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1.
Curr Probl Cancer ; 46(2): 100793, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-34565601

RESUMEN

For patients with refractory metastatic colorectal cancer (mCRC) treatment with Trifluridine/Tipiracil, also known as TAS-102, improves overall survival. This study aims to investigate the efficacy and safety of TAS-102 in a real-world population from Victoria, Australia. A retrospective analysis of prospectively collected data from the Treatment of Recurrent and Advanced Colorectal Cancer (TRACC) registry was undertaken. The characteristics and outcomes of patients receiving TAS-102 were assessed and compared to those enrolled in the registration study (RECOURSE). Across 13 sites, 107 patients were treated with TAS-102. The median age was 60 years (range: 31-83), compared to 63 for RECOURSE. Comparing registry TAS-102-treated and RECOURSE patients, 75% vs 100% were ECOG performance status 0-1, 74% vs 79% had initiated treatment more than 18 months from diagnosis of metastatic disease and 36% vs 49% were RAS wild-type. Median time on treatment was 10.4 weeks (range: 1.7-32). Median progression-free survival (PFS) was 3.3 months compared to 2 months in RECOURSE, while median overall survival was the same at 7.1 months. Two patients (2.3%) had febrile neutropenia and there were no treatment-related deaths, where TAS-102 dose at treatment initiation was at clinician discretion.TRACC registry patients treated with TAS-102 were younger than those from the RECOURSE trial, with similar overall survival observed. Less strict application of RECIST criteria and less frequent imaging may have contributed to an apparently longer PFS.


Asunto(s)
Neoplasias del Colon , Neoplasias Colorrectales , Neoplasias del Recto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Australia , Neoplasias del Colon/tratamiento farmacológico , Neoplasias Colorrectales/patología , Combinación de Medicamentos , Humanos , Persona de Mediana Edad , Recurrencia Local de Neoplasia/tratamiento farmacológico , Pirrolidinas , Estudios Retrospectivos , Timina/uso terapéutico , Trifluridina/uso terapéutico , Uracilo/uso terapéutico
3.
Clin Hemorheol Microcirc ; 61(3): 439-44, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25335813

RESUMEN

AIMS: To evaluate endothelial-dependent and - independent cutaneous vasodilator responses in the feet of patients with peripheral arterial disease (PAD) with or without Type 2 diabetes. METHODS: Cutaneous microvascular responses in the dorsum of both lower limbs were measured in the supine position using Laser Doppler Fluximetry combined with iontophoretic administration of endothelial-dependent (acetylcholine, Ach) and -independent (sodium nitroprusside, SNP) vasodilators in diabetic (n = 19) and non diabetic (n = 17) patients with PAD (presenting as unilateral calf intermittent claudication (IC). RESULTS: In patients with diabetes and IC, endothelial-dependent vasodilation was significantly impaired in the symptomatic limb [74 (57,105) vs 68 (24,81) PU, Z =-2.79, p = 0.005] compared to the asymptomatic limb. Patients without diabetes showed no impairment of vasodilation. Resting ankle-brachial pressure index did not identify the presence of abnormalities in microvascular function. CONCLUSIONS: The combination of diabetes and PAD is associated with a reduction in endothelial-dependent cutaneous vasodilation in the feet without an associated reduction in endothelial independent vasodilation.


Asunto(s)
Complicaciones de la Diabetes , Diabetes Mellitus Tipo 2/metabolismo , Pie/patología , Claudicación Intermitente/etiología , Microcirculación/fisiología , Enfermedad Arterial Periférica/etiología , Piel/irrigación sanguínea , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Vasodilatación/fisiología
4.
Dis Colon Rectum ; 54(5): 518-25, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21471751

RESUMEN

BACKGROUND: Complete pathological response has proven prognostic benefits in patients with locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy. Sequential 18-FDG PET may be an early surrogate for pathological response to chemoradiotherapy. OBJECTIVES: The aim of this study was to identify whether metabolic response measured by FDG PET following chemoradiotherapy is prognostic for tumor recurrence and survival following neoadjuvant therapy and surgical treatment for primary rectal cancer. METHODS: Patients with primary rectal cancer treated by long-course neoadjuvant chemoradiotherapy followed by surgery had FDG PET performed before and 4 weeks after treatment, before surgical resection was performed. Retrospective chart review was undertaken for patient demographics, tumor staging, recurrence rates, and survival. RESULTS: : Between 2000 and 2007, 78 patients were identified (53 male, 25 female; median age, 64 y). After chemoradiotherapy, 37 patients (47%) had a complete metabolic response, 26 (33%) had a partial metabolic response, and 14 (18%) had no metabolic response as assessed by FDG PET (1 patient had missing data). However, only 4 patients (5%) had a complete pathological response. The median postoperative follow-up period was 3.1 years during which 14 patients (19%) had a recurrence: 2 local, 9 distant, and 3 with both local and distant. The estimated percentage without recurrence was 77% at 5 years (95% CI 66%-89%). There was an inverse relationship between FDG PET metabolic response and the incidence of recurrence within 3 years (P = .04). Kaplan-Meier analysis of FDG PET metabolic response and overall survival demonstrated a significant difference in survival among patients in the 3 arms: complete, partial, and no metabolic response (P = .04); the patients with complete metabolic response had the best prognosis. CONCLUSION: Complete or partial metabolic response on PET following neoadjuvant chemoradiotherapy and surgery predicts a lower local recurrence rate and improved survival compared with patients with no metabolic response. Metabolic response may be used to stratify prognosis in patients with rectal cancer.


Asunto(s)
Antineoplásicos/uso terapéutico , Fluorodesoxiglucosa F18/farmacocinética , Tomografía de Emisión de Positrones/métodos , Neoplasias del Recto/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Radiofármacos/farmacocinética , Radioterapia Adyuvante , Neoplasias del Recto/diagnóstico por imagen , Neoplasias del Recto/terapia , Resultado del Tratamiento
5.
Colorectal Dis ; 13(3): 337-40, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19895600

RESUMEN

AIM: Digital rectal examination (DRE) is an essential skill which all newly qualified doctors should have. There is evidence in the literature that junior doctors lack this important examination technique. The aim of our study was to determine, with the help of a questionnaire, the abilities of foundation year 1 (FY1) doctors to perform DRE. METHOD: A questionnaire was developed and sent to newly qualified FY1 doctors qualified in two universities (Nottingham and Sheffield) within the first 4 weeks of starting as a FY1 doctor. RESULTS: Ninety (75%) out of 120 questionnaires were completed. Most FY1 doctors had very little experience in performing DRE on a patient, and 68 (76%) had performed less than 10 procedures prior to qualification. Very few of these doctors had their clinical findings on DRE checked by a senior doctor (n = 7, 8%). Comparing DRE with other forms of examination, newly qualified doctors were most confident at groin hernia examination followed by testicular examination. They were least confident with vaginal examination and DRE (ANOVA P = 0.0082). CONCLUSION: Digital rectal examination is frequently performed by the most inexperienced doctor and may not be verified by a more senior colleague. More training and supervision of junior doctors are required both prior to qualification and during the early stages of their medical career.


Asunto(s)
Competencia Clínica/estadística & datos numéricos , Tacto Rectal/estadística & datos numéricos , Médicos/estadística & datos numéricos , Enfermedades del Recto/diagnóstico , Análisis de Varianza , Educación de Postgrado en Medicina/normas , Educación de Pregrado en Medicina/normas , Inglaterra , Femenino , Humanos , Masculino , Encuestas y Cuestionarios
6.
Minerva Chir ; 65(2): 161-71, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20548272

RESUMEN

Intraoperative radiotherapy (IORT) is a highly specialized component of multidisciplinary management of advanced and recurrent colorectal cancer. The aim of this review was to assess its role and effectiveness in the management of colorectal cancer. A literature search was performed using Medline, Embase, Ovid and Cochrane to identify English language studies which have used IORT in the multidisciplinary management of primary and recurrent colon and rectal cancers. Improved survival and local control in patients with involved surgical margins treated with IORT have been shown in many studies, but these results have been mainly from retrospective studies. There is associated morbidity from IORT. IORT does have a role in the management of colorectal cancer. Further research needs to be performed to optimize the application of this therapy.


