Molecular, biochemical and enzymatic characterization of photorespiratory 2-phosphoglycolate phosphatase (PGLP1) in rice.

Phosphoglycolate phosphatase (PGLP, EC3.1.3.18) is a key enzyme in photorespiration. However, genes encoding the rice photorespiratory PGLP have not yet been identified or characterized. Here, PGLP for photorespiration in rice was identified and its enzymatic properties were investigated. In order to define the function of PGLP homologs, rice PGLP mutants were constructed using CRISPR/Cas9, the transcriptional expressions were analyzed by RT-qPCR, and subcellular localizations were detected via rice protoplast transient expression analysis. Based on sequence alignment, proteins encoded by genes OsPGLP1, OsPGLP2, and OsPGLP3 in the rice genome were predicted to have PGLP activity. Subsequent experimentation showed that OsPGLP1 and OsPGLP3 are chloroplast proteins, while OsPGLP2 is localized in the cytoplasm. In rice leaves, levels of PGLP1 transcript were substantially higher than those of PGLP2 and PGLP3, whereas in roots, levels of PGLP2 transcript were higher than those of PGLP1 and PGLP3. There was no detectable PGLP activity in leaves of the OsPGLP1 mutant, which was non-viable in ambient air condition (400 ppm CO2 ) and high CO2 (4000 ppm) was unable to restore normal growth. In contrast, mutations of PGLP2 or PGLP3 did not result in visible phenotypes and the leaf PGLP activities were also unaffected It is suggested that PGLP1, encoded by Os04g0490800, is responsible for photorespiration. Furthermore, PGLP1 is a dimer with an apparent molecular mass of ca.65 kDa, and its Km is 272 µM, with a higher broad optimum pH (7.5 to 10.0) for PGLP activity than that in other higher plants.

[Evaluation of the fresh air purification system in the classroom under heavy pollution weather].

Evaluate the effect of the fresh air purification system on the improvement of indoor PM2.5 levels in a primary school classroom in Jinan City, Shandong Province. Our purpose is to explore the optimal operating time of the fresh air system and the main factors that affect the fresh air purification system to improve indoor air quality. From December 9, 2019 to December 10, 2019, two classrooms of the same area on the third floor of a primary school building in Jinan City, Shandong Province were selected as monitoring points. During the operation of the fresh air purification system, the PM2.5 concentration in the classroom is reduced by an average of 48.1%-61.5% compared to the outdoor PM2.5 concentration. After running for about 2 hours, the indoor PM2.5 concentration decreased to a relatively stable concentration level. The operating time of the fresh air purification system, student activities between classes, indoor temperature, indoor relative humidity, and outdoor PM2.5 concentration are important factors that affect the indoor particulate removal rate. In the case of a certain amount of fresh air and indoor area, closing doors and windows and appropriately extending the operation time of the fresh air purification system can improve the air quality in the classroom to a certain extent and protect the health of students.

[The correlation between serum uric acid levels in the third trimester of pregnancy and adverse pregnancy outcomes].

Objective: To investigate the associations between serum uric acid levels during the third trimester of pregnancy and risks of adverse pregnancy outcomes. Methods: In this retrospective study, a cohort of 7 995 pregnant women who were hospitalized for childbirth from January 2014 to January 2019 were collected to compare pregnancy outcomes between subjects with or without hyperuricemia (HUA). A smooth curve analysis was used to evaluate the relationship between uric acid levels and preterm delivery, low birth weight and smaller than gestational age. Logistic regression analyses were performed to identify risk factors for adverse pregnancy outcomes, and the interaction of the factors. Results: During the third trimester of pregnancy, the uric acid levels of about 10% pregnant women were over 420 µmol/L. In those with HUA, the median neonatal birth weight was 2 590 (1 790, 3 410) g, the probability of premature birth was 49.81%, and the incidence of small than gestational age was 20.41%. These were significantly different from the women without HUA (the median neonatal birth weight: 3300 (2850, 3640) g; the probability of premature birth 23.09%; the incidence of small than gestational age 6.55%, respectively) (All P<0.001). Maternal uric acid levels were negatively correlated with neonatal birth weight, and positively correlated with the risk of smaller than gestational age. It has a U-shaped association with the probability of premature birth, and the lowest probability of premature birth was at 200-400 µmol/L of the uric acid. Risks of low birth weight (adjusted ß=-5.22, 95%CI-6.46--3.99) and smaller than gestational age (adjusted OR=1.03, 95%CI 1.02-1.04) were increased in the function of uric acid levels. High uric acid, hypertension, oligoamnios and preeclampsia were important risk factors for the adverse pregnancy outcomes. The risk of preterm delivery and low birth weight enhanced when hyperuricemia combined with hypertension and preeclampsia. Conclusions: Serum uric acid level can be used as one of reliable markers for predicting adverse pregnancy outcomes, which might provide theoretical basis for clinical intervention in practice.

RBBP6 aggravates the progression of ovarian cancer by targeting PIK3R6.

OBJECTIVE: RBBP6 is identified to be a cancer-associated gene by bioinformatics analysis. This study aims to explore the role of RBBP6 in regulating proliferation and metastasis in ovarian cancer, thus providing theoretical references for ovarian cancer treatment. PATIENTS AND METHODS: Differential expressions of RBBP6 in ovarian cancer and normal ones were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The relationship between RBBP6 and prognosis in ovarian cancer patients was analyzed. The interaction between RBBP6 and PIK3R6 was detected by bioinformatics analysis and Dual-Luciferase reporter assay. Moreover, regulatory effects of RBBP6 and PIK3R6 on proliferative and migratory potentials in A2780 and CAOV3 cells were examined by Cell Counting Kit-8 (CCK-8) and transwell assay, respectively. Finally, tumorigenicity assay was conducted in nude mice to illustrate the in vivo regulations of PBBP6 and PIK3R6 on ovarian cancer growth. RESULTS: RBBP6 was upregulated in ovarian cancer tissues than normal ones. RBBP6 was irrelevant to age, tumor size and tumor node metastasis (TNM) staging in ovarian cancer patients, but correlated to lymphatic metastasis and distant metastasis. RBBP6 was abundantly expressed in ovarian cancer cells, and among the tested cell lines, CAOV3 and A2780 expressed the highest level of RBBP6. Knockdown of RBBP6 attenuated in vitro proliferative and migratory potentials in CAOV3 and A2780 cells. PIK3R6 was the target gene binding RBBP6, which was positively regulated by RBBP6. Overexpression of PIK3R6 could abolish the inhibited proliferative and migratory potentials in ovarian cancer cells with RBBP6 knockdown. In addition, the knockdown of RBBP6 slowed the in vivo growth of ovarian cancer in nude mice, and the alleviated cancer progression was reversed by overexpression of PIK3R6. CONCLUSIONS: RBBP6 is highly expressed in ovarian cancer cases, which stimulates proliferative and migratory potentials by targeting PIK3R6. RBBP6 may be a novel therapeutic target for ovarian cancer.

[Predictive value of N-terminal B-type natriuretic peptide on outcome of elderly hospitalized non-heart failure patients].

Objective: To investigate the predictive value of N-terminal type B natriuretic peptide（NT-proBNP) on the prognosis of elderly hospitalized patients without heart failure（non-heart failure). Method: Elderly patients aged 65 years or older, who were admitted to Beijing Hospital from September 2018 to February 2019, were enrolled in this study. Patients with clinical diagnosis of heart failure or left ventricular ejection fraction（LVEF)<50% were excluded. The patients were divided into 2 groups based on the serum NT-proBNP level: low NT-proBNP group （<125 ng/L) and high NT-proBNP group（≥125 ng/L). Patients were followed up at 3, 6, and 12 months after enrollment, and the major adverse events were recorded. The composite endpoint events included all-cause mortality, readmission or Emergency Department visits. Cardiovascular events include death, readmission or emergency room treatment due to cardiogenic shock, myocardial infarction, angina pectoris, arrhythmia, heart failure or stroke/transient ischemic attack. Results: A total of 600 elderly patients with non-heart failure were included in the analysis. The average age was （74.9±6.5) years, including 304（50.7%) males. The median follow-up time was 344（265, 359) days. One hundred and seventy-eight（29.7%) composite endpoint events were recorded during the follow-up, 19（3.2%) patients died, and 12（2.0%) patients were lost to follow-up. There were 286(47.7%) cases in low NT-proBNP group and 314 cases（52.3%) in high NT-proBNP group. Patients were older, prevalence of atrial fibrillation and myocardial infarction was higher; MMSE scores and ADL scores, albumin and creatinine clearance rate were lower in high NT-proBNP group than in low NT-proBNP group（all P<0.05). At 1-year follow-up, the incidence of composite endpoint events was significantly higher in high NT-proBNP group than in low NT-proBNP group（33.4%（105/314) vs. 24.8%（71/286), P = 0.02). Cardiovascular events were more common in high NT-proBNP group than in low NT-proBNP group（17.5%（55/314) vs. 8.4%（24/286), P = 0.001). Kaplan-Meier survival analysis showed both composite endpoint events（Log-rank P=0.016) and cardiovascular events（Log-rank P=0.001) were higher in high NT-proBNP group than in low NT-proBNP group. All-cause mortality was also significantly higher in highNT-proBNP group than in lowNT-proBNP group（4.8%（15/314) vs. 1.4%（4/286), P = 0.020), and Kaplan-Meier survival analysis demonstrated borderline statistical significance（Log-rank P = 0.052). Cox proportional hazard regression analysis showed that after adjusting for age, sex, creatinine clearance rate, myocardial infarction, and atrial fibrillation, NT-proBNP remained as an independent risk factor for composite endpoint events（HR=1.376，95%CI 1.049-1.806, P=0.021), and cardiovascular events（HR=1.777, 95%CI 1.185-2.664, P=0.005), but not for all-cause mortality（P=0.206). Conclusions: NT-proBNP level at admission has important predictive value on rehospitalization and cardiovascular events for hospitalized elderly non-heart failure patients. NT-proBNP examination is helpful for risk stratification in this patient cohort.

Expression and significance of MiR-126 and VEGF in proliferative diabetic retinopathy.

OBJECTIVE: To study the expression and significance of micro ribonucleic acid (miR)-126 and vascular endothelial growth factor (VEGF) in the vitreous body and proliferative membrane tissues of affected eyes and plasma in proliferative diabetic retinopathy (PDR). PATIENTS AND METHODS: A total of 50 PDR patients admitted to our hospital from January 2017 to January 2018 were collected, including 17 cases in stage IV, 20 cases in stage V, and 13 cases in stage VI according to the DR staging criteria. Another 30 patients with an idiopathic macular hole were selected as control group. After admission, the examinations were performed, venous blood was drawn, and vitrectomy was performed, during which the vitreous body and proliferative membrane tissues were taken. The plasma VEGF content was detected via enzyme-linked immunosorbent assay (ELISA). The VEGF protein expression level was detected via Western blotting in vitreous body and proliferative membrane tissues. Moreover, the miR-126 expression was detected via quantitative polymerase chain reaction (qPCR). RESULTS: In the vitreous body tissues, proliferative membrane tissues and plasma, the expression level of miR-126 was significantly lower in control group than that in stage IV, V, and VI groups (p<0.05). The miR-126 expression was significantly lower in stage IV group than that in stage V and VI groups (p<0.05), meanwhile, miR-126 expression was significantly lower in stage V group than that in stage VI group (p<0.05). In the vitreous body tissues, proliferative membrane tissues and plasma, the VEGF mRNA and protein expression levels were significantly higher in control group than those in stage IV, V, and VI groups (p<0.05). The VEGF expressions were significantly higher in stage IV group than those in stage V and VI groups (p<0.05). In addition, VEGF expressions were significantly higher in stage V group than those in stage VI group (p<0.05). Furthermore, the VEGF expression level was negatively correlated with the miR-126 expression level. CONCLUSIONS: We found that the abnormally high expression of miR-126 negatively regulates VEGF, which may be one of the important mechanisms of occurrence of PDR. The miR-126 and VEGF content can serve as important predictors for the condition of PDR.

[Epidemiological characteristics and risk factors of primary intussusception in children among two years old and below, Ji'nan city].

Objective: To study the epidemiological characters and risk factors of primary intussusception among children who were ≤2 years old in Jinan city. Methods: A retrospective study was also applied to collect the disease information of inpatient cases through hospital information system of inpatient during 2011 and 2015. The attack rate (AR) was calculated in total and each year, respectively. 1∶(1) matched pared case-control study was conducted to explore the risk factors of primary intussusception. A total of new confirmed 93 residential cases were enrolled with ≤2 years old, diagnosed as primary intussusception or diseases coded as K56.1 according to the International Classification of Diseases, tenth version (ICD-10), and without any other reason for organic lesions. The 93 patients without primary intussusception inpatients were selected from the same hospital and departments as the controls, and matched with the cases as the same gender, ±3 months old, and disease onset within 7 days, visiting the hospital during January 1, 2016 and June 30, 2016. Clinical and epidemiological information was collected both from cases and controls. The difference of AR among different years was compared by Trend Chi-squiare test, and difference between gender, month old and regions was compared by Chi-squiare test, respectively. Multiple-variables factor analysis was applied to analysis the risk factors of cases compared with controls by conditional logistic regression model. Results: A total of 574 cases were found and the overall AR was 86.3 per 100 000. A significant decreasing trend (χ(2trend)=23.43, P<0.001) of AR was showed between 2011 and 2015, with the highest AR in 2011 (117.6 per 100 000), and the lower AR in 2014 (66.0 per 100 000). The lowest AR was also observed in male (106.9 per 100 000) compared with the female (63.2 per 100 000) (χ(2)=13.76, P<0.001), and in ≤12 months old (102.1 per 100 000) compared with the >12 months old (70.4 per 100 000) (χ(2)=19.46, P<0.001). The higher proportion of 57.1% (328/574) was found in 4-12 months old cases. The cases with an overweight before illness (OR=4.98, 95%CI: 1.27-19.50), with mixed feeding of breast-milk and milk-powder (OR=16.90, 95%CI: 5.25-54.20), and with instruction of solid food before 6 months old (OR=16.50, 95%CI: 1.91-143.10) could increase the risk of illness compared with keeping a healthy weight, breast feeding, and instruction of solid food after 6 months old, separately. Conclusion: A higher attack rate of primary intussusception in children with a ≤2 years old in Jinan was observed. Male and 4-12 months group had a higher risk. Body weight, breast feeding, and the instruction of solid food before and after 6 months old were related to the risk of primary intussusception among children who were ≤2 years old.

[Analysis of pesticide poisoning in Ji'nan during 2012-2016].

Objective: To study the current situation and distribution characteristics of pesticide poisoning in Ji'nan area, and to provide the basis for formulating the policy of scientific prevention and control of pesticide poisoning. Methods: The cases of pesticide poisoning from 2012 to 2016 were collected from medical institutions in Ji'nan, and the data was subjected to statistical analysis. Results: From 2012 to 2016 in Ji'nan reported a total of 2 237 cases of pesticide poisoning, non productive pesticide poisoning cases (72.78%, 2 149/2 237) and mortality (17.73%, 381/2 149) was significantly higher than that of productive pesticide poisoning. The average age is 46.78±18.57. The highest mortality rate of pesticide poisoning is more than 70 age group of the non productive pesticide poisoning. Organophosphorus pesticides (67.68%, 1 514/2 237) are the main pesticides causing poisoning, followed by herbicide (23.74%, 531/2 237). The highest mortality rate of pesticide was Paraquat (36.45%, 160/439), the second is the dichlorvos (19.19%, 170/886). Conclusion: Pesticide poisoning is a public health problem and social problem which is harmful to the health of the residents in Ji'nan. It is necessary to strengthen the control and management of high toxic pesticides. Pay attention to the psychological intervention of elderly people to reduce the incidence of pesticide poisoning.

