Spatial point pattern analysis of hemorrhagic fever with renal syndrome in Jingzhou, Hubei Province, 2017 / 中华疾病控制杂志

Objective To analyze the spatial point pattern distribution characteristics of hemorrhagic fever with renal syndrome (HFRS) in Jingzhou city, Hubei province during the two seasons spring- summer and autumn-winter of 2017, to discuss its high incidence area and reason, and to provide basis for the resource allocation of public health. Methods The analytical data was collected from Infectious Disease Reporting Information System in China, and the spring-summer season was from March to August of 2017, while the autumn-winter was from the September of 2017 to the February of 2018. The Ripley's K-function and kernel density estimation were applied to analyze the spatial point pattern distribution and compare the distribution characteristics of spatial point pattern between the two seasons. Results In 2017, 133 cases of HFRS were reported in Jingzhou city, including the spring- summer and autumn-winter two pick incidences. The strongest aggregation distance was 17.77km in spring-summer season, and 14.40 km in autumn-winter season. The spatial gathering center was located in the north of Jianli County in spring-summer, and it moved to the south of Jiangling County and Shashi District in autumn-winter. Conclusions The key areas for the prevention and control of HFRS in Jingzhou City are Jiangling County, the southern part of Shashi District and the northern part of jianli county. The key groups are the residents of the urban-rural junction in the southern part of Shashi City, residents along the route of large-scale projects, and farmers engaged in agricultural planting or crayfish breeding in the gathering areas.

[Effects and cost of four formulations of niclosamide ethanolamine salt in Oncomelania hupensis snail control in field].

OBJECTIVE: To investigate the effects and cost of four formulations of niclosamide ethanolamine salt in Oncomelania hupensis snail control in the field in marshland and lake regions, so as to provide the evidence for drawing up the plan of molluscicide using in schistosomiasis endemic areas. METHODS: One drainage channel and one channel without water in the same area with snails in Jiangling County, Jingzhou City were selected as the research fields. The drainage channel was divided into 9 sections, except one section as a blank control group where the natural death rate of snails was observed only, and the remaining 8 sections were taken as the observation groups, where different dosages of 4% niclosamide ethanolamine salt powder, 5% niclosamide ethanolamine salt granules, 25% niclosamide ethanolamine salt suspending agent, 26% metaldehyde and niclosamide ethanolamine salt suspending agent, and 50% niclosamide ethanolamine salt wettable powder were used respectively. The channel without water were divided into 4 sections, except one section as a blank control group, the other 3 segments were taken as the observation groups, where 4% niclosamide ethanolamine salt powder, 5% niclosamide ethanolamine salt granules, and 50% niclosamide ethanolamine salt wettable powder were used respectively. Before and after spraying molluscicide for 7 days and 15 days, the system sampling method was used to observe the effects of snail control. Meanwhile, the unit cost method was used to calculate the costs of the different mulluscicide formulations abovementioned in unit area (1 m2). RESULTS: In the field at the drainage channel, the snail mortality rates of the groups spraying 4% niclosamide ethanolamine salt powder (50 g/m2), 5% niclosamide ethanolamine salt granules (40 g/m2), 25% niclosamide ethanolamine suspending agent, 26% metaldehyde and niclosamide ethanolamine salt suspending agent, and 50% niclosamide ethanolamine salt wettable powder (2 g/m2 and 4 g/m2) for 7 days were 79.52%97.87%, while the rates after spraying for 15 days were 71.00%-96.30%, and compared with those before spraying, the differences were statistically significant (all P < 0.01). For the groups spraying with 2 g/m2 or 4 g/m2 suspending agent as well as wettable powder for 7 days, the snail mortality rates were significantly different (both P < 0.05). In the field at the channel without water, the snail mortality rates of the 3 observation groups after spraying molluscicide for 7 days were 97.14%-100%, while for 15 days were 94.32 %-100%, and compared with the rates before spraying, all the differences were statistically significant (all P < 0.01). The unit costs per 1 m2 of the molluscicide abovementioned were ranged from 0.280 Yuan to 0.416 Yuan. CONCLUSIONS: In marshland area inside embankment, the molluscicide formulations of the powder and granule are suitable for the environments without water or with instability water level, while the molluscicide formulations of the suspended agents and wettable powder are suitable for the water environment. Though the unit cost of powder is the lowest, the molluscicide in this formulation flies away seriously.

The antifungal effect of silver nanoparticles on Trichosporon asahii.

BACKGROUND/PURPOSE: Silver nanoparticles are receiving increasing attention in biomedical applications. This study aims at evaluating the antifungal properties of silver nanoparticles against the pathogenic fungus Trichosporon asahii. METHODS: The growth of T. asahii on potato dextrose agar medium containing different concentrations of silver nanoparticles was examined and the antifungal effect was evaluated using minimum inhibitory concentration. Scanning and transmission electron microscopy were also used to investigate the antifungal effect of silver nanoparticles on T. asahii. RESULTS: Silver nanoparticles had a significant inhibitory effect on the growth of T. asahii. The minimum inhibitory concentration of silver nanoparticles against T. asahii was 0.5 µg/mL, which was lower than amphotericin B, 5-flucytosine, caspofungin, terbinafine, fluconazole, and itraconazole and higher than voriconazole. Silver nanoparticles obviously damaged the cell wall, cell membrane, mitochondria, chromatin, and ribosome. CONCLUSION: Our results demonstrate that silver nanoparticles have good antifungal activity against T. asahii. Based on our electron microscopy observations, silver nanoparticles may inhibit the growth of T. asahii by permeating the fungal cell and damaging the cell wall and cellular components.

[A specific human scFv against malignant melanoma selected from a large human phage antibody library].

AIM: To obtain the specific human scFv against malignant melanoma (MM) using phage antibody library technology. METHODS: The library was panned with a certain kind of MM cells for 4 rounds. The antigen binding activities of random clones were tested by ELISA in order to select specific antibodies, which were then examined by DNA sequence analysis and immunohistochemistry. RESULTS: In ELISA and immunohistochemical staining, the positive clone selected from the 80 random clones was able to bind one kind of MM cell specifically, while not able to bind other irrelavant cells or antigens, such as human's squamous carcinoma cells, keratinocytes, melanocytes, keratin, trypsinase, transferrin and mouse IgG, etc. The antibody's V(H) genes belonged to human IgG V(H)5 subgroup and the V(L) belonged to human V(kappa) subtype determined by DNA sequence analysis. CONCLUSION: One specific human phage antibody against MM cells was obtained by phage display technique, which may be useful for further development of tumor-targeted therapies.