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1.
Sensors (Basel) ; 23(18)2023 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-37765897

RESUMO

Digital representations of anatomical parts are crucial for various biomedical applications. This paper presents an automatic alignment procedure for creating accurate 3D models of upper limb anatomy using a low-cost handheld 3D scanner. The goal is to overcome the challenges associated with forearm 3D scanning, such as needing multiple views, stability requirements, and optical undercuts. While bulky and expensive multi-camera systems have been used in previous research, this study explores the feasibility of using multiple consumer RGB-D sensors for scanning human anatomies. The proposed scanner comprises three Intel® RealSenseTM D415 depth cameras assembled on a lightweight circular jig, enabling simultaneous acquisition from three viewpoints. To achieve automatic alignment, the paper introduces a procedure that extracts common key points between acquisitions deriving from different scanner poses. Relevant hand key points are detected using a neural network, which works on the RGB images captured by the depth cameras. A set of forearm key points is meanwhile identified by processing the acquired data through a specifically developed algorithm that seeks the forearm's skeleton line. The alignment process involves automatic, rough 3D alignment and fine registration using an iterative-closest-point (ICP) algorithm expressly developed for this application. The proposed method was tested on forearm scans and compared the results obtained by a manual coarse alignment followed by an ICP algorithm for fine registration using commercial software. Deviations below 5 mm, with a mean value of 1.5 mm, were found. The obtained results are critically discussed and compared with the available implementations of published methods. The results demonstrate significant improvements to the state of the art and the potential of the proposed approach to accelerate the acquisition process and automatically register point clouds from different scanner poses without the intervention of skilled operators. This study contributes to developing effective upper limb rehabilitation frameworks and personalized biomedical applications by addressing these critical challenges.


Assuntos
Antebraço , Extremidade Superior , Humanos , Extremidade Superior/diagnóstico por imagem , Mãos , Algoritmos , Redes Neurais de Computação
2.
JCI Insight ; 8(18)2023 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-37607007

RESUMO

Patients with triple-negative breast cancer remain at risk for metastatic disease despite treatment. The acquisition of chemoresistance is a major cause of tumor relapse and death, but the mechanisms are far from understood. We have demonstrated that breast cancer cells (BCCs) can engulf mesenchymal stem/stromal cells (MSCs), leading to enhanced dissemination. Here, we show that clinical samples of primary invasive carcinoma and chemoresistant breast cancer metastasis contain a unique hybrid cancer cell population coexpressing pancytokeratin and the MSC marker fibroblast activation protein-α. We show that hybrid cells form in primary tumors and that they promote breast cancer metastasis and chemoresistance. Using single-cell microfluidics and in vivo models, we found that there are polyploid senescent cells within the hybrid cell population that contribute to metastatic dissemination. Our data reveal that Wnt Family Member 5A (WNT5A) plays a crucial role in supporting the chemoresistance properties of hybrid cells. Furthermore, we identified that WNT5A mediates hybrid cell formation through a phagocytosis-like mechanism that requires BCC-derived IL-6 and MSC-derived C-C Motif Chemokine Ligand 2. These findings reveal hybrid cell formation as a mechanism of chemoresistance and suggest that interrupting this mechanism may be a strategy in overcoming breast cancer drug resistance.


Assuntos
Células-Tronco Mesenquimais , Neoplasias de Mama Triplo Negativas , Humanos , Resistencia a Medicamentos Antineoplásicos , Linhagem Celular Tumoral , Recidiva Local de Neoplasia/patologia , Células-Tronco Mesenquimais/metabolismo , Neoplasias de Mama Triplo Negativas/metabolismo
3.
Int J Cancer ; 153(6): 1257-1272, 2023 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-37323038

