[Thoughts and suggestions on modern construction of disease prevention and control system].

The critical period for the prevention and control of COVID-19 in China, in response to requirements for accelerating the modernization of the disease prevention and control system, we analyzed and summarized the current situation, existing problems, and deficiencies in China's modernization of disease prevention and control system. In addition, we put forward the contents and countermeasures for the modernization of the disease prevention and control system. The modernization of the disease prevention and control system should be built around governance modernization, talent modernization, equipment modernization, scientific research modernization, and modernization of the regulatory system. The countermeasures and suggestions need to reposition the disease prevention and control system, rationalize the management system and operating mechanism, strengthen the modernization of talents and equipment, strengthen scientific research on disease prevention and control, and further improve the disease prevention and control legal system.

Intra-articular injection of microRNA-140 (miRNA-140) alleviates osteoarthritis (OA) progression by modulating extracellular matrix (ECM) homeostasis in rats.

OBJECTIVE: Disruptions of extracellular matrix (ECM) homeostasis are key events in the pathogenesis of osteoarthritis (OA). MicroRNA-140 (miRNA-140) is expressed specifically in cartilage and regulates ECM-degrading enzymes. Our objective in this study was to determine if intra-articular injection of miRNA-140 can attenuate OA progression in rats. DESIGN: miRNA-140 levels in human normal and OA cartilage derived chondrocytes and synovial fluid were assessed by polymerase chain reaction (PCR). After primary human chondrocytes were transfected with miRNA-140 mimic or inhibitor, PCR and western blotting were performed to quantify Collagen II, MMP-13, and ADAMTS-5 expression. An OA model was induced surgically in rats, and subsequently treated with one single intra-articular injection of miRNA-140 agomir. At 4, 8, and 12 weeks after surgery, OA progression were evaluated macroscopically, histologically, and immunohistochemically in these rats. RESULTS: miRNA-140 levels were significantly reduced in human OA cartilage derived chondrocytes and synovial fluid compared with normal chondrocytes and synovial fluid. Overexpressing miRNA-140 in primary human chondrocytes promoted Collagen II expression and inhibited MMP-13 and ADAMTS-5 expression. miRNA-140 levels in rat cartilage were significantly higher in the miRNA-140 agomir group than in the control group. Moreover, behavioural scores, chondrocyte numbers, cartilage thickness and Collagen II expression levels in cartilage were significantly higher, while pathological scores and MMP-13 and ADAMTS-5 expression levels were significantly lower in the miRNA-140 agomir group than in the control group. CONCLUSION: Intra-articular injection of miRNA-140 can alleviate OA progression by modulating ECM homeostasis in rats, and may have potential as a new therapy for OA.

[Impact of PM2.5 on daily outpatient numbers for respiratory diseases in Shenzhen, China].

Objective: To assess the association between the concentration of the air pollutant PM2.5 and daily outpatient visits for respiratory disease. Methods: All records of daily outpatient visits to three hospitals in Shenzhen from January 1 to December 31, 2013 were collected. Daily air pollution monitoring and meteorology data from the same period were also collected in Shenzhen. The data were analyzed using a semiparametric generalized additive model with Poisson distribution of time series analysis controlling for long-term and seasonal trends, flu, DOW, public holidays, and meteorological factors. The excess risk(ER)of respiratory disease and its 95% CI value were calculated, along with the incremental increase of 10 µg/m3 in PM2.5 concentration. Results: Number of outpatient visits for respiratory diseases totaled 1 428 672(daily range: 1 790-5 228). The annual average PM2.5 concentration was 40.2 µg/m3(daily range: 7.2-137.1 µg/m3). The lag1 factor had the most significant impact on the lag effect. We estimated that a 10 µ g/m3 increase in day-before PM2.5 concentration was associated with a 1.809%(95% CI: 1.709%-1.909%)ER of visits for respiratory disease. After controlling for other pollutants(NO2, CO, and O3), the effect remained stable. When NO2, CO, and O3 were introduced separately, for every 10 µg/m3 rise in PM2.5 concentration, the excess risk of daily outpatient visits for respiratory disease was 1.814%(95% CI: 1.706%-1.923%), 2.780%(95% CI: 2.668%-2.892%), and 1.513%(95% CI: 1.403%-1.624%), respectively. With simultaneous control of NO2 and O3, NO2 and CO, and CO and O3, for every 10 µg/m3 rise in PM2.5 concentration, the excess risk of respiratory disease was 1.369%(95% CI: 1.242%-1.497%), 2.709%(95% CI: 2.590%-2.828%), and 2.577%(95% CI: 2.452%-2.702%), respectively. With simultaneous control of NO2, CO, and O3, for every 10 µg/m3 rise in PM2.5 concentration, the excess risk of respiratory disease was 2.370%(95% CI: 2.231%-2.509%). Conclusions: PM2.5 can increase the risk of outpatient visits for respiratory disease in Shenzhen.

A quality assessment index framework for public health services: a Delphi study.

OBJECTIVES: This study sought consensus-based indices for quality assessment of the public health service (QAPHS) to evaluate the service quality of public health in Shenzhen and other cities in China. STUDY DESIGN: A qualitative study. METHODS: A list of quality assessment indices was formed based on Donabedian theory. These indices were presented to an expert panel in a two-round Delphi study to establish a consensus view. A weight of indices was established to validate the applicability and practicability of the framework. The specialist authority coefficient and Kendall's W were also calculated based on statistical analysis. RESULTS: A total of 30 experts participated in the Delphi study. Consensus was reached on four first-grade indices, nine second-grade indices and 28 third-grade indices. The specialist authority coefficient (Cr) was high (between 0.88 and 0.92), while Kendall's coefficient (W) of all the indices was ＞0.5 with statistical significant differences (P ＜ 0.05). This indicated correlation among panelists and had high reliability. CONCLUSIONS: A unified and hierarchical quality assessment index framework for public health services was established. The framework should be further tested and improved in practice.

Epidemiological features of hand-foot-and-mouth disease in Shenzhen, China from 2008 to 2010.

This study analysed the spatio-temporal distribution and propagation of hand-foot-and-mouth disease (HFMD) in Shenzhen from 2008 to 2010. Specifically, we examined the epidemiological data, temporal distribution and spatial distribution, and then the relationship between meteorological, social factors and the number of reported HFMD cases was analysed using Spearman's rank correlation. Finally, a geographically weighted regression model was constructed for the number of reported HFMD cases in 2009. It was found that three independent variables, i.e. the number of reported HFMD cases in 2008 and, annual average temperature and precipitation, had different spatial impacts on the number of reported HFMD cases in 2009. In addition, these variables accounted for the propagation mechanism of HFMD in the centre and east of Shenzhen, where the high incidence rate areas are located. These results will be of great help in understanding the spatio-temporal distribution of HFMD and developing approaches to prevent this disease.

Association of variable number of tandem repeat polymorphism in the IL-4 gene with ischemic stroke in the Chinese Uyghur population.

Ischemic stroke (IS) is a multifactorial disorder, and genetic factors act as important contributors to its onset and progression. Inflammation is a key event that is closely associated with the pathophysiology of IS. The association of genetic polymorphisms of inflammatory cytokines with IS remains poorly understood. We investigated the relationship between the variable number of tandem repeats (VNTR) for IL-4, which is an important biomarker of inflammation, and the risk of IS. To assess the nature of the VNTR polymorphism in IL-4 and identify any links with IS, we recruited 200 subjects from a unique population that has 60% European and 40% East Asian ancestry. The subjects comprised 100 IS patients diagnosed using magnetic resonance imaging within 24 h of symptom onset and 100 age-, gender- and ethnicity-matched normal healthy controls. VNTR was identified using high-performance capillary electrophoresis with specially designed tailed primers. The IL-4 VNTR polymorphism was significantly associated with IS after adjustment for cardiovascular risk factors (OR = 0.571, 95%CI = 0.330-0.949, P < 0.05). Our data indicate that IL-4 VNTR polymorphism may affect susceptibility to IS in the Chinese Uyghur population. Moreover, total cholesterol, fasting blood glucose, waist-to-hip ratio, hypertension, history of heart diseases, and negative events may increase the risk of IS, with a trend for HDL to be a protective factor for IS in the Uyghur population.

Estimate of 2009 H1N1 influenza cases in Shenzhen--the biggest migratory city in China.

The 2009 novel H1N1 influenza pandemic had a significant impact on Shenzhen's population with 2063 laboratory-confirmed human H1N1 cases and five deaths being reported. We used parameters from two population-based surveys and the Shenzhen Influenza Surveillance System to estimate the total number of H1N1 influenza infections in Shenzhen in the 2009 pandemic. The attack rate of influenza-like illness (ILI) in family households was 11·2% (95% CI 9·4-13·0), with 80·2% (95% CI 77·8-82·5) seeking medical care. The ILI attack rate in workers was 38·1% (95% CI 34·3-41·7) with 72·5% (95% CI 66·9-78·0) seeking medical care. The average H1N1 positive rate in individuals reporting ILI and testing by polymerase chain reaction was 22·7%. A total of 611 000-768 000 people, or 4·7-5·9% of the Shenzhen population, are estimated to have experienced H1N1 influenza. The estimated total number of cases of H1N1 is likely to be 330 times greater than the number of laboratory-confirmed cases.

Influenza surveillance in Shenzhen, the largest migratory metropolitan city of China, 2006-2009.

Shenzhen is one of the largest migratory metropolitan cities in China. A standardized influenza surveillance system has been operating in Shenzhen for several years. The objectives of the present study were to describe the epidemiology of influenza in Shenzhen and to assess the impact of pandemic H1N1 on influenza activity. An average rate of 71 cases of influenza-like illness (ILI)/1000 consultations was reported, which was greater than the rate in the preceding 3 years. Laboratory surveillance showed that the annual proportion of specimens positive for influenza was 25·4% in 2009, representing a significant increase over the proportions of 5·4%, 11·6% and 12·2% in 2006, 2007 and 2008, respectively. A total of 414 ILI outbreaks were reported in 2009, which was a marked increase compared to the previous 3 years. Influenza activity reached a record high in Shenzhen in 2009. Seasonal A/H3N2 was the dominant strain during the summer and was gradually replaced by pandemic H1N1. A semi-annual cycle for influenza circulation began to appear due to the emergence of pandemic H1N1.

Public health services in Shenzhen: a case study.

As one of the fastest growing cities in Pearl River Delta of southern China, Shenzhen accommodates a higher percentage and increasing number of internal migrants, mainly coming from the inland areas. The public health issues that challenge its local government include the special population structure, high incidence of infectious diseases, high prevalence of mental problems, rising chronic disease burdens, and maternal and children's health issues, although progress has been made in the past years. The health authority of Shenzhen has realized that provision of high quality equitable public health services to its residents, including migrants is of high priority, and should be supported by innovations in the health insurance system and establishment of community-based primary care networks. Making changes within the national-level health reform framework and learning from international experiences are necessary and important.

Induction of diabetes in rhesus monkeys and establishment of insulin administration strategy.

OBJECTIVES: The diabetic rhesus monkey seems to be a useful model for preclinical investigations of islet transplantation and new drug treatments for type 1 diabetes mellitus (T1DM). Information is limited regarding a standard technique to induce and assess diabetes in rhesus monkeys as well as the strategy to apply insulin administration. Herein, we have established and characterized a model of diabetic rhesus macaques. METHODS: Four monkeys were divided into 2 groups of 2 each: group 1, total pancreatectomy; and group 2, partial pancreatectomy (75%) with low-dose streptozotocin (STZ) administration. Pancreatic function was measured using intravenous glucose tolerance tests before the operation. Spiral computed tomography (CT) scans of the pancreas were obtained before and after pancreatectomy. Fasting blood glucose and postprandial blood glucose levels were monitored twice daily using blood samples from the fingers or toes. Various types and doses of insulin were administered twice daily. We performed regular assessments of hematological and serum biochemical parameters, insulin, and C-peptide. RESULTS: Both total pancreatectomy and partial pancreatectomy (75%) with STZ administration induced T1DM in rhesus monkeys; there was interindividual variation in the STZ dose. Excluding C-peptide and insulin, the hematological and serum biochemical parameters did not differ significantly from normal values postoperatively. The various insulin treatment strategies are achieved stable blood glucose (BG) levels. CONCLUSIONS: STZ injection after partial pancreatectomy may be a safe, reproducible method to induce T1DM. Porcine insulin administration was a safe, economical method to control BG levels in a diabetic rhesus monkey before islet transplantation.

Studies on long-term infection of human cells with Porcine endogenous retrovirus.

A major concern in pig-to-human xenotransplantations is the potential risk of transmission of Porcine endogenous retroviruses (PERVs) integrated in the pig genome. Our previous work has shown that PERV provirus genes and gag protein can be detected in human embryonic kidney HEK-293 cells during a long-term infection with PERV (Yu et al., Transplant. Proc. 37, 496-499, 2005). In this study, we continued studying the long-term (>6 months) PERV infection of HEK-293 cells. The results showed no significant differences in morphology, growth, apoptosis, and [(3)H]-thymidine incorporation between PERV-infected and uninfected cells. The PERV LTR sequence showed only an insignifcant mutation after the long-term infection. PERV infection had no effect on the transcription of genes of Human endogenous retrovirus (HERV) naturally occurring in HEK-293 cells. Summing up, this study indicated that a long-term PERV infection of HEK-293 cells in vitro does not result in any significant changes in host cells as well as in PERV LTR sequence.

Mesenchymal stem cells from Chinese Guizhou minipig by hTERT gene transfection.

INTRODUCTION: To provide standard implemental cells for biomedical research, an immortalized mesenchymal stem cell (MSC) lineage was established from the bone marrow of Chinese Guizhou minipigs. We investigated the characteristics of the MSC transfected with hTERT. METHODS: MSCs isolated from bone marrow (BM) were steadily transfected using a plasmid containing human telomerase reverse transcriptase gene (pCI-neo-hTERT) at population doubling (PD) time of 3. The expression of hTERT was analyzed by reverse transcriptase polymerase chain reaction; the morphology of the cells, by phase contrast microscope; cell growth curve, by MTS assay, and phenotype, flow cytometry and immunofluorescence. Karyotype and osteogenic differentiation of transfected cells were compared with normal MSCs. RESULTS: After transfection with the hTERT gene, the MSCs showed vigorous proliferation activity undergoing more than 60 PDs. Expression of the hTERT gene was detected in these cells. Transfected MSCs showed a prolonged life span, maintaining similar morphology and karyotype compared with normal MSCs. The apoptotic rate of transfected MSCs at PD60 was far below that of the normal MSCs at PD15. More than 99% of transfected MSCs were positive for stem cell markers, including SH-2, SH-3, SB-21, and CD29, and negative for CD34, CD45, and SLA-II. Transfected MSCs possessed the ability to differentiate into osteogenic as same as that of normal MSCs. CONCLUSION: The hTERT gene-induced immortalization prolonged the life span of MSCs, maintaining the overall properties identical to the original cells, findings that will be useful for basic research.

cDNA cloning, protein structure modeling of rhesus monkey (Macaca mulatta) prothrombin.

OBJECTIVE: Hemorrhagic diseases have been considered to be one of the main causes of xenotransplantation failure. To explore the role of the rhesus monkey (Macaca mulatta) coagulation system in a pig-to-human xenotransplantation model, we primarily studied the full-length cDNA and the three-dimensional (3-D) structures of the important coagulation factor-prothrombin of the rhesus. MATERIALS AND METHODS: The full-length cDNA of rhesus prothrombin was obtained by rhesus monkey liver cDNA library screening and a 5'RACE technique. The 3-D protein structure was modeled using the SWISS-MODEL program. The important macromolecular interaction sites were compared with human and porcine prothrombin. RESULTS: At first, the full-length rhesus prothrombin cDNA was cloned; the sequence was submitted to the Genebank (accession number: EF057490). The full-length cDNA is 2029 bp, with a complete open reading frame of 1884 bp, coding 626 amino acids. The deduced protein sequence contains a signal peptide, propeptide, Gla domain, two Kringle domains, and a Trypsin domain. The nucleotide similarities of rhesus-human and rhesus-porcine genes are 95.64% and 86.14%, and those of the amino acids, 94.51% and 82.82%, respectively. Some important functional sites, such as the catalytic triad DHS, RGD, Na+ -binding, and the carboxylase-binding site, are highly conserved. However, among the three species some variations are observed in potential N-glycosylation, O-glycosylation, phosphorylation, cleavage site, FXa-binding sites. Especially, the autolysis loop shows great differences in both amino acid sequence and 3-D model. CONCLUSIONS: The great similarity of prothrombin among rhesus, human, and porcine confirmed the great value of the pig-to-rhesus xenotransplantation model. The variation especially in some important recognition sites between rhesus and pig would vary the binding affinity of enzymes to xenosubstrates and their reaction velocities in postoperative coagulation processes, which would be one possible reason for the disordered regulation of clotting seen during the xenorejection in animal models.

Immortalization of mesenchymal stem cells from bone marrow of rhesus monkey by transfection with human telomerase reverse transcriptase gene.

INTRODUCTION: Our previous experiments indicated that bone marrow mesenchymal stem cells of rhesus monkey (RhBMSCs) have a low proliferative ability with a finite life span, which will hamper their application in biomedical research. Establishing an immortalized RhBMSC lineage might solve the problem. METHODS: RhBMSCs isolated from the bone marrow of rhesus monkeys using density gradient centrifugation were purified using adherence separation. Then, the cells were steadily transfected by plasmid containing human telomerase reverse transcriptase gene (pCI-neo-hTERT). We analyzed expression of hTERT, proliferation, phenotype (SH-2, SH-3, SB-10, CD29, CD34, CD45, and HLA-DR), differentiation toward osteogenic lineage, karyotype, and tumorigenesis of transfected cells. RESULTS: After transfection, the RhBMSCs proliferated vigorously, undergoing more than 50 population doublings (PDs). Apoptotic rate of transfected RhBMSCs at PD40 was only 4.5%, versus untransfected RhBMSCs at PD15, which was more than 33.5%. Compared with normal RhBMSC, the life span of transfected RhBMSCs was prolonged, retaining similar morphology, karyotype, and potential to differentiate into an osteogenic lineage. More than 99% of transfected RhBMSCs were positive for stem cell markers, including SH-2, SH-3, SB-10, and CD29, and negative for CD34, CD45, and HLA-DR. Furthermore, the transfected cell line was benign in nude mice tumor formation. CONCLUSION: Our results demonstrated that hTERT gene had been transfected into RhBMSCs. The transfected RhBMSCs proliferated vigorously. Phenotype, differentiation, and karyotype of transfected RhBMSC showed no significant difference from untransfected cells. The transfected RhBMSCs are a potential cell source for transplantation as well as tissue engineering.

A preliminary study on the feasibility of gene expression profile of rhesus monkey detected with human microarray.

OBJECTIVES: A pig-to-monkey transplant model was initiated to investigate the outcome of pig-to-human xenotransplantation. Though monkey is close to human in biology and physiology, the genetic differences between the two species remains unclear. This study sought to compare the gene expressions of three tissues from humans and rhesus monkey. METHODS: RNA samples extracted from liver, spleen, and peripheral blood cells were hybridized onto Illumina gene expression microarray. Genes with detected signals greater than 1000 and diff-scores higher than 100 were selected as significant results. The data were analyzed with Illumina software. mRNA expression levels were confirmed by semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) analysis. RESULTS: Of the 47,293 transcripts tested on every gene chip, more than 6000 genes were expressed in three tissues. Total numbers of genes detected and the similarity ratios followed the same rule as liver < PBC < spleen. The 136 IRI-related genes, 192 immunological-related genes, and 131 cell cycle-related genes selected and analyzed showed gene expression concordance rates of 82.35%, 72.92%, and 77.10%, respectively. RT-PCR tests indicated similar mRNA expression levels of RTN4, interleukin (IL)-1beta, NF-kappaB1, IL-8, and G0S2 to the results on chips. CONCLUSIONS: The detected mRNA expressions in human and monkey tissues showed an average consistency in 85.78%, indicating that a human microarray might provide a part of the information for monkey sample testing. Therefore, in pig-to-monkey transplant models, monkey microarray may be used to determine recipient gene expressions. The genetic difference between human and monkey must be taken into account in interpreting the experimental results.

Transmission of porcine endogenous retrovirus to human cells in nude mouse.

Xenotransplantation is associated with the risk of Porcine endogenous retrovirus (PERV) transmission, since it has been shown that PERV can infect human cells in vitro (Specke et al., Virology 285, 177-180, 2001). We evaluated the possibility of PERV infection of human cells in nude mice model. Porcine kidney cells PK15 carrying PERV and human liver cancer cells SMMC-7721 were injected separately into the right and left axilla of nude mice, respectively. Two months later, pig cytochrome oxidase II (COII) gene, PERV DNA, PERV mRNA, and PERV-Gag protein were detected in the mass formed in both axillas and in several organs of nude mice. The pig COII genes were detected in the right and left axilla, but not in other organs of nude mice implicating that the microchimerism of pig cells occurred in human SMMC-7721 cells and induced the formation of the mass. PERV gene and gag protein were detected in all mouse tissues except liver. These data indicated that (i) PERV may be transmitted from porcine to mouse cells, (ii) PERV genes and proteins were detectable in the mass formed by injection of human cells and consequently (iii) there was a possibility of PERV transmission to human cells after xenotransplantation.