[Analysis of the impact of health management measures for entry personnel on imported Dengue fever in Guangdong Province, 2020-2022].

Objective: To explore the impact of health management measures for entry personnel (entry management measures) against COVID-19 on the epidemiological characteristics of imported Dengue fever in Guangdong Province from 2020 to 2022. Methods: Data of imported Dengue fever from January 1, 2016 to August 31, 2022, mosquito density surveillance from 2016 to 2021, and international airline passengers and Dengue fever annual reported cases from 2011 to 2021 in Guangdong were collected. Comparative analysis was conducted to explore changes in the epidemic characteristics of imported Dengue fever before the implementation of entry management measures (from January 1, 2016 to March 20, 2020) and after the implementation (from March 21, 2020 to August 31, 2022). Results: From March 21, 2020, to August 31, 2022, a total of 52 cases of imported Dengue fever cases were reported, with an imported risk intensity of 0.12, which were lower than those before implementation of entry management measures (1 828, 5.29). No significant differences were found in the characteristics of imported cases before and after implementation of entry management measures, including seasonality, sex, age, career, and imported countries (all P>0.05). 59.62% (31/52) of cases were found at the centralized isolation sites and 38.46% (20/52) at the entry ports. However, before implementation of entry management measures, 95.08% (1 738/1 828) of cases were found in hospitals. Among 51 cases who had provided entry dates, 82.35% (42/51) and 98.04% (50/51) of cases were found within seven days and fourteen days after entry, slightly higher than before implementation [(72.69%(362/498) and 97.59% (486/498)]. There was significant difference between the monthly mean values of Aedes mosquito larval density (Bretto index) from 2020 to 2021 and those from 2016 to 2019 (Z=2.83, P=0.005). There is a strong positive correlation between the annual international airline passengers volume in Guangdong from 2011 to 2021 and the annual imported Dengue fever cases (r=0.94, P<0.001), and a positive correlation also existed between the international passenger volume and the annual indigenous Dengue fever cases (r=0.72, P=0.013). Conclusions: In Guangdong, the entry management measures of centralized isolation for fourteen days after entry from abroad had been implemented, and most imported Dengue fever cases were found within fourteen days after entry. The risk of local transmission caused by imported cases has reduced significantly.

[Impact of capsular tension ring implantation in cataract patients with high myopia].

The capsular tension ring (CTR) can stabilize the capsule, support the lax zonules, and inhibit the proliferation and migration of lens epithelial cells. Clinically, CTR is mostly used in patients with zonular weakness, which can improve the stability of intraocular lens (IOL) and reduce the incidence of posterior capsular opacity (PCO). The relatively large capsular bag volume, zonular weakness in cataract patients with high myopia may increase the instability of IOL and PCO. Therefore, many clinicians have implanted CTR in cataract patients with high myopia. In this review, we summarized the application of CTR in cataract patients with high myopia.

[Occurrence of live-born twins with birth weight-discordance and its relationship to the adverse birth outcomes].

Objective: To investigate the occurrence of live-born twins with birth weight-discordance and its relationship to adverse birth outcomes. Methods: A retrospective analysis was performed on 4 011 pairs of live-born twins in the Third Affiliated Hospital of Guangzhou Medical University from January 2011 to December 2020. Based on the birth-weight discordance (∆BW, ∆BW=(birth-weightbig-birth-weightsmall)/birth-weightbig×100%)), twins were divided into 4 groups, including ∆BW≤15%,>15%-20%,>20%-25%, and>25%. The differences in maternal and neonatal outcomes among 4 groups were explored. Then the correlation between ∆BW and neonatal adverse outcomes were explored. Results: The ΔBW was 9 (4, 16)% and males were accounted for 53.8% (4 315 cases) of 4 011 pairs of twins. The gestational age was (35.3±2.7) weeks at birth. There were 2 908 pairs (72.5%) of twins with ΔBW≤15%, 481 pairs (12.0%) with ΔBW>15%-20%, 281 pairs (7.0%) with ΔBW 20%-≤25%, and 341 twin pairs (8.5%) with ΔBW>25%. With ∆BW of 20% as the diagnostic cutoff, the incidence of birth weight discordance was 15.5% (622/4 011). The proportion of natural births in the ∆BW≤15% group was higher than that in the ∆BW>15%-20% group (10.5% (288/2 740) vs. 6.3% (29/463), P<0.008 3). The ∆BW>25% group had a significantly higher prevalence of maternal hypertensive disorders during pregnancy than that of the other 3 groups (25.5% (87/341) vs. 16.7% (47/281) vs.17.3% (83/480) vs. 13.8% (400/2 899), all P<0.008 3). Univariate analysis found that the ΔBW>25% group had a lower gestational age and a higher rate of preterm birth than the other groups. The rate of extremely low birth weight (ELBW) or very low birth weight (VLBW), small for gestational age (SGA), and transferring to the department of neonatology in the smaller twins were significantly different among the 4 groups (all P<0.05). Multivariate analysis showed that higher degree of birth weight discordance was all positively associated with the rate of ELBW, SGA, and transferring to the department of neonatology in smaller twin, even after adjusting maternal age and gestational hypertension, year of birth, mode of delivery, gender, and gestational age (all P<0.05). Moreover, the Mantel-Haenszel test also indicated that there were significantly low to moderate correlations between ΔBW and the unfavorable outcomes (r=0.22, 0.53, 0.21, all P<0.001, respectively). The receiver operating characteristic (ROC) curve found that adverse birth outcomes would be well predicted by birth weight-discordant when the diagnostic cut-off of ΔBW was 12%-17%, with an acceptable sensitivity (0.53-0.78) and a high specificity (0.72-0.79). Conclusions: Birth weight discordant is not uncommon in live-born twins, and is associated with adverse outcomes including ELBW, SGA, and transferring to the department of neonatology in the small twins. Besides, the risk is linearly related to the increase of ΔBW. In the future, more researches are needed to explore the underline mechanism and long-term impact of birth weight discordance, to guide the prevention and management.

[Effects of 4'-O-methylochnaflavone on endothelial dysfunction induced by palmitic acid in rat cavernous endothelial cells].

OBJECTIVE: To investigate the effect of biflavonoid 4'-O-methylochnaflavone (MF) on palmitic acid-induced endothelial dysfunction in rat cavernous endothelial cells (RCECs). METHODS: The isolated RCECs were commercially available and randomly divided into four groups: normal+BSA group (NC group), palmitic acid (PA) group, MF group, and icariside Ⅱ (ICA Ⅱ) group. The protein expression levels of protein kinase B (PKB/AKT) and endothelial nitric oxide synthase (eNOS) in each group were evaluated via Western blotting. The differences in the intracellular nitric oxide of RCECs treated by MF or ICA Ⅱ were detected by DAF-FM DA that served as a nitric oxide fluorescent probe. Effects of MF and ICA Ⅱ on cell proliferation of PA-stimulated RCECs were determined via CCK-8 assay. RESULTS: The content of nitric oxide in RCECs was significantly increased after the treatment of MF and ICA Ⅱ in comparison with the NC group (P < 0.05). Moreover, compared with ICA Ⅱ group, MF demonstrated a more obvious effect in promoting nitric oxide production (P < 0.05). Compared with the NC group, the expression levels of eNOS and AKT in the PA group were significantly decreased, indicating that a model for simulating the high-fat environment in vitro was successfully constructed (P < 0.05). Meanwhile, the intervention of MF and ICA Ⅱ could effectively increase the expression of eNOS and AKT, suggesting that MF and ICA Ⅱ could promote the recovery of endothelial dysfunction caused by high levels of free fatty acids (P < 0.05). The results of CCK-8 assays showed that PA could significantly reduce the proli-feration ability of RCECs (P < 0.05). Furthermore, the decreased cell viability induced by PA was significantly elevated by treatment with ICA Ⅱ and MF (P < 0.05). CONCLUSION: In RCECs, MF and ICA Ⅱ could effectively increase the content of nitric oxide. The down-regulation of the expression of proteins associated with the AKT/eNOS pathway after PA treatment revealed that this pathway was involved in the development of endothelial dysfunction, which could be effectively reversed by MF and ICA Ⅱ. In addition, the cell proliferation ability was significantly decreased following PA treatment, but MF and ICA Ⅱ could restore the above changes. Overall, biflavonoid MF has an obvious repairing effect on PA-stimulated endothelial dysfunction.

[Course of disease and related epidemiological parameters of COVID-19: a prospective study based on contact tracing cohort].

Objective: To analyze the course of disease and epidemiological parameters of COVID-19 and provide evidence for making prevention and control strategies. Methods: To display the distribution of course of disease of the infectors who had close contacts with COVID-19 cases from January 1 to March 15, 2020 in Guangdong Provincial, the models of Lognormal, Weibull and gamma distribution were applied. A descriptive analysis was conducted on the basic characteristics and epidemiological parameters of course of disease. Results: In total, 515 of 11 580 close contacts were infected, with an attack rate about 4.4%, including 449 confirmed cases and 66 asymptomatic cases. Lognormal distribution was fitting best for latent period, incubation period, pre-symptomatic infection period of confirmed cases and infection period of asymptomatic cases; Gamma distribution was fitting best for infectious period and clinical symptom period of confirmed cases; Weibull distribution was fitting best for latent period of asymptomatic cases. The latent period, incubation period, pre-symptomatic infection period, infectious period and clinical symptoms period of confirmed cases were 4.50 (95%CI:3.86-5.13) days, 5.12 (95%CI:4.63-5.62) days, 0.87 (95%CI:0.67-1.07) days, 11.89 (95%CI:9.81-13.98) days and 22.00 (95%CI:21.24-22.77) days, respectively. The latent period and infectious period of asymptomatic cases were 8.88 (95%CI:6.89-10.86) days and 6.18 (95%CI:1.89-10.47) days, respectively. Conclusion: The estimated course of COVID-19 and related epidemiological parameters are similar to the existing data.

[Analysis on characteristics and influencing factors of COVID-19 confirmed cases with viral nucleic acid re-positive after discharge in Guangdong Province].

Objective: To analyze the epidemiological characteristics and influencing factors of COVID-19 confirmed cases with viral nucleic acid re-positive in anal and/or throat swabs after discharge during the domestic imported epidemic stage in Guangdong Province in early 2020. Methods: The COVID-19 confirmed cases with the onset time before March 1, 2020 in Guangdong Province were collected to analyze the demographic data, epidemiological characteristics, and specimen collection and testing data after discharge. Logistic regression model was used for influencing factors analysis of re-positive cases. Results: A total of 1 286 COVID-19 confirmed cases were included, the M(Q1,Q3) of age was 44(32,58)years, 617 cases were male, 224 cases were re-positive in anal and/or throat swabs with the re-positive rate 17.42%. The M(Q1,Q3) of age of re-positive cases was 35(23, 50) years, which was younger than that of re-negative cases age was those 46(33, 59) years (P<0.001). With the increase of age, re-positive rate decreased (χ2trend=52.73, P<0.001). 85.27% (191/224) of re-positive cases were found in 14 d after discharge, the duration time of re-positive status was 13(7, 24) d, and 81.69% (183/224) of re-positive cases were re-tested negative in 28 d after re-positive date. No fever and other symptoms had been observed among re-positive cases during the whole follow-up. No secondary infectious cases had been found among close contacts after 14 d of centralized isolation and sampling screening. Univariate logistic regression model analysis revealed that the influencing factors of the re-positive cases included age, occupation, clusters, clinical types, and admission time. Multivariate logistic regression model analysis revealed that age was an independent risk factor. Conclusions: SARS-CoV-2 viral nucleic acid re-positive is found in COVID-19 confirmed cases after discharge in Guangdong Province. Most re-positive cases are confirmed among 14 d after discharge and re-test to negative among 28 d after re-positive date. Age is an risk factor for re-positive cases after discharge.

A peer support intervention for first-time mothers: Feasibility and preliminary efficacy of the mummy buddy program.

BACKGROUND: The transition to motherhood, although joyous, can be highly stressful, and the availability of professional postpartum support for mothers is often limited. Peer volunteer support programs may offer a viable and cost-effective method to provide community-based support for new mothers. AIM: To determine the feasibility of a peer volunteer support program-The Mummy Buddy Program-in which experienced volunteer mothers are paired with, and trained to offer social support to, first-time mothers. METHODS: Using a single-group non-randomised feasibility trial, a total of 56 experienced mothers participated in the Mummy Buddy training program, which was focused on education and practical exercises relating to the provision of various forms of social support. Experienced mothers ('Mummy Buddies') were subsequently paired with expectant first-time mothers (n=47 pairs), and were encouraged to provide support until 24-weeks postpartum. FINDINGS: In terms of key feasibility considerations, 95.1% of Mummy Buddies felt that they were trained sufficiently to perform their role, and 85.8% of New Mothers were satisfied with the support provided by their Buddy. Analyses of preliminary efficacy (i.e., program outcomes) revealed that the first-time mothers maintained normal levels of stress and depressive symptomology, and possessed relatively strong maternal functioning, across the program duration. CONCLUSION: The Mummy Buddy Program appears to be a feasible and potentially valuable peer volunteer support program for first-time mothers. This study provides a foundation for program expansion and for work designed to examine program outcomes-for first-time mothers, Mummy Buddies, and entire family units-within a sufficiently-powered randomised controlled trial.

[Analysis on the cluster epidemic of coronavirus disease 2019 in Guangdong Province].

Objective: Analysis of clustering characteristics of coronavirus disease 2019 (COVID-19) in Guangdong Province. Methods: The COVID-19 cases in Guangdong Province onset from January 1 to February 29, 2020 were collected from Chinese information system for disease control and prevention and Emergency Public Reporting System. Obtain the epidemiological survey data of the cluster epidemic situation, and clarify the scale of cluster epidemic situation, the characteristics of the index cases, family and non-family subsequent cases. Calculate serial interval according to the onset time of the index cases and subsequent cases, secondary attack rate based on the close contacts tracking results, the characteristics of different cases in the clustered epidemic were compared. Results: A total of 283 cluster were collected, including 633 index cases, 239 subsequent cases. Families are mainly clustered, the total number involved in each cluster is in the range of 2-27, M (P25, P75) are 2.0 (2.0, 4.0). During January 15 to February 29, the secondary attack rate is 2.86% (239/8 363) in Guangdong Province, the family secondary attack rate was 4.84% (276/3 697), and the non-family secondary attack rate was 1.32% (61/4 632). According to the reporting trend of the number of cases in Guangdong Province, it can be divided into four stages, the rising stage, the high platform stage, the descending stage and the low level fluctuation period. The secondary attack rate of the four stages were 3.5% (140/3 987), 2.3% (55/2 399), 2.6% (37/1 435), 1.3% (7/542), respectively. The difference was statistically significant (P=0.003). Conclusion: COVID-19 cluster mainly occurs in families in Guangdong Province. The scale of the clustered epidemic was small; the serial interval was short; and the overall secondary attack rate was low.

Retrospective Analysis of 61 Cases of Children Died of Viral Pneumonia.

ABSTRACT: Objective To retrospectively analyze the forensic pathological postmortem examination and clinical data of children who died of viral pneumonia in identification of cause of death cases and to discuss the clinical characteristics and pathological features of viral pneumonia in children, in order to provide reference to pathological diagnosis of viral pneumonia in children caused by 2019 novel coronavirus （2019-nCoV） infection. Methods Postmortem examination data from 61 cases of children whose causes of death were identified as viral pneumonia in recent years were collected from the Center of Forensic Identification, Southern Medical University. The gender, age, clinical symptoms and pathological features were comparatively analyzed. Results Among the 61 cases of children who died of viral pneumonia, most were within 2 years old （83.61%）, and a large proportion died within 2 weeks after the onset of the disease （91.80%）. Gross changes in postmortem examination included respiratory mucosal hyperemia, pleural effusion, pulmonary swelling, variegated pulmonary pleura and serosa, as well as focal pulmonary hemorrhage and pulmonary edema. A large proportion of sick children had enlarged mesenteric lymph nodes （83.61%） and thymic dysplasia （21.31%）. Histopathological changes included edema of alveoli and interstitial substance, pneumorrhagia，shedding of alveolar epithelial cells, serous and （or） fibrous exudation in the alveoli, formation of viral inclusions, formation of transparent membranes, infiltration of inflammatory cells that mainly consisted of macrophages and lymphocytes in interstitial substance and alveoli. Viral infections often affected the heart and gastrointestinal tract. Conclusion The clinical symptoms of children with viral pneumonia are difficult to notice, and because the immune systems of children are not fully developed and they have poor immunity, they can easily become severely ill and even die. Analyzing the forensic autopsies and the histopathological characteristics could provide reference for pathological diagnosis of viral pneumonia.

[Clinical outcomes of COVID-19 cases and influencing factors in Guangdong province].

Objective: To analyze the clinical courses and outcomes of COVID-19 cases and the influencing factors in Guangdong province and provide basis for the formulation or adjustment of medical care and epidemic control strategy for COVID-19. Methods: We collected demographic data, medical histories, clinical courses and outcomes of 1 350 COVID-19 patients reported in Guangdong as of 4 March 2020 via epidemiological investigation and process tracking. Disease severity and clinical course characteristics of the patients and influencing factors of severe illness were analyzed in our study. Results: Among 1 350 cases of COVID-19 cases in Guangdong, 72 (5.3%) and 1 049 (77.7%) were mild and ordinary cases, 164 (12.1%) were severe cases, 58 (4.3%) were critical cases and 7 (0.5%) were fatal. The median duration of illness were 23 days (P(25), P(75): 18, 31 days) and the median length of hospitalization were 20 days (P(25), P(75): 15,27 days). For severe cases, the median time of showing severe manifestations was on the 12(th) day after onset (P(25), P(75): 9(th) to 15(th) days), and the median time of severe manifestation lasted for 8 days (P(25), P(75): 4, 14 days). Among 1 066 discharged/fetal cases, 36.4% (36/99) and 1.0% (1/99) of the mild cases developed to ordinary cases and severe cases respectively after admission; and 5.2% (50/968) and 0.6% (6/968) of the ordinary cases developed to severe cases, and critical cases respectively after admission. In severe cases, 11.4% developed to critical cases (10/88). The influencing factors for severe illness or worse included male (aHR=1.87, 95%CI: 1.43-2.46), older age (aHR=1.67, 95%CI: 1.51-1.85), seeking medical care on day 2-3 after onset (aHR=1.73, 95%CI: 1.20-2.50) pre-existing diabetes (aHR=1.75, 95%CI: 1.12-2.73) and hypertension (aHR=1.49, 95%CI: 1.06-2.09). Conclusions: The course of illness and length of hospitalization of COVID-19 cases were generally long and associated with severity of disease clinical outcomes. The severe cases were mainly occurred in populations at high risk. In the epidemic period, classified management of COVID-19 cases should be promoted according to needs for control and prevention of isolation and treatment for the purpose of rational allocation of medical resources.

[Survey on the quadrivalent influenza vaccine intention and related factors of health care workers in the Pearl River Delta region from 2015 to 2017].

Objective: To analyze the quadrivalent influenza vaccine intention of 718 health care workers (HCWs) in the Pearl River Delta region from 2015 to 2017. Method: In May 2018, 718 HCWs from the department related to the diagnosis and treatment of influenza in 17 hospitals (6 tertiary hospitals, 5 secondary hospitals and 6 primary hospitals) from Guangzhou, Jiangmen, Zhuhai and Dongguan were selected by using stratified sampling method. Questionnaire survey and face-to-face interview were used to collect the information of influenza vaccination, the intention of the quadrivalent influenza vaccine, the acceptance of free and required vaccination policies, and recommendations for increasing influenza vaccination intentions from 2015 to 2017. The multivariate logistic regression was used to analyze factors associated with the vaccination intention. Results: A total of 718 HCWs were surveyed and 147 of them were interviewed face to face. Among them, the vaccination rate of primary hospitals [17.39%(40/230)] was higher than that of other hospitals (χ(2)=15.80, P<0.05). If the vaccine could be free, 84.82% (609/718) of HCWs would like to be vaccinated. The multivariate logistic regression showed that the factors, HCWs who were aged ≥50 years (OR=3.44, 95%CI:1.43-8.28), worked in department of prevention and health care (OR=2.35, 95%CI:1.16-4.75), learned about the quadrivalent influenza vaccine (OR=2.94, 95%CI:2.08-4.18), knowed that HCWs are priority (OR=2.33, 95%CI:1.56-3.48), and had a history of trivalent influenza vaccination from 2015 to 2017 (OR=4.70, 95%CI:3.08-7.15), were associated with the vaccination intention. Conclusion: HCWs in the Pearl River Delta region had weak inclination of getting quadrivalent influenza vaccine. HCWs who were age (≥50 years old), worked in department of prevention and health care, learned about the quadrivalent influenza vaccine, knowed that HCWs are priority, and had a history of trivalent influenza vaccination from 2015 to 2017 were factors positively associated with the vaccination intention.

The effects of Co on the enhancement of magnetic properties by modifying the intergranular phase in Nd-Fe-B alloys.

In Nd2Fe14B-based permanent materials, the intergranular phase has a strong influence on magnetic properties. Here, we study the effect of partial substitution of Fe by Co on the microstructure to gain insight into the mechanism of enhancing magnetic properties of (Nd0.8Pr0.2)2.2Fe14-xCoxB (x = 0, 1.75, 2, 2.25) alloys. Our results show that the substitution Co for Fe changes the magnetic properties obviously by tuning the chemistry and distribution of the intergranular phase between hard magnetic grains. In particular, for (Nd0.8Pr0.2)2.2Fe12Co2B (x = 2) alloy, no obvious intergranular phase is observed. And the through-thickness homogeneity and ultrafine microstructure with an average size of ~25 nm is obtained, which produces maximum product ((BH)max) of 141 kJ/m3, 29% higher than that of quaternary alloy. Our findings provide a new idea to design prospective permanent alloys with increased magnetic properties by tuning the distribution and chemical composition of the intergranular phase.

[Epidemiological characteristics of influenza in Guangdong province, during winter of 2017-2018].

Objective: To understand the epidemiological characteristics of influenza in Guangdong province, during the winter of 2017-2018, to provide evidence for response to the diversity of influenza, in different seasonal patterns. Methods: Data on weekly influenza surveillance from January 2016 to April 2018, were collected in Guangdong. Information on patients with Influenza-like illness (ILI), on influenza virus positive rates and on outbreaks during the winter of 2017 to 2018, was analyzed and compared with those in spring of 2016 and summer of 2017. χ(2) test and Fisher exact test were used. Results: In the above said winter, the average percentage of visits for ILI in 28 hospitals where sentinel surveillance program had been set, was 4.99% (157 235/3 149 656), which was above the level of the same period in the previous five years. The positive rates of influenza virus among samples collected from ILI outpatients and hospitalized cases under severe acute respiratory infection (SARI) were 28.33% (2 137/7 543) and 14.93% (256/1 715), with the proportions of B (Yamagata) as 70.43% (1 505/2 137) and 73.05% (187/256) respectively. A total of 257 influenza outbreaks were reported in the winter period, with 82.49% (212/257) occurred in elementary schools. Cases aged 6-14 years occurred in winter and spring appeared of having higher positive rate than those seen in summer (P<0.05) whereas elderly cases aged 60 and above showed higher positive rate in summer than those in winter and spring two seasons (P<0.05). Conclusions: Epidemiological characteristics of influenza appeared in Guangdong province, during the winter from 2017 to 2018, were correlated to Influenza B (Yamagata). Capacity on the implementation of surveillance programs and on the coverage of vaccination should be improved and increased in order to control influenza in different epidemic seasons, in Guangzhou.

[Analysis on epidemiological characteristics of enterovirus 71 cases of hand-foot-mouth disease based on the active monitoring in Guangdong Province in 2011-2015].

Objective: To analyze the hand-foot-mouth disease (HFMD) enterovirus 71 (EV-A71) infection epidemic characteristics of Guangdong Province from 2011 to 2015. Methods: We colleted data on common cases of hand-foot-mouth disease infected with EV-A71 reported from eight sentinel hospitals in Guangdong Province from January 2011 to December 2015, through the "Guangdong Province Acute Infectious Disease Surveillance Information Platform System" , including the age and incidence of cases. Time and etiological data, etc.We also collected data on the number of reported cases of HFMD disease and the number of laboratory-confirmed cases, through the "China Disease Prevention and Control Information System" , including data on common cases of HFMD disease, data on epidemics of severe cases and deaths, and the age, onset time, and pathogens of cases. Learning data, etc.The data from two sources were used to estimate the incidence of HFMD in EV-A71 and describe its distribution characteristics.Chi-square test was used to compare the positive rate of HF-A71 infection in hand-foot-mouth disease and the difference in estimated incidence among different age groups and months. Results: Eight sentinel hospitals from 2011 to 2015 reported a total of 1 855 common cases of EV-A71 infection, of which the highest was in 2014 (31.6%, 605/1 916) and the lowest was in 2015 (6.8%, 134/1 971) (χ(2)=521.85, P<0.001).According to the Disease Surveillance Reporting Information System, 1 772 516 cases of HFMD disease were reported from 2011 to 2015 in Guangdong Province, and 1 902 cases of severe and fatal cases of EV-A71 infection.The composition ratio of EV-A71 infected was 72.6% (1 775/2 444) and 97.0% (127/131) of severe HFMD disease in Guangdong province during 2011-2015.The average annual incidence of HF-A71 infection in all age groups showed a decreasing trend with age (χ(2trend)=990 273.20, P<0.001), and it was the highest in the 1-year-old group, which was 1 697.67/100 000, and the lowest in the 4-year-old group, which was 705.46/100 000. The difference of monthly average incidence of EV-A71 infection in HF-A71 in each month was statistically significant (χ(2)=401.23, P<0.001), the highest in May at 15.51 per 100 000, and the lowest in July at 9.42 per 100 000. Conclusion: EV-A71 infection rate of ordinary HFMD varies in different years. The most severe and death cases of HFMD were EV-A71 infected. 1 year old children were the high-risk group of infected with EV-A71 HFMD. April was the epidemic months of EV-A71 HFMD infection.

[Epidemiological characteristics of Coxsackie virus A16 caused hand foot and mouth disease cases in Guangdong province, 2012-2016].

Objective: To analyze the epidemiological characteristics of hand foot and mouth disease (HFMD) cases caused by Coxsackie virus A16 (Cox A16) in Guangdong province from 2012 to 2016. Methods: The data of mild HFMD cases caused by Cox A16 were collected from 8 sentinel hospitals in 8 prefecture-level cities in Guangdong to estimate Cox A16 infection status and its population and time distribution characteristics. Results: (1) The highest estimated incidence of Cox A16 infection was in 2014 (113.0/100 000), followed by 2016 (86.4/100 000) and 2012 (79.1/100 000), while the estimated incidence was lower in 2015 (29.0/100 000) and 2013 (28.8/100 000). (2) Cox A16 was confirmed to be the predominant pathogen causing HFMD outbreaks (54.6%, 89/163). The number of outbreaks in the year with high incidence (28 outbreaks) was 11.2 times higher than that in the year with low incidence (2.5 outbreaks). (3) Across all age groups, the annual estimated incidence of Cox A16 infection decreased with age (trend χ(2)=853 905.63, P<0.01). The incidence was highest in age group 1 year (1 449.2/100 000), followed by that in age group 3 years (1 097.0/100 000), in age group 2 years (1 083.5/100 000), in age group 4 years (687.8/100 000) and in age group 0 year (604.9/100 000). Among the age groups <12 months, the estimated incidence increased with age (trend χ(2)=5 541.77, P<0.01), which was highest in age group 11-months (2 105.1/100 000), followed by that in age groups 10-months (1 448.6/100 000), 9-months (938.3/100 000), 8-months (703.3/100 000) and 6-months (664.6/100 000). (4) The annual incidence peak was during May (143.9/100 000)-June (131.5/100 000). Conclusion: The prevalence of Cox A16 infection differed with year in Guangdong during 2012-2016. When the incidence of Cox A16 infection was high, more outbreaks occurred. The prevalence occurred mainly in nurseries and kindergartens from May to June each year. Children aged 0-4 years were the high risk group for Cox A16 infection, children aged 6-11 months were at high risk for Cox A16 infection.

Analysis of serum microRNA expression in male workers with occupational noise-induced hearing loss.

Occupational noise-induced hearing loss (ONIHL) is a prevalent occupational disorder that impairs auditory function in workers exposed to prolonged noise. However, serum microRNA expression in ONIHL subjects has not yet been studied. We aimed to compare the serum microRNA expression profiles in male workers of ONIHL subjects and controls. MicroRNA microarray analysis revealed that four serum microRNAs were differentially expressed between controls (n=3) and ONIHL subjects (n=3). Among these microRNAs, three were upregulated (hsa-miR-3162-5p, hsa-miR-4484, hsa-miR-1229-5p) and one was downregulated (hsa-miR-4652-3p) in the ONIHL group (fold change >1.5 and Pbon value <0.05). Real time quantitative PCR was conducted for validation of the microRNA expression. Significantly increased serum levels of miR-1229-5p were found in ONIHL subjects compared to controls (n=10 for each group; P<0.05). A total of 659 (27.0%) genes were predicted as the target genes of miR-1229-5p. These genes were involved in various pathways, such as mitogen-activated protein kinase (MAPK) signaling pathway. Overexpression of miR-1229-5p dramatically inhibited the luciferase activity of 3' UTR segment of MAPK1 (P<0.01). Compared to the negative control, HEK293T cells expressing miR-1229-5p mimics showed a significant decline in mRNA levels of MAPK1 (P<0.05). This preliminary study indicated that serum miR-1229-5p was significantly elevated in ONIHL subjects. Increased miR-1229-5p may participate in the pathogenesis of ONIHL through repressing MAPK1 signaling.

[Analysis on risk factors for norovirus outbreaks in Guangdong province, 2008-2015].

Objective: To analyze transmission factors of norovirus outbreaks in Guangdong province during 2008-2015 and provide evidence for the prevention and control of norovirus infection. Methods: Epidemiological analysis was performed on the data of norovirus outbreaks reported in Guangdong from January 1, 2008 to December 31, 2015, which were obtained from the Public Health Emergency Management Information System of Guangdong province. The samples collected from the norovirus outbreaks were detected for norovirus by RT-PCR and the gene sequencing of the positive PCR products were performed. Results: A total of 96 norovirus outbreaks were reported in Guangdong during 2008-2015. Sixteen outbreaks were reported during 2008-2012 and 80 outbreaks were reported during 2013-2015 (83.3%). Eighty-two outbreaks (85.4%) occurred in schools. The infection routes included foodborne transmission in 39 outbreaks (40.6%), person to person transmission in 23 outbreaks (24.0%) and waterborne transmission in 8 outbreaks (7.3%). The gene sequencing results showed that variant GⅡ.4/Sydney2012 was the predominant pathogen for 6 of the 20 outbreaks (30.0%) during 2012-2013. Variant GⅡ.17 was the predominant pathogens for 33 of the 53 outbreaks (62.3%) during 2014-2015. Conclusion: The norovirus outbreaks in Guangdong during 2008-2015 were caused by foodborne and person to person transmissions of two emerging variant: GⅡ.4/Sydney2012 and GⅡ.17.

[Let-7 miRNA silencing promotes Kaposi's sarcoma-associated herpesvirus lytic replication via activating mitogen-activated protein kinase kinase kinase kinase 4 and its downstream factors].

OBJECTIVE: To explore the effect of let-7 miRNA silencing on Kaposi's sarcoma-associated herpesvirus (KSHV) lytic replication and the underling mechanism. METHODS: The pEGFP-C2-let-7 sponge vector was transfected into BCBL-1 and 293T cells with Lipofectamine 2000 to silence the expression of let-7 miRNAs. Quantitative real-time PCR (qRT-PCR) was used to quantify the expression of let-7 miRNAs, the transcriptional levels of mitogen-activated protein kinase kinase kinase kinase 4 (MAP4K4), cyclooxygenase-2 (COX-2) and matrix metalloproteinase 13 (MMP-13), and the DNA copy numbers of KSHV open reading frame 50 (ORF50) and open reading frame 72 (ORF72). Western blot was used to detect the total and phosphorylated protein levels of MAP4K4, COX-2, extracellular regulated protein kinases (ERK1/2), c-Jun N-terminal kinase (JNK) and p38 MAPK. RESULTS: The expression of let-7 miRNAs was dramatically decreased in the let-7 sponge transfected BCBL-1 and 293T cells compared with that in the vector-transfected cells (P<0.05 for all). The gene copy number and mRNA transcriptional level of KSHV ORF50 were significantly increased in the let-7 sponge transfected BCBL-1 cells compared with that in the vector-transfected cells (1.00±0.10 vs. 2.33±0.18 and 1.08±0.48 vs 3.22±0.27, respectively,P<0.001 for both). The gene copy number and mRNA transcriptional level of KSHV ORF72 were also significantly increased in let-7 sponge transfected BCBL-1 cells compared with those in the vector-transfected cells(1.07±0.49 vs 1.67±0.45 and 1.01±0.19 vs 1.54±0.11, respectively,P<0.05 for both). Furthermore, the mRNA transcriptional levels of MAP4K4, COX-2 and MMP-13 were significantly increased in the let-7 sponge transfected BCBL-1 cells compared with those in the vector-transfected cells (1.00±0.05 vs 5.73±0.96, 1.00±0.05 vs 2.68±0.19, 1.00±0.02 vs 2.69±0.25, respectively,P<0.001 for all). Let-7 miRNAs silencing also increased the protein expression levels of MAP4K4, COX-2 and phospho-ERK1/2, while the phospho-JNK and phospho-p38 were not changed in the BCBL-1 and 293T cells. CONCLUSIONS: Let-7 silencing may activate the replication of KSHV, possibly through up-regulating MAP4K4 and its downstream molecules COX-2, MMP-13, and phosphorylation of ERK1/2, finally results in the progression of Kaposi sarcoma.

Classification of colon cancer based on the expression of randomly selected genes.

In order to ascertain the relationship between gene expression and colon cancer localization, a classification method based on random gene selection and a self-organizing map network is proposed. Different numbers of genes were selected randomly from 54,675 genes of 53 colon cancer patients in stage union for international cancer control II. These patients were then divided into two sets: a training set of 36 and a validation set of 17 patients. In this study, we randomly selected 1000, 100, 50, 30, 10, 5, and 3 genes, 1000 times, respectively. The minimum misclassification ratio of each gene group was 3/17 to 4/17, and the percentage of gene groups that were less than 0.25 was approximately 1-7%. Moreover, the misclassification ratio of most gene groups (about 82-89%) was lower than 0.4. Through the analysis of these low misclassification ratio gene groups, we found that there were few common genes between them. This revealed that colon cancer localization is not associated with a single gene group but with many gene groups. Furthermore, K-fold cross validation was used to test the reliability of the possible informative genes, and the results indicated that using gene expression to classify colon tumor localization was not feasible.