RESUMO

Adiponectin is the major adipocytes-secreted protein involved in obesity-related breast cancer growth and progression. We proved that adiponectin promotes proliferation in ERα-positive breast cancer cells, through ERα transactivation and the recruitment of LKB1 as ERα-coactivator. Here, we showed that adiponectin-mediated ERα transactivation enhances E-cadherin expression. Thus, we investigated the molecular mechanism through which ERα/LKB1 complex may modulate the expression of E-cadherin, influencing tumor growth, progression and distant metastasis. We demonstrated that adiponectin increases E-cadherin expression in ERα-positive 2D and higher extent in 3D cultures. This occurs through a direct activation of E-cadherin gene promoter by ERα/LKB1-complex. The impact of E-cadherin on ERα-positive breast cancer cell proliferation comes from the evidence that in the presence of E-cadherin siRNA the proliferative effects of adiponectin is no longer noticeable. Since E-cadherin connects cell polarity and growth, we investigated if the adiponectin-enhanced E-cadherin expression could influence the localization of proteins cooperating in cell polarity, such as LKB1 and Cdc42. Surprisingly, immunofluorescence showed that, in adiponectin-treated MCF-7 cells, LKB1 and Cdc42 mostly colocalize in the nucleus, impairing their cytosolic cooperation in maintaining cell polarity. The orthotopic implantation of MCF-7 cells revealed an enhanced E-cadherin-mediated breast cancer growth induced by adiponectin. Moreover, tail vein injection of MCF-7 cells showed a higher metastatic burden in the lungs of mice receiving adiponectin-treated cells compared to control. From these findings it emerges that adiponectin treatment enhances E-cadherin expression, alters cell polarity and stimulates ERα-positive breast cancer cell growth in vitro and in vivo, sustaining higher distant metastatic burden.


Assuntos
Adiponectina , Neoplasias , Humanos , Animais , Camundongos , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Linhagem Celular Tumoral , Células MCF-7 , Caderinas/genética
4.
Int J Mol Sci ; 24(10)2023 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-37240258

RESUMO

Obesity has a noteworthy role in breast tumor initiation and progression. Among the mechanisms proposed, the most validated is the development of chronic low-grade inflammation, supported by immune cell infiltration along with dysfunction in adipose tissue biology, characterized by an imbalance in adipocytokines secretion and alteration of their receptors within the tumor microenvironment. Many of these receptors belong to the seven-transmembrane receptor family, which are involved in physiological features, such as immune responses and metabolism, as well as in the development and progression of several malignancies, including breast cancer. These receptors are classified as canonical (G protein-coupled receptors, GPCRs) and atypical receptors, which fail to interact and activate G proteins. Among the atypical receptors, adiponectin receptors (AdipoRs) mediate the effect of adiponectin, the most abundant adipocytes-derived hormone, on breast cancer cell proliferation, whose serum levels are reduced in obesity. The adiponectin/AdipoRs axis is becoming increasingly important regarding its role in breast tumorigenesis and as a therapeutic target for breast cancer treatment. The objectives of this review are as follows: to point out the structural and functional differences between GPCRs and AdipoRs, and to focus on the effect of AdipoRs activation in the development and progression of obesity-dependent breast cancer.


Assuntos
Neoplasias da Mama , Receptores de Adiponectina , Humanos , Feminino , Receptores de Adiponectina/metabolismo , Neoplasias da Mama/etiologia , Neoplasias da Mama/metabolismo , Adiponectina/metabolismo , Obesidade/complicações , Obesidade/metabolismo , Tecido Adiposo/metabolismo , Microambiente Tumoral
5.
J Transl Med ; 21(1): 165, 2023 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-36864445

RESUMO

BACKGROUND: Breast cancer is the second leading cause of death among women after lung cancer. Despite the improvement in prevention and in therapy, breast cancer still remains a threat, both for pre- and postmenopausal women, due to the development of drug resistance. To counteract that, novel agents regulating gene expression have been studied in both hematologic and solid tumors. The Histone Deacetylase (HDAC) inhibitor Valproic Acid (VA), used for epilepsy and other neuropsychiatric diseases, has been demonstrated a strong antitumoral and cytostatic activity. In this study, we tested the effects of Valproic Acid on the signaling pathways involved in breast cancer cells viability, apoptosis and in Reactive Oxygen Species (ROS) production using ER-α positive MCF-7 and triple negative MDA-MB-231 cells. METHODS: Cell proliferation assay was performed by MTT Cell cycle, ROS levels and apoptosis were analyzed by flow cytometry, protein levels were detected by Western Blotting. RESULTS: Cell treatment with Valproic Acid reduced cell proliferation and induced G0/G1 cell cycle arrest in MCF-7 and G2/M block in MDA-MB-231 cells. In addition, in both cells the drug enhanced the generation of ROS by the mitochondria. In MCF-7 treated cells, it has been observed a reduction in mitochondrial membrane potential, a down regulation of the anti-apoptotic marker Bcl-2 and an increase of Bax and Bad, leading to release of cytochrome C and PARP cleavage. Less consistent effects are recorded in MDA-MB-231 cells, in which the greater production of ROS, compared to MCF-7cells, involves an inflammatory response (activation of p-STAT3, increased levels of COX2). CONCLUSIONS: Our results have demonstrated that in MCF-7 cells the Valproic Acid is a suitable drug to arrest cell growth, to address apoptosis and mitochondrial perturbations, all factors that are important in determining cell fate and health. In a triple negative MDA-MB 231 cells, valproate directs the cells towards the inflammatory response with a sustained expression of antioxidant enzymes. Overall, the not always unequivocal data between the two cellular phenotypes indicate that further studies are needed to better define the use of the drug, also in combination with other chemotherapy, in the treatment of breast tumors.


Assuntos
Inibidores de Histona Desacetilases , Ácido Valproico , Feminino , Humanos , Ácido Valproico/farmacologia , Células MCF-7 , Espécies Reativas de Oxigênio , Ciclo Celular , Proliferação de Células , Inibidores de Histona Desacetilases/farmacologia
6.
Breast Cancer Res Treat ; 199(1): 13-23, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36913051

RESUMO

PURPOSE: Dysregulation of the PI3K pathway is one of the most common events in breast cancer. Here we investigate the activity of the PI3K inhibitor MEN1611 at both molecular and phenotypic levels by dissecting and comparing its profile and efficacy in HER2 + breast cancer models with other PI3K inhibitors. METHODS: Models with different genetic backgrounds were used to investigate the pharmacological profile of MEN1611 against other PI3K inhibitors. In vitro studies evaluated cell viability, PI3K signaling, and cell death upon treatment with MEN1611. In vivo efficacy of the compound was investigated in cell line- and patient-derived xenografts models. RESULTS: Consistent with its biochemical selectivity, MEN1611 demonstrated lower cytotoxic activity in a p110δ-driven cellular model when compared to taselisib, and higher cytotoxic activity in the p110ß-driven cellular model when compared to alpelisib. Moreover, MEN1611 selectively decreased the p110α protein levels in PIK3CA mutated breast cancer cells in a concentration- and proteasome-dependent manner. In vivo, MEN1611 monotherapy showed significant and durable antitumor activity in several trastuzumab-resistant PIK3CA-mutant HER2 + PDX models. The combination of trastuzumab and MEN1611 significantly improved the efficacy compared to single agent treatment. CONCLUSIONS: The profile of MEN1611 and its antitumoral activity suggest an improved profile as compared to pan-inhibitors, which are limited by a less than ideal safety profile, and isoform selective molecules, which may potentially promote development of resistance mechanisms. The compelling antitumor activity in combination with trastuzumab in HER2 + trastuzumab-resistant, PIK3CA mutated breast cancer models is at the basis of the ongoing B-Precise clinical trial (NCT03767335).


Assuntos
Neoplasias da Mama , Humanos , Feminino , Trastuzumab/farmacologia , Trastuzumab/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Receptor ErbB-2/metabolismo , Inibidores de Proteínas Quinases/uso terapêutico , Inibidores de Fosfoinositídeo-3 Quinase/uso terapêutico , Classe I de Fosfatidilinositol 3-Quinases/genética
7.
ACS Nano ; 17(5): 4396-4403, 2023 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-36847392

RESUMO

We hereby apply the approach of photoacoustic chemical imaging, performing an in vivo chemical analysis that is spatially resolved (200 µm) and in real time, to predict a given tumor's response to therapy. Using triple negative breast cancer as a model, we took photoacoustic images of tumors' oxygen distributions in patient-derived xenografts (PDXs) in mice using biocompatible, oxygen-sensitive tumor-targeted chemical contrast nanoelements (nanosonophores), which function as contrast agents for photoacoustic imaging. Following radiation therapy, we established a quantitatively significant correlation between the spatial distribution of the initial oxygen levels in the tumor and its spatial distribution of the therapy's efficacy: the lower the local oxygen, the lower the local radiation therapy efficacy. We thus provide a simple, noninvasive, and inexpensive method to both predict the efficacy of radiation therapy for a given tumor and identify treatment-resistant regions within the tumor's microenvironment.


