Mammals sustain amino acid homochirality against chiral conversion by symbiotic microbes.

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.

Plasma D-asparagine and the D/L-serine ratio reflect chronic kidney diseases in children regardless of physique.

Biomarkers that accurately reflect renal function are essential in management of chronic kidney diseases (CKD). However, in children, age/physique and medication often alter established renal biomarkers. We studied whether amino acid enantiomers in body fluids correlate with renal function and whether they are influenced by physique or steroid medication during development. We conducted a prospective study of children 2 to 18 years old with and without CKD. We analyzed associations of serine/asparagine enantiomers in body fluids with major biochemical parameters as well as physique. To study consequences of kidney dysfunction and steroids on serine/asparagine enantiomers, we generated juvenile mice with uninephrectomy, ischemic reperfusion injury, or dexamethasone treatment. We obtained samples from 27 children, of which 12 had CKD due to congenital (n = 7) and perinatal (n = 5) causes. Plasma D-asparagine and the D/L-serine ratio had robust, positive linear associations with serum creatinine and cystatin C, and detected CKD with high sensitivity and specificity, uninfluenced by body size or biochemical parameters. In the animal study, kidney dysfunction increased plasma D-asparagine and the D/L-serine ratio, but dexamethasone treatment did not. Thus, plasma D-asparagine and the D/L-serine ratio can be useful markers for renal function in children.

Comparison of the characteristics and factors influencing hospital visits among children with nocturnal enuresis in Japan: The Hirakata-Urayasu population-based cohort study.

OBJECTIVES: The aim of this study was to compare the demographic characteristics of school-aged children with nocturnal enuresis and factors influencing hospital visits between two regions in Japan. METHODS: A cross-sectional survey was conducted in Hirakata City, Osaka Prefecture, and Urayasu City, Chiba Prefecture. An anonymous online questionnaire was administered to all public elementary and junior high school students (aged 6-16 years) or their guardians. Questions included age, gender, perinatal history, frequency of nocturnal enuresis, frequency of bowel movements, comorbidities, and hospital visits for nocturnal enuresis. RESULTS: The survey response rates were 15.4% in Hirakata City and 37.0% in Urayasu City. In total, 426 children with nocturnal enuresis in Hirakata City and 270 in Urayasu City were included in the final analysis. In both cities, the boy-girl ratio was approximately 2:1, and the prevalence of nocturnal enuresis gradually decreased with age. Multivariate analysis revealed that children aged ≥11 years had a significantly higher proportion of hospital visits (OR, 2.61; 95% CI: 1.49-4.56; p = 0.001; OR, 2.72; 95% CI: 1.12-6.64; p = 0.027, respectively). However, the frequency of nocturnal enuresis did not affect hospital visits. CONCLUSIONS: The findings of this study suggest that parents with school-aged children have low awareness that nocturnal enuresis is a health problem and therefore subject to medical consultation. Although the proportion of hospital visits increases for children aged ≥11 years, children and families suffering from nocturnal enuresis should be encouraged to see a doctor instead of adopting a "wait and see attitude," even at a young age.

Hydrogen-rich water reduced oxidative stress and renal fibrosis in rats with unilateral ureteral obstruction.

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-ß1-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.

The developmental origins of health and chronic kidney disease: Current status and practices in Japan.

The concept of the developmental origins of health and disease (DOHaD) views unfavorable perinatal circumstances as contributing to the development of diseases in later life. It is well known that such unfavorable circumstances play an important role as a risk factor for chronic kidney disease (CKD) in infants born with prematurity. Low birthweight (LBW) is believed to be a potential contributor to CKD in adulthood. Preterm and/or LBW infants are born with incomplete nephrogenesis. As a result, the number of nephrons is low. The poor intrauterine environment also causes epigenetic changes that adversely affect postnatal renal function. After birth, hyperfiltration of individual nephrons due to low nephron numbers causes proteinuria and secondary glomerulosclerosis. Furthermore, the risk of CKD increases as renal damage takes a second hit from exposure to nephrotoxic substances and acquired insults such as acute kidney injury after birth among infants in neonatal intensive care. Meanwhile, unfortunately, recent studies have shown that the number of nephrons in healthy Japanese individuals is approximately two-thirds lower than that in previous reports. This means that Japanese premature infants are clearly at a high risk of developing CKD in later life. Recently, several DOHaD-related CKD studies from Japanese researchers have been reported. Here, we summarize the relevance of CKD in conjunction with DOHaD and review recent studies that have examined the impact of the upward LBW trend in Japan on renal health.

YouTube videos in Japanese as a source of information on nocturnal enuresis: A content-quality and reliability analysis.

BACKGROUND: This study aimed to evaluate the quality and reliability of Japanese YouTube videos pertaining to nocturnal enuresis (NE). METHODS: In this cross-sectional study, we performed a YouTube search using the keyword "Ya-nyou-shou" ('nocturnal enuresis' in Japanese). We considered the first 200 videos listed based on the YouTube default option. Videos that were irrelevant, concerned personal experiences or adult NE, had non-Japanese content, were advertisements, were duplicated, and those without audio were excluded. Video features and upload source were recorded. The Modified DISCERN, Journal of the American Medical Association (JAMA), and Global Quality Scale (GQS) scoring systems were used for analysis. Two independent pediatricians, specialists in nephrology and urology, completed the scoring. Correlation analysis was performed between video features and the three quality analysis scores. RESULTS: In total, 72 videos were analyzed. The most common upload sources were physicians (40.3%) and non-physician health personnel (40.3%). The median modified DISCERN, JAMA, and GQS scores for the videos were 1 (lowest: 0; highest: 4), 2 (lowest: 1; highest: 3), and 2 (lowest: 1; highest: 4), respectively. The highest scores for video power index (VPI) were for independent users (6.43 points) and physicians (3.05 points). There were positive correlations between the VPI and video length and modified DISCERN and GQS scores. No video presenter disclosed conflicts of interest. CONCLUSIONS: Most Japanese YouTube videos about NE were low quality. Healthcare experts should be encouraged to upload better quality content.

Associations between size at birth and size at 6 years among preterm infants: a retrospective cohort study.

BACKGROUND: Little is known about the relationship between fetal growth and size at school age in children born prematurely. We evaluated the relationships between gestational age and anthropometric z-scores at birth and size at 6 years of age in very-low-birthweight infants born at <30 weeks' gestation. METHODS: We collected data from the medical records of 187 preterm children at birth and 6 years of age. We evaluated correlations between gestational age and z-scores for weight, body length, and head circumference at birth and z-scores for weight, height, and body mass index at 6 years of age. RESULTS: Simple regression analysis showed that, in boys and the overall group, gestational age and z-scores for weight, body length, and head circumference at birth had significant association with z-scores for weight, height, and body mass index at 6 years of age. No significant associations were found in girls, except for weight z-scores at 6 years with gestational age and head circumference z-scores at birth. Multiple regression analysis showed that gestational age and length z-score at birth were significantly and independently associated with weight and height z-score at 6 years. Gestational age was also significantly and independently associated with body mass index z-score at 6 years. CONCLUSION: Gestational age and fetal growth in length (assessed with the birth-length z-score) were associated with anthropometric z-scores at 6 years in very-low-birthweight children born at <30 weeks of gestation, especially in boys.

Evaluating nocturnal polyuria in Japanese children with nocturnal enuresis.

BACKGROUND: The purpose of this study was to assess whether enuretic Japanese patients with nocturnal polyuria (NP) who met Hoashi's criteria (6-9 years: ≥200 mL; 10 years and older: ≥250 mL) met the International Children's Continence Society (ICCS; expected bladder capacity × 130%) and Rittig's criteria for nocturnal polyuria (>[age+9] × 20 mL). We also compared the effectiveness of 1-desamino-8-d-arginine vasopressin (DDAVP) with the three criteria. METHODS: Fifty-four patients who had NP with normal bladder capacity were enrolled: 36 boys (67%); median age, 8 (interquartile range: 7-9). We compared the diagnostic differences between the Hoashi's criteria and international standards (ICCS and Rittig's) for NP and the short-term effects of DDAVP. The patients received DDAVP for 8 weeks; we evaluated the association between each evaluation method and the effects of therapy. RESULTS: Only 17% of the patients met both Hoashi's and ICCS criteria, whereas 26% met both Hoashi's and Rittig's criteria. The therapeutic effect of DDAVP did not differ significantly between these two groups: there was an effective rate of 73% (Hoashi's criteria) versus 50% (ICCS criteria), P = 0.19, and an effective rate of 71% (Hoashi's criteria) versus 62% (Rittig's criteria), P = 0.84. CONCLUSIONS: Hoashi's criteria are widely used but, according to both the ICCS and Rittig's criteria, approximately 80% of the patients did not fulfill the definition of NP. However, 8 weeks after the DDAVP treatment began, no significant difference was observed in the therapeutic effect of DDAVP according to each set of criteria. The definition of NP should account for the physical disparities between Japanese people and Westerners.

Unsatisfactory Short-Term Neurodevelopmental Outcomes of Preterm Infants Who Received Polymyxin B-Immobilized Fiber Column-Direct Hemoperfusion for Septic Shock.

Sepsis and septic shock are associated with high mortality and neurodevelopmental impairment in preterm infants. Recently, endotoxin and mediator removal using a polymyxin B-immobilized fiber column for direct hemoperfusion (PMX-DHP) has been used for the management of septic shock even in neonates. Although early withdrawal from shock with PMX-DHP contributes to survival, its effect on neurodevelopment after discharge is unclear. This study aimed to examine short-term neurodevelopmental impairment in preterm infants with septic shock who were treated with PMX-DHP. We retrospectively assessed five infants who received treatment with PMX-DHP (median 25.5 [interquartile range: 24.8-28.3] weeks and 817 [interquartile range: 667-954] g). Neurodevelopmental outcomes were assessed with the Kyoto Scale of Psychological Development 2001 at a median 34.5 (interquartile range: 29.5-44.5) months of corrected age after discharge. The short-term neurodevelopmental prognosis of preterm infants treated with PMX-DHP for septic shock was delayed (overall developmental quotient < 70) with an average quotient of 57.3. Furthermore, four (80%) of five patients presented with intraventricular hemorrhage and another four (80%) with periventricular leukomalacia. In conclusion, preterm infants with septic shock treated with PMX-DHP had unsatisfactory short-term neurodevelopmental outcomes. Hence, the effect of PMX-DHP in improving neurodevelopmental prognosis even in preterm infants with septic shock should be further evaluated.

Clinical Effects and Outcomes After Polymyxin B-Immobilized Fiber Column Direct Hemoperfusion Treatment for Septic Shock in Preterm Neonates.

OBJECTIVES: To compare the effectiveness and mortality of early-onset sepsis or late-onset sepsis treatments with polymyxin B-immobilized fiber column direct hemoperfusion in terms of effectiveness and mortality in preterm infants with septic shock. DESIGN: Retrospective cohort study. SETTING: Neonatal ICU within a tertiary care hospital. PATIENTS: Of 1,115 patients, 49 had blood culture-proven sepsis between January 2013 and December 2018; six and five patients with septic shock had undergone polymyxin B-immobilized fiber column direct hemoperfusion treatment for early-onset sepsis (early-onset sepsis group) and late-onset sepsis (late-onset sepsis group), respectively. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Baseline demographic characteristics of both groups were similar. The time from decision to treatment induction was significantly shorter in the early-onset sepsis group than that in the late-onset sepsis group (p = 0.008). The mortality rate after 28 days of treatment and the hospital mortality were significantly lower in the early-onset sepsis group than in the late-onset sepsis group (p = 0.026 and 0.015, respectively). The PaO2/FIO2 ratio was significantly higher in the early-onset sepsis group than in the late-onset sepsis group at the end of the treatment (p = 0.035). In addition, median arterial-to-alveolar oxygen tension ratio significantly improved from 0.19 to 0.55, and median blood pressure also significantly improved from 32.5 to 40.0 mm Hg after the treatment in the early-onset sepsis group. Interleukin-6 levels significantly decreased after treatment in the early-onset sepsis group (p = 0.037). The Pediatric Risk of Mortality III score was similar between the early-onset sepsis and late-onset sepsis groups before and after the treatment. Intraventricular hemorrhage events occurred in both groups, but with no significant differences (p = 0.175). CONCLUSIONS: Polymyxin B-immobilized fiber column direct hemoperfusion treatment for preterm infants with septic shock due to early-onset sepsis is associated with earlier hemodynamic and respiratory status improvements and with lower mortality than that due to late-onset sepsis. Early neonatal septic shock detection and polymyxin B-immobilized fiber column direct hemoperfusion induction may improve the prognosis of affected infants.

The influence on renal function of ibuprofen treatment for patent ductus arteriosus in extremely low birthweight infants.

BACKGROUND: Ibuprofen (IBU) has been used recently for the treatment of patent ductus arteriosus (PDA) in Japan. We aimed to investigate the efficacy and adverse events of IBU and compare them with those of indomethacin (IND) as PDA treatment for extremely low-birthweight infants (ELBWIs), focusing on short-term renal function. METHODS: A case-control study was conducted on 16 ELBWIs. The data from eligible patients were divided into two groups. Ten patients had undergone IND treatment (IND group) between January 2017 and June 2018, whereas six had undergone IBU treatment (IBU group) for PDA between July 2018 and December 2018. The IND group received 0.1 mg/kg/12h IND IV infusion for three doses, whereas the IBU group received 10 mg/kg IV IBU infusion followed by 5 mg/kg/day for 2 days. We compared the efficacy for PDA closure and renal impairment between the two groups. RESULTS: No significant differences in primary closure rates and the PDA ligation required were observed between the two groups. No significant differences were observed between the incidence of intraventricular hemorrhage and gastrointestinal complications in both groups. Changes in urine volume (%) in the IBU group were significantly higher than in the IND group at 24-36 h post-administration. The urinary L-type fatty acid binding protein concentration level at 7 days of life was significantly lower in the IBU group than in the IND group. CONCLUSION: Although IBU was comparable to IND in PDA closure rate, IBU was superior to short-term renal injury in ELBWIs.

The extent of DNA methylation anticipation due to a genetic defect in ICR1 in Beckwith-Wiedemann syndrome.

Beckwith-Wiedemann syndrome (BWS) is a representative imprinting disorder. Gain of methylation at imprinting control region 1 (ICR1-GOM), leading to the biallelic expression of IGF2 and silencing of H19, is one of the causative alterations in BWS. Twenty percent of BWS patients with ICR1-GOM have genetic defects in ICR1. Evidence of methylation anticipation in familial BWS patients with ICR1 genetic defects has been reported. However, the precise methylation pattern and extent of anticipation in these patients remain elusive. In addition, although age-related IGF2-DMR0 hypomethylation has been reported in the normal population, the period of its occurrence is unknown. In this study, we analyzed 10 sites (IGF2-DMR0, IGF2-DMR2, CTCF binding sites 1-7, and the H19 promoter) within the IGF2/H19 domain in familial BWS patients harboring a pathogenic variant in ICR1. We found that sites near the variant had relatively higher methylation in the first affected generation and observed methylation anticipation through maternal transmission in the next generation. The extent of anticipation was greater at sites far from the variant than nearby sites. The extended and severe GOM might be due to the insufficient erasure/demethylation of pre-acquired ICR1-GOM in primordial germ cells or during the preimplantation stage. In the normal population, age-related IGF2-DMR0 hypomethylation occurred; it became established by young adulthood and continued to old age. Further studies are needed to clarify (1) the precise mechanism of anticipation in patients with familial BWS and (2) the mechanism and biological significance of constitutive hypomethylation of IGF2-DMR0 and/or other imprinted differentially methylated regions.

Marked thrombocytopenia in a neonate is associated with anti-HPA-5b, anti-HLA-A31, and anti-HLA-B55 antibodies.

Maternal antibodies against human platelet antigen (HPA) and/or human leukocyte antigen (HLA) cause fetal and neonatal alloimmune thrombocytopenia (FNAIT) in 0.09-0.15% of live births. Severe cases account for 5-31% and the frequency of multiple kinds of alloantibodies is 6.9-9% of FNAIT. We present a case of severe FNAIT associated with anti-HPA-5b, anti-HLA-A31, and anti-HLA-B55 antibodies, successfully treated with immunoglobulin and platelet transfusion. The anti-HLA-B55 antibody was detected in the newborn's serum, but disappeared on the 20th day, which was followed by an increase of the platelet count. These findings suggested the potential involvement of an anti-HLA antibody in the pathogenesis of FNAIT.

Association between the frequency of bedwetting and late preterm birth in children aged ≥5 years.

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.

Long-term renal tubular damage in intrauterine growth-restricted rats.

BACKGROUND: Intrauterine growth restriction (IUGR) has been shown to be associated with increased risk of renal disease or hypertension in later life. Glomerular dysfunction, however, has mainly been reported, and limited information is available to link IUGR with renal tubular damage. The aim of this study was therefore to investigate urinary markers of tubular damage in a rat model of IUGR induced by bilateral uterine artery ligation. METHODS: Pregnant Sprague-Dawley rats underwent bilateral uterine artery ligation, while the control group underwent sham surgery. RESULTS: Birthweight was reduced, and urinary ß2-microglobulin (ß2-MG)-, cystatin C (Cys-C)-, and calbindin-to-creatinine ratios were significantly higher at weeks 4 and 8 in the IUGR group compared with the control group. These urinary markers were not significantly different at week 16 between the two groups. Increased excretion of urinary ß2-MG, Cys-C, and calbindin was observed in IUGR rats at ≥8 weeks of age. CONCLUSION: Children born with IUGR are at increased risk for renal tubular damage.

Impaired nephrogenesis in neonatal rats with oxygen-induced retinopathy.

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-ß, 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.

Effect of PMX-DHP for sepsis due to ESBL-producing E. coli in an extremely low-birthweight infant.

We report a case of early onset sepsis caused by (CTX for cefotaximase and M for Munich)-type extended-spectrum ß-lactamase-producing Escherichia coli (ESBL E. coli) in a preterm infant weighing 601 g. He was given meropenem and treated for endotoxin absorption with polymyxin B-immobilized fibers with only 8 mL of priming volume. The patient survived without any short-term neurological or respiratory sequelae. The choice of antibiotics is particularly important in seriously ill neonates with sepsis due to ESBL-producing organisms. Polymyxin B hemoperfusion might be an innovative therapy for severe neonatal sepsis and could improve outcome even in an extremely low-birthweight infant.