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1.
Forensic Sci Int ; 346: 111653, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37003121

RESUMO

An extensive literature review, combined with practical experience of forensic testing, has identified several concerns regarding existing studies into skin simulants. These can be summarised as arising due to human skin being a highly complex, multi-layered and anisotropic material whose mechanical properties depend on many factors such as age and gender of the host. In many studies (and papers) essential information is missing. Although there is some parallelism between the studies, the reported energy density at perforation is very inconsistent (a function of the natural variation of skin properties alluded to above) and differs from 0,113 J/mm2 [1] to 0,239 J/mm2 [2]. Which is, in fact, a more than 100 % variation. Such a variation is arguably insufficient to enable accurate replication with a single simulant material. Combined with the missing common agreement about the energy density threshold between countries, laboratories and researchers, this analysis clearly identifies the need for an adjustable and / or customizable skin simulant. To-date, the most often used simulation material for human skin in ballistic testing is 'Chrome crusted cow hide' [3]. However, this is a natural material and, consequently therefore, inevitably physically variable in nature - both inter and intra hide. Ballistic tests on 10 chrome crusted cow hides using 4,5 mm BB's gave v50% ranging from 113 m/s to 200 m/s, an uncontrolled variability for forensic experiments. Hence, the authors examined a skin analogue that could be produced in-house, enabling tailoring to match the desired properties, and with improved consistency. To this end, a thin, 4 mm thick, layer of gelatine (30 - 45 wt%, increasing per 1 wt%) was studied. The ballistic resistance of the gelatine skin analogue was compared to the v50%'s published values in literature, with good agreement found as the gelatine concentration was varied. In comparison to the chrome crusted cow hides this suggests that this relatively simple and accessible approach has potential to provide a more consistent standard.


Assuntos
Ferimentos por Arma de Fogo , Humanos , Balística Forense , Modelos Biológicos , Pele/lesões , Gelatina
2.
Nat Immunol ; 22(8): 1052-1063, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34168370

RESUMO

Immune-checkpoint blockade (ICB) has shown remarkable clinical success in boosting antitumor immunity. However, the breadth of its cellular targets and specific mode of action remain elusive. We find that tumor-infiltrating follicular regulatory T (TFR) cells are prevalent in tumor tissues of several cancer types. They are primarily located within tertiary lymphoid structures and exhibit superior suppressive capacity and in vivo persistence as compared with regulatory T cells, with which they share a clonal and developmental relationship. In syngeneic tumor models, anti-PD-1 treatment increases the number of tumor-infiltrating TFR cells. Both TFR cell deficiency and the depletion of TFR cells with anti-CTLA-4 before anti-PD-1 treatment improve tumor control in mice. Notably, in a cohort of 271 patients with melanoma, treatment with anti-CTLA-4 followed by anti-PD-1 at progression was associated with better a survival outcome than monotherapy with anti-PD-1 or anti-CTLA-4, anti-PD-1 followed by anti-CTLA-4 at progression or concomitant combination therapy.


Assuntos
Antígeno CTLA-4/antagonistas & inibidores , Inibidores de Checkpoint Imunológico/uso terapêutico , Linfócitos do Interstício Tumoral/imunologia , Melanoma/tratamento farmacológico , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Linfócitos T Reguladores/imunologia , Animais , Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Linfócitos T CD8-Positivos/imunologia , Linhagem Celular Tumoral , Modelos Animais de Doenças , Feminino , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Células T Auxiliares Foliculares/imunologia , Microambiente Tumoral/imunologia
3.
Cardiol J ; 28(1): 129-135, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-31225635

