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Biomedical subjects

F Chauvin

Publications and source records attributed to F Chauvin.

104 records · Page 6Linked to original sources
PubMed1987

High-dose therapy and autologous bone marrow transplantation after failure of conventional chemotherapy in adults with intermediate-grade or high-grade non-Hodgkin's lymphoma.

Adult patients with advanced non-Hodgkin's lymphoma in whom conventional chemotherapy has failed are seldom cured thereafter. We studied 100 such patients with intermediate-grade or high-grade non-Hodgkin's lymphoma who were subsequently treated with high-dose chemotherapy (61 patients) or high-dose chemotherapy plus total-body irradiation (39 patients), with bone marrow transplantation used for hematologic support. Thirty-four patients had disease that had been refractory to primary chemotherapy, and 66 patients had had a complete remission with primary chemotherapy but later relapsed. Before autologous bone marrow transplantation and high-dose chemotherapy, the 66 relapsed patients had also received conventional salvage chemotherapy; 22 had had no response or had had disease progression (a response termed "resistant relapse"), and 44 patients had responded partially or completely (a response termed "sensitive relapse"). After high-dose therapy and bone marrow transplantation, the actuarial three-year disease-free survival was zero in the refractory group, 14 percent in the resistant-relapse group, and 36 percent in the sensitive-relapse group. Patients who had had a complete remission in response to initial chemotherapy had a higher disease-free survival rate than those who had not (P less than 0.001), and patients with sensitive relapse had a higher disease-free survival rate than those with resistant relapse (P less than 0.003). These results should be considered in the planning or interpretation of trials of salvage chemotherapy in adults with non-Hodgkin's lymphoma.

Adolescent↗
PubMed1987

Effective multiagent chemotherapy in children with advanced B-cell lymphoma: who remains the high risk patient?

Between 1981 and 1985, 50 patients, mainly children and adolescents, with advanced B-cell lymphoma were entered on a protocol comprising eight drugs: cyclophosphamide, vincristine, prednisolone, high dose methotrexate, adriamycin, BCNU, cytosine arabinoside and thioguanine. Treatment to the central nervous system consisted of intrathecal methotrexate and cytosine-arabinoside in association with high dose methotrexate without irradiation. Data was collected prospectively with regard to response rate, treatment related complications and survival. Histology was reviewed in all referred cases and in 21 there was supportive evidence from immunological and cytogenetic studies. The overall complete response rate was 86%: 31/36 stage III and 12/14 stage IV. There were four treatment related deaths. The overall disease-free survival is 75% with a median follow up of 32 months. In the group of stage IV patients 5/7 with only marrow involvement, 2/4 with isolated CNS involvement and 1/3 with combined CNS and marrow infiltration survive. All the patients with CNS involvement at presentation underwent consolidation treatment with high dose chemotherapy and bone marrow transplant. These results demonstrate the very high curability of B-cell lymphoma using intensive multiagent therapy even with advanced abdominal disease. Bone marrow infiltration does not appear to be an adverse prognostic factor in isolation from bulk disease or CNS involvement. There remain, however, two groups of patients in whom further intensification of therapy is indicated, namely, those with initial CNS involvement, especially in combination with marrow infiltration, and those with extensive multiorgan involvement at presentation who fail to achieve remission with initial therapy. For the other patients, the large majority, a reduction in the intensity and duration of therapy is currently under study.

Adolescent↗
PubMed1986

[Survival and prognostic factors in cerebral metastases of breast cancer].

A number of prognostic factors have emerged from a retrospective study of 83 patients with breast cancer associated with a solid intracerebral tumour (59%), or meningeal invasion (33%) or both (8%). The median survival was 4 months without significant difference between breast tumours and meningeal carcinomatosis. Women in pre-menopause at the initial diagnosis of breast cancer (P less than or equal to 0.05) or who were 50 years of age when the cerebral metastasis occurred (P less than or equal to 0.05) or who had only one metastasis (P less than or equal to 0.02) had a better prognosis. During meningeal carcinomatosis, CSF protein and carcinoembryonic antigen levels have no prognostic value. All patients with intracerebral tumour had been irradiated (40 Gy over 4 weeks). The tumour was removed whenever possible. Intrathecal or systemic chemotherapy and hormone therapy seem to be favourable prognostic factors. This would suggest that chemotherapy may increase the survival of patients with this type of breast cancer, but only randomized studies will demonstrate its true effectiveness.

Brain Neoplasms↗
PubMed1986

gamma-Glutamyltranspeptidase activity in human breast lesions: an unfavourable prognostic sign.

The activity of gamma-glutamyltranspeptidase (gamma GT) (EC 2.3.2.2) was examined by histoenzymatic labelling on frozen sections derived from normal breast tissue, benign lesions and carcinomas. In biopsies from normal tissue and benign lesions, labelling was very intense in lumina and in the apical pole of the cells lining the lumina whilst in the cytoplasm it was slightly positive. In 34 out of 70 carcinomas, gamma GT activity was either undetectable or slightly positive while in the remaining 36 there was intense activity. Statistical examination of the results revealed no obvious correlation of gamma GT activity with histological grade of the tumour, progesterone receptor content or classification of patients by pre- or postmenopausal status. A good correlation between gamma GT activity and the following unfavourable prognostic signs: lymph node metastases and absence of oestradiol receptors. Patients with gamma GT-negative tumours may have a more favourable prognosis than those with gamma GT-positive tumours.

Adenofibroma↗
PubMed1985

Prognostic value of the topographic grid method in women with T2 N- breast cancer. Statistical results from a series of 203 patients.

In 1977, the authors described the grid method, a topographic technique for mapping the microscopic spread of breast cancer. The current report describes the relapse-free survival of a series of 203 patients with T2 N- mammary cancer (T2 N0 N1 ab N-) who were treated by mastectomy and regional lymph node dissection and have been followed since 1974. A good prognosis did not prevent relapse in 15% to 20% of patients within the first 5 years. To determine whether the grid method can identify patients at high risk within this group, disease-free survival and survival were compared in two subsets, a "limited" group (L) and a "diffuse" group (D). The difference between the two groups was statistically significant for both parameters (88%) versus 77% and 93% versus 85% after 5 years) (P less than 0.01 and P less than 0.02). Other prognostic measures were uniformative. Thus, the grid method has a good prognostic score when compared with the factors usually measured--menopausal status, estrogen receptors, histologic type--and could be used to select appropriate adjuvant therapy in breast cancer.

Breast Neoplasms↗
PubMed1985

Association states of tubulin in the presence and absence of microtubule-associated proteins. Analysis by electric birefringence.

Electric birefringence has been used to examine the states of association of tubulin in phosphocellulose-purified tubulin or depolymerized microtubule protein solutions at low temperature. In a high electric field (1000-4000 V/cm), tubulin could be orientated (owing to the existence of a permanent and/or induced dipole) and exhibited a positive birefringence (delta n), related to its intrinsic optical anisotropy. The analysis of the relaxation process (depending on hydrodynamic properties of molecules), by measurement of the time decay of delta n, revealed the existence of a multicomponent or polydisperse system, whatever the tubulin solution. Two relaxation times, representative of the smallest and the largest orientated species, were obtained by computer-fitting analysis. The mean values of relaxation time for phosphocellulose-purified tubulin were 0.8 and 8 microseconds. In microtubule protein solutions, large-sized macromolecular species with relaxation time up to 450 microseconds were detected. The largest species (relaxation times ranging from 50 to 450 microseconds) could be eliminated by centrifugation at 3000000 X g for 1 h. Addition of microtubule-associated protein to either pure tubulin or high-speed centrifuged microtubule protein led to a rapid formation of large species analogous to those present in microtubule protein. Molecular dimensions of the relaxing structures were estimated using simple hydrodynamic models and values of rotational diffusion constants calculated from the relaxation times, and compared to those of the structures described in the literature. In conclusion, we have found that (a) phosphocellulose-purified tubulin is not only composed of elementary species (dimers) but also contains tubulin-associated forms of limited size (up to 7-10 dimers), (b) depolymerized microtubule protein solutions contain ring oligomers and structures very much larger, the formation of which is dependent on the presence of microtubule-associated protein.

Animals↗
PubMed1985

Higher order structure of chromatin: influence of ionic strength and proteolytic digestion on the birefringence properties of polynucleosomal fibers.

Effects of ionic strength and proteolytic digestion on the conformation of chromatin fibers were studied by electric birefringence and relaxation measurements. The results confirm that at low ionic strength chromatin presents structural features reflecting those observed in the presence of cations. Soluble chromatin prepared from rat liver nuclei by brief nuclease digestion exhibits a positive birefringence. As the salt concentration is increased, the transition to a compact solenoidal structure is deduced from changes in electro-optical properties: the positive birefringence gradually decreases and the observed reduction in 40 mM NaCl is nearly 95%; the relaxation time decreases dramatically and the character of the kinetic changes since the decay of birefringence described initially by a spectrum of relaxation times becomes monoexponential. On digestion with proteases at low ionic strength we observe at first a rapid increase of the positive birefringence concomitant with an increase of the relaxation time. Then the birefringence decreases and becomes negative. Chromatin undergoes two successive transitions: the first transition is explained by a lengthening of nucleosomal chains without modification of the orientation of nucleosomes within the superstructure and the second one by the unwinding of the DNA tails and internucleosomal segments. When chromatin is digested at 30 mM NaCl we find a single unfolding transition characterized by the decrease of birefringence and a slight increase in the relaxation time. The results imply that the positive birefringence of chromatin does not depend on the presence of whole histone H1 and that a salt concentration of 30 mM NaCl is sufficient to modify the initial site or/and the effects of proteolytic attack.

Animals↗
PubMedDate not supplied

Safety of percutaneous internal jugular catheterization in cancer patients: prospective observational study.

PURPOSE: To determine predictors for failure and early complications of percutaneous internal jugular catheterization (IJC) in cancer patients. METHODS: Six hundred and thirty consecutive cancer patients who required central venous catheterization were included in a prospective observational study. The rates of failure (defined as the intervention of a second physician and/or failure at initial insertion site) and of early complications were prospectively ascertained. Logistic regression analysis estimated odds ratio (OR) and 95% confidence intervals (95% CI) for independent predictors for failure and early complications of percutaneous IJC. RESULTS: The failure rate was 6.7%, and the early complication rate was 6.7%. In multivariate analysis, left-side initial catheterization (p<0.01), prior catheterization at the same site (p=0.001) and physician inexperience (p<0.0001) were independently associated with failure. Placement requiring more than one needle pass (p<0.01 for two and p<0.0001 for three and more) and absence of fluoroscopy (p<0.0001) were independently associated with early complications. CONCLUSIONS: Percutaneous IJC is a valid option in the central venous catheterization of cancer patients due to its reliability and safety. Skilled physicians must manage difficult placements. If placement requires more than one needle pass or is made without fluoroscopy, patients must be carefully followed for potential complications.

Journal Article↗
PubMedDate not supplied

[The first total hip prostheses in man (1890 - 1960)].

We owe the first total prosthesis to Th. Gluck from Berlin (1880-1890), (they were in ivory), and to Jules Pean from Paris (1890-1894) (they were in platinum and cemented with plaster and pumice). Hardly successful though they were, the idea of replacing an articulation by foreign material was born. It would take sixty years to come to a successful hip total prosthesis. In the 1930 ies, Smith-Petersen, from Boston, designed moulds to be set between the femoral head and a cotyle in glass, pyrex, Bakelite and eventually a metal cupule (vitallium) either set on to the cotyle or the femoral head. After 1940 Bohlmann and Moore were the first to replace the upper part of a femur bearing a tumour and a metal prosthesis. In 1947, Jean and Robert Judet proposed a femoral head in acrylic. The first successful femoral prosthesis (more than 50 % good results) was Moore's new metal prosthesis in 1950. In the 50ies, some surgeons had the idea of connecting the two prosthetic pieces (cupule and femoral prosthesis) to get a total prosthesis, mainly in metal (Mc Kee from Norwich in 1951 and Herbert from Aix les Bains around 1955). In 1960, Charnley used dentist's methalcrylate cement for a Moore femoral prosthesis. In 1962, Charnley used this cement for a total prosthesis, with the low-friction concept and a 22 millimeter femoral head, which could move in a polyethylene cupule. This prosthesis is still in use today, in 1999.

Hip Prosthesis↗
PubMedDate not supplied

[Monitoring of clinical trials and interim analysis. 1. Monitoring committee].

In order to fulfil the ethical principles linked to the protection of patients randomized in a controlled clinical trial, monitoring procedures need to be set up. In this context, a committee of experts, called the data monitoring committee is in charge of reviewing regularly unblinded data to assess the quality and the relevance of the trial, to evaluate the evidence of an emerging treatment difference and to control the rate of occurrence of serious adverse events. After each meeting, the monitoring committee reports to the steering committee its recommendation to continue or to stop the trial prematurely. Protocol modifications might be proposed as well. Illustrated with several examples, this article reviews different situations a monitoring committee might have to tackle with.

Clinical Protocols↗
PubMedDate not supplied

[Monitoring of clinical trials and interim analysis. 2. Statistic methods].

Although the decision to continue or to stop prematurely a clinical trial is not solely based on statistical tests, they bring useful objective arguments to the data monitoring board. However, the multiple use of statistical tests leads to increase the risk of false positive conclusions in favor of one of the treatments, and several methods have been developed to address this problem. This article presents the four major strategies that are being used for monitoring clinical trials, as well as the rationale for planning and using such statistical monitoring procedures.

Bayes Theorem↗
PubMedDate not supplied

[Quality of life assessment in therapeutic trials. Conceptual aspects and presentation of a questionnaire].

The importance of assessing the quality of life is more and more emphasized when therapeutic effects are to be studied. However, if its theoretical bases appeared as rather well established, they are not yet effectively translated into the presently available instruments: there is not yet any "gold exchange standard" in this field. This fact is the result of the difficulty of this translation and of the medical tendency to reduce the assessment of the quality of life to the assessment of the health. The second part of this paper is thus devoted to the presentation of a new instrument ("PQVS" in french, or "QLPI" for "Quality of Life Profile Inventory"). It was devised for applying the theoretical bases of the study of the quality of life. It thus allows for the assessment: 1) of the quality of the global life, 2) of the quality of what is experienced in several dimensions of the life, and 3) of the individual structure of the quality of life.

Activities of Daily Living↗