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1.
Proc Natl Acad Sci U S A ; 119(8)2022 02 22.
Artículo en Inglés | MEDLINE | ID: mdl-35165190

RESUMEN

Mycobacterium tuberculosis has a lipid-rich cell envelope that is remodeled throughout infection to enable adaptation within the host. Few transcriptional regulators have been characterized that coordinate synthesis of mycolic acids, the major cell wall lipids of mycobacteria. Here, we show that the mycolic acid desaturase regulator (MadR), a transcriptional repressor of the mycolate desaturase genes desA1 and desA2, controls mycolic acid desaturation and biosynthesis in response to cell envelope stress. A madR-null mutant of M. smegmatis exhibited traits of an impaired cell wall with an altered outer mycomembrane, accumulation of a desaturated α-mycolate, susceptibility to antimycobacterials, and cell surface disruption. Transcriptomic profiling showed that enriched lipid metabolism genes that were significantly down-regulated upon madR deletion included acyl-coenzyme A (aceyl-CoA) dehydrogenases, implicating it in the indirect control of ß-oxidation pathways. Electromobility shift assays and binding affinities suggest a unique acyl-CoA pool-sensing mechanism, whereby MadR is able to bind a range of acyl-CoAs, including those with unsaturated as well as saturated acyl chains. MadR repression of desA1/desA2 is relieved upon binding of saturated acyl-CoAs of chain length C16 to C24, while no impact is observed upon binding of shorter chain and unsaturated acyl-CoAs. We propose this mechanism of regulation as distinct to other mycolic acid and fatty acid synthesis regulators and place MadR as the key regulatory checkpoint that coordinates mycolic acid remodeling during infection in response to host-derived cell surface perturbation.


Asunto(s)
Proteínas Bacterianas/metabolismo , Mycobacterium/metabolismo , Ácidos Micólicos/metabolismo , Racemasas y Epimerasas/metabolismo , Acilcoenzima A/metabolismo , Proteínas Bacterianas/fisiología , Pared Celular/metabolismo , Ácido Graso Desaturasas/metabolismo , Ácidos Grasos/metabolismo , Metabolismo de los Lípidos/fisiología , Infecciones por Mycobacterium , Mycobacterium tuberculosis/metabolismo , Racemasas y Epimerasas/fisiología , Factores de Transcripción/metabolismo
2.
Artículo en Inglés | MEDLINE | ID: mdl-38860845

RESUMEN

COVID-19 syndrome is characterized by acute lung injury, hypoxemic respiratory failure, and high mortality. Alveolar Type 2 (AT2) cells are essential for gas exchange, repair, and regeneration of distal lung epithelium. We have shown that the causative agent, SARS-CoV-2 and other ß-coronavirus genus members induce an ER stress response in vitro, however the consequences for host AT2 function in vivo are less understood. To study this, two murine models of coronavirus infection were employed- mouse hepatitis virus-1 (MHV-1) in A/J mice and a mouse adapted SARS-CoV-2 strain. MHV-1 infected mice exhibited dose-dependent weight loss with histological evidence of distal lung injury accompanied by elevated bronchoalveolar lavage fluid (BALF) cell counts and total protein. AT2 cells showed evidence of both viral infection and increased BIP/GRP78 expression, consistent with activation of the unfolded protein response (UPR). The AT2 UPR included increased IRE1α signaling and a biphasic response in PERK signaling accompanied marked reductions in AT2 and BALF surfactant protein (SP-B, SP-C) content, increases in surfactant surface tension, and emergence of a re-programmed epithelial cell population (Krt8+, Cldn4+). The loss of a homeostatic AT2 endophenotype was attenuated by treatment with the IRE1α inhibitor OPK711. As proof-of-concept, C57BL6 mice infected with mouse-adapted SARS-CoV-2 demonstrated similar lung injury and evidence of disrupted surfactant homeostasis. We conclude that lung injury from ß-coronavirus infection results from an aberrant host response activating multiple AT2 UPR pathways, altering surfactant metabolism/function, and changing AT2 endophenotypes offering a mechanistic link between SARS-CoV-2 infection, AT2 cell biology, and acute respiratory failure.

3.
Environ Microbiol ; 25(6): 1200-1215, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36752722

RESUMEN

Thermoacidophilic archaea lack sigma factors and the large inventory of heat shock proteins (HSPs) widespread in bacterial genomes, suggesting other strategies for handling thermal stress are involved. Heat shock transcriptomes for the thermoacidophilic archaeon Saccharolobus (f. Sulfolobus) solfataricus 98/2 revealed genes that were highly responsive to thermal stress, including transcriptional regulators YtrASs (Ssol_2420) and FadRSs (Ssol_0314), as well as type II toxin-antitoxin (TA) loci VapBC6 (Ssol_2337, Ssol_2338) and VapBC22 (Ssol_0819, Ssol_0818). The role, if any, of type II TA loci during stress response in microorganisms, such as Escherichia coli, is controversial. But, when genes encoding YtrASs , FadRSs , VapC22, VapB6, and VapC6 were systematically mutated in Sa. solfataricus 98/2, significant up-regulation of the other genes within this set was observed, implicating an interconnected regulatory network during thermal stress response. VapBC6 and VapBC22 have close homologues in other Sulfolobales, as well as in other archaea (e.g. Pyrococcus furiosus and Archaeoglobus fulgidus), and their corresponding genes were also heat shock responsive. The interplay between VapBC TA loci and heat shock regulators in Sa solfataricus 98/2 not only indicates a cellular mechanism for heat shock response that differs from bacteria but one that could have common features within the thermophilic archaea.


Asunto(s)
Antitoxinas , Sulfolobus solfataricus , Toxinas Biológicas , Antitoxinas/genética , Toxinas Biológicas/genética , Toxinas Biológicas/metabolismo , Respuesta al Choque Térmico/genética , Sulfolobus solfataricus/genética , Sulfolobus solfataricus/metabolismo , Escherichia coli/genética
4.
Mol Microbiol ; 113(2): 521-533, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31785114

RESUMEN

The final step in mycolic acid biosynthesis in Mycobacterium tuberculosis is catalysed by mycolyl reductase encoded by the Rv2509 gene. Sequence analysis and homology modelling indicate that Rv2509 belongs to the short-chain fatty acid dehydrogenase/reductase (SDR) family, but with some distinct features that warrant its classification as belonging to a novel family of short-chain dehydrogenases. In particular, the predicted structure revealed a unique α-helical C-terminal region which we demonstrated to be essential for Rv2509 function, though this region did not seem to play any role in protein stabilisation or oligomerisation. We also show that unlike the M. smegmatis homologue which was not essential for growth, Rv2509 was an essential gene in slow-growing mycobacteria. A knockdown strain of the BCG2529 gene, the Rv2509 homologue in Mycobacterium bovis BCG, was unable to grow following the conditional depletion of BCG2529. This conditional depletion also led to a reduction of mature mycolic acid production and accumulation of intermediates derived from 3-oxo-mycolate precursors. Our studies demonstrate novel features of the mycolyl reductase Rv2509 and outline its role in mycobacterial growth, highlighting its potential as a new target for therapies.


Asunto(s)
Mycobacterium , Ácidos Micólicos/metabolismo , Oxidorreductasas/química , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Pared Celular/metabolismo , Modelos Moleculares , Mycobacterium/genética , Mycobacterium/crecimiento & desarrollo , Mycobacterium/metabolismo , Mycobacterium bovis/genética , Mycobacterium bovis/crecimiento & desarrollo , Mycobacterium bovis/metabolismo , Mycobacterium smegmatis/genética , Mycobacterium smegmatis/crecimiento & desarrollo , Mycobacterium smegmatis/metabolismo , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/crecimiento & desarrollo , Mycobacterium tuberculosis/metabolismo , Oxidorreductasas/genética , Oxidorreductasas/metabolismo
5.
Mol Syst Biol ; 15(3): e8584, 2019 03 04.
Artículo en Inglés | MEDLINE | ID: mdl-30833303

RESUMEN

The success of Mycobacterium tuberculosis (MTB) stems from its ability to remain hidden from the immune system within macrophages. Here, we report a new technology (Path-seq) to sequence miniscule amounts of MTB transcripts within up to million-fold excess host RNA Using Path-seq and regulatory network analyses, we have discovered a novel transcriptional program for in vivo mycobacterial cell wall remodeling when the pathogen infects alveolar macrophages in mice. We have discovered that MadR transcriptionally modulates two mycolic acid desaturases desA1/desA2 to initially promote cell wall remodeling upon in vitro macrophage infection and, subsequently, reduces mycolate biosynthesis upon entering dormancy. We demonstrate that disrupting MadR program is lethal to diverse mycobacteria making this evolutionarily conserved regulator a prime antitubercular target for both early and late stages of infection.


Asunto(s)
Antígenos Bacterianos/genética , Proteínas Bacterianas/genética , Redes Reguladoras de Genes , Interacciones Huésped-Patógeno , Macrófagos/inmunología , Mycobacterium tuberculosis/fisiología , Tuberculosis/microbiología , Adaptación Fisiológica , Animales , Antígenos Bacterianos/metabolismo , Proteínas Bacterianas/metabolismo , Pared Celular/metabolismo , Macrófagos/microbiología , Ratones , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/inmunología , Ácidos Micólicos/metabolismo , Biología de Sistemas , Tuberculosis/inmunología
6.
J Biol Chem ; 293(25): 9770-9783, 2018 06 22.
Artículo en Inglés | MEDLINE | ID: mdl-29728457

RESUMEN

The Mycobacterium tuberculosis (Mtb) pathogen encodes a GlcNAc-6-phosphate deacetylase enzyme, NagA (Rv3332), that belongs to the amidohydrolase superfamily. NagA enzymes catalyze the deacetylation of GlcNAc-6-phosphate (GlcNAc6P) to glucosamine-6-phosphate (GlcN6P). NagA is a potential antitubercular drug target because it represents the key enzymatic step in the generation of essential amino-sugar precursors required for Mtb cell wall biosynthesis and also influences recycling of cell wall peptidoglycan fragments. Here, we report the structural and functional characterization of NagA from Mycobacterium smegmatis (MSNagA) and Mycobacterium marinum (MMNagA), close relatives of Mtb Using a combination of X-ray crystallography, site-directed mutagenesis, and biochemical and biophysical assays, we show that these mycobacterial NagA enzymes are selective for GlcNAc6P. Site-directed mutagenesis studies revealed crucial roles of conserved residues in the active site that underpin stereoselective recognition, binding, and catalysis of substrates. Moreover, we report the crystal structure of MSNagA in both ligand-free form and in complex with the GlcNAc6P substrate at 2.6 and 2.0 Å resolutions, respectively. The GlcNAc6P complex structure disclosed the precise mode of GlcNAc6P binding and the structural framework of the active site, including two divalent metals located in the α/ß binuclear site. Furthermore, we observed a cysteine residue located on a flexible loop region that occludes the active site. This cysteine is unique to mycobacteria and may represent a unique subsite for targeting mycobacterial NagA enzymes. Our results provide critical insights into the structural and mechanistic properties of mycobacterial NagA enzymes having an essential role in amino-sugar and nucleotide metabolism in mycobacteria.


Asunto(s)
Acetilglucosamina/análogos & derivados , Amidohidrolasas/química , Amidohidrolasas/metabolismo , Mycobacterium tuberculosis/enzimología , Acetilglucosamina/química , Acetilglucosamina/metabolismo , Amidohidrolasas/genética , Dominio Catalítico , Cristalografía por Rayos X , Metales/metabolismo , Modelos Moleculares , Mutagénesis Sitio-Dirigida , Mutación , Conformación Proteica
7.
J Antimicrob Chemother ; 73(7): 1978-1983, 2018 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-29596598

RESUMEN

Background: Surgical site infection (SSI) is one of the most common causes of healthcare-associated infection. Although the use of topical antibiotics to prevent SSI is not recommended by current guidelines, published studies document conflicting results and conclusions. Objectives: The objectives of this survey were to: (i) determine the extent of the use of topical antibiotics to prevent SSI in clinical practice; and (ii) gather the opinions of healthcare professionals most likely to be involved in their use. Methods: A questionnaire was circulated to members of BSAC and the European Wound Management Association (EWMA). Results: The questionnaire received 160 responses from a variety of healthcare professionals around the world. Most respondents (70%) did not have guidelines for the use of topical antibiotics for the prevention of SSI in their institution; if present, local guidance was based on national guidelines (20/31, 65%). Most respondents did not use or recommend topical antibiotics to prevent SSI; of those that did, gentamicin collagen sponges were most commonly used (24/96 responses, 25%). Over half of the surgeons (18/33, 55%) who responded to the survey did not use topical antibiotics for the prevention of SSI but, when used, contaminated surgery (8/33, 24%) was the most commonly stated indication. Conclusions: There are diverse opinions and practices among healthcare professionals about the use of topical antibiotics for the prevention of SSI. This considerable, and possibly inappropriate, variation in clinical practice needs to be addressed as part of antibiotic stewardship.