[Association between ambient PM(l0)/PM(2.5) concentration and outpatient department visits due to respiratory disease in a hospital in Jinan, 2013-2015: a time series analysis].

Objective: To estimate the influence of the ambient PM(l0) and PM(2.5) pollution on the hospital outpatient department visit due to respiratory diseases in local residents in Jinan quantitatively. Methods: Time serial analysis using generalized addictive model (GAM) was conducted. After controlling the confounding factors, such as long term trend, weekly pattern and meteorological factors, considering lag effect and the influence of other air pollutants, the excess relative risks of daily hospital visits associated with increased ambient PM(10) and PM(2.5) levels were estimated by fitting a Poisson regression model. Results: A 10 µg/m(3) increase of PM(10) and PM(2.5) levels was associated with an increase of 0.36%(95%CI: 0.30%-0.43%) and 0.50%(95%CI: 0.30%-0.70%) respectively for hospital visits due to respiratory diseases. Lag effect of 6 days was strongest, the excess relative risks were 0.65% (95% CI: 0.58% -0.71% ) and 0.54% (95% CI: 0.42%-0.67%) respectively. When NO(2) concentration was introduced, the daily hospital visits due to respiratory disease increased by 0.83% as a 10 µg/m(3) increase of PM(10) concentration (95% CI: 0.76%-0.91%). Conclusion: The ambient PM(l0) and PM(2.5) pollution was positively associated with daily hospital visits due to respiratory disease in Jinan, and ambient NO(2) concentration would have the synergistic effect.

Residue depletion of amoxicillin and its major metabolites in eggs.

The depletion of amoxicillin (AMO) and its major metabolites, amoxicilloic acid (AMA) and amoxicillin-diketopiperazine-2',5'-dione (DIKETO) in the albumen, yolk and whole egg was studied after the oral dose of AMO (25 and 50 mg/kg body weight) to laying hens once per day for five consecutive days. Egg samples were prepared by a simple liquid-liquid extraction procedure with acetonitrile and saturated methylene chloride and analysed using liquid chromatography-tandem mass spectrometry. The results showed that AMO, AMA and DIKETO residues were mainly distributed in the yolk, where particularly high concentrations of AMO and DIKETO were found, whereas the albumen contained high concentrations of AMA. This distribution suggested that AMO and DIKETO were depleted slowly in yolk, whereas AMA was depleted slowly in albumen. The amount of AMO residue positively correlated with the dose, and the theoretical withdrawal times, which were calculated based on the residue level falling below a safe limit, were 5.21 and 7.67 days at AMO doses of 25 and 50 mg/kg, respectively. Moreover, the theoretical withdrawal times for all residues in the whole egg were 8.00 and 9.11 days at doses of 25 and 50 mg/kg, respectively. Our findings suggested that 9 days was an appropriate withdrawal time for the use of AMO in laying hens.

Source and risk factors of a cutaneous anthrax outbreak, Jiangsu, Eastern China, 2012.

Anthrax is still a severe public health problem and threat to human health. A cutaneous anthrax outbreak occurred in Jiangsu Province, a non-endemic anthrax region of eastern China, from July to August 2012. Epidemiological and laboratory investigation were initiated to trace the source of infection and identify the risk factors of the outbreak. On 25 July 2012, 17 persons were exposed to a sick cow, which had been imported from northeast China a few days previously. Of the 17 exposed, eight developed symptoms between 1 and 8 days and were diagnosed as cutaneous anthrax cases. Three main genes of Bacillus anthracis were detected from both human and cow meat samples, indicating that the outbreak was associated with this infected cow. A retrospective cohort study showed that contact with blood and presence of skin damage contributed to the case infection with B. anthracis. The outbreak highlights the need to enhance quarantine for imported livestock, which should have been vaccinated prior to importation, the significance of education for high-risk individuals, and training for primary healthcare workers even in anthrax-free areas.

Analysis of meat flavor compounds in pedigree and two-strain Yangzhou geese.

In this study, we evaluated the meat flavor compounds of Yangzhou geese, including one group of pedigree strain (AA group) and 4 groups of 2-strain crossbreds (KA, KB, CA, and SA). Each group consisted of 100 geese comprised of 5 replicates of 10 males and 10 females each. Inosine 5'-monophosphate (IMP), amino acid (AA), and fatty acid (FA) levels in breast and thigh muscle were determined. Results showed that AA group had the highest levels of total amino acid (TAA) and dissolved free amino acids (DFAA) in breast muscle and of polyunsaturated fatty acids (PUFA) in thigh muscle (P<0.05). In SA group, the levels of C17:1, C22:0, C22:1, C20:4, and C24:1 in breast muscle were significantly higher in SA than in other groups (P<0.05). KB group had the lowest glycine levels in breast muscle (P<0.05) while MUFA levels were significantly higher in KB than in other groups (P<0.05). In KA, the levels of C18:3 in breast muscle in were higher than in CA and KB (P<0.05). CA had relevant higher IMPc levels in breast muscle than SA (P<0.05) and other groups (P>0.05); however, no significant differences were obtained in thigh muscle (P>0.05). In conclusion, Yangzhou AA goose has high levels of meat flavor compounds than its crossbreeds. Future efforts should focus on assessing meat flavor through measurement of sensory characteristics of Yangzhou geese.

Impact of changes in postnatal nutrition on puberty onset and the expression of hypothalamic GnRH and ghrelin.

OBJECTIVES: Ghrelin is an octanoylated peptide hormone with multiple and diverse physiologic functions including an important role in energy homeostasis and reproduction. In this study, the adjustment effects of different postnatal nutritional status on puberty onset and the expression of hypothalamic ghrelin and gonadotrophin-releasing hormone (GnRH) were examined in 1 day-old female Sprague-Dawley rats. MATERIALS AND METHODS: Animals were randomly assigned into four groups: overnutrition group (Group O), normal group (Group N, control group), and undernutrition groups (Group U and U2). Western blot analysis and immunohistochemistry were used to analyze the expression of hypothalamic ghrelin and GnRH. RESULTS: With a low level expression of hypothalamic ghrelin, the appearance of puberty onset and secretion peak of GnRH in Group O was earlier than the other groups. CONCLUSIONS: Undernutrition delayed puberty onset and the GnRH peak, at the same time, promoted the expression of hypothalamic ghrelin.While, the expression of hypothalamic ghrelin was suppressed at puberty onset.

The modulation of electronic and optical properties of OXD-X through introduction of the electron-withdrawing groups: a DFT study.

A comparative study using density functional theory (DFT) on the molecular structure, electronic structure and relative properties of 1,3,4-oxadiazole dimers 1,3-bis[2-(4-methylphenyl)-1,3,4-oxadiazol-5-yl]benzene (OXD-X) and its derivatives with alkoxy substituents -O(CH(2))(n-1)CH(3) (OXD-An, n=1, 2) and electron-withdrawing substituents -CN (OXD-C), -CF(3) (OXD-TFM), -NO(2) (OXD-N) added at meta-substitution in the phenyl ring are presented. The ground state structures of the title complexes are optimized at B3LYP/6-31G level of theory. In addition, the time dependent density functional theory (TDDFT) method is applied to calculate the absorption and emission spectra of the derivatives based on the ground state geometries. Comparing with the alkoxy substituents, the results show that the electron-withdrawing substituents have remarkable influences on the energy levels of the frontier molecular orbitals, the spectra and the transition compositions. Especially, -NO(2) group plays the prominent role and the fluorine improves the energy level of LUMO further. The experimental absorption wavelengths for OXD-X, OXD-A3 and OXD-A7 are well reproduced by the TDDFT technique. Moreover the absorption wavelengths and the transition compositions can be effectively adjusted through introducing electro-withdrawing groups in the phenyl ring. The reorganization energies for hole and electron are smaller than that of typical hole and electron transport materials.