[Adjuvant and palliative treatment of pancreatic cancer].
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Biomedical subjects
Publications and source records attributed to A Abad.
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BACKGROUND & AIMS: Loss of heterozygosity (LOH) on chromosome 18q is frequent in colorectal cancer (CRC) and has been associated with poor prognosis in stage II tumors. This study investigated the frequency of LOH in sporadic CRC and its effect on patient prognosis. METHODS: One hundred forty-four patients were screened for LOH at 18q by polymerase chain reaction using three polymorphic microsatellite markers. RESULTS: Nineteen patients were excluded because their tumors showed microsatellite instability in at least one marker. Of the remaining 125 patients, 121 were informative in at least one marker; 45% (54 of 121) showed 18q LOH. Five-year survival was 42% in those with 18q LOH and 73% in those without 18q LOH (P = 0.008). Multivariate analysis showed that tumor side (P = 0.0001) and 18q LOH (P = 0.01) were the only independent prognostic factors. Examining markers individually showed that only the lost of D18S474 had a significant influence on survival in patients with stage II CRC (P = 0.016). CONCLUSIONS: 18q LOH indicates an unfavorable outcome in patients with stage II CRC. Our results emphasize the importance of the 18q21.1 region, where several tumor-suppressor genes have been mapped. Microsatellite analysis may be useful in identifying high-risk patients who might benefit from adjuvant therapy.
1. Sixty chorionic vascular rings from normal term placentas were immersed in an organ bath for isometric tension recording to study (A) the contractile response to 120 mM of potassium chloride (KCl) after adjustment and equilibration to 1-5 g of passive tension; and (B) the concentration-response curve to KCl after adjustment and equilibration to the optimal passive tension. 2. Adjustment to 4 g of passive tension elicited the maximal (P < 0.007) and the latest (P < 0.006) KCl-induced contraction among arterial rings. Venous rings showed the greatest contraction when adjusted to 3 g, but the differences were not significant except when compared to 1 g of passive tension (P < 0.03). 3. The EC50 for chorionic arteries and veins was 14.2 and 25.7 mM, respectively (P < 0.003). The maximal contraction was already obtained with 40 mM of KCl. 4. Our results suggest that (A) the optimal passive tension for fresh human chorionic arteries is 4 g; (B) chorionic venous reactivity is less influenced by the initial tension; and (C) the optimal concentration of KCl to be used as a contracting agent of these tissues is 40 mM.
Twenty-two previously untreated patients who had unresectable and metastatic pancreatic cancer were treated in a prospective phase II trial with high-dose continuous infusion epirubicin (45 mg/m2 once every 24 hours continuous infusion days 4 through 6) plus quinidine (495 mg once every 24 hours on days 1-6). There were no objective responses (0 of 18 evaluable patients). Subjective responses were achieved in 2 of 21 evaluable patients (9%), all of whom had good performance status (Eastern Cooperative Oncology Group: 0-1). Median survival was 5.7 months for the overall population. Two patients who exhibited symptomatic improvement achieved responses lasting 7 and 13 months, respectively. Toxicity was generally mild and tolerable. Little benefit regarding survival and quality of life was observed with the use of this regimen. The role in chemoresistance of mdrl, p53, and the mismatch repair system was examined.
In a previous report we found an inverse correlation between pre-operative platelet count (PlC) levels and the risk of post-operative pulmonary embolism in patients undergoing hip surgery. In the present study, we prospectively evaluated the prognostic significance of pre-operative PlC levels on survival in 180 consecutive patients undergoing surgery for colorectal cancer. Other major clinicopathological parameters studied were age, gender, Dukes' stage, duration of surgery, pre-operative haemoglobin levels and transfusion requirements. There were no significant differences in mean pre-operative PlC levels according to tumor stage. Thirty-three patients (18%) died during follow-up (3-23 months, median: 13 months). Univariate analysis (Kaplan-Meier estimates) showed that advanced tumor stage (p < 0.001), duration of surgery (p < 0.05) and a high pre-operative PlC level (p < 0.001) were significantly associated to a poor survival. The multivariate Cox analysis revealed that tumor stage (RR:5.734; 95%C.I.: 2.644-12.44), a high pre-operative PlC level (RR: 2.467; 95%C.I.: 1.117-5.452), and to a lesser extent the patients' age remained independent prognostic variables for mortality. The findings of this preliminary study may be of interest from the point of view of pathogenesis, but also clinically, since they might be used in the decision as to which patients or groups of patients should receive more aggressive therapeutic intervention.
The application of an inert membrane-based, enzyme-linked immunofiltration assay (ELIFA) to the characterization of immunosorbents suitable for flow immunosensor development is described. For direct assays, eight monoclonal antibodies (MAb) raised against the insecticide carbaryl were immobilized on three sorbents, namely, controlled pore glass (CPG), hydrazide derivatized agarose beads and a hydrophilic polymer with immobilized Protein A/G. The interaction between immobilized antibodies and antigen was directly detected using a carbaryl hapten conjugated to horseradish peroxidase. Immunosorbent characterization was based on both sensitivity and re-usability. Optimal immunosorbent regeneration was achieved using 0.1 M glycine/HCl, pH 2.0 as the desorbent solution. The best covalent immunosorbent was obtained by immobilizing LIB-CNA36 MAb on hydrazide derivatized agarose beads. The best immunosorbent obtained by reversible immobilization was LIB-CNH45 MAb on Protein A/G. Using this support the eventual irreversible denaturation of covalently immobilized MAbs was overcome. For indirect assays, N-hydroxisuccinimide derivatized agarose beads and glutaraldehyde-activated CPG were used as sorbents for hapten immobilization via the amino groups of a carrier protein. In this format, antigen-MAb interactions were detected using a peroxidase-conjugated rabbit anti-mouse immunoglobulin. The highest sensitivity was achieved by LIB-CNH45 MAb in combination with derivatized agarose beads. All these results demonstrated the suitability of ELIFA as a fast, precise and easy-to-use technique for immunosorbent selection.
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A case of prune belly syndrome diagnosed by ultrasonography during the thirteenth week of gestation is described. Pathogenic data and the importance of antenatal diagnosis are discussed.
Cell wall extracts from the double-mutant mnn1 mnn9 strain were used as the immunogen to obtain a monoclonal antibody (MAb), SAC A6, that recognizes a specific mannoprotein--which we have named Icwp--in the walls of cells of Saccharomyces cerevisiae. Icwp runs as a polydisperse band of over 180 kDa in sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of Zymolyase extracts of cell walls, although an analysis of the secretory pattern of the mannoprotein shows that at the level of secretory vesicles, it behaves like a discrete band of 140 kDa. Immunofluorescence analysis with the MAb showed that Icwp lies at the inner layer of the cell wall, being accessible to the antibody only after the outer layer of mannoproteins is disturbed by treatment with tunicamycin. The screening of a lambda gt11 expression library enabled us to identify the open reading frame (ORF) coding for Icwp. ICWP (EMBL accession number YLR391w, frame +3) codes for 238 amino acids, of which over 40% are serine or threonine, and contains a putative N-glycosylation site and a putative glycosylphosphatidylinositol attachment signal. Both disruption and overexpression of the ORF caused increased sensitivities to calcofluor white and Congo red, while the disruption caused an increased sensitivity to Zymolyase digestion, suggesting for Icwp a structural role in association with glucan.
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The oral fluoropyrimidines have proved to be active in colorectal cancer in Japan and, recently, in the United States and Europe. Continuous oral administration simulates protracted fluorouracil (5-FU) continuous intravenous infusion. The purpose of this trial was to evaluate the tolerability and potential advantages of oral treatment for colorectal cancer in the elderly. The main inclusion criterion was age over 72 years. Patients were treated with UFT (tegafur plus uracil) 400 mg/24 hours (fixed doses) continuously plus folinic acid 45 mg/24 hours until toxicity. If grade 3 or 4 toxicity appeared, treatment was stopped until recovery. From September 1994 to November 1996, 126 patients were included. For the analysis in November 1996, 77 patients were evaluable for response, toxicity, and survival. The patients, including 34 women and 43 men, had a median age of 74 years (range, 72 to 82 years of age). The Karnofsky performance status was 60% to 80% for 41 patients and 90% to 100% for 36 patients. Liver metastasis was present in 48% of the cases, and 42% were locoregional and peritoneal. Toxicity was mild, with only one patient having grade 3 thrombocytopenia, 11 (14%) grade 3 or 4 nausea/vomiting, seven (9%) grade 3 or 4 diarrhea, and one grade 3 mucositis. Four patients (5%) had complete responses and nine (11.6%) partial responses, for an objective response rate of 16.9% (95% confidence interval, 9% to 27%). Twenty-two patients (28.6%) showed no change. The number of patients in whom disease did not progress (ie, patients with complete plus partial responses plus those with stable disease) was 35 (45.4%) (95% confidence interval, 34% to 57%). With a maximum follow-up of 24 months, the median actuarial survival is 14.4 months. The number without disease progression and the median survival in this preliminary analysis suggests that this schedule is a moderately effective, comfortable, treatment with only mild toxicity, that can be recommended for use in the elderly, and it warrants further study.
We investigated the clinical implications of allelic deletions at three common sites of loss of heterozygosity (LOH) in regions 5q21, 11p15.5, and 11p13 in 86 patients with non-small cell lung cancer (NSCLC). We performed a PCR-based microsatellite polymorphism assay for detection of LOH. The microsatellite markers used were D5S82 (proximal to the APC gene), MCC (within the MCC gene), D11S904 (11p13), HRAS (within the H-ras gene), and D11S860 (11p15.5). Of the 68 informative cases at 5q21 loci, LOH was found in 14 cases (20%), whereas LOH frequency in 11p15.5 and 11p13 was 31% (19 of 61 informative cases) and 19% (12 of 63 informative cases), respectively. There was a significant correlation between 5q21 LOH and mediastinal lymph node involvement (P = 0.03). However, no differences were observed in median survival times (26 months in patients with 5q21 LOH versus 37 months in the remainder; P = 0.33) nor in patients with 11p LOH (38 months versus 32 months, respectively; P = 0.72). Cox's proportional hazards model predicted that stage was the only independent poor prognostic marker in the entire cohort of NSCLC patients. Thus, the present study revealed two important abnormalities, LOH at chromosome 5q21 and LOH at chromosome 11p, both implied in NSCLC development.
BACKGROUND: This study investigated the antitumoral activity in colorectal cancer and toxicity of a 5-day continuous infusion of a new cytostatic agent, Mitonafide, that had previously shown to be neurotoxic when administered as a short daily x 5 days infusion. PATIENTS AND METHODS: Seventeen chemotherapy-naive patients with advanced or relapsed colorectal cancer and measurable disease entered the study. All but one received a 120-hour (5-day) continuous infusion of Mitonafide at a starting dose of 200 mg/m2/day every 3 weeks. Toxicity evaluation was performed after each course and response assessment every 2 courses using the standard World Health Organization (WHO) criteria completed by the "Mini-mental state" test for cognitive status examination. RESULTS: Sixteen patients received a total of 41 courses of Mitonafide which resulted to be severely myelotoxic. In total, 13/16 patients had WHO grade 3-4 neutropenia, 7 of them with infection, and the treatment had to be stopped in 3 patients after only 1 course due to excessive toxicity. No central nervous system toxicity was observed. No objective responses were evidenced. CONCLUSIONS: At the dose and schedule of administration used, Mitonafide is not active in colorectal cancer and induces severe myelotoxicity thus not deserving further studies in this indication.
BACKGROUND: Oxaliplatin (L-OHP) is a platinum complex that possesses activity against human and murine cells in vitro and in vivo, including colorectal carcinoma-derived cell lines, and cells that have been selected for resistance to cisplatin. We report two consecutive phase II trials of L-OHP for treatment of patients with advanced colorectal carcinoma. PATIENTS AND METHODS: Fifty-eight patients were entered in study I, and 51 patients in study II. All of the patients had tumor progression when they were treated, prior to their enrollment, with a fluoropyrimidine-containing regimen. In both trials treatment consisted of L-OHP, 130 mg/m2, by i.v. infusion for two hours; the treatment was repeated every 21 days. RESULTS: Response to therapy: Study I: Fifty-five patients were assessed for response. The response rate was 11% (95% CI, 0.03-0.19). Study II: All 51 patients were assessed for response. The response rate was 10% (95% CI, 0.017-0.18). The overall response rate for the 106 evaluated patients was 10% (95% CI, 0.046-0.16). Times to disease progression in responders were 4, 4, 4.5+, 5, 5, 6, 6, 6, 6+, 9, and 13 months. The dose-limiting toxic effect was sensory peripheral neuropathy. The incidence of severe peripheral neuropathy grades was: Study I: grade 3, 23% of patients, and grade 4, 8% of patients. Severe neuropathy had a favorable course in all of the patients who had long-term neurologic follow-up. Diarrhea and myeloid impairment were minor. CONCLUSION: L-OHP produced modest, but definite antitumor activity in patients with advanced colorectal carcinoma who were previously resistant to chemotherapy including fluoropyrimidines. Toxicity is within acceptable limits of tolerance at the dose and schedule of oxaliplatin used in this trial.
Central venous access devices are often essential for the administration of chemotherapy to patients with malignancy, but its use has been associated with a number of complications, mainly thrombosis. The true incidence of upper extremity deep vein thrombosis (DVT) in this setting is difficult to estimate since there are very few studies in which DVT diagnosis was based on objective tests, but its sequelae include septic thrombophlebitis, loss of central venous access and pulmonary embolism. We performed an open, prospective study in which all cancer patients who underwent placement of a long-term Port-a-Cath (Pharmacia Deltec Inc) subclavian venous catheter were randomized to receive or not 2500 IU sc of Fragmin once daily 90 days. Venography was routinely performed 90 days after catheter insertion, or sooner if DVT symptoms had appeared. Our aims were: 1) to investigate the effectiveness of low doses of Fragmin in preventing catheter-related DVT; and 2) to try to confirm if patients with high platelet counts are at a higher risk to develop subclavian DVT, as previously suggested. On the recommendation of the Ethics Committee, patient recruitment was terminated earlier than planned: DVT developed in 1/16 patients (6%) taking Fragmin and 8/13 patients (62%) without prophylaxis (Relative Risk 6.75; 95% CI: 1.05-43.58; p = 0.002, Fisher exact test). No bleeding complications had developed. As for prediction of DVT, there was a tendency towards a higher platelet count in those patients who subsequently developed DVT, but differences failed to reach any statistical significance (286 +/- 145 vs 207 +/- 81 x 10(9)/1; p = 0.067). According to our experience, Fragmin at the dosage used proved to be both effective and safe in these patients.
We have previously demonstrated a strong association between K-ras gene mutations, as determined by PCR followed by allele-specific oligonucleotide hybridization (ASO-h), and survival in non-small cell lung cancer patients. The purpose of this study was to determine the relationship between tumor aggressiveness and specific-type K-ras point mutations in non-small cell lung cancer. We developed procedures to examine the status of the K-ras gene by ASO-h and by single-strand conformation polymorphism assay of DNA obtained from formalin-fixed paraffin-embedded tumors. K-ras point mutations at codons 12 and 61 were assessed in 275 consecutively treated stage I-IV non-small cell lung cancers. Among patients with stage I disease, median survival time was 41.5 months in those whose tumors had no evidence of K-ras mutations and 27 months in those with K-ras 12 mutations; among patients with stage IIIA disease, median survival time was 7 months in those with K-ras codon 12 aspartic and serine mutations and 15 months for those with other K-ras mutations (P = 0.01). In a multivariate analysis, specific-type K-ras codon 12 point mutation remained a strong predictive factor (hazard ratio for death, 2.06; 95% confidence interval, 1.11-3.81; P = 0.02) after adjustment for other evaluated factors, including TNM stage and histology. Thus, we concluded that in patients with non-small cell lung cancer, specific K-ras 12 point mutations detected by DNA amplification and either ASO-h or single-strand conformation polymorphism methods predicted a significantly increased risk of recurrence and death, independently of stage and histology.
BACKGROUND: The primary objective of this study was to compare the single-biochemical modulation of 5-fluorouracil (5-FU) and leucovorin with that of the double-biochemical modulation of methotrexate and leucovorin. Because of the Martin et al. study in which an experimental model showed similar effects of 5-FU at maximum tolerated doses to the modulation with leucovorin at standard doses, a third treatment arm of 5-FU alone was also studied. METHODS: A randomized trial was performed using a 500-mg/m2 intravenous (i.v.) 1-hour infusion of methotrexate, and 12 hours later, a 600-mg/m2 i.v. bolus of 5-FU plus a 200-mg/m2 i.v. 1-hour infusion of leucovorin (MFL) every 2 weeks versus 5-FU plus leucovorin at an equal dose and schedule (FL), versus a 1200-mg/m2 i.v. dose of 5-FU every 2 weeks. Of 186 patients included in the study, 178 were evaluable. RESULTS: In a preliminary analysis with 94 evaluable patients, two significant statistical differences were shown. First, the toxicity rate of the 5-FU--alone (F) treatment arm was higher than that of the other arms (MFL vs. F, P = 0.0002; FL vs. F, P = 0.00001). Second, the median survival was worse in the F treatment arm with a rate of 12.6 months for the MFL and FL arms and 7.5 months for the F arm (P < 0.05). Considering these results, the F treatment arm was discontinued. The final results included 70 evaluable patients for MFL and 74 patients for FL. No difference was found in the distribution of prognostic factors. The response rates were 25.7% for MFL (95% CI, 16-37.5) and 14.8% for FL (95% CI, 7.6-25), (P = 0.1). The median survival was 14.3 months for patients treated with MFL and 12.3 months for those treated with FL. The hematologic toxicity was mild, with no grade 3/4 leukopenia in either treatment arm. The major nonhematologic toxicity in the MFL and FL treatment arms was ocular; nongrade 3/4 diarrhea also was observed. CONCLUSIONS: The results of MFL double-biochemical modulation failed to show a significant statistical difference from that of single-biochemical modulation for this dose and schedule.
The soybean heat-shock gene promoter (Gmhsp 17.5-E) has been used to direct expression of gusA and FLP genes in maize cells. At inducible temperatures, in transient expression assays, gusA gene expression controlled by the heat-shock promoter is about 10-fold higher than the expression directed by the CaMV 35S promoter. The Gmhsp 17.5-E promoter preserves its regulatory functions in heterologous maize cells after random integration into genomic DNA. Heat-shock inducible expression of the FLP gene was investigated by co-transformation of the FLP expression vector (pHsFLP) and a recombination test vector (pUFNeoFmG) into maize protoplasts. Co-transformed protoplasts were incubated at 42 degrees C for 2 h. This treatment induced recombination of 20-25% of the available FRT sites in transient assays. As a result of heat-shock treatment of stably co-transformed maize cells, activation of gusA gene expression and an associated decrease or elimination of NPT-II activity in transgenic maize lines was observed. Molecular evidence was obtained of the expected DNA excision process catalyzed by the FLP protein in maize transgenic cells. Thus, the experiments presented in this paper indicate that the FLP protein can recognize and subsequently recombine the FRT target sites that had integrated into plant genomic DNA, and that regulated expression of the FLP gene is possible in maize cells using the soybean heat-shock promoter.