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Biomedical subjects

D Khayat

Publications and source records attributed to D Khayat.

At least 37 records · Page 2Linked to original sources
PubMed2000

Gemcitabine in combination with doxorubicin in advanced breast cancer: final results of a phase II pharmacokinetic trial.

PURPOSE: Gemcitabine has promising single-agent activity in advanced breast disease. The aim of this phase II study was to determine the efficacy, toxicity, and pharmacokinetic profile of gemcitabine administered with doxorubicin as first-line treatment in patients with metastatic breast cancer. PATIENTS AND METHODS: Of the 42 women with metastatic breast cancer (age 33 to 74 years; mean age, 55 years), 13 were chemotherapy-naive and 29 had received adjuvant chemotherapy. Gemcitabine (800 or 1,000 mg/m(2)) and doxorubicin (25 mg/m(2)) were administered intravenously on days 1, 8, and 15 of each 28-day cycle. Blood samples were drawn on day 8 of cycles 1, 2, and 3 and of subsequent odd cycles for gemcitabine pharmacokinetic determinations and before and after the first dose of cycle 1 or 2 for doxorubicin determinations. RESULTS: There were three complete and 20 partial responses, for an overall response rate of 55% (95% confidence interval [CI], 40% to 70%) and a complete response rate of 7%. The median survival time for all 42 patients was 27 months (95% CI, 13.4 to 30.0 months) and the 1-year survival rate was 80%. Toxicity was mainly hematologic. The disposition of both drugs was unchanged when they were administered on the same day compared with when they were given singly. CONCLUSION: The combination of gemcitabine (800 mg/m(2)) and doxorubicin (25 mg/m(2)) can be safely administered using a weekly schedule. The disposition of both drugs is unchanged when they are administered on the same day. This combination shows promising activity with acceptable toxicity compared with other combination therapies.

Adult↗
PubMed2000

Management of advanced prostate cancer.

Most cases of advanced carcinoma of the prostate are hormonosensitive. The use of combined androgen blockade (CAB) seems to improve survival and quality of life, but only when combined with chemical castration by luteinizing-hormone-releasing hormone analog and without the use of steroidal antiandrogens. After CAB, further hormonal treatments remain efficacious, such as antiandrogen withdrawal followed by estrogens, aromatase inhibitors, and hormone-refractory prostate cancer multiple cytotoxic agents. For painful bone lesions, external beam radiotherapy, biphosphonates, and strontium 89 or samarium 153 provide pain relief. The use of new methods for the evaluation of response and quality of life will allow the rapid identification of effective treatments and permit powered phase III trials.

Androgen Antagonists↗
PubMed1999

[Clinical imaging of osteo-condensed metastases].

INTRODUCTION: Due to the occurrence of osteoblastic metastases in the course of various cancers, particularly in the course of prostate cancer, we are faced with diagnosis and follow-up issues different from those associated with lytic metastasis. We therefore analyzed the respective advantages of imaging techniques. CURRENT KNOWLEDGE AND KEY POINTS: Most of the time, osteoblastic metastases are evidenced by standard radiography. Due to its ability to demonstrate metastases localization, extent and signs, CT scan is not only of value when osteoblastic metastases are suspected but also for patient's follow-up. MRI provides further information in regard to both the lesion content and osteoblastic degree. Though MRI must be performed after all other imaging procedures, it is of value for multiplanar study of the whole spine. FUTURE PROSPECTS AND PROJECTS: Studies focusing on either the lesion content and volume or helical CT are in progress and aim at better monitoring follow-up, while the objective of dynamic MRI studies is to better analyze lesion content.

Biopsy↗
PubMed1999

Is there any relationship between interleukin-6/interleukin-6 receptor modulation and endogenous interleukin-6 release in metastatic malignant melanoma patients treated by biochemotherapy?

During recent years it has become clear that the production of most cytokines could play an important role in malignancies. We previously demonstrated that a high endogenous interleukin-6 (IL-6) level is significantly correlated with a high tumour burden and resistance to biochemotherapy in metastatic malignant melanoma patients. However, little is known about the origin of IL-6 and the pattern of IL-6 receptor (IL-6R) expression. In this report, we studied the expression of IL-6R and intracellular IL-6 using flow cytometry in tumour cells provided by fine-needle aspiration of lymph nodes and palpable metastatic lesions from 14 patients refractory to biochemotherapy and six responder patients. Moreover, we established the relationship between these parameters and the serum IL-6 level. Our results demonstrated that, following treatment, the percentage of HMB45-positive (HMB45+) cells expressing functional IL-6R, intracellular IL-6 or both IL-6R and IL-6 significantly decreased in patients refractory to biochemotherapy. In contrast, in responder patients the percentage of HMB45+ cells expressing IL-6R increased and those expressing IL-6 remained stable. Regarding the serum IL-6 level, an 11-fold increase was observed in the patients refractory to biochemotherapy, but only a 1.8-fold increase in the responder patients. In conclusion, in metastatic malignant melanoma patients with a poor prognosis, the endogenous production of IL-6 is concomitant with a decrease in functional IL-6R and intracellular IL-6 expression, suggesting the involvement of an IL-6/IL-6R complex.

