[Centromere protein U is highly expressed in colorectal cancer and associated with a poor long-term prognosis]

OBJECTIVE

To analyze the expression of centromere protein U (CENPU) in colorectal cancer and its predictive value for long-term prognosis of the patients.

METHODS

We retrospectively analyzed the data of 102 patients with colorectal cancer undergoing radical resection in our hospital between January, 2005 and December, 2011. The expression level of CENPU in colorectal cancer tissue was detected immunohistochemically, and its association with clinicopathological characteristics of the patients were analyzed. The patients were divided into low expression group (n=51) and high expression group (n=51) based on the median CENPU expression level for analysis the value of CENPU for predicting long-term prognosis of the patients after radical resection of the tumors. In the in vitro study, we constructed colorectal cancer cell lines with CENPU interference and CENPU overexpression by lentiviral transfection and assessed the changes in the proliferation, migration and invasion of the cells using CCK-8 assay and Transwell assay.

RESULTS

The protein expression level of CENPU was significantly higher in colorectal cancer tissues than in the adjacent tissues (P < 0.05) and was positively correlated with the expressions levels of Ki67 (r=0.569, P < 0.05) and VEGF-C (r=0.629, P < 0.05). CENPU expression level in colorectal cancer tissue was closely related with tumor progression and clinicopathological stage of the tumor (P < 0.05). Kaplan-Meier survival analysis showed that the patients with high CENPU expression had significantly decreased postoperative overall survival (χ²=11.155, P < 0.05); Cox multivariate regression analysis suggested that CENPU expression level was an independent risk factor affecting the overall survival of the patients after radical resection (HR=1.848, P < 0.05). The results of cell experiments demonstrated that high CENPU expression significantly promoted the proliferation, migration and invasion of the tumor cells.

CONCLUSION

CENPU is highly expressed in colorectal cancer tissues in closely correlation with tumor progression and may serve as a potential biomarker for evaluating the long-term prognosis of colorectal cancer patients.

Histidine acid phosphatase domain-containing protein from Haemonchus contortus is a stimulatory antigen for the Th1 immune response of goat PBMCs

Background

Histidine acid phosphatase (HAP), a member of the histidine phosphatase superfamily, is widely found in parasites and is also a potential vaccine antigen or drug target. However, the biological function of HAP in Haemonchus contortus is still unclear.

Methods

We cloned the HAP gene from H. contortus (Hc-HAP) and expressed the purified recombinant Hc-HAP (rHc-HAP) protein. The transcription of the Hc-HAP gene in the eggs, infective third-stage larvae (L3s), exsheathed third-stage larvae (xL3s) and adults (females/males) was analyzed by quantitative real-time-PCR (qPCR). An immunofluorescence assay was also used to detect the localization of Hc-HAP expression in adult worms. The effect of rHc-HAP on the function of peripheral blood mononuclear cells (PBMCs) was observed by co-culture of rHc-HAP protein with goat PBMCs.

Results

The qPCR results revealed that the Hc-HAP gene was transcribed at a higher level in the L3 and xL3 stages that there were gender differences in transcription at the adult stage, with females exhibiting higher transcription than males. Moreover, Hc-HAP was mainly expressed in adult intestinal microvilli. Additionally, western blot results revealed that rHc-HAP could be detected in goat sera artificially infected with H. contortus. In the experiments, rHc-HAP bound to goat PBMCs and released nitric oxide. The rHc-HAP also induced the expression of interferon gamma (IFN-γ) and the phosphorylated STAT 1 transcription factor, while inhibiting interleukin-4 expression.

Conclusions

The results shows that rHc-HAP stimulated the IFN-γ/STAT1 signaling pathway and enabled polarization of PBMCs toward T-helper 1 immune responses.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-022-05411-7.

[Construction of an adenovirus vector expressing engineered splicing factor for regulating alternative splicing of YAP1 in neonatal rat cardiomyocytes]

OBJECTIVE

To construct an adenovirus vector expressing artificial splicing factor capable of regulating alternative splicing of Yap1 in cardiomyocytes.

METHODS

The splicing factors with different sequences were constructed against Exon6 of YAP1 based on the sequence specificity of Pumilio1. The PCR fragment of the artificially synthesized PUF-SR or wild-type PUFSR was cloned into pAd-Track plasmid, and the recombinant plasmids were transformed into E. coli DH5α for plasmid amplification. The amplified plasmids were digested with Pac I and transfected into 293A cells for packaging to obtain the adenovirus vectors. Cultured neonatal rat cardiomyocytes were transfected with the adenoviral vectors, and alternative splicing of YAP1 was detected using quantitative and semi-quantitative PCR; Western blotting was performed to detect the signal of the fusion protein Flag.

RESULTS

The transfection efficiency of the adenovirus vectors was close to 100% in rat cardiomyocytes, and no fluorescent protein was detected in the cells with plasmid transfection. The results of Western blotting showed that both the negative control and Flag-SR-NLS-PUF targeting the YAPExon6XULIE sequence were capable of detecting the expression of the protein fused to Flag. The results of reverse transcription-PCR and PCR demonstrated that the artificial splicing factor constructed based on the 4th target sequence of YAP1 effectively regulated the splicing of YAP1 Exon6 in the cardiomyocytes (P < 0.05).

CONCLUSION

We successfully constructed adenovirus vectors capable of regulating YAP1 alternative splicing rat cardiomyocytes.

[Characteristics and changes of sensitization patterns of major allergens in children from 2010 to 2020 in a hospital of pediatric in Beijing]

Objective: To analyze the sensitization characteristics and change of major allergens in children from 2010 to 2020 in Beijing, so as to provide basis for diagnosis, treatment and prevention of allergic diseases in children. Methods: A retrospective study was conducted to analyze the children who were suspected of allergic diseases and tested for serum immunoglobulin E (total IgE and specific IgE) in the children's Hospital Affiliated to the Capital Institute of Pediatrics from January 2010 to December 2020. A total of 45 746 children aged 0-17 years in Beijing were enrolled with a median (interquartile range) of 3.8 (2.5, 5.3) years. There were 28 918 boys (63.2%) and 16 828 girls (36.8%) and 14 984 cases (32.8%) in the infant group (<3 years old), 22 049 cases (48.2%) in the preschool group (3-6 years old), and 8 713 cases (19.0%) in the school-age group (6 years old and above). Immunocap allergen detection system (fluorescence enzyme-linked immunosorbent assay) was used to detect and the characteristics and change trend of allergens during 11 years were statistically analyzed by Chi square test. Results: The top three positive rates of single food allergens sIgE were egg white 42.6% (2 788/6 577 tests), milk 38.4% (2 606/6 782 tests) and wheat 31.8% (1 417/4 449 tests), and the sequence of single inhaled allergens were Ragweed 42.6% (440/1 034 tests), Artemisia 38.4% (1 045/3 191 tests) and Alternaria alternata 31.3% (3 358/10 725 tests). The positive detection rates of egg white 47.0%(1 904/4 048 tests), milk 41.9%(1 769/4 226 tests) and wheat 33.9%(973/2 870 tests) in the infant group were the highest, and there have statistically significant(χ²=91.495, 73.907, 16.966, P<0.05). The positive rates of fx1 (22.5%, 121/537 tests), peanut (24.9%, 111/446 tests), soybean (20.0%, 74/370 tests) and shrimp (7.48%, 44/588 tests) were the highest in the school-age group(χ²=14.436, 10.751, 11.569, 13.703, P<0.05). The most common inhaled allergens were Alternaria alternata (14.8%, 422/2 859 tests) in the infant group, Ambrosia (34.5%, 143/415 tests) and Alternaria alternata (33.5%, 1 762/5 254 tests) in the preschool group, while in the school-age group were Ambrosia (56.4%, 282/500 tests) and Artemisia (48.2%, 573/1 189 tests). The positive rates of egg white, milk, wheat, sesame seed and peanut varied from 2010 to 2020, showing a trend of falling first and then rising(χ²=10.293,χ²=12.066,χ²=7.402,χ²=32.458,χ²=31.747,P<0.05).The positive detection rates of soybean showed a significant downward trend (21.4%, 173/809 tests in 2010, 15.4%, 70/455 tests in 2020, χ²=6.751,P=0.009), while that of shrimp and crab were at a stable low level(χ²=0.263, 1.346;P>0.05). From 2010 to 2020, mold (26.7%, 1 066/3 998 tests in 2010, 40.2% 1 705/4 243 tests in 2020), grass pollen (19.8%, 259/1 308 tests in 2010, 39.3%, 1 472/3 746 tests in 2020), tree pollen(17%, 180/1 058 tests in 2010, 29.8%, 916/3 075 tests in 2020) and animal dander (18.5%, 111/601 tests in 2010, 26.6%, 672/2 522 tests in 2020) were all showed significant upward trend (χ²=168.600, 163.601, 65.931 and 17.271 respectively, P<0.001) but dust mites (30.7%, 1 270/4 132 tests in 2010, 26.7%, 1 126/4 221 tests in 2020) showed a significant downward trend(χ²=16.822,P<0.001).In 2010, the most common inhaled allergen was dust mite 30.7% (1 270/4 132 tests), followed by mold 26.7% (1 066/3 998 tests), while they were mold 40.2% (1 705/1 243 tests), and grass pollen 39.3% (1 472/3 746 texts) respectively in 2020. Conclusion: In the past 11 years, the main food allergens in children were still egg white and milk, wheat, but the mold and pollen gradually replaced dust mite as the most common inhaled allergen.

PLGA Nanospheres as Delivery Platforms for Eimeria mitis 1a Protein: A Novel Strategy to Improve Specific Immunity

The infections of chicken coccidiosis impact the welfare of chickens and the economical production of poultry. Eimeria mitis is ubiquitous in chicken coccidiosis, and E. mitis infection can significantly affect the productivity of birds. Up to now, few efficient vaccines against E. mitis have been reported, whereas the recombinant subunit vaccines delivered by nanomaterials may elicit an encouraging outcome. Thus, in this study, we chose E. mitis 1a (Em1a) protein as the candidate antigen to generate Em1a preparations. The recombinant Em1a (rEm1a) protein was encapsulated with poly lactic-co-glycolic acid (PLGA) and chitosan (CS) nanospheres. The physical characterization of the rEm1a-PLGA and rEm1a-CS nanospheres was investigated, and the resulting nanospheres were proven to be nontoxic. The protective efficacy of rEm1a-PLGA and rEm1a-CS preparations was evaluated in E. mitis-challenged birds in comparison with two preparations containing rEm1a antigen emulsified in commercially available adjuvants. ELISA assay, flow cytometry analysis, and quantitative real-time PCR (qPCR) analysis indicated that vaccination with rEm1a-loaded nanospheres significantly upregulated the secretions of antibodies and cytokines and proportions of CD4⁺ and CD8⁺ T lymphocytes. Compared with the other three preparations, rEm1a-PLGA nanosphere was more effective in improving growth performance and inhibiting oocyst output in feces, indicating that the PLGA nanosphere was associated with optimal protection against E. mitis. Collectively, our results highlighted the advantages of nanovaccine in eliciting protective immunity and may provide a new perspective for developing effective vaccines against chicken coccidiosis.

Identification of excretory and secretory proteins from Haemonchus contortus inducing a Th9 immune response in goats

Th9 cells have been shown to play crucial roles in anti-parasite immunity, pathogenic microbe infection, and allergy. Previous studies have demonstrated that Haemonchus contortus excretory and secretory proteins (HcESPs) induce the proliferation of Th9 cells and alter the transcriptional level of IL-9 as well as its related pathways in the Th9 immune response after infection. However, the exact molecule(s) in HcESPs inducing the Th9 immune response is not yet known. In this study, flow cytometry, co-immunoprecipitation (Co-IP) and shotgun liquid chromatography tandem-mass spectrometry (LC–MS/MS) were used, and a total of 218 proteins from HcESPs that might interact with goat Th9 cells were identified. By in vitro culture of Th9 cells with HcESPs, 40 binding proteins were identified. In vivo, 38, 47, 42 and 142 binding proteins were identified at 7, 15, 35 and 50 days post-infection (dpi), respectively. Furthermore, 2 of the 218 HcESPs, named DNA/RNA helicase domain containing protein (HcDR) and GATA transcription factor (HcGATA), were confirmed to induce the proliferation of Th9 cells and promote the expression of IL-9 when incubated with goat peripheral blood mononuclear cells (PBMCs). This study represents a proteomics-guided investigation of the interactions between Th9 cells and HcESPs. It provides a new way to explore immunostimulatory antigens among HcESPs and identifies candidates for immune-mediated prevention of H. contortus infection.

