199 research outputs found

    Twelve weeks of protracted venous infusion of fluorouracil (5-FU) is as effective as 6 months of bolus 5-FU and folinic acid as adjuvant treatment in colorectal cancer.

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    We performed a multicentre randomised trial to compare the efficacy and toxicity of 12 weeks of 5-fluorouracil (5-FU) delivered by protracted intravenous infusion (PVI 5-FU) against the standard bolus regimen of 5-FU and folinic acid (5-FU/FA) given for 6 months as adjuvant treatment in colorectal cancer. A total of 716 patients with curatively resected Dukes' B or C colorectal cancer were randomised to 5-FU/FA (5-FU 425 mg m(-2) i.v. and FA 20 mg m(-2) i.v. bolus days 1-5 every 28 days for 6 months) or to PVI 5-FU alone (300 mg m(-2) day for 12 weeks). With a median follow-up of 19.8 months, 133 relapses and 77 deaths have been observed. Overall survival did not differ significantly (log rank P=0.764) between patients receiving 5-FU/FA and PVI 5-FU (3-year survival 83.2 vs 87.9%, respectively). Patients in the 5-FU/FA group had significantly worse relapse-free survival (RFS, log rank P=0.023) compared to those receiving PVI 5-FU (3-year RFS, 68.6 vs 80%, respectively). Grades 3-4 neutropenia, diarrhoea, stomatitis and severe alopecia were significantly less (P<0.0001) and global quality of life scores significantly better (P&<0.001) for patients in the PVI 5-FU treatment arm. In conclusion, infused 5-FU given over 12 weeks resulted in similar survival to bolus 5-FU and FA over a 6 month period, but with significantly less toxicity

    Thymidylate synthetase mRNA levels are increased in liver metastases of colorectal cancer patients resistant to fluoropyrimidine-based chemotherapy

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    BACKGROUND: Fluoropyrimidines such as 5-fluorouracil (5-FU) and 5-fluoro-2'deoxyuridine (FUDR) are among the most effective chemotherapeutic agents for treatment of metastatic colorectal cancer (CRC). Increased expression of thymidylate synthetase (TS) in CRC metastases has been proposed to be an important mechanism of resistance to fluoropyrimidine-based chemotherapy. METHODS: The present study investigated whether TS mRNA levels in liver metastases of 20 CRC patients before treatment with FUDR by hepatic arterial infusion (HAI) correlated with frequency of clinical response or survival duration. RESULTS: Median survival duration of patients with TS mRNA levels above and below the median was 15 and 18 months, respectively (p > 0.05). Clinical response was achieved in 40% of patients with low TS mRNA levels, but in only 20% of patients with high TS mRNA levels (p = 0.01). TS mRNA levels were also measured for liver metastases of 7 of the patients that did not achieve a clinical response. A statistically significant increase in expression of TS mRNA was observed for liver metastases resistant to chemotherapy (21 ± 14) in comparison to liver metastases of the same patients before chemotherapy (8 ± 4) (p = 0.03). CONCLUSION: This is the first report to demonstrate increased TS expression in liver metastases from CRC patients resistant to fluoropyrimidine based chemotherapy. These findings are consistent with previous studies indicating that increased TS expression is associated with resistance to fluoropyrimidine-based chemotherapy

    A phase I trial of preoperative radiotherapy and capecitabine for locally advanced, potentially resectable rectal cancer

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    The purpose of the study was to determine the maximum-tolerated dose (MTD) of oral capecitabine, combined with concurrent, standard preoperative pelvic radiotherapy, when given twice daily, from Monday to Friday throughout the course of radiotherapy, for locally advanced potentially resectable rectal cancer. Maximum-tolerated dose was defined as the total (given in two equally divided doses) oral dose of capecitabine that caused treatment-related grade 3 or 4 toxicity in one-third or more of the patients treated. Radiotherapy involved 50.4 Gy given in 28 fractions in 5 weeks and 3 days. Eligible patients had a newly diagnosed clinical stage T3–4 N0–2 M0 rectal adenocarcinoma located within 12 cm of the anal verge suitable for curative resection. Surgery was performed 4–6 weeks from completion of preoperative chemoradiotherapy. In all, 28 patients were enrolled in the study at predefined dose levels: 850 mg m−2 day−1 (n=3), 1000 mg m−2 day−1 (n=6), 1250 mg m−2 day−1 (n=3), 1650 mg m−2 day−1 (n=3), 1800 mg m−2 day−1 (n=8) and 2000 mg m−2 day−1 (n=5). The mean age was 62.3 years (range: 33–80 years). Five patients were female and 23 male. The median distance of tumour from the anal verge was 6 cm (range: 1–11 cm). Endorectal ultrasound was performed in 93% of patients. A total of 26 patients (93%) had T3 disease and two patients had resectable T4 disease. Dose-limiting toxicity (DLT) developed in one patient at dose level 1000 mg m−2 day−1 (RTOG grade 3 cystitis). Two of the five patients at dose level 2000 mg m−2 day−1 had a total of three DLT (grade 3 perineal skin reaction, grade 3 diarrhoea and grade 3 dehydration). Dose escalation of capecitabine was ceased at 2000 mg m−2 day−1 after reaching MTD. None of the eight patients at dose level 1800 mg m−2 day−1 developed DLT. All except one patient underwent surgery. A total of 15 patients had the clinical T stage reduced by at least one stage in pathologic specimens. Five patients (19%) achieved a pathologic complete response. We conclude that the MTD of capecitabine was reached at a dose level of 2000 mg m−2 day−1, given as 1000 mg m−2 twice daily, from Monday to Friday throughout the course of preoperative pelvic irradiation of 50.4 Gy. For patients with resectable rectal cancer receiving concurrent, full dose radiotherapy, the recommended dose of capecitabine for further study is 1800 mg m−2 day−1 when given in this schedule

    Conservative treatment of a comminuted cervical fracture in a racehorse

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    The 'classical' or 'Hangman' neck fracture involves the odontoid peg (process) of the second cervical vertebra (C2), and is described as an axial, dens or odontoid peg fracture in both the veterinary and human literature. Possible surgical treatment in both foals and adult horses requires a technique that allows decompression, anatomical alignment and stabilisation of the odontoid fracture. A limited number of surgical cases in foals have been reported in literature, but never in an adult horse. A mature Irish Thoroughbred racehorse was diagnosed with a type 2a odontoid peg fracture. Clinical signs included reluctance to move the head and neck, a left hind limb lameness and a neurological status of grade 2. The horse was treated conservatively and raced successfully five months after the diagnosed injury

    Downregulation of pyrophosphate: d-fructose-6-phosphate 1-phosphotransferase activity in sugarcane culms enhances sucrose accumulation due to elevated hexose-phosphate levels

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    Analyses of transgenic sugarcane clones with 45–95% reduced cytosolic pyrophosphate: d-fructose-6-phosphate 1-phosphotransferase (PFP, EC 2.7.1.90) activity displayed no visual phenotypical change, but significant changes were evident in in vivo metabolite levels and fluxes during internode development. In three independent transgenic lines, sucrose concentrations increased between three- and sixfold in immature internodes, compared to the levels in the wildtype control. There was an eightfold increase in the hexose-phosphate:triose-phosphate ratio in immature internodes, a significant restriction in the triose phosphate to hexose phosphate cycle and significant increase in sucrose cycling as monitored by 13C nuclear magnetic resonance. This suggests that an increase in the hexose-phosphate concentrations resulting from a restriction in the conversion of hexose phosphates to triose phosphates drive sucrose synthesis in the young internodes. These effects became less pronounced as the tissue matured. Decreased expression of PFP also resulted in an increase of the ATP/ADP and UTP/UDP ratios, and an increase of the total uridine nucleotide and, at a later stage, the total adenine nucleotide pool, revealing strong interactions between PPi metabolism and general energy metabolism. Finally, decreased PFP leads to a reduction of PPi levels in older internodes indicating that in these developmental stages PFP acts in the gluconeogenic direction. The lowered PPi levels might also contribute to the absence of increases in sucrose contents in the more mature tissues of transgenic sugarcane with reduced PFP activity

    Cisplatin plus oral etoposide (EoP) combination is more effective than paclitaxel in patients with advanced breast cancer pretreated with anthracyclines: a randomised phase III trial of Turkish Oncology Group

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    Our objective was to determine whether oral etoposide and cisplatin combination (EoP) is superior to paclitaxel in the treatment of advanced breast cancer (ABC) patients pretreated with anthracyclines. From December 1997 to August 2003, 201 patients were randomised, 100 to EoP and 101 to paclitaxel arms. Four patients in each arm were ineligible. The doses of etoposide and cisplatin were 50 mg p.o. twice a day for 7 days and 70 mg m−2 intravenously (i.v.) on day 1, respectively, and it was 175 mg m−2 on day 1 for paclitaxel. Both treatments were repeated every 3 weeks. A median of four cycles of study treatment was given in both arms. The response rate obtained in the EoP arm was significantly higher (36.3 vs 22.2%; P=0.038). Median response duration was longer for the EoP arm (7 vs 4 months) (P=0.132). Also, time to progression was significantly in favour of the EoP arm (5.5 vs 3.9 months; P=0.003). Median overall survival was again significantly longer in the EoP arm (14 vs 9.5 months; P=0.039). Toxicity profile of both groups was similar. Two patients in each arm were lost due to febrile neutropenia. The observed activity and acceptable toxicity of EoP endorses the employment of this combination in the treatment of ABC following anthracyclines

    Sensitivity of endorectal ecography in the staging of rectal chancre: correlation with pathological staging

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    Objectivo: Avaliar a sensibilidade da ecografia endorectal, em nossa experiência, no estadiamento do cancro do recto comparando com o resultado anatomopatológico. Material e métodos: Estudo retrospectivo, realizado entre Janeiro de 2005 e Agosto de 2009. Calculou-se a sensibilidade, a especificidade, o valor preditivo positivo e negativo para cada estadio T e N. Por meio da ela-boração de curvas ROC avaliou-se a precisão do estadiamento ecoendoscópico e por meio do teste de McNemar comparou-se com o resultado anatomopatológico. Resultados: Dos 112 doentes, 76 cumpriram os critérios de inclusão. Obtivemos uma eficácia de 75 a 97% para uT e de 75% para uN. Verificou-se sensibilidade, especificidade, valor preditivo positivo e negativo, respectivamente, de 63;98;92 e 89% para uT1; 71;76;54 e 88% para uT2; 67;81;73 e 76% para uT3; 100;97;60 e 100% para uT4; e 39;91;62 e 78% para uN. As curvas ROC indicaram que a ecografia endorectal é um bom teste para o estadiamento do T e razoável para o N. O teste de Mc-Nemar revelou que não há diferenças significativas entre o estadiamento ecoendoscópico e anatomopatológico (p>0,05). Conclusões: Conclui-se que a ecografia endorectal é uma importante ferramenta no estadiamento do cancro do recto, apresentando boa correlação com o resultado anatomopatológico.(undefined

    Antigenic Complementarity in the Origins of Autoimmunity: A General Theory Illustrated With a Case Study of Idiopathic Thrombocytopenia Purpura

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    We describe a novel, testable theory of autoimmunity, outline novel predictions made by the theory, and illustrate its application to unravelling the possible causes of idiopathic thrombocytopenia purpura (ITP). Pairs of stereochemically complementary antigens induce complementary immune responses (antibody or T-cell) that create loss of regulation and civil war within the immune system itself. Antibodies attack antibodies creating circulating immune complexes; T-cells attack T-cells creating perivascular cuffing. This immunological civil war abrogates the self-nonself distinction. If at least one of the complementary antigens mimics a self antigen, then this unregulated immune response will target host tissues as well. Data demonstrating that complementary antigens are found in some animal models of autoimmunity and may be present in various human diseases, especially ITP, are reviewed. Specific mechanisms for preventing autoimmunity or suppressing existing autoimmunity are derived from the theory, and critical tests proposed. Finally, we argue that Koch's postulates are inadequate for establishing disease causation for multiple-antigen diseases and discuss the possibility that current research has failed to elucidate the causes of human autoimmune diseases because we are using the wrong criteria

    Neoadjuvant chemotherapy prior to preoperative chemoradiation or radiation in rectal cancer: should we be more cautious?

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    Neoadjuvant chemotherapy (NACT) is a term originally used to describe the administration of chemotherapy preoperatively before surgery. The original rationale for administering NACT or so-called induction chemotherapy to shrink or downstage a locally advanced tumour, and thereby facilitate more effective local treatment with surgery or radiotherapy, has been extended with the introduction of more effective combinations of chemotherapy to include reducing the risks of metastatic disease. It seems logical that survival could be lengthened, or organ preservation rates increased in resectable tumours by NACT. In rectal cancer NACT is being increasingly used in locally advanced and nonmetastatic unresectable tumours. Randomised studies in advanced colorectal cancer show high response rates to combination cytotoxic therapy. This evidence of efficacy coupled with the introduction of novel molecular targeted therapies (such as Bevacizumab and Cetuximab), and long waiting times for radiotherapy have rekindled an interest in delivering NACT in locally advanced rectal cancer. In contrast, this enthusiasm is currently waning in other sites such as head and neck and nasopharynx cancer where traditionally NACT has been used. So, is NACT in rectal cancer a real advance or just history repeating itself? In this review, we aimed to explore the advantages and disadvantages of the separate approaches of neoadjuvant, concurrent and consolidation chemotherapy in locally advanced rectal cancer, drawing on theoretical principles, preclinical studies and clinical experience both in rectal cancer and other disease sites. Neoadjuvant chemotherapy may improve outcome in terms of disease-free or overall survival in selected groups in some disease sites, but this strategy has not been shown to be associated with better outcomes than postoperative adjuvant chemotherapy. In particular, there is insufficient data in rectal cancer. The evidence for benefit is strongest when NACT is administered before surgical resection. In contrast, the data in favour of NACT before radiation or chemoradiation (CRT) is inconclusive, despite the suggestion that response to induction chemotherapy can predict response to subsequent radiotherapy. The observation that spectacular responses to chemotherapy before radical radiotherapy did not result in improved survival, was noted 25 years ago. However, multiple trials in head and neck cancer, nasopharyngeal cancer, non-small-cell lung cancer, small-cell lung cancer and cervical cancer do not support the routine use of NACT either as an alternative, or as additional benefit to CRT. The addition of NACT does not appear to enhance local control over concurrent CRT or radiotherapy alone. Neoadjuvant chemotherapy before CRT or radiation should be used with caution, and only in the context of clinical trials. The evidence base suggests that concurrent CRT with early positioning of radiotherapy appears the best option for patients with locally advanced rectal cancer and in all disease sites where radiation is the primary local therapy
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