Mitsuru Yanai

Nihon University, Edo, Tōkyō, Japan

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Publications (74)106.42 Total impact

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    ABSTRACT: Background This study aimed to evaluate the clinical usefulness of serum 2'-5'-oligoadenylate synthetase (2-5AS) levels in diagnosing viral infection. Methods 2-5AS, procalcitonin (PCT) and C-reactive protein (CRP) serum levels and leukocyte counts were evaluated in 104 febrile patients (26 viral and 55 bacterial infections, 23 non-infectious diseases). Results Assessment of areas under the receiver-operator characteristic curves revealed that 2-5AS and CRP levels and the age of the patient differentiated between viral and bacterial infections, 2-5AS levels differentiated between viral infection and non-infectious disease and PCT levels differentiated between bacterial infection and non-infectious disease. The decision tree constructed according to the results correctly classified the origin of fever in 88 of 104 patients (85%). Conclusions 2-5AS is a useful diagnostic biomarker for viral infections and combining it with the PCT and CRP levels and leukocyte counts improves determination of causes of fever.
    No preview · Article · Dec 2015
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    ABSTRACT: The International Kidney Evaluation Association Japan (IKEAJ) was created to improve public health awareness of chronic kidney disease (CKD) by screening high-risk CKD populations. This study aimed to retrospectively examine data from KEEP Japan and detect the CKD risk factors for the onset and the progression of CKD. A total of 1,947 participants (mean age: 56.9 ± 16.4 years) to KEEP Japan were enrolled. More than 70% of the participants had no CKD. However, 7.5% of the participants were classified as high risk. The participants with a history of hypertension and older than 60 years had significantly higher odds ratio for occurrence of CKD. In addition, the participants with history of diabetes or cardiovascular disease, high blood pressure (BP), anemia, and low HDL-C had high odds ratios. It is therefore suggested that the appropriate control of BP, blood glucose, anemia, and HDL-C is important for populations with CKD risk factors to reduce the likelihood of CKD.
    No preview · Article · Mar 2015 · Clinical nephrology
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    ABSTRACT: As a part of the antimicrobial stewardship program (ASP), our hospital has held regular “conferences for appropriate use of anti-methicillin-resistant Staphylococcus aureus (MRSA) agents” since 2006. The conferences include multiple disciplines including physicians, pharmacists, microbiological technicians, and nurses, and conduct evaluation of the status of use and feedback. All patients who receive anti–MRSA agents are evaluated. Based on the medical records and bacteriological test results, correct use is defined as “infection necessitating administration of anti–MRSA agents,” “high probability of such infection,” “administration necessary from clinical viewpoint,” and “febrile neutropenia.” In cases evaluated as “unevaluable” because no sample has been submitted for culture, or “administration not needed” because bacterial infection was considered to result from colonization or contamination, the purpose of administration was confirmed with the attending physician and intervention conducted if necessary. As indices for the efficacy of ASP, the trend of use of anti–MRSA agents and the trend of S. aureus sensitivity were investigated. As a result of active intervention, the number of cases of “correct use” in 2012 increased over that in 2006 (82.3% vs. 65.3%; p<0.01), although no marked changes in the number of patients using anti–MRSA agents and the trend of use were observed. Similarly, the rates of de-escalation therapy in 2012 increased over that in 2006 (85% vs. 33%; p<0.01). The rates of sensitivity of MRSA to vancomycin, teicoplanin, arbekacin, and linezolid were well maintained. This study indicates that holding multidisciplinary conferences and feedback of the evaluation results promote correct use of anti–MRSA agents and are effective in reducing the incidence of MRSA detection.
    Preview · Article · Jan 2015 · Japanese Journal of Environmental Infections
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    ABSTRACT: We report herein on a rare case of deep-soft tissue infection due to invasive pneumococcal disease (IPD). A 77-year-old woman was admitted to our hospital with progressive pain in the right upper arm and the distal leg associated with swelling. We diagnosed the condition as multiple instances of cellulitis that were initially treated with ceftriaxone and clindamycin. Penicillin-susceptible Streptococcus pneumoniae (PSSP) was isolated from blood cultures on admission. Although inflammatory marker levels improved following susceptive antibiotic therapy (ampicillin), multiple abscesses, septic arthritis and osteomyelitis were detected with image testing. The antibiotic was then changed to meropenem and arthroscopic surgery was performed for the right shoulder; the patient's clinical symptoms improved. Since pneumococcal infection including skin and soft tissue infection (SSTI) often causes blood stream invasion or metastatic suppurative complications, metastatic lesions or multiple abscesses should be taken care of.
    No preview · Article · Nov 2014 · Kansenshogaku zasshi. The Journal of the Japanese Association for Infectious Diseases
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    ABSTRACT: Background/aims: We examined sex differences in prevalence, progression, and improvement in early-stage chronic kidney disease (CKD). Methods: We analyzed data from 533 participants who took 4 consecutive annual CKD detection tests. Results: Urine albumin-creatinine ratio (ACR), estimated glomerular filtration rate (eGFR), and hemoglobin (Hb) at baseline in men with and without CKD and in women with and without CKD were 8.3±6.1, 149.2±310.4, 10.2±5.8, and 96.7±246.8 mg/g Cr; 83.4±14.7, 63.8±18.8, 79.9±13.0, and 69.4±20.0 mL/min/1.73 m2; and 14.8±1.2, 14.3±1.4, 13.0±1.0, and 13.0±1.2 mg/dL, respectively. ACR levels decreased significantly over time in men and women with CKD and they increased significantly over time in men and women without CKD. eGFR levels in men and women with CKD did not significantly change over time, but they decreased significantly over time in men and women without CKD. CKD prevalence and progression rate were not significantly different between sexes. Among the CKD participants, significantly more women had a "cured" status at 3 years (39.1% vs. 19.4%, P<0.01). Most whose eGFR increased to >60 mL/min/1.73 m2 at 3 years had values just below those at baseline. Regression analysis showed that change in eGFR correlated significantly with ACR in men with CKD (change in eGFR = -1.707+0.022×ACR, P<0.001, r2=0.201) and with Hb and ACR in women with CKD (change in eGFR = 48.870-3.803×Hb + 0.018×ACR, P<0.05, r2=0.134). Conclusions: These results suggest that the slight decrease of Hb within a normal range and mild anemia can be managed in women with early-stage CKD. The key baseline for eGFR is 60 mL/min/1.73 m2.
    No preview · Article · Aug 2014 · Kidney and Blood Pressure Research
  • A. Satomura · M. Yanai · T. Fujita · T. Nakayama

    No preview · Article · Aug 2014 · European Journal of Neurology
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    ABSTRACT: A recent report has dealt with geriatric nephrology, including epidemiology and pathophysiology of chronic kidney disease (CKD), attempting to get nephrologists to pay more attention to elderly CKD patients. The aims of this article are to summarize the morphological and functional properties of the aging kidney, and to better understand nephrology care for elderly CKD patients. The kidneys are affected by the aging process, which results in numerous effects on the renal system. In addition, the elderly population is hetereogenous - some have a decline in GFR explained by diseases that complicate aging such as arteriosclerosis with hypertension, whereas in the most of healthy adults the decline in GFR is much more modest and not inevitable. The values for normal estimated glomerular filtration rate (eGFR) in aging population have important implications for the diagnosis of CKD in the elderly. However, the MDRD equation underestimates mean eGFR by 25% and the CKD-EPI equation underestimates mean GFR by 16%. This bias may lead to misclassifying healthy older persons as having CKD. It is also still unknown whether and how age influences the predictive role of other risk factors for end-stage renal disease (ESRD) and death in referred as well as unreferred patients. The risk of ESRD was reported to be higher than the risk of death without ESRD for ages <60 years, and independent of eGFR. Proteinuria significantly increased the risk of ESRD with advancing age. In older patients on nephrology care, the risk of ESRD prevailed over mortality even when eGFR was not severely impaired. Proteinuria increases the risk of ESRD, while the predictive role of other modifiable risk factors was unchanged compared with younger patients. The decision to initiate renal replacement therapy in the elderly is complicated by more challenges than in younger patients. Calorie restriction and Klotho deficiency may be a candidate therapeutic target for attenuating kidney aging.
    No preview · Article · Mar 2014 · Kidney and Blood Pressure Research
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    ABSTRACT: Patients and healthcare workers in a Japanese haemodialysis clinic were investigated for nasal carriage of meticillin-resistant Staphylococcus aureus (MRSA). MRSA carriage was found in 10 (8.9%) of 112 patients in the first year and four (3.9%) of 103 patients in the second year. All isolated MRSA samples carried staphylococcal cassette chromosome mec type II or III and classified as clonal complex 5, which were common as healthcare-associated strains. Pulsed-field gel electrophoresis indicated horizontal transmission limited to two pairs of patients in one session. One of 54 healthcare workers carried MRSA genetically unrelated to patients' strains. Infection control measures based on the US Centers for Disease Control and Prevention's recommendation showed limited spread of MRSA in a haemodialysis room.
    No preview · Article · Feb 2013 · The Journal of hospital infection
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    ABSTRACT: Background: Patients on hemodialysis therapy are immuno-compromised hosts and at high-risk of MRSA carriage. The aim of this study is to clarify prevalence of MRSA carriage, molecular typing of MRSA and risk factors to carry MRSA among patients in a Japanese hemodialysis clinic. Methods: The patients on hemodialysis therapy in a single hemodialysis clinic in Saitama prefecture, Japan, were tested with swabbing of anterior nares. Each swab was inoculated and cultivated on a mannitol-salt agar at 35℃ for 48 hours. MRSA was identified by PCR for the thermonuclease gene of S. aureus and mecA. The isolates were then typed for SCCmec and MLST. The relationship between MRSA carriage and clinical background including past medical history and comorbidities was also analyzed. Results: The number of study participants was 192 (66.2±11.0 years old, F: M= 76: 