An Eimeria maxima Antigen: Its Functions on Stimulating Th1 Cytokines and Protective Efficacy Against Coccidiosis

A consensus is that the Th1 immune response plays a predominant role against avian coccidiosis. Therefore, an antigen with the ability to induce Th1 cytokine responses is an ideal candidate for the development of coccidiosis vaccines. In our previous study, EmARM-β, a Th1 cytokines-stimulating antigen, was screened from the cDNA expression library of Eimeria maxima (E. maxima). Herein, we verified its stimulative effects on Th1 cytokine productions and evaluated its protective efficacy against E. maxima infection. Recombinant EmARM-β protein was expressed, and eukaryotic expression plasmid pVAX1-EmARM-β was also constructed for the immunization of birds. An immunofluorescence assay was performed to detect the native form of EmARM-β protein in the stage of sporozoites. Expressions of specific transcription factors and cytokines in immunized chickens were measured using qPCR and ELISA to verify its stimulating function on Th1 cytokines. Specific IgG antibody levels and T lymphocyte subpopulation in the immunized chickens were detected using ELISA and indirect flow cytometry to determine induced immune responses. The results showed that EmARM-β native protein is massively expressed in the sporozoites stage of E. maxima. Effective stimulation from the EmARM-β antigen to T-bet and Th1 cytokines (IL-2 and IFN-γ) was observed in vivo. After being immunized with rEmARM-β or pVAX1-EmARM-β, significant promotion to the proportion of CD4+ and CD8+ T cells and the level of antigen-specific IgG antibodies in immunized chickens was also observed. Furthermore, vaccination with rEmARM-β antigen or pVAX1-EmARM-β resulted in alleviated weight loss and enteric lesion, reduced oocyst output, and higher anticoccidial index (ACI) in challenged birds. These results indicate that EmARM-β antigen can effectively stimulate the expression of Th1 cytokines and initiate host immune responses, providing moderate protective efficacy against E. maxima. Notably, EmARM-β protein is a promising candidate for developing a novel anticoccidial vaccine.

[ALDH3B1 expression is correlated with histopathology and long-term prognosis of gastric cancer]

OBJECTIVE

To investigate the expression of aldehyde dehydrogenase 3B1 (ALDH3B1) in gastric cancer and explore its correlation with the pathological parameters and long-term prognosis of the patients.

METHODS

We analyzed the clinical data of 101 patients who underwent radical gastrectomy for gastric cancer in our hospital between January, 2013 and November, 2016, and examined the expression of ALDH3B1 in paraffin-embedded samples of gastric cancer tissues and adjacent tissues from these cases by immunohistochemical staining. We evaluated the correlation between ALDH3B1 expressions and histopathological parameters and assessed the predictive value of ALDH3B1 expression for long-term survival of the patients. We also examined the effect of lentivirus-mediated interference and overexpression of ALDH3B1 on the malignant behaviors of MGC-803 gastric cancer cells.

RESULTS

The expressions of ALDH3B1 and Ki67 were significantly higher in gastric cancer tissues than in adjacent tissues (P < 0.05). In gastric cancer patients, ALDH3B1 expression was positively correlated with peripheral blood CEA and CA19-9 levels (P < 0.01). The proportion of patients with CEA ≥5 μg/L, CA19-9 ≥37 kU/L, T stage of 3- 4, and N stage of 2-3 was significantly greater in high ALDH3B1 expression group than in low expression group. Kaplan-Meier survival analysis showed that the 5-year survival rate was significantly lower in gastric cancer patients with high ALDH3B1 expressions (P < 0.01). Univariate and Cox multiple regression analyses identified a high expression of ALDH3B1 (P < 0.05, HR= 0.231, 95% CI: 0.064-0.826), CEA≥5 μg/L (P < 0.01, HR=4.478, 95% CI: 1.530-13.110), CA19-9≥37 kU/L (P < 0.01, HR=3.877, 95% CI: 1.625-9.247), T stage of 3-4 (P < 0.01, HR=4.953, 95% CI: 1.768-13.880), and N stage of 2-3 (P < 0.05, HR=2.152, 95% CI: 1.152-4.022) as independent risk factors affecting 5-year survival after radical gastrectomy. The relative ALDH3B1 expression level, at the cut-off point of 4.66, showed a sensitivity of 76.47% and a specificity of 76% for predicting 5-year postoperative death (P < 0.01). In the cell experiment, overexpression of ALDH3B1 obviously promoted the proliferation, migration and invasion of MGC-803 cells.

CONCLUSION

As an independent risk factor affecting 5-year survival after radical gastrectomy, ALDH3B1 is highly expressed in gastric cancer and correlated with pathological parameters of the tumor, and a high ALDH3B1 expression may promote proliferation, invasion and metastasis of gastric cancer cells.

Immunization With Recombinant Haemonchus contortus Y75B8A.8 Partially Protects Local Crossbred Female Goats From Haemonchus contortus Infection

Haemonchus contortus Y75B8A.8 (Hc8) derived from H. contortus excretory–secretory (ES) products was identified as a functional inhibitor of goat interleukin 2 (IL-2). It may act as a vaccine candidate for the development of therapeutic strategies against H. contortus infection. In this research, recombinant Hc8 (rHc8) and goat anti-rHc8 polyclonal antibodies were employed to evaluate the protective capacities of Hc8 antigen against H. contortus infections via active and passive immunization trials, respectively. In both trials, local crossbred female goats aged 9–12 months old were randomly divided into three groups, five in each group, respectively. Parasitological examinations, including fecal egg counts (FEC), cumulative FEC (cFEC), and worm burdens, were performed. In addition, antibody levels in mucosal homogenate (MH) samples and hematological and immunological parameters were detected. In the passive trial, goats were intravenously immunized with 5 mg total IgG containing anti-rHc8 goat polyclonal antibodies. After twice immunization, compared with the challenged control group, cFEC was reduced by 39%. In addition, there was a 46% reduction of worm burdens compared with the challenged controls. In the active immunization trials, 500 μg of recombinant Hc8 protein was given subcutaneously twice to 9–12-month-old local crossbred female goats with a 2-week interval, resulting in the generation of high levels of antigen-specific circulating antibodies. Besides, cFEC and abomasal worm burden were reduced by 70 and 55%, respectively, compared with the challenged control group. In addition, immunized goats had higher mucosal homogenate IgA and hemoglobin levels than the challenged controls in both passive and active immunization trials. These preliminary results demonstrated the immunoprophylactic effects of Hc8 antigen and will inform new studies on ES proteins in developing subunit recombinant vaccines against H. contortus.

[Safety and efficacy of left atrial appendage closure combined with patent foramen ovale closure for atrial fibrillation patients with patent foramen ovale]

Objective: To analyze the safety and efficacy of combined left atrial appendage (LAA) and patent foramen ovale (PFO) closure in adult atrial fibrillation (AF) patients complicating with PFO. Methods: This study is a retrospective and cross-sectional study. Seven patients with AF complicated with PFO diagnosed by transesophageal echocardiography (TEE) in Zhoupu Hospital Affiliated to Shanghai University of Medicine & Health Sciences from June 2017 to October 2020 were selected. Basic data such as age, gender and medical history were collected. The atrial septal defect or PFO occluder and LAA occluder were selected according to the size of PFO, the ostia width and depth of LAA. Four patients underwent left atrial appendage closure(LAAC) and PFO closure at the same time. PFO closure was performed during a one-stop procedure of cryoablation combined with LAAC in 2 patients. One patient underwent PFO closure at 10 weeks after one-stop procedure because of recurrent transient ischemic attack (TIA). All patients continued to take oral anticoagulants. TEE was repeated 8-12 weeks after intervention. In case of device related thrombus(DRT), TEE shall be rechecked 6 months after adjusting anticoagulant and antiplatelet drug treatment. Patients were follow-up at 1, 3, 6, 12, 24 months by telephone call, and the occurrence of cardio-cerebrovascular events was recorded. Results: Among the 7 patients with AF, 2 were male, aged (68.0±9.4) years, and 3 had a history of recurrent cerebral infarction and TIA. Average PFO diameter was (3.5±0.8)mm. Three patients were implanted with Watchman LAA occluder (30, 30, 33 mm) and atrial septal defect occluder (8, 9, 16 mm). 2 patients were implanted with LAmbre LAA occluder (34/38, 18/32 mm) and PFO occluder (PF1825, PF2525). 2 patients were implanted with LACbes LAA occluder (24, 28 mm) and PFO occluder (PF2525, PF1825) respectively. The patients were followed up for 12 (11, 24) months after operation. TEE reexamination showed that the position of LAA occluder and atrial septal defect occluder or PFO occluder was normal in all patients. DRT was detected in 1 patient, and anticoagulant therapy was adjusted in this patient. 6 months later, TEE showed that DRT disappeared. No cardiovascular and cerebrovascular events occurred in all patients with AF during follow-up. Conclusions: In AF patients complicated with PFO, LAAC combined with PFO closure may have good safety and effectiveness.

