Cellular APOBEC3A deaminase drives mutations in the SARS-CoV-2 genome.

The number of genetic variations in the SARS-CoV-2 genome has been increasing primarily due to continuous viral mutations. Here, we report that the human APOBEC3A (A3A) cytidine deaminase plays a critical role in the induction of C-to-U substitutions in the SARS-CoV-2 genome. Bioinformatic analysis of the chronological genetic changes in a sequence database indicated that the largest UC-to-UU mutation signature, consistent with APOBEC-recognized nucleotide motifs, was predominant in single-stranded RNA regions of the viral genome. In SARS-CoV-2-infected cells, exogenous expression of A3A but not expression of other APOBEC proteins induced UC-to-UU mutations in viral RNA (vRNA). Additionally, the mutated C bases were often located at the tips in bulge or loop regions in the vRNA secondary structure. Interestingly, A3A mRNA expression was drastically increased by interferons (IFNs) and tumour necrosis factor-α (TNF-α) in epithelial cells derived from the respiratory system, a site of efficient SARS-CoV-2 replication. Moreover, the UC-to-UU mutation rate was increased in SARS-CoV-2 produced from lung epithelial cells treated with IFN-ß and TNF-α, but not from CRISPR/Cas9-based A3A knockout cells. Collectively, these findings demonstrate that A3A is a primary host factor that drives mutations in the SARS-CoV-2 RNA genome via RNA editing.

Fibroblast growth factor 23-Klotho and mineral metabolism in the first year after pediatric kidney transplantation: A single-center prospective study.

BACKGROUND: The role of fibroblast growth factor 23 (FGF23) levels in mineral metabolism before and after kidney transplantation in pediatric patients is poorly understood. METHODS: We prospectively evaluated 24 patients under 18 years of age (4.5 [3.3-9.8] years) who underwent living kidney transplantation between July 2016 and March 2018, and measured intact FGF23 and serum αKlotho levels, and other parameters of mineral metabolism before and after transplantation (Day 7, 1 and 4 months, and 1 year). Relationships between parameters were examined by linear analysis. RESULTS: FGF23 level was 440.8 [63.4-5916.3] pg/ml pre-transplant and decreased significantly to 37.1 [16.0-71.5] pg/ml at Day 7 post-transplant (-91.6%, p < .001). Thereafter, it remained at normal levels until 1 year. αKlotho level was 785 [568-1292] pg/ml pre-transplant and remained low at Day 7 and 1 month post-transplant, with an increasing trend at 4 months. Post-transplant phosphorus levels were significantly decreased compared with pre-transplant, with a lowest level of 1.7 [1.3-2.9] mg/dl, -5.7 [-6.8, -3.8] SD at Day 4, followed by gradual recovery. Phosphorus levels and the ratio of tubular maximum phosphate reabsorption were significantly and negatively associated with pre-transplant FGF23 until 4 months of post-transplant. Pre-transplant αKlotho was negatively associated with pre-transplant FGF23 but not FGF23 or other parameters after transplantation. CONCLUSION: FGF23 in pediatric kidney transplant patients decreased rapidly after transplantation and associated with post-transplant hypophosphatemia and increased phosphorus excretion. Post-transplant αKlotho was low early post-transplant but tended to increase subsequently. Post-transplant αKlotho was unaffected by pre-transplant FGF23 or other factors, suggesting pre-transplant chronic kidney disease status has no effect.

Changes in graft function after living donor kidney transplantation in children.

