Spatiotemporal patterns and risk factors concerning hepatitis B virus infections in the Beijing-Tianjin-Hebei area of China.

Beijing-Tianjin-Hebei is the largest urban agglomeration in northern China, but the spatiotemporal patterns and risk factors concerning hepatitis B virus (HBV) incidence in this area have been unclear. The present study aimed to reveal the spatiotemporal epidemiological features of HBV infection and quantify the association between HBV infection and socio-economic risk factors. The data on HBV cases in Beijing-Tianjin-Hebei from 2007 to 2012 was collected for each county. The Bayesian space-time hierarchy model and the GeoDetector method were used to reveal spatiotemporal patterns and detect risk factors. High-risk regions were mainly distributed in the underdeveloped rural areas in the north and mid-south of the study region, while low-risk regions were mainly distributed in the urban and western areas. The HBV annual incidence rate decreased substantially over the 6-year period, dropping from 7.34/105 to 5.51/105. Compared with this overall trend, 38.5% of high-risk counties showed a faster decrease, and 35.9% of high-risk counties exhibited a slower decrease. Meanwhile, 29.7% of low-risk counties had a faster decrease, and 44.6% of low-risk counties exhibited a slower decrease. Socio-economic factors were strongly associated with the spatiotemporal patterns and variation. The population density and gross domestic product per capita were negatively associated with HBV transmission, with determinant powers of 0.17 and 0.12, respectively. The proportion of primary industry and the number of healthcare workers were positively associated with the disease incidence, with determinant powers of 0.11 and 0.8, respectively. The interactive effect between population density and the other factors exerted a greater influence on HBV transmission than that of these factors measured independently.

Spatiotemporal risk mapping of hand, foot and mouth disease and its association with meteorological variables in children under 5 years.

Hand, foot and mouth disease (HFMD) risk has become an increasing concern in the Beijing-Tianjin-Hebei region, which is the biggest urban agglomeration in north-eastern Asia. In the study, spatiotemporal epidemiological features of HFMD were analysed, and a Bayesian space-time hierarchy model was used to detect local spatial relative risk (RR) and to assess the effect of meteorological factors. From 2009 to 2013, there was an obvious seasonal pattern of HFMD risk. The highest risk period was in the summer, with an average monthly incidence of 4·17/103, whereas the index in wintertime was 0·16/103. Meteorological variables influenced temporal changes in HFMD. A 1 °C rise in air temperature was associated with an 11·5% increase in HFMD (corresponding RR 1·122). A 1% rise in relative humidity was related to a 9·51% increase in the number of HFMD cases (corresponding RR 1·100). A 1 hPa increment in air pressure was related to a 0·11% decrease in HFMD (corresponding RR 0·999). A 1 h increase in sunshine was associated with a 0·28% rise in HFMD cases (corresponding RR 1·003). A 1 m/s rise in wind speed was related to a 6·2% increase in HFMD (corresponding RR 1·064). High-risk areas were mainly large cities, such as Beijing, Tianjin, Shijiazhuang and their neighbouring areas. These findings can contribute to risk control and implementation of disease-prevention policies.

[Analysis of clinical effects of artificial dermis in functional reconstruction in the late stage of extremely severe burn].

Objective: To explore the clinical effects of artificial dermis combined with autologous split-thickness skin transplantation in the treatment of functional reconstruction in the late stage of extremely severe burn. Methods: From May 2015 to May 2017, medical records of 40 patients with limited activity after scar hyperplasia and conforming to the study criteria, injured in August 2nd Kunshan factory aluminum dust explosion accident in 2014, and had surgeries in our hospital and rehabilitation treatment in our hospital's alliance rehabilitation hospital, Rehabilitation Hospital of Kunshan Zhou City, were retrospectively analyzed. According to the treatment methods, 20 patients (12 males and 8 females, aged 20 to 45 years) were enrolled in artificial dermis group. They were conducted with stage Ⅰ functional site scar loosening and artificial dermis (PELNAC) implanting+ stage Ⅱ transplantation of autologous split-thickness skin. Another 20 patients (14 males and 6 females, aged 20 to 45 years) were enrolled in conventional skin grafting group. They were conducted with stage Ⅰ functional site scar loosening and transplantation of autologous thin medium-thickness skin. After 5 days of autologous skin transplantation, the survival rates of autologous skin in patients of 2 groups were calculated. The autologous skin infection and complete healing time of skin grafting area in patients of 2 groups were recorded. In 3, 6, and 10 months after autologous skin transplantation, the Vancouver Scar Scale (VSS) was used to assess the scar condition of recipient site in patients of 2 groups. The complete healing time of donor site in patients of 2 groups was recorded. In 10 months after autologous skin transplantation, VSS was used to assess the scar condition of donor site in patients of 2 groups. In 12 months after autologous skin transplantation, the functional recovery of surgical function reconstruction site in patients of 2 groups was evaluated and rated. Data were processed with t test, analysis of variance for repeated measurement, Wilcoxon rank-sum test, chi-square test, Fisher's exact probability test, and Bonferroni correction. Results: (1) After 5 days of autologous skin transplantation, the survival rate of autologous skin in patients of artificial dermis group was (95±3)%, similar to (93±3)% in conventional skin grafting group (t=1.262, P>0.05). The results of autologous skin infection of patients in the 2 groups were similar (P>0.05). (2) After autologous skin grafting, the complete healing time of skin grafting area in patients of artificial dermis group was (12.3±2.5) d, similar to (12.7±2.0) d of conventional skin grafting group (t=-0.139, P>0.05). In 3, 6, and 10 months after autologous skin transplantation, the VSS scores of scars in recipient site of patients in artificial dermis group were significantly lower than those of conventional skin grafting group (t=-4.428, -5.655, -6.839, P<0.01). (3) After autologous skin grafting, the complete healing time of donor site in patients of artificial dermis group was obviously shorter than that in conventional skin grafting group (t=-12.435, P<0.01). In 10 months after autologous skin transplantation, the VSS score in donor site of patients in artificial dermis group was significantly lower than that of conventional skin grafting group (t=-16.971, P<0.01). (4) After 12 months of autologous skin transplantation, the functional improvement levels of the functional site of patients in artificial dermis group were good in 4 patients, fair in 15 patients, and bad in 1 patient, while the functional improvement levels of the functional site of patients in conventional skin grafting group were good in 5 patients, fair in 8 patients, and bad in 7 patients. The functional improvement levels of the functional site of patients between the two groups were similar (Z=371.5, P>0.05). Conclusions: Compared with conventional stage Ⅰ functional site scar loosening and transplantation of autologous thin medium-thickness skin, stage Ⅰ functional site scar loosening and artificial dermis implanting+ stage Ⅱ transplantation of autologous split-thickness skin does not affect the survival of skin in the early stage and can effectively improve functional site function, reduce VSS scores of donor site and recipient site, and shorten complete healing time of donor site.

[Application of spatial statistics in studying the distribution of food contamination].

Objective: Based on data related to arsenic contents in paddy rice, as part of the food safety monitoring programs in 2017, to discuss and explore the application of spatial analysis used for food safety risk assessment. Methods: One province was chosen to study the spatial visualization, spatial point model estimation, and kernel density estimation. Moran's I statistic of spatial autocorrelation methods was used to analyze the spatial distribution at the county level. Results: Data concerning the spatial point model estimation showed that the spatial distribution of pollution appeared relatively dispersive. From the kernel density estimation, we found that the hot spots of pollution were mainly located in the central and eastern regions. The global Moran's I values appeared as 0.11 which presented low spatial aggregation to the rice arsenic contamination and with statistically significant differences. One "high-high" and two typical "low-low" clustering were seen in this study. Conclusion: Results from our study provided good visual demonstration, identification of pollution distribution rules, hot spots and aggregation areas for research on the distribution of food pollutants. Spatial statistics can provide technical support for the implementation of issue-based monitoring programs.

[Review and prospect of burn medicine of China in 60 years].

Burn medicine of China started in 1958. Great progress has been achieved in discipline construction, scientific research, clinical treatment level, and talent team construction in 60 years. A large number of severely burned patients have been successfully treated, and plans for treatment of burn patients with Chinese characteristics have been established with world-leading treatment level. At the same time, in the continuous improvement of clinical treatment level, extensive experimental researches for the key scientific problems in clinical treatment of burn patients have been conducted, and a large number of innovative research results have been achieved by Chinese burn medicine workers. The theoretical research of burn medicine in China has stepped into advanced ranks of the world. Burn medicine will confront development opportunity and tough challenge in the future. We can take advantage of wound repair of burn discipline to deal with the situation of decreasing incidence of burn and undiminished importance of burn medicine. To establish and improve the chain of burn treatment is an important direction for burn discipline development in the future.

[Downscaling research of spatial distribution of incidence of hand foot and mouth disease based on area-to-area Poisson Kriging method].

Objective: To understand the spatial distribution of incidence of hand foot and mouth disease (HFMD) at scale of township and provide evidence for the better prevention and control of HFMD and allocation of medical resources. Methods: The incidence data of HFMD in 108 counties (district) in Shandong province in 2010 were collected. Downscaling interpolation was conducted by using area-to-area Poisson Kriging method. The interpolation results were visualized by using geographic information system (GIS). The county (district) incidence was interpolated into township incidence to get the distribution of spatial distribution of incidence of township. Results: In the downscaling interpolation, the range of the fitting semi-variance equation was 20.38 km. Within the range, the incidence had correlation with each other. The fitting function of scatter diagram of estimated and actual incidence of HFMD at country level was y=1.053 1x, R(2)=0.99. The incidences at different scale were consistent. Conclusions: The incidence of HFMD had spatial autocorrelation within 20.38 km. When HFMD occurs in one place, it is necessary to strengthen the surveillance and allocation of medical resource in the surrounding area within 20.38 km. Area to area Poisson Kriging method based downscaling research can be used in spatial visualization of HFMD incidence.

Effects of early enteral feeding on the prevention of enterogenic infection in severely burned patients.

The aim of the study was to analyse the effects of early enteral feeding on the prevention of enterogenic infection in severely burned patients. A total of 22 patients with severe burns were randomly divided into an early enteral feeding group (EF) and a delayed enteral feeding group (DF). The levels of serum endotoxin and TNF-alpha were dynamically detected in the members of both groups, and two unmetabolized sugars (lactulose and mannitol) were orally administered to these patients 1, 3 and 5 days postburn. Intestinal permeability was evaluated by detecting the concentrations of lactulose and mannitol in the urine and the lactulose-mannitol ratio (L/M) ratio. The levels of serum endotoxin and TNF-alpha in severely burned patients were significantly higher than in normal subjects (P<0.01). The endotoxin level was positively related to the TNF-alpha level (rEF=0.93, P<0.01; rDF=0.80, P<0.05). The urinary lactulose levels in both groups were significantly higher than in normal (P<0.01), the urinary mannitol levels showed no obvious changes (P>0.05). The urinary L/M ratios in both groups were significantly higher than in normal subjects (P<0.01). The urinary L/M ratio was positively related to the serum endotoxin level (r=0.95, P<0.01). The urinary lactulose levels and the urinary L/M ratios in the EF group were significantly lower than in the DF group (P<0.01). The levels of serum endotoxin and TNF-alpha in the EF group were significantly lower than in the DF group (P<0.01). It is suggested that intestinal permeability was markedly higher after burns than normal, and was positively related to the gut-derived endotoxemia. Early enteral feeding may decrease intestinal permeability, preserve the intestinal mucosal barrier and have a beneficial effect on the reduction of enterogenic infection.

Control of endotoxemia in burn patients by use of polymyxin B.

A group of patients with severe burns were entered into two sequential prospective randomized trials for reduction of endotoxemia by the use of intravenous polymyxin B. The first group underwent polymyxin administration during the first week after burn injury in a bell-shaped dosage form constructed to resemble the level of endotoxemia as previously documented. This group showed a statistically highly significant reduction in endotoxin levels and a suggestive, but not statistically significant, reduction in wound infection and mortality in the treated group compared with controls. The second group of patients underwent treatment with perioperative polymyxin B given in conjunction with an excisional procedure of the burn wound. In this group, polymyxin B also accomplished a reduction in endotoxemia from preoperative to postoperative cases, but there was no significant reduction in clinical complication rate or mortality. In the dosages used, polymyxin B is nontoxic and promises to be a useful part of the surgeon's armamentarium in dealing with severe complications of gram-negative sepsis.

[Relationship between gut origin bacteria and wound infection after thermal injury].

The pUC19 plasmid vector trace with restriction map analysis and fluorescence labelling bacteria method were applied to study the relationship between the gut origin bacteria and wound infection. According to the characteristic of pUC19 plasmid, a special animal model was designed. 110 Wistar rats received 30% TBSA full thickness burns. On hours 6, 12, 24, 48 and day 12 postburn, injured animal were killed. Subeschar tissue homogenates were examined under fluorescence microscope, and bacterial culture, isolation of plasmids and restriction map analysis were also carried out. The results show that during early stage of burns, 32.5% of fluorescence labelling bacteria and 10.81% of pUC19 plasmid vectors could be detected from the subeschar specimens. 12 day postburn, the detectable rage of pUC19 plasmid vector increased to 62.5%. Beside the factor of early colonization, the contaminative route form gut perineum and then wounds should be considered.

[Role of nitric oxide in pathogenesis of pregnancy induced hypertension].

OBJECTIVE: We attempted to investigate the role of nitric oxide(NO) in pathogenesis of pregnancy-induced hypertension(PIH). METHODS: No-nitro-L-arginine-methyl ester(L-NAME) was used to inhibit nitric oxide synthase(NOS) in pregnant rats. Indices including blood pressure, urine protein concentration, pup weight, serum NO level and plasma ET-1 level were measured. Nitroglycerin, a nitric oxide donor, was used to observe its impact on the effect of L-NAME at the same time. RESULTS: Infusion of L-NAME elevated blood pressure, increased urine protein concentration, decreased pup weight, decreased serum NO level and raised plasma ET-1 level(P < 0.01, respectively); However in the L-NAME-treated animals nitroglycerin significantly lowered blood pressure, decreased urine protein concentration, increased pup weight, increased serum NO level and decreased plasma ET-1 level(P < 0.01, respectively). CONCLUSIONS: 1. Infusion of L-NAME, an inhibitor of NOS, causes decreased serum NO level and some signs similar to preeclampsia such as hypertension, proteinuria and intrauterine growth retardation(IUGR). Nitroglycerin can reverse the lesions induced by the treatment of L-NAME. These findings indicate that reduced level of NO may be a factor responsible for PIH. 2. NO can decrease the plasma ET-1 level. NO may regulate the process of PIH via ET-1 pathway. It may be one mechanism for NO. 3. An useful animal model for PIH is provided to test novel therapeutic and preventive strategies.

[Intestinal lymphatic circulation is one of the important portals for microbial translocation after thermal injury].

The goal of this study was to determine whether the bacteria and endotoxin from GI tract could pass through the intestinal lymph circulation to the systemic circulation after severe thermal injury. Lymphatic fistula of intestine was created in 46 Wistar rats the rats were then divided randomly in scald and control groups. In scald group, animals were sustained with 30% TBSA full-thickness scald. The items studied were, the dynamic changes in intestinal lymph endotoxin level, the qualitative and quantitative bacterial culture, and pathological alterations in ileal mucosa within 24 hours postburn. Results showed that the levels of intestinal lymph endotoxin and the positive culture rate and counting of bacteria were evidently increased, and ileal mucosal lacteals were dilated and epithelial cells were necrotic and denudated in scald group. These suggested that the intestinal lymph circulation is one of the important portals for endotoxin and microbial translocation after severe thermal injury, and the intestinal mucosal damage is an important factor in pathogenesis.

Altered expression of lymphocyte Il-2 receptors in burned patients.

Impairment of T-cell function is a consistent observation in burned patients. Concomitant with this impairment is an increase in serum factors which inhibit interleukin-2-mediated T-cell functions. These factors are heat labile and do not behave like endotoxins. Nonetheless, treatment of burned patients with endotoxin-neutralizing regimens of polymyxin B reduces the levels of these factors, suggesting that they are generated in response to endotoxin exposure. In addition to factors which inhibit Il-2 responses burn serum contains increases of circulating soluble, cell-free Il-2 receptors. However, the level of Il-2R is not altered by polymyxin B treatment and does not appear to be a direct result of endotoxin exposure. These observations suggest that multiple causes contribute to T-cell impairment in burned patients.

Anaerobic infections of burns.

From August 1980 to June 1982, 102 burn wound specimens taken from 34 patients were studied for anaerobic cultures. Fifteen instances (14.7 per cent) from 8 patients were positive and altogether 12 species were found. The predominant anaerobes were Bacteroides melaninogenicus, Peptococcus, Bacteroides fragilis, and other strains of Bacteroides and Peptostreptococcus. They were mostly discovered in electric burn wounds and burn wounds affecting the perianal and oral areas. Wounds with anaerobic infection usually appeared gaseous, necrotic and ischaemic with foul odour. Nineteen blood samples from 10 burn patients were also studied for anaerobic cultures, and two were positive, one caused by Bacteroides and the other by mixed infection of Peptococcus and Serratia, indicating that the anaerobes played an important role in burn infections. It seems necessary to perform anaerobic culture studies in burn patients as a routine. A comparative study between anaerobic culture and indirect immuno-fluorescence method was undertaken for Bact. fragilis and Bact. melaninogenicus in 47 burn wounds. It showed that the immunofluorescence method was a more rapid, simple, sensitive and specific diagnostic method.

Endogenous microbial dissemination following severe burns in rats.

This study suggests that damage to the intestinal lining, an important mechanical barrier against bacterial invasion, is the main factor leading to the dissemination of endogenous microbes. Reduced phagocytic activity of Kupffer cells and compromised opsonic function also appear to contribute to the process.

Further evaluation of one-point microcapsule agglutination test for diagnosis of leptospirosis.

A total of 100 serum samples including 22 acute phase sera and 39 paired sera collected from clinically diagnosed cases of leptospirosis in Ming-shan County, Sichuan Province, China were examined by the one-point microcapsule agglutination test (MCAT), which was developed in Japan, and by conventional microscopic agglutination tests (MAT). The one-point MCAT is more reactive to IgM antibody than MAT and is superior in detecting antibodies in the early stages of the disease.