Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
1.
Artículo en Inglés | MEDLINE | ID: mdl-38426124

RESUMEN

Purpose: Advanced practice (AP) in radiation therapy (RT) is being implemented around the globe. In an effort to advance the understanding of the similarities and differences in APRT roles in Ontario, Canada, a community of practice (CoP) sought ways to provide quantitative data on the nature of APRT clinical activities and the frequency with which these activities were being executed. Methods: In 2017, a consensus building project involving 20 APRTs and 14 radiation therapy (RT) department managers in Ontario was completed to establish a mechanism to quantify APRTs' clinical impact. In Round 1 & 2, expert feedback was gathered to generate an Advanced Practice (AP) Activity List. In Round 3: 20 APRTs completed an online survey to assess the importance and applicability of each AP Activity to their role using Likert scale (0-5). A final AP Activity List & Definitions was generated. Results & discussion: Round 1: Forty-seven AP activities were identified. Round 2: 3/14 RT managers provided 145 feedback statements on Round 1 AP Activity List. The working group used RT managers' feedback to clarify AP activities and definitions, specifically merging 33 unique AP activities to create 11 inclusive AP activities and eliminating 8 activities identified from Round 1. The most inclusive AP activity created was #1 New Patient Consultation, this AP Activity is merged from 7 unique AP activities. Incorporating RT managers' feedback with the internal AP clinical workload lists from 2 Ontario cancer centres resulted in a revised AP Activity List with 20 AP inclusive activities. Round 3: 14/20 APRTs provided Likert scores on this revised list. The most applicable AP activities (mean score) were #16 Technical Consultation (4.0), #15 Contouring Target Volume (3.8) and #2 Planning Consultation (3.8); the least applicable was #18 MR Applicator Assessment (0.9). Conclusions: This is the first systematic attempt to build consensus on AP clinical activities. Non-clinical APRT activities related to research, education, innovation, and program development were not in the scope of this project. The Final AP Activity List & Definitions serves as a framework that allows standardized and continuous monitoring of AP clinical activities and impact.

2.
Nurse Educ Today ; 136: 106134, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38387213

RESUMEN

BACKGROUND: Nursing students from diverse or equity backgrounds are less likely to possess the required skills to ensure success in their studies. This research explores the impact of embedded support on student learning in a first-year foundational subject, Contexts of Nursing, in an undergraduate nursing degree.t. METHODS: The Embedded Tutor Program offers specialised tutoring support for first-year undergraduate students. Embedded tutors, with backgrounds as registered nurses and academics, provided online one-on-one feedback to students on draft assessment tasks. Outreach contact was provided to students at risk of failing. A Pearson's Chi-squared test was used to assess the impact of tutor support on grade distribution and a paired student t-test was used to assess the difference in cumulative marks for students from equity backgrounds. Statistical significance was set at p < 0.05. Feedback provided by students, tutors and staff in an online anonymous survey was thematically analysed. RESULTS: There was a significant grade shift for the 267 students who met with an embedded tutor (p < 0.05). Students who were a member of an Australian Government identified equity group had a significant increase in their cumulative mark if they met with a tutor of 9-17 % (p < 0.05). This improvement in cumulative mark was maintained for students with cumulative equity factors. The overwhelming majority of students who were identified as at risk of failing and met with a tutor following outreach support received a passing grade. Students reported growing skills and confidence in academic literacy was a key benefit of the program. CONCLUSION: A shared approach to delivering education has a positive effect on the experience of learning. The combined efforts of the subject convenor, embedded tutors, and extended student service roles within the University resulted in outcomes that were positive for student learning. Determining student capacity for learning extended beyond a student's consideration of grades or their progression in the program to include the development of self-efficacy.


Asunto(s)
Bachillerato en Enfermería , Estudiantes de Enfermería , Humanos , Bachillerato en Enfermería/métodos , Australia , Aprendizaje , Curriculum
3.
Pract Radiat Oncol ; 13(6): 499-509, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37597616

RESUMEN

The proposed recommendations are primarily based on the consensus opinion and in-field experience of the Ontario Health/Cancer Care Ontario stereotactic body radiation therapy (SBRT) for Spine Metastasis Guideline Development Group and published literature when available. Primary consideration was given to the perceived benefits for patients and the small likelihood of harm arising from recommendation implementation. Apart from the magnetic resonance imaging (MRI) follow-up strategy, all evidence was considered indirect and was provided by the working group in conjunction with their collective expertise in the field of SBRT. The application of an SBRT program requires a multidisciplinary team consisting of a radiation oncologist, spine surgeon, neuroradiologist, medical physicist, medical dosimetrist, and radiation therapist. In Canada, linear accelerators are the most used treatment delivery units and should follow technology-specific quality assurance procedures. Immobilization technique is location dependant. Treatment planning MRI sequences should be acquired no more than 14 days from the date of treatment. In the case of epidural disease, simulation MRI should be completed no more than 7 days from the date of treatment. After treatment, patients should be followed with routine clinical visits every 3 months for the first year, every 3 to 6 months during years 2 and 3, and every 4 to 6 months thereafter. The recommendations enclosed provide a framework for the minimum requirements for a cancer center in Ontario, Canada to offer SBRT for spine metastases.


Asunto(s)
Radiocirugia , Neoplasias de la Columna Vertebral , Humanos , Radiocirugia/métodos , Ontario , Consenso , Neoplasias de la Columna Vertebral/secundario , Aceleradores de Partículas
4.
Curr Opin Support Palliat Care ; 17(1): 70-76, 2023 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-36695868

RESUMEN

PURPOSE OF REVIEW: The authors aimed to highlight trends in, and evidence underlying the use of highly conformal radiotherapy (RT) techniques in conventional nonstereotactic palliative RT. The authors reviewed palliative-intent and curative-intent studies relevant to the use of intensity-modulated radiation therapy (IMRT) for the delivery of nonstereotactic conventional regimens to the brain, head and neck, thorax, abdomen and pelvis, and bone metastases. RECENT FINDINGS: The use of IMRT has become standard with certain indications for brain metastases such as hippocampus-avoiding/limiting whole brain RT. IMRT in the treatment of bone metastases is increasing at many institutions despite limited data comparing its effectiveness with that of fluoroscopy-based and three-dimensional conformal radiation therapy techniques. There is scant data describing the use of IMRT for palliation in other extracranial anatomic sites; guidance for its use in these settings must be gleaned almost exclusively from curative-intent randomized trials, consensus recommendations and contouring atlases. SUMMARY: Consistent with historical technology shifts in RT practice, the uptake of highly conformal techniques such as IMRT for conventional palliative RT will likely outpace rigorous evaluations of their advantages and disadvantages relative to simpler techniques. Opportunities exist in virtually all anatomic sites for observational and randomized studies to evaluate the clinical impacts of these modern techniques in the palliative setting.


Asunto(s)
Enfermedades de la Médula Ósea , Neoplasias Encefálicas , Radioterapia Conformacional , Radioterapia de Intensidad Modulada , Humanos , Radioterapia de Intensidad Modulada/métodos , Radioterapia Conformacional/métodos , Cuidados Paliativos/métodos
5.
Med Sci Educ ; 31(5): 1703-1713, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34422452

RESUMEN

In view of the current situation with a worldwide pandemic, the use of online teaching has become critical. This is difficult in the context of human anatomy, a subject contingent primarily on the use of human cadaveric tissues for learning through face-to-face practical laboratory sessions. Although anatomy has been taught using online resources including 3D models and anatomy applications, feedback from students and academic staff does not support the replacement of face-to-face teaching. At Charles Sturt University, we were obligated to cancel all classes on-campus in 2020 due to the COVID-19 pandemic. We ran exclusive online anatomy practical classes replacing classes usually run on campus. We designed an alternative program that consisted of twenty pre-recorded videos that were prepared in the anatomy laboratory using cadaveric tissues, and then discussed in live (and interactive) tutorials. Furthermore, innovative approaches to learning were shown and encouraged by the lecturer. Student survey responses indicated a positive response to both the anatomical videos and the innovative learning approaches. The results obtained by students showed a statistically significant increase in high distinctions and marked decrease in the amount of fail grades, compared with the previous three years (not online). The use of these videos and the encouragement of innovative learning approaches was a novel experience that will add valuable experiences for improved practice in online anatomy teaching. We propose that online anatomy videos of cadavers combined with innovative approaches are an efficient and engaging approach to replace face-to-face anatomy teaching under the current contexts.

6.
J Dent Educ ; 85(7): 1309-1315, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33825184

RESUMEN

PURPOSE: Knowledge of normal tissue architecture is essential for one of the vitally important graduate competencies in dentistry, which is the recognition and appropriate referral of patients with oral mucosal and jawbone abnormalities for timely management and improved outcomes. The aim of this study was to examine the effect of online adaptive lessons on improving perceived and measured student performance, motivation, and student perceptions in dental education. METHODS: This mixed-method study was conducted on year 1 and year 3 undergraduate dental students. Adaptive lessons supplementing a number of histology topics were designed and made available. Adaptive lesson scores and analytics, exam scores on topics that were supplemented by adaptive lessons (Experimental Questions), and those that were not (Control Questions) were compared among the year 1 students (n = 43). A validated questionnaire including Likert-type scales about the student attitudes and perceptions toward adaptive lessons followed by open-ended questions was administered to year 1 and 3 students (n = 57). RESULTS: Students obtained significantly higher scores in experimental exam questions than control exam questions (p = 0.01). A significantly larger number of students perceived that the adaptive lessons improved their knowledge of the subject (p < 0.001). CONCLUSIONS: The adaptive lessons employed in this study showed significant potential to improve student engagement, motivation, perceived knowledge, and measured exam performance. These are particularly important findings especially amid the COVID-19 pandemic as institutions transitioned to online education in lieu of face-to-face classes to comply with recommendations from Health Authorities.


Asunto(s)
COVID-19 , Instrucción por Computador , Educación en Odontología , Evaluación Educacional , Humanos , Pandemias , SARS-CoV-2 , Estudiantes
7.
J Physiol ; 598(18): 3859-3870, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32588910

RESUMEN

KEY POINTS: AMP-activated protein kinase (AMPK) is considered a major regulator of skeletal muscle metabolism during exercise. However, we previously showed that, although AMPK activity increases by 8-10-fold during ∼120 min of exercise at ∼65% V̇O2peak in untrained individuals, there is no increase in these individuals after only 10 days of exercise training (longitudinal study). In a cross-sectional study, we show that there is also a lack of activation of skeletal muscle AMPK during 120 min of cycling exercise at 65% V̇O2peak in endurance-trained individuals. These findings indicate that AMPK is not an important regulator of exercise metabolism during 120 min of exercise at 65% V̇O2peak in endurance trained men. It is important that more energy is directed towards examining other potential regulators of exercise metabolism. ABSTRACT: AMP-activated protein kinase (AMPK) is considered a major regulator of skeletal muscle metabolism during exercise. Indeed, AMPK is activated during exercise and activation of AMPK by 5-aminoimidazole-4-carboxyamide-ribonucleoside (AICAR) increases skeletal muscle glucose uptake and fat oxidation. However, we have previously shown that, although AMPK activity increases by 8-10-fold during ∼120 min of exercise at ∼65% V̇O2peak in untrained individuals, there is no increase in these individuals after only 10 days of exercise training (longitudinal study). In a cross-sectional study, we examined whether there is also a lack of activation of skeletal muscle AMPK during 120 min of cycling exercise at 65% V̇O2peak in endurance-trained individuals. Eleven untrained (UT; V̇O2peak = 37.9 ± 5.6 ml.kg-1  min-1 ) and seven endurance trained (ET; V̇O2peak = 61.8 ± 2.2 ml.kg-1  min-1 ) males completed 120 min of cycling exercise at 66 ± 4% V̇O2peak (UT: 100 ± 21 W; ET: 190 ± 15 W). Muscle biopsies were obtained at rest and following 30 and 120 min of exercise. Muscle glycogen was significantly (P < 0.05) higher before exercise in ET and decreased similarly during exercise in the ET and UT individuals. Exercise significantly increased calculated skeletal muscle free AMP content and more so in the UT individuals. Exercise significantly (P < 0.05) increased skeletal muscle AMPK α2 activity (4-fold), AMPK αThr172 phosphorylation (2-fold) and ACCß Ser222 phosphorylation (2-fold) in the UT individuals but not in the ET individuals. These findings indicate that AMPK is not an important regulator of exercise metabolism during 120 min of exercise at 65% V̇O2peak in endurance trained men.


Asunto(s)
Proteínas Quinasas Activadas por AMP , Acetil-CoA Carboxilasa , Estudios Transversales , Ejercicio Físico , Humanos , Estudios Longitudinales , Masculino , Músculo Esquelético
8.
Support Care Cancer ; 28(9): 4487-4492, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31933067

RESUMEN

PURPOSE: International guidelines are available to guide prescription of antiemetic and pain flare medications in patients receiving palliative radiotherapy for bone metastases, but prescription rates are quite variable. We hypothesized that a simple electronic quality checklist could increase the evidence-based use of these medications. MATERIALS AND METHODS: We implemented an electronic quality checklist item in our center for all patients treated with palliative radiotherapy for lumbar spine bone metastases. We retrospectively reviewed patients in the 6-month pre- and post-intervention. Patients were stratified according to if they were treated within a dedicated rapid palliative (RPAL) radiotherapy program or not. Chi-square tests were used to compare rates of antiemetic and pain flare medications pre- and post-intervention and RPAL vs not. RESULTS: A total of 375 patients were identified with 42 (11.2%) treated in dedicated RPAL program. The proportion of patients treated with prophylactic antiemetic and pain flare medications pre-intervention (n = 226) and post-intervention (n = 149) was respectively 34.1% vs 59.1% (p < 0.001) and 26.1% vs 43.0% (p = 0.01). Observed differences for antiemetic prescription rates were greater for patients who were not treated within a dedicated palliative radiotherapy program, but this was not the case for pain flare medications. CONCLUSIONS: Our data shows that a simple quality checklist item can have a significant effect on the evidence-based use of prophylactic antiemetic and pain flare medications in patients treated with palliative radiotherapy for bone metastases. We believe such strategies should be routinely included in other clinical pathways to improve the use of symptom control medications.


Asunto(s)
Antieméticos/uso terapéutico , Neoplasias Óseas/radioterapia , Dolor/tratamiento farmacológico , Cuidados Paliativos/métodos , Radioterapia/métodos , Anciano , Antieméticos/farmacología , Neoplasias Óseas/secundario , Lista de Verificación , Femenino , Humanos , Masculino , Metástasis de la Neoplasia , Estudios Retrospectivos
9.
J Med Imaging Radiat Sci ; 50(4): 543-550, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31668680

RESUMEN

INTRODUCTION: A clinical specialist radiation therapist (CSRT) position in palliative radiation therapy (RT) was created at our institution. Herein, we report the details of the CSRT's orientation, training, and support program. METHODS: We performed an audit and needs assessment of palliative RT services at our centre. This identified opportunities for improvement that could be facilitated by the CSRT. We defined the CSRT job description including priority responsibilities: (1) optimizing palliative RT services for outpatients and developing a rapid access palliative RT program, (2) optimizing palliative RT services for inpatients at our institution, (3) improving links to community physicians and hospitals caring for patients with advanced cancers. We formed a core resource team to provide ongoing support and to design and implement the orientation and training program. The program involved training in clerical and administrative systems as well as treatment planning and physics training relevant to palliative RT. Clinical placements at several hospitals were arranged in both inpatient and outpatient settings. The CSRT worked with radiation and medical oncologists, palliative care specialists, nurse practitioners, hospitalists, and social workers. RESULTS: Through clinical placements and self-directed learning, the CSRT gained knowledge and competencies in patient care coordination, history taking and physical examination, clinical oncology practice including the evidence-based use of palliative RT and symptom control measures, treatment planning, communication, patient advocacy, and advance care planning. We provided practice resources including office space and a planning station, educational opportunities including workshops in palliative and psychosocial care, and research opportunities including methodologic and research ethics training. DISCUSSION: To our knowledge, this is the first detailed report of its kind for an advanced practice radiation therapy role. We hope our report will inform the design and implementation of programs elsewhere to help prepare individuals for similar roles in palliative RT. CONCLUSION: The CSRT in palliative RT at our institution underwent a comprehensive orientation and training program. Institutions with similar CSRT positions are encouraged to report the details of their own programs.


Asunto(s)
Competencia Clínica , Personal de Salud/educación , Aprendizaje , Cuidados Paliativos , Radiología/educación , Especialización/normas , Humanos
10.
Cureus ; 10(9): e3385, 2018 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-30524913

RESUMEN

We report the case of a woman who presented with breast cancer metastases to the femur causing pathologic fracture of the femoral neck requiring surgery. She received adjuvant radiotherapy to the femur at that time that did not include the surgical scar tract. Almost four years after her surgery she presented with biopsy proven skin recurrence of breast cancer on the skin overlying her incision from her femoral surgery. Further imaging confirmed significant soft-tissue disease involving the underlying surgical scar tract. This case provides important information about the possibility of surgical scar recurrence after surgery for bone metastases which could indicate the need to include the area of the surgical scar tract and the entire prosthetic material in the post-operative radiotherapy volume.

11.
Cureus ; 10(11): e3625, 2018 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-30697501

RESUMEN

Phenytoin toxicity occurs when serum levels exceed the therapeutic level, leading to symptoms such as nystagmus, slurred speech, and decreased coordination. This toxicity is sometimes caused by drug interactions. Interactions between phenytoin and capecitabine are not commonly documented. We report the case of a 52-year-old man taking phenytoin for atypical meningioma who developed symptoms of phenytoin toxicity while receiving capecitabine in the treatment of rectal adenocarcinoma.

12.
Adv Radiat Oncol ; 2(3): 381-390, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29114606

RESUMEN

PURPOSE: Whole brain radiation therapy (WBRT) remains the standard of care for patients with multiple brain metastases, but more than half of treated patients will develop intracranial progression. Because there is no clear consensus on the optimal therapeutic approach, a prognostic index would be helpful to guide treatment options at progression. We explored whether the recursive partitioning analysis (RPA) score prior to repeat WBRT is predictive of survival. METHODS AND MATERIALS: This multi-institutional pooled analysis included patients with 2 or more brain metastases from any solid primary tumor that was treated with 2 courses of WBRT. Information on demographics, disease characteristics, and intervals between courses was collected. RPA class was abstracted or retrospectively assigned, and descriptive statistics calculated. Median survival (MS) was determined using the Kaplan-Meier method and compared using log rank tests. Univariate and multivariate analyses were performed via Cox regression analysis. RESULTS: For 205 patients, the median age was 55 years (range, 25-83 years), 68% were female, 40.5% had non-small cell lung cancer, and 31.2% had small cell lung cancer. Prior to the second WBRT, 4.9% of patients were RPA class 1, 36.6% were RPA2, and 58.5% were RPA3, with an MS of 7.5 months (95% confidence interval [CI], 4.7-10.3), 5.2 months (95% CI, 3.7-6.7 months), and 2.9 months (95% CI, 2.2-2.9 months), respectively (P = .001). On univariate and multivariate analyses, a Karnofsky Performance Status of <80, extracranial metastases, interval between courses <9 months, small cell lung cancer histology, and uncontrolled primary significantly correlated with shorter MS. By assigning a score of 1 to each of these factors, a new prognostic index was created, the reirradiation (ReRT) score. Survival on the basis of ReRT score grouping ranged from 2.2 to 7.2 months and demonstrated significant differences in MS. CONCLUSIONS: In the largest reported cohort to receive repeat WBRT, application of the RPA score was not predictive of MS. The new ReRT score is a simple tool based on readily available clinical information.

13.
Cureus ; 9(6): e1407, 2017 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-28852603

RESUMEN

Pseudomyxoma peritonei (PP) is a rare clinical condition characterized by progressive mucinous ascites, which is typically caused by a mucin-producing neoplasm. Reports of radiation therapy (RT) in the management of PP are limited. We report a unique case of a 62-year-old woman with severe, end-stage, recurrent PP and a large, mucin-secreting mass protruding through her abdominal wall. Low-dose, hypofractionated palliative RT was administered for symptom control with the hope of improving her quality of life. We suggest that radiation therapy be considered in the comprehensive palliative management of patients with PP.

14.
Future Oncol ; 11(17): 2417-26, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26271002

RESUMEN

Palliating symptoms of advanced and metastatic cancers are one of the most common indications for radiation therapy (RT), and the demand for palliative RT is increasing. Dedicated rapid access palliative RT programs improve access to care, and can deliver RT in a more efficient and evidence-based manner than standard RT programs. In this narrative review, we discuss the role of palliative RT in comprehensive cancer care, and challenges that have faced patients trying to access it. We describe how rapid access programs developed to address these challenges and provide an overview of dedicated programs worldwide. Finally, we show how these programs can serve as models for multidisciplinary care and education, and sources of exciting research opportunities in clinical care and advanced technologies.


Asunto(s)
Accesibilidad a los Servicios de Salud , Modelos Teóricos , Neoplasias/epidemiología , Neoplasias/radioterapia , Cuidados Paliativos , Técnicos Medios en Salud , Conducta Cooperativa , Prestación Integrada de Atención de Salud , Necesidades y Demandas de Servicios de Salud , Humanos , Neoplasias/patología , Radioterapia/métodos
15.
Med Sci Sports Exerc ; 43(9): 1626-34, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21311355

RESUMEN

PURPOSE: We have previously shown that local infusion of a nitric oxide synthase (NOS) inhibitor attenuates increases in leg glucose uptake during exercise in humans. We have also shown that infusion of the NOS substrate, l-arginine (l-Arg), increases glucose clearance, although the mechanisms involved were not determined. A potential mechanism for NO-mediated glucose disposal is via interactions with NOS and the energy sensor AMP-activated protein kinase (AMPK). The aim of this study was to determine the mechanism(s) by which l-Arg infusion increases glucose disposal during exercise in humans by examining total NOS activity and AMPK signaling. METHODS: Seven males cycled for 120 min at 64% ± 1% VO(2)peak, during which the [6,6-H]glucose tracer was infused. During the final 60 min of exercise, either saline alone (Control, CON), or saline containing l-Arg HCl (l-Arg, 30 g at 0.5 g·min(-1)) was coinfused in a double-blind, randomized, counterbalanced order. RESULTS: l-Arg increased the glucose rate of disappearance and glucose clearance rate during exercise; however, this was accompanied by a 150% increase in plasma insulin concentration from 65 to 75 min (P < 0.05) that remained significantly elevated until 90 min of exercise. Skeletal muscle AMPK signaling, nNOSµ phosphorylation by AMPK, and total NOS activity increased to a similar extent in the two trials. CONCLUSIONS: The increase in glucose disposal after l-Arg infusion during exercise is likely due to the significantly higher plasma insulin concentration.


Asunto(s)
Arginina/administración & dosificación , Ejercicio Físico/fisiología , Glucosa/metabolismo , Proteínas Quinasas Activadas por AMP/metabolismo , Adulto , Prueba de Esfuerzo , Humanos , Infusiones Intravenosas , Insulina/sangre , Masculino , Óxido Nítrico Sintasa de Tipo I/metabolismo , Consumo de Oxígeno/efectos de los fármacos , Adulto Joven
16.
Am J Physiol Endocrinol Metab ; 291(3): E566-73, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16670154

RESUMEN

There is evidence that increasing carbohydrate (CHO) availability during exercise by raising preexercise muscle glycogen levels attenuates the activation of AMPKalpha2 during exercise in humans. Similarly, increasing glucose levels decreases AMPKalpha2 activity in rat skeletal muscle in vitro. We examined the effect of CHO ingestion on skeletal muscle AMPK signaling during exercise in nine active male subjects who completed two 120-min bouts of cycling exercise at 65 +/- 1% V(O2 peak). In a randomized, counterbalanced order, subjects ingested either an 8% CHO solution or a placebo solution during exercise. Compared with the placebo trial, CHO ingestion significantly (P < 0.05) increased plasma glucose levels and tracer-determined glucose disappearance. Exercise-induced increases in muscle-calculated free AMP (17.7- vs. 11.8-fold), muscle lactate (3.3- vs. 1.8-fold), and plasma epinephrine were reduced by CHO ingestion. However, the exercise-induced increases in skeletal muscle AMPKalpha2 activity, AMPKalpha2 Thr(172) phosphorylation and acetyl-CoA Ser(222) phosphorylation, were essentially identical in the two trials. These findings indicate that AMPK activation in skeletal muscle during exercise in humans is not sensitive to changes in plasma glucose levels in the normal range. Furthermore, the rise in plasma epinephrine levels in response to exercise was greatly suppressed by CHO ingestion without altering AMPK signaling, raising the possibility that epinephrine does not directly control AMPK activity during muscle contraction under these conditions in vivo.


Asunto(s)
Carbohidratos de la Dieta/farmacología , Ejercicio Físico/fisiología , Complejos Multienzimáticos/metabolismo , Músculo Esquelético/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Quinasas Activadas por AMP , Acetil-CoA Carboxilasa/metabolismo , Adenosina Trifosfato/metabolismo , Adulto , Glucemia/efectos de los fármacos , Metabolismo de los Hidratos de Carbono/efectos de los fármacos , Epinefrina/sangre , Glucógeno/metabolismo , Humanos , Insulina/sangre , Cinética , Ácido Láctico/sangre , Ácido Láctico/metabolismo , Metabolismo de los Lípidos/efectos de los fármacos , Masculino , Norepinefrina/sangre , Oxidación-Reducción , Consumo de Oxígeno/efectos de los fármacos , Consumo de Oxígeno/fisiología , Fosfocreatina/metabolismo , Fosforilación/efectos de los fármacos , Intercambio Gaseoso Pulmonar/efectos de los fármacos , Intercambio Gaseoso Pulmonar/fisiología
17.
Am J Physiol Renal Physiol ; 290(1): F205-13, 2006 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16091581

RESUMEN

Renal tubular glucose reabsorption is mediated by facilitative glucose transporter (GLUT) proteins and energy-dependent sodium glucose luminal transporters. Glucose transport in the diabetic kidney is upregulated and has been implicated in the pathogenesis of progressive diabetic nephropathy. Hyperglycemia, hypertension, and activation of the renin-angiotensin system are believed important in the development of the disease. The present study examines the renal expression of the facilitative glucose transporters GLUT1 and GLUT12 in rat models of diabetic nephropathy. Sprague-Dawley and transgenic (mRen-2)27 rats received either streptozotocin-induced diabetes or vehicle. GLUT12 expression and localization were determined by immunohistochemistry, immunoblotting, in situ hybridization, and confocal immunofluorescence. GLUT1 immunolabeling was detected on the basolateral membrane throughout the nephron. GLUT12 was localized to the distal tubules and collecting ducts. A significant increase in GLUT12 immunolabeling was measured in Ren-2 controls and Ren-2 diabetic animals compared with Sprague-Dawley controls. GLUT12 expression was higher in Ren-2 diabetic compared with Sprague-Dawley diabetic rats. Long-term diabetes resulted in significant increases in GLUT1 levels in the renal proximal tubules and expression was higher in Ren-2 diabetic than Sprague-Dawley diabetic rats. GLUT12 protein was localized to the cytoplasm and to the apical membrane of human and rat distal tubules and collecting ducts. The apical localization of GLUT12 in the distal tubules and collecting ducts suggests that it could contribute to additional glucose reabsorption in the late nephron. Levels of both GLUT1 and GLUT12 are elevated in animal models of hypertension and diabetic nephropathy.


Asunto(s)
Nefropatías Diabéticas/metabolismo , Proteínas Facilitadoras del Transporte de la Glucosa/metabolismo , Transportador de Glucosa de Tipo 1/metabolismo , Hipertensión Renal/metabolismo , Animales , Animales Modificados Genéticamente , Nefropatías Diabéticas/inducido químicamente , Femenino , Hipertensión Renal/inducido químicamente , Inmunohistoquímica , Túbulos Renales Colectores/metabolismo , Microscopía Confocal , Ratas , Ratas Sprague-Dawley
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...