M F Carette

Bio: M F Carette is an academic researcher. The author has contributed to research in topics: Pneumonia & Pneumocystis carinii. The author has an hindex of 3, co-authored 6 publications receiving 54 citations.

Increased lung epithelial permeability in HIV-infected patients with isolated cytotoxic T-lymphocytic alveolitis

Abstract: HIV-related lymphocytic alveolitis is common in HIV-seropositive patients without lung infection or tumor. In some of them a fraction of alveolar lymphocytes are HIV-specific cytotoxic T-lymphocytes (CTL) bearing the CD8 and D44 cell surface markers and capable of killing HIV-infected alveolar macrophages. In order to evaluate the in vivo effect of these CTL on lung function, we measured the pulmonary clearance of aerosolized 99mTc-diethylene triamine penta-acetate (DTPA-CI) on 24 occasions in 22 patients with lymphocytic alveolitis. DTPA-CI has been selected as a highly sensitive test to detect injury of the lung epithelium. In 13 of the patients, we found a high DTPA-CI of 4.56 +/- 2.54%.min-1 (mean +/- SD), suggesting an increase of the epithelial permeability. The lymphocytic alveolitis was then characterized by a high cellularity, a high proportion of lymphocytes (59 +/- 18%), mainly composed of CD8+D44+ T-lymphocytes (149 +/- 109 cells/mm3), which spontaneously exhibited a cytolytic activity against the autologous alveolar macrophages in a standard 51Cr release assay. In the remaining 11 patients, DTPA-CI was normal (less than 1.78%.min-1), lymphocytic alveolitis being characterized by a low number or an absence of CD8+D44+ alveolar lymphocytes (9 +/- 13 cells/mm3) with no significant cytolytic activity. In the whole group, a significant correlation (r = 0.74, p = 0.0004) was found between the DTPA-CI and the number of CD8+D44+ lymphocytes and their cytotoxic activity against alveolar macrophages. Altogether, these results suggest that an injury of the lung epithelium could result from a HIV-specific CTL-induced immunologic conflict.

[Cavitary pneumocystis carinii pneumonia in AIDS: a new semiologic aspect. Apropos of 3 cases].

Abstract: Three cases of AIDS patients hospitalized for Pneumocystis carinii (PNC.C) pneumonia are reported. These cases are of interest because of the unusual radiological semiology of these pneumocytoses, i.e., their partially or totally pitted nodules. In addition, 4 related facts merit attention: the occurrence of pneumocytosis in 1 patient under prophylactic aerosol pentamidine therapy: the rarity, unusual in AIDS, of PNC.C in the bronchoalveolar lavage fluid from 2 patients; the association of pitted nodules with mediastinal adenopathies due to PNC.C in 1 patient; and the favorable outcome in all cases.

A new case of necrotizing pneumocystosis in AIDS

Abstract: The authors report the case of an AIDS patient presenting with both Streptococcus pneumoniae pneumoniae and pneumocystosis. What was remarkable in that case was the appearance, in an otherwise favourable course, of a large excavation in the territory of the pneumonia. The responsibility of Pneumocystis carinii in this excavation is discussed.

Acute respiratory failure disclosing bilateral diaphragmatic paralysis

Abstract: In the case of three patients an acute respiratory failure with alveolar hypoventilation is related to bilateral diaphragmatic paralysis apparently isolated from any other neurologic abnormalities. The current initial diagnosis of pulmonary embolism leading to admission in an intensive respiratory care unit, because of the severity of the acute respiratory failure, has to be rectified then. Bilateral diaphragmatic paralysis is suspected on account of the absence of any patent etiology, on increasing dyspnea in supine position and paradoxic movements of the upper abdomen (whether spontaneously or in attempted weaning of ventilation support). Bilateral diaphragmatic paralysis is asserted by electromyogram with measurement of nerve conduction velocities of the two phrenic nerves. In the first case, it appears early in the course of an amyotrophic lateral sclerosis; in the second case, it occurs before the presence of a herpes-zoster becomes patent. In the third case, paralysis seems to be idiopathic. Evolution is promising in the last two cases, owing to the reversibility of the lesions. The difficulty of diagnosis, the varying nature of etiology and prognosis encountered in these three cases are also apparent in the 15 cases published in medical literature. The small number of cases published up to now, contrasting with the cases we have witnessed over the last 3 years, leads us to think that this disease must exist more often and may remain unknown to us.

Cytotoxicity for lung epithelial cells is a virulence-associated phenotype of Mycobacterium tuberculosis.

Abstract: Dissemination of viable tubercle bacilli from the lung is a critical event in the establishment of Mycobacterium tuberculosis infection. We examined the possibility that M. tuberculosis bacteria could infect and damage lung epithelial cells to determine whether direct penetration of the alveolar epithelium is a plausible route of M. tuberculosis infection. While both virulent H37Rv tubercle bacilli and the attenuated Mycobacterium bovis BCG vaccine strain were able to enter A549 human lung epithelial cells in culture, only the virulent tubercle bacilli were cytotoxic for both polarized and nonpolarized epithelial monolayers and macrophages. In addition, bacterial entry into epithelial cells, but not macrophages, was increased by intracellular passage through macrophages, suggesting enhancement of a bacterially mediated cell entry mechanism in bacteria grown within macrophages. These findings suggest that M. tuberculosis bacteria might have the ability to gain access to the host lymphatics and circulatory system by directly penetrating the alveolar epithelial lining of an infected lung.

Carboxyl-terminal and central regions of human immunodeficiency virus-1 NEF recognized by cytotoxic T lymphocytes from lymphoid organs. An in vitro limiting dilution analysis.

Abstract: Cytotoxic T lymphocytes (CTL) specific for human immunodeficiency virus (HIV) proteins have been analyzed in lymphoid organs from seropositive patients. Indeed, an active HIV replication coexists with a major CD8+ lymphocytic infiltration in these organs. We have shown in a previous report that HIV-seropositive patients lungs were infiltrated by HIV specific CD8+ lymphocytes. In the present report, we show that HIV-specific CTL responses can also be detected in lymph nodes and spleens, and were mainly directed against the ENV, GAG, and NEF HIV-1 proteins. The primary NEF-specific CTL responses were further characterized by epitope mapping. Determination of epitope-specific CTL frequencies were performed by limiting dilution analysis. Our results indicated that, in addition to the central region of NEF (AA66-148), a new immunodominant region is recognized by CTL. This region corresponds to the carboxyl-terminal domain of NEF (amino acids 182-206). AA182-206 is recognized in association with at least two common human histocompatibility leukocyte antigen (HLA) molecules (HLA-A1 and B8), with clonal frequencies of one CTL per 10(-5) to 10(-6) splenic lymphocytes. Our data indicate that lymphoid organs may represent a major reservoir for in vivo activated HIV-specific CTL. Furthermore, the carboxyl-terminal domain of NEF was found to be conserved among several HIV strains. Therefore, our finding is of interest for further HIV vaccines development.

Airway and alveolar permeability and surface liquid thickness: theory

Abstract: Widdicombe, John. Airway and alveolar permeability and surface liquid thickness: theory. J. Appl. Physiol. 82(1): 3–12, 1997.—The thickness of airway surface liquid (ASL) can be calculated as the r...