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1.
Eur J Nucl Med Mol Imaging ; 51(6): 1703-1712, 2024 May.
Article in English | MEDLINE | ID: mdl-38191817

ABSTRACT

PURPOSE: Boramino acids are a class of amino acid biomimics that replace the carboxylate group with trifluoroborate and can achieve the 18F-labeled positron emission tomography (PET) and boron neutron capture therapy (BNCT) with identical chemical structure. METHODS: This study reports a trifluoroborate-derived boronophenylalanine (BBPA), a derived boronophenylalanine (BPA) for BNCT, as a promising PET tracer for tumor imaging. RESULTS: Competition inhibition assays in cancer cells suggested the cell accumulation of [18F]BBPA is through large neutral amino acid transporter type-1 (LAT-1). Of note, [18F]BBPA is a pan-cancer probe that shows notable tumor uptake in B16-F10 tumor-bearing mice. In the patients with gliomas and metastatic brain tumors, [18F]BBPA-PET shows good tumor uptake and notable tumor-to-normal brain ratio (T/N ratio, 18.7 ± 5.5, n = 11), higher than common amino acid PET tracers. The [18F]BBPA-PET quantitative parameters exhibited no difference in diverse contrast-enhanced status (P = 0.115-0.687) suggesting the [18F]BBPA uptake was independent from MRI contrast-enhancement. CONCLUSION: This study outlines a clinical trial with [18F]BBPA to achieve higher tumor-specific accumulation for PET, provides a potential technique for brain tumor diagnosis, and might facilitate the BNCT of brain tumors.


Subject(s)
Boron Compounds , Brain Neoplasms , Fluorine Radioisotopes , Phenylalanine , Positron Emission Tomography Computed Tomography , Radioactive Tracers , Animals , Female , Humans , Mice , Boron Compounds/analysis , Boron Compounds/metabolism , Boron Compounds/pharmacokinetics , Boron Neutron Capture Therapy , Brain/diagnostic imaging , Brain/metabolism , Brain Neoplasms/diagnostic imaging , Brain Neoplasms/metabolism , Fluorine Radioisotopes/analysis , Fluorine Radioisotopes/metabolism , Fluorine Radioisotopes/pharmacokinetics , Healthy Volunteers , Large Neutral Amino Acid-Transporter 1/metabolism , Magnetic Resonance Imaging , Melanoma, Experimental , Mice, Inbred C57BL , Molecular Probes/analysis , Molecular Probes/metabolism , Molecular Probes/pharmacokinetics , Phenylalanine/analogs & derivatives , Phenylalanine/analysis , Phenylalanine/metabolism , Phenylalanine/pharmacokinetics , Positron Emission Tomography Computed Tomography/methods , Xenograft Model Antitumor Assays
2.
BMC Neurol ; 24(1): 202, 2024 Jun 14.
Article in English | MEDLINE | ID: mdl-38877400

ABSTRACT

BACKGROUND: Intratumoral hemorrhage, though less common, could be the first clinical manifestation of glioma and is detectable via MRI; however, its exact impacts on patient outcomes remain unclear and controversial. The 2021 WHO CNS 5 classification emphasised genetic and molecular features, initiating the necessity to establish the correlation between hemorrhage and molecular alterations. This study aims to determine the prevalence of intratumoral hemorrhage in glioma subtypes and identify associated molecular and clinical characteristics to improve patient management. METHODS: Integrated clinical data and imaging studies of patients who underwent surgery at the Department of Neurosurgery at Peking Union Medical College Hospital from January 2011 to January 2022 with pathological confirmation of glioma were retrospectively reviewed. Patients were divided into hemorrhage and non-hemorrhage groups based on preoperative magnetic resonance imaging. A comparison and survival analysis were conducted with the two groups. In terms of subgroup analysis, we classified patients into astrocytoma, IDH-mutant; oligodendroglioma, IDH-mutant, 1p/19q-codeleted; glioblastoma, IDH-wildtype; pediatric-type gliomas; or circumscribed glioma using integrated histological and molecular characteristics, according to WHO CNS 5 classifications. RESULTS: 457 patients were enrolled in the analysis, including 67 (14.7%) patients with intratumoral hemorrhage. The hemorrhage group was significantly older and had worse preoperative Karnofsky performance scores. The hemorrhage group had a higher occurrence of neurological impairment and a higher Ki-67 index. Molecular analysis indicated that CDKN2B, KMT5B, and PIK3CA alteration occurred more in the hemorrhage group (CDKN2B, 84.4% vs. 62.2%, p = 0.029; KMT5B, 25.0% vs. 8.9%, p = 0.029; and PIK3CA, 81.3% vs. 58.5%, p = 0.029). Survival analysis showed significantly worse prognoses for the hemorrhage group (hemorrhage 18.4 months vs. non-hemorrhage 39.1 months, p = 0.01). In subgroup analysis, the multivariate analysis showed that intra-tumoral hemorrhage is an independent risk factor only in glioblastoma, IDH-wildtype (162 cases of 457 overall, HR = 1.72, p = 0.026), but not in other types of gliomas. The molecular alteration of CDK6 (hemorrhage group p = 0.004, non-hemorrhage group p < 0.001), EGFR (hemorrhage group p = 0.003, non-hemorrhage group p = 0.001), and FGFR2 (hemorrhage group p = 0.007, non-hemorrhage group p = 0.001) was associated with shorter overall survival time in both hemorrhage and non-hemorrhage groups. CONCLUSIONS: Glioma patients with preoperative intratumoral hemorrhage had unfavorable prognoses compared to their nonhemorrhage counterparts. CDKN2B, KMT5B, and PIK3CA alterations were associated with an increased occurrence of intratumoral hemorrhage, which might be future targets for further investigation of intratumoral hemorrhage.


Subject(s)
Brain Neoplasms , Glioma , Humans , Male , Female , Glioma/complications , Glioma/genetics , Glioma/surgery , Glioma/pathology , Middle Aged , Retrospective Studies , Prognosis , Adult , Brain Neoplasms/genetics , Brain Neoplasms/complications , Brain Neoplasms/surgery , Brain Neoplasms/pathology , Aged , Cohort Studies , Young Adult
3.
Molecules ; 29(5)2024 Feb 23.
Article in English | MEDLINE | ID: mdl-38474496

ABSTRACT

Chemiluminescence (CL) is of great significance in biochemical analysis and imaging due to its high sensitivity and lack of need for external excitation. In this review, we summarized the recent progress of AIE-based CL systems, including their working mechanisms and applications in biochemical analysis, bioimaging, and disease diagnosis and treatment. In ion and molecular detection, CL shows high selectivity and high sensitivity, especially in the detection of dynamic reactive oxygen species (ROS). Further, the integrated NIR-CL single-molecule system and nanostructural CL platform harnessing CL resonance energy transfer (CRET) have remarkable advantages in long-term imaging with superior capability in penetrating deep tissue depth and high signal-to-noise ratio, and are promising in the applications of in vivo imaging and image-guided disease therapy. Finally, we summarized the shortcomings of the existing AIE-CL system and provided our perspective on the possible ways to develop more powerful CL systems in the future. It can be highly expected that these promoted CL systems will play bigger roles in biochemical analysis and disease theranostics.


Subject(s)
Luminescence , Nanostructures , Precision Medicine , Diagnostic Imaging , Theranostic Nanomedicine/methods
4.
J Biol Chem ; 296: 100574, 2021.
Article in English | MEDLINE | ID: mdl-33757767

ABSTRACT

PorX/PorY is a two-component system (TCS) of Porphyromonas gingivalis that governs transcription of numerous genes including those encoding a type IX secretion system (T9SS) for gingipain secretion and heme accumulation. Here, an in vitro analysis showed that the response regulator PorX specifically bound to two regions in the promoter of porT, a known PorX-regulated T9SS gene, thus demonstrating that PorX/PorY can directly regulate specific target genes. A truncated PorX protein containing the N-terminal receiver and effector domains retained a wild-type ability in both transcription regulation and heme accumulation, ruling out the role of the C-terminal ALP domain in gene regulation. The PorX/PorY system was the only TCS essential for heme accumulation and concomitantly responded to hemin to stimulate transcription of several known PorX-dependent genes in a concentration-dependent manner. We found that PorX/PorY activated the sigH gene, which encodes a sigma factor known for P. gingivalis adaptation to hydrogen peroxide (H2O2). Consistently, both ΔporX and ΔsigH mutants were susceptible to H2O2, suggesting a PorX/PorY-σH regulatory cascade to confer resistance to oxidative stress. Furthermore, the ΔporX mutant became susceptible to high hemin levels that could induce oxidative stress. Therefore, a possible reason why hemin activates PorX/PorY is to confer resistance to hemin-induced oxidative stress. We also demonstrated that PorX/PorY was essential for P. gingivalis virulence because the ΔporX mutant was avirulent in a mouse model. Specifically, this TCS was required for the repression of proinflammatory cytokines secreted by dendritic cells and T cells in the P. gingivalis-infected mice.


Subject(s)
Bacterial Proteins/metabolism , Bacterial Secretion Systems/metabolism , Porphyromonas gingivalis/metabolism , Virulence Factors/metabolism , Animals , Bacterial Proteins/genetics , Gene Expression Regulation, Bacterial , Mice , Mutation , Porphyromonas gingivalis/genetics , Porphyromonas gingivalis/physiology , Protein Processing, Post-Translational , Virulence Factors/genetics
5.
J Bacteriol ; 203(19): e0023721, 2021 09 08.
Article in English | MEDLINE | ID: mdl-34280001

ABSTRACT

The pH 6 antigen (PsaA) of Yersinia pestis is a virulence factor that is expressed in response to high temperature (37°C) and low pH (6.0). Previous studies have implicated the PsaE and PsaF regulators in the temperature- and pH-dependent regulation of psaA. Here, we show that PsaE levels are themselves controlled by pH and temperature, explaining the regulation of psaA. We identify hundreds of binding sites for PsaE across the Y. pestis genome, with the majority of binding sites located in intergenic regions bound by the nucleoid-associated protein H-NS. However, we detect direct regulation of only two transcripts by PsaE, likely due to displacement of H-NS from the corresponding promoter regions; our data suggest that most PsaE binding sites are nonregulatory or that they require additional environmental cues. We also identify the precise binding sites for PsaE that are required for temperature- and pH-dependent regulation of psaA and psaE. Thus, our data reveal the critical role that PsaE plays in the regulation of psaA and suggest that PsaE may have many additional regulatory targets. IMPORTANCE Y. pestis, the etiologic agent of plague, has been responsible for high mortality in several epidemics throughout human history. The plague bacillus has been used as a biological weapon during human history and is currently one of the most likely biological threats. PsaA and PsaE appear to play important roles during Y. pestis infection. Understanding their regulation by environmental cues would facilitate a solution to impede Y. pestis infection.


Subject(s)
Antigens, Bacterial/metabolism , Bacterial Proteins/metabolism , Gene Expression Regulation, Bacterial/physiology , Yersinia pestis/metabolism , Antigens, Bacterial/genetics , Bacterial Proteins/genetics , Genome-Wide Association Study , Hydrogen-Ion Concentration , Photosystem I Protein Complex/genetics , Photosystem I Protein Complex/metabolism , Protein Binding , RNA Processing, Post-Transcriptional , Temperature , Transcription, Genetic , Yersinia pestis/genetics
6.
Ann Vasc Surg ; 72: 365-372, 2021 Apr.
Article in English | MEDLINE | ID: mdl-32947000

ABSTRACT

BACKGROUND: In this study, we sought to assess knowledge, attitudes, and behaviors regarding venous thromboembolism (VTE) prophylaxis among clinicians at a tertiary hospital of China. METHODS: An electronic questionnaire was sent to clinicians to gather information regarding demographic data (5 items), knowledge about VTE prophylaxis (21 items), behaviors regarding VTE prophylaxis (8 items), and attitudes regarding VTE prophylaxis (7 items). Answers of "strongly agree" and "agree" on the behaviors and attitude items were defined as affirmative responses. Clinicians were also asked to provide suggestions regarding VTE prophylaxis. RESULTS: A total of 867 clinicians were included in this study. The overall correct response rate for knowledge items was 60.9%. The median affirmative response rate for behavior items was 48.6% (range 29.5-80.3%), and the median affirmative response rate for attitude items was 98.7% (range 96.9-99.3%). Clinicians were most concerned about the adverse effects triggered by chemical VTE prophylaxis (79.5%) and possibility of a financial penalty when a patient could not be treated with VTE prophylaxis (72.3%). Low patient compliance and low level of clinician knowledge and participation were identified most commonly as difficulties involved in VTE prophylaxis. A total of 78 suggestions were collected; these suggestions generally focused on improving the quality and frequency of staff training (n = 24) and enhancing learning opportunities (n = 22). CONCLUSIONS: Although the clinicians' overall attitude toward VTE prophylaxis was positive, the knowledge level was relatively poor, and the rate of affirmative responses regarding behaviors was low. Medical institutions should improve clinician training regarding VTE prophylaxis.


Subject(s)
Attitude of Health Personnel , Clinical Competence , Fibrinolytic Agents/therapeutic use , Health Knowledge, Attitudes, Practice , Practice Patterns, Physicians' , Venous Thromboembolism/prevention & control , Adult , China , Fibrinolytic Agents/adverse effects , Health Care Surveys , Hospitalization , Humans , Middle Aged , Patient Education as Topic , Risk Assessment , Risk Factors , Surveys and Questionnaires , Venous Thromboembolism/diagnosis , Venous Thromboembolism/etiology
7.
Vascular ; 29(1): 78-84, 2021 Feb.
Article in English | MEDLINE | ID: mdl-32576119

ABSTRACT

OBJECTIVES: To investigate the cognition of nurses on the control and treatment of venous thromboembolism in China, thereby providing suitable countermeasures for clinical venous thromboembolism prophylaxis and treatment. METHODS: In December 2019, a total of 1121 registered nurses from a university-affiliated hospital were selected to answer the self-designed and electronic questionnaire (Wenquanxing: www.wjx.cn/), which was designed to evaluate the nurses' knowledge (21 items), attitudes (6 items), and behaviors (9 items) toward venous thromboembolism prophylaxis. Descriptive, correlation, and regression analyses were conducted for data analysis. RESULTS: Of the included 1121 nurses, only 55.43% nurses selected 100% correct answer. The influencing factors of knowledge included the department, education, professional ranks, and venous thromboembolism nursing experience. The nurses from ICU department gained the highest score, but the nurses from pediatrics department obtained the lowest score. The nurses with higher education level and professional ranks, and nursing experiences achieved higher scores. The total positive response rate for the attitude-related items was 68.54%. Nurses were primarily concerned about the financial penalty due to the inability to complete the work (49.0%). An increasing workload is the second primary concern of nurses (40.8%). The increasing medical cost, extension of hospital stay, and exacerbation of doctor-patient conflicts were the most serious difficulties involved in venous thromboembolism prophylaxis. The total correct score rate for the behaviors was 56.19%. Nearly half of the nurses could not offer advice for venous thromboembolism patients. The nursing experience, department, and years of work were related to the scores of knowledge-related items (all P < 0.05). CONCLUSIONS: The overall knowledge level of the nurses was not optimistic. Although their general attitude toward venous thromboembolism prophylaxis was positive, their behaviors were influenced by many factors. Administrators should, therefore, make countermeasures to deal with these problems.


