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1.
Anesth Analg ; 2024 Jun 27.
Article in English | MEDLINE | ID: mdl-38935540

ABSTRACT

BACKGROUND: Peripheral arterial line placement is a common, low-risk procedure in pediatric patients undergoing cardiac surgery. Central arterial cannulation may be used when peripheral cannulation is not feasible. At present, there are limited data to guide central arterial-line site selection in pediatric patients. We aimed to (1) quantify the rate of complications associated with central arterial-line placement in pediatric patients undergoing cardiac surgery, (2) determine risk factors associated with central arterial-line complications, and (3) describe placement trends during the last decade. METHODS: This was a retrospective, single-center cohort study of pediatric patients who underwent intraoperative placement of an axillary or femoral arterial line for cardiac surgery between July 1, 2012 and June 30, 2022. The primary outcome studied was the incidence of complications, defined as vascular compromise, pulse loss, ultrasound-confirmed thrombus or flow abnormality, and/or positive blood cultures not attributable to another source. Patients' characteristics and perioperative factors were analyzed using univariate and multivariate analysis to examine the relationship between these factors and line-associated complications. RESULTS: A total of 1263 central arterial lines were analyzed-195 axillary arterial lines and 1068 femoral arterial lines. The overall incidences of vascular compromise and pulse loss from central arterial-line placement were 17.8% and 8.3%, respectively. Axillary lines had lower rates of vascular compromise (6.2% vs 19.9%, P < .001), pulse loss (2.1% vs 9.5%, P < .001), and ultrasound-confirmed thrombus of flow abnormalities (14.3% vs 81.1%, P = .001) than femoral lines. Complications were more common in neonates and infants. By multivariate logistic regression, femoral location (odds ratio [OR], 4.16, 95% confidence interval [CI], 1.97-8.78), presence of a genetic syndrome (OR, 1.68, 95% CI, 1.21-2.34), prematurity (OR, 1.48, 95% CI, 1.02-2.15), and anesthesia time (OR, 1.17 per hour, 95% CI, 1.07-1.27 per hour) were identified as independent risk factors for vascular compromise. Femoral location (OR, 7.43, 95% CI, 2.08-26.6), presence of a genetic syndrome (OR, 1.86, 95% CI, 1.18-2.93), prematurity (OR, 1.65, 95% CI, 1.02-2.67), and 22-G catheter size (OR, 3.26, 95% CI, 1.16-9.15) were identified as independent risk factors for pulse loss. CONCLUSIONS: Axillary arterial access is associated with a lower rate of complications in pediatric patients undergoing cardiac surgery as compared to femoral arterial access. Serious complications are rare and were limited to femoral arterial lines in this study.

2.
Neuroimage ; 280: 120354, 2023 10 15.
Article in English | MEDLINE | ID: mdl-37666393

ABSTRACT

Hyperscanning is a form of neuroimaging experiment where the brains of two or more participants are imaged simultaneously whilst they interact. Within the domain of social neuroscience, hyperscanning is increasingly used to measure inter-brain coupling (IBC) and explore how brain responses change in tandem during social interaction. In addition to cognitive research, some have suggested that quantification of the interplay between interacting participants can be used as a biomarker for a variety of cognitive mechanisms aswell as to investigate mental health and developmental conditions including schizophrenia, social anxiety and autism. However, many different methods have been used to quantify brain coupling and this can lead to questions about comparability across studies and reduce research reproducibility. Here, we review methods for quantifying IBC, and suggest some ways moving forward. Following the PRISMA guidelines, we reviewed 215 hyperscanning studies, across four different brain imaging modalities: functional near-infrared spectroscopy (fNIRS), functional magnetic resonance (fMRI), electroencephalography (EEG) and magnetoencephalography (MEG). Overall, the review identified a total of 27 different methods used to compute IBC. The most common hyperscanning modality is fNIRS, used by 119 studies, 89 of which adopted wavelet coherence. Based on the results of this literature survey, we first report summary statistics of the hyperscanning field, followed by a brief overview of each signal that is obtained from each neuroimaging modality used in hyperscanning. We then discuss the rationale, assumptions and suitability of each method to different modalities which can be used to investigate IBC. Finally, we discuss issues surrounding the interpretation of each method.


Subject(s)
Brain , Thalamus , Humans , Reproducibility of Results , Brain/diagnostic imaging , Neuroimaging , Hemodynamics
3.
Cancer Immunol Immunother ; 72(3): 733-742, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36194288

ABSTRACT

BACKGROUND: The role of tumor-associated macrophages (TAMs) in glioblastoma (GBM) disease progression has received increasing attention. Recent advances have shown that TAMs can be re-programmed to exert a pro-inflammatory, anti-tumor effect to control GBMs. However, imaging methods capable of differentiating tumor progression from immunotherapy treatment effects have been lacking, making timely assessment of treatment response difficult. We showed that tracking monocytes using iron oxide nanoparticle (USPIO) with MRI can be a sensitive imaging method to detect therapy response directed at the innate immune system. METHODS: We implanted syngeneic mouse glioma stem cells into C57/BL6 mice and treated the animals with either niacin (a stimulator of innate immunity) or vehicle. Animals were imaged using an anatomical MRI sequence, R2* mapping, and quantitative susceptibility mapping (QSM) before and after USPIO injection. RESULTS: Compared to vehicles, niacin-treated animals showed significantly higher susceptibility and R2*, representing USPIO and monocyte infiltration into the tumor. We observed a significant reduction in tumor size in the niacin-treated group 7 days later. We validated our MRI results with flow cytometry and immunofluoresence, which showed that niacin decreased pro-inflammatory Ly6C high monocytes in the blood but increased CD16/32 pro-inflammatory macrophages within the tumor, consistent with migration of these pro-inflammatory innate immune cells from the blood to the tumor. CONCLUSION: MRI with USPIO injection can detect therapeutic responses of innate immune stimulating agents before changes in tumor size have occurred, providing a potential complementary imaging technique to monitor cancer immunotherapies. MANUSCRIPT HIGHLIGHT: We show that iron oxide nanoparticles (USPIOs) can be used to label innate immune cells and detect the trafficking of pro-inflammatory monocytes into the glioblastoma. This preceded changes in tumor size, making it a more sensitive imaging technique.


Subject(s)
Glioblastoma , Glioma , Niacin , Mice , Animals , Monocytes/pathology , Glioma/pathology , Models, Animal , Magnetic Resonance Imaging/methods
4.
BMC Nephrol ; 24(1): 122, 2023 05 02.
Article in English | MEDLINE | ID: mdl-37131125

ABSTRACT

BACKGROUND: Physical activity and emotional self-management has the potential to enhance health-related quality of life (HRQoL), but few people with chronic kidney disease (CKD) have access to resources and support. The Kidney BEAM trial aims to evaluate whether an evidence-based physical activity and emotional wellbeing self-management programme (Kidney BEAM) leads to improvements in HRQoL in people with CKD. METHODS: This was a prospective, multicentre, randomised waitlist-controlled trial, with health economic analysis and nested qualitative studies. In total, three hundred and four adults with established CKD were recruited from 11 UK kidney units. Participants were randomly assigned to the intervention (Kidney BEAM) or a wait list control group (1:1). The primary outcome was the between-group difference in Kidney Disease Quality of Life (KDQoL) mental component summary score (MCS) at 12 weeks. Secondary outcomes included the KDQoL physical component summary score, kidney-specific scores, fatigue, life participation, depression and anxiety, physical function, clinical chemistry, healthcare utilisation and harms. All outcomes were measured at baseline and 12 weeks, with long-term HRQoL and adherence also collected at six months follow-up. A nested qualitative study explored experience and impact of using Kidney BEAM. RESULTS: 340 participants were randomised to Kidney BEAM (n = 173) and waiting list (n = 167) groups. There were 96 (55%) and 89 (53%) males in the intervention and waiting list groups respectively, and the mean (SD) age was 53 (14) years in both groups. Ethnicity, body mass, CKD stage, and history of diabetes and hypertension were comparable across groups. The mean (SD) of the MCS was similar in both groups, 44.7 (10.8) and 45.9 (10.6) in the intervention and waiting list groups respectively. CONCLUSION: Results from this trial will establish whether the Kidney BEAM self management programme is a cost-effective method of enhancing mental and physical wellbeing of people with CKD. TRIAL REGISTRATION: NCT04872933. Registered 5th May 2021.


