Validation of an AI-Powered Automated X-ray Bone Age Analyzer in Chinese Children and Adolescents: A Comparison with the Tanner-Whitehouse 3 Method.

INTRODUCTION: Automated bone age assessment (BAA) is of growing interest because of its accuracy and time efficiency in daily practice. In this study, we validated the clinical applicability of a commercially available artificial intelligence (AI)-powered X-ray bone age analyzer equipped with a deep learning-based automated BAA system and compared its performance with that of the Tanner-Whitehouse 3 (TW-3) method. METHODS: Radiographs prospectively collected from 30 centers across various regions in China, including 900 Chinese children and adolescents, were assessed independently by six doctors (three experts and three residents) and an AI analyzer for TW3 radius, ulna, and short bones (RUS) and TW3 carpal bone age. The experts' mean estimates were accepted as the gold standard. The performance of the AI analyzer was compared with that of each resident. RESULTS: For the estimation of TW3-RUS, the AI analyzer had a mean absolute error (MAE) of 0.48 ± 0.42. The percentage of patients with an absolute error of < 1.0 years was 86.78%. The MAE was significantly lower than that of rater 1 (0.54 ± 0.49, P = 0.0068); however, it was not significant for rater 2 (0.48 ± 0.48) or rater 3 (0.49 ± 0.46). For TW3 carpal, the AI analyzer had an MAE of 0.48 ± 0.65. The percentage of patients with an absolute error of < 1.0 years was 88.78%. The MAE was significantly lower than that of rater 2 (0.58 ± 0.67, P = 0.0018) and numerically lower for rater 1 (0.54 ± 0.64) and rater 3 (0.50 ± 0.53). These results were consistent for the subgroups according to sex, and differences between the age groups were observed. CONCLUSION: In this comprehensive validation study conducted in China, an AI-powered X-ray bone age analyzer showed accuracies that matched or exceeded those of doctor raters. This method may improve the efficiency of clinical routines by reducing reading time without compromising accuracy.

Assessing bone age, or how developed a child's skeleton is, is important in medical care, but the standard method can be time-consuming. Using AI to automatically assess bone age from X-ray images may improve efficiency without reducing accuracy. In this study, we evaluated how well an AI-powered X-ray bone age analyzer performed compared to the established Tanner­Whitehouse 3 (TW-3) method. X-ray images from 900 Chinese children and adolescents were collected from 30 centers. Six doctors (three experts, three residents) and the AI system independently assessed the TW-3 radius, ulna, and short bones (RUS) and TW-3 carpal bone age. The experts' assessments were considered the gold standard. The AI analyzer had an average error of 0.48 years for TW3-RUS bone age, with 87% of assessments within 1 year of the experts. For TW3 carpal bone age, the AI had an average error of 0.48 years, with 89% within 1 year. These results were similar to or better than those of the resident raters. These findings show the AI-powered analyzer can assess bone age as accurately as human raters. This technology may improve clinical efficiency by reducing the time required for bone age assessments without compromising accuracy.

Influence of the AC field intensity and frequency on composition and growth mechanism of Au-Pd alloy nanowires.

Au-Pd alloy nanowires with controllable morphology and composition are useful sensing materials for chemical and biological sensors. This report describes the preparation of such Au-Pd alloy nanowires from an aqueous solution by alternating current (AC) varied-frequency method, focusing on determining the dependence of the composition and morphology of the alloy nanowires on the electric field intensity and frequency. An electric field varied from 0.1 V x m(-1) to 0.4 x 10(6)V x m(-1) at 300 Hz frequency was used for the nucleation, followed by variation of the frequency between 1 and 20 MHz for the growth of the nanowires. The results showed that the Pd content in the alloy nanowires increased with the field intensity and frequency. The nanowire morphology with a less branching and better alignment was obtained at the increased frequency. XRD results showed that the phase structure of the alloy nanowires was face-centered cubic lattice. The nanowire compositions were shown controllable by changing the AC field intensity, frequency, as well as the metal ion ratio in the solution. The growth of the nanowires was shown to obey the Maxwell-Wanger (M-W) law.

Mutations of the phenylalanine hydroxylase gene in patients with phenylketonuria in Shanxi, China.

The variation in mutations in exons 3, 6, 7, 11 and 12 of the phenylalanine hydroxylase (PAH) gene was investigated in 59 children with phenylketonuria (PKU) and 100 normal children. Three single nucleotide polymorphisms were detected by sequence analysis. The mutational frequencies of cDNA 696, cDNA 735 and cDNA 1155 in patients were 96.2%, 76.1% and 7.6%, respectively, whereas in healthy children the corresponding frequencies were 97.0%, 77.3% and 8.3%. In addition, 81 mutations accounted for 61.0% of the mutant alleles. R111X, H64 > TfsX9 and S70 del accounted for 5.1%, 0.8% and 0.8% mutation of alleles in exon 3, whereas EX6-96A > G accounted for 10.2% mutation of alleles in exon 6. R243Q had the highest incidence in exon 7 (12.7%), followed by Ivs7 + 2 T > A (5.1%) and T278I (2.5%). G247V, R252Q, L255S, R261Q and E280K accounted for 0.8% while Y356X and V399V accounted for 5.9% and 5.1%, respectively, in exon 11. R413P and A434D accounted for 5.9% and 2.5%, respectively, in exon 12. Seventy-two variant alleles accounted for the 16 mutations observed here. The mutation characteristics and distributions demonstrated that EX6-96A > G and R243Q were the hot regions for mutations in the PAH gene in Shanxi patients with PKU.

[Detection of exon 7 mutations of PAH gene in classical phenylketonuria by high-resolution melting analysis].

OBJECTIVE: To establish a simple, rapid, inexpensive and sensitive method for detecting hot region for mutations in exon 7 of PAH gene. METHODS: High-resolution melting (HRM) technology was used to detect a c.728G>A mutation in exon 7 in 88 patients with classical type phenylketonuria. Suspected mutations were validated by direct DNA sequencing. RESULTS: The results detected by HRM are in good agreement with the results obtained by direct sequencing. CONCLUSION: HRM analysis is a simple, rapid, inexpensive and sensitive method for detecting hot mutational region in exon 7 of PAH gene.

A Randomized Controlled Phase 3 Study on the Efficacy and Safety of Recombinant Human Growth Hormone in Children With Idiopathic Short Stature.

Background: To evaluate the safety and efficacy of daily somatropin (Jintropin®), a recombinant human growth hormone, in prepubertal children with ISS in China. Methods: This study was a multicenter, randomized, controlled, open-label, phase 3 study. All subjects were randomized 3:1 to daily somatropin 0.05 mg/kg/day or no treatment for 52 weeks. A total of 481 subjects with a mean baseline age of 5.8 years were enrolled in the study. The primary endpoint was change in (△) height standard deviation score (HT-SDS) for chronological age (CA). Secondary endpoints included △height from baseline; △bone age (BA)/CA; △height velocity (HV) and △insulin-like growth factor 1 (IGF-1 SDS). Results: △HT-SDS at week 52 was 1.04 ± 0.31 in the treatment group and 0.20 ± 0.33 in the control group (P < 0.001). At week 52, statistical significance was observed in the treatment group compared with control for △height (10.19 ± 1.47 cm vs. 5.85 ± 1.80 cm; P < 0.001), △BA/CA (0.04 ± 0.09 vs. 0.004 ± 0.01; P < 0.001), △HV (5.17 ± 3.70 cm/year vs. 0.75 ± 4.34 cm/year; P < 0.001), and △IGF-1 SDS (2.31 ± 1.20 vs. 0.22 ± 0.98; P < 0.001). The frequencies of treatment-emergent adverse events (TEAEs) were similar for the treatment and the control groups (89.8% vs. 82.4%); most TEAEs were mild to moderate in severity and 23 AEs were considered study-drug related. Conclusions: Daily subcutaneous administration of somatropin at 0.05 mg/kg/day for 52 weeks demonstrated improvement in growth outcomes and was well tolerated with a favorable safety profile. Trial Registration: ClinicalTrials.gov (identifier: NCT03635580). URL: https://clinicaltrials.gov/ct2/show/NCT03635580.

The pharmacokinetic and pharmacodynamic properties and short-term outcome of a novel once-weekly PEGylated recombinant human growth hormone for children with growth hormone deficiency.

Objectives: To investigate the pharmacokinetics (PK) and pharmacodynamics (PD) of Y-shape branched PEGylated recombinant human growth hormone (YPEG-rhGH) and evaluate its short-term efficacy and safety in children with growth hormone deficiency (GHD). Methods: A total of 43 children with GHD from 12 sites in China were enrolled in this randomized, multicenter, active-controlled, double-blind (YPEG-rhGH doses) trial. Patients were randomized 1:1:1:1 to 100, 120, and 140 µg/kg/week of YPEG-rhGH groups and daily rhGH 35 µg/kg/day groups. The treatment lasted 12 weeks. The primary outcome was the area under the curve of the change of insulin-like growth factor-1 (IGF-1). The secondary outcome was the height velocity (HV) increment at week 12. Results: A dose-dependent response of maximum plasma concentration (Cmax) and area under the concentration-time curves from 0 to 168 hours (AUC0-168h) were observed for YPEG-rhGH. The ratio of Cmax and the ratio of AUC0-168h from the first to the last dosing were 1.09~1.11 and 1.22~1.26 respectively. A YPEG-rhGH dose-dependent increase in area under effect curve (AUEC) of IGF-1 fold change was observed. Model-derived mean IGF-1 SDS was in the normal range for all three YPEG-rhGH doses. At week 12, HV was 7.07, 10.39, 12.27 cm/year, and 11.58 cm/year for YPEG-rhGH 100, 120, and 140 µg/kg/week and daily rhGH respectively. Adherence and safety were consistent with the profile of daily rhGH. No related serious adverse events were reported. Conclusion: The PK/PD suggests that YPEG-rhGH is suitable for the once-weekly treatment of pediatric GHD. YPEG-rhGH 120 ~ 140 µg/kg/week provides the closest HV increment with similar safety and tolerability compared to daily rhGH 35 µg/kg/day in children with GHD. Clinical Trial Registration: ClinicalTrials.gov, identifier [NCT04513171].

[Study on the mutations of phenylalanine hydroxylase gene in patients with phenylketonuria in Shanxi province].

OBJECTIVE: To study the mutations in exons 3, 6, 7, 11 and 12 of the phenylalanine hydroxylase gene (PAH) in Shanxi population. METHODS: The mutations in exons 3, 6, 7, 11 and 12 and flanking sequences of PAH gene were detected by PCR-DNA sequencing, in 59 patients with phynelketonuria(PKU) and 100 healthy children from Shanxi province. RESULTS: By sequence analysis, three single nucleotide polymorphism (SNP) Q232Q (CAA>CAG), V245V (GTG>GTA) and L385L (CTG>CTC) were detected in both the patients and healthy children, with the frequencies of nt 696, 735 and 1155 of the PAH cDNA up to 96.2%, 76.1% and 7.6% in patients respectively, and 97.0%, 77.3% and 8.3% respectively in the healthy controls. In addition, 72 different mutations accounting for 61.0% of mutant alleles were identified in the patients only. In exon 3, R111X, H64>TfsX9 and S70 del were found accounting for 5.1%, 0.8% and 0.8%; EX6-96A>G in exon 6 was found accounting for 10.2%. In exon 7, R243Q was the highest incidence accounting for 12.7%, followed by Ivs7+2 T>A(5.1%) and T278I(2.5%); the lowest incidences were G247V, R252Q, L255S, R261Q and E280K accounting for 0.8 %, respectively. In exon 11, Y356X (5.9%) and V399V (5.1%) were found; in exon 12, R413P and A434D were found accounting for 5.9% and 2.5%. In total, 9 missense mutations, 3 splice site mutations, 2 nonsense mutations and 2 deletions were included in 16 kinds of different mutations. CONCLUSION: The mutation characteristics and distribution in exons 3, 6, 7, 11 and 12 of the PAH gene have been identified, and it suggested that the EX6-96A>G and R243Q were the hot spots of PAH gene mutations in Shanxi PKU population.

CpG islands around exon 1 in the succinyl-CoA:3-ketoacid CoA transferase (SCOT) gene are hypomethylated even in human and mouse hepatic tissues where SCOT gene expression is completely suppressed.

In ketone body metabolism, hepatocyte-specific silencing of the succinyl-CoA:3-ketoacid CoA transferase (SCOT) gene appears to be physiologically important to avoid a futile cycle in the liver, whereas the SCOT gene is expressed in extrahepatic tissues. It is not possible to explain hepatocyte-specific silencing by cis-elements in the 2.2-kb 5' flanking region. The molecular basis of this gene silencing is unknown thus far. In the present study, the methylation status of CpG islands around exon 1 in the SCOT gene was analyzed by sodium bisulfite treatment and by sequencing of genomic DNA from the HepG2, Chang liver and HeLa human cell lines, and also from mouse liver, heart and kidney cells. Most CpG dinucleotides in the CpG island of the human SCOT promoter region were not methylated in the DNA of HeLa and Chang cells, while HepG2 DNA was hypomethylated in this CpG island. CpG dinucleotides in the mouse SCOT CpG island were almost completely unmethylated in the liver DNA as well as in the heart and kidney DNA. CpG islands around the promoter region of the SCOT gene were hypomethylated in the DNA from both human HepG2 cells and mouse liver. Hence, methylation status does not contribute to hepatocyte-specific SCOT gene silencing.

Mutation in the Q28SDD31SD site, but not in the two SQ sites of the survival of motor neuron protein, affects its foci formation.

The survival of motor neuron (SMN) protein forms a multiprotein complex (SMN complex) with Gemin proteins. The complex is known to play a crucial role in RNA metabolism. Several lines of evidence show that SMN is phosphorylated at serine and/or threonine residues. In this study, we hypothesized that SMN is phosphorylated at two kinds of serine residues, the Q28SDD31SD site and two SQ sites (80SQ and 163SQ). A FLAG-tagged wild-type construct (SMNfull) and three FLAG-tagged mutant constructs were made: an SMNAQ mutant with two AQ sites instead of two SQ sites at residues 80 and 163, an SMNQADDAD mutant with QADDAD instead of Q28SDD31SD, and an SMNAQ/QADDAD mutant with the two AQ sites and QADDAD. We expressed these mutants in HeLa cells and analyzed their phosphorylated bands by immunoblotting, the protein stability using cycloheximide, binding to Gemin 2 and foci formation. Mutations in Q28SDD31SD, but not in two SQ sites reduced the intensity of phosphorylation bands, indicating that Q28SDD31SD is the major phosphorylation site in SMN. Mutations in the two SQ sites and Q28SDD31SD did not affect protein stability and binding to Gemin 2. Whereas mutations in the two SQ sites did not cause apparent changes in foci formation, mutations in Q28SDD31SD resulted in a reduced number of large foci in the cytosol. We demonstrated that phosphorylation in Q28SDD31SD may be important in cytosolic foci formation.

Identification of Alu-mediated, large deletion-spanning introns 19-26 in PHKA2 in a patient with X-linked liver glycogenosis (hepatic phosphorylase kinase deficiency).

X-linked liver glycogenosis (XLG) is one of the most common glycogen storage diseases. We present the first case of a large PHKA2 gene deletion from intron 19 to intron 26 in an XLG patient. An aberrant cDNA with skipping of exons 20-26 was detected. Alu element-mediated unequal homologous recombination between an Alu-Jo in intron 19 and another Alu-Sg in intron 26 appears to be responsible for this deletion.

Identification of an Alu-mediated tandem duplication of exons 8 and 9 in a patient with mitochondrial acetoacetyl-CoA thiolase (T2) deficiency.

A tandem repeat of exons 8 and 9 was identified in the cDNA for mitochondrial acetoacetyl-CoA thiolase (T2) in a typical T2 deficient patient. Routine mutation analysis using PCR at the genomic level had failed to identify any mutations. Alu element-mediated unequal homologous recombination between an Alu-Jo in intron 7 and another Alu-Jo in intron 9 appears to be responsible for this duplication.

Single-base substitution at the last nucleotide of exon 6 (c.671G>A), resulting in the skipping of exon 6, and exons 6 and 7 in human succinyl-CoA:3-ketoacid CoA transferase (SCOT) gene.

Succinyl-CoA:3-ketoacid CoA transferase (SCOT, EC 2.8.3.5) is the key enzyme for ketone body utilization. Hereditary SCOT deficiency (MIM 245050) causes episodes of severe ketoacidosis. We identified a homozygous point mutation (c.671G>A) , which is a single-base substitution at the last nucleotide of exon 6, in a Turkish patient (GS12) with SCOT deficiency. This point mutation resulted in the skipping of exon 6, and exons 6 and 7 in human SCOT genes. To understand why the c.671G>A causes exons 6 and 7 skipping, nuclear RNA was separated from cytoplasmic RNA and both were analyzed by RT-PCR. In nuclear RNA, SCOT mRNA with exon 6 skipping was predominant and mRNA with exons 6 and 7 skipping was hardly detected, whereas the latter became one of major mRNA species in cytoplasmic RNA. This discrepancy was interpreted as follows: exon 6 skipping causes a frameshift and nonsense-mediated RNA decay in the cytosol, so mRNA with exon 6 skipping was unstable. On the other hand, SCOT mRNA with exons 6 and 7 is a minor transcript but it retains the reading-frame and is stable in cytosol. As a result, the latter mRNA is more abundant under steady-state conditions as compared to the former mRNA.

Kinetic and expression analyses of seven novel mutations in mitochondrial acetoacetyl-CoA thiolase (T2): identification of a Km mutant and an analysis of the mutational sites in the structure.

Mitochondrial acetoacetyl-CoA thiolase (T2) deficiency is an inborn error of metabolism that affects isoleucine catabolism and ketone body metabolism. We identified 7 novel and 2 previously reported mutations in six T2-deficient patients. Transient expression analysis of wild-type and eight mutant cDNAs was performed at 40, 37 and 30 degrees C. Although no significant residual activity was detected, mutant proteins were detected in the N158D, N158S, R208Q, Y219H and N282H mutants. Accumulation of these mutant proteins was temperature-sensitive with the highest expression levels at lower temperatures. Expression of Q73P and N353K cDNAs yielded neither residual T2 protein nor enzyme activity. An E252del mutant T2 was detected with a relative protein amount and enzyme activity of 30% and 25%, respectively, in comparison to the wild-type at 37 degrees C. The E252del mutant protein was more stable at 30 degrees C expression than 37 degrees C, but was essentially undetectable at 40 degrees C, indicating its temperature-sensitive instability. Kinetic studies revealed a twofold K(m) elevation for substrates coenzyme A and acetoacetyl-CoA in the E252del mutant, while V(max) was comparable to the wild-type. We conclude that the E252del is a temperature-sensitive K(m) mutant. This correlates well with the effect predicted from the T2 tertiary structure analysis, using the crystal structure of the human T2 homotetramer. The probable effect of the other mutations on the T2 tertiary structure was also evaluated.

Identification of Alu-mediated, large deletion-spanning exons 2-4 in a patient with mitochondrial acetoacetyl-CoA thiolase deficiency.

Mitochondrial acetoacetyl-CoA thiolase (T2) deficiency is a rare inherited metabolic disorder affecting isoleucine catabolism and ketone body metabolism. So far, more than 39 different mutations have been identified in 60 T2-deficient patients. However, no large deletions have been reported. We herein report the first case of a large T2 gene deletion from intron 1 to intron 4 in a T2-deficient patient (GK41). cDNA analysis revealed that an aberrant cDNA with exons 2-5 skipping was a major transcript, associated with a minor transcript of exons 2-4 skipping with a 94-bp insertion composed of an intron 1 sequence. Genomic analysis indicated an absence of PCR amplification of exons 2-4 and gene deletion was revealed by Southern blot analysis. Cloning and sequencing long range PCR products revealed a 6.4kb deletion. Alu element-mediated unequal homologous recombination between an Alu-Sx in intron 1 and another Alu-Y in intron 4 appears to be responsible for this deletion.