Automatic assessment of dairy cows' rumen function over time and links to feed changes and milk production

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We monitored rumen function longitudinally in dairy cows using a 3-dimensional (3D) vision-based system.

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Rumen function was associated with feed changes and milk production.

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Early-spring grazing reduced rumen fill and milk fat content in cows.

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A cow with rumen dysfunction showed deviations in rumen motility in the 3D vision system.

A 3-dimensional (3D) vision-based system was previously designed to automatically estimate the rumen motility of individual cows. This longitudinal study aimed to explore the associations between 3D vision-based rumen function assessment and dairy cow feed changes and milk production on a commercial farm. The 3D vision system was attached to an automatic milking robot to estimate the ruminal contraction frequency and rumen fill in 42 lactating cows during each milking event for 66 d. Additionally, we collected data on milk production, milk composition, general health, and changes in feeding practices. The 3D vision system showed that half the cows displayed a drastic decrease in the estimated rumen fill when all cows began grazing. The grazing and decreased rumen fill were also associated with herd-level milk fat depression. Over the 66 d, one cow was detected with reduced milk production and suspected rumen dysfunction by the farmer. The 3D vision system, however, identified this cow as having sudden decreases in estimated ruminal contraction frequency and rumen fill 4 d before detection by the farmer. In this longitudinal study, the 3D vision-based rumen function assessment system showed potential as a useful management-supporting tool for dairy farmers. The system, however, requires further validation with more cows of various breeds and ages. We suggest validating the 3D vision system with rumen boluses, quantified adjustments in feeding practices, more cases with ruminal dysfunction, and systematic health assessments for future studies.

The GT1-TPS Structural Domain Protein From Haemonchus contortus Could Be Suppressive Antigen of Goat PBMCs

Trehalose phosphate synthase (TPS), a key enzyme in trehalose synthesis, is not present in mammals but critical to the viability of a wide range of lower organisms. However, almost nothing is known about the function of Hc-TPS (GT1-TPS structural domain protein from Haemonchus contortus). In this study, Hc-TPS gene was cloned and the recombinant protein (rHc-TPS) was expressed and purified. The quantitative real-time PCR (qPCR) results showed that Hc-TPS was transcribed at different stages of H. contortus, with higher levels of transcription at the molting and embryo stages. Immunofluorescence analysis showed that Hc-TPS was widely distributed in adults, but the expression was mainly localized on the mucosal surface of the intestine as well as in the embryos of female worms. The impacts of rHc-TPS on peripheral blood mononuclear cell (PBMC) proliferation, nitric oxide (NO) generation, transcriptional expression of cytokines, and related pathways were examined by co-incubating rHc-TPS with goat PBMCs. The results showed that rHc-TPS significantly inhibited PBMC proliferation and NO secretion in a dose-dependent manner. We also found that rHc-TPS activated the interleukin (IL)-10/signal transducer and activator of transcription 3/suppressor of cytokine signaling 3 (IL-10/STAT3/SOCS3) axis and significantly promoted SOCS3 expression, while inhibiting interferon-gamma (INF-γ), IL-4, IL-9, and IL-2 pathways. Our findings may contribute to understanding the immune evasion mechanism for the parasite during host-parasite interactions and also help to provide ideas for discovering new drug targets.

[Effects of unsafe sexual behavior and sexual orientation on previous HIV testing and HIV testing willingness among college students in Harbin]

