The prevalence of soil transmitted helminths and its influential factors in Shandong Province, China: an analysis of surveillance data from 2016 to 2020.

BACKGROUND: Soil-transmitted helminths (STHs) were previously endemic in Shandong Province, China. This study aimed to analyze the STHs prevalence trend and the natural, social, and human cognitive and behavioural factors influencing the discrepancies between high and low infection levels from 2016 to 2020 in Shandong Province in eastern China. METHODS: STHs surveillance data of Shandong Province from 2016 to 2020 were obtained from China Information Management System for Prevention and Control of Parasitic Diseases. STHs infections were detected by modified Kato-Katz method. Comprehensive information on the natural and social factors, STHs-related knowledge and behaviours were collected through questionnaire surveys. Retrospective spatial scan analysis was performed using SaTScan v10.1 to evaluate any identified spatial clusters of STHs infection for statistical significance and Bayes discriminant analysis was used to discriminate the high or low infection groups of the villages. RESULTS: In total, 72,160 participants were involved in our survey from 2016 to 2020. The overall STHs prevalence rate was 1.13%, with the eastern region of Shandong Province having the highest rate (2.02%). The predominant species was T. trichiura, with the prevalence rate of 0.99% and the ≥ 70-year age group possessed the highest rate of 2.21%. The STHs prevalence rate showed an annual linear downward trend from 2016 to 2020 ([Formula: see text] = 127.600, P < 0.001). Respondents aged ≥ 60 years had the lowest awareness level of STHs-related prevention knowledge (all P < 0.05), and were the most likely to adopt the practice of fertilizing with fresh stool (χ2 = 28.354, P < 0.001). Furthermore, the southern region demonstrated the highest temperature and rainfall level and the lowest GNP and annual net income per capita (all P < 0.05). CONCLUSIONS: There is a remarkable declining in STHs prevalence in Shandong Province from 2016 to 2020. However, the prevalence rates of STHs especially T. trichiura in the southern and eastern regions were still high, and the elderly were more susceptible to be infected with STHs owning to their low awareness level of STHS-related prevention knowledge and high adoption rate of dangerous production and living behaviours. Integrated approaches of health education, environment improvement and behaviour change should be strengthened to obtain a further reduction of STHs prevalence in China.

Advection-Dispersion Behavior for Simulation of H-3 and Pu-238 Transport in Undisturbed Argillaceous Shale of a Near-Surface Repository.

In this study, a column experiment was employed to evaluate the nuclide migration behavior in the surrounding rock medium of a near-surface disposal site in China and to investigate the advection-dispersion behavior of tritium (H-3) and plutonium-238 (Pu-238) in highly weathered argillaceous shale. A reasonable numerical model was selected to fit the experimental breakthrough curves (BTCs) and to obtain the relevant migration parameters. The results show the following: (1) the internal structure of the highly weathered argillaceous shale exhibited heterogeneity, and the nuclide migration BTC showed characteristics of a "curve peak moving forward" and a "tail curve trailing"; (2) compared with other models, the stream tube mode could better fit the BTCs and obtain the average dispersion coefficient , average distribution coefficient , and other parameters; (3) compared to the results of the batch experiment, the distribution coefficient Kd obtained from the column experiment was smaller than that obtained from the batch experiment, which is speculated to be due to the influence of contact time and the contact area between the nuclide and the medium.

Comparative Proteomics Analysis for Elucidating the Interaction Between Host Cells and Toxoplasma gondii.

Toxoplasma gondii, a representative model organism belonging to the phylum Apicomplexa, can infect almost all warm-blooded organisms, including humans. The invasion of host cells via host-parasite interaction is the key step for T. gondii to complete its life cycle. Herein we performed tandem mass tag analysis to investigate global proteomic changes in host cells (human foreskin fibroblasts, HFFs) [HFFs infected with T. gondii (HT) vs. HFFs (H)] and T. gondii [HT vs. T. gondii (T)] during intracellular infection. Overall, 3477 and 1434 proteins were quantified, of which 375 and 1099 proteins were differentially expressed (adjusted p-value < 0.05 and >1.5 or <0.67-fold change) in host cells and T. gondii, respectively. T. gondii invasion relies on the secretion of numerous secretory proteins, which originate from three secretory organelles: micronemes, rhoptries, and dense granules. In the HT vs. T group, few secretory proteins were upregulated, such as microneme proteins (MICs: MIC6, MIC10), rhoptry bulb proteins (ROPs: ROP5, ROP17), and dense granule proteins (GRAs: GRA4, GRA5, GRA12). In contrast, dozens of known secretory proteins were significantly downregulated in T. gondii-infected HFFs. In HFFs, gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed a large number of differentially expressed proteins (DEPs) enriched in metabolic processes and immune-associated signaling pathways, such as NF-κB, cAMP, and Rap1 signaling pathways. Further, in case of T. gondii, DEPs were involved in ribosome biogenesis, citrate cycle, and galactose metabolism, indicating that cell biosynthesis and metabolism of T. gondii were altered after host cell invasion. These findings reveal novel modifications in the proteome of host cells as well as T. gondii, helping us better understand the mechanisms underlying host-parasite interaction.

