PubMed Health⌕ Search

Biomedical subjects

N Biot

Publications and source records attributed to N Biot.

At least 37 records · Page 2Linked to original sources
PubMed1984

[Modification of the Friedland-Silverstein technic for the determination of the activity of angiotensin I converting enzyme].

The authors studied the parameters of Friedland and Silverstein's technique for measuring the activity of the angiotensin I conversion enzyme and found a number of anomalies. The technique was modified by correcting the wide pH difference between the pH of the reagent and the pH of the reference solution. This modification made the technique optimal for the measurement of the enzyme activity by allowing a 20 to 40 per cent increase in this activity and a 15% increase in the positivity in cases of clinical sarcoidosis. The application of this modified test to the determination of the activity of the angiotension I conversion enzyme in control subjects, patients with sarcoidosis and patients with order respiratory diseases gave the following mean values, respectively: 39 +/- 10 IU; 81 +/- 23 IU; 41.5 +/- 2.5 IU in the serum and 0.2 IU; 1.1 +/- 0.5 IU; 0.2 +/- 0.1 IU in bronchoalveolar lavage fluid. The increase in enzyme activity in sarcoidosis is found in the serum in 75% of cases and in bronchoalveolar lavage fluid in 85% of cases. This modified technique can be applied in routine practice and in research.

Angiotensin I↗
PubMed1983

Phosphatidyl ethanolamine methylation in membrane from bronchoalveolar lavage mononuclear cells, in asthmatic patients: a new marker of macrophage activity.

Phosphatidyl ethanolamine methylation was compared in alveolar macrophage membrane from asthmatic and control subjects. Phosphatidyl ethanolamine methylase activity was determined by measuring the incorporation of (3H) methyl group from (3H) adenosyl methionine into membrane phospholipids. (3H) methyl group incorporation was significantly higher in macrophages from asthmatic patients. This result is consistent with macrophage membrane activation and could signify: a membrane phospholipid pool regeneration after allergenic or toxic disturbance or an enzymatic activation by inflammatory mediators.

Adult↗
PubMed1982

[Indexing protein determinations in bronchoalveolar lavage fluids to a reference substance. Value of alveolar potassium].

It is well known that a reference substance is required to determine accurately the protein content of broncho alveolar lavage but there has been disagreement as to the ideal reference substance. We studied the relative usefulness and reproductibility of potassium and albumin as reference substances in determining protein content in 8 normal subjects and 10 patients with stage 11 sarcoidosis or extrinsic allergic alveolitis. Two successive lavages were performed intentionally using different volumes of injected normal saline. The use of potassium as a reference substance not only permitted a better reproductibility in determination of protein content of sequential broncho-alveolar lavages but also a significantly better discrimination between normal and abnormal subjects.

Albumins↗
PubMed1981

Angiotensin converting enzyme in bronchoalveolar lavage fluid in pulmonary sarcoidosis.

Alveolar angiotensin converting enzyme (ACE) and serum ACE were measured simultaneously in 16 patients with histologically confirmed sarcoidosis and in 16 control subjects. Although alveolar ACE was abnormally elevated in all 15 cases of active sarcoidosis, serum ACE was not. No correlations were found between radiographic staging of pulmonary sarcoidosis and the levels of these enzymes. There was a clear correlation, however, between the levels of alveolar ACE and counts made on bronchoalveolar lavage fluid. This correlation was closer than that existing between serum ACE and bronchoalveolar lavaged lymphocytes. It is suggested that alveolar ACE is an additional biological marker of pulmonary sarcoidosis which is possibly more sensitive than serum ACE.

Adult↗
PubMed1980

[Histamine-release: present data and practical interest (author's transl)].

Histamine remains the best known humoral marker of hypersensitivity phenomena. Stored in blood basophilic cells and mast cells this histamine can be released under the influence of an immunitary factor with humoral or cellular mediation or under the dependance of irritative factors either chemical or medicinal. The authors recall the innermost mechanism of the main stages of histamine-release: recognition of membrane receptors, multiple enzymatic activations, opening of calcic membrane pores, synthesis of unpreformed mediators (SRSa and PAF), finally granular extrusion with release of histamine and of numerous mediators, among which the neutrophil chemotactic factor, one of the main responsible ones of the late phase of hypersensitivity phenomena. The regulation of histamine release is mostly done by cyclic AMP and GMP and the membrane receptors H2. The test of histamine release on whole blood or on leucocypte suspension enables by the study of effect-dose curves to differentiate the histamine release mechanisms: bell shaped curve in the case of immunitary processus and ascending curve for an irrative phenomenon. Practically this test can be used for diagnosing drugs allergies, professional asthmas or to study the pharmacological activity of a drug.

Adult↗
PubMed1980

[Contribution of biological tests in the evaluation of professional asthma (author's transl)].

The eventual difficulties of diagnosing professional asthma sometimes need the help of methods of complementary diagnosis. The histamine-release test and that of basophils granules liberation are studied in this work, concerning 12 substances with a suspected allergenic action (saw-dust, textile fibres, chemicals, products of plant origin). The histamine-release and granules liberation tests were performed according to the techniques described respectively by Lichtenstein and Benveniste. Both examinations were positive in a concording manner in 8 cases out of 12, but this positivity was difficult to interprete for etiopathogenic reasons. The study of the curve of histamine-release in relation with the dose of allergen used in the test nevertheless enables to differentiate two types of answers, one related to an allergic mechanism, the other to an irritative one. These observations led to the deduction that a positive granules liberation test could be due to a non allergic mechanism. Negativity in both tests does not allow the rejection of the part played by these substances into the genesis of respiratory signs. Indeed these tests only investigate one part of the mechanisms which can be involved: direct stimulation of vagal irritant receptors and the plain pharmacological reactions escape from this type of biological investigations. The biological tests studied in this work can be used in a complementary fashion in the etiological survey of professional asthma but they cannot replace the realistic tests, more reliable because they react whatever the etiopathogenic mechanism involved.

Adult↗
PubMed1980

[In vitro comparative study of the protective effect of different theophyllines on the leucocytes' histamine-release induced by antigen (author's transl)].

The recent discovery of the protective action of xanthic bases towards histamine-release consecutive to the antigen-antibody reaction led the authors to study the importance of this protection induced by various theophylline derivatives. The technique used was that described by LICHTENSTEIN and OSLER: isolation of leucocytes, measurement of histamine liberated in the presence of antigen, same measurement done in the presence of antigen and theophylline. The antigens used were: house dust, Dermatophagoides pteronyssimus (DP), graminaceae pollens. The tested theophyllines were: the theophylline base, aminophylline, bamiphylline, diprophylline, thio theo, piperazine acefilinate. All these substances studied brought a reduction of the histamine-release but according to a variable frequency and intensity: the thio theo, the diprophylline and the piperazine acefilinate gave the best results. Besides the latters are clearer when the antigen was dust or DP. This study enables the confirmation of the inhibiting action of theophyllines on histamine-release induced by antigen, but complementary studies on a larger number of cases seem necessary in order to determine precisely the most efficient derivatives.

Allergens↗
PubMed1979

[Value of lymphoblastic transformation test for diagnosis and treatment of microbial asthmas in adults (author's transl)].

A lymphoblastic transformation test (LTT) done on 9 germs in 30 patients (270 tests) with bacterial asthma was found positive 117 times out of 170 (43.3%) while the same study done on a control group of 100 non microbial asthma was generally negative (5% of positive responses). Positive LTT confirmed, in 59.2% of cases, the cutaneous tests. In the other cases, discrepancies can be found in both ways: positive LTT and negative cutaneous tests (16.9%) or the reverse (23.9%). The significance of disagreeing results is discussed. Specific desensitizations done only with the bacteria producing agreeing positive reactions, gave interesting though inconstant results.

Adult↗
PubMed1976

[Blood immunoglobulin deficiencies during bronchial asthma in the adult].

The study of serous immunoglobulins of 500 asthmatic patients enabled the authors to discover a deficit in one of the Ig in 93 cases (18.6%), mainly in cases of intrinsic allergic asthma with an important or dominant infectious character, or microbial asthma. It concerned partial shortages of usually only one Ig in each patient, mostly the IgG. The importance of these deficits is discussed, particularly in the origin of bacterial sensitivity of these asthmas and in the genesis of atopy. The problem of IgG reagins is also discussed. Practical deductions drawn form these findings are envisaged.

Adult↗