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1.
Sci Immunol ; 9(97): eadn6509, 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-39028827

RESUMO

Most patients treated with US Food and Drug Administration (FDA)-approved chimeric antigen receptor (CAR) T cells eventually experience disease progression. Furthermore, CAR T cells have not been curative against solid cancers and several hematological malignancies such as T cell lymphomas, which have very poor prognoses. One of the main barriers to the clinical success of adoptive T cell immunotherapies is CAR T cell dysfunction and lack of expansion and/or persistence after infusion. In this study, we found that CD5 inhibits CAR T cell activation and that knockout (KO) of CD5 using CRISPR-Cas9 enhances the antitumor effect of CAR T cells in multiple hematological and solid cancer models. Mechanistically, CD5 KO drives increased T cell effector function with enhanced cytotoxicity, in vivo expansion, and persistence, without apparent toxicity in preclinical models. These findings indicate that CD5 is a critical inhibitor of T cell function and a potential clinical target for enhancing T cell therapies.


Assuntos
Antígenos CD5 , Imunoterapia Adotiva , Linfócitos T , Animais , Imunoterapia Adotiva/métodos , Antígenos CD5/imunologia , Camundongos , Humanos , Linfócitos T/imunologia , Linfócitos T/transplante , Receptores de Antígenos Quiméricos/imunologia , Receptores de Antígenos Quiméricos/genética , Linhagem Celular Tumoral , Sistemas CRISPR-Cas , Feminino
3.
Orthop Rev (Pavia) ; 16: 94574, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38666188

RESUMO

Background: Periprosthetic fracture is a rare complication of arthroplasty but can have devastating consequences for the patient and presents a complex surgical challenge. Locking compression plate and retrograde intramedullary nail are both widely accepted surgical fixation techniques for distal femoral periprosthetic fractures around a total knee arthroplasty. Although there is still a need for further high-quality research into both techniques, there is even less literature concerning the use of distal femoral replacement to treat distal femoral periprosthetic fractures. Interest has been piqued in distal femoral replacements for the treatment of distal femoral periprosthetic fractures due to the theoretical advantages of immediate post-operative weight-bearing and lack of dependence on fracture union, but there are still understandably reservations about performing such an extensive and invasive procedure when an accepted alternative is available. This meta-analysis aims to evaluate the current literature to compare the complication rates and return to pre-operative ambulatory status of distal femoral replacement and locking compression plate. Method: A literature search was performed to identify articles related to the management of distal femoral periprosthetic fractures around a total knee arthroplasty in adherence to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. Methodological quality was assessed using the methodological index for non-randomized studies (MINORS) criteria. Articles were reviewed, and data extracted for analysis. Results: Five articles met the inclusion criteria, reporting on 345 periprosthetic fractures. The overall rates of complications for distal femoral replacement and locking compression plate were: re-operation (6.1% vs 12.1%), infection (3.0% vs 5.3%), mortality (19.7% vs 19.3%), and return to pre-operative ambulatory status (60.9% vs 71.8%) (respectively). Conclusion: This meta-analysis shows no statistically significant difference in the rates of re-operation, infection, mortality or return to pre-operative ambulatory status when comparing distal femoral replacement to locking compression plate.

4.
Osteoarthritis Cartilage ; 32(8): 990-1000, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38648876

RESUMO

OBJECTIVE: To examine associations between serum oxylipins, which regulate tissue repair and pain signalling, and knee pain/radiographic osteoarthritis (OA) at baseline and knee pain at 3 year follow-up. METHOD: Baseline, and 3 year follow-up, knee pain phenotypes were assessed from 154 participants in the Knee Pain in the Community (KPIC) cohort study. Serum and radiographic Kellgren and Lawrence (KL) and Nottingham line drawing atlas OA scores were collected at baseline. Oxylipin levels were quantified using liquid chromatography coupled with mass spectrometry. Associations were measured by linear regression and receiver operating characteristics (ROC). RESULTS: Serum levels of 8,9-epoxyeicosatrienoic acid (EET) (ß(95% confidence intervals (CI)) = 1.809 (-0.71 to 2.91)), 14,15-dihydroxyeicosatrienoic acid (DHET) (ß(95%CI) = 0.827 (0.34-1.31)), and 12-hydroxyeicosatetraenoic acid (HETE) (ß(95%CI) = 4.090 (1.92-6.26)) and anandamide (ß(95%CI) = 3.060 (1.35-4.77)) were cross-sectionally associated with current self-reported knee pain scores (numerical rating scale (NRS) item 3, average pain). Serum levels of 9- (ß(95%CI) = 0.467 (0.18-0.75)) and 15-HETE (ß(95%CI) = 0.759 (0.29-1.22)), 14-hydroxydocosahexaenoic acid (ß(95%CI) = 0.483(0.24-0.73)), and the ratio of 8,9-EET:DHET (ß(95%CI) = 0.510(0.19-0.82)) were cross-sectionally associated with KL scores. Baseline serum concentrations of 8,9-EET (ß(95%CI) = 2.166 (0.89-3.44)), 5,6-DHET (ß(95%CI) = 152.179 (69.39-234.97)), and 5-HETE (ß(95%CI) = 1.724 (0.677-2.77) showed positive longitudinal associations with follow-up knee pain scores (NRS item 3, average pain). Combined serum 8,9-EET and 5-HETE concentration showed the strongest longitudinal association (ß(95%CI) = 1.156 (0.54-1.77) with pain scores at 3 years, and ROC curves distinguished between participants with no pain and high pain scores at follow-up (area under curve (95%CI) = 0.71 (0.61-0.82)). CONCLUSIONS: Serum levels of a combination of hydroxylated metabolites of arachidonic acid may have prognostic utility for knee pain, providing a potential novel approach to identify people who are more likely to have debilitating pain in the future.


Assuntos
Artralgia , Progressão da Doença , Osteoartrite do Joelho , Humanos , Feminino , Masculino , Osteoartrite do Joelho/sangue , Pessoa de Meia-Idade , Estudos Transversais , Idoso , Artralgia/sangue , Estudos Longitudinais , Estudos de Coortes , Oxilipinas/sangue , Articulação do Joelho , Ácidos Hidroxieicosatetraenoicos/sangue , Ácidos Araquidônicos/sangue , Biomarcadores/sangue , Medição da Dor , Ácido Araquidônico/sangue
5.
Sci Rep ; 14(1): 8572, 2024 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-38609431

RESUMO

Unfractionated heparin (UFH) is an effective antithrombotic during surgery but has known adverse effects, in particular on platelets. A marked increase in platelet responsiveness has previously been observed in patients within minutes of receiving UFH, despite adequate inhibition by aspirin prior to heparin. We studied this phenomenon in patients undergoing cardiac artery bypass grafting (n = 17) to determine whether the effects of heparin were systemic or platelet-specific. All patients' platelets were fully inhibited by aspirin prior to surgery, but within 3 min of receiving heparin spontaneous aggregation and responses to arachidonic acid (AA) and ADP increased significantly (p ≥ 0.0002), and activated platelets were found in the circulation. While there was no rise in thromboxane in the plasma following heparin, levels of the major platelet 12-lipoxygenase product, 12-HETE, rose significantly. Mixing experiments demonstrated that the changes caused by heparin resided primarily in the platelets, while addition of AA pathway inhibitors, and analysis of oxylipins provided evidence that, following heparin, aggregating platelets regained their ability to synthesise thromboxane. These findings highlight potentially unrecognised pro-thrombotic and pro-inflammatory changes during CABG surgery, and provide further evidence of adverse effects associated with UFH.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Heparina , Humanos , Heparina/farmacologia , Ácido Araquidônico , Aspirina/farmacologia , Ponte de Artéria Coronária , Tromboxanos
6.
bioRxiv ; 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38659791

RESUMO

Identifying associations between phenotype and genotype is the fundamental basis of genetic analyses. Inspired by frequentist probability and the work of R.A. Fisher, genome-wide association studies (GWAS) extract information using averages and variances from genotype-phenotype datasets. Averages and variances are legitimated upon creating distribution density functions obtained through the grouping of data into categories. However, as data from within a given category cannot be differentiated, the investigative power of such methodologies is limited. Genomic Informational Field Theory (GIFT) is a method specifically designed to circumvent this issue. The way GIFT proceeds is opposite to that of GWAS. Whilst GWAS determines the extent to which genes are involved in phenotype formation (bottom-up approach), GIFT determines the degree to which the phenotype can select microstates (genes) for its subsistence (top-down approach). Doing so requires dealing with new genetic concepts, a.k.a. genetic paths, upon which significance levels for genotype-phenotype associations can be determined. By using different datasets obtained in ovis aries related to bone growth (Dataset-1) and to a series of linked metabolic and epigenetic pathways (Dataset-2), we demonstrate that removing the informational barrier linked to categories enhances the investigative and discriminative powers of GIFT, namely that GIFT extracts more information than GWAS. We conclude by suggesting that GIFT is an adequate tool to study how phenotypic plasticity and genetic assimilation are linked.

7.
Nat Med ; 30(5): 1320-1329, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38480922

RESUMO

Recurrent glioblastoma (rGBM) remains a major unmet medical need, with a median overall survival of less than 1 year. Here we report the first six patients with rGBM treated in a phase 1 trial of intrathecally delivered bivalent chimeric antigen receptor (CAR) T cells targeting epidermal growth factor receptor (EGFR) and interleukin-13 receptor alpha 2 (IL13Rα2). The study's primary endpoints were safety and determination of the maximum tolerated dose. Secondary endpoints reported in this interim analysis include the frequency of manufacturing failures and objective radiographic response (ORR) according to modified Response Assessment in Neuro-Oncology criteria. All six patients had progressive, multifocal disease at the time of treatment. In both dose level 1 (1 ×107 cells; n = 3) and dose level 2 (2.5 × 107 cells; n = 3), administration of CART-EGFR-IL13Rα2 cells was associated with early-onset neurotoxicity, most consistent with immune effector cell-associated neurotoxicity syndrome (ICANS), and managed with high-dose dexamethasone and anakinra (anti-IL1R). One patient in dose level 2 experienced a dose-limiting toxicity (grade 3 anorexia, generalized muscle weakness and fatigue). Reductions in enhancement and tumor size at early magnetic resonance imaging timepoints were observed in all six patients; however, none met criteria for ORR. In exploratory endpoint analyses, substantial CAR T cell abundance and cytokine release in the cerebrospinal fluid were detected in all six patients. Taken together, these first-in-human data demonstrate the preliminary safety and bioactivity of CART-EGFR-IL13Rα2 cells in rGBM. An encouraging early efficacy signal was also detected and requires confirmation with additional patients and longer follow-up time. ClinicalTrials.gov identifier: NCT05168423 .


Assuntos
Receptores ErbB , Glioblastoma , Imunoterapia Adotiva , Subunidade alfa2 de Receptor de Interleucina-13 , Receptores de Antígenos Quiméricos , Humanos , Glioblastoma/terapia , Glioblastoma/imunologia , Glioblastoma/diagnóstico por imagem , Glioblastoma/patologia , Subunidade alfa2 de Receptor de Interleucina-13/imunologia , Pessoa de Meia-Idade , Masculino , Receptores de Antígenos Quiméricos/imunologia , Feminino , Imunoterapia Adotiva/efeitos adversos , Imunoterapia Adotiva/métodos , Recidiva Local de Neoplasia/imunologia , Recidiva Local de Neoplasia/patologia , Adulto , Idoso , Neoplasias Encefálicas/imunologia , Neoplasias Encefálicas/terapia , Neoplasias Encefálicas/patologia , Injeções Espinhais , Dose Máxima Tolerável
8.
Scand J Med Sci Sports ; 34(3): e14592, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38458973

