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1.
Am J Otolaryngol ; 45(4): 104293, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38640812

RESUMO

OBJECTIVE: Cauliflower ear, or "hematoma auris," is a permanent condition that is typically viewed as a deformity. Despite this, it has anecdotally been observed that combat sport athletes view cauliflower ear as a respected aesthetic trait. This study characterizes and quantifies the differences in initial impressions of subjects with cauliflower ear between combat sport athletes and the general population. METHODS: In a cross-sectional survey, participants were shown frontal and profile views of four subjects with cauliflower ear and five control subjects. Respondents rated the subjects on a scale of 0-100 in perceived success, attraction, approachability, and affect display. Numeric scores were compared between combat sport athletes and the general population. Additionally, first impressions were categorized into positive, neutral, or negative classes via latent class analysis (LCA). RESULTS: 678 combat sport athletes and 129 general casual observers participated in the survey. Combat sport athletes rated subjects with cauliflower ear significantly more favorably than respondents in the general population in all personal attributes: perceived success (+4.03, 95 % CI:1.8-6.2, p = 0.0003), attractiveness (+4.11, 95 % CI:1.8-6.4, p = 0.0005), approachability (+11.57, 95 % CI: 8.4-14.7, p < 0.0001), and affect display (+4.14, 95 % CI: 1.9-6.3, p = 0.0002). They also had approximately seven times greater odds (95 % CI:4.0-12.6, p < 0.001) of reporting a positive first impression of a person with cauliflower ear than the general population. CONCLUSION: Confirming anecdotal observation, the combat sports group had a more positive perception of cauliflower ear than the general population. Conditions that are typically viewed as deformities can be looked upon favorably in specific subpopulations.


Assuntos
Atletas , Humanos , Estudos Transversais , Masculino , Adulto , Feminino , Atletas/psicologia , Adulto Jovem , Adolescente , Inquéritos e Questionários , Percepção , Pessoa de Meia-Idade
2.
Pract Neurol ; 24(4): 275-284, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-38631902

RESUMO

People with Charcot-Marie-Tooth (CMT) disease often undergo foot and ankle surgery, as foot deformities are common and cause a degree of functional limitations impairing quality of life. Surgical approaches are variable and there are no evidence-based guidelines. A multidisciplinary approach involving neurology, physical therapy and orthopaedic surgery is ideal to provide guidance on when to refer for surgical opinion and when to intervene. This review outlines the range of foot deformities associated with CMT, their clinical assessment, and their conservative and surgical and postoperative management.


Assuntos
Doença de Charcot-Marie-Tooth , Doença de Charcot-Marie-Tooth/cirurgia , Doença de Charcot-Marie-Tooth/complicações , Humanos , Adulto , Pé/cirurgia , Deformidades do Pé/cirurgia
3.
Cancer Sci ; 114(1): 236-246, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36169301

RESUMO

Photoimmunotherapy (PIT), carried out using an Ab conjugated to the near infrared dye IRDye700DX, is achieving significant success in target-specific elimination of cells. Fibroblast activation protein alpha (FAP-α) is an important target in cancer because of its expression by cancer-associated fibroblasts (CAFs) as well as by some cancer cells. Cancer-associated fibroblasts that express FAP-α have protumorigenic and immune suppressive functions. Using immunohistochemistry of human breast cancer tissue microarrays, we identified an increase of FAP-α+  CAFs in invasive breast cancer tissue compared to adjacent normal tissue. We found FAP-α expression increased in fibroblasts cocultured with cancer cells. In proof-of-principle studies, we engineered human FAP-α overexpressing MDA-MB-231 and HT-1080 cancer cells and murine FAP-α overexpressing NIH-3T3 fibroblasts to evaluate several anti-FAP-α Abs and selected AF3715 based on its high binding affinity with both human and mouse FAP-α. After conjugation of AF3715 with the phthalocyanine dye IR700, the resultant Ab conjugate, FAP-α-IR700, was evaluated in cells and tumors for its specificity and effectiveness in eliminating FAP-α expressing cell populations with PIT. Fibroblast activation protein-α-IR700-PIT resulted in effective FAP-α-specific cell killing in the engineered cancer cells and in two patient-derived CAFs in a dose-dependent manner. Following an intravenous injection, FAP-α-IR700 retention was three-fold higher than IgG-IR700 in FAP-α overexpressing tumors, and two-fold higher compared to WT tumors. Fibroblast activation protein-α-IR700-PIT resulted in significant growth inhibition of tumors derived from FAP-α overexpressing human cancer cells. A reduction of endogenous FAP-α+ murine CAFs was identified at 7 days after FAP-α-IR700-PIT. Fibroblast activation protein-α-targeted near infrared PIT presents a promising strategy to eliminate FAP-α+ CAFs.


Assuntos
Neoplasias da Mama , Fototerapia , Animais , Humanos , Camundongos , Feminino , Fototerapia/métodos , Endopeptidases/genética , Proteínas de Membrana/genética , Imunoterapia/métodos , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Ensaios Antitumorais Modelo de Xenoenxerto , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico
4.
J Evol Biol ; 36(7): 1010-1019, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36514842

RESUMO

Colour is an important component of many different defensive strategies, but signal efficacy and detectability will also depend on the size of the coloured structures, and how pattern size interacts with the background. Consequently, size-dependent changes in colouration are common among many different species as juveniles and adults frequently use colour for different purposes in different environmental contexts. A widespread strategy in many species is switching from crypsis to conspicuous aposematic signalling as increasing body size can reduce the efficacy of camouflage, while other antipredator defences may strengthen. Curiously, despite being chemically defended, the gold-striped frog (Lithodytes lineatus, Leptodactylidae) appears to do the opposite, with bright yellow stripes found in smaller individuals, whereas larger frogs exhibit dull brown stripes. Here, we investigated whether size-dependent differences in colour support distinct defensive strategies. We first used visual modelling of potential predators to assess how colour contrast varied among frogs of different sizes. We found that contrast peaked in mid-sized individuals while the largest individuals had the least contrasting patterns. We then used two detection experiments with human participants to evaluate how colour and body size affected overall detectability. These experiments revealed that larger body sizes were easier to detect, but that the colours of smaller frogs were more detectable than those of larger frogs. Taken together our data support the hypothesis that the primary defensive strategy changes from conspicuous aposematism to camouflage with increasing size, implying size-dependent differences in the efficacy of defensive colouration. We discuss our data in relation to theories of size-dependent aposematism and evaluate the evidence for and against a possible size-dependent mimicry complex with sympatric poison frogs (Dendrobatidae).


Assuntos
Mimetismo Biológico , Animais , Adulto , Humanos , Anuros , Tamanho Corporal
5.
Environ Sci Technol ; 57(49): 20736-20749, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38011905

RESUMO

Despite their ban and restriction under the 2001 Stockholm Convention, persistent organic pollutants (POPs) are still widespread and pervasive in the environment. Releases of these toxic and bioaccumulative chemicals are ongoing, and their contribution to population declines of marine mammals is of global concern. To safeguard their survival, it is of paramount importance to understand the effectiveness of mitigation measures. Using one of the world's largest marine mammals strandings data sets, we combine published and unpublished data to examine pollutant concentrations in 11 species that stranded along the coast of Great Britain to quantify spatiotemporal trends over three decades and identify species and regions where pollutants pose the greatest threat. We find that although levels of pollutants have decreased overall, there is significant spatial and taxonomic heterogeneity such that pollutants remain a threat to biodiversity in several species and regions. Of individuals sampled within the most recent five years (2014-2018), 48% of individuals exhibited a concentration known to exceed toxic thresholds. Notably, pollutant concentrations are highest in long-lived, apex odontocetes (e.g., killer whales (Orcinus orca), bottlenose dolphins (Tursiops truncatus), and white-beaked dolphins (Lagenorhynchus albirostris)) and were significantly higher in animals that stranded on more industrialized coastlines. At the present concentrations, POPs are likely to be significantly impacting marine mammal health. We conclude that more effective international elimination and mitigation strategies are urgently needed to address this critical issue for the global ocean health.


Assuntos
Golfinho Nariz-de-Garrafa , Caniformia , Poluentes Ambientais , Bifenilos Policlorados , Poluentes Químicos da Água , Orca , Animais , Poluentes Químicos da Água/toxicidade , Monitoramento Ambiental
6.
Proc Natl Acad Sci U S A ; 117(23): 12885-12890, 2020 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-32457164

RESUMO

Camouflage patterns prevent detection and/or recognition by matching the background, disrupting edges, or mimicking particular background features. In variable habitats, however, a single pattern cannot match all available sites all of the time, and efficacy may therefore be reduced. Active color change provides an alternative where coloration can be altered to match local conditions, but again efficacy may be limited by the speed of change and range of patterns available. Transparency, on the other hand, creates high-fidelity camouflage that changes instantaneously to match any substrate but is potentially compromised in terrestrial environments where image distortion may be more obvious than in water. Glass frogs are one example of terrestrial transparency and are well known for their transparent ventral skin through which their bones, intestines, and beating hearts can be seen. However, sparse dorsal pigmentation means that these frogs are better described as translucent. To investigate whether this imperfect transparency acts as camouflage, we used in situ behavioral trials, visual modeling, and laboratory psychophysics. We found that the perceived luminance of the frogs changed depending on the immediate background, lowering detectability and increasing survival when compared to opaque frogs. Moreover, this change was greatest for the legs, which surround the body at rest and create a diffuse transition from background to frog luminance rather than a sharp, highly salient edge. This passive change in luminance, without significant modification of hue, suggests a camouflage strategy, "edge diffusion," distinct from both transparency and active color change.


Assuntos
Adaptação Biológica/fisiologia , Anuros/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Pigmentação da Pele/fisiologia , Animais , Cor , Simulação por Computador , Ecossistema , Furões/fisiologia , Humanos , Modelos Biológicos , Comportamento Predatório/fisiologia
7.
Epilepsy Behav ; 128: 108558, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35078115

RESUMO

OBJECTIVE: Evaluate electroencephalographic changes in patients receiving purified pharmaceutical cannabidiol (CBD). METHODS: A total of 104 EEG studies from 52 patients with pediatric-onset refractory epilepsy, who were enrolled in the FDA-approved expanded access investigational new drug program, were retrospectively analyzed for electroencephalographic changes in the background, interictal epileptiform discharges (IEDs), ictal findings, and sleep architecture after CBD treatment. RESULTS: Patients were between 18 months and 52 years of age. After CBD treatment, 88.4% (46/52) of patients had EEG changes. Eighty-nine percent of these patients had changes in their background, 74% in IEDs, 46% in ictal findings, and 17% in sleep architecture. Seven out of 52 patients had modified hypsarrhythmia on their pre-treatment EEG. The pattern resolved in 2/7 patients (29%), diminished in prevalence in 4/7 (57%) subjects, and remained unchanged in 1/7 (14%) cases. Electrographic improvement was seen in 70% (32/46) of the patients, and worsening in 7% (3/46) of the cases. At the post-CBD EEG, 83% had a reduction in the frequency of the most predominant seizure type, and 25% reported subjective cognitive improvement. Of these patients, 88% (p = 0.09) and 92% (p = 0.45) had corresponding EEG changes, respectively. CONCLUSION: Our results revealed electrographic changes in association with the CBD treatment. Despite these changes, a substantial association between specific electrographic findings and clinical outcomes was not established.


Assuntos
Canabidiol , Epilepsia Resistente a Medicamentos , Canabidiol/uso terapêutico , Criança , Epilepsia Resistente a Medicamentos/tratamento farmacológico , Eletroencefalografia , Humanos , Preparações Farmacêuticas , Estudos Retrospectivos
8.
J Evol Biol ; 34(10): 1531-1540, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34465010

RESUMO

Optimal camouflage can, in principle, be relatively easily achieved in simple, homogeneous, environments where backgrounds always have the same colour, brightness and patterning. Natural environments are, however, rarely homogenous, and species often find themselves viewed against varied backgrounds where the task of concealment is more challenging. One result of variable backgrounds is the evolution of intraspecific phenotypic variation which may either be generalized, with multiple similarly cryptic patterns, or specialized, with each discrete colour form maximizing concealment against a single component of the background. We investigated the role of phenotypic variation in a highly variable population of the Neotropical toad Rhinella margaritifera using visual modelling and a computer-based detection task. We found that phenotypic variation was not divided into discrete colour morphs, and all toads were well camouflaged against the forest floor. However, although the whole population may appear to consist of random samples from the background, the toads were a particularly close match to the leaf litter, suggesting that they masquerade as dead leaves, which are themselves variable. Furthermore, rather than each colour form being equally effective against a single background, each toad was specialized towards its own particular local surroundings, as suggested by a specialist strategy. Taken together, these data highlight the importance of background matching to a nominally masquerading species, as well as how habitat heterogeneity at multiple spatial scales may affect the evolution of camouflage and phenotypic variation.


Assuntos
Ecossistema , Pigmentação , Cor , Meio Ambiente , Folhas de Planta
9.
Epilepsy Behav ; 117: 107856, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33639438

RESUMO

OBJECTIVE: To characterize the clinical phenotype, treatments, and impact on quality of life of Sunflower syndrome. METHODS: A 138-question survey was created focusing on seizure description, disease course, treatment history, medical history, family history, and aspects of quality of life of individuals with Sunflower syndrome. The survey was administered to individuals with Sunflower syndrome who experience hand waving episodes (HWE) and/or their caregivers via Research Electronic Data Capture (REDCap). RESULTS: Sixty-eight responses were included in analysis. Seventy-one% of respondents were female. The mean age of participants was 13.6 years, with 84% of respondents under the age of 18. The average age of onset of HWE was 6.7 years. HWE frequency varied from a few episodes per week to multiple episodes per hour. Sixty-two% of participants experienced other seizure types. Participants had been on an average of 1.9 anti-seizure medications with varying efficacy. Other methods to reduce HWE included wearing a hat or sunglasses, hand holding, using special tinted lenses, and avoiding the sun and bright lights. Sixty-nine% of participants reported anxiety or depression related to their epilepsy, and 65% said their HWE affected their social life. SIGNIFICANCE: Sunflower syndrome is a highly stereotyped, refractory epilepsy which significantly impacts the lives of affected individuals. It remains underrecognized and poorly understood. These results characterize Sunflower syndrome in a large population of affected individuals and provides a basis for future research to better understand the epilepsy and improve clinical care.


Assuntos
Epilepsia Generalizada , Adolescente , Anticonvulsivantes/uso terapêutico , Criança , Epilepsia Generalizada/tratamento farmacológico , Feminino , Humanos , Qualidade de Vida , Inquéritos e Questionários
10.
Proc Natl Acad Sci U S A ; 115(25): 6416-6421, 2018 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-29866847

RESUMO

Poison dart frogs provide classic examples of warning signals: potent toxins signaled by distinctive, conspicuous coloration. We show that, counterintuitively, the bright yellow and blue-black color of Dendrobates tinctorius (Dendrobatidae) also provides camouflage. Through computational modeling of predator vision, and a screen-based detection experiment presenting frogs at different spatial resolutions, we demonstrate that at close range the frog is highly detectable, but from a distance the colors blend together, forming effective camouflage. This result was corroborated with an in situ experiment, which found survival to be background-dependent, a feature more associated with camouflage than aposematism. Our results suggest that in D. tinctorius the distribution of pattern elements, and the particular colors expressed, act as a highly salient close range aposematic signal, while simultaneously minimizing detectability to distant observers.


Assuntos
Anuros/fisiologia , Venenos/toxicidade , Animais , Mimetismo Biológico/fisiologia , Cor , Comportamento Predatório/fisiologia
11.
Violence Vict ; 36(2): 214-232, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33361447

RESUMO

Child maltreatment and other adverse childhood experiences (ACEs) often cooccur and are related to negative socioemotional outcomes; however, limited research differentiates how maltreatment versus other ACEs predict such outcomes. These efforts are necessary to determine whether cumulative ACE screening efforts best predict those at risk for poor outcomes. We examined cumulative childhood ACEs, cumulative maltreatment subtypes, and adult attachment quality in 379 young and middle-aged adults. This sample enabled comparison between emerging adults and older adults who have navigated additional developmental tasks that may counteract the effects of early ACEs. More ACEs and maltreatment experiences predicted insecure anxious, avoidant, and fearful attachment styles; however, maltreatment failed to predict unique variance in attachment quality beyond other ACEs. Results suggest that maltreatment may be best categorized as part of a general cumulative risk profile predicting poor socioemotional outcomes. Findings support burgeoning trends in medical and social service settings assessing ACEs using simple dichotomous screening tools to identify those requiring intervention and support services.


Assuntos
Experiências Adversas da Infância , Maus-Tratos Infantis , Idoso , Ansiedade/epidemiologia , Criança , Maus-Tratos Infantis/psicologia , Humanos , Pessoa de Meia-Idade
12.
Epilepsy Behav ; 106: 106988, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32169600

RESUMO

OBJECTIVE: This study aimed to evaluate clinical efficacy and safety of purified pharmaceutical cannabidiol (CBD) as an adjunctive therapy in refractory childhood-onset epileptic spasms (ES). METHODS: Nine patients with ES were enrolled in an Institutional Review Board (IRB)- and Food and Drug Administration (FDA)-approved expanded access investigational new drug trial. Patients received plant-derived highly purified CBD in oral solution in addition to their baseline medications at an initial dosage of 5 mg/kg/day, which was increased by 5 mg/kg/day every week to an initial target dosage of 25 mg/kg/day. Seizure frequency, adverse event, and parents' subjective reports of cognitive and behavioral changes were recorded after 2 weeks and 1, 2, 3, 6, 9, and 12 months of CBD treatment. Responder rates (percent of patients with >50% reduction in ES frequency from baseline) were calculated. Electrographic changes were studied in relation to CBD initiation and clinical response. RESULTS: Overall, the responder rates in 9 patients were 67%, 78%, 67%, 56%, 78%, 78%, and 78% after 2 weeks and 1, 2, 3, 6, 9, and 12 months of CBD treatment, respectively. Three out of nine patients (33%) were ES free after two months of treatment. Parents reported subjective improvements in cognitive and behavioral domains. Side effects, primarily drowsiness, were seen in 89% of patients (n = 8). Eight of the nine (89%) patients had electroencephalographic (EEG) studies prior to and after initiation of CBD. Three out of five patients (60%) had resolution in their hypsarrhythmia pattern. SIGNIFICANCE: Purified pharmaceutical CBD may be an effective and safe adjunctive therapy in refractory ES and may also be associated with improvements in electrographic findings.


Assuntos
Anticonvulsivantes/uso terapêutico , Canabidiol/uso terapêutico , Epilepsia Resistente a Medicamentos/tratamento farmacológico , Epilepsia Resistente a Medicamentos/fisiopatologia , Adolescente , Anticonvulsivantes/farmacologia , Canabidiol/farmacologia , Criança , Pré-Escolar , Epilepsia Resistente a Medicamentos/diagnóstico , Eletroencefalografia/efeitos dos fármacos , Eletroencefalografia/tendências , Feminino , Humanos , Masculino , Convulsões/diagnóstico , Convulsões/tratamento farmacológico , Convulsões/fisiopatologia , Resultado do Tratamento
13.
Skeletal Radiol ; 49(6): 945-954, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31919587

RESUMO

INTRODUCTION: Skip metastases have been described with osteosarcoma, Ewing sarcoma and rarely chondrosarcoma. The aim of this study was to determine the incidence of skip metastases on whole bone MRI in all primary high-grade sarcomas of the major long bones. MATERIALS AND METHOD: Retrospective review of patients from April 2007 to April 2019 with high-grade primary bone sarcomas of the humerus, radius, ulna, femur, tibia or fibula who had whole bone MRI at initial staging. Data collected included age, sex, tumour type, presence and location of skip metastases based on whole bone MRI and presence of distant metastases (the skeleton and lung). RESULTS: The study included 216 males and 171 females with mean age 30.6 years (range 4-92 years). Tumour types were as follows: High-grade osteosarcoma n = 202, Ewing sarcoma n = 68, high-grade chondrosarcoma n = 44, dedifferentiated chondrosarcoma n = 37, high-grade spindle cell sarcoma n = 29 and angiosarcoma n = 7. Skip lesions were identified in 63 (16.3%). However, after taking into account the presence of distant skeletal (n = 11) and pulmonary (n = 33) metastases, the overall incidence of skip metastases was 6.5%, occurring in 15 (7.5%) high-grade osteosarcomas, 3 (4.5%) Ewing sarcoma, 1 (2.8%) high-grade chondrosarcoma, 4 (10.8%) dedifferentiated chondrosarcomas, and 2 (6.9%) high-grade spindle cell sarcomas. A false positive MRI diagnosis of skip metastasis was made in 4 cases, 3 enchondromata and one focal nodular marrow hyperplasia. CONCLUSION: The current study has documented the incidence of skip metastases in common types of high-grade primary bone sarcoma. The possibility of false positive skip metastases has also been highlighted.


Assuntos
Neoplasias Ósseas/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Metástase Neoplásica/diagnóstico por imagem , Osteossarcoma/diagnóstico por imagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Ósseas/patologia , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Osteossarcoma/patologia , Estudos Retrospectivos
14.
Skeletal Radiol ; 49(6): 913-919, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31900513

RESUMO

OBJECTIVE: Pre-operative whole-bone MRI is required to assess intra-osseous tumour extent and to identify skip metastases in cases of bone sarcoma. The current study aims to determine the sensitivity, specificity, and diagnostic accuracy of whole-bone MRI for the identification of skip metastases. MATERIALS AND METHOD: Review of 162 patients with long bone osteosarcoma or Ewing sarcoma who had undergone whole-bone MRI to assess intra-osseous tumour length and identify skip metastases. Comparison was made with post-chemotherapy MRI to look for a change in the appearance of suspected skip metastases, and resection specimens were assessed for the presence of skip metastases. The presence of local osseous recurrence was determined at final follow-up. RESULTS: There were 112 males and 50 females (mean age 18.8 years), with 119 osteosarcomas and 43 Ewing sarcomas. Skip metastases were diagnosed on whole-bone MRI in 23 cases (14.2%). In 2 cases, pre-operative needle biopsy diagnosed enchondromata, resulting in false positive diagnoses. Skip metastases were diagnosed in the resection specimens in 3 cases, and based on comparison with post-chemotherapy MRI in 12. There was no evidence of local osseous recurrence in 160 patients, while late recurrence occurred in 2 patients. Sensitivity was calculated as 88.2%, specificity as 97.6%, and diagnostic accuracy as 96.7%. CONCLUSION: Whole-bone MRI has a high sensitivity, specificity, and diagnostic accuracy for the identification of skip metastases in osteosarcoma and Ewing sarcoma. The possibility of false positive skip lesions and late local osseous recurrence is also highlighted.


Assuntos
Neoplasias Ósseas/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Metástase Neoplásica/diagnóstico por imagem , Osteossarcoma/diagnóstico por imagem , Sarcoma de Ewing/diagnóstico por imagem , Adolescente , Biópsia por Agulha , Neoplasias Ósseas/patologia , Feminino , Humanos , Masculino , Osteossarcoma/patologia , Sarcoma de Ewing/patologia , Sensibilidade e Especificidade
15.
Int J Hyperthermia ; 36(1): 712-720, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31345068

RESUMO

Purpose: A proposed mechanism for the enhanced effectiveness of hyperthermia and doxorubicin (Dox) combinations is increased intracellular Dox concentrations resulting from heat-induced cell stress. The purpose of this study was to determine whether specific varied Dox and heat combinations produce measurable effects greater than the additive combination, and whether these effects can be attributed to heat-induced increases in intracellular Dox concentrations. Methods: HCT116, HT29 and CT26 cells were exposed to Dox and water bath heating independently. A clonogenic survival assay was used to determine cell killing and intracellular Dox concentrations were measured in HCT116 cells with mass spectrometry. Cells were exposed to heating at 42 °C (60 min) and 0.5 µg/ml of Dox at varying intervals. Synergy was determined by curve-fitting and isobologram analysis. Results: All cell lines displayed synergistic effects of combined heating and Dox. A maximum synergistic effect was achieved with simultaneous cell exposure to Dox and heat. For exposures at 42 °C, the synergistic effect was most pronounced at Dox concentrations <0.5 µg/ml. Increased intracellular concentrations of Dox in HCT116 cells caused by heat-stress did not generate a concomitant thermal enhancement. Conclusions: Simultaneous exposure of HCT116 cells to heating and Dox is more effective than sequential exposure. Heat-induced cell responses are accompanied by increased intracellular Dox concentrations; however, clonogenic survival data do not support this as the cause for synergistic cytotoxicity.


Assuntos
Antibióticos Antineoplásicos/administração & dosagem , Doxorrubicina/administração & dosagem , Temperatura Alta , Transporte Biológico , Morte Celular , Linhagem Celular Tumoral , Humanos
16.
Proc Biol Sci ; 284(1858)2017 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-28679722

RESUMO

The effect of viewing distance on the perception of visual texture is well known: spatial frequencies higher than the resolution limit of an observer's visual system will be summed and perceived as a single combined colour. In animal defensive colour patterns, distance-dependent pattern blending may allow aposematic patterns, salient at close range, to match the background to distant observers. Indeed, recent research has indicated that reducing the distance from which a salient signal can be detected can increase survival over camouflage or conspicuous aposematism alone. We investigated whether the spatial frequency of conspicuous and cryptically coloured stripes affects the rate of avian predation. Our results are consistent with pattern blending acting to camouflage salient aposematic signals effectively at a distance. Experiments into the relative rate of avian predation on edible model caterpillars found that increasing spatial frequency (thinner stripes) increased survival. Similarly, visual modelling of avian predators showed that pattern blending increased the similarity between caterpillar and background. These results show how a colour pattern can be tuned to reveal or conceal different information at different distances, and produce tangible survival benefits.


Assuntos
Mimetismo Biológico , Cor , Larva/fisiologia , Comportamento Predatório , Animais , Aves
17.
Biol Lett ; 12(8)2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27484645

RESUMO

Aposematic signals are often characterized by high conspicuousness. Larger and brighter signals reinforce avoidance learning, distinguish defended from palatable prey and are more easily memorized by predators. Conspicuous signalling, however, has costs: encounter rates with naive, specialized or nutritionally stressed predators are likely to increase. It has been suggested that intermediate levels of aposematic conspicuousness can evolve to balance deterrence and detectability, especially for moderately defended species. The effectiveness of such signals, however, has not yet been experimentally tested under field conditions. We used dough caterpillar-like baits to test whether reduced levels of aposematic conspicuousness can have survival benefits when predated by wild birds in natural conditions. Our results suggest that, when controlling for the number and intensity of internal contrast boundaries (stripes), a reduced-conspicuousness aposematic pattern can have a survival advantage over more conspicuous signals, as well as cryptic colours. Furthermore, we find a survival benefit from the addition of internal contrast for both high and low levels of conspicuousness. This adds ecological validity to evolutionary models of aposematic saliency and the evolution of honest signalling.


Assuntos
Mimetismo Biológico , Animais , Aprendizagem da Esquiva , Evolução Biológica , Aves , Cor , Comportamento Predatório
18.
Mol Cell Neurosci ; 68: 186-93, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26253862

RESUMO

The cellular prion protein has been identified as a metalloprotein that binds copper. There have been some suggestions that prion protein also influences zinc and manganese homeostasis. In this study we used a series of cell lines to study the levels of zinc and manganese under different conditions. We overexpressed either the prion protein or known transporters for zinc and manganese to determine relations between the prion protein and both manganese and zinc homeostasis. Our observations supported neither a link between the prion protein and zinc metabolism nor any effect of altered zinc levels on prion protein expression or cellular infection with prions. In contrast we found that a gain of function mutant of a manganese transporter caused reduction of manganese levels in prion infected cells, loss of observable PrP(Sc) in cells and resistance to prion infection. These studies strengthen the link between manganese and prion disease.


Assuntos
ATPases Transportadoras de Cálcio/genética , Proteínas de Membrana Transportadoras/genética , Mutação/genética , Príons/metabolismo , Animais , ATPases Transportadoras de Cálcio/metabolismo , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Linhagem Celular , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Endopeptidase K/farmacologia , Manganês/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Camundongos , Receptores de AMPA/genética , Receptores de AMPA/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transfecção , Zinco/metabolismo , Fator MTF-1 de Transcrição
19.
Death Stud ; 40(5): 275-82, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26766186

RESUMO

The authors compared grief severity and its predictors in two equivalent college student samples who had experienced the death of a pet (n = 211) or a person (n = 146) within the past 2 years. The human death sample reported higher grief severity, p < .01, but effect sizes were small (ds = .28-.30). For both samples, closeness to the deceased was overwhelmingly the strongest predictor of grief severity; other predictors generally dropped out with closeness added to the model. Results highlight the importance of including closeness to deceased in grief research, and its centrality in understanding grief counseling clients.


Assuntos
Adaptação Psicológica , Luto , Pesar , Vínculo Humano-Animal , Apego ao Objeto , Animais de Estimação , Adolescente , Adulto , Animais , Morte , Feminino , Humanos , Relações Interpessoais , Masculino , Adulto Jovem
20.
Biochim Biophys Acta ; 1830(12): 5456-64, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23726993

RESUMO

BACKGROUND: Serum albumin is the major protein component of blood plasma and is responsible for the circulatory transport of a range of small molecules that include fatty acids, hormones, metal ions and drugs. Studies examining the ligand-binding properties of albumin make up a large proportion of the literature. However, many of these studies do not address the fact that albumin carries multiple ligands (including metal ions) simultaneously in vivo. Thus the binding of a particular ligand may influence both the affinity and dynamics of albumin interactions with another. SCOPE OF REVIEW: Here we review the Zn(2+) and fatty acid transport properties of albumin and highlight an important interplay that exists between them. Also the impact of this dynamic interaction upon the distribution of plasma Zn(2+), its effect upon cellular Zn(2+) uptake and its importance in the diagnosis of myocardial ischemia are considered. MAJOR CONCLUSIONS: We previously identified the major binding site for Zn(2+) on albumin. Furthermore, we revealed that Zn(2+)-binding at this site and fatty acid-binding at the FA2 site are interdependent. This suggests that the binding of fatty acids to albumin may serve as an allosteric switch to modulate Zn(2+)-binding to albumin in blood plasma. GENERAL SIGNIFICANCE: Fatty acid levels in the blood are dynamic and chronic elevation of plasma fatty acid levels is associated with some metabolic disorders such as cardiovascular disease and diabetes. Since the binding of Zn(2+) to albumin is important for the control of circulatory/cellular Zn(2+) dynamics, this relationship is likely to have important physiological and pathological implications. This article is part of a Special Issue entitled Serum Albumin.


Assuntos
Ácidos Graxos/sangue , Albumina Sérica/metabolismo , Zinco/sangue , Regulação Alostérica , Ácidos Graxos/química , Humanos , Transporte de Íons , Modelos Moleculares , Ligação Proteica , Albumina Sérica/química , Zinco/química
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