RESUMO
Background: Patients with high-risk neuroblastoma (NB) have a 5-year event-free survival of less than 50 %, and novel and improved treatment options are needed. Radiolabeled somatostatin analogs (SSTAs) could be a treatment option. The aims of this work were to compare the biodistribution and the therapeutic effects of 177Lu-octreotate and 177Lu-octreotide in mice bearing the human CLB-BAR NB cell line, and to evaluate their regulatory effects on apoptosis-related genes. Methods: The biodistribution of 177Lu-octreotide in mice bearing CLB-BAR tumors was studied at 1, 24, and 168 h after administration, and the absorbed dose was estimated to tumor and normal tissues. Further, animals were administered different amounts of 177Lu-octreotate or 177Lu-octreotide. Tumor volume was measured over time and compared to a control group given saline. RNA was extracted from tumors, and the expression of 84 selected genes involved in apoptosis was quantified with qPCR. Results: The activity concentration was generally lower in most tissues for 177Lu-octreotide compared to 177Lu-octreotate. Mean absorbed dose per administered activity to tumor after injection of 1.5 MBq and 15 MBq was 0.74 and 0.03 Gy/MBq for 177Lu-octreotide and 2.9 and 0.45 Gy/MBq for 177Lu-octreotate, respectively. 177Lu-octreotide treatment resulted in statistically significant differences compared to controls. Fractionated administration led to a higher survival fraction than after a single administration. The pro-apoptotic genes TNSFS8, TNSFS10, and TRADD were regulated after administration with 177Lu-octreotate. Treatment with 177Lu-octreotide yielded regulation of the pro-apoptotic genes CASP5 and TRADD, and of the anti-apoptotic gene IL10 as well as the apoptosis-related gene TNF. Conclusion: 177Lu-octreotide gave somewhat better anti-tumor effects than 177Lu-octreotate. The similar effect observed in the treated groups with 177Lu-octreotate suggests saturation of the somatostatin receptors. Pronounced anti-tumor effects following fractionated administration merited receptor saturation as an explanation. The gene expression analyses suggest apoptosis activation through the extrinsic pathway for both radiopharmaceuticals.
RESUMO
Stakeholders in health science education engage in site visits during student clinical education experiences, which may occur in person or remotely via videoconference, telephone, or email. Significant variability in practice highlights the need for a more consistent approach to conducting site visits based on evidence-based best practices. Site visits can be burdensome to both clinical and academic stakeholders considering the significant time and resources needed to conduct them effectively. Despite these obstacles, site visits have been shown to add value to the clinical experience for all parties involved. This paper presents the available literature in health science education regarding clinical site visits and describes how it was used to develop and implement a model of best practice for conducting clinical site visits in physical therapist education. The Site Visit Decision-Making Model is based upon findings from contemporary research exploring the interests of each stakeholder, as well as the multifaceted and purposeful decision-making process that takes place when conducting site visits in physical therapist clinical education. Implementation of this model may assist academic stakeholders in health science education in prioritizing which methods of communication for conducting site visits are most effective and efficient.
Assuntos
Tomada de Decisões , Humanos , Especialidade de Fisioterapia/educação , Fisioterapeutas/educação , Comunicação , Guias de Prática Clínica como Assunto , Prática Clínica Baseada em EvidênciasRESUMO
Genomics is a crucial part of managing surgical disease. This review focuses on some of the genomic advances that are available now and looks to the future of their application in surgical practice. Whole-genome sequencing enables unbiased coverage across the entire human genome of approximately three billion base pairs. Newer technologies, such as those that permit long-read sequence analysis, provide additional information in longer phased fragment and base pair epigenomic (methylomic) data. Whole-genome sequencing is currently available in England for cancers in children, teenagers and young adults, central nervous system tumours, sarcoma and haematological malignancies. Circulating tumour DNA (ctDNA), immunotherapy and pharmacogenomics have emerged as groundbreaking approaches in the field of cancer treatment. These are now revolutionising the way oncologists and surgeons approach curative cancer surgery. Cancer vaccines offer an innovative approach to reducing recurrence after surgery by priming the immune system to trigger an immune response. The Cancer Vaccine Launch Pad project facilitates cancer vaccine studies in England. The BNT122-01 trial is recruiting patients with ctDNA-positive high-risk colorectal cancer after surgery to assess the impact of cancer vaccines. The evolving landscape of cancer treatment demands a dynamic and integrated approach from the surgical multidisciplinary team. Immunotherapy, ctDNA, pharmacogenomics, vaccines, mainstreaming and whole-genome sequencing are just some of the innovations that have the potential to redefine the standards of care. The continued exploration of these innovative diagnostics and therapies, the genomic pathway evolution and their application in diverse cancer types highlights the transformative impact of precision medicine in surgery.
