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Biomedical subjects

F Guillemin

Publications and source records attributed to F Guillemin.

At least 145 records · Page 8Linked to original sources
PubMed1996

Spectroscopic and biological testing of photobleaching of porphyrins in solutions.

The photobleaching of protoporhyrin IX (PP IX) and hematoporphyrin derivative (HpD) solutions was followed using three different methods: spectrophotometry, fluorometry and photodynamically induced cytotoxicity. The latter entails photoirradiation of HT29 human colon adenocarcinoma cells in the presence of preirradiated solutions of HpD and PP IX (lambda < or = 415 nm). The highest cytotoxicity was observed in the presence of unirradiated dye and decreased with the time of preirradiation. This decay in photocytotoxicity was further used to determine the porphyrin photobleaching kinetics in solution. For both sensitizers, quantum yields of photobleaching obtained by matching fluorescence were higher than that obtained from absorbance measurements (10 and 11 times for HpD and PP IX, respectively). This difference reflects preferential photobleaching of photolabile monomeric forms compared to aggregated. The highest quantum yield was obtained in the biological test (decay in cytotoxicity) which was 14 times higher for HpD and 30 times higher for PP IX than the quantum yield obtained from absorbance measurements. The absence of correlation between biological and fluorescence measurements has to be taken into account in the in vivo situation. Dark storage of preirradiated sensitizers (37 degrees C, 24 h) completely restored photocytotoxity for PP IX but only partially for HpD, whereas fluorescence patterns were partially restored for both sensitizers.

Fluorometry↗
PubMed1996

[Validation of the St George's questionnaire for measuring the quality of life in patients with chronic obstructive pulmonary disease].

The validity of a French version of a disease specific quality of life instrument, the St George's Respiratory Questionnaire, has been assessed in a sample of 64 patients with chronic respiratory disease undergoing oxygen therapy. The studied properties were internal consistency, test-retest reproducibility and criterion validity. The St George's showed a good internal consistency with Cronbach's alpha coefficients from 0.61 to 0.95 and a good reproducibility with Intraclass Correlation Coefficients (ICC) from 0.67 to 0.95. High correlation with dyspnea (p=0.0004 to 0.01) showed a correct criterion validity. So psychometric properties of the French version of the questionnaire are good. However, its administration caused a few problems, and we advice it to be administered by a trained interviewer in such patients.

Activities of Daily Living↗
PubMed1996

[Unidimensionality of a functional measure for patient with an injured upper limb].

The construction of an instrument including a number of tests requires an analysis of its structure and its unidimensionality (which allows calculation of global score), and the determination of the difficulty level of various tests. This study examined a tool including 67 tests designed to evaluate the functional ability of patients with an injured upper limb. The patients seen in a rehabilitation centre during 12 months (173 subjects) were evaluated by the occupational therapists familiar with the tool. The statistical analyses were made using the principal component analysis method (PCAM), the Cronbach's coefficient and the Rasch model. The PCAM showed 3 principal factors which explained 44%, 10% and 4% of the total variance respectively in the case of patients with injured dominant limb. The predominance of the first axis and the high ratio of first by second eigenvalues suggested the unidimensionality of the tool. The Cronbach's value of 0.97 attested the good congruence of the items. The results obtained with the Rasch model seemed to be consistent with the hypothesis of the unidimensionality of the tool. This analysis also provided the difficulty scale of various tests. Similar results were obtained in patients with injured non dominant limb or with all the sample. The methods used provide complementary results.

Activities of Daily Living↗
PubMed1996

Validation of the French version of the arthritis impact measurement scales 2 and comparison with the french version of the Nottingham Health Profile. "Quality of Life in Rheumatology" Task Force.

Appropriate attention can be directed to quality of life indices in the evaluation of therapeutic interventions only if reliable, valid measurement tools with good sensitivity to change are available. The goal of this study was to validate the French version of the Arthritis Impact Measurement Scales 2 (AIMS2), called EMIR (Echelle de Mesure de l'Impact de la polyarthrite Rhumatoïde) and to compare it with the validated French version of the Nottingham Health Profile, called ISPN (Indicateur de Santé Perceptuelle de Nottingham). The French version of the AIMS2 (37 items, 12 dimensions) was obtained via several independent translations and back-translations, followed by selection of the most relevant items by a panel of experts and a preliminary evaluation in rheumatoid arthritis patients. The measurement properties of EMIR (reliability, validity and sensitivity to change) were investigated in a cohort of rheumatoid arthritis patients who were put under methotrexate therapy and followed up for six months. Reliability was evaluated by test-retest at a ten-day interval (intraclass coefficients of correlation). Principal component factorial analysis was used to study construct validity and Cronbach's alpha coefficients to study internal consistency. Convergent validity was evaluated based on correlations between the quality of life scores obtained in selected dimensions of the EMIR and a number of other parameters (number of painful/swollen joints, pain severity score on a visual analog scale, erythrocyte sedimentation rate). Sensitivity to change after three and six months was determined by calculating mean standardized response means. The EMIR and ISPN were compared based on scores and sensitivity to change for the dimensions that investigated the same concepts. One hundred twenty-seven rheumatoid arthritis patients scheduled for methotrexate therapy were entered into the study. Principal component analysis established that all dimensions of the EMIR were independent from one another, except the "walking and bending" dimension. Internal consistency was satisfactory for each of the 12 dimensions, with Cronbach's alpha coefficients ranging from 0.70 to 0.90. Most correlations between quality of life scores and clinical or laboratory parameters were significant, indicating satisfactory convergent validity. The reliability study also yielded satisfactory results, with intraclass coefficients ranging from 0.65 to 0.90. Sensitivity to change after three and six months was significant for 11 of the 12 dimensions (mean standardized responses, 0.30 to 0.77). Sensitivity to change was slightly better for the EMIR than for the ISPN. Analysis of scores demonstrated that these two instruments did not measure quality of life in exactly the same way but complemented each other.

Adult↗
PubMed1996

Validity, reliability, and sensitivity to change of a French version of the arthritis impact measurement scales 2 (AIMS2) in patients with rheumatoid arthritis treated with methotrexate.

OBJECTIVE: To develop and validate a cross cultural version of the Arthritis Impact Measurement Scales 2 (AIMS2) to be used by French speaking populations. METHODS: A French version of the AIMS2 was obtained using back translation, committee review, and pretesting. The French AIMS2 was studied in 127 patients with rheumatoid arthritis (RA) about to receive therapy with methotrexate (MTX). Construct validity of the questionnaire was assessed by factor analysis. Convergent validity was evaluated by correlation coefficients with joint counts, pain assessment, and sedimentation rate. Reliability was assessed by test-retest procedure at a 10-day interval, Cronbach's coefficients of internal consistency, and within scale factor analyses. Sensitivity to change after 12 and 24 weeks of therapy with MTX was assessed with computation of standardized response means (SRM) and paired t test comparisons. RESULTS: Factor analyses of the French version clearly identified the same scales of the AIMS2, except for the walking and bending scale which loaded on several factors. Convergent validity of the physical and symptom components of the instrument was demonstrated by significant correlations with clinical and laboratory features. All the scales were reliable (intraclass correlation coefficients: 0.65 to 0.90; percentage of explained variance larger than 50% in all but one scale; Cronbach's alpha: 0.70 to 0.90). Sensitivity to change was demonstrated in 11 of the 12 scales (SRM: 0.30 to 0.77). Most of the improvement was noted by Week 12. CONCLUSIONS: This cross cultural adaptation of AIMS2 in French is valid, reliable, and responsive in patients with RA in whom MTX therapy is instituted. It would permit international comparison studies. This study provides evidence for construct validity and responsiveness of the original version of the AIMS2, not demonstrated previously.

Activities of Daily Living↗
PubMed1996

[Cytotoxicity of tamoxifen and its principal metabolites in human breast cancer cell lines].

The antiestrogen tamoxifen (TAM) has been successfully used to treat breast cancer expressing estrogen and progesterone receptors (ER+ and PR+). However, the development of antiestrogen resistance is frequently observed in patients following long-term treatment. To better understand the mechanism of action of TAM and its main metabolites: N-desmethyltamoxifen (N-des-TAM) and 4-hydroxytamoxifen (4-OH-TAM), their growth inhibitory effect was studied in 5 breast cancer cell lines characterized by different estrogen receptor levels: MDA-MB 231 (ER-), MCF-7 R (ER-), T47D (ER+), ZR-75/1 (ER+) and MCF-7 (ER+) trying to reproduce a cellular heterogeneity encountered in human breast tumors. In this study, the effects of TAM, N-des-TAM and 40-H-TAM on the cell growth were tested at concentrations ranging from 10(-8) to 10(-6)M with or without estradiol (10(-8)M). Only 4-OH-TAM showed a clear antiestrogen dose-dependent effect. Moreover, the finding of an antiproliferative activity at the highest dose (10(-6)M) for TAM, 4-OH-TAM and N-des-TAM in the ER- and PR- cell line MDA-MB 231 supports the hypothesis that TAM could be effective on ER+ as well as ER- tumors by an ER-independent mechanism. Despite ER+ and PR+ status after 2, 4 and 6 days of treatment, the T47D cell line displayed an increased growth rate with N-des-TAM at 10(-6)M. It should be noted that such concentration is within the range of the plasma level of N-des-TAM (10(-6)M) in patients receiving TAM per os (40 mg/day). These results and the well-known cell heterogeneity of human breast tumors may significantly account for some failure of antiestrogen treatment.

Adenocarcinoma↗
PubMed1996

[In vitro comparison of the photodynamic activity of meso-tetra (m-hydroxyphenyl) chlorin and hematoporphyrin derivative].

Meso-tetra (hydroxyphenyl) chlorin (mTHPC) was evaluated in vitro in HT29 human colon adenocarcinoma cell line and compared with hematoporphyrin derivative (HpD). The incorporation kinetics, evaluated by flow cytometry showed that mTHPC and HpD cellular uptake was related to the incubation time until 12 hours, then a plateau appeared. Cytotoxicity assays were performed using MTT test after photoirradiation at 650 nm for mTHPC and 630 nm for HpD. The photodynamic activity of both photosensitizers was influenced by serum protein of the culture medium and time interval between irradiation and photocytotoxicity test with a maximal activity 24 and 48 hrs after the photoirradiation. In optimized experimental conditions i.e. 2% serum protein- containing culture medium, 24 hr-incubation period, cytotoxicity measured 48 hrs after exposure, 10 J/cm2 light fluence, mTHPC appeared approximately 20-fold more active than HpD with IC50 values of 0.2 micrograms/mL and 4.2 micrograms/mL, respectively.

Adenocarcinoma↗
PubMed1996

[Quality of life after orthopedic surgery of the lower limbs. A new approach].

Measuring quality of life is a new approach of interest to all health professionals involved in orthopedic surgery. This paper is an introduction to the multidimensional concept of health related quality of life. Various types of measurement instruments are described: first the psychometric questionnaires, distinguishing generic measures useful in various conditions and disease-specific measures for a given disease or condition, and the recently developed individual instrument; second, econometric measures based on the decision theory. The potential objectives for use and the required measurement properties of these instruments are described. The need and corresponding methods for a cross-cultural adaptation into French when using questionnaire originally developed in English are reported. A literature review focuses on studies reporting such measures used to evaluate orthopedic surgery, particularly in the way patients perceive the results of hip and knee arthroplasty. Further perspectives for clinical and epidemiological research are numerous. Several avenues for research and for use in clinical practice are proposed.

Decision Support Techniques↗
PubMed1996

[Axillary lymphoceles after breast cancer surgery. Pathogeny, prevention].

We report a retrospective series of 126 patients seen in 1992 for conservative surgery (group T) or Patey procedure (group P) for breast cancer. We looked for factors predictive of axillary lymphocele and their prevention. Axillary lymphadenectomy performed in patients undergoing surgery for breast cancer leads to a certain degree of morbidity including the development of lymphoceles. The mean number of lymph nodes removed was 16 in group T and 19 in group P. Mean lymphorrhea was 741 cm3. Two factors were significantly implicated in the pathogenesis of postoperative lymphorrhea : the number of nodes resected (p < 0.005) and obesity (p < 0.001). Prevention of lymphoceles requires meticulous lymphostasis and reduction of the surgical detachment spaces.

Adult↗
PubMed1995

Environmental and genetic factors affecting bone mass. Similarity of bone density among members of healthy families.

OBJECTIVE: To evaluate the relative importance of environmental and genetic factors in the determination of bone mineral density (BMD) and to quantify the risk of low BMD in healthy young adults in relation to the BMD of their parents. METHODS: Dual-energy x-ray absorptiometry study of a series of 129 nuclear families (441 subjects), including 183 children over age 15, was performed. Correlation of BMD in children with BMD in their parents was studied in a linear model, taking into account environmental factors. Logistic regression was used to quantify the relative risk of lower BMD according to the parents' BMD level. RESULTS: BMD was significantly correlated with weight, height, and body mass index (BMI) in all family members, and with parents' alcohol consumption and with physical activity in fathers and sons. The BMD of the children correlated with that of their parents (r = 0.27). The child's BMI, his/her father's BMD and daily calcium intake, and his/her mother's BMD, BMI, and body fat accounted for 41.4% of the variance in the child's BMD. A son had a 3.8 times higher risk of having a low BMD if his father had a low BMD, and a daughter had a 5.1 times higher risk if her mother had a low BMD. CONCLUSION: The BMD of children in healthy families was related to the BMD of their parents as well as to environmental factors, confirming the contribution of genetic inheritance in the determination of bone density in young adults, especially in girls.

Adolescent↗
PubMed1995

Segregation analysis and variance components analysis of bone mineral density in healthy families.

Bone mineral density (BMD) was measured in 1992-93 in 129 nuclear families, including 258 parents and 183 children, and was analyzed for familial resemblance factors. BMD measurements were adjusted on weight and age. Segregation analysis rejected the monogenic hypothesis and exhibited a strong polygenic component. Variance components analysis was then used to estimate the parameters of a multivariate normal model including an additive polygenic component, a common environment factor, and a residual specific to each individual. The genetic component was independent of sex and age. The common environmental factor was not significant. The variance of the residual specific factor appeared to be a quadratic function of age, reaching its minimum value at 26.4 years. Consequently, the maximum value for heritability (ratio of genetic variance to total variance) is observed at this age (h2 = 0.84). According to this model, the correlation between two relatives is a function of the ages of each individual in the pair.

Adolescent↗
PubMed1995

Evaluation of plasma 5-fluorouracil nucleoside levels in patients with metastatic breast cancer: relationships with toxicities.

This paper describes the relationship between 5-fluorouracil (FUra)-derived toxicities and plasma levels of the FUra anabolites 5-fluorouridine (FUrd) and 5-fluoro-2'-deoxyuridine (FdUrd) monitored in patients receiving continuous infusions of FUra (1000 mg/m2 per 24 h) over 5 days preceded by the administration of cisplatin (100 mg/m2). A total of 63 courses of this treatment were given as second-line chemotherapy to 17 patients with metastatic breast cancer. The active FUra anabolites FUrd and FdUrd were monitored twice daily in the plasma by high-performance liquid chromatography. Data were analyzed using multiple analysis of variance (ANOVA). Only a low proportion of patients exhibited measurable plasmatic levels of FUrd (43%) and FdUrd (70%). The areas under the plasma concentration-time curves (AUC) determined over 120 h for FUrd (AUCFUrd) and for FdUrd (AUCFdUrd) were found to be statistically significantly different for chemotherapy cycles with and those without myelosuppression. Chemotherapy cycles without neutropenia were associated with low AUCFUrd values (mean +/- SEM, 2.9 +/- 0.7 micrograms ml-1 h) and high AUCFdUrd values (14.1 +/- 2.7 micrograms ml-1 h), respectively, whereas courses with myelosuppression (WHO grades 2-4) showed inverse profiles with high AUCFUrd values (16.3 +/- 2.3 micrograms ml-1 h) and low AUCFdUrd values (3.1 +/- 1.0 micrograms ml-1 h), respectively. A statistically significant difference in AUCFdUrd values was also observed between cycles with and those without mucositis (P = 0.0027), with AUCFdUrd values being 22.6 +/- 5.6 and 7.8 +/- 1.9 micrograms ml-1 h, respectively. Whereas hematotoxicity could be correlated with both AUCFUrd and AUCFdUrd values, mucositis was associated with high AUCFdUrd levels. Moreover, a negative correlation was found between the AUCs determined for FUrd and FdUrd (P = 0.002), indicating that activation of FUra via FUrd or via FdUrd may involve competitive processes. Therefore, to follow the development of the major FUra-derived toxicities, measurement of FUrd and FdUrd plasma levels appeared very attractive.

Adult↗
PubMed1995

Development of a criterion for response to therapy at 6 months in multiple myeloma.

UNLABELLED: To investigate the prognostic value of therapy at 6 months on survival in multiple myeloma, to develop a new criterion assessing response to initial therapy at 6 months, and to compare it to a current criterion. The types of initial and 6-month therapy were considered in a prognostic factor analysis in 70 patients treated in routine practice. Using the response to initial therapy defined by the clinician's decision as grouping variable in this group, a discriminant analysis identified the characteristics of responder patients. The validity of the resulting criterion was tested in another test group. Its prognostic ability was compared to the CLMTF criterion (50% M-component reduction from baseline). The therapy at 6 months, reflecting the clinician's appraisal of response to initial therapy, predicted survival significantly. A criterion combining two variables (M-component change and haemoglobin level at 6 months) classified 70% and 72.4% of patients correctly regarding response status in the training and test groups respectively. This criterion was shown to perform better than the CLMTF criterion in predicting survival. CONCLUSION: A new criterion for response to therapy at 6 months, also presented in a nomogram, combines M-component change and haemoglobin level at 6 months.

Aged↗
PubMed1995

Antivitamin K prevents heterotopic ossification after hip arthroplasty in diffuse idiopathic skeletal hyperostosis. A retrospective study in 67 patients.

We investigated the risk of heterotopic ossification (HO) after total hip arthroplasty in 67 patients, 16 of whom had diffuse idiopathic skeletal hyperostosis (DISH). DISH was diagnosed on chest, dorsolumbar and pelvic radiographs. HO was graded according to DeLee et al. (1976). After a 1.4 year follow-up, 21 patients had HO. The risk of HO was 5 times higher in DISH than in non-DISH patients, but lower in patients receiving antivitamin K than in those receiving other anticoagulant therapy (relative risk 0.2). Our findings lead us to recommend that DISH should be diagnosed preoperatively for preventive therapy. They also suggest a preventive effect of antivitamin K against heterotopic ossification after hip arthroplasty.

Acenocoumarol↗
PubMed1995

[Statistical study of a series of 672 cases of carcinoma of the uterine cervix. Results and complications according to age and modalities of treatment].

The study bears on 672 infiltrating carcinomas of the cervix treated from 1977 until the end of 1991, by a radiosurgical combination (311 patients) or by exclusive irradiation (361 patients). The radiosurgical series includes mostly stages IB and II and patients under 50 years because of the therapeutic protocol. Most of the patients aged over 50 years and all stages III were treated by exclusive irradiation. External beam irradiation was most often performed in 4 fields by linear accelerator of 12 and 25 MeV. Uterovaginal brachytherapy used the technique of molds. In 55 cases, a complementary interstitial brachytherapy was applied on residual node. A computer dosimetry was made for each patient with calculation of the doses delivered to organs at risk and to node areas (points of calculation ICRU n degrees 38). The results at 5 years are as follows for the total series: locoregional control (LRC) 79%, specific survival (SS) 73%, overall survival 70%. For stage I, the LRC of the radiosurgical series is 92%, that of the series of exclusive irradiation 87% (no significant difference, neither for SS if we consider the tumoral size); For stage II, the LRC is 70% in the radiosurgical series and 79% in the series of exclusive irradiation. There is no difference if proximal stage II is compared. Conversely, for distal stage II, the difference is very significant in favour of exclusive irradiation (LRC 31%/77%, SS 26%/70%, p < 0.006). If we consider the results according to age, the difference for distal stage II comes mostly from patients under 50 years and especially those aged 40 years or under. For stage III, the LRC is 61% for patients over 50 years and 34% for those aged 50 years or under (p = 0.006). As the nodes, the results of surgical pieces and lymphadenectomy are studied. The patients under 40 years in stages II and III present more metastases than others (p = 0.003). Among the therapeutic factors, the dose rate and the treatment duration were particularly studied. A detailed study of the complications is made for the radiosurgical series as for the series of exclusive irradiation according to the French Italian glossary of complications as well as a study of the factors inducing them.

Adenocarcinoma↗
PubMed1995

Effectiveness of spa therapy in chronic low back pain: a randomized clinical trial.

OBJECTIVE: To assess the overall effectiveness of spa therapy compared with usual routine drug therapy in chronic low back pain (LBP). METHODS: One hundred and twenty-one patients were randomly allocated to treatment (n = 59) and control (n = 62) groups. In the treatment group, patients underwent routine drug therapy and spa therapy 6 days/week for 3 consecutive weeks in Saint-Nectaire, France. In the control group, patients received routine drug therapy. Effectiveness was assessed based on clinical measures, duration and intensity of pain, Roland and Morris' disability questionnaire, the patient's overall evaluation of back health, and drug consumption (analgesic and antiinflammatory). Groups were compared using analysis of covariance with repeated measures. RESULTS: At 3 weeks, patients in the treatment group had significant improvement in all outcome variables (p < 0.0001) except for the Schober index and analgesic and antiinflammatory drug consumption. At 6 months, improvement was still significant for the same outcome variables (p < 0.0001), plus a significant reduction in analgesic consumption. CONCLUSION: This study suggests both immediate and 6 month effectiveness of spa therapy in chronic LBP. Spa therapy may be beneficial in the management of chronic LBP.

Analysis of Variance↗