Assuntos
Nanopartículas , Neoplasias , Técnicas Fotoacústicas , Humanos , Animais , Camundongos , Oxigênio , Neoplasias/diagnóstico por imagem , Neoplasias/radioterapia , Neoplasias/patologia , Técnicas Fotoacústicas/métodos , Linhagem Celular Tumoral , Microambiente Tumoral
8.
iScience ; 25(8): 104827, 2022 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-35992062

RESUMO

Triple-negative breast cancers (TNBCs) are frequently poorly differentiated with high propensity for metastasis. Enhancer of zeste homolog 2 (EZH2) is the lysine methyltransferase of polycomb repressive complex 2 that mediates transcriptional repression in normal cells and in cancer through H3K27me3. However, H3K27me3-independent non-canonical functions of EZH2 are incompletely understood. We reported that EZH2 phosphorylation at T367 by p38α induces TNBC metastasis in an H3K27me3-independent manner. Here, we show that cytosolic EZH2 methylates p38α at lysine 139 and 165 leading to enhanced p38α stability and that p38 methylation and activation require T367 phosphorylation of EZH2. Dual inhibition of EZH2 methyltransferase and p38 kinase activities downregulates pEZH2-T367, H3K27me3, and p-p38 pathways in vivo and reduces TNBC growth and metastasis. These data uncover a cooperation between EZH2 canonical and non-canonical mechanisms and suggest that inhibition of these pathways may be a potential therapeutic strategy.

9.
Nanomaterials (Basel) ; 11(5)2021 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-33922934

RESUMO

Nanoparticles with active-targeting and stimuli-responsive behavior are a promising class of engineered materials able to recognize the site of cancer disease, targeting the drug release and limiting side effects in the healthy organs. In this work, new dual pH/redox-responsive nanoparticles with affinity for folate receptors were prepared by the combination of two amphiphilic dextran (DEX) derivatives. DEXFA conjugate was obtained by covalent coupling of the polysaccharide with folic acid (FA), whereas DEXssPEGCOOH derived from a reductive amination step of DEX was followed by condensation with polyethylene glycol 600. After self-assembling, nanoparticles with a mean size of 50 nm, able to be destabilized in acidic pH and reducing media, were obtained. Doxorubicin was loaded during the self-assembling process, and the release experiments showed the ability of the proposed system to modulate the drug release in response to different pH and redox conditions. Finally, the viability and uptake experiments on healthy (MCF-10A) and metastatic cancer (MDA-MB-231) cells proved the potential applicability of the proposed system as a new drug vector in cancer therapy.

10.
Sensors (Basel) ; 20(22)2020 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-33217994

RESUMO

3D digital models of the upper limb anatomy represent the starting point for the design process of bespoke devices, such as orthoses and prostheses, which can be modeled on the actual patient's anatomy by using CAD (Computer Aided Design) tools. The ongoing research on optical scanning methodologies has allowed the development of technologies that allow the surface reconstruction of the upper limb anatomy through procedures characterized by minimum discomfort for the patient. However, the 3D optical scanning of upper limbs is a complex task that requires solving problematic aspects, such as the difficulty of keeping the hand in a stable position and the presence of artefacts due to involuntary movements. Scientific literature, indeed, investigated different approaches in this regard by either integrating commercial devices, to create customized sensor architectures, or by developing innovative 3D acquisition techniques. The present work is aimed at presenting an overview of the state of the art of optical technologies and sensor architectures for the surface acquisition of upper limb anatomies. The review analyzes the working principles at the basis of existing devices and proposes a categorization of the approaches based on handling, pre/post-processing effort, and potentialities in real-time scanning. An in-depth analysis of strengths and weaknesses of the approaches proposed by the research community is also provided to give valuable support in selecting the most appropriate solution for the specific application to be addressed.


