Biomedical subjects

F Lavaud

Publications and source records attributed to F Lavaud.

50 records · Page 3Linked to original sources

PubMed1990

Toluene diisocyanate-induced conformational changes of serum albumin: a study on repeated inhalations in guinea-pigs.

High responder lines of Hartley guinea-pigs were sensitized by repeated inhalations of toluene diisocyanate (TDI). After 3 weeks, we demonstrated a degree of TDI substitution of the serum-albumin-enriched fraction (AEF) and we ascertained the sensitization of the most exposed animals using PCA methodology. Fourier transform infrared spectroscopy (FT-IR), used to investigate conformational changes in AEF, highlighted the structural modifications of the native protein conformation. Such crucial changes may support, at least in part, the relationship between TDI exposure and triggering of hypersensitivity reactions.

Administration, Inhalation↗

PubMed1989

[T lymphocytes in the circulating blood and pleural fluid of patients with tuberculosis or cancer].

Inflammatory pleurisies in the adult are particularly rich in CD4 lymphocytes, capable of inducing and facilitating the immune reaction. The aim of this study was to determine the percentage of CD4 and CD8 lymphocytes in pleural fluid and blood in 13 patients with tuberculous pleurisy and 12 patients with pleural neoplasms, to establish the diagnostic value of this analysis. Independent of the etiology of the effusion there is a concentration of CD4 T lymphocytes in the pleural fluid compared to the blood (49.52 +/- 12.36% and 39.28 +/- 6.74%, respectively, p value less than 0.001). However, there was a similar concentration for the two types of disorders studied with 59.92 +/- 7.26% for tuberculous pleurisies and 45.83 +/- 6.26% for neoplastic effusions, thus this technique does not make the diagnostic orientation any clearer.

Adult↗

PubMed1987

Double phenotyping of immunoregulatory T cell subsets in patients with allergic asthma.

In order to determine whether the dissection of helper/inducer (CD4+) and suppressor/cytotoxic (CD8+) lymphocyte subsets with Leu 8 reagent would reveal any differences between allergic asthma patients and non-atopic controls, we compared in both groups the 'true helper' T cell subset (Leu 8- CD4+), responsible for the major helper effect, and one of the suppressor T cell subpopulations (Leu 8- CD8+). Peripheral blood mononuclear cells from sixty-nine individuals, including nineteen extrinsic asthmatics, fifteen intrinsic asthmatics, seventeen patients with chronic obstructive lung disease and eighteen healthy controls, were comparatively analysed. Although total CD4+ cells and total CD8+ cells were similar for all groups, we found in the extrinsic asthma patients group a significant increase in the number of 'true helper' T cell sublineage (Leu 8- CD4+) and of suppressor cells expressing Leu 8- CD8+ phenotype. Such imbalances may be implicated in the pathogenesis of atopic asthma.

Adult↗

PubMed1986

[Pulmonary hydatidosis. Comparison of cytology and scanning electron microscopy].

The puncture of a hydatid cyst with a fine needle is not generally recommended as a procedure and may even be contra-indicated in the first instance. Sometimes, however, the cytologist will be surprised to discover some scolices in the aspirate when the radiology is misleading, or not suggestive, and the serology is negative. We report two cases where the diagnosis was made by the cytological examination of the aspirate. The cytological study of the liquids was compared with electron microscopy scanning, enabling the stages of development of the parasite in the tissue of the pulmonary parenchyma to be assessed.

Adolescent↗

PubMed1984

Failure to distinguish ultrastructurally between T4+ (helper) and T8+ (suppressor/cytotoxic) T-cell subsets.

Human peripheral T-cell subpopulations revealed by monoclonal antibodies by means of a rosetting method were isolated by micromanipulation and submitted to electron microscopic analysis. The T3+ subset (total T cells) displayed a high degree of heterogeneity, including multiple transitional forms, from cells with a high nuclear to cytoplasmic ratio and rare organelles to cells with a low nuclear to cytoplasmic ratio and a complex system of cytoplasmic organelles. T4+ (inducer/helper) and T8+ (suppressor/cytotoxic) cell subpopulations were shown to have no evident distinguishing characteristics. They both displayed the same morphological variation mentioned for T3+ lymphocytes. On morphometric analysis, these two cell subsets were very similar, with only slight differences for cell surface roughness, volume of mitochondria, extent of nuclear indentation, and surface area of the rough endoplasmic reticulum. The significance of these minor morphological differences is discussed.

Animals↗

PubMed1984

T-lymphocyte subsets in pleural fluids: discrimination according to traditional and monoclonal antibody-defined markers.

T-lymphocyte subpopulations in pleural fluid and in peripheral blood from 17 patients admitted for pleural effusion were identified by E-rosette formation and delineated by monoclonal antibodies OKT3 (peripheral T-cells), OKT4 (helper/inducer cells), and OKT8 (suppressor/cytotoxic cells). We studied 13 patients with specified pleural diseases (tuberculosis, malignancies, connective tissue diseases, congestive heart failure) and 4 patients with non-specified pleural diseases. Our findings showed that the percentage of T-cells increases in pleural fluid versus peripheral blood whatever the diagnosis is, and that these T-cells are predominantly helper/inducer cells. Moreover, a recently described T-lymphocyte subpopulation, which expresses neither T3 nor other monoclonal antibody-defined markers, seems to be concentrated in the pleural fluid, especially in tuberculosis and malignant effusions. Although T-lymphocyte delineation seems to fail to aid in etiological diagnosis of pleurisy, such determinations could provide informations about local pathogenic mechanisms.

Antibodies, Monoclonal↗

PubMed1984

[Acute renal failure caused by clometacin hypersensitivity].

Renal involvement is not frequently observed during therapy with clometacine and its mechanism not fully understood. We report on a case of acute renal failure occurring four times in conjunction with acute hepatitis before the causative effect of clometacine was demonstrated. Drug hypersensitivity was documented by anatomical findings consisting in renal interstitial infiltration by mononuclear cells and eosinophils and by hypereosinophilia, increase in plasma IgE and a positive basophil degranulation test.

Acute Kidney Injury↗

PubMed1983

[Phenotype of T lymphocytes and macrophages obtained by broncho-alveolar lavage of human lung].

T lymphocytes and macrophages, isolated and purified from broncho-alveolar lavages performed in normal controls and in patients with various alveolar structure diseases were identified using monoclonal antibodies against different membrane markers. For T lymphocyte subsets, our results are consistent with previous observations showing a large number of lung helper T cells in patients with sarcoidosis with high-intensity alveolitis. For macrophage subsets, we pointed out, for all cases, a weak expression of monocyte markers.

Antibodies, Monoclonal↗

PubMed1983

[Accidental poisoning by volatile hydrocarbons in children (apropos of 57 cases)].

Most of the accidentally intoxicated children who are admitted into hospital have swallowed volatile hydrocarbons. The ingested products are either aliphatic hydrocarbons, whether white spirit or petrol, or aromatic hydrocarbons. We have collected informations upon 57 children admitted into the pediatric department of The American Memorial Hospital in Reims, from 1973 to 1982. The children's average age is 24 months and they have usually swallowed very small amounts of the products. Early clinical manifestations involve mainly respiratory and digestive systems, while the most frequent manifestation is high fever. The early roentgenologic manifestations have a predominantly alveolar pattern which is to be found in the lower lobes. The appearance of pneumatoceles is the typical roentgenologic disturbance. The recovery is usually complete. Hydrocarbons directly reach the lungs down the respiratory tract-even without the children's swallowing down the wrong tract-owing to the physical characteristics of those products. That accounts for any gastric lavage being both unnecessary and dangerous.

Child, Preschool↗

PubMed1981