Objective: To analyze the effects of unsafe sexual behavior and sexual orientation on previous HIV testing and HIV testing willingness among college students in Harbin, to provide a theoretical basis for promoting and promoting HIV testing among them. Methods: A cross-sectional survey design was used to place the automatic vending machine of HIV urine test kit in 9 universities in Harbin from December 2017 to January 2018. The questionnaire star was used to design and recruit college students to carry out an anonymous online survey. The estimated sample size was 6 659. A multivariate logistic regression model was used to analyze the effects of unsafe sexual behavior and sexual orientation on previous HIV testing and HIV testing willingness among college students. WPS 2016 was used to sort out the database, and SPSS 21.0 software was used for statistical analysis. Results: A total of 60 849 valid questionnaires were collected. 19.1% (11 189/58 605) of college students reported having sex. College students who used condoms correctly every time, occasionally or never during sex in the past six months 58.5% (6 206/10 603), 25.2%(2 669/10 603)and 16.3% (1 728/10 603), respectively. Heterosexuality, homosexuality and bisexuality accounted for 94.1% (54 393/57 823), 2.4% (1 369/57 823) and 3.5% (2 061/57 823), respectively. The HIV testing willingness of college students was 73.3% (44 572/60 849). The proportion of previous HIV testing was 10.3% (951/9 241). Results of the multivariate logistic analysis showed that compared with the college students who used condoms correctly whenever they had sex in the past six months, there was no significant difference in the proportion of previous HIV testing among college students who sometimes/occasionally used or never used condoms (OR=0.94,95%CI:0.69-1.29; OR=1.11,95%CI:0.73-1.67), but their willingness to HIV testing was lower (OR=0.79, 95%CI:0.71-0.89; OR=0.48, 95%CI:0.42-0.55); Compared with heterosexual college students, homosexual or bisexual college students have a higher proportion of previous HIV testing (OR=2.62, 95%CI:1.62-4.24; OR=2.04, 95%CI:1.25-3.32), but have lower HIV testing willingness (OR=0.76, 95%CI: 0.62-0.93; OR=0.64, 95%CI: 0.53-0.77). Conclusions: Unsafe sexual behavior existed among college students in Harbin, and college students with weak awareness of HIV prevention also have weak awareness of testing. Behavioral intervention should be strengthened and HIV testing promoted. Compared with heterosexuals, homosexual or bisexual college students had a higher proportion of previous HIV testing, but their willingness to test was lower. The HIV detection mode with better concealment, accuracy, and convenience should be promoted on the college's campus.

Em14-3-3 delivered by PLGA and chitosan nanoparticles conferred improved protection in chicken against Eimeria maxima

Eimeria maxima (E. maxima) are an intracellular apicomplexan protozoan that causes intestinal coccidiosis in chickens. The purpose of this research was to develop a novel delivery approach for recombinant E. maxima (rEm) 14-3-3 antigen to elicit enhanced immunogenic protection using poly (D, L-lactide-co-glycolide) (PLGA) and chitosan (CS) nanoparticles (NPs) against E. maxima challenge. The morphologies of prepared antigen-loaded NPs (PLGA/CS-rEm14-3-3 NPs) were visualized by a scanning electron microscope. The rEm14-3-3 and PLGA/CS-rEm14-3-3 NPs-immunized chicken-induced changes of serum cytokines, IgY-antibody level, and T-lymphocyte subsets and protective efficacies against E. maxima challenge were evaluated. The results revealed that encapsulated rEm14-3-3 in PLGA and CS NPs presented spherical morphology with a smooth surface. The chickens immunized with only rEm14-3-3 and PLGA/CS-rEm14-3-3 NPs elicited a significant (p<0.05) higher level of IFN-γ cytokine, stimulated the proportions of CD4⁺/CD3⁺, CD8⁺/CD3⁺ T-cells, and provoked sera IgY-antibody immune response compared to control groups (PBS, pET-32a, PLGA, and CS). Whereas, PLGA-rEm14-3-3 NP-immunized chicken provoked a higher level of IFN- γ production and IgY-antibody response rather than CS-rEm14-3-3 and bare antigen, relatively. The animal experiment results ratified that PLGA-rEm14-3-3 NP-immunized chicken significantly alleviated the relative body weight gain (%), decreased lesion score, and enhanced oocyst decrease ratio compared to CS-rEm14-3-3 NPs and only rEm14-3-3. The anti-coccidial index of the chicken vaccinated with the PLGA-rEm14-3-3 NPs was (180.1) higher than that of the Cs-rEm14-3-3 NPs (167.4) and bare antigen (165.9). Collectively, our statistics approved that PLGA NPs might be an efficient antigen carrier system (Em14-3-3) to act as a nanosubunit vaccine that can improve protective efficacies in chicken against E. maxima challenge.

Selective synthesis and magnetic properties of iron silicide (Fe3Si and FeSi) at low temperature

In this study, iron silicides (Fe3Si and FeSi) particles have been selectively synthesized through a solid-state reaction route. The reactions are carried out at 650 ℃ in a stainless steel...

A high precision phase measurement system implemented in FPGA with phase interpolator

High precision timing distribution is crucial to many large scale cosmology and particle physics experiments. Besides the space and energy information, the accurate timing provides an extra dimension for physics event reconstruction. In the timing distribution system, accurate clock phase measurement is an indispensable tool to monitor the phase drift and to achieve accurate phase adjustment. This paper introduces a novel phase measurement method implemented in the Xilinx Field Programmable Gate Array (FPGA). It uses the dedicated phase interpolator in the multi-gigabit transceiver. A design based on this method is implemented within the Kintex Ultrascale series FPGA. The preliminary test result shows that a sub-picosecond level precision is achieved. With this system, the nonlinearity of the phase adjustment in the Xilinx transceiver is measured.

Trichinella spiralis: Knockdown of gamma interferon inducible lysosomal thiol reductase (GILT) results in the reduction of worm burden

Trichinella spiralis is mammalian skeletal muscles parasite which may cause trichinellosis in animals and humans. Gamma interferon inducible lysosomal thiol reductase (GILT) is a widespread superfamily which plays key role in processing and presentation of MHC class II restricted antigen by catalyzing disulfide bond reduction. There are no reports about GILT in T. spiralis. In present study, GILT from T. spiralis (Tsp-GILT) was cloned, analyzed by multiple-sequence alignment, and predicted by 3D structure model. Recombinant Tsp-GILT (about 46 kDa) was efficiently expressed in Escherichia coli and thiol reductase activity suggested that in acidic environment the addition of a reducing agent is needed. Soaking method was used to knockdown expression of Tsp-GILT using small interference RNA (siRNA). Immunofluorescence assay confirmed the transformation of siRNA into muscle larva (ML) and new born larva (NBL). Quantitative real time-PCR (QRT-PCR) analysis revealed that transcription level of Tsp-GILT mRNA can be up-regulated by stimulation of mouse IFN-γ and down-regulated by siRNA2 in vitro. NBLs soaked with siRNA2 showed 32.3% reduction in the generation of MLs. MLs soaked with siRNA2 showed 26.2% reduction in the next generation of MLs, but no significant effect was observed on adult worms or NBLs. These findings concluded that GILT may play important roles in the development of T. spiralis parasite.

Trichinella spiralis is the most important pathogen causing trichinellosis of animals and humans. Reports in mammal animals showed that gamma interferon inducible lysosomal thiol reductase (GILT) play key roles in processing and presentation of MHC class II restricted antigens. However, there were no reports about GILT in nematode T. spiralis. In this study, GILT gene from T. spiralis (Tsp-GILT) was cloned and analyzed. The predicted 3D structure of Ts-GILT protein was found similar with that of Homo sapiens and Sus scrofa. To further evaluate the roles of Tsp-GILT in T. spiralis development, a soaking method was used to knockdown the expression of Tsp-GILT gene by siRNA. It was found that NBLs soaked with siRNA showed 32.3% reduction in the generation of MLs, and MLs soaked with siRNA showed 26.2% reduction in the next generation of MLs. Current study concluded that siRNA knockdown of gamma interferon inducible lysosomal thiol reductase from Trichinella spiralis significantly reduce the larval infectivity, development and survival.

Enriching Atomic Cobalt in an Ultrathin Porous Carbon Shell for Enhanced Electrocatalysis

Developing nonprecious electrocatalysts operating in acidic and alkaline media for an oxygen reduction reaction (ORR) is essential for sustainable energy technologies. Increasing the metal active site density is an effective strategy to enhance the activity, but it remains challenging because of metal sintering during pyrolysis. Here, we report a novel strategy of enriching atomically dispersed cobalt species in nitrogen-doped carbon for improving the electrocatalytic performance. A hollow carbon nanosphere with reduced shell thickness was obtained by taking advantage of the carbothermic reaction between carbon and ZnO template, and the resulting cobalt enrichment in the ultrathin carbon shell leads to an increase of the density of Co atoms. Together with advantageous microstructure features such as high surface area and multiscale porosity, the corresponding catalyst demonstrated promising oxygen reduction reaction performance in strong acidic and alkaline electrolytes and has two times higher kinetic current density than the nonenriched one. The present work provides an attractive and facile route to engineer active site in electrocatalysts.