Many animal and plant pathogenic bacteria employ a type three secretion system (T3SS) to deliver type three effector proteins (T3Es) into host cells. Efficient secretion of many T3Es in the plant ...pathogen Xanthomonas campestris pv. campestris (Xcc) relies on the global chaperone HpaB. However, how the domain of HpaB itself affects effector translocation/secretion is poorly understood. Here, we used genetic and biochemical approaches to identify a novel domain at the C-terminal end of HpaB (amino acid residues 137-160) that contributes to virulence and hypersensitive response (HR). Both in vitro secretion assay and in planta translocation assay showed that the secretion and translocation of T3E proteins depend on the C-terminal region of HpaB. Deletion of the C-terminal region of HpaB did not affect binding to T3Es, self-association or interaction with T3SS components. However, the deletion of C-terminal region sharply reduced the mounts of free T3Es liberated from the complex of HpaB with the T3Es, a reaction catalyzed in an ATP-dependent manner by the T3SS-associated ATPase HrcN. Our findings demonstrate the C-terminal domain of HpaB contributes to disassembly of chaperone-effector complex and reveal a potential molecular mechanism underpinning the involvement of HpaB in secretion of T3Es in Xcc.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The lytic transglycosylases (LTs) are important enzymes that degrade peptidoglycan of the bacterial cell wall and affect many biological functions. We present here that XC_0706 and XC_3001 are ...annotated as the LTs in Xanthomonas campestris pv. campestris. XC_0706 is associated with virulence and plays a pivotal role in cell division. Mutation on XC_3001 reduced hypersensitive response induction and the translocation of type III effector, but did not affect the function of the type II secretion system. Further studies showed that multiple LTs genes contribute to efficiency of the type III secretory system in X. campestris pv. campestris.
The effects of general anesthetics on the developing brain have aroused much attention in recent years. Sevoflurane, a commonly used inhalation anesthetic especially in pediatric anesthesia, can ...induce developmental neurotoxicity. In this study, the differentially expressed mRNAs in the hippocampus of newborn rats exposed to 3% sevoflurane for 6 h were detected by RNA-Sequencing. Those data indicated that the mRNA of Klotho was increased after exposure to sevoflurane. Moreover, the protein expression of Klotho was assayed by Western Blot. Besides over-expression and under-expression of Klotho protein, we also detected changes of cell proliferation, ROS, JC-1, and Bcl-2/Bax ratio in PC12 cells exposed to sevoflurane. After exposure to 3% sevoflurane, the expression of Klotho protein increased in the hippocampus of neonatal rats. In PC12 cells, exposure to sevoflurane could increase cellular ROS level, reduce mitochondrial membrane potential and Bcl-2/Bax ratio. While overexpression of Klotho alleviated the above changes, knockdown of Klotho aggravated the injury of sevoflurane. Klotho protein could reduce oxidative stress and mitochondrial injury induced by sevoflurane in the neuron.
Background
Human adenovirus (HAdV) infection can cause a variety of diseases. It is a major pathogen of pediatric acute respiratory tract infections (ARIs) and can be life-threatening in younger ...children. We described the epidemiology and subtypes shifting of HAdV among children with ARI in Guangzhou, China.
Methods
We conducted a retrospective study of 161,079 children diagnosed with acute respiratory illness at the Guangzhou Women and Children’s Medical Center between 2010 and 2021. HAdV specimens were detected by real-time PCR and the
hexon
gene was used for phylogenetic analysis.
Results
Before the COVID-19 outbreak in Guangzhou, the annual frequency of adenovirus infection detected during this period ranged from 3.92% to 13.58%, with an epidemic peak every four to five years. HAdV demonstrated a clear seasonal distribution, with the lowest positivity in March and peaking during summer (July or August) every year. A significant increase in HAdV cases was recorded for 2018 and 2019, which coincided with a shift in the dominant HAdV subtype from HAdV-3 to HAdV-7. The latter was associated with a more severe disease compared to HAdV-3. The average mortality proportion for children infected with HAdV from 2016 to 2019 was 0.38% but increased to 20% in severe cases. After COVID-19 emerged, HAdV cases dropped to 2.68%, suggesting that non-pharmaceutical interventions probably reduced the transmission of HAdV in the community.
Conclusion
Our study provides the foundation for the understanding of the epidemiology of HAdV and its associated risks in children in Southern China.
Enterovirus 71 (EV71) is one of the major causative pathogens of hand, foot, and mouth disease (HFMD). Immune cells play a critical role in determining the outcomes of virus infection. We aimed to ...characterize the lymphocyte subsets and transcriptional levels of T lymphocytes-associated transcription factors in peripheral blood cells of children with EV71 infection.
