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d-Serine modulates excitatory neurotransmission by binding to N-methyl-d-aspartate glutamate receptors. d-Amino acid oxidase (DAO) degrades d-amino acids, such as d-serine, in the central nervous system, and is associated with neurological and psychiatric disorders. However, cell types that express brain DAO remain controversial, and whether brain DAO influences systemic d-amino acids in addition to brain d-serine remains unclear. Here, we created astrocyte-specific DAO-conditional knockout mice. Knockout in glial fibrillary acidic protein-positive cells eliminated DAO expression in the hindbrain and increased d-serine levels significantly in the cerebellum. Brain DAO did not influence levels of d-amino acids in the forebrain or periphery. These results show that astrocytic DAO regulates d-serine specifically in the hindbrain.

Purpose: Reactive oxygen species can aggravate of renal fibrosis, resulting in the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) as a biological defense factor. Nrf2 exerts a renoprotective effect by producing antioxidant response elements (AREs) that antagonize renal fibrosis. Recently, bardoxolone methyl (BARD), an Nrf2 activator, has attracted attention as a therapeutic agent for chronic kidney disease. We conducted a time course renoprotective evaluation of BARD administration among rats with unilateral ureteral obstruction (UUO)-induced renal injury. Materials and methods: Male Sprague Dawley rats which underwent UUO received BARD for 2 weeks postoperatively to investigate its renoprotective effect using quantitative real-time polymerase chain reaction (RT-PCR) and histopathological analyses of kidney samples. Results: Compared with UUO, BARD administration reduced interstitial fibrotic area, causing a substantial decline in the frequency of ED-1–positive cells and the TGF-β area. RT-PCR also showed that BARD administration suppressed the expression of renal fibrotic factors and promoted AREs. Moreover, immunostaining for Nrf2 showed that BARD administration enhanced its activation and translocation to the nucleus. Conclusions: Our results suggest that BARD induces nuclear activation of Nrf2 to activate AREsover time and enhances renal protection against inflammation and fibrosis caused by UUO.

Mammals exhibit systemic homochirality of amino acids in L -configurations. While ribosomal protein synthesis requires rigorous chiral selection for L -amino acids, both endogenous and microbial enzymes convert diverse L -amino acids to D -configurations in mammals. However, it is not clear how mammals manage such diverse D -enantiomers. Here, we show that mammals sustain systemic stereo dominance of L -amino acids through both enzymatic degradation and excretion of D -amino acids. Multidimensional high performance liquidchromatography analyses revealed that in blood, humans and mice maintain D -amino acids at less than several percent of the corresponding L -enantiomers, while D -amino acids comprise ten to fifty percent of the L -enantiomers in urine and feces. Germ-free experiments showed that vast majority of D -amino acids, except for D -serine, detected in mice are of microbial origin. Experiments involving mice that lack enzymatic activity to catabolize D -amino acids showed that catabolism is central to the elimination of diverse microbial D -amino acids, whereas excretion into urine is of minor importance under physiological conditions. Such active regulation of amino acid homochirality depends on maternal catabolism during the prenatal period, which switches developmentally to juvenile catabolism along with the growth of symbiotic microbes after birth. Thus, microbial symbiosis largely disturbs homochirality of amino acids in mice, whereas active host catabolism of microbial D -amino acids maintains systemic predominance of L -amino acids. Our findings provide fundamental insight into how the chiral balance of amino acids is governed in mammals and further expand the understanding of interdomain molecular homeostasis in host-microbial symbiosis.

Biallelic pathogenic variants in the laminin β2 (LAMB2) gene, which encodes laminin β2, are associated with Pierson syndrome characterized by a congenital nephrotic syndrome that rapidly progresses to end-stage renal disease, distinct ocular maldevelopment with bilateral microcoria, and neurodevelopmental deficits. However, the phenotypic spectrum of LAMB2-associated disorder is broader than expected, and cases with milder phenotypes such as isolated congenital or infantile nephrotic syndrome have also been reported. We report a patient with LAMB2-associated renal disorder showing an extremely mild phenotype. A 5-year-old girl presented with asymptomatic proteinuria and hematuria detected by urinalysis screening. She had been previously healthy without any additional renal symptoms. The serum albumin and creatinine levels were normal. Renal biopsy revealed minor glomerular abnormalities with occasional focal mesangial proliferation. Electron microscopy showed no structural changes in the glomerular basement membrane. Targeted sequencing of podocyte-related genes using next-generation sequencing was performed. As a result, previously reported biallelic pathogenic variants of the truncating variant (c.5073_5076dupCCAG) and a splice site variant (c.3797 + 5G > A) in the LAMB2 gene were detected, and the patient was diagnosed with LAMB2-associated renal disorder. Interestingly, a previously reported case with this splicing variant also showed an atypically mild phenotype. We suggest that clinicians should consider LAMB2-associated nephritis as an important differential diagnosis in children with asymptomatic proteinuria and microscopic hematuria if there is no structural change in the glomerular basement membrane. A comprehensive gene-screening system using next-generation sequencing is useful for diagnosing these atypical cases with isolated urine abnormalities.

