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Undergraduate research and laboratory experiences provide a wide range of benefits to student learning in science and are integral to imbed authentic research experiences in biology labs. While the benefit of courses with research experience is widely accepted, it can be challenging to measure conceptual research skills in a quick and easily scalable manner. We developed a card-sorting task to differentiate between novice and expert conceptualization of research principles. There were significant differences in the way faculty/postdocs, graduate students, and undergraduate students organized their information, with faculty/postdocs more likely to use deep feature sorting patterns related to research approach. When provided scaffolding of group names reflecting expert-like organization, participant groups were better able to sort by that organization, but undergraduate students did not reach expert levels. Undergraduates with Advanced Placement experience were more likely to display expert-like thinking than undergraduates without Advanced Placement Biology experience and non-PEER (persons excluded because of their Ethnicity or Race) students displayed more expert-like thinking than PEER students. We found evidence of undergraduates in various stages of development toward expert-like thinking in written responses. This card-sorting task can provide a framework for analyzing student's conceptualizations of research and identify areas to provide added scaffolding to help shift from novice-like to expert-like thinking.
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Formação de Conceito , Estudantes , Humanos , Etnicidade , Docentes , LaboratóriosRESUMO
Burns are physically debilitating and potentially fatal injuries. The most common etiology of burn wound infections in the US is methicillin-resistant Staphylococcus aureus (MRSA), which is particularly recalcitrant when biofilms form. The current standard of care, silver sulfadiazine (SSD) is effective in reducing bacterial load, but less effective in improving burn wound healing. New treatments that can manage infection while simultaneously improving healing would provide a benefit in the treatment of burns. Porcine models are frequently used as a model for human wound healing but can be expensive due to the need to separate wounds to avoid cross contamination. The porcine model developed in this study offers the capability to study multiple partial thickness burn wound (PTBW) sites on a single animal with minimal crosstalk to study wound healing, infection, and inflammation. The current study evaluates a wound rinse and a wound gel formulated with a non-toxic, polycationic chitosan derivative that is hypothesized to manage infection while also promoting healing, providing a potential alternate to SSD. Studies in vitro and in this PTBW porcine model compare treatment with the chitosan derivative formulations to SSD. The wound rinse and wound gel are observed to disrupt mature MRSA biofilms in vitro and reduce the MRSA load in vivo when compared to that of the standard of care. In vivo data further show increased re-epithelialization and faster healing in burns treated with wound rinse/gel as compared to SSD. Taken together, the data demonstrate the potential of the wound rinse/gel to significantly enhance healing, promote re-epithelialization, and reduce bacterial burden in infected PTBW using an economical porcine model.
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Queimaduras , Quitosana , Staphylococcus aureus Resistente à Meticilina , Lesões dos Tecidos Moles , Infecção dos Ferimentos , Animais , Queimaduras/complicações , Queimaduras/tratamento farmacológico , Quitosana/farmacologia , Quitosana/uso terapêutico , Humanos , Sulfadiazina de Prata/farmacologia , Sulfadiazina de Prata/uso terapêutico , Suínos , Cicatrização , Infecção dos Ferimentos/tratamento farmacológicoRESUMO
PURPOSE: A total proctocolectomy with subsequent creation of an ileal-pouch, such as a J-pouch or a Kock pouch, has been the most common surgery performed for ulcerative colitis (UC). A small portion of these patients will develop complications with the inflow limb into the pouch requiring operative intervention. The objective was to establish a better understanding as to the pathological mechanism by which these pouch inflow limb problems develop. METHODS: This was a retrospective cohort study conducted at a single tertiary care inflammatory bowel disease (IBD) center. A database was created of all the patients who underwent pouch-related procedures, following completion of their original pouch, between 2006 and 2018. The patients requiring operative resection for inflow limb complications were identified among this cohort. Operative and pathological data were collected. RESULTS: One hundred seventy-eight UC patients underwent surgeries on their pouches between 2006 and 2018. Sixteen patients required operative resection for inflow limb problems. Reoperations for inflow limb problems included inflow limb resection with pouch excision (n = 4) and inflow limb resection with pouch revision (n = 12). The pathology findings of the inflow limb were consistent with Crohn's disease in 9 patients (56%). Two other patients (total 69%) were eventually diagnosed with Crohn's disease due to other pathological specimens or perianal pathology. The remaining patients had chronic, non-specific enteritis/serositis. CONCLUSIONS: A small proportion of pouch patients will eventually require surgery for inflow limb complications. Among these, there was a high rate of Crohn's disease of the inflow limb and overall change in diagnosis to Crohn's disease (Plietz et al. in Official Journal of the American College of Gastroenterology | ACG 114:S453, 2019).
