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1.
IEEE Trans Neural Netw Learn Syst ; 33(9): 4945-4959, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-33729958

RESUMO

It is of great significance to apply deep learning for the early diagnosis of Alzheimer's disease (AD). In this work, a novel tensorizing GAN with high-order pooling is proposed to assess mild cognitive impairment (MCI) and AD. By tensorizing a three-player cooperative game-based framework, the proposed model can benefit from the structural information of the brain. By incorporating the high-order pooling scheme into the classifier, the proposed model can make full use of the second-order statistics of holistic magnetic resonance imaging (MRI). To the best of our knowledge, the proposed Tensor-train, High-order pooling and Semisupervised learning-based GAN (THS-GAN) is the first work to deal with classification on MR images for AD diagnosis. Extensive experimental results on Alzheimer's disease neuroimaging initiative (ADNI) data set are reported to demonstrate that the proposed THS-GAN achieves superior performance compared with existing methods, and to show that both tensor-train and high-order pooling can enhance classification performance. The visualization of generated samples also shows that the proposed model can generate plausible samples for semisupervised learning purpose.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Doença de Alzheimer/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Disfunção Cognitiva/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética/métodos , Redes Neurais de Computação , Neuroimagem
2.
World J Gastroenterol ; 27(42): 7387-7401, 2021 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-34876797

RESUMO

BACKGROUND: Image-guided radiotherapy (IGRT) has significantly improved the precision in which radiotherapy is delivered in cancer treatment. Typically, IGRT uses bony landmarks and key anatomical structures to locate the tumor. Recent studies have demonstrated the feasibility of peri-tumor fiducials in enabling even more accurate delineation of target and normal tissue. The use of gold coils as fiducials in gastrointestinal tumors has been extensively studied. However, placement requires expertise and specialized endoscopic ultrasound equipment. This article reports the long-term outcomes of using a standard gastroscopy to inject liquid fiducials for the treatment of oesophageal and gastric tumors with IGRT. AIM: To assess the long-term outcomes of liquid fiducial-guided IGRT in a cohort of oesophageal and gastric cancer patients. METHODS: A retrospective cohort study of consecutive adults with Oesophagogastric cancers referred for liquid fiducial placement before definitive/neo-adjuvant or palliative IGRT between 2013 and 2021 at a tertiary hospital in Melbourne, Australia was conducted. Up to four liquid fiducials were inserted per patient, each injection consisting of 0.2-0.5mL of a 1:1 mixture of iodized oil (Lipiodol; Aspen Pharmacare) and n-butyl 2-cyanoacrylate (Histoacryl®; B. Braun). A 23-gauge injector (Cook Medical) was used for the injection. All procedures were performed by or under the supervision of a gastroenterologist. Liquid fiducial-based IGRT (LF-IGRT) consisted of computer-assisted direct matching of the fiducial region on cone-beam computerised tomography at the time of radiotherapy. Patients received standard-IGRT (S-IGRT) if fiducial visibility was insufficient, consisting of bone match as a surrogate for tumor position. Radiotherapy was delivered to 54Gy in 30 fractions for curative patients and up to 45Gy in 15 fractions for palliative treatments. RESULTS: 52 patients were referred for liquid fiducial placement within the study period. A total of 51 patients underwent liquid fiducial implantation. Of these a total of 31 patients received radiotherapy. Among these, the median age was 77.4 years with a range between 57.5 and 88.8, and 64.5% were male. Twenty-seven out of the 31 patients were able to have LF-IGRT while four had S-IGRT. There were no complications after endoscopic implantation of liquid fiducials in our cohort. The cohort overall survival (OS) post-radiotherapy was 19 mo (range 0 to 87 mo). Whilst the progression-free survival (PFS) post-radiotherapy was 13 mo (range 0 to 74 mo). For those treated with curative intent, the median OS was 22.0 mo (range 0 to 87 mo) with a PFS median of 14.0 mo (range 0 to 74 mo). Grade 3 complication rate post-radiotherapy was 29%. CONCLUSION: LF-IGRT is feasible in 87.1% of patients undergoing liquid fiducial placement through standard gastroscopy injection technique. Our cohort has an overall survival of 19 mo and PFS of 13 mo. Further studies are warranted to determine the long-term outcomes of liquid-fiducial based IGRT.


Assuntos
Neoplasias Gastrointestinais , Radioterapia Guiada por Imagem , Adulto , Óleo Etiodado , Marcadores Fiduciais , Neoplasias Gastrointestinais/diagnóstico por imagem , Neoplasias Gastrointestinais/radioterapia , Gastroscopia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
3.
Nat Commun ; 10(1): 5175, 2019 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-31729369

RESUMO

Kidney stone disease (nephrolithiasis) is a major clinical and economic health burden with a heritability of ~45-60%. We present genome-wide association studies in British and Japanese populations and a trans-ethnic meta-analysis that include 12,123 cases and 417,378 controls, and identify 20 nephrolithiasis-associated loci, seven of which are previously unreported. A CYP24A1 locus is predicted to affect vitamin D metabolism and five loci, DGKD, DGKH, WDR72, GPIC1, and BCR, are predicted to influence calcium-sensing receptor (CaSR) signaling. In a validation cohort of only nephrolithiasis patients, the CYP24A1-associated locus correlates with serum calcium concentration and a number of nephrolithiasis episodes while the DGKD-associated locus correlates with urinary calcium excretion. In vitro, DGKD knockdown impairs CaSR-signal transduction, an effect rectified with the calcimimetic cinacalcet. Our findings indicate that studies of genotype-guided precision-medicine approaches, including withholding vitamin D supplementation and targeting vitamin D activation or CaSR-signaling pathways in patients with recurrent kidney stones, are warranted.


Assuntos
Cálcio/metabolismo , Cálculos Renais/genética , Vitamina D/metabolismo , Adulto , Idoso , Povo Asiático/genética , Diacilglicerol Quinase/genética , Diacilglicerol Quinase/metabolismo , Feminino , Variação Genética , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Japão , Cálculos Renais/metabolismo , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Estudos Prospectivos , Proteínas/genética , Proteínas/metabolismo , Receptores de Detecção de Cálcio/genética , Receptores de Detecção de Cálcio/metabolismo , Reino Unido , População Branca/genética
4.
J Med Imaging Radiat Oncol ; 63(3): 415-421, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30908894

RESUMO

INTRODUCTION: To examine the long-term outcomes of high dose rate brachytherapy boost (HDR-BT) combined with external beam radiotherapy (EBRT) for intermediate and high-risk prostate cancer patients. METHODS: Data from 95 patients who underwent combined EBRT (50.4 Gy) and HDR-BT to the prostate between 2010 and 2017 were retrospectively analysed. Biochemical progression free survival (bPFS), local recurrence free survival (LRFS), metastatic free survival (MFS) and overall survival (OS) were estimated using Kaplan-Meier method. Regression analysis was conducted to identify important predictors of outcomes. RESULTS: A total of 24 patients received an initial HDR-BT dose of 18 Gy in three fractions, with the remaining 71 patients receiving 16 Gy in two fractions as per departmental protocol changes. Most patients (88%) received androgen deprivation therapy. A transurethral resection of the prostate (TURP) was performed in 14 patients and hydrogel spacers (HS) were used in 30 patients. Median follow-up was 58 months. The 5-year bPFS, LRFS, MFS and OS were 92%, 100%, 92% and 88%. Univariate regression revealed no statistical association between patient characteristics and time to relapse (all P > 0.1). Late > grade 2 genitourinary (GU) toxicity was 6.3%. The use of HS or prior TURP had no impact on late GU toxicity. Late Grade 1 gastrointestinal (GI) toxicity was 5.3%. CONCLUSION: The combined HDR-BT with EBRT resulted in excellent bPFS. The cumulative risk of late GU and GI toxicity was low and can be further improved with preventative strategies such as a pre-emptive TURP and/or HS insertion.


Assuntos
Braquiterapia/métodos , Neoplasias da Próstata/radioterapia , Neoplasias da Próstata/cirurgia , Próteses e Implantes , Ressecção Transuretral da Próstata , Idoso , Idoso de 80 Anos ou mais , Austrália , Biomarcadores Tumorais/sangue , Fracionamento da Dose de Radiação , Humanos , Hidrogéis , Masculino , Pessoa de Meia-Idade , Lesões por Radiação/prevenção & controle , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Estudos Retrospectivos , Taxa de Sobrevida , Tomografia Computadorizada por Raios X
5.
Comput Biol Chem ; 69: 185-193, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28648470

RESUMO

Drug-target interaction (DTI) prediction is a challenging step in further drug repositioning, drug discovery and drug design. The advent of high-throughput technologies brings convenience to the development of DTI prediction methods. With the generation of a high number of data sets, many mathematical models and computational algorithms have been developed to identify the potential drug-target pairs. However, most existing methods are proposed based on the single view data. By integrating the drug and target data from different views, we aim to get more stable and accurate prediction results. In this paper, a multiview DTI prediction method based on clustering is proposed. We first introduce a model for single view drug-target data. The model is formulated as an optimization problem, which aims to identify the clusters in both drug similarity network and target protein similarity network, and at the same time make the clusters with more known DTIs be connected together. Then the model is extended to multiview network data by maximizing the consistency of the clusters in each view. An approximation method is proposed to solve the optimization problem. We apply the proposed algorithms to two views of data. Comparisons with some existing algorithms show that the multiview DTI prediction algorithm can produce more accurate predictions. For the considered data set, we finally predict 54 possible DTIs. From the similarity analysis of the drugs/targets, enrichment analysis of DTIs and genes in each cluster, it is shown that the predicted DTIs have a high possibility to be true.


Assuntos
Algoritmos , Avaliação Pré-Clínica de Medicamentos/métodos , Terapia de Alvo Molecular , Análise por Conglomerados
6.
Biomaterials ; 53: 12-24, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25890702

RESUMO

The limited efficacy of cardiac cell-based therapy is thought to be due to poor cell retention within the myocardium. Hence, there is an urgent need for biomaterials that aid in long-term cell retention. This study describes the development of injectable microcapsules for the delivery of mesenchymal stem cells (MSCs) into the infarcted cardiac wall. These microcapsules comprise of low concentrations of agarose supplemented with extracellular matrix (ECM) proteins collagen and fibrin. Dextran sulfate, a negatively charged polycarbohydrate, was added to mimic glycosaminoglycans in the ECM. Cell viability assays showed that a combination of all components is necessary to support long-term survival and proliferation of MSCs within microcapsules. Following intramyocardial transplantation, microcapsules degraded slowly in vivo and did not induce a fibrotic foreign body response. Pre-labeling of encapsulated MSCs with iron oxide nanoparticles allowed continued cell-tracking by MRI over several weeks following transplantation into infarcted myocardium. In contrast, MSCs injected as cell suspension were only detectable for two days post transplantation by MRI. Histological analysis confirmed integration of transplanted cells at the infarct site. Therefore, microcapsules proved to be suitable for stem cell delivery into the infarcted myocardium and can overcome current limitations of poor cell retention in cardiac cell-based therapy.


Assuntos
Cápsulas , Proliferação de Células , Sobrevivência Celular , Células-Tronco Mesenquimais/citologia , Infarto do Miocárdio/patologia , Animais , Masculino , Ratos , Ratos Wistar
7.
Seizure ; 13(3): 176-8, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15010055

RESUMO

We reviewed our experience with vagus nerve stimulation (VNS) in 165 patients with medically refractory epilepsy (138 partial epilepsy (PE), 13 symptomatic generalised epilepsy (SGE), 14 idiopathic generalised epilepsy (IGE)). Average duration of VNS therapy was 21.6 months. A 50% or greater reduction in seizure frequency was achieved in 47.1% of the PE group, 46.1% of the SGE group, and 57.1% of the IGE group. A 50% or greater reduction in seizure frequency and reduced antiepileptic drug (AED) regimen were achieved in: PE (9.4%), SGE (7.7%), and IGE (35.7%). These preliminary results suggest that VNS is an effective therapy for some patients with medically refractory IGE.


Assuntos
Terapia por Estimulação Elétrica/métodos , Epilepsia Generalizada/terapia , Nervo Vago/fisiologia , Adolescente , Adulto , Idoso , Criança , Epilepsia Generalizada/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
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