Lactate and succinate were produced by Corynebacterium acetoacidophilum from glucose under oxygen deprivation conditions. To construct knockout mutant, lactate dehydrogenase gene (ldh) of C. acetoacidophilum was deleted by double-crossover chromosome replacement with sacB gene. Comparing with the wild strain ATCC13870, ldhA-deficent mutant produced no lactate with glucose consumption rate decreased by 29.3%, while succinate and acetate concentrations were increased by 45.6% and 182%, respectively. Moreover, the NADH/NAD+ rate was less than 1 (about 0.7), and the activities of phosphoenolpyruvate carboxylase and acetate kinase of the ldhA-deficent mutant were enhanced by 84% and 12 times, respectively. Our studies show that succinicate and acetate production pathways are strengthened by blocking lactate synthesis. It also suggests that improving NADH supply and eliminating acetate generation are alternative strategies to get high succinate-producer.
Corynebacterium glutamicum ; genetics ; metabolism ; Glucose ; Industrial Microbiology ; L-Lactate Dehydrogenase ; genetics ; metabolism ; Lactic Acid ; metabolism ; Oxygen ; metabolism ; Phosphoenolpyruvate Carboxylase ; Succinic Acid ; metabolism

Objective To investigate the iodine nutritional status of children aged 8 to 10 in both costal and non-costal areas of Rizhao city Shandong province,and provide a basis for scientific supplementation of iodine.Methods In 2009 and 2010,townships of Lanshan and Donggang were chosen as survey points which situated close to the coast,the counties of Wulian and Juxian that were more than 50 kilometers away from the coast were selected as controls.The iodine concentration of drinking water in every village and water supply point was determined.At the county level,5 to 9 towns were selected according to their sub-area positions of east,west,south,north and center,4 villages were selected in each chosen township,8 - 15 households were selected in each chosen village,edible salt from the households was collected; 5 primary schools were selected in each chosen township,60 students aged 8 - 10 were selected to take thyroid examination in each chosen school.Twenty copies of urine samples were collected from the 60 students to detect the iodine concentration.Iodine in drinking water was tested by cerous sulfate catalytic spectrophotometry,in iodized salt by direct titration,in urine by arsenic-cerium contact method,and thyroids were examined by palpation.Results Totally 3483 copies of drinking water samples,1164 copies of edible salt samples,and 476 copies of urine samples were tested,and a total of 1200 children aged 8 to 10 were investigated; and the ratio of water iodine frequency distribution ≤ 10 μg/L (in costal and non-costal area) accounted for 90.03％ ( 1011/1123 ) and 91.10％ (2150/2360),respectively,the medians of water iodine were 5.6 and 4.2 μg/L,respectively; the iodine medians of edible salt were 29.03 and 29.99 mg/kg,respectively; the consumption rates of qualified iodized salt were 96.77％ (569/588) and 97.05％ (559/576),respectively; total goiter rates were 1.17％(7/600) and 1.33％(8/600),respectively; the medians of urinary iodine were 144.05 and 159.15 μg/L,respectively; the percentages of urinary iodine that bellow 100 μg/L were 26.58％ (63/237) and 22.59％ (54/239),respectively; between 100 - 300 μg/L were 66.75％ (158/237) and 64.02％ (153/239),respectively;above 300μg/L were 6.75％ (16/237)and13.39％ (32/239),respectively.ConclusionsThe costal of Rizhao is an iodine deficient area.The current popularity of household's consumption of qualified iodized salt is suitable.The levels of iodine nutrition of children aged 8 to 10 is appropriate,which met the national standard of elimination of iodine deficiency disorders (IDD).There is no iodine excess.There are no significant differences in levels of iodine nutrition between costal and non-costal areas on the premise that the same iodized salt is supplied in both the areas,and there is no need to make differentiated supply of iodized salt.

Aim To investigate whether rosuvastatin induced reduction of atherosclerotic plaque was related to the expression of Sialyltransferase ( ST6 Gal-Ⅰ) in ApoE-/ - mice. Methods Six-weeks old ApoE-/ -mice fed with high fat were divided randomly into three groups: baseline group ( n=12 ) , control group ( n=12 ) and rosuvastatin group ( n =12 ) . Sixteen weeks later, control group was sacrificed. Serum and aortic intima were saved. Control group and rosuvastatin group were fed for seven weeks continually. Concentra-tions of serum lipids(TC, TG, LDL and HDL) were analyzed. Sections from the aortic root were examined by Hematoxylin-Eosin( HE) staining. The size of ath-erosclerotic lesion in each section was evaluated. Ex-pression of ST6 Gal-Ⅰ in aortic intima was detected by immunohistochemistry. Results Plasma TG and LDL-C, plaque areas and intimal thickness of control group were significant higher than those of baseline group ( P<0. 05 ) . Those results indicated that the AS model was successfully constructed. After seven weeks, the plaque areas and concentrations of serum lipids of rosu-vastatin group were obviously smaller than those of con-trol group(P<0. 05). The expression of ST6Gal-Ⅰin aortic root was decreased in control group compared to the baseline, and which was increased in control group compared to the rosuvastatin group. Conclusion Ro-suvastatin could inhibit the progression of atherosclero-sis, which might be related to the expression of ST6Gal-Ⅰ in aortic root.

A strain,Actinobacillus succinogenes CGMCC 1593,producing succinic acid was isolated from bovin rumen,which could pro- duces succinic acid by anaerobic fermentation.A series of morphological and biochemical characteristics and sequence analysis of 16S rDNA reveal that it belongs to Actinobacillus succinogenes.When cultured anaerobically in medium containing 60 g/L glucose as carbon source,the strain produces 25.8 g/L of succnic acid.

