Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23
Filtrar
1.
Carbohydr Polym ; 341: 122298, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-38876710

RESUMO

Cutaneous melanoma is a lethal skin cancer variant with pronounced aggressiveness and metastatic potential. However, few targeted medications inhibit the progression of melanoma. Ganoderma lucidum, which is a type of mushroom, is widely used as a non-toxic alternative adjunct therapy for cancer patients. This study determines the effect of WSG, which is a water-soluble glucan that is derived from G. lucidum, on melanoma cells. The results show that WSG inhibits cell viability and the mobility of melanoma cells. WSG induces changes in the expression of epithelial-to-mesenchymal transition (EMT)-related markers. WSG also downregulates EMT-related transcription factors, Snail and Twist. Signal transduction assays show that WSG reduces the protein levels in transforming growth factor ß receptors (TGFßRs) and consequently inhibits the phosphorylation of intracellular signaling molecules, such as FAK, ERK1/2 and Smad2. An In vivo study shows that WSG suppresses melanoma growth in B16F10-bearing mice. To enhance transdermal drug delivery and prevent oxidation, two highly biocompatible compounds, polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP), are used to synthesize a dissolvable microneedle patch that is loaded with WSG (MN-WSG). A functional assay shows that MN-WSG has an effect that is comparable to that of WSG alone. These results show that WSG has significant potential as a therapeutic agent for melanoma treatment. MN-WSG may allow groundbreaking therapeutic approaches and offers a novel method for delivering this potent compound effectively.


Assuntos
Reishi , Fatores de Transcrição da Família Snail , Animais , Camundongos , Reishi/química , Fatores de Transcrição da Família Snail/metabolismo , Humanos , Melanoma/tratamento farmacológico , Melanoma/patologia , Melanoma/metabolismo , Linhagem Celular Tumoral , Proteína 1 Relacionada a Twist/metabolismo , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/metabolismo , Melanoma Experimental/tratamento farmacológico , Melanoma Experimental/patologia , Melanoma Experimental/metabolismo , Movimento Celular/efeitos dos fármacos , Antineoplásicos/farmacologia , Antineoplásicos/química , Álcool de Polivinil/química , Polissacarídeos/farmacologia , Polissacarídeos/química , Transdução de Sinais/efeitos dos fármacos
2.
Int J Biol Macromol ; 259(Pt 2): 129291, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38211909

RESUMO

KRAS mutations are tightly associated with lung cancer progression. Despite the unprecedented clinical success of KRASG12C inhibitors, recurrent mechanisms of resistance and other KRAS mutations require further therapeutic approaches. GMI, a protein from the medicinal mushroom Ganoderma microsporum, possesses antitumor activity; whereas, the biological function of GMI on regulating KRAS mutant lung cancer cells remains unknown. Herein, RNA-sequencing and bioinformatics showed that GMI may regulate KRAS-modulated MAPK and PI3K-AKT pathways in A549 (KRASG12S) cells. Further experiments demonstrated that GMI inhibited KRAS activation and suppressed ERK1/2 and AKT signaling in A549 cells. Intriguingly, GMI inhibited AKT signaling but increased phosphorylation of ERK in H358 (KRASG12C) cells. GMI significantly suppressed tumor growth in LLC1 cells-allograft and H358 cells-xenograft mice. GMI showed a synergistic effect with KRASG12C inhibitors in inhibiting cell growth, KRAS activation and KRAS-mediated downstream signaling, leading to apoptosis in H358 cells. Combination of GMI and KRASG12C inhibitor, AMG 510, resulted in more durable inhibition of tumor growth and KRAS activity in H358 cells-xenograft mice. This study highlights the potential of GMI, a dietary fungal protein, as a viable therapeutic avenue for KRAS-mutant lung cancer in combination with KRASG12C inhibitors.