Asunto(s)
Neoplasias Colorrectales/radioterapia , Neoplasias Colorrectales/cirugía , Cuidados Intraoperatorios , Terapia Combinada , Humanos , Recurrencia Local de Neoplasia/radioterapia , Recurrencia Local de Neoplasia/cirugía
7.
Colorectal Dis ; 12(4): 363-6, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19220380

RESUMEN

OBJECTIVE: The current evidence for fibrin glue as a treatment for anal fistulae is mixed. This study reviews the experience of fibrin glue as a treatment for anal fistulae in a single tertiary referral centre and attempts to identify factors related to failure of therapy and the length of follow-up required. METHOD: Patients with fistulae in ano that were treated with fibrin glue between February 2004 and August 2008 were analysed. All procedures were performed by two colorectal consultants based at the Queens Medical Centre, Nottingham. All patients were followed-up to assess the outcome of this treatment. RESULTS: Forty patients (21 male, 19 female) with a mean age of 46.5 years were studied. The mean duration of symptoms prior to presentation was 39 months (range 4-240 months). Presenting symptoms included perianal discharge (72.5%), perianal abscess (57.5%), pain (12.5%), PR bleeding (7.5%), itching (5%) and urgency (2.5%). Patients had a minimum of two follow-up appointments and the median follow-up period was 5.2 months (range 1-16 months). Following MRI and operative assessment, 28 (70%) of the 40 fistulae were considered complex (high trans-sphincteric, extra-sphincteric, pouch-vaginal). Patients who had inflammatory bowel disease were classified as simple tracts but all failed to heal (three patients). Twenty of the complex fistulae failed to heal. Three patients who had repeat application of glue for their complex fistulae failed to heal on follow-up. Of the remaining 12 patients who had simple fistulae in ano, five (41.7%) healed completely. There were no complications such as abscess, related to treatment. All patients who were asymptomatic at 3 months did not develop any further recurrence. CONCLUSION: Fibrin glue is a simple treatment strategy, preserves sphincter function with minimal adverse side effects. It should therefore be considered as possible first line treatment in simple fistulae but it is less likely to be successful in complex or those fistulae associated with inflammatory bowel disease. Repeat gluing is unlikely to be successful. Fistulae that have failed to heal by 3 months will need further treatment.


Asunto(s)
Adhesivo de Tejido de Fibrina/uso terapéutico , Fístula Rectal/terapia , Adhesivos Tisulares/uso terapéutico , Adulto , Anciano , Legrado , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Fístula Rectal/cirugía , Adulto Joven
8.
Colorectal Dis ; 11(5): 527-30, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19175629

RESUMEN

OBJECTIVE: Laparoscopic surgery for colorectal cancer is now widespread. Small lesions in the colon can be difficult to palpate and with lack of tactile sensation, it is essential to accurately localize them preoperatively. This is a review article on current methods of tattooing including the use of different agents and associated complications. Aim To review current techniques in preoperative tumour localization and methods used for colonic tattooing including agents used, dosage and potential complications. METHOD: A literature search (Medline and Pubmed) was performed with manual cross referencing of all articles related to colonic tattooing. RESULTS: Methods for localizing colonic tumours for laparoscopic resection include preoperative barium enema examination, CT colonography and intraoperative colonoscopy. The most effective method is, however, by tattooing with India ink performed endoscopically before surgery. CONCLUSION: India ink is a reliable method of marking tumour location within the colon as prelude to laparoscopic resection. Surgeons must, however, be aware of potential complications associated with this technique.


Asunto(s)
Neoplasias del Colon/cirugía , Tatuaje/métodos , Carbono/efectos adversos , Colonoscopía , Colorantes/efectos adversos , Humanos , Tatuaje/efectos adversos
9.
J Wound Care ; 17(10): 437-40, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18947022

RESUMEN

A survey of community nurses identified that a wide range of dressings, and in some cases unethical practices, are being used for this simple postoperative condition. Communication between hospital, community staff and patients was poor.


Asunto(s)
Absceso/enfermería , Vendajes , Enfermería en Salud Comunitaria , Enfermedades del Recto/enfermería , Alginatos , Carboximetilcelulosa de Sodio , Manejo de la Enfermedad , Drenaje , Inglaterra , Encuestas de Atención de la Salud , Humanos , Apósitos Oclusivos , Encuestas y Cuestionarios
10.
Eur J Vasc Endovasc Surg ; 31(4): 434-8, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16359882

RESUMEN

OBJECTIVES: To evaluate the effects of varicose vein surgery on cutaneous microvascular perfusion and vasodilator responses to acetylcholine (Ach) and sodium nitroprusside (SNP) in the gaiter area of patients with great saphenous vein insufficiency. METHODS: Twenty-nine patients with isolated great saphenous vein incompetence attended three study mornings (before surgery, and 6-8 weeks and 6 months after sapheno-femoral ligation+partial stripping) during which cutaneous microvascular responses were measured in the supine and standing positions using laser Doppler fluximetry (LDF) combined with incremental-dose iontophoretic administration of endothelial-dependent (Ach) and -independent (SNP) vasodilators. RESULTS: Varicose vein surgery had no significant effect on baseline cutaneous perfusion or the microvascular response to Ach: e.g. peak vasodilator responses to the 1000 microC stimulus were mean 58 SEM 7, 64 SEM 6 and 65 SEM 7PU on the pre-operative, 6-8 weeks and 6 months assessments. In contrast, the corresponding responses to SNP were significantly increased following surgery: e.g. at 2000 microC, mean 63 SEM 9, 142 SEM 4 and 157 SEM 9PU (p<0.0001) in the upright position. CONCLUSIONS: Sapheno-femoral ligation and partial stripping in patients with great saphenous vein insufficiency improves endothelial-independent cutaneous vasodilator function at the gaiter area, which may at least partly explain the benefits of surgery in reducing the risk of venous ulceration.


Asunto(s)
Tobillo/irrigación sanguínea , Endotelio Vascular/efectos de los fármacos , Piel/irrigación sanguínea , Várices/cirugía , Vasodilatación/fisiología , Vasodilatadores/farmacología , Acetilcolina/farmacología , Endotelio Vascular/fisiopatología , Femenino , Humanos , Iontoforesis , Masculino , Persona de Mediana Edad , Nitroprusiato/farmacología , Postura , Vena Safena , Várices/fisiopatología , Insuficiencia Venosa/fisiopatología , Insuficiencia Venosa/cirugía
11.
Scott Med J ; 50(1): 22-3, 2005 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15792384

RESUMEN

BACKGROUND: Although the surgical treatment of in-growing toenails is a common procedure, the success of ingrown toenail surgery is extremely variable and recurrences frequently impair the quality of lift of those who have this condition. In most hospitals this procedure is commonly performed by junior surgical trainees who may have little experience. AIM: We proposed to find out if the success of this procedure is operator-dependent by comparing the results of standard of toenail surgery performed by basic surgical trainees (BSTs) in our hospitals with already published data. METHODS: A retrospective analysis of nail bed ablation surgery performed by BSTs under local anaesthesia over a 15-month period in a district general hospital was conducted. RESULTS: 106 phenol ablations and 46 germinal matrix excisions were prformed. Symptomatic recurrence rates 12 months following the procedure were 5.7% for phenol ablation and 4.3% for germinal matrix excisions. CONCLUSION: Our results are comparable to published data, and we conclude that toenail ablation surgery can be just as successfully performed by junior surgeons after relatively little training in the procedure.


Asunto(s)
Competencia Clínica/normas , Cuerpo Médico de Hospitales/normas , Uñas Encarnadas/cirugía , Humanos , Estudios Retrospectivos , Resultado del Tratamiento
12.
Eur J Vasc Endovasc Surg ; 26(1): 100-4, 2003 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12819656

RESUMEN

OBJECTIVES: To assess the effects of posture, endothelial function and venous insufficiency on cutaneous microvascular vasodilator function in the gaiter area, in particular defining factors which may affect microangiopathy and ulcer formation. METHODS: Endothelial-dependent and -independent vasodilator responses to incremental-doses of acetylcholine (Ach) and sodium nitroprusside (SNP) were evaluated in the perimalleolar region in the supine and standing positions in middle-aged patients with isolated superficial venous insufficiency (ISVI) (n = 25) and healthy controls (n = 28) using laser Doppler fluximetry (LDF) and iontophoresis of vasodilators. RESULTS: The venoarteriolar reflex (vasoconstriction on standing) was equally present in both groups, and reduced the vasodilator responses to SNP in the upright position (e.g., for patients with ISVI, peak SNP response was 82 +/- 11 PU [standing] vs 123 +/- 15 PU [supine]). The presence of ISVI had no effect on endothelial vasodilator function in the supine position, but on standing cutaneous reactivity to Ach was significantly reduced (e.g., peak Ach response 69 +/- 8 PU [ISVI] vs 109 +/- 11 PU [controls], p < 0.003). CONCLUSIONS: Upright posture impairs cutaneous endothelial-dependent vasodilation in the gaiter area of patients with ISVI. This may be of clinical and prognostic utility in identifying which patients with uncomplicated ISVI are at highest risk of tissue breakdown and ulcer formation in the gaiter area.


Asunto(s)
Tobillo/irrigación sanguínea , Endotelio Vascular/fisiopatología , Piel/irrigación sanguínea , Vasodilatación/fisiología , Insuficiencia Venosa/fisiopatología , Acetilcolina/farmacología , Adulto , Anciano , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Iontoforesis , Flujometría por Láser-Doppler , Masculino , Microcirculación , Persona de Mediana Edad , Nitroprusiato/farmacología , Postura , Vasodilatación/efectos de los fármacos , Vasodilatadores/farmacología
13.
Eur J Vasc Endovasc Surg ; 24(1): 69-71, 2002 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12127851

RESUMEN

OBJECTIVES: the tissue renin-angiotensin system (RAS), which plays an important role in vascular structure and function, is regulated in part by an insertion-deletion polymorphism of the angiotensin converting enzyme (ACE) gene. We hypothesised that ACE genotype might affect rate of AAA expansion via modulating long-term structural changes associated with RAS activation. METHODS: fifty-eight patients (50 M, mean age 70 years, mean initial aneurysm size 4.3 cm) with current or previous AAA and serial (>3) annual ultrasound measurements of antero-posterior AAA size provided a sample of leucocyte DNA for ACE genotyping. AAA expansion rate (cm per year) for individual subjects was calculated by linear regression. RESULTS: median AAA expansion rate was 0.28 cm/year (range 0-1.8 cm/year), and the genotype distribution included DD (n=14), DI (n=29) and II (n=15). Corresponding median AAA expansion rates for each of the three genetic subgroups were 0.22, 0.32 and 0.30 cm/year, respectively (p=0.6, nonparametric). CONCLUSIONS: the wide inter-individual variability in AAA expansion rate is likely to reflect complex genetic and environmental interactions, but the lack of any relationship with ACE genotype suggests that differences in vascular ACE activity in aortic tissue are not major determinants of the variability in rate of AAA dilatation.


Asunto(s)
Aneurisma de la Aorta Abdominal/genética , Aneurisma de la Aorta Abdominal/fisiopatología , Peptidil-Dipeptidasa A/genética , Polimorfismo Genético , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos
14.
Eur J Vasc Endovasc Surg ; 23(2): 100-7, 2002 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11863326

RESUMEN

Atherosclerotic peripheral arterial disease (PAD) is a common disorder usually associated with silent or symptomatic arterial disease elsewhere in the circulation and a cluster of cardiovascular risk factors inducing atheroma progression and/or thrombotic complications. Because of these strong clinical associations, especially with coronary heart disease, the ankle-brachial pressure index (ABPI) is of prognostic significance. The clinical management of IC should include relief of symptoms combined with prevention of secondary cardiovascular complications, e.g. acute thrombotic events causing limb- or life-threatening ischaemia, which are often due to atherosclerotic plaque rupture leading to thrombotic vessel occlusion. Many patients with PAD do not receive an optimum package of secondary prevention, tailored to include maximum cholesterol reduction, BP and glycaemic control, ACE inhibition and single or combination anti-platelet therapy. This review considers recent information from large secondary prevention trials, e.g. the PAD subgroups within the HOPE, CAPRIE and statin studies. Slowing progression of atherosclerosis, and inducing stabilisation and regression of atheromatous plaques, is now feasible using long-term combination drug therapy. The phrase angle quotation mark, leftangle quotation mark, leftconservative therapyangle quotation mark, rightangle quotation mark, right, popular among vascular surgeons, implies a passive minimal-intervention strategy of surveillance and lifestyle advice; such terminology is perhaps no longer appropriate since considerable improvements in survival are likely to accrue if all patients with PAD, especially those with low ABPI, receive vigorous, titrated medical therapies, tailored to individual patients, as part of an evidence-based secondary prevention regime.


Asunto(s)
Claudicación Intermitente/terapia , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Anticoagulantes/uso terapéutico , Aspirina/uso terapéutico , Presión Sanguínea/efectos de los fármacos , Enfermedad Coronaria/etiología , Enfermedad Coronaria/prevención & control , Predicción , Humanos , Hipolipemiantes/uso terapéutico , Claudicación Intermitente/complicaciones , Enfermedades Vasculares Periféricas/etiología , Enfermedades Vasculares Periféricas/prevención & control , Factores de Riesgo , Fumar/efectos adversos , Warfarina/uso terapéutico
16.
Neuroreport ; 12(2): 329-33, 2001 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-11209945

RESUMEN

Coordinated expression of Hoxa2, Hoxd1 and Pax6 proteins were found to coincide with the three developmental stages of the diencephalon, as described for the mouse brain. In the first stage (embryonic day (E) 10-12) Hoxa2, Hoxd1 and Pax6 (an early marker gene of the diencephalon) were expressed as early as E10.5 in prosomeres (p), p2 and p3. All three proteins continue to exhibit overlapping domains of expression at E12.5-13 (beginning of the second stage) when the primitive dense cell layer begins to differentiate into the internal germinal, external germinal and mantle layers. Towards the end of the second stage (E15), Pax6 expression was down-regulated whereas Hoxa2 and Hoxd1 continued to exhibit overlapping domains of expression for both protein and mRNA. Hoxd1 expression decreased significantly in the third stage of diencephalic development (E16-postnatal) such that only Hoxa2 expression persisted in the diencephalon of newborn mice. The temporal and spatial expression of these three proteins imply that coordinated waves of Hoxa2, Hoxd1 and Pax6 expression may be required to provide positional information for the specification of the diencephalon.


Asunto(s)
Diencéfalo/embriología , Regulación del Desarrollo de la Expresión Génica , Proteínas de Homeodominio/genética , Animales , Diencéfalo/química , Proteínas del Ojo , Proteínas de Homeodominio/análisis , Inmunohistoquímica , Hibridación in Situ , Ratones , Ratones Endogámicos , Factor de Transcripción PAX6 , Factores de Transcripción Paired Box , ARN Mensajero/análisis , Proteínas Represoras
17.
Methods ; 22(1): 77-91, 2000 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11020321

RESUMEN

Surface plasmon resonance (SPR) has been successfully incorporated into an immunosensor format for the simple, rapid, and nonlabeled assay of various biochemical analytes. Proteins, complex conjugates, toxins, allergens, drugs, and pesticides can be determined directly using either natural antibodies or synthetic receptors with high sensitivity and selectivity as the sensing element. Immunosensors are capable of real-time monitoring of the antigen-antibody reaction. A wide range of molecules can be detected with lower limits ranging between 10(-9) and 10(-13) mol/L. Several successful commercial developments of SPR immunosensors are available and their web pages are rich in technical information. This review highlights many recent developments in SPR-based immunoassay, functionalizations of the gold surface, novel receptors in molecular recognition, and advanced techniques for sensitivity enhancement. Furthermore, it describes the challenge of current problems and provides some insights toward the future technologies.


Asunto(s)
Inmunoensayo/instrumentación , Inmunoensayo/métodos , Resonancia por Plasmón de Superficie/instrumentación , Resonancia por Plasmón de Superficie/métodos , Anticuerpos/genética , Anticuerpos/inmunología , Antígenos/análisis , Antígenos/inmunología , Oro , Cinética , Ingeniería de Proteínas , Sensibilidad y Especificidad , Análisis Espectral
18.
J Food Prot ; 63(7): 982-6, 2000 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10914674

RESUMEN

The emergent health issue of food allergens presents an important challenge to the food industry. More than 170 foods have been reported in the scientific literature as causing allergic reactions. Clearly, it would be impossible to deal with the presence of trace amounts of all these in the context of food labeling. If the decision to classify major allergens is based solely on the knowledge and experience of allergists and food scientists in the field, without scientifically defined criteria, it is likely to lead to a proliferation of lists. Such practices may lead to an unnecessary elimination of foods containing important nutrients. This paper defines food allergy, food intolerance, and food anaphylaxis and identifies criteria for classifying food allergens associated with frequent allergic reactions. A practical list of food allergens that may result in potentially life-threatening allergic reactions is provided. A mechanism-based (i.e., immunoglobulin E mediated), acute life-threatening anaphylaxis that is standardized and measurable and reflects the severity of health risk is proposed as the principal inclusion criterion for food allergen labeling. Where available, prevalence in the population and threshold levels of allergens should be used as an additional guide to identify possible future labeling needs.


Asunto(s)
Alérgenos/efectos adversos , Dieta/efectos adversos , Hipersensibilidad a los Alimentos/etiología , Alérgenos/inmunología , Hipersensibilidad a los Alimentos/epidemiología , Hipersensibilidad a los Alimentos/inmunología , Hipersensibilidad a los Alimentos/prevención & control , Etiquetado de Alimentos/normas , Humanos , Inmunoglobulina E/biosíntesis , Prevalencia
19.
J AOAC Int ; 83(1): 139-43, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10693015

RESUMEN

An enzyme-linked immunosorbent assay (ELISA) was developed to determine the presence of egg proteins in foods. The polyclonal antibodies developed were specific to whole egg proteins and did not cross-react with any of the 38 nuts, legumes, or other common food ingredients tested. The concentrations of egg proteins that will inhibit 50% of antibody-antigen binding, IC50, were 3-7 ng/mL, and the linear range was 0.5-62.5 ng/mL. The detection limit was 0.2 ppm for various foods. Recoveries ranged from 67 to 96%. The intra- and inter-assay coefficients of variation in this procedure were 10-13% for ice cream spiked at 0.8 and 1.6 ppm. The ELISA has been applied to ice creams, noodles, pasta, and breads. Egg proteins were identified in all declared egg products, and no false positives were found.


Asunto(s)
Proteínas del Huevo/análisis , Ensayo de Inmunoadsorción Enzimática/métodos , Análisis de los Alimentos/métodos , Especificidad de Anticuerpos , Pan/análisis , Calor , Helados/análisis , Desnaturalización Proteica , Control de Calidad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
20.
Anal Biochem ; 258(2): 161-7, 1998 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-9570825

RESUMEN

A surface plasmon resonance (SPR) immunosensor is developed to determine concentrations of the mycotoxin, fumonisin B1 (FB1), in spiked samples. Polyclonal antibodies produced against FB1 are adsorbed onto a thin gold film substrate, which is coupled to a glass prism in the Kretschmann configuration. The output beam of a planar light-emitting diode is focused through the prism to excite SPR at the surface of the gold film. When a sample containing FB1 is added to a cell on the outside of the gold film, the angular profile of reflected light intensity shifts. This changes the resonance angle and the reflected beam intensity at a selected angle, both of which are proportional to the FB1 concentration. After optimization of the antibody overlayer, a detection limit of 50 ng/mL is obtained for the direct assay with an analysis time under 10 min. Multiple sample additions and large-volume sample circulation can be used with the high-affinity antibodies to achieve lower detection limits.


Asunto(s)
Técnicas Biosensibles , Ácidos Carboxílicos/análisis , Fumonisinas , Inmunoensayo/métodos , Análisis Espectral/métodos , Sensibilidad y Especificidad
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