, detection limit, dilution linearity, reference value of serum E. histolytica antibody titer, and the correlation with the control reagent (antibody measurement method using a fluorescent dye-labeled antibody). As a result, CVs of within-run precision were less than 3.5% and CVs of between-day precision were less than 7.5%. The antibody titer increased almost linearly up to 10 GWU and then plateaued above 10 GWU, but no decrease in antibody titer due to excess antibody was observed up to around 28 GWU. This reagent had a positive concordance rate of 42.9%, a negative concordance rate of 100.0%, and a judgment concordance rate of 69.2% with respect to the control reagent. The 14 negative samples for this reagent all showed 100 times the minimum dilution factor that was judged to be positive for the control reagent. This reagent showed a good correlation with the control reagent.

  • Ayano OGAWA, Satomi ASAI, Miki MIYAZAWA, Noboru TAKANASHI, Kouichi SHI ...
    Type: Technical Article
    2021 Volume 70 Issue 3 Pages 448-455
    Published: July 25, 2021
    Released: July 28, 2021
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    Ultrasonography, which is frequently used for medical examination, may transmit pathogens from one patient to another and lead to a disease outbreak if infection control is neglected. Maintaining hygiene standards while using the ultrasound gel is essential for preventing nosocomial infections. In this study, to examine the hygiene standards of the gel and gel warmer used for ultrasonic examination in hospitals, a bacteriological survey of the environment was conducted. On the basis of the results of the survey, hygienic methods of using the gel and gel warmer were explored. Samples collected from the gel and gel warmer prior to the first use and after the last examination of the day were cultured. All the detected bacteria were indigenous to the environment or were a part of the human microbiome. No prominent bacterial growth was observed, suggesting the sanitary handling of the gel. However, it is recommended that the environmental conditions should be maintained as aseptic as possible while examining immunocompromised patients. To reduce the risk of infections, the gel at the tip of the bottle, which poses a risk of contamination, should be discarded prior to use, and the gel warmer should be cleaned at the end of daily work. The equipment should be cleaned and disinfected daily as well.

  • Kotaro HISHIKI, Yu AKIYAMA, Kiyomi KARUBE, Takashi HONMA, Mikiko HONOB ...
    Type: Technical Article
    2021 Volume 70 Issue 3 Pages 456-464
    Published: July 25, 2021
    Released: July 28, 2021
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    We evaluated the performance of AUTION EYE AI-4510 (ARKRAY, 2019), an automatic urine sediment analyzer that is based on the unstained image analysis method. Our results showed that its basic performance, such as parallel accuracy and indoor reproducibility, was satisfactory. In comparison with microscopic examination, the sensitivity and specificity for red blood cells, white blood cells, squamous epithelial cells, hyaline casts, and bacteria were 69.0% and 95.1%, 60.9% and 99.4%, 34.1% and 99.6%, 52.6% and 77.4%, and 48.5% and 93.8%, respectively. The reason for such differences was considered to be the difficulty in distinguishing similar components owing to insufficient shape recognition. However, sequential version-up improved the specificity. Improvement of working efficiency, shortening of examination time, and accurate detection of urine sediments are required for this automatic urine sediment analyzer. This device has basic performance comparable to that of microscopic examination; thus, it is considered that this device could be introduced into routine laboratory use.

  • Keizo TODA, Kazuki NAKASHIMA
    Type: Technical Article
    2021 Volume 70 Issue 3 Pages 465-474
    Published: July 25, 2021
    Released: July 28, 2021
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    Entamoeba histolytica, which is the cause of a category 5 infectious disease, needs to be differentiated from the non-pathogenic species Entamoeba dispar and Entamoeba moshkovskii. PCR analysis is a specific and highly sensitive method of detecting E. histolytica, and the technology is shifting from conventional PCR to real-time PCR analysis. Therefore, we investigated a highly sensitive method to detect the Entamoeba complex by PCR-HRM analysis, which is a further evolution of real-time PCR analysis. Furthermore, we compared HRM analysis with multiplex PCR, allele-specific PCR, allele-specific real-time PCR, and nested PCR analyses. Results showed that the sensitivity of multiplex PCR analysis is inferior to that of other methods because the sensitivity decreased as the size of the PCR product increased. When the size of the PCR product is small, sufficient detection sensitivity can be obtained, so that it is not necessary to carry out nested PCR, which increases the risk of contamination. Since PCR-HRM analysis and allele-specific real-time PCR analysis use a real-time PCR thermal cycler, there is no need to open the lid of the PCR tube. Therefore, the risk of contamination is extremely low, and the turnaround time can be shortened. Moreover, since only one tube is used in PCR-HRM analysis, running costs are low, and there is a possibility that more Entamoeba species can be detected.

