A de novo novel variant in the MT-TD gene is associated with prominent extra-neurologic manifestations.

Defects in the mitochondrial tRNA genes cause a group of highly clinically and genetically heterogeneous disorders, which poses a challenge for clinical identification and genetic diagnosis. Here, we present a pre-school boy with a novel MT-TD variant m.7560T>C at the heteroplasmy level of 76.53% in blood, 93.34% in urine sediments, and absent in the healthy mother's blood and urine. Besides convulsions, brain magnetic resonance imaging abnormalities and high plasma lactate, the boy presented with the prominent extra-neurologic phenotype including steroid-resistant nephrotic syndrome associated with focal segmental glomerulosclerosis characterized by abnormal mitochondria in podocytes, cortical blindness, and pancreatitis. To our knowledge, this is the unique case with MT-TD m.7560T>C-related multi-organ impairments, which expands the phenotypic and mutational spectrum of primary mitochondrial diseases.

The impact of vedolizumab therapy on extraintestinal manifestations in patients with inflammatory bowel disease: A systematic review and meta-analysis.

BACKGROUND AND AIM: Extraintestinal manifestations (EIMs) pose a significant threat in inflammatory bowel disease (IBD) patients. Vedolizumab (VDZ) primarily affects the gastrointestinal tract. However, its impact on EIMs remains uncertain. Therefore, we conducted this meta-analysis to examine the effects of VDZ on EIMs during treatment. METHODS: Relevant studies were identified by conducting thorough searches across electronic databases, including PubMed, Ovid Embase, Medline, and Cochrane CENTRAL. Primary outcomes focused on the proportion of patients with resolution for pre-existing EIMs in IBD patients receiving VDZ. Secondary outcomes included the proportion of patients with EIM exacerbations and new onset EIMs during VDZ treatment. RESULTS: Our meta-analysis encompassed 21 studies. The proportion of patients with resolution of pre-existing EIMs in VDZ-treated IBD patients was 39% (150/386; 95% confidence interval [CI] 0.31-0.48). The proportion of patients with EIM exacerbations occurred at a rate of 28% (113/376; 95% CI 0.05-0.50), while new onset EIMs had a rate of 15% (397/2541; 95% CI 0.10-0.20). Subgroup analysis revealed a 40% (136/337) proportion of patients with resolution for articular-related EIMs and a 50% (9/18) rate for erythema nodosum. Exacerbation rates for arthritis/arthralgia, erythema nodosum/pyoderma gangrenosum, and aphthous stomatitis during VDZ use were 28% (102/328), 18% (7/38), and 11% (3/28), respectively. The incidence rate of newly developed EIMs during treatment was 11% (564/4839) for articular-related EIMs, with other EIMs below 2%. CONCLUSION: VDZ demonstrates efficacy in skin-related EIMs like erythema nodosum and joint-related EIMs including arthritis, arthralgia, spondyloarthritis, and peripheral joint diseases. Some joint and skin-related EIMs may experience exacerbation during VDZ therapy.

Inconsistencies between prenatal diagnostic and genetic testing laboratories on variant validation of rare monogenic diseases.

BACKGROUND: The advent of next-generation sequencing (NGS) has enhanced the diagnostic efficacy for monogenic diseases, while presenting challenges in achieving consistent diagnoses. METHOD: We retrospectively analyzed the concordance rate and reasons for the inconsistency between the original diagnostic result from the genetic testing laboratory and the variant validation result from the prenatal diagnostic center. The validation procedure comprised three stages: validation of variant detection, reevaluation of variant classification, and assessment of recurrence risk, which involved verifying the mode of inheritance and parental carriage. RESULT: In total, 17 (6%) of the 286 families affected by rare monogenic diseases showed different results during the variant validation procedure. These cases comprised four (23.5%) with variant detection errors, 12 (70.5%) with inconsistent interpretation, and one (6%) with non-Mendelian inheritance patterns. False-positive NGS results confirmed by Sanger sequencing were related to pseudogenes and GC-rich regions. The classification of the 17 variants was altered in the 12 cases owing to various factors. The case with an atypical inheritance pattern was originally considered autosomal recessive inheritance, but was diagnosed as maternal uniparental disomy after additional genetic analysis. CONCLUSION: We underscored the significance of variant validation by prenatal diagnostic centers. Families affected by monogenic diseases with reproductive plans should be referred to prenatal genetic centers as early as possible to avoid different results that may postpone subsequent prenatal diagnosis.

Retrospective analysis of the prognostic factors of fetal corpus callosum dysplasia.

BACKGROUND: To analyze the genetic characteristics and long-term outcomes of fetuses with dysplasia of the corpus callosum (DCC) or partial agenesis of the corpus callosum (PACC). METHODS: A total of 42 fetuses with DCC (n = 36) or PACC (n = 6) were retrospectively analyzed from January 2016 to December 2022 at the Peking University First Hospital. The cohort was categorized into isolated (15/42, 36%) and nonisolated groups (27/42, 64%), and differences in the genetic abnormalities and long-term outcomes between the two groups were analyzed. DCC was subdivided into short CC, thin CC, and thick CC. The outcomes of the three different types of DCC were analyzed and discussed. RESULTS: (1) Thirty-nine of the 42 cases underwent CMA (chromosomal microarray analysis) and CMA + WES (whole exome sequencing), with 13/15 cases in isolated group and 26/27 cases in nonisolated group. Only pathogenic or likely pathogenic (P/LP) variants were considered, identifying P/LP variants in 2/13 cases in isolated group and 12/26 cases in nonisolated group. There was no significant difference between the two groups (χ² = 3.566, P = 0.05897). (2) In the isolated group, 8 cases were terminated, and 7 cases were delivered. Postnatal follow-up detected 1 case of gross motor development delay one year after birth; no obvious abnormalities were found in the other six cases. In the nonisolated group, 21 cases were terminated, and 6 cases were delivered. Postnatal follow-up detected 4 cases of children with different degrees of language, motor and intelligence abnormalities; 1 case died 10 days after birth. No obvious abnormalities were observed in one case. Six cases (86%, 6/7) in the isolated group showed normal development, compared with 1 case (17%, 1/6) in the nonisolated group, with a significant difference (χ² = 6.198, P = 0.01279). (3) In DCC, the delivery rates of short CCs (18 cases), thin CCs (13 cases), and thick CCs (5 cases) were 17% (3/18), 54% (7/13), and 20% (1/5), respectively, with good outcomes observed in 0% (0/3), 71% (5/7), and 0% (0/1), respectively. P/LP variants were found in 6/17 cases of short CC, 3/12 cases of thin CC, and 2/5 cases of thick CC. CONCLUSIONS: Fetuses with DCC or PACC combined with other structural abnormalities had a poor long-term prognosis compared with the isolated group. Patients with thin CCs had a higher probability of a good prognosis than those with short or thick CCs.

Survival analysis of comprehensive treatment in Chinese patients with metastatic melanoma: A retrospective analysis.

BACKGROUND: Most of the current progression of immune checkpoint inhibitors for malignant melanoma is based on data from Caucasians in Western countries, but the benefit of Chinese patients is limited, mainly due to different pathological subtypes. The patients in western countries are mainly skin melanoma (about 90%), while the acral and mucosal types are dominant in China, accounting for 41.8% and 22.6% respectively. Acral and mucosal melanoma have lower response rates to immunotherapy and chemotherapy. OBJECTIVE: Whether immune checkpoint inhibitors can improve the survival of Chinese patients with malignant melanoma, therefore, we conducted a retrospective analysis. METHODS: We analyzed 53 patients with metastatic melanoma treated in our hospital to evaluate the efficacy and safety of PD-1 mAb in Chinese patients with metastatic melanoma, and performed univariate and multivariate analyses of prognostic factors that may affect overall survival (OS). RESULTS: In a study of 125 patients with advanced malignant melanoma, 53 patients participated, with a median follow-up of 16 months. Among these, 69.8% died, and 30.2% remained on treatment. Median progression-free survival (PFS) was 6 months, and median OS was 19 months. Patients treated with immune checkpoint inhibitors had improved outcomes, with a median PFS of 7 months and a median OS of 24 months. Patients with bone metastasis and aberrant Lactate dehydrogenase (LDH) post-treatment had worse prognoses, while immunotherapy was a protective factor. Subgroup analysis showed the benefits of immunotherapy across various patient characteristics. No unexpected toxicities were observed. CONCLUSION: The study highlights the efficacy of immune checkpoint inhibitors, particularly PD-1 mAb, in improving survival outcomes for Chinese patients with metastatic melanoma.

