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1.
Insects ; 12(9)2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-34564264

RESUMO

Citrus greening disease is devastating the citrus industry in Florida, and the conventional synthetic pesticide applications used to control the vector, the Asian citrus psyllid (AsCP), Diaphorina citri, are rapidly becoming unsustainable. Various laboratory experiments indicate that the entomopathogenic fungus Cordyceps javanica, alone and in combination with horticultural oils, may offer a more sustainable strategy for the management of AsCP. Field studies conducted in 2018 and 2019 in mature citrus indicated that C. javanica alone, C. javanica mixed with white oil, and the chemical standard spinetoram mixed with white oil significantly suppressed AsCP adult populations by 61-83% up to 14 days after treatment in 2018, although colony-forming units of C. javanica were still present on the leaves 21 days after treatment (DAT). Only spinetoram + oil significantly suppressed AsCP, by 100%, up to 7 DAT in 2019. Natural enemies of AsCP, including lady beetles, lacewing larvae and the parasitoid Tamarixia radiata, were observed in the fungal treatments and the untreated control. The AsCP suppression by C. javanica and its compatibility with beneficial organisms suggest the potential use of this entomopathogenic fungus in citrus-integrated pest management.

2.
Int J Surg ; 67: 32-36, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31121326

RESUMO

INTRODUCTION: Despite making up more than half of new doctors, women are underrepresented in most surgical specialties. Various reasons have been suggested for this including issues with work-life balance, discrimination and a lack of female role models in the specialty. We sought to quantify the extent of gender discrimination in leadership roles in surgical societies in the UK. METHODS: All major Surgical Specialty Organisations were identified via the Royal College of Surgeons Website. Leadership and committee information was collected via organisation websites on 5th September 2018. All societies were then contacted requesting data including total membership, their stage of training and the gender split. RESULTS: Of the twenty-four organisations contacted, eighteen were able to provide data. Women accounted for 11.8% (2446/20 803) of consultant and 34.3% (5267/15 366) of trainee members. 2/24 presidents; 3/26 of vice presidents; 18.1% (39/215) of executive committees and 13.5% (49/364) of wider committee members were female. Thirty-four committee members were not included as they were not surgeons (23 female; 11 male). DISCUSSION: Despite accounting for 27% of the surgical workforce and indeed 24% of surgical society members, women account for only 2 of 24 Presidents and 18.1% (39/215) of the executive committees of surgical societies in the UK. Action should be taken so women are fairly represented in leadership roles in surgical societies with one of the benefits being more visible role models for prospective female surgeons.


Assuntos
Liderança , Sociedades Médicas/organização & administração , Especialidades Cirúrgicas/organização & administração , Cirurgiões/provisão & distribuição , Feminino , Identidade de Gênero , Humanos , Masculino , Estudos Prospectivos , Reino Unido
3.
Gut ; 67(3): 562-573, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-27902444

RESUMO

OBJECTIVE: Oncolytic viruses (OVs) represent promising, proinflammatory cancer treatments. Here, we explored whether OV-induced innate immune responses could simultaneously inhibit HCV while suppressing hepatocellular carcinoma (HCC). Furthermore, we extended this exemplar to other models of virus-associated cancer. DESIGN AND RESULTS: Clinical grade oncolytic orthoreovirus (Reo) elicited innate immune activation within primary human liver tissue in the absence of cytotoxicity and independently of viral genome replication. As well as achieving therapy in preclinical models of HCC through the activation of innate degranulating immune cells, Reo-induced cytokine responses efficiently suppressed HCV replication both in vitro and in vivo. Furthermore, Reo-induced innate responses were also effective against models of HBV-associated HCC, as well as an alternative endogenous model of Epstein-Barr virus-associated lymphoma. Interestingly, Reo appeared superior to the majority of OVs in its ability to elicit innate inflammatory responses from primary liver tissue. CONCLUSIONS: We propose that Reo and other select proinflammatory OV may be used in the treatment of multiple cancers associated with oncogenic virus infections, simultaneously reducing both virus-associated oncogenic drive and tumour burden. In the case of HCV-associated HCC (HCV-HCC), Reo should be considered as an alternative agent to supplement and support current HCV-HCC therapies, particularly in those countries where access to new HCV antiviral treatments may be limited.


Assuntos
Carcinoma Hepatocelular/terapia , Hepacivirus/fisiologia , Neoplasias Hepáticas/terapia , Terapia Viral Oncolítica , Vírus Oncolíticos/imunologia , Reoviridae/imunologia , Animais , Linfoma de Burkitt/imunologia , Linfoma de Burkitt/terapia , Linfoma de Burkitt/virologia , Carcinoma Hepatocelular/imunologia , Carcinoma Hepatocelular/virologia , Linhagem Celular Tumoral , Meios de Cultivo Condicionados/farmacologia , Hepacivirus/imunologia , Hepatócitos , Herpesvirus Humano 4 , Humanos , Imunidade Inata , Interferon-alfa/metabolismo , Interferon beta/metabolismo , Interferons , Interleucinas/metabolismo , Leucócitos Mononucleares , Fígado/imunologia , Neoplasias Hepáticas/imunologia , Neoplasias Hepáticas/virologia , Camundongos , Camundongos SCID , Células T Matadoras Naturais/imunologia , Replicação Viral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
4.
HPB (Oxford) ; 18(11): 879-885, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27591177

RESUMO

INTRODUCTION: Side branch IPMN (SB-IPMN) of the pancreas has a malignancy rate between 10 and 20%. We hypothesized that surveillance at longer intervals on selected patients with SB-IPMN might be indicated. METHODS: This is a retrospective study of prospectively collected data of 276 patients presenting from 2000 to 2010. After 2007, we opted to screen our patients with longer intervals, initially at 12 months then 24 months using MR if no "worrisome features" were present. RESULTS: Complete data sets for 261 patients were analysed and patients were aged 78 (40-91) years. 232 patients had sole SB-IPMN while 92% were incidental (n = 209) and 8% were symptomatic (n = 24). Single SB-IPMN accounted for 84% (n = 195) of all cases; maximum diameter of 15.5 (5-60) mm. The median follow up duration was 46 (32-53) months. Short interval radiological surveillance (3-9 months) was 39% (n = 90), while long interval surveillance (12-36 months) was performed in 61% (n = 142). The rate of pancreatic resection, due to concern for the development of pancreatic cancer, in the short and long interval surveillance groups was 4.4% (n = 4) and 3.5% (n = 5) respectively; p = 0.78. CONCLUSION: Our data suggests no difference in outcome between long and short interval MR surveillance of SB-IPMN patients.


Assuntos
Colangiopancreatografia por Ressonância Magnética , Neoplasias Císticas, Mucinosas e Serosas/diagnóstico por imagem , Ductos Pancreáticos/diagnóstico por imagem , Neoplasias Pancreáticas/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Bases de Dados Factuais , Progressão da Doença , Endossonografia , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Neoplasias Císticas, Mucinosas e Serosas/mortalidade , Neoplasias Císticas, Mucinosas e Serosas/patologia , Neoplasias Císticas, Mucinosas e Serosas/cirurgia , Pancreatectomia , Ductos Pancreáticos/patologia , Ductos Pancreáticos/cirurgia , Neoplasias Pancreáticas/mortalidade , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/cirurgia , Valor Preditivo dos Testes , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Tomografia Computadorizada por Raios X
5.
HPB (Oxford) ; 16(3): 212-9, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23870012

RESUMO

OBJECTIVE: A right and left hepatic trisectionectomy and an extended trisectionectomy are the largest liver resections performed for malignancy. This report analyses a series of 23 patients who had at least one repeat resection after a hepatic trisectionectomy for colorectal liver metastasis (CRLM). METHODS: A retrospective analysis of a single-centre prospective liver resection database from May 1996 to April 2009 was used for patient identification. Full notes, radiology and patient reviews were analysed for a variety of factors with respect to survival. RESULTS: Twenty-three patients underwent up to 3 repeat hepatic resections after 20 right and 3 left hepatic trisectionectomies. In 18 patients the initial surgery was an extended trisectionectomy. Overall 1-, 3- and 5-year survival rates after a repeat resection were 100%, 46% and 32%, respectively. No factors predictive for survival were identified. CONCLUSION: A repeat resection after a hepatic trisectionectomy for CRLM can offer extended survival and should be considered where appropriate.


Assuntos
Adenocarcinoma/secundário , Adenocarcinoma/cirurgia , Neoplasias Colorretais/patologia , Hepatectomia , Neoplasias Hepáticas/secundário , Neoplasias Hepáticas/cirurgia , Metastasectomia , Adenocarcinoma/mortalidade , Adulto , Idoso , Quimioterapia Adjuvante , Neoplasias Colorretais/mortalidade , Inglaterra , Feminino , Hepatectomia/efeitos adversos , Hepatectomia/mortalidade , Humanos , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/mortalidade , Imageamento por Ressonância Magnética , Masculino , Metastasectomia/efeitos adversos , Metastasectomia/mortalidade , Pessoa de Meia-Idade , Terapia Neoadjuvante , Reoperação , Estudos Retrospectivos , Fatores de Tempo , Tomografia Computadorizada por Raios X , Resultado do Tratamento
6.
Clin Cancer Res ; 19(18): 5104-15, 2013 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-23881927

RESUMO

PURPOSE: Surgical removal of solid primary tumors is an essential component of cancer treatment. Surgery-induced dysfunction in natural killer (NK) cells has been linked to the development of metastases in animal models and patients with cancer. We investigated the activation of NK cells using influenza vaccine in the perioperative period to eradicate micrometastatic disease. EXPERIMENTAL DESIGN: Both the B16lacZ and 4T1 tumor models in immunocompetent mice were used to assess the in vivo efficacy of perioperative influenza vaccine administration. In healthy human donors and cancer surgery patients, we assessed NK cell function pre- and post-influenza vaccination using both in vivo and ex vivo assays. RESULTS: Using the TLR3 agonist poly(I:C), we showed as proof-of-principle that perioperative administration of a nonspecific innate immune stimulant can inhibit surgery-induced dysfunction in NK cells and attenuate metastases. Next, we assessed a panel of prophylactic vaccines for NK cell activation and determined that inactivated influenza vaccine was the best candidate for perioperative administration. Perioperative influenza vaccine significantly reduced tumor metastases and improved NK cytotoxicity in preclinical tumor models. Significantly, IFNα is the main cytokine mediator for the therapeutic effect of influenza vaccination. In human studies, influenza vaccine significantly enhanced NK cell activity in healthy human donors and cancer surgery patients. CONCLUSION: These results provide the preclinical rationale to pursue future clinical trials of perioperative NK cell activation, using vaccination in cancer surgery patients. Research into perioperative immune therapy is warranted to prevent immune dysfunction following surgery and eradicate metastatic disease.


Assuntos
Vacinas contra Influenza/uso terapêutico , Células Matadoras Naturais/imunologia , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/prevenção & controle , Melanoma Experimental/cirurgia , Procedimentos Cirúrgicos Operatórios/efeitos adversos , Animais , Citotoxicidade Imunológica/imunologia , Humanos , Neoplasias Pulmonares/secundário , Neoplasias Pulmonares/cirurgia , Ativação Linfocitária , Melanoma Experimental/imunologia , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Assistência Perioperatória , Período Pós-Operatório , Receptor de Interferon alfa e beta/fisiologia , Células Tumorais Cultivadas , Vacinação
7.
Int J Cancer ; 132(10): 2327-38, 2013 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-23114986

RESUMO

Reovirus is a promising oncolytic virus, acting by both direct and immune-mediated mechanisms, although its potential may be limited by inactivation after systemic delivery. Our study addressed whether systemically delivered reovirus might be shielded from neutralising antibodies by cell carriage and whether virus-loaded blood or hepatic innate immune effector cells become activated to kill colorectal cancer cells metastatic to the liver in human systems. We found that reovirus was directly cytotoxic against tumour cells but not against fresh hepatocytes. Although direct tumour cell killing by neat virus was significantly reduced in the presence of neutralising serum, reovirus was protected when loaded onto peripheral blood mononuclear cells, which may carry virus after intravenous administration in patients. As well as handing off virus for direct oncolytic killing, natural killer (NK) cells within reovirus-treated blood mononuclear cells were stimulated to kill tumour targets, but not normal hepatocytes, in a Type I interferon-dependent manner. Similarly, NK cells within liver mononuclear cells became selectively cytotoxic towards tumour cells when activated by reovirus. Hence, intravenous reovirus may evade neutralisation by serum via binding to circulating mononuclear cells, and this blood cell carriage has the potential to investigate both direct and innate immune-mediated therapy against human colorectal or other cancers metastatic to the liver.


Assuntos
Adenocarcinoma/imunologia , Sangue/imunologia , Neoplasias do Colo/imunologia , Citotoxicidade Imunológica , Leucócitos Mononucleares/imunologia , Neoplasias Hepáticas/imunologia , Fígado/citologia , Terapia Viral Oncolítica/métodos , Reoviridae/imunologia , Adenocarcinoma/patologia , Linhagem Celular Tumoral , Neoplasias do Colo/patologia , Neoplasias Colorretais/imunologia , Citometria de Fluxo , Hepatócitos/imunologia , Humanos , Infusões Intravenosas , Células Matadoras Naturais/imunologia , Fígado/imunologia , Neoplasias Hepáticas/secundário , Fenótipo
8.
Sci Transl Med ; 4(138): 138ra77, 2012 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-22700953

RESUMO

Oncolytic viruses, which preferentially lyse cancer cells and stimulate an antitumor immune response, represent a promising approach to the treatment of cancer. However, how they evade the antiviral immune response and their selective delivery to, and replication in, tumor over normal tissue has not been investigated in humans. Here, we treated patients with a single cycle of intravenous reovirus before planned surgery to resect colorectal cancer metastases in the liver. Tracking the viral genome in the circulation showed that reovirus could be detected in plasma and blood mononuclear, granulocyte, and platelet cell compartments after infusion. Despite the presence of neutralizing antibodies before viral infusion in all patients, replication-competent reovirus that retained cytotoxicity was recovered from blood cells but not plasma, suggesting that transport by cells could protect virus for potential delivery to tumors. Analysis of surgical specimens demonstrated greater, preferential expression of reovirus protein in malignant cells compared to either tumor stroma or surrounding normal liver tissue. There was evidence of viral factories within tumor, and recovery of replicating virus from tumor (but not normal liver) was achieved in all four patients from whom fresh tissue was available. Hence, reovirus could be protected from neutralizing antibodies after systemic administration by immune cell carriage, which delivered reovirus to tumor. These findings suggest new preclinical and clinical scheduling and treatment combination strategies to enhance in vivo immune evasion and effective intravenous delivery of oncolytic viruses to patients in vivo.


Assuntos
Vírus Oncolíticos/fisiologia , Idoso , Anticorpos Neutralizantes/imunologia , Plaquetas/virologia , Neoplasias Colorretais/cirurgia , Neoplasias Colorretais/terapia , Feminino , Genoma Viral/genética , Granulócitos/virologia , Humanos , Neoplasias Hepáticas/cirurgia , Neoplasias Hepáticas/terapia , Masculino , Pessoa de Meia-Idade , Terapia Viral Oncolítica/métodos , Vírus Oncolíticos/genética , Vírus Oncolíticos/crescimento & desenvolvimento , Replicação Viral/genética , Replicação Viral/fisiologia
9.
J Am Coll Surg ; 214(2): 174-83, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22137823

RESUMO

BACKGROUND: Hepatocellular carcinoma (HCC) most commonly arises in patients with chronic liver disease. Data on outcomes after liver resection in patients with noncirrhotic, nonfibrotic, seronegative, referred to as a "normal" liver are limited. We aimed to investigate differences in prognostic factors and outcomes between patients presenting with HCC arising in "normal" liver (NLHCC) and that arising in "diseased" liver (DLHCC). STUDY DESIGN: All patients undergoing resection for HCC between 1994 and 2008 were assessed. Multivariable analysis of clincopathologic data from the NLHCC group was performed by comparing them with data from the group who had surgery for DLHCC during this period. RESULTS: During the 15-year study period, 142 patients underwent liver resection for HCC: 81 for NLHCC and 61 for DLHCC. NLHCCs were more often solitary but were larger and required more major resections. There was no significant difference in survival outcomes between patients who had NLHCC or DLHCC, with overall and recurrence-free 5-year survivals of 60% and 51% in NLHCC and 55% and 33% in DLHCC, respectively. In patients with NLHCC, significant factors predicting overall survival were blood transfusion requirement (p = 0.003) and age (p = 0.009), and the only significant factor at predicting recurrence-free survival was presence of multiple tumors (p = 0.025). In contrast, in DLHCC, the only significant prognostic variables were a preoperative tumor biopsy (p = 0.017) or a high neutrophil-to-lymphocyte ratio (p = 0.001), both of which predicted a poorer recurrence-free survival. CONCLUSIONS: HCC presenting in patients with a normal background liver parenchyma appears to present a different spectrum of the disease. However, excellent outcomes can be achieved after liver resection, although this often requires the use of advanced techniques due to late presentation.


Assuntos
Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/cirurgia , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/cirurgia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Doença Crônica , Feminino , Humanos , Cirrose Hepática/complicações , Cirrose Hepática/patologia , Neoplasias Hepáticas/etiologia , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Morbidade , Análise Multivariada , Invasividade Neoplásica , Prognóstico , Análise de Sobrevida , Adulto Jovem
10.
HPB (Oxford) ; 13(7): 483-93, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21689232

RESUMO

BACKGROUND: Perihilar cholangiocarcinoma (PHCCA) remains a surgical challenge for which few large Western series have been reported. The aims of this study were to investigate the results of surgical resection for PHCCA and assess how practice has evolved over the past 15 years. METHODS: A prospectively maintained database was interrogated to identify all resections. Clinicopathological data were analysed for impact on survival. Subsequently, data for resections carried out during the periods 1994-1998, 1999-2003 and 2004-2008 were compared. RESULTS: Eighty-three patients underwent resection. Trisectionectomy was required in 67% of resections. Overall survival was 70%, 36% and 20% at 1, 3 and 5 years, respectively. Size of tumour, margin (R0) status, lymph node status, distant metastasis, tumour grade, portal vein resection, microscopic direct vascular invasion, T-stage and blood transfusion requirement significantly affected outcome on univariate analysis. Distant metastasis (P = 0.040), percutaneous biliary drainage (P = 0.015) and blood transfusion requirement (P = 0.026) were significant factors on multivariate analysis. Survival outcomes improved and blood transfusion requirement was significantly reduced in the most recent time period. DISCUSSION: Blood transfusion requirement and preoperative percutaneous biliary drainage were identified as independent indicators of a poor prognosis following resection of PHCCA. Longterm survival can be achieved following the aggressive surgical resection of this tumour, but the emergence of a clear learning curve in our analyses indicates that these patients should be managed in high-volume centres in order to achieve improved outcomes.


Assuntos
Neoplasias dos Ductos Biliares/cirurgia , Ductos Biliares Intra-Hepáticos/cirurgia , Colangiocarcinoma/cirurgia , Tumor de Klatskin/secundário , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias dos Ductos Biliares/mortalidade , Transfusão de Sangue , Colangiocarcinoma/mortalidade , Bases de Dados Factuais , Drenagem/métodos , Endoscopia do Sistema Digestório , Feminino , Humanos , Tumor de Klatskin/mortalidade , Masculino , Pessoa de Meia-Idade , Prognóstico , Taxa de Sobrevida , Resultado do Tratamento
13.
Environ Entomol ; 37(4): 914-24, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18801257

RESUMO

Studies were conducted to assess population densities and phenology of the psyllid Diaphorina citri Kuwayama at two citrus groves in east-central Florida. One grove contained young, irrigated grapefruit trees and the other contained mature, nonirrigated orange trees. The two groves were sampled weekly for eggs, nymphs, and adults on flush shoots; for adults on mature leaves; and for adults captured on yellow sticky card traps. Because infestations of immature D. citri develop strictly on young flush, the abundance of flush was assessed weekly. Overall means of 26.5, 16.8, and 0.27 eggs, nymphs, and adults per flush shoot, respectively, were observed in the young grapefruit trees. In the grove of mature orange trees, overall means of 16.0, 12.7, and 0.31 eggs, nymphs, and adults per flush shoot were observed, respectively. Flush abundance was an inconsistent indicator of the mean density of D. citri per flush shoot. Mean density per shoot by itself was an inconsistent indicator of overall population levels of D. citri at each study site because few shoots were sometimes present when mean densities per shoot were high. May, June, and July were periods of time when immature D. citri were consistently present and most abundant at each study site, but the study indicated large infestations could occur at any time of the year depending on environmental factors and flush availability. Yellow sticky traps were effective for both male and female D. citri and useful for gauging adult population trends.


Assuntos
Citrus paradisi/fisiologia , Citrus sinensis/fisiologia , Hemípteros/fisiologia , Animais , Feminino , Florida , Hemípteros/crescimento & desenvolvimento , Estágios do Ciclo de Vida , Masculino , Densidade Demográfica , Dinâmica Populacional , Chuva , Temperatura
14.
Phys Rev Lett ; 100(14): 148501, 2008 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-18518079

RESUMO

Records of the mean annual global surface temperatures from 1850 to 1970 show annual temperatures that are correlated with temperatures of the previous years as a one-dimensional random walk with a limiting feedback. This description accounts for the variation in those temperatures observed until the present by assuming that the base temperature is proportional to the increase in carbon dioxide concentration over the level in 1890. Climate models that better fit the observed variations are shown to be statistically improbable and thus likely to be artifacts.


Assuntos
Efeito Estufa , Modelos Estatísticos , Atmosfera , Dióxido de Carbono , Clima , Processos Estocásticos
15.
Phys Rev Lett ; 100(2): 020001, 2008 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-18232838

RESUMO

Sam Goudsmit implemented his vision of converting the Letters section of Physical Review into a distinct journal fifty years ago. Physical Review Letters was designed to publish "only papers that really deserve rapid communication." The new journal became so successful with physicists throughout the world that Physical Review Letters now publishes 3500 Letters per year.

16.
Ann Surg Oncol ; 13(11): 1493-9, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17009152

RESUMO

BACKGROUND: Many colorectal liver metastasis patients are denied surgical resection on the basis of tumour size. The aim of this study was to explore the impact of metastasis size on modern liver resection. METHODS: Using a prospectively collected database, this was a retrospective analysis of 484 consecutive patients who underwent liver resection for colorectal liver metastases between 1993 and 2003. The cohort was divided into two groups: smaller metastases (< 8 cm) and larger metastases (> or = 8 cm). Those with larger metastases were then further stratified into big metastases (8-12 cm) and giant metastases (> 12 cm). Demographic, pathological, surgical technique and outcome data were compared between the groups. RESULTS: There were 88 (18%) patients with metastases measuring 8 cm or larger. There was an association between higher carcinoembryonic antigen (CEA) and cancer antigen (CA) 19-9 levels and larger metastases. The actuarial 5-year survival for patients with larger metastases was 38% compared with 42% for smaller metastases (not statistically significant). Patients with giant metastases had poorer overall and disease-free survival (both nonsignificant) compared with those with big metastases: 29% and 28% at 5 years, respectively. CONCLUSION: Patients with colorectal liver metastasis greater than 8 cm and up to 12 cm in size should not be treated differently from those with smaller lesions.


Assuntos
Neoplasias Colorretais/patologia , Neoplasias Hepáticas/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Colorretais/cirurgia , Intervalo Livre de Doença , Feminino , Hepatectomia , Humanos , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/secundário , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do Tratamento
17.
Bioelectromagnetics ; 27(4): 332-4, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16437542

RESUMO

I show that the interaction of weak DC and ELF magnetic fields with contained ions cannot generate significant biological effects through changing the character of the ion orbits.


Assuntos
Campos Eletromagnéticos , Íons
18.
Phys Rev E Stat Nonlin Soft Matter Phys ; 69(4 Pt 1): 042902, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15169052

RESUMO

Evolutionary pressures are presumed to act so as to maximize the efficiency of biological systems. However, the utility of that premise is marred by the difficulties in defining and evaluating both the efficiency of systems and the character of the available variation space. Following Hodgkin and Adrian, we examine the character of voltage gated ion channels in the nonmyelinated giant axons of the squid and find that both the channel densities and channel transition rates have values that nearly optimize signal sensitivity as well as signal velocity.


Assuntos
Potenciais de Ação/fisiologia , Axônios/fisiologia , Potenciais da Membrana/fisiologia , Modelos Neurológicos , Condução Nervosa/fisiologia , Canais de Potássio/fisiologia , Canais de Sódio/fisiologia , Simulação por Computador
19.
Proc Natl Acad Sci U S A ; 100(21): 12099-104, 2003 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-14506291

RESUMO

Using Monte Carlo techniques, I calculate the effects of internally generated noise on information transfer through the passage of action potential spikes along unmyelinated axons in a simple nervous system. I take the Hodgkin-Huxley (HH) description of Na and K channels in squid giant axons as the basis of the calculations and find that most signal transmission noise is generated by fluctuations in the channel open and closed populations. To bring the model closer to conventional descriptions in terms of thermal noise energy, kT, and to determine gating currents, I express the HH equations in the form of simple relations from statistical mechanics where the states are separated by a Gibbs energy that is modified by the action of the transmembrane potential on dipole moments held by the domains. Using the HH equations, I find that the output response (in the probability of action potential spikes) from small input potential pulses across the cell membrane is increased by added noise but falls off when the input noise becomes large, as in stochastic resonance models. That output noise response is sharply reduced by a small increase in the membrane polarization potential or a moderate increase in the channel densities. Because any reduction of noise incurs metabolic and developmental costs to an animal, the natural noise level is probably optimal and any increase in noise is likely to be harmful. Although these results are specific to signal transmission in unmyelinated axons, I suggest that the conclusions are likely to be general.


Assuntos
Canais Iônicos/metabolismo , Modelos Biológicos , Potenciais de Ação , Canais Iônicos/química , Cinética , Potenciais da Membrana , Estrutura Molecular , Método de Monte Carlo , Processos Estocásticos
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