Does reduced usage of antibiotics in livestock production mitigate the spread of antibiotic resistance in soil, earthworm guts, and the phyllosphere?

The overuse of antibiotics in animal husbandry is widespread and believed to significantly contribute to the selection of antibiotic resistance genes (ARGs) in animals. Thus, there is a global drive to reduce antibiotic use in the agricultural sector. However, it has not been established whether a reduction in the use of antibiotics in livestock production would be effective in reducing the spread of ARGs. A microcosm approach was used to determine how the addition of manure with either reduced antibiotic levels or with typical antibiotic levels could affect the spread of antibiotic resistance genes between soil, earthworms and the phyllosphere. When compared to the control soil, earthworm and phyllosphere samples had the greater increase in ARG abundance in conventional manure treatments (P < 0.05). Reduced antibiotic manure also enriched the abundance of ARGs in the phyllosphere and soil but not earthworm guts when compared to the control (P < 0.05). In both soil and earthworm guts, the enrichment of ARGs was lower in reduced antibiotic manure than in conventional manure. This study has identified bacterial transfer through the soil-earthworm-phyllosphere system as a potential means to spread ARGs between habitats after fertilization with livestock derived manures

Optimization of Preparation Process of Chitosan-carrageenan Edible Composite Membrane Based on Response Surface Methodology

Chitosan was mixed with carrageenan and tea polyphenols, and chitosan-carrageenan composite film was prepared by the fluidized bed method and its properties were tested.The light transmittance,mechanical property and water resistance of the composite film were investigated by single factor test, and then the response surface experiment was carried out to optimize the preparation process of the composite film with water vapor transmittance as the evaluation index.The results showed that the optimal process of chitosan - carrageenan edible composite film was as follows: adding 1.5% of chitosan, 0.4% of carrageenan,0.6% of glycerol, 0.6% of tea polyphenols, and drying temperature of 50 ℃.Under this condition, the thickness of the composite film was uniform and the mechanical properties were good.The water vapor transmission rate was 1.37 (10–11 g/m·s·Pa)

Transcription phase, protein characteristics of DEV UL45 and prokaryotic expression, antibody preparation of the UL45 des-transmembrane domain

<p>Abstract</p> <p>Background</p> <p>Some UL45 gene function of Herpesvirus was reported. While there was no any report of the duck enteritis virus (DEV) UL45 protein as yet.</p> <p>Results</p> <p>The UL45 gene and des-transmembrane domain of UL45 (named UL45Δ gene, 295-675bp of UL45) of DEV were amplified by PCR and subcloned into the prokaryotic expression vector pET-32a(+). The constructed recombinant plasmids were transformed into the host strain BL21(DE3) PLysS and induced by IPTG. SDS-PAGE analysis showed the UL45 gene couldn't express while UL45Δ gene was highly expressed. His Purify Kit or salting-out could purify the protein effectively. Using the purified protein to immunize New-Zealand rabbits and produce polyclonal antibody. The agar diffusion reaction showed the titer of antibody was 1:32. Western blot analysis indicated the purified rabbit anti-UL45Δ IgG had a high level of specificity and the UL45 gene was a part of DEV genome. The transcription phase study of UL45 gene showed that expression of UL45 mRNA was at a low level from 0 to 18 h post-infection (pi), then accumulated quickly at 24 h pi and peaked at 42 h pi. It can be detected till 72 h pi. Besides, western blot analysis of purified virion and different viral ingredients showed that the UL45 protein resided in the purified virion and the viral envelope.</p> <p>Conclusions</p> <p>The rabbit anti-UL45Δ IgG was produced successfully and it can serve as a good tool for penetrating studies of the function of DEV UL45 protein. The transcription phase and protein characteristics analysis indicated that DEV UL45 gene was a late gene and UL45 protein may be a viral envelope protein.</p

Association of family function and suicide risk in teenagers with a history of self-harm behaviors: mediating role of subjective wellbeing and depression

BackgroundA history of self-harm behaviors is closely associated with subsequent suicide death. Although many factors associated with suicide have been identified, it remains unclear how these factors interact to influence suicide risk, especially among teenagers with a history of self-harm behaviors.MethodsData were collected from 913 teenagers with a history of self-harm behaviors through a cross-sectional study. The Family Adaptation, Partnership, Growth, Affection, and Resolve index was used to assess teenagers' family function. The Patient Health Questionnaire-9 and the Generalized Anxiety Disorder-7 were used to evaluate depression and anxiety in teenagers and their parents, respectively. The Delighted Terrible Faces Scale was used to assess teenagers' perception of subjective wellbeing. The Suicidal Behaviors Questionnaire-Revised was used to evaluate teenagers' suicide risk. Student's t-test, one-way ANOVA, multivariate linear regression, Pearson's correlation, and a structural equation model (SEM) were applied to data analysis.ResultsOverall, 78.6% of teenagers with a history of self-harm behaviors were at risk for possible suicide. Female gender, severity of teenagers' depression, family function, and subjective wellbeing were significantly associated with suicide risk. The results of SEM suggested that there was a significant chain mediation effect of subjective wellbeing and depression between family function and suicide risk.ConclusionFamily function was closely associated with suicide risk in teenagers with a history of self-harm behaviors, and depression and subjective wellbeing were sequential mediators in the association between family function and suicide risk

The IGF2/IGF1R/Nanog Signaling Pathway Regulates the Proliferation of Acute Myeloid Leukemia Stem Cells

Acute myeloid leukemia is an aggressive disease characterized by clonal proliferation and differentiation into immature hematopoietic cells of dysfunctional myeloid precursors. Accumulating evidence shows that CD34+CD38- leukemia stem cells (LSCs) are responsible for drug resistance, metastasis, and relapse of leukemia. In this study, we found that Nanog, a transcription factor in stem cells, is significantly overexpressed in CD34+ populations from patients with acute myeloid leukemia and in LSCs from leukemia cell lines. Our data demonstrate that the knockdown of Nanog inhibited proliferation and induced cell cycle arrest and cell apoptosis. Moreover, Nanog silencing suppressed the leukemogenesis of LSCs in mice. In addition, we found that these functions of Nanog were regulated by the insulin-like growth factor receptor (IGF1R) signaling pathway. Nanog overexpression rescued the colony formation ability of LSCs treated with picropodophyllin (PPP), an IGF1R inhibitor. By contrast, knockdown of Nanog abolished the effects of IGF2 on the colony formation ability of these LSCs. These findings suggest that the IGF2/IGF1R/Nanog signaling pathway plays a critical role in LSC proliferation

Listeria monocytogenes: a promising vector for tumor immunotherapy

Cancer receives enduring international attention due to its extremely high morbidity and mortality. Immunotherapy, which is generally expected to overcome the limits of traditional treatments, serves as a promising direction for patients with recurrent or metastatic malignancies. Bacteria-based vectors such as Listeria monocytogenes take advantage of their unique characteristics, including preferential infection of host antigen presenting cells, intracellular growth within immune cells, and intercellular dissemination, to further improve the efficacy and minimize off-target effects of tailed immune treatments. Listeria monocytogenes can reshape the tumor microenvironment to bolster the anti-tumor effects both through the enhancement of T cells activity and a decrease in the frequency and population of immunosuppressive cells. Modified Listeria monocytogenes has been employed as a tool to elicit immune responses against different tumor cells. Currently, Listeria monocytogenes vaccine alone is insufficient to treat all patients effectively, which can be addressed if combined with other treatments, such as immune checkpoint inhibitors, reactivated adoptive cell therapy, and radiotherapy. This review summarizes the recent advances in the molecular mechanisms underlying the involvement of Listeria monocytogenes vaccine in anti-tumor immunity, and discusses the most concerned issues for future research

The preoperative platelet to neutrophil ratio and lymphocyte to monocyte ratio are superior prognostic indicators compared with other inflammatory biomarkers in ovarian cancer

BackgroundPrevious studies have suggested that the ratios of immune-inflammatory cells could serve as prognostic indicators in ovarian cancer. However, which of these is the superior prognostic indicator in ovarian cancer remains unknown. In addition, studies on the prognostic value of the platelet to neutrophil ratio (PNR) in ovarian cancer are still limited.MethodsA cohort of 991 ovarian cancer patients was analyzed in the present study. Receiver operator characteristic (ROC) curves were utilized to choose the optimal cut-off values of inflammatory biomarkers such as neutrophil to lymphocyte ratio (NLR), lymphocyte to monocyte ratio (LMR), platelet to lymphocyte ratio (PLR), systemic immune-inflammation index (SII), and PNR. The correlation of inflammatory biomarkers with overall survival (OS) and relapse-free survival (RFS) was investigated by Kaplan-Meier methods and log-rank test, followed by Cox regression analyses.ResultsKaplan-Meier curves suggested that LMR&lt;3.39, PLR≥181.46, and PNR≥49.20 had obvious associations with worse RFS (P&lt;0.001, P=0.018, P&lt;0.001). Multivariate analysis suggested that LMR (≥3.39 vs. &lt;3.39) (P=0.042, HR=0.810, 95% CI=0.661-0.992) and PNR (≥49.20 vs. &lt;49.20) (P=0.004, HR=1.351, 95% CI=1.103-1.656) were independent prognostic indicators of poor RFS. In addition, Kaplan-Meier curves indicated that PLR≥182.23 was significantly correlated with worse OS (P=0.039).ConclusionTaken together, PNR and LMR are superior prognostic indicators compared with NLR, PLR, and SII in patients with ovarian cancer