Assuntos
Ganoderma , Neoplasias Pulmonares , Humanos , Animais , Camundongos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Linhagem Celular Tumoral , Ganoderma/metabolismo , Mutação
3.
Life Sci ; 335: 122255, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37967792

RESUMO

BACKGROUND: Cancer metastasis is a major cause of cancer-related deaths, emphasizing the urgent need for effective therapies. Although it has been shown that GMI, a fungal protein from Ganoderma microsporum, could suppress primary tumor growth in a wide spectrum of cancer types, it is still unclear whether GMI exhibits anti-metastasis properties, particularly in lung cancers. Further investigation is needed. AIMS AND OBJECTIVES: The objective of this study is to investigate the potential inhibitory effects of GMI on lung cancer metastasis in vivo. Utilizing systematic and comprehensive approaches, our research aims to elucidate the underlying molecular mechanisms responsible for the anti-metastatic effects. MATERIALS AND METHODS: In vitro migration and cell adhesion assays addressed the epithelial-to-mesenchymal transition (EMT)-related phenotype. Proteomic and bioinformatic analyses identified the GMI-regulated proteins and cellular responses. GMI-treated LLC1-bearing mice were analyzed using IVIS Spectrum to assess the anti-metastatic effect. KEY FINDINGS: GMI inhibits EMT as well as cell migration. GMI disrupts cell adhesion and downregulates integrin, resulting in inhibition of phosphorylated FAK. GMI induces macropinocytosis and lysosome-mediated degradation of integrin αv, α5, α6 and ß1. GMI downregulates Slug via inhibition of FAK activity, which in turn enhances expressions of epithelial-related markers and decreases cell mobility. Mechanistically, GMI-induced FAK inhibition engenders MDM2 expression and enhances MDM2/p21/Slug complex formation, leading to Slug degradation. GMI treatment reduces the metastatic pulmonary lesion and prolongs the survival of LLC1-bearing mice. SIGNIFICANCE: Our findings highlight GMI as a promising therapeutic candidate for metastatic lung cancers, offering potential avenues for further research and drug development.


Assuntos
Neoplasias Pulmonares , Animais , Camundongos , Neoplasias Pulmonares/patologia , Adesões Focais/metabolismo , Adesões Focais/patologia , Proteômica , Linhagem Celular Tumoral , Movimento Celular , Transição Epitelial-Mesenquimal , Metástase Neoplásica/patologia
4.
Cancer Lett ; 578: 216458, 2023 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-37865161

RESUMO

Epidermal growth factor receptor (EGFR) abnormalities relevant to tumor progression. A newly developed strategy for cancer therapy is induction of EGFR degradation. GMI, an immunomodulatory protein from the medicinal mushroom Ganoderma microsporum, exhibits anticancer activity. However, its role in the intracellular trafficking and degradation of EGFR remains unclear. In this study, we discovered that GMI inhibits the phosphorylation of multiple tyrosine kinases. Specifically, GMI was discovered to suppress lung cancer cells harboring both wild-type and mutant EGFR by inhibiting EGFR dimerization and eliminating EGFR-mediated signaling. Functional studies revealed that GMI binds to the extracellular segment of EGFR. GMI interacts with EGFR to induce phosphorylation of EGFR at tyrosine1045, which triggers clathrin-dependent endocytosis and degradation of EGFR. Furthermore, in the mouse models, GMI was discovered to suppress tumor growth. Knockdown of EGFR in lung cancer cells abolishes GMI's anticancer activity in vivo and in vitro. Our results reveal the interaction mechanisms through which GMI induces EGFR degradation and abolishes EGFR-mediated intracellular pathway. Our study indicates that GMI is an EGFR degrader for inhibiting EGFR-expressing tumor growth.


Assuntos
Ganoderma , Neoplasias Pulmonares , Animais , Camundongos , Neoplasias Pulmonares/tratamento farmacológico , Receptores ErbB , Fosforilação , Fator de Crescimento Epidérmico , Linhagem Celular Tumoral
5.
Int J Biol Macromol ; 219: 940-948, 2022 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-35952817

RESUMO

Glioblastoma multiforme (GBM), which is a malignant primary brain tumor, is the cancer that spreads most aggressively into the adjacent brain tissue. Patients with metastatic GBM have a poor chance of survival. In this study, we examined the anti-GBM mobility effect of small protein, called GMI, which is cloned and purified from Ganoderma microsporum. Proteomic profiles showed that GMI-mediated proteins were involved in cell motility and cell growth functions. Specifically, we demonstrated that GMI significantly suppressed cell migration and invasion of GBM cells. GMI combined with temozolomide (TMZ), which is a traditional chemotherapeutic agent for GBM treatment, synergistically inhibited motility in GBM cells. Mechanistically, we demonstrated that GMI induced proteasome-dependent degradation of Slug, which is a critical transcription factor, is frequently linked to metastasis and drug resistance in GBM. Knockdown of Slug reduced cell viability and colony formation of GBM cells but enhanced TMZ-suppressed cell migration and viability. The results of this study show that targeting Slug degradation is involved in GMI-suppressed mobility of GBM cells. Moreover, GMI may be a potential supplementary agent for the suppression of GBM.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Antineoplásicos Alquilantes/farmacologia , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Movimento Celular , Resistencia a Medicamentos Antineoplásicos , Ganoderma , Glioblastoma/metabolismo , Humanos , Complexo de Endopeptidases do Proteassoma , Proteômica , Fatores de Transcrição da Família Snail , Temozolomida/farmacologia , Fatores de Transcrição/genética
6.
Fam Pract ; 39(3): 426-431, 2022 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-34964888

RESUMO

BACKGROUND: Men are more likely to develop benign prostatic hyperplasia (BPH) and gout as they age. However, the role of alpha-1-adrenergic antagonists, the medication for BPH, in the development of gout is uncertain. OBJECTIVE: To investigate the effect of alpha-1-adrenergic antagonist use on the risk of developing gout in BPH patients. METHODS: Data of patients with newly diagnosed BPH were retrieved from Taiwan's 2000-2013 National Health Insurance Research Database (total number: 15,390 patients; 7,695 patients in each cohort). Propensity score matching was conducted according to age, comorbidities, medication history for cohorts that received or did not receive alpha-1-adrenergic antagonists. Hazard ratios (HRs) were assessed for gout development using Cox proportional hazards regression models. RESULTS: Use of alpha-1-adrenergic antagonists was not associated with gout development in BPH patients (HR = 0.92; 95% confidence interval [CI], 0.78-1.10; P = 0.35). However, after stratification according to the average number of days of alpha-1-adrenergic antagonist use per year, patients with an average of >300 days had a significantly higher risk of gout development than patients who did not receive alpha-1-adrenergic antagonists (adjusted HR = 1.57; 95% CI, 1.25-1.97; P < 0.001). Patients with more days of medication use per year had a higher risk of gout development than those with fewer days of medication use (P < 0.001). CONCLUSION: Patients who received more doses of alpha-1-adrenergic antagonists per year had a higher risk of developing gout. A causal proof of the role of alpha-1-adrenergic antagonists use in gout development should be analysed in future studies designed as double blind randomized controlled trials.


Assuntos
Gota , Hiperplasia Prostática , Antagonistas de Receptores Adrenérgicos alfa 1/efeitos adversos , Estudos de Coortes , Gota/induzido quimicamente , Gota/tratamento farmacológico , Gota/epidemiologia , Humanos , Masculino , Modelos de Riscos Proporcionais , Hiperplasia Prostática/induzido quimicamente , Hiperplasia Prostática/tratamento farmacológico , Hiperplasia Prostática/epidemiologia , Ensaios Clínicos Controlados Aleatórios como Assunto
7.
J Ethnopharmacol ; 282: 114636, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34520830

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Medicinal ink is used as a traditional topical medicine for treating inflammatory diseases via detoxification, relieving pain, hemostasis, and reducing swelling. However, the effect of medicinal ink on the inhibition of inflammatory responses and the underlying molecular mechanism remain unclear. AIM OF THE STUDY: The present study aimed to investigate the anti-inflammatory function of water extract of medical ink (WEMI) and elucidate its active mechanisms. MATERIALS AND METHODS: Cell viability was assessed using crystal violet staining assay. Interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were detected by ELISA. Nitric oxide (NO) production was measured by Griess assay. The activation of inflammatory signaling molecules stimulated by lipopolysaccharide (LPS) was evaluated by assessing levels of inducible nitric oxide synthase (iNOS), phosphorylated Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) using Western blot assay. RESULTS: Water extract of medical ink (WEMI) did not present cytotoxic effect on murine macrophage Raw264.7 cells. High dosage of WEMI slightly rescued LPS-suppressed cell viability of Raw264.7 cells. WEMI did not induce NO production or IL-6 secretion, though WEMI significantly induced secretion of TNF-α on Raw264.7 cells not stimulated with LPS. On the other hand, LPS effectively stimulated inflammation on Raw264.7 cells; however, WEMI dramatically reduced LPS-induced NO production. WEMI alleviated LPS-stimulated IL-6 secretion but did not affect the content of TNF-α. In addition, WEMI effectively reduced expression of iNOS by abolishing LPS-mediated phosphorylation of JAK2 and STAT3 but not TLR4-mediated NF-κB and MAPK molecules. CONCLUSIONS: Our findings suggest that WEMI targets of the JAK2/STAT3-mediated iNOS expression play a key role in alleviating LPS-induced inflammatory responses in RAW264.7 macrophages. Therefore, medicinal ink may be a potential topical agent for treating fasciitis or synovitis via regulating the immune system.


Assuntos
Tinta , Medicina Tradicional Chinesa , Água , Animais , Sobrevivência Celular , Relação Dose-Resposta a Droga , Camundongos , Óxido Nítrico , Células RAW 264.7
8.
Polymers (Basel) ; 13(24)2021 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-34960904

RESUMO

Lung cancer has the highest global mortality rate of any cancer. Although targeted therapeutic drugs are commercially available, the common drug resistance and insensitivity to cisplatin-based chemotherapy, a common clinical treatment for lung cancer, have prompted active research on alternative lung cancer therapies and methods for mitigating cisplatin-related complications. In this study, we investigated the effect of WSG, a glucose-rich, water soluble polysaccharide derived from Ganoderma lucidum, on cisplatin-based treatment for lung cancer. Murine Lewis lung carcinoma (LLC1) cells were injected into C57BL/6 mice subcutaneously and through the tail vein. The combined administration of WSG and cisplatin effectively inhibited tumor growth and the formation of metastatic nodules in the lung tissue of the mice. Moreover, WSG increased the survival rate of mice receiving cisplatin. Co-treatment with WSG and cisplatin induced a synergistic inhibitory effect on the growth of lung cancer cells, enhancing the apoptotic responses mediated by cisplatin. WSG also reduced the cytotoxic effect of cisplatin in both macrophages and normal lung fibroblasts. Our findings suggest that WSG can increase the therapeutic effectiveness of cisplatin. In clinical settings, WSG may be used as an adjuvant or supplementary agent.

9.
Am J Transl Res ; 13(11): 13034-13042, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34956521

RESUMO

PURPOSE: To estimate differences in pain control between patients with cancer and with or without dementia during terminal cancer stages 3 months or 1 month before cancer death. PATIENTS AND METHODS: We conducted frequency matching cohort for age, sex, and year of death for both groups at a 1:4 ratio. The prescription prevalence, total cumulative dose, and average daily dose of opioids during the terminal cancer stages 3 months and 1 month before cancer death were estimated. RESULTS: Patients with cancer and dementia were prescribed lower amounts of opioids 3 months before death (57.5% vs. 73.9%, respectively; adjusted odds ratio [OR] 0.46; 95% confidence interval [CI] 0.44-0.49) and 1 month before death (54.4% vs. 70.3%, respectively; adjusted OR 0.50; 95% CI 0.47-0.53). The total cumulative dose of opioids (mg) was lower in patients with cancer and dementia 3 and 1 month(s) before death (3 months: 1,578 mg vs. 2,666 mg, respectively; ß=-1,125.9, P<0.001; 1 month: 921 mg vs. 1,533 mg, respectively; ß=-622.1, P<0.001). The average daily opioid dose (mg/day), patients with cancer and dementia received a lower dose 3 months before death (31 mg vs. 48 mg; ß=-22.6, P<0.001) and 1 month before death (38 mg vs. 60 mg; ß=-17.1, P<0.001). CONCLUSION: The prevalence of opioid prescription was significantly lower in patients with both cancer and dementia during their terminal cancer stages 3 months and 1 month before death.

10.
Int J Biol Macromol ; 193(Pt B): 1201-1208, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34742847

RESUMO

Tongue cancer, a kind of oral cancer, is common in Southeast Asian countries because of dietary habits. However, there is no specific targeted drug that could effectively inhibit oral cancer. WSG, as a water soluble glucose-enriched polysaccharide from Ganoderma lucidum, exerts excellent pharmacological efficacy of anti-lung cancer. However, its anticancer functions and mechanisms in human tongue cancer need to be further explored. Herein, we showed that WSG dramatically reduced cell viability and colony formation of tongue cancer cells. WSG increased subG1 and G2/M populations as well as induced apoptotic responses. In parallel, WSG enhanced apoptosis-related Bax/Bcl2 ratio. Mechanistic studies showed that WSG reduced phosphorylation of EGFR and AKT. In addition, we found a synergistic effect of WSG with cisplatin in inhibition of cell viability and induction of apoptosis. WSG significantly reduced the inhibition concentration 50% (IC50) of cisplatin. More importantly, WSG ameliorated cisplatin-induced cytotoxicity in normal human oral epithelial SG cells. In conclusion, our findings provided important insights into the anti-tongue cancer effects of WSG via inhibition of EGFR/AKT axis and induction of apoptosis, which indicated that WSG could be a promising supplement for tongue cancer treatment.


Assuntos
Apoptose/efeitos dos fármacos , Cisplatino/farmacologia , Polissacarídeos Fúngicos , Proteínas de Neoplasias/metabolismo , Reishi/química , Transdução de Sinais/efeitos dos fármacos , Neoplasias da Língua , Linhagem Celular Tumoral , Receptores ErbB/metabolismo , Polissacarídeos Fúngicos/química , Polissacarídeos Fúngicos/farmacologia , Humanos , Neoplasias da Língua/tratamento farmacológico , Neoplasias da Língua/metabolismo
11.
Int J Biol Macromol ; 165(Pt A): 1604-1613, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-33011264

RESUMO

WSG is a water soluble polysaccharides isolated from Ganoderma lucidum. In this study, we showed that WSG, a glucose-rich polysaccharide with an average molecular mass of approximately 1000 kDa, effectively inhibited cell viability and mobility of lung cancer cells. Functional studies revealed that WSG reduced phosphorylation of ERK1/2 in cells upon either EGF or TGFß stimulation. WSG also inhibited phosphorylation of multiple intracellular signaling molecules such as FAK, AKT and Smad2. Mechanistically, we demonstrated that WSG induced degradation of TGFß and EGF receptors via proteasome and lysosome, respectively. Moreover, we found that WSG significantly suppressed lung tumor growth, reduced the size of metastatic nodules in the lungs and prolonged the survival of LLC1-bearing mice. Our findings suggested that WSG may have potential as a therapeutic intervention for treatment of lung cancer.


Assuntos
Proliferação de Células/efeitos dos fármacos , Neoplasias Pulmonares/tratamento farmacológico , Polissacarídeos/química , Reishi/química , Animais , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias Pulmonares/patologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos , Proteínas de Neoplasias/genética , Polissacarídeos/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
12.
Int J Biol Macromol ; 153: 796-805, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32169452

RESUMO

Gefitinib is a first tyrosine kinase inhibitor (TKI) designed with an EGFR tyrosine kinase for lung cancer targeted therapy. However, some lung cancer patients with wild-type EGFR (wtEGFR) or acquired secondary EGFR mutation showed lower response rate of gefitinib. In this study, we examined the efficacy of fucoidan on altering gefitinib-sensitivity on TKI-resistant lung cancer A549 and H1975 cells. We found that the simultaneous administration of fucoidan and gefitinib synergistically inhibited lung cancer cell viability via activating apoptotic response. Moreover, we found that fucoidan effectively downregulated expressions of mesenchymal-like molecules. Mechanistically, we demonstrated that fucoidan altered the gefitinib-inhibitory rate may result from induction of proteasome-dependent Slug degradation. Abolishment of TGFß signaling enhanced gefitinib-inhibited cell viability and reduced N-cadherin, Twist and Slug levels. Moreover, knockdown of Slug contributed the increasing the gefitinib-sensitivity of H1975 cells. Our study is the first to find that fucoidan alters the gefitinib-sensitive of TKI-resistant cells by reduction of TGFß receptor-mediated expressions of mesenchymal-like molecules and induction of Slug degradation. Together, our current results indicate that combination of fucoidan and gefitinib may be a potential and effective therapeutic strategy in gefitinib non-sensitive lung cancer.


Assuntos
Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Gefitinibe/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias Pulmonares , Proteínas de Neoplasias/metabolismo , Polissacarídeos/farmacologia , Fatores de Transcrição da Família Snail/biossíntese , Fator de Crescimento Transformador beta/metabolismo , Células A549 , Animais , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Masculino , Camundongos
13.
J Phys Condens Matter ; 31(27): 275402, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-30952151

RESUMO

We employed femtosecond pump-probe technique to investigate the dynamics of coherent optical phonons in iron garnet. A phenomenological symmetry-based consideration reveals that oscillations of the terahertz T 2g mode are excited. Selective excitation by a linearly polarized pump and detection by a circularly polarized probe confirm that impulsive stimulated Raman scattering (ISRS) is the driving force for the coherent phonons. Experimental results obtained from ISRS measurements reveal excellent agreement with spontaneous Raman spectroscopy data, analyzed by considering the symmetry of the phonon modes and corresponding excitation and detection selection rules.

14.
Int J Comput Assist Radiol Surg ; 14(6): 967-976, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30888596

RESUMO

PURPOSE: Minimally invasive surgery is often built upon a time-consuming preoperative step consisting of segmentation and trajectory planning. At the temporal bone, a complete automation of these two tasks might lead to faster interventions and more reproducible results, benefiting clinical workflow and patient health. METHODS: We propose an automatic segmentation and trajectory planning pipeline for image-guided interventions at the temporal bone. For segmentation, we use a shape regularized deep learning approach that is capable of automatically detecting even the cluttered tiny structures specific for this anatomy. We then perform trajectory planning for both linear and nonlinear interventions on these automatically segmented risk structures. RESULTS: We evaluate the usability of segmentation algorithms for planning access canals to the cochlea and the internal auditory canal on 24 CT data sets of real patients. Our new approach achieves similar results to the existing semiautomatic method in terms of Dice but provides more accurate organ shapes for the subsequent trajectory planning step. The source code of the algorithms is publicly available. CONCLUSION: Automatic segmentation and trajectory planning for various clinical procedures at the temporal bone are feasible. The proposed automatic pipeline leads to an efficient and unbiased workflow for preoperative planning.


Assuntos
Imageamento Tridimensional/métodos , Cirurgia Assistida por Computador/métodos , Osso Temporal/cirurgia , Algoritmos , Automação , Humanos , Software , Osso Temporal/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos
15.
Beilstein J Nanotechnol ; 9: 2609-2617, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30416911

RESUMO

Enhancement of X-ray emission was observed from a micro-jet of a nano-colloidal gold suspension in air under double-pulse excitation of ultrashort (40 fs) near-IR laser pulses. Temporal and spatial overlaps between the pre-pulse and the main pulse were optimized for the highest X-ray emission. The maximum X-ray intensity was obtained at a 1-7 ns delay of the main pulse irradiation after the pre-pulse irradiation with the micro-jet position shifted along the laser beam propagation. It was revealed that the volume around gold nanoparticles where the permittivity is near zero, ε ≈ 0, accounts for the strongest absorption, which leads to the effective enhancements of X-ray emission.

16.
Nanomaterials (Basel) ; 8(7)2018 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-30011794

RESUMO

Simultaneous emission of the THz wave and hard X-ray from thin water free-flow was induced by the irradiation of tightly-focused femtosecond laser pulses (35 fs, 800 nm, 500 Hz) in air. Intensity measurements of the THz wave and X-ray were carried out at the same time with time-domain spectroscopy (TDS) based on electro-optic sampling with a ZnTe(110) crystal and a Geiger counter, respectively. Intensity profiles of the THz wave and X-ray emission as a function of the solution flow position along the incident laser axis at the laser focus show that the profile width of the THz wave is broader than that of the X-ray. Furthermore, the profiles of the THz wave measured in reflection and transmission directions show different features and indicate that THz wave emission is, under single-pulse excitation, induced mainly in laser-induced plasma on the water flow surface. Under double-pulse excitation with a time separation of 4.6 ns, 5⁻10 times enhancements of THz wave emission were observed. Such dual light sources can be used to characterise materials, as well as to reveal the sequence of material modifications under intense laser pulses.

17.
Opt Express ; 25(16): 19497-19507, 2017 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-29041143

RESUMO

Photoacoustic signal enhancements were observed with a pair of time-delayed femtosecond pulses upon excitation of gold nanosphere colloidal suspension. A systematic experimental investigation of photoacoustic intensity within the delay time, Δt = 0 to 15 ns, was carried out. The results revealed a significant enhancement factor of ∼2 when the pre-pulse energy is 20-30% of the total energy. Pre-pulse and main pulse energy ratios, Ep(1):Es(2), were varied to determine the optimal ratio that yields to maximum photoacoustic signal enhancement. This enhancement was ascribed to the initial stage of thermalization and bubble generation in the nanosecond time scale. Pre-pulse scattering intensity measurements and numerical finite-difference time-domain calculations were performed to reveal dynamics and light field enchancement, respectively.

18.
Opt Express ; 25(20): 24109-24118, 2017 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-29041357

RESUMO

Femtosecond double-pulsed laser excitation of a water film in air showed enhancements of X-ray intensity as compared with single pulse irradiation. The position of the highest yield of X-rays strongly depends on temporal separation between the pre-pulse and the main-pulse (energy ratios where ∼ 1 : 10). The strongest X-ray emission was observed at 10-15 ns delay of the main-pulse. Nanoscale roughening of water surface can account for the observation.

19.
Opt Express ; 24(18): 19994-20001, 2016 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-27607607

RESUMO

Femtosecond laser-induced hard X-ray generation in air from a 100-µm-thick solution film of distilled water or Au nano-sphere suspension was carried out by using a newly-developed automatic positioning system with 1-µm precision. By positioning the solution film for the highest X-ray intensity, the optimum position shifted upstream as the laser power increased due to breakdown. Optimized positioning allowed us to control X-ray intensity with high fidelity. X-ray generation from Au nano-sphere suspension and distilled water showed different power scaling. Linear and nonlinear absorption mechanism are analyzed together with numerical modeling of light delivery.

20.
Opt Express ; 24(13): 14781-92, 2016 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-27410630

RESUMO

Enhanced photoacoustic (PA) intensity from gold nanosphere and nanorod colloidal suspensions in water under tightly-focused femtosecond pulsed laser irradiation was systematically investigated. PA signal amplitudes were measured by ultrasound transducers at frequencies of 5, 10, and 25 MHz. The experimental results revealed a linear-dependence of the relative photoacoustic amplitude on the laser power and the mechanism was attributed to non-radiative relaxation dynamics of surface plasmon oscillations. When gold nanorod with longitudinal absorption/extinction peak at 800 nm coincides with the wavelength of femtosecond laser pulses, the most efficient PA signal is generated. Laser excitation was kept within a thermal stability region of gold nanoparticles, i.e., colloidal suspension can be continuously reused for PA generation.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA