165 research outputs found

    The Category of Node-and-Choice Forms, with Subcategories for Choice-Sequence Forms and Choice-Set Forms

    Full text link
    The literature specifies extensive-form games in many styles, and eventually I hope to formally translate games across those styles. Toward that end, this paper defines NCF\mathbf{NCF}, the category of node-and-choice forms. The category's objects are extensive forms in essentially any style, and the category's isomorphisms are made to accord with the literature's small handful of ad hoc style equivalences. Further, this paper develops two full subcategories: CsqF\mathbf{CsqF} for forms whose nodes are choice-sequences, and CsetF\mathbf{CsetF} for forms whose nodes are choice-sets. I show that NCF\mathbf{NCF} is "isomorphically enclosed" in CsqF\mathbf{CsqF} in the sense that each NCF\mathbf{NCF} form is isomorphic to a CsqF\mathbf{CsqF} form. Similarly, I show that CsqFa~\mathbf{CsqF_{\tilde a}} is isomorphically enclosed in CsetF\mathbf{CsetF} in the sense that each CsqF\mathbf{CsqF} form with no-absentmindedness is isomorphic to a CsetF\mathbf{CsetF} form. The converses are found to be almost immediate, and the resulting equivalences unify and simplify two ad hoc style equivalences in Kline and Luckraz 2016 and Streufert 2019. Aside from the larger agenda, this paper already makes three practical contributions. Style equivalences are made easier to derive by [1] a natural concept of isomorphic invariance and [2] the composability of isomorphic enclosures. In addition, [3] some new consequences of equivalence are systematically deduced.Comment: 43 pages, 9 figure

    Oxaliplatin, 5-fluorouracil/leucovorin and epirubicin as first-line treatment in advanced gastric carcinoma: a phase II study

    Get PDF
    The association between oxaliplatin and 5-fluorouracil (5-FU) has been extensively reported to improve prognosis of gastric cancer patients. The present study is aimed at evaluating response rate and the toxicity profile of the association with oxaliplatin, 5-FU/lecovorin and epirubicin in gastric cancer patients with locally advanced or metastatic disease. Thirty-six patients have been enrolled and 35 evaluated. The treatment schedule was oxaliplatin (100 mg m−2), 5-FU (400 mg m−2), leucovorin (40 mg m−2) and epirubicin (60 mg m−2) intravenously. administered every 3 weeks for 6 months, for a total of 185 therapy cycles . Response rate and toxicity were assessed according to the international WHO criteria. Every patient received a mean of 5.3 therapy cycles in a day-hospital setting. Sixteen of 35 patients (46%) showed an objective response, two complete response and 14 partial response. Median time to progression was 33 weeks with an overall median survival of 49 weeks. During the study, anaemia grade 3 and neutropenia grade 3 were observed in 9 and 11% of patients respectively. A grade 3 periferic sensorial neuropathy was observed in 6% of patients. No life threatening or cardiac toxicity was recorded. The regimen used showed anticancer activity against gastric carcinoma, a tolerable toxicity profile and excellent patient compliance

    Oxaliplatin plus raltitrexed and leucovorin-modulated 5-fluorouracil i.v. bolus: a salvage regimen for colorectal cancer patients

    Get PDF
    The aim of the present study was to define the activity and tolerability of a triplet regimen including oxaliplatin 130 mg m−2 (2 h i.v. infusion) and raltitrexed 3.0 mg m−2 (15 min i.v. infusion) given on day 1, followed by levo-folinic acid 250 mg m−2 (2 h i.v. infusion) and 5-fluorouracil 1050 mg m−2 i.v. bolus on day 2, every 2 weeks, in pretreated colorectal cancer patients. From April 1999 to December 2000, 50 patients were enrolled: 26 were males and 24 females, their median age was 63 (range, 43–79) years; ECOG performance status was 0 in 26 patients, ⩾1 in 24 patients; 26 patients had received previous adjuvant chemotherapy, 40 patients had been exposed to one or two lines of palliative chemotherapy (including irinotecan in 31 cases); 18 patients were considered chemo-refractory. A total of 288 cycles were administered, with a median number of 6 (range 1–12) courses per patient. A complete response was obtained in three patients, and a partial response in nine patients, giving a major response rate of 24% (95% confidence interval, 13–38%), while 15 further patients showed a stable disease, for an overall control of tumour growth in 60% of patients. Three complete responses and three partial responses were obtained in patients pretreated with irinotecan (response rate, 19%); among refractory patients, three achieved partial responses (response rate, 13%). After a median follow-up of 18 (range, 10–30) months, 40 patients showed a progression of disease: the growth modulation index ranged between 0.2 and 2.5: it was ⩾1.33 (showing a significant delay of tumour growth) in 16 (40%) patients. Actuarial median progression-free survival time was 7.6 months, and median survival time was 13.6 months: estimated probability of survival was 55% at 1 year. Main severe toxicity was neutropenia: World Health Organisation grade 4 affected 32% of patients; non-haematological toxicity was mild: World Health Organisation grade 3 diarrhoea was complained of by 8%, and grade 3 stomatitis by 4% of patients; neurotoxicity (according to Lévi scale) was scored as grade 3 in 8% of patients. In conclusion, this regimen was manageable and active as salvage treatment of advanced colorectal cancer patients; it showed incomplete cross-resistance with irinotecan-based treatments, and proved to delay the progression of disease in a relevant proportion of treated patients

    Hypersensitivity reactions related to oxaliplatin (OHP)

    Get PDF
    Patients treated with platinum compounds are subject to hypersensitivity reactions. Our study has highlighted the reactions related to oxaliplatin (OHP) infusion. One hundred and twenty-four patients affected by advanced colorectal cancer were treated with different schedules containing OHP, at the Institute of Haematology and Medical Oncology 'L. and A. Seragnoli' of Bologna and at the Medical Oncology Division of Livorno Hospital. Seventeen patients (13%) showed hypersensitivity reactions after a few minutes from the start of the OHP infusion. Usually, these reactions were seen after 2-17 exposures to OHP (Mean\ub1s.e.: 9.4\ub11.07). No patient experienced allergic reactions at his/her first OHP infusion. Eight patients developed a mild reaction consisting of flushing and swelling of the face and hands, itching, sweating and lachrymation. The remaining nine patients showed a moderate-severe reaction with dyspnoea, wheezing, laryngospasm, psycho-motor agitation, tachycardia, precordial pain, diffuse erythema, itching and sweating. Six patients out of 17 were re-exposed to the drug with premedication of steroids and all except one developed the hypersensitivity reaction again. The cumulative dose, the time of exposure to OHP and the clinical features are variable and unpredictable. The risk of developing hypersensitivity reactions in patients treated with a short infusion of OHP cannot be underestimated. \ua9 2003 Cancer Research UK

    Schedule-selective biochemical modulation of 5-fluorouracil in advanced colorectal cancer – a phase II study

    Get PDF
    BACKGROUND: 5-fluorouracil remains the standard therapy for patients with advanced/metastatic colorectal cancer. Pre-clinical studies have demonstrated the biological modulation of 5-fluorouracil by methotrexate and leucovorin. This phase II study was initiated to determine the activity and toxicity of sequential methotrexate – leucovorin and 5-fluorouracil chemotherapy in patients with advanced colorectal cancer. METHODS: Ninety-seven patients with metastatic colorectal cancer were enrolled onto the study. Methotrexate – 30 mg/m(2) was administered every 6 hours for 6 doses followed by a 2 hour infusion of LV – 500 mg/m(2). Midway through the leucovorin infusion, patients received 5-fluorouracil – 600 mg/m(2). This constituted a cycle of therapy and was repeated every 2 weeks until progression. RESULTS: The median age was 64 yrs (34–84) and the Eastern Cooperative Group Oncology performance score was 0 in 37%, 1 in 55% and 2 in 8% of patients. Partial and complete responses were seen in 31% of patients with a median duration of response of 6.4 months. The overall median survival was 13.0 months. The estimated 1-year survival was 53.7%. Grade III and IV toxic effects were modest and included mucositis, nausea and vomiting. CONCLUSIONS: This phase II study supports previously reported data demonstrating the modest clinical benefit of 5-FU modulation utilizing methotrexate and leucovorin in patients with metastatic colorectal cancer. Ongoing studies evaluating 5-fluorouracil modulation with more novel agents (Irinotecan and/or oxaliplatin) are in progress and may prove encouraging

    New insights into the role of age and carcinoembryonic antigen in the prognosis of colorectal cancer

    Get PDF
    The aim of this study was to verify through relative survival (an estimate of cancer-specific survival) the true prognostic factors of colorectal cancer. The study involved 506 patients who underwent locally radical resection. All the clinical, histological and laboratory parameters were prognostically analysed for both overall and relative survival. This latter was calculated from the expected survival of the general population with identical age, sex and calendar years of observation. Univariate and multivariate analyses were applied to the proportional hazards model. Liver metastases, age, lymph node involvement and depth of bowel wall involvement were independent prognosticators of both overall and relative survival, whereas carcinoembryonic antigen (CEA) was predictive only of relative survival. Increasing age was unfavourably related to overall survival, but mildly protective with regard to relative survival. Three out of the five prognostic factors identified are the cornerstones of the current staging systems, and were confirmed as adequate by the analysis of relative survival. The results regarding age explain the conflicting findings so far obtained from studies considering overall survival only and advise against the adoption of absolute age limits in therapeutic protocols. Moreover, the prechemotherapy CEA level showed a high clinical value

    Surgical outcomes for colon and rectal cancer over a decade: results from a consecutive monocentric experience in 902 unselected patients

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>This study evaluates the surgical morbidity and long-term outcome of colorectal cancer surgery in an unselected group of patients treated over the period 1994–2003.</p> <p>Methods</p> <p>A consecutive series of 902 primary colorectal cancer patients (489 M, 413 F; mean age: 63 years ± 11 years, range: 24–88 years) was evaluated and prospectively followed in a university hospital (mean follow-up 36 ± 24 months; range: 3–108 months). Perioperative mortality, morbidity, overall survival, curative resection rates, recurrence rates were analysed.</p> <p>Results</p> <p>Of the total, 476 colorectal cancers were localized to the colon (CC, 53%), 406 to the rectum (RC, 45%), 12 (1%) were multicentric, and 8 were identified as part of HNPCC (1%). Combining all tumours, there were 186 cancers (20.6%) defined as UICC stage I, 235 (26.1%) stage II, 270 (29.9%) stage III and 187 (20.6%) stage IV cases. Twenty-four (2.7%) cases were of undetermined stage. Postoperative complications occurred in 38% of the total group (37.8% of CC cases, 37.2% of the RC group, 66.7% of the synchronous cancer patients and 50% of those with HNPCC, p = 0.19) Mortality rate was 0.8%, (1.3% for colon cancer, 0% for rectal cancer; p = 0.023). Multivisceral resection was performed in 14.3% of cases. Disease-free survival in cases resected for cure was 73% at 5-years and 72% at 8 years. The 5- and 8-year overall survival rates were 71% and 61% respectively (total cases). At 5-year analysis, overall survival rates are 97% for stage I disease, 87% for stage II, 73% for stage III and 22% for stage IV respectively (p < 0.0001). The 5-year overall survival rates showed a marked difference in R0, R1+R2 and non resected patients (82%, 35% and 0% respectively, p < 0.0001). On multivariate analysis, resection for cure and stage at presentation but not tumour site (colon vs. rectum) were independent variables for overall survival (p < 0.0001).</p> <p>Conclusion</p> <p>A prospective, uniform follow-up policy used in a single institution over the last decade provides evidence of quality assurance in colorectal cancer surgery with high rates of resection for cure where only stage at presentation functions as an independent variable for cancer-related outcome.</p

    Phase I trial of oxaliplatin with fluorouracil, folinic acid and concurrent radiotherapy for oesophageal cancer

    Get PDF
    This dose escalation study was designed to determine the maximum tolerated dose (MTD) and recommended doses (RDs) of 5-fluorouracil (5FU), folinic acid and oxaliplatin (FOLFOX) with concomitant radiotherapy in inoperable/metastatic oesophageal squamous cell carcinoma or adenocarcinoma. Patients received three courses of LV5FU2 regimen (folinic acid 200 mg m−2, bolus 5FU 300–400 mg/m2, continuous infusion 5FU 400–600 mg m−2 on days 1 and 2) and escalating doses of oxaliplatin 50 to 100 mg m−2 on day 1 (FOLFOX). This regimen was repeated every 2 weeks, concomitant to a 50-gray radiotherapy per 5 weeks. Three more cycles were delivered after completion of radiation therapy. Three to six patients were allocated to each of the five dose levels until MTD was reached. Thirty-three patients were enroled and 21 had metastatic disease. Maximum tolerated dose was oxaliplatin 100 mg m−2, and continuous infusion 5FU was 600 mg m−2 day− (level 5). The most common toxicities were neutropenia, dysphagia and oesophagitis. The RDs were those of FOLFOX-4 regimen (oxaliplatin 85 mg m−2 and full doses of LV5FU2). The overall response was 48.5%, including 12% complete response. Response rate on primary tumour was 62.9%. This FOLFOX-4 regimen was reasonably well tolerated and effective in inoperable/metastatic oesophageal carcinoma and warrants additional investigation

    Phase II study of weekly oxaliplatin and 24-h infusion of high-dose 5-fluorouracil and folinic acid in the treatment of advanced gastric cancer

    Get PDF
    [[abstract]]To investigate the efficacy and safety of combining weekly oxaliplatin with weekly 24-h infusion of high-dose 5-fluorouracil (5-FU) and folinic acid ( FA) in treatment of patients with advanced gastric cancer. Patients with histologically confirmed, locally advanced or recurrent/metastatic gastric cancer were studied. Oxaliplatin 65 mg m(-2) 2-h intravenous infusion, and 5-FU 2600 mg m(-2) plus FA 300 mg m(-2) 24-h intravenous infusion, were given on days 1 and 8, repeated every 3 weeks. Between January 2001 through January 2002, 55 patients were enrolled. The median age was 64 years (range: 22-75). In all, 52 patients (94.5%) had recurrent or metastatic disease and three patients had locally advanced disease. Among 50 patients evaluable for tumour response, 28 patients achieved partial response, with an overall response rate of 56% (95% confidence interval (CI): 41.8-70.3%). All 55 patients were evaluated for survival and toxicities. Median time to progression and overall survival were 5.2 and 10.0 months, respectively, during median follow-up time of 24.0 months. Major grades 3-4 toxicities were neutropenia in 23 cycles (7.1%) and thrombocytopenia in 16 cycles (5.0%). Treatment was discontinued for treatment-related toxicities in nine patients (16.4%), of whom eight were due to oxaliplatin-related neurotoxicity. One patient (1.8%) died of neutropenic sepsis. This oxaliplatin-containing regimen is effective in the treatment of advanced gastric cancer. Except for neurotoxicity that often develops after prolonged use of oxaliplatin, the regimen is well tolerated

    Molecular mechanisms of action and prediction of response to oxaliplatin in colorectal cancer cells

    Get PDF
    The platinum compound oxaliplatin has been shown to be an effective chemotherapeutic agent for the treatment of colorectal cancer. In this study, we investigate the molecular mechanisms of action of oxaliplatin to identify means of predicting response to this agent. Exposure of colon cancer cells to oxaliplatin resulted in G2/M arrest and apoptosis. Immunofluorescent staining demonstrated that the apoptotic cascade initiated by oxaliplatin is characterised by translocation of Bax to the mitochondria and cytochrome c release into the cytosol. Oxaliplatin treatment resulted in caspase 3 activation and oxaliplatin-induced apoptosis was abrogated by inhibition of caspase activity with z-VAD-fmk, but was independent of Fas/FasL association. Targeted inactivation of Bax or p53 in HCT116 cells resulted in significantly increased resistance to oxaliplatin. However, the mutational status of p53 was unable to predict response to oxaliplatin in a panel of 30 different colorectal cancer cell lines. In contrast, the expression profile of these 30 cell lines, assessed using a 9216-sequence cDNA microarray, successfully predicted the apoptotic response to oxaliplatin. A leave-one-out cross-validation approach was used to demonstrate a significant correlation between experimentally observed and expression profile predicted apoptosis in response to clinically achievable doses of oxaliplatin (R=0.53; P=0.002). In addition, these microarray experiments identified several genes involved in control of apoptosis and DNA damage repair that were significantly correlated with response to oxaliplatin
    corecore