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Biomedical subjects

F Courtois

Publications and source records attributed to F Courtois.

At least 19 recordsLinked to original sources

[Organization of urgent blood transfusion in France: analysis of practice patterns in centers involved in care delivery to multiple trauma patients].

OBJECTIVE: To describe the organization of medical and transfusion services within the framework of hospital admission for multiple trauma. STUDY DESIGN: National survey in France. MATERIAL AND METHODS: All French hospitals caring for multiple trauma patients were sent a questionnaire. Organization of the medical and transfusion services, and their related resources were evaluated. RESULTS: Among 372 questionnaires sent, 116 replies were received from structures which care for 18 (1-500) multiple trauma patients each year. An orthopaedic and an abdominal surgery unit were widely available whereas a neurosurgeon was available in 21% of responding centers. A transfusion site was found in 43%, whereas others have either a deposit for distribution to specific patients (40%) or a small deposit to cover urgent situations (17%). Comparison with legal or expert based rules of adequate transfusion process disclosed a variable incidence of practice dysfunctions (2-49%) depending on the parameter assessed. CONCLUSION: The French organization of multiple trauma patients' care and blood transfusion delivered for these patients is not homogenous. Dysfunctions were found in all types of hospitals. Recommendations describing good practice seem necessary to be built at the national level.

Blood Transfusion↗

[Management of blood products in the event of postpartum hemorrhage].

Transfusion during the treatment of postpartum hemorrhages is rare. It always occurs in complex situations: failure of the initial manipulations or cataclysmic bleeding. Its management is multidisciplinary and should aim at obtaining blood products within thirty minutes while preventing any risk of alloimmunization detrimental to the obstetrical future of the patient. Upstream process management is essential. The following points will be described: Within the legal bounds, the different options for blood products supply; the best practices procedures that every maternity hospital should set up and formalize; the immunohematologic documents to be used for transfusions, their validity and the criteria for the prescription of irregular antibody testing; the rules for antenatal management to anticipate the transfusion difficulties; the blood products available and their constraints of use to optimize the prescription. Effective management can be achieved only through the strict respect of procedures at every stage. These procedures should be written in conjunction with all actors, issued and regularly assessed.

Blood Transfusion↗

[Are the indications and choice of labile blood products adapted? National survey on prescriber's knowledge].

OBJECTIVE: There is little data available on current practice related to prescription of labile blood products (LBP) by French physicians. The aim of this study was to assess whether prescriptions were conform to Anaes (French Medicine's agency) guidelines, with regard not only to indications but also quality of the products, so as to define the improvements that could be made. METHOD: Thirty-four clinical case reports, classified by specialties were sent to prescribing physicians working in the regional health centers, from 17 different blood banks, from October 1997 to February 1998. The prescribers were requested to answer only the questions that were specific to their particular field of experience. Each case description included multiple choice questions on the indication for transfusion of concentrated of red blood cells (RBC) and/or platelets (CP) and/or plasma, and the possible requirements for specification or modification of the guidelines applicable to these products. The primary end point of analysis was the adequation of the answers to the Anaes recommendations. RESULTS: Answers were obtained regarding 5092 clinical cases from 818 physicians. The participation rate was of 30%. The specialties were as follows: 34% anesthesiologists, 14% oncologists-haematologists, 13% internal medicine specialists, 11% emergency physicians, 10% paediatricians, 8% obstetricians, 7% geriatricians, and 3% transplantation surgeons. Eighty-two percent of the answers came from physicians working in the public health services. The adequation with the indication for transfusion was of 90.3% for RBC, 92.3% for platelets and 93.8% for plasma. The percentages of correct answers regarding the indications for specification or modification of the LBP were as follows: 90.3% were correct for irradiation (of either RBC or platelets); 68.8% and 53.2% respectively for leukocyte depletion from RBC and platelets; 64% for phenotyped RBC; 68.2% for compatibilized RBC; and 57.3% for apheresis platelet concentrates. There was no difference in results depending on the type of center, private or public, and the quality of LBP prescribed. The answers obtained from the anaesthesiologists' clinical cases were less accurate with regard to RBC but more accurate with regard to PC compared with other specialists. CONCLUSION: This study shows the correct management of the indications for transfusion by the prescribing physicians who participated in the study, but the lack of knowledge with regard to the indications for specifications and/or transformations of LBP. The respect of the indications for transfusion is the corner stone of safe transfusion and this phase should be optimized with improved dissemination of information on transfusion and training for the physicians and programs that would improve the quality.

Blood Component Transfusion↗

[Insisting on intravenous polyvalent immunoglobulin therapy in polymyositis in spite of the occurrence of sever hemolytic anemia].

A 23-year-old female with polymyositis received high dose intravenous immunoglobulin (IVIg) therapy. The patient suffered severe hemolytic anemia after receiving first course of IVIg infusion. This adverse reaction was likely due to allohemaglutinin A and B and from or high molecular weight IgG complexes contained in the preparation. Though this effect was observed, the treatment was repeated six times. A mild hemolysis occurred following each IVIg, with no clinical consequence. Involvement of the saturation of macrophagic receptors might explain this partial destruction of erythrocytes.

Adhesins, Bacterial↗

Regulation of plastid rDNA transcription by interaction of CDF2 with two different RNA polymerases.

The plastid genome is known to be transcribed by a plastid-encoded prokaryotic-type RNA polymerase (PEP) and by a nucleus-encoded phage-type RNA polymerase (NEP). The spinach plastid rrn operon promoter region harbours three different, overlapping promoters. Two of them are of the prokaryotic type. The third promoter is a non-consensus-type NEP promoter. We separated three different transcriptional activities from spinach chloroplasts: PEP, the phage-type RNA polymerase NEP-1, and a third, hitherto undescribed transcriptional activity (NEP-2). NEP-2 specifically transcribes the rrn operon in the presence of the transcription factor CDF2. CDF2 was previously shown to recruit PEP to the rrn promoter to repress transcription. Together, our results suggest the existence of a third RNA polymerase in plastids and a mechanism of rDNA transcriptional regulation that is based on the interaction of the transcription factor CDF2 with two different transcriptional systems.

Blotting, Western↗

Reappraisal of the association between the DRD2 gene, alcoholism and addiction.

We analysed the impact of the TaqI A1 allele of the D2 dopamine receptor gene on the risk for alcoholism, trying to depict three explanations frequently proposed to explain discrepancies in association and linkage studies: that the A1 allele may act as a marker rather than as a vulnerability factor, that stratification biases and unevaluated controls may explain positive results, and that the A1 allele is modifying the phenotype rather than increasing the risk for alcoholism. We thus tested another (dinucleotide STRP) marker within the DRD2 gene, selected a new homogenous sample of 113 alcoholic patients and 49 unaffected controls strictly matched for ethnic origins, and systematically assessed both samples with a semi-structured interview to detect (in both samples) alcohol dependence, but also such related traits as specificities of complications. The frequency of the A1 allele was not significantly different between alcoholics and controls but when comparing different subgroups of alcoholics, the A1 allele was significantly more frequent in alcoholic patients with somatic complications (OR = 3.00, CI[1.37-6.62]), social and professional complications (OR = 2. 72, CI[1.25-5.90]), or with co-morbid dependence (OR = 2.88, 95% IC [1.16-7.15]). The association for co-morbid dependence and somatic complications was also positive when taking into consideration both STRP and TaqIA polymorphisms. The A1 allele does not increase the risk for alcoholism per se in our sample, but may be involved in a related trait which is partially dependent on the diagnosis of alcoholism, through a disequilibrium with another close mutation.

Adult↗

Iron-ascorbate alters the efficiency of Caco-2 cells to assemble and secrete lipoproteins.

Although oxidative stress has been implicated in development of gut pathologies, its role in intestinal fat transport has not been investigated. We assessed the effect of Fe(2+)-ascorbate-mediated lipid peroxidation on lipid synthesis, apolipoprotein biogenesis, and lipoprotein assembly and secretion. Incubation of postconfluent Caco-2 cells with iron(II)-ascorbate (0.2 mM/2 mM) in the apical compartment significantly promoted malondialdehyde formation without affecting sucrase activity, transepithelial resistance, DNA and protein content, and cell viability. However, addition of the oxygen radical-generating system reduced 1) [(14)C]oleic acid incorporation into cellular triglycerides (15%, P < 0.0002) and phospholipids (16%, P < 0.0005); 2) de novo synthesis of cellular apolipoprotein A-I (apo A-I) (18%, P < 0.05), apo A-IV (38%, P < 0.05), and apo B-48 (45%, P < 0.003) after [(35)S]methionine addition; and 3) production of chylomicrons (50%), VLDL (40%), LDL (37%), and HDL (30%) (all P < 0.0001). In contrast, increased total cellular cholesterol formation (96%, P < 0.0001), assayed by [(14)C]acetate incorporation, was noted, attributable to marked elevation (70%, P < 0.04) in activity of DL-3-hydroxy-3-methyl-glutaryl-CoA reductase, the rate-limiting enzyme in cholesterol synthesis. The ratio of Acyl-CoA to cholesterol acyltransferase, the esterifying cholesterol enzyme, remained unchanged. Fe(2+)-ascorbate-mediated lipid peroxidation modifies intracellular fat absorption and may decrease enterocyte efficiency in assembling and transporting lipids during gut inflammation.

Antineoplastic Agents↗

Increases in intracavernous penile pressure following injections of excitatory amino acid receptor agonists in the hypothalamic paraventricular nucleus of anesthetized rats.

PURPOSE: We examined whether N-methyl-D-aspartate (NMDA), amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid (AMPA) or trans-1-amino-1,3-cyclo-pentadicarboxylic acid (ACPD) increase intracavernous pressures when injected in the paraventricular nucleus of the hypothalamus. MATERIALS AND METHODS: Sprague-Dawley rats weighing 250 to 300 gm. were anesthetized with pentobarbital and placed in a stereotaxic apparatus after catheterization of the carotid artery and insertion of a 25 gauge needle in the corpus cavernosum. Both catheters were coupled to pressure transducer systems. Electrical stimulations with glass tungsten microelectrodes and chemical injections with a 0.5 microl. syringe were done in the paraventricular nucleus. At the end of each experiment rats were perfused with saline and 10% formalin solutions. Brains slices 16 microm. thick were mounted and stained with cresyl violet to identify chemical and electrical stimulation sites. RESULTS: Electrical stimulations of the paraventricular nucleus increased intracavernous pressure from 15.5 +/- 5.7 to 50.02 +/- 20.4 cm. H2O in 10 rats (p <0.001) and decreased central pressure in 10 (p <0. 001). Intracavernous pressure increased from 17.2 +/- 5.26 to 60.6 +/- 14.36 cm. H2O with NMDA, 26.0 +/- 8.9 to 49.6 +/- 12.2 cm. H2O with AMPA and 18.0 +/- 2.3 to 41.0 +/- 22.68 cm. H2O with ACPD when injected in the paraventricular nucleus of 5 rats (analysis of variance 12.18, df 3, p <0.007). Mean delays and durations varied between 3.6 to 4.0 and 5.6 to 7.0, respectively, and were similar for all agonists (analysis of variance not significant). CONCLUSIONS: Glutamate receptor subtypes NMDA, ACPD and AMPA cause an increase in intracavernous pressure when injected in the paraventricular nucleus. Therefore, increases in intracavernous pressure following injection of glutamate must be initiated by the synergistic or additive effects of all of these receptor subtypes.

Animals↗

[The Hemovigilance Commission of the University Hospital Center].

As suggested by the National Blood Council, a Hemovigilance Committee was set up in the University Hospital of Liège in 1995. A multidisciplinary discussion takes place on any action aiming at the improvement of transfusion safety, and the follow-up of its implementation. The first issue to be discussed was the set up of a detailed documentation of all blood transfusions. The data are now recorded on a single document allowing proper identification of people and products involved, and of the eventual incidents. This document has lead to a better transfusion safety and to an improved administrative management of blood transfusion. The Commission has been coordinating two multi-centric studies analyzing the consumption of fresh blood products and the incidence of transfusion reactions. Among blood-saving policies, autologous transfusion and volume reduction of samples drawn for laboratory purposes have been discussed. Other measures were taken to improve the labeling of samples for cross-mach and to actively follow-up transfusion reactions. By its actions and advises, the Commission aims to direct strategies towards a safe and rational use of blood products.

Belgium↗

[Risk behavior among blood donors: efficacy of a new questionnaire].

The clinical selection of volunteers for blood donation is essential to reduce the risk of viral transmission by blood transfusion. The aim of this study was to evaluate a new questionnaire for a pre-donation medical interview. This questionnaire was developed by transfusion practitioners, epidemiologists and professional investigators, and focused on risk behaviors of blood donors and their partners. Five blood banks in the French Ile-de-France region (around Paris), participated in the study from May 1995 to January 1996. All participating doctors were specifically trained by professional investigators. The sex and the age of donors, the type of collection, the duration of interviews and the reasons for exclusion from donation were recorded. The results were compared to those of a prior study dealing with a sample of 15,000 donors presenting the same characteristics, whose blood was taken of at the same collection sites in 1993. Of the 1,527 volunteers donating blood, 14% were interviewed in fixed centers and 86% by moving teams (38% in firms, 22% in towns, 13% in civil service facilities, 13% in school or academic centers). For 15.9% of the volunteers, this was the first donation (range: 7.3% in fixed centers to 41.5% in school and academic centers). The mean duration of the interview was 11 min (10 min for volunteers included, 14 min for donors excluded from donation). It decreased from 14 min at the beginning of the study to 10 min by the end of the study. The percentage of donors excluded for risk behavior (3.7% in 1995-96 vs 1.5% in 1993, P < 0.001), or medical reasons (12.2% in 1995-96 vs 8.4%, in 1993, P < 0.001) was significantly greater in 1995-96 than in 1993 (15.9% vs 9.9%, P < 0.001). In 1995-96, 35.0% of exclusions for risk behavior were related to male homosexuality, multiple partners or the risk behavior of the partner vs 12% in 1993 (P < 0.001). The risk of exclusion was 5.5 times higher for donors not living in a couple. The results obtained demonstrated the value of this new approach to the medical interview.

Adult↗

[Feasibility of following up transfused patients].

The aim of this study was to assess the natural history of patients after transfusion and the acceptability of a standardized biological follow-up. In 1995, during 1 month, in 13 French hospitals, a follow-up at 3 and 6 months after blood transfusion was proposed to all blood recipients who had not received any blood transfusion within the past 6 months (eligible patients): screening for red cell antibodies, alanine aminotransferase (ALT) activity and specific viral markers of hepatitis B (hepatitis B surface antigen and antibody to hepatitis virus core antigen), of hepatitis C (antibodies) and of Human Immunodeficiency Virus (antibodies). At the beginning of the study, 296 patients were followed for 6 months. A complete follow-up was available at 3 months for 183 patients (62%), at 6 months for 168 (57%) and after 6 months, 198 patients (67%) have been once followed. Of eligible patients, 76% were alive at six months. After transfusion, the incidence of red cell alloantibodies and elevated ALT concentration were respectively 4% and 17%. At 6 months, one patient had Hepatitis B surface antigen; the responsibility of blood transfusion was excluded. Within the first 24 hours, 68 patients (23%) required another blood transfusion and 42% of units were transfused to patients with malignant disease. Our study quantifies in real conditions the difficulty of a biological follow-up in a transfused population, mostly composed of patients that could not be followed in the hospital where they were transfused.

Adult↗

[Pilot study of the characteristics of transfused patients and utilized labile blood products].

The aim of this study was to describe blood recipients and blood components transfused during the first 24 hours in 13 French hospitals. We included all blood recipients who had not had any blood transfusion within the past six months. Recipients were screened for red cell alloantibodies, the alanine aminotransferase activity and specific viral markers (hepatitis B and C, Human Immunodeficiency Virus). Eligible patients represented 47% of the all transfused. Among the 371 patients included, 57% were males and 71% were transfused in a surgical unit. Alloantibodies, non specific and specific viral markers were detected in 3%, 19% and 2% respectively. Among the patients included, 42 received 172 autologous units. In total, 1056 allogeneic units (an average of 3 units per patient) were transfused; blood products were leucocyte-depleted (49%) or leucocyte-poor (20%); 54% of red cell units were matched for antigens Rh and Kell. Neoplasms were the most frequently reported disease for which patients were transfused. This study provides baseline blood transfusion information on recipients and blood utilization for a specific period in French hospitals. Following this study, a national study will allow the clarification of the characteristics, for instance the surgical procedures requiring transfusion.

Adolescent↗

Stimulation of the medial preoptic area of the hypothalamus in the rat elicits increases in intracavernous pressure.

Penile erection can be elicited by various stimuli integrated in the spinal cord and/or higher central nervous structures. The medial preoptic area (MPOA) of the hypothalamus is known to play a key role in the regulation of the male sexual behavior. In anesthetized male rats we performed MPOA stimulation via stereotaxically implanted electrodes or canulae delivering L-glutamate. An erectile response, assessed by an increase of intracavernous pressure (ICP), was recorded during electrical stimulation of the MPOA. Stimulating the posterior region of the MPOA elicited a greater erectile response than stimulation applied to the anterior region. Microinjections of L-glutamate also elicited an ICP increase. Stimulation of MPOA neurons therefore elicits activation of neural pathways controlling penile erection.

Analysis of Variance↗

Most cases of medium-chain acyl-CoA dehydrogenase deficiency escape detection in France.

DNA from 414 French blood donors from the Paris area was assessed for the A985G mutation responsible for most cases of autosomal recessive medium-chain acyl-CoA dehydrogenase (MCAD) deficiency. The mutant gene frequency averaged 1/140, predicting a frequency of mutant homozygotes of 1/19 000. Discrepancy between the numbers of expected (42 per year) and recorded cases of MCAD (6 per year) suggests that most MCAD-deficient patients escape detection in France.

Acyl-CoA Dehydrogenase↗

[Transfusion at home? An alternative to the day hospital].

In response to the needs of the Home Medical Services a project was set up in the Hemobiology Transfusion Service of Beaujon Hospital. The objective of this project was to avoid the difficult transfer of patients who were receiving for the most part palliative treatment. This required strict organization between consultants, haemobiologist physicians and healthcare personnel. The exclusion criteria have been respected (geographical distance, state of the non-compensated clinic, absence of family/patient cooperation). During the last 4 years of activity, 1,662 transfusions have been carried out on 757 patients, of which 80% had hematological affections, 10% solid tumours and 10% AIDS affections. 5,548 blood components have been transfused (2,104 red cell concentrates, 3,152 pooled platelet concentrates and 292 apheresis platelet concentrates). Thirty-one minor incidents were observed representing a prevalence of 0.56%. The poor codification of cases has slowed down the development of this project. The centralization of requests with coordination by the haemobiologist physicians within the Paris region should allow a guaranteed response to the numerous requests.

Adolescent↗

Hepatitis C virus genotypes in French blood donors.

The prevalence of different hepatitis C virus (HCV) genotypes in HCV infected individuals and the relation between the HCV genotypes and the source of the infection are controversial. The aim of this study was to determine the HCV genotypes in French blood donors. Fifty-one anti-HCV positive blood donors were studied with detectable serum HCV RNA by nested polymerase chain reaction (PCR) using primers derived from the 5' non-coding region. For genotyping HCV, we used a method based on analysis of the restriction fragment length polymorphisms (RFLP) after amplification by PCR of the HCV non-structural 5 (NS5) genome domain. Using this technique, the genotypes of 39 of the 51 blood donors (76%) were determined. Three previously described genotypes were found: 19 blood donors were infected by HCV genotype I (37%), 14 were infected by HCV genotype II (27%), 3 were infected by HCV genotype III (6%), and 3 were coinfected by two genotypes (6%). All three blood donors infected with two different genotypes were intravenous drug abusers. A past history of intravenous drug abuse was more frequent in blood donors with HCV genotype I. However, there was no difference in alanine transaminase (ALT) levels, histological lesions, and RIBA-2 patterns in blood donors infected with either HCV genotype I or HCV genotype II. These findings indicate that most HCV genotypes isolated from French blood donors belong to HCV genotype I and HCV genotype II, and that risk factors for HCV infection may differ for different genotypes of HCV.

Adult↗