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Dive into the research topics where Mizuho Nara is active.

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Featured researches published by Mizuho Nara.


Modern Rheumatology | 2013

Validation of the 2010 histopathological classification of ANCA-associated glomerulonephritis in a Japanese single-center cohort

Masaru Togashi; Atsushi Komatsuda; Mizuho Nara; Ayumi Omokawa; Kenichi Sawada; Hideki Wakui

Abstract Objectives. To validate the 2010 histopathological classification system of anti-neutrophil cytoplasmic antibodies (ANCA)-associated glomerulonephritis (GN) in a Japanese single-center cohort. Methods. We retrospectively studied 54 patients (28 renally limited pauci-immune GN, 25 microscopic polyangiitis, and one Churg–Strauss syndrome). Results. There were 17 patients with focal GN, eight patients with crescentic GN, 19 patients with mixed GN, and 10 patients with sclerotic GN. Detailed information regarding treatment was available in 39 patients. All these patients were treated with steroids with or without immunosuppressive agents. Hemodialysis was introduced in two patients with crescentic GN and three patients with sclerotic GN. During the follow-up period, 27 of 54 patients died. The major cause of death was pneumonia. Significant differences were observed in estimated glomerular filtration rate among patients with focal, crescentic, mixed, and sclerotic GN at entry and 1- and 5-year follow-up. Patients with focal GN had preserved renal function and favorable outcome. Conclusions. Our validation study suggests that the 2010 histopathological classification of ANCA-associated GN might aid in prognostication of patients at the time of diagnosis and in therapy selection.


Annals of Clinical Biochemistry | 2010

A simple, sensitive high-performance liquid chromatography -ultraviolet method for the quantification of concentration and steady-state pharmacokinetics of itraconazole and hydroxyitraconazole.

Masatomo Miura; Naoto Takahashi; Mizuho Nara; Naohito Fujishima; Hideaki Kagaya; Yoshihiro Kameoka; Hirobumi Saitoh; Hiroyuki Tagawa; Kenichi Sawada

Background A steady-state trough plasma itraconazole concentration greater than 500 ng/mL is a therapeutic target for itraconazole. A simple, rapid and sensitive high-performance liquid chromatography-based method was developed for quantitation of itraconazole and hydroxyitraconazole in human plasma. Methods Itraconazole and hydroxyitraconazole were separated using a mobile phase of 0.5% KH2PO4 (pH 6.0)-acetonitrile (30:70, v/v) on a CAPCELLPAK C18 MGII column at a flow rate of 0.5 mL/min and ultraviolet absorbance at 260 nm. Results The analysis required 200 μL of plasma and involved a rapid, simple solid-phase extraction with an Oasis HLB cartridge, which resulted in recoveries of 87–92% for itraconazole and 91–94% for hydroxyitraconazole. The lower limit of quantification for itraconazole and hydroxyitraconazole was 5 ng/mL each. Intra- and interday coefficients of variation for itraconazole and hydroxyitraconazole were less than 11.3% and 12.2%, respectively, and accuracies were within 11.7% and 4.5% over the linear range, respectively. Although the steady-state plasma concentrations of itraconazole and hydroxyitraconazole ranged from 506 to 2482 ng/mL and from 766 to 2444 ng/mL, respectively, after a two-day loading dose of 400 mg/day intravenous itraconazole followed by the administration of 200 mg/day itraconazole oral solution, calibration curves of itraconazole and hydroxyitraconazole showed positive linearity in a concentration range of 5–2500 and 50–2500 ng/mL, respectively. Conclusions Our results indicate that this method is applicable for the monitoring of plasma levels of itraconazole and hydroxyitraconazole in a clinical setting. Furthermore, the regimen presented here might also be effective in preventing infection, but further studies with large sample sizes are necessary to investigate this avenue.


Modern Rheumatology | 2014

Serum interleukin 6 levels as a useful prognostic predictor of clinically amyopathic dermatomyositis with rapidly progressive interstitial lung disease

Mizuho Nara; Atsushi Komatsuda; Ayumi Omokawa; Masaru Togashi; Kenichi Sawada; Hideki Wakui

Abstract Objectives. Rapidly progressive interstitial lung disease (RP-ILD) is life-threatening in patients with clinically amyopathic dermatomyositis (CADM). Useful prognostic markers are necessary for treatment selection. This study aimed to investigate differences in clinical and laboratory characteristics between surviving and non-surviving patients. Methods. Twelve CADM patients with RP-ILD were enrolled. Six patients lived (Group A) and six patients died (Group B) after immunosuppressive treatment for RP-ILD. Clinical manifestations and laboratory data before treatment were compared between the two groups. Results. Among the clinical manifestations and laboratory data examined, serum interleukin 6 (IL-6) levels in Group B were significantly higher than those in Group A (mean ± SD 28.5 ± 21.0 vs. 7.2 ± 1.6 pg/mL; p = 0.009). Simple regression analysis showed that serum IL-6 was the only significant prognostic factor (p = 0.032). Kaplan–Meier estimates showed that the cumulative survival rate was significantly lower in patients with serum IL-6 levels of ≥ 9 pg/mL than in patients with those of < 9 pg/mL (p = 0.04). Conclusions. Serum IL-6 levels may predict the prognosis of CADM patients with RP-ILD. The intensity of immunosuppressive treatment can be decided according to serum IL-6 levels at an early phase of the disease.