Assuntos
Vacinas Anticâncer , DNA Tumoral Circulante , Neoplasias , Cirurgiões , Criança , Humanos , Adolescente , DNA Tumoral Circulante/genética , GenômicaRESUMO
Background: Co-use of alcohol and other drugs within a certain time frame (i.e., polysubstance use) has become increasingly prevalent, particularly among college-aged individuals, but understanding motives for co-use remains limited. Polysubstance use has been associated with a higher likelihood of negative health consequences as compared to single substance use. Objectives: The current study examined associations between motivations for using alcohol, tobacco, and cannabis among college students who use multiple substances versus students using only one substance or no substances. Additionally, we examined the effect of trauma and daily stress on polysubstance use in self-report data from individuals (N=134) participating in the MAPme Study. Results: First, the observed prevalence of polysubstance use was greater than expected by chance, with most individuals co-using alcohol and cannabis. "Alcohol and Other Drug Users" were more frequently motivated to drink for social (ß=0.27, CI=[0.07, 0.44]), enhancement (ß=0.26, CI=[0.01, 0.42]) and coping (ß=0.21, CI=[0.06, 0.47]) reasons compared to individuals who consumed alcohol alone. Conclusions: Individual differences in motivations for use were partly explained by frequency of alcohol use and alcohol problem severity, but not by history of trauma or stress. Finally, while patterns of correlations among motivations for use across substances suggested a general tendency to be motivated to use substances for similar reasons, this was not supported by confirmatory factor models. Overall, shared motives may inform potential behavioral patterns for co-use of substances during college and might advise future treatment efforts.
Emerging adults tend to use multiple substances, particularly alcohol and cannabisCorrelation patterns suggest shared motives within rather than across substancesAlcohol problem severity and alcohol frequency predict motives for use.
Assuntos
Motivação , Estresse Psicológico , Estudantes , Transtornos Relacionados ao Uso de Substâncias , Humanos , Masculino , Feminino , Estudantes/psicologia , Adulto Jovem , Universidades , Estresse Psicológico/psicologia , Estresse Psicológico/epidemiologia , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Transtornos Relacionados ao Uso de Substâncias/psicologia , Individualidade , Adolescente , Adulto , Consumo de Álcool na Faculdade/psicologia , Adaptação Psicológica , Consumo de Bebidas Alcoólicas/epidemiologia , Consumo de Bebidas Alcoólicas/psicologiaRESUMO
INTRODUCTION: Echinoderm microtubule-associated protein-like 4 (EML4)-Anaplastic Lymphoma Kinase (ALK) rearrangements occur in 3% to 7% of lung adenocarcinomas and are targets for treatment with tyrosine kinase inhibitors (TKIs). Here we have developed three novel EML4-ALK-positive patient-derived Non-Small-Cell-Lung-Cancer (NSCLC) cancer cell lines, CUTO8 (variant 1), CUTO9 (variant 1) and CUTO29 (variant 3) and included a fourth ALK-positive cell line YU1077 (variant 3) to study ALK-positive signaling and responses. Variants 1 and 3 are the most common EML4-ALK variants expressed in ALK-positive NSCLC, and currently cell lines representing these EML4-ALK variants are limited. MATERIALS AND METHODS: Resazurin assay was performed to evaluate cell viability. Protein levels were determined using western blotting. RNA sequencing was performed in all four cell lines to identify differentially expressed genes. Whole-genome sequencing was performed to determine the presence of EML4-ALK fusion and ALK tyrosine kinase inhibitor resistance mutations. RESULTS: In this study, we have confirmed expression of the corresponding ALK fusion protein and assessed their sensitivity to a range of ALK tyrosine kinase inhibitors. These patient derived cell lines exhibit differential sensitivity to lorlatinib, brigatinib and alectinib, with EML4-ALK variant 3 containing cell lines exhibiting increased sensitivity to lorlatinib and brigatinib as compared to alectinib. These cell lines were further characterized by whole genome sequencing and RNA-seq analysis that identified the ribonucleotide reductase regulatory subunit 2 (RRM2) as a downstream and potential therapeutic target in ALK-positive NSCLC. CONCLUSION: We provide a characterization of four novel EML4-ALK-positive NSCLC cell lines, highlighting genomic heterogeneity and differential responses to ALK TKI treatment. The RNA-Seq characterization of ALK-positive NSCLC CUTO8, CUTO9, CUTO29 and YU1077 cell lines reported here, has been compiled in an interactive ShinyApp resource for public data exploration (https://ccgg.ugent.be/shiny/nsclc_rrm2_2022/).
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Ribonucleosídeo Difosfato Redutase , Quinase do Linfoma Anaplásico/genética , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Proteínas de Fusão Oncogênica/genética , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Ribonucleosídeo Difosfato Redutase/metabolismoRESUMO
The chapter presents an argument supporting the view that taste, defined as the receptor-mediated signaling of taste cells and consequent sensory events, is proper subject matter for the field of pharmacology. The argument develops through a consideration of how the field of pharmacology itself is to be defined. Though its application toward the discovery and development of therapeutics is of obvious value, pharmacology nevertheless is a basic science committed to examining biological phenomena controlled by the selective interactions between chemicals - regardless of their sources or uses - and receptors. The basic science of pharmacology is founded on the theory of receptor occupancy, detailed here in the context of taste. The discussion then will turn to consideration of the measurement of human taste and how well the results agree with the predictions of receptor theory.
Assuntos
Farmacologia , Papilas Gustativas , Humanos , Transdução de Sinais , PaladarRESUMO
Human taste threshold measurements often are used to infer tastant receptor functionality. However, taste thresholds can be influenced by receptor-independent variables. Examination of the full range of taste-active concentrations by taste discrimination has been hampered by logistics of testing multiple concentrations in replicate with human subjects. We developed an automated rapid throughput operant methodology for taste discrimination and applied it to concentration-response analysis of human taste. Tastant solutions (200 µl) drawn from a 96-well plate and self-administered to the tongue served as discriminative stimuli for money-reinforced responses on a touch-sensitive display. Robust concentration-response functions for "basic taste" stimuli were established, with particular focus on agonists of the taste 1 receptor member 2-taste 1 receptor member 3 heterodimer receptor (TAS1R2/R3). With a training cue of 100 mM sucrose, EC50 values of 56, 79, and 310 µM and 40 mM were obtained for rebaudioside A, sucralose, acesulfame potassium, and sucrose, respectively. Changing the sucrose training cue to 300 mM had no impact, but changing to 30 mM resulted in slight leftward shifts in potencies. A signal detection method also was used to determine values of d', a probabilistic value for discriminability, which indicated that 5 mM was near the limits of detection for sucrose. With repeated testing, both EC50 values and 5 mM sucrose d' values were established for each individual subject. The results showed little correspondence between threshold sensitivities and EC50 values for sucrose. We conclude that concentration-response analysis of taste discrimination provides a more reliable means of inferring receptor function than measurement of discriminability at the lowest detectable tastant concentrations. SIGNIFICANCE STATEMENT: Many inferences about human tastant receptor functionality have been made from taste threshold measurements, which can be influenced by variables unrelated to receptors. We herein report a new methodology that enables rigorous concentration-response analysis of human taste discrimination and its use toward quantitative characterization of tastant agonist activity. Our data suggest that taste discrimination concentration-response functions are a more reliable reflection of underlying receptor activity than threshold measures obtained at the lowest detectable tastant concentrations.
Assuntos
Discriminação Psicológica , Ensaios de Triagem em Larga Escala/métodos , Limiar Gustativo , Adulto , Automação Laboratorial/instrumentação , Automação Laboratorial/métodos , Relação Dose-Resposta a Droga , Feminino , Ensaios de Triagem em Larga Escala/instrumentação , Humanos , Masculino , Pessoa de Meia-Idade , Receptores Acoplados a Proteínas G/metabolismo , Sacarose/farmacologia , Percepção Gustatória , Língua/efeitos dos fármacos , Língua/metabolismo , Língua/fisiologiaRESUMO
Although the changes in melting behaviour on the nanoscale have long attracted the interest of researchers, the mechanism by which nanoparticles melt remains an open problem. We report the direct observation, at atomic resolution, of surface melting in individual size-selected Au clusters (2-5 nm diameter) supported on carbon films, using an in situ heating stage in the aberration corrected scanning transmission electron microscope. At elevated temperatures the Au nanoparticles are found to form a solid core-liquid shell structure. The cluster surface melting temperatures, show evidence of size-dependent melting point suppression. The cluster core melting temperatures are significantly greater than predicted by existing models of free clusters. To explore the effect of the interaction between the clusters and the carbon substrate, we employ a very large-scale ab initio simulation approach to investigate the influence of the support. Theoretical results for surface and core melting points are in good agreement with experiment.
RESUMO
OBJECTIVES: Maternal health behaviours (MHBs) can influence pregnancy outcomes. Despite efforts internationally to encourage positive MHBs, women often fail to comply with pregnancy guidelines. International studies show differences in MHBs between nationalities and an effect of time spent in the host country. There is limited Irish data in this area, with no previous research relating to the effect of time in Ireland. STUDY DESIGN: This study is a cross-sectional analysis of the Growing Up in Ireland infant cohort, a nationally representative longitudinal study. METHODS: Examination of the MHBs of non-Irish nationals during pregnancy and the effect of time in Ireland on the said behaviours. RESULTS: An association was found between time spent in Ireland and increased alcohol consumption prevalence. Those living in Ireland for ≤5 years were 60.8% less likely to consume alcohol during pregnancy (0.000) and 29.3% less likely to take folic acid before conception (0.021). Those who smoked during pregnancy were 98.6% more likely to consume alcohol (0.000) and those who consumed alcohol were 95.2% more likely to smoke during pregnancy (0.000). CONCLUSIONS: The results demonstrate differences in MHBs and the influence of time living in Ireland. These findings are of relevance for policy and intervention planning to optimise pregnancy outcomes among non-nationals.
Assuntos
Emigrantes e Imigrantes/psicologia , Emigração e Imigração/estatística & dados numéricos , Comportamentos Relacionados com a Saúde , Gestantes/psicologia , Aculturação , Adulto , Consumo de Bebidas Alcoólicas/epidemiologia , Estudos Transversais , Emigrantes e Imigrantes/estatística & dados numéricos , Feminino , Ácido Fólico , Humanos , Irlanda/epidemiologia , Estudos Longitudinais , Gravidez , Resultado da Gravidez , Prevalência , Fumar/epidemiologia , Fatores de TempoRESUMO
The study of taste has been guided throughout much of its history by the conceptual framework of psychophysics, where the focus was on quantification of the subjective experience of the taste sensations. By the mid-20th century, data from physiologic studies had accumulated sufficiently to assemble a model for the function of receptors that must mediate the initial stimulus of tastant molecules in contact with the tongue. But the study of taste as a receptor-mediated event did not gain momentum until decades later when the actual receptor proteins and attendant signaling mechanisms were identified and localized to the highly specialized taste-responsive cells of the tongue. With those discoveries a new opportunity to examine taste as a function of receptor activity has come into focus. Pharmacology is the science designed specifically for the experimental interrogation and quantitative characterization of receptor function at all levels of inquiry from molecules to behavior. This review covers the history of some of the major concepts that have shaped thinking and experimental approaches to taste, the seminal discoveries that have led to elucidation of receptors for taste, and how applying principles of receptor pharmacology can enhance understanding of the mechanisms of taste physiology and perception.
Assuntos
Receptores Acoplados a Proteínas G/fisiologia , Paladar/fisiologia , Trifosfato de Adenosina/fisiologia , Animais , Bioensaio , HumanosAssuntos
Cloridrato de Fingolimode/efeitos adversos , Imunossupressores/efeitos adversos , Linfoma Anaplásico de Células Grandes/induzido quimicamente , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Neoplasias Cutâneas/induzido quimicamente , Biópsia , Feminino , Humanos , Antígeno Ki-1/metabolismo , Linfoma Anaplásico de Células Grandes/diagnóstico , Linfoma Anaplásico de Células Grandes/patologia , Pessoa de Meia-Idade , Receptores de Lisoesfingolipídeo/antagonistas & inibidores , Receptores de Lisoesfingolipídeo/metabolismo , Pele/citologia , Pele/efeitos dos fármacos , Pele/patologia , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/patologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismoRESUMO
The equilibrium structures and dynamics of a nanoscale system are regulated by a complex potential energy surface (PES). This is a key target of theoretical calculations but experimentally elusive. We report the measurement of a key PES parameter for a model nanosystem: size-selected Au nanoclusters, soft-landed on amorphous silicon nitride supports. We obtain the energy difference between the most abundant structural isomers of magic number Au561 clusters, the decahedron and face-centred-cubic (fcc) structures, from the equilibrium proportions of the isomers. These are measured by atomic-resolution scanning transmission electron microscopy, with an ultra-stable heating stage, as a function of temperature (125-500 °C). At lower temperatures (20-125 °C) the behaviour is kinetic, exhibiting down conversion of metastable decahedra into fcc structures; the higher state is repopulated at higher temperatures in equilibrium. We find the decahedron is 0.040 ± 0.020 eV higher in energy than the fcc isomer, providing a benchmark for the theoretical treatment of nanoparticles.
RESUMO
Textile fibres can be transferred directly, person to person or person to scene (primary transfer), or indirectly via an intermediate (secondary transfer). In criminal cases involving a transfer of textile fibres, it is often the case that whilst the provenance of recovered 'crime significant' fibres is accepted by the defence, it is a particular activity leading to their transfer to a surface in question which is disputed. In such circumstances, transfer and persistence studies relating to fibres on a particular substrate in particular conditions assist in evaluating whether the presence of crime relevant fibres is more likely to have occurred by one particular activity compared to another. This study investigates the effect of a time delay between the primary transfer of fibres to a garment on the numbers of subsequently secondarily transferred fibres to a seat. Two donor garments composed of polyester and cotton fibres respectively were employed in this study and secondarily transferred to seats after time intervals of 0, 0.5, 2, 6 and 24h. The number of secondarily transferred fibres were recorded according to fibre type and time interval and compared against levels recorded at the primary transfer stage. The results showed that only a relatively small percentage of the original primary transfer is likely to be secondarily transferred and that the numbers found were inversely proportional to the time interval between the primary and secondary transfer. In addition, it was found that the secondary transfer of cotton fibres was an order of magnitude higher than for polyester.
Assuntos
Apoptose/genética , Queratinócitos/fisiologia , Transtornos de Fotossensibilidade/genética , Adulto , Análise de Variância , Estudos de Casos e Controles , Feminino , Expressão Gênica/genética , Regulação da Expressão Gênica/genética , Genes/genética , Predisposição Genética para Doença/genética , Estudo de Associação Genômica Ampla , Humanos , Pessoa de Meia-Idade , Adulto JovemRESUMO
One of the main limitations to the application of clusters on applied areas is the limited production; therefore, it is of great interest to up scale cluster production while keeping good size control. The Matrix-Assembly Cluster Source is a new high flux cluster source, which exploits cluster formation inside a solid rare gas matrix that is sputtered by an ion beam. Clusters are formed and ejected in this process. Here we report the production of Ag clusters when the rare gas is replaced by CO2 for the matrix formation at 20 K. Size distributions were determined from scanning transmission electron microscopy analysis of samples with four different metal loadings, 4%, 8%, 14%, and 23% of Ag atoms to CO2 molecules, and two ion beam energies, 1 keV and 2 keV. Cluster mean size showed weak dependence on metal loading, being ≈80 atoms for the first three concentrations, whereas the change in ion beam energy has caused cluster mean size to shift from 86 to 160 atoms. The results are interpreted in terms of bonding energy between Ag and CO2 and compared to the rare gas (Ar) matrix.
RESUMO
The tip of a scanning tunnelling microscope is an atomic-scale source of electrons and holes. As the injected charge spreads out, it can induce adsorbed molecules to react. By comparing large-scale 'before' and 'after' images of an adsorbate covered surface, the spatial extent of the nonlocal manipulation is revealed. Here, we measure the nonlocal manipulation of toluene molecules on the Si(111)-7 × 7 surface at room temperature. Both the range and probability of nonlocal manipulation have a voltage dependence. A region within 5-15 nm of the injection site shows a marked reduction in manipulation. We propose that this region marks the extent of the initial coherent (that is, ballistic) time-dependent evolution of the injected charge carrier. Using scanning tunnelling spectroscopy, we develop a model of this time-dependent expansion of the initially localized hole wavepacket within a particular surface state and deduce a quantum coherence (ballistic) lifetime of â¼10 fs.
RESUMO
The first-in-class inhibitor of ALK, c-MET and ROS1, crizotinib (Xalkori), has shown remarkable clinical efficacy in treatment of ALK-positive non-small cell lung cancer. However, in neuroblastoma, activating mutations in the ALK kinase domain are typically refractory to crizotinib treatment, highlighting the need for more potent inhibitors. The next-generation ALK inhibitor PF-06463922 is predicted to exhibit increased affinity for ALK mutants prevalent in neuroblastoma. We examined PF-06463922 activity in ALK-driven neuroblastoma models in vitro and in vivo In vitro kinase assays and cell-based experiments examining ALK mutations of increasing potency show that PF-06463922 is an effective inhibitor of ALK with greater activity towards ALK neuroblastoma mutants. In contrast to crizotinib, single agent administration of PF-06463922 caused dramatic tumor inhibition in both subcutaneous and orthotopic xenografts as well as a mouse model of high-risk neuroblastoma driven by Th-ALK(F1174L)/MYCN Taken together, our results suggest PF-06463922 is a potent inhibitor of crizotinib-resistant ALK mutations, and highlights an important new treatment option for neuroblastoma patients.
Assuntos
Lactamas Macrocíclicas/uso terapêutico , Proteína Proto-Oncogênica N-Myc/antagonistas & inibidores , Neuroblastoma/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Aminopiridinas , Quinase do Linfoma Anaplásico , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ensaios Clínicos como Assunto , Crizotinibe , Lactamas , Lactamas Macrocíclicas/farmacologia , Camundongos Endogâmicos BALB C , Camundongos Nus , Mutação/genética , Proteína Proto-Oncogênica N-Myc/metabolismo , Neuroblastoma/patologia , Células PC12 , Inibidores de Proteínas Quinases/farmacologia , Pirazóis/farmacologia , Pirazóis/uso terapêutico , Piridinas/farmacologia , Piridinas/uso terapêutico , Ratos , Receptores Proteína Tirosina Quinases/genética , Receptores Proteína Tirosina Quinases/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
A vast array of oncogenic variants has been identified for anaplastic lymphoma kinase (ALK). Therefore, there is a need to better understand the role of ALK in cancer biology in order to optimise treatment strategies. This review summarises the latest research on the receptor tyrosine kinase ALK, and how this information can guide the management of patients with cancer that is ALK-positive. A variety of ALK gene alterations have been described across a range of tumour types, including point mutations, deletions and rearrangements. A wide variety of ALK fusions, in which the kinase domain of ALK and the amino-terminal portion of various protein partners are fused, occur in cancer, with echinoderm microtubule-associated protein-like 4 (EML4)-ALK being the most prevalent in non-small-cell lung cancer (NSCLC). Different ALK fusion proteins can mediate different signalling outputs, depending on properties such as subcellular localisation and protein stability. The ALK fusions found in tumours lack spatial and temporal regulation, which can also affect dimerisation and substrate specificity. Two ALK tyrosine kinase inhibitors (TKIs), crizotinib and ceritinib, are currently approved in Europe for use in ALK-positive NSCLC and several others are in development. These ALK TKIs bind slightly differently within the ATP-binding pocket of the ALK kinase domain and are associated with the emergence of different resistance mutation patterns during therapy. This emphasises the need to tailor the sequence of ALK TKIs according to the ALK signature of each patient. Research into the oncogenic functions of ALK, and fast paced development of ALK inhibitors, has substantially improved outcomes for patients with ALK-positive NSCLC. Limited data are available surrounding the physiological ligand-stimulated activation of ALK signalling and further research is needed. Understanding the role of ALK in tumour biology is key to further optimising therapeutic strategies for ALK-positive disease.
Assuntos
Neoplasias/enzimologia , Receptores Proteína Tirosina Quinases/fisiologia , Quinase do Linfoma Anaplásico , Animais , Desenvolvimento Embrionário , Humanos , Linfoma Anaplásico de Células Grandes/enzimologia , Neoplasias/genética , Neoplasias/terapia , Neuroblastoma/enzimologia , Proteínas de Fusão Oncogênica/genética , Mutação Puntual , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Receptores Proteína Tirosina Quinases/química , Receptores Proteína Tirosina Quinases/genética , Transdução de SinaisRESUMO
We demonstrate for the first time a waveguide-based frequency shifter on the silicon photonic platform using single-sideband modulation. The device is based on silicon-organic hybrid (SOH) electro-optic modulators, which combine conventional silicon-on-insulator waveguides with highly efficient electro-optic cladding materials. Using small-signal modulation, we demonstrate frequency shifts of up to 10 GHz. We further show large-signal modulation with optimized waveforms, enabling a conversion efficiency of -5.8 dB while suppressing spurious side-modes by more than 23 dB. In contrast to conventional acousto-optic frequency shifters, our devices lend themselves to large-scale integration on silicon substrates, while enabling frequency shifts that are several orders of magnitude larger than those demonstrated with all-silicon serrodyne devices.