Adult↗
PubMed1998

S9788 modulation of P-glycoprotein- and Multidrug-related protein-mediated multidrug resistance by Servier 9788 in doxorubicin-resistant MCF7 cells.

Inherent or acquired resistance to multiple natural drugs, termed multidrug resistance (MDR), represents a major obstacle to chemotherapy. Expression of P-glycoprotein (P-gp) in MCF7mdr and MCF7R resistant cells was detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. MCF7R, but not the MDR1 gene-transfected MCF7mdr cells, expressed multidrug-related protein (MRP) concomitantly. Efficacy of an MDR modulator, designated as Servier 9788 (S9788), was estimated by doxorubicin (Dox) sensitization, Dox incorporation, and functional rhodamine 123 assay on MCF7 cell lines. Results showed that S9788 modulates the P-gp-associated MDR of MCF7mdr cells as well as the Multidrug-related protein-associated MDR of MCF7R cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1998

Actions of HSVtk and connexin43 gene delivery on gap junctional communication and drug sensitization in hepatocellular carcinoma.

We have previously demonstrated that transfected hepatocellular carcinoma cells (Hepa1-6) with one copy (pAGO) and two copies (pYED) of the HSVtk gene, using liposomes, induced cell death of untransfected cells in the presence of ganciclovir (GCV). This phenomenon is called the 'bystander effect'. To determine whether an elevated level of connexin43 increases the bystander effect, we have cotransfected Hepa1-6 cells with a plasmid containing the HSVtk gene driven by the alpha-fetoprotein promoter (pFTK) or pAGO or pYED and connexin43. The results showed that, after GCV treatment, the percentage of growth inhibition was higher (25-30%) in cells cotransfected with HSVtk and connexin43 than in cells transfected only with HSVtk gene. The IC50 of GCV on cells transfected with pFTK/Connexin43 was 17.85-fold lower than cells transfected with pFTK alone. To improve these results, stable connexin43 transduced Hepa1-6 cells were transfected with pFTK followed by GCV treatment. In this case, the cell growth was markedly inhibited as compared with parental cells. Furthermore, we have studied the correlation between the expression of the HSVtk and the connexin43 proteins. Using flow cytometric analysis, scrape loading/dye transfer and immunoblotting assay we found that the cells transfected separately by pAGO, pYED, pFTK and pLTR-Cx43 showed an increase of connexin43 protein. This study indicates that transfecting Hepa1-6 cells with both connexin43 and HSVtk genes up-regulates connexin43 expression which enhances the bystander effect and subsequently tumor cell death.

Animals↗
PubMed1998

Review article: Overview of medical treatments in unresectable hepatocellular carcinoma--an impossible meta-analysis?

BACKGROUND: Controversies surrounding medical treatment in patients with unresectable hepatocellular carcinoma continue to persist. AIM: To perform a meta-analysis of therapeutic modalities which had been evaluated in two or more randomized trials. METHODS: Fifty-two randomized trials were studied; only 30 were included. This overview identified seven therapeutic modalities which had been evaluated in two or more trials: adriamycin, 5-fluorouracil, interferon, percutaneous ethanol injection, transarterial chemotherapy, the combination of lipiodol with transarterial chemotherapy, and tamoxifen. RESULTS: Comparisons of survival between control groups showed substantial heterogeneity. There was no survival benefit at 1 year with adriamycin (mean difference 4%), 5-fluorouracil (mean difference -3%), percutaneous ethanol injection (mean difference 6%) or transarterial chemotherapy (mean difference -2%). For interferon, the survival benefit was significant with the Der Simonian & Laird method (mean difference 9%, 95% CI = 1-18%, P = 0.04) but not with the Peto et al. method (2.4 mean odds ratio, 95% CI = 0.9-6.8). The meta-analysis of tamoxifen showed a borderline survival benefit (mean difference 25%, 95% CI = 0-49%, P = 0.05). However, in sensitivity analyses, the survival benefit of tamoxifen was no longer significant. CONCLUSIONS: No treatment has clearly proven efficacy in survival. 5-Fluorouracil, adriamycin and transarterial chemotherapy were not associated with survival benefit at 1 year. The number of randomized controlled trials was insufficient to enable a conclusion to be reached for interferon and percutaneous ethanol injection. Controversy persists concerning tamoxifen efficacy. Interferon and tamoxifen require new randomized controlled trials on a larger population of patients.

Administration, Cutaneous↗
PubMed1998

Results of interleukin-2-based treatment in advanced melanoma: a case record-based analysis of 631 patients.

PURPOSE: In patients with stage IV melanoma, durable responses have been reported with treatment regimens that involve high-dose interleukin-2 (IL-2). We analyze long-term results of 631 melanoma patients from 12 institutions who had received IL-2 alone, in combination with interferon alfa 2a or 2b (IFNalpha), or with cytotoxic drugs. METHODS: Case records that contained pretreatment parameters, response data, and updated survival information were collected. After univariate analysis, the multivariate evaluation of the impact of pretreatment parameters on response and survival was performed by logistic regression and Cox's regression, respectively. RESULTS: Patients were divided into four groups according to treatment: IL-2 alone (n=117), IL-2 and chemotherapy (n=49), IL-2 and IFNalpha (n=153), and IL-2, chemotherapy, and IFNalpha (n=312). The median survival of all patients was 10.5 months and the 2- and 5-year survival rates were 19.9% and 10.4%, respectively. Independent prognostic factors for response and survival were entirely different, treatment group being the only significant factor for response, and serum lactate dehydrogenase (LDH), metastatic site, and performance predicting survival. The addition of IFNalpha to IL-2 was associated with prolonged survival, but the effect of additional chemotherapy was less obvious. CONCLUSION: Serum LDH, metastatic site, and performance status are useful stratification factors for randomized trials in metastatic melanoma. The improved long-term survival rates observed in melanoma patients treated with IL-2/IFNalpha-containing regimens are notable in contrast to the reported 5-year survival rates of 2% to 6% achieved with chemotherapy, but because selection bias cannot be ruled out, the impact of IL-2, as well as all other components of the treatment regimens, on survival needs to be confirmed in prospective randomized trials.

Adult↗
PubMed1998

Ifosfamide and gemcitabine: a phase II trial in advanced inoperable non-small cell lung cancer.

The novel nucleoside agent gemcitabine has demonstrated antitumor activity against a variety of solid tumors and is associated with low toxicity. A phase I trial in Germany of gemcitabine combined with the alkylating agent ifosfamide has shown encouraging activity against non-small cell lung cancer. The efficacy and toxicity of this combination was further evaluated in a phase II trial involving chemotherapy-naive patients with non-small cell lung cancer (mostly stage IV disease). Gemcitabine was administered at a dose of 1,000 mg/m2 on days 1, 8, and 15, followed by a 1-week rest, while ifosfamide was given at a dose of 1,500 mg/m2 on days 8 through 12. Fifty-five patients were treated, 49 of whom are evaluable for response. Six patients were not evaluable because they had not received sufficient therapy (less than one complete cycle) because of early disease progression or early death. Twelve patients responded, for an overall objective response rate of 24.5%. The median survival time was 8.9 months, and the 1-year survival rate was 30.9%. Grades 3 and 4 neutropenia occurred in 30.2% and 24.5% of patients, respectively, but the incidence of infection was low. These results indicate that the combination of gemcitabine and ifosfamide is active against non-small cell lung cancer and has a mild toxicity profile, and suggest that further evaluation of this combination is warranted.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1998

European experience with irinotecan plus fluorouracil/folinic acid or mitomycin.

Tremendous progress has been made in the medical treatment of advanced colorectal cancer during the past 2 to 3 years, due to the availability of several new drugs. Of these new agents, irinotecan (CPT-11 [Camptosar]) seems to be one of the most active against advanced colorectal cancer. It is, therefore, a good candidate for combination with the more classic cytotoxic agents for this disease. This article summarizes several European phase I and II studies in which irinotecan has been combined with (1) fluorouracil (5-FU) alone, given as a repeated bolus injection or a protracted infusion; (2) 5-FU modulated by folinic acid (leucovorin) according to different schedules; or (3) mitomycin (Mutamycin). All of these studies have demonstrated clinical responses in patients with advanced colorectal carcinoma, including complete responses. The toxicity profiles of the various combinations seem to be acceptable; neutropenia and delayed diarrhea are the most frequent side effects. Large phase III studies are still warranted to demonstrate the benefit of these irinotecan-based regimens.