Peripheral blood samples from 32 children with EV71 infection and 32 control subjects were included in this study. The frequencies of T-, B-lymphocytes, and their subsets were determined by flow cytometry. The expression of transcription factors, including T-bet, Gata3, ROR γ t, Foxp3, TCF-1, and BCL-6 in the whole blood cells were evaluated by real-time reverse-transcription quantitative polymerase chain reaction (RT-qPCR).
The frequencies of T cells, helper T cells (Th), cytotoxic T cells (Tc), IFN-γ+ Th1, IFN-γ+ Tc1, and regulatory T (Treg) cells were significantly decreased (P < 0.01) in children with EV71 infection. As for IL-4+ Th2, IL-4+ Tc2, IL-17+ Th17, IL-17+ Tc17, follicular helper T cells (Tfh), CD3+CD8+IL-21+ T cells, CD19+ B cells, and CD19+IL-10+ B10 cells, their frequencies were significantly increased in the EV71 group (P < 0.01). The EV71 group had lower mRNA expressions of T-bet, Gata3, and Foxp3 than the control group (P < 0.05), whereas the expressions of ROR γ t, TCF-1, and BCL-6 showed no significant difference between two groups.
EV71 infection in children caused a decreased frequency of total Th, Tc and Treg cells, and increased percentages of B cell, Th2 and Th17 cells in blood.
Objective To show mutational analysis for 11β-hydroxylase deficiency (11β-OHD). Design Case report. Setting A laboratory of endocrinology at a university hospital. Patient(s) One Chinese woman with ...11β-OHD referred to our clinic was observed in our study. Intervention(s) Genomic DNA was extracted from peripheral blood leukocytes, and coding sequence abnormalities of the CYP11B1 gene were assessed by polymerase chain reaction and then direct sequencing analysis. Main Outcome Measure(s) Molecular characterization of the CYP11B1 gene. Result(s) A novel missense mutation (p.R454C) in the CYP11B1 gene was identified in our patient. Conclusion(s) Our study identified one novel mutation in the CYP11B1 gene. The expanded mutation database should benefit patients in the diagnosis and treatment of 11β-OHD.
Abstract Previous studies showed the relationship between fatty acids and the risk of developing Alzheimer's disease (AD). However, they did not address potential differences in free fatty acid (FFA) ...profiles that could be used to distinguish between AD patients and healthy controls. In the present study we used gas chromatography-mass spectrometry (GC-MS) technology coupled with multivariate statistical analysis to study profiles of FFA in AD. The results indicated 2 saturated fatty acids (C14:0 and C16:0; p < 0.001 and p < 0.05, respectively), 3 unsaturated fatty acids (C18:1, C18:3, and C22:6; p < 0.05, p < 0.05, and p < 0.001, respectively), where mean levels in serum from AD patients were significantly lower than controls. Partial least squares discriminant analysis (PLS-DA) models with unit variance (UV) scaling and orthogonal signal correction (OSC) data preprocessing methods were employed to refine intergroup differences between FFA profiles. The results of the analysis have highlighted docosahexaenoic acid (DHA) as the FFA with the greatest potential as a biomarker of AD, and this study has demonstrated that FFA biomarkers have considerable potential in diagnosing and monitoring AD.
Background Hemocoagulase Agkistrodon for injection is a single component thrombin which has passed phases I and II clinical trials. The purpose of this phase III clinical trial was to evaluate the ...effect of Hemocoagulase Agkistrodon on hemostasis and coagulation in abdominal skin and subcutaneous incisions and to assess the safety of this agent in surgical patients. Methods This is a phase III, prospective, randomized, double-blind, and controlled multicenter clinical trial including 432 consecutive patients randomized into either a study group （injected with hemocoagulase Agkistrodon at 2 U, n=-324） or a control group （injected with hemocoagulase Atrox, n=108）. The hemostatic time, hemorrhagic volume, hemorrhagic volume per unit area, blood coagulation, and adverse events were measured and compared between the two groups. Results The mean hemostatic time in the study group was （36.8±18.7） seconds; the hemorrhagic volume was （3.77±3.93） g; and the hemorrhagic volume per unit area was （0.091±0.125） g/cm2. In the control group, the corresponding values were （38.1±19.7） seconds, （4.00±4.75） g, and （0.095±0.101） g/cm2, respectively. No significant difference in values existed between the two groups （P 〉0.05）. Blood coagulation results and hepatic and renal function were also similar between the two groups. Adverse events were reported in two cases, but were deemed non-drug-related. Conclusions Hemocoagulase Agkistrodon has good hemostatic and coagulative function and is safe for the use of arresting capillary hemorrhage that occurs while incising the abdomen during surgery.
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