Delayed progressive sensorineural hearing loss due to a novel compound heterozygous PTPRQ mutation in a Chinese patient.

BACKGROUND: The Protein tyrosine phosphatase receptor Q (PTPRQ) gene encodes a member of the type III receptor-like protein tyrosine phosphatase family found in the stereocilium. Mutations in PTPRQ are mostly associated with deafness, autosomal recessive type 84 (DFNB 84), which usually results in progressive familial hearing loss. METHODS: A 25-year-old woman and her sister, both with postlingual-delayed progressive sensorineural hearing loss, were examined. They were from a nonconsanguineous marriage and had no family history of hearing loss. New compound heterozygous PTPRQ gene mutations, nonsense (c.90C > A, p.Y30X) and splice (c.5426 + 1G > A) mutations in two PTPRQ alleles, were identified in the two sisters and were presumably autosomal recessive. The c.90C > A (p.Y30X) mutation was mapped to exon 2 of PTPRQ (NM_001145026). RESULTS: The c.90C > A mutation leads to a premature stop codon and a truncated protein. The c.5426 + 1G > A mutation leads to a truncated protein lacking the extracellular domain. Hence, both mutations were predicted to be pathogenic, leading to a deficiency of the extracellular, transmembrane, and phosphatase domains because of nonsense-mediated mRNA degradation. CONCLUSIONS: This study increases the spectrum of PTPRQ gene mutations that might be involved in delayed progressive autosomal recessive non-syndromic hearing loss.

Single-Tube Multiplex Digital Polymerase Chain Reaction Assay for Molecular Diagnosis and Prediction of Severity of Spinal Muscular Atrophy.

Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disease characterized by the degeneration of motor neurons and progressive muscle atrophy. Accurate detection of SMN1 and SMN2 copy numbers is essential for SMA diagnosis, carrier screening, disease severity prediction, therapy, and prognosis. However, a method for SMN1 and SMN2 copy number determination that is simultaneously accurate, simple, rapid, multitargeted, and applicable to various samples has not previously been reported. Here, we developed a single-tube multiplex digital polymerase chain reaction (dPCR) assay for simultaneous determination of the copy numbers of SMN1 exons 7 and 8 and SMN2 exons 7 and 8. A total of 317 clinical samples, including peripheral blood, amniotic fluid, chorionic villus, buccal swabs, and dried blood spots, were collected to evaluate the performance of this dPCR-based assay. The test results were accurate for all the clinical samples. Our assay is accurate, rapid, easy to handle, and applicable to many types of samples and uses a small amount of DNA; it is a powerful tool for SMA molecular diagnosis, large-scale screening, and disease severity assessment.

Mitochondrial DNA Copy Number in Rett Syndrome Caused by Methyl-CpG-Binding Protein-2 Variants.

OBJECTIVE: To determine changes in mitochondrial DNA (mtDNA) copy number in peripheral blood in Rett syndrome caused by methyl-CpG-binding protein-2 (MECP2) variants and explore the mechanism of mitochondrial dysfunction in Rett syndrome. STUDY DESIGN: Female patients who were diagnosed with Rett syndrome and had an MECP2 variant (n = 142) were recruited in this study, along with the same number of age- and sex-matched healthy controls. MtDNA copy number was quantified by real-time quantitative polymerase chain reaction with TaqMan probes. The differences in mtDNA copy number between the Rett syndrome group and the control group were analyzed using the independent-samples t test. Linear regression, biserial correlation analysis, and one-way ANOVA were applied for the correlations between mtDNA copy number and age, clinical severity, variant types, functional domains, and hot-spot variants. RESULTS: MtDNA copy number was found to be significantly increased in the patients with Rett syndrome with MECP2 gene variants compared with the control subjects. Age, clinical severity, variant types, functional domains, and hot-spot variants were not related to mtDNA copy number in patients with Rett syndrome. CONCLUSIONS: MtDNA copy number is increased significantly in patients with Rett syndrome, suggesting that changes in mitochondrial function in Rett syndrome trigger a compensatory increase in mtDNA copy number and providing new possibilities for treating Rett syndrome, such as mitochondria-targeted therapies.

