Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 77
Filtrar
1.
PLoS Genet ; 18(9): e1010375, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36121899

RESUMO

In plants, regulated cell expansion determines organ size and shape. Several members of the family of redundantly acting Small Auxin Up RNA (SAUR) proteins can stimulate plasma membrane (PM) H+-ATPase proton pumping activity by inhibiting PM-associated PP2C.D phosphatases, thereby increasing the PM electrochemical potential, acidifying the apoplast, and stimulating cell expansion. Similarly, Arabidopsis thaliana SAUR63 was able to increase growth of various organs, antagonize PP2C.D5 phosphatase, and increase H+-ATPase activity. Using a gain-of-function approach to bypass genetic redundancy, we dissected structural requirements for SAUR63 growth-promoting activity. The divergent N-terminal domain of SAUR63 has a predicted basic amphipathic α-helix and was able to drive partial PM association. Deletion of the N-terminal domain decreased PM association of a SAUR63 fusion protein, as well as decreasing protein level and eliminating growth-promoting activity. Conversely, forced PM association restored ability to promote H+-ATPase activity and cell expansion, indicating that SAUR63 is active when PM-associated. Lipid binding assays and perturbations of PM lipid composition indicate that the N-terminal domain can interact with PM anionic lipids. Mutations in the conserved SAUR domain also reduced PM association in root cells. Thus, both the N-terminal domain and the SAUR domain may cooperatively mediate the SAUR63 PM association required to promote growth.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Membrana Celular/genética , Membrana Celular/metabolismo , Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos/metabolismo , Lipídeos , Monoéster Fosfórico Hidrolases/genética , ATPases Translocadoras de Prótons/genética , ATPases Translocadoras de Prótons/metabolismo , Prótons , RNA/metabolismo
2.
Appl Opt ; 61(30): 8974-8981, 2022 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-36607025

RESUMO

Tolerancing is a necessary task for practical designs. The system Jacobian is utilized here for the three sub-tasks of tolerancing. The first is tolerance analysis, which is evaluation of the perturbed system. Second is tolerance allocation, also known as tolerance budgeting and more widely known as error budgeting. The automatic allocation of tolerances is tolerance synthesis. The algorithm described accomplishes this by fitting an orthotope inside an ellipsoid. Third is compensator selection. Metrics are presented that correlate with the looseness of the allocated tolerances and hence with the effectiveness of the compensator set, thus enabling identification of the most optimum combination of compensators.

3.
Indian J Plast Surg ; 54(1): 53-57, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33814742

RESUMO

Background The process of reconstruction of tracheal defects is complex and still not optimum. Options range from using staged reconstructions, combining flaps with autologous or alloplastic implants, as well as use of tissue-engineered constructs combined with vascularized tissues which are lined with cell cultures. Staged reconstructions using prelaminated epithelium, and prefabricated flaps, help in reconstruction of this complex structure. Prefabricating the flap at a different site allows for integration of the tissues prior to its transfer. Method This article reports two patients planned for tracheal reconstruction for the purpose of advanced papillary carcinoma of the thyroid invading the trachea. Staged reconstruction using a prefabricated radial artery forearm flap (RAFF) and split rib cartilage was performed. In the second patient, a young girl, a similar construct of the RAFF, prelaminated with buccal mucosa, was performed. However, in the latter case, an intraoperative decision by the head and neck team to limit excision of the trachea sparing the mucosa was taken; the reconstruct in the forearm was redundant and needed to be discarded, replacing the defect with a free superficial circumflex iliac artery perforator (SCIP) flap. Result At 3 years follow-up, both the patients are free of disease, with the construct serving its purpose in the older female.

9.
Eur Arch Otorhinolaryngol ; 277(4): 1155-1165, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31897720

RESUMO

PURPOSE: Adequacy of surgical margins impacts outcomes in oral cancer. We sought to determine whether close and positive margins have different outcomes in patients with oral cancer. METHODS: Retrospective data from 612 patients with oral carcinoma were analyzed for the effect of margin status on locoregional recurrence-free survival (LRFS), disease-free survival (DFS) and overall survival (OS). RESULTS: A total of 90 cases (14.7%) had close margins and 26 patients (4.2%) had positive margins. Recurrences were documented in 173 patients (28%), of which 137 (22% of the study sample) were locoregional, and 164 patients (27%) had died. Among patients with close or positive margins, a cutoff of 1 mm optimally separated LRFS (adjusted p = 0.0190) and OS curves (adjusted p = 0.0168) whereas a cutoff of 2 mm was sufficient to significantly separate DFS curves (adjusted p = 0.0281). CONCLUSIONS: Patients with oral carcinoma with positive margins (< 1 mm) had poorer outcomes compared to those with close margins (1-5 mm) in terms of LRFS, DFS and OS. There is a suggestion that a cutoff of < 2 mm might provide slightly more separation for DFS.


Assuntos
Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Neoplasias Bucais , Carcinoma de Células Escamosas/cirurgia , Humanos , Margens de Excisão , Neoplasias Bucais/cirurgia , Recidiva Local de Neoplasia/epidemiologia , Estudos Retrospectivos , Carcinoma de Células Escamosas de Cabeça e Pescoço
14.
Appl Opt ; 54(6): 1439-42, 2015 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-25968211

RESUMO

This work explores the use of linear principal component analysis (PCA) during an optical design's tolerancing analysis. Chapman et al. [Proc. SPIE3331, 102 (1998)PSISDG0277-786X] have shown the usefulness of the singular value decomposition in realizing an alignment algorithm for a system. This paper explores some insights that can be gained from performing PCA on the Monte Carlo data set obtained during the tolerancing step and comparing it with the singular components of the Jacobian (sensitivity matrix) of the system.

16.
Cureus ; 16(9): e68661, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39371806

RESUMO

Solitary fibrous tumors (SFTs) of the central nervous system (CNS) are rare mesenchymal neoplasms with diverse histological characteristics ranging from benign to malignant. Their higher chance for metastasis and recurrence poses significant diagnostic and therapeutic challenges. In this study, we present a 53-year-old female with a recurrent SFT of the cervical spine that was diagnosed initially 12 years ago. The patient underwent repeated surgical resections including laminectomy and gamma knife radiosurgery, as well as temozolomide, bevacizumab, and pazopanib therapy. Despite these interventions, she experienced continuous disease progression, with the cancer spreading to vital CNS locations. This study demonstrates the locally invasive nature of CNS SFTs and their complicated treatments involving surgical excision, radiotherapy, and systemic chemotherapy. This study highlights the need for new therapeutic approaches, as the existing methods fall short in meeting all the requirements and continue to lag in targeted therapy research for CNS SFTs. Consequently, it is important to develop individualized treatment strategies for patients affected by such difficult conditions.

17.
J Orthop Case Rep ; 14(3): 29-34, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38560313

RESUMO

Introduction: To improve hemostasis and visibility, a tourniquet was used throughout the majority of hand and wrist procedures, despite the fact that patient experience unnecessary and excruciating pain from the tourniquet. The more current method known as wide-awake local anesthesia without tourniquet (WALANT) enables intraoperative function evaluation while the patient is completely conscious. Materials and Methods: Individuals with displaced distal radius fractures that required surgery and isolated, non-concomitant injuries requiring spinal or general anesthesia were considered for WALANT technique. In our study, five patients underwent dorsal plate fixation and five patients underwent volar plate fixation. Patients receiving dorsal plate fixation required definite dorsal buttress to prevent radiocarpal dislocation. Conclusion: The WALANT technique is a simple, reliable, and effective anesthetic method for internal fixation and open reduction of distal radius fractures. Since a tourniquet is not necessary, the patient is protected from the discomfort and risks associated with one.

18.
Cureus ; 16(9): e68542, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39364500

RESUMO

Immune checkpoint inhibitors (ICIs), including Imfinzi (durvalumab), have revolutionized cancer treatment by stimulating the body's immune system to target cancerous cells. Although pharmaceuticals offer therapeutic benefits, several drugs have been associated with immune-related adverse events (irAEs), including the uncommon but serious condition known as myasthenia gravis (MG). This review synthesizes data from pertinent research to offer a thorough evaluation of the literature on the underlying mechanisms, clinical manifestations, and therapeutic approaches for durvalumab-induced MG. The incidence of MG in patients on durvalumab and other ICIs is typically low, with less than 1% documented, despite the potential for severe problems associated with the disease. Durvalumab disrupts immunological tolerance by stimulating autoreactive T-cells and inducing the production of autoantibodies. The clinical consequences of MG need meticulous monitoring, prompt identification, and suitable management to efficiently control the condition. Medical practitioners must carefully weigh the positive effects of ICIs against the possible hazards, emphasizing the necessity for more extensive investigation to improve patient results and establish uniform treatment protocols.

19.
Cureus ; 16(8): e67010, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39280497

RESUMO

Cardiovascular diseases (CVDs) are a leading cause of mortality worldwide. Recent research has identified gut dysbiosis - an imbalance in the gut microbiota - as a significant factor in the development of CVDs. This complex relationship between gut microbiota and cardiovascular health involves various mechanisms, including the production of metabolites such as trimethylamine N-oxide (TMAO) and short-chain fatty acids (SCFAs). These metabolites influence lipid metabolism, inflammation, and blood pressure regulation. In addition, the gut-brain axis and neurohormonal pathways play crucial roles in cardiovascular function. Epidemiological studies have linked gut dysbiosis to various cardiovascular conditions, highlighting the potential for therapeutic interventions. Dietary changes, probiotics, and prebiotics have shown promise in modulating gut microbiota and reducing cardiovascular risk factors. This underscores the critical role of gut health in preventing and treating CVDs. However, further research is needed to develop targeted therapies that can enhance cardiovascular outcomes.

20.
Cureus ; 16(9): e68748, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39371877

RESUMO

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that causes extensive inflammation and tissue destruction across several organs. Conventional therapies, such as nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, and immunosuppressive drugs, can have serious adverse effects and are not always successful. This study looks at the possibility of low-dose interleukin-2 (IL-2) therapy as a new treatment for SLE, focusing on its mechanics, effectiveness, and clinical applicability. Low-dose IL-2 treatment selectively increases and activates regulatory T cells (Tregs), which are essential for immunological tolerance but are often lacking in SLE patients. Unlike standard medicines, which widely inhibit the immune system, low-dose IL-2 provides a more tailored approach with fewer side effects. We examined preclinical and clinical research and discovered that low-dose IL-2 dramatically enhances Treg numbers and function, lowers disease activity, and improves clinical outcomes. The primary molecular processes include the stimulation of the Janus kinase - signal transducer of activators of transcription (JAK-STAT), phosphatidylinositol 3-kinase - protein kinase B (PI3K-Akt), and mitogen­activated protein kinase (MAPK) pathways, which enhance Treg proliferation, survival, and activity. A thorough review of clinical studies finds that low-dose IL-2 treatment is well-tolerated and effective, with fewer side effects than biologics like belimumab and rituximab. Furthermore, IL-2 therapy provides prospects for combination therapies, which may improve therapeutic success by addressing numerous components of the immune response. Despite these encouraging findings, problems such as patient response variability and the need for long-term safety data persist. Future research should prioritize refining dose regimes, discovering biomarkers for patient selection, and investigating combination medicines. Addressing these issues might solidify low-dose IL-2 treatment as a cornerstone in SLE care, providing a more accurate and individualized approach to immune regulation while considerably improving patient outcomes.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA