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1.
Nature ; 606(7915): 694-699, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35732762

RESUMEN

The realization of controllable fermionic quantum systems via quantum simulation is instrumental for exploring many of the most intriguing effects in condensed-matter physics1-3. Semiconductor quantum dots are particularly promising for quantum simulation as they can be engineered to achieve strong quantum correlations. However, although simulation of the Fermi-Hubbard model4 and Nagaoka ferromagnetism5 have been reported before, the simplest one-dimensional model of strongly correlated topological matter, the many-body Su-Schrieffer-Heeger (SSH) model6-11, has so far remained elusive-mostly owing to the challenge of precisely engineering long-range interactions between electrons to reproduce the chosen Hamiltonian. Here we show that for precision-placed atoms in silicon with strong Coulomb confinement, we can engineer a minimum of six all-epitaxial in-plane gates to tune the energy levels across a linear array of ten quantum dots to realize both the trivial and the topological phases of the many-body SSH model. The strong on-site energies (about 25 millielectronvolts) and the ability to engineer gates with subnanometre precision in a unique staggered design allow us to tune the ratio between intercell and intracell electron transport to observe clear signatures of a topological phase with two conductance peaks at quarter-filling, compared with the ten conductance peaks of the trivial phase. The demonstration of the SSH model in a fermionic system isomorphic to qubits showcases our highly controllable quantum system and its usefulness for future simulations of strongly interacting electrons.

2.
BMC Musculoskelet Disord ; 24(1): 934, 2023 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-38042799

RESUMEN

BACKGROUND: The purpose of this study was to investigate the relationship between preoperative aspartate aminotransferase-to-platelet ratio index (APRI) and postoperative complications following total hip arthroplasty (THA). METHODS: All THA for osteoarthritis patients from 2007 to 2020 within the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database were included in this study. Subjects were subsequently divided into cohorts based on APRI. Four groups, including normal range, some liver damage, significant fibrosis, and cirrhosis groups, were created. Comparisons between groups were made for demographics, past medical history, and rate of major and minor complications. Other outcomes included readmission, reoperation, discharge destination, mortality, periprosthetic fracture, and postoperative hip dislocation. Multivariate logistic regression analysis was performed to determine the role of preoperative APRI in predicting adverse outcomes. Statistical significance was set at p < 0.05. RESULTS: In total, 104,633 primary THA patients were included in this study. Of these, 103,678 (99.1%) were in the normal APRI group, 444 (0.4%) had some liver damage, 256 (0.2%) had significant fibrosis, and 253 (0.2%) had cirrhosis. When controlling for demographics and relevant past medical history, the abnormal APRI groups had a significantly higher likelihood of major complication, minor complication, intraoperative or postoperative bleeding requiring transfusion, readmission, and non-home discharge (all p < 0.05) compared to normal APRI individuals. CONCLUSIONS: Abnormal preoperative APRI is linked with an increasing number of adverse outcomes following THA for osteoarthritis for patients across the United States. LEVEL OF EVIDENCE: Level I.


Asunto(s)
Artroplastia de Reemplazo de Cadera , Osteoartritis , Humanos , Estados Unidos , Artroplastia de Reemplazo de Cadera/efectos adversos , Factores de Riesgo , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Osteoartritis/cirugía , Cirrosis Hepática/diagnóstico , Cirrosis Hepática/cirugía , Cirrosis Hepática/complicaciones , Aspartato Aminotransferasas , Estudios Retrospectivos
3.
PLoS Genet ; 15(7): e1008224, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31276487

RESUMEN

The gastrointestinal pathogen, Clostridioides difficile, initiates infection when its metabolically dormant spore form germinates in the mammalian gut. While most spore-forming bacteria use transmembrane germinant receptors to sense nutrient germinants, C. difficile is thought to use the soluble pseudoprotease, CspC, to detect bile acid germinants. To gain insight into CspC's unique mechanism of action, we solved its crystal structure. Guided by this structure, we identified CspC mutations that confer either hypo- or hyper-sensitivity to bile acid germinant. Surprisingly, hyper-sensitive CspC variants exhibited bile acid-independent germination as well as increased sensitivity to amino acid and/or calcium co-germinants. Since mutations in specific residues altered CspC's responsiveness to these different signals, CspC plays a critical role in regulating C. difficile spore germination in response to multiple environmental signals. Taken together, these studies implicate CspC as being intimately involved in the detection of distinct classes of co-germinants in addition to bile acids and thus raises the possibility that CspC functions as a signaling node rather than a ligand-binding receptor.


Asunto(s)
Proteínas Bacterianas/metabolismo , Ácidos y Sales Biliares/farmacología , Proteínas Portadoras/metabolismo , Clostridioides difficile/fisiología , Esporas Bacterianas/crecimiento & desarrollo , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Proteínas Portadoras/química , Proteínas Portadoras/genética , Cristalografía por Rayos X , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Modelos Moleculares , Mutación , Conformación Proteica , Estrés Fisiológico
4.
Biochem J ; 477(8): 1459-1478, 2020 04 30.
Artículo en Inglés | MEDLINE | ID: mdl-32242623

RESUMEN

Clostridioides difficile is a spore-forming bacterial pathogen that is the leading cause of hospital-acquired gastroenteritis. C. difficile infections begin when its spore form germinates in the gut upon sensing bile acids. These germinants induce a proteolytic signaling cascade controlled by three members of the subtilisin-like serine protease family, CspA, CspB, and CspC. Notably, even though CspC and CspA are both pseudoproteases, they are nevertheless required to sense germinants and activate the protease, CspB. Thus, CspC and CspA are part of a growing list of pseudoenzymes that play important roles in regulating cellular processes. However, despite their importance, the structural properties of pseudoenzymes that allow them to function as regulators remain poorly understood. Our recently solved crystal structure of CspC revealed that its pseudoactive site residues align closely with the catalytic triad of CspB, suggesting that it might be possible to 'resurrect' the ancestral protease activity of the CspC and CspA pseudoproteases. Here, we demonstrate that restoring the catalytic triad to these pseudoproteases fails to resurrect their protease activity. We further show that the pseudoactive site substitutions differentially affect the stability and function of the CspC and CspA pseudoproteases: the substitutions destabilized CspC and impaired spore germination without affecting CspA stability or function. Thus, our results surprisingly reveal that the presence of a catalytic triad does not necessarily predict protease activity. Since homologs of C. difficile CspA occasionally carry an intact catalytic triad, our results indicate that bioinformatic predictions of enzyme activity may underestimate pseudoenzymes in rare cases.


Asunto(s)
Proteínas Bacterianas/metabolismo , Proteínas Portadoras/metabolismo , Clostridioides difficile/enzimología , Esporas Bacterianas/crecimiento & desarrollo , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Proteínas Portadoras/química , Proteínas Portadoras/genética , Catálisis , Clostridioides difficile/química , Clostridioides difficile/genética , Clostridioides difficile/crecimiento & desarrollo , Regulación Bacteriana de la Expresión Génica , Regulación del Desarrollo de la Expresión Génica , Esporas Bacterianas/enzimología , Esporas Bacterianas/genética
5.
Colorectal Dis ; 22(11): 1741-1748, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32663345

RESUMEN

AIM: Currently, there is no established colorectal specific robotic surgery Train the Trainer (TTT) course. The aim was to develop and evaluate such a course which can then be further developed to be incorporated within the planned European Society of Coloproctology (ESCP)/European School of Coloproctology (ESC) robotic colorectal surgery training curriculum. METHOD: After identifying the need for such a course within a training programme, the course was developed by a subgroup of the ESCP/ESC. A scoping literature review was performed and the content and materials for the course were developed by a team consisting of two gastroenterologists with a combined experience of 30 years of facilitating TTT courses, a robotic surgeon and proctor with laparoscopic TTT faculty experience and experienced robotic and laparoscopic colorectal trainers. The course was evaluated by asking delegates to complete pre- and post-course questionnaires. RESULTS: There were eight delegates on the course from across Europe. Delegates increased their knowledge of each of the course learning objectives and identified learning points in order to change practice. The feedback from the delegates of the course was positive across several areas and all felt that they had achieved their own personal objectives in attending the course. CONCLUSION: This pilot robotic colorectal TTT course has achieved its aim and demonstrated many positives. There is a need for such a course and the evaluation processes have provided opportunities for reflection, which will allow the development/tailoring of future robotic colorectal TTT courses to help develop robotic training further.


Asunto(s)
Neoplasias Colorrectales , Cirugía Colorrectal , Procedimientos Quirúrgicos Robotizados , Robótica , Cirugía Colorrectal/educación , Curriculum , Humanos
6.
Phys Chem Chem Phys ; 20(42): 26853-26858, 2018 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-30328852

RESUMEN

Although the hydrogenous analogue of the D2-D2O system has been well explored in the regimes above 1 GPa, and below 0.2 GPa, there have been very few studies in the region between these pressures. The recent discovery in the range 0.5-0.7 GPa of a new phase, C0, that possesses a new clathrate structure with a new H2O network, along with the proposal of another structure stable at similar conditions, has prompted further studies of the hydrogen water system in this intermediate pressure region. Here, we report the results of neutron-diffraction experiments that observed transitions from metastable to stable structures in the D2-D2O system around 0.2-0.3 GPa between 130 K and 280 K. These metastable structures were observed in the stability region of the sII hydrogen hydrate clathrate and computational studies of their relative enthalpies suggest that transition sequence observed is in line with Ostwald's 'Rule of Stages'.

7.
PLoS Genet ; 11(10): e1005562, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26465937

RESUMEN

Sporulation is an ancient developmental process that involves the formation of a highly resistant endospore within a larger mother cell. In the model organism Bacillus subtilis, sporulation-specific sigma factors activate compartment-specific transcriptional programs that drive spore morphogenesis. σG activity in the forespore depends on the formation of a secretion complex, known as the "feeding tube," that bridges the mother cell and forespore and maintains forespore integrity. Even though these channel components are conserved in all spore formers, recent studies in the major nosocomial pathogen Clostridium difficile suggested that these components are dispensable for σG activity. In this study, we investigated the requirements of the SpoIIQ and SpoIIIA proteins during C. difficile sporulation. C. difficile spoIIQ, spoIIIA, and spoIIIAH mutants exhibited defects in engulfment, tethering of coat to the forespore, and heat-resistant spore formation, even though they activate σG at wildtype levels. Although the spoIIQ, spoIIIA, and spoIIIAH mutants were defective in engulfment, metabolic labeling studies revealed that they nevertheless actively transformed the peptidoglycan at the leading edge of engulfment. In vitro pull-down assays further demonstrated that C. difficile SpoIIQ directly interacts with SpoIIIAH. Interestingly, mutation of the conserved Walker A ATP binding motif, but not the Walker B ATP hydrolysis motif, disrupted SpoIIIAA function during C. difficile spore formation. This finding contrasts with B. subtilis, which requires both Walker A and B motifs for SpoIIIAA function. Taken together, our findings suggest that inhibiting SpoIIQ, SpoIIIAA, or SpoIIIAH function could prevent the formation of infectious C. difficile spores and thus disease transmission.


Asunto(s)
Proteínas Bacterianas/genética , Clostridioides difficile/genética , Enterocolitis Seudomembranosa/genética , Factor sigma/genética , Esporas Bacterianas/genética , Adenosina Trifosfato/genética , Secuencias de Aminoácidos/genética , Diferenciación Celular/genética , Pared Celular/genética , Clostridioides difficile/patogenicidad , Enterocolitis Seudomembranosa/microbiología , Mutación , Unión Proteica
8.
Surgeon ; 16(3): 141-145, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28549528

RESUMEN

INTRODUCTION: Road traffic accidents (RTAs) are the leading cause of trauma related mortality in Ireland. The penalty points system (PPS) was introduced in Ireland in 2002 to incentivise safer driving and reduce injury. Its early effect was studied previously1 which concluded that there was a slight reduction in RTA related femoral shaft fractures (a sensitive indicator of high energy trauma) and a dramatic reduction in RTA related discharges. We hypothesized that over the following 14 years, the penalty points system might lose its effectiveness. METHODS: Data was again collected from the same HIPE departments from six Dublin teaching hospitals and also University Hospital Waterford (to represent both an urban and a more rural population cohort respectively) examining RTA related femoral shaft fractures over an identical 6 month period (October-April). RTA related discharge data over an identical 6 month period was again acquired and analysed from Beaumont Hospital, Dublin (identical data source to previous study). These results were compared with the identical 6 month period in 2001/02 & 2002/03 (October-April). RESULTS: The total number of RTA related femoral shaft fracture discharges in Dublin decreased from 16 post introduction of PPS in the 2002/03 6-month period to 7 in 2015/16 6-month period. The number remained the same in the Waterford region (n = 5). The total RTA related discharges in Beaumont Hospital, Dublin decreased from 70 post PPS introduction to 57 in the 2015/16 6-month period. This represents an incidence rate of 4.5/1000 discharges (vs 6.9 post introduction) which was a statistically significant reduction (p = 0.014). The mean length of stay for these patients reduced from 13 to 7.7 days. There were consistent reductions in head injury (major & minor), lower limb fracture and facial fracture since the introduction of the PPS. The upper limb, pelvic/acetabular and thoracic injuries remained largely unchanged. Whilst RTA related spinal and abdominal injuries decreased after the introduction of the PPS, this study shows that these injuries have unfortunately increased since the post-PPS study in 2002/03. CONCLUSIONS: These results further support the effectiveness of the penalty points system and at a time where road death figures are under the spotlight, endorse the efficacious strategies implemented by the road safety authority in Ireland.


Asunto(s)
Prevención de Accidentes/legislación & jurisprudencia , Accidentes de Tránsito/legislación & jurisprudencia , Accidentes de Tránsito/prevención & control , Conducción de Automóvil/legislación & jurisprudencia , Fracturas del Fémur/epidemiología , Prevención de Accidentes/estadística & datos numéricos , Accidentes de Tránsito/mortalidad , Accidentes de Tránsito/estadística & datos numéricos , Adolescente , Adulto , Conducción de Automóvil/normas , Conducción de Automóvil/estadística & datos numéricos , Femenino , Fracturas del Fémur/prevención & control , Humanos , Irlanda/epidemiología , Masculino , Persona de Mediana Edad , Adulto Joven
9.
Ir Med J ; 111(10): 839, 2018 12 06.
Artículo en Inglés | MEDLINE | ID: mdl-30560635

RESUMEN

Introduction Drain usage is commonplace in head and neck surgery. There is an increasing body of literature disputing their routine placement in certain procedures. The aim of this study is to explore modern-day practice in terms of drain usage and the use of haemostatic agents. Methods A simple questionnaire was devised and sent to 35 ENT Surgeons across 10 units nationally. Results There was an overall response rate of 77.1% (n=27). There was considerable heterogeneity amongst surgeons in terms of indication for insertion, how the decision is made to remove the drain and if any alternative/adjunctive haemostatic agents are being used. Discussion The management of drains is poorly defined and guidelines are lacking. With increased pressure on resources, the risk of infection and discomfort to the patient, further reflection is required to evaluate if careful patient selection rather than habitual drain insertion in every case is more appropriate.


Asunto(s)
Drenaje/estadística & datos numéricos , Cabeza/cirugía , Cuello/cirugía , Utilización de Procedimientos y Técnicas/estadística & datos numéricos , Cirujanos/estadística & datos numéricos , Biopsia , Branquioma/cirugía , Hemostáticos , Irlanda/epidemiología , Ganglios Linfáticos/cirugía , Disección del Cuello , Paratiroidectomía , Glándulas Salivales/cirugía , Encuestas y Cuestionarios , Quiste Tirogloso/cirugía , Tiroidectomía
10.
J Pharmacol Exp Ther ; 360(2): 346-355, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-27965369

RESUMEN

Although the physiologic role of muscarinic receptors in bladder function and the therapeutic efficacy of muscarinic antagonists for the treatment of overactive bladder are well established, the role of ß3-adrenergic receptors (ß3ARs) and their potential as therapeutics is just emerging. In this manuscript, we characterized the pharmacology of a novel ß3AR agonist vibegron (MK-4618, KRP-114V) and explored mechanistic interactions of ß3AR agonism and muscarinic antagonism in urinary bladder function. Vibegron is a potent, selective full ß3AR agonist across species, and it dose dependently increased bladder capacity, decreased micturition pressure, and increased bladder compliance in rhesus monkeys. The relaxation effect of vibegron was enhanced when combined with muscarinic antagonists, but differentially influenced by muscarinic receptor subtype selectivity. The effect was greater when vibegron was co-administered with tolterodine, a nonselective antagonist, compared with coadministration with darifenacin, a selective M3 antagonist. Furthermore, a synergistic effect for bladder strip relaxation was observed with the combination of a ß3AR agonist and tolterodine in contrast to simple additivity with darifenacin. To determine expression in rhesus bladder, we employed a novel ß3AR agonist probe, [3H]MRL-037, that selectively labels ß3 receptors in both urothelium and detrusor smooth muscle. Vibegron administration caused a dose-dependent increase in circulating glycerol and fatty acid levels in rhesus and rat in vivo, suggesting these circulating lipids can be surrogate biomarkers. The translation of our observation to the clinic has yet to be determined, but the combination of ß3AR agonists with M2/M3 antimuscarinics has the potential to redefine the standard of care for the pharmacological treatment of overactive bladder.


Asunto(s)
Agonistas de Receptores Adrenérgicos beta 3/farmacología , Antagonistas Muscarínicos/farmacología , Pirimidinonas/farmacología , Pirrolidinas/farmacología , Receptores Adrenérgicos beta 3/metabolismo , Vejiga Urinaria Hiperactiva/tratamiento farmacológico , Agonistas de Receptores Adrenérgicos beta 3/uso terapéutico , Animales , Interacciones Farmacológicas , Femenino , Humanos , Macaca mulatta , Masculino , Antagonistas Muscarínicos/uso terapéutico , Músculo Liso/efectos de los fármacos , Músculo Liso/fisiopatología , Transporte de Proteínas/efectos de los fármacos , Pirimidinonas/uso terapéutico , Pirrolidinas/uso terapéutico , Ratas , Especificidad de la Especie , Vejiga Urinaria/efectos de los fármacos , Vejiga Urinaria/fisiopatología , Vejiga Urinaria Hiperactiva/metabolismo , Vejiga Urinaria Hiperactiva/fisiopatología , Urodinámica/efectos de los fármacos
11.
PLoS Pathog ; 11(10): e1005239, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26496694

RESUMEN

Clostridium difficile is a Gram-positive spore-forming pathogen and a leading cause of nosocomial diarrhea. C. difficile infections are transmitted when ingested spores germinate in the gastrointestinal tract and transform into vegetative cells. Germination begins when the germinant receptor CspC detects bile salts in the gut. CspC is a subtilisin-like serine pseudoprotease that activates the related CspB serine protease through an unknown mechanism. Activated CspB cleaves the pro-SleC zymogen, which allows the activated SleC cortex hydrolase to degrade the protective cortex layer. While these regulators are essential for C. difficile spores to outgrow and form toxin-secreting vegetative cells, the mechanisms controlling their function have only been partially characterized. In this study, we identify the lipoprotein GerS as a novel regulator of C. difficile spore germination using targeted mutagenesis. A gerS mutant has a severe germination defect and fails to degrade cortex even though it processes SleC at wildtype levels. Using complementation analyses, we demonstrate that GerS secretion, but not lipidation, is necessary for GerS to activate SleC. Importantly, loss of GerS attenuates the virulence of C. difficile in a hamster model of infection. Since GerS appears to be conserved exclusively in related Peptostreptococcaeace family members, our results contribute to a growing body of work indicating that C. difficile has evolved distinct mechanisms for controlling the exit from dormancy relative to B. subtilis and other spore-forming organisms.


Asunto(s)
Proteínas Bacterianas/fisiología , Clostridioides difficile/fisiología , Lipoproteínas/fisiología , Animales , Proteínas Portadoras/fisiología , Cricetinae , Esporas Bacterianas/fisiología
12.
Artículo en Inglés | MEDLINE | ID: mdl-28169490

RESUMEN

To identify and clarify definitions and methods of measuring cancer-related cognitive impairment among prostate cancer patients treated with androgen deprivation therapy (ADT) and to assess the incidence and prevalence of cognitive impairment. A systematic review of Medline, EMBASE, PubMed, PsycINFO and CINAHL up to December 2015 was undertaken to identify English-language reviews. A total of 28 reviews were identified describing 20 primary studies. There were no studies of incidence. Reported prevalence rates varied between 10% and 69%. Cognitive domains impaired by ADT included: verbal memory, visuospatial ability and executive functions. Cognitive impairment was infrequently defined and four definitions were reported. A variety of measures and methods were used to assess cognitive function including neuropsychological tests, self-report measures and clinical assessments. The finding that, often, one measure was used to assess more than one aspect of cognition is likely to have contributed to imprecise estimates. There is a need to agree a definition of cognitive impairment in the clinical epidemiology of cancer and to standardise the selection of measures in order to aid accurate assessment and fair comparisons across studies regarding the prevalence of cognitive impairment among prostate cancer patients.


Asunto(s)
Disfunción Cognitiva/epidemiología , Neoplasias de la Próstata/psicología , Antagonistas de Andrógenos/efectos adversos , Antagonistas de Andrógenos/uso terapéutico , Disfunción Cognitiva/diagnóstico , Disfunción Cognitiva/etiología , Humanos , Incidencia , Masculino , Prevalencia , Neoplasias de la Próstata/tratamiento farmacológico
14.
J Bacteriol ; 198(11): 1694-1707, 2016 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-27044622

RESUMEN

UNLABELLED: The spore-forming obligate anaerobe Clostridium difficile is a leading cause of antibiotic-associated diarrhea around the world. In order for C. difficile to cause infection, its metabolically dormant spores must germinate in the gastrointestinal tract. During germination, spores degrade their protective cortex peptidoglycan layers, release dipicolinic acid (DPA), and hydrate their cores. In C. difficile, cortex hydrolysis is necessary for DPA release, whereas in Bacillus subtilis, DPA release is necessary for cortex hydrolysis. Given this difference, we tested whether DPA synthesis and/or release was required for C. difficile spore germination by constructing mutations in either spoVAC or dpaAB, which encode an ion channel predicted to transport DPA into the forespore and the enzyme complex predicted to synthesize DPA, respectively. C. difficile spoVAC and dpaAB mutant spores lacked DPA but could be stably purified and were more hydrated than wild-type spores; in contrast, B. subtilis spoVAC and dpaAB mutant spores were unstable. Although C. difficile spoVAC and dpaAB mutant spores exhibited wild-type germination responses, they were more readily killed by wet heat. Cortex hydrolysis was not affected by this treatment, indicating that wet heat inhibits a stage downstream of this event. Interestingly, C. difficile spoVAC mutant spores were significantly more sensitive to heat treatment than dpaAB mutant spores, indicating that SpoVAC plays additional roles in conferring heat resistance. Taken together, our results demonstrate that SpoVAC and DPA synthetase control C. difficile spore resistance and reveal differential requirements for these proteins among the Firmicutes IMPORTANCE: Clostridium difficile is a spore-forming obligate anaerobe that causes ∼500,000 infections per year in the United States. Although spore germination is essential for C. difficile to cause disease, the factors required for this process have been only partially characterized. This study describes the roles of two factors, DpaAB and SpoVAC, which control the synthesis and release of dipicolinic acid (DPA), respectively, from bacterial spores. Previous studies of these proteins in other spore-forming organisms indicated that they are differentially required for spore formation, germination, and resistance. We now show that the proteins are dispensable for C. difficile spore formation and germination but are necessary for heat resistance. Thus, our study further highlights the diverse functions of DpaAB and SpoVAC in spore-forming organisms.


Asunto(s)
Proteínas Bacterianas/metabolismo , Clostridioides difficile/enzimología , Oxidorreductasas/metabolismo , Ácidos Picolínicos/metabolismo , Esporas Bacterianas/enzimología , Proteínas Bacterianas/genética , Clostridioides difficile/genética , Clostridioides difficile/crecimiento & desarrollo , Clostridioides difficile/metabolismo , Calor , Mutación , Oxidorreductasas/genética , Esporas Bacterianas/genética , Esporas Bacterianas/crecimiento & desarrollo , Esporas Bacterianas/metabolismo
15.
Mol Genet Genomics ; 290(1): 201-15, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25213601

RESUMEN

Insecticide resistance is a major impediment to the control of vectors and pests of public health importance and is a strongly selected trait capable of rapid spread, sometimes even between closely related species. Elucidating the mechanisms generating insecticide resistance in mosquito vectors of disease, and understanding the spread of resistance within and between populations and species are vital for the development of robust resistance management strategies. Here, we studied the mechanisms of resistance in two sympatric members of the Anopheles gambiae species complex-the major vector of malaria in sub-Saharan Africa-to understand how resistance has developed and spread in eastern Uganda, a region with some of the highest levels of malaria. In eastern Uganda, where the mosquitoes Anopheles arabiensis and An. gambiae can be found sympatrically, low levels of hybrids (0.4 %) occur, offering a route for introgression of adaptively important variants between species. In independent microarray studies of insecticide resistance, Gste4, an insect-specific glutathione S-transferase, was among the most significantly up-regulated genes in both species. To test the hypothesis of interspecific introgression, we sequenced 2.3 kbp encompassing Gste4. Whilst this detailed sequencing ruled out introgression, we detected strong positive selection acting on Gste4. However, these sequences, followed by haplotype-specific qPCR, showed that the apparent up-regulation in An. arabiensis is a result of allelic variation across the microarray probe binding sites which artefactually elevates the gene expression signal. Thus, face-value acceptance of microarray data can be misleading and it is advisable to conduct a more detailed investigation of the causes and nature of such signal. The identification of positive selection acting on this locus led us to functionally express and characterise allelic variants of GSTE4. Although the in vitro data do not support a direct role for GSTE4 in metabolism, they do support a role for this enzyme in insecticide sequestration. Thus, the demonstration of a role for an up-regulated gene in metabolic resistance to insecticides should not be limited to simply whether it can metabolise insecticide; such a strict criterion would argue against the involvement of GSTE4 despite the weight of evidence to the contrary.


Asunto(s)
Anopheles/genética , Evolución Biológica , Inactivación Metabólica , Proteínas de Insectos/metabolismo , Piretrinas/metabolismo , Selección Genética , Animales , Anopheles/metabolismo , Secuencia de Bases , Regulación de la Expresión Génica , Genoma de los Insectos , Técnicas de Genotipaje , Haplotipos/genética , Concentración de Iones de Hidrógeno , Proteínas de Insectos/química , Proteínas de Insectos/genética , Resistencia a los Insecticidas/efectos de los fármacos , Cinética , Datos de Secuencia Molecular , Nitrilos/toxicidad , Análisis de Secuencia por Matrices de Oligonucleótidos , Filogenia , Polimorfismo de Nucleótido Simple/genética , Piretrinas/toxicidad , Proteínas Recombinantes/metabolismo , Reproducibilidad de los Resultados , Temperatura
16.
Gynecol Oncol ; 136(3): 460-5, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25462201

RESUMEN

OBJECTIVE: Although robotic surgery decreases pain compared to laparotomy, postoperative pain can be a concern near the site of a larger assistant trocar site. The aim of this study was to determine the efficacy of transversus abdominis plane (TAP) block on 24-hour postoperative opiate use after robotic surgery for gynecologic cancer. METHODS: Sixty-four subjects with gynecologic malignancies who were scheduled to undergo robotic surgery were enrolled into the study. They were randomized to receive a unilateral TAP block to the side of the assistant port via ultrasound guidance. The block was comprised of 30 cc of 0.25% bupivacaine with 3 mcg/mL epinephrine or saline. Opiate use was measured and converted into IV morphine equivalents. Patient-reported pain was measured using the Brief Pain Inventory (BPI) and Visual Analog Scale (VAS). RESULTS: The treatment group used a mean of 64.9 mg morphine in the first 24h compared to 69.3mg for controls (primary outcome, p=0.52). After age-adjustment, the treatment group used a mean of 11.1mg morphine less than controls (p=0.09). Postoperative pain scores assessed by the BPI (6.44 vs. 6.97, p=0.37) and the VAS (3.12 vs. 3.61, p=0.30) were equivalent. Block placement was uncomplicated in 98.4% of participants with mean BMI of 35.3 kg/m(2). Linear regression revealed an approximate 8.1mg decrease in morphine equivalents used per additional decade of life (p=0.0008). There was a positive correlation between the amount of opiates and BMI with an additional 8.8 mg of morphine per 10 kg/m(2) increase in BMI (p=0.0012). CONCLUSIONS: TAP block is safe and feasible in this patient population with a large proportion of morbid obesity. Preoperative TAP block does not significantly decrease opiate use. However; based on these data, a clinically useful nomogram has been created to aid clinicians in postoperative opiate-dosing for patients based on age and BMI.


Asunto(s)
Anestésicos Locales/uso terapéutico , Bupivacaína/uso terapéutico , Neoplasias de los Genitales Femeninos/cirugía , Laparoscopía , Bloqueo Nervioso/métodos , Dolor Postoperatorio/prevención & control , Robótica , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Analgésicos Opioides/uso terapéutico , Método Doble Ciego , Femenino , Estudios de Seguimiento , Humanos , Modelos Lineales , Persona de Mediana Edad , Morfina/uso terapéutico , Nomogramas , Dimensión del Dolor , Dolor Postoperatorio/tratamiento farmacológico , Resultado del Tratamiento , Adulto Joven
17.
J Chem Phys ; 142(12): 124503, 2015 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-25833592

RESUMEN

Urea, like many network forming compounds, has long been known to form inclusion (guest-host) compounds. Unlike other network formers like water, urea is not known to form such inclusion compounds with simple molecules like hydrogen. Such compounds if they existed would be of interest both for the fundamental insight they provide into molecular bonding and as potential gas storage systems. Urea has been proposed as a potential hydrogen storage material [T. A. Strobel et al., Chem. Phys. Lett. 478, 97 (2009)]. Here, we report the results of high-pressure neutron diffraction studies of urea and D2 mixtures that indicate no inclusion compound forms up to 3.7 GPa.

18.
J Chem Phys ; 142(9): 094707, 2015 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-25747099

RESUMEN

The disordered-molecular-alloy phase (DMA) of ammonia hydrates [J. S. Loveday and R. J. Nelmes, Phys. Rev. Lett. 83, 4329 (1999)] is unique in that it has substitutional disorder of ammonia and water over the molecular sites of a body centred cubic lattice. Whilst this structure has been observed in ammonia di- and mono-hydrate compositions, it has not been conclusively observed in the ammonia hemihydrate system. This work presents investigations of the structural behaviour of ammonia hemihydrate as a function of P and T. The indications of earlier studies [Ma et al. RSC Adv. 2, 4290 (2012)] that the DMA structure could be produced by compression of ammonia hemihydrate above 20 GPa at ambient temperature are confirmed. In addition, the DMA structure was found to form reversibly both from the melt, and on warming of ammonia hemihydrate phase-II, in the pressure range between 4 and 8 GPa. The route used to make the DMA structure from ammonia mono- and di-hydrates--compression at 170 K to 6 GPa followed by warming to ambient temperature--was found not to produce the DMA structure for ammonia hemihydrate. These results provide the first strong evidence that DMA is a thermodynamically stable form. A high-pressure phase diagram for ammonia hemihydrate is proposed which has importance for planetary modelling.

19.
J Public Health (Oxf) ; 36(2): 275-84, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23912464

RESUMEN

BACKGROUND: This paper describes the development of a complex intervention to promote mental wellbeing using the revised framework for developing and evaluating complex interventions produced by the UK Medical Research Council (UKMRC). METHODS: Application of the first two phases of the framework is described--development and feasibility and piloting. The theoretical case and evidence base were examined analytically to explicate the theoretical and empirical foundations of the intervention. These findings informed the design of a 12-week mental wellbeing promotion programme providing early intervention for people showing signs of mental health difficulties. The programme is based on the theoretical constructs of self-efficacy, self-esteem, purpose in life, resilience and social support and comprises 10 steps. A mixed methods approach was used to conduct a feasibility study with community and voluntary sector service users and in primary care. RESULTS: A significant increase in mental wellbeing was observed following participation in the intervention. Qualitative data corroborated this finding and suggested that the intervention was feasible to deliver and acceptable to participants, facilitators and health professionals. CONCLUSIONS: The revised UKMRC framework can be successfully applied to the development of public health interventions.


Asunto(s)
Promoción de la Salud/métodos , Salud Mental , Modelos Teóricos , Medicina Basada en la Evidencia , Femenino , Investigación sobre Servicios de Salud , Humanos , Masculino , Desarrollo de Programa , Evaluación de Programas y Proyectos de Salud , Escalas de Valoración Psiquiátrica , Reino Unido
20.
Eur J Cancer Care (Engl) ; 23(3): 333-9, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24313908

RESUMEN

This study aimed to measure the health status and care needs of people who provide informal care to cancer survivors in the UK. Semi-structured interviews were conducted with a purposive sample of 24 cancer professionals to identify the care needs of caregivers. In addition, we conducted a postal survey measuring the health and well-being [36-item short-form health survey (SF-36)] and health service utilisation of 98 primary caregivers of a random sample of cancer survivors, 2-20 years post-treatment. Interviews indicated that caregivers' needs were largely unmet. In particular, there appeared to be a need in relation to statutory healthcare provision, information, psychological support and involvement in decision-making. There were no significant differences between survivors and caregivers in terms of mental health scores; and caregivers performed better on physical health domains compared with cancer survivors. Compared with UK norms and norms for caregivers of other chronic conditions, cancer caregivers had substantially lower scores on each SF-36 health domain. Cancer may impact negatively on an informal caregiver's health long after treatment has ended. Providing appropriate and cancer-specific information may alleviate difficulties and improve health and well-being. Specific concentration should be given to the development and delivery of information support for caregivers of post-treatment cancer survivors.


Asunto(s)
Cuidadores , Necesidades y Demandas de Servicios de Salud , Estado de Salud , Neoplasias/enfermería , Actitud del Personal de Salud , Femenino , Humanos , Masculino , Persona de Mediana Edad , Investigación Cualitativa , Encuestas y Cuestionarios , Sobrevivientes , Reino Unido
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