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Biomedical subjects

F Villard

Publications and source records attributed to F Villard.

13 recordsLinked to original sources
PubMed2003

[Polyarteritis nodosa revealed by acute cholecystitis].

UNLABELLED: Acute cholecystitis revealing polyarteritis nodosa is classic but rare in adulthood. We report two cases observed during childhood. CASE REPORTS: The association of a persistent inflammatory syndrome, positive antineutrophil cytoplasm antibodies and of a vasculitis with fibrinoïd necrosis led to the diagnosis in two pediatric patients. CONCLUSION: The diagnosis of polyarteritis nodosa is difficult and often delayed. Cholecystectomy can help to such a diagnosis in the presence of acute cholecystitis.

Child↗
PubMed2002

Butyrate affects differentiation, maturation and function of human monocyte-derived dendritic cells and macrophages.

We studied the in vitro effects of butyric acid on differentiation, maturation and function of dendritic cells (DC) and macrophages (M(Phi)) generated from human monocytes. A non-toxic dose of butyrate was shown to alter the phenotypic differentiation process of DC as assessed by a persistence of CD14, and a decreased CD54, CD86 and HLA class II expression. The more immature differentiation stage of treated cells was confirmed further by their increased phagocytic capability, their altered capacity to produce IL-10 and IL-12, and their weak allostimulatory abilities. Butyrate also altered DC terminal maturation, regardless of the maturation inducer, as demonstrated by a strong down-regulation of CD83, a decreased expression of CD40, CD86 and HLA class II. Similarly, butyrate altered M(Phi) differentiation, down-regulating the expression of the restricted membrane antigens and reducing the phagocytic capacity of treated cells. To investigate further the mechanism by which butyrate hampers the monocyte dual differentiation pathway, we studied the effects of 1,25(OH)2D3 alone or in combination with butyrate on the phenotypic features of DC. Unlike 1,25(OH)2D3, butyrate inhibited DC -differentiation without redirecting it towards M(Phi). Combined treatment gave rise to a new cell subset (CD14(high), CD86 and HLA-DR(low)) phenotypically distinct from monocytes. These results reveal an alternative mechanism of inhibition of DC and M(Phi) differentiation. Altogether, our data demonstrate a novel immune suppression property of butyrate that may modulate both inflammatory and immune responses and support further the interest for butyrate and its derivatives as new immunotherapeutic agents.

Antigen Presentation↗
PubMed2001

[Collagen gastritis, an unusual cause of anemia in children. Report of 2 cases].

UNLABELLED: When a child presents a severe anemia or resistant to iron supplementation, an upper gastrointestinal endoscopy has to be realized to find special causes. CASE REPORTS: We report observations of two patients, respectively 11 and 12 years old, who were admitted to hospital for a severe microcytic, hypochromic, aregenerative anemia (hemoglobin less than 50 g/L) due to an iron deficiency. The two children's history did not reveal a deficient diet, gastrointestinal tract disorder, ingested toxic or gastrotoxic drugs, or exteriorized hemorrhage. Upper gastrointestinal endoscopy showed a macroscopic pattern of gastritis. The stomach biopsies revealed subepithelial collagenous deposits. CONCLUSION: The collagenous gastritis involves lesions similar to those described in the small intestine (collagenous sprue) and colon (collagenous colitis). The pathogenic factors of the three entities are presently unknown, but they are often associated with autoimmune pathology. These two observations are the third and the fourth pediatric cases described.

Anemia↗
PubMed2001

Plateletpheresis concentrates produced with the COMTEC cell separator: the French experience.

The latest generation of cell separators such as Trima (Gambro), Amicus (Baxter) and AS-TEC 204 (Fresenius), allow the collection of leucocyte-reduced platelet concentrates without secondary filtration. Fresenius has recently developed the COMTEC cell separator whose performance has been evaluated by several teams in France. This new cell separator is an improved version of the Fresenius AS-TEC 204 cell separator, designed to allow more efficient platelet collections. This study reports on the experience of six French teams (from Bordeaux, Clermont-Ferrand, Creteil, Dijon, Lille and Nancy) who obtained 696 leucocyte-reduced plateletpheresis concentrates in the course of collection using the new Fresenius COMTEC cell separator. All healthy volunteer donors fulfilled French selection criteria for platelet apheresis. Donors were eligible if they had suitable venous accesses, if their bodyweight was *50 kg and if their pre-apheresis platelet count was >150 x 10(9) l(-1). Between 4606 and 5229 ml of blood were processed. The mean volume of the platelet concentrates was between 439 and 493 ml (mean 460 +/- 63 ml). The platelet yield was of the order of 5.18 +/- 1.02 x 10(11) with only one platelet concentrate below the norm of 2 x 10(11) platelets (0.91 x 10(11)). No plausible explanation for this was found. The residual leucocyte levels conform to current norms. The platelet concentrates contained less than 1 x 10(6) leucocytes per concentrate (mean 0.233 +/- 0.150 x 10(6) leucocytes) in more than 97% of the components produced with >95% statistical confidence. The efficacy of the cell separator (52.44 +/- 7.35%) is comparable to that of other separators. The Fresenius COMTEC cell separator makes it possible to obtain leucocyte-reduced platelet concentrates which comply with current standards both in terms of platelet content and residual leucocyte level.

Adult↗
PubMed2000

[Liver transplantation in infants and children. Evaluation of the first 40 cases (March 1991-March 1997)].

BACKGROUND: Liver transplantation (LT) is the treatment of end-stage liver disease in children. We report our experience with LT using grafts from living related (LRD) and cadaver donors (CD). POPULATION: From March 1991 to March 1997, 40 children and infants received a total of 42 liver grafts. A reduced-size liver was used in 28 cases. We studied pre-transplantation status, survival rate, and medical and surgical complications in these patients. RESULTS: The survival rate in our series was respectively 85 and 80% at 1 and 7 years after LT. Low weight infants required a prolonged ventilatory assistance. Five of the six deaths noticed during the first three months after LT occurred in children weighing less than 12 kg. One year after LT, no significant difference in the incidence of rejection was found, neither between low-weight children and the others, nor between patients transplanted from CD or LRD. Biliary tract stricture was the major surgical complication. CONCLUSION: This series consisted of a majority of low-weight children. The survival rate in the patients weighting less than 12 kg is lower than in the others. This may be explained by the nutritional status of these patients and early postsurgical complications. The use of grafts from living donors offers more flexibility since the operation is performed electively, but it did not seem to modify the incidence of acute rejections and surgical complications.

Adolescent↗
PubMed2000

[Peripheral stem cell collection, search for predictive factors: a multicenter study. Working Group on Transfusion and Therapeutic Techniques of the French Blood Transfusion Society ].

AIMS: A multicentric study involving 12 centers was made to investigate the results of peripheral stem cell collection carried out between 1996 and 1997 from 655 patients with hemopathic syndromes or malignant tumors, The aim of this investigation was to determine the predictive factors for transplant quality, and to thereby optimize collection procedures. PATIENTS AND METHODS: Information sheets were completed for 1,346 cytapheretic sessions, i.e., 655 grafts. The samples were taken after induction chemotherapy and exposure to hematopoeitic colony-stimulating growth factors (except the LMCs). Each graft was defined as being of good or bad quality depending on the number of CD34+ cells that it contained. Based on the data available in the literature, a workgroup consensus was reached that a level of CD34+ cells +/- 2.10(6)/kg recipient body weight constituted a good transplant criterion. The 2 subgroups (good graft versus lower quality graft) were compared by univariate analysis followed by discriminant multivariate analysis. RESULTS: It was established that a number of parameters were significantly linked to the criterion of collection quality; however, 3 predictive factors emerged from the multivariate analysis--the level of circulating CD34+ cells; the number of cytaphereses; the number of blood volumes treated. CONCLUSION: It was concluded that the level of circulating CD34+ cells seems to be an essential aspect in predicting the quality of the transplant and the number of cytaphereses required to obtain a sufficiently rich collection. Moreover, it also appears that at least 2 blood volumes should be treated to optimize the results.

Adult↗
PubMed1994

[Immunohematologic surveillance of patients treated with ABO incompatible bone marrow allografts].

Direct antiglobulin test (DAT), ABO typing and isoagglutinins titers were regularly performed in 26 patients who received a marrow transplant from a major ABO incompatible donor (M = 10 cases), from a minor ABO incompatible donor (m = 10 cases) or both (B = 6 cases). Erythrocyte or plasma depletion of bone marrow infusate was used in all major or certain minor ABO incompatibilities respectively. A positive DAT was recorded in 19/26 patients at various times, but only a few of them, belonging to groups M or B, exhibited a significant hemolysis. No serious complication was observed after bone marrow infusion. Five patients showed evidence of hemolysis after transplantation, 1 patient died with a graft rejection and 3 patients had a delayed erythropoietic engraftment. In all cases of major ABO incompatibility, the erythrocyte recovery was preceeded by a decrease of antibodies against the donor's blood group. These antibodies finally disappeared in all patients except one who had a persistence of isoagglutinins beyond day + 650. A transient appearance of isoagglutinins against the recipient blood group was sometimes detected in minor ABO incompatibility without any clinical complications.

ABO Blood-Group System↗
PubMed1993

Borate complexation of flavonoid-O-glycosides in capillary electrophoresis. II. Separation of flavonoid-3-O-glycosides differing in their sugar moiety.

Capillary electrophoresis was found to give significantly higher efficiency, selectivity and speed than high-performance liquid chromatography for the separation of a mixture of flavonoid-3-O-glycosides differing in their sugar moiety. Boric acid running buffer (0.2 M, pH 10.5) was used for this electrophoretic separation. The migration order in free solution capillary electrophoresis (CE) and the selectivity of these flavonoid-3-O-glycosides can be mainly explained by in situ borate complexation of both the sugar moiety and the cis-1,2-hydroxyl groups on the flavonoid skeleton and, to a lesser extent, by the ionization of hydroxyl groups on the flavonoid skeleton due to alkaline pH conditions. The correlation of the electrophoretic mobilities with the configuration and conformation of the compounds is discussed.

Anions↗
PubMedDate not supplied

[Cytapheresis].

Explore the source record for details and available documents.

Anemia, Aplastic↗