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Biomedical subjects

M Lecomte-Houcke

Publications and source records attributed to M Lecomte-Houcke.

At least 73 records · Page 4Linked to original sources
PubMed1996

Ductal cyst formation in collagen-embedded adult human islet preparations. A means to the reproduction of nesidioblastosis in vitro.

Neogenesis of endocrine islets from ductal epithelium termed nesidioblastosis has been described in vivo after various experimental conditions (90% pancreatectomy or pancreas wrapping in the rodent) and in clinical pathologies. In the adult regenerating pancreas, a proliferation and organization of ductal epithelium into tubular structures precedes its differentiation into endocrine cells. Reproduction of nesidioblastosis in vitro may provide a novel approach to human islet propagation in vitro. With this aim, adult human islet preparations were cultured in diverse three-dimensional (3D) gels in the presence of serum. After 3-5 days in rat tail collagen gels, proliferating (bromodeoxyuridine-positive) cystic structures appeared associated with islets and as isolated spheres. Percentage labeling indexes of the cysts were 4.1, 18.7, 15.4, and 13.3% after 3, 5, 7, and 10 days of culture, respectively. Immunohistochemistry confirmed the ductal (carbohydrate antigen 19-9) and epithelial (keratin-1) nature of the cysts. No cysts were formed in agarose gels or Vitrogen 100, whereas the cyst number was increased by the quantity of serum (20% > 10%) and gels rich in extracellular matrix components and growth factors (Matrigel). The latter lead to tubular networks. Single endocrine islet cells were observed in the ductal cysts after 7 (2.8%) to 10 (5.6%) days in rat tail collagen. Our observations paralleled the changes characteristic of the regenerating pancreas in vivo. 3D culture may permit the identification of matrix and media constituents promoting the neogenesis of islets and may be the means to increase the mass of endocrine tissue obtained from adult cadaveric pancreases for transplantation.

Adult↗
PubMed1996

[Atypical decubitus fibroplasia: a recent entity. Apropos of a case of an adolescent girl].

Atypical decubital fibroplasia (FAD) occurs especially in elderly and physically debilited or immobilized patients. We report one observation which is peculiar due to the patient's young age and its circumstances. The painless mass is situated in hyperpressure areas (shoulder, posterior or lateral chest wall, sacrum). The lesion is situated in the deep subcutis and has ill defined limits; it is characterized by zones of fibrinoid necrosis and fibrosis and a prominent myxoid stroma. The differential diagnoses includes mesenchymatous malignant tumors and non neoplastic fibroblastic proliferations such as proliferative fasciitis and decubitus ulcer. The prominent underlying factor and the initial event contributing to its pathogenesis seems to be ischemia. Although some recurrent cases have been reported, FAD is a benign lesion whose treatment is surgical removal.

Adolescent↗
PubMed1996

[Fatigue rupture of a Harris-Galante shell in contact with an autograft of the femur head. Analysis of bone, mechanical and metallurgical factors].

We observed, after 38 months of follow-up, the rupture of the metallic shell of a Harris-Galante cup implanted in a dysplastic acetabulum augmented with a femoral head autograft. Bone ingrowth was extended to 53% of the porous surface, but only in the areas in contact with the true acetabulum. No bone ingrowth was identified in the fiber mesh in contact with the autograft. The graft was necrotic on histologic examination and showed collapse radiographically. These last conditions were responsible for shear stress in the part of the cup that was in contact with the graft-acetabulum junction. These stresses were involved in the fatigue rupture mechanism identified on microscopic examination of rupture surfaces. We observed metallic structure anomalies in the failed cup by comparing with another Harris-Galante cup considered as a reference: larger alpha elements, reduction of the titanium equiaxial structure. These defects could be related to uncontrolled temperature during the sintering process utilized for fiber mesh fixation. These structural anomalies, by reducing the metallic fatigue strength, potentiated the deleterious effect of partial bone ingrowth and graft collapse.

Acetabulum↗
PubMed1996

[Uterine leiomyosarcomas: a surprising pathology. Review of the literature. Six case reports].

OBJECTIVE: The aim of this study was to determine the clinical features and laboratory tests which define a population with a high risk of leiomyosarcoma. METHOD: A retrospective analysis of 660 hysterectomies performed between 1989 and 1994 was conducted. There were 414 cases of leiomyoma and 6 leiomyosarcomas (1.4%). RESULTS: The indication for hysterectomy was complication of fibromyomatous uterus in all cases. Diagnosis of leiomyosarcoma was never suspected before surgery and the pathology examination. Complimentary radiotherapy was given in 2 patients among the 6 with leiomyosarcoma. Mean survival was 35 months. There were no cases of recurrence or metastasis. None of the laboratory tests performed provided clues to diagnosis. CONCLUSION: Physicians should be aware of possible misdiagnosis of a leiomyosarcoma when proposing medical treatment of uterine fibroma.

Adult↗
PubMed1996

[Total pancreatectomy for diffuse and malignant mucinous ductal ectasia of the pancreas. Apropos of 2 cases].

Two cases of mucinous duct ectasia are reported. Epithelial changes were spread along the pancreatic duct and ductal ectasia was diffuse. Multi focal infiltrating carcinoma was observed in one case, microinvasive carcinoma located in the head of the pancreas was observed. Morphologic features by computed tomography, endoscopic ultrasonography pancreatography were useful for preoperative diagnosis of mucinous pancreatic duct ectasia. In one case, malignancy was suggested by measurement of tumor markers in cystic fluid aspirated during percutaneous pancreatography. Total duodenopancreatectomy was performed in both cases. The two patients were alive and disease-free with a follow-up in both cases of 18 and 36 months.

Aged↗
PubMed1995

Synovial haemangioma of the knee: a frequently misdiagnosed lesion.

OBJECTIVE: The objective of this study was to assess the contribution of magnetic resonance (MR) imaging in the diagnosis and surgical planning of five cases of synovial haemangioma of the knee. PATIENTS AND METHODS: The clinical, radiological and arthroscopic features of five pathologically proven synovial haemangiomas of the knee were retrospectively reviewed. RESULTS: A diagnostic delay, on average of 8 years, had occurred in four of the cases. Plain films were unremarkable, except for one case with arthropathy mimicking haemophilia, Arteriography, performed in three patients, was normal in one. CT, performed in three patients, showed the lesion, but the extent of the latter was better demonstrated with MR imaging. Synovial haemangiomas had a high signal intensity of T2-weighted images, without any extensive mass effect. Fibrofatty septa within the lesion were observed in three cases and muscular and/or fatty invasion in two. Arthroscopy allowed diagnosis of the lesion in two cases, but showed only nonspecific synovitis in another two. CONCLUSION: This study emphasizes the valuable contribution of MR imaging in the diagnosis and surgical planning of synovial haemangiomas.

Adolescent↗
PubMed1995

Characterization, quantification, and localization of passenger T lymphocytes and NK cells in human liver before transplantation.

Quantification and localization of the main lymphocyte populations were studied in the livers of normal (n = 8) and brain dead (n = 8) subjects. Cytometric analysis performed on mononuclear cell suspensions obtained from liver biopsies was compared to an automatic image analysis of immunostained sections. The overall number of liver associated lymphocytes was in the usual range of peripheral blood content (2 to 9x10(9) cells). Phenotypic analysis showed predominant NK and CD8+ cells that highly expressed class II antigen and CD25 and CD69 activation markers. Quantitative mapping of these activated lymphocytes revealed their preferential localization in the portal tract and the perisinusoidal area as compared to the pericentrolobular zone, especially in donor livers. This strategic localization could suggest a possible early cooperation between donor lymphocytes and initial infiltrating cells from the recipient and could explain the special immunological status of allografted livers.

Biopsy↗
PubMed1995

[Obstruction: a rare complication of congenital giant blue nevus].

BACKGROUND: The blue nevus is an acquired or congenital dermal melanosis, usually small in size. It is sometimes giant and responsible for complications. CASE REPORT: A newborn had a large infiltrated blue news located on buttocks, lombosacral and perianal areas. He was admitted at the age of 3 weeks for an intestinal obstruction which was due to an impassable anal stenosis secondary to the infiltrated nevus. The tumor was excised twice, completed by plastic surgery at the age of 10 months. CONCLUSIONS: This rare congenital giant blue nevus was responsible for an unreported intestinal obstruction. The risk of malignant transformation was another reason for complete excision.

Anal Canal↗
PubMed1995

[Mento-sternal fistulae. Review of the literature. Apropos of 4 cases].

Mentosternal fistula is a very rare entity. 70 cases had been reported in the French literature up until 1984. Mentosternal fistula is very different from cyst and fistula of the thyroglossal duct. There is no consensus concerning both pathologically and embryologically, the ethiopathogenesis of mentosternal fistula, but the most widely accepted embryological theory seems to be inclusion of ecto or endodemic material at the time of fusion of the branchial tissues in the cervical midline. Clinical features, in the complete form, are very typical and must be distinguished from thyroglossal duct anomalies. No thyroid exploration is required before the surgical procedure which must be simple and complete.

Child↗
PubMed1995

[Cutaneous pseudolymphoma during treatment of rheumatoid polyarthritis with low-dose methotrexate].

INTRODUCTION: Over the last three years, there have been over twenty case reports of lymphoma in patients given low-dose methotrexate for rheumatoid arthritis. We observed the first case of cutaneous pseudolymphoma. CASE REPORT: A 56-year-old man had been treated with methotrexate (15 mg/day) for 6 years due to rheumatoid arthritis. He developed three isolated papulonodular ulcerations on the limbs. The histology and immunohistochemical examinations demonstrated T and B lymphoplasmocyte infiltration without epidermotropism nor destruction of the annexes. Immunolabelling for anti-Epstein-Barr virus was negative. There was a IgG lambda type monoclonal hypergammaglobulinaemia, Bence-Jones proteinuria and an increase in beta 2-microglobulin. The thoracoabdominal scan, bone marrow biopsy and gallium scintigraphy were normal. There was no sign of a Gougerot-Sjögren syndrome nor of a Felty syndrome. The skin lesions and the Bence-Jones proteinuria disappeared rapidly after withdrawal of methotrexate. There has been no recurrence with a follow-up of 16 months. DISCUSSION: The diagnosis of pseudolymphoma was retained on the basis of the clinical features, the histological and immunohistochemical evidence and especially on the clinical course after methotrexate withdrawal, i.e. spontaneous regression of the lesions within 3 weeks. A similar course has been observed in three cases of lymphocyte proliferation suggesting that this immunosuppressor would be the most probable causative agent. Lymphocyte proliferation, mainly B-cell lymphomas in haematopoietic organs occurring under methotrexate administration have occurred mainly in patients with rheumatoid arthritis. Three cases have also been described in patients with dermatomyositis, but none have been reported in patients with psoriasis. This would suggest that cofactors involved in these autoimmune diseases could also have an effect: immunodepression, potentialization due to associated treatment (corticosteroids), Epstein-Barr virus... CONCLUSION: Data on these observations should be combined in order to analyse the question of the safety of low-dose methotrexate in these patients.

Arthritis, Rheumatoid↗