Subject(s)
Quality of Life , Renal Insufficiency, Chronic , Adult , Female , Humans , Male , Middle Aged , Exercise , Prospective Studies , Renal Insufficiency, Chronic/therapy , Waiting Lists , Telemedicine
5.
J Cardiothorac Vasc Anesth ; 36(12): 4364-4369, 2022 12.
Article in English | MEDLINE | ID: mdl-36216687

ABSTRACT

OBJECTIVES: As life expectancy for patients born with congenital heart disease (CHD) continues to rise, these patients will present increasingly for noncardiac surgery during childhood and adolescence. This study aimed to map the lifespan of noncardiac surgical needs among patients with CHD and explore how these needs may change over time. DESIGN: All patients with CHD presenting for noncardiac surgery between 2008 and 2014 were selected for review. SETTING: The study was conducted at a single urban academic tertiary pediatric hospital. PARTICIPANTS: All patients with CHD presenting for noncardiac surgery during the study period were included and grouped by cardiac diagnosis. INTERVENTIONS: Descriptive analysis included patient demographics, CHD diagnosis, procedures performed, and clinical data, including baseline saturation and underlying cardiac function. MEASUREMENTS AND MAIN RESULTS: A total of 3,011 noncardiac surgical procedures were performed on patients with CHD during the study period. The most common CHD diagnoses were patent ductus arteriosus (27.6%), ventricular septal defects (24.7%), and patent foramen ovale (24.3%). The median age was 4 years, 87% of all the patients were ≤10 years, and 41% had associated syndromes. Of the patients, 76% underwent a preoperative echocardiogram, and 10% had depressed cardiac function at the time of surgery. The most common procedures performed were ear, nose, and throat (20%), general surgery (14%), and radiology (11%). Intraoperative events were reported in 488 out of 3,010 encounters (16.2%), with the highest rates reported in patients with single-ventricle physiology (55/179; 30.7%). CONCLUSIONS: These findings suggested a greater burden of noncardiac surgery in lower age groups, with ear, nose, and throat and general surgery most common in young children and orthopedic and dental procedures increasing in adolescence.


Subject(s)
Heart Defects, Congenital , Heart Septal Defects, Atrial , Heart Septal Defects, Ventricular , Adolescent , Humans , Child , Child, Preschool , Adult , Risk Factors , Heart Defects, Congenital/diagnosis , Heart Defects, Congenital/epidemiology , Heart Defects, Congenital/surgery , Heart Septal Defects, Ventricular/complications , Heart Septal Defects, Atrial/complications , Echocardiography , Retrospective Studies
6.
Phys Rev Lett ; 126(25): 256601, 2021 Jun 25.
Article in English | MEDLINE | ID: mdl-34241516

ABSTRACT

We demonstrate that the Berry curvature monopole of nonmagnetic two-dimensional spin-3/2 holes leads to a novel Hall effect linear in an applied in-plane magnetic field B_{∥}. Remarkably, all scalar and spin-dependent disorder contributions vanish to leading order in B_{∥}, while there is no Lorentz force and hence no ordinary Hall effect. This purely intrinsic phenomenon, which we term the anomalous planar Hall effect (APHE), provides a direct transport probe of the Berry curvature accessible in all p-type semiconductors. We discuss experimental setups for its measurement.