Mutations in SLC4A1, encoding the chloride–bicarbonate exchanger known as anion exchanger 1, have been reported as the sole genetic cause of autosomal dominant distal renal tubular acidosis (dRTA). This disorder is extremely rare and most patients show no clinical symptoms during childhood. Here, we report a case of an infant with early-onset autosomal dominant dRTA caused by SLC4A1 mutation p.Gly609Arg that is detected as a hot spot world widely. Despite the fact that the patient’s mother and sister had the same SLC4A1 mutation, all family members presented different clinical courses. A 9-month-old boy was referred to our hospital because of insufficient body weight gain. At the initial visit, his height and weight were 68.2 cm (−1.0 SD) and 6.4 kg (−2.2SD) respectively. Metabolic acidosis with a normal serum anion gap and inappropriate alkaline urine were detected. Abdominal ultrasound indicated bilateral renal medullary high-echoic lesions which suspected nephrocalcinosis. The genetic test revealed a heterozygous mutation c.1825G > A (p.Gly609Arg) in SLC4A1 that directed his diagnosis of autosomal dominant dRTA. The genetic test was performed on the patient’s family members, indicating that the same SLC4A1 mutation was detected in his mother and sister. His mother had nephrocalcinosis and metabolic acidosis at the age of 35 years. However, his sister had no clinical symptoms at the age of 6 years without any laboratory abnormalities. This familial case demonstrated that the significant heterogeneity in clinical manifestations may develop even among familial members sharing the same variant.

Background Congenital obstructive nephropathy (CKD) is commonly implicated in the pathophysiology of chronic kidney disease occurring in the pediatric and adolescent age groups and the release of reactive oxygen species contribute to the worsening of renal fibrosis. Molecular hydrogen (H2) protects against tissue injury by reducing oxidative stress. We evaluated the efficacy of oral H2-rich water (HW) intake in preventing unilateral ureteral obstruction (UUO)-induced renal injury in rats. Methods Male Sprague-Dawley UUO or control rats were administered with distilled water (DW) or HW for 2 weeks post-surgery. Histopathological and immunohistochemical analyses of kidney samples were performed. Results Histological changes were not apparent in the sham-operated kidneys. However, UUO kidneys were found to have widened interstitial spaces and tubular dilatation. Compared with the UUO + DW group, HW administration attenuated tubulointerstitial injury and reduced interstitial fibrotic area, causing a substantial decline in the frequency of α-SMA-, ED-1-, and TGF-β1-positive cells in the UUO + HW group. The decrease in the klotho mRNA expression in the UUO + HW group was less pronounced than that in the UUO + DW group. Conclusion Oral HW intake reduced oxidative stress and prevented interstitial fibrosis in UUO kidneys, potentially involving klotho in the underlying mechanism. Impact Oral intake of hydrogen-rich water (HW) can reduce oxidative stress and suppress interstitial fibrosis in unilateral ureteral obstruction-induced renal injury in rats. This mechanism possibly involves klotho, which is known for its antiaging roles. The association between molecular hydrogen and klotho in renal fibrosis is well known; this is the first report on the association in a unilateral ureteral obstruction model. Drinking HW is a safe and convenient treatment for oxidative stress-induced pathologies, without side effects. As a prospect for future research, oral HW intake to treat oxidative stress may improve renal fibrosis in congenital obstructive nephropathy.

AIM We examined the associations between late preterm (LPT) birth children aged ≥5 years and the frequency of bedwetting. Moreover, those who were born full-term/low birthweight (BW), LPT/low BW, LPT/normal BW and LPT/low BW were compared. METHODS In total, we evaluated 614 patients who underwent assessments for frequent bedwetting at the three hospitals from January 2014 to December 2016. Data at the initial visit were collected from the electronic medical records. We assessed the patients' bladder diaries and questionnaires containing detailed information on demographics and frequency of bedwetting per month. Neonatal data were collected from the Maternal and Child Health Handbook. RESULTS Frequency of bedwetting in the LPT/low BW group was higher than in the term/low BW group (28 vs. 22.5, p < 0.05). However, the frequency between the LPT/normal BW group and the LPT/low BW group was not significantly different (28 vs. 28, p = 1.00). Multiple regression analyses were conducted to eliminate potential confounding factors, attention-deficit/hyperactivity disorder and intellectual disability, but results were not changed. CONCLUSION This study revealed that LPT/low BW was associated with increased frequency of bedwetting in children. The results suggest that gestational age should be considered when examining patients with severe bedwetting.

