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1.
Phys Med Biol ; 69(11)2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38749468

RESUMO

Objective.Fast and accurate deformable image registration (DIR), including DIR uncertainty estimation, is essential for safe and reliable clinical deployment. While recent deep learning models have shown promise in predicting DIR with its uncertainty, challenges persist in proper uncertainty evaluation and hyperparameter optimization for these methods. This work aims to develop and evaluate a model that can perform fast DIR and predict its uncertainty in seconds.Approach.This study introduces a novel probabilistic multi-resolution image registration model utilizing convolutional neural networks to estimate a multivariate normal distributed dense displacement field (DDF) in a multimodal image registration problem. To assess the quality of the DDF distribution predicted by the model, we propose a new metric based on the Kullback-Leibler divergence. The performance of our approach was evaluated against three other DIR algorithms (VoxelMorph, Monte Carlo dropout, and Monte Carlo B-spline) capable of predicting uncertainty. The evaluation of the models included not only the quality of the deformation but also the reliability of the estimated uncertainty. Our application investigated the registration of a treatment planning computed tomography (CT) to follow-up cone beam CT for daily adaptive radiotherapy.Main results.The hyperparameter tuning of the models showed a trade-off between the estimated uncertainty's reliability and the deformation's accuracy. In the optimal trade-off, our model excelled in contour propagation and uncertainty estimation (p <0.05) compared to existing uncertainty estimation models. We obtained an average dice similarity coefficient of 0.89 and a KL-divergence of 0.15.Significance.By addressing challenges in DIR uncertainty estimation and evaluation, our work showed that both the DIR and its uncertainty can be reliably predicted, paving the way for safe deployment in a clinical environment.


Assuntos
Processamento de Imagem Assistida por Computador , Redes Neurais de Computação , Incerteza , Processamento de Imagem Assistida por Computador/métodos , Humanos , Algoritmos , Planejamento da Radioterapia Assistida por Computador/métodos , Tomografia Computadorizada de Feixe Cônico/métodos
2.
J Clin Invest ; 134(9)2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38530366

RESUMO

Aberrant expression of the E26 transformation-specific (ETS) transcription factors characterizes numerous human malignancies. Many of these proteins, including EWS:FLI1 and EWS:ERG fusions in Ewing sarcoma (EwS) and TMPRSS2:ERG in prostate cancer (PCa), drive oncogenic programs via binding to GGAA repeats. We report here that both EWS:FLI1 and ERG bind and transcriptionally activate GGAA-rich pericentromeric heterochromatin. The respective pathogen-like HSAT2 and HSAT3 RNAs, together with LINE, SINE, ERV, and other repeat transcripts, are expressed in EwS and PCa tumors, secreted in extracellular vesicles (EVs), and are highly elevated in plasma of patients with EwS with metastatic disease. High human satellite 2 and 3 (HSAT2,3) levels in EWS:FLI1- or ERG-expressing cells and tumors were associated with induction of G2/M checkpoint, mitotic spindle, and DNA damage programs. These programs were also activated in EwS EV-treated fibroblasts, coincident with accumulation of HSAT2,3 RNAs, proinflammatory responses, mitotic defects, and senescence. Mechanistically, HSAT2,3-enriched cancer EVs induced cGAS-TBK1 innate immune signaling and formation of cytosolic granules positive for double-strand RNAs, RNA-DNA, and cGAS. Hence, aberrantly expressed ETS proteins derepress pericentromeric heterochromatin, yielding pathogenic RNAs that transmit genotoxic stress and inflammation to local and distant sites. Monitoring HSAT2,3 plasma levels and preventing their dissemination may thus improve therapeutic strategies and blood-based diagnostics.


Assuntos
Dano ao DNA , Vesículas Extracelulares , Proteínas de Fusão Oncogênica , Proteína Proto-Oncogênica c-fli-1 , Proteína EWS de Ligação a RNA , Regulador Transcricional ERG , Humanos , Vesículas Extracelulares/metabolismo , Vesículas Extracelulares/genética , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Regulador Transcricional ERG/genética , Regulador Transcricional ERG/metabolismo , Masculino , Proteína EWS de Ligação a RNA/genética , Proteína EWS de Ligação a RNA/metabolismo , Proteína Proto-Oncogênica c-fli-1/genética , Proteína Proto-Oncogênica c-fli-1/metabolismo , Sarcoma de Ewing/genética , Sarcoma de Ewing/patologia , Sarcoma de Ewing/metabolismo , Sarcoma de Ewing/imunologia , Linhagem Celular Tumoral , RNA Neoplásico/genética , RNA Neoplásico/metabolismo , Inflamação/genética , Inflamação/metabolismo , Inflamação/patologia , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Neoplasias da Próstata/metabolismo , Camundongos , Animais , Heterocromatina/metabolismo , Heterocromatina/genética
3.
Biomater Sci ; 12(7): 1801-1821, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38407241