Clinical and genetic features of infancy-onset congenital myopathies from a Chinese paediatric centre.

BACKGROUND: Congenital myopathies are a group of rare neuromuscular diseases characterized by specific histopathological features. The relationship between the pathologies and the genetic causes is complex, and the prevalence of myopathy-causing genes varies among patients from different ethnic groups. The aim of the present study was to characterize congenital myopathies with infancy onset among patients registered at our institution. METHOD: This retrospective study enrolled 56 patients based on the pathological and/or genetic diagnosis. Clinical, histopathological and genetic features of the patients were analysed with long-term follow-up. RESULTS: Twenty-six out of 43 patients who received next-generation sequencing had genetic confirmation, and RYR1 variations (12/26) were the most prevalent. Eighteen novel variations were identified in 6 disease-causing genes, including RYR1, NEB, TTN, TNNT1, DNM2 and ACTA1. Nemaline myopathy (17/55) was the most common histopathology. The onset ages ranged from birth to 1 year. Thirty-one patients were followed for 3.83 ± 3.05 years (ranging from 3 months to 11 years). No patient died before 1 year. Two patients died at 5 years and 8 years respectively. The motor abilities were stable or improved in 23 patients and deteriorated in 6 patients. Ten (10/31) patients developed respiratory involvement, and 9 patients (9/31) had mildly abnormal electrocardiograms and/or echocardiograms. CONCLUSION: The severity of congenital myopathies in the neonatal/infantile period may vary in patients from different ethnic groups. More concern should be given to cardiac monitoring in patients with congenital myopathies even in those with static courses.

LSO-FastSLAM: A New Algorithm to Improve the Accuracy of Localization and Mapping for Rescue Robots.

This paper improves the accuracy of a mine robot's positioning and mapping for rapid rescue. Specifically, we improved the FastSLAM algorithm inspired by the lion swarm optimization method. Through the division of labor between different individuals in the lion swarm optimization algorithm, the optimized particle set distribution after importance sampling in the FastSLAM algorithm is realized. The particles are distributed in a high likelihood area, thereby solving the problem of particle weight degradation. Meanwhile, the diversity of particles is increased since the foraging methods between individuals in the lion swarm algorithm are different so that improving the accuracy of the robot's positioning and mapping. The experimental results confirmed the improvement of the algorithm and the accuracy of the robot.

Pseudomonas viciae sp. nov., isolated from rhizosphere of broad bean.

A Gram-stain-negative aerobic bacterium, strain 11K1T, was isolated from a rhizosphere soil of broad bean collected from Qujing, Yunnan, PR China and characterized by using polyphasic taxonomy. The bacterial cells of strain 11K1T were rod-shaped, motile by two polar flagella and positive for oxidase and catalase. Results of phylogenetic analysis based on 16S rRNA gene sequences revealed that the strain had the highest similarities to Pseudomonas thivervalensis DSM 13194T (99.52 %), Pseudomonas lini CFBP 5737T (99.45 %), Pseudomonas chlororaphis subsp. chlororaphis NBRC 3904T (99.31 %), Pseudomonas kilonensis DSM 13647T (99.25 %) and Pseudomonas brassicacearum JCM11938T (99.24 %). Multilocus sequence analysis using the 16S rRNA, gyrB, rpoB and rpoD gene sequences demonstrated that strain 11K1T was a member of the Pseudomonas corrugata subgroup within the Pseudomonas fluorescens lineage, but was distant from all closely related species. The average nucleotide identity and in silico DNA-DNA hybridization values were lower than recommended thresholds of 95 and 70 %, respectively, for species delineation. The major isoprenoid quinone of strain 11K1T was ubiquinone (Q-9) and the major cellular fatty acids were C16 : 0, summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c), summed feature 8 (C18 : 1 ω7c/C18 : 1 ω6c) and C17 : 0 cyclo. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, aminophospholipid and two unidentified lipids. Based on the results of phenotypic characterization, phylogenetic analysis and genome comparison, strain 11K1T represents a novel species of the genus Pseudomonas, for which the name Pseudomonas viciae sp. nov. is proposed. The type strain is 11K1T (=GDMCC 1.1743T=KACC 21650T).

The prevalence of CGG repeat expansion mutation in FMR1 gene in the northern Chinese women of reproductive age.

