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1.
Colorectal Dis ; 13(7): 744-7, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20374265

RESUMO

AIM: Ischaemic colitis is uncommon. Aetiological factors include abdominal aortic surgery, drugs (especially inotropics) or rheumatoid diseases, such as Takayasu's or Buerger's diseases. However, there is often no triggering factor, and it may be part of multifactorial cardiac, respiratory, renal or metabolic failure. METHOD: A systematic review of the current literature on the management of ischaemic colitis was carried out. RESULTS: Ten retrospective trials (841 patients) were included. No randomized controlled or prospective trial of the management of ischaemic colitis was found. CONCLUSION: There is very little evidence base for the management of this condition.


Assuntos
Colite Isquêmica/terapia , Antibacterianos/uso terapêutico , Colectomia , Dieta , Hidratação , Humanos
2.
Aliment Pharmacol Ther ; 29(10): 1096-105, 2009 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-19222408

RESUMO

BACKGROUND: Prolonged gastro-oesophageal reflux resulting in columnar metaplasia of the oesophagus is the main risk factor for oesophageal adenocarcinoma. AIM: To examine the duration of symptoms and associations of different symptoms with the development of columnar-lined oesophagus, dysplasia and adenocarcinoma. METHODS: UK multicentre cohort study of patients with columnar-lined oesophagus whose date of symptom onset (1082 patients) and/or types of symptoms reported (1681 patients) were documented. Follow-up was examined by analysis of histological reports from the registering centers. RESULTS: Symptoms of dysphagia/odynophagia and nausea/vomiting were associated with development of dysplasia. High-grade dysplasia and adenocarcinoma were associated with dysphagia/odynophagia and weight loss. Median duration from symptom onset to detection of columnar-lined oesophagus without intestinal metaplasia: 2.6 years, columnar-lined oesophagus with intestinal metaplasia: 5.0 years, indefinite changes for dysplasia: 19.3 years and low-grade dysplasia: 30.0 years. One tenth of patients had developed high-grade dysplasia at 9.6 years and one tenth had developed adenocarcinoma at 13.8 years from symptom onset. CONCLUSIONS: In patients with columnar-lined oesophagus, symptoms of dysphagia/odynophagia and nausea/vomiting were associated with a higher risk of development of dysplasia and adenocarcinoma. There is a trend for longer duration of symptoms to the detection of dysplasia.


Assuntos
Esôfago de Barrett/patologia , Transtornos de Deglutição/patologia , Neoplasias Esofágicas/patologia , Estudos de Coortes , Esôfago/patologia , Humanos , Metaplasia/patologia , Fatores de Risco , Fatores de Tempo
3.
Colorectal Dis ; 9(7): 625-31, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17824980

RESUMO

OBJECTIVE: Insulin-like growth factor (IGF)-I induces proliferation of transformed cells. Its binding proteins (IGFBP) are involved in local regulation of IGF. This study assessed the effects of overexpression of IGFBP-4 on the development of cancer in vivo. METHOD: Nude mice were subcutaneously inoculated with HT-29 colorectal cancer cells (3 x 10(6)). When the tumour became visible (1 week after inoculation), animals received either 150 microg of mammalian expression vector containing IGFBP-4 cDNA or vector alone (n = 6 each) by peritumoural injection. Tumour size was measured during the growth. After 3 weeks of IGFBP-4 induction, animals were killed and tumour tissue samples were collected for examining the level of IGFBP-4 expression. Tumour mitotic activities were determined by counting numbers of mitotic cells on the tissue section. Apoptosis was investigated by terminal deoxynucleotidyl transferase-mediated dUDP nick end labelling assay. RESULTS: Following IGFBP-4 treatment, tumour showed large necrotic areas, significantly increased numbers of apoptotic cells (36.67 +/- 7.36 vs 7.07 +/- 1.91, P < 0.01 vs control), decreased cells undergoing mitosis (2.31 +/- 0.32 vs 3.61 +/- 0.27, P < 0.01 vs control) and higher expression of IGFBP-4 (P < 0.05 vs control). CONCLUSION: IGFBP-4 gene transfer increased apoptosis and decreased mitosis, but tumour volume was not significantly altered possibly due to cellular debris filling the centre of tumours.


Assuntos
Apoptose , Neoplasias Colorretais/patologia , Neoplasias Colorretais/terapia , Terapia Genética/métodos , Proteína 4 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Animais , Linhagem Celular Tumoral , Proliferação de Células , DNA Complementar/metabolismo , Regulação Neoplásica da Expressão Gênica , Técnicas de Transferência de Genes , Humanos , Proteína 4 de Ligação a Fator de Crescimento Semelhante à Insulina/uso terapêutico , Camundongos , Camundongos Nus , Mitose , Ligação Proteica
4.
Ann R Coll Surg Engl ; 89(4): 354-8, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17535610

RESUMO

INTRODUCTION: Surgical intervention has become a common component in the management of patients infected with the human immunodeficiency virus (HIV) or suffering from the clinical consequences of acquired immunodeficiency syndrome (AIDS). We investigated the evolution of this involvement at a tertiary referral centre for this condition over a 16-year period. PATIENTS AND METHODS: Detailed retrospective examination of the medical records of HIV-positive patients treated at the Royal Free Hospital between 1986 and 2002 was undertaken. Clinical, pathological and operative details of those patients who underwent surgical intervention were recorded. RESULTS: Of the 2100 cases reviewed, 477 patients underwent a combined total of 772 surgical procedures. Of the 772 operations, 95 (12.3%) were performed as emergencies. Anorectal surgery represented the highest group with a total of 195 procedures (25.26%) being undertaken. The majority of patients (59%) had AIDS at the time of surgery, and 27.04% had a significant co-existing medical problem. Overall postoperative complication rate was 10.1%, with the risk being significantly greater in those undergoing intra-abdominal surgery and emergency procedures. CONCLUSIONS: This is the largest study to audit the impact of HIV/AIDS in general surgical practice in the UK retrospectively. Surgery for HIV patients can be safely conducted with a low complication rate for the diagnostic and anorectal procedures that comprise the vast majority of surgery in HIV/AIDS patients. Medical treatment for patients with HIV/AIDS has developed dramatically over the last two decades. In parallel, this has resulted in a heavy, new and varied workload for general surgeons, who have also had to adapt in order to deal with the challenging spectrum of this disease.


Assuntos
Infecções por HIV/complicações , Procedimentos Cirúrgicos Operatórios/estatística & dados numéricos , Biópsia/métodos , Estudos de Coortes , Feminino , Infecções por HIV/cirurgia , Infecções por HIV/transmissão , Humanos , Transmissão de Doença Infecciosa do Paciente para o Profissional , Londres , Masculino , Estudos Retrospectivos , Fatores de Risco
5.
Br J Cancer ; 96(7): 1013-9, 2007 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-17325709

RESUMO

Despite advances in surgery and adjuvant regimes, gastrointestinal malignancy remains a major cause of neoplastic mortality. Immunotherapy is an emerging and now successful treatment modality for numerous cancers that relies on the manipulation of the immune system and its effector functions to eradicate tumour cells. The discovery that the pan-epithelial homotypic cell adhesion molecule EpCAM is differentially expressed on gastrointestinal tumours has made this a viable target for immunotherapy. Clinical trials using naked anti EpCAM antibody, immunoconjugates, anti-idiotypic and dendritic cell vaccines have met variable success. The murine IgG2a Edrecolomab was shown to reduce mortality and morbidity at a level slightly lower than treatment with 5FU and Levamisole when administered to patients with advanced colorectal carcinoma in a large randomised controlled trial. Fully human and trifunctional antibodies that specifically recruit CD3-positive lymphocytes are now being tested clinically in the treatment of minimal residual disease and ascites. Although clinical trials are in their infancy, the future may bring forth an EpCAM mediated approach for the effective activation and harnessing of the immune system to destroy a pathological aberrance that has otherwise largely escaped its attention.


Assuntos
Moléculas de Adesão Celular/antagonistas & inibidores , Neoplasias Gastrointestinais/terapia , Imunoterapia , Antígenos de Neoplasias/metabolismo , Complexo CD3 , Moléculas de Adesão Celular/metabolismo , Molécula de Adesão da Célula Epitelial , Neoplasias Gastrointestinais/metabolismo , Humanos
7.
Br J Surg ; 92(9): 1169-76, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16044427

RESUMO

BACKGROUND: Ischaemia-reperfusion (IR) injury of the intestine occurs commonly during abdominal surgery. Ischaemic preconditioning (IPC) provides a way of protecting the organ from damage inflicted by IR. This study was designed to evaluate the beneficial effect of IPC, focusing on the intestinal microcirculation and oxygenation in intestinal IR injury. METHODS: Rats were allocated to three groups. Animals in the IR and IPC groups underwent 30 min of intestinal ischaemia followed by 2 h of reperfusion. In the IPC group this was preceded by 10 min of ischaemia and 10 min of reperfusion. Animals in the third group underwent laparotomy but no vascular occlusion. Intestinal microvascular perfusion, oxygenation and portal venous blood flow (PVF) were monitored continuously. At the end of the reperfusion period, blood samples were obtained for measurement of lactate dehydrogenase (LDH) and biopsies of ileum for histological evaluation. RESULTS: : IPC improved intestinal microvascular perfusion and tissue oxygenation significantly at the end of the reperfusion period (P < 0.001). PVF improved significantly in the IPC compared with the IR group (P = 0.005). The serum LDH concentration was significantly lower in the IPC than the IR group (mean(s.e.m.) 667.1(86.8) versus 1973.8(306.5) U/l; P < 0.001) Histological examination showed that ileal mucosa was significantly less injured in the IPC group. CONCLUSIONS: This study demonstrated that IPC improves intestinal microvascular perfusion and oxygenation.


Assuntos
Intestinos/irrigação sanguínea , Precondicionamento Isquêmico , Microcirculação/fisiologia , Oxigênio/análise , Traumatismo por Reperfusão/prevenção & controle , Animais , Velocidade do Fluxo Sanguíneo , Fluxometria por Laser-Doppler , Masculino , Sistema Porta/fisiologia , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Reperfusão/efeitos adversos , Traumatismo por Reperfusão/fisiopatologia
8.
Colorectal Dis ; 7(2): 128-32, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15720348

RESUMO

Colorectal cancer (CRC) is the second most common cause of cancer-related death in the Western world and its prevalence is increasing. Potential causes of this increase are changes in diet and the increases in obesity seen. This paper looks at the literature surrounding diet and obesity and the links to this increase in CRC. Heralded as a weight loss miracle we investigate whether the literature suggests the Atkins diet may actually do more harm than good by acting to increase an individual's risk of CRC. Obesity has been demonstrated to be a major factor in the increase in CRC although links to changes in diet are more tenuous. Published studies on diet suggest the Atkins diet may help reduce rather than increase the risk of CRC.


Assuntos
Neoplasias Colorretais/etiologia , Dietas da Moda/efeitos adversos , Dieta/efeitos adversos , Obesidade/complicações , Neoplasias Colorretais/epidemiologia , Humanos , Obesidade/dietoterapia , Fatores de Risco
9.
Colorectal Dis ; 6(4): 220-5, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15206962

RESUMO

Intestinal obstruction is a common cause of emergency surgical admission. The most frequent causes are well known and may often be safely treated conservatively in the first instance. The rarer causes of intestinal obstruction require prompt diagnosis and surgery if they are not to progress rapidly to strangulation and gangrene. One such cause is the ileosigmoid knotting, which is associated with a high morbidity and mortality. With increasing travel activity and population migration this condition is now being seen outside its original geographical sites of origin. This article focuses on the aetiology, pathophysiology, clinical features, investigations and the various surgical options for the management of the ileosigmoid knotting. Studies and case reports in English literature were identified by PubMed, ISIS, Embase and CAS searches between the years 1966-2004 using the following free text keywords: ileo- sigmoid knotting, ileosigmoid knot(ting), intestinal knot(ting), compound volvulus and double volvulus. All the reference lists were reviewed to retrieve additional articles. Aggressive resuscitation, prompt surgical relief of obstruction, appropriate antibiotics, accurate intra-operative assessment of the viability of the involved loops of intestine and the use of modern postoperative intensive care will help reduce the mortality and morbidity associated with this life threatening condition.


Assuntos
Doenças do Íleo/complicações , Volvo Intestinal/diagnóstico , Volvo Intestinal/terapia , Doenças do Colo Sigmoide/complicações , Humanos , Volvo Intestinal/etiologia
10.
Int J Surg ; 2(2): 109-12, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-17462232

RESUMO

Tetanus remains an important disease worldwide. In the United Kingdom, the elderly and intravenous drug users are at particular risk of acquiring clinical tetanus. Tetanus is associated with a high morbidity and mortality. Once the diagnosis of tetanus is suspected, intensive management is necessary. In this article we review the history, epidemiology, microbiology, clinical features, mode of transmission, pathogenesis, differential diagnosis, management, complications and prevention of this life threatening disease.

11.
Br J Surg ; 90(11): 1317-22, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14598408

RESUMO

BACKGROUND: Appendiceal carcinoid tumours are found in 0.3-0.9 per cent of patients undergoing appendicectomy. Controversy exists over the management following appendicectomy, especially with regard to the role of right hemicolectomy in patients with tumours smaller than 2 cm in diameter. METHODS AND RESULTS: The literature pertaining to the behaviour of appendiceal carcinoids was reviewed in order to formulate indications for right hemicolectomy. Metastatic disease from appendiceal carcinoids is a rare occurrence, but is more common when lesions are larger than 2 cm in diameter. The risk-benefit balance of right hemicolectomy needs to be better defined, and an improved understanding of tumour cell biology may aid prognostic accuracy and decision-making. CONCLUSION: There is limited evidence on which to base clear indications for right hemicolectomy in patients with a diagnosis of appendiceal carcinoid. Acceptable indications are carcinoids larger than 2 cm in size, any high-grade malignant carcinoid (including those with a high mitotic index), mesoappendiceal invasion, lesions at the base of the appendix with tumour-positive margins, and goblet cell adenocarcinoid tumours.


Assuntos
Neoplasias do Apêndice/cirurgia , Tumor Carcinoide/cirurgia , Colectomia/métodos , Neoplasias do Apêndice/patologia , Tumor Carcinoide/patologia , Humanos , Metástase Neoplásica , Estadiamento de Neoplasias , Segunda Neoplasia Primária/diagnóstico , Prognóstico
12.
Anticancer Res ; 23(3C): 2995-9, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12926152

RESUMO

BACKGROUND: Anal squamous cell carcinoma (SCC) develops from dysplastic anal warts. This study quantifies the expression of p53 and Ki67 in pre-invasive and invasive anal lesions. MATERIALS AND METHODS: Samples of 70 patients with anal warts (n = 20), low grade anal intraepithelial neoplasia (LG AIN) (n = 12), high grade anal intraepithelial neoplasia (HG AIN) (n = 27) and anal SCC (n = 11) were stained using immunohistochemical techniques. Eight patients with normal anal skin were used as controls. RESULTS: Both the expression of p53 and Ki67 increased significantly (p < 0.001) and gradually as the lesions became dysplastic and invasive. The main increase in p53 expression was as the lesions progressed from anal warts (7.38 +/- 11.93-mean +/- SD) to low grade AIN (20.778 +/- 13.14). CONCLUSION: p53 is involved in the progression of anal cancer and its expression increases from early in the development of pre-invasive anal lesions. p53 and Ki67 may be useful markers of early dysplasia and should be considered in the screening of high risk patients.


Assuntos
Neoplasias do Ânus/metabolismo , Biomarcadores Tumorais/biossíntese , Carcinoma de Células Escamosas/metabolismo , Lesões Pré-Cancerosas/metabolismo , Proteína Supressora de Tumor p53/biossíntese , Neoplasias do Ânus/patologia , Carcinoma de Células Escamosas/patologia , Divisão Celular/fisiologia , Progressão da Doença , Humanos , Imuno-Histoquímica , Antígeno Ki-67/biossíntese , Lesões Pré-Cancerosas/patologia , Verrugas/metabolismo , Verrugas/patologia
13.
Colorectal Dis ; 5(4): 353-7, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12814415

RESUMO

INTRODUCTION: Most cases of anal carcinoma seem to develop from high grade anal intraepithelial neoplasia (AIN) caused by persistent anal warts. Similar pre-invasive epithelial genital lesions (e.g. those of the cervix and vulva) have been shown to be associated with increased angiogenesis. In this study we examined biopsies of anal lesions ranging from warts to invasive anal carcinoma, with the aim of assessing the degree of angiogenesis in pre-invasive anal lesions. METHOD: Samples from 70 patients (51 male) who had undergone excision biopsy or resection of anal wart lesions (20), low grade AIN (12), high grade AIN (27) and anal squamous cell carcinoma (SCC) (11) were studied. Samples (6) from normal HIV-anal skin were used as controls. The samples were stained for von Willebrand factor, a specific marker of endothelial cells. Angiogenesis was measured by microvessel density (MVD) analysis, quantifying the microvessels in the stroma adjacent to the epithelial lesion. RESULTS: There was a statistically significant (P < 0.001) progressive increase in MVD between low grade AIN, high grade AIN and anal SCC. The difference in MVD between normal skin, warts and low grade AIN was not statistically significant. CONCLUSION: There are progressive abnormal patterns of angiogenesis in highly dysplastic lesions, similar to those found in cervical and vulvar pathology. These findings may have biological, prognostic and therapeutic implications.


Assuntos
Canal Anal/irrigação sanguínea , Neoplasias do Ânus/patologia , Carcinoma in Situ/patologia , Carcinoma de Células Escamosas/patologia , Neovascularização Patológica , Neoplasias do Ânus/fisiopatologia , Carcinoma in Situ/fisiopatologia , Carcinoma de Células Escamosas/fisiopatologia , Feminino , Humanos , Imuno-Histoquímica , Masculino , Invasividade Neoplásica
14.
Colorectal Dis ; 5(2): 123-8, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12780899

RESUMO

INTRODUCTION: Carcinoid tumours are rare neoplasms that originate from neuroendocrine cells of the primitive gastrointestinal tract. Mid- and hind-gut tumours comprise the majority of these rare tumours. With many recent advances in medical treatment the role and importance of surgery and the surgeon needs to be assessed. METHOD: A Medline, Pubmed and Embase databases search was undertaken. All relevant articles were cross-referenced. RESULTS AND CONCLUSIONS: Incidental findings of carcinoid tumours should be treated at initial surgery whilst elective surgery and further management should be undertaken in specialist centres by a multidisciplinary team. Asymptomatic patients have a better prognosis than those with symptoms. In advanced cases surgery combined with chemotherapy and liver resection is appropriate. The outlook for the majority of cases is good.


Assuntos
Tumor Carcinoide/cirurgia , Neoplasias Gastrointestinais/cirurgia , Tumor Carcinoide/patologia , Ensaios Clínicos como Assunto , Neoplasias Gastrointestinais/patologia , Humanos , Assistência Perioperatória , Prognóstico
16.
Hosp Med ; 61(3): 194-9, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10789391

RESUMO

The rising incidence of gastro-oesophageal reflux disease and its sequelae means the evaluation of oesophageal disease is set to expand beyond routine endoscopic assessment. The techniques used in the evaluation of both benign and malignant oesophageal disease are outlined in this article.


