1.Migration and spread of Bacillus cereus in mice with endophthalmitis and influence on inflammation
Bianjin SUN ; Yi XU ; Liping MAO ; Yuyu LI ; Tian WAN ; Jie XU ; Meiqin ZHENG
Chinese Journal of Microbiology and Immunology 2021;41(12):919-926
Objective:To investigate the causes of strong pathogenicity of Bacillus cereus ( B. cereus) in a mouse model of B. cereus endophthalmitis and the factors that might be related to the prognosis of the disease. Methods:C57BL/6J mice aged 6-8 weeks were injected with 1 μl PBS solution containing 100 CFU B. cereus into the vitreous cavity to construct traumatic endophthalmitis model, and a control group was set up by injecting the contralateral eyeball with 1 μl sterile PBS. A mouse model of Staphylococcus epidermidis ( S. epidermidis) endophthalmitis was constructed in the same way as disease control group. Real-time fluorescent quantitative polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) were used to detect the levels of inflammatory cytokines at different time points. Histology, electroretinogram and transmission electron microscopy were used to detect the progression of endophthalmitis and retinal function at different time points. Results:B. cereus grew significantly faster than S. epidermidis in the eyes of C57BL/6 mice and gradually moved to the cornea 12 h after infection. The results of transmission electron microscopy showed that many more B. cereus were found in the iris with sparse pigment particles, while S. epidermidis could not be detected in the anterior segment after infection. The electroretinogram results showed that the amplitude of A wave and B wave of mice with B. cereus endophthalmitis decreased significantly 6 h after infection, and the B wave could not be detected 12 h after infection. Moreover, the amplitude reduction at different time points was significantly larger than that in the S. epidermidis endophthalmitis group. Histological examination found that compared with the S. epidermidis endophthalmitis group, the mice with B. cereus endophthalmitis had significantly increased inflammatory cells in the anterior chamber and vitreous cavity with a higher degree of infiltration, which was more destructive to the tissue structure. ELISA results showed that the activity of myeloperoxidase (MPO) was significantly stronger in the B. cereus endophthalmitis group than in the S. epidermidis endophthalmitis group, suggesting that a much more severe inflammation was induced. The expression of IL-6, TNF-α and IL-1β at the transcription and protein levels in the mouse model of B. cereus endophthalmitis were significantly higher than those in the mice with S. epidermidis endophthalmitis. Conclusions:B. cereus could induce severe endophthalmitis and tissue destruction in the eye due to its rapid growth and migration ability, which was an important factor leading to vision loss.
2. Necessity and feasibility of viral RNA detection in specialist ophthalmic institute during the COVID-19 epidemic
Meiqin ZHENG ; Wencan WU ; Wei CHEN ; Xinping YU ; Yinghui SHI ; Jia QU
Chinese Journal of Experimental Ophthalmology 2020;38(0):E008-E008
The prevention and treatment of COVID-19 in China is now at a key stage. The tasks faced by the medical organs are fighting against the COVID-19 while providing the medical services orderly. As a Specialist medical institution nationwide, ophthalmic hospitals are resuming receiving patients and performing operations gradually, including precision interruption of the epidemic, prevention of the secondary virus transmission, and avoidance of nosocomial cross infection among health care providers are required. We explored a multifaceted management for the prevention and control of epidemic, with a special focus on the individual protection for patients and medical staffs. A preliminary positive effect can be observed as a result. The main measures taken cover two aspects. On the one hand, 2019-nCoV ribonucleic acid (RNA) detection and hematological indices inspection including C-reactive protein (CRP) and serum amyloid A (SAA) are listed as routine tests of preoperative screening for ocular surgical patients. These tests are required to be completed upon the admission to avoid the possibility of accepting any asymptomatic infected individual and to reduce the risk of nosocomial cross infection. On the other hand, the 2019-nCoV RNA detection is also provided to high-risk employees who visited affected area recently. This assists in obtaining guarantee in both safety and quality of medical services provided, but also helps in lessening the mental and spiritual stress for medical staffs. It is expected that these measures can contribute to the work of our peers of ophthalmology in the prevention and control of COVID-19 and to the safe environment where the medical services are provided, and provide a reference for other outbreak of virus-causing disease.
3.Intermittent Cold Stress Reducing the Collagen Content of Atherosclerotic Plaque in Experimental ApoE-/-Mice
Xi ZHENG ; Yongjian YANG ; Meiqin SUN ; Shuangtao MA ; Liping ZHANG ; Qiang WANG ; Tingqiao YE
Chinese Circulation Journal 2015;(1):68-71
Objective: To investigate the influence of intermittent cold stress on collagen content of atherosclerotic plaque in experimental ApoE-/-mice.
Methods: A total of 20 male ApoE-/-mice at 8 weeks of age were divided into 2 groups:Experimental group, the mice had intermittent cold exposure at (4 ± 1)°C from 8am to 12noon and Control group, the mice were living at (24 ± 2) °C. All animals were treated for 12 weeks, n=10 in each group. The collagen content of atherosclerotic plaque at the aortic root in ApoE-/-mice was observed by Masson staining, the protein expressions of aortic MMP-2, MMP-9 and TIMP-1 were examined by Western blot analysis.
Results: Compared with Control group, the Experimental group presented the lower collagen content of atherosclerotic plaque at the aortic root, higher protein expressions of MMP-2, MMP-9 and lower protein expression of TIMI 1.
Conclusion: Intermittent cold stress may disturb the balance of MMP/TIMP and decrease collagen content of atherosclerotic plaque to form vulnerable plaque in experimental ApoE-/-mice which may cause acute coronary syndrome.
4.Pathogenicity of Ureaplasma urealyticum serotype 1 and 8 in the genital tract of female BALB/c mice
Bingjie ZHENG ; Yueping YIN ; Yan HAN ; Meiqin SHI ; Zhi XIANG ; Ruixing YU
Chinese Journal of Dermatology 2014;47(5):324-327
Objective To compare the pathogenicity between Ureaplasma urealyticum serotype 1 (Up1)and 8 (Uu8) in the genital tract of BALB/c mice.Methods A total of 48 BALB/c mice were randomly and equally divided into four groups:blank control group receiving no treatment,estradiol group pretreated with intramuscular injection of estradiol followed by intravaginal inoculation with sterial liquid culture media,Up1 and Uu8 groups pretreated with intramuscular injection of estradiol followed by intravaginal inoculation with suspensions of Up1 and Uu8 respectively.Three mice were randomly selected from each group to be sacrificed after the collection of vaginal lavage fluid on day 3,7,14 and 21 after the inoculation.Vaginal and uterine tissue specimens were obtained from these sacrificed mice and underwent hematoxylin and eosin (HE) staining.Vaginal lavage fluid samples were subjected to culture of Uu and measurement of tumor necrosis factor-α (TNF-α).Results No evidences were observed for Uu growth in either the blank control group or estradiol group at any of the time points after the inoculation,with the average level of TNF-α in vaginal lavage fluid being (4.17 ± 0.85) pg/ml at these time points in both groups.Uu grew in all the vaginal lavage fluid samples from the Up1 and Uu8 groups at the four time points,with the color change unit (CCU) value decreasing with time.The level of TNF-α in vaginal lavage fluid peaked on day 14 after the inoculation in the Up 1 ((14.93 ± 1.11) pg/ml) and Uu8 ((27.04 ± 24.26) pg/ml) groups.Both Up1 and Uu8 infection caused acute and chronic inflammatory responses in the mice,which were mainly located in the uterus,and Up1 might cause intrauterine adhesion.Conclusions At the same inoculation concentration,no significant difference is found in the pathogenicity between Up1 and Uu8,both of which appear to mainly cause cervicitis.Upl might be partially responsible for intrauterine adhesion in mice.
5.Effects of arsenic trioxide on the mRNA expression of toll like receptor-9 and interferon regulatory factor-5 in patients with systemic lupus erythematosus
Sijian WEN ; Wenjun ZHENG ; Youkun LIN ; Meiqin XU ; Cuili HUANG ; Hui LIU
Chinese Journal of Rheumatology 2014;18(4):227-231,后插1
Objective To investigate the mRNA expression of toll like receptor-9 (TLR9) and interferon regulatory factors-5 (IRF5) of AS2O3 on peripheral blood mononuclear cells (PBMCs) in systemic lupus erythematosus (SLE) patients.Methods PBMCs of 15 SLE patients and 15 healthy subjects were treated with different concentrations of AS2O3 and cyclophosphamide (CTX) in vitro.Real-time quantitative polymerase chain reaction was used to amplify TLR9 and IRF5 gene before and after 12 and 24 hours drug intervention and the mRNA expressions were measured.Differences between groups were analyzed by paired t test or variance analysis.Results The mRNA expression levels of TLR9 [12 h(1.38±0.26) and 24 h (1.28±0.35)] on PBMCs in SLE patients were significantly higher than those in healthy controls [12 h(1.05±0.35) and 24 h (0.97±0.19)](t=2.37,P=0.03; t=2.44,P=0.02).The IRF5 mRNA expression levels [12 h (0.95±0.27) and 24 h (0.91 ±0.35)] in SLE patients were obviously higher than those in healthy controls [12 h (0.62 ±0.23) and 24 h (0.60±0.39)] (t =3.07,P=0.01 ; t =3.45,P<0.01).AS2O3 could suppress the mRNA expression of TLR9 on PBMCs and the effect was gradually increasing with the increasing concentration of AS2O3 and processing time [0.2 mg/L AS2O3 group 12 h (0.430±0.110) and 24 h(0.290±0.050),0.4 mg/L AS2O3 group 12 h (0.170±0.038) and 24 h (0.090±0.017),0.8 mg/L AS2O3 group 12 h (0.023±0.011) and 24 h (0.003±0.001)].Comparing with CTX [12 h (0.814±0.081) and 24 h(0.755±0.139)],AS2O3 had a more significant strong effect on inhibiting the expression of TLR9 mRNA in SLE patients [F=165.32(12 h),P<0.01; F=99.20 (24 h),P<0.01].The mRNA expression of IRF5 on PBMCs was not suppressed by AS2O3 and CTX and there was no statistically significant difference between groups (P>0.05).Conclusion There is abnormal expression of IRF5 and TLR9 mRNA in SLE patients.AS2O3 may suppress the TLR9 mRNA expression in SLE patients,which may be one mechanism of clinical effectiveness.
6.Establishment of a method for detection of IVS-2-654 (C>T) and -28 (A>G) gene mutations by high-resolution melting analysis in β-thalassemia and its clinical application
Lingling YU ; Kegang TIAN ; Jingjing FENG ; Huiyan WANG ; Meiqin ZHENG ; Xiaoqun ZHENG ; Jianxin Lü
Chinese Journal of Laboratory Medicine 2012;35(8):730-735
Objective To establish a method for detection of gene mutations in β-thalassemia by high-resolution melting (HRM) and study its preliminary clinical application.Methods Two common mutations [ IVS-2-654 ( C > T ) and -28 ( A > G ) ]of β-thalassemia in Wenzhou city population were selected.The plasmid DNA fragments of these mutations were constructed by TA clone technology as PCR templates or genotyping controls.A method for detection of β-thalassemia gene mutations based on HRM analysis was established and its specificity,sensitivity and repeatability were methodologically evaluated.One hundred and seventeen patients with clinically suspected β-thalassemia from Second Affiliated Hospital and Yu ying Children's Hospital of Wenzhou Medical College were enrolled into this study.The genomic DNA was extracted from whole blood cells and detected by HRM method.The results were compared with the direct sequencing data.Results HRM method could detect the mutations [ IVS-2-654( C > T) and -28 ( A > G ) ]of β-thalassemia and the results did not show any non-specific amplified fragments.All within-run and between-run coefficients of variation for different DNA types' Tm were smaller than 0.1%.And minimum 103 copies of DNA of each assay and 10% mutation could be determined by this method.One hundred and seventeen patients with clinically suspected β-thalassemia were detected with HRM and all the results were in accordance with direct DNA sequencing.There were 45 IVS-2-654 ( C > T)heterozygous mutation and 9-28 ( A > G)heterozygous mutation and none homozygous mutation.Conclusion The method of rapid identification of β-thalassemia gene mutations based on HRM analysis is successfully established,which is a convenient,rapid,specific,sensitive and accurate technique for screening gene mutations in β-thalassemia as well as a general technical platform to identify other gene mutations.
7.Identification of hemolysin BL from Bacillus cereus of patients with endophthalmitis and its biological activity detection in vitro
Meiqin ZHENG ; Liping MAO ; Yuhong ZHONG ; Lini PAN ; Yali LI ; Yongliang LOU
Chinese Journal of Microbiology and Immunology 2012;(12):1047-1052
Objective To identify the hemolysin BL(HBL) gene from Bacillus cereus of patients with endophthalmitis comfirmed by API bacterial identification test strip,and detect its biological activity in vitro.Methods Three pairs of specific primers were designed according to the gene sequence of HBL(B,L1 and L2 components),then the PCR assay were established through condition optimization,and to further detect five Bacillus cereus strains isolated from clinical patients with endophthalmitis.HBL with biological activity was extracted by salt fractionation from a randomly selected strain,and a series of different concentrations of HBL were prepared and acted on sheep red blood cells(SRBC),Vero cells and Hela cells; virulence of HBL was also assessed through observating lethal effect of which on mice with intraperitoneal injection.Results Three genes of HBL were detected in all B.cereus strains from clinical patients; Strong hemolytic activity of HBL showed obvious time-and dose-dependent.In the study,we found the morphological changes of Vero and Hela cells caused by HBL were different,but cell death were the same result with contents released; Within 48 h after infection,lethality of HBL for mice showed 100% with the concentration of more than 2.0 HU/ml,and was also in a time-and dose-dependent manner.Conclusion HBL isolated from B.Cereus had high hemolysis activity and low concentration.The expression of all BL genes provided a strong basis for the clinical feature of B.Cereus infection,which was developed rapidly and with a poor prognosis.It also provided a new method for rapid diagnosis and molecular epidemiology investigation in clinical.
8.Synthesis and anti-tubercular activity of novel alkyl substituted riminophenazine derivatives.
Yuli LI ; Chunlin ZHANG ; Dongfeng ZHANG ; Yu LU ; Bin WANG ; Meiqin ZHENG ; Chun LI ; Dali YIN ; Haihong HUANG
Acta Pharmaceutica Sinica 2012;47(6):745-54
A series of novel riminophenazine derivatives bearing an alkyl substituent attached to N-5 and imino nitrogen at C-3 position of the phenazine ring were obtained through rational drug design, aiming to maintain high anti-tubercular activity, lower toxicity and reduce lipophilicity. All target compounds were prepared by utilizing simple and flexible synthetic route and evaluated against Mycobacterium tuberculosis H37Rv and screened for mammalian cytotoxicity. The results demonstrated that compounds with a cyclopropyl substituent at N-5 position were more active than the reference compound clofazimine. In particular, 2-(4-chloroanilino)-5-cyclopropyl-3-(4-methoxycyclohexyl) imino-3, 5-dihydrophenazine (25) was found to be the most potent compound with low cytotoxicity and lipophilicity. This compound could serve as a valuable lead molecule for further optimization.
9.Analysis of β-globin gene mutation in β-thalassemia in Han population of Wenzhou region
Meiqin ZHENG ; Wei LI ; Jianxin Lü
Chinese Journal of Laboratory Medicine 2010;33(3):236-240
Objective To analysis the β-globin gene mutation in β-thalassemia in the population of Wenzhou natives,and identify the major mutation in Wenzhou and further provide valuable information for genetic counseling,prenatal diagnosis and prevention programs in this region.Methods Patients with β-thalassemia were diagnosed and the genomics DNA were extracted from whole blood cells and amplified with PCR,sequenced and compared to the standard sequence.Some mutations were further identified by subcloned.Results 44 of 66 patients were diagnosed β-Thalassemia,9 mutations were found in the 44 sporadic patients with the sequence analysis,2 of which were known polymorphisms(exonl 59,IVS-2-665),3 belonged to the common mutations in Chinese(IVS-2-654,CD_(41/42)-TTCT and TATA box nt-28),2 were scarce abnormalities(CD_(47),CD_(66))and 2 novel variants(-24T→C,CD_(26A)→G,same sense mutation,unreported).Conclusion The mutations of β-globin gene in Han Chinese in Wenzhou are complex (9 mutations found in all),the rare and novel mutations are identified,which provide the valuable information for genetic counseling in Wenzhou.
10.Advances in research on the anti-tumor effect of curcumin
Jiali ZHENG ; Jankai YAN ; Meiqin CAI
Chinese Journal of Clinical Nutrition 2009;17(4):251-256
cancer,and prostatic cancer has been reported.

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