Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 82
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Small ; 20(16): e2305831, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38088536

RESUMO

A novel combined setup, with a scanning thermal microscope (SThM) embedded in a scanning electron microscope (SEM), is used to characterize a suspended silicon rough nanowire (NW), which is epitaxially clamped at both sides and therefore monolithically integrated in a microfabricated device. The rough nature of the NW surface, which prohibits vacuum-SThM due to loose contact for heat dissipation, is circumvented by decorating the NW with periodic platinum dots. Reproducible approaches over these dots, enabled by the live feedback image provided by the SEM, yield a strong improvement in thermal contact resistance and a higher accuracy in its estimation. The results-thermal resistance at the tip-sample contact of 188±3.7K µW-1 and thermal conductivity of the NW of 13.7±1.6W m-1 K-1-are obtained by performing a series of approach curves on the dots. Noteworthy, the technique allows measuring elastic properties at the same time-the moment of inertia of the NW is found to be (6.1±1.0) × 10-30m4-which permits to correlate the respective effects of the rough shell on heat dissipation and on the NW stiffness. The work highlights the capabilities of the dual SThM/SEM instrument, in particular the interest of systematic approach curves with well-positioned and monitored tip motion.

2.
Colorectal Dis ; 26(6): 1214-1222, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38803003

RESUMO

AIM: Attention is increasingly being turned to functional outcomes as being central to colorectal cancer (CRC) survivorship. The current literature may underestimate the impact of evacuatory dysfunction on patient satisfaction with bowel function after anterior resection (AR) for CRC. The aim of this study was to investigate the impact of post-AR symptoms of storage and evacuatory dysfunction on patient satisfaction and health-related quality of life (HRQoL). METHOD: A cross-sectional study was performed at an Australian hospital of patients post-AR for CRC (2012-2021). The postoperative bowel function scores used were: low anterior resection syndrome (LARS), St Mark's incontinence, Cleveland Clinic constipation and Altomare obstructive defaecation syndrome scores. Eight 'storage' and 'evacuatory' dysfunction symptoms were derived. A seven-point Likert scale measured patient satisfaction. The SF36v2® measured HRQoL. Linear regression assessed the association between symptoms, patient satisfaction and HRQoL. RESULTS: Overall, 248 patients participated (mean age 70.8 years, 57.3% male), comprising 103 with rectal cancer and 145 with sigmoid cancer. Of the symptoms that had a negative impact on patient satisfaction, six reflected evacuatory dysfunction, namely excessive straining (p < 0.001), one or more unsuccessful bowel movement attempt(s)/24 h (p < 0.001), anal/vaginal digitation (p = 0.005), regular enema use (p = 0.004), toilet revisiting (p = 0.004) and >10 min toileting (p = 0.004), and four reflected storage dysfunction, namely leaking flatus (p = 0.002), faecal urgency (p = 0.005), use of antidiarrhoeal medication (p = 0.001) and incontinence-related lifestyle alterations (p < 0.001). A total of 130 patients (53.5%) had 'no LARS', 56 (23.1%) had 'minor LARS' and 57 (23.4%) had 'major LARS'. Fifty-seven (44.5%) patients classified as having 'no LARS' had evacuatory dysfunction. CONCLUSION: Postoperative storage and evacuatory dysfunction symptoms have an adverse impact on patient satisfaction and HRQoL post-AR. The importance of comprehensively documenting symptoms of evacuatory dysfunction is highlighted. Further research is required to develop a patient satisfaction-weighted LARS-specific HRQoL instrument.


Assuntos
Neoplasias Colorretais , Constipação Intestinal , Incontinência Fecal , Satisfação do Paciente , Complicações Pós-Operatórias , Qualidade de Vida , Humanos , Feminino , Masculino , Estudos Transversais , Idoso , Síndrome , Complicações Pós-Operatórias/etiologia , Satisfação do Paciente/estatística & dados numéricos , Constipação Intestinal/etiologia , Constipação Intestinal/fisiopatologia , Neoplasias Colorretais/cirurgia , Neoplasias Colorretais/complicações , Pessoa de Meia-Idade , Incontinência Fecal/etiologia , Incontinência Fecal/psicologia , Incontinência Fecal/fisiopatologia , Fenótipo , Protectomia/efeitos adversos , Austrália , Idoso de 80 Anos ou mais , Neoplasias Retais/cirurgia , Defecação/fisiologia , Síndrome de Ressecção Anterior Baixa
3.
World J Surg Oncol ; 21(1): 152, 2023 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-37198644

RESUMO

BACKGROUND: The role of adjuvant chemotherapy (AC) in stage III rectal cancer (RC) has been argued based on evidence from its use in colon cancer. Previous trials have analysed disease-free and overall survivals as endpoints, rather than disease recurrence. This study compares the competing risks incidences of recurrence and cancer-specific death between patients who did and did not receive AC for stage III RC. METHODS: Consecutive patients who underwent a potentially curative resection for stage III RC (1995-2019) at Concord Hospital, Sydney, Australia, were studied. AC was considered following multidisciplinary discussion. Primary outcome measures were the competing risks incidences of disease recurrence and cancer-specific death. Associations between these outcomes and use of AC (and other variables) were tested by regression modelling. RESULTS: Some 338 patients (213 male, mean age 64.4 years [SD12.7]) were included. Of these, 208 received AC. The use of AC was associated with resection year (adjusted OR [aOR] 1.74, 95%CI 1.27-2.38); age ≥75 years (aOR0.04, 95%CI 0.02-0.12); peripheral vascular disease (aOR0.08, 95%CI 0.01-0.74); and postoperative abdomino-pelvic abscess (aOR0.23, 95%CI 0.07-0.81). One hundred fifty-seven patients (46.5%) were diagnosed with recurrence; death due to RC occurred in 119 (35.2%). After adjustment for the competing risk of non-cancer death, neither recurrence nor RC-specific death was associated with AC (HR0.97, 95%CI 0.70-1.33 and HR0.72, 95%CI 0.50-1.03, respectively). CONCLUSION: This study found no significant difference in either recurrence or cancer-specific death between patients who did and did not receive AC following curative resection for stage III RC.


Assuntos
Neoplasias do Colo , Neoplasias Retais , Humanos , Masculino , Pessoa de Meia-Idade , Idoso , Estadiamento de Neoplasias , Recidiva Local de Neoplasia/patologia , Neoplasias Retais/cirurgia , Neoplasias Retais/tratamento farmacológico , Neoplasias do Colo/patologia , Quimioterapia Adjuvante , Estudos Retrospectivos
4.
Ann Surg ; 276(1): e24-e31, 2022 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-33074895

RESUMO

OBJECTIVE: To examine the independent prognostic value of ALN status in patients with stage III CRC. SUMMARY OF BACKGROUND DATA: Early CRC staging classified nodal involvement by level of involved nodes in the operative specimen, including both locoregional and apical node status, in contrast to the American Joint Committee on Cancer/tumor nodes metastasis (TNM) system where tumors are classified by the number of nodes involved. Whether ALN status has independent prognostic value remains controversial. METHODS: Consecutive patients who underwent curative resection for Stage III CRC from 1995 to 2012 at Concord Hospital, Sydney, Australia were studied. ALN status was classified as: (i) ALN absent, (ii) ALN present but not histologically involved, (iii) ALN present and involved. Outcomes were the competing risks incidence of CRC recurrence and CRC-specific death. Associations between these outcomes and ALN status were compared with TNM N status results. RESULTS: In 706 patients, 69 (9.8%) had an involved ALN, 398 (56.4%) had an uninvolved ALN and 239 (33.9%) had no ALN identified. ALN status was not associated with tumor recurrence [adjusted hazard ratio (HR) 1.02, 95% confidence interval (CI) 0.84-1.26] or CRC-specific death (HR 1.14, CI 0.91-1.43). However, associations persisted between TNM N-status and both recurrence (HR 1.58, CI 1.21-2.06) and CRC-specific death (HR 1.59, CI 1.19-2.12). CONCLUSIONS: No further prognostic information was conferred by ALN status in patients with stage III CRC beyond that provided by TNM N status. ALN status is not considered to be a useful additional component in routine TNM staging of CRC.


Assuntos
Neoplasias Colorretais , Neoplasias Colorretais/patologia , Neoplasias Colorretais/cirurgia , Humanos , Estadiamento de Neoplasias , Prognóstico , Modelos de Riscos Proporcionais , Medição de Risco
5.
Nano Lett ; 21(11): 4524-4529, 2021 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-34037401

RESUMO

A huge amount of thermal energy is available close to material surfaces in radiative and nonradiative states, which can be useful for matter characterization or energy harvesting. Even though a full class of novel nanoengineered devices has been predicted over the last two decades for exploiting near-field thermal photons, efficient near-field thermophotovoltaic conversion could not be achieved experimentally until now. Here, we realize a proof of principle by using a micrometer-sized indium antimonide photovoltaic cell cooled at 77 K and approached at nanometer distances from a hot (∼730 K) graphite microsphere emitter. We demonstrate a near-field power conversion efficiency of the cell above 14% and unprecedented electrical power density outputs (0.75 W cm-2), which are orders of magnitude larger than all previous attempts. These results highlight that near-field thermophotovoltaic converters are now competing with other thermal-to-electrical conversion devices and also pave the way for efficient photoelectric detection of near-field thermal photons.

6.
Int J Colorectal Dis ; 36(8): 1573-1596, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33604737

RESUMO

INTRODUCTION: For the past two decades, microsatellite instability (MSI) has been reported as a robust clinical biomarker associated with survival advantage attributed to its immunogenicity. However, MSI is also associated with high-risk adverse pathological features (poorly differentiated, mucinous, signet cell, higher grade) and exhibits a double-edged sword phenomenon. We performed a systematic review and meta-analysis to evaluate the rate of dissemination and the prognosis of early and advanced stage colorectal cancer based on MSI status. METHODS: A systematic literature search of original studies was performed on Ovid searching MEDLINE, Embase, Cochrane Database of Systematic Reviews, American College of Physicians ACP Journal Club, Database of Abstracts of Reviews of Effects DARE, Clinical Trials databases from inception of database to June 2019. Colorectal cancer, microsatellite instability, genomic instability and DNA mismatch repair were used as key words or MeSH terms. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline was followed. Data were pooled using a random-effects model with odds ratio (OR) as the effect size. Statistical analysis was performed using RevMan ver 5.3 Cochrane Collaboration. RESULTS: From 5288 studies, 136 met the inclusion criteria (n = 92,035; MSI-H 11,746 (13%)). Overall, MSI-H was associated with improved OS (OR, 0.81; 95% CI 0.73-0.90), DFS (OR, 0.73; 95% CI 0.66-0.81) and DSS (OR, 0.69; 95% CI 0.52-0.90). Importantly, MSI-H had a protective effect against dissemination with a significantly lower rate of lymph node and distant metastases. By stage, the protective effect of MSI-H in terms of OS and DFS was observed clearly in stage II and stage III. Survival in stage I CRC was excellent irrespective of MSI status. In stage IV CRC, without immunotherapy, MSI-H was not associated with any survival benefit. CONCLUSIONS: MSI-H CRC was associated with an overall survival benefit with a lower rate of dissemination. Survival benefit was clearly evident in both stage II and III CRC, but MSI-H was neither a robust prognostic marker in stage I nor stage IV CRC without immunotherapy.


Assuntos
Neoplasias Colorretais , Instabilidade de Microssatélites , Neoplasias Colorretais/genética , Reparo de Erro de Pareamento de DNA , Humanos , Imunoterapia , Repetições de Microssatélites , Prognóstico
7.
Colorectal Dis ; 23(10): 2604-2618, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34252253

RESUMO

AIM: Clinical presentation with large bowel obstruction has been proposed as a predictor of poor long-term oncological outcomes after resection for colorectal cancer. This study examines the association between obstruction and recurrence and cancer-specific death after resection for colon cancer. METHOD: Consecutive patients who underwent resection for colon cancer between 1995 and 2014 were drawn from a prospectively recorded hospital database with all surviving patients followed for at least 5 years. The outcomes of tumour recurrence and colon cancer-specific death were assessed by competing risks multivariable techniques with adjustment for potential clinical and pathological confounding variables. RESULTS: Recurrence occurred in 271 of 1485 patients who had a potentially curative resection. In bivariate analysis, obstruction was significantly associated with recurrence [hazard ratio (HR) 2.23, CI 1.52-3.26, p < 0.001] but this association became nonsignificant after adjustment for confounders (HR 1.53, CI 0.95-2.46, p = 0.080). Colon cancer-specific death occurred in 238 of 295 patients who had a noncurative resection. Obstruction was not significantly associated with cancer-specific death (HR 1.02, CI 0.72-1.45, p = 0.903). In patients who had a noncurative resection, the competing risks incidence of colon cancer-specific death was not significantly greater in obstructed than in unobstructed patients (HR 1.02, CI 0.72-1.45, p = 0.903). CONCLUSION: Whilst the immediate clinical challenge of an individual patient presenting with large bowel obstruction must be addressed by the surgeon, the patient's long-term oncological outcomes are unrelated to obstruction per se.


Assuntos
Neoplasias do Colo , Obstrução Intestinal , Colectomia , Neoplasias do Colo/complicações , Neoplasias do Colo/cirurgia , Humanos , Obstrução Intestinal/etiologia , Obstrução Intestinal/cirurgia , Recidiva Local de Neoplasia , Medição de Risco
8.
Ann Pathol ; 41(4): 399-404, 2021 Jul.
Artigo em Francês | MEDLINE | ID: mdl-34120784

RESUMO

Sarcomas are rare tumours that represent less than 1% of all malignant tumours in adults. Liposarcomas are among the most common malignant mesenchymal tumours. They are preferentially located in the limbs and the retroperitoneum. Liposarcomas primarily arising in the digestive tract are exceptional with a few cases reported in the literature. Their clinical presentation is variable and the symptoms are not specific. Anatomopathological examination remains the gold standard for the diagnosis and the classification of these tumours, which are divided into 5 histological types according to the 5th edition of the WHO classification of soft tissue tumours. We report two observations of unusual digestive liposarcomas, located in the oesophagus and the colon, emphasizing the variability of the diagnostic challenges, depending on the clinical presentation, the histological type and the analysed material.


Assuntos
Lipossarcoma , Sarcoma , Neoplasias de Tecidos Moles , Adulto , Trato Gastrointestinal , Humanos , Lipossarcoma/diagnóstico
9.
Opt Express ; 27(4): A11-A24, 2019 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-30876001

RESUMO

Simulations of near-field thermophotovoltaic devices predict promising performance, but experimental observations remain challenging. Having the lowest bandgap among III-V semiconductors, indium antimonide (InSb) is an attractive choice for the photovoltaic cell, provided it is cooled to a low temperature, typically around 77 K. Here, by taking into account fabrication and operating constraints, radiation transfer and low-injection charge transport simulations are made to find the optimum architecture for the photovoltaic cell. Appropriate optical and electrical properties of indium antimonide are used. In particular, impact of the Moss-Burstein effects on the interband absorption coefficient of n-type degenerate layers, and of parasitic sub-bandgap absorption by the free carriers and phonons are accounted for. Micron-sized cells are required to minimize the huge issue of the lateral series resistance losses. The proposed methodology is presumably relevant for making realistic designs of near-field thermophotovoltaic devices based on low-bandgap III-V semiconductors.

10.
Opt Express ; 26(4): 4346-4357, 2018 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-29475285

RESUMO

Easy-to-fabricate, high-temperature, thermally-stable radiators are critical elements for developing efficient and sustainable thermophotovoltaic energy conversion devices. In this frame, a trilayer-on-substrate structure is selected. It is composed of a refractory metal -molybdenum - constituting the substrate and an intermediate thin film sandwiched between two hafnia transparent layers. An in-depth analysis shows that two spectrally distinct interference regimes take place in the hafnia layer-molybdenum thin film substructure, and that backward and forward thermally-emitted waves by the thin film are selected in two distinct interferential resonating cavities. The interference regimes within and between these cavities are key to the spectral shaping of thermal emission. The radiative performances of the structures are evaluated by introducing a figure of merit. Using the example of a GaSb cell, it is shown that the structure can be optimized for providing the broadband large emission with a steep cutoff required for mitigating photoconversion losses.

11.
Colorectal Dis ; 2017 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-28977739

RESUMO

AIM: The aim of this study was to investigate the detailed, in situ, morphology of Denonvilliers fascia (DVF) in cadavers using sheet plastination and confocal microscopy and to review and describe the optimal anterior plane for mobilisation of the distal rectum.. METHOD: Six, male cadavers (age range, 46-87 years) were prepared as six sets of transverse (x2), coronal (x1) and sagittal (x3) plastinated sections which were examined under a confocal laser scanning microscope. RESULTS: In this study a consistent space between the anterior rectal wall and the posterior surface of the prostate and seminal vesicles above the level of the perineal body was termed the prerectal space. Within that prerectal space we identified fibres which take their origin from the external urethral sphincter (EUS), together with others from the longitudinal rectal muscle (LRM) and the connective tissue sheaths of neurovascular bundles. Neither the EUS- nor the LRM-originated fibres were continuous with the endopelvic fascia;they are interposed laterally and cranially by multiple neurovascular bundles. Further, our results suggest that the peritoneum does not descend deep within the prerectal space. CONCLUSION: This study reveals the undisturbed, in situ, structural detail of membrane-like structures in the prerectal space and confirms that the optimal plane for anterolateral mobilization of the rectum is posterior to the multilayered DVF. This article is protected by copyright. All rights reserved.

12.
Opt Express ; 24(2): A374-87, 2016 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-26832589

RESUMO

We investigate the thermal radiative emission of few-layer structures deposited on a metallic substrate and its dependence on temperature with the Fluctuational Electrodynamics approach. We highlight the impact of the variations of the optical properties of metallic layers on their temperature-dependent emissivity. Fabry-Pérot spectral selection involving at most two transparent layers and one thin reflective layer leads to well-defined peaks and to the amplification of the substrate emission. For a single Fabry-Pérot layer on a reflective substrate, an optimal thickness that maximizes the emissivity of the structure can be determined at each temperature. A thin lossy layer deposited on the previous structure can enhance interference phenomena, and the analysis of the participation of each layer to the emission shows that the thin layer is the main source of emission. Eventually, we investigate a system with two Fabry-Pérot layers and a metallic thin layer, and we show that an optimal architecture can be found. The total hemispherical emissivity can be increased by one order of magnitude compared to the substrate emissivity.

13.
Neuroradiology ; 58(5): 459-66, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26879914

RESUMO

INTRODUCTION: We conducted a retrospective study to identify morphological subgroups of patients referred for AD or aMCI and to seek for differences across neuropsychological performances. METHODS: One hundred forty-five patients (mean age = 76.01, 88 women and 57 men) referred for AD, either at the stage of dementia or aMCI, were examined using structural MRI. Five observers reviewed blindly twice all examinations. We rated microangiopathy, hippocampal, parietal atrophies, including a gradient of fronto-parietal atrophy (GFPA). A multiple component analysis (MCA) followed by a hierarchical ascending classification was conducted to identify morphologically distinct subgroups. Among these, 76 patients completed all the neuropsychological tests. Univariate and multivariate analyses were further conducted on these data across morphological subgroups. The institutional review board approved the research protocol. RESULTS: Inter- and intra-raters' agreements were excellent and very good for microangiopathy and hippocampal atrophy ratings. They were higher for GFPA than for the parietal atrophy scale. MCA without priors identified three groups: group 1 was characterized by no/discrete microangiopathy, severe hippocampal, and predominant parietal atrophy; group 2 had significant microangiopathy, severe hippocampal atrophy, and no predominant parietal atrophy; group 3 had a mild hippocampal atrophy and parietal atrophies. In group 1, working memory profile was less impaired than in group 2 (p = 0.01). Neuropsychological performances of group 3 were higher in most domains. CONCLUSION: Combined characterization of microangiopathy, hippocampal, parietal, and GFPA allows identifying morphological subgroups among patients referred for AD and at risk. These groups have some neuropsychological differences, suggesting different pathophysiological mechanisms or co-existing conditions.


Assuntos
Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/diagnóstico , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Testes Neuropsicológicos , Idoso de 80 Anos ou mais , Doença de Alzheimer/patologia , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Estatística como Assunto
15.
Int J Cancer ; 134(12): 2820-8, 2014 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-24259266

RESUMO

Colonic and rectal cancers differ in their clinicopathologic features and treatment strategies. Molecular markers such as gene methylation, microsatellite instability and KRAS mutations, are becoming increasingly important in guiding treatment decisions in colorectal cancer. However, their association with clinicopathologic variables and utility in the management of rectal cancer is still poorly understood. We analyzed CDKN2A gene methylation, CpG island methylator phenotype (CIMP), microsatellite instability and KRAS/BRAF mutations in a cohort of 381 rectal cancers with extensive clinical follow-up data. BRAF mutations (2%), CIMP-high (4%) and microsatellite instability-high (2%) were rare, whereas KRAS mutations (39%), CDKN2A methylation (20%) and CIMP-low (25%) were more common. Only CDKN2A methylation and KRAS mutations showed an association with poor overall survival but these did not remain significant when analyzed with other clinicopathologic factors. In contrast, this prognostic effect was strengthened by the joint presence of CDKN2A methylation and KRAS mutations, which independently predicted recurrence of cancer and was associated with poor overall and cancer-specific survival. This study has identified a subgroup of more aggressive rectal cancers that may arise through the KRAS-p16 pathway. It has been previously shown that an interaction of p16 deficiency and oncogenic KRAS promotes carcinogenesis in the mouse and is characterized by loss of oncogene-induced senescence. These findings may provide avenues for the discovery of new treatments in rectal cancer.


Assuntos
Inibidor p16 de Quinase Dependente de Ciclina/genética , Metilação de DNA/genética , DNA de Neoplasias/genética , Proteínas Proto-Oncogênicas/genética , Neoplasias Retais/genética , Proteínas ras/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Ilhas de CpG/genética , DNA de Neoplasias/metabolismo , Feminino , Humanos , Masculino , Instabilidade de Microssatélites , Pessoa de Meia-Idade , Mutação , Recidiva Local de Neoplasia/genética , Regiões Promotoras Genéticas/genética , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas p21(ras) , Neoplasias Retais/mortalidade
16.
Dis Colon Rectum ; 57(8): 916-26, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25003286

RESUMO

BACKGROUND: Extramural venous invasion is a known independent predictor of poor prognosis after resection of colorectal adenocarcinoma, but the prognostic value of mural venous invasion alone and the association between venous invasion and prognosis within tumor stages has received little research attention. OBJECTIVE: This study aimed to determine whether associations between mural and extramural venous invasion and outcome differ among tumor stages after adjustment for other factors known to influence prognosis. DESIGN: This study is a retrospective analysis of prospectively collected data. SETTINGS: Data were drawn from a registry of 3040 consecutive patients undergoing resection between 1980 and 2005 under the care of specialist surgeons in a tertiary referral public hospital and an affiliated private hospital. A standardized protocol was used for the pathological assessment of specimens. MAIN OUTCOME MEASURES: The primary outcomes measured were overall survival, cancer-specific survival, and recurrence. RESULTS: There was no significant association between venous invasion and survival in stages A (n = 544) or B (n = 1078). In stage C (n = 899), overall survival time was significantly shorter in patients with mural invasion alone or extramural invasion (both p < 0.001) than in those without invasion, and this persisted after adjustment for other prognostic variables. Equivalent bivariate associations were found in stage D, but only the effect of extramural invasion persisted after adjustment. LIMITATIONS: Our findings arise from the experience of a single surgical group and may not be generalizable to other settings. Only hematoxylin and eosin staining was used. CONCLUSIONS: The association between venous invasion and prognosis was stage specific. Both mural venous invasion alone and extramural venous invasion independently predicted overall survival in patients with stage C tumors, but not in patients with stages A, B, or D tumors. Although mural invasion alone was rare, the separate reporting of both mural and extramural invasion in patients with stage C tumor is informative and desirable.


Assuntos
Adenocarcinoma/patologia , Neoplasias Colorretais/patologia , Invasividade Neoplásica/patologia , Neoplasias Vasculares/patologia , Adenocarcinoma/cirurgia , Idoso , Neoplasias Colorretais/cirurgia , Feminino , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Recidiva Local de Neoplasia , Estadiamento de Neoplasias , Prognóstico , Sistema de Registros , Estudos Retrospectivos , Taxa de Sobrevida
17.
ANZ J Surg ; 94(4): 560-565, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38366706

RESUMO

The liver is the most frequent and often the only site of distant disease in colorectal cancer and, of all treatment protocols currently in use, resection is the most likely to result in long-term cure. Within the liver, tumour proximity to major vasculature and biliary structures poses a resection challenge, requiring a balance of achieving negative margins while preserving adequate vascular circulation and biliary drainage. The focus on parenchymal sparing resections are important but just as important may be the 'biological' behaviour of the tumour. In colorectal liver metastases (CRLM), biomarkers such as the Kirsten rat sarcoma oncogene homologue (KRAS) gene and histological growth patterns (HGPs) further improve the prognostication after resection. However, to date, the association between the KRAS status and HGPs in CRLM and their impact on resection margins around major vasculature or biliary structures in terms of overall survival and recurrence rates are unclear. The aim of this review was to explore the available evidence for the association between KRAS and HGPs in CRLM and attempt to define their impact on resection margins near major structures.


Assuntos
Neoplasias Colorretais , Neoplasias Hepáticas , Humanos , Ductos Biliares/patologia , Neoplasias Colorretais/patologia , Hepatectomia , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/cirurgia , Neoplasias Hepáticas/secundário , Margens de Excisão , Prognóstico , Proteínas Proto-Oncogênicas p21(ras)/genética
18.
ANZ J Surg ; 94(3): 309-319, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37850417

RESUMO

According to Hohenberger's original description, complete mesocolic excision for colon cancer involves precise dissection of the avascular embryonic plane between the parietal retroperitoneum and visceral peritoneum of the mesocolon. This ensures mesocolic integrity, access to high ligation of the supplying vessels at their origin and an associated extended lymphadenectomy. Results from centres which have adopted this approach routinely have demonstrated that oncological outcomes can be improved by the rigorous implementation of established principles of cancer surgery. Meticulous anatomical dissection along embryonic planes is a well-established principle of precision cancer surgery used routinely by the specialist colorectal surgeon. Therefore, the real question concerns the need for true central vascular ligation and associated extended (D3) lymphadenectomy or otherwise, particularly along the superior mesenteric vessels when performing a right colectomy. Whether this approach results in improved overall or disease-free survival remains unclear and its role remains controversial particularly given the potential for significant morbidity associated with a more extensive central vascular dissection. Current literature is limited by considerable bias, as well as inconsistent and variable terminology, and the results of established randomized trials are awaited. As a result of the current state of equipoise, various national guidelines have disparate recommendations as to when complete mesocolic excision should be performed if at all. This article aims to review the rationale for and technical aspects of complete mesocolic excision, summarize available short and long term outcome data and address current controversies.


Assuntos
Neoplasias do Colo , Laparoscopia , Mesocolo , Humanos , Mesocolo/cirurgia , Excisão de Linfonodo/métodos , Dissecação/métodos , Ligadura , Colectomia/métodos , Laparoscopia/métodos
19.
Ann Surg ; 257(5): 909-15, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23579542

RESUMO

OBJECTIVE: Prolonged ileus-the failure of postoperative ileus to resolve within a few days after major abdominal surgery-leads to significant medical consequences for the patient and costs to the hospital system. The aim of this retrospective analysis of prospectively collected data was to identify independent preoperative and intraoperative risk factors for prolonged ileus in a large consecutive series of patients who had undergone resection for colorectal cancer. METHODS: Patients were drawn from a hospital registry of 2400 consecutive resections over the period 1995-2009. Thirty-four potential predictors of prolonged ileus were analyzed by logistic regression. RESULTS: Prolonged ileus occurred in 14.0% of patients. Statistically significant independent predictors of prolonged ileus were male sex (OR: 1.7, P < 0.001), peripheral vascular disease (OR: 1.8, P < 0.001), respiratory comorbidity (OR: 1.6, P < 0.001), resection at urgent operation (OR: 2.2, P < 0.001), perioperative transfusion (OR: 1.6, P < 0.010), stoma constructed (OR: 1.4, P < 0.001), and operation lasting ≥3 hours (OR: 1.6, P < 0.001). CONCLUSIONS: These features can be used to alert medical and nursing staff to patients likely to experience prolonged ileus after bowel resection so that they can be monitored closely in the postoperative period and available treatments targeted toward them. These features may also be useful in the research context to facilitate the more efficient selection of high-risk patients as subjects in clinical trials of prevention or treatment.


Assuntos
Colectomia , Neoplasias Colorretais/cirurgia , Íleus/etiologia , Complicações Pós-Operatórias/etiologia , Reto/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Íleus/epidemiologia , Estimativa de Kaplan-Meier , Tempo de Internação/estatística & dados numéricos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Complicações Pós-Operatórias/epidemiologia , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento
20.
Phys Rev Lett ; 110(14): 146103, 2013 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-25167011

RESUMO

We report local spectra of the near-field thermal emission recorded by a Fourier transform infrared spectrometer, using a tungsten tip as a local scatterer coupling the near-field thermal emission to the far field. Spectra recorded on silicon carbide and silicon dioxide exhibit temporal coherence due to thermally excited surface waves. Finally, we evaluate the ability of this spectroscopy to probe the frequency dependence of the electromagnetic local density of states.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA