Improving the second-tier classification of methylmalonic acidemia patients using a machine learning ensemble method.

INTRODUCTION: Methylmalonic acidemia (MMA) is a disorder of autosomal recessive inheritance, with an estimated prevalence of 1:50,000. First-tier clinical diagnostic tests often return many false positives [five false positive (FP): one true positive (TP)]. In this work, our goal was to refine a classification model that can minimize the number of false positives, currently an unmet need in the upstream diagnostics of MMA. METHODS: We developed machine learning multivariable screening models for MMA with utility as a secondary-tier tool for false positives reduction. We utilized mass spectrometry-based features consisting of 11 amino acids and 31 carnitines derived from dried blood samples of neonatal patients, followed by additional ratio feature construction. Feature selection strategies (selection by filter, recursive feature elimination, and learned vector quantization) were used to determine the input set for evaluating the performance of 14 classification models to identify a candidate model set for an ensemble model development. RESULTS: Our work identified computational models that explore metabolic analytes to reduce the number of false positives without compromising sensitivity. The best results [area under the receiver operating characteristic curve (AUROC) of 97%, sensitivity of 92%, and specificity of 95%] were obtained utilizing an ensemble of the algorithms random forest, C5.0, sparse linear discriminant analysis, and autoencoder deep neural network stacked with the algorithm stochastic gradient boosting as the supervisor. The model achieved a good performance trade-off for a screening application with 6% false-positive rate (FPR) at 95% sensitivity, 35% FPR at 99% sensitivity, and 39% FPR at 100% sensitivity. CONCLUSIONS: The classification results and approach of this research can be utilized by clinicians globally, to improve the overall discovery of MMA in pediatric patients. The improved method, when adjusted to 100% precision, can be used to further inform the diagnostic process journey of MMA and help reduce the burden for patients and their families.

Effect of glucose metabolism disorders on the short-term prognosis in neonates with asphyxia: a multicenter study in Hubei Province, China / 中国当代儿科杂志

OBJECTIVES@#To study the effect of glucose metabolism disorders on the short-term prognosis in neonates with asphyxia.@*METHODS@#A retrospective analysis was performed on the medical data of the neonates with asphyxia who were admitted to 52 hospitals in Hubei Province of China from January to December, 2018 and had blood glucose data within 12 hours after birth. Their blood glucose data at 1, 2, 6, and 12 hours after birth (with an allowable time error of 0.5 hour) were recorded. According to the presence or absence of brain injury and/or death during hospitalization, the neonates were divided into a poor prognosis group with 693 neonates and a good prognosis group with 779 neonates. The two groups were compared in the incidence of glucose metabolism disorders within 12 hours after birth and short-term prognosis.@*RESULTS@#Compared with the good prognosis group, the poor prognosis group had a significantly higher proportion of neonates from secondary hospitals (48.5% vs 42.6%, @*CONCLUSIONS@#Recurrent hyperglycemia in neonates with asphyxia may suggest poor short-term prognosis, and it is necessary to strengthen the early monitoring and management of the nervous system in such neonates.

Coupling bootstrap with synergy self-organizing map-based orthogonal partial least squares discriminant analysis: Stable metabolic biomarker selection for inherited metabolic diseases.

Biomarker selection has played an increasingly important part in modern medicine with advances of omics techniques. Kohonen self-organizing map is a well-established variable reduction algorithm in identifying significant biomarkers based on variable clustering. However, high dimensionality but small sample size of omics data makes self-organizing map-based model problematic in terms of selection stability and reproducibility. A novel feature screening system is presented in this study by coupling bootstrap with synergy self-organizing map-based orthogonal partial least squares discriminant analysis for stable and biologically meaningful metabolic biomarker selection. In the proposed feature screening system, particle swarm optimization algorithm is utilized to configure synergy self-organizing map-based orthogonal partial least squares discriminant analysis to perform the combination of clusters in a heuristic learning manner, enabling flexible selection of more informative features cost-effectively. Based on the paradigm of ensemble feature selection, bootstrap is adopted to explore significant variables consistently identified across multiple feature selectors rather than a single one. The feasibility of the novel feature screening system is evaluated by two most common inherited metabolic diseases, methylmalonic academia and propionic academia, using urinary metabolomics data. With the desirable classification performance, the proposed feature screening system outperforms simpler techniques in the identification of more features closely correlated with the metabolic mechanisms and the stability of selected candidate biomarkers against sample variations. Besides, the novel feature screening system greatly degrades the sensitivity of identified candidate biomarkers to the network size of self-organizing map, benefiting the identification of a suitable and stable final candidate biomarker list.

Evaluation of a panel of very long-chain lysophosphatidylcholines and acylcarnitines for screening of X-linked adrenoleukodystrophy in China.

BACKGROUND: Elevated blood C24:0- and C26:0-carnitines and lysophosphatidylcholines (LPCs) were reported as diagnostic biomarkers for X-linked adrenoleukodystrophy (X-ALD). Our aim was to establish the reference intervals of very long-chain (VLC) acylcarnitines (C20-C26) and LPCs in Chinese population, and evaluate valuable biomarkers and develop panel for screening X-ALD in China. METHODS: The method of FIA-MS/MS-based quantification of VLC acylcarnitines and LPCs was validated in order to determine their concentrations in dried blood spots from 7 X-ALD boys, 396 age-matched healthy controls, and 3078 putative normal newborns. Screening performance of these metabolites for X-ALD was clinically evaluated. RESULTS: The reference intervals of VLC acylcarnitines, LPCs and their ratios were established in Chinese population, and for some metabolites like C26 and C26:0-LPC, the reference intervals were found to be significantly different between children and newborns. C24 and C26, C26:0-LPC, C24/C22 and C26/C22 ratios were found to have better performance than other analytes to identify X-ALD boys from normal children. CONCLUSION: C26:0-LPC, C24 and C26 are three most valuable biomarkers for screening of X-ALD in children group. The information of age-related variations in concentration of some biomarkers is helpful for accurate screening of X-ALD.

Investigation on level and influencing factors of first aid knowledge among dentists in Sichuan province / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The study aims to investigate the cognition degree and influencing factors of first aid knowledge among dentists in Sichuan province, and to provide suggestions for the training of oral clinician.</p><p><b>METHODS</b>A questionnaire was designed for this study. It included the basic situation of population, first aid knowledge level, emergency situation often encountered in stomatology clinic, first aid training situation, learning approach and attitude of first aid knowledge, etc. This questionnaire was used to investigate the dentists of medical institutions in various cities in Sichuan province. The survey results was statistical analyzed.</p><p><b>RESULTS</b>There were 245 valid questionnaires. 1) The level of first aid knowledge of dentists was generally lower in Sichuan province. Work department and other departments work experience were the influencing factors of knowledge level of first aid knowledge among dentists. 2) 87.3% of dentists believed that it was very necessary to master the knowledge of first aid, but in the event of an emergency situation, 73.5% of dentists only can find other doctors to guide themselves to help. 3) The most common way to learn first aid knowledge was through work experience and medical school's first aid course.</p><p><b>CONCLUSIONS</b>Dentists should strengthen the learning and training to improve the first aid skill.</p>

Reduced glutathione and glutathione disulfide in the blood of glucose-6-phosphate dehydrogenase-deficient newborns.

BACKGROUND: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is commonly detected during mass screening for neonatal disease. We developed a method to measure reduced glutathione (GSH) and glutathione disulfide (GSSG) using tandem mass spectrometry (MS/MS) for detecting G6PD deficiency. METHODS: The concentration of GSH and the GSH/GSSG ratio in newborn dry-blood-spot (DBS) screening and in blood plus sodium citrate for test confirmation were examined by MS/MS using labeled glycine as an internal standard. RESULTS: G6PD-deficient newborns had a lower GSH content (242.9 ± 15.9 µmol/L)and GSH/GSSG ratio (14.9 ± 7.2) than neonatal controls (370.0 ± 53.2 µmol/L and 46.7 ± 19.6, respectively). Although the results showed a significance of P < 0.001 for DBS samples plus sodium citrate that were examined the first day after preparation, there were no significant differences in the mean GSH concentration and GSH/GSSG ratio between the G6PD deficiency-positive and negative groups when examined three days after sample preparation. CONCLUSION: The concentration of GSH and the ratio of GSH/GSSG in blood measured using MS/MS on the first day of sample preparation are consistent with G6PD activity and are helpful for diagnosing G6PD deficiency.

Neonatal Intrahepatic Cholestasis Caused by Citrin Deficiency Differentiated from Biliary Atresia.

Purpose The aim of this article is to differentiate neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) from biliary atresia (BA) by total hexose. Methods A total of 11 patients with NICCD, 29 patients with BA, and 4,898 children as controls were involved in this study. The blood concentration of amino acids, carnitine, acylcarnitines, and total hexose were measured in dry blood spots (DBS) using tandem mass spectrometry (MS/MS). Results In the patients with NICCD, the blood concentration of the total hexose (15.3 ± 9.0 mmol/L vs. 7.3 ± 2.7 mmol/L; p < 0.001), citrulline (Cit) (197.9 ± 93.7 µmol/L vs. 17.5 ± 7.4 µmol/L; p < 0.001) were higher than those of patients with BA. Using total hexose (> 10 mmol/L), Cit (> 55 µmol/L) to diagnose NICCD, the sensitivity and specificity were 66.7 and 97.8% and 90.0 and 99.1%, respectively, and all of the areas under the receiver-operating characteristic curves were greater than 0.85. Conclusion Elevated total hexose in DBS measured by MS/MS associated with elevated amino acids, especially Cit can be used to diagnose NICCD and differentiate it from BA.

Rapid and reliable detection of glucose-6-phosphate dehydrogenase (G6PD) gene mutations in Han Chinese using high-resolution melting analysis.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency, an X-linked inherited disease, is one of the most common enzymopathies and affects over 400 million people worldwide. In China at least 21 distinct point mutations have been identified so far. In this study high-resolution melting (HRM) analysis was used to screen for G6PD mutations in 260 unrelated Han Chinese individuals, and the rapidity and reliability of this method was investigated. The mutants were readily differentiated by using HRM analysis, which produced distinct melting curves for each tested mutation. Interestingly, G1388A and G1376T, the two most common variants accounting for 50% to 60% of G6PD deficiency mutations in the Chinese population, could be differentiated in a single reaction. Further, two G6PD mutations not previously reported in the Chinese population were identified in this study. One of these mutations, designated "G6PD Jiangxi G1340T," involved a G1340T substitution in exon 11, predicting a Gly447Val change in the protein. The other mutation involved a C406T substitution in exon 5. The frequencies of the common polymorphism site C1311T/IVS (intervening sequence) XI t93c between patients with G6PD and healthy volunteers were not significantly different. Thus, HRM analysis will be a useful alternative for screening G6PD mutations.

[Blood spot carnitine and acylcarnitine in newborn to adolescence: measured by tandem mass spectrometry].

OBJECTIVE: To determine the levels of blood spot carnitine and acylcarnitine in children aged 0-15 years by tandem mass spectrometry, offer basic data for evaluating carnitine nutritional status and diagnosing metabolic diseases of organic acid and fatty acid. METHODS: The concentration of carnitine and acylcarnitines were measured in blood spot by tandem mass spectrometry using underivatized samples. The samples included those from 1376 perinatal neonates, 49 neonates above 1 week of life, 64 children aged up to 1 year and 401 children aged 1 year to 15 years. A few premature infants and low birth weight infants were involved in perinatal neonates without selection. Other samples were taken from mainly outdoor patients for little surgical preoperative examination. Patients suffering from fever, diarrhea, liver disease, severe fat-metabolic diseases were excluded from this study. RESULTS: The concentrations of carnitine (C(0)); short-chain acylcarnitines (SC-AC), including acetyl (C(2)), propionyl (C(3)), malonyl (C(3)DC), butyryl (C(4)), methylmalonyl (C(4)DC), isovaleryl (C(5)), glutaryl (C(5)DC); middle-chain acylcarnitines (MC-AC), including hexanoyl (C(6)), hexanediol (C(6)DC), octylenoyl (C(8:1)), octanoyl (C(8)), decadienoyl (C(10:2)), decanoyl (C(10:1)), decanoyl (C(10)); total carnitine and acylcarnitines (TCAC)were lower in neonate, highest in 1-3 months of age, higher in 6-12 months of age, and kept at the same level between 2 and 15 years of age. The concentrations of total long-chain acylcarnitines (LC-AC), including lauren (C(12:1)), lauroyl (C(12)), tetradecanoyl (C(14:1)), tetradecanoyl (C(14)), 3-hydroxy-tetradecanoyl (C(14)OH), hexadecenoyl (C(16:1)), hexadecanoyl (C(16)), 3-hydroxy-hexadecanoyl (C(16)OH), 3-hydroxy-hexadecanoyl (C(16:1)OH), octadecadienoyl (C(18:2)), octadecenoyl (C(18:1)), octadecanoyl (C(18)), 3-hydroxy-octadecenoyl (C(18:1)OH), and 3-hydroxy-octadecanoyl (C(18)OH) were the highest in neonate, decreased gradually, and kept the same level between 2 and 15 years of age. The concentrations of C(0) (23.387 ± 7.702) µmol/L, (30.064 ± 8.252) µmol/L, (25.021 ± 6.630) µmol/L, of LC-AC (4.998 ± 1.557) µmol/L, (2.854 ± 0.821) µmol/L, (2.459 ± 0.553) µmol/L, of TCAC (43.497 ± 12.632) µmol/L, (49.013 ± 12.497) µmol/L, (39.656 ± 9.257) µmol/L were significantly different among the groups of neonate, up to 1 year and above 1 year (P < 0.01). The concentrations of C(0) (24.115 ± 7.715) µmol/L and TCAC (43.65 ± 5.252) µmol/L in perinatal male neonates were higher than that (22.696 ± 7.246) µmol/L, TCAC (41.90 ± 5.038) µmol/L in female neonates. The C(0)/TCAC ratio of neonatal group (54.0% ± 7.1%) was significantly lower than that in the children group (62.1% ± 6.1%, P < 0.05), LC-AC/TCAC (33.5% ± 6.0%), MC-AC/TCAC (1.3% ± 0.3%), SC-AC/TCAC (11.6% ± 2.5%)ratios of neonatal group were higher than that of children group respectively (30.1% ± 4.9%; 0.9% ± 0.6%; 6.5% ± 2.3%, P < 0.05). CONCLUSIONS: Concentrations and profiles of carnitine and acylcarnitines change significantly during the first year of life, the age should be considered as a factor when evaluating carnitine nutritional status and diagnosing metabolic diseases of organic acid and fatty acid. Concentrations of carnitine and acylcarnitines were a little higher in male neonates than in female.

[Adrenal function evaluation using ACTH stimulation test in children with sepsis and septic shock].

OBJECTIVE: Sepsis and septic shock remain a common problem that results in significant mortality and morbidity in pediatric intensive care units (PICU). According to literature, the use of more physiologic steroid replacement therapy is associated with hemodynamic and survival benefits in adult patients with relative adrenal insufficiency (RAI) and catecholamine-resistant septic shock. But little information is available in children. The aim of the current prospective study was to determine the prevalence of adrenal insufficiency in children with sepsis and septic shock using a low-dose adrenocorticotropic hormone (ACTH) stimulation test (1 microg/1.73 m2) in children. METHODS: The authors performed cortisol estimation at baseline and after low-dose (1 microg/1.73 m2) ACTH stimulation at 30 mins in children during the first 24 hours in patients with sepsis or septic shock admitted to our PICU. Adrenal insufficiency was defined as a response < or = 90 microg/L. Absolute adrenal insufficiency (AAI) was further defined as baseline cortisol (T0) < 200 microg/L and RAI insufficiency by T0 > or = 200 microg/L. RESULTS: Sixty-two consecutive cases with sepsis and septic shock admitted to PICU of Shanghai Jiaotong University Affiliated Children's Hospital from April, 2006 to March, 2007. The median age was 37.6 months (range, 2 - 168 months), and their gender distribution was 42 (67.7%) males and 20 (32.3%) females, 53 cases had sepsis (85.5%) and 9 had septic shock (14.5%). The mean pediatric critical illness score (PCIS) was 79.3 +/- 9.2 and median pediatric risk of mortality score (PRMSIII) 11.3 (5 - 19), respectively. Overall mortality of sepsis and septic shock was 27.42%. The evaluation of adrenal insufficiency was conducted as follows. (1) The mean cortisol levels at baseline (T0) and 30 mins after ACTH stimulation (T1) were (318.6 +/- 230.4) microg/L, (452.3 +/- 230.7) microg/L and (454.7 +/- 212.7) microg/L, (579.3 +/- 231.9) microg/L in patients with severe sepsis and septic shock group, respectively. There were no significant difference between the two groups (P > 0.05). (2) The proportion of patients with adrenal insufficiency in the study population was 40.3% as defined by a response < or = 90 microg/L post test. The proportion of patients with adrenal insufficiency in sepsis and septic shock were 39.6% and 44.4%, respectively (chi2) = 0.073, P > 0.05). (3) The serum T0 and T1 levels were (320.5 +/- 223.9) microg/L, (462.3 +/- 212.0) microg/L and (384.3 +/- 258.3) microg/L, (500.7 +/- 470.6) microg/L, respectively, and the proportion of patients with adrenal insufficiency were 37.8% and 47.1% in the survivors and the dead (P > 0.05). The levels of T0 and T1 were related to the PCIS (P < 0.05). The morbidity of adrenal insufficiency was not related to the PCIS, PRISMIII, and number of organ that developed functional insufficiency (P > 0.05). CONCLUSIONS: Adrenal insufficiency may occur in patients with sepsis and septic shock in children. ACTH stimulation test may be helpful to determine whether corticosteroid therapy has a survival benefit in patients with relative adrenal insufficiency. A low-dose ACTH stimulation test can be used to evaluate the adrenal function status of severe sepsis and septic shock in children.