BACKGROUND: The prevalence of CGG repeat expansion mutation in FMR1 gene varies among different populations. In this study, we investigated the prevalence of this mutation in women of reproductive age from northern China. METHODS: A total of 11,891 pre-conceptional or pregnant women, including 5037 pregnant women and 7357 women with the history of spontaneous abortion or induced abortion due to delayed growth of the embryos, were recruited. The number of CGG repeats in FMR1 was measured by the TRP-PCR method. We also offered genetic counseling and prenatal diagnosis to the women carrying pre-mutation or full mutation alleles. RESULTS: The prevalence of pre-mutation in reproductive women in northern China was 1/410, higher than that in southern China and Korea but lower than that in western countries. We also found that the prevalence of pre-mutation was relatively high (1/320) in women with abortion history. CONCLUSION: Screening for CGG repeat expansion mutation in FMR1 should be recommended to the women with the history of spontaneous abortion or induced abortion due to delayed growth of the embryos.

Involvement of microRNA-141-3p in 5-fluorouracil and oxaliplatin chemo-resistance in esophageal cancer cells via regulation of PTEN.

microRNAs (miRNAs) act as a major regulator of acquired chemo-resistance in various types of cancer therapeutics. This study investigated the contribution of miRNAs in influencing multiple drug resistance in esophageal squamous cell carcinoma (ESCC). The sensitivity of four ESCC cell lines (EC109, EC9706, TE-1 and KYSE-150) to 5-fluorouracil (5-FU) and oxaliplatin (OX) was determined by MTT assay. A 5-FU and OX-resistant subline, EC9706R, was established by continuous exposure to stepwise increasing concentration of 5-FU and OX. Microarray technology was used to compare the differential expression of miRNAs between resistant cells and parental cells. Chemo-sensitivity assay was performed to evaluate drug response in EC9706R cells transfected with miRNA mimic or inhibitor. The direct targets of miRNA were identified by employing pathway analysis and then confirmed with luciferase assay. Sixty ESCC tissue samples and their paired adjacent normal tissues were collected to validate the expression of identified miRNA. Mouse models were further utilized to investigate the function of miRNA on acquired chemo-resistance. MicroRNA panel results indicated that a total of 12 miRNAs were differentially expressed and miR-141-3p was highly over expressed in resistant cells. Inhibition of miR-141-3p reversed acquired chemo-resistance in EC9706R cells by stimulating apoptosis. The expression of miR-141-3p was significantly increased in ESCC tissue samples compared to their matched distant normal tissues. In addition, the elevated miR-141-3p expression was found to be associated with ESCC differentiation status and TNM stage. Moreover, Phosphatase and tensin homolog (PTEN) was identified as direct target of miR-141-3p. Western blot exhibited altered protein levels of PTEN, Akt, and PI3k with miR-141-3p inhibitor. An inverse correlation between PTEN expression and miR-141-3p expression was also observed in tissue samples. EC9706R xenograft mouse model became sensitized to 5-FU and OX treatment following miR-141-3p inhibitor transfection in vivo. Our study demonstrated that miR-141-3p contributed to an acquired chemo-resistance through PTEN modulation both in vitro and in vivo.

Overexpression of G9a and MCM7 in oesophageal squamous cell carcinoma is associated with poor prognosis.

AIMS: Histone methyltransferase G9a has been primarily understood as a co-repressor of gene expression, but it has been shown that G9a also positively regulates nuclear receptor-mediated transcription. MCM7, a critical component of the DNA replication licensing complex, is amplified and overexpressed in a variety of human malignancies. The objectives of the present study were to study the relationship between the expression of G9a and MCM7 and the pathological grade, clinical stage and prognosis of oesophageal squamous cell carcinoma (OSCC). METHODS AND RESULTS: We collected 139 formalin-fixed and paraffin-embedded tissues from patients with OSCC and surveyed them by tissue microarray-based immunohistochemical staining. Associations between the expression of MCM7 and G9a and clinicopathological parameters and prognosis of OSCC were examined. From tissue microarray immunohistochemistry staining results, we found that nuclear staining intensity for MCM7 and G9a was associated with histological grade (both P < 0.001), tumour depth (P = 0.050, 0.034), lymph node metastasis (P = 0.001, 0.009) and tumour stage (P < 0.001, =0.003). G9a expression was correlated with that of MCM7. G9a overexpression independently predicted poor cancer-specific survival in OSCC (hazard ratio 0.05, 95% confidence interval 0.006-0.417, P = 0.006) and MCM7 (hazard ratio 0.05, 95% confidence interval 0.013-0.441, P = 0.004). OSCC patients whose tumours showed double-positive expression of G9a and MCM7 (G9a(+) MCM7(+) ) had much shorter survival than those from either the G9a or MCM7 low expression groups (G9a(-) MCM7(-) , G9a(+) MCM7(-) , G9a(-) MCM7(+) ). CONCLUSIONS: MCM7 and G9a may serve as effective prognostic factors and could also be used as biomarkers for predicting various clinical outcomes of OSCCs in the Chinese population.

Genetic variations in the one-carbon metabolism pathway genes and susceptibility to hepatocellular carcinoma risk: a case-control study.

Hepatocellular carcinoma (HCC) is the sixth common cancer and the third common cause of cancer mortality worldwide. However, the exact molecular mechanism of HCC remains uncertain. Many enzymes are involved in one-carbon metabolism (OCM), and single nucleotide polymorphisms (SNPs) in the corresponding genes may play a role in liver carcinogenesis. In this study, we enrolled 1500 HCC patients and 1500 cancer-free controls, which were frequency-matched by age, gender, and HBV infection status. Then eight SNPs from seven OCM genes (MTHFR, MTR, MTRR, FTHFD, GART, SHMT, and CBS) were evaluated. Results showed that six SNPs (MTHFR rs1801133, MTRR rs2287780, MTRR rs10380, FTHFD rs1127717, GART rs8971, and SHMT rs1979277) were significantly associated with HCC risk in Chinese population, with P values range from 2.26 × 10(-4) to 0.035). The most significant association was detected for GART rs8971. Compared with individuals with the TT genotype, the age- and sex-adjusted odds ratio (OR) for developing HCC was 1.44 (95% confidence interval (CI): 1.03-2.02) among those with the CC genotype and 1.30 (95% CI: 1.10-1.53) for those with CT genotype. Under the log-additive model, each additional copy of minor allele C was associated with a 1.28-fold increased risk of HCC (OR = 1.28, 95% CI: 1.12-1.45). These findings indicated that genetic variants in OCM genes might contribute to HCC susceptibility.

Smart surfaces based on thermo-responsive polymer brushes prepared from L-alanine derivatives for cell capture and release.

Two novel thermo-responsive polymer brushes were prepared from L-alanine derivatives using the surface-initiated atom transfer radical polymerization (SI-ATRP) technique. The temperature-induced cell capture and release on both polymer brush modified substrates were further explored.

Identification of a New Genotype of Fusarium oxysporum f. sp. vasinfectum on Cotton in China.

Genetic composition of Fusarium oxysporum f. sp. vasinfectum strains, including race 3, 7, and 8, Australian genotype strain, and 80 strains collected from China, were studied using amplified fragment length polymorphism (AFLP). Based on AFLP analysis, these strains were separated into four groups. Race 3, strain CN3, was the only strain in group A. Race 8, strain CN8, was the only strain in group B. Race 7, strain CN7, was grouped with 75 strains from China in group C. The Australian genotype strain ATCC96291 was grouped with five strains from China in group D. Evolution of the five native strains in group D was studied using multigene genealogies. Phylogenetic tree analysis revealed that the five strains of group D had a closer genetic relationship to the Australian genotype strain than the other races based on the combined elongation factor, ß-tubulin, and phosphate permase gene sequence data. Group D was further tested for pathogenicity and virulence on four cotton cultivars from Upland (Gossypium hirsutum) and Sea Island (G. barbadense) cotton. All five strains caused typical Fusarium wilt symptoms on all four cotton cultivars but virulence were relatively low compared with race 3, race 7, and race 8.

[G14453A mutation in mitochondrial myopathy encephalomyopathy with lactic acidosis and stroke-like episodes].

OBJECTIVE: To analyz mitochondrial DNA mutation in one case of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS). METHODS: The patient, a 10-years-old boy,clinically diagnosed as MELAS. The clinical information was collected, and the normal mitochondrial mutations (such as A3243G, A8344G, T8993G/C, G13513A etc) were excluded. PCR-sequencing was used to analyz the whole-mitochondrial genome (16.6 kb), and PCR-RFLP was used to confirm the mutations. RESULTS: m.G14453A mutation was detected from the patient's peripheral blood and urine, but it was not found in his parents and 100 normal controls. The m.G14453A mutation was confirmed by PCR-RFLP, and mutation ratio of in blood was 56.8% and urine was 72.5%. The activity of complex I was decreased (67.6 nmol·min⁻¹·mg⁻¹). This was the first report that m.G14453A mutation could lead to MELAS in China according www.mitomap.org web and NCBI. CONCLUSION: m.G14453A mutation is one of the causative mutations in MELAS, but the mechanism of the mutation should be studied in future.

[Analysis of the relationship between mitochondrial DNA deletion and clinical complexity of mitochondrial disease].

OBJECTIVE: To analyze the relationship between proportion of mitochondrial DNA 4 977 bp deletion (ΔmtDNA(4977)) or copy number in blood and the clinical complexity to find the pathogenesis of mitochondrial disease. METHODS: A total of 160 patients with mitochondrial disease and 101 healthy controls of Peking University First Hospital from December 2003 to December 2013 were collected in this study. Their peripheral blood showed no hot-point mutation which detected by polymerase chain reaction-restriction fragment length polymorphism. All the patients were divided into younger group (age<10y) and elder group (10y≤age<20y). The incidence of ΔmtDNA(4977) was detected by real-time quantitative PCR. Internal gene was used to calculate the number of mitochondrial DNA in each cell. Statistical analysis were carried out by the independent t-test, one-way ANOVA and Spearman's bivariate correlation analysis. RESULTS: ΔmtDNA (4977) proportion in the younger group was (2.66 ± 0.63)% and in the elder group was (3.09 ± 0.74)%, both of them were higher than that of healthy control group with the same age (the younger group: t=8.57, P<0.01; the elder group: t=4.38, P<0.01); ΔmtDNA(4977) copy number per cell in the younger group was (2.79 ± 0.50) copy and in the elder group was (2.97 ± 0.48) copy, both of them were higher than that of healthy control group with the same age (the younger group: t=4.50, P<0.01; the elder group: t=-3.67, P<0.01). The ΔmtDNA (4977) proportion was positively correlated with the complexity of the mitochondrial disease(the younger group: r=0.519, P<0.01; the elder group: r=0.772, P<0.01). The ΔmtDNA (4977) copy number per cell was positively correlated with the complexity of the mitochondrial disease(the younger group: r=0.389, P<0.01; the elder group: r=0.607, P<0.05). However, the total mtDNA copy number per cell was negatively correlated with the complexity of the mitochondrial disease (the younger group: r=-0.260, P<0.01; the elder group: r=-0.430, P<0.05). CONCLUSIONS: The proportion or copy number of ΔmtDNA (4977) or total mtDNA copy number in blood are correlated with the complexity of mitochondrial diseases, especially the proportion of ΔmtDNA (4977).

Oxidation-responsive OEGylated poly-L-cysteine and solution properties studies.

The oxidation-responsive behaviors of OEGylated poly-L-cysteine homopolypeptides, that is, poly(L-EG(x)MA-C)n, were investigated. These poly-L-cysteine derivatives adopted mixed conformation in water, in which the ß-sheet accounted for a significant proportion. Upon oxidation, the thioethers in polypeptide side chains were converted to polar sulfone groups, which triggered the secondary structure transition from ß-sheet preferred conformation to random coil. Accordingly, the increase of side-chain polarity together with conformation changes increased samples' water solubility and cloud point temperature. Using mPEG45-NH2 as macroinitiator, we synthesized PEG45-b-poly(L-EG2MA-C)22 diblock copolymer via ring-opening polymerization (ROP) of L-EG2MA-C N-carboxyanhydride (NCA). The PEG45-b-poly(L-EG2MA-C)22 was able to self-assemble into spherical micelles in aqueous solution, and the micelles could undergo an oxidation-triggered disassembly due to the oxidation-responsive thioethers. Such a new class of oxidation-responsive polypeptides might provide a promising platform to construct inflammation targeting drug delivery systems.