Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 51
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Clin Transplant ; 36(10): e14649, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35297508

RESUMEN

BACKGROUND: The optimal analgesic strategy for patients undergoing donor hepatectomy is not known and the potential short- and long-term physical and psychological consequences of complications are significant. OBJECTIVES: To identify whether a multimodal approach to pain of the donor intraoperatively enhances immediate and short-term outcomes after living liver donation, and to provide international expert panel recommendations. DATA SOURCES: Ovid MEDLINE, Embase, Scopus, Google Scholar, and Cochrane Central. METHODS: Systematic review following PRISMA guidelines and recommendations using the GRADE approach derived from an international expert panel. PROSPERO 2021 CRD42021260699. RESULTS: Nine studies assessing multi-modal analgesia strategies were included in a qualitative assessment. Interventions included local, regional, and neuro-axial anesthetic techniques, pharmacological intervention (NSAIDs, COX-2 inhibitors, ketamine, dexmedetomidine, and lidocaine), and acupuncture. Overall, there was a significant (40%) reduction in opioid requirement on day 1 and a significant reduction in pain scores in the intervention vs control groups. Significant reductions in either length of stay or post-operative complications were demonstrated in four of nine studies. CONCLUSIONS: Opioid use for patients undergoing donor hepatectomy is likely to impact both their short- and long-term outcomes. To reduce post-operative pain scores, shorten length of hospital stay, and promote earlier post-operative return of bowel function, we recommend that multi-modal analgesia be offered to patients undergoing living donor hepatectomy. Further research is required to confirm which multi-modal techniques are most associated with enhanced recovery in living liver donors.


Asunto(s)
Analgésicos Opioides , Manejo del Dolor , Humanos , Manejo del Dolor/efectos adversos , Manejo del Dolor/métodos , Analgésicos Opioides/uso terapéutico , Dolor Postoperatorio/inducido químicamente , Lidocaína/efectos adversos , Hepatectomía , Hígado
2.
BMC Gastroenterol ; 22(1): 118, 2022 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-35272611

RESUMEN

BACKGROUND: The natural history and incidence of hepatocellular carcinoma (HCC) arising from indeterminate liver lesions are not well described. We aimed to define the incidence of HCC in a cohort of patients undergoing surveillance by magnetic resonance imaging (MRI) and estimate any associations with incident HCC. METHODS: We performed a retrospective follow-up study, identifying MRI scans in which indeterminate lesions had been reported between January 2006 and January 2017. Subsequent MRI scan reports were reviewed for incident HCC arising from indeterminate lesions, data were extracted from electronic patient records and survival analysis performed to estimate associations with baseline factors. RESULTS: One hundred and nine patients with indeterminate lesions on MRI were identified. HCC developed in 19 (17%) patients over mean follow up of 4.6 years. Univariate Cox proportional hazards analysis found incident HCC to be significantly associated with baseline low platelet count (hazard ratio (HR) = 7.3 (95% confidence intervals (CI) 2.1-24.9), high serum alpha-fetoprotein level (HR = 2.7 (95% CI 1.0-7.1)) and alcohol consumption above fourteen units weekly (HR = 3.1 (95% CI 1.1-8.7)). Multivariate analysis, however, found that only low platelet count was independently associated with HCC (HR = 5.5 (95% CI 0.6-5.1)). CONCLUSIONS: HCC arises in approximately one fifth of indeterminate liver lesions over 4.6 years and is associated with a low platelet count at the time of first diagnosis of an indeterminate lesion. Incidence of HCC was more common in people with viral hepatitis and in those consuming > 14 units of alcohol per week. Our data may be used to support a strategy of enhanced surveillance in patients with indeterminate lesions.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Carcinoma Hepatocelular/complicaciones , Estudios de Seguimiento , Humanos , Neoplasias Hepáticas/complicaciones , Imagen por Resonancia Magnética/métodos , Estudios Retrospectivos
3.
Br J Cancer ; 125(7): 983-993, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34253873