Nephrology Dialysis Transplantation | 2012

Distribution of glomerular IgG subclass deposits in patients with membranous nephropathy and anti-U1 ribonucleoprotein antibody

Ayumi Omokawa; Atsushi Komatsuda; Mizuho Nara; Satoshi Fujiwara; Ryuta Sato; Masaru Togashi; Kenichi Sawada; Hideki Wakui

BACKGROUND It is known that a predominant glomerular deposition of IgG4 is characteristic of idiopathic membranous nephropathy (MN) and that significant deposition of other IgG subclasses is also observed in lupus MN. However, there is no report focusing on the distribution of glomerular IgG subclass deposits in MN patients with anti-U1 ribonucleoprotein (RNP) antibody. METHODS We evaluated clinicopathological features and the distribution patterns of glomerular IgG subclass deposits in seven MN patients with positive anti-RNP antibody and negative antibodies to double-stranded DNA (dsDNA) and Smith antigen (Sm) (RNP-MN group) and in seven age- and sex-matched lupus MN patients with positive anti-dsDNA antibody and negative antibodies to RNP and Sm (L-MN group). RESULTS Mixed connective tissue disease was diagnosed in four patients in the RNP-MN group. Two patients in the RNP-MN group and three patients in the L-MN group developed nephrotic syndrome. Renal insufficiency was not present in all patients in both groups. Hypocomplementemia was found in two patients in the RNP-MN group and six patients in the L-MN group. In the RNP-MN group, positive stainings for glomerular IgG1, IgG2, IgG3 and IgG4 were observed in one, seven, zero and five patients, respectively. On the contrary, in the L-MN group, positive stainings for glomerular IgG1, IgG2, IgG3 and IgG4 were observed in seven, seven, seven, and six patients, respectively. CONCLUSIONS This is the first study showing striking differences in the distribution of glomerular IgG subclass deposits between RNP-MN and L-MN groups. RNP-MN and L-MN may result from different immunological mechanisms.


Clinical Nephrology | 2012

Renal biopsy in patients aged 80 years and older: a single-center experience in Japan.

Ayumi Omokawa; Atsushi Komatsuda; Mizuho Nara; Takashi Fujiwara; Ryuta Sato; Masaru Togashi; Kenichi Sawada; Hideki Wakui

BACKGROUND There is a paucity of data on renal biopsy in a large number of the very elderly (age ≥ 80 years) worldwide. METHODS Clinicopathological features in 73 patients aged ≥ 80 years were evaluated and compared with control groups of 172 patients aged 60 - 61 years and 128 patients aged 70 - 71 years. RESULTS The common indications for biopsy in the very elderly were nephrotic syndrome (NS), followed by proteinuria without NS and/or hematuria, and acute kidney injury (AKI). Histological diagnoses were considered to potentially modify treatment in 57 cases (78.1%): the most frequent diagnosis was membranous nephropathy, followed by minimal change disease, and various other diseases. There were no biopsy procedure-related serious complications. Clinical assessment of treatments was evaluated in 38 of 54 patients with AKI and/or NS. Improvement in renal dysfunction or NS was observed in 24 of 30 (80%) patients who received immunosuppressive therapy. There were statistically significant differences in the disease spectrum between the very elderly and control groups. CONCLUSIONS This is the first report of renal biopsy findings in a relatively large number of Japanese very elderly patients. Histological observations are useful aids in estimating the prognosis and therapy selection for renal disorders, even in the very elderly.


Internal Medicine | 2015

Relapsing Polychondritis with Encephalitis: A Case Report and Literature Review

Mizuho Nara; Atsushi Komatsuda; Masaru Togashi; Hideki Wakui

We herein report the case of a 39-year-old man who developed bilateral auricular chondritis, conjunctivitis, and central neurological symptoms. He was diagnosed with encephalitis associated with relapsing polychondritis (RP) based on the findings of an ear cartilage biopsy, cerebrospinal fluid examination and magnetic resonance imaging. Although oral prednisolone (60 mg/day) was administered, the initial steroid therapy did not improve his symptoms. In contrast, methylprednisolone (mPSL) pulse therapy followed by prednisolone gradually ameliorated his condition. There were no episodes of recurrence during the two-year follow-up period. A review of the literature revealed that meningoencephalitis and encephalitis are rare, but important, complications of RP responsive to mPSL pulse therapy.