Asunto(s)
Administración Tópica , Antibacterianos/administración & dosificación , Profilaxis Antibiótica/métodos , Personal de Salud , Infección de la Herida Quirúrgica/prevención & control , Programas de Optimización del Uso de los Antimicrobianos , Consenso , Infección Hospitalaria/prevención & control , Europa (Continente) , Gentamicinas/administración & dosificación , Humanos , Guías de Práctica Clínica como Asunto , Encuestas y Cuestionarios
8.
bioRxiv ; 2024 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-38585863

RESUMEN

Alveolar epithelial type II (AT2) cell dysfunction is implicated in the pathogenesis of familial and sporadic idiopathic pulmonary fibrosis (IPF). We previously described that expression of an AT2 cell exclusive disease-associated protein isoform (SP-CI73T) in murine and patient-specific induced pluripotent stem cell (iPSC)-derived AT2 cells leads to a block in late macroautophagy and promotes time-dependent mitochondrial impairments; however, how a metabolically dysfunctional AT2 cell results in fibrosis remains elusive. Here using murine and human iPSC-derived AT2 cell models expressing SP-CI73T, we characterize the molecular mechanisms governing alterations in AT2 cell metabolism that lead to increased glycolysis, decreased mitochondrial biogenesis, disrupted fatty acid oxidation, accumulation of impaired mitochondria, and diminished AT2 cell progenitor capacity manifesting as reduced AT2 self-renewal and accumulation of transitional epithelial cells. We identify deficient AMP-kinase signaling as a key upstream signaling hub driving disease in these dysfunctional AT2 cells and augment this pathway to restore alveolar epithelial metabolic function, thus successfully alleviating lung fibrosis in vivo.

9.
RNA ; 17(7): 1381-92, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21622901

RESUMEN

The phylum Crenarchaeota includes hyperthermophilic micro-organisms subjected to dynamic thermal conditions. Previous transcriptomic studies of Sulfolobus solfataricus identified vapBC6 as a heat-shock (HS)-inducible member of the Vap toxin-antitoxin gene family. In this study, the inactivation of the vapBC6 operon by targeted gene disruption produced two recessive phenotypes related to fitness, HS sensitivity and a heat-dependent reduction in the rate of growth. In-frame vapBC6 deletion mutants were analyzed to examine the respective roles of each protein. Since vapB6 transcript abundance was elevated in the vapC6 deletion, the VapC6 toxin appears to regulate abundance of its cognate antitoxin. In contrast, vapC6 transcript abundance was reduced in the vapB6 deletion. A putative intergenic terminator may underlie these observations by coordinating vapBC6 expression. As predicted by structural modeling, recombinant VapC6 produced using chaperone cosynthesis exhibited heat-dependent ribonucleolytic activity toward S. solfataricus total RNA. This activity could be blocked by addition of preheated recombinant VapB6. In vivo transcript targets were identified by assessing the relative expression of genes that naturally respond to thermal stress in VapBC6-deficient cells. Preferential increases were observed for dppB-1 and tetR, and preferential decreases were observed for rpoD and eIF2 gamma. Specific VapC6 ribonucleolytic action could also be demonstrated in vitro toward RNAs whose expression increased in the VapBC6-deficient strain during heat shock. These findings provide a biochemical mechanism and identify cellular targets underlying VapBC6-mediated control over microbial growth and survival at temperature extremes.


Asunto(s)
Adaptación Fisiológica/genética , ARN/metabolismo , Sulfolobus solfataricus/genética , Sulfolobus solfataricus/fisiología , Temperatura , Toxinas Biológicas/genética , Adaptación Fisiológica/fisiología , Línea Celular , Perfilación de la Expresión Génica , Regulación de la Expresión Génica Arqueal , Hidrólisis/efectos de los fármacos , Modelos Biológicos , ARN/efectos de los fármacos , Sulfolobus solfataricus/metabolismo , Toxinas Biológicas/metabolismo , Toxinas Biológicas/farmacología , Toxinas Biológicas/fisiología
10.
Violence Against Women ; : 10778012231166399, 2023 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-37019434

RESUMEN

This study explored the experiences of lesbian, bisexual, and queer (LBQ) students' (N = 9, aged 19-24) of sexual harassment via semistructured interviews. Data were analysed using a thematic analysis. Three overarching themes emerged: (a) the paradox of men's unwanted sexual attention, (b) the negative impact on relationships, and (c) the LGBTQ* community as a refuge. The women reported enduring unwanted heteronormative sexual attention, and heterosexist and homophobic harassment which forced some to conceal their sexuality. Support for the LGBTQ* community was central in developing confidence to call-out harassment. The findings call for the inclusion of LBQ-specific messages in sexual violence awareness and prevention interventions.

11.
JCI Insight ; 8(24)2023 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-37934604

RESUMEN

Idiopathic pulmonary fibrosis (IPF) is a chronic parenchymal lung disease characterized by repetitive alveolar cell injury, myofibroblast proliferation, and excessive extracellular matrix deposition for which unmet need persists for effective therapeutics. The bioactive eicosanoid, prostaglandin F2α, and its cognate receptor FPr (Ptgfr) are implicated as a TGF-ß1-independent signaling hub for IPF. To assess this, we leveraged our published murine PF model (IER-SftpcI73T) expressing a disease-associated missense mutation in the surfactant protein C (Sftpc) gene. Tamoxifen-treated IER-SftpcI73T mice developed an early multiphasic alveolitis and transition to spontaneous fibrotic remodeling by 28 days. IER-SftpcI73T mice crossed to a Ptgfr-null (FPr-/-) line showed attenuated weight loss and gene dosage-dependent rescue of mortality compared with FPr+/+ cohorts. IER-SftpcI73T/FPr-/- mice also showed reductions in multiple fibrotic endpoints for which administration of nintedanib was not additive. Single-cell RNA-Seq, pseudotime analysis, and in vitro assays demonstrated Ptgfr expression predominantly within adventitial fibroblasts, which were reprogrammed to an "inflammatory/transitional" cell state in a PGF2α /FPr-dependent manner. Collectively, the findings provide evidence for a role for PGF2α signaling in IPF, mechanistically identify a susceptible fibroblast subpopulation, and establish a benchmark effect size for disruption of this pathway in mitigating fibrotic lung remodeling.


Asunto(s)
Dinoprost , Fibrosis Pulmonar Idiopática , Ratones , Animales , Dinoprost/metabolismo , Fibroblastos/metabolismo , Fibrosis Pulmonar Idiopática/patología , Fibrosis , Dinámica Poblacional
12.
RSC Med Chem ; 13(10): 1225-1233, 2022 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-36320433

RESUMEN

Tuberculosis, caused by Mycobacterium tuberculosis, claims ∼1.5 million lives annually. Effective chemotherapy is essential to control TB, however the emergence of drug-resistant strains of TB have seriously threatened global attempts to control and eradicate this deadly pathogen. Trehalose recycling via the LpqY-SugABC importer is essential for the virulence and survival of Mtb and inhibiting or hijacking this transport system is an attractive approach for the development of novel anti-tubercular and diagnostic agents. Therefore, we interrogated the drug-like compounds in the open-source Medicines for Malaria Pathogen Box and successfully identified seven compounds from the TB, kinetoplastids and reference compound disease sets that recognise LpqY. The molecules have diverse chemical scaffolds, are not specific trehalose analogues, and may be used as novel templates to facilitate the development of therapeutics that kill Mtb with a novel mechanism of action via the mycobacterial trehalose LpqY-SugABC transport system.

13.
Sleep Med Rev ; 64: 101658, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35777346

RESUMEN

Unpaid caregivers often experience sleep impairments as an unintended consequence of providing care. This systematic review and meta-analysis investigated the efficacy of interventions to improve sleep in unpaid caregivers. Six databases were searched from journal inception to 7-Sep-2021 to identify randomised controlled trials. Random-effects meta-analyses estimated mean differences (MD) at end-of-intervention. Twenty-one studies were identified (15 eligible for meta-analysis). Compared to control, interventions improved sleep quality (Pittsburgh Sleep Quality Index; 12 studies, 1153 participants, MD = -1.66, 95% CI [-2.91, -0.41], p = 0.009, I2 = 90.51%, GRADE = low), and total sleep time (hours; two studies, 122 participants, MD = 0.45, 95% CI [0.42, 0.48], p = 0.003, I2 = 0.00%, GRADE = low), but not sleeping problems (sleep item on Symptom Distress Scale of the Omega Screening Questionnaire; two studies, 529 participants, MD = -0.06, 95% CI [-0.69, 0.58], p = 0.458, I2 = 0.01%, GRADE = low). There is low quality evidence that interventions improve sleep quality in unpaid caregivers compared to control. Limitations include the lack of evidence for specific intervention modes and limited use of objective sleep measures. Future research should explore potential effect modifiers such as care recipient condition (CRD42021278670).


Asunto(s)
Cuidadores , Trastornos del Sueño-Vigilia , Humanos , Calidad de Vida , Sueño
14.
JAMA Ophthalmol ; 139(9): 964-973, 2021 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-34236406

RESUMEN

IMPORTANCE: Quantitative volumetric measures of retinal disease in optical coherence tomography (OCT) scans are infeasible to perform owing to the time required for manual grading. Expert-level deep learning systems for automatic OCT segmentation have recently been developed. However, the potential clinical applicability of these systems is largely unknown. OBJECTIVE: To evaluate a deep learning model for whole-volume segmentation of 4 clinically important pathological features and assess clinical applicability. DESIGN, SETTING, PARTICIPANTS: This diagnostic study used OCT data from 173 patients with a total of 15 558 B-scans, treated at Moorfields Eye Hospital. The data set included 2 common OCT devices and 2 macular conditions: wet age-related macular degeneration (107 scans) and diabetic macular edema (66 scans), covering the full range of severity, and from 3 points during treatment. Two expert graders performed pixel-level segmentations of intraretinal fluid, subretinal fluid, subretinal hyperreflective material, and pigment epithelial detachment, including all B-scans in each OCT volume, taking as long as 50 hours per scan. Quantitative evaluation of whole-volume model segmentations was performed. Qualitative evaluation of clinical applicability by 3 retinal experts was also conducted. Data were collected from June 1, 2012, to January 31, 2017, for set 1 and from January 1 to December 31, 2017, for set 2; graded between November 2018 and January 2020; and analyzed from February 2020 to November 2020. MAIN OUTCOMES AND MEASURES: Rating and stack ranking for clinical applicability by retinal specialists, model-grader agreement for voxelwise segmentations, and total volume evaluated using Dice similarity coefficients, Bland-Altman plots, and intraclass correlation coefficients. RESULTS: Among the 173 patients included in the analysis (92 [53%] women), qualitative assessment found that automated whole-volume segmentation ranked better than or comparable to at least 1 expert grader in 127 scans (73%; 95% CI, 66%-79%). A neutral or positive rating was given to 135 model segmentations (78%; 95% CI, 71%-84%) and 309 expert gradings (2 per scan) (89%; 95% CI, 86%-92%). The model was rated neutrally or positively in 86% to 92% of diabetic macular edema scans and 53% to 87% of age-related macular degeneration scans. Intraclass correlations ranged from 0.33 (95% CI, 0.08-0.96) to 0.96 (95% CI, 0.90-0.99). Dice similarity coefficients ranged from 0.43 (95% CI, 0.29-0.66) to 0.78 (95% CI, 0.57-0.85). CONCLUSIONS AND RELEVANCE: This deep learning-based segmentation tool provided clinically useful measures of retinal disease that would otherwise be infeasible to obtain. Qualitative evaluation was additionally important to reveal clinical applicability for both care management and research.


Asunto(s)
Aprendizaje Profundo , Retinopatía Diabética , Edema Macular , Degeneración Macular Húmeda , Retinopatía Diabética/diagnóstico por imagen , Femenino , Humanos , Edema Macular/diagnóstico por imagen , Masculino , Tomografía de Coherencia Óptica/métodos , Degeneración Macular Húmeda/diagnóstico
15.
Contemp Clin Trials Commun ; 17: 100506, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31909291

RESUMEN

The majority of people receiving treatment for their heroin addiction, are prescribed methadone; for which there is an extensive evidence base. When treatment starts, people take their daily dose of methadone under supervision at a community pharmacy. Supervision guarantees methadone is taken as directed by the individual for whom it has been prescribed, helps to ensure individuals take their correct dose every day, and safeguards against diversion and overdose. However, individuals often fail to attend the pharmacy to take their methadone. Each missed dose is of concern. If a patient misses their daily dose of methadone, they will start to experience opiate withdrawal and cravings and are more likely to use heroin. If they miss three days dose, there are concerns that they may lose tolerance to the drug and may be at risk of overdose when the next dose is taken. Hence there is an urgent need to develop effective interventions for medication adherence. Research suggests that incentive-based medication adherence interventions may be very effective, but there are few controlled trials and the provision of incentives requires time and organisational systems which can be challenging in pharmacies. The investigators have developed the technology to deliver incentives by mobile telephone. This cluster randomised trial will test the feasibility of conducting a future trial evaluating the clinical and cost effectiveness of using telephone delivered incentives (praise and modest financial rewards via text messaging) to encourage adherence with supervised consumption of methadone in community pharmacies. Three drug services (each with two or three community pharmacies supervising methadone consumption that will enrol 20 individuals, a total of 60 participants) will be recruited and randomly allocated to deliver either i) telephone delivered incentives, ii) telephone delivered reminders or iii) no telephone system. Acceptability, recruitment, follow-up, and suitable measures of clinical and cost effectiveness will be assessed. Findings from this feasibility study will be assessed against stated progression criteria and used to inform a future confirmatory trial of the clinical and cost effectiveness of telephone delivered incentives to encourage medication adherence. TRIAL REGISTRATION: ISRCTN58958179 (retrospectively registered).

16.
Biochem Soc Trans ; 37(Pt 1): 123-6, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19143615

RESUMEN

TA (toxin-antitoxin) loci are ubiquitous in prokaryotic micro-organisms, including archaea, yet their physiological function is largely unknown. For example, preliminary reports have suggested that TA loci are microbial stress-response elements, although it was recently shown that knocking out all known chromosomally located TA loci in Escherichia coli did not have an impact on survival under certain types of stress. The hyperthermophilic crenarchaeon Sulfolobus solfataricus encodes at least 26 vapBC (where vap is virulence-associated protein) family TA loci in its genome. VapCs are PIN (PilT N-terminus) domain proteins with putative ribonuclease activity, while VapBs are proteolytically labile proteins, which purportedly function to silence VapCs when associated as a cognate pair. Global transcriptional analysis of S. solfataricus heat-shock-response dynamics (temperature shift from 80 to 90 degrees C) revealed that several vapBC genes were triggered by the thermal shift, suggesting a role in heat-shock-response. Indeed, knocking out a specific vapBC locus in S. solfataricus substantially changed the transcriptome and, in one case, rendered the crenarchaeon heat-shock-labile. These findings indicate that more work needs to be done to determine the role of VapBCs in S. solfataricus and other thermophilic archaea, especially with respect to post-transcriptional regulation.


Asunto(s)
Antitoxinas/metabolismo , Proteínas Arqueales/metabolismo , Estrés Fisiológico , Sulfolobus solfataricus/metabolismo , Temperatura , Toxinas Biológicas/metabolismo , Proteínas Arqueales/genética , Genoma Arqueal/genética , Respuesta al Choque Térmico , Sulfolobus solfataricus/genética , Toxinas Biológicas/genética
17.
Curr Opin Biotechnol ; 19(5): 445-53, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18760359

RESUMEN

The extremely thermoacidophilic archaea are a particularly intriguing group of microorganisms that must simultaneously cope with biologically extreme pHs (< or = 4) and temperatures (Topt > or = 60 degrees C) in their natural environments. Their expanding biotechnological significance relates to their role in biomining of base and precious metals and their unique mechanisms of survival in hot acid, at both the cellular and biomolecular levels. Recent developments, such as advances in understanding of heavy metal tolerance mechanisms, implementation of a genetic system, and discovery of a new carbon fixation pathway, have been facilitated by the availability of genome sequence data and molecular genetic systems. As a result, new insights into the metabolic pathways and physiological features that define extreme thermoacidophily have been obtained, in some cases suggesting prospects for biotechnological opportunities.


Asunto(s)
Ácidos/metabolismo , Archaea/fisiología , Proteínas Arqueales/metabolismo , Ecosistema , Modelos Biológicos , Transducción de Señal/fisiología , Supervivencia Celular , Calor , Concentración de Iones de Hidrógeno
18.
J AOAC Int ; 2018 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-30060779

RESUMEN

Background: The Thermo Scientific RapidFinder™ Salmonella species, Typhimurium and Enteritidis Multiplex PCR Kit is a real-time multiplex PCR assay for the detection and differentiation of Salmonella species, Salmonella Typhimurium, and S. Enteritidis from poultry, pork, and environmental samples. The method has previously been granted certification as Performance Tested Method SM (PTM) 081701, validated according to the AOAC Research Institute (RI) PTM program for poultry (chicken thighs with skin, chicken wings with skin, and chicken nuggets), raw pork sausage matrixes, and stainless steel environmental surface sponges. Objective: This report details the method modification study to validate ground turkey (375 g sample size), chicken carcass rinse, and shell egg matrixes. Methods: The candidate method was compared with the U.S. Food and Drug Administration's Bacteriological Analytical Manual Chapter 5 for shell eggs and the U.S. Department of Agriculture Food Safety and Inspection Service's Microbiology Laboratory Guidebook 4.09 for ground turkey (375 g) and chicken carcass rinse matrixes. Results: The statistically significant differences found between the candidate and reference methods upon analysis by probability of detection were in favor of the candidate method. Inclusivity and exclusivity testing demonstrated that the RapidFinder Salmonella species, Typhimurium and Enteritidis Multiplex PCR Kit was able to detect all the major groups of Salmonella. All exclusivity isolates were correctly excluded. Conclusions: The data presented in this report show that the candidate is suitable for the detection and differentiation of Salmonellae from shell egg, chicken carcass rinse, and ground turkey (375 g) matrixes. Highlights: Thermo Scientific RapidFinder Salmonella species, Typhimurium and Enteritidis Multiplex PCR Kit (candidate method) matrix claims extended to include ground turkey (375 g), chicken carcass rinse and shell egg samples.

19.
Psychopharmacology (Berl) ; 233(18): 3429-35, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27503474

RESUMEN

RATIONALE: An increasing body of evidence links the occurrence of sleep continuity disturbances with increased inflammation and both sleep disturbances and inflammation are associated with clinical depression. Typhoid vaccination results in a mild inflammatory response that significantly increases levels of the proinflammatory cytokine, interleukin (IL)-6. OBJECTIVES: The present exploratory study aimed to enhance our understanding of the link between inflammation, sleep and depression by examining the effects of typhoid vaccine on the sleep polysomnogram. METHODS: We studied the effects of a single injection of typhoid polysaccharide vaccine and placebo (saline solution) on sleep in 16 healthy male and female participants aged 20-38 years, sleeping at home in a randomized, double-blind, balanced order, crossover design. Subjective measures of mood, sleep and adverse effects were elicited and plasma samples analysed for IL-6 levels. RESULTS: IL-6 levels (in picogramme per millilitre) significantly increased 2 h post vaccine compared to placebo (0.90 vs 0.53, p = 0.026, r = 0.55). Relative to placebo, typhoid vaccination produced significant impairment in several measures of sleep continuity. Total sleep time (in minute) (426.1 vs 410.7, p = 0.005, r = 0.62) and sleep efficiency percent (94.3 vs 91.5, p = 0.007, r = 0.65) were decreased; with increases in wake after sleep onset (in minute) (25.5 vs 38.8, p = 0.007,r = 0.65), total wake (in minute) (34.9 vs 50.3, p = 0.005,r = 0.67), sleep stage transitions (155.9 vs 173.1, p = 0.026, r = 0.56), number of awakenings (27.2 vs 36.1, p = 0.007, r = 0.64) and awakening index (3.8 vs 5.3, p = 0.005, r = 0.67) (means, significance level and effect size). CONCLUSIONS: Inflammatory mechanisms may underlie the impairment in sleep efficiency which is a hallmark of major depression. Because impaired sleep is also a predictor of major depression, there may be a role for suitable anti-inflammatory approaches in strategies designed to prevent the onset of depression. ClinicalTrials.gov ( http://www.clinicaltrials.gov ): NCT02628054.


Asunto(s)
Afecto/efectos de los fármacos , Inflamación/inmunología , Interleucina-6/inmunología , Sueño/efectos de los fármacos , Vacunas Tifoides-Paratifoides/farmacología , Adulto , Estudios Cruzados , Citocinas/efectos de los fármacos , Citocinas/inmunología , Depresión/inmunología , Trastorno Depresivo Mayor/inmunología , Método Doble Ciego , Femenino , Voluntarios Sanos , Humanos , Masculino , Polisomnografía , Adulto Joven
20.
Psychopharmacology (Berl) ; 233(14): 2655-61, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27256357

RESUMEN

RATIONALE: Lithium remains the most effective treatment for bipolar disorder and also has important effects to lower suicidal behaviour, a property that may be linked to its ability to diminish impulsive, aggressive behaviour. The antioxidant drug, ebselen, has been proposed as a possible lithium-mimetic based on its ability in animals to inhibit inositol monophosphatase (IMPase), an action which it shares with lithium. OBJECTIVES: The aim of the study was to determine whether treatment with ebselen altered emotional processing and diminished measures of risk-taking behaviour. METHODS: We studied 20 healthy participants who were tested on two occasions receiving either ebselen (3600 mg over 24 h) or identical placebo in a double-blind, randomized, cross-over design. Three hours after the final dose of ebselen/placebo, participants completed the Cambridge Gambling Task (CGT) and a task that required the detection of emotional facial expressions (facial emotion recognition task (FERT)). RESULTS: On the CGT, relative to placebo, ebselen reduced delay aversion while on the FERT, it increased the recognition of positive vs negative facial expressions. CONCLUSIONS: The study suggests that at the dosage used, ebselen can decrease impulsivity and produce a positive bias in emotional processing. These findings have implications for the possible use of ebselen in the disorders characterized by impulsive behaviour and dysphoric mood.


Asunto(s)
Azoles/farmacología , Inhibidores de la Ciclooxigenasa/farmacología , Emociones/efectos de los fármacos , Conducta Impulsiva/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Compuestos de Organoselenio/farmacología , Reconocimiento en Psicología/efectos de los fármacos , Adulto , Análisis de Varianza , Animales , Trastorno Bipolar/tratamiento farmacológico , Estudios Cruzados , Toma de Decisiones/efectos de los fármacos , Método Doble Ciego , Expresión Facial , Femenino , Humanos , Isoindoles , Masculino , Monoéster Fosfórico Hidrolasas , Recompensa , Asunción de Riesgos , Adulto Joven
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