Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 96
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Am J Physiol Heart Circ Physiol ; 323(5): H1010-H1018, 2022 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-36206050

RESUMEN

The cisterna chyli is a lymphatic structure found at the caudal end of the thoracic duct that receives lymph draining from the abdominal and pelvic viscera and lower limbs. In addition to being an important landmark in retroperitoneal surgery, it is the key gateway for interventional radiology procedures targeting the thoracic duct. A detailed understanding of its anatomy is required to facilitate more accurate intervention, but an exhaustive summary is lacking. A systematic review was conducted, and 49 published human studies met the inclusion criteria. Studies included both healthy volunteers and patients and were not restricted by language or date. The detectability of the cisterna chyli is highly variable, ranging from 1.7 to 98%, depending on the study method and criteria used. Its anatomy is variable in terms of location (vertebral level of T10 to L3), size (ranging 2-32 mm in maximum diameter and 13-80 mm in maximum length), morphology, and tributaries. The size of the cisterna chyli increases in some disease states, though its utility as a marker of disease is uncertain. The anatomy of the cisterna chyli is highly variable, and it appears to increase in size in some disease states. The lack of well-defined criteria for the structure and the wide variation in reported detection rates prevent accurate estimation of its natural prevalence in humans.


Asunto(s)
Conducto Torácico , Humanos , Conducto Torácico/diagnóstico por imagen , Conducto Torácico/anatomía & histología , Prevalencia
2.
Microcirculation ; 29(6-7): e12748, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35092129

RESUMEN

OBJECTIVE: Conventionally, in vivo mesenteric lymphatic contractile function is measured using a high magnification transmission microscope (field of view 0.3-1.5 mm), which precludes visualization of extended lengths of vessels embedded in mesenteric fat. Existing software is not optimized for imaging at a low magnification using a contrast agent. We aimed to develop a simple and clinically transferable method for in situ visualization, image analysis, and quantitative assessment of mesenteric lymphatic contractile function over an extended area. METHODS: Subserosal injection of various blue dyes was taken up by mesenteric lymphatics and visualized under a stereomicroscope (25×), allowing for video recording of 1.4 × 1.1 cm of intact mesentery. A new R package ("vmeasur") that combines multiple high-performance image analyses into a single workflow was developed. The edges of each vessel were determined by applying an automated threshold to each frame (with real-time manual verification). The vessel width at every point in each frame was plotted to provide contractile parameters over time and along the lymphatic vessel length. RESULTS: Contractile parameters and their differences along the length of the vessel were accurately calculated in a rodent model. In a human mesenteric lymphatic, the algorithm was also able to measure changes in diameter over length. CONCLUSION: This software offers a low cost, rapid, and accessible method to measure lymphatic contractile function over a wide area, showing differences in contractility along the length of a vessel. Because the presence of mesenteric fat has less of an impact on imaging, due to the use of an exogenous contrast agent, there is potential for clinical application.


Asunto(s)
Medios de Contraste , Vasos Linfáticos , Humanos , Vasos Linfáticos/diagnóstico por imagen , Contracción Muscular , Mesenterio , Programas Informáticos
3.
PLoS Biol ; 17(12): e3000486, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31856185

RESUMEN

The conduit network is a hallmark of lymph node microanatomy, but lack of suitable imaging technology has prevented comprehensive investigation of its topology. We employed an extended-volume imaging system to capture the conduit network of an entire murine lymph node (comprising over 280,000 segments). The extensive 3D images provide a comprehensive overview of the regions supplied by conduits, including perivascular sleeves and distinctive "follicular reservoirs" within B cell follicles, surrounding follicular dendritic cells. A 3D topology map of conduits within the T-cell zone showed homogeneous branching, but conduit density was significantly higher in the superficial T-cell zone compared with the deep zone, where distances between segments are sufficient for T cells to lose contact with fibroblastic reticular cells. This topological mapping of the conduit anatomy can now aid modeling of its roles in lymph node function, as we demonstrate by simulating T-cell motility in the different T-cell zones.


Asunto(s)
Procesamiento de Imagen Asistido por Computador/métodos , Imagenología Tridimensional/métodos , Ganglios Linfáticos/diagnóstico por imagen , Animales , Linfocitos B/inmunología , Movimiento Celular , Fibroblastos , Ratones/inmunología , Linfocitos T/inmunología
4.
Clin Anat ; 35(4): 447-453, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-34658062

RESUMEN

The thoracic duct (TD) drains most of the body's lymph back to the venous system via its lymphovenous junction (LVJ), playing a pivotal role in fluid homeostasis, fat absorption and the systemic immune response. The respiratory cycle is thought to assist with lymph flow, but the precise mechanism underpinning terminal TD lymph flow into the central veins is not well understood. The aim of this study was to use ultrasonography (US) to explore the relationship between terminal TD lymph flow, the respiratory cycle, and gravity. The left supraclavicular fossa was scanned in healthy non-fasted volunteers using high-resolution (13-5 MHz) US to identify the terminal TD and the presence of a lymphovenous valve (LVV). The TD's internal diameter was measured in relation to respiration (inspiration vs. expiration) and body positioning (supine vs. Trendelenburg). The terminal TD was visualized in 20/33 (61%) healthy volunteers. An LVV was visualized in only 4/20 (20%) cases. The mean terminal TD diameter in the supine position was 1.7 mm (range 0.8-3.1 mm); this increased in full inspiration (mean 1.8 mm, range 0.9-3.2 mm, p < 0.05), and in the Trendelenburg position (mean 1.8 mm, range 1.2-3.1 mm, p < 0.05). The smallest mean terminal TD diameter occurred in full expiration (1.6 mm, range 0.7-3.1 mm, p < 0.05). Respiration and gravity impact the terminal TD diameter. Due to the challenges of visualizing the TD and LVJ, other techniques such as dynamic magnetic resonance imaging will be required to fully understand the factors governing TD lymph flow.


Asunto(s)
Respiración , Conducto Torácico , Humanos , Posición Supina , Conducto Torácico/diagnóstico por imagen , Ultrasonografía
5.
Mol Pharm ; 16(12): 4987-4999, 2019 12 02.
Artículo en Inglés | MEDLINE | ID: mdl-31625752

RESUMEN

Drugs are commonly administered via the intraperitoneal (IP) route to treat localized infections and cancers in patients and to test drug efficacy and toxicity in preclinical studies. Despite this, there remain large gaps in our understanding of drug absorption routes (lymph vs blood) and pharmacokinetics following IP administration. This is particularly true when drugs are administered in complex delivery systems such as liposomes which are the main marketed formulation for several drugs that are administered intraperitoneally. This study investigated the impact of liposome surface properties (charge and PEGylation) on absorption into lymph and blood, and lymphatic disposition patterns, following IP administration. To achieve this, stable 3H-dipalmitoyl-phosphatidylcholine (DPPC) and 14C-sucrose-radiolabeled liposomes of 100-150 nm diameter with negative, neutral, or positive surface charge, or a PEGylated surface, were prepared and administered intraperitoneally to rats. Radiolabel concentrations were measured in lymph, blood, and lymph nodes (LNs). Lymph was collected from the thoracic lymph duct at either the abdomen (ABD) or the jugular-subclavian junction (JSJ). The lymphatic recovery of the radiolabels was substantially lower after administration in positively charged compared to the neutral, negative, or PEGylated liposomes. Radiolabel recovery was substantially greater (up to 18-fold) in the thoracic lymph collected at the JSJ when compared to that at the ABD, suggesting that liposomes entered the lymphatics at the diaphragm. Consistent with this, the concentration of the liposome labels was substantially higher (up to seven-fold) in mediastinal than in mesenteric LNs. Overall, this study shows how the peritoneal absorption and lymphatic disposition of drugs administered intraperitoneally can be manipulated through a careful selection of the drug delivery system and may thus be optimized to treat localized conditions such as cancers, infections, inflammatory diseases, and acute and critical illness.


Asunto(s)
Liposomas/química , Ganglios Linfáticos/metabolismo , Peritoneo/metabolismo , 1,2-Dipalmitoilfosfatidilcolina/química , Animales , Sistemas de Liberación de Medicamentos , Inyecciones Intraperitoneales , Masculino , Ratas , Sacarosa/química
6.
Biochem Biophys Res Commun ; 482(4): 625-631, 2017 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-27865831

RESUMEN

Pancreatic islet ß-cells secrete the hormones insulin and amylin, and defective ß-cell function plays a central role in the pathogenesis of type-2 diabetes (T2D). Human amylin (hA, also termed hIAPP) misfolds and forms amyloid aggregates whereas orthologous mouse amylin does neither. Furthermore, hA elicits apoptosis in cultured ß-cells and ß-cell death in ex-vivo islets. In addition, hA-transgenic mice that selectively express hA in their ß-cells, manifest ß-cell apoptosis and progressive islet damage that leads to diabetes closely resembling that in patients with T2D. Aggregation of hA is thus linked to the causation of diabetes. We employed time-dependent thioflavin-T spectroscopy and ion-mobility mass spectrometry to screen potential suppressors of hA misfolding for anti-diabetic activity. We identified the dietary flavonol rutin as an inhibitor of hA-misfolding and measured its anti-diabetic efficacy in hA-transgenic mice. In vitro, rutin bound hA, suppressed misfolding, disaggregated oligomers and reverted hA-conformation towards the physiological. In hA-transgenic mice, measurements of glucose, fluid-intake, and body-weight showed that rutin-treatment slowed diabetes-progression by lowering of rates of elevation in blood glucose (P = 0.030), retarding deterioration from symptomatic diabetes to death (P = 0.014) and stabilizing body-weight (P < 0.0001). In conclusion, rutin treatment suppressed hA-aggregation in vitro and doubled the lifespan of diabetic mice (P = 0.011) by a median of 69 days compared with vehicle-treated control-diabetic hA-transgenic mice.


Asunto(s)
Amiloide/metabolismo , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Hipoglucemiantes/uso terapéutico , Polipéptido Amiloide de los Islotes Pancreáticos/metabolismo , Pliegue de Proteína/efectos de los fármacos , Rutina/uso terapéutico , Amiloide/genética , Animales , Glucemia/metabolismo , Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patología , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patología , Humanos , Hipoglucemiantes/farmacología , Polipéptido Amiloide de los Islotes Pancreáticos/genética , Islotes Pancreáticos/efectos de los fármacos , Islotes Pancreáticos/metabolismo , Islotes Pancreáticos/patología , Masculino , Ratones Transgénicos , Agregación Patológica de Proteínas/tratamiento farmacológico , Agregación Patológica de Proteínas/genética , Agregación Patológica de Proteínas/metabolismo , Agregación Patológica de Proteínas/patología , Deficiencias en la Proteostasis/tratamiento farmacológico , Deficiencias en la Proteostasis/genética , Deficiencias en la Proteostasis/metabolismo , Deficiencias en la Proteostasis/patología , Rutina/farmacología
7.
J Surg Res ; 211: 21-29, 2017 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-28501119

RESUMEN

BACKGROUND: Nonocclusive mesenteric ischemia can cause intestinal infarction but the diagnosis is challenging. This prospective study evaluated three plasma biomarkers of intestinal infarction after cardiac surgery. MATERIALS AND METHODS: Patients were recruited after cardiac surgery if they required laparotomy (with or without intestinal resection) for suspected nonocclusive mesenteric ischemia. Plasma levels of D-lactate, intestinal fatty acid-binding protein (i-FABP), and smooth muscle actin (SMA) before laparotomy were measured. RESULTS: Twenty patients were recruited (68 ± 9 y, EuroSCORE: 8.7 ± 2.8, mortality 70%). A positive laparotomy (n = 13) was associated with no change in D-lactate (P = 0.95), decreased i-FABP (P = 0.007), and increased SMA (P = 0.01). All patients with high SMA had a positive laparotomy. A subgroup analysis was undertaken in the eight patients who required multiple laparotomies. D-lactate increased between the two laparotomies in nonsurvivors (n = 4). Plasma i-FABP (P = 0.008) and SMA (P = 0.036) significantly decreased after the bowel resection, regardless of survival outcome. CONCLUSIONS: None of the biomarkers were accurate enough to reliably diagnose intestinal infarction. However, all patients with high values of SMA developed intestinal infarction, thus warranting further investigation. An increasing D-lactate after intestinal resection suggests impending death.


Asunto(s)
Actinas/sangre , Procedimientos Quirúrgicos Cardíacos , Proteínas de Unión a Ácidos Grasos/sangre , Infarto/diagnóstico , Ácido Láctico/sangre , Isquemia Mesentérica/diagnóstico , Complicaciones Posoperatorias/diagnóstico , Anciano , Anciano de 80 o más Años , Biomarcadores/sangre , Femenino , Humanos , Infarto/sangre , Infarto/etiología , Infarto/cirugía , Intestinos/irrigación sanguínea , Laparotomía , Masculino , Isquemia Mesentérica/sangre , Isquemia Mesentérica/etiología , Isquemia Mesentérica/cirugía , Persona de Mediana Edad , Proyectos Piloto , Complicaciones Posoperatorias/sangre , Complicaciones Posoperatorias/cirugía , Estudios Prospectivos , Curva ROC
8.
Int Wound J ; 14(6): 1225-1236, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28730726

RESUMEN

Chronic wounds are a growing problem worldwide with no effective therapeutic treatments available. Our objective was to understand the composition of the dermal tissue surrounding venous leg ulcers and diabetic foot ulcers (DFU). We used novel 2-photon imaging techniques alongside classical histology to examine biopsies from the edges of two common types of chronic wound, venous leg ulcers and DFU. Compared to normal intact skin, we found that collagen levels are significantly reduced throughout the dermis of venous leg ulcer biopsies and DFU, with a reduction in both fibril thickness and abundance. Both wound types showed a significant reduction in elastin in the upper dermis, but in DFU, the loss was throughout the dermis. Loss of extracellular matrix correlated with high levels of CD68- and CD18-positive leukocytes. 2-photon imaging of the extracellular matrix in the intact tissue surrounding a chronic wound with a hand-held device may provide a useful clinical indicator on the healing progression or deterioration of these wounds.


Asunto(s)
Dermis/diagnóstico por imagen , Pie Diabético/diagnóstico por imagen , Diagnóstico por Imagen de Elasticidad/métodos , Matriz Extracelular/ultraestructura , Úlcera Varicosa/diagnóstico por imagen , Cicatrización de Heridas/fisiología , Heridas y Lesiones/diagnóstico por imagen , Anciano , Anciano de 80 o más Años , Enfermedad Crónica , Humanos , Masculino , Persona de Mediana Edad , Heridas y Lesiones/fisiopatología
9.
Pancreatology ; 16(2): 181-8, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26777539

RESUMEN

BACKGROUND: Impaired motor and hormonal gastrointestinal functions have been implicated in the pathogenesis of acute pancreatitis. The aim of the present study was to investigate the predictive value of the Gastroparesis Cardinal Symptom Index and serum ghrelin in the development of clinically meaningful outcomes in patients with acute pancreatitis. METHODS: This was a prospective clinical study. The Gastroparesis Cardinal Symptom Index and serum ghrelin were measured for 48 h after hospitalization. Univariate and multivariate logistic regression analyses were conducted. RESULTS: The Gastroparesis Cardinal Symptom Index total score alone on day 2 was a significant predictor of oral feeding intolerance in both unadjusted (odds ratio 1.21 (1.01-1.46), P = 0.04) and adjusted (odds ratio 1.30 (1.01-1.69), P = 0.05) analyses. Adding ghrelin to Gastroparesis Cardinal Symptom Index further improved prediction in both unadjusted (odds ratio 1.26 (1.02-1.56), P = 0.03) and adjusted (odds ratio 1.53 (1.00-2.35), P = 0.05) analyses. CONCLUSION: This pilot study demonstrates that the Gastroparesis Cardinal Symptom Index has a potential to be used as a predictor of oral feeding intolerance. Ghrelin, when combined with the Gastroparesis Cardinal Symptom Index, may further improve the predictive accuracy. These findings need to be confirmed in larger studies.


Asunto(s)
Gastroparesia/complicaciones , Ghrelina/sangre , Pancreatitis/complicaciones , Adulto , Anciano , Estudios de Cohortes , Femenino , Humanos , Hiperglucemia , Masculino , Persona de Mediana Edad , Pancreatitis/patología , Resultado del Tratamiento
10.
Pancreatology ; 16(5): 739-47, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27473495

RESUMEN

BACKGROUND/OBJECTIVES: Mitochondrial dysfunction occurs in vital organs in experimental acute pancreatitis (AP) and may play an important role in determining severity of AP. However, obtaining vital organ biopsies to measure mitochondrial function (MtF) in patients with AP poses considerable risk of harm. Being able to measure MtF from peripheral blood will bypass this problem. Furthermore, whether mitochondrial dysfunction is detectable in peripheral blood in mild AP is unknown. Therefore, the objective was to evaluate peripheral blood MtF in experimental and clinical AP. METHOD: Mitochondrial respiration was measured using high resolution oxygraphy in an experimental study in caerulein induced AP and in a separate study, in patients with mild AP. Superoxide, cytochrome c, mitochondrial membrane potential (ΔΨ) and adenine triphosphate (ATP) were also measured as other markers of MtF. RESULTS: Even though some states of mitochondrial respiration were increased in both experimental and clinical AP, this did not lead to an increase in net ATP in patients with AP. The increased leak respiration in both studies was further proof of dyscoupled mitochondria. In the clinical study there were also features of mitochondrial dysfunction with increased leak flux control ratio, superoxide, ΔΨ and decreased cytochrome c. CONCLUSION: There is evidence of mitochondrial dysfunction with dyscoupled mitochondria, increased superoxide and decreased cytochrome c in patients with mild acute pancreatitis. Further studies should now determine whether mitochondrial function alters with severity in AP and whether mitochondrial dysfunction responds to treatments.


Asunto(s)
Enfermedades Mitocondriales/metabolismo , Monocitos/metabolismo , Pancreatitis/metabolismo , Enfermedad Aguda , Adenosina Trifosfato/metabolismo , Adulto , Anciano , Animales , Ceruletida , Citocromos c/metabolismo , Femenino , Humanos , Masculino , Potencial de la Membrana Mitocondrial , Persona de Mediana Edad , Estrés Oxidativo , Consumo de Oxígeno , Pancreatitis/inducido químicamente , Ratas , Ratas Wistar , Superóxidos/metabolismo
11.
Liver Transpl ; 21(3): 396-407, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25312517

RESUMEN

Steatotic livers are susceptible to cold ischemia, which is thought to be secondary to mitochondrial dysfunction. Ischemic preconditioning (IPC) has been reported to improve liver function in the setting of warm ischemia/reperfusion injury, but the effect of IPC on steatotic liver mitochondrial function (MF) with cold ischemia has not been previously evaluated. We aimed to evaluate MF with various severities of hepatic steatosis after various durations of cold ischemia storage with or without IPC. Male Sprague-Dawley rats were fed a normal diet or a high-fat/high-sucrose diet for 1, 2, or 4 weeks to induce mild (<30%), moderate (30%-60%), or severe (>60%) macrovesicular steatosis, respectively. Liver MF was tested with high-resolution respirometry after 1.5, 4, 8, 12, 18, and 24 hours of cold ischemia. Rats in each group (n = 10) underwent 10 minutes of IPC or no IPC before cold ischemia. The baseline (time 0) respiration was similar for lean and severely steatotic livers despite decreased mitochondrial complex I (C-I) activity in severely steatotic livers. Hepatic steatosis was associated with increased C-I-mediated leaks and decreased respiratory control ratios (RCRs) after cold ischemia. Mildly, moderately, and severely steatotic livers showed significantly lower RCRs after 8, 1.5, and 1.5 hours of cold ischemia, respectively, in comparison with lean livers. IPC restored RCRs in mildly steatotic livers to levels comparable to those in lean livers for up to 24 hours of cold ischemia via the attenuation of C-I-mediated leaks, but it had no beneficial effect on moderately and severely steatotic livers. In conclusion, steatotic livers exhibited apparent mitochondrial dysfunction through an alteration in C-I activity, and this made them more susceptible to prolonged cold ischemia. The clinically based IPC protocol used here restored MF in cases of mild hepatic steatosis by attenuating C-I-mediated leaks after prolonged cold ischemia, but it did work not in livers with moderate or severe steatosis.


Asunto(s)
Isquemia Fría/efectos adversos , Complejo I de Transporte de Electrón/metabolismo , Hígado/enzimología , Mitocondrias Hepáticas/enzimología , Enfermedad del Hígado Graso no Alcohólico/complicaciones , Daño por Reperfusión/etiología , Animales , Modelos Animales de Enfermedad , Precondicionamiento Isquémico/métodos , Hígado/patología , Masculino , Enfermedad del Hígado Graso no Alcohólico/diagnóstico , Enfermedad del Hígado Graso no Alcohólico/enzimología , Ratas Sprague-Dawley , Daño por Reperfusión/diagnóstico , Daño por Reperfusión/enzimología , Daño por Reperfusión/prevención & control , Factores de Riesgo , Índice de Severidad de la Enfermedad , Factores de Tiempo
12.
FASEB J ; 28(12): 5083-96, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25138158

RESUMEN

The aggregation of human amylin (hA) to form cytotoxic structures has been closely associated with the causation of type 2 diabetes. We sought to advance understanding of how altered expression and aggregation of hA might link ß-cell degeneration with diabetes onset and progression, by comparing phenotypes between homozygous and hemizygous hA-transgenic mice. The homozygous mice displayed elevated islet hA that correlated positively with measures of oligomer formation (r=0.91; P<0.0001). They also developed hyperinsulinemia with transient insulin resistance during the prediabetes stage and then underwent rapid ß-cell loss, culminating in severe juvenile-onset diabetes. The prediabetes stage was prolonged in the hemizygous mice, wherein ß-cell dysfunction and extensive oligomer formation occurred in adulthood at a much later stage, when hA levels were lower (r=-0.60; P<0.0001). This is the first report to show that hA-evoked diabetes is associated with age, insulin resistance, progressive islet dysfunction, and ß-cell apoptosis, which interact variably to cause the different diabetes syndromes. The various levels of hA elevation cause different extents of oligomer formation in the disease stages, thus eliciting early- or adult-onset diabetes syndromes, reminiscent of type 1 and 2 diabetes, respectively. Thus, the hA-evoked diabetes phenotypes differ substantively according to degree of amylin overproduction. These findings are relevant to the understanding of the pathogenesis and the development of experimental therapeutics for diabetes.


Asunto(s)
Biopolímeros/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Polipéptido Amiloide de los Islotes Pancreáticos/metabolismo , Islotes Pancreáticos/metabolismo , Animales , Secuencia de Bases , Biopolímeros/química , Muerte Celular , Cartilla de ADN , Diabetes Mellitus Tipo 2/patología , Prueba de Tolerancia a la Glucosa , Insulina/sangre , Polipéptido Amiloide de los Islotes Pancreáticos/química , Islotes Pancreáticos/citología , Ratones , Ratones Transgénicos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
13.
Pancreatology ; 15(1): 25-33, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25464938

RESUMEN

BACKGROUND: With the rising prevalence of obesity, its impact on the severity and outcome of acute pancreatitis remains an important consideration when managing obese patients with acute pancreatitis. OBJECTIVE: To determine the clinical relevance of obesity in acute pancreatitis. METHODS: A series of clinically relevant questions were framed which formed the basis of our literature search using PubMed and EMBASE databases. These related to acute pancreatitis severity, systemic inflammatory response, mortality, local and systemic complications. The search was restricted to human studies. Studies were classified according to the Oxford Centre for Evidence Based Medicine levels of evidence 1 for prognostic studies. Obesity was defined according to the guidelines of the World Health Organization. In keeping with studies included the binary classification (mild and severe) of acute pancreatitis was used. RESULTS: Obesity is associated with an amplified systemic inflammatory response in acute pancreatitis and is a prognostic factor for mortality, local, systemic complications and severity in acute pancreatitis. Obesity was not found to be an independent prognostic factor for mortality and organ failure in patients with acute pancreatitis. It was evident that further studies are required to determine whether incorporating obesity into existing scoring systems improves severity prediction. Emerging evidence suggests that an obesity paradox is present in patients with acute pancreatitis. CONCLUSION: This review demonstrates that obesity has a clinically relevant impact on the course and outcome of acute pancreatitis.


Asunto(s)
Obesidad/complicaciones , Pancreatitis/complicaciones , Enfermedad Aguda , Humanos , Pancreatitis/diagnóstico , Pancreatitis/mortalidad , Pronóstico , Factores de Riesgo , Índice de Severidad de la Enfermedad , Síndrome de Respuesta Inflamatoria Sistémica/etiología
14.
HPB (Oxford) ; 17(1): 1-10, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24712641

RESUMEN

BACKGROUND: Steatotic livers are vulnerable to the deleterious effects of ischaemia-reperfusion injury (IRI) that occur after hepatic surgery. Ischaemic preconditioning (IPC) has been shown to abrogate the effects of IRI in patients undergoing hepatic surgery. Experimental studies have suggested that IPC may be beneficial in steatotic livers subjected to IRI. OBJECTIVE: The aim of this systematic review was to evaluate the effects of IPC on steatotic livers following hepatic IRI in experimental models. METHODS: An electronic search of the OVID Medline and EMBASE databases was performed to identify studies that reported clinically relevant outcomes in animal models of hepatic steatosis subjected to IPC and IRI. RESULTS: A total of 1093 articles were identified, of which 18 met the inclusion criteria. There was considerable heterogeneity in the type of animal model, and duration and type of IRI. Increased macrovesicular steatosis (> 30%) was associated with a poor outcome following IRI. Ischaemic preconditioning was found to be beneficial in > 30% steatotic livers and provided for decreased histological damage, improved liver function findings and increased survival. CONCLUSIONS: Experimental evidence supports the use of IPC in steatotic livers undergoing IRI. These findings may be applicable to patients undergoing liver surgery. However, clinical studies are required to validate the efficacy of IPC in this setting.


Asunto(s)
Isquemia Fría/efectos adversos , Hígado Graso/cirugía , Precondicionamiento Isquémico/métodos , Hígado/irrigación sanguínea , Hígado/cirugía , Daño por Reperfusión/prevención & control , Isquemia Tibia/efectos adversos , Animales , Modelos Animales de Enfermedad , Hígado Graso/complicaciones , Hígado Graso/diagnóstico , Hígado/patología , Daño por Reperfusión/diagnóstico , Daño por Reperfusión/etiología , Factores de Riesgo , Índice de Severidad de la Enfermedad
15.
Gut ; 63(5): 818-31, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-23929695

RESUMEN

BACKGROUND: Diabetes mellitus (DM) is common in the general population and it poses a heavy burden to society in the form of long-term disability, healthcare use and costs. The pancreas is a key player in glucose homeostasis, but the occurrence of newly diagnosed DM after acute pancreatitis (AP), the most frequent disease of the pancreas, has never been assessed systematically. The aim of this study was to conduct a systematic literature review to determine the prevalence and time course of DM and related conditions after the first attack of AP as well as the impact of covariates. METHODS: Relevant literature cited in three electronic databases (Scopus, EMBASE and MEDLINE) was reviewed independently by two authors. The main outcome measures studied were newly diagnosed prediabetes, DM, or DM treated with insulin. Pooled prevalence and 95% CIs were calculated for all outcomes. RESULTS: A total of 24 prospective clinical studies, involving 1102 patients with first episode of AP, met all the eligibility criteria. Prediabetes and/or DM was observed in 37% (95% CI 30% to 45%) individuals after AP. The pooled prevalence of prediabetes, DM and treatment with insulin after AP was 16% (95% CI 9% to 24%), 23% (95% CI 16% to 31%), and 15% (95% CI 9% to 21%), respectively. Newly diagnosed DM developed in 15% of individuals within 12 months after first episode of AP and the risk increased significantly at 5 years (relative risk 2.7 (95% CI 1.9 to 3.8)). A similar trend was observed with regard to treatment with insulin. The severity of AP, its aetiology, individuals' age and gender had minimal effect on the studied outcomes. CONCLUSIONS: Patients with AP often develop prediabetes and/or DM after discharge from hospital, and have a greater than twofold increased risk of DM over 5 years. Further studies are warranted to determine the optimal strategy for its detection and whether the risk of developing DM after AP can be reduced.


Asunto(s)
Diabetes Mellitus Tipo 1/etiología , Diabetes Mellitus Tipo 2/etiología , Pancreatitis/complicaciones , Estado Prediabético/etiología , Diabetes Mellitus Tipo 1/epidemiología , Diabetes Mellitus Tipo 2/epidemiología , Humanos , Modelos Estadísticos , Prevalencia
16.
Liver Transpl ; 20(3): 281-90, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24395145

RESUMEN

The effects of pretransplant obesity, diabetes mellitus (DM), coronary artery disease (CAD), and hypertension (HTN) on outcomes after liver transplantation (LT) are controversial. Questions have also been raised about the appropriateness of the body mass index (BMI) for assessing obesity in patients with end-stage liver disease. Both issues have implications for organ allocation in LT. To address these questions, we undertook a cohort study of 202 consecutive patients (2000-2010) undergoing LT at a national center in New Zealand. BMI and body fat percentage (%BF) values (dual-energy X-ray absorptiometry) were measured before transplantation, and the methods were compared. The influence of pretransplant risk variables (including obesity, DM, CAD, and HTN) on the 30-day postoperative event rate, length of hospital stay, and survival were analyzed. There was agreement between the calculated BMI and the measured %BF for 86.0% of the study population (κ coefficient = 0.73, 95% confidence interval = 0.61-0.85), and this was maintained across increasing Model for End-Stage Liver Disease scores. Obesity was an independent risk factor for the postoperative event rate [count ratio (CR) = 1.03, P < 0.001], as was DM (CR = 1.4, P < 0.001). Obesity with concomitant DM was the strongest predictor of the postoperative event rate (CR = 1.75, P < 0.001) and a longer hospital stay (5.81 days, P < 0.01). Independent metabolic risk factors had no effect on 30-day, 1-year, or 5-year patient survival. In conclusion, BMI is an adequate tool for assessing obesity-associated risk in LT. Early post-LT morbidity is highest for patients with concomitant obesity and DM, although these factors do not appear to influence recipient survival.


Asunto(s)
Enfermedades Cardiovasculares/complicaciones , Complicaciones de la Diabetes , Enfermedad Hepática en Estado Terminal/complicaciones , Enfermedad Hepática en Estado Terminal/cirugía , Trasplante de Hígado , Obesidad/complicaciones , Adulto , Anciano , Índice de Masa Corporal , Enfermedad Hepática en Estado Terminal/mortalidad , Femenino , Fibrosis/complicaciones , Fibrosis/cirugía , Hepatitis C/complicaciones , Hepatitis C/cirugía , Humanos , Tiempo de Internación , Masculino , Persona de Mediana Edad , Nueva Zelanda , Estudios Retrospectivos , Factores de Riesgo , Resultado del Tratamiento , Adulto Joven
17.
Cardiovasc Diabetol ; 13: 100, 2014 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-24927960

RESUMEN

BACKGROUND: Heart disease is the leading cause of death in diabetic patients, and defective copper metabolism may play important roles in the pathogenesis of diabetic cardiomyopathy (DCM). The present study sought to determine how myocardial copper status and key copper-proteins might become impaired by diabetes, and how they respond to treatment with the Cu (II)-selective chelator triethylenetetramine (TETA) in DCM. METHODS: Experiments were performed in Wistar rats with streptozotocin (STZ)-induced diabetes with or without TETA treatment. Cardiac function was analyzed in isolated-perfused working hearts, and myocardial total copper content measured by particle-induced x-ray emission spectroscopy (PIXE) coupled with Rutherford backscattering spectrometry (RBS). Quantitative expression (mRNA and protein) and/or activity of key proteins that mediate LV-tissue-copper binding and transport, were analyzed by combined RT-qPCR, western blotting, immunofluorescence microscopy, and enzyme activity assays. Statistical analysis was performed using Student's t-tests or ANOVA and p-values of < 0.05 have been considered significant. RESULTS: Left-ventricular (LV) copper levels and function were severely depressed in rats following 16-weeks' diabetes, but both were unexpectedly normalized 8-weeks after treatment with TETA was instituted. Localized myocardial copper deficiency was accompanied by decreased expression and increased polymerization of the copper-responsive transition-metal-binding metallothionein proteins (MT1/MT2), consistent with impaired anti-oxidant defences and elevated susceptibility to pro-oxidant stress. Levels of the high-affinity copper transporter-1 (CTR1) were depressed in diabetes, consistent with impaired membrane copper uptake, and were not modified by TETA which, contrastingly, renormalized myocardial copper and increased levels and cell-membrane localization of the low-affinity copper transporter-2 (CTR2). Diabetes also lowered indexes of intracellular (IC) copper delivery via the copper chaperone for superoxide dismutase (CCS) to its target cuproenzyme, superoxide dismutase-1 (SOD1): this pathway was rectified by TETA treatment, which normalized SOD1 activity with consequent bolstering of anti-oxidant defenses. Furthermore, diabetes depressed levels of additional intracellular copper-transporting proteins, including antioxidant-protein-1 (ATOX1) and copper-transporting-ATPase-2 (ATP7B), whereas TETA elevated copper-transporting-ATPase-1 (ATP7A). CONCLUSIONS: Myocardial copper deficiency and defective cellular copper transport/trafficking are revealed as key molecular defects underlying LV impairment in diabetes, and TETA-mediated restoration of copper regulation provides a potential new class of therapeutic molecules for DCM.


Asunto(s)
Membrana Celular/metabolismo , Quelantes/uso terapéutico , Cobre/metabolismo , Diabetes Mellitus Experimental/metabolismo , Cardiomiopatías Diabéticas/metabolismo , Animales , Membrana Celular/efectos de los fármacos , Quelantes/farmacología , Cobre/deficiencia , Diabetes Mellitus Experimental/tratamiento farmacológico , Cardiomiopatías Diabéticas/tratamiento farmacológico , Masculino , Ratas , Ratas Wistar
18.
Pancreatology ; 14(6): 436-43, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25455539

RESUMEN

BACKGROUND AND AIM: Extra-pancreatic infectious complications in acute pancreatitis increase morbidity, but their incidence and association with infected pancreatic necrosis is unknown. Half of bacterial cultures of pancreatic necrosis are of non-enteric origin, raising the possibility of other sources of infection. The aim of this systematic review was to assess the incidence of extra-pancreatic infectious complications in acute pancreatitis, their timing, and relation to severity of pancreatitis and mortality. METHODS: A systematic review was performed using Ovid MEDLINE, Embase and Cochrane Libraries, following PRISMA guidelines. Search terms were "Pancreatitis" AND "Infection" AND ("Complication" OR "Outcome"). RESULTS: 19 studies with 1741 patients were included. Extra-pancreatic infectious complication incidence was 32% (95% CI 23-41%), with the commonest being respiratory infection (9.2%) and bacteraemia (8.4%). Extra-pancreatic infectious complications were not associated with the predicted severity or the mortality of acute pancreatitis. Only 3 studies reported a relation of timing between extra-pancreatic and pancreatic infectious complications. CONCLUSIONS: This is the first systematic review to evaluate the incidence of extra-pancreatic infectious complications in acute pancreatitis, which a third of patients with acute pancreatitis will develop. Implications are vigilance and prompt treatment of extra-pancreatic infection, to reduce possibility of progression to infected pancreatic necrosis.


Asunto(s)
Infecciones/complicaciones , Pancreatitis/complicaciones , Enfermedad Aguda , Humanos , Incidencia , Infecciones/epidemiología , Infecciones/mortalidad , Pancreatitis/mortalidad , Pancreatitis Aguda Necrotizante/complicaciones , Resultado del Tratamiento
19.
Microorganisms ; 12(2)2024 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-38399697

RESUMEN

Cancer therapies developed using bacteria and their components have been around since the 19th century. Compared to traditional cancer treatments, the use of bacteria-derived compounds as cancer therapeutics could offer a higher degree of specificity, with minimal off-target effects. Here, we explored the use of soluble bacteria-derived toxins as a potential squamous cell carcinoma (SCC) therapeutic. We optimized a protocol to generate Staphylococcus aureus biofilm-conditioned media (BCM), where soluble bacterial products enriched in the development of biofilms were isolated from a bacterial culture and applied to SCC cell lines. Bioactive components of S. aureus ATCC 29213 (SA29213) BCM display selective toxicity towards cancerous human skin SCC-12 at low doses, while non-cancerous human keratinocyte HaCaT and fibroblast BJ-5ta are minimally affected. SA29213 BCM treatment causes DNA damage to SCC-12 and initiates Caspase 3-dependent-regulated cell death. The use of the novel SA29213 bursa aurealis transposon mutant library led to the identification of S. aureus alpha hemolysin as the main bioactive compound responsible for the observed SCC-12-specific toxicity. The antibody neutralisation of Hla eradicates the cytotoxicity of SA29213 BCM towards SCC-12. Hla displays high SCC-12-specific toxicity, which is exerted primarily through Hla-ADAM10 interaction, Hla oligomerisation, and pore formation. The high target specificity and potential to cause cell death in a controlled manner highlight SA29213 Hla as a good candidate as an alternative SCC therapeutic.

20.
Biomech Model Mechanobiol ; 23(1): 3-22, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37902894

RESUMEN

Historically, research into the lymphatic system has been overlooked due to both a lack of knowledge and limited recognition of its importance. In the last decade however, lymphatic research has gained substantial momentum and has included the development of a variety of computational models to aid understanding of this complex system. This article reviews existing computational fluid dynamic models of the lymphatics covering each structural component including the initial lymphatics, pre-collecting and collecting vessels, and lymph nodes. This is followed by a summary of limitations and gaps in existing computational models and reasons that development in this field has been hindered to date. Over the next decade, efforts to further characterize lymphatic anatomy and physiology are anticipated to provide key data to further inform and validate lymphatic fluid dynamic models. Development of more comprehensive multiscale- and multi-physics computational models has the potential to significantly enhance the understanding of lymphatic function in both health and disease.


Asunto(s)
Hidrodinámica , Vasos Linfáticos , Sistema Linfático/fisiología , Vasos Linfáticos/fisiología , Simulación por Computador , Física
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA