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1.
Clin Trials ; : 17407745241238444, 2024 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-38576071

RESUMEN

BACKGROUND: The Online Resource for Recruitment in Clinical triAls (ORRCA) and the Online Resource for Retention in Clinical triAls (ORRCA2) were established to organise and map the literature addressing participant recruitment and retention within clinical research. The two databases are updated on an ongoing basis using separate but parallel systematic reviews. However, recruitment and retention of research participants is widely acknowledged to be interconnected. While interventions aimed at addressing recruitment challenges can impact retention and vice versa, it is not clear how well they are simultaneously considered within methodological research. This study aims to report the recent update of ORRCA and ORRCA2 with a special emphasis on assessing crossover of the databases and how frequently randomised studies of methodological interventions measure the impact on both recruitment and retention outcomes. METHODS: Two parallel systematic reviews were conducted in line with previously reported methods updating ORRCA (recruitment) and ORRCA2 (retention) with publications from 2018 and 2019. Articles were categorised according to their evidence type (randomised evaluation, non-randomised evaluation, application and observation) and against the recruitment and retention domain frameworks. Articles categorised as randomised evaluations were compared to identify studies appearing in both databases. For randomised studies that were only in one database, domain categories were used to assess whether the methodological intervention was likely to impact on the alternate construct. For example, whether a recruitment intervention might also impact retention. RESULTS: In total, 806 of 17,767 articles screened for the recruitment database and 175 of 18,656 articles screened for the retention database were added as result of the update. Of these, 89 articles were classified as 'randomised evaluation', of which 6 were systematic reviews and 83 were randomised evaluations of methodological interventions. Ten of the randomised studies assessed recruitment and retention and were included in both databases. Of the randomised studies only in the recruitment database, 48/55 (87%) assessed the content or format of participant information which could have an impact on retention. Of the randomised studies only in the retention database, 6/18 (33%) assessed monetary incentives, 4/18 (22%) assessed data collection location and methods and 3/18 (17%) assessed non-monetary incentives, all of which could have an impact on recruitment. CONCLUSION: Only a small proportion of randomised studies of methodological interventions assessed the impact on both recruitment and retention despite having a potential impact on both outcomes. Where possible, an integrated approach analysing both constructs should be the new standard for these types of evaluations to ensure that improvements to recruitment are not at the expense of retention and vice versa.

2.
Antimicrob Agents Chemother ; 67(10): e0056723, 2023 10 18.
Artículo en Inglés | MEDLINE | ID: mdl-37702508

RESUMEN

Multidrug resistance (MDR) transporters such as ATP-Binding Cassette (ABC) and Major Facilitator Superfamily proteins are important mediators of antifungal drug resistance, particularly with respect to azole class drugs. Consequently, identifying molecules that are not susceptible to this mechanism of resistance is an important goal for new antifungal drug discovery. As part of a project to optimize the antifungal activity of clinically used phenothiazines, we synthesized a fluphenazine derivative (CWHM-974) with 8-fold higher activity against Candida spp. compared to the fluphenazine and with activity against Candida spp. with reduced fluconazole susceptibility due to increased MDR transporters. Here, we show that the improved C. albicans activity is because fluphenazine induces its own resistance by triggering expression of Candida drug resistance (CDR) transporters while CWHM-974 induces expression but does not appear to be a substrate for the transporters or is insensitive to their effects through other mechanisms. We also found that fluphenazine and CWHM-974 are antagonistic with fluconazole in C. albicans but not in C. glabrata, despite inducing CDR1 expression to high levels. Overall, CWHM-974 is one of the few examples of a molecule in which relatively small structural modifications significantly reduced susceptibility to multidrug transporter-mediated resistance.


Asunto(s)
Antifúngicos , Candida albicans , Antifúngicos/farmacología , Antifúngicos/metabolismo , Fluconazol/farmacología , Fluconazol/metabolismo , Flufenazina/farmacología , Flufenazina/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Pruebas de Sensibilidad Microbiana , Proteínas de Transporte de Membrana/genética , Proteínas de Transporte de Membrana/metabolismo , Resistencia a Múltiples Medicamentos , Candida , Farmacorresistencia Fúngica/genética
3.
J Exp Med ; 220(10)2023 10 02.
Artículo en Inglés | MEDLINE | ID: mdl-37432393

RESUMEN

Immune-related adverse events (irAEs) are a notable complication of PD-1 cancer immunotherapy. A better understanding of how these iatrogenic diseases compare with naturally arising autoimmune diseases is needed for treatment and monitoring of irAEs. We identified differences in anti-PD-1-induced type 1 diabetes (T1D) and spontaneous T1D in non-obese diabetic (NOD) mice by performing single-cell RNA-seq and TCR-seq on T cells from the pancreas, pancreas-draining lymph node (pLN), and blood of mice with PD-1-induced T1D or spontaneous T1D. In the pancreas, anti-PD-1 resulted in expansion of terminally exhausted/effector-like CD8+ T cells, an increase in T-bethi CD4+FoxP3- T cells, and a decrease in memory CD4+FoxP3- and CD8+ T cells in contrast to spontaneous T1D. Notably, anti-PD-1 caused increased TCR sharing between the pancreas and the periphery. Moreover, T cells in the blood of anti-PD-1-treated mice expressed markers that differed from spontaneous T1D, suggesting that the blood may provide a window to monitor irAEs rather than relying exclusively on the autoimmune target organ.


Asunto(s)
Diabetes Mellitus Tipo 1 , Animales , Ratones , Ratones Endogámicos NOD , Páncreas , Factores de Transcripción Forkhead , Receptores de Antígenos de Linfocitos T
4.
Nat Med ; 29(7): 1681-1691, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37291213

RESUMEN

Critically ill infants and children with rare diseases need equitable access to rapid and accurate diagnosis to direct clinical management. Over 2 years, the Acute Care Genomics program provided whole-genome sequencing to 290 families whose critically ill infants and children were admitted to hospitals throughout Australia with suspected genetic conditions. The average time to result was 2.9 d and diagnostic yield was 47%. We performed additional bioinformatic analyses and transcriptome sequencing in all patients who remained undiagnosed. Long-read sequencing and functional assays, ranging from clinically accredited enzyme analysis to bespoke quantitative proteomics, were deployed in selected cases. This resulted in an additional 19 diagnoses and an overall diagnostic yield of 54%. Diagnostic variants ranged from structural chromosomal abnormalities through to an intronic retrotransposon, disrupting splicing. Critical care management changed in 120 diagnosed patients (77%). This included major impacts, such as informing precision treatments, surgical and transplant decisions and palliation, in 94 patients (60%). Our results provide preliminary evidence of the clinical utility of integrating multi-omic approaches into mainstream diagnostic practice to fully realize the potential of rare disease genomic testing in a timely manner.


Asunto(s)
Enfermedad Crítica , Enfermedades Raras , Lactante , Niño , Humanos , Enfermedades Raras/diagnóstico , Enfermedades Raras/genética , Enfermedades Raras/terapia , Multiómica , Secuenciación Completa del Genoma/métodos , Secuenciación del Exoma
5.
bioRxiv ; 2023 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-37205554

RESUMEN

Multidrug resistance (MDR) transporters such as ATP Binding Cassette (ABC) and Major Facilitator Superfamily (MFS) proteins are important mediators of antifungal drug resistance, particularly with respect to azole class drugs. Consequently, identifying molecules that are not susceptible to this mechanism of resistance is an important goal for new antifungal drug discovery. As part of a project to optimize the antifungal activity of clinically used phenothiazines, we synthesized a fluphenazine derivative (CWHM-974) with 8-fold higher activity against Candida spp. compared to the fluphenazine and with activity against Candida spp. with reduced fluconazole susceptibility due to increased multidrug resistance transporters. Here, we show that the improved C. albicans activity is because fluphenazine induces its own resistance by triggering expression of CDR transporters while CWHM-974 induces expression but does not appear to be a substrate for the transporters or is insensitive to their effects through other mechanisms. We also found that fluphenazine and CWHM-974 are antagonistic with fluconazole in C. albicans but not in C. glabrata , despite inducing CDR1 expression to high levels. Overall, CWHM-974 represents a unique example of a medicinal chemistry-based conversion of chemical scaffold from MDR-sensitive to MDR-resistant and, hence, active against fungi that have developed resistance to clinically used antifungals such as the azoles.

6.
Methods Mol Biol ; 2658: 191-200, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37024703

RESUMEN

This chapter illustrates a method to generate Candida glabrata conditional depletion mutants for SNF2, an ATPase subunit of the SWI/SNF chromatin remodeling complex with potential roles in the response to azole drugs. The strategy employed utilizes a plant-specific proteolysis pathway which allows for the rapid degradation of a target protein in the presence of the phytohormone, auxin. The steps taken to generate strains expressing the auxin-inducible plant F-box protein, Tir1, and in which the auxin-binding target, IAA17, is C-terminally fused to Snf2 are described. This acute depletion strategy is suitable for studying the effects of the loss of growth-critical proteins. The rapid depletion afforded by the auxin-induced degradation avoids the potential complications of a null allele causing a severe growth defect and allows a more rapid assessment of the consequences of reduced levels of a protein of interest.