RESUMEN

BACKGROUND: Breast cancer stem cells (BCSCs) are drivers of therapy-resistance, therefore are responsible for poor survival. Molecular signatures of BCSCs from primary cancers remain undefined. Here, we identify the consistent transcriptome of primary BCSCs shared across breast cancer subtypes, and we examine the clinical relevance of ITGA7, one of the genes differentially expressed in BCSCs. METHODS: Primary BCSCs were assessed using immunohistochemistry and fluorescently labelled using Aldefluor (n = 17). Transcriptomes of fluorescently sorted BCSCs and matched non-stem cancer cells were determined using RNA-seq (n = 6). ITGA7 expression was examined in breast cancers using immunohistochemistry (n = 305), and its functional role was tested using siRNA in breast cancer cells. RESULTS: Proportions of BCSCs varied from 0 to 9.4%. 38 genes were significantly differentially expressed in BCSCs; genes were enriched for functions in vessel morphogenesis, motility, and metabolism. ITGA7 was found to be significantly downregulated in BCSCs, and low expression significantly correlated with reduced survival in patients treated with chemotherapy, and with chemoresistance in breast cancer cells in vitro. CONCLUSIONS: This study is the first to define the molecular profile of BCSCs from a range of primary breast cancers. ITGA7 acts as a predictive marker for chemotherapy response, in accordance with its downregulation in BCSCs.


Asunto(s)
Antígenos CD/genética , Neoplasias de la Mama/genética , Regulación hacia Abajo , Resistencia a Antineoplásicos , Cadenas alfa de Integrinas/genética , Células Madre Neoplásicas/metabolismo , Antígenos CD/metabolismo , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/metabolismo , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Femenino , Perfilación de la Expresión Génica/métodos , Humanos , Cadenas alfa de Integrinas/metabolismo , Células MCF-7 , Análisis de Secuencia de ARN , Análisis de Supervivencia
4.
Breast Cancer Res Treat ; 187(1): 207-213, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33389407

RESUMEN

PURPOSE: Chemoprevention reduces the risk of developing breast cancer in women with increased family history (FH) risk of breast cancer. However, chemoprevention uptake remains low and the reasons for this remain unclear. METHODS: Patients with moderate- or high-risk FH of breast cancer were counselled about chemoprevention (n = 1620; September 2015 to July 2018) in breast clinics. A postal questionnaire survey was subsequently sent to these patients in order to explore the potential factors influencing their decision on chemoprevention uptake. RESULTS: 518 patients (32%) completed the questionnaire survey; 75% were pre-menopausal and the majority had moderate as opposed to high-risk FH (87.5% vs. 12.5%). Breast cancer chemoprevention uptake rate was 10.8% (56/518). The identified incentives were more commonly stated for patients who took chemoprevention when compared to those who refused chemoprevention. The commonest incentives were breast cancer prevention (89.3% vs. 61.7%; p = 0.001), belief in the effectiveness of chemoprevention (76.8% vs. 63.4%; p = 0.048), and personal perception of breast cancer risk (67.9% vs. 45.5%; p = 0.002). Similarly, the identified barriers were more commonly stated for patients who refused chemoprevention when compared to those who took chemoprevention. The commonest barriers were side effects (79.4% vs. 55.4%; p = 0.001) and lack of information (53% vs. 28.6%; p = 0.001). CONCLUSION: Despite its proven efficacy, chemoprevention uptake in patients with a significant FH of breast cancer remains low. We have identified important factors which influence the patient's decision making. Future clinic consultations should focus on exploring these factors to aid patient decision making.


Asunto(s)
Neoplasias de la Mama , Neoplasias de la Mama/epidemiología , Neoplasias de la Mama/genética , Neoplasias de la Mama/prevención & control , Quimioprevención , Femenino , Humanos , Anamnesis , Medición de Riesgo , Moduladores Selectivos de los Receptores de Estrógeno , Encuestas y Cuestionarios , Tamoxifeno
5.
BMC Gastroenterol ; 21(1): 268, 2021 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-34182924

