Urinary extracellular vesicles signature for diagnosis of kidney disease

Congenital disorders characterized by the quantitative and qualitative reduction in the number of functional nephrons are the primary cause of chronic kidney disease (CKD) in children. We aimed to describe the alteration of urinary extracellular vesicles (uEVs) associated with decreased renal function during childhood. By nanoparticle tracking analysis and quantitative proteomics, we identified differentially expressed proteins in uEVs in bilateral renal hypoplasia, which is characterized by a congenitally reduced number of nephrons. This expression signature of uEVs reflected decreased renal function in CKD patients by congenital anomalies of the kidney and urinary tract or ciliopathy. As a proof-of-concept, we constructed a prototype ELISA system that enabled the isolation of uEVs and quantitation of expression of molecules representing the signature. The system identified decreased renal function even in its early stage. The uEVs signature could pave the way for non-invasive methods that can complement existing testing methods for diagnosing kidney diseases.

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Urinary extracellular vesicles (uEVs) are altered in chronic kidney disease (CKD)

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Characteristic expression signatures associated with childhood CKD are identified

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An ELISA utilizing the signature detected decreased renal function

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uEVs signature has potential in diagnosing kidney diseases

Evaluation of screening with urine dipsticks and renal ultrasonography for 3-year-olds in Chiba City over 30 years

BACKGROUND

Urinary screening for 3-year-olds cannot adequately detect congenital anomalies of the kidney and urinary tract (CAKUT).

METHODS

Urinary screening for 3-year-olds was investigated over 30 years. Dipsticks for proteinuria, hematuria, glycosuria, leukocyturia, and nitrite at first screening, and dipsticks, urinary sediments, and renal ultrasonography at second screening were performed. Screening results were evaluated.

RESULTS

The positive rates of proteinuria, hematuria, leukocyturia, and nitrite relative to 218,831 children at the first screening were 1.0%, 4.6%, 2.3%, and 0.88%, respectively. Thirty-seven glomerular disease, 122 CAKUT, and 5 urological disease cases were found. We detected 6 stage 3-4 chronic kidney disease (CKD) and 3 end-stage kidney disease cases, including 3 CAKUT, comprising 2 bilateral renal hypoplasia and 1 vesicoureteral reflux (VUR), and 6 glomerular diseases, comprising 4 focal segmental glomerulosclerosis and 2 Alport syndrome. The positive rates relative to 218,831 children and CKD detection rates for each tentative diagnosis of mild hematuria, severe hematuria, proteinuria and hematuria, proteinuria, and suspected urinary tract infection were 1.4% and 0.67%, 0.11% and 3.7%, 0.01% and 28.6%, 0.02% and 45.0%, and 0.08% and 9.7%, respectively. Among 14 VUR cases with significant bacteriuria, 13 were found by leukocyturia, 12 had grade ≥ IV VUR, and 10 had severe renal scars.

CONCLUSIONS

Nine stage 3-5 CKD cases comprising 3 CAKUT and 6 glomerular disease were found by urinary screening of 3-year-olds among 218,831 children. The combination of urine dipsticks including leukocyturia at the first screening and ultrasonography at the second screening appeared useful.

A case of 1-month-old female infant delaying peritoneal dialysis introduction by low-potassium anti-allergic formula treated with sodium polystyrene sulfonate

The 8806H formula is the only renal formula available for pediatric patients with chronic kidney disease in Japan. A 1-month-old female infant could not be administered 8806H because of milk allergy. Administration of low-potassium anti-allergic formula treated with sodium polystyrene sulfonate maintained adequate serum potassium levels, and introduction of peritoneal dialysis could be delayed. The patient had severe renal dysfunction secondary to bilateral hypoplastic and multi-cystic kidneys. Although she received the 8806H formula, this product was switched to hydrolyzed casein formula because she developed allergy to 8806H at 28 days of age, which led to hyperkalemia. We initiated treatment with sodium polystyrene sulfonate at 40 days of age to lower the potassium concentration in milk, which prevented hyperkalemia and maintained the patient's nutritional status to ensure appropriate increase in body weight. We monitored electrolyte levels in milk and confirmed reduction in potassium levels before feeding. Although such condition is rare and there are few reports of potassium reduction in anti-allergic formulas, this strategy may be useful for pediatric patients with renal insufficiency who cannot be treated with renal formulas because of milk allergy.

Laminin β2 variants associated with isolated nephropathy that impact matrix regulation

Mutations in LAMB2, encoding laminin β₂, cause Pierson syndrome and occasionally milder nephropathy without extrarenal abnormalities. The most deleterious missense mutations that have been identified affect primarily the N-terminus of laminin β₂. On the other hand, those associated with isolated nephropathy are distributed across the entire molecule, and variants in the β₂ LEa-LF-LEb domains are exclusively found in cases with isolated nephropathy. Here we report the clinical features of mild isolated nephropathy associated with 3 LAMB2 variants in the LEa-LF-LEb domains (p.R469Q, p.G699R, and p.R1078C) and their biochemical characterization. Although Pierson syndrome missense mutations often inhibit laminin β₂ secretion, the 3 recombinant variants were secreted as efficiently as WT. However, the β₂ variants lost pH dependency for heparin binding, resulting in aberrant binding under physiologic conditions. This suggests that the binding of laminin β₂ to negatively charged molecules is involved in glomerular basement membrane (GBM) permselectivity. Moreover, the excessive binding of the β₂ variants to other laminins appears to lead to their increased deposition in the GBM. Laminin β₂ also serves as a potentially novel cell-adhesive ligand for integrin α₄β₁. Our findings define biochemical functions of laminin β₂ variants influencing glomerular filtration that may underlie the pathogenesis of isolated nephropathy caused by LAMB2 abnormalities.

Valganciclovir prophylaxis for cytomegalovirus infection in pediatric kidney transplant recipients: a single-center experience

BACKGROUND

There are two approaches for treating cytomegalovirus (CMV) infection occurring after kidney transplantation (KTx). One is preemptive therapy in which treatment is started after confirming positive CMV antigenemia using periodic antigenemia assay. The other approach is prophylactic therapy in which oral valganciclovir (VGCV) is started within 10 days after KTx and continued for 200 days. The Transplantation Society guidelines recommend prophylactic therapy for high-risk (donor's CMV-IgG antibody positive and recipient's negative) pediatric recipients. However, the adequate dose and side effects of VGCV are not clear in children, and there is no sufficient information about prophylaxis for Japanese pediatric recipients.

METHODS

A single-center retrospective analysis was conducted on case series of high-risk pediatric patients who underwent KTx and received oral VGCV prophylaxis at the Department of Pediatric Nephrology, Tokyo Women's Medical University, between August 2018 and March 2019. Data were collected using medical records.

RESULTS

The dose of administration was 450 mg in all the study patients (n = 5). Reduction or discontinuation was required in four of five patients due to adverse events, which included neutropenia in one patient, anemia in two patients, and neutropenia and digestive symptoms in one patient. Late-onset CMV disease occurred in all patients. No seroconversion was observed during prophylaxis.

CONCLUSIONS

Our preliminary study suggests that the dosage endorsed by The Transplantation Society may be an overdose for Japanese pediatric recipients. Further studies are required to examine the safety and efficacy of VGCV prophylaxis in Japanese pediatric recipients.

Individualized concept for the treatment of autosomal recessive polycystic kidney disease with end-stage renal disease

Management of children with autosomal recessive polycystic kidney disease (ARPKD) who develop end-stage renal disease (ESRD) remains challenging because of concomitant liver disease. Patients with recurrent cholangitis are candidates for liver-kidney transplantation, while the treatment for patients with splenomegaly and pancytopenia due to portal hypertension is controversial. Herein, we report 7 children who were treated using an individualized treatment strategy stratified by liver disease. Two patients with recurrent cholangitis underwent sequential liver-kidney transplantation, while 4 patients with splenomegaly and pancytopenia but without recurrent cholangitis underwent splenectomy followed by isolated kidney transplantation. The remaining patient, who did not have cholangitis and pancytopenia, underwent isolated kidney transplantation. Blood cell counts were normalized after splenectomy was performed at the median age of 8.7 (range, 7.4-11.7) years. Kidney transplantation was performed at the median age of 8.8 (range, 1.9-14.7) years in all patients. Overwhelming post-splenectomy infections and cholangitis did not occur during the median follow-up period of 6.3 (range, 1.0-13.2) years. The estimated glomerular filtration rate at the last follow-up was 53 (range, 35-107) mL/min/1.73 m² . No graft loss occurred. Our individualized treatment strategy stratified by recurrent cholangitis and pancytopenia can be a feasible strategy for children with ARPKD who develop ESRD and warrants further evaluation.

Long-term outcome of renal transplantation in childhood-onset anti-neutrophil cytoplasmic antibody-associated vasculitis

BACKGROUND

There have been a few reports of RTx for AAV in children; however, post-transplant recurrence rate and long-term prognosis remain unclear. Here, we describe the long-term outcomes of RTx in childhood-onset AAV.

METHODS

We conducted a retrospective study of children who underwent RTx for AAV between 1999 and 2017 and had a follow-up period of >2 years.

RESULTS

Seven patients consisting of three children with MPA and four with RLV were analyzed. Age at Dx was 5.9 (median; range, 4.1-14.5) years. PD was instituted in all patients, and median time on dialysis was 26 (range, 14-63) months. Age at RTx was 12.8 (median; range, 8.7-16.3) years. There were no recurrences of AAV noted during the median follow-up period of 7.0 (range, 2.7-18.8) years after RTx. Graft loss occurred in one patient due to non-adherence. Estimated glomerular filtration rate of the remaining patients at the last follow-up was 73.0 (median; range, 50.7-93.9) mL/min/1.73 m² . No malignancies and deaths occurred during the observational period.

CONCLUSIONS

Our study suggests that RTx for AAV with ESRD is a potentially safe and effective treatment choice for children with AAV.

Persistent Primary Cytomegalovirus Infection After Deceased Donor Kidney Transplant: Ganciclovir Susceptibility of Human Cytomegalovirus With UL97 D605E Mutation: A Case Report

BACKGROUND

Cytomegalovirus (CMV) could cause rejection in immunocompromised patients during early post-renal transplant stage. The American Transplant Society guidelines recommend prophylactic therapy with ganciclovir (GCV) for 3 to 6 months to prevent CMV infections in adult renal transplant patients. However, there is no recommended CMV treatment regimen for pediatric patients.

MAIN FINDINGS

We performed deceased donor kidney transplant from an anti-CMV antibody-positive donor to an anti-CMV antibody-negative 15-year-old female recipient with end-stage renal disease caused by bilateral renal hypoplasia. One month after transplant, increase in positive cells in the CMV antigenemia assay indicated a primary CMV infection in the patient, who immediately received GCV. She was switched to foscarnet after 4 months of anti-CMV therapy because of clinical GCV resistance. CMV was isolated from the peripheral blood mononuclear cells but neutralizing antibody was not detected. Isolated CMV was susceptible to GCV and foscarnet, although it carried the UL97 D605E mutation, assumed to be associated with GCV resistance.

CONCLUSIONS

The primary CMV infection presented a phenotypic clinical drug resistance, but all recovered CMV isolates were drug-susceptible even if isolated after prolonged anti-CMV therapy, indicating that immune status was more important for recovery from primary CMV infection than anti-CMV therapy.

Predominant but silent C1q deposits in mesangium on transplanted kidneys - long-term observational study

Background

C1q nephropathy (C1qN) was first described as glomerular disease characterized by predominant meangial C1q deposits in patients with proteinuria and no evidence of systemic lupus erythematosus. Several studies, however, revealed the clinical heterogeneity of C1qN, showing some cases with normal urinalysis. To confirm the existence of cases with predominant mesangial C1q deposits and negative or mild proteinuria and/or hematuria, we investigated renal graft biopsy specimens showing negative to mild proteinuria (less than or equal to 1+ by dip stick test) and/or hematuria.

Methods

Eligible participants were kidney transplant cases who corresponded to the criteria for C1qN and were followed more than 10 years. Their medical records were reviewed to determine the age at detection of predominant mesangial C1q deposits, gender, original renal disease and reason for renal graft biopsy, blood pressure, degree of proteinuria and hematuria, and serum creatinine levels.