Asunto(s)
Candida glabrata , Proteínas F-Box , Candida glabrata/genética , Reguladores del Crecimiento de las Plantas/farmacología , Ácidos Indolacéticos/metabolismo , Farmacorresistencia Fúngica , Proteínas F-Box/metabolismo , Antifúngicos/farmacología
7.
Pediatr Emerg Med Pract ; 20(2): 1-20, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36689544

RESUMEN

Early recognition and treatment of electrolyte abnormalities protect the patient from derangements in the renal, myocardiac, and central nervous systems. Correction of electrolyte derangements decreases both morbidity and mortality. This issue reviews sodium, potassium, calcium, magnesium, and phosphorus abnormalities and provides a systematic approach to the evaluation and management of the ill child with an electrolyte emergency.


Asunto(s)
Electrólitos , Urgencias Médicas , Niño , Humanos , Calcio , Potasio , Servicio de Urgencia en Hospital
8.
BMC Med Genomics ; 15(1): 70, 2022 03 26.
Artículo en Inglés | MEDLINE | ID: mdl-35346197

RESUMEN

BACKGROUND: Next generation sequencing for oncology patient management is now routine in clinical pathology laboratories. Although wet lab, sequencing and pipeline tasks are largely automated, the analysis of variants for clinical reporting remains largely a manual task. The increasing volume of sequencing data and the limited availability of genetic experts to analyse and report on variants in the data is a key scalability limit for molecular diagnostics. METHOD: To determine the impact and size of the issue, we examined the longitudinally compiled genetic variants from 48,036 cancer patients over a six year period in a large cancer hospital from ten targeted cancer panel tests in germline, solid tumour and haematology contexts using hybridization capture and amplicon assays. This testing generated 24,168,398 sequenced variants of which 23,255 (8214 unique) were clinically reported. RESULTS: Of the reported variants, 17,240 (74.1%) were identified in more than one assay which allowed curated variant data to be reused in later reports. The remainder, 6015 (25.9%) were not subsequently seen in later assays and did not provide any reuse benefit. The number of new variants requiring curation has significantly increased over time from 1.72 to 3.73 variants per sample (292 curated variants per month). Analysis of the 23,255 variants reported, showed 28.6% (n = 2356) were not present in common public variant resources and therefore required de novo curation. These in-house only variants were enriched for indels, tumour suppressor genes and from solid tumour assays. CONCLUSION: This analysis highlights the significant percentage of variants not present within common public variant resources and the level of non-recurrent variants that consequently require greater curation effort. Many of these variants are unique to a single patient and unlikely to appear in other patients reflecting the personalised nature of cancer genomics. This study depicts the real-world situation for pathology laboratories faced with curating increasing numbers of low-recurrence variants while needing to expedite the process of manual variant curation. In the absence of suitably accurate automated methods, new approaches are needed to scale oncology diagnostics for future genetic testing volumes.


Asunto(s)
Neoplasias , Genómica/métodos , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Humanos , Neoplasias/diagnóstico , Neoplasias/genética , Neoplasias/patología , Patología Molecular , Medicina de Precisión/métodos
9.
Clin Trials ; 19(1): 71-80, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34693794

RESUMEN

BACKGROUND: Addressing recruitment and retention challenges in trials is a key priority for methods research, but navigating the literature is difficult and time-consuming. In 2016, ORRCA (www.orrca.org.uk) launched a free, searchable database of recruitment research that has been widely accessed and used to support the update of systematic reviews and the selection of recruitment strategies for clinical trials. ORRCA2 aims to create a similar database to map the growing volume and importance of retention research. METHODS: Searches of Medline (Ovid), CINAHL, PsycINFO, Scopus, Web of Science Core Collection and the Cochrane Library, restricted to English language and publications up to the end of 2017. Hand searches of key systematic reviews were undertaken and randomised evaluations of recruitment interventions within the ORRCA database on 1 October 2020 were also reviewed for any secondary retention outcomes. Records were screened by title and abstract before obtaining the full text of potentially relevant articles. Studies reporting or evaluating strategies, methods and study designs to improve retention within healthcare research were eligible. Case reports describing retention challenges or successes and studies evaluating participant reported reasons for withdrawal or losses were also included. Studies assessing adherence to treatments, attendance at appointments outside of research and statistical analysis methods for missing data were excluded. Eligible articles were categorised into one of the following evidence types: randomised evaluations, non-randomised evaluations, application of retention strategies without evaluation and observations of factors affecting retention. Articles were also mapped against a retention domain framework. Additional data were extracted on research outcomes, methods and host study context. RESULTS: Of the 72,904 abstracts screened, 4,364 full texts were obtained, and 1,167 articles were eligible. Of these, 165 (14%) were randomised evaluations, 99 (8%) non-randomised evaluations, 319 (27%) strategies without evaluation and 584 (50%) observations of factors affecting retention. Eighty-four percent (n = 979) of studies assessed the numbers of participants retained, 27% (n = 317) assessed demographic differences between retained and lost participants, while only 4% (n = 44) assessed the cost of retention strategies. The most frequently reported domains within the 165 studies categorised as 'randomised evaluations of retention strategies' were participant monetary incentives (32%), participant reminders and prompts (30%), questionnaire design (30%) and data collection location and method (26%). CONCLUSION: ORRCA2 builds on the success of ORRCA extending the database to organise the growing volume of retention research. Less than 15% of articles were randomised evaluations of retention strategies. Mapping of the literature highlights several areas for future research such as the role of research sites, clinical staff and study design in enhancing retention. Future studies should also include cost-benefit analysis of retention strategies.


Asunto(s)
Bases de Datos Bibliográficas , Humanos , Encuestas y Cuestionarios , Revisiones Sistemáticas como Asunto
10.
mBio ; 12(5): e0232021, 2021 10 26.
Artículo en Inglés | MEDLINE | ID: mdl-34488444

RESUMEN

During induced differentiation, the process often involves a commitment event, after which induced cells, when returned to noninducing conditions, continue to differentiate. The commitment event is rarely identified. Candida albicans differentiates from the white to opaque phenotype, a prerequisite for mating and a process accompanying colonization of the lower gastrointestinal tract and skin. In analyses of white cell populations induced to synchronously differentiate from the white to opaque phenotype, opaque commitment occurs at approximately the same time as evagination and chitin ring formation in the process of daughter cell formation, several hours after the master switch gene WOR1 is upregulated. Mutational analyses of transcription factor binding regions P1, P2, P3, P4, and P6 of the WOR1 promoter reveal that individual deletion of any of the five transcription factor binding regions does not eliminate morphological differentiation to the opaque cell phenotype under opaque-inducing conditions, but individual deletion of P2, P3, or P4, blocks opaque commitment and maintenance of the opaque phenotype after transition to noninducing conditions. These results suggest that commitment occurs at the level of the WOR1 promoter and that morphological differentiation can be dissociated from phenotypic commitment. IMPORTANCE Candida albicans, the most pervasive fungal pathogen colonizing humans, undergoes a phenotypic transition between a white and opaque phenotype. The unique opaque phenotype is necessary for mating and colonization of the lower gastrointestinal tract. Wor1, a transcription factor (TF), plays a central role in activating this transition. Under physiological conditions that induce mass conversion from white to opaque in vitro, cells commit to the opaque phenotype at the time of evagination to form a daughter cell, but several hours after upregulation of WOR1 expression. By analyzing deletion derivatives of the WOR1 promoter, we demonstrate that three of five regulatory regions of WOR1 that bind TFs involved with the regulation of the phenotypic switch are individually required for commitment to the opaque phenotype, but are not necessary for expressing the opaque phenotype. These results demonstrate that morphological differentiation can be dissociated from phenotypic commitment and that commitment occurs at the level of the WOR1 promoter.


Asunto(s)
Candida albicans/crecimiento & desarrollo , Proteínas Fúngicas/metabolismo , Candida albicans/genética , Candida albicans/metabolismo , Color , Proteínas Fúngicas/genética , Regulación del Desarrollo de la Expresión Génica , Regulación Fúngica de la Expresión Génica , Fenotipo
11.
Cureus ; 13(6): e15665, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34277257

RESUMEN

Objective The use of high-flow nasal cannula (HFNC) as non-invasive respiratory support in children with bronchiolitis has increased over the last several years. Several studies have investigated enteral feeding safety while on HFNC. This study compares the safety of oral feeding prior to and following implementation of an HFNC feeding guideline. Patients and methods A retrospective study was designed, in children ≤2 years of age with bronchiolitis, requiring HFNC, from 2017 to 2019. We defined feeding complications on HFNC and defined safety as the absence of such complications. We gathered the following data: oral feeding timing from the HFNC initiation, duration of enteral feeding on HFNC, and HFNC flow rate at which the feeding was initiated. We compare the data prior to and post-implementation of an HFNC feeding guideline. Results Descriptive statistics were calculated separately by pre and post guideline implementation. Patients in both pre and post guideline implementation groups had no feeding complications on HFNC. Subjects in the post (n=50) vs. pre-guideline implementation (n=36) had a higher median amount of liters flow when initiating enteral feeding (8.0 vs. 6.0 respectively, p<0.024), spent fewer days in the pediatric intensive care unit (PICU) (two days vs. 0 days). Post guideline implementation, enteral feeding was initiated sooner (days nil per os [NPO] 1.0 vs 2.0). No other significant differences between the two cohorts with respect to other variables were observed.  Conclusions Our data supports that oral feeding in patients with bronchiolitis on HFNC is safe. Utilization of current guidelines allowed safe earlier feeding of children on HFNC, reducing the time spent NPO.

12.
Cochrane Database Syst Rev ; 3: MR000032, 2021 03 06.
Artículo en Inglés | MEDLINE | ID: mdl-33675536

RESUMEN

BACKGROUND: Poor retention of participants in randomised trials can lead to missing outcome data which can introduce bias and reduce study power, affecting the generalisability, validity and reliability of results. Many strategies are used to improve retention but few have been formally evaluated. OBJECTIVES: To quantify the effect of strategies to improve retention of participants in randomised trials and to investigate if the effect varied by trial setting. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Scopus, PsycINFO, CINAHL, Web of Science Core Collection (SCI-expanded, SSCI, CPSI-S, CPCI-SSH and ESCI) either directly with a specified search strategy or indirectly through the ORRCA database. We also searched the SWAT repository to identify ongoing or recently completed retention trials. We did our most recent searches in January 2020. SELECTION CRITERIA: We included eligible randomised or quasi-randomised trials of evaluations of strategies to increase retention that were embedded in 'host' randomised trials from all disease areas and healthcare settings. We excluded studies aiming to increase treatment compliance. DATA COLLECTION AND ANALYSIS: We extracted data on: the retention strategy being evaluated; location of study; host trial setting; method of randomisation; numbers and proportions in each intervention and comparator group. We used a risk difference (RD) and 95% confidence interval (CI) to estimate the effectiveness of the strategies to improve retention. We assessed heterogeneity between trials. We applied GRADE to determine the certainty of the evidence within each comparison. MAIN RESULTS: We identified 70 eligible papers that reported data from 81 retention trials. We included 69 studies with more than 100,000 participants in the final meta-analyses, of which 67 studies evaluated interventions aimed at trial participants and two evaluated interventions aimed at trial staff involved in retention. All studies were in health care and most aimed to improve postal questionnaire response. Interventions were categorised into broad comparison groups: Data collection; Participants; Sites and site staff; Central study management; and Study design. These intervention groups consisted of 52 comparisons, none of which were supported by high-certainty evidence as determined by GRADE assessment. There were four comparisons presenting moderate-certainty evidence, three supporting retention (self-sampling kits, monetary reward together with reminder or prenotification and giving a pen at recruitment) and one reducing retention (inclusion of a diary with usual follow-up compared to usual follow-up alone). Of the remaining studies, 20 presented GRADE low-certainty evidence and 28 presented very low-certainty evidence. Our findings do provide a priority list for future replication studies, especially with regard to comparisons that currently rely on a single study. AUTHORS' CONCLUSIONS: Most of the interventions we identified aimed to improve retention in the form of postal questionnaire response. There were few evaluations of ways to improve participants returning to trial sites for trial follow-up. None of the comparisons are supported by high-certainty evidence. Comparisons in the review where the evidence certainty could be improved with the addition of well-done studies should be the focus for future evaluations.


Asunto(s)
Cooperación del Paciente/estadística & datos numéricos , Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricos , Manejo de Caso , Correspondencia como Asunto , Humanos , Cooperación del Paciente/psicología , Pacientes Desistentes del Tratamiento/estadística & datos numéricos , Selección de Paciente , Recompensa , Encuestas y Cuestionarios
14.
HRB Open Res ; 3: 81, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-34056536

RESUMEN

On the 11 th of March 2020, the World Health Organisation (WHO) declared a global pandemic due to the SARS-CoV-2 virus, which causes coronavirus disease 2019 (COVID-19). This was one month after Dr. Tedros Adhanom Ghebreyesus, Director-General of the WHO declared that we are also fighting an 'infodemic'. The WHO has described an infodemic as an "over-abundance of information - some accurate and some not - that makes it hard for people to find trustworthy sources and reliable guidance when they need it". iHealthFacts.ie is an Irish resource where the public can quickly and easily check the credibility and reliability of health claims circulating on social media. Unreliable claims can lead to poorly informed health choices. iHealthFacts is an initiative that supports the public to think critically about health claims and make well-informed choices. Here, we describe the role iHealthFacts plays in providing reliable information to the public and offer reflections from those involved in launching this initiative during a pandemic.

15.
PLoS One ; 14(6): e0218854, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31233557

RESUMEN

Tumorigenic cells undergo cell aggregation and aggregate coalescence in a 3D Matrigel environment. Here, we expanded this 3D platform to assess the interactions of normal human dermal fibroblasts (NHDFs) and human primary mammary fibroblasts (HPMFs) with breast cancer-derived, tumorigenic cells (MDA-MB-231). Medium conditioned by MDA-MB-231 cells activates both types of fibroblasts, imbuing them with the capacity to accelerate the rate of aggregation and coalescence of MDA-MB-231 cells more than four fold. Acceleration is achieved 1) by direct physical interactions with MDA-MB-231 cells, in which activated fibroblasts penetrate the MDA-MB-231/Matrigel 3D environment and function as supporting scaffolds for MDA-MB-231 aggregation and coalescence, and 2) through the release of soluble accelerating factors, including matrix metalloproteinase (MMPs) and, in the case of activated NHDFs, SDF-1α/CXCL12. Fibroblast activation includes changes in morphology, motility, and gene expression. Podoplanin (PDPN) and fibroblast activation protein (FAP) are upregulated by more than nine-fold in activated NHDFs while activated HPMFs upregulate FAP, vimentin, desmin, platelet derived growth factor receptor A and S100A4. Overexpression of PDPN, but not FAP, in NHDF cells in the absence of MDA-MB-231-conditioned medium, activates NHDFs. These results reveal that complex reciprocal signaling between fibroblasts and cancer cells, coupled with their physical interactions, occurs in a highly coordinated fashion that orchestrates aggregation and coalescence, behaviors specific to cancer cells in a 3D environment. These in vitro interactions may reflect events involved in early tumorigenesis, particularly in cases of field cancerization, and may represent a new mechanism whereby cancer-associated fibroblasts (CAFs) promote tumor growth.


Asunto(s)
Neoplasias de la Mama/fisiopatología , Fibroblastos Asociados al Cáncer/fisiología , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Fibroblastos Asociados al Cáncer/patología , Agregación Celular , Comunicación Celular , Línea Celular Tumoral , Movimiento Celular , Forma de la Célula , Quimiocina CXCL12/metabolismo , Técnicas de Cocultivo , Colágeno , Medios de Cultivo Condicionados , Combinación de Medicamentos , Femenino , Fibroblastos/patología , Fibroblastos/fisiología , Expresión Génica , Humanos , Laminina , Metaloproteinasas de la Matriz/metabolismo , Glicoproteínas de Membrana/metabolismo , Modelos Biológicos , Proteoglicanos , Transducción de Señal , Esferoides Celulares/patología , Esferoides Celulares/fisiología , Microambiente Tumoral/genética , Microambiente Tumoral/fisiología
16.
mSphere ; 4(2)2019 04 17.
Artículo en Inglés | MEDLINE | ID: mdl-30996111

