Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 116
Filtrar
2.
J Commun Healthc ; : 1-15, 2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-37213185

RESUMO

BACKGROUND: This article summarizes a global study of the effect of the COVID-19 pandemic on junior health professions students' outlook on medicine. The pandemic has significantly affected health professions education. There is limited understanding of how students' pandemic experiences will affect them, and what impact these events may have on their career paths or the future of the professions. This information is important as it impacts the future of medicine. METHODS: In the Fall 2020 semester, 219 health professions students at 14 medical universities worldwide responded to the question: 'Has this experience (with COVID-19) changed your outlook on medicine as a profession?'. Short essay responses were semantically coded and organized into themes and subthemes using an inductive approach to thematic analysis. RESULTS: 145 responses were submitted. Themes were identified: (1) students reflected on the interaction between politics and healthcare; (2) reported becoming more aware of the societal expectations placed on healthcare professionals, including undertaking high risks and the sacrifices that healthcare professionals must make; (3) found reassurance from the recognized importance of healthcare professionals and expressed pride to be entering the profession; and (4) reflected on the current state of healthcare, including its limitations and future. CONCLUSION: Most students, independent of the extent of the pandemic in their respective countries, noted a change in their outlook regarding medicine. An overall positive outlook was noted in most junior students. Educators need to work on nurturing these sentiments and attitudes to help young students maintain a healthy relationship towards their chosen profession.

3.
Med Cannabis Cannabinoids ; 5(1): 20-31, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35950052

RESUMO

Introduction: Medicinal cannabis is prescribed in Australia for patients with chronic refractory pain conditions. However, measures of safety and effectiveness of different cannabinoids are lacking. We designed an observational study to capture effectiveness, adverse events (AEs), and health-related quality of life (HRQoL) measures in patients prescribed an oral medicinal cannabis formulation at Cannabis Access Clinics through the Cannabis Access Clinics Observational study (CACOS). Objectives: We aimed to evaluate effectiveness, reported AEs, and change in patient-reported outcomes in individuals prescribed a cannabinoid oil formulation for management of chronic pain. Methods: A cross-sectional analysis was conducted on patients prescribed an oil formulation of Δ9-tetrahydrocannabinol and cannabidiol for pain symptoms of at least 3-month duration. Clinician-reported AEs were organized by system, organ, class, and frequency. Analysis of patient-reported responses to a questionnaire was conducted using published minimal clinically important differences to determine meaningful change in HRQoL over time. Results: More than half (n = 91/151, 60.3%) of the participants experienced at least one AE during the observation period (mean 133 ± 116 days). No serious AEs were reported. Patient-reported pain impact scores were significantly reduced across the cohort (p = 0.034), and pain intensity scores verged on significance (p = 0.053). The majority of patients saw meaningful improvements in sleep (49.3%) and fatigue (35.6%). Conclusion: This analysis presents real-world data collected as part of standard of care. More than one-third of patients benefited from oral medicinal cannabis, which is impactful given the refractory nature of their pain. Amelioration of the impact of pain confirms continued prescribing of this formulation and validates our observational methodology as a tool to determine the therapeutic potency of medicinal cannabinoids.

4.
J Foot Ankle Surg ; 61(5): e41-e47, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34876341

RESUMO

Nonuremic calciphylaxis is a rare condition presenting with peripheral ischemic ulcerations. Calciphylaxis is the deposition of calcium and phosphate into arteriolar walls caused by exceeding their solubility range in the blood. It is most commonly seen in patients with end-stage renal disease; however, nonuremic calciphylaxis occurs in patients with normal or mildly impaired renal function. Risk factors for nonuremic calciphylaxis include Coumadin therapy, obesity, and diabetes mellitus. Histopathologic examination of deep skin biopsy containing subcutaneous adipose tissue reveals medial calcification of dermal and subcutaneous arterioles. This diagnosis must be managed locally with wound care and systemically by control of blood calcium solubility. Avoidance of infection is critical to survival. Here we report a case of calciphylaxis in a patient with normal renal function and serum levels of calcium and phosphorus who presented with gangrene of the extremities. Increased awareness of this debilitating disease will lead to earlier diagnosis, proper treatment and improved patient outcomes.


Assuntos
Calciofilaxia , Falência Renal Crônica , Calciofilaxia/diagnóstico , Calciofilaxia/etiologia , Calciofilaxia/terapia , Cálcio , Extremidades , Gangrena/complicações , Humanos , Falência Renal Crônica/complicações , Falência Renal Crônica/terapia
5.
J Clin Med ; 10(13)2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34209541

RESUMO

The Food and Drug Administration (FDA) has been regulating human islets for allotransplantation as a biologic drug in the US. Consequently, the requirement of a biological license application (BLA) approval before clinical use of islet transplantation as a standard of care procedure has stalled the development of the field for the last 20 years. Herein, we provide our commentary to the multiple FDA's position papers and guidance for industry arguing that BLA requirement has been inappropriately applied to allogeneic islets, which was delivered to the FDA Cellular, Tissue and Gene Therapies Advisory Committee on 15 April 2021. We provided evidence that BLA requirement and drug related regulations are inadequate in reassuring islet product quality and potency as well as patient safety and clinical outcomes. As leaders in the field of transplantation and endocrinology under the "Islets for US Collaborative" designation, we examined the current regulatory status of islet transplantation in the US and identified several anticipated negative consequences of the BLA approval. In our commentary we also offer an alternative pathway for islet transplantation under the regulatory framework for organ transplantation, which would address deficiencies of in current system.

6.
Mod Pathol ; 34(9): 1795-1805, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33986461

RESUMO

Allograft survival of deceased donor kidneys with suboptimal histology (DRTx/suboptimal histology: >10% glomerulosclerosis, >10% tubulointerstitial scarring, or >mild vascular sclerosis) is inferior to both DRTx with optimal histology (DRTx/optimal histology) and living donor kidneys irrespective of histologic changes (LRTx). In this report, we explored the reasons behind this guarded outcome with a special focus on the role of alloimmunity. We initially assessed gene expression in 39 time-zero allograft biopsies using the Nanostring 770 genes PanCancer Immune Profiling Panel. Subsequently, we studied 696 consecutive adult kidney allograft recipients that were grouped according to allograft type and histology at time-zero biopsy [DRTx/suboptimal histology (n = 194), DRTx/optimal histology (n = 166), and LRTx (n = 336)]. Part-1: Several immune pathways were upregulated in time-zero biopsies from DRTx/suboptimal histology (n = 11) compared to LRTx (n = 17) but not to DRTx/optimal histology (n = 11). Part-2: Amongst the three groups of recipients, DRTx/suboptimal histology had the highest incidence of acute rejection episodes, most of which occurred during the first year after transplantation (early rejection). This increase was mainly attributed to T cell mediated rejection, while the incidence of antibody-mediated rejection was similar amongst the three groups. Importantly, early acute T cell mediated rejection was a strong independent predictor for allograft failure in DRTx/suboptimal histology (adjusted HR: 2.13, P = 0.005) but not in DRTx/optimal histology nor in LRTx. Our data highlight an increased baseline immunogenicity in DRTx/suboptimal histology compared to LRTx but not to DRTx/optimal histology. However, our results suggest that donor chronic histologic changes in DRTx may help transfer such increased baseline immunogenicity into clinically relevant acute rejection episodes that have detrimental effects on allograft survival. These findings may provide a rationale for enhanced immunosuppression in recipients of DRTx with baseline chronic histologic changes to minimize subsequent acute rejection and to prolong allograft survival.


Assuntos
Aloenxertos/patologia , Rejeição de Enxerto , Transplante de Rim/métodos , Doadores de Tecidos/provisão & distribuição , Transplantes/patologia , Humanos , Projetos Piloto , Estudos Retrospectivos , Transcriptoma
7.
Am J Transplant ; 21(4): 1365-1375, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33251712

RESUMO

Islet allotransplantation in the United States (US) is facing an imminent demise. Despite nearly three decades of progress in the field, an archaic regulatory framework has stymied US clinical practice. Current regulations do not reflect the state-of-the-art in clinical or technical practices. In the US, islets are considered biologic drugs and "more than minimally manipulated" human cell and tissue products (HCT/Ps). In contrast, across the world, human islets are appropriately defined as "minimally manipulated tissue" and not regulated as a drug, which has led to islet allotransplantation (allo-ITx) becoming a standard-of-care procedure for selected patients with type 1 diabetes mellitus. This regulatory distinction impedes patient access to islets for transplantation in the US. As a result only 11 patients underwent allo-ITx in the US between 2016 and 2019, and all as investigational procedures in the settings of a clinical trials. Herein, we describe the current regulations pertaining to islet transplantation in the United States. We explore the progress which has been made in the field and demonstrate why the regulatory framework must be updated to both better reflect our current clinical practice and to deal with upcoming challenges. We propose specific updates to current regulations which are required for the renaissance of ethical, safe, effective, and affordable allo-ITx in the United States.


Assuntos
Produtos Biológicos , Diabetes Mellitus Tipo 1 , Transplante das Ilhotas Pancreáticas , Custos e Análise de Custo , Diabetes Mellitus Tipo 1/cirurgia , Humanos , Transplante Heterólogo , Estados Unidos
8.
Prev Chronic Dis ; 17: E69, 2020 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-32701431

RESUMO

Community pharmacists assist patients to manage disease and prevent complications. Despite the enormous challenge the coronavirus disease 2019 (COVID-19) pandemic has dealt to the health care system, community pharmacists have maintained the delivery of critical health services to communities, including those most at risk for COVID-19. Community pharmacists are in a key position to deliver priority pandemic responses including point-of-care testing for chronic disease management, vaccinations, and COVID-19 testing.


Assuntos
Betacoronavirus , Serviços Comunitários de Farmácia/organização & administração , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/terapia , Pandemias/prevenção & controle , Farmacêuticos , Pneumonia Viral/prevenção & controle , Pneumonia Viral/terapia , Papel Profissional , Adulto , COVID-19 , Criança , Infecções por Coronavirus/epidemiologia , Atenção à Saúde , Gerenciamento Clínico , Humanos , Pneumonia Viral/epidemiologia , Testes Imediatos , SARS-CoV-2 , Estados Unidos/epidemiologia , Vacinação
10.
Clin Podiatr Med Surg ; 37(2): 287-293, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32146984

RESUMO

Nonunion rate of first metatarsophalangeal joint (MTP) joint arthrodesis is reportedly less than 6%, regardless of fixation type. Robust modern plating constructs aim to decrease incidence of nonunion while also allowing early postoperative weight-bearing. Quicker transition to weight-bearing postoperatively increases patient adherence, decreases adjacent joint stiffness, and reduces risk of deep vein thrombosis in the postoperative period. The purpose of this study was to investigate the effect tibial sesamoid fixation has on first MTP joint arthrodesis.


Assuntos
Artrodese , Fixação Interna de Fraturas , Articulação Metatarsofalângica/cirurgia , Ossos Sesamoides/cirurgia , Tíbia/cirurgia , Suporte de Carga/fisiologia , Idoso , Cadáver , Feminino , Hallux Rigidus/cirurgia , Humanos , Masculino , Articulação Metatarsofalângica/fisiopatologia , Pessoa de Meia-Idade
11.
Clin Podiatr Med Surg ; 37(2): 295-304, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32146985

RESUMO

Direct repair of deep deltoid ruptures after traumatic ankle fracture is not commonly performed. Previous studies overlook the contributions of the medial deltoid to overall ankle stability and long-term patient satisfaction. Historically, deep deltoid injuries have been addressed indirectly through syndesmotic ligament repair. This technique fails to restore, however, the anatomic function of the primary medial stabilizing structure. The oversight of direct deltoid repair may be one contributing factor to the less than optimal outcomes after ankle fractures with syndesmotic injuries. This article reports a positive response with direct deep deltoid repair, at average 5-year follow-up, with 93% positive return to normal function.


Assuntos
Fraturas do Tornozelo/cirurgia , Traumatismos do Tornozelo/cirurgia , Ligamentos Articulares/lesões , Adolescente , Adulto , Idoso , Fraturas do Tornozelo/complicações , Traumatismos do Tornozelo/complicações , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Recuperação de Função Fisiológica , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
12.
Ultramicroscopy ; 204: 55-72, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31129494

RESUMO

Quantitative chemical analyses of Ni3Al based hardening precipitates (γ') in polycrystalline Ni based superalloys have been conducted using energy dispersive X-ray spectroscopy (EDX), coupled with a scanning transmission electron microscope (STEM). The aim of the current investigation is (1) to evaluate the accuracy of calibration (k factor determinations and absorption corrections using a combination of differential X-ray absorption (DXA) and convergent beam electron diffraction (CBED)) by comparing with thermodynamic calculations and (2) to demonstrate the importance of the EDX chemical analysis by taking advantage of its unique capabilities to analyse sub-micron scale chemistries within a mesoscopic field of view under STEM. Our experimental findings show good agreement with the mole fraction ratio of γ' to the disordered γ matrix predicted using the Lever rule on a thermodynamically stabilised unimodal superalloy, RR1000. The significance of analysing a statistically viable number of samples in thermodynamically metastable superalloys and the chemical fluctuations found in coarse γ', sized above 200 nm on a scale of a few hundred nanometres in the context of solving a complex morphological evolution of γ' particles is demonstrated.

13.
Coron Artery Dis ; 30(5): 346-351, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31094895

RESUMO

OBJECTIVE: We sought to describe a technique for ultra-low-contrast angiography (ULCA) in patients with advanced chronic kidney disease (CKD) and previous coronary artery bypass surgery (CABG). BACKGROUND: Patients with advanced CKD and previous CABG are at high risk of developing contrast-induced nephropathy (CIN) because of the additional contrast often required to identify bypass grafts. Apart from hydration, reduced contrast administration is the only established method to minimize the risk of CIN. PATIENTS AND METHODS: Ten patients underwent ULCA, whereby an intracoronary injection of saline and coronary guidewires were used instead of test injections of contrast for engagement of bypass grafts with catheters. Estimated glomerular filtration rate (eGFR) before and 30 days following angiography were recorded as was the need for renal replacement therapy 1 year after the procedure. RESULTS: All patients completed a diagnostic angiogram without complications. The median volume of contrast delivered was 13.5 ml (interquartile range: 10.5-17.8). The median eGFR was 18.3 ml/min/1.73 m (interquartile range: 16.5-28.2). There was no statistically significant difference in eGFR before the procedure and 30 days after the procedure (P=0.79). No patient required dialysis 30 days after the procedure. Two patients required initiation of dialysis at 1 year after the procedure. CONCLUSION: In patients with advanced CKD and previous CABG, ULCA may be performed with high procedural success and without complications, minimizing the risk of CIN in these high-risk patients.


Assuntos
Injúria Renal Aguda/prevenção & controle , Meios de Contraste/administração & dosagem , Angiografia Coronária , Ponte de Artéria Coronária , Taxa de Filtração Glomerular/efeitos dos fármacos , Rim/efeitos dos fármacos , Insuficiência Renal Crônica/complicações , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/diagnóstico , Injúria Renal Aguda/fisiopatologia , Idoso , Meios de Contraste/efeitos adversos , Angiografia Coronária/efeitos adversos , Ponte de Artéria Coronária/efeitos adversos , Feminino , Humanos , Rim/fisiopatologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Insuficiência Renal Crônica/diagnóstico , Insuficiência Renal Crônica/fisiopatologia , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo
14.
Am J Health Syst Pharm ; 75(23): 1930-1937, 2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-30463868

