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D Lefebvre

Publications and source records attributed to D Lefebvre.

At least 37 records · Page 2Linked to original sources
PubMed1996

Predicting daily maintenance dose of fluindione, an oral anticoagulant drug.

Due to large inter-individual variations, the dose of vitamin K antagonist required to target the desired hypocoagulability is hardly predictible for a given patient, and the time needed to reach therapeutic equilibrium may be excessively long. This work reports on a simple method for predicting the daily maintenance dose of fluindione after the third intake. In a first step, 37 patients were delivered 20 mg of fluindione once a day, at 6 p.m. for 3 consecutive days. On the morning of the 4th day an INR was performed. During the following days the dose was adjusted to target an INR between 2 and 3. There was a good correlation (r = 0.83, p < 0.001) between the INR performed on the morning of day 4 and the daily maintenance dose determined later by successive approximations. This allowed us to write a decisional algorithm to predict the effective maintenance dose of fluindione from the INR performed on day 4. The usefulness and the safety of this approach was tested in a second prospective study on 46 patients receiving fluindione according to the same initial scheme. The predicted dose was compared to the effective dose soon after having reached the equilibrium, then 30 and 90 days after. To within 5 mg (one quarter of a tablet), the predicted dose was the effective dose in 98%, 86% and 81% of the patients at the 3 times respectively. The mean time needed to reach the therapeutic equilibrium was reduced from 13 days in the first study to 6 days in the second study. No hemorrhagic complication occurred. Thus the strategy formerly developed to predict the daily maintenance dose of warfarin from the prothrombin time ratio or the thrombotest performed 3 days after starting the treatment may also be applied to fluindione and the INR measurement.

Administration, Oral↗
PubMed1996

[Vascularization of the wall of the superficial veins. Anatomic study of the vasa vasorum].

INTRODUCTION: The blood vessel wall is almost always nourished by two ways; from the blood stream itself and through the outer part of the wall by vasa vasorum. AIM OF THE STUDY: The aim of this study was to demonstrate that this kind of nutrition is also available for the venous wall and to define the distribution pattern in superficial venous walls. MATERIALS AND METHODS: 50 long saphenous veins and 20 short saphenous veins latex or barium injections, dissections with magnifying glasses and microradiographies. Topographical evaluation of the origin of vasa vasorum. RESULTS: The results showed that vasa vasorum originated from perforating arteries coming from several levels and getting a lot of anastomosis. We showed that the main sources for the long saphenous vein are the external pudendal artery and descending artery of the knee and for the short saphenous vein, the short saphenous vein artery. In thrombosis and varicose veins, the vasa were strongly altered. CONCLUSION: This study outlines the fact that superficial veins are supplied by arterial and venous vasa vasorum, and the role of vasa vasorum must be considered when questioning the pathogenesis of varicose and post thrombotic disease.

Arteriovenous Anastomosis↗
PubMed1995

Identification of two regulatory elements within the promoter region of the mouse connexin 43 gene.

To define the minimal sequences required for expression of the connexin 43 gene (cx43) in myometrial cells, we generated 5' deletion constructs of a fragment extending 1686 base pairs upstream and 162 base pairs downstream of the transcription start site and determined their ability to drive expression of the chloramphenicol acetyltransferase reporter gene in transfected myometrial cell lines. Our investigation revealed two cis-acting regulatory elements within this fragment. Deletion of a region extending from -102 to -92 led to an increase of the promoter activity by greater than 10-fold, indicating a presence of a repressor element. Deletion of a region extending from -72 to -62 caused a decrease of the promoter activity of a similar extent, implying the existence of a positive element. Electrophoretic mobility shift assays demonstrated that synthetic oligonucleotides derived from these two small regions can each bind with a nuclear protein(s) prepared from myometrial cells, and an introduction of three and two base substitutions into each of these oligomers was sufficient to abolish their protein binding capability. These same mutations, when incorporated in the chloramphenicol acetyltransferase constructs, diminished regulatory functions of the negative and positive elements, and the protein(s) that bind to these functional elements was found in several tissues known to express cx43 gene.

Animals↗
PubMed1994

[Erythromelalgia: a familial case. Discussion on the role of mercury].

Erythromelalgia is an acrosyndrome characterized by paroxysmal manifestations associating erythema, local sensations of warmth and pain which improve with exposure to cold. Childhood forms, exceptional and usually primary, are quite severe and particularly resistant to treatment. The search for a causal agent is most often negative and the pathogenesis remains to be determined. We report a case of erythromelalgia observed in a 4-year-old girl, her father and her younger sister. This case was particular due to an association with mercury poisoning. The symptomatology was improved after different therapeutic attempts including Clomipramide and, particularly effective, rerigerating socks (D(r) Comet, CNES, Toulouse). In the literature we were unable to find any case of erythromelalgia related to mercury poisoning. The cases of familial erythromelalgia reported suggest X-linked dominant transmission. Finally, this case demonstrated the difficulties in diagnosing and treating erythromelalgia, especially in the child.

Acrodermatitis↗
PubMed1993

A tridimensional study using cuts at a low temperature of the infratemporal region.

Although the infratemporal region is well defined anatomically, its complex topography has been the subject of numerous, and sometimes, opposite works. That is the reason why it appeared necessary for the authors to re-evaluate this topic using the original method of Combelles and Boyer, allowing to define three referential planes, and thereby, a tridimensional shape and the volume of this region. This study allows to conclude that the infratemporal region is a triangular prism with an horizontal main axis 47 mm long. Its anterior base has a mean area of 733 mm2. The posterior top consists of the Juvara slot and has a mean area of 490 mm2. This infratemporal prism contains another one, the pterygomandibular space, prismatic too. It widens out from coronoïd plane (93 mm2) to mandibular foramen plane (169 mm2) before ending as a narrow groove between the neck of the mandibular condyle and the interpterygoïd fascia. The volume of the pterygomandibular space is quite superior to the value usually reported in the dental literature. It is of 4.8 ml to 5.8 ml according to denture. These results point out the opportunity to accomodate more important volumes of anesthesic solutions, than the 1.8 ml usually performed, without any leak out of the infratemporal region.

Aged↗
PubMed1993

Pediatric cardiac transplantation for congenital heart defects: surgical considerations and results.

Among 54 children who underwent 55 heart transplantations, 24 (44%) (mean age, 4.9 +/- 4.8 years; range, 9 days to 18 years) had congenital defects with the following diagnoses: single-ventricle variants (6), hypoplastic left heart syndrome variants (5), transposition complex (6), and miscellaneous defects (7). Twenty patients (83%) had undergone 43 prior operations. Additional surgical procedures included repositioning of transposed great arteries (11), reconstruction of the aortic pathway (4), reconstruction of the pulmonary pathway (8), correction of situs inversus (1), and correction of anomalous pulmonary (1) or systemic (1) venous drainage. Reconstructive procedures were performed using donor or recipient tissue or both. There were six early deaths (hyperacute rejection, 1 patient; pulmonary hypertension, 1; graft failure, 2 patients; infection, 2) and six late deaths (sudden death, 2; chronic rejection, 2; nonspecific graft dysfunction, 1; lymphoproliferative disease, 1). The survival rate was 43% +/- 12% at 3 years. No deaths were related to surgical technique. Survival was not significantly different in pediatric recipients with cardiomyopathy (67% +/- 9%; p = 0.22). Accelerated coronary artery disease was noted in 4 operative survivors (22%; 70% confidence limits, 12% to 36%). All late survivors were free from cardiac symptoms after a mean follow-up of 34 +/- 24 months (range, 6 to 71 months). Based on this study, we reached three conclusions. (1) Careful planning of both harvesting and transplantation procedures allows heart transplantation in recipients with congenital heart diseases. (2) The surgical technique may be demanding, but the early risk is not increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Effects of self-evaluation on the independent work skills of preschool children with disabilities.

This study examined the effects of a self-evaluation treatment package on the independent work skills of preschool children with disabilities. Children learned to conduct self-assessments and to compare their ratings with those of the teacher. Data were collected on children's percentages of appropriate behavior, the level of teacher prompting, and the match between child and teacher ratings. Results indicated that the treatment produced immediate and substantial improvements in child behavior and that it was possible to systematically withdraw each component while maintaining a high level of appropriate child behavior.

Achievement↗
PubMed1990

[Percutaneous transluminal endarterectomy of femoro-popliteal atheromatous lesions. Technique. Indications. Results after 6 months].

Percutaneous atherectomy was performed in 25 patients with 30 symptomatic femoro-popliteal stenosis. INITIAL RESULTS: 23 patients were successfully treated with disappearance of claudication and a mean 0.35 increase in the ankle-arm-index. Two early thrombosis occurred. Angiographic analysis: residual stenosis lower than 30% in 25 lesions; no dissection or embolization; effective treatment of eccentered and calcified lesions; no significant dissection after additional angioplasty. RESULTS AT 6 MONTHS FOLLOW-UP: (17 patients, 19 lesions): stable improvement in 14 patients; 2 restenosis; 1 new disease. Atherectomy restores a large lumen with minimal wall trauma, thus perhaps decreasing the restenosis rate.

Adult↗
PubMed1989

[Percutaneous transluminal atherectomy of the femoropopliteal arteries. Technic, indications, results after 6 months].

Percutaneous atherectomy was performed in 25 patients with 30 symptomatic femoro-popliteal stenoses. Twenty-three patients were successfully treated with resolution of claudication and a mean 0.35 increase in the ankle-arm-index. Two early thromboses occurred. Residual stenosis was less-than 30% in 25 lesions, with no dissection, and no embolization. Atherectomy seems to be an effective treatment for eccentric and calcified lesions. At 6 months follow-up (17 patients, 19 lesions) clinical and Doppler improvement remained stable in 14 patients; 2 restenosis and 1 new disease occurred. Atherectomy restores a large lumen with minimal wall trauma, thereby possibly decreasing the restenosis rate.

Adult↗
PubMed1989

[Interosseous dorsal artery of the first intermetatarsal space: anatomic variations and value in functional vascular studies].

The first dorsal metatarsal artery (MDA) is usually described as the last collateral branch of dorsalis pedis artery (DPA, which anastomoses with the lateral plantar branch of the posterior tibial artery (PTA). Doppler assessment on DMA of a flow does not always mean that DPA is free, but may show a functional plantar arch. The aim of this study was to determinate the patency rate of this plantar arch and to appreciate the part of DPA in the vascularisation of the foot. Anatomical descriptions were compared with our own dissections, (25 cadavers and 55 arteriographies in fetus), angiographic analysis and vascular plastic casts. The functional aspect of this study was made by Doppler examination of DMA using alternative or simultaneous compression of the main arteries of the ankle, until doppler curves were canceled. That was done on healthy volunteers and arteriosclerotic patients. The results show that, from the anatomical viewpoint, the plantar arch is almost always present, since it was found in 88% of adult pieces. Nevertheless, on Doppler examination, the plantar arch was found functional only in 64% of healthy people. The difference between the two rates emphasizes the fact that anatomical anastomosis are note always open, according to the subject and probably to the age. Looking after MDA permeability in patients with arteriosclerosis leads to point out the main vascular access to the foot, for limb salvage, and the leading part of distal anastomosis to keep good trophicity of the toes.

Adult↗
PubMed1988

Human IL-3 and GM-CSF act synergistically in stimulating hematopoiesis in primates.

Interleukin-3 (IL-3) is a member of a family of growth factors, each of which supports the proliferation and development of hematopoietic precursors in culture. Although the biologic effects of the different hematopoietic growth factors have been well documented in different culture systems, it has only recently become possible to study the activities of these molecules in vivo. In comparison with the later acting hematopoietic growth factors granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor, IL-3 elicited a delayed and relatively modest leukocytosis when continuously infused intravenously in primates. The IL-3 infusion, however, greatly potentiated the responsiveness of the animal to subsequent administration of a low dose of GM-CSF. These results suggest that IL-3 expands an early cell population in vivo that subsequently requires the action of a later acting factor such as GM-CSF to complete its development. Optimal stimulation of hematopoiesis may be achieved with combinations of hematopoietic growth factors.

Animals↗
PubMed1987

Facilitating transition times with handicapped preschool children: a comparison between peer-mediated and antecedent prompt procedures.

We examined the effects of a peer-mediated versus an antecedent prompt condition on the rate of independent movement and appropriate behavior of handicapped preschool children during three classroom transition times. Using an alternating treatments design, results showed that each treatment condition yielded increases in target behaviors; however, the antecedent prompt condition was superior during all three transition settings. In addition, teacher prompts to these children were significantly reduced during the intervention conditions, indicating that the children were making these transitions more independently.

Autistic Disorder↗
PubMed1986

Regulation of vasopressin gene expression in rat hypothalamic neurons. Response to osmotic stimulation.

Although the steps involved in biosynthesis and secretion of the neuropeptide vasopressin (AVP) have been extensively studied, the factors which regulate AVP gene expression remain unknown. Therefore, we sought to determine the dynamics of AVP mRNA accumulation in response to a strong stimulus for AVP release, i.e. during salt imbibition and the ensuing period of rehydration. AVP mRNA levels were determined in terms of absolute amounts by a novel quantitative densitometric hybridization assay, using in vitro synthesized sense-strand RNA as a quantitative standard and complementary anti-sense RNA as a specific probe. The template used for RNA transcription consisted of a 196-base pair genomic DNA fragment corresponding to exon C of the rat AVP gene. Determination of basal hypothalamic AVP mRNA levels yielded 12.5 +/- 2.7 fmol/hypothalamus. Salt imbibition, which induced a 6% rise in blood osmolality and an 82% loss of pituitary AVP, resulted in a 3-fold increase of AVP mRNA to 35 +/- 5 fmol/hypothalamus. Following rehydration, plasma osmolality returned to control levels by day 2, pituitary AVP by day 6, and hypothalamic AVP by day 14. By contrast, AVP mRNA levels remained significantly elevated throughout the 30-day rehydration period. Furthermore, pituitary AVP reached a level of 177% of control by day 14 of rehydration. These data show that osmotic stimulation results in a long-lasting elevation of hypothalamic AVP mRNA; during rehydration, these elevated mRNA levels direct AVP biosynthesis at a rate which surpasses secretory demands; AVP mRNA accumulation does not appear to be directly regulated by either pituitary or hypothalamic AVP. Therefore, either an unusually long half-life of greater than or equal to 7 days must be assumed for AVP mRNA or, alternatively, a continued stimulation of AVP gene transcription must occur, even in the absence of a secretory stimulus and following complete repletion of cellular AVP stores.

Animals↗
PubMed1986

[Anatomical organization, organogenesis and innervation of the arteries of the hand].

The authors sum up the anatomical aspects of the arteries of the hand. They emphasise the fact that, by the side of the classical description; there is a lot of variations. These can be explained by organogenesis, showing that hand arteries pass over several stages, before reaching the terminal one. Generally, it seems that the classical diagram correspond to the majority of cases, and that there is a main flow for hand's arteries: this are the superficial and deep arches, which give common and proper digital arteries. About the innervation, this structures are very richly innervated, but this sympathetic innervation is not so precisely delimited in its topography, and for that reason, its seems to be difficult to give an clear diagram of its origin and distribution. That can explain surgical treatment's failure in vasomotor syndromes of upper limbs.

Arm↗
PubMed1984

[Our experience with the pectoralis major musculocutaneous flap. Apropos of 57 cases].

One of the most important technical advances in cervicofacial plastic surgery over the last few years is undoubtedly the use of the musculocutaneous flap from pectoralis major. A review of its application in 57 cases showed the flap to be of excellent viability (5% total necrosis of flap), and to offer multiple possibilities during primary surgery or that following radiation. Indications and excision limits can be extended, particularly in buccopharyngeal surgery, providing and appreciable functional gain (particularly disappearance of pain), even though long-term carcinologic advantages are deceiving.

Adult↗