Machine learning-based prediction model for myocardial ischemia under high altitude exposure: a cohort study.

High altitude exposure increases the risk of myocardial ischemia (MI) and subsequent cardiovascular death. Machine learning techniques have been used to develop cardiovascular disease prediction models, but no reports exist for high altitude induced myocardial ischemia. Our objective was to establish a machine learning-based MI prediction model and identify key risk factors. Using a prospective cohort study, a predictive model was developed and validated for high-altitude MI. We consolidated the health examination and self-reported electronic questionnaire data (collected between January and June 2022 in 920th Joint Logistic Support Force Hospital of china) of soldiers undergoing high-altitude training, along with the health examination and second self-reported electronic questionnaire data (collected between December 2022 and January 2023) subsequent to their completion on the plateau, into a unified dataset. Participants were subsequently allocated to either the training or test dataset in a 3:1 ratio using random assignment. A predictive model based on clinical features, physical examination, and laboratory results was designed using the training dataset, and the model's performance was evaluated using the area under the receiver operating characteristic curve score (AUC) in the test dataset. Using the training dataset (n = 2141), we developed a myocardial ischemia prediction model with high accuracy (AUC = 0.86) when validated on the test dataset (n = 714). The model was based on five laboratory results: Eosinophils percentage (Eos.Per), Globulin (G), Ca, Glucose (GLU), and Aspartate aminotransferase (AST). Our concise and accurate high-altitude myocardial ischemia incidence prediction model, based on five laboratory results, may be used to identify risks in advance and help individuals and groups prepare before entering high-altitude areas. Further external validation, including female and different age groups, is necessary.

Fever of unknown origin (FUO) in children: a single-centre experience from Beijing, China.

OBJECTIVE: To date, there is no standard diagnostic practice to identify the underlying disease-causing mechanism for paediatric patients suffering from chronic fever without any specific diagnosis, which is one of the leading causes of death in paediatric patients. Therefore, we aimed this retrospective study to analyse medical records of paediatric patients with fever of unknown origin (FUO) to provide a preliminary basis for improving the diagnostic categories and facilitate the treatment outcomes. DESIGN: A retrospective study. SETTING: Beijing Children's Hospital. PARTICIPANTS: Clinical data were collected from 1288 children between 1 month and 18 years of age diagnosed with FUO at Beijing Children's Hospital between January 2010 and December 2017. INTERVENTIONS: According to the aetiological composition, age, duration of fever and laboratory examination results, the diagnostic strategies were analysed and formulated. PRIMARY AND SECONDARY OUTCOME MEASURES: The statistical analyses were carried out using SPSS V.24.0 platform along with the χ2 test and analysis of variance (p<0.05). RESULTS: The duration of fever ranged from 2 weeks to 2 years, with an average of 6 weeks. There were 656 cases (50.9%) of infectious diseases, 63 cases (4.9%) of non-infectious inflammatory diseases (NIIDs), 86 cases (6.7%) of neoplastic diseases, 343 cases (26.6%) caused by miscellaneous diseases and 140 cases (10.9%) were undiagnosed. With increasing age, the proportion of FUO from infectious diseases gradually decreased from 73.53% to 44.21%. NIID was more common in children over 3 years old, and neoplastic diseases mainly occurred from 1 to 6 years of age. Among miscellaneous diseases, the age distribution was mainly in school-aged children over 6 years. Respiratory tract infection was the most common cause of FUO in children, followed by bloodstream infections. Bacterial infection was the most common cause in children with less than 1 year old, while the virus was the main pathogen in children over 1 year old. CONCLUSIONS: The diagnosis of neoplastic diseases and miscellaneous diseases-related diseases still depends mainly on invasive examination. According to our clinical experience, the diagnostic process was formulated based on fever duration and the type of disease. This process can provide a guide for the diagnosis and treatment of paediatric FUO in the future.

Application of Restriction Site-Associated DNA Sequencing (RAD-Seq) for Copy Number Variation and Triploidy Detection in Human.

At present, low-pass whole-genome sequencing (WGS) is frequently used in clinical research and in the screening of copy number variations (CNVs). However, there are still some challenges in the detection of triploids. Restriction site-associated DNA sequencing (RAD-Seq) technology is a reduced-representation genome sequencing technology developed based on next-generation sequencing. Here, we verified whether RAD-Seq could be employed to detect CNVs and triploids. In this study, genomic DNA of 11 samples was extracted employing a routine method and used to build libraries. Five cell lines of known karyotypes and 6 triploid abortion tissue samples were included for RAD-Seq testing. The triploid samples were confirmed by STR analysis and also tested by low-pass WGS. The accuracy and efficiency of detecting CNVs and triploids by RAD-Seq were then assessed, compared with low-pass WGS. In our results, RAD-Seq detected 11 out of 11 (100%) chromosomal abnormalities, including 4 deletions and 1 aneuploidy in the purchased cell lines and all triploid samples. By contrast, these triploids were missed by low-pass WGS. Furthermore, RAD-Seq showed a higher resolution and more accurate allele frequency in the detection of triploids than low-pass WGS. Our study shows that, compared with low-pass WGS, RAD-Seq has relatively higher accuracy in CNV detection at a similar cost and is capable of identifying triploids. Therefore, the application of this technique in medical genetics has a significant potential value.

Hand Hygiene Knowledge and Self-Reported Hand Washing Behaviors among Restaurant Kitchen Chefs in Jiangsu Province, China.

Inadequate hand washing among chefs is a major contributor to outbreaks of foodborne illnesses originating in restaurants. Although many studies have evaluated hand hygiene knowledge (HHK) and self-reported hand washing behaviors (HWBs) in restaurant workers in different countries, little is known about HHK and HWBs in restaurant kitchen chefs, particularly in China. In this study, we interviewed 453 restaurant kitchen chefs in Jiangsu Province in China regarding their HHK and HWBs and used Chi-square tests (Fisher exact tests), pairwise comparisons, and linear regression models to analyze the responses and identify determinants of HHK and HWBs. Results reveal that less frequent hand washing after leaving work temporarily and after touching used cutlery were the main issues among restaurant kitchen chefs in Jiangsu Province. Kitchen hands had lower levels of HHK and engaged less frequently in good HWBs than the other type of chefs. Furthermore, working in a large restaurant and having worked in the restaurant industry for a longer amount of time were correlated with better HHK and HWBs. These findings suggest that close attention should be paid to the HWBs of chefs during food preparation, that kitchen hands are the key group of restaurant kitchen workers who need training in HHK, and that regulatory activities should focus on small-scale restaurants.

Characteristics of Pediatric Recurrent Bacterial Meningitis in Beijing Children's Hospital, 2006-2019.

BACKGROUND: Few data on recurrent bacterial meningitis (RBM) in children are available. Here, we estimated the frequency of RBM in children and investigated the predisposing conditions, etiology, and clinical characteristics of RBM in children. METHODS: Cases of RBM in the Beijing Children's Hospital medical record database between January 2006 and December 2019 were collected. RESULTS: In total, 1905 children with bacterial meningitis (BM) were documented in the Beijing Children's Hospital medical record database. A total of 43 patients had RBM. The rate of RBM in children was 2.3% (43/1905). Forty (93.0%) patients had predisposing conditions, including 15 (34.9%) cases of inner ear malformations, 5 (11.6%) cases of dermal sinus tracts, 9 (20.9%) cases of head injury, 5 (11.6%) cases of congenital cranial meningocele, 3 (7.0%) cases of congenital skull base defects, 3 (7.0%) cases of immunodeficiency, and other 3 (7.0%) cases of unknown reason. Among all the 121 BM episodes, a total of 64 episodes were etiologically confirmed BM and the other 57 episodes were probable BM. Streptococcus pneumoniae (n = 52) was accounted for 81.3% of confirmed BM episodes. Thirty-four of the 37 patients with congenital or acquired anatomical defects were available to follow up after surgeries, and all of them had no BM after surgeries. Three patients with antibody deficiencies got intravenous immunoglobulin therapy and they did not suffer BM anymore. CONCLUSIONS: RBM is rare in children. The majority of children with RBM had predisposing conditions including congenital/acquired anatomical defects and immunodeficiency. Interventions should be implemented to solve the underlying conditions to avoid RBM.

[Advances in quality research of Cinnamomum cassia].

Cinnamomum cassis is one of the commonly used traditional Chinese medicines in China. Its genuine producing areas distribute in Guangdong and Guangxi provinces. As an important edible herb and export variety of China, the quality control and internationalization of quality standards of C. cassis is extremely significant. In the recent years, with the development of the cinnamon industry, relevant academic research and the upgrade of the international standards, it is necessary to summarize the quality-related progress of C. cassis. In the present review, the germplasm resources, specific quality marker(Q-marker) and quality standards of C. cassis were summarized on the basis of published research during the last 10 years.

[Alleles dropout patterns of Y-short tandem repeats in infertile males with Y chromosome microdeletions].

Y chromosomal short tandem repeat (Y-STR) typing is the most commonly used genetic technique in forensic studies. However, there may be a limit to the application of Y-STR in forensic science as Y-STR loci are subject to loss or variation caused by the higher chromosomal structures' spontaneous mutation rate. Located in the long arm of the Y chromosome, azoospermia factor (AZF) have been shown to participate in spermatogenesis and its deletion could cause infertility. However, little is known about the Y-STR dropout pattern in individuals with Y chromosome microdeletions. In this study, 85 infertile males with Y chromosome interstitial deletion were identified and special Y-STR allele dropout patterns were analyzed by employing a Y-STR Commercial Kit and a Y chromosome Deletion Kit. Results demonstrate that AZF a region deletion are related to DYS439-DYS389I-DYS389II alleles dropout, while AZF b region or c region deletions correlate to DYS448 allele dropout. Null DYS385-DYS392-DYS448 alleles were observed in AZF b+c+d region deletion individuals. While null DYS390-Y-GATA-H4-DYS385-DYS392-DYS448 alleles were observed in AZF a+b+c+d large region deletion individuals. Our data suggest that Y chromosome microdeletions may indicate specific Y-STR locus dropout patterns.

Microarray-based analysis of whole-genome DNA methylation profiling in early detection of breast cancer.

Emerging evidence indicated that changes in DNA methylation early in breast cancer (BC) development might be clinically relevant for therapeutic decisions. Through analysis of whole-genome gene expression microarray and DNA methylation microarray, we explored genes with abnormal DNA methylation in BC for early detection. Firstly, human BC tissues and adjacent non-cancerous tissues were collected from nine BC patients. Gene expression microarray sequencing was conducted for identifying differentially expressed genes and DNA methylation microarray sequencing for differentially methylated genes in BC. Differentially expressed genes and methylated genes in BC were further explored using the Cancer Genome Atlas database. The correlation between DNA methylation and gene expression was illustrated by multiple comparisons. In other 60 clinical samples, methylation specific polymerase chain reaction (PCR) and reverse transcription quantitative PCR were applied for the methylation of HOXA4 and IGF1 genes in BC and adjacent non-cancerous tissues. In total, 1680 upregulated genes and 1249 downregulated genes were determined in BC. Chromosome 16 and 17 showed more differentially methylated genes, and DNA methylation level was increased in BC tissues in each gene region. Chromosome 19 showed more differentially methylated genes, and DNA methylation level was increased in BC tissues in the exoniensis 1, untranslated region-5 and transcriptional start site 200 gene regions. In other 60 clinical samples, HOXA4 and IGF1 in BC tissues presented increased DNA methylation and decreased gene expression in BC. MCF7 cells treated with RG108 showed decreased HOXA4 and IGF1 expressions. It was estimated that HOXA4 and IGF1 were identified with increased DNA methylation and decreased gene expression in BC, which may serve as biomarkers in early BC detection.

Down-regulated long non-coding RNA RNAZFHX4-AS1 suppresses invasion and migration of breast cancer cells via FAT4-dependent Hippo signaling pathway.

Breast cancer is ranked as the second leading cause of cancer-related deaths among women. Accumulating evidences have revealed that long non-coding RNAs (lncRNAs) are involved in human tumorigenesis owing to the regulation of essential pathways for tumor initiation and progression. Herein, the current study aimed to explore the regulatory mechanism of lncRNA ZFHX4-AS1 in breast cancer in relation to the Hippo signaling pathway. Initially, microarray analysis was conducted to screen out differentially expressed lncRNAs related to breast cancer. Next, the functional role of lncRNA ZFHX4-AS1 in breast cancer was determined using ectopic expression, knockdown, and reporter assay experiments. Subsequently, lncRNA ZFHX4-AS1, TAF4, TAZ, and YAP expressions were determined, followed by verification of the targeting relationship between lncRNA ZFHX4-AS1 and TAF4. Then cell proliferation, invasion, migration, cell cycle, and apoptosis were measured. Lastly, tumor growth and metastasis were detected by tumor xenograft in nude mice. LncRNA ZFHX4-AS1 was found to be highly expressed while FAT4 was poorly expressed in breast cancer tissues. FAT4 was the target gene of lncRNA ZFHX4-AS1, and lncRNA ZFHX4-AS1 silencing increased FAT4 expressions, while decreased YAP and TAZ expressions. In addition, knockdown of lncRNA ZFHX4-AS1 suppressed breast cancer cell proliferation, migration, and invasion as well as tumor growth, blocked cell cycle entry, while promoted cell apoptosis by inhibiting the Hippo signaling pathway. In conclusion, our findings reveal that lncRNA ZFHX4-AS1 silencing exerts an inhibitory effect on breast cancer development by suppressing the activation of the Hippo signaling pathway via FAT4.

The Impact of Cysteine-Rich Intestinal Protein 1 (CRIP1) on Thyroid Carcinoma.

BACKGROUND/AIMS: CRIP1 (cysteine-rich intestinal protein 1) has been found in several tumor types; however, its prognostic impact and role in cellular processes, particularly in thyroid carcinoma, are still unclear. METHODS: To elucidate the prognostic impact of CRIP1, we analyzed tissues from 58 primary invasive thyroid carcinomas using immunohistochemistry. Western blotting was performed to investigate CRIP1 protein expression in the thyrocyte cell line Nthy-ori 3-1 and four different thyroid carcinoma cell lines, K1, TPC-1, TT, and SW579. Endogenous expression of CRIP1 was suppressed using a siRNA (si-CRIP1). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to investigate cell viability. Flow cytometric analysis was used to detect cell cycle progression and cell apoptosis. The effects of silencing CRIP1 on cell migration and invasion were detected using the transwell assay. RESULTS: The immunohistochemistry results showed that CRIP1 was overexpressed in thyroid carcinoma. CRIP1 expression was associated with tumor size, TNM stage, and lymphatic metastasis, but not with age, gender, and tumor location. In addition, the expression of CRIP1 in K1, TPC-1, TT, and SW529 cells was higher than that in the Nthy-ori 3-1 cells. The highest expression was observed in the SW579 and TT cells. Furthermore, silencing CRIP1 inhibited the proliferation, migration, and invasion of thyroid carcinoma cell lines SW579 and TT. We also found that silencing CRIP1 induced G1 arrest and apoptosis of thyroid carcinoma cell lines SW579 and TT. CONCLUSION: In conclusion, CRIP1 acts as an oncogene in the cell proliferation, migration, and invasion processes of thyroid carcinoma. CRIP1 may serve well as an independent prognostic marker with significant predictive power for use in thyroid carcinoma therapy.

Characteristics and outcomes of cryptococcal meningitis in HIV seronegative children in Beijing, China, 2002-2013.

BACKGROUND: Data regarding HIV-seronegative pediatric patients with cryptococcal meningitis (CM) have been very limited. METHODS: We retrospectively reviewed non-HIV-infected in patients with CM from January 2002 through December 2013 in Beijing Children's Hospital. Records of the all patients were obtained and compared. RESULTS: The 34 children had a median age of 5.6 years. Most of the patients were male (67.6 %). Only 23.5 % of the cases had identifiable underlying diseases. The sensitivity of the CSF cryptococcal antigen, India ink smear and CSF culture in our study were 81.5, 85.3 and 82.4 %, respectively. And the sensitivity of combinations of these tests was 91.2 %. Out of the 34 patients, 16 (47.1 %) had other organs involvement in addition to the brain. The main abnormal features via magnetic resonance imaging (MRI) were Virchow-Robin space dilatation (44.4 %), hydrocephalus (38.9 %), gelatinous pseudocysts (33.3 %), brain atrophy (33.3 %), meningeal enhancement (27.8 %) and local lesions (27.8 %). In total, 64.7 % of the patients were successfully treated at discharge, whereas treatment failed in 35.3 % of the patients. CONCLUSIONS: Cryptococcal meningitis is an infrequent disease with a high fatality rate in children in China. The majority of patients were apparently healthy. Clinicians should consider cryptococcal infection as a potential pathogen of pediatric meningitis. Cryptococcal antigen, India ink smear and culture tests are recommended for diagnosis.

Digital gene expression analysis of transcriptomes in lipopolysaccharide-induced acute respiratory distress syndrome.

BACKGROUND: The mortality from acute respiratory distress syndrome (ARDS) is high, and its exact pathogenesis remains unclear, which forms a major obstacle for prevention and treatment of this disease. In the present study, we used digital gene expression (DGE) to detect the differentially expressed genes of the lung at 4h after lipopolysaccharide (LPS) exposure in a mouse model. METHODS: Mice were treated with LPS or control saline by intratracheal instillation for 4h, and their lung tissues were collected for DGE analysis. We used a false discovery rate ≤0.001 and an absolute value of the log2 ratio≥1 as the thresholds for judging the significance of any difference in gene expression between the two members of each pair of mice. RESULTS: We obtained 3,387,842 clean tags (i.e., after filtering to remove potentially erroneous tags) and about 84,513 corresponding distinct clean tags (i.e., types of tag). Approximately 91.20% of the clean tags could be mapped, and 82.71% could be uniquely mapped, to the reference tags, and 3.82% were unknown tags. At least 2200 differentially expressed genes were identified and analyzed for enrichment of Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway. Twenty genes with the greatest difference in expression levels between the two members of every pair of mice were chosen. The majority of these genes are involved in signaling transduction, molecular adhesion, and metabolic pathways. CONCLUSIONS: Using the powerful technology of DGE, we present, to our knowledge, the first in-depth transcriptomic analysis of mouse lungs after LPS exposure. We found some differentially expressed genes that might play important roles in the pathogenesis of ARDS.

[Clinical value of cranial MRI in the diagnosis and treatment of central nervous system candidiasis].

OBJECTIVE: To study the clinical value of cranial magnetic resonance imaging (MRI) in the diagnosis and treatment of central nervous system candidiasis (CNSC), which has no specific clinical manifestations and has no rapid and specific diagnostic tools. METHODS: A retrospective analysis was performed on the clinical data of 10 children who were diagnosed with CNSC in Beijing Children's Hospital Affiliated to Capital Medical University between 2009 and 2013. RESULTS: Nine of the 10 children underwent cranial MRI within 8 days after admission, and 5 of the 9 children underwent contrast-enhanced MRI at the same time. Eight of the 9 children showed the features of meningoencephalitis, and 6 cases were accompanied by varying degrees of brain atrophy; one case showed hydrocephalus and cerebral abscess, and another case showed leukoencephalopathy. Six cases were found to have the features of cerebral vasculitis after infection in the first MRI after admission, including cerebral infarction (2 cases), venous sinus thrombosis (3 cases), and Moyamoya disease (1 case). Infectious granulomatous lesions were confirmed by contrast-enhanced MRI in 3 cases. Given the clinical manifestations, 8 of the 9 cases were diagnosed as suspected CNSC after MRI, and 7 of these cases received antifungal therapy before the pathogen test results were returned. The lesions on MRI were improved in 6 cases after 3-4 weeks of antifungal treatment. All the 10 children were diagnosed with CNSC by positive cerebrospinal fluid culture results. CONCLUSIONS: Cranial MRI, especially contrast-enhanced MRI, is of great significance for the diagnosis and treatment of CNSC. To confirm the guidance of MRI in the diagnosis and treatment of CNSC, further case-control studies are needed.

[Preparation and application of the quinonyl chloromethylation polystyrene in biological treatment of wastewater].

The technology of non-water-soluble mediator anaerobic biological catalysis has attracted more and more attention in the field of environment technology. In this study, five kinds of quinonly compounds were grafted on the chloromethylation polystyrene macromolecular carrier by Friedel-Crafts reaction. Reaction factors of temperature and molar ratio for the 1,4-naphthoquinone grafting carrier were optimized, and the optimal temperature was 78 degreesC while the optimal molar ratio of 1, 4-naphthoquinone and chloromethylation polystyrene was 2: 1. Fourier infrared spectrum analysis confirmed that the quinone groups were successfully grafted on the macromolecular backbone chloromethylation polystyrene. Catalysis using the five kinds of quinonly materials as non-water-soluble redox mediators enhanced the biological denitrification rate and the decoloration of azo dyes, meanwhile these materials showed good reusability in the biodegradation of azo dye. This study developed a new method for the preparation of quinonly materials and revealed a new field in the technology of mediator catalysis.

Aberrant PTPRO methylation in tumor tissues as a potential biomarker that predicts clinical outcomes in breast cancer patients.

BACKGROUND: Aberrant hypermethylation of gene promoter regions is a primary mechanism by which tumor suppressor genes become inactivated in breast cancer. Epigenetic inactivation of the protein tyrosine phosphatase receptor-type O gene (PTPRO) has been described in several types of cancer. RESULTS: We screened primary breast cancer tissues for PTPRO promoter hypermethylation and assessed potential associations with pathological features and patient outcome. We also evaluated its potential as a breast cancer biomarker. PTPRO methylation was observed in 53 of 98 (54%) breast cancer tissues but not in adjacent normal tissue. Among matched peripheral blood samples from breast cancer patients, 33 of 98 (34%) exhibited methylated PTPRO in plasma. In contrast, no methylated PTPRO was observed in normal peripheral blood from 30 healthy individuals. PTPRO methylation was positively associated with lymph node involvement (P = 0.014), poorly differentiated histology (P = 0.037), depth of invasion (P = 0.004), and HER2 amplification (P = 0.001). Multivariate analysis indicated that aberrant PTPRO methylation could serve as an independent predictor for overall survival hazard ratio (HR): 2.7; 95% CI: 1.1-6.2; P = 0.023), especially for patients with HER2-positive (hazard ratio (HR): 7.5; 95% CI: 1.8-31.3; P = 0.006), but not in ER + and PR + subpopulation. In addition, demethylation induced by 5-azacytidine led to gene reactivation in PTPRO-methylated and -silenced breast cancer cell lines. CONCLUSIONS: Here, we report that tumor PTPRO methylation is a strong prognostic factor in breast cancer. Methylation of PTPRO silences its expression and plays an important role in breast carcinogenesis. The data we present here may provide insight into the development of novel therapies for breast cancer treatment. Additionally, detection of PTPRO methylation in peripheral blood of breast cancer patients may provide a noninvasive means to diagnose and monitor the disease.

Role of Angptl4 in vascular permeability and inflammation.

BACKGROUND: Angptl4 is a secreted protein involved in the regulation of vascular permeability, angiogenesis, and inflammatory responses in different kinds of tissues. Increases of vascular permeability and abnormality changes in angiogenesis contribute to the pathogenesis of tumor metastasis, ischemic-reperfusion injury. Inflammatory response associated with Angptl4 also leads to minimal change glomerulonephritis, wound healing. However, the role of Angptl4 in vascular permeability, angiogenesis, and inflammation is controversy. Hence, an underlying mechanism of Angptl4 in different kind of tissues needs to be further clarified. METHODS: Keywords such as angptl4, vascular permeability, angiogenesis, inflammation, and endothelial cells were used in search tool of PUBMED, and then the literatures associated with Angptl4 were founded and read. RESULTS: Data have established Angptl4 as the key modulator of both vascular permeability and angiogenesis; furthermore, it may also be related to the progression of metastatic tumors, cardiovascular events, and inflammatory diseases. This view focuses on the recent advances in our understanding of the role of Angptl4 in vascular permeability, angiogenesis, inflammatory signaling and the link between Angptl4 and multiple diseases such as cancer, cardiovascular diseases, diabetic retinopathy, and kidney diseases. CONCLUSIONS: Taken together, Angptl4 modulates vascular permeability, angiogenesis, inflammatory signaling, and associated diseases. The use of Angptl4-modulating agents such as certain drugs, food constituents (such as fatty acids), nuclear factor (such as PPARα), and bacteria may treat associated diseases such as tumor metastasis, ischemic-reperfusion injury, inflammation, and chronic low-grade inflammation. However, the diverse physiological functions of Angptl4 in different tissues can lead to potentially deleterious side effects when used as a therapeutic target. In this regard, a better understanding of the underlying mechanisms for Angptl4 in different tissues is necessary.

[Clinical value of MLPA in the prenatal gene diagnosis of Duchenne muscular dystrophy].

OBJECTIVE: To investigate the clinical value of multiplex ligation-dependent probe amplification (MLPA) in the prenatal gene diagnosis of high risk pregnant women from Duchenne muscular dystrophy (DMD) families. METHODS: The 155 high risk pregnant women from DMD families were recruited from 2005 to 2012 in 4 hospitals in Guangzhou, such as Southern Hospital of Southern Medical University and the Third Affiliated Hospital of Guangzhou Medical University. Among all the samples, 7 were chorionic villus samples taken from early-stage pregnancy and 148 were amniotic fluid samples from mid-stage pregnancy. After the maternal contamination was eliminated, the fetal DMD gene screening was carried out by using MLPA. The mutation rates in DMD exons were calculated in all the 155 families. RESULTS: (1) Among the 155 fetuses of the DMD high risk pregnant women, there were 72 male fetuses and 83 female fetuses. In the male fetuses, there were 27 sufferers (38%). In the female fetuses, there were 28 carriers (34%). And there were 100 normal fetuses. (2) Among the 27 DMD sufferers, 22 cases were DMD exon homozygous deletions (14.2%, 22/155) and 5 cases were DMD exon duplications (3.2%, 5/155). Among the 28 carriers, 25 cases were gene heterozygous deletions (16.1%, 25/155) and 3 cases were gene heterozygous duplications (1.9%, 3/155). In the 155 families, the DMD mutations mainly occurred in exons 45-52, and the exon 49 had the highest mutation rates of 22 times. (3) Among the 7 cases of prenatal gene diagnosis using chorionic villus samples, 2 fetuses had the identical DMD genotypes with their mothers and probands. One was a DMD sufferer and the other was a carrier. Termination or continuation of pregnancy was suggested based on the genotype of the fetus. CONCLUSIONS: MLPA provides an accurate method in the prenatal diagnosis of DMD. It could be used to distinguish DMD gene homozygous deletions from heterozygous deletions and duplications. Therefore, it is valuable for DMD prenatal diagnosis in high-risk women. Chorionic villus sampling can be applied to the early prenatal diagnosis for DMD disease.

[Analysis of de novo copy number variations in a family affected with autism spectrum disorders using high-resolution array-based comparative genomic hybridization].

OBJECTIVE: To analyze de novo copy number variations (CNVs) in a Chinese family affected with autism spectrum disorders (ASD). METHODS: Affymetrix Cytogenetics Whole Genome 2.7M Array assay was performed to identify potential CNVs in four members from the family. RESULTS: A total of 89 de novo CNV regions were identified in the autistic siblings. The CNV regions in total have exceeded 1/1000 of the lengths of chromosomes 5, 11 and 14. In addition, de novo CNV regions were also identified at 3p26.1, 4q22.2, and 5p15.2, which encompassed 10 genes associated with nerve development including GRM7, GRID2 and CTNND2. CONCLUSION: A number of nerve development associated genes were at the de novo CNV sites, which may provide new clues for genetic research of ASD. High-resolution array-comparative genomic hybridization is an effective method for detecting submicroscopic chromosomal imbalances.

[Study of dystrophin gene non-deletion/duplication mutations causing Becker muscular dystrophy].

OBJECTIVE: To identify potential mutations in patients featuring Becker muscular dystrophy (BMD) and to enhance the understanding of non-deletion/duplication mutations of the dystrophin gene causing BMD. METHODS: Clinical data of two patients affected with BMD were collected. Potential mutations in the dystrophin gene were screened with multiplex ligation-dependent probe amplification assay (MLPA). Biopsied muscle samples were examined with HE staining, immnostaining with anti-dystrophin antibody, and electronic microscopy. RESULTS: MLPA assay suggested that both cases were probably due to non-deletion/duplication mutations of the dystrophin gene. Light and electronic microcopy of skeletal muscle biopsies confirmed dystrophic changes in both patients. For patient A, immunostaining showed non-contiguous weak staining for most parts of sarcolemma. For patient B, immunostaining showed positive result with N-terminal anti-dystrophin antibody and negative result with C-terminal anti-dystrophin antibody. CONCLUSION: For patients with mild phenotypes but without dystrophin gene deletion/duplication, muscle biopsy and immunochemistry are helpful for diagnosis and prognosis.

[Association of mutation types and distribution characteristics of dystrophin gene with clinical symptoms in Chinese population].

Duchenne muscular dystrophy (DMD) is X-linked disorder caused by mutations in the dystrophin gene. To investigate mutation types and distribution characteristics of dystrophin gene in Chinese DMD patients, we used Multiplex Ligation-Dependent Probe Amplification (MLPA) to analyze the dystrophin gene in 720 DMD patients, their mothers, and 20 normal adult males. Results showed that detection rate was 64.9% (467/720) in all the patients, gene deletion rate was 54.3% (391/720), and gene duplication rate was 10.6% (76/720). The rate of deletion mutant occurred in Exon 45-54 was 71.9% (281/391) in all gene deletion patients; meanwhile, the rate of gene duplication occurred in Exon 1-40 was 82.9% (63/76) in all gene duplication ones. In all the patients with gene deletion and duplication, the rate of DMD and IMD was 90.6% (423/467), and BMD, 9.4% (44/467). This indicates that the main reason of duchenne muscular dystrophy is dystrophin gene deletion mutation, which would occur in any gene unevenly with hot spots of mutation. The location and fragment length of gene deletion and duplication cannot decide the severity of clinical symptoms directly.