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Biomedical subjects

G Martet

Publications and source records attributed to G Martet.

At least 55 records · Page 3Linked to original sources
PubMed1995

Effect of polycations on barrier and transport properties of alveolar epithelium in situ.

We examined the effect of polycations, classes of which are released by activated leukocytes, on the transport properties of the alveolar epithelium in isolated-perfused rat lungs. Protamine, polylysines, and ruthenium red produced rapid, dose-dependent increases in mannitol permeability (PAmann) when instilled into airspaces. The coupling between active transepithelial Na+ transport and alveolar fluid absorption was not altered, despite > 10-fold increases in PAmann. The increase in albumin permeability compared with that in mannitol suggested preservation of alveolar barrier-size selectivity. Tracheal instillation of protamine produced no cellular abnormality, whereas its addition to the perfusate resulted in damage to endothelial and type I cells. Protamine produced an even larger (P < 0.05) increase in PAmann in the presence of isoproterenol or dibutyryl adenosine 3',5'-cyclic monophosphate + 3-isobutyl-1-methyl-xanthine. The stimulation of Na+ and fluid transport by these agents was unaffected by protamine. Mastoparan, a peptide that activates G proteins, produced effects comparable to those of the polycations. The protamine- and mastoparan-induced increase in PAmann was abolished by barium, a K+ channel blocker, but not by zinc, a membrane-protective cation. Other K+ channel blockers, tetraethylammonium and quinine, had no effect. Thus short-term apical application of polycations and mastoparan alter alveolar epithelium paracellular permeability by a noncytotoxic mechanism that is inhibited by barium. The resulting increase in paracellular permeability does not alter fluid absorption driven by active Na+ transport. Polycations have very different effects, depending on whether they are present on one side or the other side of the alveolar capillary barrier.

Absorption↗
PubMed1995

[Disseminated Histoplasma capsulatum histoplasmosis in African AIDS patients (3 cases)].

The authors describe three cases of Histoplasma capsulatum histoplasmosis that occurred in black AIDS patients living in France but originally from Guinea and Ivory Coast. In all three cases histoplasmosis was disseminated with fever. In two cases there were cutaneous manifestations. One patient had renal insufficiency and nephrotic syndrome and another presented ulcerative colitis with histoplasma in the chorion. The outcome was favorable in two patients. These three cases are in addition to the five previously reported cases in african AIDS patients. These cases stress the need for awareness of this opportunistic infection as a complication of AIDS in patients from Black Africa.

AIDS-Related Opportunistic Infections↗
PubMed1995

[Round pulmonary lesions after returning from French Guyana. Six cases of american pulmonary histoplasmosis].

From 1989 to 1994, 71 patients were hospitalized for diagnosis of round lung lesions including 49 servicemen under the age of 45 years who had been stationed in tropical areas. In 6 of these servicemen, the diagnosis was pulmonary histoplasmosis at the tertiary stage of histoplasmoma. All had done duty in French Guyana and were negative for human immunodeficiency virus. The subpleural lung opacity was the only lesion in 5 out of 6 patients and was calcified in 4 out of 6 patients. Since skin tests with histoplasmin and serologic testing for histoplasmosis failed to achieve definitive diagnosis, surgical biopsy was performed by conventional thoracotomy in 2 cases and video-assisted thoracic surgery in 4 cases. The specimens obtained confirmed diagnosis of histoplasmosis on mycologic criteria in 3 cases and on a combination of findings including compatible histologic evidence in 3 cases. Treatment consisted in surgical excision of the nodules, for which video-assisted thoracoscopic surgery proved to be an excellent technique because of its simplicity and rapidity.

Adult↗
PubMed1995

[Pathogenic approach of thrombopenia in dengue and its hemorrhagic complications].

Dengue is a frequent viral infection in the intertropical countries. The frequency and the severe forms of this infection are a real problem of public health. The haemorrhagic forms of the disease are constantly associated with thrombocytopenia. Its pathophysiology is still unclear. Among the different hypothesis, immune mechanisms play the main role. The authors discussed here the responsibility of the binding of immune complexes and the role of cytokines.

Antigen-Antibody Complex↗
PubMed1995

[Diagnosis of malaria in Africa using the Parasight F test].

The purpose of this study which was carried out in the Central African Republic between January and February 1994 was to evaluate the effectiveness of the Parasight F test in diagnosing malaria in the indigenous population. Comparison of test results in a series of 62 malaria suspects who had been residing in the country for more than 10 years and 67 malaria suspects who had been living abroad showed significant differences but the overall value of the test was satisfactory. The test was specific for Plasmodium falciparum. In-field trials showed that the test could be used effectively by paramedics and community health care workers. Basing the decision to perform antimalarial treatment in semi-immune subjects with suspected malarial solely on the results of the Parasight F test would have led to unwarranted non-treatment in 10% of cases. Presumptive treatment of malaria is justified. The Parasight F test allows identification of Plasmodium falciparum and adaptation of therapy if required by the spread of chemoresistance.

Blood Proteins↗
PubMed1995

ParaSight-F rapid manual diagnostic test of Plasmodium falciparum infection.

The ParaSight(R)-F test is a qualitative diagnostic test of Plasmodium falciparum, which is based on the detection by a monoclonal antibody of a species-specific soluble antigen (histidine-rich protein (HRP-II)) in whole blood and which can be performed without special equipment. A visual reading is given by a polyclonal antibody coupled with dye-loaded liposomes; when positive, a pink line appears. The test has been compared with microscopic examination of thin blood smears and with Quantitative Buffy Coat malaria test (QBC(R) in a single-blind study. A total of 358 patients who had returned to France from malarial areas and consulted their doctor with symptoms or for a routine examination were enrolled in the study; 33 of them were found to have a falciparum malaria infection by the diagnostic test. On the day of consultation, the specificity of the ParaSight(R)-F test was 99% and its sensitivity 94%. The follow-up of infected patients after treatment showed that the test became negative later than the other reference tests. There was no correlation between antigen persistence and the intensity of the ParaSight(R)-F signal or circulating parasitaemia. No cross-reaction was noted for seven malaria cases due to other Plasmodium species. The test was performed quickly (10 tests in 20 minutes), was easy to read, and required minimal space. For cases of imported malaria, the test's specificity and low threshold for detection could make it a valuable adjunct test. However, in its present form, it cannot replace microscopic techniques which are species-specific and quantitative. In endemic areas, the test seems to be very promising by its results and ease of use according to published field studies.

Adolescent↗
PubMed1994

Characteristics of serogroup A Neisseria meningitidis strains isolated in the Central African Republic in February 1992.

A severe epidemic of serogroup A meningococcus meningitis occurred in the northwest Central African Republic from January to March 1992. Strains from 24 patients were characterized using serotyping, testing of susceptibility to antibiotics, and multilocus enzyme electrophoresis. In 23 of the 24 patients the causal strain was found to be 4:P1.9/clone III-1. These results indicate that such strains continue to spread in Africa and have taken hold in areas outside the "meningitis belt." This may be a consequence of changing climatic conditions.

Adolescent↗
PubMed1994

[Demonstration of subclinical pulmonary alveolitis in spondylarthropathies].

Restrictive ventilatory dysfunction, lowered diffusing capacity, and apical fibrosis have been reported in ankylosing spondylitis. To investigate the pathogenesis of these abnormalities, we studied distal airspace cytology by performing bronchoalveolar lavage in 34 spondyloarthropathy patients (ankylosing spondylitis, n = 16; reactive arthritis, n = 4; axial psoriatic arthritis, n = 2; and undifferentiated spondyloarthropathy with HLA B27-positivity in every case but one, n = 12). Mean age was 32.4 +/- 13.7 years. None of the study patients had apical fibrosis, lower respiratory tract infection, or exposure to airborne pollutants other than tobacco smoke. The control group was composed of nine subjects who had no lung or inflammatory diseases and were not using medications. Significantly higher proportions of lymphocytes were found in bronchoalveolar lavage specimens from patients, as compared with controls. This difference was not influenced by smoking or medication use (non steroidal antiinflammatory drugs, sulfasalazopyridine). Alveolar lymphocytosis was not correlated with laboratory tests for disease activity (erythrocyte sedimentation rate, serum IgA levels) or with the presence of restrictive ventilatory dysfunction. Increases in the proportion of lymphocytes were of similar magnitude in patients with ankylosing spondylitis and in those with other spondyloarthropathies. Absolute total cell counts and relative neutrophil counts were similar in patients and controls. However, among the patients with spondyloarthropathies, those with a disease duration of more than five years had a significantly higher proportion of neutrophils than those with a disease duration of less than five years. These findings demonstrate that spondyloarthropathy patients have subclinical lymphocyte alveolitis. Although of unclear significance, this alveolitis may be related to the development of apical fibrosis in some patients with ankylosing spondylitis.

Adult↗
PubMed1994

[A case of nasal entomophtoral phycomycosis observed in an arid African region (Somalia)].

On the African continent, rhinophycomycosis entomophtorae, a deep mycosis due to Conidiobolus coranatus, has been encountered mainly in wet forest areas. Only one case, which involved a Tchadian, has been reported in a dry zone. The present report describes a case observed in a 30-year-old Somalian, who lived all his life in the rural zone of Dinsoor where the climate is hot (temperature between 22 degrees C and 30 degrees C) and dry (annual rainfall less than 400 mm). In this patient, diagnosis was based on the presence of a characteristic bifocal deformation of the central region of the face and on histological findings typical of rhinophycomycosis entomophtorae. This case underlines the fact that this deep mycosis can occur outside of wet forest areas in Africa. Thus practitioners should not rule this diagnosis out simply on the basis of climatic conditions.

Adult↗