1.In vitro inducing effect of dendritic cells cotransfected with survivin and granulocyte-macrophage colony-stimulating factor on cytotoxic T cell to kill leukemic cells.
Xiong-peng ZHU ; Zhi-zhe CHEN ; Chun-tuan LI ; Xu LIN ; Jian-liang ZHUANG ; Jian-da HU ; Ting YANG ; Zheng-shu XU
Chinese Medical Journal 2008;121(21):2180-2184
BACKGROUNDSurvivin is a rather specific gene in tumor tissue. We transfected dendritic cells (DCs) with recombinant adenovirus (Ad) containing survivin gene and granulocyte-macrophage colony-stimulating factor (GM-CSF) gene and tested the inducing effect of the transfected DCs on cytotoxic T lymphocytes (CTL) to kill leukemic cells.
METHODSAfter derived from the peripheral, DCs was assayed by mixed leukocyte reaction (MLR) tests. Lactate dehydrogenase (LDH) release test was used to evaluate cytotoxicity of CTL.
RESULTSExpression of survivin in transfected DCs was confirmed by Western blotting analysis. GM-CSF expression was confirmed by enzyme-linked immunosorbent assay (ELISA). In MLR assay, DCs coinfected with Ad-survivin and Ad-GM-CSF induced higher allogeneic lymphocyte reaction than control DCs at ratios of 1:5, 1:10, 1:50 and 1:100. DCs coinfected with Ad-survivin and Ad-GM-CSF had much higher activity of CTL to HL-60 cells than DCs infected with Ad-survivin only, Ad-GM-CSF only, or control DCs. Levels of interleukin-12 (IL-12) and interferon gamma (IFN-gamma) in lymphocyte supernatants containing DCs coinfected with Ad-survivin and Ad-GM-CSF were significantly higher than those in the control group.
CONCLUSIONDCs coinfected with Ad-survivin and Ad-GM-CSF induce much higher anti-leukemic response in vitro than those infected with either factor. Therefore, adenovirus vectors containing survivin and GM-CSF genes may be promising vaccine candidates for leukemia therapy.
Adenoviridae ; genetics ; Cytotoxicity, Immunologic ; Dendritic Cells ; physiology ; ultrastructure ; Genetic Therapy ; Granulocyte-Macrophage Colony-Stimulating Factor ; genetics ; HL-60 Cells ; Humans ; Inhibitor of Apoptosis Proteins ; Interferon-gamma ; biosynthesis ; Interleukin-12 ; biosynthesis ; Leukemia ; therapy ; Lymphocyte Activation ; Microtubule-Associated Proteins ; genetics ; Neoplasm Proteins ; genetics ; T-Lymphocytes, Cytotoxic ; immunology ; Transfection
2.Metabolism of 3-cyanomethyl-4-methyl-DCK, a new anti-HIV candidate, in human intestinal microsomes.
Xiao-mei ZHUANG ; Yuan-yuan WEN ; Hua LI ; Jing-ting DENG ; Wei-li KONG ; Xing-tao TIAN ; Shu-li CUI ; Lan XIE
Acta Pharmaceutica Sinica 2010;45(9):1116-1122
The biotransformation, CYP reaction phenotyping, the impact of CYP inhibitors and enzyme kinetics of 3-cyanomethyl-4-methyl-DCK (CMDCK), a new anti-HIV preclinical candidate belonging to DCK analogs, were investigated in human intestinal microsomes and recombinant cytochrome P450 (CYP) enzymes. CMDCK (4 micromol L(-1)) was incubated with a panel of rCYP enzymes (CYP1A2, 2C9, 2C19, 2D6 and 3A4) in vitro. The remaining parent drug in incubates was quantitatively analyzed by a LC-MS method. CYP3A4 was identified as the principal CYP isoenzyme responsible for its metabolism in intestinal microsomes. The major metabolic pathway of CMDCK was oxidation and a number of oxidative metabolites were screened with LC-MS. The Km, Vmax, CLint and T1/2 of CMDCK obtained from human intestinal microsome were 45.6 micromol L(-1), 0.33 micromol L(-1) min(-1), 12.1 mL min(-1) kg(-1) and 25.7 min, respectively. Intestinal clearance of CMDCK was estimated from in vitro data to be 3.3 mL min(-1) kg(-1), and was almost equal to the intestinal blood flow rate (4.6 mL min(-1) kg(-1)). The selective CYP3A4 inhibitors, ketoconazole, troleandomycin and ritonavir demonstrated significant inhibitory effects on CMDCK intestinal metabolism, which suggested that co-administration of CMDCK with potent CYP3A inhibitors, such as ritonavir, might decrease its intestinal metabolic clearance and subsequently improve its bioavailability in body.
