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Biomedical subjects

A Flahault

Publications and source records attributed to A Flahault.

At least 19 recordsLinked to original sources
PubMed1998

Fetal hemoglobin and F-cell responses to long-term hydroxyurea treatment in young sickle cell patients. The French Study Group on Sickle Cell Disease.

We have studied the cellular and molecular responses to long-term hydroxyurea (HU) treatment in 29 severely affected young patients with sickle cell disease (mean age, 10.9 +/- 4.1 years). Patients received HU at 20 mg/kg/d on 4 consecutive days per week initially, with a monthly escalated dose avoiding marrow-toxicity (mean steady-state dose, 34.2 +/- 4.6 mg/kg/d) for 12 to 36 months (mean duration, 22 months). The studied parameters were hemoglobin F (HbF), F reticulocytes (F retics), F cells, the amount of HbF per F cell (F/F cell), polymer tendency at 40% and 70% oxygen saturation, and hemolysis. Initial HbF (Fi) was dispersed (from 0.85% to 13.9%). HbF increased in all patients but 1. HbF at maximal response (Fmax) reached a sustained level varying from a 1.5-fold to a 16-fold Fi after a variable delay (6 to 24 months). Fmax was not related to HU dosage, but triangle upF (Fmax - Fi) was strongly correlated to triangle upMCV (MCVmax - MCVi). HbF increase resulted from the increase of both F cells and F/F cell. In this rather short series, Fi and Fmax were not significantly associated with age, gender, or beta-globin haplotype. Neither Fmax nor triangle upF was related to bone marrow reserve, as measured by baseline reticulocyte or neutrophil counts. However, Fmax was highly dependent on Fi. When patients are individualized into three groups according to Fmax (group 1, Fmax >20% [12 patients]; group 2, 10% < Fmax < 20% [11 patients]; group 3, Fmax <10% [5 patients]), Fi is significantly different between groups, being the highest in group 1. In addition, the best responders (group 1) were significantly different from patients in the two other groups with higher levels of total hemoglobin, decreased bilirubin, and decreased polymer tendency.

Adolescent↗
PubMed1998

Comparative evaluation by semiquantitative reverse transcriptase polymerase chain reaction of MDR1, MRP and GSTp gene expression in breast carcinomas.

Identification and quantitative evaluation of drug resistance markers are essential to assess the impact of multidrug resistance (MDR) in clinical oncology. The MDR1 gene confers pleiotropic drug resistance in tumour cells, but other molecular mechanisms are also involved in drug resistance. In particular, the clinical pattern of expression of the other MDR-related genes is unclear and their interrelationships are still unknown. Here, we report standardization of the procedures used to determine a reliable method of semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) using a standard series of drug-sensitive and increasingly resistant cell lines to evaluate the expression of three MDR-related genes, i.e. MDR1 (multidrug resistance gene 1), MRP (multidrug resistance related protein) and GSTp (glutathione-S-transferase p), reported to be endogenous standard genes for normalization of mRNAs. A total of 74 breast cancer surgical biopsies, obtained before any treatment, were evaluated by this method. When compared with classical clinical and laboratory findings, GSTp mRNA level was higher in diploid tumours. However, the main finding of our study suggests a clear relationship between two of these MDR-related gene expressions, namely GSTp and MRP. This finding provides new insight into human breast tumours, which may possibly be linked to the glutathione conjugate carrier function of MRP. Well defined semiquantitative RT-PCR procedures can therefore constitute a powerful tool to investigate MDR phenotype at mRNA levels of different related genes in small and precious tumour biopsy specimens.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1998

Neuropsychological prediction of dementia in Parkinson's disease.

OBJECTIVE: To identify neuropsychological characteristics predictive of later dementia in Parkinson's disease. METHODS: A comprehensive neuropsychological test battery was administered to a cohort of 89 initially non-demented patients with Parkinson's disease consecutively enrolled at a specialised Parkinson's disease clinic. They were reassessed after a mean of 3.5 years for the diagnosis of dementia. The Cox proportional hazards model was used to identify baseline characteristics predictive of dementia. RESULTS: Only four of the baseline clinical characteristics of Parkinson's disease and neuropsychological variables remained independently linked to subsequent development of dementia: the age of onset of Parkinson's disease (>60 years; relative risk (RR) 4.1, 95% confidence interval (95% CI) 1.8-24.0, p<0.03), the picture completion subtest of the Wechsler adult intelligence scale (score<10; RR 4.9, 95% CI 1.0-24.1, p<0.02), the interference section of the Stroop test (score<21; RR 3.8, p=0.08), and a verbal fluency task (score<9; RR 2.7, 95% CI 0.8-9.1, p=0.09). Depressive symptoms and the severity of motor impairment were not predictive of dementia. CONCLUSION: These features are different from the neuropsychological characteristics predictive of Alzheimer's dementia in healthy elderly people (mainly memory and language performance). They are in keeping with the well known specificity of the impairments in Parkinson's disease for visuospatial abilities and difficulties in inhibiting irrelevant stimuli. It is postulated that the composite nature of the picture completion subtest, involving several cognitive abilities impaired in Parkinson's disease, explains its sensitivity.

Aged↗
PubMed1998

Neutrophil alveolitis in bronchioloalveolar carcinoma: induction by tumor-derived interleukin-8 and relation to clinical outcome.

Tumor infiltrate, predominantly constituted by lymphocytes, may represent an important prognostic factor in bronchioloalveolar carcinoma (BAC), in addition to tumor extension and histological type. In the present study, we determined the presence, the origin, and the prognostic importance of neutrophils that also participate in leukocyte infiltrates of BAC. Neutrophil alveolitis was determined immunohistochemically in both lung biopsies and bronchoalveolar lavage (BAL) fluid samples from 29 patients with histologically proved BAC. The local expression of interleukin (IL)-8 was determined by immunohistochemical and immunoenzymatic techniques. Neutrophil counts were analyzed in relation to the clinical outcome of patients by the Kaplan-Meier method and Cox's univariate and stepwise multivariate models. Lymphocytes and neutrophils dominated the inflammatory cell population in the lower respiratory tract of patients with BAC. Neutrophils were located mainly in the alveolar lumen and seldom in alveolar wall whereas lymphocytes were exclusively present in alveolar wall. A relationship was observed between the number of neutrophils and the level of IL-8 in BAL fluid suggesting the involvement of that chemokine in neutrophil recruitment. The tumor cells were the predominant cells that appeared to express IL-8 by immunolocalization. The presence of increased numbers of neutrophils was significantly associated with a poorer outcome in patients with BAC (P = 0.02). In a multivariate analysis, the neutrophil percentage in BAL fluid was an independent predictor of clinical outcome. The risk of death was increased substantially (rate ratio, 5.2; 95% confidence interval, 1.1 to 24.7) among patients with BAL neutrophil percentage of > or = 39% (median of the distribution) as compared with the others. In BAC, neutrophils accumulate in the alveolar lumen. Elaboration of IL-8 by tumor cells may be responsible for this event, which is associated with a significantly higher risk of death.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1996

Increased placental antifibrinolytic potential and fibrin deposits in pregnancy-induced hypertension and preeclampsia.

Preeclampsia is characterized by maternal hypercoagulable state and intravascular coagulation, microthromboses in several organs, and impairment of uteroplacental circulation. Excessive fibrin deposition occurs in the placenta, suggesting that disorders of placental coagulation and fibrinolysis physiologic systems may have a role in hemostasis activation. Term placentas were collected from 17 hypertensive/preeclamptic women and from 17 healthy pregnant women, and processed for both histologic and hemostasis studies. Placental fibrinoid deposition was visualized by cresyl-violet staining and quantified by histomorphometric analysis. The content in hemostasis factors was measured on extracts from homogenized placentas treated by a nonionic detergent. The percentage of villi with fibrinoid deposits was higher in the diseased placentas than in controls: 13.2 +/- 11.2 versus 6.75 +/- 2.7% (p < 0.001) for the total amount of deposits; 4.8 +/- 6.7 versus 1.5 +/- 1.0% (p = 0.04) for perivillous fibrinoid deposits, which are considered as histologic markers of intraplacental fibrin. The content in type 2 plasminogen activator inhibitor (PAI-2) antigen was higher in the diseased placentas than in controls: 124 +/- 8 versus 104 +/- 6 ng/mg placental protein (p = 0.046); there was a negative correlation between PAI-2 antigen and thrombomodulin activity (r = -0.57, p = 0.02) in the diseased placentas. No significant differences were found between the two groups for placental procoagulant tissue factor and anticoagulant thrombomodulin activities, and for the content in plasminogen activators and PAI-1 antigens. Placental antifibrinolytic potential is increased in pregnancy-induced hypertension and preeclampsia. This change, and the association of the highest PAI-2 placental concentrations with the lowest concentrations of thrombomodulin, may contribute to the prethrombotic state and to the excessive placental perivillous fibrin deposition observed in these situations.

Adult↗
PubMed1996

[Management of bronchial infectious episodes in general medicine].

BACKGROUND: Acute bronchitis and chronic obstructive pulmonary disease exacerbations are frequent reasons for consultation with a general practitioner (GP). Since no consensus exists about the use of antibiotics in such indications and little is known about the use of pulmonary function tests in general practice, our objective was to describe GP's attitudes and prescription habits when faced with patients suffering from acute bronchitis (AB) or chronic bronchitis (CB) exacerbation. METHODS: The GPs participating in public health surveillance through the "réseau Sentinelles" (French Communicable Diseases Network) in March 1993 answered a postal questionnaire. This questionnaire collected their clinical attitude and prescriptions for 7 clinical cases of varying severity. RESULTS: 430 (94.7%) of the GPs answered the questionnaire. Of these more than 95% prescribed antibiotics in all the clinical cases, including for common acute bronchitis. Wide spectrum penicillins and macrolides were prescribed significantly less often as the past history increased in severity, whereas tetracyclins and oral cephalosporins were prescribed significantly more often in severe cases. Fluoroquinolones were nearly exclusively reserved for the treatment of advanced CB. Smoking cessation was systematically advised by the GPs. Faced with AB and a smoking history, 44.2% of the GPs prescribed a chest x-ray. In the case of repeat episodes of winter bronchitis, more than 70% of them evoked the diagnosis of CB. 98.% of the GPs had easy access to pulmonary function tests (PFTs) which 69.2% of the GPs prescribed as soon as CB was suspected. CONCLUSION: In the absence of a therapeutical consensus regarding bronchitis, antibiotics were prescribed virtually systematically. PFTs were not yet a routine gesture in general practice even though they were widely available and prescribed.

Acute Disease↗
PubMed1996

The "SentiWeb" method for exploring a database on the Net.

Return of information is one of the main goals of any public health information system. About 25,000 maps and 10,000 graphs may be obtained from the time-series collected in the database of the French Communicable Diseases Network (FCDN). Furthermore, this huge epidemiological atlas is updated each week. What is the optimal way of returning such information? This report discloses the strategies used for enhancing the access facilities to the FCDN database for any users, particularly those without specific training in epidemiology or database query language. The technical options implemented in the SentiWeb server (http:/(/)www.b3e.jussieu.fr) are discussed.

Communicable Diseases↗
PubMed1995

Human papillomavirus infection in the malignant and premalignant head and neck epithelium.

A prospective study was undertaken to determine the prevalence and histological correlates of human papillomavirus infection in the head and neck epithelium. Oral, pharyngeal, and laryngeal paraffin-embedded samples were analyzed by polymerase chain reaction with use of human papillomavirus E6 consensus sequence primers. Human papillomavirus infection was detected in 20 of 126 (15.9%) patients. Twenty-five of 230 (10.9%) samples contained human papillomavirus DNA. Papillomaviruses were detected in 15 of 131 (11.4%) head and neck squamous cell carcinomas, in 3 of 32 (9.4%) dysplasias, and 2 of 19 (10.5%) keratoses. The most commonly identified human papillomavirus in cancerous, precancerous, and keratotic lesions was type 16 (80.0% of the isolates). Five papillomas were shown to contain human papillomavirus type 6. No other lesion in 42 samples contained human papillomavirus. Our data are consistent with the hypothesis that infection with certain types of human papillomavirus contributes to head and neck cancer although this may be so only in a minority of cases. Human papillomavirus infection may play a role in the earliest stages of tumorigenesis, since papillomaviruses can be found in laryngeal premalignant and keratotic lesions, which are closely linked to tobacco use.

Adolescent↗
PubMed1994

A mathematical model for the European spread of influenza.

Following a study modelling the geographical spread of influenza in France, on the basis of population movements through the use of railroad data, we applied the same methodology on a European scale. We simulated an epidemic within a network of 9 European cities (Amsterdam, Berlin, Budapest, Copenhagen, London, Madrid, Milano, Paris, Stockholm), only taking into account regular between-cities air transport. Transportation data were obtained from the International Civil Aviation Organization (1991). The theoretical results show that the time lag for action is probably short (less than one month) after the first detection of an epidemic focus.

Aviation↗
PubMed1993

Resistance to methicillin and virulence of Staphylococcus aureus strains in bacteriemic cancer patients.

OBJECTIVE: To estimate the relation between resistance to methicillin and virulence in strains of Staph. aureus by estimating the survival at day 30. DESIGN: Case control analysis. SETTING: Inpatients at a major Cancer Referral Center. PATIENTS: 21 patients with methicillin-resistant Staph. aureus (MRSA) bactaeremia and 45 patients with methicillin-susceptible Staph. aureus (MSSA) bactaeremia, all treated with vancomycin. MEASUREMENTS AND MAIN RESULTS: Fewer MRSA than MSSA patients were neutropenic (p = 0.04), but more MRSA patients were hospitalized in intensive care units (p = 0.03), had had surgical episodes (p = 0.06). MRSA patients also had more microbiological samples cultured (p = 0.007). The outcome of the bacteriemic episodes in 14 MRSA and 14 MSSA patients matched for these four factors showed that blood cultures from MRSA patients remained positive significantly longer (p = 0.04), but that survival and length of hospital stay were not significantly different. CONCLUSIONS: These results do not indicate that methicillin-resistance in Staph. aureus is associated with increased virulence.

Adolescent↗
PubMed1993

Causality assessment of adverse reactions to drugs--II. An original model for validation of drug causality assessment methods: case reports with positive rechallenge.

Standards are lacking for validation of drug causality assessment methods. An original model is proposed using a positive rechallenge as an external standard. This model was used to validate the novel causality assessment method (RUCAM) described in the previous article (Part I; J Clin Epidemiol 1993; 46: 1323). Seventy seven reports of drug-induced acute liver injuries with positive rechallenge were collected from the medical literature and divided into 49 cases and 28 controls. The RUCAM was applied to information obtained prior to readministration. The score was significantly higher (p < 10(-4)) in cases than in controls with high levels of sensitivity, specificity and predictive values. It is concluded that (1) adverse drug reaction reports with a positive rechallenge can provide a standard for validation of causality assessment methods, (2) RUCAM applied to drug-induced liver injuries has been validated.

Age Factors↗