Subject(s)
Attitude of Health Personnel , Health Knowledge, Attitudes, Practice , Nurses/psychology , Venous Thromboembolism/prevention & control , Adult , China , Clinical Competence , Humans , Middle Aged , Practice Patterns, Nurses' , Risk Factors , Specialization , Surveys and Questionnaires , Venous Thromboembolism/etiology
8.
BMC Med ; 18(1): 274, 2020 09 07.
Article in English | MEDLINE | ID: mdl-32892742

ABSTRACT

BACKGROUND: The coronavirus disease 2019 (COVID-19) has been a pandemic worldwide. Old age and underlying illnesses are associated with poor prognosis among COVID-19 patients. However, whether frailty, a common geriatric syndrome of reduced reserve to stressors, is associated with poor prognosis among older COVID-19 patients is unknown. The aim of our study is to investigate the association between frailty and severe disease among COVID-19 patients aged ≥ 60 years. METHODS: A prospective cohort study of 114 hospitalized older patients (≥ 60 years) with confirmed COVID-19 pneumonia was conducted between 7 February 2020 and 6 April 2020. Epidemiological, demographic, clinical, laboratory, and outcome data on admission were extracted from electronic medical records. All patients were assessed for frailty on admission using the FRAIL scale, in which five components are included: fatigue, resistance, ambulation, illnesses, and loss of weight. The outcome was the development of the severe disease within 60 days. We used the Cox proportional hazards models to identify the unadjusted and adjusted associations between frailty and severe illness. The significant variables in univariable analysis were included in the adjusted model. RESULTS: Of 114 patients, (median age, 67 years; interquartile range = 64-75 years; 57 [50%] men), 39 (34.2%), 39 (34.2%), and 36 (31.6%) were non-frail, pre-frail, and frail, respectively. During the 60 days of follow-up, 43 severe diseases occurred including eight deaths. Four of 39 (10.3%) non-frail patients, 15 of 39 (38.5%) pre-frail patients, and 24 of 36 (66.7%) frail patients progressed to severe disease. After adjustment of age, sex, body mass index, haemoglobin, white blood count, lymphocyte count, albumin, CD8+ count, D-dimer, and C-reactive protein, frailty (HR = 7.47, 95% CI 1.73-32.34, P = 0.007) and pre-frailty (HR = 5.01, 95% CI 1.16-21.61, P = 0.03) were associated with a higher hazard of severe disease than the non-frail. CONCLUSIONS: Frailty, assessed by the FRAIL scale, was associated with a higher risk of developing severe disease among older COVID-19 patients. Our findings suggested that the use of a clinician friendly assessment of frailty could help in early warning of older patients at high-risk with severe COVID-19 pneumonia.


Subject(s)
Coronavirus Infections , Frail Elderly , Frailty/diagnosis , Frailty/virology , Geriatric Assessment/methods , Pandemics , Pneumonia, Viral , Aged , Aged, 80 and over , Betacoronavirus , COVID-19 , China , Female , Humans , Male , Middle Aged , Proportional Hazards Models , Prospective Studies , SARS-CoV-2
9.
J Bacteriol ; 201(2)2019 01 15.
Article in English | MEDLINE | ID: mdl-30373755

ABSTRACT

By screening a collection of Salmonella mutants deleted for genes encoding small proteins of ≤60 amino acids, we identified three paralogous small genes (ymdF, STM14_1829, and yciG) required for wild-type flagellum-dependent swimming and swarming motility. The ymdF, STM14_1829, and yciG genes encode small proteins of 55, 60, and 60 amino acid residues, respectively. A bioinformatics analysis predicted that these small proteins are intrinsically disordered proteins, and circular dichroism analysis of purified recombinant proteins confirmed that all three proteins are unstructured in solution. A mutant deleted for STM14_1829 showed the most severe motility defect, indicating that among the three paralogs, STM14_1829 is a key protein required for wild-type motility. We determined that relative to the wild type, the expression of the flagellin protein FliC is lower in the ΔSTM14_1829 mutant due to the downregulation of the flhDC operon encoding the FlhDC master regulator. By comparing the gene expression profiles between the wild-type and ΔSTM14_1829 strains via RNA sequencing, we found that the gene encoding the response regulator PhoP is upregulated in the ΔSTM14_1829 mutant, suggesting the indirect repression of the flhDC operon by the activated PhoP. Homologs of STM14_1829 are conserved in a wide range of bacteria, including Escherichia coli and Pseudomonas aeruginosa We showed that the inactivation of STM14_1829 homologs in E. coli and P. aeruginosa also alters motility, suggesting that this family of small intrinsically disordered proteins may play a role in the cellular pathway(s) that affects motility.IMPORTANCE This study reports the identification of a novel family of small intrinsically disordered proteins that are conserved in a wide range of flagellated and nonflagellated bacteria. Although this study identifies the role of these small proteins in the scope of flagellum-dependent motility in Salmonella, they likely play larger roles in a more conserved cellular pathway(s) that indirectly affects flagellum expression in the case of motile bacteria. Small intrinsically disordered proteins have not been well characterized in prokaryotes, and the results of our study provide a basis for their detailed functional characterization.


Subject(s)
Bacterial Proteins/metabolism , Flagella/physiology , Intrinsically Disordered Proteins/metabolism , Locomotion , Salmonella enterica/physiology , Bacterial Proteins/chemistry , Bacterial Proteins/genetics , Circular Dichroism , Escherichia coli/genetics , Escherichia coli/physiology , Gene Deletion , Gene Expression Profiling , Intrinsically Disordered Proteins/chemistry , Intrinsically Disordered Proteins/genetics , Pseudomonas aeruginosa/genetics , Pseudomonas aeruginosa/physiology , Salmonella enterica/genetics
10.
Clin Endocrinol (Oxf) ; 91(1): 201-208, 2019 07.
Article in English | MEDLINE | ID: mdl-31004514

ABSTRACT

OBJECTIVE: To evaluate the value of shear wave elastography (SWE) in avoiding repeat fine-needle aspiration of thyroid nodules with nondiagnostic and undetermined cytology. METHODS: A total of 232 thyroid nodules with nondiagnostic (n = 132) and undetermined (n = 100) cytology underwent ultrasound (US) and SWE, followed by repeat ultrasound (US)-guided fine-needle aspiration cytology (FNAC). The final diagnosis was based on cytological or pathological findings. The US and SWE characteristics of benign and malignant nodules were compared using the χ2 -test. The receiver operating characteristic (ROC) curves of the thyroid imaging reporting and data system (TI-RADS) categories from the US and the EMean and ESD from the SWE were graphed, and the areas under the curves (AUCs) were compared using a Z test. RESULTS: There were significant differences between the benign and malignant nodules in terms of the echogenicity, shape, margin, calcification and TI-RADS categories (all P < 0.05). The differences were significant between the malignant and benign nodules for EMean [(34.57 ± 14.81) kPa vs. (19.18 ± 7.09) kPa] and ESD [(13.68 ± 13.01) kPa vs. (3.97 ± 2.58) kPa] (both P < 0.001). Though the difference in the AUCs of EMean (0.864) and ESD (0.876) was not significant (P = 0.745), they both had higher diagnostic performances in comparison with TI-RADS categories (0.762) (all P < 0.05). Moreover, ESD attained a sensitivity of 100% with a relatively higher specificity of 49.75% when its cut-off value was 3.3 kPa. CONCLUSIONS: Shear wave elastography is a promising imaging method for reducing repeat FNAC for benign thyroid nodules with nondiagnostic and undetermined cytology when using ESD as an index.


Subject(s)
Biopsy, Fine-Needle/methods , Elasticity Imaging Techniques/methods , Thyroid Gland/pathology , Thyroid Neoplasms/pathology , Thyroid Nodule/diagnostic imaging , Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , ROC Curve , Retrospective Studies , Young Adult
12.
Mar Drugs ; 17(8)2019 Jul 24.
Article in English | MEDLINE | ID: mdl-31344874

ABSTRACT

Undaria pinnatifida sporophyll (U. pinnatifida) is a major byproduct of U. pinnatifida (a brown algae) processing. Its phenolic constituents, phlorotannins, are of special interest due to their intrinsic ability to precipitate proteins. Herein, a high-temperature extraction procedure was used to isolate these biologically active compounds. The heating temperature, heating time, and extraction solvent (ethanol) concentration were examined with response surface analysis to determine the optimal conditions to achieve the maximum extraction rate. The analysis revealed the optimal conditions to be: 170 °C of heating temperature, 5.2 h of heating time, and 52% ethanol concentration for a yield of 10.7 ± 0.2 mg gallic acid equivalent/g dry weight (GAE/g DW) of sample. Compared to epigallocatechin gallate (EGCG), the extracted phlorotannins displayed higher antioxidant activity on H2O2-induced RAW 264.7 cells with improved efficiency. Furthermore, the compounds exhibited strong anti-inflammatory activity. These findings potentially can be utilized to guide development of novel functional foods and food supplements from sea-originated resources such as brown algae.


Subject(s)
Anti-Inflammatory Agents/chemistry , Anti-Inflammatory Agents/pharmacology , Antioxidants/chemistry , Antioxidants/physiology , Undaria/chemistry , Animals , Cell Line , Functional Food , Mice , Phaeophyceae/chemistry , Phenols/chemistry , RAW 264.7 Cells
14.
Biochim Biophys Acta ; 1864(12): 1686-1695, 2016 12.
Article in English | MEDLINE | ID: mdl-27618760

ABSTRACT

In pathogenic bacteria, the two-component regulatory systems (TCSs) play important roles in signal transduction and regulation of their pathogenesis. Here, we used quantitative proteomic methods to comparatively analyze functional networks under the control of the RstA/RstB system versus the PhoP/PhoQ system in Salmonella typhimurium. By comparing the proteomic profile from a wild-type strain to that from a ΔrstB strain or a ΔphoPQ strain under a condition known to activate these TCSs, we found that the levels of 159 proteins representing 6.92% of the 2297 proteins identified from the ΔrstB strain and 341 proteins representing 14.9% of the 2288 proteins identified from the ΔphoPQ strain were significantly changed, respectively. Bioinformatics analysis revealed that the RstA/RstB system and the PhoP/PhoQ system coordinated with regard to the regulation of specific proteins as well as metabolic processes. Our observations suggested that the regulatory networks controlled by the PhoP/PhoQ system were much more extensive than those by the RstA/RstB system, whereas the RstA/RstB system specifically regulated expression of the constituents participating in pyrimidine metabolism and iron acquisition. Additional results also suggested that the RstA/RstB system was required for regulation of Salmonella motility and invasion.


Subject(s)
Salmonella typhimurium/genetics , Salmonella typhimurium/metabolism , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Computational Biology , Gene Expression Regulation, Bacterial , Genes, Bacterial , Humans , Iron/metabolism , Mutation , Proteomics , Pyrimidines/metabolism , Salmonella typhimurium/pathogenicity , Virulence
15.
J Biol Chem ; 289(16): 11353-11366, 2014 Apr 18.
Article in English | MEDLINE | ID: mdl-24596096

ABSTRACT

Riboswitches are a class of cis-acting regulatory RNAs normally characterized from the 5'-UTR of bacterial transcripts that bind a specific ligand to regulate expression of associated genes by forming alternative conformations. Here, we present a riboswitch that contributes to transcriptional regulation through sensing Mn(2+) in Salmonella typhimurium. We characterized a 5'-UTR (UTR1) from the mntH locus encoding a Mn(2+) transporter, which forms a Rho-independent terminator to implement transcription termination with a high Mn(2+) selectivity both in vivo and in vitro. Nucleotide substitutions that cause disruption of the terminator interfere with the regulatory function of UTR1. RNA probing analyses outlined a specific UTR1 conformation that favors the terminator structure in Mn(2+)-replete condition. Switch sequence GCUAUG can alternatively base pair duplicated hexanucleotide CAUAGC to form either a pseudoknot or terminator stem. Mn(2+), but not Mg(2+), and Ca(2+), can enhance cleavage at specific nucleotides in UTR1. We conclude that UTR1 is a riboswitch that senses cytoplasmic Mn(2+) and therefore participates in Mn(2+)-responsive mntH regulation in Salmonella. This riboswitch domain is also conserved in several Gram-negative enteric bacteria, indicating that this Mn(2+)-responsive mechanism could have broader implications in bacterial gene expression. Additionally, a high level of cytoplasmic Mn(2+) can down-regulate transcription of the Salmonella Mg(2+) transporter mgtA locus in a Mg(2+) riboswitch-dependent manner. On the other hand, these two types of cation riboswitches do not share similarity at the primary or secondary structural levels. Taken together, characterization of Mn(2+)-responsive riboswitches should expand the scope of RNA regulatory elements in response to inorganic ions.


Subject(s)
Bacterial Proteins/biosynthesis , Cation Transport Proteins/biosynthesis , Gene Expression Regulation, Bacterial/physiology , Genetic Loci/physiology , Manganese/metabolism , Riboswitch/physiology , Salmonella typhimurium/metabolism , 5' Untranslated Regions/physiology , Adenosine Triphosphatases/biosynthesis , Adenosine Triphosphatases/genetics , Bacterial Proteins/genetics , Calcium/metabolism , Cation Transport Proteins/genetics , Ion Transport/physiology , Magnesium/metabolism , Membrane Transport Proteins/biosynthesis , Membrane Transport Proteins/genetics , Salmonella typhimurium/genetics
16.
J Biol Chem ; 289(47): 32571-82, 2014 Nov 21.
Article in English | MEDLINE | ID: mdl-25294881

ABSTRACT

A genome-wide susceptibility assay was used to identify specific CpxR-dependent genes that facilitate Escherichia coli resistance to a model cationic antimicrobial peptide, protamine. A total of 115 strains from the Keio Collection, each of which contained a deletion at a demonstrated or predicted CpxR/CpxA-dependent locus, were tested for protamine susceptibility. One strain that exhibited high susceptibility carried a deletion of tolC, a gene that encodes the outer membrane component of multiple tripartite multidrug transporters. Concomitantly, two of these efflux systems, AcrAB/TolC and EmrAB/TolC, play major roles in protamine resistance. Activation of the CpxR/CpxA system stimulates mar transcription, suggesting a new regulatory circuit that enhances the multidrug resistance cascade. Tripartite multidrug efflux systems contribute to bacterial resistance to protamine differently from the Tat system. DNase I footprinting analysis demonstrated that the CpxR protein binds to a sequence located in the -35 and -10 regions of mar promoter. This sequence resembles the consensus CpxR binding site, however, on the opposite strand. aroK, a CpxR-dependent gene that encodes a shikimate kinase in the tryptophan biosynthesis pathway, was also found to facilitate protamine resistance. Specific aromatic metabolites from this pathway, such as indole, can stimulate expression of well studied CpxR-dependent genes degP and cpxP, which are not components of the tripartite multidrug transporters. Thus, we propose a novel mechanism for E. coli to modulate resistance to protamine and likely other cationic antimicrobial peptides in which the CpxR/CpxA system up-regulates mar transcription in response to specific aromatic metabolites, subsequently stimulating the multidrug resistance cascade.


Subject(s)
Bacterial Proteins/metabolism , Drug Resistance, Multiple, Bacterial , Escherichia coli Proteins/metabolism , Escherichia coli/drug effects , Protamines/pharmacology , Protein Kinases/metabolism , Antimicrobial Cationic Peptides/pharmacology , Bacterial Outer Membrane Proteins/genetics , Bacterial Outer Membrane Proteins/metabolism , Bacterial Proteins/genetics , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Escherichia coli/genetics , Escherichia coli Proteins/genetics , Gene Expression Regulation, Bacterial/drug effects , Membrane Transport Proteins/genetics , Membrane Transport Proteins/metabolism , Microbial Viability/drug effects , Microbial Viability/genetics , Models, Genetic , Mutation , Phosphotransferases (Alcohol Group Acceptor)/genetics , Phosphotransferases (Alcohol Group Acceptor)/metabolism , Promoter Regions, Genetic/genetics , Protein Binding , Protein Kinases/genetics , Repressor Proteins/genetics , Repressor Proteins/metabolism , Signal Transduction/drug effects , Signal Transduction/genetics , Up-Regulation
17.
EMBO J ; 30(8): 1485-96, 2011 Apr 20.
Article in English | MEDLINE | ID: mdl-21399613

ABSTRACT

We have characterized a 17-residue peptide, MgtL, which is translated specifically in high Mg(2+) from an open reading frame (ORF) embedded in the Mg(2+) riboswitch domain, previously identified in the 5' leader region of Mg(2+) transporter gene mgtA in Salmonella. We demonstrate that mgtL translation is required to prematurely terminate mgtA transcription. Abrogation of mgtL translation by mutation of its start codon results in transcription of the mgtA-coding region in high Mg(2+), suggesting that ribosome stalling is not required for preventing premature transcription termination. Consistently, the Mg(2+) riboswitch responds to cytoplasmic Mg(2+), but not to proline or arginine, both repeatedly present in the MgtL sequence, to mediate mgtL translation-coupled regulation. RNA structural probing and nucleotide substitution analysis show that the riboswitch loop A region alters base pairing in response to Mg(2+), and favours stem-loop A1 in high Mg(2+), subsequently opening the ribosome-binding sequence for mgtL translation. Presumably, mgtL ORF directs translation to localize a ribosome in cis to act on downstream RNA in a manner similar to some upstream ORFs in prokaryotes and eukaryotes.


Subject(s)
Magnesium/pharmacology , Peptide Chain Termination, Translational/drug effects , Protein Sorting Signals/genetics , Ribosomes/physiology , Riboswitch/physiology , Transcription, Genetic/drug effects , Adenosine Triphosphatases/genetics , Adenosine Triphosphatases/metabolism , Amino Acid Sequence , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Base Sequence , Codon, Initiator , Membrane Transport Proteins/genetics , Membrane Transport Proteins/metabolism , Molecular Sequence Data , Nucleic Acid Conformation , Open Reading Frames , Salmonella typhimurium/genetics , Salmonella typhimurium/growth & development , Salmonella typhimurium/metabolism , Sequence Homology, Amino Acid , Sequence Homology, Nucleic Acid
18.
J Allergy Clin Immunol ; 131(3): 718-23, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23146376

ABSTRACT

BACKGROUND: We previously showed that impulse oscillometry (IOS) indices of peripheral airway function are associated with asthma control in children. However, little data exist on whether dysfunction in the peripheral airways can predict loss of asthma control. OBJECTIVE: We sought to determine the utility of peripheral airway impairment, as measured by IOS, in predicting loss of asthma control in children. METHODS: Fifty-four children (age, 7-17 years) with controlled asthma were enrolled in the study. Spirometric and IOS indices of airway function were obtained at baseline and at a follow-up visit 8 to 12 weeks later. Physicians who were blinded to the IOS measurements assessed asthma control (National Asthma Education and Prevention Program guidelines) on both visits and prescribed no medication change between visits. RESULTS: Thirty-eight (70%) patients maintained asthma control between 2 visits (group C-C), and 16 patients had asthma that became uncontrolled on the follow-up visit (group C-UC). There was no difference in baseline spirometric results between the C-C and C-UC groups, except for FEV1/forced vital capacity ratio (86% vs 82%, respectively; P < .01). Baseline IOS results, including resistance of the respiratory system at 5 Hz (R5; 6.4 vs 4.3 cm H2O · L(-1) · s), frequency dependence of resistance (difference of R5 and resistance of the respiratory system at 20 Hz [R5-20]; 2.0 vs 0.7 cm H2O · L(-1) · s), and reactance area (13.1 vs 4.1 cm H2O · L(-1)), of group C-UC were significantly higher than those of group C-C (P < .01). Receiver operating characteristic analysis showed baseline R5-20 and reactance area effectively predicted asthma control status at the follow-up visit (area under the curve, 0.91 and 0.90). CONCLUSION: Children with controlled asthma who have increased peripheral airway IOS indices are at risk of losing asthma control.


Subject(s)
Airway Resistance , Asthma/physiopathology , Adolescent , Asthma/diagnosis , Child , Female , Humans , Lung/physiopathology , Male , Oscillometry , Spirometry
19.
Plant Methods ; 20(1): 96, 2024 Jun 20.
Article in English | MEDLINE | ID: mdl-38902736

ABSTRACT

BACKGROUND: Pesticide efficacy directly affects crop yield and quality, making targeted spraying a more environmentally friendly and effective method of pesticide application. Common targeted cabbage spraying methods often involve object detection networks. However, complex natural and lighting conditions pose challenges in the accurate detection and positioning of cabbage. RESULTS: In this study, a cabbage detection algorithm based on the YOLOv8n neural network (YOLOv8-cabbage) combined with a positioning system constructed using a Realsense depth camera is proposed. Initially, four of the currently available high-performance object detection models were compared, and YOLOv8n was selected as the transfer learning model for field cabbage detection. Data augmentation and expansion methods were applied to extensively train the model, a large kernel convolution method was proposed to improve the bottleneck section, the Swin transformer module was combined with the convolutional neural network (CNN) to expand the perceptual field of feature extraction and improve edge detection effectiveness, and a nonlocal attention mechanism was added to enhance feature extraction. Ablation experiments were conducted on the same dataset under the same experimental conditions, and the improved model increased the mean average precision (mAP) from 88.8% to 93.9%. Subsequently, depth maps and colour maps were aligned pixelwise to obtain the three-dimensional coordinates of the cabbages via coordinate system conversion. The positioning error of the three-dimensional coordinate cabbage identification and positioning system was (11.2 mm, 10.225 mm, 25.3 mm), which meets the usage requirements. CONCLUSIONS: We have achieved accurate cabbage positioning. The object detection system proposed here can detect cabbage in real time in complex field environments, providing technical support for targeted spraying applications and positioning.

20.
Front Public Health ; 12: 1404407, 2024.
Article in English | MEDLINE | ID: mdl-38975361

ABSTRACT

Objectives: Depression is largely preventable, and strategies that can effectively suppress its development are imperative. We aimed to examine whether physical activity and sedentary behavior were associated with depression and explore the possible mediatory role of complete blood count in this association. Methods: In this cross-sectional study, data were integrated from the National Health and Nutrition Examination Study (2007-2018). Depression was defined using the Patient Health Questionnaire-9. The risk for depression, expressed as odds ratio (OR) and 95% confidence interval (CI), was quantified by survey-weighted logistic regression analyses. Results: A total of 31,204 respondents were analyzed. Significance was identified for all, except walking or bicycling per week, types of physical activity, and sedentary behavior. Per 1 standard deviation (SD) increment in metabolic equivalent of task (MET) of weekly vigorous recreational physical activity was associated with 31.3% decreased depression risk (adjusted OR: 0.687, 95% CI: 0.5663-0.840). Per 1 SD increment in sitting time can increase depression risk by 22.4% (adjusted OR: 1.224, 95% CI: 1.131-1.325). In subsidiary analyses, the association with depression was reinforced in respondents aged ≤65 years and those overweight or obese. Mediation analyses revealed significant effects for red blood cell (RBC) on total MET (19.4%) and moderate work-related physical activity (MWPA) (22.0%), and for red cell distribution wide (RCDW) on vigorous work-related physical activity (17.7%), moderate work-related physical activity (13.1%), total MET (11.2%), and sitting time (16.4%) (p < 0.01). Conclusion: Our findings indicate that more physical activity and less sitting time were associated with a lower likelihood of having depression among US adults, and this association was probably mediated by RBC and RCDW.


Subject(s)
Depression , Exercise , Nutrition Surveys , Sedentary Behavior , Humans , Male , Female , Cross-Sectional Studies , Middle Aged , United States/epidemiology , Depression/epidemiology , Adult , Aged , Risk Factors , Young Adult
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