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Biomedical subjects

V Guerin

Publications and source records attributed to V Guerin.

At least 19 recordsLinked to original sources

Listing of common HLA alleles and haplotypes based on the study of 356 families residing in the Paris, France, area: implications for unrelated hematopoietic stem cell donor selection.

In this study we have identified frequent human leukocyte antigen (HLA)-A, -B, -C,-DRB1, and -DQB1 alleles, frequent HLA-B/C, HLA-DRB1/DQB1 two-allele associations, and the most common HLA-A/B/C/DRB1/DQB1 five-locus haplotypes in a population residing in the Paris, France, area. The study was carried out in 356 families of children awaiting hematopoietic stem-cell transplantation (HSCT), with the selection criterion that haplotypes could be assigned with certainty to both the patient and at least one parent. Parental haplotypes were HLA-A, -B serologically typed, and HLA-C, -DRB1, -DQB1 broadly typed by polymerase chain reaction-sequence-specific oligonucleotide probe. The alleles of the most frequent haplotypes were subsequently defined at a high-resolution level by polymerase chain reaction-sequence-specific primer. The results on the distribution of common alleles and common allele associations demonstrated similarities with the previously published data in Caucasian populations, as expected from the geographic origin of the studied population. More importantly, this study provides the largest listing of common B/C and DRB1/DQB1 associations and of common five-allele haplotypes defined with certainty in a Caucasian population to date. These results can be used to help estimate the likelihood of finding a suitable donor in unrelated HSCT and to delineate search strategies for potential donors.

Alleles↗

[Lower limb occlusive arteriopathy: retrospective analysis of 73 patients with onset before the age of 50 years].

OBJECTIVES: Juvenile peripheral obstructive arterial diseases (POAD) have been poorly investigated but account for 1 to 7% of POAD. We analyzed retrospectively a cohort of patients with onset before the age of 50 years. PATIENTS AND METHODS: Seventy-three patients (60 males and 13 females) were divided into 4 groups (Buerger's disease: TAO, atheromatous PAOD, auto-immune POAD, arteriopathy of undetermined origin). RESULTS: The first symptoms occurred at 38 +/- 8 years of age. Fourteen patients (20%) had TAO, 51 (70%) atheromatous POAD, 4 (5%) POAD with systemic or autoimmune disease, and 4 (5%) undetermined POAD. Age of onset was earlier in TAO (35 +/- 8 vs 40 +/- 8 years, p=0.046), smoking greater in the atheroma group (33 +/- 16 vs 24 +/- 14 pack-years, p=0.033). Fifty-three POAD patients had dyslipidaemia and 26% hypertension. Regular cannabis intake was more frequent in the TAO group (21 vs 8%). At the time of medical care, Fontaine's stage was more frequently stage II in atheroma patients (57 vs 14%) and stage IV in TAO patients (86 vs 35%). TAO was diagnosed in 43% cannabis users and in 19% non users. CONCLUSION: The main etiology of juvenile POAD is atheroma, followed by TAO. Cannabis users account for at least 10% of these patients. They are characterized by lower tobacco intake, more distal lesions, more frequent involvement of the upper limbs. They present more frequently as TAO.

Adult↗

Topical treatment of vaginal candidosis with sertaconazole and econazole sustained-release suppositories.

OBJECTIVE: To compare the efficacy and safety of sertaconazole and econazole sustained-release suppositories in the treatment of vulvovaginal candidosis. STUDY DESIGN: 369 women with symptoms and signs of vulvovaginitis were enrolled in this multicenter, randomized, double-blind study. After clinical examination and vaginal sampling, 183 women were treated with a 300-mg sertaconazole suppository and the other 186 with a 150-mg econazole suppository. They were evaluated 1 week after treatment and those who were clinically uncured received a second suppository and were re-assessed 1 week later. All women were evaluated 1 month after the last administration. At each follow-up visit, clinical efficacy was assessed and a vaginal sampling was performed for microscopic examination and culture. RESULTS: Of the 369 women included, only the 310 who had a positive culture for a strain of Candida were taken into account for efficacy analysis: 150 in the sertaconazole group and 160 in the econazole group. One hundred and five women (49 in the sertaconazole group and 56 in the econazole group) were not clinically cured after 1 week and received a second suppository. There were no differences between the two groups for the rates of clinical recovery (disappearance of signs and symptoms) and mycological recovery (negative culture), 1 week after the first application (62.1 and 67.7%, respectively), 1 week after the second application for women treated twice (72.3 and 80.6%, respectively) and for all patients 1 month after the last application (65.3 and 62.0%, respectively). Among the patients cured 1 week after the last application, the mycological recurrence rate after 1 month was significantly higher in the econazole group (32.7 vs. 19.8%, P=0.035). There was a trend towards better efficacy of sertaconazole after the first application, whereas the two treatments had similar efficacy in women treated twice. There were no serious adverse events and only local irritation was reported, without any statistically significant difference between the two groups. CONCLUSION: Single topical administration of sertaconazole and econazole had similar efficacy and safety but the former is associated with a lower rate of mycological recurrence one month after achieving a negative culture.

Administration, Intravaginal↗

Beware of commercial human thrombins used to stimulate cultured endothelial cells.

In the field of in vitro biocompatibility testing, the investigation of cell response at the interface with a biomaterial is of great importance; there is a need for standard conditions and thus of well-defined and reliable sources of materials for an objective evaluation of cellular function. Thrombin is often used in vitro as a stimulating agent to check the specific functions of cultured endothelial cells. In the present work, and in order to select a thrombin of commercial origin, two criteria were borne in mind: purity towards the presence of the von Willebrand factor (vWF) and effectiveness towards vWF release by human umbilical venous endothelial cells (HUVEC) that have been submitted to four human commercial thrombins. We detected the presence of vWF in some thrombin solutions that have not yet been in contact with HUVEC. The different thrombins contained vWF antigen ranging from less than 0.1 mUnit per NIH unit of thrombin (from Diagnostica Stago and Sigma Chemical Co.) to 10-20 mUnit per NIH unit of Fibrindex thrombin (from Ortho Diagnostic Systems). Thus, if vWF is present in commercial thrombins, it contributes to and overestimates the vWF appearance in the media resulting from cell stimulation. Consequently, we fixed on thrombin from Diagnostica Stago for further studies involving HUVEC on biomaterials.

Biocompatible Materials↗

In vitro study of the hemocompatibility of superparamagnetic contrast agent for magnetic resonance imaging.

Five different nanoparticles, potentially useful in magnetic resonance imaging (MRI) after venous administration, were studied for their hemocompatibility. The in vitro methodology evaluated these materials by several parameters: cytotoxicity towards cells cultured in vitro, aggregation ability of platelets, hemolysis inducibility, intrinsic and extrinsic coagulation pathway activation, and complement activation. With the proposed clinical dose, regardless of the cell type used (murine cell line or human endothelial cells) no toxicity was observed. The presence of the particles in blood did not produce any considerable damage: either hemolysis or platelet aggregation or blood coagulation were recorded. However, a slight decrease in aggregation ability of platelets was noticed as well as an increase in partial thromboplastin time. Because of the quick removal of the particles from the bloodstream, these phenomena must be short-lived, thus avoiding significant adverse clinical effects.

Animals↗

Endothelial cell compatibility testing of three different Pellethanes.

There is a need for viable small diameter vascular grafts, the luminal surface of which could be seeded by endothelial cells (ECs) to prevent thrombosis. In order to select candidates for EC seeding before implantation, the in vitro cytocompatibility of three different Pellethanes (polyetherurethanes) using human ECs was investigated. The methodology included two stages depending on either direct contact between cells and materials or contact between cells and material extracts, obtained under standardized conditions. By the latter method, we observed a cytotoxic effect on cell growth with 2363-55 D Pellethane extract at a 50% (v/v) concentration in the nutrient medium, likely provoked by leachables and correlated with the lowest levels of tPA, PAI1, and vWF antigens in the supernatants. By the former method, we studied EC attachment and growth. Morphology was studied by classical means and completed by scintigraphy and microautoradiography after 111Indium-labeling of the EC monolayer. Differentiation was determined by the release of vWF antigen and measurement of vWF activity (multimeric organization) after human thrombin stimulation. Despite an inhibition of proliferation for both 55 D and 75 D types (compared to the control), a functional monolayer of ECs was obtained on 75 D. Pellethane 75 D could be the best support for in vitro endothelization.

Blood Vessel Prosthesis↗

Identification of some clinically significant actinomycetes.

Early recognition of infections caused by actinomycetes tend to be highly dependent on at least a tentative diagnosis derived from microbiological tests, since the clinical symptoms can be difficult to interpret. Reliable identification of clinically significant actinomycetes depends upon the application of taxonomic techniques that are not yet widely used in clinical laboratories. The value of rapid enzyme, chemical and molecular fingerprinting techniques is exemplified by their application to the identification of representatives of clinically significant actinomycete taxa.

Actinomycetales Infections↗

Cushing's disease and cutaneous alternariosis.

Alternaria species are common plant pathogens, but a rare cause of human infection. We present a patient with cutaneous alternariosis that revealed a relapse of an old case of Cushing's disease. Immunosuppression following the excessive glucocorticoid production seemed to contribute to the development of dermatosis. We also present a review of the literature on the association of Cushing's disease and cutaneous alternariosis. Our case is unique because the ketoconazole therapy that we used was successful in the treatment of both diseases.

Aged↗

Early alterations of plasma free amino acids in chronic renal failure.

In order to assess the influence of renal failure and nutritional status on the fasting concentrations of free plasma amino acids, we studied 81 ambulatory adult patients with varying degrees of chronic renal failure. Each of the patients was in good general and nutritional condition. Compared to 33 healthy controls, patients with mild renal failure (Ccr greater than 25 ml/mn) exhibited significantly (p less than 0.01, Student's t test) raised concentrations of cystine, citrulline, ornithine, taurine and 3-methyl-histidine and low level of serine. Concentrations of cystine, citrulline, and 3-methyl-histidine in plasma but not of taurine or ornithine rose in parallel with the progression of renal failure. A significant, but moderate decrease in valine, leucine and isoleucine concentrations was observed in patients with the most marked degree of renal failure (Ccr less than 10 ml/mn). We conclude that changes in the plasma concentration of several non essential amino acids are already present in the early stage of renal failure in patients with no sign of protein malnutrition: these may result from altered metabolic pathways of amino acids related to uremia and/or nephron loss per se whereas the moderate decrease in branched-chain amino acids that is observed only in the advanced stage of renal failure may be, at least in part, nutritional in origin.

Adult↗

Nitrogen Fixation (C(2)H(2) Reduction) by Broad Bean (Vicia faba L.) Nodules and Bacteroids under Water-Restricted Conditions.

Water potentials of leaves and nodules of broad bean (Vicia faba L.) cultivated on a sandy mixture were linearly and highly (r(2) = 0.99) correlated throughout a water deprivation of plants. A decrease of 0.2 megapascal of the nodule water potential (Psi(nod)) induced an immediate 25% inhibition of the highest level of acetylene reduction of broad bean nodules attached to roots. This activity continued to be depressed when water stress increased, but the effect was less pronounced. Partial recovery of optimal C(2)H(2) reduction capacity of mildly water stressed nodules (Psi(nod) = -1.2 megapascals) was possible by increasing the external O(2) partial pressure up to 60 kilopascals. The dense packing of the cortical cells of nodules may be responsible for the limitation of O(2) diffusion to the central tissue. Bacteroids isolated from broad bean nodules exhibited higher N(2) fixation activity with glucose than with succinate as an energy-yielding substrate. Bacteroids from stressed nodules appeared more sensitive to O(2), and their optimal activity declined with increasing nodule water deprivation. This effect could be partly due to decreased bacteroid respiration capacity with water stress. Water stress was also responsible for a decrease of the cytosolic protein content of the nodule and more specifically of leghemoglobin. The alteration of the bacteroid environment appears to contribute to the decline in N(2) fixation under water restricted conditions.

Journal Article↗

Suppression of HLA class II expression on thyrocytes by interferon-alpha 1.

Inappropriate expression of HLA class II molecules by human thyroid epithelial cells (thyrocytes) is commonly associated with autoimmune thyroid disease. HLA class II expression can be modulated in thyrocytes in vitro by a variety of substances: in particular, it is readily induced by interferon-gamma (IFN-gamma). Here we show that recombinant IFN-alpha 1 (rIFN-alpha 1) does not induce HLA class II expression by thyrocytes, but rather it suppresses the induction of such expression by rIFN-gamma. Similar effects were observed with IFN-alpha derived from a lymphoblastoid cell line. The effect of rIFN-alpha 1 on thyrocytes differs from its effect on human monocytes, reported by others, in which it was found to enhance the expression of HLA class II. Thus, rIFN-alpha 1 appears to have a differential effect on HLA class II expression, depending on the cell type involved.

Cells, Cultured↗

[Dysthyroidism and Parkinson's disease].

Associations between hyperthyroidism and Parkinson disease have been reported. The treatment of the hyperthyroid state seems to improve the extrapyramidal symptomatology. We report a case of a woman suffering from Parkinson disease and hypothyroidism. The treatment with thyroxine increased parkinsonian tremor. Dopamine regulation of TSH circadian and pulsatile release is not clear. These observations stress the possible role of thyroid hormones in regulating dopaminergic metabolism.

Aged↗

Decreased lymphocyte function-associated antigen-1 molecule expression on peripheral blood lymphocytes from patients with Graves' disease.

Humoral and cellular abnormalities have been described in autoimmune thyroid diseases, but a deficient cooperation between humoral and cellular systems has been poorly investigated in such diseases. Lymphocyte function-associated antigen-1 (LFA-1), a glycoprotein expressed on T- and B-lymphocytes, plays an important role in cell-cell interaction mechanisms and is involved in the homing phenomenon. The expression of this molecule was investigated on peripheral blood lymphocytes from patients suffering from various thyroid disorders. Decreased numbers of LFA-1-positive cells were observed in 30 patients with Graves' disease, while normal values were present in 8 patients with Hashimoto's thyroiditis and 37 subjects with nonautoimmune thyroid disorders. Treatment-induced improvement of Graves' disease was associated with an increase in LFA-1-positive cell number.

Adult↗

[Prevalence of non-thyroid autoantibodies in autoimmune dysthyroidies].

Organ- and non organ-specific autoantibodies can be detected in patients with AITD but large comparative studies have seldom been performed. This study evaluated the prevalence of anti-thyroid, -smooth muscle, -mitochondria, -parietal gastric cells, -salivary duct, -nuclear and -ds DNA autoantibodies assayed by indirect immunofluorescence in 224 patients with Graves' disease or Hashimoto's thyroiditis. Results evidenced a high prevalence of antinuclear antibodies, mostly of non homogenous fluorescence in Graves' (63.1%) and Hashimoto's patients (65.5%), as well as for antisalivary duct antibodies (55.2 and 75%). No positive anti-ds DNA were noticed. No correlation was found between antithyroid antibodies and the others. Different hypothesis could explain this observation which favours a general dysregulation of the autoimmune system.

Adolescent↗

Effect of manganese ions on the immune response of carp (Cyprinus carpio) against Yersinia ruckeri.

The effect of manganese ions Mn2+ (Mn Cl2) on hematocrit and the antibody response of carp (Cyprinus carpio) was investigated after exposure of fish to contaminated water for 2.5 months. Contamination of water with 50 mg/l Mn2+ did not decreased antibody production against Yersinia ruckeri (measured by agglutination) but significantly decreased hematocrit. The levels of manganese in lymphoid organs (spleen and kidney) increased progressively during the experiment. The effect of manganese in vitro on phagocytosis of opsonized Yersinia ruckeri was studied by chemiluminescence. Mn2+ has a stimulating effect on phagocytosis in a range of 6.25 to 50 mg/l.

Animals↗