Protective immunity induced by a DNA vaccine cocktail expressing TgSAG1, TgROP2, and the genetic adjuvant HBsAg against Toxoplasma gondii infection.

Toxoplasma gondii is an intracellular obligate parasitic protozoon that can infect all warm-blooded animals, causing zoonotic toxoplasmosis. So far, there is no commercial toxoplasmosis vaccine for human use. In the present study, we constructed a DNA vaccine cocktail which includes the surface protein (SAG1) and the rhoptry protein ROP2 denoted as pEGFP-N1-SAG1-ROP2. In order to improve the efficacy, HBsAg was used as a genetic adjuvant to construct pEGFP-N1-HBsAg-SAG1-ROP2. Two eukaryotic plasmids were transiently transfected into HEK293T cells and the expression was examined using fluorescence microscopy and western blotting. We then immunized Kunming mice intramuscularly with the DNA vaccine. After three immunizations, the immune response was evaluated by measuring antibody levels, cytokine production, percentages of CD4+ and CD8+ T lymphocytes, and the survival times of the T. gondii RH strain challenged mice. The results showed that the two DNA vaccines stimulated Th1 responses, and had a higher antibody titer, IL-2, IL-12, and IFN-γ levels, and percentage of CD4+ and CD8+ T lymphocytes than the control group. In addition, mice immunized with the pEGFP-N1-HBsAg-SAG1-ROP2 vaccine showed increased survival times compared with pEGFP-N1-SAG1-ROP2.

Mutation Profile of pfdhfr and pfdhps in Plasmodium falciparum among Returned Chinese Migrant Workers from Africa.

We evaluated markers of sulfadoxine-pyrimethamine (SP) resistance in Plasmodium falciparum among 254 returned migrant workers in China from Africa from 2013 to 2016. High prevalences of pfdhfr (97.2%) and pfdhps (96.5%) mutations were observed. The partially resistant genotype was homogeneously distributed in Africa with a modestly high prevalence (48%), whereas the super resistant genotype was only found in West Africa with a very low frequency (1.2%). The findings provided baseline data about the molecular markers of SP resistance.

Increasing number of imported Plasmodium ovale wallikeri malaria in Shandong Province, China, 2015-2017.

Since 2012, no indigenous malaria case have been reported in Shandong Province, China, whereas the number of imported cases and the genetic diversity of Plasmodium spp. have increased. Beginning in 2015, the number of Plasmodium ovale cases were increased and the P. ovale wallikeri malaria case began to arise. From 2015 to 2017, a total of 676 imported malaria cases were detected and 76 P. ovale spp. isolates were identified, of which 48 were P. ovale curtisi and 28 P. ovale wallikeri. The number of P. ovale wallikeri malaria cases increased yearly, six were identified in 2015, eight were identified in 2016, and 14 were identified in 2017. All cases with an attached travel history from Africa, with represented source countries of Equatorial Guinea (n = 9), Republic of the Congo (n = 4), and Democratic Republic of the Congo (n = 3). P. ovale wallikeri is increasing among travelers returning to Shandong Province from Africa. Although the P. ovale spp. infection rarely progressed to severity, this species is suspected to generate hypnozoites which have the potential to relapse. The ability to cause relapse is the threat to public health and should be concerned.

Protective immune response against Toxoplasma gondii elicited by a novel yeast-based vaccine with microneme protein 16.

Toxoplasma gondii is an obligate intracellular protozoan that can invade all eukaryotic cells and infect all warm-blood animals, causing the important zoonosis toxoplasmosis. Invasion of host cells is the key step necessary for T. gondii to complete its life cycle and microneme proteins play an important role in attachment and invasion of host cells. Microneme protein 16 (TgMIC16) is a new protective protein in T. gondii and belongs to transmembrane microneme proteins (TM-MIC). The TM-MICs are released onto the parasite's surface as complexes capable of interacting with host cell receptors. In the present study, we expressed the TgMIC16 protein on the surface of Saccharomyce cerevisiae (pCTCON2-TgMIC16/EBY100) and evaluated it as a potential vaccine for BALB/c mice against challenge infection with the RH strain of T. gondii. We immunized BALB/c mice both orally and intraperitoneally. After three immunizations, the immune response was evaluated by measuring antibody levels, lymphocyte proliferative responses, percentages of CD4+ and CD8+ T lymphocytes, cytokine production, and the survival times of challenged mice. The results showed that the pCTCON2-TgMIC16/EBY100 vaccine stimulated humoral and cellular immune responses. In addition, mice immunized with the pCTCON2-TgMIC16/EBY100 vaccine showed increased survival times compared with non-immunized controls. In summary, TgMIC16 displayed on the cell surface of S. cerevisiae could be used as potential vaccine against toxoplasmosis.

Design of a sorbent to enhance reactive adsorption of hydrogen sulfide.

A series of novel zinc oxide-silica composites with three-dimensionally ordered macropores (3DOM) structure were synthesized via colloidal crystal template method and used as sorbents for hydrogen sulfide (H2S) removal at room temperature for the first time. The performances of the prepared sorbents were evaluated by dynamic breakthrough testing. The materials were characterized before and after adsorption using scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). It was found that the composite with 3DOM structure exhibited remarkable desulfurization performance at room temperature and the enhancement of reactive adsorption of hydrogen sulfide was attributed to the unique structure features of 3DOM composites; high surface areas, nanocrystalline ZnO and the well-ordered interconnected macroporous with abundant mesopores. The introduction of silica could be conducive to support the 3DOM structure and the high dispersion of zinc oxide. Moisture in the H2S stream plays a crucial role in the removal process. The effects of Zn/Si ratio and the calcination temperature of 3DOM composites on H2S removal were studied. It demonstrated that the highest content of ZnO could reach up to 73 wt % and the optimum calcination temperature was 500 °C. The multiple adsorption/regeneration cycles showed that the 3DOM ZnO-SiO2 sorbent is stable and the sulfur capacity can still reach 67.4% of that of the fresh sorbent at the fifth cycle. These results indicate that 3DOM ZnO-SiO2 composites will be a promising sorbent for H2S removal at room temperature.

Pichia pastoris expressed EtMic2 protein as a potential vaccine against chicken coccidiosis.

Chicken coccidiosis caused by Eimeria species leads to tremendous economic losses to the avian industry worldwide. Identification of parasite life cycle specific antigens is a critical step in recombinant protein vaccine development against Eimeria infections. In the present study, we amplified and cloned the microneme-2 (EtMIC2) gene from Eimeria tenella wild type strain SD-01, and expressed the EtMic2 protein using Pichia pastoris and Escherichia coli expression systems, respectively. The EtMic2 proteins expressed by P. pastoris and E. coli were used as vaccines to immunize chickens and their protective efficacies were compared and evaluated. The results indicated that both P. pastoris and E. coli expressed EtMic2 proteins exhibited good immunogenicity in stimulating host immune responses and the Pichia expressed EtMic2 provided better protection than the E. coli expressed EtMic2 did by significantly increasing growth rate, inducing high specific antibody response, reducing the oocyst output and cecal lesions. Particularly, the Pichia expressed EtMic2 protein exhibited much better ability in inducing cell mediated immune response than the E. coli expressed EtMic2.

Display of heterologous proteins on the Saccharomyces cerevisiae surface display system using a single constitutive expression vector.

In this study, we constructed a novel and simple yeast surface display system with a single expression vector. The newly established system uses a bidirectional expression vector carrying the AGA1 gene driven by the PGK1 promoter in one direction and the AGA2-expression cassette driven by the TEF1 promoter in the reverse direction, and uses the geneticin, a G418-resistant gene, as the selection marker for transformants. Because all the display elements are put into one expression vector, the new system is much simpler to use, and there is no need for any genetic modification of the host strains; therefore, the new system can be used in wild type as well as laboratory strains of Saccharomyces cerevisiae. The display efficiency of heterologous proteins using the new system has been confirmed by displaying enhanced green fluorescent protein and Eimeria tenella (a chicken protozoan parasite) microneme protein2 (EtMic2) on several S. cerevisiae strains. We also tested the new system with an aga2 mutant strain of S. cerevisiae. The results indicate that the native expressed Aga2 protein has no effect on the display efficiency of heterologous proteins.

Display of Eimeria tenella EtMic2 protein on the surface of Saccharomyces cerevisiae as a potential oral vaccine against chicken coccidiosis.

S. cerevisiae is generally regarded as safe and benign organism and its surface display system may be used as a unique eukaryotic expression system that is suitable for expressing eukaryotic antigen. In addition to the convenience of vaccine delivery, the yeast cell wall has been shown to enhance the innate immunity when immunized with the yeast live oral vaccine. In the present study, we expressed the chicken coccidian E. tenella EtMic2, a microneme protein, on the surface of the S. cerevisiae and evaluated it as a potential oral vaccine for chicken against E. tenella challenge. The protective efficacy against a homologous challenge was evaluated by body weight gains, lesion scores and fecal oocyst shedding. The results showed that the live oral vaccine can improve weight gains, reduced cecal pathology and lower oocyst fecal shedding compared with non immunized controls. In addition, the yeast oral vaccine could stimulate humoral as well as cell mediate immune responses. These results suggested that EtMic2 displayed on the cell surface of S. cerevisiae could be used as potential live vaccine against chicken coccidiosis.

The establishment of Saccharomyces boulardii surface display system using a single expression vector.

In the present study, an a-agglutinin-based Saccharomyces boulardii surface display system was successfully established using a single expression vector. Based on the two protein co-expression vector pSP-G1 built by Partow et al., a S. boulardii surface display vector-pSDSb containing all the display elements was constructed. The display results of heterologous proteins were confirmed by successfully displaying enhanced green fluorescent protein (EGFP) and chicken Eimeria tenella Microneme-2 proteins (EtMic2) on the S. boulardii cell surface. The DNA sequence of AGA1 gene from S. boulardii (SbAGA1) was determined and used as the cell wall anchor partner. This is the first time heterologous proteins have been displayed on the cell surface of S. boulardii. Because S. boulardii is probiotic and eukaryotic, its surface display system would be very valuable, particularly in the development of a live vaccine against various pathogenic organisms especially eukaryotic pathogens such as protistan parasites.

[Three-dimensional construction of the relation between the anterior branches of lumbar nerves 4, 5, lumbosacral trunk and sacroiliac joint].

OBJECTIVE: To construct a three-dimensional model to demonstrate the relation between the anterior branches of lumbosacral 4,5, lumbosacral trunk, and the pelvis. METHODS: An formaldehyde-fixed adult cadaver was dissected to expose the anterior branches of the lumbar nerves 4 and 5, lumbosacral trunk and the sacroiliac. The mixture of titanium powder and adhesive was smeared on the surface of the major branches of L4 and L5 nerves, lumbosacral trunk, femoral nerves and obturator nerves. As soon as the mixture solidified, the specimen was scanned by spiral CT at 3 mm intervals to obtain 159 two-dimensional sectional images for three-dimensional model reconstruction on a personal computer using the software 3-D DOCTOR. RESULTS AND CONCLUSION: The reconstructed model can well demonstrate the spatial relation between the nerves and the pelvis, and allows rotation in every direction, which at the same time can be conveniently applied for purpose of clinical teaching.

[Clinical applications of the postfemur island flap pedicled with the postfemur neurocutaneous nutrient vessel].

OBJECTIVE: To investigate the application of the island flap based on the postfemur neurocutaneous nutrient vessel. METHODS: The flap was designed and applied to repair the defects in the gluteal, popliteal fossa or the bilateral postfemur areas. A total of 11 cases (12 defects) were treated with this method. The size of the defects ranged from 4.0 cm x 7.8 cm to 8.3 cm x 16.6 cm. RESULTS: Of the 12 defects, 9 achieved complete success. Epidermal necrosis occurred in the distal part of the flap in 3 defects owing to venous stasis, which were cured with skin grafting. Postoperative follow-up for 8-19 months showed that the appearance, texture, and function of the flap were satisfactory. CONCLUSIONS: The advantages of the flap lie in the reliable blood supply, constant anatomy, and without sacrificing a major artery. The key points for the flap survival are utilizing the "Superficial vein-nutrient vessel of the cutaneous nerve system" and retaining a comet tail-shaped soft-tissue pedicle in the flap creation.

Construction of dataset for Virtual Chinese Male No.1.

OBJECTIVE: To establish digitized Virtual Chinese Human Male No.1 (VCH-M1) image dataset with a 0.2-mm equal interval. METHODS: The body of a 24-year-old male was used for this study. Perfusion with phenol and vermilion of the arteries was performed, followed by body shape adjustment by cold saline and pre-embedding with broken ices in an upside-down position, which was completed in a stepwise procedure to minimize body shape deformation. Section milling was conducted subsequently with the section thickness of 2 mm and the section images were captured by digital camera, which were immediately transferred to a computer for storage and processing. RESULTS: A total of 9 232 sections were obtained for the whole body, and the resolution of each of the image in TIF format was 3 024x2 016 pixels, resulting in the size of approximately 18 M for each image and about 161 G for the whole dataset. CONCLUSIONS: Compared with VCH-F1, the image quality in VCH-M1 dataset is significantly improved, demonstrated by much clearer tissue boundary in the images and minimized body shape deformation during the embedding process.