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Biomedical subjects

J Guilhot

Publications and source records attributed to J Guilhot.

At least 19 recordsLinked to original sources

The status of CDKN2A alpha (p16INK4A) and beta (p14ARF) transcripts in thyroid tumour progression.

CDKN2A locus on chromosome 9p21 encodes two tumour suppressor proteins pl6INK4A, which is a regulator of the retinoblastoma (RB) protein, and p14ARF, which is involved in the ARF-Mdm2-p53 pathway. The aim of this study was to determine if CDKN2A gene products are implicated in differentiated thyroid carcinogenesis and progression. We used real-time quantitative RT-PCR and immunohistochemistry to assess both transcripts and proteins levels in 60 tumours specimens. Overexpression of p14ARF and pl6INK4A was observed in follicular adenomas, follicular carcinomas and papillary carcinomas, while downregulation was found in oncocytic adenomas compared to nontumoral paired thyroid tissues. These deregulations were statistically significant for pl6INK4a (P=0.006) in follicular adenomas and close to statistical significance for p14ARF in follicular adenomas (P=0.06) and in papillary carcinomas (P=0.05). In all histological types, except papillary carcinomas, we observed a statistically significant relationship between p14ARF and E2F1 (r=0.64 to 1, P<0.05). Our data are consistent with involvement of CDKN2A transcript upregulation in thyroid follicular tumorigenesis as an early event. However, these deregulations do not appear to be correlated to the clinical outcome and they could not be used as potential prognostic markers.

Adenocarcinoma, Follicular↗

Prognostic value of increase in transcript levels of Tp73 DeltaEx2-3 isoforms in low-grade glioma patients.

Glial tumours are a devastating, poorly understood condition carrying a gloomy prognosis for which clinicians sorely lack reliable predictive parameters facilitating a sound treatment strategy. Tp73, a p53 family member, expresses two main classes of isoforms--transactivatory activity (TA)p73 and DeltaTAp73--exhibiting tumour suppressor gene and oncogene properties, respectively. The authors examined their expression status in high- and low-grade adult gliomas. Isoform-specific real-time reverse transcription-polymerase chain reaction was used for the analysis of Tp73 isoform transcript expression in a series of 51 adult patients harbouring glial tumours, in order to compare tumour grades with each other, and with non-tumoural samples obtained from epileptic patients as well. Our data demonstrate increase of TAp73 and DeltaTAp73 transcript levels at onset and early stage of the disease. We also show that DeltaEx2-3 isoform expression in low-grade tumours anticipates clinical and imaging progression to higher grades, and correlates to the patients' survival. Expression levels of P1 promoter generated Tp73 isoforms--and particularly DeltaEx2-3--indeed allow for prediction of the clinical progression of low-grade gliomas in adults. Our data are the first such molecular biology report regarding low-grade tumours and as such should be of help for sound decision-making.

Adult↗

Imatinib mesylate is effective in children with chronic myelogenous leukemia in late chronic and advanced phase and in relapse after stem cell transplantation.

A multicentric phase 2 study was conducted to determine the efficiency and the tolerance of imatinib mesylate in children with chronic myelogenous leukemia (CML) in advanced phase of the disease, in relapse after stem cell transplantation, or in case of failure to an interferon alpha-based regimen. In all, 30 children from eight European countries were enrolled. In 18 children assessable for hematologic response, imatinib mesylate induced complete hematologic response in eight (80%) of the 10 patients included in chronic phase and in six (75%) of eight enrolled in advanced phase of the disease with acceptable toxicity. In 27 patients assessable for cytogenetic response, imatinib mesylate induced disappearance of Philadelphia chromosome-positive bone marrow cells in 12 (60%) of 20 children included in chronic phase and in two (29%) of seven included in advanced phase. A reduction of the bcr-abl/abl ratio to less than 10(-4) was achieved in 11 (50%) of the children included in chronic phase. Estimated 12-month overall survival rate was 95% (95% CI, 87-100%) for the patients included in chronic phase and 75% (95%CI, 45-100%) for those enrolled in advanced phase. Imatinib mesylate is well tolerated and molecular remission can be achieved in children with CML.

Adolescent↗

Expression of TAp73 and DeltaNp73 isoform transcripts in thyroid tumours.

AIM: This study was aimed to determine p73 status in thyroid tumours. METHODS: Differential expression of the TAp73, DeltaTAp73 transcripts was measured in a panel of 60 thyroid malignancies by quantitative RT-PCR. RESULTS: By comparison to normal thyroid tissue surrounding the tumours, we observed significant downregulation of TP73 transcripts in adenomas and in differentiated carcinomas. Correlations were found in normal tissue specimens between the expression of TAp73 and DeltaNp73 transcripts and that of p53, p14ARF p16INK4a, but these correlations were lost in carcinomas (PTC or FTC). CONCLUSIONS: We have found significant variations of TAp73, DeltaNp73, p53, p14ARF p16INK4a, expressions and correlations between the expressions of those different genes in thyroid cancer.

Adenocarcinoma, Follicular↗

Topoisomerase II alpha and telomerase expression in papillary thyroid carcinomas.

BACKGROUND: Altered topoisomerase II alpha (Topo II alpha) expression and telomerase activity (TA) reflect tumour cell growth and malignant transformation. METHODS: We examined TA by using a TRAP assay and expression of Topo II alpha by immunohistochemical analysis in a series of 27 cases of papillary thyroid carcinoma (PTC). RESULTS: Topo II alpha labelling index (LI) ranged from 0.1 to 4.2% and was significantly associated with patient age (r=-0.42, p=0.003), with higher levels of Topo II alpha in patients under 40 years. There was no relationship between Topo II alpha LI, AGES score or other clinical outcome. TA was detected in 14 PTC, with relative levels ranging from 1.2 to 102 units. A significant positive correlation between the multiplicity of tumoral foci and the TA levels (p<10(-2)) was noted. CONCLUSION: We concluded that Topo II alpha cannot be used as a marker of tumour aggressiveness. Furthermore, enhanced Topo II alpha expression in PTCs from patients less than 40 years old suggests that this age group might benefit from Topo II inhibitor chemotherapy.

Adult↗

Correlation of clinical features and methylation status of MGMT gene promoter in glioblastomas.

In an effort to extend the potential relationship between the methylation status of MGMT promoter and response to CENU therapy, we examined the methylation status of MGMT promoter in 44 patients with glioblastomas. Tumor specimens were obtained during surgery before adjuvant treatment, frozen and stored at -80 degrees C until for DNA extraction process. DNA methylation patterns in the CpG island of the MGMT gene were determined in every tumor by methylation specific PCR (MSP). These results were then related to overall survival and response to alkylating agents using statistical analysis. Methylation of the MGMT promoter was detected in 68% of tumors, and 96.7% of methylated tumors exhibited also an unmethylated status. There was no relationship between the methylation status of the MGMT promoter and overall survival and response to alkylating agents. Our observations do not lead us to consider promoter methylation of MGMT gene as a prognostic factor of responsiveness to alkylating agents in glioblastomas.

Aged↗

The prevalence and cost of diabetes in metropolitan France: what trends between 1998 and 2000?*.

OBJECTIVES: Our aim was to update available data concerning the prevalence and cost of diabetes in metropolitan France. METHODS: We performed a retrospective study using patient reimbursement data from all the 128 local health offices (CPAM) in metropolitan France. We selected patients who received reimbursements for an oral hypoglycemic agent or insulin. Thus, 704,423 patients were studied by using 1998 data and 1,145,603 patients were studied by using data from 2000. The expenditures studied represented the total amount reimbursed by national health insurance to diabetic patients. The cost differential which could be attributed to diabetes was calculated by determining the difference between costs generated by diabetic patients to those generated by the rest of the population of the same age. RESULTS: Between 1998 and 2000, the prevalence of diabetes treated in the population of affiliates covered by the general scheme increased from 2.78% to 2.96%. The total amount paid by the general scheme for care to diabetic patients (related to diabetes or not) was 5.710 billion euros in 2000 compared to 4.862 billion euros in 1998. The amount which can be attributed to diabetes alone can be estimated to be 2.414 billion euros in 2000 compared to 2.021 billion euros in 1998. After considering the impact of the increase in the number of treated diabetics, a modification in the modalities of medical care probably accounts for 183 million euros of the cost increase. Medical equipment (self blood glucose monitoring devices, reagent strips, finger lancets...) accounts for 39.3% (72 million euros) of this cost differential, medications account for 34.4% (63 million euros) and nursing care 16.9% (31 million euros). There was no change in the cost of diabetes with relation to expenses for medical consultations.

Costs and Cost Analysis↗

Allogeneic bone marrow transplantation for chronic myeloid leukemia in childhood: a report from the Société Française de Greffe de Moelle et de Thérapie Cellulaire (SFGM-TC).

To determine the results of allogeneic hematopoietic stem cell (HSC) transplantation for chronic myelogenous leukemia (CML) at various stages of the disease in children, a retrospective analysis was carried out on the outcome of transplants performed on 76 children and teenagers with CML between 1982 and 1998. In all, 60 patients were transplanted from a matched sibling donor (MSD) and 16 from a matched unrelated donor (MUD). There was a higher incidence of acute graft-versus-host disease after MUD transplantation (P<10(-3)). The main cause of death was transplant-related toxicity in both groups. In MSD recipients, the probability of relapse at 5 years for patients transplanted in the first chronic phase was lower than in patients transplanted in the advanced phase (relative risk (rr)=5.90; 95% confidence interval (CI), 1.85-18.82, P<0.01). The estimated 5-year event-free survival (EFS) rate was higher after MSD vs MUD transplantation (61% (95% CI, 48-73%) vs 27% (95% CI, 4-49%), rr=0.25, P<10(-3)). In children transplanted from MSD, the 5-year EFS was higher when transplantation was performed in the first chronic phase vs the advanced phases (73% (95% CI, 59-87%) vs 32% (95% CI, 10-54%), P<10(-3)). Disease status at transplantation was the unique factor influencing survival in patients undergoing transplantation from MSD with a better outcome for those transplanted in the first chronic phase. Allogeneic HSC offers a possibility of curing childhood CML with a significant advantage for patients transplanted in chronic phase using a human leukocyte antigen-identical sibling donor.

Adolescent↗

Comparison of reticulated platelet count and mean platelet volume determination in the evaluation of bone marrow recovery after aplastic chemotherapy.

Reticulated platelet count provides an estimate of thrombopoiesis in the same way as reticulocyte count is a measure of erythropoiesis. We applied thiazole orange (TO) staining, followed by fluorescence-activated flow-cytometric analysis, to platelets in whole-blood samples from normal subjects and 18 aplastic patients after chemotherapy for haematologic malignancies. The percentage of TO-positive platelets in 30 control subjects was 5.7 +/- 2.4% (mean +/- 1 SD), determining the threshold of reticulated platelet positivity as up to 10.5% (mean + 2 SD). In the 18 patients studied, the mean percentage of TO-positive platelets was 4.3 +/- 1.89% during aplasia and 23.3 +/- 9.43% during bone marrow recovery, respectively (P < 0.05). All patients had a percentage of TO-positive platelets of up to 10.5%. In comparison, mean platelet volume during bone marrow recovery increased in 12 cases of the 18 patients studied. We conclude that flow cytometric analysis of reticulated platelets is a sensitive and specific test for evaluating thrombopoiesis recovery during aplastic chemotherapy, and platelet transfusion should be reconsidered in these patients.

Adult↗

Results of a phase II trial of a combination of oral cytarabine ocfosfate (YNK01) and interferon alpha-2b for the treatment of chronic myelogenous leukemia patients in chronic phase.

Cytarabine ocfosfate (YNK01) is a prodrug analogue of cytarabine which is resistant to systemic deamination after oral administration. Following initial studies indicating significant anti-tumour activity of YNK01 a phase II trial was initiated in order to assess the tolerability and efficacy of a combination of this agent with interferon alpha-2b (IFN-alpha2b) in recently diagnosed chronic phase CML patients (n = 98). The treatment was subdivided into cycles consisting of 4 weeks of continuous administration of IFN-alpha-2b (3 MU/m(2)/day 1st week and then 5 MU/m(2)/day) and 14 days of oral YNK01 (600 mg/day 1st cycle). At the end of each cycle the dose of YNK01 was adjusted according to the blood count observed during the previous 4 weeks. The median time from diagnosis to inclusion in the trial was 2 months (range 6 days to 7.5 months). At 12 weeks, 62 patients (63%; 95% CI, 54-73) achieved a complete hematological response. At 24 weeks, of 98 patients, two achieved a complete cytogenetic response, 14 a partial response (16% major cytogenetic response rate; 95% CI, 9-24) and 34 a minor response; 19 patients were not evaluable for cytogenetic response. During the trial, 20 patients progressed to accelerated (6) or blastic phases (14). The median time to progression was 15 months (range 2-38 months). At 3 years the overall survival was 79% (95% CI, 70-88). Although the complete hematological response rate compared favorably with the 40% response rate previously obtained with the subcutaneous formulation of Ara-c, the cytogenetic response rate was less than expected. Most of the patients experienced side-effects and all permanently stopped YNK01. Although the combination seems attractive the initial dose of 600 mg per day is probably too high and should be reconsidered in further trials.

Administration, Oral↗

Chronic myeloid leukemia and interferon-alpha: a study of complete cytogenetic responders.

Achieving a complete cytogenetic response (CCgR) is a major target in the treatment of chronic myeloid leukemia (CML) with interferon-alpha (IFN-alpha), but CCgRs are rare. The mean CCgR rate is 13%, in a range of 5% to 33%. A collaborative study of 9 European Union countries has led to the collection of data on 317 patients who were first seen between 1983 and 1997 and achieved CCgRs with IFN-alpha alone or in combination with hydroxyurea. The median time to first CCgR was 19 months (95% CI, 17-21; range, 3-84 months). At last contact, 212 patients were still alive and in continuous CCgR; 105 patients had lost CCgR, but 53% of them were still alive and in chronic phase. IFN-alpha treatment was discontinued permanently in 23 cases for response loss, in 36 cases for chronic toxicity (15 are still in unmaintained continuous CCgR), and in 8 cases because it was believed that treatment was no longer necessary (7 of these 8 patients are still in unmaintained continuous CCgR). The 10-year survival rate from first CCgR is 72% (95% CI, 62%-82%) and is related to the risk profile. High-risk patients lost CCgR more frequently and more rapidly and none survived more than 10 years. Low-risk patients survived much longer (10-year survival probability 89% for Sokal low risk and 81% for Euro low risk). These data point out that a substantial long-term survival in CCgRs is restricted mainly to low-risk and possibly intermediate-risk patients and occurs significantly less often in high-risk patients.

Adult↗

Rapid quality control for testing the radiochemical purity of 99Tc(m)-tetrofosmin.

We describe a new thin-layer chromatography (TLC) method to evaluate the radiochemical purity of 99Tc(m)-tetrofosmin without the drawbacks of toxicity, solvent ratios and time requirement associated with the standard TLC method. The new method uses miniaturized instant TLC plates impregnated with silica gel (ITLCTM/SG, 2.5 x 10 cm) for the stationary phase and 2-butanone for the mobile phase. The standard TLC method was performed with ITLCTM/SG plates (5 x 20 cm) and dichloromethane/acetone (65:35, v/v). Thirty five preparations were analysed by both methods with a storage phosphor imaging system to determine the percentages of hydrolyzed-reduced 99Tc(m) compound (99Tc(m)O2), 99Tc(m)-tetrofosmin and free 99Tc(m)-pertechnetate (99Tc(m)O4(-)). Using the miniaturized TLC method, 99Tc(m)-tetrofosmin had a mean Rf value of 0.55 (standard deviation, 0.05), while 99Tc(m)O4(-) migrated with the solvent front (Rf=1) and 99Tc(m)O2 remained at the origin of the strips (Rf=0). No significant difference was found between miniaturized and standard TLC methods for the radiochemical purity of 99Tc(m)-tetrofosmin using the Wilcoxon matched-pair signed-rank test (P=0.82). Furthermore, the two methods showed a good correlation as measured by the Spearman rank coefficient (r=0.89) and were in perfect agreement, with a kappa index of +1, for a cut-point between positive and negative set at 90%. In conclusion, the results indicate that the miniaturized TLC method is effective for the routine evaluation of the radiochemical purity of 99Tc(m)-tetrofosmin, without some of the drawbacks of the standard method.

Chromatography, Thin Layer↗

Cytarabine added to interferon improves the cost-effectiveness of initial therapy for patients with early chronic phase chronic myelogenous leukemia.

The French Chronic Myeloid Leukemia Study Group prospective randomized study results indicate that the addition of cytarabine to alpha interferon (IFN-alpha) increases the rate of major cytogenetic response and prolongs survival in patients with early chronic phase chronic myelogenous leukemia (CML). The French group study design permitted a single crossover to include or discontinue cytarabine or interferon. Endpoints were overall survival, complete hematologic remission (CHR) at six months, and major cytogenetic response at 12 months. We modified a published Markov model that compared IFN-alpha alone to IFN-alpha plus cytarabine and included the possibility of crossover as in the French study. The model permits allogeneic and autologous stem cell transplantation (SCT), and follows cytogenetic response and acceleration of CML through death. Treatment response, toxicity, and survival are drawn from the French Chronic Myeloid Leukemia Study Group population of 810 patients on an intention-to-treat model. Survivals are extended to 62 months based on currently available follow-up. Costs from a United States oncology specialty institution, and state utilities from previous research and a quality-adjusted Time Without Symptoms or Toxicity analysis of the subject study were discounted at 3% per annum. At the median cohort age of 50, cytarabine offers 21 months of added median survival to IFN-alpha, which itself is superior to conventional chemotherapy by 21 months. Cost-effectiveness estimates for cytarabine added to IFN-alpha range from $7,000 per quality-adjusted life year (QALY) to $35,000 per QALY, under all plausible assumptions superior to IFN-alpha alone. The model is sensitive to the quality of life on therapy, as well as to remission rate with additive cytarabine, although the cost-effectiveness calculations are robust over the entire range of clinical assumptions. Based on data from the French study, cytarabine added to IFN-alpha substantially improves the cost-effectiveness of initial therapy for early chronic phase CML.

Antineoplastic Combined Chemotherapy Protocols↗

Study of the variations of the cesarean sections rate in the Rhône-Alpes region (France): effect of women and maternity service characteristics.

OBJECTIVE: To analyze the variations of the rate of prophylactic cesarean sections and cesarean sections during labor according to the women's and maternity services' characteristics. STUDY DESIGN: The study population was a sample of 8470 women having delivered in one of the 86 maternity services of the Rhône-Alpes region (France) in 1990. The women's characteristics were risk factors for pregnancy or delivery. The maternity services' characteristics included those describing the service structure and the mode of recruitment. For the statistical analysis we used a two-level logistic model. RESULTS: After taking into account the women's characteristics, there remained a variation between the maternity services. This variation was in part explained by the type of recruitment of the maternity service. When the proportion of women with a previous cesarean section or a dystocia increased in the maternity service the cesarean sections rate decreased in women presenting similar characteristics. CONCLUSION: Thus, the maternity services which receive many "at risk" women tend to have higher cesarean section rates than the others. However, in comparison with women presenting similar characteristics, these same maternity services tend to perform fewer cesarean sections.

Cesarean Section↗