Clinical and Experimental Nephrology | 2011

Renal paradoxical embolism in a hypertensive young adult without acute ischemic symptoms

Mizuho Nara; Atsushi Komatsuda; Masumi Fujishima; Naohito Fujishima; Miho Nara; Takako Iino; Hiroshi Ito; Kenichi Sawada; Hideki Wakui

A 22-year-old woman, who often carried heavy books, was admitted for evaluation of hyperreninemic hypertension. Two months prior to admission, she noted leg edema. Radiological examinations revealed bilateral renal infarction with no other abnormal findings. An echocardiography showed a patent foramen ovale (PFO). Hypertension was considered secondary to renal infarction caused by paradoxical embolism through PFO. Antihypertensive and anticoagulant therapy led to improvement of hypertension. In previously reported cases of renal paradoxical embolism, multiorgan involvement was usually observed. Our case is unique in that embolism was confirmed only in the kidneys, and that clinical characteristics of renal embolism were not observed.


Internal Medicine | 2017

Two Cases of Thrombocytopenia, Anasarca, Fever, Reticulin Fibrosis/Renal Failure, and Organomegaly (TAFRO) Syndrome with High Serum Procalcitonin Levels, Including the First Case Complicated with Adrenal Hemorrhaging

Mizuho Nara; Atsushi Komatsuda; Fumiko Itoh; Hajime Kaga; Masaya Saitoh; Masaru Togashi; Yoshihiro Kameoka; Hideki Wakui; Naoto Takahashi

Thrombocytopenia, Anasarca, Fever, Reticulin fibrosis/Renal failure, and Organomegaly (TAFRO) syndrome is a recently described systemic inflammatory disorder characterized by thrombocytopenia, anasarca, fever, reticulin fibrosis/renal failure, and organomegaly. It has an acute or subacute onset of unknown etiology, although some pathological features resemble those of multicentric Castleman disease. We here report two cases of TAFRO syndrome. The symptoms and pathological findings in these cases met the 2015 diagnostic criteria. Our cases showed high serum procalcitonin levels, suggesting bacterial infection as an onset trigger. In addition, Case 1 is the first case complicated with adrenal hemorrhaging. Case 2 is the second case of tocilizumab-resistant TAFRO syndrome successfully treated with rituximab.


Xenobiotica | 2015

Effects of CYP3A5 polymorphism and the tacrolimus 12 h concentration on tacrolimus-induced acute renal dysfunction in patients with lupus nephritis

Takenori Niioka; Atsushi Komatsuda; Shotaro Kato; Masaru Togashi; Ayumi Omokawa; Mizuho Nara; Hideki Wakui; Naoto Takahashi; Masatomo Miura

Abstract 1. The purpose of the present study was to investigate the effect of tacrolimus concentration in blood 12 h after administration (C12h) on acute renal dysfunction in patients with lupus nephritis (LN) taking tacrolimus once daily. 2. Five of the 35 LN patients experienced tacrolimus-induced acute renal dysfunction. 3. The average annual C12h of tacrolimus was higher for patients with events of elevated serum creatinine level than for patients not experiencing these events [6.4 (5.6–8.8) versus 2.8 (2.2–4.6) ng/mL, respectively, p = 0.001]. 4. The average annual tacrolimus C12h was higher for patients with CYP3A5*3/*3 (PM) than for patients with the CYP3A5*1 allele (EM) [4.6 (3.2–6.6) versus 2.5 (2.0–3.1) ng/mL, respectively, p = 0.002]. 5. The area under the receiver operating characteristic was 0.887, which gave the best sensitivity (80.0%) and specificity (86.7%) at a tacrolimus C12h (average annual C12h or C12h at events) threshold of 5.2 ng/mL. 6. C12h measurements, CYP3A5 genotyping and dose adjustments of tacrolimus should be performed to prevent acute renal dysfunction in LN patients taking tacrolimus once daily.


Internal Medicine | 2018

Anti-neutrophil Cytoplasmic Antibody-associated Vasculitis Complicated by Periaortitis and Cranial Hypertrophic Pachymeningitis: A Report of An Autopsy Case

Hajime Kaga; Atsushi Komatsuda; Masaya Saitoh; Mizuho Nara; Ayumi Omokawa; Masaru Togashi; Hideki Wakui; Naoto Takahashi

Anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) is a systemic inflammatory disorder categorized as small-vessel vasculitis. We herein report an elderly Japanese man with AAV (granulomatosis with polyangiitis affecting the eyes, nose, lungs, and kidneys) who also showed periaortitis at the diagnosis and developed cranial hypertrophic pachymeningitis (HP) during steroid maintenance therapy. His consciousness disturbance caused by HP improved after steroid pulse therapy, but he died of aspiration pneumonia. Autopsy findings showed giant cells in the thickened pachymeninges and obsolete inflammatory lesions in the aortic adventitia and renal tubulointerstitium. This is the first case of AAV complicated by periaortitis and cranial HP.

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