Assuntos
Imageamento Tridimensional , Extremidade Superior/anatomia & histologia , Artefatos , Membros Artificiais , Humanos , Aparelhos Ortopédicos
11.
Colloids Surf B Biointerfaces ; 185: 110537, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31629094

RESUMO

Self-assembling prodrug containing pH- and redox-responsive functional groups was prepared by covalent conjugation of Doxorubicin (Dox) and lipoic acid (LA) to a polyaldehyde Dextran (PAD). The resultant amphiphilic DoxPADLA forms, in a single step, hemocompatible vesicular systems able to respond to intracellular signals without using external crosslinking agents. Camptothecin (CPT) was encapsulated exploiting the hydrophobic interactions with the vesicle membrane, and release experiments, carried out in media mimicking the physiological and endolysosomial compartments, in the absence or presence of Glutathione, proved the ability of the system to modulate drug release in relation to the variation of pH and redox potential. Cytotoxicity assays and confocal experiments demonstrated the efficacy of the vesicle formulation in enhancing the synergistic anticancer effect of the delivered Dox and CPT and a rapid and significant internalization of the carrier in cancer cells.


Assuntos
Antineoplásicos/administração & dosagem , Antineoplásicos/uso terapêutico , Dextranos/química , Sistemas de Liberação de Medicamentos , Pró-Fármacos/química , Camptotecina/administração & dosagem , Camptotecina/uso terapêutico , Sobrevivência Celular , Dextranos/síntese química , Doxorrubicina/administração & dosagem , Doxorrubicina/uso terapêutico , Liberação Controlada de Fármacos , Endocitose , Esterificação , Humanos , Concentração de Íons de Hidrogênio , Células MCF-7 , Oxirredução , Pró-Fármacos/síntese química , Espectroscopia de Prótons por Ressonância Magnética , Espectroscopia de Infravermelho com Transformada de Fourier
12.
Eur J Cardiothorac Surg ; 56(3): 488-494, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31321408

RESUMO

OBJECTIVES: We examined the incidence, the impact of subsequent cerebrovascular events and the clinical or procedural predictors of leaflet thrombosis (LT) in patients undergoing transcatheter aortic valve implantation (TAVI). METHODS: MEDLINE/PubMed was systematically screened for studies reporting on LT in TAVI patients. Incidence [both clinical and subclinical, i.e. detected with computed tomography (CT)] of LT was the primary end point of the study. Predictors of LT evaluated at multivariable analysis and impact of LT on stroke were the secondary ones. RESULTS: Eighteen studies encompassing 11 124 patients evaluating incidence of LT were included. Pooled incidence of LT was 0.43% per month [5.16% per year, 95% confidence interval (CI) 0.21-0.72, I2 = 98%]. Pooled incidence of subclinical LT was 1.36% per month (16.32% per year, 95% CI 0.71-2.19, I2 = 94%). Clinical LT was less frequent (0.04% per month, 0.48% per year, 95% CI 0.00-0.19, I2 = 93%). LT increased the risk of stroke [odds ratio (OR) 4.21, 95% CI 1.27-13.98], and was more frequent in patients with a valve diameter of 28-mm (OR 2.89: 1.55-5.8), for balloon-expandable (OR 8: 2.1-9.7) or after valve-in-valve procedures (OR 17.1: 3.1-84.9). Oral anticoagulation therapy reduced the risk of LT (OR 0.43, 95% CI: 0.22-0.84, I2 = 64%), as well as the mean transvalvular gradient. CONCLUSIONS: LT represents an infrequent event after TAVI, despite increasing risk of stroke. Given its full reversal with warfarin, in high-risk patients (those with valve-in-valve procedures, balloon expandable or large-sized devices), a protocol which includes a control CT appears reasonable.


Assuntos
Acidente Vascular Cerebral/induzido quimicamente , Trombose/etiologia , Substituição da Valva Aórtica Transcateter/efeitos adversos , Anticoagulantes/uso terapêutico , Estenose da Valva Aórtica/cirurgia , Angiografia por Tomografia Computadorizada , Feminino , Próteses Valvulares Cardíacas/efeitos adversos , Humanos , Masculino , Estudos Observacionais como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de Risco , Acidente Vascular Cerebral/prevenção & controle
13.
Drug Des Devel Ther ; 13: 4265-4274, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31908413