BACKGROUND: This study aimed to evaluate the change in graft function in two groups stratified by the estimated glomerular filtration rate (eGFR) at 1 month after transplantation (eGFR-1 M) in pediatric living donor kidney transplant recipients. METHODS: Forty-three pediatric recipients were classified as those with an eGFR-1 M ≥ 90 mL/min/1.73 m2 (n = 19; high eGFR group) or those with an eGFR-1 M of 60-89 mL/min/1.73 m2 (n = 24; middle eGFR group). In the two groups, changes in the eGFR were retrospectively evaluated for 5 years after kidney transplantation. RESULTS: The mean recipient age at transplantation in the high/middle eGFR group was 6.1 ± 3.4/7.8 ± 4.0 years (P = 0.14). The mean eGFR-1, -12, and -60 M (mL/min/1.73 m2) in the high/middle eGFR group were 106.8 ± 2.99/78.5 ± 1.52 (P < 0.001), 79.3 ± 3.22/62.7 ± 2.38 (P < 0.001), and 73.1 ± 4.16/59.2 ± 2.79 (P = 0.006), respectively. The change in the mean eGFR remained mostly parallel in the two groups. In both groups, the eGFR significantly decreased only between 1 and 12 months after transplantation (P < 0.0001). Approximately 70% of the patients had an eGFR-60 M ≥ 60 mL/min/1.73 m2. CONCLUSIONS: The high and middle eGFR groups showed a rapid decline in the eGFR by 1 year after transplantation, but the change thereafter was gradual. In pediatric living donor kidney transplant recipients, the eGFR was relatively well maintained up to 5 years after transplantation. A higher resolution version of the Graphical abstract is available as Supplementary information.

Transport Form and Pathway from the Intestine to the Peripheral Tissues and the Intestinal Absorption and Metabolism Properties of Oleamide.

This study aimed to obtain information on the transport form and pathway from the intestine to the peripheral tissues and on the intestinal absorption and metabolism properties of oleamide (cis-9-octadecenamide). Oleamide was primarily transported via the portal vein. Density gradient centrifugation indicated that plasma oleamide was enriched in the fractions containing albumin in the portal and peripheral blood. Oleamide formed a complex with albumin in an endothermic reaction (apparent Kd = 4.4 µM). The CD36 inhibitor inhibited the oleamide uptake into the intestinal epithelial Caco-2 cells, and oleamide decreased the cell surface CD36 level. The fatty acid amide hydrolase (FAAH) inhibitor increased the transepithelial transport of oleamide across Caco-2 cells and the plasma oleamide concentration in mice intragastrically administered with oleamide. These results indicate that oleamide is transported primarily via the portal vein as a complex with albumin. Furthermore, we suggest that oleamide is taken up via CD36 in the small intestine and degraded intracellularly by FAAH.

Nanopore Sequencing for Characterization of HIV-1 Recombinant Forms.

High genetic diversity, including the emergence of recombinant forms (RFs), is one of the most prominent features of human immunodeficiency virus type 1 (HIV-1). Conventional detection of HIV-1 RFs requires pretreatments, i.e., cloning or single-genome amplification, to distinguish them from dual- or multiple-infection variants. However, these processes are time-consuming and labor-intensive. Here, we constructed a new nanopore sequencing-based platform that enables us to obtain distinctive genetic information for intersubtype RFs and dual-infection HIV-1 variants by using amplicons of HIV-1 near-full-length genomes or two overlapping half-length genome fragments. Repeated benchmark tests of HIV-1 proviral DNA revealed consensus sequence inference with a reduced error rate, allowing us to obtain sufficiently accurate sequence data. In addition, we applied the platform for sequence analyses of 9 clinical samples with suspected HIV-1 RF infection or dual infection according to Sanger sequencing-based genotyping tests for HIV-1 drug resistance. For each RF infection case, replicated analyses involving our nanopore sequencing-based platform consistently produced long consecutive analogous consensus sequences with mosaic genomic structures consisting of two different subtypes. In contrast, we detected multiple heterologous sequences in each dual-infection case. These results demonstrate that our new nanopore sequencing platform is applicable to identify the full-length HIV-1 genome structure of intersubtype RFs as well as dual-infection heterologous HIV-1. Since the genetic diversity of HIV-1 continues to gradually increase, this system will help accelerate full-length genome analysis and molecular epidemiological surveillance for HIV-1. IMPORTANCE HIV-1 is characterized by large genetic differences, including HIV-1 recombinant forms (RFs). Conventional genetic analyses require time-consuming pretreatments, i.e., cloning or single-genome amplification, to distinguish RFs from dual- or multiple-infection cases. In this study, we developed a new analytical system for HIV-1 sequence data obtained by nanopore sequencing. The error rate of this method was reduced to ~0.06%. We applied this system for sequence analyses of 9 clinical samples with suspected HIV-1 RF infection or dual infection, which were extracted from 373 cases of HIV patients based on our retrospective analysis of HIV-1 drug resistance genotyping test results. We found that our new nanopore sequencing platform is applicable to identify the full-length HIV-1 genome structure of intersubtype RFs as well as dual-infection heterologous HIV-1. Our protocol will be useful for epidemiological surveillance to examine HIV-1 transmission as well as for genotypic tests of HIV-1 drug resistance in clinical settings.

Evaluation of the Geenius HIV 1/2 confirmatory assay for HIV-2 samples isolated in Japan.

BACKGROUND: Although the number of HIV-2-infected individuals is quite low in Japan, at least three groups of HIV-2 (A, B and CRF01_AB) have been detected thus far. In particular, CRF01_AB HIV-2 cases have been found only in limited areas, Cote d'Ivoire and Japan. Here, we demonstrate that Geenius HIV 1/2 Confirmatory Assay (Geenius, Bio-Rad Laboratories) is able to detect HIV-2 samples, including groups A, B and CRF01_AB, isolated in Japan. STUDY DESIGN: A total of 57 plasma samples, including three panels (Ⅰ: HIV-2-positive samples [n=9], Ⅱ: HIV-1 infection with HIV-2 antibody cross-reactivity samples [n=37], and Ⅲ: HIV negative with biological false-positive HIV-2 samples [n=11]) were tested by Geenius. RESULTS: Geenius determined Panel I to be "HIV-2 positive with/without HIV-1 cross-reactivity (n=4, respectively)", including HIV-2 group A and CRF01_AB. In the case with HIV-2 group B, all bands were detected, resulting in a Geenius interpretation of "HIV positive untypable". Geenius classified Panels II and III as "HIV-1 positive (n=37)" or "HIV negative (n=9)", "HIV indeterminate (n=1)" and "HIV-2 indeterminate (n=1)", suggesting 95.8% HIV-2 differentiation by Geenius. CONCLUSIONS: With Geenius, there were fewer false-positives for HIV-1/-2 negativity and fewer cross-reactions with HIV-2 among HIV-1-positive samples. Additionally, the assay could detect HIV-2 genetic group CRF01_AB. Geenius can be expected to be a useful diagnostic tool that is an alternative to conventional Western blotting.

Dietary oleamide attenuates obesity induced by housing mice in small cages.

Physical inactivity due to prolonged sedentary behavior induces obesity. Therefore, we investigated whether housing mice in small cages to mimic sedentary behavior induced obesity and whether dietary oleamide (cis-9,10-octadeceneamide) suppressed the induced obesity. A single oral administration of oleamide (50 mg/kg) to mice resulted in the accumulation of the exogenous oleamide in abdominal visceral fat. Next, mice were housed in small cages and oleamide (50 mg/kg/d) was orally administered for 12 weeks. Housing mice in small cages impaired glucose tolerance and increased food efficiency. It also increased body weight and abdominal fat mass. Dietary oleamide improved the impairment and inhibited their increase in mice housed in small cages. Furthermore, dietary oleamide suppressed the mRNA expression of inflammation-related factors in the abdominal fat of mice housed in small cages. Hence, these results indicate that although housing mice in small cages induces obesity and increases abdominal fat mass, dietary oleamide suppresses the obesity.

Molecular epidemiological features of SARS-CoV-2 in Japan, 2020-1.

There were five epidemic waves of coronavirus disease 2019 in Japan between 2020 and 2021. It remains unclear how the domestic waves arose and abated. To better understand this, we analyzed the pangenomic sequences of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and characterized the molecular epidemiological features of the five epidemic waves in Japan. In this study, we performed deep sequencing to determine the pangenomic SARS-CoV-2 sequences of 1,286 samples collected in two cities far from each other, Tokyo Metropolis and Nagoya. Then, the spatiotemporal genetic changes of the obtained sequences were compared with the sequences available in the Global Initiative on Sharing All Influenza Data (GISAID) database. A total of 873 genotypes carrying different sets of mutations were identified in the five epidemic waves. Phylogenetic analysis demonstrated that sharp displacements of lineages and genotypes occurred between consecutive waves over the 2 years. In addition, a wide variety of genotypes were observed in the early half of each wave, whereas a few genotypes were detected across Japan during an entire wave. Phylogenetically, putative descendant genotypes observed late in each wave displayed regional clustering and evolution in Japan. The genetic diversity of SARS-CoV-2 displayed uneven dynamics during each epidemic wave in Japan. Our findings provide an important molecular epidemiological basis to aid in controlling future SARS-CoV-2 epidemics.

SARS-CoV-2 accessory protein ORF8 is secreted extracellularly as a glycoprotein homodimer.

ORF8 is an accessory protein encoded by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Consensus regarding the biological functions of ORF8 is lacking, largely because the fundamental characteristics of this protein in cells have not been determined. To clarify these features, we herein established an ORF8 expression system in 293T cells. Using this system, approximately 41% of the ORF8 expressed in 293T cells were secreted extracellularly as a glycoprotein homodimer with inter/intramolecular disulfide bonds. Intracellular ORF8 was sensitive to the glycosidase Endo H, whereas the secreted portion was Endo-H-resistant, suggesting that secretion occurs via a conventional pathway. Additionally, immunoblotting analysis showed that the total amounts of the major histocompatibility complex class Ι (MHC-I), angiotensin-converting enzyme 2 (ACE2), and SARS-CoV-2 spike (CoV-2 S) proteins coexpressed in cells were not changed by the increased ORF8 expression, although FACS analysis revealed that the expression of the cell surface MHC-I protein, but not that of ACE2 and CoV-2 S proteins, was reduced by ORF8 expression. Finally, we demonstrate by RNA-seq analysis that ORF8 had no significant stimulatory effects in human primary monocyte-derived macrophages (MDMs). Taken together, our results provide fundamental evidence that the ORF8 glycoprotein acts as a secreted homodimer, and its functions are likely associated with the intracellular transport and/or extracellular signaling in SARS-CoV-2 infection.

Long-term social outcome after pediatric kidney transplantation: a single-center experience.

BACKGROUND: Patient and graft survival rates after pediatric kidney transplantation have improved recently. Therefore, the quality of life or social outcome after kidney transplantation has become important for patients and their families. METHODS: Patients who underwent kidney transplantation at < 18 years old and were observed for > 10 years were included in this study. The median age at first kidney transplantation was 9.2 (interquartile range [IQR] = 5.6-13.0) years; there were 56 males and 50 females. The median age at last follow-up was 29.9 (IQR = 22.2-36.0) years. We evaluated the patients' renal function, growth, professional status, and marital status at the last follow-up. RESULTS: The percentage of functioning grafts at the last follow-up was 81.1%; 73 patients (68.9%) had a first graft. The mean estimated GFR was 51.0 ± 20.5 mL/min/1.73 m2. Twenty patients received dialysis for graft failure. The mean final heights of the males and females were 158.1 ± 9.2 cm (- 2.2 standard deviations) and 149.1 ± 6.4 cm (- 1.7 standard deviations), respectively. Excluding 23 students, 63 patients (75.9%) were employed. Office worker was the most common profession. Twelve patients (14.5%) were unemployed. Of patients > 20 years old, 14 (16.7%), three males and 11 females, were married. Five females had one child each. CONCLUSIONS: The graft survival rate was favorable. The final height was short, particularly in male. The rate of employment was relatively high. The rate of marriage and having children were still low. Improving the social outcome is an important problem after pediatric kidney transplantation.

Specific mutations in the HIV-1 G-tract of the 3'-polypurine tract cause resistance to integrase strand transfer inhibitors.

