Biomedical subjects

Olivier Bletry

Publications and source records attributed to Olivier Bletry.

4 recordsLinked to original sources

PubMed2006

Takayasu's arteritis: An update on physiopathology.

Takayasu's arteritis (TA) is a chronic large vessel vasculitis. The physiopathology of TA has not been completely elucidated, but it appears to be multifactorial and to mainly involve cellular immunity. The pathologic sequence could implicate stimulation from an antigen that triggers heat shock protein (HSP)-65 expression in aortic tissue which, in turn, induces MHC class I-related chain A (MICA). T-cells and natural killer (NK) cells expressing NKG2D receptors could recognize MICA, resulting in acute inflammation. Pro-inflammatory cytokines released from these infiltrating cells induce matrix metalloproteinases and amplify the inflammatory response, inducing more MHC antigen and costimulatory molecule expression on vascular cells and, thus, recruiting more mononuclear cells. Alpha-beta T-cells then infiltrate and specifically recognize one or a few autoantigens presented by a shared epitope associated with specific MHC on the dendritic cells (DC). These DC simultaneously cooperate to some extent with B-cells and determine a humoral immunity mainly constituted by anti-endothelial cell autoantibodies that could trigger complement-dependent cytotoxicity against endothelial cells. The use of corticosteroids and of other immunosuppressive agents can bring TA into remission in most patients. A better understanding of the immunological mechanisms responsible for the vascular injury has led to trials of anti-TNF-alpha agents with encouraging results. In the near future, new drugs specifically designed to target some of the mechanisms described above may be able to expand the physician's therapeutic arsenal in TA.

Journal Article↗

PubMed2005

Leuconostoc osteomyelitis.

Leuconostoc spp. is a variety of streptococcus that can cause disease in humans, most notably those with HIV infection or other causes of immunodepression. We report the case of a patient who had Leuconostoc osteomyelitis in an area of lymphedema.

Gram-Positive Bacterial Infections↗

PubMed2003

The expanding spectrum of renal diseases associated with antiphospholipid syndrome.

BACKGROUND: The association of thrombotic events and/or pregnancy complications with circulating antiphospholipid antibodies defines antiphospholipid syndrome (APS). In previous reports, renal involvement in APS consisted mainly of thrombotic vascular complications involving large vessels or intrarenal small-sized vessels (APS nephropathy). We report 9 cases of glomerulonephritis associated with APS. These cases are characterized by predominant pathological features distinct from vascular APS nephropathy. METHODS: We reviewed consecutive renal biopsies examined in 2 French university hospitals between 1980 and 2002 and identified renal biopsies performed in patients with primary APS. RESULTS: We identified 29 biopsies performed in patients with APS. Twenty biopsies showed characteristic features of APS nephropathy. In 9 cases, predominant pathological features distinct from vascular APS nephropathy were noted: membranous nephropathy (3 cases), minimal change disease/focal segmental glomerulosclerosis (3 cases), mesangial C3 nephropathy (2 cases), and pauci-immune crescentic glomerulonephritis (1 case). In 7 cases, the presentation of renal symptoms was subacute or chronic. Two patients experienced episodes of acute renal failure. At referral, median creatinine clearance was 50 mL/min (0.83 mL/s) (range, 18 to 117 mL/min [0.30 to 1.95 mL/s]). Proteinuria was noted in all cases (range, 1.5 to 15 g/d), with nephrotic syndrome in 4 cases. Lupus anticoagulant was present in all cases, and anticardiolipin antibodies, in 8 cases. Anti-DNA antibodies repeatedly were negative in all cases. Treatment consisted of antihypertensive therapy (6 cases), anticoagulant drugs (5 cases), steroids (4 cases), and antiplatelet drugs (3 cases). At last follow-up, renal function remained stable in 7 patients. Of 2 patients presenting with acute renal failure, 1 patient recovered normal renal function, whereas the other patient progressed to end-stage renal failure. CONCLUSION: The cases reported here represent a new aspect of the expanding spectrum of renal diseases encountered in association with APS.

Adrenal Cortex Hormones↗

PubMedDate not supplied

[Primary retroperitoneal synovial sarcoma revealed by hemorrhagic shock].

INTRODUCTION: Primary retroperitoneal synovial sarcoma is a rare malignant neoplasm that typically arises in young adults. We report here an unusual presentation of this tumor during hemorrhagic shock and retroperitoneal hematoma. CASE: A 31-year-old man was admitted complaining of acute violent pain of the right lower abdominal quadrant. Physical examination was normal. The computed tomography scan showed a heterogeneous retroperitoneal mass near the iliac bifurcation, with a diameter of 3 cm and spontaneous contrast. The tumor ruptured shortly afterwards and the patient underwent emergency surgery for hemorrhagic shock and retroperitoneal hematoma. No metastases were observed. Although six cycles of doxorubicin and ifosfamide led to initial clinical and tomographic remission, relapse occurred 17 months later. DISCUSSION: Only 20 cases of primary retroperitoneal synovial sarcoma have been described. They are most often discovered following abdominal pain or anemia. Tumor rupture with retroperitoneal hematoma has not previously been reported. Surgical ablation remains the basis for management of this tumor, and survival appears to depend on its quality. Prognosis is poor. Our case is original by the tumor's location and mode of discovery.

Adult↗