RESUMO

PURPOSE: Neuroendocrine differentiation of prostate cancer, induced by androgen deprivation therapy, is mainly related to advanced disease and poor clinical outcome. Genetic and epigenetic alterations are the key elements of the prostate carcinogenesis. A group of compounds able to induce changes in this sense is inhibitors of histone deacetylase, to which it belongs valproic acid (VPA). In the present paper, we evaluated the role of this molecule on the neuroendocrine differentiation of LNCaP cells together with the effect on proliferation and survival signals. METHODS: Cell growth was analyzed by MTT and flow cytometry, while expression of proteins through Western blot analysis. RESULTS: Our results have documented that VPA in LNCaP cells reduces cell proliferation, decreases the S phase and Cyclin A, and up-regulates the cyclin-dependent kinase inhibitors p21waf and p27. The acquisition of androgen-independent condition is consistent with an induction of ß-III Tubulin and gamma Enolase, both markers of neuroendocrine phenotype. However, all these features cease with the removal of valproate from the culture medium, demonstrating the transitory nature of the epigenetic event. The VPA treatment does not compromise the survival phosphorylated signals of Akt, ERK1/2 and mTOR/p70S6K that remain up-regulated. Consistently, there is an increase of phospho-FOXO3a, to which corresponds the decreased expression of the corresponding oncosuppressor protein. CONCLUSION: Overall, our findings indicate that VPA in LNCaP prostate tumor cells, although it reduces cell proliferation, is able to drive neuroendocrine phenotype and to maintain the survival of these cells. Keeping in mind that neuroendocrine differentiation of prostate cancer appears to be associated with a poor prognosis, it is necessary to develop new treatments that do not induce neurodifferentiation but able to counteract cell survival.


Assuntos
Tumores Neuroendócrinos/tratamento farmacológico , Neoplasias Pancreáticas/tratamento farmacológico , Ácido Valproico/farmacologia , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Humanos , Tumores Neuroendócrinos/patologia , Neoplasias Pancreáticas/patologia , Fenótipo , Células Tumorais Cultivadas
14.
Sensors (Basel) ; 18(2)2018 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-29385051

RESUMO

The combination of mirrors and lenses, which defines a catadioptric sensor, is widely used in the computer vision field. The definition of a catadioptric sensors is based on three main features: hardware setup, projection modelling and calibration process. In this paper, a complete description of these aspects is given for an omnidirectional sensor based on a spherical mirror. The projection model of a catadioptric system can be described by the forward projection task (FP, from 3D scene point to 2D pixel coordinates) and backward projection task (BP, from 2D coordinates to 3D direction of the incident light). The forward projection of non-central catadioptric vision systems, typically obtained by using curved mirrors, is usually modelled by using a central approximation and/or by adopting iterative approaches. In this paper, an analytical closed-form solution to compute both forward and backward projection for a non-central catadioptric system with a spherical mirror is presented. In particular, the forward projection is reduced to a 4th order polynomial by determining the reflection point on the mirror surface through the intersection between a sphere and an ellipse. A matrix format of the implemented models, suitable for fast point clouds handling, is also described. A robust calibration procedure is also proposed and applied to calibrate a catadioptric sensor by determining the mirror radius and center with respect to the camera.

15.
Proc Inst Mech Eng H ; 232(1): 54-66, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29160155

RESUMO

Orthodontic treatments are usually performed using fixed brackets or removable oral appliances, which are traditionally made from alginate impressions and wax registrations. Among removable devices, eruption guidance appliances are used for early orthodontic treatments in order to intercept and prevent malocclusion problems. Commercially available eruption guidance appliances, however, are symmetric devices produced using a few standard sizes. For this reason, they are not able to meet all the specific patient's needs since the actual dental anatomies present various geometries and asymmetric conditions. In this article, a computer-aided design-based methodology for the design and manufacturing of a patient-specific eruption guidance appliances is presented. The proposed approach is based on the digitalization of several steps of the overall process: from the digital reconstruction of patients' anatomies to the manufacturing of customized appliances. A finite element model has been developed to evaluate the temporomandibular joint disks stress level caused by using symmetric eruption guidance appliances with different teeth misalignment conditions. The developed model can then be used to guide the design of a patient-specific appliance with the aim at reducing the patient discomfort. At this purpose, two different customization levels are proposed in order to face both arches and single tooth misalignment issues. A low-cost manufacturing process, based on an additive manufacturing technique, is finally presented and discussed.


Assuntos
Desenho Assistido por Computador , Desenho de Equipamento/métodos , Aparelhos Ortodônticos , Análise de Elementos Finitos , Humanos , Modelos Teóricos , Suporte de Carga
16.
Dis Markers ; 2017: 6870614, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29259349

RESUMO

Prediction of benefit from combined chemotherapy and the antiepidermal growth factor receptor cetuximab is a not yet solved question in head and neck squamous cell carcinoma (HNSCC). In a selected series of 14 long progression-free survival (PFS) and 26 short PFS patients by whole gene and microRNA expression analysis, we developed a model potentially predictive of cetuximab sensitivity. To better decipher the "omics" profile of our patients, we detected transcript fusions by RNA-seq through a Pan-Cancer panel targeting 1385 cancer genes. Twenty-seven different fusion transcripts, involving mRNA and long noncoding RNA (lncRNA), were identified. The majority of fusions (81%) were intrachromosomal, and 24 patients (60%) harbor at least one of them. The presence/absence of fusions and the presence of more than one fusion were not related to outcome, while the lncRNA-containing fusions resulted enriched in long PFS patients (P = 0.0027). The CD274-PDCD1LG2 fusion was present in 7/14 short PFS patients harboring fusions and was absent in long PFS patients (P = 0.0188). Among the short PFS patients, those harboring this fusion had the worst outcome (P = 0.0172) and increased K-RAS activation (P = 0.00147). The associations between HNSCC patient's outcome following cetuximab treatment and lncRNA-containing fusions or the CD274-PDCD1LG2 fusion deserve validation in prospective clinical trials.


Assuntos
Antineoplásicos Imunológicos/uso terapêutico , Biomarcadores Tumorais/genética , Carcinoma de Células Escamosas/genética , Cetuximab/uso terapêutico , Neoplasias de Cabeça e Pescoço/genética , Proteínas de Fusão Oncogênica/genética , Antígeno B7-H1/genética , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/metabolismo , Receptores ErbB/metabolismo , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/metabolismo , Humanos , Proteína 2 Ligante de Morte Celular Programada 1/genética
17.
PLoS One ; 12(11): e0182640, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29099834

RESUMO

Notch signaling plays an important role in several cellular functions including growth, differentiation, cell fate determination and stemness. Increased Notch activity has been linked to several types of cancers. Activation of Notch signaling is triggered by the interaction of Notch receptors (Notch1-4) with 5 different ligands (Jagged1-2 and Dll1-3-4) expressed on the neighbouring cells. Currently, indirect approaches to inhibit Notch signalling are based on the inhibition of the key step of Notch activation catalyzed by the γ-Secretase and thereby affect several different γ-Secretase substrates; conversely direct strategies get advantage of antibody-based drugs. The evidence that Jagged-mediated Notch activation plays a key role in cancer cell biology and the interplay with the surrounding microenvironment prompted us to develop a strategy to directly inhibit Notch activation by uncoupling its interaction with the Jagged, using an unprecedented approach based on small molecules. We set-up a screening strategy based on: protein::protein docking of crystallographic structures of Notch1 with Jagged1; comparative modelling of the Notch2:Jagged2 complex, based on the Notch1::Jagged1 complex; in silico high-throughput screening directed to Notch2 interaction surface of a virtual chemical library containing a large variety of molecules commercially available. The predicted pharmacological activity of the selected compounds was validated in vitro by a gene reporter and a viability assay. This approach led to the successful identification of two candidates with different anti-proliferative potency and efficacy. This represents the first step towards the rational identification of candidate molecules for the development of entirely novel drugs directed to inhibit Notch signaling in cancer.


Assuntos
Ensaios de Triagem em Larga Escala/métodos , Proteína Jagged-2/metabolismo , Receptores Notch/metabolismo , Humanos , Modelos Moleculares , Ligação Proteica
18.
Am J Orthod Dentofacial Orthop ; 149(6): 838-46, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27241994

RESUMO

INTRODUCTION: Moment-to-force ratios (M:F) define the type of tooth movement. Typically, the relationship between M:F and tooth movement has been analyzed in a single plane. Here, to improve the 3-dimensional tooth movement theory, we tested the hypothesis that the mathematical relationships between M:F and tooth movement are distinct, depending on force system directions. METHODS: A finite element model of a maxillary first premolar, scaled to average tooth dimensions, was constructed based on a cone-beam computed tomography scan. We conducted finite element analyses of the M:F and tooth movement relationships, represented by the projected axis of rotation in each plane, for 510 different loads. RESULTS: We confirmed that a hyperbolic equation relates the distance and M:F; however, the constant of proportionality ("k") varied nonlinearly with the force direction. With a force applied parallel to the tooth's long axis, "k" was 12 times higher than with a force parallel to the mesiodistal direction and 7 times higher than with a force parallel to the buccolingual direction. CONCLUSIONS: The M:F influence on tooth movement depends on load directions. It is an incomplete parameter to describe the quality of an orthodontic load system if it is not associated with force and moment directions.


Assuntos
Análise de Elementos Finitos , Mobilidade Dentária , Fenômenos Biomecânicos , Humanos
19.
Oncotarget ; 6(29): 26826-40, 2015 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-26308486

RESUMO

Despite recent therapeutic advances, multiple myeloma (MM) is still an incurable neoplasia due to intrinsic or acquired resistance to therapy. Myeloma cell localization in the bone marrow milieu allows direct interactions between tumor cells and non-tumor bone marrow cells which promote neoplastic cell growth, survival, bone disease, acquisition of drug resistance and consequent relapse. Twenty percent of MM patients are at high-risk of treatment failure as defined by tumor markers or presentation as plasma cell leukemia. Cumulative evidences indicate a key role of Notch signaling in multiple myeloma onset and progression. Unlike other Notch-related malignancies, where the majority of patients carry gain-of-function mutations in Notch pathway members, in MM cell Notch signaling is aberrantly activated due to an increased expression of Notch receptors and ligands; notably, this also results in the activation of Notch signaling in surrounding stromal cells which contributes to myeloma cell proliferation, survival and migration, as well as to bone disease and intrinsic and acquired pharmacological resistance. Here we review the last findings on the mechanisms and the effects of Notch signaling dysregulation in MM and provide a rationale for a therapeutic strategy aiming at inhibiting Notch signaling, along with a complete overview on the currently available Notch-directed approaches.


Assuntos
Mieloma Múltiplo/metabolismo , Receptores Notch/metabolismo , Animais , Anticorpos Monoclonais/química , Células da Medula Óssea/citologia , Células da Medula Óssea/metabolismo , Proliferação de Células , Sobrevivência Celular , Ensaios Clínicos como Assunto , Progressão da Doença , Resistencia a Medicamentos Antineoplásicos , Regulação Neoplásica da Expressão Gênica , Humanos , Leucemia Plasmocitária/metabolismo , Ligantes , Mutação , Neoplasias/patologia , Receptor Notch1/metabolismo , Transdução de Sinais , Células Estromais/metabolismo
20.
Comput Med Imaging Graph ; 43: 112-21, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25670149

RESUMO

In the field of orthodontic planning, the creation of a complete digital dental model to simulate and predict treatments is of utmost importance. Nowadays, orthodontists use panoramic radiographs (PAN) and dental crown representations obtained by optical scanning. However, these data do not contain any 3D information regarding tooth root geometries. A reliable orthodontic treatment should instead take into account entire geometrical models of dental shapes in order to better predict tooth movements. This paper presents a methodology to create complete 3D patient dental anatomies by combining digital mouth models and panoramic radiographs. The modeling process is based on using crown surfaces, reconstructed by optical scanning, and root geometries, obtained by adapting anatomical CAD templates over patient specific information extracted from radiographic data. The radiographic process is virtually replicated on crown digital geometries through the Discrete Radon Transform (DRT). The resulting virtual PAN image is used to integrate the actual radiographic data and the digital mouth model. This procedure provides the root references on the 3D digital crown models, which guide a shape adjustment of the dental CAD templates. The entire geometrical models are finally created by merging dental crowns, captured by optical scanning, and root geometries, obtained from the CAD templates.


Assuntos
Desenho Assistido por Computador , Planejamento de Prótese Dentária , Modelos Dentários , Radiografia Dentária Digital , Radiografia Panorâmica , Humanos , Imageamento Tridimensional , Ortodontia/instrumentação , Planejamento de Assistência ao Paciente
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