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Biomedical subjects

R Loire

Publications and source records attributed to R Loire.

At least 19 recordsLinked to original sources

Fibrosing vasculitis in Wegener's granulomatosis: ultrastructural and immunohistochemical analysis of the vascular lesions.

This study of two cases of pulmonary Wegener's granulomatosis (WG) focuses on the ultrastructural aspects of the vascular wall injury and on the immunohistochemical characterization of the perivascular connective matrix. The iterative waves of endothelial cell necrosis and regeneration are demonstrated by the multilamellar appearance of the basal lamina. Neutrophils infiltrate the vessel wall and myofibroblasts are recruited to injured vessels. The perivascular connective matrix associates basement-membrane like and fibrillar material with fibrin deposits. The initiation of the fibrosing process was assessed by the visualization of matrix molecules involved in targeting (p-fibronectin), organizing (cellular fibronectin and tenascin) and stabilizing (lysyl-oxidase) the fibrogenic activity. These elementary lesions affect different levels of the vascular tree, and capillaritis is involved in the extension of the pathological process. Lysyl-oxidase labelling reveals the fibrosing front which is located on the border of dense fibrosis. The markers of fibrosing activity disappear in the areas of fibrosis following vasculitis and/or ischaemic necrosis and/or granulomatosis. Vasculitis plays a major role in both the genesis and progression of the fibrosis observed in the late stage of WG.

Arteries

Primary pulmonary non-Hodgkin's lymphomas.

We report a retrospective study of the pathological features in 69 primary pulmonary non-Hodgkin's lymphomas which have previously been clinically reviewed. The tumours consisted of 61 (88%) low-grade and eight (12%) high-grade malignant lymphomas. Fifty-four of the low-grade malignant lymphomas were MALT lymphomas. Lymphoepithelial lesions were observed in bronchial, bronchiolar and alveolar lining. All tumours were composed of nodules, forming a lymphangitic pattern at the periphery and a confluent central mass. Invasion of pleura and vessels was often seen but this without any consequence on survival. Granulomas were found in 20% of cases. Six of the eight high-grade tumours were centroblastic and another two were B-cell lymphomas of undetermined type. In four cases, associated areas of low-grade malignant lymphoma with lympho-epithelial lesions indicated a preexisting MALT lymphoma. Clinical data suggest that limited surgery or non-aggressive chemotherapy can provide long-term survival in patients with such slowly developing neoplasms. However, non-invasive diagnostic methods need to be developed.

Adult

Bronchiectasis detected with thin-section CT as a predictor of chronic lung allograft rejection.

PURPOSE: To evaluate bronchiectasis detected with thin-section computed tomography (CT) as a potential early finding of chronic lung allograft rejection. MATERIALS AND METHODS: Forty patients were studied at least 6 months after transplantation. Follow-up CT scans were obtained 6-48 months after transplantation and were retrospectively reviewed for evidence and anatomic extent of bronchiectasis. Irreversible dysfunction of the lung transplant, called the bronchiolitis obliterans syndrome (BOS), was staged according to pulmonary function testing. Pathologic proof of bronchiolitis obliterans was obtained. RESULTS: BOS occurred in 14 (35%) of the 40 patients. When considering bronchiectasis preceding BOS, bronchiectasis was a predictor of chronic rejection with a sensitivity of 14%, a specificity of 77%, a positive predictive value of 25%, and a negative predictive value of 63%. Bronchiectasis appeared concomitantly with BOS in eight (67%) of 12 patients. CONCLUSION: The diagnosis of chronic rejection relies on the degree of impairment of pulmonary function. When the diagnosis is only suspected on the basis of minimal impairment, CT can aid in the diagnosis of rejection by depicting early pulmonary changes.

Adolescent

Lymphocytic bronchitis/bronchiolitis in a patient with primary biliary cirrhosis.

A 39 year old woman with severe primary biliary cirrhosis progressively developed exercise dyspnoea due to airflow obstruction. Sjögren's syndrome was not present. Bronchial and pulmonary biopsies demonstrated constrictive lymphocytic bronchitis/bronchiolitis, possibly a component of a generalized autoimmune process in this patient.

Adult

Migratory organizing pneumonitis "primed" by radiation therapy.

We report on two women presenting with cough and fever, 4 and 7 months, respectively, after starting breast radiation therapy following surgery for breast carcinoma. Chest roentgenogram and computed tomographic (CT) scan demonstrated alveolar opacities, initially limited to the pulmonary area next to the irradiated breast, but later migrating within both lungs. Intra-alveolar granulation tissue was found in transbronchial lung biopsies. Corticosteroid treatment resulted in dramatic clinical improvement, together with complete clearing of the pulmonary opacities on chest imaging. However, clinical and imaging relapses occurred when corticosteroids were withdrawn too rapidly; with further improvement when they were reintroduced. The reported cases clearly differ from radiation pneumonitis. They were fairly typical of cryptogenic organizing pneumonitis, also called idiopathic bronchiolitis obliterans organizing pneumonia, with the exception of the radiation therapy, partially affecting the lung, which had been performed within the previous months. Since focal radiation therapy involving the lung may induce diffuse bilateral lymphocytic alveolitis, we hypothesize that this may "prime" the lung to further injury, leading to cryptogenic organizing pneumonitis.

Aged

High-resolution computed tomographic findings associated with histologically diagnosed acute lung rejection in heart-lung transplant recipients.

A group of 32 lung (single lung, [n = 14] and double lung [n = 1]) or heart-lung (n = 17) transplant recipients were studied with serial high-resolution computed tomography (HRCT) scans and transbronchial biopsies from the time of surgery. These investigations were carried out routinely every 2 weeks for the first 2 months, every 2 months for a year, every 4 months in the second year, and on any clinical suspicion of acute lung rejection or infection. A total of 190 transbronchial biopsy specimens and concurrent HRCT scans were obtained. Forty (21%) of the biopsy specimens, showed histologic evidence of lung rejection, 111 (58%) were normal, and 39 (21%) were not conclusive. The more frequent HRCT pattern encountered during an acute rejection episode was the presence of patchy "ground-glass" density areas (65%). This finding was sparsely observed during minimal and mild acute rejection episodes. Using histologic diagnosis as a standard for acute rejection, ground-glass opacities on HRCT had a sensitivity of 65% in detecting lung rejection. Although ground-glass opacities were also intermittently observed during cytomegalovirus pneumonia (14%), this finding had a specificity of 85% for detecting occurrence of an acute lung complication. The detection of ground-glass opacities on lung HRCT after lung transplantation, more particularly after the first month after surgery, can aid the decision of when and where to undertake transbronchial lung biopsy.

Acute Disease

[Value of coronary angiography in the diagnosis of coronary artery disease of the transplanted heart. Coronary angiography and arteriosclerosis of the graft].

The diagnostic value of coronary angiography, a widespread method of detection of transplant coronary artery disease, was studied in 17 cardiac transplant patients with reference to histological examination. In the 6 coronary segments studied, the only significant but weak correlation that was found was for the distal left anterior descending artery: the correlations were not statistically significant in the other 5 segments. Coronary angiography underestimated lesions and false negative results were frequently reported (66 and 27% respectively). The limitations of coronary angiography may be explained by the technical artefacts related to both methods of evaluation and the anatomically diffuse and distal nature of transplant coronary artery atherosclerosis. A more reliable diagnostic method would seem to be required in view of the clinical importance of this pathology.

Coronary Angiography

Bronchiolitis obliterans organizing pneumonia associated with minocycline therapy: a possible cause.

We report the case of a woman who presented with dyspnoea whilst taking minocycline for acne. Imaging features of bilateral patchy alveolar opacities suggested a diagnosis of bronchiolitis obliterans organizing pneumonia, which was confirmed by lung biopsy. The patient improved, partially, after stopping minocycline, and then completely on treatment with corticosteroids, without relapse when these where stopped 8 weeks later.

Acne Vulgaris

[Guidelines for the diagnosis of endocarditis. Pathology of the cardiac valves].

This article reports the difficulties of the diagnosis of endocarditis, especially when blood cultures are negative. It emphasizes the respective roles of the microbiology and pathology laboratories for the processing of cardiac valves removed by surgery. It clarifies the morphological characteristics of the endocarditis.

Endocarditis

[Fatal acute silicosis caused by voluntary inhalation of scouring powder].

We report a case of acute fatal fibrosing silico-proteinosis occurring in nine months in a young woman who had voluntarily inhaled scouring powder. We recall the reports in the literature of the subacute or chronic forms associated with systemic diseases occurring after such inhalational practices. We recall the need for specific questioning and to complete the study, the need for microscopy and electron-microscopy associated with X-ray defraction, either on the alveolar lavage fluid or on a lung biopsy.

Acute Disease

[Lambl's excrescence: an uncommon cause of cerebral embolism].

A 31 year old right handed woman presented with acute onset of aphasia which cleared over two days. CT-scan showed a left middle cerebral artery infarct within Wernicke area. Initial transesophageal two-dimensional echocardiography disclosed a mitral valve lesion suggesting a thrombus. She was discharged on oral anticoagulant treatment. A second stroke occurred ten months later involving left lenticulo-striate arteries area. Echocardiography remain unchanged. Subsequently, giant Lambl's excrescences of mitral valve was confirmed by operation and pathologic examination. The majority of patients with Lambl's excrescences are asymptomatic. However surface thrombus is common with this tumors which reposant a potential us for cerebral embolization. These tumors should be operated since complete excision is the only definitive means of eliminating the source of recurrent embolization.

Adult

[The past, present and future of arterial infection].

Today, the pathology of large and medium-sized arteries is in most part considered as degenerative or inflammatory. The role of infection has been preponderant (syphilis) but has become quite modest now, restricted to infectious aneurysms. According to certain observations, infections may participate in initiating arterial inflammation, whether it be specific (Kawasaki's disease, Takayasu's arteritis, coronary artery disease of cardiac grafts) or less so ("plain" atherosclerosis). Suspected microbes (herpes viruses, Chlamydia pneumoniae, etc.) would damage the arterial wall either directly by infecting it, or indirectly by provoking an autoimmune reaction against some of its components (e.g. heat shock proteins). These hypotheses are worth serious consideration because, if established as correct, they would modify radically our etiologic, therapeutic and prophylactic conceptions of arterial diseases, including of course the main one, atherosclerosis.

Acquired Immunodeficiency Syndrome

Is continuous warm retrograde blood cardioplegia completely safe for coronary artery surgery?

Sixty consecutive coronary patients operated on by the same team in 1992 were divided into two groups: group 1 (30 patients) using intermittent oxygenated cold Fresenius solution antegrade and retrograde (FR), group 2 (30 patients) using warm retrograde blood cardioplegia (WRC) with the Fremes solution initially antegrade and retrograde (high potassium solution) then continuous retrograde low potassium solution. All patients were submitted to only arterial grafts (3 to 4) using both internal mammary arteries and the the right gastroepiploic artery. There were no differences in mean preoperative data between the 2 groups. The times of aortic cross-clamping (P < 0.05) and bypass after release of the aortic clamp (P < 0.01) were significantly higher in the WRC group. No significant difference was observed in the number of postoperative supraventricular arrhythmias or electrocardiographic infarctions. A significant difference was observed with higher values of the enzymes (aspartate amino transferase, creatine kinase) for the WRC group on the first (P < 0.05) and the second postoperative days (P < 0.01). More patients in the WRC group received vasoactive or inotropic drugs in the intensive care unit, where they stayed a longer time because of hemodynamic instability or enzyme elevation (P < 0.05). In conclusion, for coronary arterial revascularization, WRC is technically more demanding and does not appear to afford optimal myocardial protection.

Aged

Disseminated Scedosporium prolificans (S. inflatum) infection after single-lung transplantation.

This report concerns the first case of disseminated infection with Scedosporium prolificans (S. inflatum) that occurred in a patient who had received an organ transplant and was verified at autopsy. The patient underwent single (right)-lung transplantation and subsequently died on the 33rd postoperative day in a context of septic shock. S. prolificans was isolated from various specimens, including two cultured blood samples. The organism was associated with Candida albicans in some of these specimens. Autopsy revealed the presence of numerous nodular abscesses in the lungs, myocardium, kidneys, spleen, and gall bladder. These abscesses contained mycelial filaments and numerous oval conidia suggestive of Scedosporium species but no yeasts. MIC studies demonstrated the resistance of the S. prolificans isolate to amphotericin B, fluctyosine, miconazole, ketoconazole, and itraconazole, whereas the isolate of C. albicans was susceptible to amphotericin B, flucytosine, miconazole, and ketoconazole. From the data from our case and six published reports of cases of disseminated S. prolificans infection, it can be concluded that this filamentous fungus is a new agent responsible for the most serious mycoses in both neutropenic patients and patients who have undergone organ transplantation.

Candidiasis