7.
Gynecol Oncol ; 163(3): 524-530, 2021 12.
Article in English | MEDLINE | ID: mdl-34625284

ABSTRACT

BACKGROUND: Aromatase inhibitors have been used empirically to treat a subset of patients with hormone receptor positive uterine leiomyosarcomas(LMS) and carcinosarcomas (UCS) mainly supported by retrospective data. We evaluated the activity of anastrozole in two rare cohorts; patients with recurrent/metastatic LMS and UCS enrolled in PARAGON, a basket trial of anastrozole in estrogen receptor (ER+)/progesterone receptor positive (PR+) gynecological cancers. METHOD: An investigator-initiated, single-arm, prospective open-label trial of anastrozole 1 mg/day in patients with ER &/or PR + ve LMS or UCS with measurable disease, treated until progression or unacceptable toxicity. Primary endpoint was clinical benefit (complete/partial response + stable disease) rate (CBR) at 3 months. Secondary endpoints include progression-free survival (PFS), quality of life and toxicity. RESULTS: 39 eligible patients were enrolled, 32 with LMS and 7 with UCS. For the LMS cohort CBR at 3 months was 35% (95% CI: 21-53%) with a median duration of clinical benefit of 5.8 months. Best response was a partial response in one patient. Two patients remained on treatment for more than one year. The median progression-free survival was 2.8 months (95% CI: 2.6-4.9). For the UCS cohort CBR at 3 months was 43% (95% CI: 16-75%) with a median duration of clinical benefit of 5.6 months. Stable disease was seen in 3 patients but no objective responses were seen. The median progression-free survival was 2.7 months (95% CI, 1.1-8.2). Safety was acceptable with 5/39 evaluable patients showing grade 3 toxicities. CONCLUSION: Whilst objective response rates with anastrozole are low, the clinical benefit rate and good tolerance suggests that aromatase inhibitor therapy may have a role in a subset of patients with metastatic LMS and UCS.


Subject(s)
Anastrozole/therapeutic use , Carcinosarcoma/drug therapy , Leiomyosarcoma/drug therapy , Uterine Neoplasms/drug therapy , Adult , Aged , Aged, 80 and over , Anastrozole/adverse effects , Aromatase Inhibitors/adverse effects , Aromatase Inhibitors/therapeutic use , Carcinosarcoma/metabolism , Carcinosarcoma/pathology , Female , Humans , Leiomyosarcoma/metabolism , Leiomyosarcoma/pathology , Middle Aged , Neoplasm Metastasis , Prospective Studies , Quality of Life , Receptors, Estrogen/metabolism , Receptors, Progesterone/metabolism , Uterine Neoplasms/metabolism , Uterine Neoplasms/pathology
8.
Brain ; 143(3): 862-876, 2020 03 01.
Article in English | MEDLINE | ID: mdl-32155246

ABSTRACT

Humans are uniquely able to retrieve and combine words into syntactic structure to produce connected speech. Previous identification of focal brain regions necessary for production focused primarily on associations with the content produced by speakers with chronic stroke, where function may have shifted to other regions after reorganization occurred. Here, we relate patterns of brain damage with deficits to the content and structure of spontaneous connected speech in 52 speakers during the acute stage of a left hemisphere stroke. Multivariate lesion behaviour mapping demonstrated that damage to temporal-parietal regions impacted the ability to retrieve words and produce them within increasingly complex combinations. Damage primarily to inferior frontal cortex affected the production of syntactically accurate structure. In contrast to previous work, functional-anatomical dissociations did not depend on lesion size likely because acute lesions were smaller than typically found in chronic stroke. These results are consistent with predictions from theoretical models based primarily on evidence from language comprehension and highlight the importance of investigating individual differences in brain-language relationships in speakers with acute stroke.


Subject(s)
Frontal Lobe/pathology , Parietal Lobe/pathology , Speech Disorders/pathology , Stroke/pathology , Temporal Lobe/pathology , Adult , Aged , Aged, 80 and over , Case-Control Studies , Female , Functional Laterality , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Neuroimaging , Speech Disorders/complications , Stroke/complications , Young Adult
9.
Cereb Cortex ; 29(4): 1398-1413, 2019 04 01.
Article in English | MEDLINE | ID: mdl-29522178

ABSTRACT

Buffer versus embedded processes accounts of short-term memory (STM) for phonological information were addressed by testing subjects' perception and memory for speech and non-speech auditory stimuli. Univariate and multivariate (MVPA) approaches were used to assess whether brain regions recruited in recognizing speech were involved in maintaining speech representations over a delay. As expected, a left superior temporal region was found to support speech perception. However, contrary to the embedded processes approach, this region failed to show a load effect, or any sustained activation, during a maintenance delay. Moreover, MVPA decoding during the maintenance stage was unsuccessful in this region by a perception classifier or an encoding classifier. In contrast, the left supramarginal gyrus showed both sustained activation and a load effect. Using MVPA, stimulus decoding was successful during the delay period. In addition, a functional connectivity analysis showed that, as memory load increased, the left temporal lobe involved in perception became more strongly connected with the parietal region involved in maintenance. Taken together, the findings provide greater support for a buffer than embedded processes account of phonological STM.


Subject(s)
Memory, Short-Term/physiology , Parietal Lobe/physiology , Phonetics , Speech Perception/physiology , Temporal Lobe/physiology , Acoustic Stimulation , Adult , Brain Mapping , Female , Humans , Magnetic Resonance Imaging , Male , Neural Pathways/physiology , Young Adult
10.
Rev Sci Tech ; 39(1): 81-91, 2020 Apr.
Article in English | MEDLINE | ID: mdl-32729576

ABSTRACT

The World Trade Organization (WTO) Agreement on the Application of Sanitary and Phytosanitary Measures contains several key provisions that are important for trade in animals and animal products, namely on risk assessment, equivalence and regionalisation. The risk assessment provision allows countries to adopt, on the basis of a risk assessment, measures which achieve a higher level of sanitary protection than that embodied in existing relevant international standards. The equivalence provision requires importing countries to acknowledge that, while the production methods of the exporting country may differ from their own, they may still provide an equivalent level of health protection. Finally, the regionalisation provision enables countries to export animals and animal products from diseasefree areas, even if other areas within that country have experienced outbreaks of a particular animal disease. This paper explores how these provisions, and the scientific concept of the appropriate level of protection, facilitate trade while at the same time allowing Members to establish their sanitary measures. This paper also provides information on the relevant discussions of these provisions within the Committee on Sanitary and Phytosanitary Measures.


L'Accord de l'Organisation mondiale du commerce (OMC) sur l'application des mesures sanitaires et phytosanitaires contient d'importantes dispositions relatives aux échanges internationaux d'animaux et de produits d'origine animale qui concernent les aspects suivants : l'évaluation du risque, l'équivalence et la régionalisation. La disposition sur l'évaluation du risque permet à un pays d'adopter des mesures conférant un niveau de protection plus élevé que celui prévu dans les normes internationales en vigueur, dès lors que cette décision se fonde sur une évaluation du risque. En vertu du principe d'équivalence, un pays importateur est tenu de reconnaître que les méthodes de production appliquées par un pays exportateur peuvent différer de celles qu'il applique luimême et apporter néanmoins des garanties de protection sanitaire équivalentes aux siennes. Enfin, la régionalisation permet aux pays d'exporter des animaux et des produits d'origine animale à partir des régions de leur territoire qui sont indemnes de maladies, même si des foyers d'une maladie animale particulière ont été enregistrés dans d'autres régions. L'auteure explique en quoi ces dispositions et le concept scientifique de « niveau approprié de protection ¼ facilitent le commerce tout en permettant aux Membres d'instaurer leurs propres mesures sanitaires. L'auteure décrit également les discussions dont ces dispositions font l'objet au sein du Comité des mesures sanitaires et phytosanitaires.


El Acuerdo sobre la Aplicación de Medidas Sanitarias y Fitosanitarias (Acuerdo MSF) de la Organización Mundial del Comercio (OMC) contiene varias disposiciones básicas que son importantes para el comercio de animales y productos de origen animal, a saber, las relativas a la determinación del riesgo, a la equivalencia y a la regionalización. La disposición sobre determinación del riesgo permite que los países, basándose en una determinación del riesgo, adopten medidas que conlleven un nivel de protección sanitaria mayor que el que establecen las normas internacionales existentes en la materia. La disposición sobre equivalencia exige que los países importadores reconozcan que los métodos de producción del país exportador, aun pudiendo diferir de los propios, pueden ofrecer un nivel equivalente de protección sanitaria. La disposición sobre regionalización, por último, permite que un país exporte animales y productos de origen animal procedentes de zonas libres de enfermedad aun cuando otras zonas de ese mismo país hayan sufrido brotes de una enfermedad animal en particular. La autora explica cómo estas disposiciones y el concepto científico de «nivel apropiado de protección¼ facilitan el comercio y a la vez permiten a los Miembros instaurar sus propias medidas sanitarias. Asimismo, proporciona información sobre los debates y reflexiones del Comité de Medidas Sanitarias y Fitosanitarias en torno a estas disposiciones.


Subject(s)
Animal Diseases , International Cooperation , Animals , Commerce , Organizations , Risk Assessment
11.
Phys Rev Lett ; 121(8): 087701, 2018 Aug 24.
Article in English | MEDLINE | ID: mdl-30192606

ABSTRACT

Classical charge transport, such as longitudinal and Hall currents in weak magnetic fields, is usually not affected by quantum phenomena. Yet relativistic quantum mechanics is at the heart of the spin-orbit interaction, which has been at the forefront of efforts to realize spin-based electronics, new phases of matter, and topological quantum computing. In this work we demonstrate that quantum spin dynamics induced by the spin-orbit interaction is directly observable in classical charge transport. We determine the Hall coefficient R_{H} of two-dimensional hole systems at low magnetic fields and show that it has a sizable spin-orbit contribution, which depends on the density p, is independent of temperature, is a strong function of the top gate electric field, and can reach ∼20% of the total. We provide a general method for extracting the spin-orbit parameter from magnetotransport data, applicable even at higher temperatures where Shubnikov-de Haas oscillations and weak antilocalization are difficult to observe. Our work will enable experimentalists to measure spin-orbit parameters without requiring large magnetic fields, ultralow temperatures, or optical setups.

12.
Phys Rev Lett ; 121(3): 036601, 2018 Jul 20.
Article in English | MEDLINE | ID: mdl-30085815

ABSTRACT

Coupled 2D sheets of electrons and holes are predicted to support novel quantum phases. Two experiments of Coulomb drag in electron-hole (e-h) double bilayer graphene (DBLG) have reported an unexplained and puzzling sign reversal of the drag signal. However, we show that this effect is due to the multiband character of DBLG. Our multiband Fermi liquid theory produces excellent agreement and captures the key features of the experimental drag resistance for all temperatures. This demonstrates the importance of multiband effects in DBLG: they have a strong effect not only on superfluidity, but also on the drag.

13.
Phys Rev Lett ; 121(7): 077701, 2018 Aug 17.
Article in English | MEDLINE | ID: mdl-30169055

ABSTRACT

Semiconductor holes with strong spin-orbit coupling allow all-electrical spin control, with broad applications ranging from spintronics to quantum computation. Using a two-dimensional hole system in a gallium arsenide quantum well, we demonstrate a new mechanism of electrically controlling the Zeeman splitting, which is achieved through altering the hole wave vector k. We find a threefold enhancement of the in-plane g-factor g_{∥}(k). We introduce a new method for quantifying the Zeeman splitting from magnetoresistance measurements, since the conventional tilted field approach fails for two-dimensional systems with strong spin-orbit coupling. Finally, we show that the Rashba spin-orbit interaction suppresses the in-plane Zeeman interaction at low magnetic fields. The ability to control the Zeeman splitting with electric fields opens up new possibilities for future quantum spin-based devices, manipulating non-Abelian geometric phases, and realizing Majorana systems in p-type superconductor systems.

14.
Mol Cell Neurosci ; 80: 66-74, 2017 04.
Article in English | MEDLINE | ID: mdl-28185854

ABSTRACT

The outgrowth of new dendritic spines is closely linked to the formation of new synapses, and is thought to be a vital component of the experience-dependent circuit plasticity that supports learning. Here, we examined the role of the RhoGEF Ephexin5 in driving activity-dependent spine outgrowth. We found that reducing Ephexin5 levels increased spine outgrowth, and increasing Ephexin5 levels decreased spine outgrowth in a GEF-dependent manner, suggesting that Ephexin5 acts as an inhibitor of spine outgrowth. Notably, we found that increased neural activity led to a proteasome-dependent reduction in the levels of Ephexin5 in neuronal dendrites, which could facilitate the enhanced spine outgrowth observed following increased neural activity. Surprisingly, we also found that Ephexin5-GFP levels were elevated on the dendrite at sites of future new spines, prior to new spine outgrowth. Moreover, lowering neuronal Ephexin5 levels inhibited new spine outgrowth in response to both global increases in neural activity and local glutamatergic stimulation of the dendrite, suggesting that Ephexin5 is necessary for activity-dependent spine outgrowth. Our data support a model in which Ephexin5 serves a dual role in spinogenesis, acting both as a brake on overall spine outgrowth and as a necessary component in the site-specific formation of new spines.


Subject(s)
Dendritic Spines/genetics , Neurons/classification , Rho Guanine Nucleotide Exchange Factors/metabolism , Synapses/genetics , Animals , Dendritic Spines/physiology , Excitatory Amino Acids/pharmacology , Female , Glutamic Acid/pharmacology , Green Fluorescent Proteins , Hippocampus/cytology , In Vitro Techniques , Male , Mice, Inbred C57BL , Mice, Knockout , Microscopy, Confocal , Neuronal Plasticity/physiology , Organ Culture Techniques , RNA, Small Interfering/genetics , RNA, Small Interfering/metabolism , Rats , Rats, Sprague-Dawley , Rho Guanine Nucleotide Exchange Factors/genetics
15.
Tech Coloproctol ; 22(7): 529-533, 2018 07.
Article in English | MEDLINE | ID: mdl-29987695

ABSTRACT

Robotic transanal minimally invasive surgery (TAMIS) (RT) represents a compelling new alternative capable of overcoming the limitations of conventional TAMIS for the local excision of rectal lesions. We describe our RT technique using the dVXi™ (Intuitive Surgical, Sunnyvale, CA, USA) which we have used to efficiently and completely excise eight cases of rectal lesions which were not endoscopically resectable. We also include a video vignette of the procedure. With the patient in the prone jackknife position, we insert a GelPOINT™ Path Transanal Access Platform (Applied Medical, Rancho Santa Margarita, CA, USA) in combination with the dVXi and AirSeal™ insufflation system (Conmed, Niagara. Falls, ON, Canada). Our technique aims to be ergonomically efficient to minimise docking difficulties and to reduce instrument clash in the limited space, whilst maximising the capabilities of the dVXi for RT. At 3-month endoscopic follow-up, no evidence of recurrence was detected in any of the eight patients. RT is safe, feasible and has advantages over conventional laparoscopic TAMIS (LT). Our described technique addresses some of the long-standing challenges of LT and the novel RT. The immediate challenge to its widespread use remains the cost, expertise and availability.


Subject(s)
Intestinal Polyps/surgery , Rectum/surgery , Robotic Surgical Procedures/methods , Transanal Endoscopic Surgery/methods , Female , Humans , Intestinal Polyps/pathology , Middle Aged , Rectum/pathology , Robotic Surgical Procedures/instrumentation , Transanal Endoscopic Surgery/instrumentation , Treatment Outcome
16.
Tech Coloproctol ; 22(9): 649-655, 2018 09.
Article in English | MEDLINE | ID: mdl-30255213

ABSTRACT

Achieving a high-quality total mesorectal excision (TME) resection specimen is a central tenet of curative rectal cancer management. However, operating at the caudal extremity of the pelvis is inherently challenging and a number of patient- and tumour-related factors may increase the risk of obtaining a poor TME specimen and positive resection margins. Transanal TME (TaTME) is an advanced surgical technique developed to overcome the limitations in pelvic exposure and instrumentation of transabdominal surgery. This up-to-date narrative review describes the evolution of TME surgery, the indications for TaTME, current published outcomes, its limitations and future developments.


Subject(s)
Rectal Neoplasms/surgery , Transanal Endoscopic Surgery/adverse effects , Transanal Endoscopic Surgery/methods , Humans , Transanal Endoscopic Surgery/education , Treatment Outcome
17.
Phys Rev Lett ; 119(17): 176805, 2017 Oct 27.
Article in English | MEDLINE | ID: mdl-29219474

ABSTRACT

We investigate zero-bias conductance peaks that arise from coalescing subgap Andreev states, consistent with emerging Majorana zero modes, in hybrid semiconductor-superconductor wires defined in a two-dimensional InAs/Al heterostructure using top-down lithography and gating. The measurements indicate a hard superconducting gap, ballistic tunneling contact, and in-plane critical fields up to 3 T. Top-down lithography allows complex geometries, branched structures, and straightforward scaling to multicomponent devices compared to structures made from assembled nanowires.

18.
Phys Rev Lett ; 119(11): 116803, 2017 Sep 15.
Article in English | MEDLINE | ID: mdl-28949235

ABSTRACT

In-plane hole g factors measured in quantum point contacts based on p-type heterostructures strongly depend on the orientation of the magnetic field with respect to the electric current. This effect, first reported a decade ago and confirmed in a number of publications, has remained an open problem. In this work, we present systematic experimental studies to disentangle different mechanisms contributing to the effect and develop the theory which describes it successfully. We show that there is a new mechanism for the anisotropy related to the existence of an additional B_{+}k_{-}^{4}σ_{+} effective Zeeman interaction for holes, which is kinematically different from the standard single Zeeman term B_{-}k_{-}^{2}σ_{+} considered until now.

19.
Phys Rev Lett ; 118(14): 146801, 2017 Apr 07.
Article in English | MEDLINE | ID: mdl-28430471

ABSTRACT

We investigate the relationship between the Zeeman interaction and the inversion-asymmetry-induced spin-orbit interactions (Rashba and Dresselhaus SOIs) in GaAs hole quantum point contacts. The presence of a strong SOI results in the crossing and anticrossing of adjacent spin-split hole subbands in a magnetic field. We demonstrate theoretically and experimentally that the anticrossing energy gap depends on the interplay between the SOI terms and the highly anisotropic hole g tensor and that this interplay can be tuned by selecting the crystal axis along which the current and magnetic field are aligned. Our results constitute the independent detection and control of the Dresselhaus and Rashba SOIs in hole systems, which could be of importance for spintronics and quantum information applications.

20.
Colorectal Dis ; 2017 Dec 11.
Article in English | MEDLINE | ID: mdl-29227015

ABSTRACT

Anastomotic leaks are a dreaded complication of all colorectal surgery with the main factors contributing to it being tension on the anastomosis, intra-abdominal or systemic sepsis, distal obstruction, inadequate blood supply and improper surgical techniques. The leak rate of left-sided high colorectal resections can have a clinically significant leak rate from as low as 1-5% in high anterior resections to 7.9% in low anastomoses. This article is protected by copyright. All rights reserved.

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