Anti-HIV Agents
;
metabolism
;
pharmacokinetics
;
Biological Availability
;
Bridged Bicyclo Compounds, Heterocyclic
;
metabolism
;
pharmacokinetics
;
Coumarins
;
metabolism
;
pharmacokinetics
;
Cytochrome P-450 CYP3A
;
Cytochrome P-450 CYP3A Inhibitors
;
Humans
;
Intestines
;
metabolism
;
Ketoconazole
;
pharmacology
;
Metabolic Clearance Rate
;
Microsomes
;
metabolism
;
Ritonavir
;
pharmacology
;
Troleandomycin
;
pharmacology
3.Effect of Shihu Mixture on Autophagy Protein of AMPK/TFEB Signaling Pathway in Rats with T2DM-NAFLD
Shu-ting ZHUANG ; Jia-lin ZHANG ; Yu-qing ZOU ; Xin LIU ; Jia-min CHEN ; Hong SHI
Chinese Journal of Experimental Traditional Medical Formulae 2020;26(24):53-58
Objective:To observe the expression of adenosine monophosphate activated protein kinase (AMPK)/transcription factor EB (TFEB) autophagy signaling pathway protein in type 2 diabetes (T2DM) complicated with nonalcoholic fatty liver disease (NAFLD) rats after intervention with Shihu mixture (SHM). Method:Among 40 male SD rats, 10 rats were randomly selected as normal group according to body weight. The remaining 30 rats were fed with high-fat and high-sugar diet for 6 weeks, and then intraperitoneally injected with streptozotocin (STZ) to establish a T2DM NAFLD model. They were divided into normal control group (10 mL·kg-1·d-1), model control group (10 mL·kg-1·d-1), metformin group (100 mg·kg-1·d-1), SHM group (11.3 g·kg-1·d-1). The rats in each group were gavaged for 4 weeks. After gavage, the rats were euthanized. Abdominal aortic blood and liver tissue were collected to detect fasting blood glucose (FBS), glycated serum protein (GSP), insulin (INS), triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol(HDL-C), low-density lipoprotein cholesterol(LDL-C) content. Htoxylin eosin (HE) staining was performed to observe changes in liver tissue morphology. Western blot was used to detect AMPK/TFEB signaling pathway-related protein expression. Result:Compared with the model control group, FBS and GSP of the SHM group and the DMBG group decreased (
4.Effect of electroacupuncture on protein expressions of SOCS3 and IRS-1 in hypothalamus and pancreas islet morphology in diabetic fatty rats.
Shu-Ting ZHUANG ; Rui LI ; Shan-Shan SONG ; Hao-Ru DUAN ; Qiu-Yan LI
Chinese Acupuncture & Moxibustion 2022;42(9):1024-1028
OBJECTIVE:
To observe the effect of electroacupuncture (EA) on protein expressions of suppressor of cytokine signaling 3 (SOCS3) and insulin receptor substrate-1 (IRS-1) in hypothalamus and morphology of pancreas islet in Zucker diabetic fatty (ZDF) rats, and to explore its possible mechanism on improving plasma glucose and insulin resistance of type 2 diabetes mellitus (T2DM).
