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Biomedical subjects

R Favre

Publications and source records attributed to R Favre.

At least 37 records · Page 2Linked to original sources

Population pharmacokinetics of cisplatin after 120-h infusion: application to routine adaptive control with feedback.

OBJECTIVE: A Bayesian population pharmacokinetics study of data from routine therapeutic drug monitoring cisplatin during a 5-day infusion of cisplatin. METHODS: A total of 95 kinetics data sets (58 patients) were available to perform this study. Individual pharmacokinetic parameters, estimated from 20 courses of treatment in 18 patients, were used to calculate the population parameters (cl: 0.175 +/- 0.034 L/h; t(1/2): 327 +/- 91 h). The accuracy of Bayesian forecasting was tested by comparing in 40 other patients the clearance values calculated either from a complete kinetics profile (eight sampling times) or from three early samples and the new population parameters. Finally, drug monitoring efficacy was assessed by comparing the target Cmax values with the Cmax obtained after dose adjustment based upon early Bayesian estimation of the individual pharmacokinetic parameters. RESULTS: : No significant difference was found between Bayesian and experimental clearances. Besides, dose-individualization proved to successfully adjust Cmax values around their respective target. CONCLUSION: The new reference pharmacokinetic population parameters lead to accurate estimation of individual pharmacokinetic parameters from a limited number of samples, thus allowing efficient therapeutic drug monitoring during 5-day infusion regimens of cisplatin.

Adolescent↗

Recurrent neural tube defects associated with partial trisomy 2p22-pter: report of two siblings and review of the literature.

We report on two male siblings with partial trisomy 2p22-pter and partial monosomy 15q26-qter resulting from a maternally derived translocation t(2;15)(p22;q26). Both fetuses had different neural tube defects (craniorachischisis in the first fetus and anencephaly in the second fetus) which were detected by sonographic examination at the end of the first trimester of pregnancy. This report demonstrates the importance of chromosomal analysis in the etiologic exploration of neural tube defects and supports the importance of 2p24 triplication in neural tube development.

Anencephaly↗

The prescription of opioid analgesics to terminal cancer patients: impact of physicians' general attitudes and contextual factors.

OBJECTIVE: This study aimed to examine factors associated with the prescription of opioid analgesics to terminal cancer patients, including physicians' general attitudes toward morphine and contextual factors. METHODS: A survey was conducted among a sample of French general practitioners (GPs) and oncologists. Respondents were asked to describe the last three terminally ill patients they had followed up to death. RESULTS: Overall, 526 GPs and oncologists (global response rate: 57%) described 1,082 cancer patients, among whom 85.4% received opioid analgesics. Among other significant predictors (patient age, cancer type, family assistance), this prescription was less frequent for female patients followed by male physicians (OR = 0.53), and more frequent for patients followed by physicians trained in palliative care (OR = 2.70). On the other hand, physicians' attitudes toward morphine were not associated with prescription of morphine and other opioid analgesics. SIGNIFICANCE OF RESULTS: Although nonprescription of opioid analgesics is only a crude proxy measure for undertreatment of cancer pain, our findings suggest the need to develop training in palliative care in order to standardize practices among GPs and specialists. Our results also highlight the necessity to study pain assessment as an interaction between the physician and the patient, and to consider patients' and physicians' respective genders as a key variable within this interaction.

Adult↗

Acentromeric micronuclei are increased in peripheral blood lymphocytes of untreated cancer patients.

Increased micronucleated cell rates, dicentric chromosomes, and other chromosomal damages have been reported in lymphocytes of cancer patients prior to the initiation of chemotherapy, and/or radiotherapy. The cause of these chromosomal damages in these lymphocytes remains unclear. In the present work, we investigated whether these micronuclei mainly reflect structural or numerical chromosomal aberrations by applying the cytokinesis-blocked micronucleus (CBMN) assay in combination with fluorescent in situ hybridization (FISH) of a DNA centromeric probe on blood samples of 10 untreated cancer patients (UCPs), and 10 healthy subjects (HSs). Micronucleated binucleated lymphocyte rate was significantly increased in patients (mean+/-S.D.: 19.0 per thousand +/-14.1 versus 9.2 per thousand +/-4.6 in controls). Trinucleated cytokinesis-blocked cells were not significantly higher in patients than in controls. Acentromeric, centromeric, and multicentromeric micronucleus levels were two-fold higher in patients than in controls, but the difference was significant only with acentromeric micronuclei. The percentage of micronuclei containing one or more centromeres averaged 69.2, and 71.5% in patients, and controls, respectively. The percentage of micronuclei containing several centromeres was 44.7% in patients, and 54.6% in controls. Among centromere-positive micronuclei, the percentage of micronuclei containing several centromeres averaged 59.7% in patients, and 75.4% in controls. These results indicate that genetic instability in peripheral blood lymphocytes of UCPs occurs because of enhanced chromosome breakage. However, a substantial proportion of this genetic instability occurs because of defects in chromosome segregation.

Adult↗

Phylogenetic characterization of the blue filamentous bacterial community from an Icelandic geothermal spring.

Molecular phylogenetic analysis of a blue filamentous community from an alkaline thermal spring (79-83 degrees C) in Iceland revealed that the blue filaments were affiliated with the Aquificales. The dominant sequence type, pIce1, was most closely related to a sequence (SRI-48) found in a white filamentous community from a separate Icelandic thermal spring and the pink filaments (EM17) from Yellowstone National Park. Fluorescent in situ hybridization with clone-specific oligonucleotide probes showed that the sample analyzed was essentially a monoculture of a single phylotype.

Journal Article↗

[Nutritional workshops for cancer patients: a pilot approach].

The authors describe an original experience with 3 years of a nutritional workshop for cancer patients. This intervention combine an information about nutritional aspects of cancer with psychosocial support, to buffer psychological and nutritional consequences of cancer. The workshop, leaded by two specialized teams, one in medical oncology, the other in public health, is proposed to patients during and after a specific treatment. In one day, it provided information about nutrition and cancer, diet education and psychosocial support with supportive-expressive group. At this day, the evaluation of this intervention is only subjective. Fifty-six patients participated in at least one workshop, with majority of women (91%). Nineteen workshops were leaded with average participant number of 7 per workshop the third year. The authors believe that nutritional workshops are of great help for cancer patients, by enhancing social reinsertion, giving opportunity of emotional expression and humanizing the treatment. Our experience show it is possible to propose psychosocial intervention in institution in the context of Mediterranean country. We are leading currently a study that will permit a more systematic evaluation of the effects of this intervention.

Adult↗

Osteosarcomas of flat bones in adolescents and adults.

BACKGROUND: Osteosarcomas typically are long bone tumors and rarely affect the flat bones of the axial or appendicular skeleton. METHODS: The authors examined cases of high grade osteosarcoma of flat bones diagnosed at La Timone Adults University Hospital during a 16-year period. RESULTS: Sixteen patients with flat bone osteosarcomas were treated between 1980-1997. The median age of the patients was 25 years, with a male-to-female ratio of 14:2. Common presenting symptoms were swelling, pain, or both. Primary therapy included resection (n = 11 patients: alone in 8 patients and with radiation therapy in 3 patients), radiation therapy (n = 2 patients), or no local treatment (n = 3 patients). All patients received polychemotherapy, 7 preoperatively and postoperatively and 9 in the adjuvant setting. The overall 5-year survival rate was 47.7%; the overall median survival was 39 months (range, 4-211 months). The adequate local control rate was 68.7%. The local recurrence rate in patients who benefited from local treatment was 54%. Significant adverse prognostic factors on survival included the presence of synchronous metastases (three patients), metastases at any time during the course of the disease (eight patients), and inadequate local control (five patients). The overriding predictor of survival appeared to be the presence of metastases. Local recurrence appeared to have no influence on survival. No patient with metastases was alive at 3 years, whereas patients without recurrence or with local recurrence alone had a 5-year survival rate of 100%. Because the majority of patients with flat bone osteosarcomas ultimately die of metastatic disease, intensive systematic polychemotherapy should be an important component of treating these tumors. CONCLUSIONS: Based on the very encouraging results observed in the treatment of long bone osteosarcomas, the therapy for flat bone osteosarcomas should combine radical surgery with preoperative and postoperative adjuvant chemotherapy.

Adolescent↗

Identification of a new subset of cells exhibiting dendritic phenotypes in patients affected by breast proliferative disorders.

We report that a subset of circulating cells reacting with a monoclonal antibody raised against a protein marker is significantly increased in the peripheral blood of women carrying benign or malignant breast diseases, particularly in patients under 55 years of age with ductal mammary carcinomas. These cells were statistically (confidence level of 99%) less represented in a control population including healthy women or women carrying carcinomas of origin other than breast. Double staining analysis showed that they harbor markers of dendritic cells and exhibit endo- cytic activity, as determined by their ability to internalize FITC-dextran particles. Their dendritic morphology was further demonstrated by electron microscopy of sorted antibody-positive cells. However, expression of surface molecules, such as CD34 and CD14, usually not present in differentiated populations of dendritic cells was also observed. Adherent cells of patients with breast ductal carcinoma including mostly cells of this new subset were efficient stimulators of mixed lymphocyte reaction, attaining maximal stimulatory activity attained after TNFalpha treatment. In conclusion, we have shown that a subset of cells characterized by a phenotype suggestive of a yet undescribed stage of maturation of the dendritic cell lineage is accumulated in the blood of patients affected by breast proliferative disorders.

Adult↗

Fetal serum beta2-microglobulin predicts postnatal renal function in bilateral uropathies.

BACKGROUND: Predicting postnatal renal function is crucial for the prenatal evaluation of fetal bilateral uropathies. Prenatal ultrasound can identify intrauterine terminal renal failure, but is not sensitive enough to identify those infants who would survive with an impaired renal function. Because it reflects fetal glomerular filtration, fetal serum beta2-microglobulin is a potential predictor of postnatal renal function. METHODS: Fetal serum beta2-microglobulin (beta2m) was assayed in 61 cases of bilateral or low obstructive uropathy, 74 controls, and 17 cases of bilateral renal agenesis, and was correlated with renal function. RESULTS: Fetal serum beta2m was 3.2 mg/L (range 1.5 to 4.7) in controls (N = 74), 9.5 mg/L (range 6.7 to 11.3) in bilateral renal agenesis (N = 17), 7 mg/L (5.1 to 10.6) in uropathy in which terminal renal failure resulted in termination of pregnancy (N = 26), and 3.7 mg/L (range 2.3 to 11.2) in live births with uropathy (N = 35). In the latter subgroup, fetal serum beta2m was significantly and positively correlated (r2 = 0.91) with postnatal serum creatinine. All survivors with a postnatal serum creatinine < or =50 micromol/L ha a fetal serum beta2m lower than 5 mg/L. Four of 6 survivors with a postnatal serum creatinine> 50 micromol/L had a fetal serum beta2m greater than 5 mg/L. CONCLUSION: Fetal serum beta2-microglobulin is a marker for renal function and predicts postnatal serum creatinine in bilateral or low fetal obstructive uropathy.

Biomarkers↗

Nodule invasion and symbiosome differentiation during Rhizobium etli-Phaseolus vulgaris symbiosis.

By means of a detailed ultrastructural analysis of nodules induced by Rhizobium etli on the roots of Phaseolus vulgaris, we observe that the development of host-invaded cells is not synchronous. An accumulation of mitochondria was found in freshly invaded host cells, containing only a few symbiosomes (SBs) that are released from highly branched intracellular ramification of the infection threads. Moreover, besides the fusion between the SB membrane with host secretory vesicles, we observe also a great number of fusions between the outer leaflets of adjoining SB membranes, thus resulting in structures that resemble the tight junction network (zona occludens with a five-layered structure) of epithelian cells. This process was found to be induced strongly and earlier both in the invaded host cells of ineffective nodules (elicited by Fix- mutant strains of R. etli) and in the older (senescence) invaded cells of effective nodules, whereas bacteroid division is seldom if ever observed. Our observations strongly suggest that multiple-occupancy SBs also arise by fusion of single-occupancy SBs and the physiological consequence of this process is discussed.

Cell Differentiation↗

Micronucleated lymphocyte rates from head-and-neck cancer patients.

We investigated whether head-and-neck cancers are associated with an increased micronucleated cell rates (MN cell rates) and whether risk factors for these cancers are associated with alterations in micronucleated lymphocytes. MN cell rates were assessed in cytokinesis-blocked lymphocytes of 57 head-and-neck cancer patients (CP) before any anticancer treatment and of 198 male and female healthy subjects (HS). In the HS group, only smoking status significantly affect MN cell rates. In CP group age, sex, tobacco status, alcohol status, tumor stage, family history of cancer had no significant effect. For the non-smokers, the comparison between MN cell rates in HS and CP adjusted for age and sex showed a significant difference. The increase of MN cell rates in non-smokers patients may be attributable to cancer status. For the smokers, the comparison of MN cell rates in HS and CP matched for age and sex showed no significant difference. Pathological status could mask the smoking effect on peripheral blood lymphocytes in patients. Moreover, it probably could partly explain why MN cell rates in matched-CP smokers and HS smokers were similar. The authors do not recommend the CBMN assay in this present form to study smoking DNA-damage effects in peripheral blood lymphocytes of cancer patients, especially for patients with upper aero-digestive tract cancers or lung cancers for which tobacco is the major risk factor.

Adult↗

Evaluation of the genotoxic activity of paclitaxel by the in vitro micronucleus test in combination with fluorescent in situ hybridization of a DNA centromeric probe and the alkaline single cell gel electrophoresis technique (comet assay) in human T-lymphocytes.

Paclitaxel is a recent chemotherapeutic agent that inhibits tubulin depolymerization in tumoral cells. Despite its increasing use against various human cancers, the genotoxicity of paclitaxel has never been studied on normal human cells. The in vitro genotoxic effects of the drug were evaluated with two complementary mutagenesis tests on human T-lymphocytes: (1) the cytokinesis-blocked micronuclei assay (CBMN) in combination with fluorescent in situ hybridization (FISH) of nonspecific centromeric probes and (2) the comet assay performed in three ways: on stimulated lymphocytes as in the CBMN, and on freshly isolated lymphocytes at both 4 and 37 degrees C. A slight cytotoxicity of 2.5 to 10 nM paclitaxel was found in the CBMN and a significant increase in the binucleated micronucleated cell rates was observed, with a concentration-dependent manner. In the FISH analysis, more than 85% of the micronuclei (MN) were centromere positive, and a ratio of 72. 2 to 78.6% of these MN contained more than one centromere. Moreover, at 10 nM of paclitaxel, 35.6% of the cells are multimicronucleated lymphocytes. Unexpectedly, paclitaxel induced single-strand breaks on proliferating lymphocytes at 5 and 7.5 nM but not in resting cells, even at 5 to 15 microM. These in vitro results showed that (1) paclitaxel does not present any direct DNA action in resting cells, (2) DNA damage detected in stimulated lymphocytes may be linked either to a high frequency of cells in the S-phase cell cycle or to a direct DNA damaging effect on replicating cells, and (3) paclitaxel is a strong in vitro aneugenic drug on human normal cells, at clinically relevant concentrations.

Adult↗

Early fetal megacystis between 11 and 15 weeks of gestation.

OBJECTIVE: The purpose of this study was to evaluate the prognostic criteria of early fetal megacystis. DESIGN: A prospective, transvaginal ultrasound, cross-sectional study at 11-15 weeks of gestation at a tertiary referral fetal medicine unit. SUBJECTS AND METHODS: Sixteen pregnancies out of a total of 5240 were identified with early fetal megacystis. Fetal biometry, morphology, amniotic fluid, bladder size and volume were also evaluated. The karyotype was available in 15 cases. Vesicocentesis was performed in six fetuses and three had concomitant cystoscopies. RESULTS: In six fetuses, the megacystis was isolated. In the remaining ten, we detected associated hygroma (n = 5), nuchal translucency (n = 3), omphalocele (n = 1), mild pyelectasis (n = 1) and bilateral talipes (n = 1). In three cases the fetuses demonstrated renal hyperechogenicity with cysts, and in two cases oligohydramnios was found; four cases (25%) had chromosomal abnormalities; 47, XY + 13 (two cases), 47, XY + 18 and 47, XY + 21. Only one fetus from this study survived. In the remaining 13 cases, termination was proposed after counselling of the patients on the poor prognosis. The mean gestational age at termination was 15.5 +/- 2.4 weeks (range 12-20). Three fetal transabdominal cystoscopies did not allow us to view the valves; one urethral atresia was suspected, and confirmed postnatally. CONCLUSIONS: We found a high rate of associated malformations, especially intestinal malformations. The systematic evaluation of the intestinal enzymes in the amniotic fluid and urine samples might be an important aid in the diagnosis of multiple malformations, such as cloacal dysgenesis.

Abnormalities, Multiple↗

The Rhizobium etli trpB gene is essential for an effective symbiotic interaction with Phaseolus vulgaris.

A mutant strain (CTNUX4) of Rhizobium etli carrying Tn5 unable to grow with ammonium as the sole nitrogen source was isolated and characterized. Sequence analysis showed that Tn5 is inserted into a trpB (tryptophan synthase)-homologous gene. When tested on the roots of Phaseolus vulgaris, strain CTNUX4 was able to induce only small, slightly pink, ineffective (Fix-) nodules. However, under free-living conditions, strain CTNUX4 was unable to produce flavonoid-inducible lipo-chitin oligosaccharides (Nod factors) unless tryptophan was added to the growth medium. These data and histological observations indicate that the lack of tryptophan biosynthesis affects the symbiotic behavior of R. etli.

Amino Acid Sequence↗

[Congenital generalized dropsy and intrapericardial fetal teratoma. Report of a case of prenatal diagnosis].

Intrapericardial teratomas are rare tumors usually occurring in early infancy. Such a case was diagnosed in a 20 week old fetus, with a lethal outcome. About fifteen cases of intrapericardial teratoma have been reported in the fetal period. They are usually symptomatic, with a more or less severe pericardial effusion, sometimes complicated by cardiac compression and/or hydrops fetalis. Prognosis of the prenatally diagnosed pericardial teratomas is more related to the occurrence of hydrops fetalis than to the behavior of the tumor itself. The main interest of sonographic ante-natal diagnosis consists of the possible improvement of hemodynamic consequences through in utero pericardiocentesis. Macroscopic and microscopic features of this cardiac tumor are similar to those of extrapericardial teratomas. Most tumors discovered in fetal period are mature and histologically benign lesions. Only one case showed immature components. The coexistence of a malignant component (germ cell or non germ cell tumor) has been described in the postnatal and adulthood.

Adult↗

[Prenatal and neonatal management of digestive tract duplications. Diagnostic difficulties and therapeutic implications].

OBJECTIVE: To insist on the difficulty of the antenatal diagnosis of digestive duplications, to show the importance of a complete malformative screening, and the need for immediate management at birth. MATERIAL AND METHODS: A cystic duplication of the tongue, a duplication, abdomino-thoracic transdiaphragmatic, and a duplication of the small bowel are described and compared with cases previously reported in th literature. RESULTS: Antenatal evacuation puncture of a duplication of the tongue must be reserved for exceptional situations. Foregut duplications are often associated with other malformations. The duplication of the small intestine can exceptionally expose to a mechanical complication, mostly during the postnatal period, which may require emergency surgery. CONCLUSION: Duplications of the alimentary tract should be detectable on prenatal ultrasound examination. A complete antenatal malformative screening is required and in utero transfer is warranted because emergency surgery may be required.

Abnormalities, Multiple↗

[Nuchal translucency: screening for chromosomal abnormalities and congenital malformations. Multicenter study].

OBJECTIVE: To value the rate of chromosomal abnormalities and evolution of children who had a prenatal diagnosis of fetal nuchal translucency in the first trimester. MATERIAL AND METHODS: Multicenter prospective study conducted in 4,582 patients who had a first ultrasonography between 10 and 14 weeks' gestation (abdominal and/or transvaginal sonography). The measurement of fetal nuchal translucency was performed by mid-sagittal section and when it was higher than 2.5 mm a fetal karyotype was made. RESULTS: Three hundred and fifty eight nuchal translucencies (> 2.5 mm) were diagnosed and 334 karyotypes were done. We found 25 chromosomal anomalies (7.4%): 14 trisomies 21; 7 trisomies 18; 2 trisomies 13; one triploidy and one trisomy X. The postnatal examination of children detected three congenital malformations (0.9%): one facial dysmorphia, one complex abnormal heart anatomy and one renal agenesia. CONCLUSION: Nuchal translucency (> 2.5 mm) is therefore a sonography sign associated with 7.4% of chromosomal anomalies. The distribution by size and mother ages is low. It should need superior larger-scale studies are needed for representative data. But this study shows that if fetal karyotype is normal, the incidence of congenital malformations seems to be the same by comparison with the general population.

Chromosome Aberrations↗