Search PubMed⌕ Search

Biomedical subjects

D Khayat

Publications and source records attributed to D Khayat.

At least 73 records · Page 4Linked to original sources
PubMed1996

CPT-11 (irinotecan) and 5-fluorouracil: a promising combination for therapy of colorectal cancer.

CPT-11 (Campto, irinotecan) is a new topoisomerase I inhibitor and one of very few new cytotoxic agents to demonstrate clinical activity in colorectal cancer since the introduction of 5-fluorouracil (5-FU) into clinical practice almost 40 years ago. Because of the unique mechanism of action of CPT-11, its proven activity in colorectal cancer, and its lack of cross-resistance with 5-FU, the combination of CPT-11 with 5-FU is a logical approach to attempt to improve on the results obtained with CPT-11 or 5-FU-based treatments alone. Various administration schedules of CPT-11/5-FU combinations have been investigated in phase I studies in Japan, the U.S. and Europe. Preliminary results indicate that concurrent administration of substantial doses of CPT-11, 5-FU and folinic acid is feasible in terms of safety. Preliminary analysis of controlled pharmacokinetic data suggests that 5-FU has no substantial effect on the metabolism of CPT-11 to its active metabolite SN-38. Major objective responses and other indicators of clinical activity have been observed with the combination in both chemotherapy-naive and pretreated patients with colorectal cancer. Studies are ongoing to define fully optimum dosage schedules of CPT-11/5-FU combinations, and some of these schedules will soon enter phase II and III clinical trials. It is hoped that such a combination will prove to be an important advance in the treatment of colorectal cancer.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

Peripheral blood progenitor cell transplantation: where do we stand? Chairman's Summary of the European School of Oncology Task Force meeting Peripheral Blood progenitor cell's held September 29-30, 1995.

Whether or not peripheral stem cells have an unlimited capacity for self renewal is debated. However, everyday haematopoietic requirements are met by progenitors; and it seems that few "real' stem cells are needed. Although we may not yet have identified these "true' stem cells, for practical purposes the long term culture-initiating cells (LTC-ICs) are a close approximation. To date, experience in peripheral blood progenitor cell (PBPC) transplantation is largely confined to non-ablative regimens. It is therefore difficult to determine the number of PBPCs needed to effect long-term reconstitution. The number of tumour cells present among mobilised PBPCs can be reduced using the CD34 affinity column and by positive purging methods. The ex vivo expansion of CD34 cells also has the effect of diluting tumour cell concentration. In clinical use, PBPC transplantation has a proven role in support of high dose chemotherapy in certain haematological and oncological malignancies but the concept of dose intensification is not universally accepted. With the exception of leukaemia, lymphoma, myeloma or relapsed testicular cancer and possibly some subgroups of breast cancer; high dose chemotherapy does not demonstrate a survival benefit. For patients with CML, autografting with Ph- cells appears to become a useful alternative to allogeneic BMT. Allogeneic PBPC transplantation may have potential, though work is preliminary. Cord blood transplantation between matched siblings is viable, but it is not yet clear whether this source will increase the donor pool for adults needing allogeneic transplantation. For gene therapy using haematopoietic cells to be effective, a greatly increased rate of transduction will be needed. Meeting in Paris in September 1995, a European School of Oncology Task Force considered a number of important questions relating to peripheral blood progenitor cell (PBPC) physiology and transplantation. This review is a brief account of their conclusions.

Antineoplastic Agents↗
PubMed1996

Novel enzyme-linked immunosorbent assays for the detection of anti-Fc gamma receptor autoantibodies.

There is a substantial interest in the role of antineutrophil antibodies since Fc gamma receptors (Fc gamma Rs) have been identified as the target for the majority of such autoantibodies. Antineutrophil antibodies have long been detected by an indirect immunofluorescence technique. Following optimization of the flow cytometric method of detection, we developed three enzyme-linked immunosorbent assays (ELISAs), each specific for autoantibodies against one of the three classes of human Fc gamma R. Fc gamma RI and Fc gamma RII were purified from cultured cells, and Fc gamma RIII was produced as a recombinant molecule. These were then used as capture agents in the respective ELISAs. When applied in parallel to a sizeable group of patients with primary Sjögren's syndrome, both methods established that anti-Fc gamma R autoantibodies were heterogeneous. This finding indicates that different populations of partly cross-reactive antibodies are detectable by these two methods.

Autoantibodies↗
PubMed1996

Cisplatin-fluorouracil exclusive chemotherapy for T1-T3N0 glottic squamous cell carcinoma complete clinical responders: five-year results.

PURPOSE: To evaluate cisplatin-fluorouracil exclusive chemotherapy (EC) for T1-T3N0 glottic squamous cell carcinoma complete clinical responders (CCR) after cisplatin-fluorouracil induction chemotherapy (IC). PATIENTS AND METHODS: A retrospective analysis was performed of 58 patients with T1-T3N0 glottic squamous cell carcinoma CCR after IC consecutively managed at our department between 1985 and 1992. Twenty-one CCR were managed with EC. Thirty-seven CCR were managed with IC and a conventional laryngeal-preservation modality. Analyses of survival, local control, nodal recurrence, distant metastasis, and metachronous second primary tumor were performed using the Kaplan-Meier actuarial life-table method. In CCR managed with EC, the independent factors of age, tumor classification, exact tumor location, true vocal cord motion, arytenoid cartilage motion, total dosage of drugs delivered, and number of courses received were tested for potential correlation with survival, local recurrence, nodal recurence, and distant metastasis. RESULTS: The 5-year survival, local control, nodal recurrence, distant metastasis, and metachronous second primary tumor rates in CCR managed with EC were 95.2%, 70.7%, 0%, 0%, and 14.3%, respectively. The 5-year rates of survival, local control, nodal recurrence, distant metastasis, and metachronous second primary tumor in CCR managed with IC and a conventional laryngeal-preservation modality were 86.1%, 97%, 2.7%, 6%, and 14.5%, respectively. Local recurrence was statistically more likely in CCR managed with EC (P = .002). Local recurrence in CCR managed with EC was always salvaged with partial laryngectomy or radiation therapy, which resulted in an overall 100% local control and laryngeal-preservation rate within this group. In CCR managed with EC, none of the variables analyzed was statistically related to survival, local recurrence, nodal recurrence, or distant metastasis. CONCLUSION: The present retrospective studies demonstrated that within T1-T3N0 glottic squamous cell carcinoma CCR, there is clearly a significant subset of patients with chemocurable tumors who achieved both perfect preservation of structure-supporting voice and long-term survival after EC. Careful monthly follow-up evaluation allowed for timely successful salvage of local recurrence after EC without the need for total laryngectomy. Such management did not appear to increase the risk for subsequent nodal failure, subsequent distant metastasis, or reduced survival.

Adult↗
PubMed1996

Gene transfer in hepatocarcinoma cell lines: in vitro optimization of a virus-free system.

Many approaches exist for hepatic gene delivery, including viral vectors and non-viral vectors. In this study, we tested a panel of liposomes to transfer pAGO, a plasmid containing one copy of herpes simplex virus (HSVtk) gene, and pYED11, a plasmid containing two copies of the HSVtk gene, into a murine hepatocarcinoma cell line (Hepa 1-6) and a human hepatocarcinoma cell line (Hep-G2). The efficiency of gene delivery and expression was characterized by beta-galactosidase staining, flow cytometric analysis and quantitative lacZ activity. Different combinations of liposomes and DNA and the ratio of the concentration of liposome to DNA were tested. The efficient transfer was shown with DOTAP followed by transfectam and lipofectamine. Under these conditions, we tested the cytotoxicity of ganciclovir (GCV) exposure on Hepa 1-6 and Hep-G2 transfected separately with liposome-pAGO and liposome-pYED11 complexes. This study demonstrates the in vitro efficacy of each liposome tested to transduce the HSVtk gene into hepatocarcinoma cell lines. The transfer of two copies of the HSVtk gene rendered cells 1.5 times more sensitive to GCV than cells transduced by pAGO as compared to controls. This was achieved most efficiently by the DOTAP-pYED11 complex. Thus, pYED11 may be considered as an alternative to pAGO as a gene transfer vector.

Animals↗
PubMed1996

In vitro sensitization of the B16 murine melanoma cells to ganciclovir by different RNA and plasmid DNA constructions encoding HSVtk.

The antiviral drug ganciclovir (GCV) is toxic for mammalian cells transfected with the herpes simplex virus thymidine kinase (HSVtk) gene. To improve the results obtained by our group previously on nonviral transfection of tumor cells, we have examined here in vitro virus-free transfection of murine B16 melanoma cells via lipofectamine-nucleic acid complexes carrying either HSVtk gene transcripts or plasmid DNAs containing single and double copies of the HSVtk gene. The HSVtk gene transcripts as well as plasmids containing the HSVtk gene(s) rendered cells sensitive to GCV treatment. Tumor sensitivity to GCV conferred by the HSVtk gene transcripts was of the same level as the sensitivity conferred by plasmid DNAs containing a single copy of the HSVtk gene. However, when the plasmids containing double copies of the HSVtk gene were used, sensitivity to low GCV concentrations increased dramatically. One could appreciate this finding as an essential advantage of the plasmids containing double copies of the HSVtk gene since it allows use of the GCV concentration range which is common in clinical applications.

Animals↗
PubMed1996

[Endometrial cancer: progress in the evaluation of locoregional extension by imaging techniques].

In the evaluation of loco regional extension, MRI and ultrasound provide highly valuable information, with respect to the invasion of deep myometrium, which determines prognosis, being highly similar for the two techniques. This gives ultrasound techniques a role of primary intention for reasons of public health economics. MRI, however, improves the work-up of other types of loco regional extension, and CT scan remains an indispensable tool for evaluating overall lymph node involvement and visceral extension.

Endometrial Neoplasms↗
PubMed1996

Phase I/II study of paclitaxel, cisplatin, and cyclophosphamide in advanced ovarian carcinoma: preliminary results.

In this phase I/II study, we assessed the impact of paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) in the treatment of advanced ovarian carcinoma combined with the standard regimen cisplatin/cyclophosphamide given as follows: paclitaxel 175 mg/m2 (over 3 hours perfusion with standard premedication), cisplatin 80 mg/m2 (6 to 12 hours after paclitaxel), and cyclophosphamide 400 mg/m2. From February 1994 to January 1996, 27 patients (median age, 55 years; age range, 35 to 74 years) were entered into the study. Eight patients had distant metastases and 19 had early locoregional disease (stage III, 18 patients; stage IC, one patient). Twenty-two patients had undergone prior surgery (simple biopsy, six patients; optimally debulked, nine patients; suboptimally debulked, seven patients). Twenty-one patients had received no prior chemotherapy and six were previously treated with at least one platinum-based regimen. A maximum of six courses of paclitaxel/cisplatin/cyclophosphamide were given every 21 days. Twenty-three patients were evaluable for toxicity: neutropenia (World Health Organization grade 3/4), 91% of patients; thrombopenia (World Health Organization grade 3/4), 13% of patients; two episodes of neutropenia with fever; and neurotoxicity grade 3, 17% of patients. Alopecia grade 3 was reported in all patients. No hypersensitivity reactions and no cardiac toxicity was observed. Among 17 patients evaluable for response (patients with stage IV disease or stage III suboptimally debulked), 12 (70%) clinical complete responses (CRs) and three (18%) partial responses were observed. Among the 12 patients with CRs, 10 underwent second-look laparotomy and seven of them (70%) achieved a pathologic CR. In the group of 11 chemotherapy-naive patients evaluable for response, eight (72%) achieved a CR and three (28%) achieved a partial response. This combination seems to be safe, with very acceptable toxicity, and also seems to be highly active in the treatment of patients with advanced ovarian carcinoma.

Adult↗
PubMed1996

A double-blind, randomised comparison of the anti-emetic efficacy of two intravenous doses of dolasetron mesilate and granisetron in patients receiving high dose cisplatin chemotherapy.

This multicentre, double-blind, double-dummy, randomised trial was designed to compare the efficacy and safety of single intravenous doses of dolasetron mesilate and granisetron in the prevention of acute emesis and nausea due to high-dose (> or = 80 mg/m2) cisplatin. Single intravenous doses of 1.8 or 2.4 mg/kg of dolasetron mesilate or 3 mg of granisetron hydrochloride were administered in a volume of 50 ml over a 5-min period, beginning 30 min prior to cisplatin (> or = 80 mg/m2) administration. The number and timing of emetic episodes, time to administration of escape anti-emetic medication, severity of nausea by visual analogue scale (VAS), and safety were monitored for 24 h after the start of cisplatin-containing chemotherapy. Investigators' evaluations of overall efficacy and patients' satisfaction with therapy were recorded at the end of the 24-h study period. Of the 474 patients evaluable for efficacy, complete responses were achieved by 54, 47 and 48% of patients given dolasetron mesilate 1.8 mg/kg, dolasetron mesilate 2.4 mg/kg and granisetron, respectively. Statistically, treatment groups had comparable complete and complete plus major responses, times to first emesis, and use of escape medication; patient maximum nausea severity and treatment satisfaction ratings; and physician nausea severity and overall efficacy assessments. For the majority of efficacy endpoints, 1.8 mg/kg dolasetron mesilate produced numerically superior responses compared with the 2.4 mg/kg dose. Gender and prior chemotherapy were significant predictors of complete response; males and chemotherapy-naive patients had higher responses. The overall incidences of adverse events were comparable among the treatment groups; headache and diarrhoea were most common. In conclusion, 1.8 and 2.4 mg/kg of dolasetron mesilate and granisetron (3 mg) were equally effective in preventing nausea and vomiting induced by highly emetogenic cisplatin-containing chemotherapy. In addition, because no additional benefit was observed with 2.4 mg/kg of dolasetron mesilate and numerically greater responses were observed with the 1.8 mg/kg dose, the lower dose of 1.8 mg/kg is optimal for further clinical development.

Adult↗
PubMed1996

Virus-free transfer of the herpes simplex virus thymidine kinase gene followed by ganciclovir treatment induces tumor cell death.

We report virus-free transfer of a "suicide" gene into tumoral cells. The system can be used in vitro or in vivo to induce tumor cell death. A plasmid carrying the herpes simplex virus thymidine kinase (HSV-TK) gene with its 5'- and 3'-flanking regions was used both alone and in liposomes to transduce B16 cells. In vitro, a 5-day treatment with ganciclovir after transfection with the HSV-TK gene in liposomes induced a significant lysis of B16 melanoma cells as assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test. The efficacy of transfection was determined using liposomes harboring the beta-galactosidase reporter gene and was around 10%. Thus, the cytotoxicity observed resulted presumably from a large bystander effect. In vivo, direct transfer of the TK DNA into established B16 melanoma tumors in C57B6 mice followed by i.p. ganciclovir treatment induced a 50% reduction of tumor weight after 8 days and an increased necrosis. Despite the use of the nonspecific strong TK promoter, no necrosis was detected in normal tissues surrounding the tumor or elsewhere. Thus, this system of tumor transfection, which does not involve any viral vector, is safe and straightforward and seems to be suitable for testing in clinical trials.

Animals↗
PubMed1996

Endogenous interleukin 6 levels in patients with metastatic malignant melanoma: correlation with tumor burden.

The involvement of interleukin (IL-) 6 in malignant disease has been investigated in a variety of different malignancies. To evaluate whether serum IL-6 is a useful disease marker in metastatic malignant melanoma (MMM), we studied the time course of endogenous IL-6 secretion in 41 patients treated with cisplatinum, IL-2, and IFN-alpha. Furthermore, the relationship of endogenous IL-6 concentrations to the tumor burden and/or the clinical response was also evaluated. The baseline serum IL-6 levels were significantly higher in patients with MMM than in the control group (P = 0.002). When tumor burden was taken into consideration, we found that IL-6 levels were higher in patients with high tumor burden than in patients with low tumor burden. During treatment in the whole patient population, a higher serum IL-6 level was observed in nonresponding as compared to responding patients at days 7 (P = 0.0005), 21 (P = 0.002), and 35 (P = 0.009). The follow-up of serum IL-6 in patients with MMM according to the tumor burden and clinical response demonstrated that: (a) IL-6 levels were significantly higher at days 7 and 21 in patients with high tumor burden as compared to those with low tumor burden; and (b) IL-6 levels remain significantly higher in nonresponding patients as compared to responding patients regardless of the tumor burden. From these results, we can conclude that endogenous IL-6 may play a role in the failure of IL-2 therapy in such patients, since the very early IL-6 increase is correlated with the tumor mass and nonresponse to biochemotherapy. Therefore, it seems that the early detection of endogenous IL-6 may represent valuable information for monitoring the response to biochemotherapy in patients with MMM.

Adult↗
PubMed1995

Anti-Fc gamma receptor III autoantibody is associated with soluble receptor in rheumatoid arthritis serum and synovial fluid.

We sought to detect anti-Fc gamma receptor (Fc gamma R) autoantibodies and soluble Fc gamma R in the serum and synovial fluid (SF) from patients with rheumatoid arthritis (RA) and to correlate these serological abnormalities to the polymorphonuclear cell (PMN) activation state. Paired samples of blood and SF were obtained from 33 RA patients as well as blood from 25 normal adults from SF from 20 non-RA patients. Anti-Fc gamma R autoantibodies were assessed by an enzyme-linked immunosorbent assay (ELISA) using recombinant human Fc gamma R as the substrate. Soluble Fc gamma RIII was determined by an ELISA based on the combination of two monoclonal antibodies (MAb). The mean fluorescence intensity (MFI) of complement receptor 1 (CD35) and 3 (CD11b) and Fc gamma RIII (CD16) was evaluated by flow cytometry on the membrane of PMN. IgM anti-Fc gamma RIII activity was present in seven RA sera and five SF, and IgG in eight RA sera and six SF. The average concentration of soluble Fc gamma RIII was 1.80 +/- 3.50 micrograms/ml in RA patients and 0.33 +/- 0.06 micrograms/ml in normal adults (P < 0.05). This was elevated in the SF of 15 RA, while normal in that of all the non-RA patients. There was an inverse correlation between the CD16 MFI on the PMN and the serum/SF soluble Fc gamma RIII level, whereas the density of CD35 and CD11b was markedly augmented. Anti-Fc gamma RIII activity exists in RA patients, associated with soluble Fc gamma RIII. PMN activation could be due to these autoantibodies and thereby obviate the clearance of immune complexes.

Adult↗
PubMed1995

Granulocyte growth factors: achieving a consensus.

A consensus meeting held under the auspices of the European School of Oncology concluded that the use of granulocyte growth factors is definitely indicated, or acceptable given existing evidence, in the following circumstances: to alleviate congenital neutropenia; in the mobilisation of peripheral blood progenitor cells for autotransfusion; to encourage engraftment following bone marrow transplantation and in cases of failed engraftment; to support continuation of ganciclovir anti-CMV therapy in certain patients with AIDS, where the switch to foscarnet is contraindicated or where toxicity to foscarnet develops. It was also agreed that there is an overwhelming need for carefully controlled clinical trials in a wide range of indications in which growth factor use may improve outcome. In the majority of tumours, the possible benefit of dose optimisation and intensification, and therefore the role of growth factors in support of such measures has still to be defined. Extramedullary toxicities may in these instances become dose limiting.

AIDS-Related Opportunistic Infections↗
PubMed1995

[Breast cancer: role of MRI in follow-up of cases treated].

Conventional imaging (CI) for breast cancer includes mammography and ultrasound. Its limited efficiency is especially manifest for breast cancer follow-up after breast-conserving therapy (i.e. exclusive radiation therapy) and after breast implant. Lack of evidence for definitive diagnosis increases the number of invasive explorations. To improve the specificity of the diagnosis between recurrence or fibrosis, we describe the interest of new imaging (NI) techniques: post-contrast MRI, and MR angiography (MRA), realized in 1 exam. Between October 1993 and December 1994, 82 patients were eligible for these investigations. All patients had an history of conservative breast cancer treatment of breast implant following mastectomy. In all cases CI was not contributive for a precise diagnosis; therefore a biopsy was performed and confirmed the diagnosis of breast cancer. NI was done before biopsy and compared results are following. 19 more patients were evaluated for primary chemotherapeutic response, including a total of 101 patients. Regarding the follow-up of prosthesis and conservative treatment, the correlation with histological control was obtained in 95% with four false diagnoses due to confusion between retroprosthesis relapse and inflammation. Historadiologic correlation were close to 90% for the evaluation of primary chemotherapeutic response. Studies are ongoing to confirm those preliminary findings. Though expansive, these techniques might be cost-effective if they result in a substantial decrease of unnecessary surgical invasive procedures.

Adult↗