METHODS:
Twelve SPF male ZDF rats were selected and fed with high-fat diet for 4 weeks to establish the T2DM model, after modeling, the rats were randomly divided into a model group and an EA group, 6 rats in each one. Besides, 6 SPF male Zucker lean rats were selected as a blank group. In the EA group, EA was applied at "Pishu" (BL 20), "Weiwanxiashu" (EX-B 3), "Zusanli" (ST 36) and "Sanyinjiao" (SP 6), with continuous wave, 15 Hz in frequency, 2 mA in intensity, once a day, 20 min each time, 6 times a week for 4 weeks. The fasting plasma glucose (FPG) was measured before and after intervention. The serum level of fasting insulin (FINS) was measured by radioimmunoassay, and the homeostasis model assessment of insulin resistance index (HOMA-IR) was calculated; the morphological change of pancreas islets was observed by HE staining; the protein expressions of SOCS3 and IRS-1 in hypothalamus were detected by Western blot.
RESULTS:
Before intervention, compared with the blank group, FPG in the model group and the EA group was increased (P<0.01). After intervention, compared with the blank group, FPG, serum level of FINS and HOMA-IR were increased (P<0.01), the protein expression of SOCS3 was increased while IRS-1 was decreased in the hypothalamus in the model group (P<0.01). Compared with the model group, FPG, serum level of FINS and HOMA-IR were decreased (P<0.01), the protein expression of SOCS3 was decreased while IRS-1 was increased in the hypothalamus in the EA group (P<0.01). In the model group, the shape of pancreas islets was irregular, the area of pancreas islets and the number of islet β cell nuclei were decreased, the nuclei of islet β cell was compensatory enlargement. In the EA group, the shape and the area of pancreas islets and the number of islet β cell nuclei were improved, the compensatory increase of islet β cell nuclei was alleviated compared with the model group.
CONCLUSION
Electroacupuncture can reduce the fasting plasma glucose, improve the morphology of pancreas islets, and alleviate the insulin resistance in ZDF rats. The mechanism may relate to the down-regulation of SOCS3 and up-regulation of IRS-1 in the hypothalamus, and improving the function of hypothalamus in regulating peripheral glucose metabolism.
Acupuncture Points
;
Animals
;
Blood Glucose/metabolism*
;
Diabetes Mellitus, Type 2/therapy*
;
Electroacupuncture
;
Hypothalamus/metabolism*
;
Insulin Receptor Substrate Proteins/metabolism*
;
Insulin Resistance
;
Male
;
Pancreas/metabolism*
;
Rats
;
Rats, Zucker
;
Suppressor of Cytokine Signaling 3 Protein/metabolism*
5.Effect of leukoreduction on tumor-associated cytokine accumutation in supernatant of stored packed red cells and its effect on tumor cell proliferation in vitro.
Yuan ZHUANG ; Ting ZHANG ; Chao WEI ; Ji-Chun PAN ; Shu-Fang WANG ; Ai-Qun ZHANG ; De-Qing WANG
Journal of Experimental Hematology 2015;23(1):217-221
OBJECTIVEThis study was to investigate whether prestorage leukoreduction could decrease the accumulative concentration of tumor-associated cytokines in supernatant of stored packed red blood cells (pRBC) and to study the effect of prestorage leukoreduction on proliferation of HepG2 tumor cells by in vitro. The leukoreduced (LR) and non-leukoreduced (NLR) pRBC were equally obtained from one donation and were stored under 2 °C-6°C. The supernatants of pRBC in these two group were performed by centrifugation with 1 006×g for 10 min at day 0 and 35 d. The enzyme-linked immunosorbent assay (ELISA) was used to detect the expression of normal T cells and secretory factor (RANTES/CCL5), as well as the accumulative concentrations of tumor-necrosis factor (TNF-α), platelet derived growth factor (PDGF), vascular endothelial growth factor (VEGF) and monocyte chemotactic protein-1 (MCP-1) in pRBC supernantant of above-mentioned two groups. After HepG2 cells was cultured with the supernatant of NLR-pRBC and LR-pRBC at the end of day 35 together for 48 hours, the methyl thiazolil tetracolium (MTT) method was used to measure the proliferation of tumor cells in vitro.
RESULTSThe accumulative concentration of 5 cytokines in supernatants of above menthioned two groups increased in different degrees along with the prolongation of storage time,that is, the accumulative concentrations of 5 cytokines at 35 d were higher than that at day 0, in which the change of VEGF accumu-lative concentration showed statistical significance, its accumulative concentration in NLR group at day 35 elevated to 549.61 ± 299.43 pg/ml, and was higher than that in LR group (95.46 ± 110.87 pg/ml) (P < 0.05). The experiment of HepG2 cell proliferation indicated that the supernatant of LR pRBC group produced less proliferation of tumor cells with OD value 0.40 (95% CI, 0.38-0.42) than that of NLR pRBC group with OD value 0.49 (95% CI, 0.43-0.55) (P < 0.05).
CONCLUSIONThe prestorage leukoreduction has been confirmed to decrease the accumulative level of cytokines, particalarly decrease the accumulative level of VEGF, moreover, it may be a factor for inhibiting the proliferation of tumor cells in vitro.
Blood Preservation ; Cell Proliferation ; Cytokines ; Enzyme-Linked Immunosorbent Assay ; Erythrocytes ; Humans ; In Vitro Techniques ; Leukocytes ; Neoplasms ; Platelet-Derived Growth Factor ; Vascular Endothelial Growth Factor A
6.Effect of Storage Time on Cumulation of Platelet-related Growth Factors in the Supernatant of Leukoreduced Packed Red Cells and Tumor Cell Proliferation In Vitro.
Yuan ZHUANG ; Ting ZHANG ; Chao WEI ; Ji-Chun PAN ; Shu-Fang WANG ; Ai-Qun ZHANG ; De-Qing WANG
Journal of Experimental Hematology 2015;23(2):541-545
OBJECTIVETo investigate the effect of storage time on accumulation of platelet-related growth factors in the supernatant of leukoreduced packed red blood cells (LR-pRBC) and on tumor cell proliferation in vitro.
METHODSLR-pRBC were quartered and stored at 2 °C-6 °C. The supernatant of pRBC was obtained by centrifugation with 1 006 × g for 10 min at day 0, 14, 21 and 35 d. The enzyme-linked immunosorbent assay (ELISA) was used to detect the expression of platelet-derived growth factor(PDGF) and vascular endothelial growth factor (VEGF). After HepG2 cells was cultured with the supernatant of LR pRBC at day 0 and day 35 together for 48 hours, methylthiazoliltetracolium (MTT) method was used to measure the proliferation of tumor cells in vitro.
RESULTSThe concentrations of 2 cytokines were still increased with the storage time prolonging. As compared to LR-pRBC at day 0 [611.84 (95%CI, 356.45-867.23) pg/ml], the level of VEGF reached 900.16 (95% CI, 552.26-1248.07) pg/ml (P<0.05). There was a similar tendency in PDGF level with less increment in the supernatant of LR pRBC at day 35 [2.23 (95% CI, 0-5.37) ng/L vs 5.66 (95% CI, 0-12.48), P=0.073], but there was no significant statistical difference. Likewise, in vitro study of HepG2 cell proliferation showed that the LR-pRBC at day 35 promoted more proliferation of tumor cells with OD value 0.40 (95% CI, 0.38-0.42) (P<0.05).
CONCLUSIONThe residual platelets in LR-pRBC were activated, disintegrated and released the dense granules and α-granules which induce the accumulation of VEGF and PDGF. It seemed that the supernatant of LR-pRBC promoted the proliferation of tumor cells in vitro.
Blood Platelets ; Blood Preservation ; Cell Proliferation ; Cytokines ; Enzyme-Linked Immunosorbent Assay ; Humans ; In Vitro Techniques ; Platelet-Derived Growth Factor ; Time Factors ; Vascular Endothelial Growth Factor A
7.Effect of electroacupuncture on liver Akt/FoxO1 signaling pathway in rats with diabetic fatty.
Ying DONG ; Rui LI ; Wei-Xing GUO ; Fang-Fang MO ; Shan-Shan SONG ; Hao-Ru DUAN ; Shu-Ting ZHUANG ; Meng-Wei GUO
Chinese Acupuncture & Moxibustion 2023;43(6):679-683
OBJECTIVE:
To observe the effect of electroacupuncture (EA) on liver protein kinase B (Akt)/forkhead box transcription factor 1 (FoxO1) signaling pathway in Zucker diabetic fatty (ZDF) rats, and to explore the possible mechanism of EA on improving liver insulin resistance of type 2 diabetes mellitus.
METHODS:
Twelve male 2-month-old ZDF rats were fed with high-fat diet for 4 weeks to establish diabetes model. After modeling, the rats were randomly divided into a model group and an EA group, with 6 rats in each group. In addition, six male Zucker lean (ZL) rats were used as the blank group. The rats in the EA group were treated with EA at bilateral "Zusanli" (ST 36), "Sanyinjiao" (SP 6), "Weiwanxiashu" (EX-B 3), and "Pishu" (BL 20). The ipsilateral "Zusanli" (ST 36) and "Weiwanxiashu" (EX-B 3) were connected to EA device, continuous wave, frequency of 15 Hz, 20 min each time, once a day, six times a week, for a total of 4 weeks. The fasting blood glucose (FBG) in each group was compared before modeling, before intervention and after intervention; the serum levels of insulin (INS) and C-peptide were measured by radioimmunoassay method, and the insulin resistance index (HOMA-IR) was calculated; HE staining method was used to observe the liver tissue morphology; Western blot method was used to detect the protein expression of Akt, FoxO1 and phosphoenolpyruvate carboxykinase (PEPCK) in the liver.
RESULTS:
Before intervention, compared with the blank group, FBG was increased in the model group and the EA group (P<0.01); after intervention, compared with the model group, FBG in the EA group was decreased (P<0.01). Compared with the blank group, the serum levels of INS and C-peptide, HOMA-IR, and the protein expression of hepatic FoxO1 and PEPCK were increased (P<0.01), while the protein expression of hepatic Akt was decreased (P<0.01) in the model group. Compared with the model group, the serum levels of INS and C-peptide, HOMA-IR, and the protein expression of hepatic FoxO1 and PEPCK were decreased (P<0.01), while the protein expression of hepatic Akt was increased (P<0.01) in the EA group. In the model group, the hepatocytes were structurally disordered and randomly arranged, with a large number of lipid vacuoles in the cytoplasm. In the EA group, the morphology of hepatocytes tended to be normal and lipid vacuoles were decreased.
CONCLUSION
EA could reduce FBG and HOMA-IR in ZDF rats, improve liver insulin resistance, which may be related to regulating Akt/FoxO1 signaling pathway.
Male
;
Animals
;
Rats
;
Rats, Zucker
;
Proto-Oncogene Proteins c-akt/genetics*
;
Diabetes Mellitus, Type 2/therapy*
;
Insulin Resistance
;
C-Peptide
;
Electroacupuncture
;
Liver
;
Signal Transduction
;
Insulin
;
Lipids
8.Effects of electroacupuncture on the glucose-lipid metabolism and the expression of ZAG and GLUT4 in the femoral quadriceps and adipose tissue in the rats with type 2 diabetes mellitus.
Cai-Feng GUO ; Rui LI ; Shan-Shan SONG ; Hao-Ru DUAN ; Rong-Yuan ZHANG ; Shu-Ting ZHUANG ; Wei-Xing GUO ; Ying DONG
Chinese Acupuncture & Moxibustion 2023;43(12):1425-1430
OBJECTIVES:
To observe the effects on the glucose-lipid metabolism and the expression of zinc-α2-glycoprotein (ZAG) and glucose transporter 4 (GLUT4) in the femoral quadriceps and adipose tissue after electroacupuncture (EA) at "Pishu" (BL 20), "Weiwanxiashu" (EX-B 3), "Zusanli" (ST 36) and "Sanyinjiao" (SP 6) in the rats with diabetes mellitus type 2 (T2DM), so as to explore the effect mechanism of EA in treatment of T2DM.
METHODS:
Twelve ZDF male rats were fed with high-sugar and high-fat fodder, Purina #5008 for 4 weeks to induce T2DM model. After successfully modeled, the rats were randomly divided into a model group and an EA group, with 6 rats in each one. Additionally, 6 ZL male rats of the same months age were collected as the blank group. The rats in the EA group were treated with EA at bilateral "Pishu" (BL 20), "Weiwanxiashu" (EX-B 3), "Zusanli" (ST 36) and "Sanyinjiao" (SP 6), with continuous wave, 15 Hz in frequency, and 2 mA in intensity. The electric stimulation lasted 20 min each time. EA was delivered once daily, 6 times a week for 4 weeks. Separately, the levels of fasting blood glucose (FBG) was measured before modeling, before and after intervention, and the body mass of each rat was weighted before and after intervention. After intervention, the levels of the total cholesterol (TC), triacylglycerol (TG) and free fatty acid (FFA) in serum were detected using enzyme colorimetric method; and the levels of the serum insulin (INS) and ZAG were detected by ELISA. Besides, the insulin sensitivity index (HOMA-ISI) was calculated. With Western blot technique adopted, the protein expressions of ZAG and GLUT4 in the femoral quadriceps and adipose tissue were determined.
RESULTS:
After intervention, compared with the blank group, the levels of FBG and body mass, and the levels of serum TC, TG, FFA and INS increased (P<0.01), while HOMA-ISI decreased (P<0.01); the level of ZAG in the serum and the protein expressions of ZAG and GLUT4 in the femoral quadriceps and adipose tissue dropped (P<0.01) in the model group. In the EA group, compared with the model group, the levels of FBG and body mass, and the levels of serum TC, TG, FFA and INS were reduced (P<0.01), and HOMA-ISI increased (P<0.01); the level of ZAG in the serum and the protein expressions of ZAG and GLUT4 in the femoral quadriceps and adipose tissue increased (P<0.01, P<0.05).
CONCLUSIONS
Electroacupuncture can effectively regulate glucose-lipid metabolism, improve insulin resistance and sensitivity in the rats with T2DM, which is associated with the modulation of ZAG and GLUT4 expression in the skeletal muscle and adipose tissue.
Rats
;
Male
;
Animals
;
Glucose/metabolism*
;
Electroacupuncture
;
Rats, Sprague-Dawley
;
Diabetes Mellitus, Type 2/therapy*
;
Lipid Metabolism
;
Triglycerides
;
Adipose Tissue/metabolism*
;
Acupuncture Points
9.Effects of Combination of 1,25(OH) 2D 3 and TLR-4 Inhibitor on the Damage to HaCaT Cells Caused by UVB Irradiation.
Peng CHEN ; Chuan Ning ZHUANG ; Jia Jing CUI ; Ping Wei WANG ; Dong Ge LIU ; Shu Qi YAN ; Li Ting ZHOU ; Shu Ping REN
Biomedical and Environmental Sciences 2022;35(11):1051-1062
OBJECTIVE:
Vitamin D and Toll-like receptor-4 (TLR-4) inhibition are involved in the protection of keratinocytes. The effects of combination of 1,25(OH) 2D 3 and TLR-4 inhibitor on the protection of keratinocytes against ultraviolet radiation B (UVB) irradiation remain unclear. This study was undertaken to explore the effects of combination of 1,25(OH) 2D 3 and TAK-242 (TLR-4 inhibitor) on the damage to HaCaT cells caused by UVB irradiation.
METHODS:
In vitro, HaCaT cells were treated with 1,25(OH) 2D 3 or/and TAK-242 prior to UVB irradiation at the intensity of 20 mJ/cm 2, then the production of reactive oxygen species (ROS), cell migration, apoptosis of cells, and the expression of oxidative stress, endoplasmic reticulum stress, and apoptosis related proteins were determined.
RESULTS:
Compared with the HaCaT cells treated with 1,25(OH) 2D 3 or TAK-242, the cells treated with both 1,25(OH) 2D 3 and TAK-242 showed, 1) significantly lower production of ROS ( P < 0.05); 2) significantly less apoptosis of HaCaT cells ( P < 0.05); 3) significantly lower expression of NF- κB, Caspase-8, Cyto-C, Caspase-3 ( P < 0.05).
CONCLUSION
The combination of 1,25(OH) 2D 3 and TAK-242 could produce a better protection for HaCaT cells via inhibiting the oxidative stress, endoplasmic reticulum stress and apoptosis than 1,25(OH) 2D 3 or TAK-242 alone.
Humans
;
HaCaT Cells
;
NF-kappa B
;
Reactive Oxygen Species
;
Toll-Like Receptor 4
;
Ultraviolet Rays/adverse effects*
;
Cholecalciferol/analogs & derivatives*
10.Epidemiologic characteristics and influencing factors of influenza outbreaks in Guangdong Province, 2015-2022.
Ya Li ZHUANG ; Jie LU ; Shu Kai WU ; Zhan Hui ZHANG ; Zhi Mei WEI ; Yi Hong LI ; Ting HU ; Min KANG ; Ai Ping DENG
Chinese Journal of Epidemiology 2023;44(6):942-948
Objective: To grasp the epidemiological characteristics of influenza outbreaks in Guangdong Province by analyzing the outbreaks of influenza-like cases reported in Guangdong Province from January 2015 to the end of August 2022. Methods: In response to the outbreak of epidemics in Guangdong Province from 2015 to 2022, information on on-site epidemic control was collected, and epidemiological analysis was conducted to describe the characteristics of the epidemics. The factors that influence the intensity and duration of the outbreak were determined through a logistic regression model. Results: A total of 1 901 influenza outbreaks were reported in Guangdong Province, with an overall incidence of 2.05%. Most outbreak reports occurred from November to January of the following year (50.24%, 955/1 901) and from April to June (29.88%, 568/1 901). A total of 59.23% (1 126/1 901) of the outbreaks were reported in the Pearl River Delta region, and primary and secondary schools were the main places where outbreaks occurred (88.01%, 1 673/1 901). Outbreaks with 10-29 cases were the most common (66.18%, 1 258/1 901), and most outbreaks lasted less than seven days (50.93%,906/1 779). The size of the outbreak was related to the nursery school (aOR=0.38, 95%CI:0.15-0.93), the Pearl River Delta region (aOR=0.60, 95%CI:0.44-0.83), the time interval between the onset of the first case and the time of report (>7 days compared with ≤3 days: aOR=3.01, 95%CI:1.84-4.90), the influenza A(H1N1) (aOR=2.02, 95%CI:1.15-3.55) and the influenza B (Yamagata) (aOR=2.94, 95%CI: 1.50-5.76). The duration of outbreaks was related to school closures (aOR=0.65, 95%CI: 0.47-0.89), the Pearl River Delta region (aOR=0.65, 95%CI: 0.50-0.83) and the time interval between the onset of the first case and the time of report (>7 days compared with ≤3 days: aOR=13.33, 95%CI: 8.80-20.19; 4-7 days compared with ≤3 days: aOR=2.56, 95%CI: 1.81-3.61). Conclusions: An influenza outbreak in Guangdong Province exhibits two peaks, one in the winter and spring seasons and the other in the summer. Primary and secondary schools are high-risk areas, and early reporting of outbreaks is critical for controlling influenza outbreaks in schools. Furthermore, comprehensive measures should be taken to prevent the spread of the epidemic.
Humans
;
Influenza A Virus, H1N1 Subtype
;
Influenza, Human/epidemiology*
;
Disease Outbreaks
;
Epidemics
;
China/epidemiology*