RESUMO

BACKGROUND: ST2 is a circulating biomarker that is well established for predicting outcome in heart failure (HF). This is the first study to look at ST2 concentrations in optimally treated patients with stable but significant left ventricular systolic dysfunction (LVSD) compared to patients with severe aortic stenosis (AS). METHODS: Two cohorts were retrospectively studied: 94 patients undergoing transcatheter aortic valve implantation for severe AS (63 with normal ejection fraction [EF] and 31 with reduced EF), and 50 patients with severe LVSD from non-valvular causes. ST2 pre-procedural samples were taken, and repeated again at 3 and 6 months. Patients were followed-up for 2 years. Data was analyzed using SPSS software. RESULTS: Baseline concentrations of soluble ST2 did not differ significantly between the HF group and AS group with normal EF (EF ≥ 50%). However, in the AS group with a low EF (EF < 50%) ST2 concentrations were significantly higher that the HF group (p = 0.009). New York Heart Association class IV HF, baseline N-terminal pro-B-type natriuretic peptide and gender were all independent predictors of soluble ST2 (sST2) baseline concentrations. CONCLUSIONS: Raised ST2 concentrations in the context of severe AS may be a marker for subclinical or clinical left ventricular dysfunction. More research is required to assess its use for assessment of prognosis and response to treatment.


Assuntos
Estenose da Valva Aórtica , Insuficiência Cardíaca , Substituição da Valva Aórtica Transcateter , Disfunção Ventricular Esquerda , Estenose da Valva Aórtica/cirurgia , Biomarcadores , Humanos , Peptídeo Natriurético Encefálico/química , Peptídeo Natriurético Encefálico/metabolismo , Estudos Retrospectivos , Volume Sistólico/fisiologia
4.
Proc Math Phys Eng Sci ; 476(2242): 20200551, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33223950

RESUMO

Winkler's mattress model is often used as a simplified model to understand how a thin elastic layer, such as a coating, deforms when subject to a distributed normal load: the deformation of the layer is assumed proportional to the applied normal load. This simplicity means that the Winkler model has found a wide range of applications from soft matter to geophysics. However, in the limit of an incompressible elastic layer the model predicts infinite resistance to deformation, and hence breaks down. Since many of the thin layers used in applications are elastomeric, and hence close to incompressible, we consider the question of when the Winkler model is appropriate for such layers. We formally derive a model that interpolates between the Winkler and incompressible limits for thin elastic layers, and illustrate this model by detailed consideration of two example problems: the point-indentation of a coated elastomeric layer and self-sustained lift in soft elastohydrodynamic lubrication. We find that the applicability (or otherwise) of the Winkler model is not determined by the value of the Poisson ratio alone, but by a compressibility parameter that combines the Poisson ratio with a measure of the layer's slenderness, which itself depends on the problem under consideration.

5.
Transpl Int ; 33(2): 174-180, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31538677

RESUMO

The duration of warm ischaemia time is associated with short- and long-term kidney transplant function. A quick rise in graft temperature is reported during the vascular anastomosis. This study was initiated to gain insight into the effect of graft temperature on short-term transplant function. From 2013 to 2015, data of living donor kidney transplant recipients were prospectively collected. At set intraoperative time points, the graft temperature was measured using a noncontact infrared thermometer. Primary endpoint was measured glomerular filtration rate (mGFR) at 3- and 6-month post-transplantation. Univariable and multivariable associations were identified using linear regression analyses. Multivariable analysis included models with donor, recipient and procedure characteristics. We evaluated 152 patients, 83 (55%) were male, mean ±SD age was 50.3 ± 13.4 years, and 79 (52%) were pre-emptively transplanted. In univariable analysis graft temperature, after 10 min of warm ischaemia was significantly associated with 3- and 6-month mGFR, ß -0.22 (95% CI -0.39 to -0.04, P = 0.01) and ß-0.22 (95% CI: -0.44 to -0.01, P = 0.04). The association remained significant in multivariable models. An independent association between kidney graft temperature and 3- and 6-month mGFR was identified. This association opens up the opportunity to further investigate the clinical impact of kidney rewarming during transplantation.


