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1.
Artigo em Inglês | MEDLINE | ID: mdl-39083504

RESUMO

INTRODUCTION: Matching into an orthopaedic surgery residency consistently reinforces a competitive landscape, challenging the applicants and programs. A group of orthopaedic surgery residency programs implemented video prompts asking applicants to respond to a standardized question by video recording. Assessing the impact of this video on the decision to offer an interview can help guide programs and applicants through the interview process. METHODS: Twenty residency applications to one institution requiring video prompts were randomly selected and deidentified. Thirteen experienced faculty from various orthopaedic surgery programs served as applicant reviewers. The reviewers evaluated the electronic residency application service (ERAS) application and determined whether they would grant the applicant an interview ("no," "maybe," or "yes") before and after watching the video prompt. The reviewer also scored the impact of the applicant's dress, facial presentation, and video background distractions on their evaluation of the video. Multivariable logistic regressions were conducted using a group of applicants where interview status was not impacted by the video compared with the group of applicants where the interview status changed after video review. An alpha value of 0.05 was used to define significance. RESULTS: The video prompt impacted the decision to offer an interview 29.3% of the time; 15.8% were switched from "yes" or "maybe" to "no" and 13.5% were switched from "no" or "maybe" to "yes." For the positively impacted applicants, facial presentation score was significantly higher (P = 0.005). No recorded variables were associated with decreased chance of interview. DISCUSSION: Video prompts impacted the decision to offer interviews to orthopaedic surgery applicants approximately one-third of the time, with a similar number of applicants being positively and negatively impacted. Facial presentation score was associated with increased chance of interview, and no variables were associated with decreased chance of interview. Thus, the answer to the videos presumably negatively impacted applicants.

2.
bioRxiv ; 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38915707

RESUMO

Injury can cause differentiated cells to undergo massive reprogramming to become proliferative to repair tissue via a cellular program called paligenosis. Gastric digestive-enzyme-secreting chief cells use paligenosis to reprogram into progenitor-like Spasmolytic-Polypeptide Expressing Metaplasia (SPEM) cells. Stage 1 of paligenosis is to downscale mature cell architecture via a process involving lysosomes. Here, we noticed that sulfated glycoproteins (which are metaplasia and cancer markers in mice and humans) were not digested during paligenosis but excreted into the gland lumen. Various genetic and pharmacological approaches showed that endoplasmic reticulum membranes and secretory granule cargo were also excreted and that the process proceeded in parallel with, but was independent lysosomal activity. 3-dimensional light and electron-microscopy demonstrated that excretion occurred via unique, complex, multi-chambered invaginations of the apical plasma membrane. As this lysosome-independent cell cleansing process does not seem to have been priorly described, we termed it "cathartocytosis". Cathartocytosis allows a cell to rapidly eject excess material (likely in times of extreme stress such as are induced by paligenosis) without waiting for autophagic and lysosomal digestion. We speculate the ejection of sulfated glycoproteins (likely mucins) would aid in downscaling and might also help bind and flush pathogens (like H pylori which causes SPEM) away from tissue.

3.
EMBO J ; 43(13): 2530-2551, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38773319

RESUMO

A pervasive view is that undifferentiated stem cells are alone responsible for generating all other cells and are the origins of cancer. However, emerging evidence demonstrates fully differentiated cells are plastic, can be coaxed to proliferate, and also play essential roles in tissue maintenance, regeneration, and tumorigenesis. Here, we review the mechanisms governing how differentiated cells become cancer cells. First, we examine the unique characteristics of differentiated cell division, focusing on why differentiated cells are more susceptible than stem cells to accumulating mutations. Next, we investigate why the evolution of multicellularity in animals likely required plastic differentiated cells that maintain the capacity to return to the cell cycle and required the tumor suppressor p53. Finally, we examine an example of an evolutionarily conserved program for the plasticity of differentiated cells, paligenosis, which helps explain the origins of cancers that arise in adults. Altogether, we highlight new perspectives for understanding the development of cancer and new strategies for preventing carcinogenic cellular transformations from occurring.


Assuntos
Diferenciação Celular , Neoplasias , Humanos , Animais , Neoplasias/patologia , Neoplasias/genética , Proteína Supressora de Tumor p53/metabolismo , Proteína Supressora de Tumor p53/genética , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/patologia , Células-Tronco , Carcinogênese/patologia
4.
Sarcoma ; 2024: 9926675, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38476458

RESUMO

Introduction: Bone sarcomas are known to have a predilection for pulmonary metastasis. Surveillance protocols are thus focused on periodic chest imaging, typically with CT scan. Pulmonary nodules can be easily identified with this modality, but smaller nodules are not readily biopsied and may not represent metastatic disease. These are called indeterminate. The natural history of indeterminate nodules in a bone sarcoma population and factors associated with progression to true metastatic disease are not clearly defined. Methods: All bone sarcoma patients treated at a single institution from 2010 to 2020 were eligible for inclusion. We treated 327 patients over this period; 119 were excluded for age less than 16 years, 31 were excluded for evident metastatic disease at presentation, and 60 were excluded for incomplete clinical follow-up or CT chest imaging either at staging or in surveillance. We assessed chest CT images for presence of pulmonary nodules and selected variables both at the staging and on surveillance images. Nodules were considered metastatic if proven histologically with a biopsy or by clinical interpretation by the multidisciplinary sarcoma team. Clinical and imaging factors were assessed for the association of indeterminate nodule progression to true metastatic disease. Results: Seventy three of the 117 patients had indeterminate nodules on their staging CT scan; 41.1% of those patients progressed to metastatic disease compared to 43.2% of the patients that did not have indeterminate nodules on staging CT. Fifty eight of the 117 patients developed indeterminate nodules on surveillance chest CT, and 55.2% of those patients progressed to metastatic disease. There were no clinical or imaging factors that predicted the development of metastatic disease in the group that had indeterminate nodules at presentation; however, the number and size of nodules did correlate with progression to metastasis in those that developed indeterminate nodules on surveillance. Conclusion: Indeterminate pulmonary nodules are common on staging CT scans in patients with a bone sarcoma. The presence or absence of these indeterminate nodules was not predictive of progression to true metastatic disease in this cohort. However, the development of indeterminate nodules on surveillance imaging was associated with progression to metastatic disease with the size and number of nodules being important factors.

5.
Neoplasia ; 48: 100956, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38199172

RESUMO

INTRODUCTION: Pleomorphic liposarcoma is a rare and aggressive subset of soft-tissue sarcomas with a high mortality burden. Local treatment largely consists of radiation therapy and wide surgical resection, but options for systemic therapy in the setting of metastatic disease are limited and largely ineffective, prompting exploration of novel therapeutic strategies and experimental models. As with other cancers, sarcoma cell lines and patient-derived xenograft models have been developed and used to characterize these tumors and identify therapeutic targets, but these models have inherent limitations. The establishment of genetically engineered mouse models represents a more realistic framework for reproducing clinically relevant conditions for studying pleomorphic liposarcoma. METHODS: Trp53fl/fl/Rb1fl/fl/Ptenfl/fl (RPP) mice were used to reliably generate an immunocompetent model of mouse pleomorphic liposarcoma through Cre-mediated conditional silencing of the Trp53, Rb1, and Pten tumor suppressor genes. Evaluation of tumor-infiltrating lymphocytes was assessed with immunostaining for CD4, CD8, and PD-L1, and flow cytometry with analysis of CD45, CD3, CD4, CD8, CD19, F4/80, CD11b, and NKp46 sub-populations. RESULTS: Mice reliably produced noticeable soft-tissue tumors in approximately 6 weeks with rapid tumor growth between 100 and 150 days of life, after which mice reached euthanasia criteria. Histologic features were consistent with pleomorphic liposarcoma, including widespread pleomorphic lipoblasts. Immunoprofiling and assessment of tumor-infiltrating lymphocytes was consistent with other soft-tissue sarcomas. CONCLUSION: Genetically engineered RPP mice reliably produced soft-tissue tumors consistent with pleomorphic liposarcoma, which immunological findings similar to other soft-tissue sarcomas. This model may demonstrate utility in testing treatments for this rare disease, including immunomodulatory therapies.


Assuntos
Lipossarcoma , Sarcoma , Neoplasias de Tecidos Moles , Humanos , Animais , Camundongos , Imunofenotipagem , Lipossarcoma/genética , Lipossarcoma/patologia , Sarcoma/genética , Neoplasias de Tecidos Moles/genética , Neoplasias de Tecidos Moles/patologia , Neoplasias de Tecidos Moles/terapia
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