Antidotes↗
PubMed1998

[The role of new drugs in the treatment of locally advanced urothelial tumors of the bladder].

Although the optimal management of muscle-invasive bladder cancer remains a continued subset of controversy, results achieved with either radical cystectomy, or radiation therapy or combinations of the two lead to cure rates of only 50% with up to 50% of patients who will develop metastases, usually within two years. For the past ten years, chemotherapy of advanced urothelial tumors has focused on cisplatin-based combinations such as methotrexate-vinblastine-adriamycin-cisplatin (M-VAC), cisplatin-methotrexate-vinblastine (CMV) or cisplatin-adriamycin-cyclophosphamide (CISCA). Such regimens have provided interesting results with responses rate up to 70% and some long term survival (in 10 to 20% of patients), but this has focused achieved with moderate to severe toxicity. Thus, if the chemosensitivity of advanced urothelial tumors is obvious, it is clear that a therapeutic plateau has been reached and only the search for new active agents can provide any hope to improve the results of these established regimens. Recently some single agents under investigation including taxanes (paclitaxel and docétaxel) and gemcitabine have been identified and have entered clinical development. Preliminary data of several phase II studies are now available and they appear promising, providing the basis of new combinations regimens that will attempt to improve results that have been achieved with standard regimens during the past decade. The activity of these new single agents and new combination are reviewed.

Antineoplastic Agents↗
PubMed1998

Hypertextual navigation operationalizing generic clinical practice guidelines for patient-specific therapeutic decisions.

Despite the proliferation of implemented clinical practice guidelines, there is still little evidence of physicians compliance to formal standards. The ONCODOC project proposes a framework for elaborating generic decision support guidelines in a document-based paradigm with a knowledge-based approach. It has been first applied to assist clinicians in the treatment of breast cancer patients. Therapeutic expertise has been encoded as a decision tree. The decision process is driven by the clinician who interactively browses a hypertext version of the decision tree. During the navigation, he incrementally assigns values to decision parameters on the basis of his free interpretation of his patient's condition and thus builds a clinical context leading to patient-specific therapeutic recommendations. These guidelines are distributed on a hospital intranet and are evaluated at the point of care in an oncology department.

Breast Neoplasms↗
PubMed1998

[Irinotecan in combination for colon cancer].

As a single agent, irinotecan has demonstrated efficacy in metastatic 5FU resistant colorectal metastatic cancer. Chemotherapy with fluorouracil (5FU) plus leucovorin remains a standard in the treatment of patients with metastatic colorectal cancer. It seemed logical to test the combination of this reference treatment and the new agent. The first trials gave rather disappointing results, suggesting an inhibition of the metabolism of irinotecan into SN38 when 5FU was present in the circulation. More recent studies have given totally different results with a very good tolerance and strong efficacy of the combination of weekly folinic acid + 5FU and irinotecan or LV5FU2 (the so-called de Gramont regimen) and irinotecan. The results were so good that these new schedules are currently developed as first line regimen. Another way to combine 5FU, folinic acid and irinotecan is to alternate a cycle of 5FU, folinic acid and a cycle of irinotecan. Such an alternated schedule has given encouraging results with an objective response rate greater than 30% and a long median survival time (more than 16 months). It is also very easy to combine irinotecan with other drug which have demonstrated activity in the treatment of colorectal cancer. The combinations of irinotecan and mitomycin C or oxaliplatin have given very good results with high objective response rates and good tolerance. Irinotecan plays now an important part in the treatment of metastatic colorectal cancer. This part becomes larger due to the results of the combination trials already presented which have shown strong efficacy and good tolerance.

Adenocarcinoma↗
PubMed1997

A flow cytometric method for the rapid detection of beta-galactosidase transfected cells: an in vitro and in vivo study.

A flow cytometric method has been developed for the rapid analysis of lacZ transduced cells. The method described is based on an indirect immunofluorescence staining procedure using a monoclonal antibody which binds specifically to beta-galactosidase from E. coli and to beta-galactosidase fusion proteins. This technique was used for the quantification in vitro as well as in vivo of beta-galactosidase expression in B16 melanoma cells. The described method is appropriate for a variety of cell types (species, lineage), is simple, quantitative, reliable, rapid and applicable to all constructs containing the lacZ selectable markers. It should prove to be very helpful (1) for the quantification of cells expressing the lacZ reporter gene and (2) for studying gene regulation, including transfection modality, promoter efficacy, enhancer activity, and other regulatory factors.

Bacterial Proteins↗