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Biomedical subjects

C Mayaud

Publications and source records attributed to C Mayaud.

At least 19 recordsLinked to original sources
PubMed1998

Neutrophil alveolitis in bronchioloalveolar carcinoma: induction by tumor-derived interleukin-8 and relation to clinical outcome.

Tumor infiltrate, predominantly constituted by lymphocytes, may represent an important prognostic factor in bronchioloalveolar carcinoma (BAC), in addition to tumor extension and histological type. In the present study, we determined the presence, the origin, and the prognostic importance of neutrophils that also participate in leukocyte infiltrates of BAC. Neutrophil alveolitis was determined immunohistochemically in both lung biopsies and bronchoalveolar lavage (BAL) fluid samples from 29 patients with histologically proved BAC. The local expression of interleukin (IL)-8 was determined by immunohistochemical and immunoenzymatic techniques. Neutrophil counts were analyzed in relation to the clinical outcome of patients by the Kaplan-Meier method and Cox's univariate and stepwise multivariate models. Lymphocytes and neutrophils dominated the inflammatory cell population in the lower respiratory tract of patients with BAC. Neutrophils were located mainly in the alveolar lumen and seldom in alveolar wall whereas lymphocytes were exclusively present in alveolar wall. A relationship was observed between the number of neutrophils and the level of IL-8 in BAL fluid suggesting the involvement of that chemokine in neutrophil recruitment. The tumor cells were the predominant cells that appeared to express IL-8 by immunolocalization. The presence of increased numbers of neutrophils was significantly associated with a poorer outcome in patients with BAC (P = 0.02). In a multivariate analysis, the neutrophil percentage in BAL fluid was an independent predictor of clinical outcome. The risk of death was increased substantially (rate ratio, 5.2; 95% confidence interval, 1.1 to 24.7) among patients with BAL neutrophil percentage of > or = 39% (median of the distribution) as compared with the others. In BAC, neutrophils accumulate in the alveolar lumen. Elaboration of IL-8 by tumor cells may be responsible for this event, which is associated with a significantly higher risk of death.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1997

Tuberculosis generates a microenvironment enhancing the productive infection of local lymphocytes by HIV.

Tuberculosis (TB) contributes to the progression of HIV disease but, so far, the mechanism involved is not clear. Several cytokines accumulating in vivo at the site of mycobacterial infection up-regulate HIV expression in vitro. In this study, we assessed the role of pleural fluids recovered from seronegative patients with TB on HIV replication in acutely infected blast cells. Pleural fluids from subjects with congestive heart failure served as controls. In all cases, TB pleural fluids stimulated HIV replication in vitro. TNF-alpha, IL-6, IFN-gamma, and granulocyte/macrophage (GM)-CSF, as well as very low levels of IL-2, were detected in TB pleural fluids. An anti-IL-2 Ab preincubated with TB pleural fluids exhibited no blocking effect on HIV replication similarly to anti-IFN-gamma and anti-GM-CSF Abs. In contrast, anti-TNF-alpha and anti-IL-6 Abs decreased HIV replication by 60 and 90%, respectively. Recombinant TNF-alpha and IL-6 stimulated HIV replication, while IFN-gamma and GM-CSF had a more ambiguous role. The capacity of pleural fluids to stimulate HIV replication was specific for TB, since the capacity of control fluids was significantly lower. Finally, in contrast to PBL, which require in vitro activation for their productive infection by HIV, unstimulated tuberculous pleural lymphocytes were productively infectable by HIV. Taken together, our data suggest that the microenvironment generated by TB might increase the HIV burden in infected subjects, partly through cytokines other than IL-2, namely TNF-alpha and IL-6.

Bronchoalveolar Lavage Fluid↗
PubMed1997

[Epidemiology of acute lower respiratory tract infections in adults. Role of Chlamydia pneumoniae and Mycoplasma pneumoniae].

INCIDENCE: Mycoplasma pneumoniae and Chlamydia pneumoniae infections cause 15 to 40% of acute pneumonia cases treated by community physicians. This incidence is lower for cases of pneumonia treated in a hospital setting, falling to less than 3% for cases treated in intensive care units. Incidence varies with the geographical area, season, age and patient population. BRONCHIAL INVOLVEMENT: Mycoplasma pneumoniae and Chlamydia pneumoniae cause 6 to 15% of all cases of acute bronchitis and are the causal agents in approximately 5% of acute episodes in patients with chronic bronchitis. PATHOGENESIS: Chlamydia pneumoniae and Mycoplasma pneumoniae are general identified as the causal agents on the basis of clinical features, microbiological results and the clinical course. The question of the role of carriers or chronic infection is debated; it most likely has a real effect.

Acute Disease↗
PubMed1997

Diagnosis of smear-negative pulmonary tuberculosis using sequence capture polymerase chain reaction.

Techniques based on the polymerase chain reaction (PCR) can be used to rapidly identify DNA from Mycobacterium tuberculosis in clinical samples from patients with tuberculosis, but prior studies evaluating this approach in the diagnosis of paucibacillary forms of pulmonary tuberculosis have reported poor sensitivity and/or specificity. We have developed a procedure in which mycobacterial DNA in crude samples is specifically captured prior to amplification, thereby concentrating the target sequences and removing irrelevant DNA and other inhibitors of the amplification reaction (sequence capture PCR). To evaluate the usefulness of this approach in the diagnosis of paucibacillary forms of pulmonary tuberculosis, sequence capture PCR was performed prospectively on samples of bronchoalveolar lavage fluid from consecutive patients suspected of having pulmonary tuberculosis but for whom three consecutive samples of respiratory secretions were smear negative. Of the 27 patients evaluated, active tuberculosis was diagnosed in nine; sequence capture PCR was positive for all of these patients, including the three for whom all specimens submitted for culture were negative. No positive results were obtained for lavage fluid from the 18 patients for whom the diagnosis of active tuberculosis was subsequently excluded or 25 additional patients undergoing bronchoalveolar lavage for evaluation of other pulmonary problems, even though many of these patients had a history of prior tuberculosis or radiographic evidence of prior tuberculous infection. Paucibacillary forms of pulmonary tuberculosis can be rapidly identified with high sensitivity and specificity using sequence capture PCR performed on samples obtained by bronchoalveolar lavage.

Adult↗
PubMed1997

[Asthma and Chlamydia pneumoniae. A future prospect for macrolides in general and roxithromycin in particular?].

A LOGICAL HYPOTHESIS: Recent publications raise the question of an association between Chlamydia pneumoniae and asthma. There has been no formal proof justifying routine search for C.pneumoniae in patients with uncontrolled asthma nor for systematic treatment with an antibiotic. OPEN QUESTIONS: Can Chlamydia pneumoniae infection initiate or aggravate asthma? Are acute manifestations of asthma associated with an overly high frequency of recent C.pneumoniae infection? Is a past history of C.pneumoniae infection abnormally frequent in patients with chronic asthma? PERSPECTIVES: Rigorously controlled clinical trials evaluating the efficacy of antibiotics such as macrolides which are active against C.pneumoniae are warranted to further elucidate these questions.

Anti-Bacterial Agents↗
PubMed1997

[Primary pulmonary lymphoma].

There are three distinct clinico-anatomical entities today covered by the definition of a primary clonal pulmonary lymphoid proliferation. These are pulmonary lymphomas of B cell phenotype, of low grade malignancy, B cell lymphomas of high grade malignancy and finally lymphomatoid granulomatosis whose clonal characteristic is sometimes difficult to confirm. This general review aims to specify the pathophysiological, diagnostic, prognostic and therapeutic aspects of these different types. Low grade B cell lymphoma is the most common pulmonary lymphoma. Their development depends on mucosa associated lymphoid tissue. They are most often indolent and present as a chronic alveolar opacity. Their prognosis is excellent and the modalities of treatment are discussed (no therapy, surgery or monochemotherapy). High grade B cell pulmonary lymphomas are much rarer and may result from the transformation of a low grade lymphoma or arise in a particular situation such as imunodepression. Their prognosis is poor and the therapeutic possibilities depend most often on the underlying disease. The presence of lymphomatoid granulomatosis in this group of pulmonary lymphomas is debatable. The demonstration of a clonal character of this proliferation is practically never obtained and there is often extra pulmonary disease. The prognosis of this type of illness is extremely variable because certain studies have shown a cure using corticosteroids and cyclophosphamide whilst others have found that the disease is always fatal in spite of using strong polychemotherapy.

Humans↗
PubMed1997

[Multicentric Castleman's disease with mediastinal involvement in a patient with HIV infection].

Castleman's disease is most often seen by a thoracic physician as a mediastinal tumour which is discovered fortuitously and whose surgical excision leads to a cure. We report a case of a patient of 30 who was seropositive for HIV and was suffering from Castleman's disease initially localised to the mediastinum. The disease was associated with a cutaneous and bronchial Kaposi sarcoma. The mediastinal disease, associated with cutaneous and bronchial Kaposi sarcoma, was marked by evolving in a multicentric manner. We review the histological definition and recent data concerning the pathophysiology and the diagnostic and therapeutic management of this disorder and the very varied clinical expression.

Adult↗
PubMed1996

[From pseudolymphomas to primary pulmonary lymphomas of MALT type].

Primary lung lymphomas are uncommon and the use of immunohistochemical and molecular biological techniques have widely contributed to their understanding. Generally, they are of low grade malignancy and most develop from mucosa-associated lumphoid tissue (MALT). Cellular analyses of samples obtained routinely by endoscopy (transbronchial biopsy or bronchoalveolar lavage) will probably enable the clinician to avoid invasive diagnostic procedures, such as surgical lung biopsy. Treatment of limited forms is usually surgical. As to bilateral forms or those with lesions of other mucosae e.g. gut, the best therapeutic strategy remains to be defined.

Diagnosis, Differential↗
PubMed1996

Treatment of non-meningeal cryptococcosis in patients with AIDS. Centre d'Informations et de Soins de l'Immunodéficience Humaine de l'Est Parisien.

Amphotericin B, alone or combined with flucytosine, is the reference curative treatment for neuromeningeal cryptococcosis associated with the acquired immune deficiency syndrome (AIDS). Treatment of non-meningeal forms is less well standardized. Out of 75 human immunodeficiency virus (HIV)-infected patients with cryptococcosis, 16 had no meningeal involvement. One died before receiving any treatment, another received amphotericine B and recovered, and the remaining 14 received curative therapy with fluconazole (200-400 mg/day); 11 of the latter entered complete remission, while three deteriorated during the first week of treatment but recovered on amphotericin B combined, in two cases, with fluconazole. Only one relapse occurred during maintenance treatment with low-dose fluconazole (100 mg/day). No adverse effects of fluconazole treatment were observed. One of the patients on amphotericin B developed acute renal impairment requiring drug withdrawal. These results suggest that first-line fluconazole therapy is effective and well tolerated in patients with AIDS-associated non meningeal cryptococcosis.

AIDS-Related Opportunistic Infections↗
PubMed1996

Cytomegalovirus-induced alveolar hemorrhage in patients with AIDS: a new clinical entity?

We report five cases of alveolar hemorrhage associated with intravascular hemolysis in patients with AIDS. Cytomegalovirus was the only pathogen recovered from the lungs of these patients. There was evidence of multivisceral spread of the virus in all patients, and all had viremia. All had clinical, biological, and pathological features of pulmonary vasculitis, and the conditions of four improved with specific anti-cytomegalovirus therapy.

AIDS-Related Opportunistic Infections↗
PubMed1996

Diffuse panbronchiolitis in an Asian immigrant.

Diffuse panbronchiolitis (DPB) is a disease with chronic inflammation exclusively located in the region of the respiratory bronchiole. It is largely restricted geographically to the Far East, and cases in Western countries are exceptional, even among Asian immigrants. A patient of Asian origin with DPB who had been living in France for 10 years is described. Only re-examination of the initial open lung biopsy specimen after an eight year period allowed this rare disease to be diagnosed correctly. The known efficacy of low dose erythromycin in DPB was again confirmed after failure of long term high dose corticosteroid therapy administered before an accurate diagnosis had been made.

Adult↗
PubMed1996

[Current aspects of pulmonary nocardiosis].

The nocardioses are most often due to Nocardia asteroides. Other types of Nocardia may be implicated. These infections may occur in immunocompetent patients and in that situation are most often cutaneous. They occur most frequently in patients whose immunity is depressed by cytotoxic therapy or in the group with AIDS (SIDA). The clinical presentation in these two latter groups are most often pulmonary. Haematological or lymphatic dissemination is seen in approximately one case out of two with preferential involvement of the central nervous system. Currently a recrudescence of these infections is noted. It is important to emphasise that these infections are curable with antibiotic therapy and that the prognosis depends on the rapidity of the diagnosis and the earliness of treatment.

AIDS-Related Opportunistic Infections↗