A prokaryotic expression vector for the mutant diphtheria toxin CRM197 was constructed and expressed in Esch-erichia coli cells.Anti-CRM197 antibody concentrations were detected in serum samples of healthy volunteers.The crm 197 gene was codon-optimized in E.coli and cloned into the plasmid pET28a(+)under optimized expression conditions.CRM197 was purified using Ni-NTA spin columns and ion exchange chromatography,and confirmed by western blot analysis.The puri-fied CRM197 was used to detect specific anti-CRM197 antibody levels in serum samples of different age groups.The results showed that soluble codon-optimized CRM197 was successfully expressed under optimized expression conditions.The purity of CRM197 was more than 95％,as determined with Ni-NTA spin columns and ion exchange chromatography,consistent with the single specific bands obtained by western blot analysis and detection of serum levels of the anti-CRM197 antibody.Collec-tively,these results confirmed that the proposed expression strategy achieved high-yield production of soluble CRM197,al-though high levels in human serum may affect evaluation of immune interactions with glycan-CRM197 conjugates for applica-tion as a diagnostic antigen.The diphtheria mutant toxin CRM197 is used in many conjugate vaccines.The synthetic crm 197 gene with codon optimization in pET28a was transformed into E.coli Origami B(DE3)cells.CRM197 was induced by isopro-pyl β-d-1-thiogalactopyranoside and high level accumulation of soluble CRM197 was purified using Ni-NTA spin columns and ion exchange chromatography.The purity of the final prepara-tion reached 95％.CRM197 was used to detect the concentra-tions of the anti-CRM197 antibody in serum samples of healthy volunteers of different ages.The proposed expression strategy yielded high production of CRM197,which could interfere with evaluations of induced immune interactions by glycan-CRM197 conjugates and prohibit application as a diagnostic antigen.

Abstract: Objective　To investigate the clinical characteristics and diagnosis key points of brain abscess caused by Nocardia asiatica, and provide a clinical basis for diagnosing and treating intracranial infection caused by Nocardia. Methods　A case of pulmonary Nocardia asiatica complicated with brain abscess diagnosed at the Second Affiliated Hospital of Hainan Medical University was selected to analyze the clinical manifestations, cerebrospinal fluid characteristics, pulmonary and cranial imaging features, and treatment plan, and to summarize the diagnosis and treatment experience. Results　The patient was an elderly woman with a history of diabetes, dry cough was the first symptom without fever or headache. At the beginning of the course, it was diagnosed as pulmonary infection and tuberculosis in the local hospital, and received conventional antimicrobial and anti-tuberculosis therapies, but showed no improvement. The patient developed progressive limb weakness, followed by consciousness disorders, and coma. Cerebrospinal fluid (CSF) adenosine deaminase and lactate dehydrogenase were not abnormal, CSF pressure, protein and white blood cells were high, mainly with multiple nuclear cells. CSF glucose and chloride were normal in the early stage of the disease, but decreased significantly in the later stage. Metagenomic analysis of cerebrospinal fluid indicated Nocardia asiatica with a specific sequence number of 537. Lung CT showed exudation, abscess, and cavity in the right lung. Skull MRI scan + enhancement suggested multiple scattered abscesses in both cerebral hemispheres. The abscesses were of different sizes and showed ring enhancement, with extensive surrounding edema, and ventricular compression. After treatment with meropenem, linezolid, and compound sulfamethoxazole tablets, the cerebrospinal fluid recovered, and the lesions in the lungs and intracranial structures improved. Conclusions　Brain abscess caused by Nocardia asiatica is similar to the tuberculous brain in clinical symptoms, cerebrospinal fluid examination, craniocerebral imaging, so we should be alert to the possibility of Nocardia infection in patients with diabetes. At the same time, metagenomic testing of the cerebrospinal fluid can help confirm the diagnosis. The mortality and disability rates of brain abscess caused by Nocardia are high. Early diagnosis and treatment can improve the prognosis.

OBJECTIVE: Campylobacter jejuni NCTC11168 is commonly used as a standard strain for flagellar biosynthesis research. In this report, two distinguished phenotypic isolates (CJ1Z, flhA mutant strain, lawn; CJ2S, flhA complemented strain, normal colony) appeared during laboratory passages for NCTC11168. METHODS: Phenotypic assessments, including motility plates, transmission electron microscopy, biofilm formation assay, autoagglutination assay, and genome re-sequencing for these two isolates (CJ1Z, flhA mutant strain; CJ2S, flhA complemented strain) were carried out in this study. RESULTS: Transmission electron microscopy revealed that the flagellum was lost in CJ1Z. Phenotypic assessments and genome sequencing of the two isolates were performed in this study. The capacity for biofilm formation, colony auto-agglutination, and isolate motility was reduced in the mutant CJ1Z. Comparative genomic analysis indicated a unique native nucleotide insertion in flhA (nt, 2154) that caused the I719Y and I720Y mutations and early truncation in flhA. CONCLUSION FlhA has been found to influence the expression of flagella in C. jejuni. To the best of our knowledge, this is the first study to describe the function of the C-terminal of this protein.
Campylobacter jejuni/genetics* ; Bacterial Proteins/metabolism* ; Mutation ; Biological Variation, Population

Objective To determine the distribution of two important virulence factors [lipooligosaccharide (LOS) and capsular polysaccharide (CPS)] in Campylobacter jejuni (C. jejuni) isolated from different sources in China and to develop a rapid screening method for Guillain–Barré syndrome (GBS)-associated strains. Methods Whole-genome sequencing was carried out for 494 C. jejuni strains. The OrthoMCL software was used to define the LOS/CPS gene clusters. CPS genotyping was performed with serotype-specific sequence alignment using the BLAST software. Real-time Polymerase chain reaction (PCR) was developed with the unique sequences of specific CPS types. Results Nine novel and 29 previously confirmed LOS classes were identified. LOS classes A, B, and C were the most common (48.2％, 238/494) among the 494 strains. Twenty-six capsular types were identified in 448 strains. HS2, HS4c, HS5/31, HS19, and HS8/17 were the most frequent CPS genotypes (58.7％, 263/448). Strains of 17 CPS genotypes (strain number > 5) had one or two prevalent LOS classes (P < 0.05). Multiplex real-time PCR for rapid identification of HS2, HS19, and HS41 was developed and validated with strains of known serotypes. Conclusion Our results describe the genetic characteristics of the important virulence factors in C. jejuni strains in China. The multiplex real-time PCR developed in this study will facilitate enhanced surveillance of GBS-associated strains in China.

OBJECTIVE: To summarize and compare the clinical baseline characteristics of patients with monoclonal gammopathy of undetermined significance (MGUS), primary light chain amyloidosis (pAL), multiple myeloma (MM), or MM with concurrent amyloidosis, especially the differences in cytogenetic abnormalities. METHODS: The clinical data of 15 cases of MGUS, 34 cases of pAL, 842 cases of MM and 23 cases of MM with concurrent amyloidosis were analyzed and compared retrospectively. RESULTS: Cytogenetic statistics showed that the incidence of t (11; 14) in the four groups (MGUS vs pAL vs MM vs MM with concurrent amyloidosis) was 0%, 33.3%, 16.4%, and 15.8%, respectively (P=0.037); that of 13q deletion was 20.0%, 14.7%, 45.8% and 56.5%, respectively (P<0.001); gain of 1q21 was 50.0%, 12.5%, 47.4% and 40.9%, respectively (P=0.001). Proportion of pAL patients with 0, 1 and≥2 cytogenetic abnormalities (including 13q deletion, 17p deletion, 1q21 amplification and IgH translocation) accounted for 41.9%, 41.9% and 16.1%, respectively; while the proportion of the same category in MM was 17.6%, 27.3%, and 55.2% respectively; this ratio of MM with concurrent amyloidosis was more similar to MM. Subgroup analysis showed that genetic abnormalities (including 13q deletion, 17p deletion and 1q21 amplification) were comparable within t (11; 14) negative and positive groups. Compared with positive cases, t(11; 14) negative patients with MM or MGUS were more likely to have 13q deletions and multiple genetic abnormalities. CONCLUSION Clinical characteristics of pAL, especially cytogenetic abnormalities, are significantly different from MM with concurrent amyloidosis. It suggests that although the onset characteristics are similar, actually the two diseases belong to different disease subtypes which should be carefully predicted and identified.
Amyloidosis ; Humans ; In Situ Hybridization, Fluorescence ; Monoclonal Gammopathy of Undetermined Significance/complications* ; Multiple Myeloma ; Retrospective Studies

Objective:To establish the sequence-related amplified polymorphism （SRAP）-polymerase chain reaction （PCR） system for Valeriana officinalis var. latifolia，so as to lay the theoretical and technical foundations for the breeding of V. officinalis var. latifolia. Method:Single factor test was applied to investigate the effects of Taq Mix dose，Mg²⁺ concentration，template DNA concentration，and Taq DNA polymerase content on SRAP-PCR amplification of V. officinalis var. latifolia，based on which the orthogonal experiments were performed to optimize the SRAP-PCR system for V. officinalis var. latifolia. The effective primers that could be used for genetic diversity studies of V. officinalis var. latifolia were selected under the optimal reaction condition. Result:The results of the single factor test showed that Taq Mix dose within the range of 8-11 μL resulted in better amplification. The addition of a low concentration of Mg²⁺，the medium to low concentrations of template DNA，or the low concentration of Taq DNA polymerase enhanced the amplification efficiency or richness. As demonstrated by the orthogonal experiments，the influencing degrees of related factors on SRAP-PCR amplification of V. officinalis var. latifolia were sorted in a descending order as follows： Taq Mix dose>Taq DNA polymerase content>Mg²⁺ concentration>template DNA concentration. The optimal reaction system for V. officinalis var. latifolia was determined to consist of 11 μL of Taq Mix，30 ng of template DNA，0.025 mmol·L^-1 Mg²⁺，1.5 U of Taq DNA polymerase，5 μmol·L^-1 forward primer，and 5 μmol·L^-1 reverse primer，which was supplemented to 20 μL with ddH₂O. The optimal annealing temperature was 36.8 ℃. A total of 17 pairs of effective primers with high band resolution and polymorphism were selected from 88 primer pairs for SRAP-PCR of V. officinalis var. latifolia. Conclusion:The established SRAP-PCR system for V. officinalis var. latifolia is stable， which can be used for genetic diversity studies of V. officinalis var. latifolia.

Background: Malignant pleural effusion (MPE) is a complicated condition of patients with advanced tumors. Further dissecting the microenvironment of infiltrated immune cells and malignant cells are warranted to understand the immune-evasion mechanisms of tumor development and progression. Methods: The possible involvement of microRNAs (miRNAs) in malignant pleural fluid was investigated using small RNA sequencing. Regulatory T cell (Treg) markers (CD4, CD25, forkhead box P3), and Helios (also known as IKAROS Family Zinc Finger 2 [IKZF2]) were detected using flow cytometry. The expression levels of IKZF2 and miR-4772-3p were measured using quantitative real-time reverse transcription polymerase chain reaction. The interaction between miR-4772-3p and Helios was determined using dual-luciferase reporter assays. The effects of miR-4772-3p on Helios expression were evaluated using an in vitro system. Correlation assays between miR-4772-3p and functional molecules of Tregs were performed. Results: Compared with non-malignant controls, patients with non-small cell lung cancer had an increased Tregs frequency with Helios expression in the MPE and peripheral blood mononuclear cells. The verified downregulation of miR-4772-3p was inversely related to the Helios⁺ Tregs frequency and Helios expression in the MPE. Overexpression of miR-4772-3p could inhibit Helios expression in in vitro experiments. However, ectopic expression of Helios in induced Tregs reversed the effects induced by miR-4772-3p overexpression. Additionally, miR-4772-3p could regulate Helios expression by directly targeting IKZF2 mRNA. Conclusion Downregulation of miR-4772-3p, by targeting Helios, contributes to enhanced Tregs activities in the MPE microenvironment.

OBJECTIVETo investigate the expression characteristics of the gene of coiled-coil domain-containing protein 70 (Ccdc70) in the mouse testis and its potential role in spermatogenesis.

METHODSUsing expression profile microarray, we screened the mouse testis-specific gene Ccdc70, studied its expression characteristics in the mouse testis by RT-PCR, real-time PCR, Western blot and immunohistochemistry, followed by bioinformatic analysis of the Ccdc70 protein.

RESULTSThe Ccdc70 gene was expressed highly in the testis but lowly in the epididymis of the mice. The Ccdc70 protein was expressed mainly in the spermatocytes and round spermatids of the testis and in the epithelial cells of the epididymis. Bioinformatic analysis showed a structural domain in the Ccdc70 protein, which was highly conserved in mammalian evolution.

CONCLUSIONThe Ccdc70 gene is highly expressed in the mouse testis and mainly in the spermatocytes, round spermatids, and epididymal epithelial cells, which indicates that it is involved in the regulation of spermatogenesis and epididymal sperm maturation.

Animals ; Computational Biology ; Gene Expression Regulation, Developmental ; Male ; Mice ; Proteins ; genetics ; Spermatogenesis ; genetics ; Testis ; metabolism

OBJECTIVETo investigate the impact of impoundment and active public health interventions on rodent populations and rodent-borne diseases in the Three Gorges reservoir region from 1997 to 2012.

METHODSSurveillance data from 1997 to 2012 were extracted from the Public Health Surveillance System of The Three Gorges established in 1997. Temporal changes in the incidences of hemorrhagic fever with renal syndrome (HFRS) and leptospirosis, rodent density, pathogen-carrying rates, and their correlations were analyzed.

RESULTSThe average indoor and outdoor rodent densities decreased overall from 1997 to 2012. The average densities decreased by 47.72% (from 4.38% to 2.29%) and 39.68% (from 4.41% to 2.66%), respectively, after impoundment (2003-2012) compared with before impoundment (1997-2002). The average annual incidence rates of HFRS and leptospirosis were 0.29/100,000 and 0.52/100,000, respectively, and decreased by 85.74% (from 0.68/100,000 to 0.10/100,000) and 95.73% (from 1.47/100,000 to 0.065/100,000), respectively, after impoundment compared with before impoundment. Incidences of HFRS and leptospirosis appear to be positively correlated with rodent density in the reservoir area.

CONCLUSIONThis study demonstrated that rodent density and incidences of rodent-borne diseases decreased and were maintained at low levels during construction of the Three Gorges dam. Measures that reduce rodent population densities could be effective in controlling rodent-borne diseases during large-scale hydraulic engineering construction.

Animal Distribution ; Animals ; China ; epidemiology ; Disease Reservoirs ; Hantavirus Infections ; epidemiology ; veterinary ; Leptospirosis ; epidemiology ; virology ; Population Density ; Rodent Diseases ; epidemiology ; microbiology ; virology ; Rodentia ; Seasons ; Time Factors ; Water Supply ; Zoonoses

OBJECTIVETo investigate the causes of unintentional injuries in children and to provide reference for reducing the incidence of unintentional injuries in children.

METHODSA retrospective analysis was performed on the clinical data of 924 children with unintentional injuries who were hospitalized in Zhongshan Boai Hospital from January 2008 to December 2010.

RESULTSOf the 924 cases, 26.4% suffered falls, which was the most common cause of injuries, 15.7% suffered burns and scalds, 14.0% were injured by foreign bodies, and 13.1% were injured in traffic accidents. Unintentional injuries occurred mainly among children aged 0-3 years (67%). The proportion of cases in summer (July to September) was significantly higher than in any other season (P < 0.05), and burns were the common causes of injuries in summer. Home was the most common place where unintentional injuries occurred (36.9%). The incidence of traffic accidents was significantly higher in non-local children than in local children (P < 0.001). As for the parents' educational levels, the children whose parents had an education level below junior middle school accounted for the highest proportion of all cases of unintentional injury (45.5%). Injuried cases in rural areas accounted for a significantly higher percentage than in urban areas (P < 0.05).

CONCLUSIONSFalls are the principal cause of unintentional injuries in children. Young children (0-3 years) are most vulnerable to unintentional injuries. Unintentional injuries mostly occur at home. The incidence of traffic accidents is higher in non-local children than in local children. Parents' education levels are associated with the incidence of unintentional injuries. In order to reduce the incidence of unintentional injuries in children, preventive measures must be carried out, and safety education should be enhanced in consideration of children's age, sex and family background.

Accidents ; statistics & numerical data ; Adolescent ; Child ; Child, Preschool ; Educational Status ; Female ; Humans ; Infant ; Infant, Newborn ; Male ; Parents ; Retrospective Studies