Desmopressin is a synthetic V2 specific analogue of antidiuretic hormone (arginine vasopressin) that is widely used as first line treatment for monosymptomatic nocturnal enuresis. However, no biomarkers to predict desmopressin effectiveness have yet been established. Because arginine vasopressin is unstable, we prospectively measured the major urine concentration factor aquaporin 2 and serum copeptin (as a surrogate marker for vasopressin) in patients with monosymptomatic nocturnal enuresis, and evaluated whether they are useful for predicting desmopressin treatment outcome.The study included 32 children 6 to 11 years old with monosymptomatic nocturnal enuresis and nocturnal polyuria. Exclusion criteria were daytime urinary symptoms and underlying diseases causing nocturnal enuresis. Subjects were treated with 120 μg or 240 μg desmopressin oral disintegrating tablet and were divided into responders (at 120 or 240 μg) and nonresponders (at 240 μg). Day/night ratios of plasma copeptin and urinary aquaporin 2 were measured during desmopressin treatment.There was no significant difference in baseline day/night ratio of urinary aquaporin 2 between desmopressin responders and nonresponders. After 8 weeks of treatment there was a significant correlation between day/night ratio of aquaporin 2 and percentage of wet nights. In responders (but not nonresponders) there was a significant difference in the change in aquaporin 2 day/night ratio from before treatment to complete remission (p = 0.0004). For plasma copeptin the baseline day/night ratio for responders at 120 μg was significantly lower than in the 240 μg nonresponder group (p = 0.02).Urinary aquaporin 2 appears to be a biomarker of desmopressin treatment effectiveness during therapy, while plasma copeptin levels before treatment are predictive of desmopressin response.

Background Preterm neonates are born while nephrogenesis is ongoing, and are commonly exposed to factors in a hyperoxic environment that can impair renal development. Oxidative stress has also been implicated in the development of retinopathy of prematurity (ROP). The rat model of oxygen-induced retinopathy (OIR) is the most clinically relevant model of ROP because its biologic features closely resemble those of ROP in preterm infants. We investigated impaired renal development in a rat model of OIR. Methods Newborn Sprague-Dawley rats were maintained in either a normoxic (room air, 21% O2 ; control group) or a controlled hyperoxic (80% O2 ; OIR group) environment from birth to postnatal day (P) 12. All pups were then raised in room air from P12 to P19. Results The hyperoxic environment led to significantly higher urinary excretion of 8-hydroxy-2'-deoxyguanosine, a marker of oxidative DNA damage, and a reduction in nephrogenic zone width at P5 in OIR pups. Additionally, glomerular count was significantly reduced by 20% in the OIR group, and avascular and neovascular changes in the retina were observed only in the OIR group at P19. Messenger RNA levels of vascular endothelial growth factor-A (VEGF-A) and platelet-derived growth factor-β, essential angiogenic cytokines for glomerulogenesis, in the renal cortex were significantly lower at P5 and significantly higher at P19 in the OIR group compared with controls. Conclusion Renal impairment was caused by exposure to a hyperoxic environment during nephrogenesis, and the pathology of the impaired nephrogenesis in this OIR model reflects the characteristics of ROP observed in preterm infants.

Background Although the evidence-based treatment for nocturnal enuresis is established, nearly one-third of patients are still enuretic with desmopressin, anti-cholinergic treatment and alarm. The fourth option, imipramine, is limited because of the risk of cardiotoxicity on overdose. Clonidine, an α2 -adrenoceptor agonist that also has noradrenergic effects like imipramine, is a new option for refractory enuresis. Methods A total of 148 patients (6-14 years of age; mean, 9.1 years) with refractory enuresis under desmopressin, anti-cholinergic treatment and alarm were enrolled. The patients consisted of 100 boys and 48 girls, of whom 23 had monosymptomatic nocturnal enuresis and 125 had non-monosymptomatic nocturnal enuresis. Clonidine 4 μg/kg/day (maximum, 75 μg/day) orally 30 min before bedtime was added and its effects were evaluated after 4 weeks of treatment. Results A total of 83 patients (56.1%) achieved partial or complete response with the additional clonidine. No significant adverse reactions were noted. Conclusions Clonidine could be an aid for refractory enuresis, although further randomized controlled trials are needed.

First described in Japanese patients, Kabuki syndrome (KS) is a congenital condition associated with multiple anomalies and mental retardation. Although urological and immune abnormalities are common in KS, immune complex nephritis such as membranoproliferative glomerulonephritis (MPGN) has not yet been reported. We describe the first reported case of a KS patient with common variable immunodeficiency (CVI) and recurrent otitis media who developed severe proteinuria and hematuria due to MPGN Type 3 detected during the school urinary screening program in Japan. The patient was intravenously treated with methylprednisolone pulses followed by alternate-day prednisolone and an angiotensin receptor blocker. The patient showed remarkable improvement in both histological and urinary analyses. This case report suggests that immune abnormalities associated with KS can play an important role in the development of MPGN. Urinalysis should be regularly performed in KS patients with hypogammaglobulinemia and/or recurrent infection.

Nocturnal enuresis (NE) is a common problem in children,and its prevalence rate is 20% among children aged 5; 15% of children recover in each subsequent year. However,this problem remains in approximately 0.5% of the adult population. The major pathogenic factors involved in NE are nocturnal polyuria,small bladder capacity and/or detrusor overactivity,as well as a high arousal threshold. Desmopressin is the first-line medication for patients with dieresis-dependent nocturnal enuresis and its efficacy rate is nearly 70%. An enuresis alarm device is also commonly used,especially for patients with a small bladder capacity; it is effective for 65-70% of patients with NE. For patients who do not respond to desmopressin or an enuresis alarm,anticholinergics or tricyclic antidepressants are used; however,they are beneficial only for some of them. Since several clinical studies have shown that disrupted sleep architecture in patients with NE might explain in part the etiology of the disease,we evaluated the sleep conditions in our refractory patients and started treatment with yokukansan. Yokukansan was effective in two-thirds of the refractory cases with nocturnal enuresis by improving the quality of their sleep.

Background Although desmopressin therapy is effective in treating polyuric monosymptomatic nocturnal enuresis (MNE), the relatively high rates of recurrence are problematic. To date, the treatment protocol on the discontinuation of oral desmopressin melt (ODM) tablet, MinirinMelt, has not been established. We tested two protocols of tapering ODM when the patients achieved full response on ODM, and compared the treatment outcomes. Methods One hundred and fifty-seven polyuric MNE children were newly treated with ODM at the authors' outpatient clinics (Juntendo Nerima Hospital and Musashi-Murayama Hospital). When the patients did not respond to the 8 week ODM therapy, we added another options such as alarm, anti-cholinergics, and imipramine (92 patients; 58.6%). Sixty-five patients (41.4%) achieved full response on ODM alone, and 49 of them accepted gradual tapering of ODM: group B (n = 25), 240 μg ODM per day → 120 μg ODM per day → 120 μg ODM per alternate day → cessation; and group C (n = 24), 240 μg ODM per day → 120 μg ODM per day → 60 μg ODM per day → 60 μg ODM per alternate day → cessation. Results Fourteen patients in group B (56%) and four in group C (17%) had relapses of enuresis after the discontinuation of ODM (P = 0.026). Conclusions Gradual tapering of ODM therapy in MNE patients leads to better outcome.

Recent advancements in perinatal and neonatal care have increased the survival of preterm infants with lower birth weight and very low birth weight (VLBW;1,500 g) infants. Such infants are exposed to a higher risk of renal insufficiency in later life due to congenitally fewer nephrons; however, urinalysis in order to detect renal insufficiency in those infants at school age has not yet been established. The aim of the study was to assess chronic renal impairment in VLBW infants during their childhood after discharge from the neonatal intensive care unit (NICU) until adolescence using urinary angiotensinogen (uAGT).We compared serum levels of angiotensinogen (sAGT), creatinine, β2-microglobulin (sβ2MG) and cystatin C (sCysC), and urinary levels of uAGT, creatinine (uCre),β2-microglobulin (uβ2MG) and albumin between two infant groups-the VLBW group (50 children who were admitted to our NICU as infants), and a control group of 25 children who were born as full-term infants with birth weight ≥2,500 g. The median age of the VLBW group and control group infants was 60 months (range 7-135) and 57 months (range 5-144), respectively, at the time of evaluation.In the VLBW group, sCysC levels were high (p0.05) and estimated glomerular filtration rate (eGFR) was low (p0.05). There were no significant differences in the ratios of uβ2MG to creatinine and urinary albumin to creatinine between the two groups. Although there were no differences in concentration of sAGT between the two groups (p = 0.062), the ratio of uAGT to creatinine was significantly higher in the VLBW group (p0.01). The examination of 19 VLBW infants (19/50) with eGFR ≤90 ml/min/1.73 m(2) showed a positive correlation between uAGT/creatinine and urinary albumin/creatinine (r = 0.531, p 0.05). Furthermore, the analysis of correlation between the ratio of uAGT to creatinine and eGFR showed a reverse correlation in 19 VLBW infants (19/50) with eGFR ≤90 ml/min/1.73 m(2), 18 of whom had stage II chronic kidney disease and one who had stage III disease (r = -0.512, p ≤ 0.05).uAGT is an effective marker for predicting the progression of chronic renal impairment in preterm VLBW infants after their growth. uAGT measurement is easier to conduct, less invasive and more sensitive than conventional uβ2MG or urinary albumin measurement.

Chronic cyclosporine A (CsA) nephrotoxicity is manifested by renal dysfunction, progressive histopathological kidney lesions characterized by afferent arteriolopathy, and tubulointerstitial fibrosis. In addition to the direct toxic effect of CsA, many other etiological factors such as angiotensin II, transforming growth factor (TGF)-β, and macrophage infiltration are involved in this pathogenesis. This study investigated the hypothesis that concomitant administration of mizoribine (MZR) and angiotensin II receptor blockade (ARB) may prevent CsA nephrotoxicity in rats.Sprague-Dawley male rats were divided into the following seven groups: group 1, treated with CsA; group 2, treated with CsA + MZR; group 3, treated with CsA + valsartan (Val); group 4, treated with CsA + MZR + Val; group 5, treated with MZR; group 6, treated with Val; and group 7, controls (n = 5 each). Renal histopathology and the effect of CsA-induced nephrotoxicity on inflammatory mediators were evaluated.Results of this study demonstrated that ARB administration significantly decreased arteriolopathy and that in comparison with monotherapy, concomitant administration of MZR and ARB further decreased arteriolopathy, fibrosis, macrophage infiltration, and TGF-β1 mRNA expression associated with CsA nephrotoxicity.These findings indicate that MZR and ARB combination treatment provides synergistic protective effects against chronic CsA nephrotoxicity.

Background The major pathogenic factors involved in nocturnal enuresis are nocturnal polyuria, small bladder capacity and/or detrusor overactivity, and a high arousal threshold. Desmopressin is the first-line therapy for the patients with diuresis-dependent nocturnal enuresis. Yokukansan, a traditional Japanese medicine, has been used in Japan to treat patients with nervousness, insomnia, and children with night terrors and temper tantrums. We experienced the positive effect of Yokukansan in some of the patients who did not respond well to desmopressin therapy. Methods In total, 32 children with monosymptomatic nocturnal enuresis with nocturnal polyuria were treated with oral desmopressin melt tablets, which were approved for clinical use in Japan on 29 May 2012. This treatment was effective for 14 of them. For the rest (n = 18), Yokukansan was introduced in combination with desmopressin. Results Yokukansan was effective for 12 out of the 18 cases. Conclusions: Yokukansan should be a candidate for the medication of nocturnal enuresis.

Renal hypouricemia type 1 is caused by mutations in the SLC22A12 gene, whereas type 2 is caused by defects in the SLC2A9 gene. Although both subtypes predispose to exercise-induced acute kidney injury (EIAKI), posterior reversible encephalopathy syndrome (PRES) occurring with this disorder is an uncommon phenomenon that has only been reported to date in a patient with renal hypouricemia type 2. We describe a 13-year-old boy with renal hypouricemia type 1 (serum uric acid, 0.9 mg/dL) with a homozygous W258X mutation in the SLC22A12 gene, presenting with EIAKI and PRES. On admission, his body weight was 61 kg (11 kg above the dry weight), and blood pressure was 153/88 mmHg. Cranial magnetic resonance imaging revealed high-intensity areas in the cortical and subcortical white matter of the occipital lobe. After admission, the patient responded well to a combination of hemodialysis and intravenous nicardipine. This is the first case of concurrent PRES and EIAKI in a patient with renal hypouricemia type 1. We suggest that PRES is not due to severe hypouricemia caused by SLC2A9 mutation but is a manifestation of severe EIAKI associated with renal hypouricemia.

The efficacy of rituximab (RTX) as the sole therapy for preventing relapses of nephrotic syndrome (NS) is transient in most patients; therefore, the optimal therapy required for maintaining a successful response to a biological agent remains a challenge. We conducted a prospective study to compare the efficacy of cyclosporine (CsA) with that of mycophenolate mofetil (MMF) as maintenance therapy after a single infusion of RTX. Of 29 patients with persistent steroid-dependent NS despite the use of CsA and/or MMF, 13 without chronic nephrotoxicity continued CsA therapy, maintaining a 2-h post-dose CsA level of 400–500 ng/ml (CsA group). The remaining 16 were treated with MMF, maintaining a pre-dose level of 2–5 μg/ml of mycophenolic acid (MMF group). The median duration of CsA and MMF treatment was 18 and 19 months, respectively. Despite the mean number of relapses before RTX treatment being significantly lower in the MMF group than in the CsA group (2.3/year vs. 4.6/year, p < 0.01), treatment failure occurred more frequently in the MMF group (7/16) than in the CsA group (2/13). The rate of sustained remission was also significantly higher in the CsA group than in the MMF group (p < 0.05). Conclusion: In patients with severe steroid-dependent NS, CsA appears to be more effective than MMF for maintaining remission after a single infusion of RTX.

Background Recent studies have shown that incontinence and attention-deficit/hyperactivity disorder (ADHD) coexist and there is an interaction between them. The treatment for nocturnal enuresis (NE) and ADHD, however, has not been established. Methods At the first visit to the outpatient clinic, physical examination and history taking were carried out in 265 new patients with NE. After excluding the possibility of comorbid ADHD and related disorders, patients with monosymptomatic NE (MNE) were treated with desmopressin and/or alarm, and those with non-monosymptomatic NE (NMNE) were treated with anti-cholinergics and/or alarm. This 12 week treatment did not work in 65 patients, and they were re-assessed for comorbid ADHD. A total of 24 were diagnosed with ADHD, and they were treated with atomoxetine (1.8 mg/kg/day) in addition to ongoing therapy for NE. Results After 8 weeks of atomoxetine, the average wet nights per months was significantly decreased: 18.5–4.6 in the MNE group (P = 0.001), and 22.1–12.4 in the NMNE group (P = 0.0251). Overall, atomoxetine was beneficial in 19 of 24 patients. Conclusions Atomoxetine may be a suitable option for refractory NE with comorbid ADHD.

Although once-daily cyclosporine (CsA) therapy may have greater nephrotoxic-sparing effects than standard twice-daily therapy, little information is available in children with steroid-dependent minimal change nephrotic syndrome (MCNS) regarding histological analysis after long-term once-daily administration.A prospective study of the clinical efficacy and comparison between pre- and post-treatment renal biopsy findings in ten children (mean age, 8.8 years) with steroid-dependent MCNS who were administered once-daily CsA therapy for more than 24 months (mean ± SD, 30 ± 3.7) was performed in Saitama Children's Medical Center. Administration of once-daily CsA therapy (mean dose, 2.8 ± 0.6 mg/kg/day; mean C2 levels, 670 ± 64 ng/ml) resulted in a significant reduction in the median relapse rate from 4.6 to 0.2 times per year, and five patients did not experience a relapse of NS. Furthermore, mean threshold of prednisolone dose significantly reduced from 1.2 to 0.02 mg/kg on alternate days. However, two patients showed evidence of chronic CsA nephrotoxicity (CsAN).Once-daily CsA therapy appears to be effective in children with steroid-dependent MCNS. However, follow-up renal biopsies should be performed to investigate the presence of CsAN after more than 24 months of treatment with once-daily regimen as well as with the conventional twice-daily regimen.

目的: 初発有熱性UTIにおいて，急性期DMSAとUSを組み合わせることでVCUGの適応を絞れるかを検討した。 対象と方法: 当センターにおいて，初発有熱性UTIと診断された27例 (男児20例，女児7例，中央値年齢3か月) を対象とした。入院後7日以内にDMSAおよびUSを施行し，その後VCUGを施行。 結果: VURは11例 (40%) に認められた。8例は片側，3例は両側で，grade II度が3例で他はすべてIII度以上であった。急性期DMSAによる高度VURの検出率は88%であったが，急性期DMSAとUSを組み合わせると高度VURをすべて検出することが可能となり，感度・陰性的中率はともに100%であった。結果として27例中10例 (37%) の児がVCUGを回避できたと考えられた。 結語: 急性期DMSAおよびUSいずれかに異常が認められた場合のみVCUGを施行すれば，不必要なVCUGを回避できると考えられた。

Although cyclosporine (CsA) therapy is effective in the management of children with steroid-dependent nephrotic syndrome (SDNS), a recent study has revealed that the use of CsA itself was a significant predictor of NS relapse in adulthood. The efficacy of single daily high-dose mizoribine (MZR) therapy was assessed in 10 children with SDNS (mean age, 6.2 years) who had never been treated with CsA previously. MZR was started at 5 mg/kg, administered as a single daily dose after breakfast, and the dose was adjusted to achieve 2-h post-dose MZR levels (C2) of approximately 3 μg/ml. In 9 of the 10 patients, treatment with a single daily dose of MZR (mean dose, 8.4 mg/kg/day) over a period of 22 months (median) resulted in significant reduction of the mean prednisolone dose from 0.39 to 0.15 mg/kg/day and the median 12-month relapse rate from 3.0 to 0.4 episodes/12 months. Although cyclophosphamide was initiated in one patient because of treatment failure, none of the 10 patients required treatment with CsA during the observation period (median, 33 months). These data indicate that single daily high-dose MZR therapy is possibly useful in treating children with SDNS and that it may also eliminate the need for CsA in some patients.

The nephritis-associated plasmin receptor is a recently identified nephritogenic antigen associated with acute poststreptococcal glomerulonephritis and proposed to play a pathogenic role, but its precise glomerular localization in acute poststreptococcal glomerulonephritis has not been elucidated. We therefore analyzed renal biopsy sections from 10 acute poststreptococcal glomerulonephritis patients by using immunofluorescence staining with anti-nephritis-associated plasmin receptor antibody and various markers of glomerular components. Nephritis-associated plasmin receptor was detected in the glomeruli of all patients, and double staining for nephritis-associated plasmin receptor and collagen IV showed nephritis-associated plasmin receptor to be predominantly on the inner side of the glomerular tufts. Nephritis-associated plasmin receptor-positive areas within glomerular tufts were further characterized with markers for neutrophils, mesangial cells, endothelial cells, and macrophages. In 6 of the patients, nephritis-associated plasmin receptor staining was seen mainly in neutrophils and to a lesser degree in mesangial and endothelial cells. In the other 4 patients, nephritis-associated plasmin receptor staining was seen mainly in mesangial cells and to a lesser degree in neutrophils and endothelial cells. In all patients, macrophages showed little staining. Elevated plasmin activity in glomerular neutrophils was identified by combining in situ zymography staining for plasmin activity and immunofluorescence staining for neutrophils. The glomerular localizations of nephritis-associated plasmin receptor and another nephritogenic antigen, streptococcal pyrogenic exotoxin B, were compared by double immunofluorescence staining and found to be similar. These findings indicate the nephritogenic potential of nephritis-associated plasmin receptor and offer valuable information with respect to the pathogenic mechanism of acute poststreptococcal glomerulonephritis.

Rituximab (RTX) has been successfully used as a rescue therapy in children with steroid-dependent nephrotic syndrome (SDNS). However, little is known regarding maintenance therapy after a successful response to RTX in such patients. The efficacy and safety of a single RTX infusion (375 mg/m(2)) were assessed in ten patients who had persistent SDNS associated with minimal-change disease (MCD) despite the long-term use of cyclosporine (CsA). The mean follow-up after RTX infusion was 17 months. Applying RTX resulted in a significant reduction in the mean prednisolone (PSL) dose from 0.39 +/-0.18 to 0.15 +/- 0.14 mg/kg per day. The mean 12-month relapse rates significantly decreased from 4.1 +/- 1.7 to 0.6 +/- 0.6. All but one patient who had continued CsA as maintenance therapy after a single RTX infusion were able to withdraw from PSL without any relapses during the study period, whereas the remaining five patients who discontinued CsA experienced relapses after CD19 cells re-emerged, leading to the reintroduction of CsA or an additional RTX infusion. Infusion reactions occurred in five of ten patients. These data indicate that a single RTX infusion may improve response to CsA in patients with persistent SDNS due to the phenomenon of secondary resistance to CsA.

【目的】 後部尿道弁 (PUV) の長期腎機能予後規定因子を明らかにすること。【対象・方法】 過去22年間に当院にてPUVと診断された46例 (中央値年齢8か月，平均観察期間6.9年間) を後方視的に検討した。予後不良群と予後良好群の2群に分け，予後規定因子の解析を行った。【結果】 46例のうち5例が予後不良群に，残りの41例が予後良好群に分類された。 単変量解析の結果，初診時腎機能障害 (p 1.0mg/dl (p 1.0mg/dlがPUV患児における長期腎機能予後規定因子であった。 危険因子を有する児に対して早期の介入を行うことにより，腎後遺症を防ぐことができる可能性がある。

Although recent studies on adults with lupus nephritis indicate that mycophenolate mofetil (MMF) may be effective in maintaining remission for patients who previously received short-term intravenous cyclophosphamide (IVCY) induction therapy, the experience with the new immunosuppressive agent in children with severe lupus nephritis has not been as satisfactory thus far. To assess the efficacy and safety of maintenance therapy with MMF, we prospectively analyzed four patients with biopsy-proven severe lupus nephritis (three girls, one boy; mean age 12 years; two with class IIIA, two with class IVG(A); mean duration of lupus nephritis 7 months) receiving MMF for at least 6 months after induction treatment. These patients had been treated previously with 6 months of low-dose IVCY combined with oral mizoribine and steroids for induction, followed by therapy with MMF adjusted to maintain predose mycophenolic acid (C0-MPA) levels at 2-5 mcg/ml. Mean follow-up after staring MMF was 27.5 months (range 6-41). The mean MMF dose required was 405 +/- 49 mg/m(2) per 12 h, which maintained mean C0-MPA levels of 3.3 +/- 0.41 mcg/ml. No patient experienced renal flares during maintenance therapy with MMF, which permitted a significant reduction in mean prednisolone dose from 11.9 +/- 1.3 to 3.9 +/- 2.6 mg/day (P = 0.003). No significant gastrointestinal or hematologic side effects of MMF were noted. This preliminary study demonstrates that maintenance therapy with MMF after a low-dose IVCY regimen appears to be a promising intervention without adverse effects in children with severe lupus nephritis. These data should be confirmed by a prospective randomized multicenter clinical trial.

Although diffuse crescentic formation in immunoglobulin A (IgA) nephropathy, histologically characterized by extensive extracapillary proliferation, is assumed to have a poor prognosis, there has still been no established treatment because of the low prevalence of the condition, especially in pediatric patients. This paper reports on a 5-year-old boy with rapidly progressive IgA nephropathy requiring dialysis for 1 month. He had been treated with plasma exchange (PE) combined with immunosuppressive treatment, including steroids and mizoribine, because renal function deteriorated rapidly despite initial treatment with intravenous methylprednisolone pulse. The histological findings at that time revealed IgA nephropathy, with large circumferential cellular crescent formation in approximately 80% of the glomeruli. Three weeks after PE initiation, serum levels of creatinine and IgA-containing immune complexes returned to normal, and urinary protein excretion gradually decreased. The second renal biopsy taken 7 months later demonstrated mild IgA nephropathy with small fibrocellular crescents. This case report indicates that PE combined with immunosuppressive treatment may benefit children with rapidly progressive IgA nephropathy, even when extensive crescent formations are present.

Thin basement membrane nephropathy (TBMN) is characterized clinically by persistent hematuria, minimal proteinuria, normal renal function, another family member with hematuria, and a benign course. Especially in childhood TBMN, proteinuria of any degree is reported to be uncommon. We report on a boy with benign familial hematuria found by urinary screening at 3 years of age who presented with nephrotic syndrome (NS) at 15 years of age. His renal histology showed TBMN associated with minimal change disease (MCD). Treatment with corticosteroid resulted in complete remission of NS in a short period of time, while isolated hematuria persisted during the follow-up period despite this therapy. We speculate, therefore, that the nephrotic range proteinuria is not due to TBMN but rather is the manifestation of associated MCD. Several cases of TBMN with NS have been reported in adults, but it has not yet been reported in children in the literature. To our knowledge, this is the first case of childhood TBMN associated with NS resulting from coincidental MCD.

To determine whether laparoscopic nephrectomy (LN), open nephrectomy (ON), or observation (OB) is most efficient for managing multicystic dysplastic kidney (MCDK).We performed a retrospective review of the management of our 12-year clinical experience of 32 MCDK patients to analyze the estimated total cost (ETC) of various treatment options and compare them with respect to survival, development of hypertension, and postoperative cosmetic appearance, to determine the most efficient treatment option.There were 12 cases in the LN group, 6 in the ON group, and 14 in the OB group. ETC was lower for ON than for LN. But the length of preoperative observation and length of follow-up after spontaneous regression greatly affected ETC. If MCDK cases were observed5 years with standard investigations performed regularly, ETC was higher for the OB group than for the LN group. In 6/14 (42.9%) of OB cases, MCDK resolved within 5 years, and this subgroup had the lowest ETC up to the time of this review. Six cases initially in the OB group were managed surgically (4 by LN and 2 by ON) in accordance with parental requests, and ETC in these cases was highest. All cases are well after a mean follow-up of 5.7 years, without any impairment of renal function, or hypertension.The decision to operate after lengthy observation increases costs. Overall, the most efficient surgical technique for managing MCDK was LN because of greater patient satisfaction with postoperative cosmesis. We recommend MCDK be treated by LN after a short period of observation.