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Biomedical subjects

L Nicod

Publications and source records attributed to L Nicod.

At least 55 records · Page 3Linked to original sources
PubMed1992

Procoagulant activity in bronchoalveolar fluids: no relationship with tissue factor pathway inhibitor activity.

Abnormalities in local coagulation may explain alveolar fibrin deposition which often accompanies human lung injuries. The purpose of this study was to investigate the generation of procoagulant activity (PCA) and tissue factor pathway inhibitor (TFPI) in selected bronchoalveolar lavage fluids (BAL) from controls (n = 7) and from patients with interstitial lung diseases (n = 9), Pneumocystis carinii (PCP) pneumonia (n = 11) and bacterial pneumonia (n = 8). As compared with controls a significant increase of PCA was observed in the three groups with lung diseases. PCA in BAL from patients with untreated interstitial lung diseases (PC Units mean of 162 +/- 48) was significantly higher than PCA of treated patients (PC Units 36 +/- 10; p less than 0.05). Increases of PCA paralleled protein levels in BAL and the protein/albumin ratios were comparable in the four groups. TFPI was significantly increased in PCP (p less than 0.02) and bacterial pneumonia (p less than 0.03), but only marginally increased in interstitial lung diseases when compared with controls. No correlation was found between TFPI and PCA in any of the four groups. These data indicate that increased procoagulant activity observed in various lung diseases is not counterbalanced by TFPI.

Adult↗
PubMed1992

Suppression of metalloproteinase biosynthesis in human alveolar macrophages by interleukin-4.

To study the interaction of lymphocytes and macrophages in the control of extracellular matrix turnover, we determined the effects of several soluble T cell products on mononuclear phagocyte production of metalloproteinases. Cytokines including IL-2, IL-4, IL-6, tumor necrosis factor alpha (TNF alpha), GM-CSF, and IFN-gamma were each tested for capacity to modulate macrophage metalloproteinase and tissue inhibitor of metalloproteinases (TIMP) expression. The addition of IL-4 to cells cultured under basal conditions caused a dose-dependent suppression in the release of 92-kD type IV collagenase without affecting TIMP production. 92-kD enzyme secretion was inhibited by 50% with 1-2 ng/ml of IL-4 and by 90% with 10 ng/ml of IL-4. When cells were first exposed to killed Staphylococcus aureus to induce metalloproteinase production, IL-4 potently blocked the stimulated release of both interstitial collagenase and 92-kD type IV collagenase, again without effect upon TIMP. Metabolic labeling experiments and Northern hybridizations demonstrated that IL-4 exerted its action at a pretranslational level. Furthermore, IL-4 possessed the capacity to inhibit metalloproteinase expression even in the relatively immature peripheral blood monocyte. As reported previously (Shapiro, S. D., E. J. Campbell, D. K. Kobayashi, and H. G. Welgus. 1990. J. Clin. Invest. 86:1204), IFN-gamma suppressed constitutive macrophage production of 92-kD type IV collagenase. Despite the frequent antagonism observed between IL-4 and IFN-gamma in other systems, the combination of these two agents lowered metalloproteinase biosynthesis dramatically, whereas IL-4 opposed the IFN-gamma-stimulated production of cytokines (IL-1 and TNF alpha). IL-6 had only minimal effect upon metalloproteinase production, but appeared to specifically augment TIMP release. In summary, cytokines released by activated T cells may profoundly reduce the capacity of the macrophage to mediate extracellular matrix degradation.

Gene Expression↗
PubMed1992

Procoagulant and fibrinolytic activities in bronchoalveolar fluid of HIV-positive and HIV-negative patients.

Imbalance between intra-alveolar procoagulant activity (PCA) and fibrinolytic activity may lead to fibrin deposition, as described in several pneumopathies, and may eventually contribute to fibrotic changes as observed in Pneumocystis carinii pneumonia (PCP). The aim of our study was to compare these activities in bronchoalveolar lavages of human immunodeficiency virus (HIV)-positive and HIV-negative patients. The material comprised: a) controls (n = 7); b) HIV-positive patients subdivided into PCP (n = 11), bacterial pneumonia (n = 8) and other pneumopathies (n = 22); and c) HIV-negative patients with bacterial pneumonia (n = 8). PCA was significantly increased (p less than 0.05) in all patient groups compared to controls. The urokinase-type plasminogen activator (u-PA) antigen levels were highest during bacterial pneumonia. Regardless of the HIV status, in bacterial pneumonia there was a marked elevation of plasminogen activator inhibitor antigens with little residual fibrinolytic activity. In contrast, the fibrinolytic activity was not decreased in PCP. D-dimer were elevated during PCP compared to controls; the highest levels were found in HIV-negative bacterial pneumonia. These data indicate that transient fibrotic changes seen in PCP may be favoured by increased PCA, but not by a depressed fibrinolytic activity. In bacterial pneumonia PCA is increased and fibrinolysis decreased independently of the HIV status.

Acquired Immunodeficiency Syndrome↗
PubMed1991

[The immunology of tuberculosis and human immunodeficiency virus].

The mechanisms of humoral and cellular immunity in the body's defences against tuberculosis are reviewed in the light of recent fundamental works. Major progress has been made in understanding the structure of mycobacteria, in particular in those areas concerning antigenic determinants which may have diagnostic or therapeutic implications. The impact of the human immunodeficiency virus infection on the antituberculous defences is discussed, on the epidemiological aspects as well as clinical and physiopathological.

HIV↗
PubMed1990

Effects of one-year hyposensitization in allergic rhinitis. Comparison of two house dust mite extracts.

In an open study, 21 patients suffering from chronic non-seasonal rhinitis and allergic to house mites (HDM) have been treated for 1 year with either a new extract (Pharmalagen; n = 10) or an allergoid, pyridine denatured, extract (Alavac; n = 11), both precipitated with AlOH3 (depot). The following investigations were performed before and after therapy: clinical scoring (for 4 weeks), quantified skin prick tests (SPT) and nasal provocation tests (NPT) with HDM, and determination in serum of HDM-specific IgE and IgG. Both groups were compared with six patients who remained untreated and underwent the same investigations. Hyposensitization with either extract induced an improvement in clinical scores (P less than 0.05), a decrease in SPT reactivity (Pharmalgen: P less than 0.001; Alavac: P less than 0.01), a marked increase in the nasal tolerance to HDM (P less than 0.001) and in HDM-specific IgG (P less than 0.001). In the group of untreated patients, all these parameters remained unchanged. Compared with the Alavac extract, the Pharmalgen extract was more active in decreasing SPT reactions (P less than 0.05) and inducing a HDM-specific IgG rise (P less than 0.05). Although both extracts induced some untoward allergic reactions, no adrenaline was used at any time during the study. These data suggest that hyposensitization with depot extracts of HDM can be considered a safe and active adjunct to the treatment of allergic rhinitis.

Adolescent↗
PubMed1985

Evidence for pancreas injury in adult respiratory distress syndrome.

The purpose of this study was to investigate the relation between serum lipase (LP), serum immunoreactive trypsin (IRT), and its inhibitors in patients with adult respiratory distress syndrome (ARDS) of diverse origin and to compare their time course with other acute conditions. The IRT and LP levels were determined at regular intervals in 41 patients hospitalized in the intensive respiratory unit with ARDS (n = 9), acute pancreatitis (n = 5), shock (n = 9), bronchopneumonia (n = 10), or acute cardiogenic pulmonary edema (n = 8). Several trypsin inhibitors were measured simultaneously: serum trypsin inhibitory capacity (TIC), alpha 1-antitrypsin, alpha 2-macroglobulin, and antithrombin III. Concomitantly, angiotensin-converting enzyme (ACE) activity was determined as a potential marker of the endothelial injury. A respective 19- and 13-fold increase in IRT and LP values were observed in patients with ARDS after a mean evolution of 6 days; similar increases were seen in patients with pancreatitis. These values were significantly higher than those observed in the other conditions studied. In patients with ARDS and acute pancreatitis, the evolution of IRT and LP values were associated with a sixfold rise in TIC. A low TIC/IRT ratio in patients with ARDS appeared to be an index of poor prognosis. Conversely, ACE activity evolution was characterized by an early decrease in all the conditions studied. These observations indicate that there is an acute delayed pancreas injury in ARDS. Thus, the release of pancreatic enzymes are not reliable markers of the early evolution of the disease but they may represent secondary mediators for enhancement of the increased endothelial permeability.

Adult↗
PubMed1984

[Choice of positive criteria in specific bronchial provocation tests with a purified acarian extract (Pharmalgen)].

Bronchial provocation tests (PT) were performed with a purified and standardized extract of the house dust mite Dermatophagoides pteronyssinus (D. ptero.) in an attempt to determine the most sensitive criteria of bronchospasm. Nineteen asthmatic patients with skin test and RAST positive for D. ptero. had a positive bronchial PT. More than 40% increase of Raw insp. simultaneously with dyspnea or wheezing was found in each patient, whereas only 6/19 had a 20% increase of FEV1. 47% of the patients had a slight to moderate late phase of bronchial obstruction. None of the 9 asthmatic patients with skin test and RAST negative for mites had bronchospasm. It is concluded that a 40% in Raw insp., combined with clinical signs of bronchospasm, is a sensitive, specific and safe method of determining the threshold of bronchial sensitivity to a standardized allergen.

Allergens↗
PubMed1984

[Skin tests, RAST and provocation tests with a purified acarian extract (Pharmalgen) in respiratory hypersensitivity].

The diagnostic value of a purified and standardized extract of the house dust mite Dermatophagoides pteronyssinus (Pharmalgen, Pharmacia) has been tested by nasal or bronchial allergic provocation tests (PT). 50 patients (31 with rhinitis and 19 with asthma) who had a skin test and RAST positive for D. ptero. were tested: all had a positive PT. 47% of the patients with asthma had a late phase of bronchial obstruction. PT were negative in 18 subjects not allergic to D. ptero. It is concluded that, although specific, PT are not necessary if the diagnosis has already been established by the association of a positive skin test and RAST.

Adult↗
PubMed1976

[Radiologic signs of severe head transformation disorders arising with the treatment of the congenital dislocation of the hip (author's transl)].

After a general review of the pertinent literature, a classification of the head transformation disorders arising with the dislocation of the hip in degrees of severity (stages of development) is made with the help of the patients of the above-mentioned hospital. The significance of the different head transformation disorders as a warning sign for the development of a later head necrosis is shown in a subdivided form. The condensation, either a partial or a complete one, has the most unfavourable prognosis. The text is illistrated with series of radiographs of own cases.

Child↗
PubMed1976

[The etiology of hallux valgus].

Modifications of the forefoot in weightbearing are conductive to hallux valgus, some are congenital and constitutional: supination of the forefoot, adductus of the metatarsal bones, metatarsus varus primus brevis. Others are acquired: transversal flatfoot. Measurement of the different angles observed on a dorsi-plantar X-ray in relation to the external and internal limits of the Lisfranc joint has an etiological signification. To look for changes in the weightbearing configuration of the foot, an element in the formation of hallux valgus, is of use in the choice of a method of correction.

Body Weight↗