MicroRNAs(miRNAs)are a class of small RNA molecules which play a pivotal role in the regulation of genes involved in diverse processes.Recently,many viral-encoded miRNAs have been discovered,which suggests that viruses also use this fundamental mode of gene regulation.Although the functions of most viral- encoded miRNAs are unknown,some of them are involved in evading CTL,mediating latent infection,apoptosis suppression,etc.Uncovering the role of viral miRNAs in the pathopoiesis offers an immense opportunity not only to develope effective antiviral therapies,but also to identifying novel molecular targets for developing antiviral reagents.Therefore,recent progress on vmiRNAs was reviewed.

MicroRNAs (miRNAs) are a newly identified class of non-protein-coding small RNAs that play important roles in multiple biological processes. Recent evidence indicates that the expression of many miRNAs is both temporally and spatially regulated by RNA editing, differential processing and tissue-specific enhancers, and the potential for ultimately designing molecular medicines based on the modulation of miRNAs seems good. A better understanding of the mechanism which regulates miRNAs is very helpful to reveal the pathogenesis of some diseases, discover novel molecular targets for treatment by interference, and develop an effective gene therapy. Therefore, the latest progress in the mechanism regulating miRNAs is summarized.

Abstract: Objective　To understand the density changes and seasonal fluctuation of larvae and adults of Aedes albopictus in Hainan Province from 2017 to 2021, and to provide a scientific basis for the prevention and control of dengue fever and other vector-borne diseases in Hainan Province. Methods　The Breteau index method was used to monitor the larvae of Aedes mosquitoes, and the breeding sites of all small indoor and outdoor water containers and their larvae was checked and recorded. The adult mosquitoes were monitored by double lamination and light trap. Results　A total of 1 962 adult female Aedes albopictus mosquitoes were captured in Hainan Province from 2017 to 2021, accounting for 2.17% of the total captured mosquitoes. There were significant differences in mosquito species composition in different habitats in different years (χ2=312.258, P<0.01). In 2017, the density of mosquitoes in livestock sheds was the highest (9.71 per lamp·night), but the composition ratio of Aedes albopictus was the lowest (1.29%). In 2020, the mosquito density in hospitals was the lowest (2.22 mosquitoes per lamp·night), and in 2019, the proportion of Aedes albopictus in residential areas and hospitals was the highest (3.27% on average).The mosquito density in different habitats was the lowest in 2020. The proportion of Aedes albopictus in residential areas and livestock sheds showed an increasing trend from 2017 to 2021, while the proportion of other habitats showed significant fluctuations. The proportion of Aedes albopictus in hospitals showed an obvious decreasing trend in 2020. From 2017 to 2021, the average mosquito density was 5.97, 4.26, 3.82, 3.39 and 3.68 mosquitoes per lamp·night, respectively, showing a decreasing trend year by year except 2021. Except for 2019, the lure index also showed a decreasing trend, with an average value of 1.5/(hour·net), showing a decreasing trend year by year. From 2017 to 2021, the annual average density of Aedes albopictus in Hainan Province was 0.09 mosquitoes per lamp·night, showing obvious seasonal fluctuation. The Breteau index showed a slow decline from 2017 to 2021, and its annual peak was between June and August, which was 1-2 months later than the peak of adult mosquito density. Conclusions　The population density of Aedes albopictus in Hainan shows obvious seasonal characteristics. Mosquito control activities should be carried out according to the seasonal characteristics of mosquitoes to reduce the risk of dengue fever and other infectious diseases.

Objective To evaluate peak left ventricular(LV) apical rotation velocity during early diastole by speckle tracking echocardiography in normal peopleand patients with myocardial hypertrophy because of hypertension. Methods Two dimensional images of left basal and apical ventricular short axis view were recorded in 20 healthy people and 20 patients with hypertension and left ventricular hypertrophy(LVH). Rotation velocity-time curves of six segments in LV apex and base were obtained using Qlab software. The peak rotation velocity in early diastole of LV apex(A-Vel) and base (B-Vel) were acquired through Excel software. Results In LVH group,A-Vel was significantly decreased(P<0. 05) while B-Vel appeared no difference (P = 0.58) compared with healthy individuals. Conclusions Peak LV apical rotation velocity in early diastole can evaluate the change of LV diastolic function in patients with hypertension and LVH.

To study the antiviral effect of Hypericum perforatum L. extract (HPE) on influenza A virus (IAV) (H1N1) in vitro and in vivo. Cytopathic effect (CPE) and neutral red (NR) dye uptake were used to examine the antiviral effect of HPE on Madin Darby Canine Kidney (MDCK) cells which were infected with IAV in vitro. HPE was effective against influenza A virus (IAV) in vitro, with a 50% effective concentration (EC50) of 40 μg/mL. The mean 50% cytotoxic concentration (CC50) in the MDCK used in these experiments was 1.5 mg/mL. Ribavirin was run in parallel with EC50 values of 5.0 μg/mL; the mean CC50 for ribavirin was 520 μg/mL. Oral gavage administrations of HPE or ribavirin to mice infected with the IAV were highly effective in preventing death, slowing the decline of arterial oxygen saturation, inhibiting lung consolidation and reducing lung virus titers. The minimum effective dose of HPE in these studies was 31.25 mg/kg/day, which was administered twice daily for 5 d beginning 4 h prior to virus exposure. Below a dosage of 2000 mg/kg/day, almost all treated mice survived, which suggests that HPE is of low toxicity. Ribavirin's minimum effective dose was 40 mg/kg/day with the LD50 determined to be 200 mg/kg/day. Delay of the initiation of either HPE or ribavirin therapy, using approximately 1/3 LD50 dose each time, could still be protective as late as 48 h after exposure to the IAV. While both agents appeared to have similar efficacy against IAV infections, HPE was considered to be less toxic and may warrant further evaluation as a possible therapy for influenza.