RESUMO

OBJECTIVES: Popliteal artery entrapment syndrome (PAES) is a rare condition where musculoskeletal structures compress the popliteal artery (POPA) leading to vascular compromise. This study investigates the effect of dynamic plantar- and dorsi-flexion loading on POPA hemodynamic parameters to develop a robust diagnostic ultrasound-based protocol for diagnosing functional PAES. METHODS: Healthy individuals (n = 20), recreational athletes (n = 20), and symptomatic (n = 20) PAES patients were consented. Triplex ultrasound imaging of lower limb arteries was performed (n = 120 limbs). Proximal and distal POPA's in dorsi-/plantar-flexion, in prone and erect positions, were imaged at rest and flexion. Peak systolic velocities (cm/s) and vessel diameter (antero-posterior, cm) was measured. RESULTS: Distal vessel occlusion was noted across all three groups whilst prone during plantar-flexion (62.7%). POPA occlusion was only noted in the proximal vessel within the patient group (15.8%). When prone, 50% of control (n = 40 limbs), 70% of athletes (n = 40 limbs), and 65% of patients (n = 40 limbs) had distal POPA occlusion in plantar-flexion. When prone, recreational athletes (5%), and patients (12.5%) had distal POPA compression under dorsi-flexion. POPA occlusions with the patient in erect position were only noted in the symptomatic patient group under both dorsi-flexion (15.8%) and plantar-flexion (23.7%). CONCLUSION: Compression of the POPA on ultrasound should not be the sole diagnostic criteria for PAES. POPA compression exists in asymptomatic individuals, primarily under prone plantar-flexion. To reduce false positives, ultrasound-based protocols should focus on scanning patients in the erect position only to diagnose PAES, rather than asymptomatic POPA compression. A distinction should be made between the two.


Assuntos
Arteriopatias Oclusivas , Doença Arterial Periférica , Síndrome do Aprisionamento da Artéria Poplítea , Humanos , Arteriopatias Oclusivas/diagnóstico por imagem , Hemodinâmica , Ultrassonografia
9.
Am J Sports Med ; 52(4): 987-997, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38406872

RESUMO

BACKGROUND: Despite an acute knee injury being a major risk factor for osteoarthritis, the factors that initiate and maintain this risk of longer-term knee symptoms are poorly understood. Bioactive lipids derived from omega-3 and -6 polyunsaturated fatty acids have key roles in the regulation of the inflammatory response and have been linked to joint damage and osteoarthritis pain in translational models. HYPOTHESIS: There would be associations between systemic levels of bioactive lipids and knee symptoms longitudinally after an acute knee injury and related knee surgery. STUDY DESIGN: Controlled laboratory study. METHODS: This study analyzed a subset of young, active adults who had sustained an acute knee injury (recruited via a surgical care pathway) and healthy age- and sex-matched controls. Surgery, if performed, was conducted after the baseline serum sample was taken and before the 3-month and 2-year visits. Liquid chromatography-tandem mass spectrometry of 41 bioactive lipids was carried out in sera of (1) 47 injured participants (median age, 28 years) collected at baseline (median, 24 days after injury), 3 months, and 2 years, along with the Knee injury and Osteoarthritis Outcome Score, and (2) age- and sex-matched controls. RESULTS: Levels of the omega-3 polyunsaturated fatty acids eicosapentaenoic acid (P≤ .0001) and docosahexaenoic acid (P≤ .0001) and the pro-resolving lipid mediators 17- and 14-hydroxydocosahexaenoic acid, and 18-hydroxyeicosapentaenoic acid were all significantly greater at baseline in injured participants compared with the later time points and also higher than in healthy controls (P = .0019 and P≤ .0001, respectively). Levels of pro-inflammatory prostaglandins E2 and D2, leukotriene B4, and thromboxane B2 were significantly lower at baseline compared with the later time points. Higher levels of 8,9-, 11,12-, and 14,15-dihydroxyeicosatrienoic acid (DHET) were cross-sectionally associated with more severe knee pain/symptoms according to the Knee injury and Osteoarthritis Outcome Score at 2 years (P = .0004, R2 = 0.251; P = .0002, R2 = 0.278; and P = .0012, R2 = 0.214, respectively). CONCLUSION: The profile of pro-resolving versus pro-inflammatory lipids at baseline suggests an initial activation of pro-resolution pathways, followed by the later activation of pro-inflammatory pathways. CLINICAL RELEVANCE: In this largely surgically managed cohort, the association of soluble epoxide hydrolase metabolites, the DHETs, with more severe knee symptoms at 2 years provides a rationale for further investigation into the role of this pathway in persisting knee symptoms in this population, including potential therapeutic strategies.


Assuntos
Traumatismos do Joelho , Osteoartrite , Adulto , Humanos , Anti-Inflamatórios , Ácidos Graxos Insaturados , Traumatismos do Joelho/cirurgia , Dor
10.
Nurs Open ; 11(2): e2100, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38366769

RESUMO

AIM: The aim of the study was to assess the suitability of an online education package to prepare health professionals to use a new paediatric early warning system. DESIGN: Quasi-experimental mixed methods using co-production. METHODS: Participants completed the Package and participated in up to four clinical scenarios. Data were collected using self-report surveys, and during clinical scenarios; escalation of care, documentation, family involvement, communication handovers were assessed, and recorded debriefings were thematically analysed. Data were integrated using tabulated joint displays. RESULTS: Eleven nurses and three doctors were recruited from three mixed adult and paediatric hospitals. Following completion of the Package and clinical scenarios 13/14 (93%) participants agreed preparedness and confidence to use the ESCALATION System had increased. For 53% handovers, the communication framework was followed, for 79% charts, documentation was complete. Participants engaged with the parent (actor) for 97% scenario interactions. The Package was effective and participation in clinical scenarios appeared to enhance learning. PATIENT OR PUBLIC CONTRIBUTION: Consumers participated in the steering group overseeing the study and in the expert panel who reviewed the education package and clinical scenarios.


Assuntos
Pessoal de Saúde , Médicos , Adulto , Humanos , Criança , Aprendizagem , Simulação de Paciente , Pesquisa Empírica
11.
J Patient Exp ; 11: 23743735241229384, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38313864

RESUMO

The purpose of this study is to provide an overview of patients' experiences using a precision medicine (PM) clinic that conducts pharmacogenomics-based (PGx) testing for adverse drug reactions. The study aimed to identify the features of the clinic valued most by patients and areas for improvement. A paper survey was used to collect data. Survey questions focused on patients' perceptions of the PM testing and the overall clinic experience. Sixty-seven patients completed the survey. Quantitative data were analyzed using SPSS and frequencies were reported. Open-ended responses were coded and organized thematically. Patients reported that the clinic services increased confidence in their medication usage. Feeling respected by staff, receiving education, and quick appointments were highly valued by patients. Suggested areas for improvement included better communication from the clinic to patients, expansion of clinic services, and education for other healthcare providers. The findings demonstrate that patient experience goes beyond the clinical care provided. Current and potential future providers of PM should invest the time and energy to configure their care delivery system to enhance the patient experience.

13.
Mol Ther ; 31(12): 3376-3388, 2023 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-37927037

RESUMO

Progress in the understanding of human diseases has coincided with the advent of precision medicine, whereby the underlying genetic and molecular contributors can be used as diagnostic and therapeutic biomarkers. To address these, drug developers have designed a range of different treatment strategies, including gene therapy, which the American Society of Gene and Cell Therapy defines as the use of genetic material to treat or prevent disease. A number of approaches exist, including the delivery of genetic material in vivo or ex vivo, as well as the use of RNA species to alter gene expression in particular disease states. Through the end of the first quarter of 2023, there were more than 100 different approved gene, cell, and RNA therapies throughout the world, with over 3,700 more in clinical and preclinical development. This review comprehensively captures the landscape for such advanced therapies, including the different genetic technologies used and diseases targeted in clinical trials.


Assuntos
Terapia Baseada em Transplante de Células e Tecidos , Terapia Genética , Humanos , Estados Unidos , RNA
14.
Evid Based Nurs ; 2023 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-37949635
16.
Cancer Cell ; 41(10): 1689-1695, 2023 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-37714150

RESUMO

Successful implementation of adoptive cell therapy (ACT) of cancer requires comprehensively addressing biological and practical challenges. This approach has been largely overlooked, resulting in a gap between the potential of ACT and its actual effectiveness. We summarize the most promising technical strategies in creating an "ideal" ACT product, focusing on chimeric antigen receptor (CAR)-engineered cells. Since many requirements for effective ACT are common to most cancers, what we outline here might have a broader impact.


Assuntos
Neoplasias , Receptores de Antígenos Quiméricos , Humanos , Imunoterapia Adotiva , Neoplasias/terapia , Receptores de Antígenos de Linfócitos T/genética
17.
Anal Methods ; 15(24): 2925-2934, 2023 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-37309212

RESUMO

In comprehensive lipidomics studies, accurate quantification is essential but biological and/or clinical relevance is often hindered due to unwanted variations such as lipid degradation during sample preparation, matrix effects and non-linear responses of analytical instruments. In addition, the wide chemical diversity of lipids can complicate the accurate identification of individual lipids. These analytical limitations can potentially be corrected efficiently by the use of lipid-specific isotopically labelled internal standards (IS) but currently such IS mixtures have limited coverage of the mammalian lipidome. In this study, an in vivo13C labelling strategy was employed to explore four species (Escherichia coli, Arthrospira platensis, Saccharomyces cerevisiae and Pichia pastoris) as a source of 13C-labelled internal standards (13C-ISs) for more accurate and quantitative liquid chromatography (LC)-mass spectrometry (MS)-based lipidomics. Results showed that extracts from 13C-labelled P. pastoris and S. cerevisiae contain the highest percentage of uniformly labelled lipids (both 83% compared to 67% and 69% in A. platensis and E. coli, respectively) and 13C-labelled P. pastoris extract was identified as the optimum source of 13C-ISs for comprehensive data normalisation to correct unwanted variations during sample preparation and LC-MS analysis. Overall, use of a biologically generated 13C-IS lipid mixture of 357 identified lipid ions resulted in significant reduction in the lipid CV% of normalisation compared with other normalisation methods using total ion counts or a commercially available deuterated internal standard mixture. This improved normalisation using 13C-IS was confirmed in a typical lipidomics analysis using a large number of samples (>100+) and long analysis time (>70 h). This study highlights the benefit of an in vivo labelling strategy for reducing technical and analytical variations introduced during sample preparation and analysis in lipidomics studies.


Assuntos
Lipidômica , Saccharomyces cerevisiae , Animais , Cromatografia Líquida/métodos , Escherichia coli , Espectrometria de Massas em Tandem/métodos , Lipídeos/análise , Lipídeos/química , Isótopos de Carbono/química , Mamíferos
18.
EFORT Open Rev ; 8(5): 313-318, 2023 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-37158410

RESUMO

The anterior part (third space) of the knee appears important in the soft tissue functional outcome following knee replacement surgery. Native patellofemoral kinematics are complex and variable, and further understanding has led to prosthetic redesign. Attention to soft tissue tension anteriorly (balancing the third space) during knee replacement may maximise post-operative function and avoid issues with understuffing and overstuffing. Patellofemoral compression forces may now be measured dynamically during knee replacement, allowing an objective approach to balancing the third space.

20.
Microbiology (Reading) ; 169(4)2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-37018121

RESUMO

In Pseudomonas aeruginosa, quorum sensing (QS) depends on an interconnected regulatory hierarchy involving the Las, Rhl and Pqs systems, which are collectively responsible for the co-ordinated synthesis of a diverse repertoire of N-acylhomoserine lactones (AHLs) and 2-alkyl-4-quinolones (AQs). Apparent population density-dependent phenomena such as QS may, however, be due to growth rate and/or nutrient exhaustion in batch culture. Using continuous culture, we show that growth rate and population density independently modulate the accumulation of AHLs and AQs such that the highest concentrations are observed at a slow growth rate and high population density. Carbon source (notably succinate), nutrient limitation (C, N, Fe, Mg) or growth at 25 °C generally reduces AHL and AQ levels, except for P and S limitation, which result in substantially higher concentrations of AQs, particularly AQ N-oxides, despite the lower population densities achieved. Principal component analysis indicates that ~26 % variation is due to nutrient limitation and a further 30 % is due to growth rate. The formation of N-(3-oxododecanoyl)-l-homoserine lactone (3OC12-HSL) turnover products such as the ring opened form and tetramic acid varies with the limiting nutrient limitation and anaerobiosis. Differential ratios of N-butanoyl-homoserine lactone (C4-HSL), 3OC12-HSL and the AQs as a function of growth environment are clearly apparent. Inactivation of QS by mutation of three key genes required for QS signal synthesis (lasI, rhlI and pqsA) substantially increases the concentrations of key substrates from the activated methyl cycle and aromatic amino acid biosynthesis, as well as ATP levels, highlighting the energetic drain that AHL and AQ synthesis and hence QS impose on P. aeruginosa.


Assuntos
Pseudomonas aeruginosa , Percepção de Quorum , Pseudomonas aeruginosa/genética , Lactonas/química , Lactonas/metabolismo , 4-Butirolactona/metabolismo , Acil-Butirolactonas/metabolismo , Proteínas de Bactérias/genética
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