BACKGROUND:Delayed therapy widely occurs in patients with dementia praecox;therefore,it brings a series of difficulties for clinical treatment and rehabilitation.OBJECTIVE:To analyze the influential factors of delayed therapy in patients with dementia praecox.DESIGN:Cross-sectional study based on patients with dementia praecox.SETTING:The Second Affiliated Hospital of Xinxiang Medical College.PARTICIPANTS:A total of 96 patients with dementia praecox,including 52 males and 44 females,were selected from the Second Affiliated Hospital of Xinxiang Medical College from January to June 2005.Their ages ranged from 16 to 55 years and the mean age was (32.7±12.3) years.Among them,54 patients had middle-school education and 42 patients had high-school education.METHODS:A domestic inventory was used to carefully record basically clinical data of each patient.and the inventory included sex,marriage status,educational level,attack styles,home address,home environment,economic status,family history,etc.All data were classified and analyzed in details.In addition,condition of delayed therapy,which determined as the duration over 1 year from onset of psychiatric symptoms to accepted treatment,in each classification was surveyed gradually.MAIN OUTCOME MEASURES:Delayed therapeutic rate and occurent rate of related factors.RESULTS:Among 96 patients,60 patients had delayed therapy,and the delayed therapeutic rate was 62.5%.Influential factors of delayed therapy:Logistic regression analysis demonstrated that regression equation was involved in educational level,family history,attack style and economic status.Meanwhile,the standard regression coefficient was 0.332 1,0.210 1,0.190 3 and 0.101 2. CONCLUSION:Educationallevel,family history,attack style and economic status of patients with dementia praecox are risk factors of delayed therapy. It is of importance for strengthening these factors to interfere and reduce delayed therapeutic rate at an early phase.

A 1 270 bp full-length cDNA fragment was obtained from the Schistosoma japonicum (Chinese strain) adult cDNA library after the '3' and 5' ends of the incomplete expression sequence tag (EST) of hypoxanthine-guanine phosphoribosyltransferase of Schistosoma japonicum (SjHGPRT) were amplified by the anchored PCR with 2 pairs of primer that were designed according to the published incomplete SjHGPRT EST and the sequence of multiclone sites of library λgt1 1 vector. Sequence analysis indicated that this fragment, with an identity of 82% to hypoxanthine-guanine phosphoribosyltransferase ofSchistosoma mansoni (SmHGPRT), contained a complete open reading frame(ORF). The deduced amino acid sequence showed 83% identity to that of SmHGPRT. This fragment was cloned into the prokaryotic expression vector pQE30, and subsequently sequenced and expressed in Escherichia coli. SDS-PAGE revealed that M of the recombinant protein was about 28 ku. Western-blot analysis showed that the recombinant protein was recognized by the polyclonal antisera from rabbits immunized with Schistosoma japonicum adult worm antigen. Mice vaccinated with recombinant protein revealed significant worm burden, liver eggs per gram (LEPG), fecal eggs per gram (FEPG) and intrauterine eggs of the female worms reduction percentage, compared with the controls. Taken together, the SjHGPRT full-length cDNA can be cloned and expressed in E. coli as a recombinant protein that elicited immunity against the challenge infection with Schistosoma japonicum, indicating its potential as a partia1 protection vaccine candidate.

As a typical food safety industrial model strain, Bacillus subtilis has been widely used in the field of metabolic engineering due to its non-pathogenicity, strong ability of extracellular protein secretion and no obvious codon preference. In recent years, with the rapid development of molecular biology and genetic engineering technology, a variety of research strategies and tools have been used to construct B. subtilis chassis cells for efficient synthesis of biological products. This review introduces the research progress of B. subtilis from the aspects of promoter engineering, gene editing, genetic circuit, cofactor engineering and pathway enzyme assembly. Then, we also summarized the application of B. subtilis in the production of biological products. Finally, the future research directions of B. subtilis are prospected.
Bacillus subtilis/genetics* ; Bacterial Proteins/genetics* ; Gene Editing ; Metabolic Engineering ; Promoter Regions, Genetic

Functional membrane microdomains (FMMs) that are mainly composed of scaffold proteins and polyisoprenoids play important roles in diverse cellular physiological processes in bacteria. The aim of this study was to identify the correlation between MK-7 and FMMs and then regulate the MK-7 biosynthesis through FMMs. Firstly, the relationship between FMMs and MK-7 on the cell membrane was determined by fluorescent labeling. Secondly, we demonstrated that MK-7 is a key polyisoprenoid component of FMMs by analyzing the changes in the content of MK-7 on cell membrane and the changes in the membrane order before and after destroying the integrity of FMMs. Subsequently, the subcellular localization of some key enzymes in MK-7 synthesis was explored by visual analysis, and the intracellular free pathway enzymes Fni, IspA, HepT and YuxO were localized to FMMs through FloA to achieve the compartmentalization of MK-7 synthesis pathway. Finally, a high MK-7 production strain BS3AT was successfully obtained. The production of MK-7 reached 300.3 mg/L in shake flask and 464.2 mg/L in 3 L fermenter.
Bacillus subtilis/metabolism* ; Vitamin K 2/metabolism* ; Bioreactors/microbiology* ; Membrane Microdomains/metabolism*

Chitinase has a wide industrial application prospect. For example, it can degrade shrimp shells, crab shells and other crustacean waste into high value-added chitooligosaccharides. However, the low catalytic efficiency of chitinase greatly limits the production of chitooligosaccharides. In previous study, the we expressed a chitinase Chisb with high catalytic efficiency and studied its enzymatic properties. In order to further improve the catalytic efficiency of Chisb, with R13NprB-C-SP-H as the parent, here error-prone PCR was used to construct random mutant library to conduct directed evolution of chitinase Chisb. Two mutants C43D and E336R were obtained with 96-well plate primary screening and shaker-screening, and their enzymatic properties were also studied. The optimum temperature of C43D and E336R was 55 °C, and the optimum pH of C43D was 5.0, while that of E336R was 9.0. The catalytic efficiency of C43D and E336R was 1.35 times and 1.57 times higher than that of control. The chitooligosaccharide concentration of E336R and C43D was 2.53 g/L and 2.06 g/L, improved by 2.84 times and 2.31 times compared with the control (0.89 g/L), respectively. In addition, the substrate conversion rate of mutants E336R and C43D was 84.3% and 68.7%, improved by 54.6% and 39% compared with the control (29.7%), respectively. In summary, the study indicates that random mutation introduced by error-prone PCR can effectively improve the catalytic efficiency of chitinase Chisb. The positive mutants with higher catalytic efficiency obtained in the above study and their enzymatic property analysis have important research significance and application value for the biosynthesis of chitooligosaccharides.
Biocatalysis ; Chitin ; analogs & derivatives ; Chitinases ; Hydrogen-Ion Concentration ; Polymerase Chain Reaction

Bacillus subtilis is recognized as a generally-regarded-as-safe strain, and has been widely used in the biosynthesis of high value-added products, including N-acetylneuraminic acid (NeuAc) which is widely used as a nutraceutical and a pharmaceutical intermediate. Biosensors responding to target products are widely used in dynamic regulation and high-throughput screening in metabolic engineering to improve the efficiency of biosynthesis. However, B. subtilis lacks biosensors that can efficiently respond to NeuAc. This study first tested and optimized the transport capacity of NeuAc transporters, and obtained a series of strains with different transport capacities for testing NeuAc-responsive biosensors. Subsequently, the binding site sequence of Bbr_NanR responding to NeuAc was inserted into different sites of the constitutive promoter of B. subtilis, and active hybrid promoters were obtained. Next, by introducing and optimizing the expression of Bbr_NanR in B. subtilis with NeuAc transport capacity, we obtained an NeuAc-responsive biosensor with wide dynamic range and higher activation fold. Among them, P535-N2 can sensitively respond to changes in intracellular NeuAc concentration, with the largest dynamic range (180-20 245) AU/OD. P566-N2 shows a 122-fold of activation, which is 2 times of the reported NeuAc-responsive biosensor in B. subtilis. The NeuAc-responsive biosensor developed in this study can be used to screen enzyme mutants and B. subtilis strains with high NeuAc production efficiency, providing an efficient and sensitive analysis and regulation tool for biosynthesis of NeuAc in B. subtilis.
N-Acetylneuraminic Acid/metabolism* ; Bacillus subtilis/metabolism* ; Promoter Regions, Genetic/genetics* ; Binding Sites ; Biosensing Techniques