Results

From 414 cases in adults and children, five pediatric patients (the male to female ratio, 1:1.5) were eligible. At the time when predominant mesangial C1q deposits were detected, 2 cases presented with mild proteinuria without hematuria, but the other 3 cases showed normal urinalysis. Light microscopy revealed minor glomerular abnormality in all the cases. Immunofluorescent study showed predominant mesangial C1q deposits with IgG, IgM and C3 in all cases. All selected specimens presented electron dense-depos in the mesangium. Ten years later from the detection, 2 cases continued to be normal urinalysis and 3 cases had mild proteinuria without hematuria. During this follow-up period, no cases presented with persistent proteinuria and/or hematuria greater than or equal to 2+ by dip stick test. And no cases developed systemic lupus erythematosus. Follow-up renal graft biopsies were performed once in 2 cases 8 years later from the detection. They showed minor glomerular abnormalities. C1q deposit disappeared in one case. In another case, immunofluorescent study was not examined.

Conclusions

This long-term observational study on transplanted kidneys confirms the existence of cases with predominant but silent C1q deposits in the mesangium who have negative or mild proteinuria.

Electronic supplementary material

The online version of this article (10.1186/s12882-018-0874-9) contains supplementary material, which is available to authorized users.

Lower urinary tract symptoms in children and adolescents with Williams-Beuren syndrome

INTRODUCTION

Williams-Beuren syndrome (WBS) is a genetic condition caused by a microscopic deletion in the chromosome band 7q11.23. Individuals with WBS may present with congenital cardiovascular defects, neurodevelopmental disturbances and structural abnormalities of the urinary tract. Lower urinary tract symptoms (LUTS) seem to be frequent in this population, but studies on this topic are scarce and based on small case series.

OBJECTIVE

To systematically evaluate the prevalence of lower urinary tract symptoms (LUTS) and the acquisition of bladder control in a large population with WBS.

STUDY DESIGN

A cross-sectional study evaluating 87 consecutive patients with WBS; there were 41 girls and 46 boys. Genetic studies confirmed WBS in all patients. Subjects were clinically evaluated with: a history of LUTS obtained from the parents and child, a structured questionnaire of LUTS, a 3-day urinary frequency-volume chart, a quality of life question regarding LUTS, and physical examination. A history regarding the acquisition of bladder control was directly evaluated from the parents.

RESULTS

Mean age of patients was 9.0 ± 4.2 years, ranging from 3 to 19 years. Based on the symptoms questionnaire and the frequency-volume chart, 70 patients (80.5%) were symptomatic. The most common symptom was urgency, affecting 61 (70.1%) patients, followed by increased urinary frequency in 60 (68.9%) patients, and urge-incontinence in 53 (60.9%), as shown in Summary Fig. More than half of the children reported nocturnal enuresis, including 61% of the girls and 52% of the boys. Twenty-three patients (25.6%) had a history of urinary tract infections. The mean age for acquisition of dryness during the day was 4.4 ± 1.9 years. Parents of 61 patients (70.1%) acknowledged that LUTS had a significant impact on the quality of life of their children.

DISCUSSION

A high prevalence of LUTS was confirmed with a significant negative impact on quality of life in a large population of children and adolescents with WBS. It was shown for the first time that the achievement of daytime bladder control is delayed in children with WBS. Although LUTS are not recognized as one of the leading features of the syndrome, it is believed that it should be considered as a significant characteristic of the clinical diagnosis of WBS.

CONCLUSIONS

LUTS are highly prevalent in children and adolescents with WBS and have a significant negative impact on patient's quality of life.

Molecular genetic analysis of 30 families with Joubert syndrome

Joubert syndrome (JS) is rare recessive disorders characterized by the combination of hypoplasia/aplasia of the cerebellar vermis, thickened and elongated superior cerebellar peduncles, and a deep interpeduncular fossa which is defined by neuroimaging and is termed the 'molar tooth sign'. JS is genetically highly heterogeneous, with at least 29 disease genes being involved. To further understand the genetic causes of JS, we performed whole-exome sequencing in 24 newly recruited JS families. Together with six previously reported families, we identified causative mutations in 25 out of 30 (24 + 6) families (83.3%). We identified eight mutated genes in 27 (21 + 6) Japanese families, TMEM67 (7/27, 25.9%) and CEP290 (6/27, 22.2%) were the most commonly mutated. Interestingly, 9 of 12 CEP290 disease alleles were c.6012-12T>A (75.0%), an allele that has not been reported in non-Japanese populations. Therefore c.6012-12T>A is a common allele in the Japanese population. Importantly, one Japanese and one Omani families carried compound biallelic mutations in two distinct genes (TMEM67/RPGRIP1L and TMEM138/BBS1, respectively). BBS1 is the causative gene in Bardet-Biedl syndrome. These concomitant mutations led to severe and/or complex clinical features in the patients, suggesting combined effects of different mutant genes.

Autoimmune-type atypical hemolytic uremic syndrome treated with eculizumab as first-line therapy

We report a case of atypical hemolytic uremic syndrome (aHUS) in a 4-year-old boy. Although the patient had the typical triad of aHUS (microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury), urgent dialysis was not indicated because he had neither oliguria nor severe electrolyte abnormality. He was given eculizumab as first-line therapy, which led to significant clinical improvement, thus avoiding any risk of complications associated with plasma exchange and central venous catheterization. Retrograde functional analysis of the patient's plasma using sheep erythrocytes indicated an increase in hemolysis, suggesting impairment of host cell protection by complement factor H. The use of eculizumab as first-line therapy in place of plasma exchange might be reasonable for pediatric patients with aHUS.

Mutational analyses of the ATP6V1B1 and ATP6V0A4 genes in patients with primary distal renal tubular acidosis

BACKGROUND

Mutations in the ATP6V1B1 and the ATP6V0A4 genes cause primary autosomal-recessive distal renal tubular acidosis (dRTA). Large deletions of either gene in patients with dRTA have not been described.

METHODS

The ATP6V1B1 and ATP6V0A4 genes were directly sequenced in 11 Japanese patients with primary dRTA from nine unrelated kindreds. Large heterozygous deletions were analyzed by quantitative real-time polymerase chain reaction (PCR). The clinical features of the 11 patients were also investigated.

RESULTS

Novel mutations in the ATP6V1B1 gene were identified in two kindreds, including frameshift, in-frame insertion and nonsense mutations. Large deletions in the ATP6V0A4 gene were identified in two kindreds. Exon 15 of ATP6V0A4 was not amplified in one patient, with a long PCR confirming compound heterozygous deletions of 3.7- and 6.9-kb nucleotides, including all of exon 15. Direct DNA sequencing revealed a heterozygous frameshift mutation in ATP6V0A4 in another patient, with quantitative real-time PCR indicating that all exons up to exon 8 were deleted in one allele. Clinical investigation showed that four of the six patients with available clinical data presented with hyperammonemia at onset.

CONCLUSIONS

To our knowledge, these dRTA patients are the first to show large deletions involving one or more entire exons of the ATP6V0A4 gene. Quantitative PCR amplification may be useful in detecting heterozygous large deletions. These results expand the spectrum of mutations in the ATP6V0A4 and ATP6V1B1 genes associated with primary dRTA and provide insight into possible structure-function relationships.

Pretransplantation combined therapy with plasmapheresis and rituximab in a second living-related kidney transplant pediatric recipient with a very high risk for focal segmental glomerulosclerosis recurrence

Prophylactic PP can provide some protection against post-transplantation recurrences of FSGS, but it cannot prevent recurrences in all cases. Therefore, new preventive therapies are needed. We report on a 7.9-yr-old girl treated with pretransplantation prophylactic combined therapy consisting of four sessions of PP and one dose of rituximab before a second living-related KTX. The patient had a very high risk of post-transplantation FSGS recurrence because this had occurred after the first KTX. During the 36 months since the second transplantation, she has had no evidence of proteinuria or significant infectious complications. Although our experience is too preliminary to draw any generalizable conclusions, pretransplantation combined therapy with PP and rituximab might be a possible option for the prevention of FSGS recurrence in very high-risk recipients undergoing living-donor KTXs.

Darbepoetin alfa for the treatment of anemia in children undergoing peritoneal dialysis: a multicenter prospective study in Japan

BACKGROUND

Darbepoetin alfa (DA) is an attractive alternative to recombinant human erythropoietin (rHuEPO) in managing renal anemia. Since DA has not been approved by the appropriate Japanese drug regulatory agencies for the indication of renal anemia in children in Japan, we have conducted a multicenter prospective study to determine the efficacy and safety of DA in Japanese children undergoing peritoneal dialysis (PD).

METHODS

Pediatric patients subcutaneously receiving rHuEPO were switched to DA treatment for a period of 28 weeks. The conversion to the initial dose of DA was calculated as 1 μg DA for 200 IU rHuEPO, and DA was administered intravenously once every 2 weeks. The target hemoglobin (Hb) concentration was defined as 11.0 to ≤13.0 g/dL. In some patients, the dose of DA was adjusted appropriately to achieve this target level, and/or the dosing frequency changed to once every 4 weeks.

RESULTS

In the 25 patients switched from rHuEPO to DA the mean Hb concentration increased from 9.9 ± 1.0 to 11.1 ± 1.0 g/dL at 8 weeks following commencement of the DA treatment. The target Hb concentration was achieved in 88 % of these patients, and 60 % maintained this target value on completion of the study. The dosing frequency was extended to once every 4 weeks in 60 % of patients. Twenty-four adverse events were noted in 11 of 25 patients (44 %); however, there was no causality between DA and adverse events.

CONCLUSIONS

The results of this study suggest that intravenous administration of DA once every 2 or 4 weeks is an effective and safe treatment for renal anemia in Japanese children undergoing PD.

V2 vasopressin receptor (V2R) mutations in partial nephrogenic diabetes insipidus highlight protean agonism of V2R antagonists

Inactivating mutations of the V2 vasopressin receptor (V2R) cause cross-linked congenital nephrogenic diabetes insipidus (NDI), resulting in renal resistance to the antidiuretic hormone AVP. In two families showing partial NDI, characterized by an apparently normal response to diagnostic tests and an increase in the basal ADH levels suggesting AVP resistance, we have identified two V2R mutations, Ser-333del and Y128S. Both mutant V2Rs, when expressed in COS-7 cells, show partial defects in vasopressin-stimulated cAMP accumulation and intracellular localization. The inhibition of internalization does not rescue their localization. In contrast, the non-peptide V2R antagonists OPC41061 and OPC31260 partially rescue the membrane localization and basal function of these V2R mutants, whereas they inhibit the basal activity of the wild-type V2R. These results indicate that a partial loss of function of Ser-333del and Y128S mutant V2Rs results from defective membrane trafficking. These findings further indicate that V2R antagonists can act as protean agonists, serving as pharmacological chaperones for inactivating V2R mutants and also as inverse agonists of wild-type receptors. We speculate that this protean agonism could underlie the possible dual beneficial effects of the V2R antagonist: improvement of hyponatremia with heart failure or polycystic kidney disease and potential rescue of NDI.

Asymptomatic high Epstein-Barr viral load carriage in pediatric renal transplant recipients

High viral load carriage of EBV is one of the risks for PTLD in transplant recipients. We reviewed retrospectively in pediatric renal transplant recipients with EBV seronegative. EBV loads in peripheral blood and EBV-CTLs were measured every 1-3 months in 13 patients after grafting. Immunosuppressants were reduced when the patients were considered to have persistent high EBV loads (>1000 copies/μgDNA for over six months). All showed primary EBV infection: six with asymptomatic persistent high EBV loads (group A) and seven with neither EBV-associated symptoms nor persistent high EBV loads (group B). No patient developed PTLD in either group. Chronic rejection occurred in one patient in group A after immunosuppressants' reduction. There was no difference in renal dysfunction rates between the two groups. The maximum and increase rates in EBV loads were significantly higher in group A. The CTLs' percentage was significantly lower in group A when EBV loads first rose above 100 copies/μg DNA. This study suggests the possibility that EBV loads and CTLs' monitoring may be useful for avoidance of PTLD, as patients with asymptomatic persistent high EBV loads had higher EBV loads and lower percentages of CTLs.

Vitamin B6 deficiency and anemia in pregnancy

Iron deficiency is the most common cause of anemia in pregnancy. Pregnant women with anemia are, in general, exclusively treated with iron supplementation. We observed that several pregnant women with anemia who were nonresponsive to iron supplementation also had vitamin B6 deficiency, and that anemia in these cases improved with the administration of vitamin B6. Our prospective study in healthy pregnant women showed that blood levels of iron, ferritin and vitamin B6, in particular, fell to the lower limit of the nonpregnant reference range by the third trimester. We conclude that it is important to take into account the deficiency of vitamin B6 besides iron in the evaluation of anemia during pregnancy.

Pharmacokinetic study of mizoribine in child-onset glomerulonephritis

BACKGROUND

Mizoribine (MZR) has been successfully used without serious adverse effects in patients with various types of glomerulonephritis, but there are only a few pharmacokinetic studies of MZR. The purpose of the present paper was to report the results of a pharmacokinetic study of MZR in child-onset glomerulonephritis.

METHODS

Nine patients were enrolled. MZR was administered orally at 60-300 mg/day (3.0-8.4 mg/kg bodyweight/day) divided in one or two daily doses. Blood samples were collected 7-10 times before and after drug administration. Urine samples were also collected during the blood sampling periods. Twenty-three concentration curves of MZR were analyzed in the present study. Pharmacokinetic parameters for mizoribine were estimated using concentration-time profiles. The non-parametric Spearman correlation coefficient was calculated to determine significant associations between variables. P < 0.05 was considered significant.

RESULTS

The obtained pharmacokinetic values at a dose of 3.36 +/- 1.91 mg/kg bodyweight were as follows: time to peak serum MZR concentration, 2.94 +/- 0.82 h; peak serum MZR concentration, 1.59 +/- 1.16 microg/mL; half-life, 1.96 +/- 0.92 h; area under the serum MZR concentration-time curve from time zero to infinity, 9.36 +/- 6.58 microg h/mL; volume of the distribution of MZR at a steady state, 2.03 +/- 0.80 L/kg; and rate of urinary excretion of MZR, 49.1 +/- 18.7%.

CONCLUSIONS

The parameters estimated in the present study may be useful for the MZR treatment of patients with child-onset glomerulonephritis.

Monitoring of Epstein-Barr virus load and antibody in pediatric renal transplant patients

BACKGROUND

Epstein-Barr virus (EBV) infection can lead to life-threatening post-transplant lymphoproliferative disorder (PTLD). The aim of the present study was to establish EBV monitoring methods to prevent PTLD.

METHODS

EBV-DNA load was investigated, using real-time polymerase chain reaction (PCR) and anti-EBV antibody titers, in peripheral blood mononuclear cells of 21 renal transplant patients (seven recipients who were EBV-seronegative, R[-]; 14 who were EBV-seropositive, R[+]) before grafting. The mean age at entry and the mean follow-up period was 7.8 years of age (range, 3.3-12.0 years) and 1.8 years (range, 0.4-4.0 years), respectively, in the R(-) group, and 12.5 years of age (range, 3.9-17.7 years) and 3.8 years (range, 0.8-8.2 years) in the R(+) group, respectively.

RESULTS

The mean maximum load of the EBV genome was 1071 copies/microg DNA (range, 106-20700 copies/microg DNA) in the R(-) group, and 61 copies/microg DNA (range, <50-552 copies/microg DNA) in the R(+) group. During follow up no patient in the R(+) group had any noticeable symptoms that could be related to EBV, but three recipients in the R(-) group developed EBV-related symptoms including adenoid hypertrophy, cervical lymphadenopathy, and PTLD (B cell lymphoma), in one patient each. In the R(-) group the first leukocyte-associated viremia was detected at 30-180 days, and seroconversion at 43-266 days after transplantation.

CONCLUSIONS

Viral DNA detection using PCR is a useful tool for EBV surveillance, but the maximum EBV load was not markedly elevated (2474 copies/microg DNA) in a patient with PTLD. Therefore, EBV surveillance using only monitoring of EBV load in peripheral leukocyte may be insufficient. Histology may therefore be necessary to accurately diagnose PTLD.

Clinical features and mutational survey of NPHS2 (podocin) in Japanese children with focal segmental glomerulosclerosis who underwent renal transplantation

Recurrent FSGS is a major challenge in the field of nephrology. To clarify the role of NPHS2 defects in the pathogenesis of FSGS recurrence, we sequenced all eight exons of NPHS2 in 11 Japanese pediatric FSGS patients with or without post-transplant recurrence. All patients had biopsy-proven primary FSGS, had no family history of renal diseases or consanguinity, were steroid-resistant, and received living-related renal transplantation. The mean age at onset was 5.0 +/- 3.1 yr and mean age at renal transplantation was 10.4 +/- 4.1 yr. Mutational analysis of NPHS2 was performed using polymerase chain reaction and direct sequencing. We found a synonymous T/C polymorphism at alanine 318 (GCC to GCT) in seven of 11 patients but no other causative NPHS2 mutations. FSGS recurred immediately after transplant in seven patients, while the remaining four patients had no recurrence for 3.2-5.8 yr. There were no differences between recurrent and non-recurrent patients in the onset age and the interval from onset to ESRD. In conclusion, we detected no causative NPHS2 mutations in Japanese pediatric FSGS patients with or without post-transplant recurrence. Further studies on the involvement of other genes are required to better understand recurrent FSGS.

Nonsurgical correction of skeletal Class III malocclusion with lateral shift in an adult

In an adult patient with a severe skeletal Class III malocclusion with midline deviation, combined surgical-orthodontic therapy is often the treatment of choice because it has a satisfying outcome, and the results tend to be stable. Sometimes, however, patients will not accept surgery as a part of the treatment. We report a nonsurgical treatment approach and its outcomes for an adult patient with a skeletal Class III malocclusion with a lateral shift. Treatment included distal movement of the mandibular arch and extraction of the third molars.

Patterns of dental crowding in the lower arch and contributing factors. A statistical study

OBJECTIVE

To investigate the patterns of dental crowding in the lower arch and their contributing morphological and functional factors.

MATERIALS AND METHODS

Pretreatment diagnostic materials from 168 patients exhibiting dental crowding were selected, and the patients, dental casts, lateral cephalograms, and occlusal forces were evaluated. The crowding in the lower dental arch was quantified and the patterns of crowding were identified. Crowding patterns in the anterior region were classified by cluster analysis. The relationship between the crowding patterns and morphological and functional factors was investigated by correspondence analysis.

RESULTS

The prevalence of dental crowding was highest in the anterior region and was related to the same tooth on each side (eg, right lateral incisor vs left lateral incisor). In the premolar and molar region, the prevalence of dental crowding was related to the adjacent tooth (eg, right first premolar vs second premolar). Three crowding patterns were found in the anterior region: (1) a "symmetry pattern," (2) a "rotation pattern," and (3) an "irregular pattern." The first pattern was related to the factors of discrepancy, whereas the latter two patterns were related to functional factors such as occlusal force and its center of gravity.

CONCLUSIONS

These results suggest that crowding patterns can be useful information for treatment planning and achieving dental stability.

Functional relationships between the masseter and sternocleidomastoid muscle activities during gum chewing:

The purpose of this study was to investigate the functional relationship between masseter muscle (MM) and sternocleidomastoid muscle (SCM) activities and between mandibular and head movements during mastication, under experimental muscle fatigue. The sample consisted of 12 adults with individually normal occlusion. The subjects were asked to chew gum at three different times: before maximum clenching, immediately after maximum clenching, and 3 minutes after maximum clenching. At these times, we examined the activity of the MM and SCM as well as the movement of the mandible and head. The activity and movement were simultaneously measured using both electromyography and the motion capture system. The MM activity time after clenching was significantly shorter than that before clenching, whereas the SCM activity time was significantly longer after clenching. There was no significant difference in the changes of three-dimensional distance of the mandibular movement between the respective times. On the other hand, the changes in the three-dimensional distance of head movement after clenching increased when compared with before clenching. Furthermore, the difference in the time of MM and SCM activity onset and of mandibular and head movement onset after clenching was shorter than that before clenching. A functional relationship exists between the MM and SCM activities and between mandibular and head movements during mastication.

Vertical control by combining a monoblock appliance in adult class III overclosure treatment

Monoblock appliances were used in combination with intermaxillary elastics for treatment of adult skeletal Class III patients. The patients showed predisposing upper incisors problems, significant mobility in patient 1 and root resorption in patient 2, which contraindicated direct intrusion of the incisors. Using the monoblock with selective extrusion of the molars, a clockwise rotation was induced to reduce overbite and to achieve a better profile. It was also possible to reduce the excessive force to the upper incisors during and after treatment, which improved incisor mobility to a physiologic extent (patient 1) and prevented further progression of root resorption (patient 2). Stability was high after the 2-year follow-up, which suggests a stable vertical control approach by using the monoblock appliance in combination with a fixed appliance in adults.

Temporomandibular joint internal derangement in mandibular asymmetry. What is the relationship?

The purpose of this study was to clarify the contributing factors and their influences on temporomandibular joint internal derangement (TMJ ID) symptoms in subjects with mandibular asymmetry. Postero-anterior (PA) cephalograms of 187 pre-orthodontic treatment subjects (aged 18-45 years, mean 23.9 years) were used to investigate the inclination of the frontal occlusal (FOP) and frontal mandibular (FMP) planes to determine vertical asymmetry. Mandibular dental midline shift (DMS) and mandibular midline shift (MMS) were studied to determine transverse asymmetry. The degree of asymmetry was analysed in conjunction with the results from self-administered TMJ ID history forms. A prevalence of TMJ ID was most related to the inclination of the FMP (P < 0.01), with the symptoms being notably higher when the cant was greater than 3 degrees. The symptomatic side was related only to the inclination of the FOP and FMP. Symptoms confined to the ipsilateral side were primarily found in subjects with mild asymmetry, whereas symptoms on both sides and those on the contralateral side were greater in those with moderate and severe asymmetry, respectively. No significant correlation was found for DMS and MMS. The results suggest that the degree of asymmetry in the vertical dimension is significantly correlated with TMJ ID symptoms.

Effect of biomechanical disturbance of the temporomandibular joint on the prevalence of internal derangement in mandibular asymmetry

The aim of the present study was to elucidate the relationship between biomechanical changes of the temporomandibular joint (TMJ) and internal derangement (ID) symptoms in mandibular asymmetry. Posteroanterior cephalograms (PA) of 140 patients with TMJ ID associated with mandibular asymmetry were used to investigate the inclination of the frontal occlusal plane (FOP), and were analysed in conjunction with the results of a report providing information on ID symptoms. A three-dimensional (3D) finite element model (FEM) of the entire mandible was created to investigate the distribution of TMJ forces during clenching. The inclination of the FOP was modified to simulate various degrees of vertical asymmetry. The stresses on the TMJ on the ipsilateral and contralateral sides were analysed and their values were compared with those of the standard model. The results showed that the symptomatic sides were significantly related to the degree of inclination of the FOP. Increasing its angulation resulted in a decrease of the symptoms on the ipsilateral side and an increase of those on the contralateral side. The analysis showed that stress-distribution patterns and overall stresses of the articular disc were influenced by the angulation of inclination of the FOP. These mechanical changes exhibited a distinct relationship with the prevalence of ID in the patients. These results suggest that disturbances in the stresses either in amount or direction due to occlusal inclination can be responsible for ID. Therefore, an attempt to establish a flat occlusal plane is an important orthodontic treatment objective in maintaining the normal health and structure of the TMJ.

Urinary leukotriene E4 in Henoch-Schonlein purpura

BACKGROUND

Children with Henoch-Schonlein purpura (HSP) occasionally have allergic disease. We have previously shown that pranlukast hydrate was effective for purpura in HSP. Pranlukast hydrate is a leukotriene (LT) receptor antagonist; therefore, it is likely that LTs take part in the cause of HSP. Urinary leukotriene E4 (LTE4u) levels are a useful index of whole-body cysteinyl LT production in vivo. In this study, LTE4u was examined in children with HSP.

OBJECTIVE

The purpose of this study was to examine the relation between the level of LTE4u and the cause of HSP.

METHODS

Eighteen HSP children (six boys and 12 girls) and six healthy children were enrolled.

RESULTS

LTE4u levels in patients with HSP were significantly higher (P< 0.05) at the onset than those in healthy children. Four weeks therapy with pranlukast hydrate lowers LTE4u levels in patients with HSP (P< 0.05). There were no differences in LTE4u between the group of HSP patients with purpura nephritis and the group of HSP patients without purpura nephritis.

CONCLUSION

These results indicate that csyteinyl LTs may play a role in the pathophysiology of purpura in HSP.

Articular disc displacement in mandibular asymmetry patients

Mechanisms of disc displacement in temporomandibular joint (TMJ) internal derangement (ID) in mandibular asymmetry have not been clearly defined. This study examines the degree and direction of disc displacement and their relationship with vertical asymmetry in terms of both clinical and biomechanical aspects. A retrospective study of disc displacement was performed in 31 mandibular asymmetry patients using MR imaging. The degree and direction of disc displacements on the shifted side and contralateral side TMJ were investigated with the degree of vertical asymmetry. Furthermore, three-dimensional finite element models of entire mandible include TMJ and maxillary teeth in occlusion were created to simulate displacement of the articular disc during clenching condition. The direction of displacement on the shifted side and contralateral side were significantly different. Articular disc has tendencies to displace more on the shifted side even in mild degree of vertical asymmetry. The degree of displacement was correlated with the amount of asymmetry. The MR results were consistent with the tendencies of disc displacement predicted from the finite element models. We suggest that disturbance in the direction of stress distribution through asymmetry of the mandible is one of the mechanisms related to disc displacement.

Dynamic analysis for clarifying occlusal force transmission during orthodontic archwire application: difference between ISW and stainless steel wire

The purpose of our study was to utilize the dynamic finite element analysis to clarify the difference between Improved Super-elastic Ti-Ni alloy Wire (ISW) and Stainless Steel Wire (SSW) on occlusal force transmission during orthodontic treatment. ABAQUS/Standard was used to analyze three finite models over a 30-ms period: ISW, SSW, and wireless models; which consisting of premolar, molar, periodontal ligament (PDL), and alveolar bone. Wire model was established by beam element. A Joint C, which exhibits viscoelasticity to buffer occlusal force, was applied between the wire and bracket. The load was applied on the occlusal surface. At load withdrawal point, the average amounts of von Mises stress on PDL in three models were of the same value. However as time progressed, the stress in wireless model became higher than ISW and SSW models. In contrast, as time progressed further, the stress in SSW model became higher than the other two models and maintained its higher level until the end of analysis. Results showed that high damping capacity of ISW had an ability to buffer the transmission of occlusal force to the PDL. Besides, the dynamic analysis demonstrated an advantage to investigate the stress alterative response between models versus time period.

The interrelationship between bolus breakdown, mandibular first molar displacement and jaw movement during mastication

The purpose of this study was to clarify the interrelationship between food bolus breakdown, mandibular first molar displacement and jaw movement during mastication. Finite element models were constructed of the maxillary first molar crown, the mandibular first molar consisting of crown, root, periodontal ligament and alveolar bone, as well as the food bolus were constructed. Based on the actual measurement of the jaw movement pattern and the characteristics of food bolus, the patterns of mandibular first molar displacement and bolus breakdown on time course in the progress of mastication were simulated, to investigate the biomechanical significance of tooth displacement and jaw movement during mastication, using finite element non-linear dynamic analysis. The results showed that the patterns of tooth displacement and jaw movement and characteristics of food bolus changed with an interrelationship to each other as mastication progressed. Particularly at the initial phase, it was suggested that the patterns of mandibular first molar displacement and jaw movement worked inter-dependently to accomplish an efficient hard-bolus breakdown.

Investigation of cervical muscle mechanisms during jaw movement--using a prototype head-jaw-neck model--

To explain the pain and dysfunction of neck during jaw movement associated with malocclusion, the physiologic relationships between jaw and cervical movement should be understood. However the complicated reflex effects made it difficult to investigate the biomechanical relationship between the head-neck components. For this reason we have created a model for mechanical system dynamic analysis of the normal stomatognathic system to assess the biomechanics of the cervical movement and muscle activity during jaw movement. We have also statistically validated the model and quantitatively verified the model to the human subject by the amounts and conditions of cervical muscle activity. During jaw opening-closing phases the movement of the model was highly correlated to the subject with an identical movement. However low consistency was achieved during intercuspid phase. These findings indicate the establishment of a valid system, which can be used to evaluate the biomechanical relationships between jaw and cervical movement. Moreover the model verification of cervical muscle activity indicate the mechanical action of jaw can be the primary factor to modify cervical muscles, and cervical muscles coordinate to resist changes in head balance during jaw movement to maintains head posture.

Temporary tongue thrust: failure during orthodontic treatment

This report presents the case of a 25-year-old male patient who sought orthodontic treatment. Oral examination revealed an Angle Class I relation, with a bimaxillary dento-alveolar protrusion, evidence of anterior crowding, and a large overbite and overjet. Radiographic examination revealed a skeletal Class I occlusion. During the distal movement of the canines, occlusal interferences between the canines occurred and the commencement of a tongue thrust was observed. After correction of the applied forces, the canine movement was completed and the habit was no longer detectable. The incident indicates that an unusual oral habit suspiciously occurring during treatment should lead to an immediate reconsideration of the orthodontic treatment strategy.

Relationship between the flow of bolus and occlusal condition during mastication--computer simulation based on the measurement of characteristics of the bolus

The purpose of the present study was to clarify the relationship between the flow of a bolus and occlusal condition during mastication. First, the characteristics of a bolus under mastication was measured in subjects having different occlusal conditions. Secondly, the flow of a bolus between the upper and lower first molars under mastication was simulated using finite element non-linear dynamic analysis. Measurement of the elasticity of the bolus clarified the phenomenon of its communition. The measurement of the viscosity of the bolus clarified the phenomenon of its mixing with saliva. In addition, a relationship between the elasticity and the viscosity of the bolus at the point of just before swallowing was investigated. The flow of the bolus under mastication was revealed to vary according to the occlusal condition. These results suggest a close relationship between the occlusal condition, the flow of the bolus and its characteristics.

Head movements in the occlusal phase of mastication

It has been recognized that mandibular movements evoke head movements during jaw tapping. However there have been only a few studies that investigated the aspects of head movements during mastication. The objective of this study was to demonstrate the hypothesis that the head moves actively in mastication in order to achieve effective destruction of a food bolus. Head and mandibular movements during gum, gummi candies and kelp chewing among nine adult volunteers have been recorded as time series data with a three-dimensional motion capture system and the vertical components of the movements have been analyzed. To focus on occlusal phase of mastication, the following parameters have been examined: time lag of the head movements at the beginning of occlusal phase, perpendicular velocity of the head at the beginning of the phase of occlusion, and average velocity of the head during occlusal phase. The results showed that the head moved downward in mastication and the velocity of the head movements increased in the order of gum, gummi candies and kelp chewing. There is a possibility that the elasticity of a food bolus affects the activity of head movements, and the kinetic energy was increased to achieve effective destruction of a food bolus.

Immunomodulatory effect of gold sodium thiomalate on murine acquired immunodeficiency syndrome

Induction of IL-2 production and increased expression of CD25 were observed in C57BL/10 mice after weekly treatment with gold sodium thiomalate (GST). LP-BM5 murine leukemia virus (MuLV) infected mice treated with GST survived longer, had less cervical lymph node swelling, lower spleen weight, and fewer abnormalities in the expression of the cell surface markers, CD4, CD8a and CD45R/B220 on spleen cells than those that were not treated with GST. Thus, GST treatment may be beneficial through a decrease in disease progression via IL-2 induction in MuLV infected mice. This may have application in human immunodeficiency virus-infected individuals.

Tyrosine phosphorylation of the linker for activator of T cells in mast cells by stimulation with the high affinity IgE receptor

Aggregation of the high affinity IgE receptors (FcepsilonRI) on basophils and mast cells, members of the immune receptor family, initiates a cascade of events that results in the release of inflammatory mediators. This pathway involves the activation of several protein-tyrosine kinases, including Lyn, Syk, Btk, and Fak that induce the tyrosine phosphorylation of various proteins. The linker for activation of T cells (LAT), was originally found as a ZAP-70 tyrosine kinase substrate that linked T cell receptors to cellular activation, and was expressed in T cells, NK cells and mast cells. Here we show that LAT expressed in the RBL-2H3 rat mast cell line is tyrosine-phosphorylated after aggregation of FcepsilonRI. The tyrosine phosphorylation of the LAT was dramatically enhanced after receptor aggregation. Furthermore, a tyrosine-phosphorylated 80-kDa protein associated with LAT transiently after receptor aggregation. GST fusion proteins containing parts of PLCgamma or PI3 kinase can bind LAT. These results suggest that LAT plays an important role not only in T cell, but also in mast cell activation, and that the association among these signaling molecules is critical for FcepsilonRI-mediated intracellular signal transduction in mast cells.

The inhibitory effect of anti-allergic agent suplatast tosilate (IPD-1151T) on methacholine- and allergen-induced bronchoconstriction in sensitized mice. asakazu@med.showa-u.dc.jp

The influence of an anti-allergic agent, suplatast tosilate (IPD-1151T; (+/-)-[2-[4-(3-ethoxy-2-hydroxypropoxy)phenyl-carbamoyl]-ethyl] dimethylsulfonium p-toluenesulfonate) on allergic bronchoconstriction induced by allergen and methacholine (MCh) were examined in mice. BALB/c mice were sensitized by intraperitoneal injection of dinitrophenylated-keyhole limpet hemocyanin (DNP-KLH) mixed with A1(OH)3 (DNP-KLH). IPD-1151T was administered orally once a day for either 5 or 14 days in doses of 10, 30 or 100 mg/kg. Bronchoconstriction was measured 24h after the final drug administration. IPD-1151T inhibited both antigen- and MCh-mediated bronchoconstriction in actively sensitized mice. The inhibition induced was closely related to the dose and frequency of oral administration of the agent. We also examined the effect of IPD-1151T on IgE production in response to DNP-KLH immunization. IPD-1151T inhibited dose-dependently both total and specific IgE concentrations in serum prepared from mice 15 days after immunization. These results strongly indicate that IPD-1151T inhibits IgE production in vivo and results in attenuating effect on bronchoconstriction.

Energy-based re-evaluation of Angle's class I molar relationship

The energy used to break down food was calculated in Angle Class I and rigid interdigitation, as well as in various malocclusions using a computer simulation. As a result, the energy applied to the food was the highest in Angle's Class I molar relationship and rigid interdigitation, with a simple pattern of masticatory movement. This relationship also tended to produce maximum efficiency in the posterior teeth, including the premolars. Furthermore, energy decreased with the degree of malocclusion. Thus, we were able to provide an alternative definition of Angle's Class I molar relationship and rigid interdigitation. In addition, the extent of malocclusion could be evaluated quantitatively.

Energy-based evaluation of occlusion

The purpose of this study was to establish an index for evaluating occlusal conditions using energy levels. For this purpose, first, the movement of mastication under five occlusal conditions in which the positional relationship varied mesiodistally was simulated and the energy applied to the food being masticated was calculated, based on theoretical values of computing mechanics using finite element static analysis. As a model experiment, the energy generated under each occlusal condition was then measured using the electrical output from an occlusion pressure sensor composed of pressure-sensitive rubber. By comparing the theoretical values of computing mechanics and the measured values, the changes in the energy level under occlusal conditions were consistent with the trends, and the maximum value of the energy was obtained under the occlusal condition of Angle Class I and consisting of rigid interdigitation. In conclusion, our results demonstrated that occlusal conditions can be evaluated using the energy level as an index.