116) which was 99.0% of all hemodialysis patients in this clinic. Ten patients carried MRSA (5.2%) and all carriers were men (8.6% of male patients). None of them shared hemodialysis beds or equipment. SCCmec typing and MLST showed that 9 MRSA strains had SCCmec type II and belonged to ST5, and the exceptional one had SCCmectype III and belonged to ST764, even though both of STs belonged to CC5. Univariate regression analysis among male patients showed history of blood access infection (OR: 10.9, 95%CI: 2.0-58.7) and stroke (OR: 4.9, 95%CI: 1.3-18.7) were related to MRSA carriage (p<0.05). History of blood access infection was an independent risk factor of MRSA carriage in multivariate logistic regression analysis (OR: 8.8, 95%CI: 1.4-52.6, p<0.05). Conclusion: Infectious diseases due to community-associated MRSA strain were reported to be increasing among hemodialysis patients in other countries, but all strains were healthcare-associated MRSA in this facility. Exposure not only to hemodialysis clinic but also to other healthcare environment should be mentioned as risk factors of MRSA carriage. Further investigation is needed considering confounding factors such as ADL and hygienic condition.
    No preview · Conference Paper · Oct 2012
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    ABSTRACT: Objective: This study compared the circadian variations in blood pressure (BP) and pulse rate (PR) in children (CD), middle aged (MA) people, and elderly (EL) people. Methods: CD (age, 9-10 years), MA subjects (age, 30-35 years) and EL subjects (age, 65-70 years) provided blood and urine samples and underwent 24-h ambulatory BP monitoring. Circadian variation patterns in their BP and PR were compared. The serum and urinary creatinine (SCr and UCr), urinary Na (UNa), and urinary K (UK) levels were measured to determine renal function and UNa and UK excretion values. None of the subjects had previously received any antihypertensive agents or other any medication. Results: The difference in the daytime and night time BP was highest in CD and lowest in EL subjects. The whole day PR was highest in CD and lowest in EL subjects. The non-dipper pattern prevalence was 24.4% in CD, 43.5% in MA subjects, and 78.6% in EL subjects. The UNa excretion value did not differ between the 3 groups. The UK excretion value was the lowest in the non-dipper EL subjects. Multiple regression analysis showed that the mean BP value was directly related with the SCr and UNa excretion values. Conclusion: The difference in the daytime and nighttime BP values in CD may be attributable to the elasticity of young blood vessels. Furthermore, potassium intake may be related to the elasticity of blood vessels in EL people.
    No preview · Article · Sep 2012 · Journal of Hypertension
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    ABSTRACT: Innate immunity is generally impaired in chronic renal failure (CRF). Mannose-binding lectin (MBL) has an important role in first-line host defense against pathogens via the lectin pathway. We recently reported that functional MBL was significantly lower in CRF patients than in healthy subjects. In this study, we aimed to determine whether functional MBL would be improved following hemodialysis (HD) therapy. This study included 22 patients with end-stage renal disease (ESRD) on maintenance HD. Functional MBL was measured every 6 months for 1 year after HD using an enzyme-linked immunosorbent assay. Median serum functional MBL levels of ESRD patients were significantly higher after 6 and 12 months than at the start of HD therapy (p < 0.05 and p < 0.01, respectively). Furthermore, median functional MBL levels at 12 months were significantly higher than those at 6 months (p < 0.05). We found significant increases in serum functional MBL levels in patients on HD. Our results indicated that HD tailored to remove uremic toxins could improve functional MBL levels in these patients.
    No preview · Article · Feb 2012 · Journal of Innate Immunity
  • Mitsuru Yanai · Kazuyoshi Okada · Susumu Takahashi

    No preview · Article · Apr 2011 · American Journal of Kidney Diseases
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    ABSTRACT: Mannose-binding lectin (MBL) plays an important role in first-line host defence against pathogens via the lectin pathway. The binding affinity for ligands is greatly increased by oligomerization, although the basic triplet does not bind solid phase mannan and cannot activate complement. Besides, MBL is a positive acute-phase protein. In this study, we examined the relationship between oligomer and functional serum MBL in chronic renal failure patients who were either uraemic [Pre-haemodialysis (pre-HD) patients], or who were receiving maintenance haemodialysis treatment (HD patients). This study included a total of 20 Pre-HD patients, 130 HD patients and 28 healthy subjects. The oligomer and functional serum MBL levels were measured using enzyme-linked immunosorbent assays established previously. The median serum functional MBL levels were significantly reduced in both Pre-HD and HD patients compared with healthy subjects (P<0·05 for both). Furthermore, the median functional MBL level in Pre-HD patients was significantly lower than that in HD patients (P<0·05). The median serum oligomer MBL levels in both Pre-HD and HD patients were significantly higher compared with healthy subjects (P<0·05 for both). Furthermore, the median oligomer MBL level in HD patients was significantly (P<0·05) higher than that in Pre-HD patients. The ratios of median serum functional MBL levels to oligomer MBL levels were significantly reduced in both Pre-HD and HD patients compared with healthy subjects (P<0·05 for both). We found significant reductions in the ratios of serum functional MBL levels to oligomer MBL levels in HD and Pre-HD patients compared with healthy subjects.
    No preview · Article · Oct 2010 · European Journal of Clinical Investigation
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    ABSTRACT: A patient on continuous cyclic peritoneal dialysis for chronic kidney disease due to type 2 diabetes mellitus developed peritoneal dialysis-associated peritonitis induced by Pasteurella multocida that was isolated from a sample of dialysis effluent. The route of infection was unknown for this case; however, P. multocida was also isolated from a culture of a pharyngeal swab obtained from the patient's cat. There was no evidence that the cat had bitten and ruptured the peritoneal dialysis tubing or bags. Pulsed-field gel electrophoresis (PFGE) showed that the P. multocida isolated from the patient was completely identical to the strain isolated from the domestic cat. As there is a rise in the pet-keeping population, an increase in zoonoses is to be expected. It is necessary to be carefully informed of hygiene rules in keeping pets because a pet may transmit zoonoses, even on casual contact.
    Full-text · Article · Jun 2010 · Therapeutic apheresis and dialysis: official peer-reviewed journal of the International Society for Apheresis, the Japanese Society for Apheresis, the Japanese Society for Dialysis Therapy
  • Mitsuru Yanai · Kazuyoshi Okada · Susumu Takahashi

    No preview · Article · Apr 2010 · American Journal of Kidney Diseases
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    Susumu Takahashi · Kazuyoshi Okada · Mitsuru Yanai
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    ABSTRACT: The International Kidney Evaluation Association Japan evaluated chronic kidney disease (CKD) in Japan, using a Japanese version of the US National Kidney Foundation's Kidney Early Evaluation Program (KEEP). The screening criteria for the first 1065 participants were presence of diabetes or hypertension, or family history of diabetes, hypertension, or kidney disease. Mean age was 59.7+/-16.1 years; 501 participants were men, 564 women. Of participants, 26.9% had diabetes, 59.2% had hypertension (with an additional 21.5% diagnosed after the program), 16.9% had history of diabetes and hypertension together, and 30.6% had neither, but had family history of diabetes, hypertension, or kidney disease. CKD (stages 1-4) prevalence was 26.7%, defined by albumin-creatinine ratio and estimated glomerular filtration rate. CKD prevalence was 35.0% among diabetic participants, 34.8% among hypertensive participants, and 37.1% among participants with cardiovascular disease (CVD). The following baseline conditions were significantly associated with discovered CKD: diabetes, odds ratio 1.71 (95% confidence interval 1.28-2.30); hypertension, 3.42 (2.15-5.44); CVD, 1.88 (1.37-2.57). CKD prevalence was high compared with the general Japanese population. KEEP Japan seems to define a high-risk population with evidence of CKD based on the targeted nature of the program.
    Preview · Article · Mar 2010 · Kidney international. Supplement
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    ABSTRACT: We had encountered a 74-year-old woman on hemodialysis therapy suffering from liver abscess of Actinomyces israelii. Percutaneous drainage of the abscess before starting antimicrobial therapy followed by correct microbiological identification and susceptibility test led us to determine long treatment with ampicillin and to a successful outcome. Periodontitis was thought to be a possible entry of actinomyces. Hepatic actinomycosis should be recognized as one of the important infectious diseases among patients of end-stage renal disease.
    No preview · Article · Jan 2010 · Internal Medicine
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    ABSTRACT: We assessed the usefulness of reporting direct blood Gram stain results compared with the results of positive blood cultures in 482 episodes and monitored impact on selection of antimicrobial treatment. We found that the reporting groups "Staphylococcus spp," "Pseudomonas spp and related organisms," and "yeasts" identified in this way matched perfectly with later culture identification. When the report indicated Staphylococcus spp or Pseudomonas spp and related organisms, physicians started or changed antimicrobials suitable for these bacteria more frequently than when "other streptococci" and "family Enterobacteriaceae" were reported (P < .05). Incorrect recognition of Acinetobacter spp as Enterobacteriaceae family is still the most challenging problem in this context. Gram stain results that definitively identify Staphylococcus spp, Pseudomonas spp and related organisms, and yeasts reliably can be rapidly provided by clinical laboratories; this information has a significant impact on early selection of effective antimicrobials. Further investigation is needed to assess the clinical impact of reporting Gram stain results in bacteremia.
    Preview · Article · Jul 2009 · American Journal of Clinical Pathology
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    ABSTRACT: The MB fraction of creatine kinase (CK-MB) has long been used as a cardiac marker. It is known that the CK-MB immunoinhibition method lacks selectivity and accuracy, because the appearance of macro CK type 2, corresponding to mitochondrial creatine kinase (MtCK) in some patient serum may render CK-MB activity measured by conventional method abnormally high. Thus, to improve the specificity and accuracy of the CK-MB assay, we developed two types of monoclonal anti-MtCK antibodies against sarcomeric MtCK and ubiquitous MtCK, and present herein the performance of a new method using these antibodies. The performance of our test for detecting CK-MB activity was compared with other methods, and the range of CK-MB activities in normal human serum was investigated. The two types of monoclonal antibodies developed by us were isoenzyme-specific to sMtCK or uMtCK. The correlation coefficients of our method and conventional method to electrophoresis were 0.973 and 0.873, respectively. The mean CK-MB activity in normal human serum by our method and the conventional method was 2.4 and 11.7 U/L, respectively. Thus, our data indicated that about 80% of CK-MB activity, determined using the conventional method, seems to correspond to the MtCK activity. Our method is novel in offering higher accuracy of measuring true CK-MB contents in human serum as compared to the conventional method. The possibility of accurately estimating CK-MB activity by our method which can inhibit MtCKs in healthy person and patient serum is likely to bring a break-through in clinical diagnostics.
    Full-text · Article · Jun 2009 · Scandinavian journal of clinical and laboratory investigation
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    ABSTRACT: Seasonal variations in laboratory test results have been pointed out in dialysis patients. Although the mechanism for this phenomenon is not clear, this could result in changes in dialysis and medication prescriptions. We investigated the effect of the circannual rhythm on laboratory test parameters in chronic haemodialysis patients. Data of 38 laboratory test parameters were collected every month and analyzed for 150 stable haemodialysis patients, with non-linear sine wave regression and paired t test between data of peak and trough months. Serum urea nitrogen, unsaturated iron binding capacity, lactate dehydrogenase, alkaline phosphatase, amylase, and neutrophil count showed significant circannual rhythms with high amplitudes. Additionally, serum creatinine, uric acid, chloride, calcium, phosphate, magnesium, total cholesterol, total protein, leucocyte count, mean corpuscular haemoglobin level, mean corpuscular haemoglobin concentration, and platelet count showed significant circannual rhythms with little amplitudes. The circannual rhythm of laboratory test parameters could be attributed to seasonal variations in food intake. Awareness of these variations should be taken into account in the interpretation of laboratory results.
    No preview · Article · Feb 2008 · Blood Purification

Publication Stats

392 Citations
106.42 Total Impact Points


  • 1991-2014
    • Nihon University
      • • Department of Internal Medicine II
      • • School of Medicine
      • • Department of Laboratory Medicine
      • • Department of Pathology
      • • Department of Clinical Pathology
      Edo, Tōkyō, Japan
  • 2010
    • Brigham and Women's Hospital
      Boston, Massachusetts, United States
  • 1993
    • Châteauroux Central Hospital
      Bourges, Centre, France
    • Centre Henri Becquerel
      Rouen, Haute-Normandie, France