RESUMO

PURPOSE: The design and implementation of a tool that combines clinical teaching with cutting-edge, simplified technology for providing medication education to solid organ transplant (SOT) recipients are described. METHODS: In a retrospective study of adults who received kidney transplants from February 2015 through May 2017, patients were educated about their medications using a tablet computer application, Medication Regimen Education (MRxEd), that presented concise videos describing the name, indication, dose, adverse effects, and associated interactions of all medications received, as well as special considerations applicable to each agent. Assessment questions were used to reinforce key concepts and identify knowledge gaps. RESULTS: The digital educational intervention was provided to 282 kidney transplant recipients. Patients were predominantly white (48%) and/or male (63%), with a median age of 51 years (interquartile range, 37-61 years). Patients came from a variety of education backgrounds. Most patients (81%) were educated on dual maintenance immunosuppression (with tacrolimus and mycophenolate) and 3 infection prophylaxis agents (nystatin, sulfamethoxazole-trimethoprim, and valganciclovir). Most patients (90%) correctly answered questions related to medication indications, dosing, and special rules, but many (61%) had difficulty correctly answering questions about adverse effects. CONCLUSION: An innovative approach for interactive and engaging medication teaching with the MRxEd application enhanced the education process for SOT recipients.


Assuntos
Antibioticoprofilaxia , Instrução por Computador/métodos , Imunossupressores/uso terapêutico , Transplante de Órgãos/educação , Educação de Pacientes como Assunto/métodos , Adulto , Antibacterianos/efeitos adversos , Antibacterianos/uso terapêutico , Antibioticoprofilaxia/efeitos adversos , Antibioticoprofilaxia/métodos , Feminino , Humanos , Imunossupressores/efeitos adversos , Transplante de Rim/educação , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
15.
Drug Alcohol Rev ; 37(7): 887-896, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30280448

RESUMO

INTRODUCTION AND AIMS: Despite large increases in pharmaceutical opioid dependence and related mortality, few studies have focused on the characteristics and treatment experiences of those with pharmaceutical opioid dependence. We describe the formation of a prospective cohort of people receiving treatment for pharmaceutical opioid dependence and describe their baseline characteristics. DESIGN AND METHODS: People who had entered treatment for pharmaceutical opioid dependence (n = 108) were recruited through drug treatment services in New South Wales, Australia. We describe baseline characteristics of those that commenced pharmaceutical opioids for pain or other reasons and conducted a thematic analysis of responses regarding their treatment experience. RESULTS: Mean age was 41 years (SD 11), half were male (48%). Just over half reported lifetime heroin use (57%). Oxycodone (49%) and codeine (29%) were the most common opioids reported. Most (85%) reported past-year problematic pain, 38% reported chronic pain. Half (52%) reported moderate to severe depression symptoms. Most (66%) commenced opioids for pain, and this group were older, less likely to report a previous overdose and less likely to report use of illicit drugs compared to those commencing for other reasons. Five themes related to treatment expectations: (i) stigma; (ii) the restrictive nature of treatment; (iii) knowledge; (iv) pain; and (v) positive experience with buprenorphine. DISCUSSION AND CONCLUSIONS: This study describes the complexities in an important emerging treatment population of pharmaceutical opioid-dependent people. Findings highlights that addressing knowledge and perceptions around treatment may be critical to address the rising mortality associated with pharmaceutical opioid dependence.


Assuntos
Analgésicos Opioides/efeitos adversos , Compreensão , Transtornos Relacionados ao Uso de Opioides/epidemiologia , Transtornos Relacionados ao Uso de Opioides/terapia , Vigilância da População , Adulto , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos Relacionados ao Uso de Opioides/diagnóstico , Vigilância da População/métodos , Estudos Prospectivos , Transtornos Relacionados ao Uso de Substâncias/diagnóstico , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Transtornos Relacionados ao Uso de Substâncias/terapia , Resultado do Tratamento
16.
J Foot Ankle Surg ; 57(6): 1067-1072, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30368423

RESUMO

Charcot neuroarthropathy is a rare but often difficult to manage disease in the neuropathic patient. Early signs such as unremarkable edema, marginal trauma, or minor infection can activate a cascade of bony destruction and lead to gross prominence or deformity, with dire consequences. The exact molecular mechanism is poorly understood. Current theory states that an inflammatory reaction leads to the activation of osteoclasts mediated by specific cytokines. Our study sought to test the genetic expression of certain biomarkers in diabetic patients with and without Charcot neuroarthropathy compared with patients with and without diabetes or neuropathy. A total of 30 patients participated in the study, 17 (57%) males and 13 (43%) females. Peripheral blood samples were drawn, and gene expression was measured using real-time polymerase chain reaction. The expression levels of receptor activator of nuclear factor kappa-B ligand and osteoprotegerin showed no significant increase in the Charcot neuroarthropathy group compared with the healthy control group. We determined that the levels of receptor activator of nuclear factor kappa-B ligand and osteoprotegerin were not significantly increased in Charcot neuroarthropathy patients compared with healthy control patients. These results demonstrate a need for further investigation into alternative molecular pathways to determine the exact mechanism of the disease process.


Assuntos
Artropatia Neurogênica/sangue , Artropatia Neurogênica/etiologia , Neuropatias Diabéticas/sangue , Osteoprotegerina/sangue , Ligante RANK/sangue , Adulto , Idoso , Artropatia Neurogênica/patologia , Biomarcadores/sangue , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
17.
J Foot Ankle Surg ; 57(4): 844-849, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29661673

RESUMO

Fibular fractures in the setting of an unstable ankle joint require surgical fixation; however, several factors contradict open surgical correction. Severe soft tissue compromise can delay adequate fracture reduction and preclude the standard incisional approach. The soft tissue envelope in the setting of obesity, diabetes, and/or peripheral vascular disease further complicates definitive treatment. Poorly timed open fixation can lead to delayed healing of the incision site, with wound breakdown and the potential for hardware failure. Proximal fibular fractures are also at unique risk of neurovascular compromise with open reduction and internal fixation. Surgical fixation has now focused on minimizing the soft tissue insult using percutaneous techniques in the comorbid patient. We present a case that highlights a minimally invasive technique that provides dynamic stable internal fixation of fibular fractures with the use of flexible pediatric intramedullary nails, typically used in long bone fractures of children.


Assuntos
Pinos Ortopédicos , Fíbula/lesões , Fixação Interna de Fraturas/instrumentação , Fixação Intramedular de Fraturas/instrumentação , Fraturas Ósseas/cirurgia , Idoso de 80 Anos ou mais , Feminino , Fixação Interna de Fraturas/métodos , Fraturas Ósseas/diagnóstico por imagem , Humanos , Radiografia
18.
Transplantation ; 102(10): 1603-1613, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29677072

RESUMO

Despite decades of research, the induction and maintenance of long-term allograft tolerance without immunosuppression remains an elusive goal in the field of solid organ and cell transplantation. Immunosuppressive medications frequently prevent or minimize acute cellular rejection but have failed to halt antidonor antibody production and chronic organ rejection. Past efforts aimed at promoting lasting allograft tolerance have focused primarily on peripheral T-cell depletion, augmentation of regulatory T cells, or induction via simultaneous hematopoietic stem cell transplantation and facilitation of donor chimerism. So far, none of these methods have led to consistently safe, feasible and long lasting donor organ acceptance. Over the course of the past 4 decades, the study of a unique population of antigen-presenting cells known as dendritic cells has shown promise for breaking new ground in achieving indefinite allograft survival without immunosuppression and its associated adverse effects. In this review, we discuss the discovery and early investigations of dendritic cells and chronicle some of the key studies demonstrating their role in transplantation, particularly in indirect allorecognition, the immunologic pathway thought to drive chronic rejection and perhaps tolerance induction.


Assuntos
Transplante de Células/métodos , Células Dendríticas/imunologia , Rejeição de Enxerto/imunologia , Transplante de Órgãos/efeitos adversos , Tolerância ao Transplante/imunologia , Animais , Células Dendríticas/transplante , Rejeição de Enxerto/prevenção & controle , Sobrevivência de Enxerto/imunologia , Humanos , Isoanticorpos/imunologia , Depleção Linfocítica/efeitos adversos , Depleção Linfocítica/métodos , Linfócitos T Reguladores/imunologia , Quimeras de Transplante/imunologia
19.
Kidney Int ; 93(5): 1227-1239, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29544662

RESUMO

Ischemia-reperfusion injury increases allograft immunogenicity and enhances myeloid dendritic cell maturation and trafficking to recipient's secondary lymphoid tissue. Here, we used postreperfusion biopsies from patients who received kidney allografts from deceased donors between 2006 and 2009 to assess the impact of ischemia-reperfusion damage and myeloid dendritic cell density on subsequent allograft rejection episodes. Histologic changes of severe ischemia-reperfusion damage in postreperfusion biopsies were found to be associated with subsequent rejection episodes and suboptimal allograft survival. Using BDCA-1 as a marker of myeloid dendritic cells, postreperfusion biopsies from deceased donors had lower dendritic cell density compared to postreperfusion biopsies from living donors or normal controls. This suggests a rapid emigration of donor dendritic cells out of the allograft. In our cohort, low dendritic cell density was associated with a subsequent increase in rejection episodes. However, it appears that the donor's cause of death also influenced dendritic cell density. Therefore, we assessed the additive impact of severe ischemia-reperfusion changes and low dendritic cell density on subsequent rejection. The aforementioned combination was a powerful and independent predictor of allograft rejection. Thus, our data highlight the prognostic value of histopathologic changes associated with ischemia-reperfusion in postreperfusion biopsies and suggest a rapid posttransplant emigration of myeloid dendritic cells out of the allograft to enhance alloimmunity. These findings may provide a rationale for minimizing ischemia-reperfusion injury and therapeutic targeting of donor-derived dendritic cells to promote rejection-free allograft survival.


Assuntos
Células Dendríticas/patologia , Rejeição de Enxerto/etiologia , Transplante de Rim/efeitos adversos , Rim/patologia , Traumatismo por Reperfusão/etiologia , Adulto , Idoso , Aloenxertos , Antígenos CD1/análise , Biomarcadores/análise , Biópsia , Causas de Morte , Movimento Celular , Células Dendríticas/imunologia , Feminino , Glicoproteínas/análise , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/patologia , Sobrevivência de Enxerto , Humanos , Rim/imunologia , Transplante de Rim/métodos , Doadores Vivos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Traumatismo por Reperfusão/imunologia , Traumatismo por Reperfusão/patologia , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Doadores de Tecidos , Resultado do Tratamento , Adulto Jovem
20.
Tissue Eng Part A ; 24(9-10): 740-751, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-28938862

RESUMO

Cell implantation for tissue repair is a promising new therapeutic strategy. Although direct injection of cells into tissue is appealing, cell viability and retention are not very good. Cell engraftment and survival following implantation are dependent on a sufficient supply of oxygen and nutrients through functional microcirculation as well as a suitable local microenvironment for implanted cells. In this study, we describe the development of a porous, biocompatible, three-dimensional (3D) alginate scaffold covalently modified with the synthetic cyclic RGDfK (Arg-Gly-Asp-D-Phe-Lys) peptide. Cyclic RGDfK peptide is protease resistant, highly stable in aqueous solutions, and has high affinity for cellular integrins. Cyclic RGDfK-modified alginate scaffolds were generated using a novel silicone sheet sandwich technique in combination with freeze-gelation, resulting in highly porous nonimmunogenic scaffolds that promoted both human and rodent cell survival in vitro, and neoangiogenesis in vivo. Two months following implantation in abdominal rectus muscles in rats, cyclic RGDfK-modified scaffolds were fully populated by host cells, especially microvasculature without an overt immune response or fibrosis, whereas unmodified control scaffolds did not show cell ingrowth. Importantly, modified scaffolds that were seeded with human mesenchymal precursor cells and were patched to the epicardial surface of infarcted myocardium induced myocardial neoangiogenesis and significantly improved cardiac function. In summary, purified cyclic RGDfK peptide-modified 3D alginate scaffolds are biocompatible and nonimmunogenic, enhance cell viability, promote angiogenesis, and may be used as a means to deliver cells to myocardial infarct areas to improve neovascularization and cardiac function.


Assuntos
Oligopeptídeos/química , Alicerces Teciduais/química , Animais , Materiais Biocompatíveis/química , Adesão Celular/fisiologia , Linhagem Celular , Transplante de Células/métodos , Humanos , Masculino , Células-Tronco Mesenquimais/citologia , Microscopia Eletrônica de Varredura , Miocárdio/citologia , Neovascularização Fisiológica/fisiologia , Ratos , Engenharia Tecidual/métodos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...