RESUMEN

BACKGROUND: Alcohol is the main cause of chronic liver disease. The Enhanced Liver Fibrosis (ELF) test is a serological biomarker for fibrosis staging in chronic liver disease, however its utility in alcohol-related liver disease warrants further validation. We assessed the diagnostic and prognostic performance of ELF in alcohol-related liver disease. METHODS: Observational cohort study assessing paired ELF and histology from 786 tertiary care patients with chronic liver disease due to alcohol (n = 81) and non-alcohol aetiologies (n = 705). Prognostic data were available for 64 alcohol patients for a median of 6.4 years. Multiple ELF cut-offs were assessed to determine diagnostic utility in moderate fibrosis and cirrhosis. Survival data were assessed to determine the ability of ELF to predict liver related events and all-cause mortality. RESULTS: ELF identified cirrhosis and moderate fibrosis in alcohol-related liver disease independently of aminotransferase levels with areas under receiver operating characteristic curves of 0.895 (95% CI 0.823-0.968) and 0.923 (95% CI 0.866-0.981) respectively, which were non-inferior to non-alcohol aetiologies. The overall performance of ELF was assessed using the Obuchowski method: in alcohol = 0.934 (95% CI 0.908-0.960); non-alcohol = 0.907 (95% CI 0.895-0.919). Using ELF < 9.8 to exclude and ≧ 10.5 to diagnose cirrhosis, 87.7% of alcohol cases could have avoided biopsy, with sensitivity of 91% and specificity of 85%. A one-unit increase in ELF was associated with a 2.6 (95% CI 1.55-4.31, p < 0.001) fold greater odds of cirrhosis at baseline and 2.0-fold greater risk of a liver related event within 6 years (95% CI 1.39-2.99, p < 0.001). CONCLUSIONS: ELF accurately stages liver fibrosis independently of transaminase elevations as a marker of inflammation and has superior prognostic performance to biopsy in alcohol-related liver disease.


Asunto(s)
Cirrosis Hepática , Hepatopatías , Biomarcadores , Biopsia , Estudios de Cohortes , Humanos , Hígado/patología , Cirrosis Hepática/diagnóstico , Cirrosis Hepática/patología , Hepatopatías/patología , Pruebas de Función Hepática , Pronóstico
6.
Opt Express ; 27(3): 3169-3179, 2019 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-30732342

RESUMEN

Optical sensing has shown great potential for both quantitative and qualitative analysis of compounds. In particular sensors which are capable of detecting changes in refractive index at a surface as well as in bulk material have received much attention. Much of the recent research has focused on developing technologies that enable such sensors to be deployed in an integrated photonic device. In this work we demonstrate experimentally, using a sub-wavelength grating the detection of ethanol in aqueous solution by interrogating its large absorption band at 9.54 µm. Theoretical investigation of the operating principle of our grating sensor shows that in general, as the total field interacting with the analyte is increased, the corresponding absorption is also increased. We also theoretically demonstrate how sub-wavelength gratings can detect changes in the real part of the refractive index, similar to conventional refractive index (RI) sensors.

7.
Ophthalmic Physiol Opt ; 39(2): 104-112, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30600544

RESUMEN

AIM: To examine the accuracy of referrals by community optometrists for suspected primary angle closure, including primary angle closure suspects, primary angle closure and primary angle closure glaucoma. METHODS: A retrospective review of 769 consecutive patients referred by community optometrists to the glaucoma clinic at a university hospital in Scotland. Ninety-five of 715 eligible subjects (13%) were referred due to suspected angle closure. All subjects had a comprehensive eye examination in the glaucoma clinic, including gonioscopy, with angle closure defined according to the International Society of Geographical and Epidemiological Ophthalmology classification as iridotrabecular contact over at least 270 degrees. RESULTS: Fifty-nine of 95 subjects referred due to suspected angle closure were confirmed to have an occludable angle, while 36 of 95 (38%) had open angles (positive predictive value = 62%). Of 620 patients referred to the glaucoma clinic for reasons other than narrow angles, 601 (97%) had open angles on gonioscopy and 19 (3%) had narrow angles. Using the 620 patients referred with 'open angles' as a control group, sensitivity was estimated as 76% and specificity 94%. Eleven of 95 (12%) patients referred for possible angle closure were discharged at the first visit compared to 156 of 620 (25%) referred to the glaucoma clinic for other reasons (p = 0.003). In a multivariable model, suspect angle closure detected by the optometrist (OR = 56.0, 95% CI 35.2-89.2, p < 0.001) and female gender (OR = 1.9, 95% CI 1.2-3.1, p = 0.008) were associated with increased odds of angle closure on gonioscopy. CONCLUSION: Community optometrists had good ability to detect eyes at risk of angle closure. There was also greater accuracy of referrals for suspected angle closure than for other glaucoma referrals.


Asunto(s)
Segmento Anterior del Ojo/diagnóstico por imagen , Glaucoma de Ángulo Cerrado/diagnóstico , Gonioscopía/métodos , Optometristas/normas , Tomografía de Coherencia Óptica/métodos , Anciano , Femenino , Estudios de Seguimiento , Glaucoma de Ángulo Cerrado/epidemiología , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Derivación y Consulta , Reproducibilidad de los Resultados , Estudios Retrospectivos , Escocia/epidemiología
8.
Opt Express ; 26(10): 13205-13213, 2018 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-29801347

RESUMEN

Sub-wavelength gratings (SWG) have shown much promise for applications such as lightweight high bandwidth reflectors, polarising filters and focusing lenses. Unfortunately, grating performance may be rapidly degraded through variability in grating dimensions. We demonstrate, in particular, how an error in depth of etch can be detrimental to the performance of zero contrast grating reflectors. We mitigate the impact of this fabrication error through the introduction of an etch stop layer and in so doing we experimentally realise a high bandwidth reflector based on this modified structure. Another common fabrication error is variation in the duty-cycle of fabricated gratings. This duty-cycle variation can weaken grating performance, however we demonstrate that grating designs that exhibit tolerance to duty-cycle fluctuation can be identified through simulation. Finally, we discuss the impact of lateral etching and the resulting sidewall concavity. We present our approach for numerically predicting the spectral response from such a grating and also for convenience we outline an approach for quickly approximating grating performance. Good agreement is observed between these numerical predictions and measurements made on a HCG with concave sidewalls.

9.
Gut ; 66(3): 519-529, 2017 03.
Artículo en Inglés | MEDLINE | ID: mdl-26860769

RESUMEN

OBJECTIVE: In order to explain the increased susceptibility to serious infection in alcoholic hepatitis, we evaluated monocyte phagocytosis, aberrations of associated signalling pathways and their reversibility, and whether phagocytic defects could predict subsequent infection. DESIGN: Monocytes were identified from blood samples of 42 patients with severe alcoholic hepatitis using monoclonal antibody to CD14. Phagocytosis and monocyte oxidative burst (MOB) were measured ex vivo using flow cytometry, luminometry and bacterial killing assays. Defects were related to the subsequent development of infection. Intracellular signalling pathways were investigated using western blotting and PCR. Interferon-γ (IFN-γ) was evaluated for its therapeutic potential in reversing phagocytic defects. Paired longitudinal samples were used to evaluate the effect of in vivo prednisolone therapy. RESULTS: MOB, production of superoxide and bacterial killing in response to Escherichia coli were markedly impaired in patients with alcoholic hepatitis. Pretreatment MOB predicted development of infection within two weeks with sensitivity and specificity that were superior to available clinical markers. Accordingly, defective MOB was associated with death at 28 and 90 days. Expression of the gp91 phox subunit of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase was reduced in patients with alcoholic hepatitis demonstrating defective MOB. Monocytes were refractory to IFN-γ stimulation and showed high levels of a negative regulator of cytokine signalling, suppressor of cytokine signalling-1. MOB was unaffected by 7 days in vivo prednisolone therapy. CONCLUSIONS: Monocyte oxidative burst and bacterial killing is impaired in alcoholic hepatitis while bacterial uptake by phagocytosis is preserved. Defective MOB is associated with reduced expression of NADPH oxidase in these patients and predicts the development of infection and death.


Asunto(s)
Infecciones Bacterianas/inmunología , Hepatitis Alcohólica/fisiopatología , Monocitos/fisiología , NADPH Oxidasas/metabolismo , Fagocitosis , Estallido Respiratorio , Adulto , Antiinflamatorios/uso terapéutico , Estudios de Casos y Controles , Células Cultivadas , Técnicas de Cocultivo , Recuento de Colonia Microbiana , Escherichia coli/inmunología , Femenino , Hepatitis Alcohólica/tratamiento farmacológico , Hepatitis Alcohólica/enzimología , Humanos , Interferón gamma/farmacología , Masculino , Glicoproteínas de Membrana/metabolismo , Persona de Mediana Edad , NADPH Oxidasa 2 , Valor Predictivo de las Pruebas , Prednisolona/uso terapéutico , Estallido Respiratorio/efectos de los fármacos , Transducción de Señal , Proteína 1 Supresora de la Señalización de Citocinas/metabolismo
10.
Liver Transpl ; 23(3): 386-395, 2017 03.
Artículo en Inglés | MEDLINE | ID: mdl-27875636

RESUMEN

Improvements in the management of patients undergoing liver transplantation (LT) have resulted in a significant increase in survival in recent years. Cardiac disease is now the leading cause of early mortality, and the stress of major surgery, hemodynamic shifts, and the possibilities of hemorrhage or reperfusion syndrome require the recipient to have good baseline cardiac function. The prevalence of coronary artery disease (CAD) is increasing in LT candidates, especially in those with nonalcoholic fatty liver disease. In assessing LT recipients, we suggest a management paradigm of "quadruple assessment" to include (1) history, examination, and electrocardiogram; (2) transthoracic echocardiogram; (3) functional testing; and (4) where appropriate, direct assessment of CAD. The added value of functional testing, such as cardiopulmonary exercise testing, has been shown to be able to predict posttransplant complications independently of the presence of CV disease. This approach gives the assessment team the greatest chance of detecting and preventing complications related to CAD. Liver Transplantation 23 386-395 2017 AASLD.


Asunto(s)
Enfermedad de la Arteria Coronaria/diagnóstico , Enfermedad Hepática en Estado Terminal/cirugía , Trasplante de Hígado/efectos adversos , Enfermedad del Hígado Graso no Alcohólico/complicaciones , Atención Perioperativa/métodos , Angiografía Coronaria , Enfermedad de la Arteria Coronaria/complicaciones , Enfermedad de la Arteria Coronaria/epidemiología , Enfermedad de la Arteria Coronaria/terapia , Electrocardiografía , Enfermedad Hepática en Estado Terminal/complicaciones , Enfermedad Hepática en Estado Terminal/mortalidad , Prueba de Esfuerzo , Humanos , Complicaciones Intraoperatorias/prevención & control , Persona de Mediana Edad , Monitoreo Intraoperatorio/métodos , Enfermedad del Hígado Graso no Alcohólico/mortalidad , Enfermedad del Hígado Graso no Alcohólico/cirugía , Periodo Perioperatorio , Prevalencia , Factores de Riesgo , Índice de Severidad de la Enfermedad , Receptores de Trasplantes
11.
J Clin Gastroenterol ; 51(3): 268-277, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27380461

RESUMEN

BACKGROUND: Advancing fibrosis is regarded as the most important factor when stratifying patients with chronic hepatitis C for retreatment. GOALS: (1) To compare the performance of 10 biomarkers of fibrosis, including patented tests, among patients with chronic hepatitis C and treatment failure; and (2) to assess the impact on biomarker performance of using 2 different assays of hyaluronic acid (HA). STUDY: For 80 patients, liver histology (Metavir) was compared with biomarker scores using sera obtained within 6 months of liver biopsy (indirect biomarkers: AST:ALT ratio, APRI, Forns index, FIB-4, Fibrometer V3G; direct biomarkers: ELF, Fibrospect II, Hyaluronic acid-HA, Fibrometer V2G, Hepascore). Direct biomarker scores were calculated using 2 validated assays for HA (ELISA and radiometric). RESULTS: Using the ELISA assay for HA to calculate the direct panels, all 10 of the biomarkers exhibited comparable overall discriminatory performance (unweighted Obuchowski measure, ordROC 0.92-0.94, P-value>0.05) except AST:ALT ratio and APRI (ordROC 0.86-0.88, P-value<0.05). For the detection of moderate (F2-4) and advanced (F3-4) fibrosis, the AUROC of Fibrometer 2G were significantly higher than AST:ALT ratio and APRI but none of the other biomarkers. Good correlation was observed between the 2 HA assays (intraclass correlation coefficient=0.873) with the ELISA assay exhibiting superior diagnostic performance (ordROC 0.92 vs. 0.88, P-value=0.003). Importantly, the performance of many of the direct biomarkers at their diagnostic thresholds was heavily influenced by the choice of HA assay. CONCLUSIONS: Although many biomarkers exhibited good diagnostic performance for the detection of advancing fibrosis, our results indicate that diagnostic performance may be significantly affected by the selection of individual component assays.


Asunto(s)
Biomarcadores/sangre , Hepatitis C Crónica , Ácido Hialurónico/sangre , Cirrosis Hepática/sangre , Adolescente , Adulto , Anciano , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Sensibilidad y Especificidad , Índice de Severidad de la Enfermedad , Adulto Joven
12.
Opt Lett ; 41(21): 5130-5133, 2016 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-27805701

RESUMEN

We present a new material pairing that can be used to realize high-contrast gratings at wavelengths of 10 µm and greater. Using only optical lithography, the material pair solves the absorption issue limiting the popular Si/SiO2 pairing from operation above 6 µm. We describe the obstacles that exist with the currently used grating materials for this wavelength range and outline why our chosen materials overcome this obstacle. We numerically demonstrate that gratings utilizing these materials are capable of wideband high reflectivity. We experimentally show that the spectral response of gratings that are fabricated using such a process show good agreement with theoretically predicted performance.

13.
Transpl Int ; 28(4): 455-64, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25557691

RESUMEN

The gold standard to diagnose acute cellular rejection (ACR) after liver transplantation (LT) is histological evaluation, but there is no consensus to select patients for liver biopsy. We aimed to evaluate the agreement among clinicians to select candidates for liver biopsy early after LT. From a protocol biopsy population (n = 690), we randomly selected 100 LT patients in whom the biopsy was taken 7-10 days after LT. The clinical information between LT and protocol biopsy was given to nine clinicians from three transplant centres who decided whether a liver biopsy was needed. The agreement among clinicians to select candidates for liver biopsy was poor: κ = 0.06-0.62, being κ < 0.40 in 76% of comparisons. The concordance between indication for liver biopsy and moderate-severe ACR in the protocol biopsy was κ < 0.30 in all cases. A multivariate model based on the product age-by-MELD (OR = 0.81; P = 0.013), delta eosinophils (OR = 1.5; P = 0.002) and mean tacrolimus trough concentrations <6 ng/ml within the prior 4 days (OR = 11.4; P = 0.047) had an AUROC = 0.84 to diagnose moderate-severe histological ACR. In conclusion, the agreement among clinicians to select patients for liver biopsy is very poor. If further validated the proposed model would provide an objective method to select candidates for liver biopsy after LT.


Asunto(s)
Rechazo de Injerto/diagnóstico , Trasplante de Hígado/estadística & datos numéricos , Hígado/patología , Adulto , Biopsia , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Selección de Paciente
14.
Environ Sci Technol ; 48(11): 6444-52, 2014 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-24803287

RESUMEN

Carbonaceous particles produced from combustion of fossil fuels have strong impacts on air quality and climate, yet quantitative relationships between particle characteristics and combustion conditions remain inadequately understood. We have used a shock tube to study the formation and properties of diesel combustion soot, including particle size distributions, effective density, elemental carbon (EC) mass fraction, mass-mobility scaling exponent, hygroscopicity, and light absorption and scattering. These properties are found to be strongly dependent on the combustion temperature and fuel equivalence ratio. Whereas combustion at higher temperatures (∼2000 K) yields fractal particles of a larger size and high EC content (90 wt %), at lower temperatures (∼1400 K) smaller particles of a higher organic content (up to 65 wt %) are produced. Single scattering albedo of soot particles depends largely on their organic content, increasing drastically from 0.3 to 0.8 when the particle EC mass fraction decreases from 0.9 to 0.3. The mass absorption cross-section of diesel soot increases with combustion temperature, being the highest for particles with a higher EC content. Our results reveal that combustion conditions, especially the temperature, may have significant impacts on the direct and indirect climate forcing of atmospheric soot aerosols.


Asunto(s)
Hollín/química , Aerosoles/análisis , Aerosoles/química , Carbono/análisis , Carbono/química , Calor , Tamaño de la Partícula , Hollín/análisis
15.
Int J Surg Protoc ; 28(1): 20-26, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38433867

RESUMEN

Background: Despite a UK 5-year breast cancer survival rate of 86.6%, patients may develop breast cancer recurrence within the same breast after breast conserving surgery, as well as in the remaining skin or chest wall after mastectomy or in the ipsilateral lymph glands. These recurrences, collectively termed locoregional recurrence (LRR), occur in around 8% of patients within 10 years of their original diagnosis. Currently, there is a lack of robust information on the presentation and prevalence of LRR with no UK-specific clinical guidelines available for the optimal management of this patient group. Additionally, there is a need to identify patterns of LRR presentation and their progression, which will enable prognostic factors to be determined. This will subsequently enable the tailoring of treatment and improve patient outcome. Methods: The MARECA study is a prospective, multicentre cohort study recruiting patients diagnosed with breast cancer LRR +/- associated distant metastases. Over 50 UK breast units are participating in the study with the aim of recruiting at least 500 patients over a recruitment period of 24 months. The data collected will detail the tumour pathology, imaging results, surgical treatment, radiotherapy and systemic therapy of the primary and recurrent breast cancer. Study follow-up will be for up to 5 years following LRR diagnosis to determine subsequent oncological outcomes and evaluate potential prognostic factors. Discussion: This study will address the current knowledge gap and identify subgroups of patients who have less successful treatment outcomes. The results will determine the current management of LRR and the prognosis of patients diagnosed with breast cancer LRR +/- distant metastases in the UK, with the aim of establishing best practice and informing future national guidelines. The results will direct future research and inform the design of additional interventional trials and translational studies.

17.
Frontline Gastroenterol ; 13(6): 531-534, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36250168

RESUMEN

The decision-making around transjugular intrahepatic portosystemic shunt (TIPSS) placement in the management of patients with chronic liver disease and portal hypertension (PH) is a regular challenge for hepatologists. In the UK, access has improved, with more than 35 hospitals now offering this service. However, its role in acute variceal bleeding, refractory ascites and other complications of PH continues to be redefined and expanded. In particular, the role of pre-emptive TIPSS has become more established and requires re-evaluation of pathways to enable equitable access for patients. Here, we summarise the key recommendations from the recently published British Society of Gastroenterology guidelines and expand on the challenges posed.

18.
Thromb Haemost ; 122(6): 1006-1016, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-34638152

RESUMEN

INTRODUCTION: Hemorrhage and venous thromboembolism (VTE) are recognized complications of chronic liver disease (CLD), but their prevalence and risk factors in critically ill patients are uncertain. PATIENTS AND METHODS: We studied a retrospective cohort of patients with CLD nonelectively admitted to a specialist intensive care unit (ICU) determining the prevalence and timing of major bleeding and VTE (early, present on admission/diagnosed within 48 hours; later, diagnosed >48 hours post-ICU admission). Associations with baseline clinical and laboratory characteristics, multiorgan failure (MOF), blood product administration, and mortality were explored. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression. RESULTS: Of 623 patients with median age 52, bleeding (>48 hours after admission) occurred in 87 (14%) patients. Bleeding was associated with greater illness severity and increased mortality. Gastrointestinal bleeding accounted for 72% of events, secondary to portal hypertension in >90%. Procedure-related bleeding was uncommon. VTE occurred in 125 (20%) patients: early VTE in 80 (13%) and involving the portal vein in 85%. Later VTE affected 45 (7.2%) patients. Hepatocellular carcinoma (HCC) and nonalcoholic liver disease were independently associated with early VTE (OR: 2.79, 95% CI: 1.5-5.2 and OR: 2.32, 95% CI: 1.4-3.9, respectively), and HCC, sepsis, and cryoprecipitate use with late VTE (OR: 2.45, 95% CI: 1.11-5.43; OR: 2.26, 95% CI: 1.2-4.3; and OR: 2.60, 95% CI: 1.3-5.1). CONCLUSION: VTE was prevalent on admission to critical care and less commonly developed later. Bleeding was associated with MOF and increased mortality. Severe MOF was not associated with an increased rate of VTE which was linked with HCC, and specific etiologies of CLD.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Trombosis , Tromboembolia Venosa , Anticoagulantes , Carcinoma Hepatocelular/complicaciones , Carcinoma Hepatocelular/epidemiología , Enfermedad Crítica , Hemorragia Gastrointestinal/epidemiología , Humanos , Neoplasias Hepáticas/complicaciones , Neoplasias Hepáticas/epidemiología , Persona de Mediana Edad , Prevalencia , Estudios Retrospectivos , Factores de Riesgo , Trombosis/complicaciones , Tromboembolia Venosa/diagnóstico , Tromboembolia Venosa/epidemiología , Tromboembolia Venosa/etiología
19.
Eur J Surg Oncol ; 48(7): 1510-1519, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35410760

RESUMEN

INTRODUCTION: Evidence based guidelines for the optimal management of breast cancer locoregional recurrence (LRR) are limited, with potential for variation in clinical practice. This national practice questionnaire (NPQ) was designed to establish the current practice of UK breast multidisciplinary teams (MDTs) regarding LRR management. METHODS: UK breast units were invited to take part in the MARECA study MDT NPQ. Scenario-based questions were used to elicit preference in pre-operative staging investigations, surgical management, and adjuvant therapy. RESULTS: 822 MDT members across 42 breast units (out of 144; 29%) participated in the NPQ (February-August 2021). Most units (95%) routinely performed staging CT scan, but bone scan was selectively performed (31%). For patients previously treated with breast conserving surgery (BCS) and radiotherapy, few units (7%) always/usually offered repeat BCS. However, in the absence of radiotherapy, most units (90%) always/usually offered repeat BCS. For patients presenting with isolated local recurrence following previous BCS and SLNB (sentinel lymph node biopsy), most units (95%) advocated repeat SLNB. Where SLNs could not be identified, 86% proceeded to a four-node axillary sampling procedure. For ER positive, HER2 negative, node negative local recurrence, 10% of units always/usually offered chemotherapy. For ER positive, HER2 negative, node positive local recurrence, this recommendation increased to 64%. For triple negative breast cancer local recurrence, 90% of units always/usually offered chemotherapy. CONCLUSION: This survey has highlighted where consistencies and variations exist in the multidisciplinary management of breast cancer LRR. However, further research is required to determine how these management patterns influence patient outcomes, which will further refine optimal treatment pathways.


Asunto(s)
Neoplasias de la Mama , Axila/patología , Neoplasias de la Mama/patología , Toma de Decisiones , Femenino , Humanos , Escisión del Ganglio Linfático , Metástasis Linfática , Recurrencia Local de Neoplasia/patología , Biopsia del Ganglio Linfático Centinela/métodos , Encuestas y Cuestionarios
20.
Ann Surg ; 253(2): 360-4, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21169805

RESUMEN

OBJECTIVE: Postoperative wound complications after excisional surgery for primary breast cancer can result in patients requiring additional treatments and delay adjuvant therapy and are associated with worse prognoses.We investigated factors that might predispose patients to wound complications. BACKGROUND: A number of patient characteristics have been associated with wound complications, but there is currently no quantitative measure of the risk of their occurrence. Our hypothesis was that wound complications are related, in part, to the immune status of patients. METHODS: We recruited patients undergoing surgery for primary breast cancer and determined their circulating levels of various immune cells shortly before and after surgery as a measure of immune status. RESULTS: One hundred seventeen patients were recruited; 16 (13.7%) developed wound complications. The following patient and tumor characteristics were associated with higher wound complication rates: diabetes (P = 0.02); larger tumors (T2/3 vs T1; P = 0.02); metastatic axillary nodes (P = 0.006). With respect to immune status, no significant differences in preoperative levels of circulating immune cells were detected between patients who developed wound complications and those who did not. However, patients who developed complications showed greater reductions in lymphocyte levels 4 hours postoperatively than those who did not (P <0.001). Multivariate analyses demonstrated that falls in lymphocyte levels of greater than 20% or 50% 4 hours postoperatively acted as a significant and independent predictor of wound complications (P < 0.005 and P < 0.0001,respectively). CONCLUSIONS: Perioperative changes in lymphocyte levels could provide a practical predictive marker for wound complications on which selective antibiotic prophylaxis could be based.


Asunto(s)
Neoplasias de la Mama/cirugía , Recuento de Linfocitos , Mastectomía Segmentaria/efectos adversos , Mastectomía/efectos adversos , Complicaciones Posoperatorias/inmunología , Infección de la Herida Quirúrgica/inmunología , Anciano , Femenino , Humanos , Subgrupos Linfocitarios , Persona de Mediana Edad
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA