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Biomedical subjects

M Huerre

Publications and source records attributed to M Huerre.

At least 55 records · Page 3Linked to original sources
PubMed1999

Mucous-cell metaplasia and inflammatory-cell recruitment are dissociated in allergic mice after antibody- and drug-dependent cell depletion in a murine model of asthma.

Inflammatory-cell infiltration and epithelial modifications are prominent lesions of the bronchial mucosa in asthma and in experimental allergic bronchopulmonary inflammation. However, the recruitment of inflammatory cells and their relationship to the epithelial modifications and to functional alterations such as bronchopulmonary hyperreactivity (BHR) are less known. We studied the mechanisms of antigen-dependent inflammatory-cell recruitment to the lungs and the associated lesions and their relationship using drug- and antibody-dependent cell-depletion procedures. A single intranasal ovalbumin challenge in BP2 mice was found to induce hyperreactivity within 1 h after challenge, followed by the massive infiltration of immunoglobulin (Ig)E-bearing polymorphonuclear leukocytes (PMN), and eosinophils, and by a mucous-cell metaplasia of the bronchiolar epithelium. Similarly challenged BALB/c mice did not exhibit BHR, despite a moderate recruitment of inflammatory cells and mucous-cell metaplasia. Inflammatory-cell recruitment, mucous-cell metaplasia, and BHR were prevented by prior antibody-dependent depletion of CD3(+) lymphocytes and partially inhibited by the depletion of CD4(+) lymphocytes. Treatment with the granulocytopenic drug vinblastine before challenge completely abolished the recruitment of granulocytes without affecting the antigen-induced mucous-cell metaplasia. In this study two new key elements of the murine model of allergic pulmonary inflammation are described: the recruitment of IgE-bearing PMN between 3 and 72 h after challenge, and the dissociation between granulocytes and mucous-cell metaplasia.

Animals↗
PubMed1999

Quantitative computer image analysis of chondroitin sulfate A expression in placentas infected with Plasmodium falciparum.

Most pathological conditions resulting from infection with the human malaria parasite Plasmodium falciparum occur as a consequence of the sequestration by several adhesion molecules of parasite-infected red blood cells (IRBCs). Recent reports have provided evidence that placental vascular endothelial ligands for IRBCs were mostly restricted to chondroitin sulfate A (CSA). The expression of CSA in malaria-infected placentas was investigated in a prospective case-control study in a hypoendemic area (Dakar, Senegal). The tissue distribution of CSA was measured in the terminal villi by immunostaining combined with image processing in 20 infected and 20 noninfected frozen sections of placenta. The villous surface immunostained by anti-CSA antibody was higher in infected than in noninfected placentas (p<0.03), in placentas with active infection than in those with past chronic infection (p<0.05), and in infected placentas with positive imprints than in those with negative imprints (not significant; p=0.06). Labeling was found in the extracellular matrix and in endothelial and stromal cells of all the placentas. Syncytiotrophoblast immunostaining was detected in all placentas associated with active or active chronic infection (n=7) but in only 4/13 placentas with past chronic infection (p<0.01). The presence of P. falciparum in the imprint was significantly correlated with immunostaining of CSA in syncytiotrophoblasts (p=0.003). These results suggest that CSA can play an important role in the sequestration of P. falciparum in human placentas during the acute phase of infection.

Animals↗
PubMed1999

[Disseminated histoplasmosis detected by lingual and tonsillar erosions in an immunocompetent patient].

BACKGROUND: Histioplasmosis is a usually asymptomatic fungal infection. In the immunocompetent patient, it leads to chronic disseminated infection. Mucosal involvement is common and can provide the diagnosis. CASE REPORT: A metropolitan Frenchman with a history of alcoholism and smoking and living in Guyana consulted for lingual and tonsil erosion. Squamous cell carcinoma was suspected but not confirmed at pathology. The patient had a bi-apical infiltration on the chest x-ray and was treated empirically for tuberculosis. The diagnosis of histoplasmosis was reached when rare Histoplasma capsulatum were evidenced from a buccal swab. Itraconazole led to cure in 6 months. DISCUSSION: This case illustrates the importance of mucosal signs in the diagnosis of disseminated histoplasmosis in immunocompetent subjects. Histoplasmosis is rarely the cause of active infection in immunocompetent subjects. In these patients, the fungal infection generally progresses to chronic dissemination. Mucosal signs are frequent in this form but are rare in case of cutaneous histoplasmosis. Itraconazole (200 mg/d) is indicated for 6 months.

Alcoholism↗
PubMed1999

[Adiaspiromycosis, 2 cases of incidental finding].

Two apparently solitary granulomas, each containing an adiaconidia, 200 and 300 microm in diameter, were incidentally found in the lung parenchyma on a pleuro-pneumonectomy specimen for malignant mesothelioma, and in the stroma of a pulmonary adenocarcinoma, respectively. These two cases of adiaspiromycosis illustrate well the characteristic morphology of this strictly pulmonary, rare, ubiquitous, and histologically diagnosed mycosis.

Adenocarcinoma↗
PubMed1999

[Squamous cell carcinoma arising from chromomycosis. Report of two cases].

Madagascar is the principal area of endemic chromomycosis in the world with 1 400 cases registered from 1955 to 1996. Malignant transformation is rare and only 12 cases have been reported. We describe herein two new cases of squamous carcinoma arising from chronic lesions of chromomycosis. These carcinomas which develop slowly and are non invasive, are similar to those arising from burns, tropical phagedenic ulcers and chronic leprosy ulcers. Epidemiological aspects, histopathology and treatment are described.

Adult↗
PubMed1999

Yeast tissue phase of Emmonsia pasteuriana inoculated in golden hamster by intratesticular way.

The scope of our study was to present an experimental model reproducing the dimorphic yeast-like population (as for Histoplasma capsulatum, Blastomyces dermatitidis) similar to that observed in the cutaneous biopsy of an Italian woman who had never traveled abroad, being intravenous drug user and HIV positive for 10 years, finally infected with the new dimorphic fungus Emmonsia pasteuriana. Experimental inoculation was unsuccessful by intraperitoneal (i.p.) and intravenous (i.v.) ways in a mouse and in a guinea-pig model inoculated by cutaneous or subcutaneous routes, reason for that we chose the golden hamster, highly sensitive to dimorphic fungi as agents of systemic mycoses as histoplasmosis, blastomycosis, sporotrichosis, penicilliosis marneffei, paracoccidioidomycosis when the inoculation was done by intraperitoneal route. We inoculated young golden hamsters by i.p. and intratesticular ways. Only by this last route we reproduced an orchiepididymitis with necrosis, haemorrhages and a polymorphic yeast-like population similar to the polymorphism observed in the cutaneous biopsy of the patient. The intratesticular affinity of E. pasteuriana provided an interesting model for this infection.

Adult↗
PubMed1998

Systemic administration of endotoxin induces bronchopulmonary hyperreactivity dissociated from TNF-alpha formation and neutrophil sequestration into the murine lungs.

Bronchopulmonary hyperreactivity (BHR), an increased responsiveness to nonspecific bronchoconstrictor agents, is a well-known characteristic of bronchial asthma. It has been recently suggested that the severity of this disease is related to the endotoxin content of house dust. In the present report, it is shown that the i.p. administration of bacterial LPS to mice is followed by a marked early dose-dependent BHR in response to methacholine. The microscopic examination showed no ultrastructural lesions of the lungs or of the airways, but a marked neutrophil accumulation in the capillaries, as confirmed by an increase of the lung content in the neutrophil enzyme marker myeloperoxidase. In parallel, high levels of TNF-alpha were found in plasma as well as its transcripts in the lung tissues. Using immunologic (anti-TNF-alpha and anti-granulocyte Abs), and pharmacologic (dexamethasone and vinblastine) tools, it is demonstrated that BHR is apparently neither related to the presence of neutrophils in the pulmonary microvasculature nor to the synthesis of TNF-alpha.

Aerosols↗
PubMed1998

A case of Aspergillus myocarditis associated with septic shock.

We report a case of isolated myocardial involvement due to Aspergillus sp., in a patient with multiple organ failure but no demonstrable immune deficiency apart from corticosteroid therapy given for the three weeks prior to hospitalization. This patient died of septic shock 7 days after hospitalization. Aspergillus was isolated only once from a sputum specimen obtained 24 h before death. At post-mortem examination there are emboli and myocardial lesions containing clusters of hyphae as Aspergillus confirmed by indirect immunofluorescence. The other organs were free of fungi. This observation is remarkable because the cardiac involvement was isolated and no immunodeficiency was present.

Aged↗
PubMed1998

Cutaneous T cell lymphomas: mycosis fungoides, Sezary syndrome and HTLV-I-associated adult T cell leukemia (ATL) in Mali, West Africa: a clinical, pathological and immunovirological study of 14 cases and a review of the African ATL cases.

Cutaneous T cell lymphomas (CTCL) are rare lymphoproliferative diseases, which are frequently suspected to be of viral origin. As very few data were available concerning cutaneous T cell lymphomas in tropical Africa, we undertook a clinical, histopathological, immunological and viro-molecular study of patients with a clinical diagnosis of cutaneous lymphoma, in Bamako, Mali. While prior to this study, no case of CTCL had been reported in this country, 14 patients (five women, nine men; mean age 58 years) with a diagnosis of cutaneous lymphoma were seen over a period of 30 months (1992-1994) in the only dermatological department in Mali. Clinically, the most frequent pattern was an infiltrated erythrodermia similar to Sezary syndrome. Nodular lesions and/or plaques were rarely observed. All these cutaneous tumors were T cell lymphoproliferations, only one expressing the CD8+ antigen. A comprehensive analysis of all the available data permitted characterization of three cases of adult T cell leukemia/lymphoma (ATL) associated with HTLV-I (one definitive case, of leukemic type, with demonstration of clonal integration of HTLV-I proviral genome and two probable ATL cases), three cases of Sezary syndrome (SS), two cases of mycosis fungoides (MF) and five cases of pleomorphic cutaneous lymphoma. In one case, the differentiation between MF and pleomorphic cutaneous lymphoma could not be established. HTLV-I serological and/or molecular markers were restricted to the three ATL cases. From the unique definitive ATL case, a T cell line was established from culture of peripheral blood mononuclear cells and sequence analysis of the env gene and the U3-LTR region demonstrated that the virus present in this patient belonged to the cosmopolitan subtype A. Thus, we report here the first evidence of HTLV-I infection and associated ATL in Mali. This is the second ATL case described for the whole Sahelian region (one ATL of the lymphoma type was reported previously in a Mauritanian patient). Furthermore, we demonstrate that the main types of CTCL described in Europe and North America are also present in this African area and that the prevalence of these diseases is greatly underestimated in such regions. Furthermore, no association was observed between HTLV-I/II infection and SS, MF or pleomorphic cutaneous lymphoma in Mali in contrast to other studies.

Adult↗
PubMed1998

Immune responses of specific-pathogen-free mice to chronic Helicobacter pylori (strain SS1) infection.

A model permitting the establishment of persistent Helicobacter pylori infection in mice was recently described. To evaluate murine immune responses to H. pylori infection, specific-pathogen-free Swiss mice (n = 50) were intragastrically inoculated with 1.2 x 10(7) CFU of a mouse-adapted H. pylori isolate (strain SS1). Control animals (n = 10) received sterile broth medium alone. Animals were sacrificed at various times, from 3 days to 16 weeks postinoculation (p.i.). Quantitative culture of gastric tissue samples from inoculated mice demonstrated bacterial loads of 4.0 x 10(4) to 8 x 10(6) CFU per g of tissue in the animals. Infected mice had H. pylori-specific immunoglobulin M (IgM) and IgG antibodies in serum (at day 3 p.i.) and IgG and IgA antibodies in their gastric contents (weeks 4 and 16 p.i.) and saliva (week 16 p.i.). Mucosal IgM antibodies were not detected. Histological examination of the gastric mucosae from control and infected mice revealed mild chronic gastritis, characterized by the presence of polymorphoneutrophil cell infiltrates and submucosal lymphoid aggregates, in infected animals at 16 weeks p.i. Differences in the quantities of IgG1 and IgG2a subclass antibodies detected in the sera of mouse strains (Swiss, BALB/c, and C57BL/6) infected by H. pylori suggested that host factors influence the immune responses induced against this bacterium in the host. In conclusion, immune responses to H. pylori infection in mice, like those in chronically infected humans, appear to be ineffective in resolving the infection.

Animals↗
PubMed1998

[Cutaneous Alternaria infectoria infection after liver transplantation].

We report a case of cutaneous alternariosis after liver transplantation. This rare phaeohyphomycosis is mainly observed in patients treated by corticosteroids. This case is remarkable for the species isolated: Alternaria infectoria. Clinical and histopathological features are studied and diagnostic problems are discussed.

Adrenal Cortex Hormones↗
PubMed1997

Transferrin is an early marker of hepatic differentiation, and its expression correlates with the postnatal development of oligodendrocytes in mice.

Transferrin (Tf), the iron transport protein, is essential for the growth and differentiation of cells. Therefore, it provides an excellent model to analyze the regulatory mechanisms controlling the expression of a eukaryotic gene in different cell types and during fetal and adult life. In this study, the tissue-specific and developmental regulation of the Tf gene in vivo were analyzed. Human Tf mRNA was detected mainly in fetal and adult liver. A weaker expression was observed in adult and fetal brain and in fetal spleen. By in situ hybridization the presence of mouse Tf mRNA was detected in the hepatic primordia. This is the first observation pointing out Tf as an early marker of hepatic differentiation, prior to the formation of the liver. Thus, TF may be an important tool to follow the hepatic specification of the gut endoderm. Mouse Tf mRNA was also detected in the liver bud and subsequently in the liver throughout fetal life, and in newborn and adult animals. No expression of the Tf gene was observed in the mouse fetal central nervous system (CNS). In contrast, Tf mRNA was detected from the 5th day after birth in the derivatives of the caudal part of the neural tube and subsequently in the derivatives of the rhomboencephalon and that of the prosencephalon. These results indicate that Tf gene expression correlates with the postnatal development of oligodendrocytes in the mouse CNS. To test whether the control elements of the human gene previously found in ex vivo experiments were also active in vivo during fetal and adult life, we fused the -4000/+395' flanking region of the human gene to the coding region of the lacZ gene and generated transgenic mice. The expression of the reporter gene during development was analyzed.

Aging↗
PubMed1997

Endotoxin induces expression of type II phospholipase A2 in macrophages during acute lung injury in guinea pigs: involvement of TNF-alpha in lipopolysaccharide-induced type II phospholipase A2 synthesis.

Elevated levels of secretory type II phospholipase A2 (sPLA2-II) have been associated with a poor clinical outcome in the acute respiratory distress syndrome. This study identifies the cell source(s) and the mechanisms of sPLA2-II synthesis in the guinea pig model of acute respiratory distress syndrome induced by intratracheal injection of LPS. Administration of LPS led to an increase in lung membrane-associated calcium-dependent sPLA2 activity, which was abrogated by LY311727, a selective inhibitor of sPLA2-II. No sPLA2 activity was detected in the vascular compartment of the lung. LPS administration induced a parallel accumulation of sPLA2-II mRNA in lung tissues. In situ hybridization showed that sPLA2-II transcripts were synthesized in interstitial and alveolar macrophages (AM). Incubation of AM with LPS enhanced the expression of sPLA2-II mRNA, leading to stimulation of sPLA2-II synthesis and secretion. This increase was prevented by the addition of anti-TNF-alpha and anti-p55 TNF receptor Abs. Furthermore, the addition to AM of cellfree bronchoalveolar fluid collected from LPS-treated guinea pigs increased sPLA2-II expression, which was abrogated by anti-TNF-alpha Ab. These findings demonstrate that 1) macrophages are in vivo the major cell source of sPLA2-II in LPS-induced acute lung injury; 2) in contrast to that in other cell systems, regulation of LPS-induced sPLA2-II synthesis in AM is TNF-alpha dependent; and 3) production of TNF-alpha in the air-lung interface is an important step for sPLA2-II synthesis in macrophages.

Animals↗
PubMed1997

Strategy for the detection of Helicobacter species by amplification of 16S rRNA genes and identification of H. felis in a human gastric biopsy.

The aim of the present work was to develop polymerase chain reactions (PCRs) based on the conserved nucleotide sequence of the 16S rRNA gene for detection of bacteria of the Helicobacter genus in human antral biopsy samples. The assay for Helicobacter spp was developed by amplifying a 399-bp 16S rRNA gene sequence specific to the genus Helicobacter. The identity of the amplicon was confirmed by hybridization with an internal probe and by restriction by endonuclease VspI showing two expected fragments of 295 and 104 base pairs. A total of 65 dyspeptic patients from France and New Caledonia were screened for Helicobacter spp infection through the use of the following diagnostic assays on biopsy specimens collected through endoscopy: direct detection of bacteria in histological sections by Giemsa and Warthin Starry staining, urease test and bacterial isolation, PCR for Helicobacter pylori ureC/glmM gene, and PCR targeted to 16S rRNA genes. The 16S rRNA gene PCR assay was able to detect down to 680 bacterial cells, as assessed by agarose gel electrophoresis, and down to 4 bacterial cells by hybridization of amplicon with the internal probe. The 16S rRNA PCR test was 100% specific and sensitive; results obtained with this test were in agreement with the visualization of bacteria by histology. Urease test and culture were 86.4% and 22.7% sensitive, and 96.5 and 100% specific, respectively. The H. pylori ureC/glmM gene-based PCR was 100% specific and only 95.4% sensitive, since one biopsy from a Melanesian patient contained a Helicobacter strain other than H. pylori. For this Melanesian patient, a branch-specific PCR targeting the epsilon branch of Proteobacteria was used to amplify a 967-bp amplicon. This amplicon was sequenced and matched with the H. felis sequence. This was confirmed using an H. felis-specific urease PCR test.

Biopsy↗