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Biomedical subjects

K Renaudin

Publications and source records attributed to K Renaudin.

7 recordsLinked to original sources

[Endobronchial stenosis in Wegener's granulomatosis].

INTRODUCTION: Endobronchial stenoses are rare in the course of Wegener's granulomatosis, and they occur even more rarely than subglottic stenoses. EXEGESIS: We report seven cases of endobronchial stenoses in the setting of Wegener granulomatosis. Neither the pulmonary symptoms nor the systemic manifestations of vasculitis were specific. However 6/7 patients presented a wheezing or an hemoptysis. Bronchial endoscopy has permitted the diagnosis in all cases. Local evolution was cicatricial and symptomatic stenosis in 3 cases (42,8%). CONCLUSION: Thus these lesions must be research in any case of pulmonary abnormality in the course of Wegener's granulomatosis, because they may lead to a pejorative prognosis. Moreover general and local treatment must be given early (at the inflammatory stage). After this stage, the local treatments are difficult and not efficient.

Adrenal Cortex Hormones↗

Induction of tolerance by exosomes and short-term immunosuppression in a fully MHC-mismatched rat cardiac allograft model.

Exosomes are MHC-bearing vesicles secreted by a wide array of cells. We have previously shown that donor-haplotype exosomes from bone marrow dendritic cells (DCs) injected before transplantation significantly prolong heart allograft survival in congenic and fully MHC-mismatched Lewis rats. Here we show that donor exosomes administered after transplantation are similarly able to prolong allograft survival, however, without inducing tolerance. We therefore tested the effect of exosomes combined with short-term LF 15-0195 (LF) treatment, which blocks the maturation of DCs, so that donor-MHC antigens from exosomes could be presented in a more tolerogenic environment. LF treatment does not preclude the development of a strong antidonor cellular response, and while LF, but not exosome, treatment inhibits the antidonor humoral response and decreases leukocyte graft infiltration, allografts from LF-treated recipients were either acutely or strongly chronically rejected. Interestingly, when combined with LF treatment, exosomes induced a donor-specific allograft tolerance characterized by a strong inhibition of the antidonor proliferative response. This donor-specific tolerance was transferable to naïve allograft recipients. Moreover, exosomes/LF treatment prevented or considerably delayed the appearance of chronic rejection. These results suggest that under LF treatment, presentation of donor-MHC antigens (from exosomes) can induce regulatory responses that are able to modulate allograft rejection and to induce donor-specific allograft tolerance.

Animals↗

Loss of NOS1 expression in high-grade renal cell carcinoma associated with a shift of NO signalling.

In normal human kidney, NOS1 and soluble guanylate cyclase (sGC) are expressed in tubular epithelial cells, suggesting a physiological autocrine NO signalling pathway. Therefore, we investigated both NOS1 and sGC expressions in benign and malignant renal tumours. In addition, we examined the pattern of protein tyrosine nitration in normal and tumour tissue. NOS1 expression and activity were found to be downregulated, correlating with the tumour grade, as shown by immunohistochemistry, quantitative RT-PCR analysis, and histochemical detection of the NADPH-diaphorase activity of nitric oxide synthases (NOS). These results show that the autocrine NO signalling pathway is maintained in benign tumours and lost in malignant tumours. In contrast, sGC expression was maintained in renal tumours whatever the tumour type, a finding showing that tumour cells remain sensitive to the bioregulatory role of exogeneous NO(*). Finally, the staining pattern of protein tyrosine nitration, assessed by immunohistochemistry, parallelled that of NOS1 expression in normal renal parenchyma and benign tumours, supporting the concept that protein nitration was accounted for by NOS1 activity. In contrast, in malignant tumours, protein tyrosine nitration was accounted for by the production of reactive nitrogen oxide species by the inflammatory infiltrate. Altogether, these findings argue for a pattern of NO signalling similar in normal kidney and benign renal tumours, whereas it is completely different in malignant renal tumours.

Carcinoma, Renal Cell↗

Fatal acute granulomatous pulmonary aspergillosis in a healthy subject after inhalation of vegetal dust.

A previously healthy 28-year-old man presented a few hours after inhalation of vegetal dust with acute bilateral community-acquired pneumonia, which caused death in 10 days despite treatment with broad-spectrum antibiotics, intravenous amphotericin B, inotropic support, and mechanical ventilation. A postmortem lung biopsy indicated miliary granulomatous pulmonary aspergillosis. Six similar previously published cases of acute granulomatous pulmonary aspergillosis are reviewed. This entity in adulthood may reveal a defect in neutrophil or macrophage function, such as late-onset chronic granulomatous disease.

Acute Disease↗

[Bronchopulmonary aspergillosis: new developments].

Bronchopulmonary aspergillosis are in the news. Invasive pulmonary aspergillosis raise early diagnostic problems and prevention problems in immunocompromised patients. These infections are no unusual in chronic obstructive pulmonary disease. The diagnosis between aspergilloma and chronic necrotizing pulmonary aspergillosis can be difficult. In allergic bronchopulmonary aspergillosis, epidemiology and therapy are questionable. Real progress has been made due to thoracic computed tomographic scan and mycological methods. Better use of amphotericin B, of amphotericin B lipid formulations and of azole antifungal agents, combined with surgical resection if necessary should improve aspergillosis prognosis.

Amphotericin B↗

[Tumoral calcinosis of the foot in patient on hemodialysis].

We report a new case of tumoral calcinosis in a renal failure patient. In this patient the pseudotumoral formation was found in an unusual localization on the medial border of the foot. The condition progressed with successive development of bilateral tumors and septic contamination. Pathology confirmed the diagnosis. The patient was successfully treated with tumor resection and renal graft. The origin of these pseudotumors remains a question of debate. Several pathogenc mechanisms have been put forward. Pronosis is always favorable. Several authors have suggested a phosphorus calcium work-up can be useful for classifying these tumors, guiding surgical treatment if required and managing the underlying cause.

Adult↗