Escherichia coli AFP111 is a spontaneous mutant with mutations in the glucose specific phosphotransferase system (ptsG) in NZN111 (delta pflAB deltaldhA). In AFP111, conversion of xylose to succinic acid generates 1.67 molecule of ATP per xylose. However, the strain needs 2.67 molecule ATP for xylose metabolism. Therefore, AFP111 cannot use xylose due to insufficient ATP under anaerobic condition. Through an atmospheric and room temperature plasma (ARTP) jet, we got a mutant strain named DC111 that could use xylose under anaerobic condition in M9 medium to produce succinic acid. After 72 h, DC111 consumed 10.52 g/L xylose to produce 6.46 g/L succinic acid, and the yield was 0.78 mol/mol. Furthermore, the reaction catalyzed by the ATP-generating PEP-carboxykinase (PCK) was enhanced. The specific activity of PCK was 19.33-fold higher in DC111 than that in AFP111, which made the strain have enough ATP to converse xylose to succinic acid.
Atmosphere ; Escherichia coli ; genetics ; metabolism ; Fermentation ; Industrial Microbiology ; Metabolic Engineering ; Mutation ; Plasma Gases ; pharmacology ; Succinic Acid ; metabolism ; Temperature ; Xylose ; metabolism

During the anaerobic fermentation by Escherichia coli AFP111 for succinic acid production, the viable cell concentration and productivity were decreased with the raising of succinic acid concentration. In order to restore cellular succinic acid productivity and prolong fermentation time, we collected strains and refreshed medium for repetitive succinic acid production. However, productivity is lower than that in the anaerobic fermentation before reusing strains. To enhance the productivity, strains were aerobically cultivated for 3 h in pure water before anaerobic fermentation. The activities of key enzymes were enhanced for better performance in producing succinic acid at anaerobic stage. After three rounds of repetitive fermentations, succinic acid concentration and yield reached to 56.50 g/L and 90% respectively. The succinic acid productivity was 0.81 g/(L x h), which was 13% higher than the repetitive fermentations without aerobic activation of the strains.
Aerobiosis ; Anaerobiosis ; Culture Media ; Escherichia coli ; genetics ; metabolism ; Fermentation ; Genetic Engineering ; Glucose ; metabolism ; Industrial Microbiology ; Succinic Acid ; metabolism

Escherichia coli BA002, in which the ldhA and pflB genes are deleted, cannot utilize glucose anaerobically due to the inability to regenerate NAD+. To restore glucose utilization, overexpression of nicotinic acid phosphoribosyltransferase (NAPRTase) encoded by the pncB gene, a rate-limiting enzyme of NAD(H) synthesis pathway, resulted in a significant increase in cell mass and succinate production under anaerobic conditions. However, a high concentration of pyruvate was accumulated. Thus, co-expression of NAPRTase and the heterologous pyruvate carboxylase (PYC) of Lactococcus lactis subsp. cremoris NZ9000 in recombinant E. coli BA016 was investigated. Results in 3 L fermentor showed that OD600 is 4.64 and BA016 consumed 35.00 g/L glucose and produced 25.09 g/L succinate after 112 h under anaerobic conditions. Overexpression of pncB and pyc in BA016, the accumulation of pyruvic acid was further decreased, and the formation of succinic acid was further increased.
Anaerobiosis ; Escherichia coli ; enzymology ; genetics ; metabolism ; Fermentation ; Genetic Engineering ; Glucose ; metabolism ; Industrial Microbiology ; Lactococcus lactis ; enzymology ; NAD ; metabolism ; Pentosyltransferases ; biosynthesis ; genetics ; Pyruvate Carboxylase ; biosynthesis ; genetics ; Succinic Acid ; metabolism

Objective To estimate the clinical value of thinprep cytologic test (TCT) in screening cervical lesion. Methods 4234 TCT samples were interpreted according to the Besthesda System (TBS), 272positive cases (ASC-US or above) were taken colposcopic examination and biopsy. Results The coincidence of the results between TCT and biopsy in low-grade squamous intraepithelial lesion (LSIL), high-grade squamous intraepithelial lesion (HSIL), squamous cell carcinoma (SCC), adenocarcinoma (AC) were 85.71%(12/14), 100 % (20/20), 75 % (3/4) and 100 % (2/2), respectively. The positive rates of over ASC-H by TCT and of over CIN Ⅰ by biopsy were 23.16 % (63/272) and 24.26 % (66/272), respectively. There is no difference between two positive rates (x2 = 0.868, P = 0.581). Conclusion TCT and histopathological diagnosis had a high coincidence, a combination of both can greatly enhance HSIL and cervical cancer and reduce the incidence of missed diagnosis. TCT would be a rapid and convenient method for screening cervical cancer.

[ ABSTRACT] AIM: To investigate the effect of chronic intermittent hypoxia on AMP-activated protein kinase ( AMPK) pathway in the brain of young rats.METHODS:Part one:SD mice (3~4 weeks old) were randomly divided into 4 groups (n=8): simulated air control group for 2 weeks (2AC), chronic intermittent hypoxia group for 2 weeks (2IH), simulated air control group for 4 weeks (4AC) and chronic intermittent hypoxia group for 4 weeks (4IH).Part two:SD mice (3~4 weeks old) were randomly divided into 2 groups (n=8): chronic intermittent hypoxia group for 4 weeks (4IH) and chronic intermittent hypoxia group treated with AMPK inhibitor for 4 weeks (4IHI).After modeling, the eight-arm maze test was performed.TUNEL method was used to detect the neuronal apoptosis in the hippocampal and pre-frontal cortical tissues.The mRNA expression of adenosine A2a receptor was examined by RT-qPCR, and the protein levels of phosphorylated AMPK (p-AMPK) and mammalian target of rapamycin (p-mTOR) were determined by Western blot.
RESULTS:Compared with control group, the numbers of reference memory error ( RME) , working memory error ( WME) and total error (TE) in 2IH group and 4IH group significantly increased (P<0.01).Compared with 2IH group, the num-bers of errors in 4IH group also increased significantly (P<0.01).Compared with 4IH group, the values in 4IHI group significantly decreased.Compared with control group, the neuronal apoptosis of hippocampus and prefrontal cortex in 2IH group and 4IH group increased, and that in 4IH group was more evident (P<0.05).In 4IHI group, the neuronal apopto-sis decreased.The mRNA expression of adenosine A2a receptor in the hippocampal and cortical tissues in 2IH group and 4IH group was higher than that in control group.The protein level of p-AMPK was higher, and p-mTOR was lower in 2IH group and 4IH group, and those in 4IH group were more evident (P<0.05).Compared with 4IH group, the protein level of p-AMPK was lower, and p-mTOR was higher in 4IHI group.CONCLUSION: Chronic intermittent hypoxia induces neuronal apoptosis, resulting in impairment of learning and memory in a time-dependent manner by upregulating adenosine A2a receptor, activating AMPK activity, and inhibiting mTOR phosphorylation in rats.

Objective To explore the efficacy of triple therapy and sequential therapy in the eradication of Helicobacter pylori (Hp) in patients receiving long-term non-steroidal antiinflammatory drugs (NSAID) treatment.Methods Patients receiving long-term NSAID treatment were enrolled in this study.Patients diagnosed as Hp infection were divided into triple therapy and sequential therapy groups.The patients in triple therapy group received omeprazole,clarithromycin and amoxicillin theray for 10 days.The patients in sequential group received esomeprazole with amoxicillin for five days,and then esomeprazole with clarithromycin and metronidazole for another five days.All patients were given mucosal protective therapy as maintenance treatment after eradication therapy and followed up for 12 weeks.Patients underwent endoscopy examination and Hp testing before and after follow-up.Hp eradication rates were compared with the intention-to-treat (ITT) and per protocol (PP) analysis.Results According to ITT analysis,the eradication rates of Hp in triple therapy group and sequential therapy group were 78.4 ％ (40/51) and 80.0 ％ (40/50) respectively,there was no significant difference between these two groups (x2 =0.038,P=0.846).According to PP analysis,the eradication rates of Hp in triple therapy group and sequential therapy group were 84.4％ (38/45) and 87.0％ (40/46) respectively,there was no significant difference between these two groups either (x2=0.117,P=0.732).Conclusion There was no significant difference in Hp eradication between triple therapy and sequential therapy in patients receiving long-term NSAID treatment.

Objective To analyze the condition and characteristics of hand-foot-mouth disease ( HFMD) from 2010 to 2012 in Renqiu city.Methods Surveillance and detecetion of HFMD was collected according to Renqiu city system for diseases control and prevention .The pathogen of HFMD severe case was deteceted .Results 12 293 cases including 735 severe cases were recorded in Renqiu city from 2010 to 2012,The highest of the resident population was in 2012 and the lowest one was in 2010(r=0.47,P<0.05).The total morbidity presented the obvious seasonal char-acteristic,which reached the summit in June ,July,August.The population morbidity was the clustered children .The average incidence rate of severe cases was 5.98%.The incidence rate in 2012 and 2011 was higher than that in 2010 (r=0.43,0.39,all P<0.05).There was significant difference of the pathogens types in severe cases among three years with the pathogen of CoxA 16 in 2010,2011 and humantero virus 71 viruses in 2012.Conclusion The inci-dence of HFMD presents the increasing and seasonal characteristics with the prevalence in the scattered children and the pathogens of CoxA16 in 2010,2011,humantero virus 71 in 2012.

This study sought to determine the impact of dental fluorosis severity on demineralization and remineralization of human fluorosed teeth in vitro. Surface enamel microhardness was measured on the enamel blocks before and after demineralization and after remineralization. The results showed that after demineralization, the sequence of % Surface microhardness demineralization (% SMHD) was TFI4 (18.92 +/- 1.31) < TFI3 (20.50 +/- 1.32) < TFI2 (25.08 +/- 1.69) < TFI1 (27.77 +/- 1.79) < TFI0 (30.70 +/- 1.35) (P < 0.05), and there was no statistically significant differences between TFI1 (27.77 +/- 1.79) and the normal group TFI0 (30.70 +/- 1.35). After remineralization, the sequence of % Surface microhardness remineralization (% SMHR) was TFI1 (55.17 +/- 1.23) > TFI0 (53.97 +/- 3.05) > TFI2 (49.17 +/- 1.81) > TFI3 (44.85 +/- 1.89) > TFI4 (36.51 +/- 2.95) (P < 0.05). Moderately fluorosed enamel showed a significatnt resistance to caries, but mildly fluorosed enamel could get better remineralization. These facts and figures deserve clinicians' attention.
Dental Enamel ; chemistry ; pathology ; Fluorosis, Dental ; metabolism ; Humans ; In Vitro Techniques ; Tooth Demineralization ; Tooth Remineralization

OBJECTIVETo study the efficacy and safety of Naoxintong capsule treatment of stroke recovery with Qi-deficiency and blood-stasis syndrome (cerebral infarction), and to compared the non-inferiority analysis with the positive drug Tongxinluo capsule.

METHODTaking Tongxinluo capsules as control, randomized, double-blind, controlled, multi-center clinical experiments were studied. The evaluating indexes included the decrease of integral value of stroke patients, changes in traditional Chinese medicine, the improvement of the patient viability status (disability level), Chinese stroke scale (CSS), activities of daily living (DAL) scale and barthel index (BI ) points.

RESULTThe total effect of the two groups, Chinese and other symptoms, showed no significant statistical significance.

CONCLUSIONNaoxintong capsule stroke recovery, with Qi-deficiency and blood-stasis syndrome (cerebral infarction) has a therapeutic effect, and more secure.

Activities of Daily Living ; Adult ; Aged ; Capsules ; Double-Blind Method ; Drugs, Chinese Herbal ; therapeutic use ; Female ; Humans ; Male ; Middle Aged ; Qi ; Stroke ; drug therapy ; Treatment Outcome

Escherichia coli strain NZN111 is a promising candidate for the fermentative production of succinate. However, because lactate dehydrogenase and pyruvate formate lyase were inactivated in NZN111, this strain had an unbalanced NADH/NAD+ ratio and could not use glucose under anaerobic conditions. In this study, a recombinant strain E. coli NZN111/pTrc99a-pncB was constructed to overexpress the nicotinic acid phosphoribosyl transferase gene (pncB). Under anaerobic conditions with the addition of 0.5 mmol/L nicotinic acid and 0.3 mmol/L isopropyl beta-D-thiogalactopyranoside (IPTG), the specific nicotinic acid phosphoribosyl transferase (NAPRTase, EC 2.4.2.11) activity in the recombinant strain was 11-fold higher than that in E. coli NZN111, the concentration of NAD(H) was increased by 3.85-fold, especially the concentration of NAD+ was increased by 5.17-fold and NADH/NAD+ was decreased from 0.640 to 0.125. The recombinant strain regained the capability of growth and glucose utilization under anaerobic conditions.
Acetyltransferases ; genetics ; metabolism ; Anaerobiosis ; Escherichia coli ; classification ; genetics ; metabolism ; Fermentation ; Genetic Enhancement ; methods ; Glucose ; metabolism ; L-Lactate Dehydrogenase ; genetics ; metabolism ; NAD ; metabolism ; Nicotinamide Phosphoribosyltransferase ; biosynthesis ; genetics ; Succinic Acid ; metabolism