Objective:To construct an estimating equation to accurately reflect the aging phenomenon of the glomerular filtration rate(GFR).Methods:Healthy subjects receiving physical examinations at the First Affiliated Hospital of Nanjing Medical University between January 2017 and April 2018 were included in the study, and the aging phenomenon of renal function indicators such as serum creatinine(Scr)was used as the reference standard to evaluate the accuracy of four Scr-based GFR equations during GFR aging, including the full age spectrum(FAS)equation, the Chronic Kidney Disease Epidemiology Collaboration(CKD-EPI)equation, the Osaka equation and the Xiangya equation.Results:Of 37 636 individuals receiving physical examinations, 6 534 met the criteria specified in this study.Scr, serum urea nitrogen, serum uric acid, and serum albumin showed a significant aging phenomenon( H=191.640, 196.693, 83.271, 414.585, P<0.001 for all).The GFR estimated by the four equations all decreased with aging, but the starting point and rate of decline were significantly different.The GFR aging phenomenon estimated by the FAS equation was closer to the trend of renal function indicators. Conclusions:The FAS equation may be more applicable to healthy people to understand the aging phenomenon of GFR.

The modern bio-fermentation industry requires design and creation of efficient microbial cell factories for directed conversion of raw materials to target products. The main criteria for assessing the performance of microbial cell factories are their product synthesis capacity and stability. Due to the deficiencies of plasmids in gene expression such as instability and being easy to lose, integration of genes into chromosome is often a better choice for stable expression in microbial hosts. To this end, chromosomal gene integration technology has received much attention and has developed rapidly. In this review, we summarize the recent research progresses of chromosomal integration of large DNA fragments in microorganisms, illustrate the principles and features of various technologies, highlight the opportunity brought by the CRISPR-associated transposon systems, and prospect future research direction of this technology.
Chromosomes ; Plasmids ; DNA ; Cloning, Molecular ; Fermentation

Objective:To explore the phenotype and molecular genetic features of spinocerebellar ataxia type 2 (SCA2) cases with ATXN2 intermediate-length CAG-repeat expansion.Methods:Fragment analysis by capillary electrophoresis was performed to detect the dynamic mutations in the samples of the probands in 1 383 pedigrees with autosomal dominant inherited ataxia in Research Center for Motor Disorders and Neurogenetic Diseases, Department of Neurology, China-Japan Friendship Hospital from 2005 to 2018. The clinical and genetic features of individuals carrying the ATXN2 intermediate-length CAG-repeat expansion were carefully analyzed.Results:Two hundred and three individuals (including the probands and members of their families) in 163 families carried the expanded CAG repeats in ATXN2 gene, among which 107 individuals in 93 families carried the intermediate-length CAG-repeats. Within 20 parent-child pairs, the CAG repeats increased 0-28 copies in 16 pairs with paternal inheritance, and 0-4 copies in 4 pairs with maternal inheritance.Conclusions:For suspected SCA2 cases, ATXN2 gene testing should be performed on the parental members and adult offspring members in the family. Dynamic mutations testing is essential to identify the individuals with ATXN2 intermediate-length repeat expansion, which is very important for genetic counseling.

Rare diseases have been a major challenge for clinical medicine and public health challenge in China. One of the effective measures is to conduct proactive research on rare diseases to deal with the disease burden of the diseases. However, low prevalence, disperse distribution of patients, lack of knowledge about the disease course, and phenotype heterogeneity hamper the development of research for rare diseases. Recently, it has been found that patients registry is effective in understanding the course of the disease and accu- mulating the cases and data of clinical research or clinical trial design. At present, most of developed countries or regions in the world have promoted clinical research and clinical trials of new medications on rare diseases by using the registration of rare disease. In 2016, Peking Union Medical College Hospital established China's first registry system at the national level-National Rare Disease Registry System of China(NRDRS). NRDRS has accumulated 68 137 cases data registered by the researchers from China's 101 collaborating hospitals in 29 provinces/municipalities/autonomous regions, covering 171 different, and forming 188 cohorts. To date, NRDRS complete the initial stage of resources buildup.Nex stage will be focused on clinical research and clinical trials related to rare diseases based on NRDRS. This article is on the process of building NRDRS, the potential support for conducting clinical research and clinical trials related to rare diseases, and the challenges will be faced.

Objective:To investigate the prevalences of overweight and obesity and its relationship with the risk factors of cardiovascular diseases among physical examination population in Nanjing Drum Tower Hospital.Methods:A retrospective analysis was performed on 384 061 adults aged 20 years and older. Age- and sex-standardized prevalences of overweight and obesity were calculated using Chinese census data in 2010. Multivariate logistic regression analysis was used to assess the associations of overweight and obesity with the risk factors of cardiovascular diseases.Results:The age-standardized prevalences of overweight and obesity were 42.8% and 13.2% in men and 23.9% and 6.6% in women. A gradually increasing trend was observed in the prevalences of overweight and obesity from 2008 to 2016, especially in subjects aged 20-39 years. Overweight and obesity were significantly associated with increased risks of dyslipidemia, diabetes mellitus, hypertension, and hyperuricemia. These associations were found to be the strongest among subjects aged 20-39 years, which became weaker along with the increasing of age. The OR(95% CI) of dyslipidemia, diabetes mellitus, hypertension, and hyperuricemia were 4.23(4.01-4.47), 3.70(2.97-4.60), 6.19(5.76-6.64), and 3.66(3.45-3.88) in obese men aged 20-39 years, while 5.29(4.63-6.04), 6.38(3.86-10.55), 9.36(7.86-11.13), and 6.65(5.70-7.74) in obese women aged 20-39 years, respectively. Conclusion:The increasing trend in the prevalence of overweight and obesity is a risk factor for cardiovascular diseases in Nanjing adults, especially in individuals aged 20-39 years.

The use of microbial cell factories to achieve efficient conversion of raw materials and synthesis of target substances is one of the important research directions of synthetic biology. Traditional industrial microorganisms have mainly used sugar-based raw materials as fermentation substrates. How to adopt cheaper carbon resources and realize their efficient use has been widely concerned. Formic acid is an important organic one-carbon source and widely used in industrial manufacturing of pesticides, leather, dyes, medicine and rubber. In recent years, due to the demand fluctuation in downstream industries, formic acid production is facing the dilemma of overcapacity, and therefore, requiring new conversion paths for expansion and extension of the related industrial chain. Biological route is one of the important options. However, natural formate-utilizing microorganisms generally grow slowly when metabolizing formic acid, and moreover, are difficult to be artificially modified by the absence of effective genetic tools. Construction of non-natural formate-utilizing microorganisms is another alternative strategy, but still in its infancy and has a huge space for further improvements. Here, we briefly summarize the recent research progress of biological utilization of formic acid, and also propose the future research focus and direction.
Fermentation ; Formates ; metabolism ; Industrial Microbiology ; trends ; Synthetic Biology ; trends

Objective:To investigate the clinical and genetic characteristics of patients with CTA/CTG trinucleotide repeat expansion of ATXN8OS gene.Methods:The CTA/CTG trinucleotide repeats of ATXN8OS gene were detected in 1 689 spinocerebellar ataxia cases from Research Center for Movement Disorders and Neurogenetics, Department of Neurology, China-Japan Friendship Hospital in 2005—2017. The correlation between clinical phenotypes and expanded CTA/CTG repeats in the ATXN8OS gene of patients was studied carefully, and compared with 100 healthy controls.Results:Twenty-one patients with pathological CTA/CTG repeat expansion of ATXN8OS gene were collected. Eighteen of them carried the alleles with more than 80 repeats, whose common initial symptom was gait instability, followed by dysarthria and dysphagia with disease progression. Four of the 18 patients presented with head or truncal tremor. The other three patients carried the alleles with the repeats ranging from 70 to 79, whose initial symptom was walking instability, gradually appeared dysarthria, with no dysphagia or tremor. The repeat lengths ranged from 19 to 42 in the 100 healthy controls. The brain magnatic resonance imaging of almost all the patients showed moderate to severe cerebellar atrophy, and some patients with mild atrophy of the brainstem except one case with corpus callosum dysplasia.Conclusions:Most of the patients with CTA/CTG repeat expansion presented with ataxia and dysarthria. Brain magnetic resonance imaging showed significant cerebellar atrophy, suggesting that the mutation is related to SCA8 gene.

Objective:To explore the clinical, imaging features and pathogenic mutations in three cases of Gerstmann-Str?ussler-Scheinker syndrome (GSS) with ataxia.Methods:Since 2014, totally 137 probands with autosomal dominant or sporadic ataxia were treated in the Department of Neurology, China-Japan Friendship Hospital. They were screened for mutations in prion protein (PRNP) gene using next-generation sequencing. Spinocerebellar ataxia 1, 2, 3, 6, 7, 8, 12, 17 and dentatorubral-pallidoluysian atrophy were excluded by capillary electrophoresis. Potential pathogenic variants were confirmed by Sanger sequencing. Pathogenicity assessment was interpreted according to the American College of Medical Genetics standards and guidelines. Clinical phenotypes and imaging features of patients were analyzed in detail.Results:Three pedigrees of GSS caused by PRNP gene variants were found. The probands of three pedigrees carried reported heterozygous missense mutation c.305C>T (p.P102L), all onset in adults. All of the three probands showed walking instability and dysarthria, additionally, the proband of pedigree 1 showed parkinsonian signs, the proband of pedigree 2 had cognitive impairment. Brain magnetic resonance imaging showed cerebellar atrophy of different degrees in probands 2 and 3, while pallidum hyperintense signal in proband 1.Conclusions:GSS as a rare subtype of prion disease, could be characterized by cerebellar ataxia. For patients with ataxia, attention should be paid to GSS disease-causing gene mutations in genetic testing. Early diagnosis based on genetic testing will be instrumental in genetic counseling and birth defect intervention in pedigree members.

Pre-testing preparation is the basis and starting point of genetic testing.The process includes collection of clinical information,formulation of testing scheme,genetic counseling before testing,and completion of informed consent and testing authorization.To effectively identify genetic diseases in clinics can greatly improve the diagnostic rate of next generation sequencing (NGS),thereby reducing medical cost and improving clinical efficacy.The analysis of NGS results relies,to a large extent,on the understanding of genotype-phenotype correlations,therefore it is particularly important to collect and evaluate clinical phenotypes and describe them in uniform standard terms.Different types of genetic diseases or mutations may require specific testing techniques,which can yield twice the result with half the effort.Pre-testing genetic counseling can help patients and their families to understand the significance of relevant genetic testing,formulate individualized testing strategies,and lay a foundation for follow-up.

With high accuracy and precision,next generation sequencing (NGS) has provided a powerful tool for clinical testing of genetic diseases.To follow a standardized experimental procedure is the prerequisite to obtain stable,reliable,and effective NGS data for the assistance of diagnosis and/or screening of genetic diseases.At a conference of genetic testing industry held in Shanghai,May 2019,physicians engaged in the diagnosis and treatment of genetic diseases,experts engaged in clinical laboratory testing of genetic diseases and experts from third-party genetic testing companies have fully discussed the standardization of NGS procedures for the testing of genetic diseases.Experts from different backgrounds have provided opinions for the operation and implementation of NGS testing procedures including sample collection,reception,preservation,library construction,sequencing and data quality control.Based on the discussion,a consensus on the standardization of the testing procedures in NGS laboratories is developed with the aim to standardize NGS testing and accelerate implementation of NGS in clinical settings across China.