Investigation on plague foci and epidemic risk analysis in Qiaojia County, Yunnan / 中国热带医学

@#Abstract: Objective　A survey on the plague foci in Qiaojia County of Jinsha River Basin was conducted to understand the composition of plague host vectors and the prevalence of plague among animals, to explore the occurrence and epidemic risk of plague, and to provide scientific basis for plague monitoring and control in this area. Methods　Seven villages and towns in Qiaojia County were selected as the research areas, and the cage night method and the clamp line method were used to investigate the small mammals and their surface parasitic fleas. The host animal organs, serum and surface parasitic flea's samples were collected. The plague indicator animal serum was collected simultaneously on the spot, and the collected host animal organs and flea's samples were cultured and detected for Yersinia pestis. The indirect hemagglutination test (IHA) was used to detect the fraction 1 capsular antigen (F1) antibody of the host animal and the indicator animal serum samples. Results　A total of 525 small mammals belonging to 3 orders, 6 families, 12 genera and 23 species were captured. The dominant species in farming areas were Apodemus chevrieri (31.05%), Niviventer confucianus (13.90%) and Anourosorex squamipes Milne-Edwards (11.43%). The dominant species in residential areas were Rattus norvegicus (66.67%) and Rattus tanezumi (20.00%). The rat densities in agricultural and residential areas were 20.98% and 1.00%, respectively. A total of 277 external parasitic fleas belonging to 15 species, 13 genera, 5 families were collected. The dominant species were Palaeopsylla remota (22.02%), Neopsylla specialis specialis (20.58%), Frontopsylla diqingensis (18.77%) and Ctenophthalmus (Sinoctenophthalmus) quadratus (11.55%), and the rat fleas index was 0.53. No Yersinia pestis was isolated from all rodent organs and flea samples. A total of 167 serum samples from dogs and 15 serum samples from rats were collected, and plague F1 antibody was detected by IHA. IHA detection of plague F1 antibody were negative. Conclusions　Qiaojia County has the distribution of the main host and main vector of plague, and the rat density is high, but the rat body flea index is low. There is no positive detection of plague host animals, vector fleas and indicator animals. It can be considered that the risk of plague occurrence and epidemic in the region is not high in the near future. It is necessary to further strengthen the monitoring and control of plague and other rodent-borne diseases in the region.

Dietary fatty acids and risk for Alzheimer's disease, dementia, and mild cognitive impairment: A prospective cohort meta-analysis.

The association between dietary fatty acid intake and Alzheimer's disease (AD), dementia, and mild cognitive impairment (MCI) risk is inconsistent. This meta-analysis examined the effect of dietary fatty acid intake in prospective cohort studies including patients with AD, dementia, and MCI. PubMed, China Biology Medicine (CBM), China National Knowledge Infrastructure (CNKI), Wanfang Data, and VIP Database were systematically searched through September 2020. The random-effects model was used to combine the highest and lowest categories of multivariable adjusted relative risk (RR). Prospective cohort studies that included associations between dietary fatty acid intake and the risk for AD, dementia, or MCI were included. Fourteen studies were included, comprising 54 177 participants: 1696 patients with AD, 1118 patients with dementia, and 2889 with MCI. The pooled RR showed a significant association only between ω-3 polyunsaturated fatty acid (PUFA) intake and MCI risk (RR, 0.86; 95% CI, 0.75-0.98), with no heterogeneity between studies (I2 = 0%). The intake of total fatty acids, saturated fatty acids (SFAs), cholesterol, monounsaturated fatty acids (MUFAs), PUFAs, ω-3 PUFAs, ω-6 PUFAs, docosahexaenoic acids (DHAs), and eicosapentaenoic acids (EPAs) was not significantly associated with AD risk. The intake of total fatty acids, SFAs, MUFAs, PUFAs, and ω-3 PUFAs was not significantly associated with dementia risk. This meta-analysis provided evidence that ω-3 PUFA intake may be negatively associated with MCI risk.

Construction of EVA/chitosan based PEG-PCL micelles nanocomposite films with controlled release of iprodione and its application in pre-harvest treatment of grapes.

A novel nanocomposite poly(ethylene-co-vinyl acetate) (EVA) film with controlled in vitro release of iprodione (ID) was prepared. Chitosan (CS) was used as the reinforcement which enhances the water and oxygen permeability of films. ID loaded poly(ethylene glycol)-poly(ε-caprolactone) (PEG-PCL) (IPP) micelles were used as the drug carrier which endows the films with antifungal and controlled release ability. IPP micelles with spherical shape and uniform size were obtained, and the maximum encapsulation efficacy (EE) was 91.17 ± 5.03% by well controlling the feeding amount of ID. Incorporation CS could improve the oxygen and moisture permeability of films, and the maximum oxygen permeability (OP) and water vapor transmission rate (WVTR) were 477.84 ± 13.03 cc/(m2·d·0.1 MPa) and 8.60 ± 0.25 g m-2 d-1, respectively. After loading IPP micelles, the films showed an improved antifungal ability and temperature-sensitive drug release behavior, and were found to enhance the quality of grapes by pre-harvest spraying.

[Human umbilical cord mesenchymal stem cells with adenovirus-mediated interleukin 12 gene transduction inhibits the growth of ovarian carcinoma cells both in vitro and in vivo].

OBJECTIVE: To study the inhibitory effect of human umbilical cord mesenchymal stem cells (UC-MSCs) infected by a adenoviral vector containing interleukin 12 (IL-12) gene on the proliferation of ovarian carcinoma SKOV3 in vitro and the growth of tumor explants in nude mice. METHODS: Cultured human UC-MSCs were infected with the recombinant adenovirus vector harboring IL-12 gene to establish the IL-12-expressing cell line AdIL-12-MSCs. Western blotting and RT-PCR were used to detect IL-12 expressions in AdIL-12-MSCs at the protein and mRNA levels, respectively. ELISA were used to detect IL-12 content in the supernatant of AdIL-12-MSCs, whose effect on the proliferation and apoptosis of ovarian carcinoma SKOV3 cells was evaluated with MTT assay and flow cytometry, respectively. In a nude mouse model bearing subcutaneous SKOV3 tumor explants, AdIL-12-MSCs were infused via the tail vein and the inhibitory effect on the tumor growth was observed. RESULTS: The exogenous IL-12 gene was successfully transduced into UC-MSCs by the recombinant adenovirus vector, resulting in efficient IL-12 expression in the cell at both the protein and mRNA levels. The supernatant of AdIL-12-MSCs significantly inhibited the proliferation of SKOV3 cells and induced cellular apoptosis in vitro as compared with UC-MSC supernatant. In the tumor-bearing nude mouse model, the transplantation of AdIL-12-MSCs significantly inhibited the growth of SKOV3 tumor explants (P<0.05). CONCLUSION: Human UC-MSCs with IL-12 gene transduction, which express IL-12 at protein and mRNA levels, can inhibit the proliferation and induce apoptosis of ovarian carcinoma SKOV3 cells in vitro, and suppress the growth of ovarian cancer explants in nude mice.