Atypical hemolytic uremic syndrome (aHUS) is a rare disease caused by overactivation of the complement alternative pathway. aHUS involves the presence of antibodies against complement factor H and ...its mutations in the complement genes. A 2-month-old boy presented with discoid rash, hemolytic anemia, thrombocytopenia, multiple antibodies, and hypocomplementemia with a very low level of C4 (< 3 mg/dL), indicating activation of the complement pathway, together fulfilling the systemic lupus erythematosus (SLE) criteria of the American College of Rheumatology at 5 months of age. However, most of these findings normalized spontaneously without any intervention. Further investigations revealed a high level of anti-complement factor H antibodies and a novel heterozygous missense mutation (p.Glu1172Ala, located in exon 22) in a complement gene,
. At 2 years of age, his SLE-like symptoms have not recurred, but hematuria and schistocytes were persistent. Eventually, aHUS was diagnosed rather than SLE. Our findings suggest that multiple antibody complex, including anti-complement factor H antibody, may temporarily activate the classical pathway, resulting in SLE-like findings.
Ornithine transcarbamylase deficiency (OTCD), caused by X-linked OTC mutations, is characterized by life-threatening hyperammonemia. Heterozygous female patients are often asymptomatic and usually ...have milder disease than affected male patients, but can have higher morbidity and mortality rates if the disease progresses prior to diagnosis. Our purpose was to establish a screening method for female heterozygotes with OTCD. We retrospectively identified female patients who underwent plasma amino acid analysis at the National Center for Child Health and Development, using data from electronic medical records from March 2002 to September 2021. We extracted patient age, medical history, and biochemical data, including plasma amino acid levels. Patients were categorized into several groups according to their underlying diseases; those with underlying diseases that could potentially affect plasma amino acid levels, such as mitochondrial disease or short bowel syndrome, were excluded, except for untreated OTCD. Biochemical values were compared between OTCD patients and others using the Mann-Whitney U test. The receiver operator characteristic analysis was performed to assess the diagnostic capability for detecting OTCD in each subject. For patients with multiple test data, the most recent of the measurement dates was used in the analysis. The data sets of 976 patients were included. There were significant differences in values of glutamine, citrulline, arginine, and ammonia, but the diagnostic capacity of each alone was inadequate. By contrast, the (glutamine + glycine)/(citrulline + arginine) ratio was appropriate for discriminating heterozygous female patients with OTCD, with a sensitivity of 100% and specificity of 98.6% when the cutoff level was 15.8; the AUC for this discrimination was 0.996 (95% confidence interval, 0.992 to 1.000). These findings could help identify heterozygous female patients with OTCD before the onset of clinical disease.
Objectives
The present study analyzed surgical outcomes of laryngotracheal separation (LTS) in children with neurological disorders. The purpose of this study was to investigate respiratory ...impairment and severe complications after LTS in children, and identify the possibility of permanent tracheostomy without a tracheostomy tube as the safest respiratory management method.
Methods
Twenty‐eight patients (male:female = 16:12) with neurological disorders (6 months to 32 years) who underwent LTS between January 2012 and April 2018 were reviewed. Tracheal diameter, Cobb angle, and sternocervical spine distance (SCD) were measured to assess the potential risk and possibility of removing tracheostomy tube management.
Results
Tracheostomy tube could be removed shortly after LTS in 57% (16/28). However, nine of these patients developed respiratory problems that required tracheostomy tube placement 2 years after LTS. New requirements for a tracheostomy tube as a stent were strongly correlated with SCD (P < .05, odds ratio > 1) as well as tracheal deformity.
Conclusions
Respiratory management in neurologically impaired children after LTS without a tracheostomy tube is challenging because thoracic deformity during physical growth affects tracheal disfiguration. Thoracic deformities and progression of scoliosis should be considered in respiratory management approaches in children with neurological disorders, and long‐term follow‐up by computed tomography is necessary.
LEVEL OF EVIDENCE
IV
The construction of a repository for the geological disposal of radioactive waste will include the use of cement-based materials. Following closure, groundwater will saturate the repository, and the ...extensive use of cement will result in the development of a highly alkaline porewater, pH > 12.5; this fluid will migrate into and react with the host rock. The chemistry of the fluid will evolve over time, initially with high Na and K concentrations, evolving to a Ca-rich fluid, and finally returning to the natural background groundwater composition. This evolving chemistry will affect the long-term performance of the repository, altering the physical and chemical properties, including radionuclide behaviour. Understanding these changes forms the basis for predicting the long-term evolution of the repository. This study focused on the determination of the nature and extent of the chemical reaction, as well as the formation and persistence of secondary mineral phases within a granite, comparing data from sequential flow experiments with the results of reactive transport modelling. The reaction of the granite with the cement leachates resulted in small changes in pH and the precipitation of calcium aluminium silicate hydrate (C-(A-)S-H) phases of varying compositions, of greatest abundance with the Ca-rich fluid. As the system evolved, secondary C-(A-)S-H phases redissolved, partly replaced by zeolites. This general sequence was successfully simulated using reactive transport modelling.
Abstract Methylmalonic acidemia (MMA) should be diagnosed in early infancy and receive appropriate management promptly after the diagnosis to prevent severe complications leading to death. At ...present, a newborn screening (NBS) method using tandem mass spectrometry (MS/MS) identifies suspected patients with MMA by elevated propionylcarnitine. In addition, a liquid chromatography tandem mass spectrometry (LC/MS/MS) method using dried blood spot is effective to detect some metabolites as a second-tier test, and reduces the false-positive rate in NBS. However, these tests were only used in screening, and not applied as an examination for evaluating treatment. Herein, we describe a 57-day-old girl with MMA under treatment with cobalamin who had elevated urinary methylmalonic acid levels. We applied the LC/MS/MS method with a separation column to evaluate her cobalamin responsiveness, and discovered an insufficient cobalamin dose earlier than would have been possible using other methods. Based on the current data, this method seems to be applicable for the follow-up of the treatment of MMA patients. However, this should be confirmed with more experience with a larger number of cases and a wider spectrum of disorders.
Neonatal omphalitis is a postpartum infection of periumbilical superficial soft tissues that usually has a good prognosis in developed countries. In rare cases, it could progress to periumbilical ...necrotizing fasciitis (NF), which is an infection of the deep soft tissues, including muscle fascia, and has a high mortality rate. However, the signs and timing of developing NF secondary to omphalitis are unclear. We encountered a neonatal case of NF following omphalitis. In the initial days of the clinical course, general symptoms and condition of the patient were good, and abdominal physical findings were mild; however, the patient rapidly developed NF. The patient was successfully treated by emergent surgical debridement, broad-spectrum antibiotics, and intensive care. To determine the area of blood perfusion, we intravenously injected indocyanine green by intraoperative angiography, and then extensively removed necrotic and hypoperfused tissues. In neonatal omphalitis, the deterioration can suddenly occur despite good initial conditions; intensive monitoring should be required during the first few days of the clinical course.
Asn46Asp/Asp52Ser or Asn46Glu/Asp52Ser hen egg white lysozyme (HEL) mutant was designed by introducing the substituted catalytic residue Asp46 or Glu46, respectively, based on Venerupis philippinarum ...(Vp) lysozyme structure as a representative of invertebrate‐type (i‐type) lyzozyme. These mutations restored the bell‐shaped pH‐dependency of the enzyme activity from the sigmoidal pH‐dependency observed for the Asp52Ser mutant. Furthermore both lysozyme mutants possessed retaining mechanisms like Vp lysozyme and HEL. The Asn46Glu/Asp52Ser mutant, which has a shorter distance between two catalytic residues, formed a glycosyl adduct in the reaction with the N‐acetylglucosamine oligomer. Furthermore, we found the accelerated turnover through its glycosyl adduct formation and decomposition. The turnover rate estimated from the glycosyl formation and decomposition rates was only 20% of the observed hydrolysis rate of the substrate. Based on these results, we discussed the catalytic mechanism of lysozymes.
PDB Code(s): 3WW5; 3WW6
Proper nutritional management is important for the growth and development of children with motor or intellectual disabilities; however, few studies have investigated the nutrient intake of children ...with disabilities. This study aimed to investigate the nutrient intake and food groups that are the main sources of nutrients for children with disabilities. This cross-sectional observational study included twenty-five children (mean age, 11⋅8 years) from five hospitals in Japan. Using a 3-d weighed dietary record, we estimated the daily nutrient intake and food and beverage sources that contributed to nutrient intake. The mean values of calcium, magnesium, iron, vitamin A, thiamine, riboflavin, and vitamin C intake were below the recommended dietary allowance, and those of dietary fiber and potassium were below the levels recommended by the Tentative Dietary Goal for Preventing Lifestyle-related Diseases (DG). In contrast, the mean intake values of fat, saturated fatty acids, and sodium were above the DG levels. Dairy products, meat, vegetables, and cereals were found to be the major contributors of nutrients. Increased intake of vegetables may help alleviate insufficient micronutrient intake in children with disabilities.
Menkes disease (MD) is an X-linked recessive disorder caused by mutations in ATP7A. Patients with MD exhibit severe neurological and connective tissue disorders due to copper deficiency and typically ...die before 3 years of age. Early treatment with copper injections during the neonatal period, before the occurrence of neurological symptoms, can alleviate neurological disturbances to some degree. We investigated whether early symptoms can help in the early diagnosis of MD. Abnormal hair growth, prolonged jaundice, and feeding difficulties were observed during the neonatal period in 20 of 69, 16 of 67, and 3 of 18 patients, respectively. Only three patients visited a physician during the neonatal period; MD diagnosis was not made at that point. The mean age at diagnosis was 8.7 months. Seven patients, who were diagnosed in the prenatal stage or soon after birth, as they had a family history of MD, received early treatment. No diagnosis was made based on early symptoms, highlighting the difficulty in diagnosing MD based on symptoms observed during the neonatal period. Patients who received early treatment lived longer than their elderly relatives with MD. Three patients could walk and did not have seizures. Therefore, effective newborn screening for MD should be prioritized.
The construction of a repository for geological disposal of radioactive waste will include the use of cement-based materials. Following closure, groundwater will saturate the repository and the ...extensive use of cement will result in the development of a highly alkaline porewater, pH > 12.5; this fluid will migrate into and react with the host rock. The chemistry of the fluid will evolve over time, initially high Na and K, evolving to a Ca-rich fluid, and finally returning to the groundwater composition. This evolving chemistry will affect the long-term performance of the repository, altering the physical and chemical properties, including radionuclide behaviour. Understanding these changes forms the basis for predicting the long-term evolution of the repository. This study focused on the determination of the nature and extent of the chemical reaction, as well as the formation and persistence of secondary mineral phases within a mudstone, comparing data from sequential flow experiments with the results of reactive transport modelling. The reaction of the mudstone with the cement leachates resulted in small changes in pH with the precipitation of calcium aluminium silicate hydrate (C-(A-)S-H) phases of varying compositions. As the system evolves, secondary C-(A-)S-H phases re-dissolve and are replaced by secondary carbonates. This general sequence was successfully simulated using reactive transport modelling.
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