RESUMEN

Candida albicans remains the most pervasive fungal pathogen colonizing humans. The majority of isolates from hosts are heterozygous at the mating type locus (MTLa/α), and a third of these have recently been shown to be capable of switching to the opaque phenotype. Here we have investigated the roles of two transcription factors (TFs) Sfl2 and Efg1, in repressing switching in a/α strains. Deleting either gene results in the capacity of a/α cells to switch to opaque en masse under facilitating environmental conditions, which include N-acetylglucosamine (GlcNAc) as the carbon source, physiological temperature (37°C), and high CO2 (5%). These conditions are similar to those in the host. Our results further reveal that while glucose is a repressor of sfl2Δ and efg1Δ switching, GlcNAc is an inducer. Finally, we show that when GlcNAc is the carbon source, and the temperature is low (25°C), the efg1Δ mutants, but not the sfl2Δ mutants, form a tiny, elongate cell, which differentiates into an opaque cell when transferred to conditions optimal for a/α switching. These results demonstrate that at least two TFs, Sfl2 and Efg1, repress switching in a/α cells and that a/α strains with either an sfl2Δ or efg1Δ mutation can switch en masse but only under physiological conditions. The role of opaque a/α cells in commensalism and pathogenesis must, therefore, be investigated.IMPORTANCE More than 95% of Candida albicans strains isolated from humans are MTLa/α, and approximately a third of these can undergo the white-to-opaque transition. Therefore, besides being a requirement for MTL-homozygous strains to mate, the opaque phenotype very likely plays a role in the commensalism and pathogenesis of nonmating, a/α populations colonizing humans.


Asunto(s)
Candida albicans/genética , Proteínas de Unión al ADN/genética , Proteínas Fúngicas/genética , Factores de Transcripción/genética , Candida albicans/fisiología , Eliminación de Gen , Regulación Fúngica de la Expresión Génica , Glucosa , Humanos , Mutación , Fenotipo
17.
Monoclon Antib Immunodiagn Immunother ; 37(1): 45-51, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29474160

RESUMEN

Firefly luciferase (FLuc) is commonly used as a reporter gene PpyLuc1 in bioanalytical assays. We have produced five mouse-derived monoclonal antibodies (mAbs) that recognize FLuc. The mAbs, DSHB-LUC-2, DSHB-LUC-3, DSHB-LUC-9, DSHB-LUC-16, and DSHB-LUC-24, were generated by immunizing mice with purified 6xHIS-tagged FLuc (6xHis-FLuc) in suspension with an adjuvant. All five were validated by dot blots. Four of the mAbs provided strong signals in western blot analysis, and one a weak signal. All five were validated for immunostaining in fixed cell culture. Only one stained cells embedded in paraffin. The five mAbs are available at cost through the Developmental Studies Hybridoma Bank (DSHB), a nonprofit National Resource created by the National Institutes of Health.


Asunto(s)
Anticuerpos Monoclonales/biosíntesis , Anticuerpos Monoclonales/inmunología , Luciferasas de Luciérnaga/metabolismo , Glándulas Mamarias Animales/metabolismo , Proteínas Recombinantes/inmunología , Animales , Western Blotting , Células Cultivadas , Femenino , Hibridomas , Inmunización , Immunoblotting , Luciferasas de Luciérnaga/inmunología , Ratones , Ratones Endogámicos BALB C
18.
Genome Med ; 9(1): 38, 2017 04 24.
Artículo en Inglés | MEDLINE | ID: mdl-28438193

RESUMEN

BACKGROUND: The increasing affordability of DNA sequencing has allowed it to be widely deployed in pathology laboratories. However, this has exposed many issues with the analysis and reporting of variants for clinical diagnostic use. Implementing a high-throughput sequencing (NGS) clinical reporting system requires a diverse combination of capabilities, statistical methods to identify variants, global variant databases, a validated bioinformatics pipeline, an auditable laboratory workflow, reproducible clinical assays and quality control monitoring throughout. These capabilities must be packaged in software that integrates the disparate components into a useable system. RESULTS: To meet these needs, we developed a web-based application, PathOS, which takes variant data from a patient sample through to a clinical report. PathOS has been used operationally in the Peter MacCallum Cancer Centre for two years for the analysis, curation and reporting of genetic tests for cancer patients, as well as the curation of large-scale research studies. PathOS has also been deployed in cloud environments allowing multiple institutions to use separate, secure and customisable instances of the system. Increasingly, the bottleneck of variant curation is limiting the adoption of clinical sequencing for molecular diagnostics. PathOS is focused on providing clinical variant curators and pathology laboratories with a decision support system needed for personalised medicine. While the genesis of PathOS has been within cancer molecular diagnostics, the system is applicable to NGS clinical reporting generally. CONCLUSIONS: The widespread availability of genomic sequencers has highlighted the limited availability of software to support clinical decision-making in molecular pathology. PathOS is a system that has been developed and refined in a hospital laboratory context to meet the needs of clinical diagnostics. The software is available as a set of Docker images and source code at https://github.com/PapenfussLab/PathOS .


Asunto(s)
Servicios de Laboratorio Clínico , Genómica/métodos , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Neoplasias/genética , Programas Informáticos , Humanos , Neoplasias/diagnóstico , Medicina de Precisión , Análisis de Secuencia de ADN/métodos
19.
PLoS One ; 12(1): e0168996, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28045955

RESUMEN

Noseband tightness is difficult to assess in horses participating in equestrian sports such as dressage, show jumping and three-day-eventing. There is growing concern that nosebands are commonly tightened to such an extent as to restrict normal equine behaviour and possibly cause injury. In the absence of a clear agreed definition of noseband tightness, a simple model of the equine nose-noseband interface environment was developed in order to guide further studies in this area. The normal force component of the noseband tensile force was identified as the key contributor to sub-noseband tissue compression. The model was used to inform the design of a digital tightness gauge which could reliably measure the normal force component of the noseband tensile force. A digital tightness gauge was developed to measure this parameter under nosebands fitted to bridled horses. Results are presented for field tests using two prototype designs. Prototype version three was used in field trial 1 (n = 15, frontal nasal plane sub-noseband site). Results of this trial were used to develop an ergonomically designed prototype, version 4, which was tested in a second field trial (n = 12, frontal nasal plane and lateral sub-noseband site). Nosebands were set to three tightness settings in each trial as judged by a single rater using an International Society for Equitation Science (ISES) taper gauge. Normal forces in the range 7-95 N were recorded at the frontal nasal plane while a lower range 1-28 N was found at the lateral site for the taper gauge range used in the trials. The digital tightness gauge was found to be simple to use, reliable, and safe and its use did not agitate the animals in any discernable way. A simple six point tightness scale is suggested to aid regulation implementation and the control of noseband tightness using normal force measurement as the objective tightness discriminant.


Asunto(s)
Caballos/fisiología , Fisiología/instrumentación , Animales , Fenómenos Biomecánicos , Calibración , Diseño de Equipo , Presión , Tamaño de la Muestra , Estadística como Asunto , Resistencia a la Tracción , Soporte de Peso
20.
EBioMedicine ; 9: 170-179, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27333036

RESUMEN

Mycobacterium tuberculosis (M. tuberculosis) is considered innately resistant to ß-lactam antibiotics. However, there is evidence that susceptibility to ß-lactam antibiotics in combination with ß-lactamase inhibitors is variable among clinical isolates, and these may present therapeutic options for drug-resistant cases. Here we report our investigation of susceptibility to ß-lactam/ß-lactamase inhibitor combinations among clinical isolates of M. tuberculosis, and the use of comparative genomics to understand the observed heterogeneity in susceptibility. Eighty-nine South African clinical isolates of varying first and second-line drug susceptibility patterns and two reference strains of M. tuberculosis underwent minimum inhibitory concentration (MIC) determination to two ß-lactams: amoxicillin and meropenem, both alone and in combination with clavulanate, a ß-lactamase inhibitor. 41/91 (45%) of tested isolates were found to be hypersusceptible to amoxicillin/clavulanate relative to reference strains, including 14/24 (58%) of multiple drug-resistant (MDR) and 22/38 (58%) of extensively drug-resistant (XDR) isolates. Genome-wide polymorphisms identified using whole-genome sequencing were used in a phylogenetically-aware linear mixed model to identify polymorphisms associated with amoxicillin/clavulanate susceptibility. Susceptibility to amoxicillin/clavulanate was over-represented among isolates within a specific clade (LAM4), in particular among XDR strains. Twelve sets of polymorphisms were identified as putative markers of amoxicillin/clavulanate susceptibility, five of which were confined solely to LAM4. Within the LAM4 clade, 'paradoxical hypersusceptibility' to amoxicillin/clavulanate has evolved in parallel to first and second-line drug resistance. Given the high prevalence of LAM4 among XDR TB in South Africa, our data support an expanded role for ß-lactam/ß-lactamase inhibitor combinations for treatment of drug-resistant M. tuberculosis.


Asunto(s)
Antibacterianos/farmacología , Mycobacterium tuberculosis/efectos de los fármacos , Amoxicilina/farmacología , Teorema de Bayes , Ácido Clavulánico/farmacología , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Farmacorresistencia Bacteriana Múltiple/genética , Genes Bacterianos , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Meropenem , Pruebas de Sensibilidad Microbiana , Mutación , Mycobacterium tuberculosis/enzimología , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/aislamiento & purificación , Filogenia , Análisis de Secuencia de ADN , Tienamicinas/farmacología , Tuberculosis/diagnóstico , Tuberculosis/microbiología , beta-Lactamasas/química , beta-Lactamasas/metabolismo
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