Assuntos
Refluxo Gastroesofágico/etiologia , Adenocarcinoma/complicações , Adenocarcinoma/diagnóstico , Esôfago de Barrett/diagnóstico , Endossonografia , Transtornos da Motilidade Esofágica/diagnóstico , Neoplasias Esofágicas/complicações , Neoplasias Esofágicas/diagnóstico , Esofagoscopia , Esôfago/anatomia & histologia , Esôfago/fisiologia , Feminino , Humanos , Masculino
17.
Clin Cancer Res ; 6(5): 1711-9, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10815889

RESUMO

In radioimmunoguided surgery (RIGS), a radiolabeled antibody is given i.v. before surgery and a hand-held gamma-detecting probe is used to locate tumor in the operative field. The rapid blood clearance and good tumor penetration of single-chain Fv antibodies (scFv) offer potential advantages over larger antibody molecules used previously for RIGS. A Phase I clinical trial is reported on RIGS with scFv (MFE-23-his) to carcinoembryonic antigen (CEA). Thirty-four patients undergoing surgery for colorectal carcinoma (17 primary tumors, 16 liver metastases, and 1 anastomotic recurrence) and 1 patient with liver metastases of pancreatic carcinoma received 125I-labeled MFE-23-his scFv (125I-MFE-23-his) 24, 48, 72, or 96 h before operation. 125I-MFE-23-his showed biexponential blood clearance with alpha and beta half-lives of 0.32 and 10.95 h, respectively. The abdomen was scanned during surgery with a hand-held gamma detecting probe (Neoprobe Corp.). 125I-MFE-23-his showed good tumor localization; comparison with histology showed overall accuracy of 84%. Highest median ratios for tumor:normal tissue and tumor:blood were recorded 72 or 96 h after scFv injection for patients undergoing resection of liver metastases. High levels of radioactivity were found in the kidneys. Five patients had grade 1 fever, and three had a grade 1 rise in blood pressure according to the Common Toxicity Criteria. There was a significant correlation between these ratios and those measured in excised tissues using a laboratory gamma counter (P < 0.001). MFE-23-his scFv antibody localizes in CEA-producing carcinomas. The short interval between injection and operation, the lack of significant toxicity, and the relatively simple production in bacteria make MFE-23-his scFv suitable for RIGS.


Assuntos
Anticorpos/uso terapêutico , Antígeno Carcinoembrionário/imunologia , Neoplasias Colorretais/cirurgia , Fragmentos de Imunoglobulinas/uso terapêutico , Radioimunodetecção/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos/genética , Colo/efeitos dos fármacos , Colo/metabolismo , Colo/patologia , Neoplasias Colorretais/diagnóstico por imagem , Neoplasias Colorretais/patologia , DNA Recombinante/farmacocinética , DNA Recombinante/uso terapêutico , Feminino , Engenharia Genética , Humanos , Fragmentos de Imunoglobulinas/genética , Radioisótopos do Iodo/farmacocinética , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/secundário , Linfonodos/metabolismo , Linfonodos/patologia , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Distribuição Tecidual
18.
Eur J Surg Oncol ; 25(5): 529-39, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10527603

RESUMO

Radioimmunodetection (RAID) is a technique which uses radiolabelled antibodies to visualize tumours, taking advantage of antigens preferentially expressed by malignant tissue. Gamma radiation emitted by radioisotopes can be detected using an external gamma camera (RAID), or intraoperatively with a hand-held Geiger counter (radioimmunoguided surgery, RIGS). RAID has significant inherent problems. Many have been overcome as a result of nearly 50 years of research, and others still remain as obstacles precluding the routine use of the technique. This article summarizes the technical limitations of RAID and outlines the relative successes of the methods evolved to overcome them.


Assuntos
Anticorpos Monoclonais , Antígenos de Neoplasias/sangue , Biomarcadores Tumorais/sangue , Radioimunodetecção/métodos , Anticorpos Monoclonais/administração & dosagem , Antígeno Carcinoembrionário/sangue , Raios gama , Humanos , Fatores Imunológicos , Radioisótopos de Índio , Radioisótopos do Iodo , Tecnécio
19.
Cryobiology ; 39(2): 130-7, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10529305

RESUMO

The ability of brief hypothermic reperfusion (HtR) to restore hepatic energy metabolism following periods of cold hypoxic preservation was studied in isolated rat livers after storage times of 5, 10, and 24 h. In addition, investigations were performed on the effects of HtR used to restore liver oxidative metabolism in the middle of a prolonged (24 h) hypoxic preservation period. A histidine-lactobionate-raffinose solution was used for the initial cold portal flush in all groups. Results showed that cold hypoxia for either 5 or 10 h yielded livers capable of similar recoveries of ATP, energy charge, and total adenine nucleotides, but that HtR after 24 h cold preservation resulted in reduced regeneration of ATP, a lower energy charge, and a fall in tissue adenine nucleotides. When livers were stored for 24 h but subjected to brief HtR after either 5 or 10 h before return to hypoxic storage, improved recoveries of the energy metabolites were seen over those recorded after 24 h hypoxia alone. The fact that these improvements were not due to an improved supply of adenine nucleotide precursors was demonstrated by studying groups which were given HtR with perfusate containing precursors of adenine nucleotides (adenosine, adenine, and inosine) after 24 h cold hypoxia. These data are consistent with the hypothesis that poor metabolic recovery after long-term hepatic cold preservation results more from decreased mitochondrial oxidative phosphorylation than from a lack of precursors for adenine nucleotide resynthesis. In addition, restoring oxidative metabolism at hypothermia for brief periods can to some extent protect final metabolic status after prolonged storage.


Assuntos
Nucleotídeos de Adenina/metabolismo , Fígado/metabolismo , Preservação de Órgãos , Trifosfato de Adenosina/metabolismo , Animais , Temperatura Baixa , Metabolismo Energético , Hipóxia/metabolismo , Técnicas In Vitro , Transplante de Fígado/fisiologia , Masculino , Perfusão , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/prevenção & controle
20.
Br J Cancer ; 79(11-12): 1665-71, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10206275

RESUMO

Intra-arterial Lipiodol has been used to deliver targeted therapies to primary, and some metastatic, liver cancers. Targeted radiotherapy has been used by substituting the iodine in Lipiodol with 131Iodine (131I). Early clinical results are encouraging, but the variable response may partly depend on local pharmacokinetics. This study evaluated the in vitro cytotoxic effects of 131I-Lipiodol on human hepatocellular carcinoma (Hep-G2), human colorectal metastatic cancer (SW620), human colorectal hepatic cancer (LoVo) and human umbilical vein endothelial cells (HUVEC) cell lines. The cell cultures were exposed to 131I-Lipiodol for 48 h, following which cell counts and viability were assessed by haemocytometer, S-Rhodamine uptake and radioactivity assay. The effect of exposure to control Lipiodol, 131I-Lipiodol and 131I alone was evaluated. 131I-Lipiodol was cytotoxic against all the cancer cell lines but not against the non-malignant (HUVEC) cell line. The cytotoxicity effects were very similar in all the cancer cell lines. There were no cytotoxic effects following exposure to plain 131I in any of the cell lines (malignant and non-malignant). A similar trend was seen with radioactivity counts using a gamma counter. The cytotoxic effect of 131I-Lipiodol had a graded effect with an increase in cytotoxicity following the increase in the radioactive dose. This study showed that there was a marked cytotoxic effect by 131I-Lipiodol on all the cancer cell lines. There was no difference between the controls and the 131Iodine. This suggests that effective 131I-Lipiodol targeted therapy is dependent on the uptake and retention of Lipiodol by malignant cells.


Assuntos
Neoplasias Colorretais/radioterapia , Óleo Iodado , Neoplasias Hepáticas/radioterapia , Divisão Celular/efeitos da radiação , Linhagem Celular , Meios de Contraste , Estudos de Avaliação como Assunto , Humanos , Radioterapia/métodos , Rodaminas , Células Tumorais Cultivadas
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