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Colite Ulcerativa , Bolsas Cólicas , Doença de Crohn , Proctocolectomia Restauradora , Colite Ulcerativa/complicações , Bolsas Cólicas/efeitos adversos , Doença de Crohn/complicações , Doença de Crohn/diagnóstico , Doença de Crohn/cirurgia , Humanos , Complicações Pós-Operatórias/diagnóstico , Proctocolectomia Restauradora/efeitos adversos , Proctocolectomia Restauradora/métodos , Estudos RetrospectivosRESUMO
Radiation therapy has been increasingly employed as a tool to cure and palliate majority of solid tumors. Although radiotherapy has shown promising results in preserving structure and function of organs, it is associated with late side effects mainly manifested in the form of tissue fibrosis. Recent advances in molecular biology techniques has helped better understand the molecular mechanisms involved in radiation induced fibrosis. Currently, very few treatment modalities are available to treat the condition with moderate success rate. Stem cell therapies and particularly adipose tissue and adipose derived stem cells therapies have shown promising results in clinical applications. Identification of the key factors involved in the mitigation process will help to enhance the beneficial effects and develop new therapy approaches.
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Fibrose/terapia , Radioterapia/efeitos adversos , Transplante de Células-Tronco/métodos , Animais , HumanosRESUMO
An 87-year-old woman not known to have either a lymphoma or leukemia developed a left multinodular, fish-flesh superior epibulbar and forniceal mass. A biopsy disclosed a blastic tumor with scattered multinucleated immature megakaryoblasts. Immunophenotyping of bone marrow cells revealed strong positivity for CD7, CD31, CD43, CD45, CD61, and CD117; CD71, myeloperoxidase, and lysozyme were also positive in scattered cells. Forty percent of the neoplastic cells were Ki-67 positive. Cytogenetic studies indicated a trisomy 8 (associated with worse prognosis) and a t(12; 17) translocation. Desmin, smooth muscle actin, pancytokeratin, CAM 5.2, adipophilin, tryptase, S100, SOX10, MART1, and E-cadherin were negative, ruling out a nonhematopoietic tumor. The conjunctival lesion was diagnosed as a myeloid sarcoma with megakaryoblastic differentiation, a rare variant. It probably arose from a myelodysplastic syndrome. This is the first case of its type to develop in the conjunctiva.
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OBJECTIVE: We hypothesized that the Oncotype Dx® 21-gene Recurrence Score (RS) could guide neoadjuvant systemic therapy (NST) to facilitate breast conserving surgery (BCS) for hormone receptor positive (HR+) breast cancers. METHODS: This study enrolled patients with HR+, HER2-negative, invasive breast cancers not suitable for BCS (size ≥ 2 cm). Core needle biopsy blocks were tested. For tumors with RS < 11, patients received hormonal therapy (NHT); patients with RS > 25 tumors received chemotherapy (NCT); patients with RS 11-25 were randomized to NHT or NCT. Primary endpoint was whether 1/3 or more of randomized patients refused assigned treatment. RESULTS: Sixty-four patients were enrolled. Of 33 patients with RS 11-25, 5 (15%) refused assignment to NCT. This was significantly lower than the 33% target (binomial test, P = 0.0292). Results for clinical outcomes (according to treatment received for 55 subjects) included successful BCS for 75% of tumors with RS < 11 receiving NHT, 72% for RS 11-25 receiving NHT, 64% for RS 11-25 receiving NCT, and 57% for RS > 25 receiving NCT. CONCLUSIONS: Using the RS to guide NST is feasible. These results suggest that for patients with RS < 25 NHT is a potentially effective strategy.
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Antineoplásicos/uso terapêutico , Inibidores da Aromatase/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/cirurgia , Perfilação da Expressão Gênica/métodos , Mastectomia Segmentar , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia com Agulha de Grande Calibre , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Quimioterapia Adjuvante , Tomada de Decisão Clínica , Feminino , Humanos , Pessoa de Meia-Idade , Terapia Neoadjuvante , Projetos Piloto , Estudos Prospectivos , Receptores de Estrogênio , Receptores de ProgesteronaRESUMO
Undifferentiated lymphoepithelial carcinoma (exhibiting both begin lymphoid and malignant epithelial components) most commonly arises in the head and neck, especially in the nasopharynx. It may also be encountered in various ocular adnexal sites, including the nasolacrimal duct. A 63-year-old woman developed a swelling in the region of the right lacrimal sac accompanied by epiphora. CT scanning revealed an enlargement of the nasolacrimal duct from the lacrimal sac to the inferior nasal meatus. A biopsy during dacryocystorhinostomy for symptomatic epiphora revealed hypercellular sheets of small lymphocytes which were interpreted as evidence for a chronic dacryocystitis. Two years later the subtotally excised lesion had substantially grown in size. Repeat CT scans demonstrated an inferonasal anterior orbital mass with further enlargement of the nasolacrimal duct with a solid mass in its lumen, and bone erosion. The biopsy combined a rich background of lymphocytes within which were clusters of undifferentiated carcinoma cells that were cytokeratin and p63 positive. Critical review of the earlier biopsy led to the detection of the same cells, but in smaller numbers, that had been overlooked. An awareness of the possibility of lymphoepithelial carcinoma of the lacrimal sac/duct should improve diagnostic accuracy with the aid of immunohistochemistry. Radiation therapy is often successful in managing this highly sensitive malignant tumor.
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Neoplasias Oculares/diagnóstico , Imunidade Celular , Doenças do Aparelho Lacrimal/diagnóstico , Ducto Nasolacrimal/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Antígenos CD20/imunologia , Linfócitos B/imunologia , Biomarcadores Tumorais/imunologia , Biópsia , Complexo CD3/imunologia , Terapia Combinada , Neoplasias Oculares/imunologia , Neoplasias Oculares/terapia , Feminino , Humanos , Doenças do Aparelho Lacrimal/imunologia , Doenças do Aparelho Lacrimal/terapia , Pessoa de Meia-Idade , Linfócitos T/imunologiaRESUMO
Non-cultured, autologous cell-spray grafting is an alternative to mesh grafting for larger partial- and deep partial-thickness burn wounds. The treatment uses a suspension of isolated cells, from a patient's donor site skin tissue, and cell-spray deposition onto the wound that facilitates re-epithelialization. Existing protocols for therapeutic autologous skin cell isolation and cell-spray grafting have defined the donor site area to treatment area ratio of 1:80, substantially exceeding the coverage of conventional mesh grafting. However, ratios of 1:100 are possible by maximizing the wound treatment area with harvested cells from a given donor site skin tissue according to a given burn area. Although cell isolation methods are very well described in the literature, a rational approach addressing critical aspects of these techniques are of interest in planning clinical study protocols. We considered in an experimental study the cell yield as a function of the donor site skin tissue, the cell density for spray grafting, the liquid spray volume, the sprayed distribution area, and the percentage of surface coverage. The experimental data was then used for the development of constants and mathematical equations to give a rationale for the cell isolation and cell-spray grafting processes and in planning for clinical studies.
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Queimaduras/terapia , Separação Celular/métodos , Queratinócitos/transplante , Transplante de Pele/métodos , Superfície Corporal , Contagem de Células , Centrifugação , Colagenases , Endopeptidases , Humanos , Técnicas In Vitro , Sítio Doador de Transplante , Transplante Autólogo , Tripsina , CicatrizaçãoRESUMO
BACKGROUND: Strategies aiming at minimization or elimination of systemic immunosuppression are key immediate goals for clinical expansion of vascularized composite allotransplantation (VCA). We compared the in vitro and in vivo immunomodulatory efficacy of adipose-derived mesenchymal stem cells (AD-MSCs) and bone marrow (BM)-derived MSCs in a rat VCA model. METHODS: Both cell types were tested in vitro for suppressor function using mixed lymphocyte reactivity assays. AD-MSCs or BM-MSCs were administered intravenously (1 × 10 or 5 × 10 cells/animal) to Lewis rat recipients of mismatched Brown Norway hindlimb transplants. Short course tacrolimus (FK-506) monotherapy was withdrawn at postoperative day 21. In vivo regulatory T-cell induction, peripheral blood chimerism, and microchimerism in lymphatic organs were analyzed. RESULTS: AD-MSCs and BM-MSCs exhibited strong dose-dependent suppressor function in vitro, which was significantly more pronounced for AD cells. In vivo, all animals revealed peripheral multi-lineage chimerism at four weeks (P < 0.01) independent of cell type and dosage. Regulatory T-cell levels were increased with both cell types, the most in AD-MSC groups. These immunomodulatory effects were only transient. MSC treatment resulted in long-term (>120 day) allograft survival in 47% of the animals, which correlated with durable microchimerism in BM and spleen. CONCLUSIONS: AD-MSCs and BM-MSCs exert immunomodulatory effects that prolong survival of immunogenic skin-bearing VCA grafts with short course (21 day) tacrolimus induction therapy. The in vivo findings in terms of allograft survival did not reflect superior immunomodulatory characteristics of AD-MSCs found in vitro.
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Tecido Adiposo/citologia , Transplante de Medula Óssea , Aloenxertos Compostos/irrigação sanguínea , Aloenxertos Compostos/transplante , Sobrevivência de Enxerto , Membro Posterior/irrigação sanguínea , Membro Posterior/transplante , Terapia de Imunossupressão/métodos , Transplante de Células-Tronco Mesenquimais , Transplante de Pele , Alotransplante de Tecidos Compostos Vascularizados , Animais , Células Cultivadas , Aloenxertos Compostos/efeitos dos fármacos , Esquema de Medicação , Sobrevivência de Enxerto/efeitos dos fármacos , Membro Posterior/efeitos dos fármacos , Imunossupressores/administração & dosagem , Masculino , Ratos Endogâmicos BN , Ratos Endogâmicos Lew , Linfócitos T Reguladores/imunologia , Tacrolimo/administração & dosagem , Fatores de Tempo , Quimeras de Transplante , Tolerância ao TransplanteAssuntos
Adenocarcinoma Sebáceo/patologia , Neoplasias da Túnica Conjuntiva/patologia , Neoplasias das Glândulas Sebáceas/patologia , Adenocarcinoma Sebáceo/metabolismo , Adenocarcinoma Sebáceo/cirurgia , Biomarcadores/metabolismo , Neoplasias da Túnica Conjuntiva/metabolismo , Neoplasias da Túnica Conjuntiva/cirurgia , Feminino , Humanos , Técnicas Imunoenzimáticas , Antígeno Ki-67/metabolismo , Proteínas de Membrana/metabolismo , Pessoa de Meia-Idade , Perilipina-2 , Receptores Androgênicos/metabolismo , Neoplasias das Glândulas Sebáceas/metabolismo , Neoplasias das Glândulas Sebáceas/cirurgiaRESUMO
The U.S. Food and Drug Administration is the government agency responsible for oversight of the safety and efficacy of pharmaceuticals and devices, including biologics and devices that combine biologics with other materials. Within the U.S. Food and Drug Administration, the Center for Biologics Evaluation and Research is specifically responsible for the evaluation and approval of biological products. This department of the U.S. Food and Drug Administration has a series of mechanisms in place to aid researchers in the process of developing new biologics. This article outlines the study phases involved in developing new biologics and how the Center for Biologics Evaluation and Research and investigators can work together to facilitate this process. It also discusses issues specific to biologics that have been encountered in the past and that investigators should consider when developing and obtaining approval for new biologics. The equivalent center within the U.S. Food and Drug Administration for approving medical devices is the Center for Devices and Radiological Health. The equivalent process of development and approval of medical devices is similarly discussed. Finally, essential contacts for investigators within the Center for Biologics Evaluation and Research and the Center for Devices and Radiological Health are provided.
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Aprovação de Equipamentos , United States Food and Drug Administration/organização & administração , Produtos Biológicos , Terapia Baseada em Transplante de Células e Tecidos , Colágeno , Humanos , Pele Artificial , Estados UnidosRESUMO
BACKGROUND: Lapatinib in combination with capecitabine is approved for the treatment of patients with advanced or metastatic breast cancer whose tumors overexpress the human epidermal growth factor receptor 2 (HER2) and who have received prior therapy including an anthracycline, a taxane, and trastuzumab. Based on our phase I trial, we conducted a single arm, multicenter phase II study of lapatinib in combination with vinorelbine. PATIENT AND METHODS: Women with HER2-positive advanced breast cancer, who had received up to one prior regimen for metastatic disease, were eligible. Prior trastuzumab was allowed. Patients received daily lapatinib 1500 mg orally and vinorelbine 20 mg/m(2) intravenously on days 1, 8 and 15 of a 28-day cycle. The primary endpoint was overall response rate (ORR). RESULTS: Forty-four patients received the combination treatment, including 48% as second-line therapy. The ORR was 41% (95% confidence interval [CI] 26-55%), including 9% with a complete response. Median progression-free survival was 24.1 weeks (95% CI 17-37 weeks) and median duration of response was 32 weeks (95% CI 18-42 weeks). Nearly 80% of patients did not require a dose reduction in lapatinib, although most patients required one dose reduction of vinorelbine secondary to neutropenia. The most common toxicities were grade 1 and 2 diarrhea, nausea, fatigue and rash, and grade 3 and 4 neutropenia. One case of grade 3 asymptomatic decreased left ventricular ejection fraction event was reported. CONCLUSION: The combination of lapatinib and vinorelbine was active, feasible and well tolerated in patients with HER2-positive advanced breast cancer.
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The revalidation of doctors was introduced in the UK in December 2012, and means that all licensed doctors must demonstrate periodically that they are up-to-date and fit to practise. Regular appraisals, based on the General Medical Council's core guidance for doctors, will be used by responsible officers to evaluate a doctor's practice based on six types of supporting information, including feedback from patients and colleagues. In this commentary, as the Chair of the General Medical Council and Consultant Physician, I provide an overview of the history of revalidation and discuss the role of the new system of checks (which is being watched with interest by regulators around the world) ensuring that medical practice is of a high quality, that doctors are supported in their professional development and, most importantly, that patients can have confidence in the doctors they consult.
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UNLABELLED: Cell banked epidermal skin progenitor cells have the potential to provide an "off-the-freezer" product. Such cells may provide a skin donor area-independent cell-spray grafting therapy for the treatment of burns. We first characterized fetal skin samples of gestational ages ranging from 6 to 21 weeks. As the results suggest that the phenotypic differentiation occurs after 10 weeks, which may complicate follow-up in vitro studies, we developed and compared different cell isolation techniques for human fetal skin-derived epithelial cells from tissue ages 6 to 9 weeks. We initially screened seven methods of characterization, concluding that two methods warranted further investigation: incubating the epidermal tissue in Petri-dishes with culture medium for spontaneous cell outgrowth, and wiping the epidermal tissue onto a dry Petri-dish culture surface followed by adding culture medium. Non-controllable culture contamination with dermal cells was the reason for excluding the other five methods. The results suggest that epidermal cells can be isolated from tissue exhibiting a single homogeneous layer of CK15(+) basal keratinocytes up to week 9. At later gestational ages, the ongoing skin differentiation results in a multi-layer basal structure and progenitors associated with the hair bulb would have to be considered. Spraying the resulting cells with a clinical spray device was successfully demonstrated in an in vitro model. CONCLUSION: Gestational age 6-9 weeks epidermal human fetal skin cells from the basal layer can be reproducibly isolated and transferred into culture for studies on the development of skin cell transplantation therapies.
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Queimaduras/cirurgia , Técnicas de Cultura de Células/métodos , Derme/citologia , Transplante de Pele/métodos , Células-Tronco/citologia , Transplante de Células/métodos , Derme/embriologia , Idade Gestacional , HumanosRESUMO
Beginning in December 2012, all UK doctors will be required to complete a periodic revalidation process conducted by the General Medical Council (GMC) to retain their licence to practise medicine. Regular appraisals, based on the GMC's core guidance for doctors, will be used by responsible officers to evaluate a doctor's practice based on six types of supporting information. Feedback from patients and colleagues, referred to as multisource feedback (MSF), is one element of supporting information that doctors will present at appraisal to support their revalidation.This commentary by the Chair of the GMC expands on the research in this issue by Wright and colleagues to provide an overview of the history of revalidation in the United Kingdom, discuss the role of appraisal in revalidation, and examine the need for and value of MSF in this process. The author highlights the support that the GMC has received from UK patient organizations and ends by focusing on the benefits of revalidation and the expectations for its development in the future.