  • Chihiro FUKUMITSU, Hideyuki ABE, Eiji SADASHIMA, Yorihiko TAKASE, Yuka ...
    Type: Technical Article
    2021 Volume 70 Issue 3 Pages 475-481
    Published: July 25, 2021
    Released: July 28, 2021
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    The workload in our pathology laboratory is steadily increasing. To improve medical safety and reduce the burden of pathological technologists, we introduced an automated tissue-sectioning machine. From the start of its introduction, we had already been making efforts to improve our method of preparing paraffin blocks to maintain tissue section quality. Here, we report on the performance of the automated tissue-sectioning machine and evaluated the improvement of the quality of slide sections of different tissue types. A total of 43,488 paraffin blocks from surgical pathology specimens were prepared routinely from January 2017 to June 2018. Initially, the paraffin blocks were roughly trimmed and hard tissues were removed by pathological technologists. The paraffin blocks were then automatically cut into sections of 5 µm thickness, and the quality of slide sections of various tissues was evaluated. A total of 28,876 paraffin blocks were automatically sectioned, and 91.9% (26,541/28,876) were evaluated as high-quality slide sections. Slide sectioning of the ovary (97.4%) and uterus (95.5%) was particularly successful compared with other tissues, and the overall quality of the slide sections of various tissues was clearly improved compared with the quality at the time of introduction of the automated tissue-sectioning machine (p < 0.001).In conclusion, high-quality sections were obtained from the automated tissue-sectioning machine, and this machine will be useful for reducing the burden of pathological technologists. Preparing paraffin blocks suitable for an automated tissue-sectioning machine is important to maintain the quality of slide sections.

  • Natsuki NARUMI, Takashi KONDO, Ryosuke MORIAI, Akemi ENDOH, Koichi ASA ...
    Type: Technical Article
    2021 Volume 70 Issue 3 Pages 482-488
    Published: July 25, 2021
    Released: July 28, 2021
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    In this study, we evaluated the performance of a new method of measuring Presepsin, the “HISCL Presepsin”. Presepsin was measured with the HISCL Presepsin reagent using HISCL-5000. The control reagent was STACIA CLEIA Presepsin. Existing samples were measured. We evaluated whether HISCL Presepsin is satisfactory in terms of precision, long-term stability, linearity, detection limit, interference from substances, correlations, and method of mixing. Satisfactory results in terms of precision and linearity were obtained.There was good long-term stability for nine weeks.The detection limit when using the 2SD method was 9.4 pg/mL. There was no interference from substances such as hemoglobin, unconjugated bilirubin, conjugated bilirubin, and rheumatoid factor.A strong correlation was observed between the HISCL Presepsin and STACIA CLEIA Presepsin (r = 0.997, y = 0.91x − 89.21). In addition, we examined three effects of agitation on the measurement of Presepsin. The STACIA CLEIA Presepsin showed a larger increase in percentage of rate of increase test value. However, we need to pay attention to the handling of premeasurement samples because of the possibility of an abnormally high Presepsin concentration caused by excessive agitation. In summary, our results suggest that HISCL Presepsin may be useful for the early diagnosis of sepsis.

  • Hidehiro IWATA, Kamiyu TSUNEKAWA, Aya UMEMURA, Kenji NITTA, Hiroe MIZU ...
    Type: Technical Article
    2021 Volume 70 Issue 3 Pages 489-496
    Published: July 25, 2021
    Released: July 28, 2021
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    In the manual HER2-FISH test for breast cancer, the observer measures the HER2 and CEP17 signals of more than 20 cancer cells and calculates the mean number of HER2 copies and the HER2/CEP17 ratio. However, the results obtained manually may differ depending on the observer. The purpose of this study is to examine the usefulness of the automatic counting method by having multiple observers perform manual and automatic counting on the same sample. Eight breast cancer cases determined to be HER2 protein 2+ by immunohistochemical staining were included. The average number of cells measured by the automatic counting method was 222. The manual method showed discrepancies in four of the eight cases. In these four cases, the average HER2 copy number between observers was significantly different. Three of the four cases that did not match in the manual method were negative in the automatic counting method. Compared with the visual method, the automatic counting method showed a high degree of consistency in the HER2-FISH test. The automatic counting method can measure a large number of cells, and highly objective and reproducible results can be obtained. The automatic counting method is also useful as a means of quality control and may contribute to improving the accuracy of the HER2-FISH test.

  • Keishiro KAWANO, Ayumi TAGASHIRA, Hideyuki MATSUNAGA, Eri CHIKAMI, Yuk ...
    Type: Technical Article
    2021 Volume 70 Issue 3 Pages 497-503
    Published: July 25, 2021
    Released: July 28, 2021
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    The performances of “CHROMagar mSuper CARBA” (Kanto Chemical Co., Inc.) and “chromIDTMCARBA” (bioMérieux Japan Ltd.) in screening for carbapenemase-producing Enterobacterales (CPE) were evaluated. We used 20 CPE strains (17 IMP-1 group strains including nine stealth-type strains, one KPC group strain, and two OXA-48 group strains) for the growth ability test based on the Miles and Misra method and the test in the presence of feces. We used 27 CPE strains (24 IMP-1 group strains, one KPC group strain, and two OXA-48 group strains) and 137 non-carbapenemase-producing carbapenem-resistant Enterobacterales (non-CP-CRE) strains for the test performed at the same concentration of 103 CFU/mL. mSuper CARBA showed a high sensitivity of 95% or more at 103 CFU/mL in all tests, but that of chromIDTMCARBA was around 30%, suggesting the usefulness of mSuper CARBA. On the other hand, mSuper CARBA had a specificity of 66.4% (91/137) in the growth ability test at the same concentration, and we found that the MEPM-resistant non-CP-CRE strains tended to be detected as false positives. Although it is necessary to understand the characteristics of mSuper CARBA, the high sensitivity for detecting CPE strains including those of the stealth type is useful for screening tests, and it will contribute to the proper use of antibiotics and the prevention of nosocomial infections.

  • Rika WATARAI, Ryosuke KIKUCHI, Satoru YOKOYAMA, Atsuo SUZUKI, Hui Jeon ...
    Type: Technical Article
    2021 Volume 70 Issue 3 Pages 504-510
    Published: July 25, 2021
    Released: July 28, 2021
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    The Cancer Antigen 72-4 (CA72-4) assay by electrochemiluminescence immunoassay (ECLIA) is a one-step method with only one bound/free separation. However, the method is susceptible to the prozone effect and biotin interference during the immunochemical reaction. Recently, the ARCHITECT CA72-4 reagent, which is based on the chemiluminescence immunoassay (CLIA), has been developed. In this study, we carried out a basic performance evaluation of the CA72-4 reagent by the CLIA method. We used the same residual serum after routine testing by the CA72-4 ECLIA assay has been performed. The CA72-4 value obtained using the ARCHITECT CA72-4 reagent showed linearity up to 300 U/mL. The within-run precision of the CLIA method was excellent for both control samples and pooled sera with a coefficient of variation of less than 5%. The correlation between the ECLIA and CLIA methods was good (regression equation: y = 1.08x − 1.65; correlation coefficient (r): 0.974). Sequential data for CA72-4 showed stability under any storage conditions, including seven days of refrigeration, 24 hours at room temperature, and freezing and thawing. With the CLIA method, biotin did not interfere with the CA72-4 measurements, whereas the ECLIA method decreased the CA72-4 value in a biotin-concentration-dependent manner. Our results indicated that the performance of the CLIA method for the CA72-4 assay was sufficient.

Materials
  • Keiko INOMTA, Youko FUKUYOSHI, Hitoshi NISHIMURA, Shinji TANAKA, Kaoru ...
    Type: Material
    2021 Volume 70 Issue 3 Pages 511-517
    Published: July 25, 2021
    Released: July 28, 2021
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    A workshop-style seminar was held during the conference of the 54th Kyushu branch of the Japanese Association of Medical Technologists (JAMT) with the aim of acquiring the nontechnical skills necessary for medical technologists to play an active role in a medical team. Ninety-five clinical laboratory technologists in their 20s to 50s who attended the conference from all over Kyushu and 25 third- and fourth-year college students studying medical laboratory science participated in the workshop. The workshop consisted of two parts: the first part for learning and experiencing “nontechnical skills” and the second part for learning and experiencing “membership”. In the second part of the workshop, a “problem-solving exercise” using a training game was conducted in the group work, and 80% of the groups succeeded in solving problems by demonstrating leadership and actively exchanging information among members. In addition, some groups solved problems through autonomous discussions while flexibly exchanging roles between leaders and followers. Workshops that combine lectures and hands-on experience are expected to be effective in developing the nontechnical skills required of medical technologists.

  • Anna KAZUSA, Teruhito TAKAKUWA, Tomoko FUKUYAMA, Akari HISANABE, Koji ...
    Type: Material
    2021 Volume 70 Issue 3 Pages 518-524
    Published: July 25, 2021
    Released: July 28, 2021
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    An estimated 20% of platelet transfusion refractoriness (PTR) is reported to be related to immunological factors, 95% or more of which are anti-human leukocyte antigen (anti-HLA) antibodies. Although the corrected count increment at 1-hour post-transfusion (CCI-1) is commonly used to assess the efficacy of platelet transfusion, CCI-1 is not always routinely measured owing to the need for additional blood collection. To develop a method for the easy prediction of immunological PTR, we retrospectively analyzed the medical records of 50 patients with PTR in our hospital and who were screened for anti-HLA and anti-HPA antibodies from July 2005 to December 2018. Among these patients, 96% (48 patients) had hematological disorders, and antibody-dependent PTR was observed in 23 patients. In this study, significant factors for immunological PTR were sex (female), C reactive protein (CRP) levels of < 2.2 mg/dL, and CCI-1 of < 3,500/μL. Using two factors, female sex and CRP levels of ≤ 2.2 mg/dL, we were able to predict immunological PTR with a sensitivity of 69.6% and a specificity of 77.8%. Furthermore, among patients with a hematological malignancy, the sensitivity and specificity increased to 86.7% and 75.0%, respectively. Although CCI-1 predicted immunological PTR with a specificity of ≥ 90%, it was not measured in 38% of patients. Currently, CCI-1 is the standard method for distinguishing PTR. Therefore, if platelet transfusion is ineffective, a medical technologist should suggest the measurement of CCI-1 to the attending doctor as well as organize the information, such as the disease that causes PTR, sex, and CRP level, so that antiplatelet antibody testing is performed promptly.

  • Nobuhisa TANAKA, Daiki JINGU
    Type: Material
    2021 Volume 70 Issue 3 Pages 525-528
    Published: July 25, 2021
    Released: July 28, 2021
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    The levels of serum immunoglobulins vary depending on age, particularly in children. Therefore, an age-related reference range of individuals must be used when evaluating a patient’s immunoglobulin levels. We determined reference ranges for serum immunoglobulins (IgG, IgA, and IgM) in the early neonatal period (0–6 days after birth). Data were from patients in the early neonatal period admitted to our Neonatal Intensive Care Unit and Growing Care Unit. Our subjects were divided into three groups on the basis of gestational age (GA): 21–27 weeks, 28–36 weeks, and 37–42 weeks. There was a significant difference in the serum IgG level among the three groups. Thus, for IgG, considering the effect of GA is useful for estimating the reference range for infants in the early neonatal period. On the other hand, there was no correlation among the three groups in terms of serum IgA and IgM levels; thus, it was not necessary to consider the effect of GA in these groups.

  • Masaya YOSHIDA, Kiho TANAKA, Arisa UCHIDA, Taki KUROKAWA, Masaki RYU, ...
    Type: Material
    2021 Volume 70 Issue 3 Pages 529-534
    Published: July 25, 2021
    Released: July 28, 2021
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    [Introduction] In cases of lower thoracic aortic surgery at low temperatures, hemostasis after cardiopulmonary bypass detachment is sometimes difficult to achieve owing to coagulopathy. Cryoprecipitate (Cryo) is a concentrated form of a coagulation factor containing fibrinogen (Fbg), which can be efficiently supplemented in small volumes. We started the preparation of Cryo from November 2017 and analyzed its effects on acute aortic dissection. [Materials and Methods] For 28 cases without Cryo transfusion (Non-Cryo group) and 22 cases with Cryo transfusion (Cryo group), changes in the blood products (RBC, FFP, and PC) used during and after surgery, the use of Cryo, and the Fbg concentration before and after Cryo transfusion were analyzed. [Results] During surgery, the mean RBC units transfused decreased (Non-Cryo group, 10.6 units; Cryo group, 6.9 units), and the mean FFP units transfused decreased (Non-Cryo group, 17.0 units; Cryo group, 13.4 units). After surgery, the mean RBC units transfused decreased (Non-Cryo group, 10.1 units; Cryo group, 5.7 units), and the mean FFP units transfused decreased (Non-Cryo group, 15.1 units; Cryo group, 5.7 units). After Cryo administration, the mean Fbg concentration increased significantly (before Cryo transfusion, 113 mg/dL; after Cryo transfusion, 185 mg/dL). [Discussion] Cryo can not only reduce the amount of blood components used and our workload, but also enabled the efficient replacement of Fbg. To use Cryo properly, it is important to check the Fbg concentration before transfusion and control the inventory of blood products. [Conclusion] Our current study showed that Cryo is useful for reducing the amounts of blood products used and Fbg replacement therapy.

  • Yuta TORII, Go YAMAMOTO, Naoko SUGANUMA, Shoji MIYAGAWA, Kazushi MINOW ...
    Type: Material
    2021 Volume 70 Issue 3 Pages 535-541
    Published: July 25, 2021
    Released: July 28, 2021
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    COVID-19 is an emerging infectious disease caused by SARS-Cov-2 and has spread worldwide. We have encountered many problems in the prevention and control of COVID-19 in the hospital, many aspects of which remain unknown. As indicated in the statements from each academic society, many laboratories have suspended or postponed physiological function tests with a high risk of aerosol transmission, except for emergencies, because the risk of infection occurs even before the onset of symptoms of the disease, and there is concern about the possibility of a large number of contacts among hospital staff members at the time of disease onset. Also, the PCR test is not highly sensitive because of the sampling method and other factors, and it is possible that patients who tested negative may still have the virus (i.e., false negative). If a confirmed COVID-19 patient obtains a negative PCR test result after being quarantined for two weeks, COVID-19 can be ruled out to the maximum extent possible at this stage. However, it is still an unsatisfactory infection control. Therefore, it is necessary to take adequate measures to prevent infection. We report on the operation of a physiological function test with a high risk of aerosol transmission during the COVID-19 pandemic in our hospital.

