1.Recombinant expression, purification and characterization of a novel DyP-type peroxidase in Escherichia coli.
Liqun WANG ; Alan K CHANG ; Wenjie YUAN ; Fengwu BAI
Chinese Journal of Biotechnology 2013;29(6):772-784
Dye-decolorizing peroxidase (DyP-type peroxidase) represents a group of heme-containing peroxidases able to decolour various organic dyes, most of which are xenobiotics. To identify and characterize a new DyP-type peroxidase (ZmDyP) from Zymomonas mobilis ZM4 (ATCC 31821), ZmDyP was amplified from the genomic DNA of Z. mobilis by PCR, and cloned into the Escherichia coli expression vector pET-21b(+). Alignment of the amino acid sequence of ZmDyP with other members of the DyP-type peroxidases revealed the presence of the active site conserved residues D149, R239, T254, F256 as well as the typical GXXDG motif, indicating that ZmDyP is a new member of the Dyp-type peroxidase family. pET-21b(+) containing ZmDyP gene was expressed in E. coli by IPTG induction. The expressed enzyme was purified by Ni-Chelating chromatography. SDS-PAGE analysis of the purified enzyme revealed a molecular weight of 36 kDa, whereas activity staining gave a molecular weight of 108 kDa, suggesting that the enzyme could be a trimer. In addition, ZmDyP is a heme-containing enzyme as shown by a typical heme absorption peak of Soret band. Moreover, ZmDyP showed high catalytic efficiency with 2, 2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) as a substrate. These results enrich the pool of DyP-type peroxidases and lay a foundation for further studies.
Amino Acid Sequence
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Catalysis
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Coloring Agents
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metabolism
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Escherichia coli
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genetics
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metabolism
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Molecular Sequence Data
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Peroxidases
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biosynthesis
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genetics
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isolation & purification
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Recombinant Proteins
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biosynthesis
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genetics
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isolation & purification
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Zymomonas
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enzymology
2.LncRAN MEG3 regulates the radiosensitivity of cervical cancer cells by targeting miR-181a-5p
Ge HOU ; Cheng WANG ; Ruping LI ; Chenhu XIAO ; Alan CHU ; Zongwen LIU
Chinese Journal of Radiation Oncology 2020;29(10):894-900
Objective:To evaluate the effect of long-chain non-coding RNA MEG3(LncRNA MEG3) on the radiosensitivity of cervical cancer cells, and to explore its underlying mechanism.Methods:The expression of LncRNA MEG3 in cervical cancer cells was detected by qRT-PCR. In the overexpression control group (transfected with pcDNA 3.1), LncRNA MEG3 overexpression group (transfected with pcDNA 3.1-LncRNA MEG3), miR-NC inhibition group (transfected with anti-miR-NC), miR-181a-5p inhibition group (transfected with anti-miR-181a-5p), LncRNA MEG3+ miR-NC overexpression group (co-transfected with pcDNA3.1-LncRNA MEG3 and anti-miR-NC), LncRNA MEG3+ miR-181a-5p overexpression group (co-transfected with pcDNA 3.1-LncRNA MEG3 and anti-miR-181a-5p), all plasmids were transfected into SiHa cells by liposome method. The cell survival fraction was assessed by colony formation assay. The cell apoptosis rate was evaluated by flow cytometry. The cell fluorescence activity was assessed by dual luciferase reporter assay. The expression levels of PTEN, p-Akt and Akt proteins were detected by Western blot.Results:Compared with the radiosensitive group, the expression of LncRNA MEG3 was significantly down-regulated in radiation-resistant cervical cancer tissues ( P<0.05), and its expression level was positively correlated with the sensitivity of cervical cancer cells. Overexpression of LncRNA MEG3 or inhibition of miR-181a-5p could significantly enhance the irradiation sensitivity and promote the apoptosis of cervical cancer cell line SiHa (both P<0.05). The fluorescence activity of wild-type LncRNA MEG3 cells was inhibited by miR-181a-5p. Overexpression of miR-181a-5p reversed the irradiation sensitization and pro-apoptosis effect of LncRNA MEG3 and the regulation of the PTEN/Akt signaling pathway on cervical cancer cell. Conclusion:LncRNA MEG3 can enhance the sensitivity of cervical cancer cells to radiation exposure, probably by targeting the miR-181a-5p and regulating the PTEN/Akt signaling pathway, which will provide a new direction for improving clinical prognosis of cervical cancer patients.
3.Agricultural biotechnology safety assessment.
Scott MCCLAIN ; Wendelyn JONES ; Xiaoyun HE ; Gregory LADICS ; Andrew BARTHOLOMAEUS ; Alan RAYBOULD ; Petra LUTTER ; Haibin XU ; Xue WANG
Chinese Journal of Preventive Medicine 2015;49(1):78-87
Genetically modified (GM) crops were first introduced to farmers in 1995 with the intent to provide better crop yield and meet the increasing demand for food and feed. GM crops have evolved to include a thorough safety evaluation for their use in human food and animal feed. Safety considerations begin at the level of DNA whereby the inserted GM DNA is evaluated for its content, position and stability once placed into the crop genome. The safety of the proteins coded by the inserted DNA and potential effects on the crop are considered, and the purpose is to ensure that the transgenic novel proteins are safe from a toxicity, allergy, and environmental perspective. In addition, the grain that provides the processed food or animal feed is also tested to evaluate its nutritional content and identify unintended effects to the plant composition when warranted. To provide a platform for the safety assessment, the GM crop is compared to non-GM comparators in what is typically referred to as composition equivalence testing. New technologies, such as mass spectrometry and well-designed antibody-based methods, allow better analytical measurements of crop composition, including endogenous allergens. Many of the analytical methods and their intended uses are based on regulatory guidance documents, some of which are outlined in globally recognized documents such as Codex Alimentarius. In certain cases, animal models are recommended by some regulatory agencies in specific countries, but there is typically no hypothesis or justification of their use in testing the safety of GM crops. The quality and standardization of testing methods can be supported, in some cases, by employing good laboratory practices (GLP) and is recognized in China as important to ensure quality data. Although the number of recommended, in some cases, required methods for safety testing are increasing in some regulatory agencies, it should be noted that GM crops registered to date have been shown to be comparable to their nontransgenic counterparts and safe . The crops upon which GM development are based are generally considered safe.
Agriculture
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Animal Feed
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Animals
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Biotechnology
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China
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Consumer Product Safety
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Food, Genetically Modified
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Humans
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Models, Animal
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Plants, Genetically Modified
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Safety
4.Radiotherapy, volume reduction, and short-term surgical outcomes in the treatment of large myxoid liposarcomas
Linus Hyunsuk LEE ; Sarah TEPPER ; Grant OWEN ; Dian WANG ; Nicolas LOPEZ-HISIJOS ; Matthew W. COLMAN ; Steven GITELIS ; Alan T. BLANK
Radiation Oncology Journal 2022;40(3):172-179
Purpose:
While tumor volume reduction following radiation has been documented in myxoid liposarcomas, it is unclear whether large tumors experience similar volume reduction to smaller tumors.
Materials and Methods:
MRI studies performed before and after completion of pre-operative radiation therapy (RT) were examined. Tumor sizes were noted and categorized as large versus small based on size >10 cm. Tumor volumes were calculated, and operative duration and major wound complications were recorded.
Results:
The median largest tumor dimension was 12.4 cm before RT and 8.7 cm after RT. The median tumor volume was 298.9 cm3 before RT and 106.9 cm3 after RT. There was no significant difference in the mean percent tumor volume reduction between large tumors and small tumors (p = 0.11, 56.3% vs. 64.5%). Operative duration most strongly correlated to post-RT MRI volume (R2=0.674, p<0.001). Despite volume reduction, tumors that were large on presentation were more likely to experience major wound complications post-operatively.
Conclusion
Radiation appears to be as effective at reducing myxoid liposarcoma tumor volume in large and small tumors. However, large tumors on presentation appear more likely to experience wound complications despite tumor volume reduction. Future studies should investigate disease-related outcomes as a factor of volume reduction in myxoid liposarcoma.
5.Assessing Neurobehavioral Alterations Among E-waste Recycling Workers in Hong Kong
Gengze LIAO ; Feng WANG ; Shaoyou LU ; Yanny Hoi Kuen YU ; Victoria H. ARRANDALE ; Alan Hoi-shou CHAN ; Lap Ah TSE
Safety and Health at Work 2024;15(1):9-16
Background:
E-waste workers in Hong Kong are handling an unprecedented amount of e-waste, which contains various neurotoxic chemicals. However, no study has been conducted to evaluate the neurological health status of e-waste workers in Hong Kong. This study aimed to evaluate the prevalence of neurobehavioral alterations and to identify the vulnerable groups among Hong Kong e-waste workers.
Methods:
We recruited 109 Hong Kong e-waste workers from June 2021 to September 2022. Participants completed standard questionnaires and wore a GENEActiv accelerometer for seven days. Pittsburgh Sleep Quality Index and Questionnaire 16/18 (Q16/18) were used to assess subjective neurobehavioral alterations. The GENEActiv data generated objective sleep and circadian rhythm variables. Workers were grouped based on job designation and entity type according to the presumed hazardous level. Unconditional logistic regression models measured the associations of occupational characteristics with neurobehavioral alterations after adjusting for confounders.
Results:
While dismantlers/repairers and the workers in entities not funded by the government were more likely to suffer from neurotoxic symptoms in Q18 (adjusted odds ratio: 3.18 [1.18–9.39] and 2.77 [1.10–7.46], respectively), the workers from self-sustained recycling facilities also have poor performances in circadian rhythm. Results also showed that the dismantlers/repairers working in entities not funded by the government had the highest risk of neurotoxic symptoms compared to the lowest-risk group (i.e., workers in government-funded companies with other job designations).
Conclusion
This timely and valuable study emphasizes the importance of improving the working conditions for high-risk e-waste workers, especially the dismantlers or repairers working in facilities not funded by the government.
6.Comparative study of risk assessment tools for patients with non-varicose gastrointestinal bleeding
Qiuxia JIANG ; Jinfeng LIU ; Feng YANG ; Alan LIU ; Changfeng WANG
Chinese Journal of Modern Nursing 2020;26(24):3261-3267
Objective:To compare the evaluation value of Glascow-Scoring Scoring System (GBS) and Modified Glascow-Scoring System (mGBS) for clinical intervention and prognosis of patients with non-varicose gastrointestinal bleeding.Methods:The convenient sampling method was used to retrospectively analyze 254 patients with non-varicose gastrointestinal bleeding who were admitted to a Class Ⅲ Grade A hospital in Anhui province from January 2017 to May 2018, and GBS and revised GBS scores of all patients were calculated. The value of the two scoring systems in predicting of rebleeding rate during hospitalization, blood transfusion, endoscopic intervention, deaths of patients and the rate of patients transferring to ICU.Results:Area under the ROC curve ( AUC) of GBS scoring system for blood transfusion, rebleeding, death and ICU transfer in patients with non-varicose gastrointestinal bleeding were 0.761, 0.714, 0.865 and 0.829, respectively. AUC of mGBS scoring system for blood transfusion, rebleeding, death and ICU transfer in non-varicose gastrointestinal bleeding patients were 0.753, 0.718, 0.871 and 0.792, respectively. Both scoring systems had good predictive ability. The predicted AUC of GBS scoring system for endoscopic intervention was 0.540, and that of mGBS scoring system was 0.542, showing a low predictive value. The cut-off points for blood transfusion, rebleeding, death and transfer to ICU were respectively 8, 11, 12, and 11 for the GBS scoring system, and those were respectively 7, 8, 10, and 11 for mGBS scoring system. The optimal cutoff point increased with the increase of disease severity, and there was no statistically significant difference between the two scoring systems ( P>0.05) . Conclusions:Both scoring systems can better predict the disease intervention needs and prognosis of patients with non-varicose gastrointestinal bleeding. It is recommended to use the simpler and modified GBS scoring system in clinical practice.
7.ROR2 gene is associated with risk of non-syndromic cleft palate in an Asian population.
Hong WANG ; Jacqueline B HETMANSKI ; Ingo RUCZINSKI ; Kung Yee LIANG ; M Daniele FALLIN ; Richard J REDETT ; Gerald V RAYMOND ; Yah-Huei Wu CHOU ; Philip Kuo-Ting CHEN ; Vincent YEOW ; Samuel S CHONG ; Felicia Sh CHEAH ; Ethylin Wang JABS ; Alan F SCOTT ; Terri H BEATY
Chinese Medical Journal 2012;125(3):476-480
BACKGROUNDThe receptor tyrosine kinase-like orphan receptor 2 (ROR2) gene has been recently shown to play important roles in palatal development in animal models and resides in the chromosomal region linked to non syndromic cleft lip with or without cleft palate in humans. The aim of this study was to investigate the possible association between ROR2 gene and non-syndromic oral clefts.
METHODSHere we tested 38 eligible single-nucleotide polymorphisms (SNPs) in ROR2 gene in 297 non-syndromic cleft lip with or without cleft palate and in 82 non-syndromic cleft palate case parent trios recruited from Asia and Maryland. Family Based Association Test was used to test for deviation from Mendelian inheritance. Plink software was used to test potential parent of origin effect. Possible maternally mediated in utero effects were assessed using the TRIad Multi-Marker approach under an assumption of mating symmetry in the population.
RESULTSSignificant evidence of linkage and association was shown for 3 SNPs (rs7858435, rs10820914 and rs3905385) among 57 Asian non-syndromic cleft palate trios in Family Based Association Tests. P values for these 3 SNPs equaled to 0.000068, 0.000115 and 0.000464 respectively which were all less than the significance level (0.05/38 = 0.0013) adjusted by strict Bonferroni correction. Relevant odds ratios for the risk allele were 3.42 (1.80 - 6.50), 3.45 (1.75 - 6.67) and 2.94 (1.56 - 5.56), respectively. Statistical evidence of linkage and association was not shown for study groups other than non-syndromic cleft palate. Neither evidence for parent-of-origin nor maternal genotypic effect was shown for any of the ROR2 markers in our analysis for all study groups.
CONCLUSIONOur results provided evidence of linkage and association between the ROR2 gene and a gene controlling risk to non-syndromic cleft palate.
Asian Continental Ancestry Group ; genetics ; Cleft Lip ; genetics ; Cleft Palate ; genetics ; Genetic Predisposition to Disease ; genetics ; Genotype ; Humans ; Linkage Disequilibrium ; genetics ; Polymorphism, Single Nucleotide ; genetics ; Receptor Tyrosine Kinase-like Orphan Receptors ; genetics
8.Insights from a Prospective Follow-up of Thyroid Function and Autoimmunity among COVID-19 Survivors
David Tak Wai LUI ; Chi Ho LEE ; Wing Sun CHOW ; Alan Chun Hong LEE ; Anthony Raymond TAM ; Carol Ho Yi FONG ; Chun Yiu LAW ; Eunice Ka Hong LEUNG ; Kelvin Kai Wang TO ; Kathryn Choon Beng TAN ; Yu Cho WOO ; Ching Wan LAM ; Ivan Fan Ngai HUNG ; Karen Siu Ling LAM
Endocrinology and Metabolism 2021;36(3):582-589
Background:
The occurrence of Graves’ disease and Hashimoto thyroiditis after coronavirus disease 2019 (COVID-19) raised concerns that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may trigger thyroid autoimmunity. We aimed to address the current uncertainties regarding incident thyroid dysfunction and autoimmunity among COVID-19 survivors.
Methods:
We included consecutive adult COVID-19 patients without known thyroid disorders, who were admitted to Queen Mary Hospital from July 21 to September 21, 2020 and had serum levels of thyroid-stimulating hormone, free thyroxine, free triiodothyronine (fT3), and anti-thyroid antibodies measured both on admission and at 3 months.
Results:
In total, 122 patients were included. Among 20 patients with abnormal thyroid function tests (TFTs) on admission (mostly low fT3), 15 recovered. Among 102 patients with initial normal TFTs, two had new-onset abnormalities that could represent different phases of thyroiditis. Among 104 patients whose anti-thyroid antibody titers were reassessed, we observed increases in anti-thyroid peroxidase (TPO) (P<0.001) and anti-thyroglobulin (P<0.001), but not anti-thyroid stimulating hormone receptor titers (P=0.486). Of 82 patients with negative anti-TPO findings at baseline, 16 had a significant interval increase in anti-TPO titer by >12 U, and four became anti-TPO-positive. Worse baseline clinical severity (P=0.018), elevated C-reactive protein during hospitalization (P=0.033), and higher baseline anti-TPO titer (P=0.005) were associated with a significant increase in anti-TPO titer.
Conclusion
Most patients with thyroid dysfunction on admission recovered during convalescence. Abnormal TFTs suggestive of thyroiditis occurred during convalescence, but infrequently. Importantly, our novel observation of an increase in anti-thyroid antibody titers post-COVID-19 warrants further follow-up for incident thyroid dysfunction among COVID-19 survivors.
9.Insights from a Prospective Follow-up of Thyroid Function and Autoimmunity among COVID-19 Survivors
David Tak Wai LUI ; Chi Ho LEE ; Wing Sun CHOW ; Alan Chun Hong LEE ; Anthony Raymond TAM ; Carol Ho Yi FONG ; Chun Yiu LAW ; Eunice Ka Hong LEUNG ; Kelvin Kai Wang TO ; Kathryn Choon Beng TAN ; Yu Cho WOO ; Ching Wan LAM ; Ivan Fan Ngai HUNG ; Karen Siu Ling LAM
Endocrinology and Metabolism 2021;36(3):582-589
Background:
The occurrence of Graves’ disease and Hashimoto thyroiditis after coronavirus disease 2019 (COVID-19) raised concerns that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may trigger thyroid autoimmunity. We aimed to address the current uncertainties regarding incident thyroid dysfunction and autoimmunity among COVID-19 survivors.
Methods:
We included consecutive adult COVID-19 patients without known thyroid disorders, who were admitted to Queen Mary Hospital from July 21 to September 21, 2020 and had serum levels of thyroid-stimulating hormone, free thyroxine, free triiodothyronine (fT3), and anti-thyroid antibodies measured both on admission and at 3 months.
Results:
In total, 122 patients were included. Among 20 patients with abnormal thyroid function tests (TFTs) on admission (mostly low fT3), 15 recovered. Among 102 patients with initial normal TFTs, two had new-onset abnormalities that could represent different phases of thyroiditis. Among 104 patients whose anti-thyroid antibody titers were reassessed, we observed increases in anti-thyroid peroxidase (TPO) (P<0.001) and anti-thyroglobulin (P<0.001), but not anti-thyroid stimulating hormone receptor titers (P=0.486). Of 82 patients with negative anti-TPO findings at baseline, 16 had a significant interval increase in anti-TPO titer by >12 U, and four became anti-TPO-positive. Worse baseline clinical severity (P=0.018), elevated C-reactive protein during hospitalization (P=0.033), and higher baseline anti-TPO titer (P=0.005) were associated with a significant increase in anti-TPO titer.
Conclusion
Most patients with thyroid dysfunction on admission recovered during convalescence. Abnormal TFTs suggestive of thyroiditis occurred during convalescence, but infrequently. Importantly, our novel observation of an increase in anti-thyroid antibody titers post-COVID-19 warrants further follow-up for incident thyroid dysfunction among COVID-19 survivors.