Discrimination of blood metabolomics profiles in neonates with idiopathic polyhydramnios.

This study aimed to compare the blood metabolic status of neonates with idiopathic polyhydramnios (IPH) and those with normal amniotic fluid, and to explore the relationship between IPH and fetal health. Blood metabolites of 32 patients with IPH and 32 normal controls admitted to the Sixth Affiliated Hospital of Sun Yat-sen University between January 2017 and December 2022 were analyzed using liquid chromatography-mass spectrometry (LC-MS/MS). Orthogonal partial least squares discriminant analysis (OPLS-DA) and metabolite enrichment analyses were performed to identify the differential metabolites and metabolic pathways. There was a significant difference in the blood metabolism between newborns with IPH and those with normal amniotic fluid. Six discriminant metabolites were identified: glutamate, serine, asparagine, aspartic acid, homocysteine, and phenylalanine. Differential metabolites were mainly enriched in two pathways: aminoacyl-tRNA biosynthesis, and alanine, aspartate, and glutamate metabolism. CONCLUSIONS: This study is the first to investigate metabolomic profiles in newborns with IPH and examine the correlation between IPH and fetal health. Differential metabolites and pathways may affect amino acid synthesis and the nervous system. Continuous attention to the development of the nervous system in children with IPH is necessary. WHAT IS KNOWN: • There is an increased risk of adverse pregnancy outcomes with IPH, such as perinatal death, neonatal asphyxia, neonatal intensive care admission, cesarean section rates, and postpartum hemorrhage. • Children with a history of IPH have a higher proportion of defects than the general population, particularly central nervous system problems, neuromuscular disorders, and other malformations. WHAT IS NEW: • In neonates with IPH, six differential metabolites were identified with significant differences and good AUC values using LC-MS/MS analysis: glutamic acid, serine, asparagine, aspartic acid, homocysteine, and phenylalanine, which were mainly enriched in two metabolic pathways: aminoacyl-tRNA biosynthesis and alanine, aspartate, and glutamate metabolism. • These differential metabolites and pathways may affect amino acid synthesis and development of the nervous system in neonates with IPH.

[Blood metabolites in preterm infants with retinopathy of prematurity based on tandem mass spectrometry: a preliminary study]. / åŸºäºŽè´¨è°±æŠ€æœ¯çš„æ—©äº§å„¿è§†ç½‘è†œç— è¡€ä»£è°¢äº§ç‰©çš„åˆæ­¥ç ”ç©¶.

OBJECTIVES: To study new biomarkers for the early diagnosis of retinopathy of prematurity (ROP) by analyzing the differences in blood metabolites based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) and metabolomics. METHODS: Dried blood spots were collected from 21 infants with ROP (ROP group) and 21 infants without ROP (non-ROP group) who were hospitalized in the Sixth Affiliated Hospital of Sun Yat-sen University from January 2013 to December 2016. LC-MS/MS was used to measure the metabolites, and orthogonal partial least squares-discriminant analysis was used to search for differentially expressed metabolites and biomarkers. RESULTS: There was a significant difference in blood metabolic profiles between the ROP and non-ROP groups. The pattern recognition analysis, Score-plot, and weight analysis obtained 10 amino acids with a relatively large difference. Further statistical analysis showed that the ROP group had significant increases in blood levels of glutamic acid, leucine, aspartic acid, ornithine, and glycine compared with the non-ROP group (P<0.05). The receiver operating characteristic curve analysis showed that glutamic acid and ornithine had the highest value in diagnosing ROP. CONCLUSIONS: Blood metabolites in preterm infants with ROP are different from those without ROP. Glutamic acid and ornithine are the metabolic markers for diagnosing ROP. LC-MS/MS combined with metabolomics analysis has a potential application value in the early identification and diagnosis of ROP.

[Analysis of clinical characteristics and genetic variant in a child with Nicolaides-Baraitser syndrome due to maternal mosaicism].

OBJECTIVE: To carry out genetic testing for a child featuring global developmental delay, abnormal liver function, congenital heart disease, and brain malformation. METHODS: Peripheral blood samples of the child and his parents were collected for the extraction of genomic DNA and trio-whole exome sequencing. Candidate variant was verified by Sanger sequencing. RESULTS: Genetic testing revealed that the child has harbored a heterozygous c.2002G>T (p.Glu668Ter) variant of the SMARCA2 gene, which was predicted to be likely pathogenic by bioinformatic analysis. His mother was found to be a low-percentage mosaic for the same variant, with a ratio of 0.054 (246/4549). CONCLUSION: The child was diagnosed with Nicolaides-Baraitser syndrome resulting from maternal mosaicism for the SMARCA2 gene variant.

[Tatton-Brown-Rahman syndrome associated with the DNMT3A gene: a case report and literature review].

This article reports the clinical and genetic features of a case of Tatton-Brown-Rahman syndrome (TBRS) caused by DNMT3A gene mutation. A girl, aged 8 months and 14 days, had the clinical manifestations of psychomotor retardation, hypotonia, ventricular enlargement, and tonsillar hernia malformation. Gene analysis identified a novel heterozygous mutation, c.134C>T(p.A45V), in the DNMT3A gene, and the wild type was observed at this locus in her parents. This mutation was determined as a possible pathogenic mutation according to the guidelines of American College of Medical Genetics and Genomics, which had not been reported in previous studies and conformed to autosomal dominant inheritance. This child was diagnosed with TBRS. TBRS often has a good prognosis, with overgrowth and mental retardation as the most common clinical manifestations, and behavioral and psychiatric problems, scoliosis, and afebrile seizures are possible complications of TBRS. The possibility of TBRS should be considered for children with overgrowth and mental retardation, and genetic diagnosis should be conducted when necessary.

Expression and clinical significance of PD-L1 and BRAF expression in nasopharyngeal carcinoma.

BACKGROUND: The prognostic value of programmed death-ligand 1 (PD-L1) and BRAF expression in nasopharyngeal carcinoma (NPC) is not well-defined. In this study we investigated alterations in PD-L1, BRAF and EGFR by using immunohistochemistry analysis in a cohort of consecutively enrolled NPC patients. METHODS: A retrospective review of 154 NPC patients form our previous study (BMC Cancer. 2013; 13:226) were conducted. Survival and prognostic impacts were analyzed based on PD-L1, BRAF and EGFR expression levels. RESULTS: One hundred fifty four patients were included in this study. PD-L1 expression was detected in 87.7% of patients; 14.3% had 1-5% PD-L1 expression, 47.4% had 5-49% expression while 26% had ≥50% expression Higher PD-L1 expression was significantly associated with shorter PFS and OS. The median PFS was 25 months (95% CI 15.7-34.3 months) and OS was 35 months (95% CI 22.60-47.4 months) for patients with PD-L1 expression ≥50%; both median PFS and OS were not yet reached for patients with PD-L1 expression < 50%. PFS was significantly higher in BRAF mutation positive patients (5-year PFS: 55.1% vs. 30.8%, P = 0.044). CONCLUSION: Tumor PD-L1 expression and BRAF mutation are associated with poor outcomes in patients with NPC. This study was retrospectively registered in ClinicalTrials.gov (NCT03989297) on 2019-6-18.

MicroRNA-23a promotes colorectal cancer cell survival by targeting PDK4.

MicroRNA (miR) is important regulators of gene expression, and aberrant miR expression has been linked to oncogenesis; however, little is understood about their contribution to colorectal cancer (CRC). Here, we determined that miR-23a is overexpressed in human colorectal cancer cell lines and tissues compared with that of normal cells. The stable over-expression of miR-23a in CRC cells was sufficient to promote cell proliferation in vitro and in vivo. Further studies showed that miR-23a can directly bind to the 3'untranslated region (3'UTR) of PDK4 mRNA and subsequently repress both the mRNA and protein expressions of PDK4. PDK4 negatively regulate CRC proliferation via suppressing PDH activity. Ectopic expression of PDK4 by transiently transfected with PDK4 vector encoding the entire coding sequence could reverse the effects of miR-23a on CRC proliferation. By this way, miR-23a promotes PDH activation and oxidative phosphorylation to generate sufficient ATP for cell proliferation. Our results illustrated that the up-regulation of miR-23a played an important role in CRC cell proliferation through direct repressing PDK4, suggesting a potential application of miR-23a in prognosis prediction and therapeutic application in CRC.

[Clinical and variant analysis of 15 patients with methylmalonic acidemia].

OBJECTIVE: To report on clinical characteristics and genetic findings in 15 Chinese patients with methylmalonic acidemia (MMA). METHODS: For the 15 MMA patients detected by tandem mass spectrometry, genetic analysis was carried out in twelve pedigrees. Clinical characteristics, genetic finding, treatment and outcomes were retrospectively analyzed. RESULTS: The main features of the patients included poor feeding, recurrent vomiting, lethargy, seizure and development retardation. Blood propionylcarnitine (except for 3 patients), its ratio with acetylcarnitine, and urine methylmalonic acid were increased in all patients. Twelve patients were diagnosed genetically, which included 7 with MUT variants, 4 with MMACHC variants, and 1 with MMAB variant. Nine MUT variants were detected, among which c.1159A>C, 753+1delGinsTGGTTATTA and c.504del were novel. Six known pathogenic MMACHC variants and two novel MMAB variants (c.289_290delGG, c.566G>A) were also detected. Seven patients died of metabolic crises within a year, others had improved effectively following the treatment, but had mild to severe growth delay and/or developmental retardation. CONCLUSION: The clinical manifestation of MMA are complex. Most patients have variants of the MUT and MMACHC genes. High mortality may occur before one year of age.

[Construction of a mouse model of cblC type methylmalonic acidemia with W203X mutation based on the CRISPR/Cas9 technology].

OBJECTIVE: To construct a W203X-mutant mouse model of cblC type methylmalonic acidemia based on the CRISPR/Cas9 technology. METHODS: At first, BLAST was used to compare the conservative nature of the cblC gene and protein sequences in humans and mice, and then, the CRISPR/Cas9 technology was used for microinjection of mouse fertilized eggs to obtain heterozygous F1 mice. Hybridization was performed for these mice to obtain homozygous W203X-mutant mice. The blood level of the metabolite propionyl carnitine (C3) was measured for homozygous mutant mice, heterozygous littermates, and wild-type mice. RESULTS: The gene and protein sequences of MMACHC, the pathogenic gene for cblC type methylmalonic acidemia, were highly conserved in humans and mice. The homozygous W203X-mutant mice were successfully obtained by the CRISPR/Cas9 technology, and there was a significant increase in C3 in these mice at 24 hours after birth (P<0.001). CONCLUSIONS: A W203X-mutant mouse model of cblC type methylmalonic acidemia is successfully constructed by the CRISPR/Cas9 technology.

Association of Heparin-binding EGF-like Growth Factor Polymorphisms With Necrotizing Enterocolitis in Preterm Infants.

Heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF) protects the intestines from injury in experimental necrotizing enterocolitis (NEC). We hypothesized that polymorphisms in the HB-EGF gene lead to low HB-EGF production in peripheral blood and increased risk of NEC in the Chinese Han population. To test this hypothesis, 30 NEC patients and 80 control subjects were selected. Five HB-EGF single-nucleotide polymorphisms (SNPs) and its plasma levels were measured by genotyping and enzyme-linked immunosorbent assay, respectively. Only 1 out of the 5 SNPs showed a notable result. The notable SNP (rs4912711) was associated with NEC in its minor allele frequency and its "G/T" genotype distribution. In addition, plasma HB-EGF levels were reduced especially the "G/T" genotype in NEC patients. Our data suggest that if validated in larger studies screening for HB-EGF SNPs/genotypes and plasma levels may be useful as a risk factor for NEC in the future.

Gene Mutation Analysis and Prenatal Diagnosis of the Ornithine Transcarbamylase (OTC) Gene in Two Families with Ornithine Transcarbamylase Deficiency.

BACKGROUND The aim of this study was to perform gene detection in 2 clinical cases of highly suspected ornithine transcarbamylase deficiency (OTCD) pediatric patients by first-generation sequencing technology in order to confirm the pathogenic genetic factors of their families and allow the families to undergo genetic counselling and prenatal diagnosis. MATERIAL AND METHODS The peripheral DNA samples of 2 children with highly suspected OTCD (the probands) and their parents were collected. DNA fragments corresponding to exons 1-10 of the OTC gene from the samples were amplified using polymerase chain reaction (PCR), and then subjected to Sanger sequencing to confirm the pathogenic mutation sites. RESULTS The probands were both confirmed to have OTCD. The proband in Family 1 was a male carrying a c.867+1G>C mutation at a splice site within the OTC gene. The gene detection results of amniotic fluid cells at 16 weeks of pregnancy showed that the fetus was a male who also carried the c.867+1G>C mutation. The proband in Family 2 was a male carrying a c.782T>C(p. I261T) mutation in the OTC gene. The gene detection results of amniotic fluid cells at 18 weeks showed that the fetus was a male without pathogenic mutations in the OTC gene. The gene detection results of peripheral blood from the fetus after birth were consistent with those obtained from amniotic fluid cells. CONCLUSIONS Pediatric children who are clinically suspected of OTCD can receive a definitive diagnosis through OTC gene detection.

Fluorescent sensors based on [12]aneN3-modified BODIPY: Discrimination of different biological thiols in aqueous solution and living cells.

Two fluorescent probes, 1 and 2, derived from borondipyrromethene (BODIPY) modified with macrocyclic polyamine [12]aneN3, were synthesized and applied in the discrimination of cysteine (Cys), homocysteine (Hcy), and glutathione (GSH) with absorption and fluorescent spectroscopy in comparison. It was found that Boc-protected 1 showed highly sensitive and selective recognition of GSH over Cys and Hcy; while probe 2 was able to distinguish the three different thiols due to their different reactivities. With its water-solubility, rapid responsiveness, high sensitivity and low cytotoxicity, probe 2 was successfully applied in the fast detection of three biothiols in living cells.

Melatonin alleviates necrotizing enterocolitis by reducing bile acid levels through the SIRT1/FXR signalling axis.

Bile acids (BAs) have increasingly been implicated in the onset and progression of necrotizing enterocolitis (NEC); multiple findings have demonstrated their ability to induce damage to the intestinal epithelium, thereby exacerbating disease severity. Although we previously showed that melatonin was able to treat NEC by correcting the Treg/Th17 imbalance, the modulatory effect of melatonin on BAs remains unclear. In this study, we conducted transcriptome analysis on intestinal tissues from patients with NEC and validated these findings. Subsequently, we treated mice with melatonin alone or in combination with an agonist/inhibitor of Sirtuin 1 (SIRT1) to assess faecal and serum BA levels, the expression levels of BA transporters and regulators, and the extent of intestinal injury. Our transcriptome results indicated dysregulation of BA metabolism and abnormal expression of BA transporters in patients with NEC, which were also observed in our NEC mouse model. Furthermore, exogenous BAs were found to aggravate NEC severity in mice. Notably, melatonin effectively restored the aberrant expression of BA transporters, such as apical membrane sodium-dependent bile acid transporters (ASBT), ileal bile acid-binding protein (IBABP), and organic solute transporter-alpha (OST-α), by upregulating SIRT1 expression while reducing farnesoid X receptor (FXR) acetylation, consequently leading to decreased serum and faecal BA levels and mitigated NEC severity. Thus, we propose a potential mechanism through which melatonin reduces BA levels via the SIRT1/FXR signalling axis in an NEC mouse model. Collectively, these results highlight that melatonin holds promise for reducing BA levels and represents a promising therapeutic strategy for treating NEC.

Description of a new species of the genus Woznessenskia from Xizang, China (Orthoptera: Gryllacrididae).

The gryllacridid genus Woznessenskia Gorochov, 2002 comprises 13 extant species from Asia, with 8 species reported from China and 5 species reported from Vietnam. A new species from Xizang, China, Woznessenskia lianhua sp. nov., is reported in this paper.

Hsa_circ_0026344 suppresses gastric cancer progression via modulating the miR-1290/FBP2 axis.

BACKGROUND: Circular RNAs (circRNAs) are a novel type of noncoding RNAs and play important roles in tumorigenesis, including gastric cancer (GC). However, the functions of most circRNAs remain poorly understood. In our study, we mainly learn the influence of hsa_circ_0026344 (circ_0026344) in GC progression. METHODS: Circ_0026344, miR-1290 and Fructose-1,6-bisphosphatase 2 (FBP2) expression was determined by quantitative real-time polymerase chain reaction (qRT-PCR). GC cell proliferation, migration, and invasion were detected by colony formation, 5-ethynyl-2'-deoxyuridine (EdU), and transwell assays, respectively. The interaction between circ_0026344 and miR-1290 complex was evaluated by RNA pull-down assay. The interaction of miR-1290 with circ_0026344 or FBP2 was detected using dual-luciferase reporter assay. A xenograft model was established to determine the effect of circ_0026344 on GC tumor growth in vivo. RESULTS: Circ_0026344 expression was dramatically decreased in GC cells and tissues. Circ_0026344 overexpression inhibited GC cell proliferation, migration and invasion. MiR-1290 was predicted as a target of circ_0026344 and miR-1290 overexpression attenuated the anti-tumor effect of circ_0026344 on GC cells. Furthermore, we predicted FBP2 as the target of miR-1290. FBP2 knockdown reversed the effects of circ_0026344 knockdown on GC cell malignant behaviors. Functional analysis showed that circ_0026344 upregulated FBP2 expression via miR-1290. Additionally, in vivo studies demonstrated that circ_0026344 suppressed GC tumor progression. CONCLUSION: In conclusion, circ_0026344 inhibited GC cell proliferation via the miR-1290/FBP2 axis, which might provide a new therapeutic target for GC patients.

Brownfield redevelopment evaluation based on structure-process-outcome theory and continuous ordered weighted averaging operator-topology method.

As an important part of urban renewal, brownfield restoration and renovation are of great significance to the sustainable development of cities. The structure-process-outcome theory was introduced into this study to improve the rationality and scientific vigor of the redevelopment assessment process and to evaluate whether brownfield sites meet the conditions for redevelopment. Based on this theory, the relationship among structures, processes and outcomes can be well elucidated. Specifically, a good structure should contribute to an effective process, which will increase the possibility of a favorable outcome. The basic conditions, practice principles, and result orientation in the whole procedure of brownfield redevelopment were comprehensively analyzed. In addition, a more complete and reasonable three-level evaluation index system for brownfield redevelopment was established. In order to reduce the subjectivity in the evaluation process, an unbiased scientific brownfield redevelopment evaluation model was constructed using the continuous ordered weighted averaging operator-topology method. The evaluation decision system was applied to the renovation of a tract project in Chengdu, China. The results proved that the model could effectively and accurately evaluate the quality level of the brownfield redevelopment project, and the proposed recommendations can provide a basis for decision-making.

Adipose tissue macrophage-derived exosomal miR-210-5p in modulating insulin sensitivity in rats born small for gestational age with catch-up growth.

Background: Insulin resistance has been implicated in the pathogenesis of children born small for gestational age (SGA) with catch-up growth (CUG). Adipose tissue macrophages (ATMs) regulate insulin resistance by secreting exosomes containing microRNA (miRNA) cargo; however, their pathogenic roles and molecular mechanism are not fully understood. This study aimed to investigate the role of miR-210-5p in rats born SGA with CUG and insulin resistance. Methods: The dietary needs of pregnant rats were restricted to ensure the birth of SGA rats. Transmission electron microscopy (TEM) and Western blot analysis were used to identify the exosomes from ATMs of CUG-SGA and adequate-for-gestational-age (AGA) rats. PKH-67 staining was performed to confirm the uptake of exosomes. miR-210-5p expression was measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Glucose uptake and output were detected with glucose uptake and output assays, respectively. Insulin resistance was detected with glucose and insulin tolerance tests in vivo. The interaction between miR-210-5p and SID1 transmembrane family member 2 (SIDT2) was validated with dual-luciferase reporter assay. Results: miR-210-5p was observed to be highly expressed in the exosomes derived from the ATMs of CUG-SGA rats. ATM-derived exosomes can serve as vehicles to deliver miR-210-5p into adipocytes, myocytes, and hepatocytes, where it can enhance cellular insulin resistance. SIDT2 was identified as a direct target gene of miR-210-5p. The miR-210-5p-induced insulin resistance was reversed by the restored SIDT2 expression. However, overexpression of SIDT2 abolished the inhibitory effect of CUG-SGA-ATM-exosomal miR-210-5p on insulin sensitivity in vivo. Conclusions: ATM-derived exosomal miR-210-5p promoted insulin resistance in CUG-SGA rats by targeting SIDT2, which may act as a new potential therapeutic target for children born SGA with CUG.

High-dimensional mass cytometry reveals systemic and local immune signatures in necrotizing enterocolitis.

Objective: Patients with necrotizing enterocolitis display severe gastrointestinal complications of prematurity, but the mechanism driving this clinical profile remains unknown. We used mass cytometry time-of-flight to characterize and compare immune cell populations in the blood and intestine tissue from patients with and without (controls) necrotizing enterocolitis at single-cell resolution. Methods: We completed a deep mapping of the immune system of the peripheral blood mononuclear cells and intestinal mucosa tissue using mass cytometry to evaluate immune cell types, which revealed global immune dysregulation characteristics underlying necrotizing enterocolitis. Results: Compared with controls, natural killer cells display signs of heightened activation and increased cytotoxic potential in the peripheral blood and mucosa of patients with necrotizing enterocolitis. Furthermore, CD4+ T effector memory cells, non-classical monocytes, active dendritic cells, and neutrophils were specifically enriched in the mucosa, suggesting trafficking from the periphery to areas of inflammation. Moreover, we mapped the systemic and local distinct immune signatures suggesting patterns of cell localization in necrotizing enterocolitis. Conclusion: We used mass cytometry time-of-flight technology to identify immune cell populations specific to the peripheral blood and intestinal mucosa tissue from patients with necrotizing enterocolitis and controls. This information might be used to develop precise diagnosis and therapies that target specific cell populations in patients with necrotizing enterocolitis.

Multiphase holdup measurement of oil-gas-water flow using new dual receiver fiber-optical probe array multiphase logging tool.

To solve the problem of multiphase holdup measurement, a new dual-receiver fiber-optical probe array multiphase logging tool (NDRFOPA_MLT) is designed and developed. This paper first constructed the mechanism model of an NDRFOP for phase holdup measurement by using the ray tracing method and theoretically analyzed the feasibility of NDRFOP to measure phase holdup; considering the shortcomings of NDRFOP local measurement, a NDRFOPA sensor for oil production three-phase flow is designed and developed. At the same time, the volume of fluid model was used to simulate the distribution characteristics of the medium in the NDRFOPA_MLT measurement pipeline under the working conditions of oil-gas-water flow with a total flow rate range of 0.42-1.25 m3/h, water holdup range of 50%-80%, oil holdup range of 10%-30%, and gas holdup range of 10%-40%. In addition, the NDRFOPA_MLT measurement models for different multiphase flow conditions were established by the ZEMAX ray tracing method, and the sensitivity distribution, response characteristics, and phase holdup measurement methods were studied to obtain the phase holdup measurement results under multiphase flow conditions. Finally, a multiphase flow experimental platform with a measurement pipe diameter of 20 mm and a measurement pipe length of 300 mm was established, and experiments were conducted under multiphase flow conditions, such as a gas flow rate range of 0.04-0.16 m3/h, oil flow rate range of 0.64-1.70 m3/h, and water flow rate range of 0.53-2.58 m3/h. The experimental results showed that phase holdup measurement error was mainly kept within 10%.

Dynamic changes of the gut microbial colonization in preterm infants with different time points after birth.

Risks associated with preterm birth are unevenly distributed across all gestations. At earlier gestational ages, complications such as necrotizing enterocolitis (NEC) and late-onset sepsis (LOS) conditions are significantly more common and are associated with a shift in the composition of the gut microbiome. Conventional bacterial culture techniques demonstrate that the colonization of the gut microbiota of preterm infants differs significantly from that of healthy-term infants. The current study aimed to investigate the impact of preterm infancy on the dynamic changes of fecal microbiota in preterm infants at different time points (1, 7, 14, 21, 28, and 42 days) after birth. We selected 12 preterm infants hospitalized in the Sixth Affiliated Hospital of Sun Yat-sen University from January 2017 to December 2017. A total of 130 fecal specimens from preterm infants were analyzed using 16S rRNA gene sequencing. We found that the colonization process of fecal microbiota in preterm infants is highly dynamic at different time points after birth, i.e., Exiguobacterium, Acinetobacter, and Citrobacter showed a declining abundance pattern with the advancement of age, while the bacterial groups of Enterococcus (Klebsiella and Escherichia coli) gradually grew and became the main microbiota during the development of fecal microbiota in preterm infants at the age of 42 days. Furthermore, the colonization of intestinal Bifidobacteria in preterm infants was relatively late and did not rapidly become the predominant microbiota. Moreover, the results also showed the presence of Chryseobacterium bacterial group, whose colonization was different in different time point groups. Conclusively, our findings deepen our comprehension and offer new perspectives on targeting particular bacteria in the treatment of preterm infants at different time points after birth.

Increased acylcarnitine ratio indices in newborn screening for carnitine-acylcarnitine translocase deficiency shows increased sensitivity and reduced false-positivity.

Background: Carnitine-acylcarnitine translocase (CACT) deficiency is a rare autosomal recessive metabolic disorder of mitochondrial long-chain fatty acid oxidation. Newborn screening via tandem mass spectrometry (MS/MS) technology enables early diagnosis. However, previous analyses of MS/MS data of patients showed that some results were misdiagnosed because they did not show typical acylcarnitine profiles of CACT deficiency. This study aimed to identify additional indices to assist the diagnosis of CACT deficiency. Methods: To evaluate the acylcarnitine profile and the acylcarnitine ratios of individuals with CACT deficiency, the MS/MS data of 15 patients diagnosed via genetic testing were retrospectively analysed. The sensitivity and false-positive rates of primary acylcarnitine markers and ratio indices were validated using the data from 28,261 newborns and 53 false-positive cases. Additionally, the MS/MS data of 20 newborns carrying the c.199-10T>G mutation in SLC25A20 and 40 normal controls were compared to verify whether the carriers had abnormal acylcarnitine concentrations. Results: The acylcarnitine profiles from 15 patients were classified into three categories using C12, C14, C16, C18, C16:1, C18:1, and C18:2 as the primary diagnostic markers. The first category represented a typical profile (P1-P6). The second category for patients P7 and P8 showed a significant decrease in the C0 level and a normal concentration of long-chain acylcarnitines. The third category for patients P9-P15 showed the presence of interfering acylcarnitines. The second and third categories may have been misdiagnosed. An acylcarnitine ratio analysis showed that C14/C3, C16/C2, C16/C3, C18/C3, C16:1/C3, and C16:1-OH/C3 were significantly increased in all 15 patients. The verification of 28,261 newborn screening results showed that the false-positive rate of ratios, except for (C16 + C18)/C0, was lower than that of acylcarnitine indices (0.02-0.08% vs. 0.16-0.88%). None of the single long-chain acylcarnitines could separate patients from the false-positive cases; however, all ratios produced good discrimination between the two groups. Conclusions: Based on the primary acylcarnitine markers alone, CACT deficiency can be misdiagnosed in newborn screening. The ratios of the primary markers (C16 + C18:1)/C2, C16/C2, C16:1/C3, and C16:1-OH/C3 can facilitate the diagnosis of CACT deficiency, thereby increasing sensitivity and reducing false-positivity.