BACKGROUND: In vitro selection experiments identified viruses resistant to integrase strand transfer inhibitors (INSTIs) carrying mutations in the G-tract (six guanosines) of the 3'-polypurine tract (3'-PPT). A clinical study also reported that mutations in the 3'-PPT were observed in a patient receiving dolutegravir monotherapy. However, recombinant viruses with the 3'-PPT mutations that were found in the clinical study were recently shown to be susceptible to INSTIs. OBJECTIVES: To identify the specific mutation(s) in the G-tract of the 3'-PPT for acquiring INSTI resistance, we constructed infectious clones bearing single or multiple mutations and systematically characterized the susceptibility of these clones to both first- and second-generation INSTIs. METHODS: The infectious clones were tested for their infectivity and susceptibility to INSTIs in a single-cycle assay using TZM-bl cells. RESULTS: A single mutation of thymidine (T) at the fifth position (GGG GTG) in the G-tract of the 3'-PPT had no effect on INSTI resistance. A double mutation, cytidine (C) or 'T' at the second position and 'T' at the fifth position (GCG GTG and GTG GTG), increased resistance to INSTIs, with the appearance of a plateau in the maximal percentage inhibition (MPI) of the dose-response curves, consistent with a non-competitive mechanism of inhibition. CONCLUSIONS: Mutations at the second and fifth positions in the G-tract of the 3'-PPT may result in complex resistance mechanism(s), rather than simply affecting INSTI binding at the IN active site.

Comparison of live donor predonation and post-transplant kidney volumes and glomerular size in pediatric patients weighing less than 15 kg - a retrospective study.

Renal transplantation of adult-size kidneys presents a size mismatch in small children. This study presents a comparison of live donor predonation and recipient post-transplant kidney volumes (k-vol) and glomerular size at 1 year after transplantation. We analyzed 47 pediatric renal transplant recipients weighing <15 kg between 2009 and 2017. The k-vol before and 1 year after transplantation and glomerular size at implant and 1 year post-transplant were evaluated. We estimated the relationships between these changes and graft function, and the factors associated with k-vol. Pretransplant k-vol was 158.1 ± 25.1 ml, and the k-vol at 1 year post-transplant was significantly reduced by -17.2% to 132.3 ± 27.3 ml (P < 0.001). Implant glomerular size showed the diameter was 165.3 ± 15.1 µm and the area 20 737.1 ± 3230.6 µm2 . One-year post-transplant, the glomerular diameter was 150.6 ± 11.4 µm and the area 17 428.3 ± 2577.9 µm2 , significantly reduced compared with implantation values (both P < 0.001). The change in k-vol was affected by pretransplant abdominal cavity (ml/200 ml cavity volume, partial regression coefficient = 0.029, SE = 0.009, P = 0.004) and recipient's weight gain (ml/5% of weight gain, partial regression coefficient = 0.020, SE = 0.006, P = 0.002). In small pediatric transplants, an adult-size kidney is acceptable with reduction in k-vol. Moreover, the post-transplant k-vol might be regulated by pretransplant physique and post-transplant somatic growth.

ABO-incompatible pediatric kidney transplantation without antibody removal.

BACKGROUND: Because of the severe shortage of suitable deceased donors, ABO-incompatible living donor kidney transplantation (ABOi LDKT) is performed even in pediatric recipients in Japan. We performed pediatric ABOi LDKT using rituximab without anti-A/B antibody removal. METHODS: Thirteen pediatric recipients (mean age 7.4, range 3.4-15.7, four females) whose baseline anti-A/B IgG titers were ≤ × 64 underwent ABOi LDKT without antibody removal and splenectomy between July 2013 and April 2017 at Toho University. Mycophenolate mofetil (MMF) was initiated on day - 10. Rituximab (100 mg) was administered twice. Basiliximab and triple maintenance immunosuppression (calcineurin inhibitor, MMF, and steroids) were administered. Protocol biopsy was performed at 3 months and 1 year after transplantation. We retrospectively compared the clinical outcomes between these recipients and 37 children (mean age 9.0, range 2.6-18.9, 15 female) who underwent ABO-compatible (ABOc) LDKT during the same period. RESULTS: The mean follow-up periods of ABOi and ABOc groups were 31.9 ± 13.5 and 28.8 ± 14.4 months, respectively. In the ABOi group, no clinical acute rejection (AR) was noted and subclinical AR was observed in four patients without evidence of acute antibody-mediated rejection. In the ABOc group, clinical and subclinical AR developed in 3 and 10 patients, respectively. No significant difference was identified for the mean eGFR between the ABOi and ABOc groups (98.3 ± 48.8 vs. 86.9 ± 39.4, P = 0.452 at 3 months; 78.2 ± 21.2 vs. 79.7 ± 21.3, at 1 year, P = 0.830). Death-censored graft survival at follow-up was 100% in the ABOi group and 94.6% in the ABOc group. Patient survival during the follow-up period in both the groups was 100%. Late-onset neutropenia (LON) requiring granulocyte colony-stimulating factor occurred more frequently in the ABOi group than in the ABOc group (4 vs. 0 patients) (P < 0.001). CONCLUSIONS: Pre- and post-transplantation antibody removal is not a prerequisite for successful pediatric ABOi LDKT, at least in patients with a low anti-A/B IgG antibody titer. However, LON caused by rituximab should be monitored.

Changes in cardiac function after renal transplantation in children: Significance of pre-transplantation left ventricular hypertrophy.

LVH is a significant risk factor for the development of cardiovascular morbidity. However, few studies have evaluated the changes in cardiac function that occur in pediatric patients with ESRD undergoing RTx. Therefore, we assessed the changes in parameters associated with LVH in children within the first year after RTx. We retrospectively evaluated patients aged < 18 years who underwent initial RTx from April 2014 to December 2016. The patients were divided into 2 groups according to the presence of LVH before RTx. Clinical, biochemical, and echocardiographic parameters including the LVMI before and 1 year after RTx were evaluated in both groups. Twenty-six patients were included in this study. Seven of the 26 patients had LVH before RTx. Among the echocardiographic parameters, the LVMI was significantly improved 1 year after RTx in the initial LVH group (57.79 ± 11.86 vs 42.20 ± 6.03 g/cm2.7 , P = .018), while no change was observed in the initial non-LVH group (32.66 ± 7.52 vs 35.17 ± 12.86 g/cm2.7 , P = .376). Improvement of the ejection fraction was also observed only in the initial LVH group (66.5% ± 5.3% vs 72.2% ± 5.2%, P = .042). Children who had LVH before RTx showed significant improvements in the LVMI and ejection fraction even within 1 year after RTx. To minimize aggravation of cardiac function, early RTx should be considered for patients with LVH.

Transplantation of adult-size kidneys in small pediatric recipients: A single-center experience.

RTx of adult-size kidneys presents a size mismatch in small pediatric recipients, and there are potential surgical complications. This study reveals the outcomes of intra- and extraperitoneal RTx in low-weight (less than 15 kg) pediatric recipients. We studied 51 pediatric patients weighing less than 15 kg who received a living-related donor renal transplant between 2009 and 2017. The intraperitoneal (group A, n = 24) and extraperitoneal (group B, n = 27) approaches were compared. In group A, the mean age, Ht, and weight were 3.8 ± 1.6 years, 83.7 ± 6.5 cm, 10.5 ± 1.8 kg; in group B, 5.0 ± 1.9 years, 95.3 ± 7.3 cm, and 13.0 ± 1.4 kg. Single renal artery grafts (21 in group A and 16 in group B) and double renal artery grafts (three in group A and 11 in group B) were performed. Of the patients with double renal artery transplants, one in group A and six in group B underwent ex vivo arterial reconstruction. The eGFR (mL/min/1.73 m2 ) at 1-week post-transplant in group A was significantly higher than that in group B; the eGFRs at 4 weeks post-transplant did not differ. One graft was lost in group B because of vascular thrombosis. Post-transplant complications included ileus and transplant ureteral stenosis. There was no significant difference in 5-year graft survival rate (group A 100%, group B 91.7%). Both transplant approaches are feasible to adapt to a size mismatch between the adult-size donor kidney and low-weight pediatric recipients.

Management of patients with severe Epstein syndrome: Review of four patients who received living-donor renal transplantation.

AIM: Epstein syndrome is a hereditary disease characterized by macrothrombocytopaenia and progressive nephritis. The abnormality of the MYH9 gene has a strong relationship to the severity of the disease. Severe Epstein syndrome progresses to end-stage renal disease rapidly after adolescence. There is no established therapy. We sought to clarify appropriate management of Epstein syndrome nephropathy. METHODS: Epstein syndrome patients who underwent renal transplantation at our institution between March 2009 and March 2017 were enrolled. Epstein syndrome was diagnosed based on clinical features and genetic testing. Patient medical records were reviewed retrospectively. RESULTS: Four male patients with Epstein syndrome, all with severe MYH9 gene mutations (p.R702C in three and p.S96L in one), were enrolled. Despite treatment with renin-angiotensin system blockers, nephropathy was refractory and progressed rapidly, and the patients required dialysis or renal transplantation after adolescence. Early preparation for treatment based on early and accurate diagnosis of Epstein syndrome enabled two patients to undergo pre-emptive renal transplantation. For these patients, we kept the platelet count above 100 × 109 /L until day 7 after renal transplantation with platelet transfusions for macrothrombocytopaenia, and no postoperative bleeding episodes occurred. CONCLUSION: Epstein syndrome nephropathy due to a severe MYH9 gene mutation can be refractory and progress rapidly; therefore, early and accurate diagnosis is important for safer therapeutic options including pre-emptive renal transplantation. By keeping the platelet count above 100 × 109 /L during the perioperative period, renal transplantation can be a safe treatment option for severe Epstein syndrome nephropathy.

Surgical Challenge in Pediatric Kidney Transplant Vascular Anastomosis.

During pediatric kidney transplant, surgical challenges occasionally occur. In particular, vascular anastomosis should be considered for children with small body weight < 12 kg, multiple renal arteries, vascular anomaly, and inferior vena cava occlusion. In pediatric patients, a living-donor renal graft is usually donated from a parent. Therefore, the renal artery and vein are too large to be anastomosed with the recipient's internal iliac artery and external iliac vein. In children who are > 12 kg, the renal artery and vein could be anastomosed with the external iliac artery and the external iliac vein. In children who are < 10 kg, the renal artery and vein should be anastomosed directly with the aorta and inferior vena cava. A pediatric transplant surgeon should consider arterial and venous anastomosis sites before transplant surgery. In small children with partial or total inferior vena cava occlusion, the venous anastomosis site should be evaluated. If the graft is placed on the left side, a venous graft must be used as a bridge between the renal vein and inferior vena cava. In 13 kidney transplants in children with inferior vena cava occlusion, 7 were on the left and 6 were on the right side. A patent segment of the inferior vena cava, the left original renal vein, an ascending lumbar vein, an azygos vein, the first graft renal vein, and a portal vein were used for venous anastomosis in 6, 2, 2, 1, 1 and 1 recipient, respectively. One child had graft loss due to renal vein thrombosis and one died of hemorrhage immediately posttransplant. Three had grafts with relatively long-term function, but these were lost due to chronic allograft nephropathy 100, 122, and 137 months posttransplant. However, the other 8 recipients have so far maintained graft function from 6 to 138 months since transplant.

Surgical Challenge in Pediatric Kidney Transplant: Lower Urinary Tract Abnormality.

Lower urinary tract abnormalities are difficult to resolve in pediatric kidney transplant patients. Measure of residual urine, voiding cystourethrography, retrograde urethrography, cystometry, electromyography of urethral external sphincter muscle, urethrometry, and uroflowmetry are the primary methods for evaluation of lower urinary tract abnormalities. Endoscopic resection or ablation of urethral valves is required in children with posterior urethral valve to treat obstruction, but bladder function does not always recover and may deteriorate to end-stage renal failure even after the obstruction is released. This bladder dysfunction in posterior urethral valve defines valve bladder syndrome. Vesicoureteral reflux caused by high vesical pressure can cause even worse renal graft function posttransplant. In our patient group, urinary diversion occurred with Mitrofanoff conduit using an appendix in 6 children, a Yang-Monti channel conduit using ileum in 1 patient, with cystostomy in 3 children, and with augmented cystoplasty in 9 children before or simultaneously with kidney transplant. These procedures should be selected based on the type of lower urinary tract abnormality including bladder function. Recently, we have preferred a continent diversion for self-catheterization in children with lower urinary tract abnormalities. We have conducted 9 augmented cystoplasty procedures using a portion of the sigmoid colon or ileum. Seventeen children retained their own bladders when the transplant ureter was implanted. Most patients needed clean intermittent catheterization, depending on the residual urine volume and a bladder function. Ten-year graft survival rate in kidney transplant in our department is 98% in 36 children with lower urinary tract abnormalities. Lower urinary tract abnormality is not always a risk factor for pediatric kidney transplant; however, a preoperative evaluation is important to choose the best option for urinary diversion.

Republication: Two Premature Neonates of Congenital Syphilis with Severe Clinical Manifestations.

Congenital syphilis (CS) is a public health burden in both developing and developed countries. We report two cases of CS in premature neonates with severe clinical manifestations; Patient 1 (gestational age 31 weeks, birth weight 1423 g) had disseminated idiopathic coagulation (DIC) while Patient 2 (gestational age 34 weeks and 6 days, birth weight 2299 g) had refractory syphilitic meningitis. Their mothers were single and had neither received antenatal care nor undergone syphilis screening. Both neonates were delivered via an emergency cesarean section and had birth asphyxia and transient tachypnea of newborn. Physical examination revealed massive hepatosplenomegaly. Laboratory testing of maternal and neonatal blood showed increased rapid plasma reagin (RPR) titer and positive Treponema pallidum hemagglutination assay. Diagnosis of CS was further supported by a positive IgM fluorescent treponemal antibody absorption test and large amounts of T. pallidum spirochetes detected in the placenta. Each neonate was initially treated with ampicillin and cefotaxime for early bacterial sepsis/meningitis that coexisted with CS. Patient 1 received fresh frozen plasma and antithrombin III to treat DIC. Patient 2 experienced a relapse of CS during initial antibiotic treatment, necessitating parenteral penicillin G. Treatment was effective in both neonates, as shown by reductions in RPR. Monitoring of growth and neurological development through to age 4 showed no evidence of apparent delay or complications. Without adequate antenatal care and maternal screening tests for infection, CS is difficult for non-specialists to diagnose at birth, because the clinical manifestations are similar to those of neonatal sepsis and meningitis. Ampicillin was insufficient for treating CS and penicillin G was necessary.

Complex formation with layered double hydroxides for the remediation of hygroscopicity.

Layered double hydroxides (LDHs) have been used commercially as antacids, to stabilize drugs, to allow the controlled release of incorporated drugs, and to act as drug carriers to reduce drug accumulation within the body. Several types of LDH were investigated: nitrate type (LDH-NO3); chloride type (LDH-Cl); and carbonate type (LDH-CO3). Each type was added to an aqueous or methanol (MeOH) solution containing a drug (pravastatin or nateglinide). With pravastatin sodium, the interlayer distance expanded after reaction with LDH-NO3 and LDH-Cl in aqueous solution. In contrast, the interlayer distance of LDH-CO3 increased in methanol with nateglinide. Each drug was intercalated into the interlayer space of LDH by ion exchange. The hygroscopicity of the drug substances, complexes, and physical mixtures were determined at 70% relative humidity. Increases in weight (%) of the complexes were less than those of the physical mixtures, which demonstrates that hygroscopicity was reduced upon complexation with LDH due to the layer of LDH over the drugs.