Assuntos
Taxa de Filtração Glomerular , Transplante de Rim , Rim/fisiologia , Temperatura , Adulto , Feminino , Sobrevivência de Enxerto , Humanos , Doadores Vivos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Isquemia Quente
6.
J Mech Behav Biomed Mater ; 77: 586-593, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29096124

RESUMO

Tissue analogues employed for ballistic purposes are often monolithic in nature, e.g. ballistic gelatin and soap, etc. However, such constructs are not representative of real-world biological systems. Further, ethical considerations limit the ability to test with real-world tissues. This means that availability and understanding of accurate tissue simulants is of key importance. Here, the shock response of a wide range of ballistic simulants (ranging from dermal (protective/bulk) through to skeletal simulant materials) determined via plate-impact experiments are discussed, with a particular focus on the classification of the behaviour of differing simulants into groups that exhibit a similar response under high strain-rate loading. Resultant Hugoniot equation-of-state data (Us-up; P-v) provides appropriate feedstock materials data for future hydrocode simulations of ballistic impact events.


Assuntos
Osso e Ossos/patologia , Tecido Conjuntivo/patologia , Epitélio/patologia , Teste de Materiais , Modelos Biológicos , Músculo Esquelético/patologia , Animais , Colágeno/química , Simulação por Computador , Elasticidade , Desenho de Equipamento , Ácidos Graxos/química , Géis , Lipídeos/química , Poliuretanos/química , Pressão , Reprodutibilidade dos Testes , Silicones , Estresse Mecânico , Suínos , Temperatura , Ferimentos por Arma de Fogo
7.
J Oral Pathol Med ; 46(2): 82-88, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27237745

RESUMO

There is now compelling evidence that the tumour stroma plays an important role in the pathogenesis of cancers of epithelial origin. The pre-eminent cell type of the stroma is carcinoma-associated fibroblasts. These cells demonstrate remarkable heterogeneity with activation and senescence being common stress responses. In this review, we summarise the part that these cells play in cancer, particularly oral cancer, and present evidence to show that activation and senescence reflect a unified programme of fibroblast differentiation. We report advances concerning the senescent fibroblast metabolome, mechanisms of gene regulation in these cells and ways in which epithelial cell adhesion is dysregulated by the fibroblast secretome. We suggest that the identification of fibroblast stress responses may be a valuable diagnostic tool in the determination of tumour behaviour and patient outcome. Further, the fact that stromal fibroblasts are a genetically stable diploid cell population suggests that they may be ideal therapeutic targets and early work in this context is encouraging.


Assuntos
Fibroblastos/fisiologia , Neoplasias Bucais/patologia , Senescência Celular , Fibroblastos/citologia , Fibroblastos/metabolismo , Humanos , Metaboloma , Neoplasias Bucais/metabolismo , Neoplasias Bucais/fisiopatologia
8.
Transpl Int ; 30(2): 162-169, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27864901

RESUMO

Little is known about the actual kidney graft temperature during the 2nd warm ischemia time (WIT2). We aimed to determine the actual temperature course of the WIT2, with emphasis on the 15 °C metabolic threshold. Data of 152 consecutive adult living donor kidney transplantations were collected. The mean WIT2 was 41.3 ± 10.1 (SD) minutes with a temperature of 5.4 °C at baseline which gradually increased to 13.7, 17.4, and 20.2 °C after 10, 20, and 30 min, respectively. The percentage of kidneys with a temperature of 15 °C or higher was 81.2% after 20 min and 97.5% after 30 min. Duration of surgery (95% CI: -0.017 to -0.002, P = 0.02), multiple veins (95% CI: 0.0003-2.720, P = 0.05) and WIT2 (95% CI: 0.016-0.099, P = 0.006) were associated with a rapid temperature increase. No correlation could be determined between a rapid temperature rise and diminished graft function. This study showed a rapid increase in kidney temperature during WIT2, wherein the 15 °C threshold was reached within 20 min in more than 80% of the patients.


Assuntos
Transplante de Rim , Temperatura , Coleta de Tecidos e Órgãos , Isquemia Quente , Adulto , Idoso , Feminino , Humanos , Doadores Vivos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
9.
New Horiz Transl Med ; 3(1): 9-21, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27275004

RESUMO

Solid tumours comprise, not only malignant cells but also a variety of stromal cells and extracellular matrix proteins. These components interact via an array of signalling pathways to create an adaptable network that may act to promote or suppress cancer progression. To date, the majority of anti-tumour chemotherapeutic agents have principally sought to target the cancer cell. Consequently, resistance develops because of clonal evolution, as a result of selection pressure during tumour expansion. The concept of activating or inhibiting other cell types within the tumour microenvironment is relatively novel and has the advantage of targeting cells which are genetically stable and less likely to develop resistance. This review outlines key players in the stromal tumour microenvironment and discusses potential targeting strategies that may offer therapeutic benefit.

11.
Br J Cancer ; 113(1): 107-18, 2015 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-26110972

RESUMO

BACKGROUND: Oesophageal adenocarcinoma (OAC) is one of the fastest rising malignancies with continued poor prognosis. Many studies have proposed novel biomarkers but, to date, no immunohistochemical markers of survival after oesophageal resection have entered clinical practice. Here, we systematically review and meta-analyse the published literature, to identify potential biomarkers. METHODS: Relevant articles were identified via Ovid medline 1946-2013. For inclusion, studies had to conform to REporting recommendations for tumor MARKer (REMARK) prognostic study criteria. The primary end-point was a pooled hazard ratio (HR) and variance, summarising the effect of marker expression on prognosis. RESULTS: A total of 3059 articles were identified. After exclusion of irrelevant titles and abstracts, 214 articles were reviewed in full. Nine molecules had been examined in more than one study (CD3, CD8, COX-2, EGFR, HER2, Ki67, LgR5, p53 and VEGF) and were meta-analysed. Markers with largest survival effects were COX-2 (HR=2.47, confidence interval (CI)=1.15-3.79), CD3 (HR=0.51, 95% CI=0.32-0.70), CD8 (HR=0.55, CI=0.31-0.80) and EGFR (HR=1.65, 95% CI=1.14-2.16). DISCUSSION: Current methods have not delivered clinically useful molecular prognostic biomarkers in OAC. We have highlighted the paucity of good-quality robust studies in this field. A genome-to-protein approach would be better suited for the development and subsequent validation of biomarkers. Large collaborative projects with standardised methodology will be required to generate clinically useful biomarkers.


Assuntos
Adenocarcinoma/metabolismo , Biomarcadores Tumorais/metabolismo , Neoplasias Esofágicas/metabolismo , Adenocarcinoma/patologia , Adenocarcinoma/cirurgia , Neoplasias Esofágicas/patologia , Neoplasias Esofágicas/cirurgia , Humanos , Imuno-Histoquímica , Prognóstico
12.
Mol Cancer Res ; 13(7): 1095-1105, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25934693

RESUMO

UNLABELLED: Transglutaminase-2 (TG2) is a critical cross-linking enzyme in the extracellular matrix (ECM) and tumor microenvironment (TME). Although its expression has been linked to colorectal cancer, its functional role in the processes that drive disease appears to be context dependent. There is now considerable evidence of a role for microRNAs (miRNA) in the development and progression of cancer, including metastasis. A cell model of metastatic colon adenocarcinoma was used to investigate the contribution of miRNAs to the differential expression of TG2, and functional effects on inflammatory and invasive behavior. The impact of TG2 in colorectal cancer was analyzed in human colorectal tumor specimens and by manipulations in SW480 and SW620 cells. Effects on invasive behavior were measured using Transwell invasion assays, and cytokine production was assessed by ELISA. TG2 was identified as a target for miR-19 by in silico analysis, which was confirmed experimentally. Functional effects were evaluated by overexpression of pre-miR-19a in SW480 cells. Expression of TG2 correlated inversely with invasive behavior, with knockdown in SW480 cells leading to enhanced invasion, and overexpression in SW620 cells the opposite. TG2 expression was observed in colorectal cancer primary tumors but lost in liver metastases. Finally, miR-19 overexpression and subsequent decreased TG2 expression was linked to chromosome-13 amplification events, leading to altered invasive behavior in colorectal cancer cells. IMPLICATIONS: Chromosome-13 amplification in advanced colorectal cancer contributes to invasion and metastasis by upregulating miR-19, which targets TG2.


Assuntos
Adenocarcinoma/patologia , Neoplasias Colorretais/patologia , Proteínas de Ligação ao GTP/metabolismo , Neoplasias Hepáticas/secundário , MicroRNAs/metabolismo , Transglutaminases/metabolismo , Adenocarcinoma/metabolismo , Linhagem Celular Tumoral , Cromossomos Humanos Par 13/genética , Neoplasias Colorretais/metabolismo , Citocinas/metabolismo , Humanos , Inflamação/metabolismo , Invasividade Neoplásica , Proteína 2 Glutamina gama-Glutamiltransferase
13.
Infection ; 42(6): 999-1005, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25129565

RESUMO

PURPOSE: The Society for Healthcare Epidemiology of America and Infectious Diseases Society of America (SHEA-IDSA) guidelines for the treatment of Clostridium difficile infection (CDI) recommend initial treatment of CDI based on disease severity. This severity definition has not been validated or evaluated based on clinical outcomes. The ATLAS scoring system is a validated tool useful in predicting treatment response and mortality in CDI. The main purpose of this study is to evaluate the concordance of the ATLAS scoring system and the SHEA-IDSA staging for CDI severity. METHODS: This was a retrospective study which included hospitalized patients with confirmed CDI. Bivariate analyses compared baseline demographics and clinical information between patients with nonsevere and severe CDI based on the SHEA-IDSA criteria for CDI severity. Kappa scores were calculated to compare the concordance of the two scoring systems in defining CDI severity. Sensitivity and specificity of the ATLAS scoring system to determine CDI severity were calculated using the SHEA-IDSA criteria as the reference standard. RESULTS: Sixty-four patients met inclusion criteria. Of those, 62.5% were classified as mild to moderate CDI, 25% were severe, uncomplicated, and 12.5% were severe, complicated based on SHEA-IDSA criteria. In the bivariate analyses, ATLAS score breakpoints of ≥ 4, ≥ 5, and ≥ 6 revealed moderate agreement with the SHEA-IDSA classification for severity. The sensitivities and specificities for ATLAS scores in predicting CDI severity ranged from 58.3 to 87.5, and 67.5-87.5%, respectively. CONCLUSION: The ATLAS score may be useful in evaluating CDI severity and determining drug therapy selection.


Assuntos
Clostridioides difficile/isolamento & purificação , Infecções por Clostridium/classificação , Infecções por Clostridium/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Feminino , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Sensibilidade e Especificidade , Índice de Gravidade de Doença
14.
Philos Trans A Math Phys Eng Sci ; 372(2023): 20130204, 2014 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-25071240

RESUMO

Magnesium, titanium and zirconium and their alloys are extensively used in industrial and military applications where they would be subjected to extreme environments of high stress and strain-rate loading. Their hexagonal close-packed (HCP) crystal lattice structures present interesting challenges for optimizing their mechanical response under such loading conditions. In this paper, we review how these materials respond to shock loading via plate-impact experiments. We also discuss the relationship between a heterogeneous and anisotropic microstructure, typical of HCP materials, and the directional dependency of the elastic limit and, in some cases, the strength prior to failure.

15.
Br J Cancer ; 110(2): 489-500, 2014 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-24169344

RESUMO

BACKGROUND: Human papillomavirus (HPV)-positive oropharyngeal cancer (OPSCC) is associated with improved survival compared with HPV-negative disease. However, a minority of HPV-positive patients have poor prognosis. Currently, there is no generally accepted strategy for identifying these patients. METHODS: We retrospectively analysed 270 consecutively treated OPSCC patients from three centres for effects of clinical, pathological, immunological, and molecular features on disease mortality. We used Cox regression to examine associations between factors and OPSCC death, and developed a prognostic model for 3-year mortality using logistic regression analysis. RESULTS: Patients with HPV-positive tumours showed improved survival (hazard ratio (HR), 0.33 (0.21-0.53)). High levels of tumour-infiltrating lymphocytes (TILs) stratified HPV-positive patients into high-risk and low-risk groups (3-year survival; HPV-positive/TIL(high)=96%, HPV-positive/TIL(low)=59%). Survival of HPV-positive/TIL(low) patients did not differ from HPV-negative patients (HR, 1.01; P=0.98). We developed a prognostic model for HPV-positive tumours using a 'training' cohort from one centre; the combination of TIL levels, heavy smoking, and T-stage were significant (AUROC=0·87). This model was validated on patients from the other centres (detection rate 67%; false-positive rate 5.6%; AUROC=0·82). INTERPRETATION: Our data suggest that an immune response, reflected by TIL levels in the primary tumour, has an important role in the improved survival seen in most HPV-positive patients, and is relevant for the clinical evaluation of HPV-positive OPSCC.


Assuntos
Linfócitos do Interstício Tumoral/patologia , Neoplasias Orofaríngeas/patologia , Neoplasias Orofaríngeas/virologia , Infecções por Papillomavirus/imunologia , Infecções por Papillomavirus/patologia , Idoso , Feminino , Humanos , Linfócitos do Interstício Tumoral/imunologia , Masculino , Pessoa de Meia-Idade , Neoplasias Orofaríngeas/imunologia , Papillomaviridae , Prognóstico , Estudos Retrospectivos
16.
Plant Dis ; 98(2): 285, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30708758

RESUMO

In eastern Australia, there have been several as yet unconfirmed reports of Wheat mosaic virus (WMoV) infecting wheat (3). WMoV, previously known as High plains virus (HPV), is transmitted by the wheat curl mite (WCM, Aceria tosichella). It is often found in mixed infections with Wheat streak mosaic virus (WSMV), also transmitted by WCM (2,3). WSMV was first identified in Australia in 2003 (3). In October 2012, stunted wheat plants with severe yellow leaf streaking were common in a field experiment near Corrigin in Western Australia consisting of nine wheat cultivars. These symptoms were also common in two commercial crops of wheat cv. Mace near Kulin. Leaf samples (one per plant) from each location were tested by ELISA using specific antiserum to WMoV (syn. HPV 17200, Agdia, Elkhart, IN). At the field experiment, 20 leaf samples were collected at random from each wheat plot (4 replicates) and tested individually by ELISA. WMoV incidence was 5% for cv. Yipti, 16% for cvs Emu Rock, Wyalkatchem and Mace, 22% for cvs. Corack, Fortune, Calingiri, and Magenta, and 55% for cv. Cobra. From the two commercial wheat crops, 100 leaf samples were collected at random from each and tested by ELISA. WMoV incidence was 2 and 4%. In addition, 50 leaf samples of Hordeum leporinum (barley grass) and 20 of Lolium rigidum (annual ryegrass) were collected and tested by ELISA. WMoV incidence was 2% in H. leporinum, but 0% in L. rigidum. Infected H. leporinum plants were symptomless. Symptomatic wheat leaf samples from both sites were tested by RT-PCR using WMoV specific primers designed from its RNA3 sequence (1). The PCR products (339 bp) were sequenced and lodged in GenBank (Accession Nos KC337341 and KC337342). WMoV isolates from Corrigin (WA-CG12) and Kulin (WA-KU12) had identical sequences. When the nucleic acid sequences of WA-CG12 and WA-KU12 were compared with those of the three other WMoV isolates on GenBank, they had 100% nucleotide sequence identity with a Nebraska isolate (U60141), and 99.7% identity to two United States sweet corn isolates (AY836524 and AY836525). Ten symptomatic wheat plants were collected from each location, transplanted into pots and leaf samples tested individually for WMoV and WSMV (07048, Loewe, Germany) by ELISA. All were infected with both viruses and infested with WCM. WCM-infested glumes (>10 WCM/glume) were placed on the leaf sheaths of 60 wheat plants cv. Calingiri (35 with WA-CG12 and 25 with WA-KU12) and 13 sweet corn plants cv. Snow Gold (WA-CG12 only). In addition, 20 wheat and 10 sweet corn plants were left without infested glumes to be uninoculated controls. All 60 WCM-inoculated wheat plants became stunted with severe leaf streaking. When leaf samples from each plant were tested by ELISA 18 to 30 days later, both viruses were detected. WMoV was detected in all 13 WCM-inoculated sweet corn plants and WSMV in two of them. Plants with WMoV alone initially had short chlorotic leaf streaks that subsequently combined, causing broad streaks. These are typical WMoV symptoms for sweet corn (1). No symptoms developed and no virus was detected in any of the uninoculated wheat or sweet corn control plants. The WMoV nucleotide sequence obtained from an infected sweet corn plant was identical to those of WA-CG12 and WA-KU12. To our knowledge, this is the first confirmed report of WMoV presence in Australia. References: (1) B. S. M. Lebas et al. Plant Dis. 89:1103, 2005. (2) D. Navia et al. Exp. Appl. Acarol. 59:95, 2013. (3) J. M. Skare et al. Virology 347:343, 2006.

17.
J Mech Behav Biomed Mater ; 33: 124-35, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-23778063

RESUMO

The high strain-rate response of four readily available tissue simulants has been investigated via plate-impact experiments. Comparison of the shock response of gelatin, ballistic soap (both sub-dermal tissue simulants), lard (adipose layers) and Sylgard(®) (a potential brain simulant) allowed interrogation of the applicability of such monolithic tissue surrogates in the ballistic regime. The gelatin and lard exhibited classic linear Hugoniot equations-of-state in the US-uP plane; while for the ballistic soap and Sylgard(®) a polymer-like non-linear response was observed. In the P/σX-v/v0 plane there was evidence of separation of the simulant materials into distinct groups, suggesting that a single tissue simulant is inadequate to ensure a high-fidelity description of the high strain-rate response of complex mammalian tissue. Gelatin appeared to behave broadly hydrodynamically, while soap, lard and Sylgard(®) were observed to strengthen in a material-dependent manner under specific loading conditions at elevated shock loading pressures/stresses. This strengthening behaviour was tentatively attributed to a further polymeric-like response in the form of a re-arrangement of the molecular chains under loading (a steric effect). In addition, investigation of lateral stress data from the literature showed evidence of operation of a material-independent strengthening mechanism when these materials were stressed above 2.5-3.0GPa, tentatively linked to the generically polymeric-like underlying microstructure of the simulants under consideration.


Assuntos
Materiais Biomiméticos , Teste de Materiais , Estresse Mecânico , Fenômenos Biomecânicos , Humanos
18.
Cell Death Dis ; 4: e684, 2013 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-23788041

RESUMO

The oncogene microRNA-21 (miRNA; miR-21) is overexpressed in most solid organ tumours; however, a recent examination of stage II colorectal cancer (CRC) specimens suggests this may be a stromal phenomenon and not only a feature of cancer cells. In vitro and in vivo studies show that miR-21 has potent pro-metastatic effects in various malignant carcinoma cell lines. The tumour microenvironment has also been identified as a key actor during the metastatic cascade; however to date the significance of deregulated miR-21 expression within the cancer-associated stroma has not been examined. In the present study, a quantitative RT-PCR-based analysis of laser microdissected tissue confirmed that miR-21 expression is associated with a four-fold mean increase in CRC stroma compared with normal tissue. In situ hybridisation using locked nucleic acid probes localised miR-21 expression predominantly to fibroblasts within tumour-associated stroma. To study the molecular and biological impact of deregulated stromal miR-21 in CRC, stable ectopic expression was induced in immortalised fibroblasts. This resulted in upregulated α-smooth muscle actin expression implying miR-21 overexpression is driving the fibroblast-to-myofibroblast transdifferentiation. Conditioned medium from miR-21-overexpressing fibroblasts protected CRC cells from oxaliplatin-induced apoptosis and increased their proliferative capacity. 3D organotypic co-cultures containing fibroblasts and CRC cells revealed that ectopic stromal miR-21 expression was associated with increased epithelial invasiveness. Reversion-inducing cysteine-rich protein with kazal motifs, an inhibitor of matrix-remodelling enzyme MMP2, was significantly downregulated by ectopic miR-21 in established and primary colorectal fibroblasts with a reciprocal rise in MMP2 activity. Inhibition of MMP2 abrogated the invasion-promoting effects of ectopic miR-21. This data, which characterises a novel pro-metastatic mechanism mediated by miR-21 in the CRC stroma, highlights the importance of miRNA deregulation within the tumour microenvironment and identifies a potential application for stromal miRNAs as biomarkers in cancer.


Assuntos
Adenocarcinoma/metabolismo , Neoplasias Colorretais/metabolismo , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Adenocarcinoma/patologia , Antineoplásicos/farmacologia , Apoptose , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular/efeitos dos fármacos , Neoplasias Colorretais/patologia , Resistencia a Medicamentos Antineoplásicos , Fibroblastos/metabolismo , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/metabolismo , Expressão Gênica , Pleiotropia Genética , Humanos , Metaloproteinase 2 da Matriz/metabolismo , MicroRNAs/metabolismo , Invasividade Neoplásica , Compostos Organoplatínicos/farmacologia , Oxaliplatina , Interferência de RNA , Células Estromais/metabolismo , Microambiente Tumoral
19.
Oncogene ; 32(40): 4758-65, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23128396

RESUMO

ΔNp63 is a transcription factor that is critical for the development of stratified epithelia and is overexpressed or amplified in >80% of squamous cell carcinomas (SCCs). We identified the RING finger E3 ubiquitin ligase PIR2/Rnf144b as a direct transcriptional target of ΔNp63α and showed that its expression parallels that of ΔNp63α in keratinocytes, SCC cell lines and SCCs. We used primary keratinocytes as a model system to investigate the function of PIR2/Rnf144b in stratified epithelia. Depletion of PIR2/Rnf144b severely impaired keratinocyte proliferation and differentiation, associated with accumulation of p21(WAF1/CIP1); a known target of PIR2/Rnf144b. More importantly, we found that PIR2/Rnf144b binds and mediates proteasomal degradation of ΔNp63α, generating a hitherto unknown auto-regulatory feedback loop. These findings substantiate PIR2/Rnf144b as a potentially critical component of epithelial homeostasis, acting downstream of ΔNp63α to regulate cellular levels of p21(WAF1/CIP1) and ΔNp63α.


Assuntos
Proteínas de Transporte/fisiologia , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Epitélio/metabolismo , Homeostase/fisiologia , Proteínas de Membrana/metabolismo , Ubiquitina-Proteína Ligases/fisiologia , Processamento Alternativo , Diferenciação Celular , Linhagem Celular , Proliferação de Células , Humanos , Queratinócitos/citologia , Proteólise , Ativação Transcricional , Ubiquitina-Proteína Ligases/genética
20.
Rev Sci Instrum ; 83(6): 063904, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22755640

RESUMO

Plate-impact experiments have been used to interrogate the influence of gauge alignment on the shock response of wire-element lateral manganin stress gauges in PMMA and aluminium targets. Embedded gauges were progressively rotated relative to the target impact face. Peak stress and lateral gauge rise-times were found be proportional (negatively and positively, respectively) to the resolved angle of the embedded gauge element. However, lateral stress gradients behind the shock were found to be relatively insensitive to gauge alignment. In addition, investigation of the effects of release arrival showed no connection to either peak stress or behaviour behind the shock.

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