RESUMO

The degeneration of neurons due to the accumulation of misfolded amyloid aggregates in the central nervous system (CNS) is a fundamental neuropathology of Alzheimer's disease (AD). It is believed that dislodging/clearing these amyloid aggregates from the neuronal tissues could lead to a potential cure for AD. In the present work, we explored biocompatible polydopamine-coated piezoelectric polyvinylidene fluoride (DPVDF) nanospheres as acoustic stimulus-triggered anti-fibrillating and anti-amyloid agents. The nanospheres were tested against two model amyloidogenic peptides, including the reductionist model-based amyloidogenic dipeptide, diphenylalanine, and the amyloid polypeptide, amyloid beta (Aß42). Our results revealed that DPVDF nanospheres could effectively disassemble the model peptide-derived amyloid fibrils under suitable acoustic stimulation. In vitro studies also showed that the stimulus activated DPVDF nanospheres could efficiently alleviate the neurotoxicity of FF fibrils as exemplified in neuroblastoma, SHSY5Y, cells. Studies carried out in animal models further validated that the nanospheres could dislodge amyloid aggregates in vivo and also help the animals regain their cognitive behavior. Thus, these acoustic stimuli-activated nanospheres could serve as a novel class of disease-modifying nanomaterials for non-invasive electro-chemotherapy of Alzheimer's disease.


Assuntos
Doença de Alzheimer , Nanosferas , Animais , Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/uso terapêutico , Fragmentos de Peptídeos/uso terapêutico , Amiloide , Modelos Animais de Doenças
4.
Phys Chem Chem Phys ; 25(44): 30211-30222, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37830431

RESUMO

Clean energy is one of the immediate requirements all over the world to tackle the global energy demands. Natural gas hydrates (NGHs) are one of the proposed alternatives that could be used to extract methane as clean energy and simultaneously sequestrate carbon dioxide. However, the formation of CH4-CO2 mixed hydrates and the first hydrate layer besides the interface reduces the rate of CO2 sequestration and methane extraction in NGHs, and thus, multistep extraction of methane is one of the proposed solutions. We report the atomic level factors that could enhance CO2 sequestration in the newly formed first hydrate layer besides the interface in the presence of flue and noble gases using DFT calculations and molecular dynamics simulations at 250 K and 0.15 kbar. The simulations show the formation of stable dual cages (large-large or small-large) that lead to the formation of a four-caged, Y-shaped cluster (growth synthon) which leads to the formation of a hydrate unit cell in heterogeneous medium. Among the flue and noble gases, only argon forms energetically favorable dual cages with itself and CO2 due to which enhanced CO2 sequestration is observed at different concentrations of Ar and CO2 where the CO2 : Ar (2.5 : 1.5) system shows the best CO2 sequestration in the first layer besides the interface. The results also provide understanding into the previously reported concentration dependent CO2 selectivity in sI hydrates in the presence of third gases (N2 and H2S).

5.
Sci Rep ; 13(1): 18293, 2023 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-37880299

RESUMO

Nano-scale extracellular vesicles are lipid-bilayer delimited particles that are naturally secreted by all cells and have emerged as valuable biomarkers for a wide range of diseases. Efficient isolation of small extracellular vesicles while maintaining yield and purity is crucial to harvest their potential in diagnostic, prognostic, and therapeutic applications. Most conventional methods of isolation suffer from significant shortcomings, including low purity or yield, long duration, need for large sample volumes, specialized equipment, trained personnel, and high costs. To address some of these challenges, our group has reported a novel insulator-based dielectrophoretic device for rapid isolation of small extracellular vesicles from biofluids and cell culture media based on their size and dielectric properties. In this study, we report a comprehensive characterization of small extracellular vesicles isolated from cancer-patients' biofluids at a twofold enrichment using the device. The three-fold characterization that was performed using conventional flow cytometry, advanced imaging flow cytometry, and microRNA sequencing indicated high yield and purity of the isolated small extracellular vesicles. The device thus offers an efficient platform for rapid isolation while maintaining biomolecular integrity.


Assuntos
Vesículas Extracelulares , Neoplasias , Humanos , Biomarcadores , Neoplasias/diagnóstico , Dispositivos Lab-On-A-Chip
6.
Front Oncol ; 13: 1124838, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37143943

RESUMO

Purpose: The aim of this work was two-fold: a) to assess two treatment planning strategies for accounting CT artifacts introduced by temporary tissue-expanders (TTEs); b) to evaluate the dosimetric impact of two commercially available and one novel TTE. Methods: The CT artifacts were managed using two strategies. 1) Identifying the metal in the RayStation treatment planning software (TPS) using image window-level adjustments, delineate a contour enclosing the artifact, and setting the density of the surrounding voxels to unity (RS1). 2) Registering a geometry template with dimensions and materials from the TTEs (RS2). Both strategies were compared for DermaSpan, AlloX2, and AlloX2-Pro TTEs using Collapsed Cone Convolution (CCC) in RayStation TPS, Monte Carlo simulations (MC) using TOPAS, and film measurements. Wax slab phantoms with metallic ports and breast phantoms with TTEs balloons were made and irradiated with a 6 MV AP beam and partial arc, respectively. Dose values along the AP direction calculated with CCC (RS2) and TOPAS (RS1 and RS2) were compared with film measurements. The impact in dose distributions was evaluated with RS2 by comparing TOPAS simulations with and without the metal port. Results: For the wax slab phantoms, the dose differences between RS1 and RS2 were 0.5% for DermaSpan and AlloX2 but 3% for AlloX2-Pro. From TOPAS simulations of RS2, the impact in dose distributions caused by the magnet attenuation was (6.4 ± 0.4) %, (4.9 ± 0.7)%, and (2.0 ± 0.9)% for DermaSpan, AlloX2, and AlloX2-Pro, respectively. With breast phantoms, maximum differences in DVH parameters between RS1 and RS2 were as follows. For AlloX2 at the posterior region: (2.1 ± 1.0)%, (1.9 ± 1.0)% and (1.4 ± 1.0)% for D1, D10, and average dose, respectively. For AlloX2-Pro at the anterior region (-1.0 ± 1.0)%, (-0.6 ± 1.0)% and (-0.6 ± 1.0)% for D1, D10 and average dose, respectively. The impact in D10 caused by the magnet was at most (5.5 ± 1.0)% and (-0.8 ± 1.0)% for AlloX2 and AlloX2-Pro, respectively. Conclusion: Two strategies for accounting for CT artifacts from three breast TTEs were assessed using CCC, MC, and film measurements. This study showed that the highest differences with respect to measurements occurred with RS1 and can be mitigated if a template with the actual port geometry and materials is used.

7.
3 Biotech ; 13(5): 151, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37131965

RESUMO

Antibiotics and immunotherapies possess unavoidable adverse effects that hinder sepsis management. Herbal drugs have demonstrated potential immunomodulatory properties vital for sepsis treatment. We hypothesized in the present study that the use of Carica papaya leaves extract had the potential to improve survival and modulate immune cytokine release during sepsis. Animals were subjected to cecal ligation and puncture (CLP) to induce sepsis. Septic rats divided into 10 groups received ethanol extract of C. papaya leaves (50 and 100 mg/kg), imipenem (120 mg/kg) and cyclophosphamide (CP, 10 mg/kg). To investigate the immunomodulatory potentials of EE, cytokine levels like interleukin (IL-6), tumor necrosis factor (TNF-α), and IL-10 along with hematological and biochemical parameters were analyzed. Our results exhibited improved survival rates concerning ethanol extract treatment alone and in combination with imipenem and CP (100%) as compared to the CLP group (33.3%) on day 7 post-surgery. The combination treatment of ethanol extract with imipenem and CP significantly (P < 0.001) ameliorated cytokine levels and hematological and biochemical parameters in septic rats. A histopathological examination suggested improved liver and kidney tissue condition after combination treatment as compared to the CLP group. Therefore, it was concluded that combination therapy of extract with imipenem and CP improved survival rates and marked immunomodulatory potential in septic rats compared to monotherapy. The findings suggested the use of a mixture of these drugs in clinical settings to treat sepsis.

8.
Front Cell Infect Microbiol ; 13: 1134119, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37091679

RESUMO

Mucosal-associated invariant T (MAIT) cells are protective against tuberculous and non-tuberculous mycobacterial infections with poorly understood mechanisms. Despite an innate-like nature, MAIT cell responses remain heterogeneous in bacterial infections. To comprehensively characterize MAIT activation programs responding to different bacteria, we stimulated MAIT cells with E. coli to compare with Bacillus Calmette-Guérin (BCG), which remains the only licensed vaccine and a feasible tool for investigating anti-mycobacterial immunity in humans. Upon sequencing mRNA from the activated and inactivated CD8+ MAIT cells, results demonstrated the altered MAIT cell gene profiles by each bacterium with upregulated expression of activation markers, transcription factors, cytokines, and cytolytic mediators crucial in anti-mycobacterial responses. Compared with E. coli, BCG altered more MAIT cell genes to enhance cell survival and cytolysis. Flow cytometry analyses similarly displayed a more upregulated protein expression of B-cell lymphoma 2 and T-box transcription factor Eomesodermin in BCG compared to E.coli stimulations. Thus, the transcriptomic program and protein expression of MAIT cells together displayed enhanced pro-survival and cytotoxic programs in response to BCG stimulation, supporting BCG induces cell-mediated effector responses of MAIT cells to fight mycobacterial infections.


Assuntos
Antineoplásicos , Células T Invariantes Associadas à Mucosa , Mycobacterium bovis , Tuberculose , Humanos , Células T Invariantes Associadas à Mucosa/microbiologia , Vacina BCG , Transcriptoma , Escherichia coli/genética
9.
Int J Radiat Oncol Biol Phys ; 116(5): 1202-1217, 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37121362

RESUMO

FLASH radiation therapy (FLASH-RT), delivered with ultrahigh dose rate (UHDR), may allow patients to be treated with less normal tissue toxicity for a given tumor dose compared with currently used conventional dose rate. Clinical trials are being carried out and are needed to test whether this improved therapeutic ratio can be achieved clinically. During the clinical trials, quality assurance and credentialing of equipment and participating sites, particularly pertaining to UHDR-specific aspects, will be crucial for the validity of the outcomes of such trials. This report represents an initial framework proposed by the NRG Oncology Center for Innovation in Radiation Oncology FLASH working group on quality assurance of potential UHDR clinical trials and reviews current technology gaps to overcome. An important but separate consideration is the appropriate design of trials to most effectively answer clinical and scientific questions about FLASH. This paper begins with an overview of UHDR RT delivery methods. UHDR beam delivery parameters are then covered, with a focus on electron and proton modalities. The definition and control of safe UHDR beam delivery and current and needed dosimetry technologies are reviewed and discussed. System and site credentialing for large, multi-institution trials are reviewed. Quality assurance is then discussed, and new requirements are presented for treatment system standard analysis, patient positioning, and treatment planning. The tables and figures in this paper are meant to serve as reference points as we move toward FLASH-RT clinical trial performance. Some major questions regarding FLASH-RT are discussed, and next steps in this field are proposed. FLASH-RT has potential but is associated with significant risks and complexities. We need to redefine optimization to focus not only on the dose but also on the dose rate in a manner that is robust and understandable and that can be prescribed, validated, and confirmed in real time. Robust patient safety systems and access to treatment data will be critical as FLASH-RT moves into the clinical trials.


Assuntos
Credenciamento , Elétrons , Humanos , Instalações de Saúde , Posicionamento do Paciente , Tecnologia , Dosagem Radioterapêutica
10.
Adv Exp Med Biol ; 1408: 291-308, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37093434

RESUMO

Prostate-specific membrane antigen (PSMA) is expressed in epithelial cells of the prostate gland and is strongly upregulated in prostatic adenocarcinoma, with elevated expression correlating with metastasis, progression, and androgen independence. Because of its specificity, PSMA is a major target of prostate cancer therapy; however, detectable levels of PSMA are also found in other tissues, especially in salivary glands and kidney, generating bystander damage of these tissues. Antibody target therapy has been used with relative success in reducing tumor growth and prostate specific antigen (PSA) levels. However, since antibodies are highly stable in plasma, they have prolonged time in circulation and accumulate in organs with an affinity for antibodies such as bone marrow. For that reason, a second generation of PSMA targeted therapeutic agents has been developed. Small molecules and minibodies have had promising clinical trial results, but concerns about their specificity had arisen with side effects due to accumulation in salivary glands and kidneys. Herein we study the specificity of small molecules and minibodies that are currently being clinically tested. We observed a high affinity of these molecules for PSMA in prostate, kidney and salivary gland, suggesting that their effect is not prostate specific. The search for specific prostate target agents must continue so as to optimally treat patients with prostate cancer, while minimizing deleterious effects in other PSMA expressing tissues.


Assuntos
Neoplasias da Próstata , Masculino , Humanos , Neoplasias da Próstata/patologia , Antígenos de Superfície/metabolismo , Antígeno Prostático Específico
11.
J Oncol Pharm Pract ; 29(8): 1928-1934, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36862651

RESUMO

PURPOSE: In this study, we investigate renal function and anaemia during imatinib treatment in patients with chronic myeloid leukaemia. METHODS: The patients with chronic myeloid leukaemia with chronic phase who had been treated with only imatinib for 12 months at Rajiv Gandhi Cancer Institute and Research Centre (New Delhi, India) were enrolled and prospectively analysed. The chronic renal impairment parameters, including estimated glomerular filtration rate and haemoglobin levels for anaemia from June 2020 to June 2022, were monitored in newly diagnosed in patients with chronic myeloid leukaemia-chronic phase. The data were analysed by SPSS software version 22. RESULTS: In total 55 patients with chronic myeloid leukaemia chronic phase who had been on imatinib for 12 months were monitored. The mean estimated glomerular filtration rate was significantly decreased (74 ± 14 to 59 ± 12 mL/min/1.73m2, p < 0.001) with a decrease in mean haemoglobin levels after 12 months (10.9 ± 2.01 to 9.0 ± 1.02, p < 0.004). The decreased estimated glomerular filtration rate was negatively correlated with haemoglobin levels after 1 year of imatinib administration (correlation coefficient = 0.892, R2 = 0.7976, p < 0.05). CONCLUSION: We recommended close monitoring of renal function and haemoglobin levels in patients with chronic myeloid leukaemia patients.


Assuntos
Anemia , Antineoplásicos , Leucemia Mielogênica Crônica BCR-ABL Positiva , Insuficiência Renal Crônica , Humanos , Mesilato de Imatinib/efeitos adversos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Anemia/induzido quimicamente , Hemoglobinas , Inibidores de Proteínas Quinases/uso terapêutico , Antineoplásicos/efeitos adversos
12.
Curr Rev Clin Exp Pharmacol ; 18(2): 148-157, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35293301

RESUMO

BACKGROUND: Imatinib is one of the tyrosine kinase inhibitors used for the treatment of chronic myeloid leukemia (CML) patients. The exact association of imatinib with anemia in CML patients is still unclear. AIM: The current study aimed to find the prevalence of anemia in chronic myeloid leukemia patients treated with imatinib. METHODS: The relevant articles were searched in PubMed, Google scholar, and Clinical trials registries till 31st July, 2021. The quality of the articles was assessed using the Newcastle-Ottawa Scale. The prevalence rate with 95% CI was calculated using StatsDirect Statistical analysis software V.3. RESULTS: A total of 18 studies containing 3537 patients were found relevant for the analysis. The pooled prevalence of anemia in CML was found to be 34% (95% CI: 23%-46%). However, the heterogeneity among studies was found to be high. CONCLUSION: The monitoring of hemoglobin levels and identifying the cause of anemia are major concerns for the CML patients treated with Imatinib.


Assuntos
Anemia , Leucemia Mielogênica Crônica BCR-ABL Positiva , Humanos , Mesilato de Imatinib/efeitos adversos , Prevalência , Inibidores de Proteínas Quinases/efeitos adversos , Pirimidinas/efeitos adversos , Leucemia Mielogênica Crônica BCR-ABL Positiva/complicações , Anemia/epidemiologia
13.
J Nepal Health Res Counc ; 20(2): 499-504, 2022 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-36550735

RESUMO

BACKGROUND: Cervical cancer is the most common cancer among Nepalese women. Cervical cancer screening plays a vital role in reducing the morbidity and mortality of the disease. In this study, we assessed the prevalence of precancerous lesions of cervical cancer from community-based screening programs in Nepal. METHODS: In this cross-sectional study involving record review, data were drawn from community-based screening programs in 14 districts by B.P. Koirala Memorial Cancer Hospital in Nepal. All women who underwent cervical cancer screening using visual inspection with acetic acid between June 2017 to December 2018 were included. RESULTS: A total of 7,270 women were screened during the study period with the prevalence of cervical precancerous lesions among 153 (2.1%; 95% Confidence Interval 1.8-2.5) participants. Of which, the highest positivity rate was observed in the age group 30 years and below (46, 3%). The majority (4453, 61%) of the total women screened, were married at age below 20 years and 188 (3%) reported a history of cancer in their families. The most common presenting complaints were low abdominal pain (1236, 17%), low back pain (1152, 16%), itching in the anogenital region (828, 11%), and per vaginal discharge (818, 11%). Cervical cancer was suspected in 25 (0.3%) women. CONCLUSIONS: The prevalence of precancerous lesions of cervical cancer is low but with high existing risk factors among Nepalese women of selected districts. The government should implement effective and sustained cervical cancer awareness and population-based screening programs along with a continuum of care. The national criteria for screening should also include young women with known risk factors.


Assuntos
Lesões Pré-Cancerosas , Neoplasias do Colo do Útero , Feminino , Humanos , Adulto Jovem , Adulto , Masculino , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/epidemiologia , Neoplasias do Colo do Útero/patologia , Ácido Acético , Detecção Precoce de Câncer , Estudos Transversais , Nepal/epidemiologia , Lesões Pré-Cancerosas/diagnóstico
14.
Int J Radiat Oncol Biol Phys ; 114(3): 537-544, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-35863671

RESUMO

PURPOSE: To develop and compare tumor-control probability (TCP) models for single-fraction stereotactic radiosurgery (SRS) for brain metastasis (BMs) with and without retreatment. METHODS AND MATERIALS: We developed three different schemas to model TCP of BMs treated with linear accelerator-based SRS. Dose to 99% of each planning target volume (PTV D99) and 6-month local control were fit using linear-quadratic-linear (LQ-L) models based on equivalent-dose conversions in 2 Gy (EQD2). The M1 schema had separate LQ-L TCP models for initial dose (M1-initial) and retreatment dose (M1-retreat), and the M2 schema had an LQ-L model using the sum of 50% of the initial SRS dose plus the retreatment SRS dose. The M1-initial and M1-retreat schema modeled local control after first SRS to 48 lesions (patients = 22) and second SRS to 46 lesions (patients = 21). The M0 schema included a whole data set of 349 lesions (patients = 136) receiving first SRS (no retreatment and M1-initial). RESULTS: LQ-L models fitted the data well (χ2 = 0.059-0.525 and P = 0.999-1.000). For M0 and M1-retreat, the fitted models EQD250 and γ50 parameters were similar. The LQ-L fitted EQD250 was ∼8.0 Gy for M0 and M1-retreat, ∼24 Gy for M1-initial, and ∼19 Gy for M2. The model fitted γ50 was 0.1 Gy for M0, M1-retreat, and M2 and 0.5 for M1-initial. For the PTV D99 of 10 and 20 Gy, the steepest to shallowest dose-response or largest change in TCP, that is, TCP20Gy - TCP10Gy, was observed in M1-initial (0.49) and M2 (0.17). M0 and M1-retreat showed a similar change in TCP of 0.21. CONCLUSIONS: The model-fitted parameters predicted the recurrent BMs required a higher threshold dose and had a steeper dose-response for first SRS versus second SRS and M0. Alternatively, the recurrent BMs required ∼2 Gy higher predicted PTV D99 dose for first SRS to achieve the same TCP of 0.75 compared with second SRS and M0. Further investigations on larger patient cohorts are needed for validating our findings in predictive modeling of recurrent BMs.


Assuntos
Neoplasias Encefálicas , Radiocirurgia , Neoplasias Encefálicas/secundário , Humanos , Probabilidade , Radiocirurgia/métodos , Retratamento
15.
Radiother Oncol ; 166: 195-202, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34843841

RESUMO

PURPOSE: To suggest PTV margins for liver SBRT with different motion management strategies based on a systematic review and meta-analysis. METHODS: In accordance with Preferred-Reporting-Items-for-Systematic-Reviews-and-Meta-Analyses (PRISMA), a systematic review in PubMed, Embase and Medline databases was performed for liver tumor position variability. From an initial 533 studies published before October 2020, 36 studies were categorized as 18 free-breathing (FB; npatients = 401), 9 abdominal compression (AC; npatients = 145) and 9 breath-hold (BH; npatients = 126). A meta-analysis was performed on inter- and intra-fraction position variability to report weighted-mean with 95% confidence interval (CI95) in superior-inferior (SI), left-right (LR) and anterior-posterior (AP) directions. Furthermore, weighted-mean ITV margins were computed for FB (nstudies = 15, npatients = 373) and AC (nstudies = 6, npatients = 97) and PTV margins were computed for FB (nstudies = 6, npatients = 95), AC (nstudies = 7, npatients = 106) and BH (nstudies = 8, npatients = 133). RESULTS: The FB weighted-mean intra-fraction variability, ITV margins and weighted-standard-deviation in mm were SI-9.7, CI95 = 9.3-10.1, 13.5 ± 4.9; LR-5.4, CI95 = 5.3-5.6, 7.3 ± 7.9; and AP-4.2, CI95 = 4.0-4.4, 6.3 ± 7.6. The inter-fraction-based results were SI-4.7, CI95 = 4.3-5.1, 5.7 ± 1.7; LR-1.4, CI95 = 1.1-1.6, 3.6 ± 2.7; and AP-2.8, CI95 = 2.5-3.1, 4.8 ± 2.1. For AC intra-fraction results in mm were SI-1.8, CI95 = 1.6-2.0, 2.6 ± 1.2; LR-0.7, CI95 = 0.6-0.8, 1.7 ± 1.5; and AP-0.9, CI95 = 0.8-1.0, 1.9 ± 1.7. The inter-fraction results were SI-2.6, CI95 = 2.3-3.0, 5.2 ± 2.9; LR-1.9, CI95 = 1.7-2.1, 4.0 ± 2.2; and AP-2.9, CI95 = 2.5-3.2, 5.8 ± 2.7. For BH the inter-fraction variability, and the weighted-mean PTV margins and weighted-standard-deviation in mm were SI-2.4, CI95 = 2.1-2.7, 5.6 ± 2.9; LR-1.8, CI95 = 1.3-2.2, 5.5 ± 1.7; and AP-1.4; CI95 = 1.2-1.7, 6.1 ± 2.1. CONCLUSION: Our meta-analysis suggests a symmetric weighted-mean PTV margin of 6 mm might be appropriate for BH. For AC and FB, asymmetric PTV margins (weighted-mean margin of 4 mm (AP), 6 mm (SI/LR)) might be appropriate. For FB, if larger (>ITV margin) intra-fraction variability observed, the additional intra- and inter-fraction variability should be accounted in the PTV margin.


Assuntos
Neoplasias Hepáticas , Radiocirurgia , Suspensão da Respiração , Humanos , Neoplasias Hepáticas/radioterapia , Neoplasias Hepáticas/cirurgia , Movimento (Física) , Planejamento da Radioterapia Assistida por Computador
16.
Nephrology (Carlton) ; 27(4): 318-326, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34894374

RESUMO

BACKGROUND: Recently, multiple epidemiological studies have linked imatinib with the alteration of renal function in chronic myeloid leukaemia (CML) patients. This meta-analysis aimed to summarize the impact of imatinib use on renal function in CML patients. METHODS: A systematic search was conducted on MEDLINE and Embase to identify articles assessing the impact of imatinib exposure on renal function in CML patients. The risk of bias was assessed using the Newcastle-Ottawa scale (NOS). Two authors independently performed literature-screening, risk of bias and data extraction. The risk of renal dysfunction (chronic kidney disease or acute kidney injury) among imatinib users was computed as the primary outcome of interest. The certainty of findings was assessed using the grading of recommendations assessment, development and evaluation (GRADE) criteria. RESULTS: A total of nine articles qualified for inclusion in the systematic review, of which four articles were eligible for meta-analysis. Based on the scoring on NOS, majority of the included studies were found to be of moderate risk of bias. Majority of the studies (n = 6) reported significantly (p < .05) decrease in estimated glomerular filtration rate (eGFR) after imatinib treatment. The risk of developing renal dysfunction (chronic kidney disease or acute kidney injury) was found to be significantly higher in imatinib users as compared to other tyrosine kinase inhibitor (TKI) users with a pooled relative risk of 2.70 (95% CI: 1.49-4.91). Sensitivity analysis also revealed a consistently high risk of renal dysfunction with imatinib use. GRADE criteria revealed low certainty of evidence. CONCLUSION: This meta-analysis found an increased risk of renal dysfunction in imatinib users compared to other TKI users.


Assuntos
Leucemia Mielogênica Crônica BCR-ABL Positiva , Doença Crônica , Humanos , Mesilato de Imatinib/efeitos adversos , Rim/fisiologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/induzido quimicamente , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Inibidores de Proteínas Quinases/efeitos adversos
17.
Acta Biomater ; 131: 581-594, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34192572

RESUMO

Adverse local tissue reactions (ALTRs) are a prominent cause of hip implant failure. ALTRs are characterized by aseptic necrosis and leukocyte infiltration of synovial tissue. The prevalence of ALTRs in hips with failing metal implants, with highest rates occurring in patients with metal-on-metal articulations, suggests a role for CoCrMo corrosion in ALTR formation. Although hypersensitivity reactions are the most accepted etiology, the precise cellular mechanism driving ALTR pathogenesis remains enigmatic. Here we show that cobalt ions released by failing hip implants induce mitochondrial stress and cytokine secretion by synovial fibroblasts: the presumptive initiators of ALTR pathogenesis. We found that in-vitro treatment of synovial fibroblasts with cobalt, but not chromium, generated gene expression changes indicative of hypoxia and mitophagy responses also observed in ALTRs biopsies. Inflammatory factors secreted by cobalt-exposed synovial fibroblasts were among those most concentrated in ALTR synovial fluid. Furthermore, both conditioned media from cobalt-exposed synovial fibroblasts, and synovial fluid from ALTRs patients, elicit endothelial activation and monocyte migration. Finally, we identify the IL16/CTACK ratio in synovial fluid as a possible diagnostic marker of ALTRs. Our results provide evidence suggesting that metal ions induce cell stress in synovial fibroblasts that promote an inflammatory response consistent with initiating ALTR formation. STATEMENT OF SIGNIFICANCE: We demonstrate that the cytotoxic effects of cobalt ions on the synovial cells (fibroblast) is sufficient to trigger inflammation on hip joints with metal implants. Cobalt ions affect mitochondrial function, leading to the auto phagocytosis of mitochondria and trigger a hypoxic response. The cell's hypoxic response includes secretion of cytokines that are capable of trigger inflammation by activating blood vessels and enhancing leukocyte migration. Among the secreted cytokines is IL-16, which is highly concentrated in the synovial fluid of the patients with adverse local tissue reactions and could be use as diagnostic marker. In conclusion we define the cells of the hip joint as key players in triggering the adverse reactions to hip implants and providing biomarkers for early diagnosis of adverse reactions to hip implants.


Assuntos
Artroplastia de Quadril , Prótese de Quadril , Próteses Articulares Metal-Metal , Quimiocinas , Cromo , Cobalto/toxicidade , Citocinas , Fibroblastos , Prótese de Quadril/efeitos adversos , Humanos , Íons , Desenho de Prótese , Falha de Prótese , Estresse Fisiológico
18.
ACS Appl Mater Interfaces ; 12(39): 44180-44194, 2020 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-32870652

RESUMO

The aggregation of neurotoxic amyloid-ß (Aß) polypeptides into aberrant extracellular senile plaques is the major neuropathological hallmark of Alzheimer's disease (AD). Inhibiting aggregation of these peptides to control the progression of this deadly disease can serve as a viable therapeutic option. In the current work, inherently fluorescent theranostic dopamine-tryptophan nanocomposites (DTNPs) were developed and investigated for their amyloid inhibition propensity along with their ability to act as a cellular bioimaging agent in neuronal cells. The antiaggregation potency of the nanocomposites was further investigated against an in vitro established reductionist amyloid aggregation model consisting of a mere dipeptide, phenylalanine-phenylalanine (FF). As opposed to large peptide/protein-derived robust and high-molecular-weight amyloid aggregation models of Alzheimer's disease, our dipeptide-based amyloid model provides an edge over others in terms of the ease of handling, synthesis, and cost-effectiveness. Results demonstrated positive antiaggregation behavior of the DTNPs toward both FF-derived amyloid fibrils and preformed Aß-peptide fibers by means of electron microscopic and circular dichroism-based studies. Our results further pointed toward the neuroprotective effects of the DTNPs in neuroblastoma cells against FF amyloid fibril-induced toxicity and also that they significantly suppressed the accumulation of Aß42 oligomers in both cortex and hippocampus regions and improved cognitive impairment in an intracerebroventricular streptozotocin (ICV-STZ)-induced animal model of dementia. Besides, DTNPs also exhibited excellent fluorescent properties and light up the cytoplasm of neuroblastoma cells when being coincubated with cells, confirming their ability to serve as an intracellular bioimaging agent. Overall, these results signify the potency of the DTNPs as promising multifunctional theranostic agents for treating AD.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/antagonistas & inibidores , Corantes Fluorescentes/farmacologia , Nanocompostos/química , Fármacos Neuroprotetores/farmacologia , Nanomedicina Teranóstica , Doença de Alzheimer/induzido quimicamente , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Dopamina/química , Dopamina/farmacologia , Corantes Fluorescentes/química , Humanos , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Fármacos Neuroprotetores/química , Tamanho da Partícula , Agregados Proteicos/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Estreptozocina/administração & dosagem , Propriedades de Superfície , Triptofano/química , Triptofano/farmacologia
19.
Int J Biol Macromol ; 163: 2374-2391, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32961180

RESUMO

Cataract, the major cause of blindness worldwide occurs due to the misfolding and aggregation of the protein crystallin, which constitute a major portion of the lens protein. Other than the whole protein crystallin, the peptide sequences generated from crystallin as a result of covalent protein damage have also been shown to possess and foster protein aggregation, which can be established as crystallin aggregation models. Thus, the disaggregation or inhibition of these protein aggregates could be a viable approach to combat cataract and preserve lens proteostasis. Herein, we tried to explore the disruption as well as inhibition of the intact α-crystallin protein and α-crystallin derived model peptide aggregates by l-3,4-dihydroxyphenylalanine (levodopa) coated gold (Au) nano/micro-roses as modulators. Thioflavin T fluorescence enhancement assay, and electron microscopic analysis were being employed to probe the anti-aggregation behavior of the Au nano/micro-roses towards the aggregating α-crystallin peptides/protein. Further, computational studies were performed to reveal the nature of molecular interactions between the levodopa molecule and the α-crystallin derived model peptides. Interestingly, both levodopa coated Au nano/micro-roses were found to be capable of inhibiting as well as preventing the aggregation of the intact α-crystallin protein and other model peptides derived from it.


Assuntos
Anisotropia , Nanopartículas Metálicas/química , Peptídeos/química , alfa-Cristalinas/química , Ouro/química , Levodopa/farmacologia , Peptídeos/antagonistas & inibidores , Agregação Patológica de Proteínas/genética , alfa-Cristalinas/genética
20.
Brachytherapy ; 19(2): 228-233, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32085930

RESUMO

PURPOSE: To analyze the dosimetric impact and periprocedural outcomes with a bioabsorbable hydrogel rectal spacer injected during low-dose-rate (LDR) prostate brachytherapy implants. METHODS AND MATERIALS: A consecutive series of 80 patients implanted with stranded I-125 LDR brachytherapy seeds were evaluated, of which 40 underwent a transperineal injection of polyethylene glycol (5 cc) in between the prostate and rectum. Same day CT-based dosimetry was compared between patients with and without hydrogel spacer to evaluate for differences in rectal and prostate dosimetry. Physician-reported toxicities were coded with Common Terminology Criteria for Adverse Events (CTCAE) v4. RESULTS: Baseline patient and implant characteristics were similar. There were no acute genitourinary or rectal toxicities attributed to the hydrogel spacer. Comparing patients with and without hydrogel, the mean separation between the prostate and rectum was 13.9 ± 5.2 mm vs. 6.5 ± 5.0 mm (p < 0.0001), respectively. The adjusted mean dose to 1 cc, 2 cc, and 5 cc of the rectum relative to prescription dose was decreased by 32% (p < 0.01), 26% (p < 0.01), and 17% (p < 0.01), respectively. There were no statistically significant differences in prostate coverage: mean V100 (92% vs. 91%), V150 (45% vs. 48%), and D90 (106% vs. 106%), respectively. At 1 month followup, grade 1 rectal toxicity was 12.5% vs. 17.5% (p = 0.35). No patients developed Grade ≥2 rectal toxicity with hydrogel, although one did without. CONCLUSION: Hydrogel rectal spacers significantly reduced rectal exposure to LDR brachytherapy seeds without an observable impact on prostate coverage or periprocedural side effects. These outcomes reflect only LDR implants that used stranded seeds.


Assuntos
Braquiterapia , Órgãos em Risco , Polietilenoglicóis/administração & dosagem , Neoplasias da Próstata/radioterapia , Doses de Radiação , Reto , Idoso , Braquiterapia/efeitos adversos , Humanos , Hidrogéis/administração & dosagem , Injeções , Radioisótopos do Iodo/uso terapêutico , Masculino , Pessoa de Meia-Idade , Radiometria , Dosagem Radioterapêutica
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