To study the roles of glucosylglycerol phosphate synthase (Ggps) in glucosylglycerol (GG) and glycerol biosynthesis, we over-expressed Ggps from either Synechocystis sp. PCC 6803 or Synechococcus sp. PCC 7002 in a Synechocystis strain with a high GG titer, and determined the GG and glycerol accumulation in the resultant mutants grown under different NaCl-stress conditions. Ion chromatography results revealed that GG yield was not improved, but glycerol production was significantly enhanced by over-expression of Ggps from Synechocystis sp. PCC 6803 (6803ggpS). In addition, increasing the NaCl concentration of medium from 600 to 900 mmol/L led to a further 75% increase of glycerol accumulation in the mutant strain with 6803ggpS over-expression. These findings show the role of ggpS in driving the carbon flux to the glycerol biosynthesis pathway, and will be helpful for further improvement of GG and glycerol production in Synechocystis.
Bacterial Proteins ; metabolism ; Culture Media ; Glucosides ; biosynthesis ; Glucosyltransferases ; metabolism ; Glycerol ; metabolism ; Industrial Microbiology ; Sodium Chloride ; Synechococcus ; enzymology ; Synechocystis ; enzymology ; metabolism

The purpose of this study is to find out anti-HIV-1 reverse transcriptase (RT)/protease (PR) activity and inhibition of virus replication in cell cultures of novel coumarin analogs and determine their structure-activity relationship. Coumarin derivatives have been demonstrated to inhibit the activity of HIV-1 RT/PR in cell free system. It also shows inhibition effects to HIV-1 replication in cell culture. Based on the Chinese traditional pharmacological characteristics and protein three dimension computer aided design, analogs of tetracyclic dipyranocoumarin were synthesized from natural leading compounds. We studied the relationship of antiviral effects and chemical structures via HIV-1 PR/RT enzyme models and cell culture model system. Seven compounds were designed and tested. Several compounds showed anti-HIV-1 activity in varying degrees, especially V0201 showed much higher anti-HIV-1 activity with 3.56 and 0.78 micromol x L(-1) of IC50 against HIV-1 PR/RT and 0.036 micromol x L(-1) against HIV-1 replication in PBMC cultures. V0201 with a novel structure may be a new leading compound. These new compounds are valuable for development of new anti-HIV drugs in the future.

Human nerve growth factor (NGF) is a nerve cell growth regulation factor, which can provide nutrition for the neurons and promote the neurites outgrowth. In order to produce large-scale recombinant human nerve growth factor (rh-beta-NGF), we constructed a plasmid vector, which can stably express the rh-beta-NGF in the HEK293 cell lines. First, the plasmid of pCMV-beta-NGF-IRES-dhfr was constructed and transformed into HEK293 cells. Then MTX pressurized filter and limiting dilution methods were used to obtain monoclonal HEK293 cell lines. After stepwise reducing serum in culture media, the cells eventually adapted to serum-free medium and secreted rh-beta-NGF. SDS-PAGE analysis revealed that the expression product owned a molecular weight of about 13 kDa and a purity of more than 50%. The peptide mapping sequencing analysis demonstrated the sequences of rh-beta-NGF matched with the theoretical ones. Later we purified this protein by ion exchange and molecular sieve chromatograph. Finally, our experimental results exhibited that the recombinant cell lines can stably express rh-beta-NGF with a high efficiency of more than 20 pg/cell x day. In addition, this protein could successfully induce differentiation of PC12 cells. In summary, our recombinant HEK293 cells can express bio-active rh-beta-NGF with great efficiency and stability, which supply a valid basis to large-scale production of rh-beta-NGF.
Cell Differentiation ; Genetic Vectors ; HEK293 Cells ; Humans ; Nerve Growth Factor ; biosynthesis ; Plasmids ; Recombinant Proteins ; biosynthesis

An improved and practical synthesis of racemic 11-demethylcalanolide A [(±)-1] was developed. This improved process involved Pechmann reaction on phloroglucinol with ethyl butyrylacetate to give 5, 7,-dihydroxy-4-n-propylcoumarin(3). Poly phosphoric acid (PPA) catalyzed acylation of compound(3) with crotonic acid, then intramolecular cyclization was achieved simultaneously in one step to afford the key intermediate chromanone(4). A microwave assisted synthetic method preparing chromene(6) using chromenynation of chromanone(4) with 1, 1-diethoxy-methyl-2-butene was conducted. Luche reduction of chromene(6) using NaBH<,4> with CeCl3·7H2O preferably gave (±)-1. The overall yield of this four step synthesis of (±)-1 was around 32% increasing one fold more than that of the previous method. An in vitro investigation showed that (±)-1 exhibited inhibitory activities against both wild-type and drug-resistant HIV-1 in HIV-1 RT and cell culture assay, and significant synergistic effects in combination with AZT, T-20, and indinavir. Its LD50 of acute toxicity in mice by intragastric administration and by intraperitoneal injection were 735.65mg·kg-1 and 525.10mg·kg-1, respectively. The C<,max> and AUC<,0-∞> were 0.54μg·mL-1 and 1.08(μg·mL-1)·h, respectively. The dynamics study of the inhibition of mice sera on HIV-1 RT showed that mice treated with 100mg·kg-1 (±)-1 once intraperitoneally were similar to that of 5mg·kg-1 of known clinical effective anti-HIV-1 drug neverapine. The results suggested that further investigation of the anti-HIV candidate (±)-1 was warranted.

Objective:To verify the revised method of cerium sulfate catalytic spectrophotometry for iodide index of "Standard Examination Methods for Drinking Water-Nonmetal Parameters" (GB/T 5750.5-2006).Methods:From July to September 2019, the Laboratory of Department for Endemic Disease Prevention and Control of Qinghai Institute for Disease Prevention and Control verified the revised method (determination of iodide in drinking water by cerium sulfate catalytic spectrophotometry) of cerium sulfate catalytic spectrophotometry (hereinafter referred to as original method) in "Standard Examination Methods for Drinking Water-Nonmetal Parameters" (GB/T 5750.5-2006). The revised method was verified according to the requirements of "Standard Examination Methods for Drinking Water-Water Analysis Quality Control" (GB/T 5750.3-2006), including standard curve, detection limit, precision, accuracy and actual sample determination.Results:The linear range of the revised method was 0 - 20.0 μg/L, the correlation coefficient was - 0.999 4 - 0.999 8, and the detection limit was 0.231 μg/L. The relative standard deviation ( RSD) of low, medium and high iodine water samples of 6 times detection ranged from 1.4% to 9.6%, and the recoveries of low and medium water samples ranged from 89.0% to 108.0%. The detection results of national first-class reference materials for iodine composition analysis in water were within the range of standard value ± uncertainty. There was no significant difference in the test of results of 12 tap water samples between the revised method and the original standard method ( t = - 0.075, P > 0.05). Conclusion:The revised method has a good linear relationship of standard curve, high precision and accuracy, and good reproducibility, is simple and easy to operate, and is suitable for promotion and application.

Objective To investigate the changes of sex hormone and androgen receptor levels and evaluate the relationship of the sex hormones and androgen receptor with coronary heart disease (CHD) in elderly men. Methods A cross-sectional study was performed in 539 elderly men, including 400 healthy people aged 62-92 years and 139 CHD patients aged 60-88 years. The plasma concentrations of total testosterone (TT), free testosterone (FT), dehydroepiandrosterone sulfate (DHEAS), sex hormone binding globulin (SHBG), estradiol (E2), luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured. The androgen receptor (AR) level was tested by flow cytometry. Results The fluorescence intensity of DHEAS, TT, SHBG, FT and AR were significantly lower in CHD group than in healthy group (P<0.01);however, FSH and E2 in CHD group were higher(P(0.01). Age was negatively correlated with TT(r=-0.28,P<0.01) and FT (r=-0.17,P<0.05), and positively correlated with SHBG(r=0.14,P<0.05) and E2 (r=0.33, P<0.01). AR fluorescence intensity was negatively correlated with systolic blood pressure (r=-0.12,P<0.01). Logistic regression analysis indicated that TT (OR=1.065,9% CI: 1.012～1.121,P<0.05), SHBG(OR=0.994,95% CI:0.990～0.998,P<0.01) and AR (OR=0.971,95%CI:0.956～0.986, P<0.01)were significantly associated with CHD in elderly male patients. Conclusions The levels of DHEAS, TT, SHBG, FT and AR are lower in elderly men with CHD than in elderly healthy men;however, the FSH and E2 concentrations are higher. Low levels of TT, SHBG and AR may be the independent risk factors for CHD in elderly men.

Objective To detect urinary bio-markers of hydroxyproline (HYP) and c-terminal telopeptide of collagen type Ⅱ (CTX-Ⅱ) among population from Kashin-Beck disease (KBD) regions in Qinghai Province,and to provide the scientific data for prevention and control of adult KBD.Methods According to the "Diagnosis of Kashin-Beck Disease" (WS/T 207-2010),using case-control study,120 KBD patients (males 55,females 65) and 89 healthy controls (males 41,females 48) in Qinghai KBD regions were divided into case group and control group.Morning urine samples were collected.HYP and CTX-Ⅱ contents were analyzed by enzyme-linked immunosorbent assay (ELISA),then these results were corrected with creatinine.All the data were analyzed by SPSS 17.0 software.Results There was no significant difference in the age of male and female between case group and control group (t =1.813,1.131,P ＞ 0.05).The medians of urinary HYP and CTX-Ⅱ contents among male patients were 74.91 μg/μmol Cr and 630.77 ng/μmol Cr,respectively,which were higher than those of control groups (51.38 μg/μ mol Cr,401.32 ng/μmol Cr,Z =3.068,3.246,P ＜ 0.01).The medians of urinary HYP and CTX-Ⅱ contents among female patients were 91.07 μg/μmol Cr and 637.17 ng/μmol Cr,respectively,compared with those of control groups (88.37μg/μmol Cr,546.47 ng/μmol Cr),there was no significant difference in HYP content (Z =0.273,P ＞ 0.05),however,the difference in CTX-Ⅱ content was statistically significant (Z =2.002,P ＜ 0.05).Conclusion The urinary HYP contents of male patients with KBD change significantly,while the degradation of type Ⅱ collagen in male and female patients increases,and CTX-Ⅱ could reflect the metabolic changes of collagen in KBD.

Objective:To follow up the iodine nutrition and intellectual development of school children aged 8-10 years old in Nangqian County of Qinghai Province after 9 years of the implementation of iodine deficiency disorders intervention measures with iodine supplement as the main measure.Methods:In order to improve the iodine nutritional status of the population in Nangqian County, free iodized salt distribution, health education and other intervention measures for iodine deficiency disorders were implemented for 9 consecutive years since 2013. In May 2012 (before iodine supplementation) and September 2021 (after iodine supplementation), the same 5 townships (towns) were selected, and children aged 8-10 years old (half male and half female, age balanced) born locally in the central primary school of each township (town) were selected as the survey subjects. Household edible salt samples and random urine samples were collected for salt iodine and urinary iodine detection; the second revised version of the Chinese Combined Raven's Test (rural version) was used to assess the intelligence quotient (IQ) of children. The Flynn effect (FE) gain was used to adjust IQ, the corrected IQ = (IQ starting point value - current year's IQ value) - FE gain (calculated by 0.74/year). The differences of salt iodine and urinary iodine related indexes, IQ value and corrected IQ were compared before and after iodine supplementation.Results:After iodine supplementation, the coverage rate of iodized salt reached 100.00% (300/300), and the consumption rate of qualified iodized salt reached95.00% (285/300), the median urinary iodine increased to 157.20 μg/L, and all indexes met the elimination standard of iodine deficiency disorders. The IQ value of children aged 8-10 years old after iodine supplementation was 99.00 ± 14.90, significantly higher than that before iodine supplementation (82.00 ± 13.20, F = 156.82, P < 0.001). The FE gain in 9 years was 6.66, and the actual IQ gain of children aged 8-10 years old after iodine supplementation was 10.34. There were statistically significant differences in IQ value before and after iodine supplementation in male and female children ( F = 78.84, 78.88, P < 0.001). After iodine supplementation, there was a statistically significant difference in IQ value between children in the 8-year-old group and the 10-year-old group ( P = 0.010). There were statistically significant differences in IQ value before and after iodine supplementation in 8, 9 and 10 years old groups ( F = 55.23, 65.79, 36.85, P < 0.001). Conclusion:Intervention measures for iodine deficiency disorders, mainly iodine supplement, can significantly improve the iodine nutrition status of children aged 8-10 years old, and significantly promote the intellectual development of children.

Objective:To investigate the prevalence of adult skeletal fluorosis caused by drinking tea-type endemic fluorosis in Yushu Tibetan Autonomous Prefecture (hereinafter referred to as Yushu Prefecture), Qinghai Province, and provide scientific basis for prevention and control of the disease.Methods:In August 2021, one village was selected as a survey site in six counties (cities) in Yushu Prefecture, including Nangqian, Chindu, Yushu, Zadoi, Qumarlêb, and Zhiduo. Drinking water samples and 10 brick tea samples were collected from each village to determine the fluoride content in water and brick tea; at least 100 permanent residents aged ≥ 25, who had a habit of drinking brick tea and had lived in the local area for more than 5 years, were selected for X-ray imaging to examine the prevalence of adult skeletal fluorosis.Results:A total of 75 samples of residential drinking water were collected, with a fluoride content of (0.21 ± 0.05) mg/L, ranging from 0.11 to 0.34 mg/L; 60 samples of brick tea, with a fluoride content of (626.70 ± 157.27) mg/kg, ranging from 324.00 to 2 102.00 mg/kg. A total of 1 136 adults were examined, and 318 cases of skeletal fluorosis were diagnosed, with a detection rate of 27.99%. Among them, the detection rates of mild, moderate, and severe skeletal fluorosis were 20.95% (238/1 136), 6.07% (69/1 136), and 0.97% (11/1 136), respectively, with mild symptoms being the main. The detection rates of skeletal fluorosis in males and females were 29.09% (121/416) and 27.36% (197/720), respectively, with no statistically significant difference between the gender (χ 2 = 0.39, P = 0.533). Comparison of the skeletal fluorosis in different gender, the differences were statistically significant (χ 2 = 22.31, P < 0.001). The detection rates of skeletal fluorosis in the age groups of 25 - 35, 36 - 45, 46 - 55, 56 - 65, 66 - 75, and ≥76 years old were 6.86% (7/102), 22.37% (51/228), 24.02% (92/383), 37.44% (73/195), 43.48% (70/161), and 37.31% (25/67), respectively. The differences between the groups were statistically significant (χ 2 = 59.84, P < 0.001). Moreover, there was a statistically significant difference in the composition of skeletal fluorosis among different age groups ( H = 37.66, P < 0.001). The Spearman correlation analysis results showed that the severity of adult skeletal fluorosis was positively correlated with age ( r = 0.34, P < 0.001). Conclusions:There is a certain degree of prevalence of adult skeletal fluorosis in Yushu Prefecture. And as age increases, the condition of skeletal fluorosis becomes more severe.