  • Akifumi TERAYAMA, Toshiaki MIIKE, Mamiko KOGA, Mieko SAITO, Toki MITOM ...
    Type: Material
    2021 Volume 70 Issue 3 Pages 542-550
    Published: July 25, 2021
    Released: July 28, 2021
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    There have been few reports on the internalization of microbiological testing in mid-sized hospitals. To contribute to better management of the future hospitalization of patients with microbial diseases in a mid-sized hospital, we report on the efforts and problems that have led to the establishment of microbiology laboratories. In April 2018, we conducted a microbiology laboratory establishment project led by hospital administrators in relation to location, equipment, systems, necessary works, communication with the administration, visits to other facilities and external training, and a study session by external instructors among others. After that, we created a microbiology working group led by the Infection Control Team and discussed the contents of the tests and the duties of the microbiology team. As a result, the microbiology laboratory officially started operation in August 2019. Blood culture bottles were stored in the laboratory after collection when it outsourced. After the start of operation, we were able to start cultivation within two hours after collection. During the first month of operation, we frequently encountered system failures. In addition, the number of specimens exceeded the capacity of the laboratory, and all specimens other than outpatient specimens and urgent specimens were outsourced to other laboratories. This meant that only specimens from emergency rooms and hospitalized patients were processed in the hospital. In addition, human resource development is an urgent task. Internalization has shortened the reporting time for blood-culture-positive cases and increased the chances for more inquiries regarding microbiology test results and specimen collection.

  • Naoki SHIRAISHI, Ryuichiro KIMURA, Tatsufumi MORI, Takahiro SAWADA, Sh ...
    Type: Material
    2021 Volume 70 Issue 3 Pages 551-559
    Published: July 25, 2021
    Released: July 28, 2021
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    The development of molecularly targeted drugs has progressed rapidly in recent years. As for companion diagnostics especially in primary lung cancer, many of these drugs are prescribed. Kindai University has established in the Faculty of Medicine the Center of Genomic Medicine, which performs the companion diagnostics specialized for lung cancer. We have started to receive clinical examinations of markers such as PD-L1 (22C3), ALK (IHC), ALK (fluorescence in situ hybridization (FISH)) and EGFR. The center has received and tested 517 samples in its two years of operation, 365 (70.6%) of which contained a sufficient amount of malignant tumors to perform the examination successfully. The numbers of cases for which examinations were carried out were 81 for EGFR in seven months and 350 for PD-L1 (22C3), 278 for ALK (IHC) and 237 for ALK (FISH) in two years. It took 11.8 days (including Saturdays, Sundays and holidays on average to return the results of genomic examinations after receiving the formalin-fixed samples. However, it took only 7.73 days for EGFR. We obtained a turnaround time that is short enough compared with outsourcing. The Center of Genomic Medicine has stopped receiving new samples because we set up in our hospital a new department that will perform genetic screenings using a next-generation sequencer. We report the advantages and disadvantages of performing clinical examinations in our facilities, which we found through these approaches, by posting the possible problems associated with introducing these examinations in the center.

  • Akira KAMIDA, Kaori SANADA, Yuya TAMAI, Mitsue KAWAMOTO, Mami SUGIYAMA
    Type: Material
    2021 Volume 70 Issue 3 Pages 560-565
    Published: July 25, 2021
    Released: July 28, 2021
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    Occasionally, the results of initial and confirmatory hepatitis B surface antigen (HBsAg) tests are different. We defined samples both indicating 0.05 ≤ < 10 IU/mL in the initial test and finally resulting in negative results as false positives and those finally resulting in positive results as true positives. The aims of this study were to clarify the samples considered false positives, compare the initial and confirmatory test values, and compare results of HBsAg tests with those of antibody to the hepatitis B core antigen (anti-HBc) tests. In total, 12,407 samples were included in this study. One hundred and sixty-two samples indicated positivity in the initial tests. Fifty-five samples indicating 0.05 ≤ < 10 IU/mL in the initial tests were tested again after high-speed centrifugation, and 21 samples were tested with neutralization. As a result, 39 samples were found to be false positives and 16 samples were true positives. Thirty samples indicated negative conversion after high-speed centrifugation, and nine samples indicated negative conversion on neutralization. There was no significant difference in the initial test values of false positives and true positives. Anti-HBc results were obtained from seven samples. Four samples indicated negativity for both HBsAg and anti-HBc, one sample indicated positivity for both HBsAg and anti-HBc, and two samples indicated HBsAg negativity and anti-HBc positivity. In summary, false positives in HBsAg tests were found in our hospital, and we were unable to distinguish true positives from false positives among the initial test values. Therefore, we suggest that confirmatory tests should be carried out to obtain accurate results. Furthermore, anti-HBc may help identify false positives.

  • Nobuhisa TANAKA, Natsuko ARAI
    Type: Material
    2021 Volume 70 Issue 3 Pages 566-570
    Published: July 25, 2021
    Released: July 28, 2021
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    Exchange transfusion (ET) is an effective treatment for severe neonatal jaundice. In this study, we reviewed the cases of infants with ET in Gunma Children’s Medical Center from 2011–2020. Of the total of 56 infants with ETs, 30 with severe neonatal jaundice were identified. Clinical and laboratory data were collected retrospectively from their medical records. Most infants who underwent ET were full term (gestational age 37–41 weeks) (25/30; 83.3%) and were admitted to our hospital after birth (26/30; 86.7%). Out of these 30 infants, 10 were diagnosed as having ABO incompatibility. In eight of these 10 infants, the mothers’ blood group was O and the infants’ blood group was B. Six of these infants (6/10; 60.0%) showed positive results of the direct antiglobulin test. The identified adverse events secondary to ET included thrombocytopenia and others. The majority of adverse events associated with ET were laboratory abnormalities that were asymptomatic. No deaths or complications were reported arising from the treatment.

Case Reports
  • Takashi URAGAMI, Tomomi TSUBONE, Tomoka YUMI, Mikiko ASANO, Yuichi NAK ...
    Type: Case Report
    2021 Volume 70 Issue 3 Pages 571-576
    Published: July 25, 2021
    Released: July 28, 2021
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    Synovial fluid is a viscous extracellular fluid containing proteins produced by the synovium in addition to plasma-derived proteins. Although some pathologic crystals, such as monosodium urate in cases of gout or calcium pyrophosphate in pseudo-gout, are found in the synovial fluid, it is rare that cholesterol crystals are detected in the synovial fluid. We report the case of a patient with cholesterol crystals found in the synovial fluid who underwent left artificial knee joint replacement due to osteoarthritis xx years ago. In our patient, it was postulated that the accumulation of cholesterol crystals was caused by repeated tissue destruction due to abrasion by the artificial joint.

  • Miyuki OGATA, Hisamitsu ONITSUKA, Aya KUWAHARA, Miyo TANAKA, Chiyoko S ...
    Type: Case Report
    2021 Volume 70 Issue 3 Pages 577-582
    Published: July 25, 2021
    Released: July 28, 2021
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    We report a rare case of coronary arteriovenous fistula draining into the coronary sinus with giant coronary artery aneurysm. A 65-year-old woman was referred to our hospital with leg edema and shortness of breath, which are indicative of heart failure. Echocardiography showed enlargement of both ventricles and each atrium, moderate functional mitral regurgitation, normal ejection fraction, and pulmonary hypertension. From the parasternal aortic short-axis view, we noticed an enlargement of the left main trunk coronary artery. Color Doppler echocardiography revealed a huge spherical mass with a blood flow signal on the surface of the lateral wall. This huge mass spread with a beaded appearance on the posterior wall. In addition, an enlarged coronary sinus was detected from the parasternal long-axis view. A blood flow signal from the enlarged coronary sinus draining into the right atrium was detected in the entire cardiac cycle measured by continuous-wave Doppler echocardiography (flow velocity, 1.6 m/s). These findings suggested the presence of coronary arteriovenous fistula complicated by a giant coronary aneurysm. Cardiac CT (computed tomography) showed similar findings, and the diameter of the aneurysm was 50 mm. Resection of the aneurysm, coronary artery bypass grafting, and mitral valve repair were performed because the pulmonary-to-systemic blood flow ratio was 2.4 on cardiac catheterization and the diameter of the aneurysm was large, which was considered to be at high risk of rupture. We must pay attention to abnormal blood flow signals in the right heart cavity and pulmonary artery, bearing in mind the presence of coronary arteriovenous fistula, when coronary aneurysms are observed on echocardiography.

  • Kosuke IIJIMA, Kumiko YAMADA, Yasunao WADA, Masaki INAMURA, Noriko KIT ...
    Type: Case Report
    2021 Volume 70 Issue 3 Pages 583-587
    Published: July 25, 2021
    Released: July 28, 2021
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    We experienced treating a case of overwhelming postsplenectomy infection (OPSI) by noncapsulated Neisseria meningitidis . A female patient in her 60s visited the outpatient department of a local hospital owing to fever and vomiting. Since she could not articulate clearly and acute cerebral infarction was suspected following brain MRI examination, she was urgently transported and admitted to our hospital. Because of the increase in the levels of serum inflammatory markers, meropenem (MEPM) and vancomycin (VCM) were administered at doses appropriate for the initial treatment of suspected systemic infection. Gram-negative cocci were then detected from blood culture tests, and it was revealed that the patient had had a splenectomy; thus, the antibiotic drug was changed to ceftriaxone (CTRX). The gram-negative cocci were identified as fluoroquinolone-resistant N. meningitidis by mass spectrometry and drug sensitivity tests. Since no increase in the number of cells in her cerebrospinal fluid was observed after CTRX administration and the culture became negative, she was discharged on the 17th day. The serotypes and genotypes of N. meningitidis in this case were later identified as a noncapsulated strain.

Investigation of Clinical Usefulness
  • Masatoshi HIRATA, Maki HATTORI, Saho TAKEICHI, Misaki TAKADA, Miyoko N ...
    Type: Investigation of Clinical Usefulness
    2021 Volume 70 Issue 3 Pages 588-594
    Published: July 25, 2021
    Released: July 28, 2021
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    Chronic obstructive pulmonary disease (COPD) is reported to be not detected in many patients with airflow limitation. Here, we examined the usefulness of preoperative spirometry in identifying patients with latent airflow limitation. The data of 1,496 patients aged 7 to 94 years who had undergone preoperative spirometry, including their history of smoking and past and present illnesses, were collected. When airflow limitation was defined as forced expiratory volume in 1 second/forced vital capacity < 70%, airflow limitation was observed in 222 (14.8%) of all the patients [138 (18.1%) men, and 84 (11.4%) women]. Regarding the relationship between airflow limitation and smoking, the number of patients with airflow limitation was larger among smokers than among nonsmokers, both in men and women. Regarding comorbidities, airflow limitation was observed to be related to heart disease (p = 0.0013) and hypertension (p = 0.0207) in all patients, hypertension (p = 0.0449) in men, and heart disease (p = 0.0019) and osteoporosis (p = 0.0040) in women. Therefore, attention should be paid to not only airflow limitation per se, but also its relationship with comorbidities. Among patients with air flow limitation, those who were diagnosed as having COPD and started receiving treatment for it were only four. Preoperative spirometry may lead to early detection and treatment of COPD patients with latent airflow limitation.

Investigation of Basic Research
  • Yuuyu MIZUUCHI, Yoko MANO, Nobuhiko FURUYA
    Type: Investigation of Basic Research
    2021 Volume 70 Issue 3 Pages 595-601
    Published: July 25, 2021
    Released: July 28, 2021
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    In healthy individuals, Pseudomonas aeruginosa infection is less toxic and rarely causes symptoms. However, it often causes opportunistic infections in immunocompromised hosts. P. aeruginosa infection routes may be exogenous (from contaminated catheters) or endogenous (involving infiltration of P. aeruginosa from the intestinal niche into the blood). P. aeruginosa also has several pathogenic factors that can facilitate evasion from the host immune system. Maoto, a herbal medicine, is reported to exert anti-influenza virus effects; however, the effects of Maoto on P. aeruginosa infection is unknown. In this study, we examined in vitro the effects of Maoto on the growth rate, biofilm formation, and protease-producing abilities of P. aeruginosa strain PAO1, as well as its swarming, swimming, and twitching motility and capacity of invading Caco-2 cells. PAO1 showed a significantly suppressed growth rate at 4 and 8 h after Maoto treatment, but showed no suppression after 18 h. The swarming motility was 61%, the total protease was 15%, and the cell invasion ability was significantly suppressed. These changes were accompanied by a significant reduction in the cellular invasive capacity of P. aeruginosa.

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