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Biomedical subjects

A Pelletier

Publications and source records attributed to A Pelletier.

50 records · Page 3Linked to original sources
PubMed1984

[Practical value of the assay of serum angiotensin converting enzyme activity in sarcoidosis].

Serum levels of angiotensin conversion enzyme (A.C.E.) are increased in 60 to 80% of cases of sarcoidosis. A.C.E. levels were measured as part of the initial assessment of 70 patients with the disease, with repeated measurements in 18 of them. The subsequent course of sarcoidosis was evaluated over a minimum period of 7 months, in relation to initial serum A.C.E. levels. A high serum A.C.E. level is indicative of the secretion of the cells of the epithelioid and giant cell granuloma and reflects the activity of the disease at the particular time without providing any definite prognostic information. Study of 6 patients treated with corticosteroids showed that serum A.C.E. levels rose again when treatment was reduced or stopped in 4 of them, this renewed rise appearing to precede the radiological recurrence. Whilst the prognostic value of alveolar lymphocytosis is greater than that of serum A.C.E. levels in sarcoidosis, measurement of serum A.C.E. is easier in the context of therapeutic surveillance.

Humans↗
PubMed1984

[Preliminary results concerning the value of chemotherapy in the treatment of inoperable bronchial carcinoma (excluding small-cell anaplastic carcinoma)].

Inoperable non- microcellular primary bronchial carcinomas have been reputed up to now to be chemo-resistant. The introduction of Cis-platinum into a polychemotherapy protocol leads to revision of this concept. The authors report the preliminary results of a polychemotherapy protocol (including Cis-platinum, Vindesine, CCNU, Cyclophosphamide) associated, in cases of non- metastasized carcinomas, with radiotherapy to the tumour itself, the mediastinum and the supraclavicular fossae. These results confirmed the value of such chemotherapy in forms with metastases. In localised inoperable forms, conclusions could be reached only on the basis of a randomised comparative trial of chemotherapy + radiotherapy versus radiotherapy alone.

Adult↗
PubMed1984

[Diffuse interstitial pneumopathy related to tungsten carbide, confirmed by bronchoalveolar lavage, and responding to corticotherapy].

The authors report a case of severe diffuse interstitial hard metal lung disease responding to corticosteroid therapy. They point out that the course of this disease may be regressive and emphasise that analysis of broncho-alveolar washings showed no abnormality in the differential cell count. Mineralogical study of the same material confirmed exposure.

Adrenal Cortex Hormones↗
PubMed1983

The functional activity of alpha 1-proteinase inhibitor in bronchoalveolar lavage fluids from healthy human smokers and non-smokers.

Cigarette smoking is an important risk factor for pulmonary emphysema. In vitro experiments document cigarette smoke-induced inactivation of alpha 1-proteinase inhibitor, a protein which is thought to protect the lung interstitium against the deleterious action of neutrophil elastase. To assess the relevance of this in in vitro findings, we have measured the functional activity of alpha 1-proteinase inhibitor collected by bronchoalveolar lavage from twenty healthy volunteers (10 heavy smokers and 10 non-smokers). The total inhibitor concentration was measured by radial immunodiffusion. The active inhibitor concentration was determined by virtue of its elastase inhibitory capacity. We used pure and active site-titrated porcine pancreatic elastase and a kinetic assay with succinyl-trialanine-p-nitroanilide in order to get reliable and accurate results. In smokers and in non-smokers the percentage of functionally active alpha 1-proteinase inhibitor in bronchoalveolar lavage fluid is 54 +/- 12 and 38 +/- 14%, respectively. This difference is not significant. Serum alpha 1-proteinase inhibitor is 100% active in both groups. Our data disagree with previous reports suggesting the presence of fully active alpha 1-proteinase inhibitor in bronchoalveolar lavage fluid of non-smokers and of partially active inhibitor in the lavage fluid of smokers.

Adult↗
PubMed1982

[Proteases, antiproteases and pulmonary emphysema].

A deficiency of alpha 1 antiproteases is associated with severe and early emphysema. This emphysema can be experimentally produced in animals by endotracheal instillation of elastolytic proteases. Thus it would seem that emphysema is linked to an imbalance between proteases and antiproteases at the pulmonary level. This work studies the proteases, whose role in the genesis of emphysema is highly probable in view of the data in the literature (leukocyte elastase), disputed (macrophage elastase) or transitory (microbial elastases). We contrast the main agents capable of inhibiting these proteases (alpha 1 antiprotease and bronchial inhibitors) or of changing their activity (alpha 2 macroglobulins). The relative importance of these antiproteases is discussed in the light of studies made on bronchial secretions and bronchoalveolar lavage. These irritants may influence the protease - antiprotease equilibrium and favour the development of emphysema by increasing the proteases or decreasing the antiproteases. It appears that tobacco, as well as infection and anything which sets in motion the pulmonary phagocytes favour the liberation of leucocyte elastase. These attacks inactive the alpha 1 antiproteases in addition to the bronchial inhibitor. They may be recognized by a change in elastolytic and anti-elastolytic activity observed in bronchial secretions and in bronchoalveolar lavage (which is more disputed in the latter).

Animals↗
PubMed1981

[The prognostic significance of pulmonary arterial hypertension in chronic obstructive airway disease (author's transl)].

In 175 cases of chronic obstructive airway disease (most often chronic bronchitis) with severe ventilatory deficit in the majority of cases, the prognostic value of mean pulmonary arterial pressure (PAP) and other respiratory function parameters (FEV1, blood gases) was studied by calculation of survival rates using the actuarial method. The patients were cathetherised between 1968 and 1972 and the maximum period of follow-up is 10 years. The results demonstrated the definite prognostic value of PAP : 4 and 7 year survival rates were markedly different according to whether initial PAP was above or below 20 mmHg. However other haemodynamic (motor pressure through the pulmonary circulation) and non-haemodynamic (FEV1, PaCO2) parameters also would appear to be as useful as PAP in predicting survival in such patients. The prognosis is particularly bad in patients with severe pulmonary arterial hypertension (PAP greater than 30 mmHg). In this type of study, it is essential to bear in mind the influence of age. Survival rates differed significantly according to whether the subjects were over 60 years in age initially.

Adult↗
PubMed1981

[Transbronchial lymph node biopsy in the diagnosis of sarcoidosis (author's transl)].

Two hundred and fifty eight transbronchial lymph node biopsies using a Menghini type needle 1.5 mm in diameter were performed in 193 patients with a radiological and clinical picture suggestive of sarcoidosis. In 73 cases, the histological argument for the diagnosis was provided solely by this technique. The combination of two methods of obtaining material (multiple biopsies and transbronchial puncture) during rigid bronchoscopy led to a histological diagnosis in 77.7% of patients. The authors emphasize the relative safety of the method, as well as its value when material obtained by fibroscopy has proven to be unsatisfactory.

Biopsy↗
PubMedDate not supplied

The tus gene of Escherichia coli: autoregulation, analysis of flanking sequences and identification of a complementary system in Salmonella typhimurium.

The tus gene of Escherichia coli encodes a DNA-binding protein that, when bound to terminator sites, blocks replication forks. One of these sites, TerB, is immediately upstream from tus, and we have determined that the 5' end of tus mRNA is in the TerB site, that tus is autoregulated and that pTus is a very low efficiency promoter. Analysis of the DNA upstream from tus and TerB indicates a set of sensor/regulator genes which are comparable to envZ/ompR. Although tus mutants exhibit no growth phenotype in laboratory conditions, Salmonella typhimurium and E. coli have nevertheless maintained similar termination systems. Sequence homology can be demonstrated by Southern hybridizations, and the systems also exhibit functional complementation: the Tus protein of S. typhimurium blocks DNA replication at the TerA site of E. coli.

Bacterial Proteins↗
PubMedDate not supplied

Cardiopulmonary bypass pumps and thrombin generation: what goes around comes around.

Thrombin generation and subsequent fibrin deposition occur during cardiopulmonary bypass (CPB) using roller pumps (RPs) despite the administration of high dose heparin. The authors attempted to determine if less thrombin is generated and less fibrin is deposited during CPB using a centrifugal pump (CP). In Part 1 of the experiment, 12 pigs receiving 400 U/kg heparin underwent CPB, including hypothermia, cardioplegia, and aortic cross-clamping, using a CP or RP. Blood samples were collected throughout CPB to measure thrombin generation. At the end of CPB, the amount of fibrin deposited onto each filter was assessed spectrophotometrically. In Part 2, blood samples and arterial in-line filters were obtained from 20 patients undergoing CPB, using either RP or CP, and studied as described previously. The Part 1 results showed that thrombin generation and fibrin deposition in CP pigs were <50% of those seen in the RP pigs (p < 0.01 and p < 0.01, respectively). In Part 2, thrombin generation was significantly attenuated both during and after CPB in the CP patients (p < 0.01 and p < 0.01, respectively). However, there was no significant difference in fibrin deposition between the two types of pumps after their use in the patients undergoing cardiopulmonary bypass. It is concluded that there is less thrombin generation and subsequent fibrin deposition during CPB when using a CP instead of RP in a defined experimental in vivo situation, suggesting that there is less hypercoagulability during CPB when using a CP instead of an RP. However, a large study in more patients undergoing CPB for longer pump runs is required to determine the relevance of these observations on subsequent clinical endpoints.

Animals↗
PubMedDate not supplied

Induction of LFA-1 independent human B cell proliferation and differentiation by binding of CD40 with its ligand.

Engagement of CD40 on resting B cells in the presence of IL-4 triggers B cell proliferation, differentiation and homotypic adhesion. This study was designed to investigate the role of LFA-1/ICAM-1 interactions in homotypic adhesion and proliferation of CD40-activated human B lymphocytes. Freshly isolated B cells were cultured in vitro in the presence of IL-4 and of L cells expressing CD40L, the CD40 ligand. The addition to the culture medium of LFA-1 and ICAM-1 antibodies inhibited homotypic B lymphocyte adhesion. However, these antibodies failed to affect B lymphocyte proliferation and antibody production. These results indicate that aggregation and proliferation are independent events although both induced by CD40 activation.

Animals↗
PubMedDate not supplied

[Computerized data processing in the Pharmacovigilance Center of Bordeaux-Aquitaine. Analysis of clientele of the Center].

Practitioners inquiries addressed to our Drug Information Centre are computerized since 1986. Their analysis allows to pinpoint special problems and needs for practitioners information, and to detect new adverse drug reactions. Time series analysis of calls (according to the practitioners specialities or geographic stay) allows to evaluate the effectiveness of the services provided by the Bordeaux Drug Information Centre.

Drug Information Services↗