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X Le Loet

Publications and source records attributed to X Le Loet.

At least 19 recordsLinked to original sources
PubMed1999

IgM anti-myeloperoxidase antibody-secreting lymphocytes are present in the peripheral repertoire of lupus mice but rarely differentiate into IgG-producing cells.

Two IgM, kappa anti-myeloperoxidase (MPO) monoclonal antibodies, 6D6 and 9B5, bound to MPO in a solid-phase enzyme-linked immunosorbent assay were derived from the splenocytes of (NZB x NZW) F1 and MRL/lpr-lpr mice, respectively. 6D6 gave a characteristic perinuclear immunofluorescence staining pattern on ethanol-fixed human neutrophils, bound to the native form of MPO by immunoblotting and had a high constant affinity for MPO as demonstrated by real-time specific interaction. 9B5 produced a cytoplasmic immunofluorescence staining pattern, reacted with the heavy chain of MPO and had a low constant affinity for MPO. The heavy-and light-chain variable region genes of monoclonal antibodies (mAb) 6D6 and 9B5 were sequenced and found to be highly homologous to germline genes and to contain negatively charged amino acids in the complementarity determining regions. IgM MPO-binding activity was observed in most BW and MRL/lpr-lpr mouse sera, which may correspond to polyclonal activation of B cells, whereas IgG anti-MPO antibodies could be rarely detected. Thus, this study indicates that (i) BW and MRL/lpr-lpr mice do not delete IgM anti-MPO secreting B cells, do not maintain these B cells in a state of anergy, but most individuals are not able to spontaneously induce the class-switching of this autoantibody population; (ii) IgM anti-MPO antibodies can recognize different epitopes on MPO and produce different immunofluorescence staining pattern on ethanol-fixed human neutrophils, as demonstrated by the immunochemical properties of the two lupus-mouse derived mAb.

Amino Acid Sequence↗
PubMed1997

Leiomyosarcoma of the tibia. Report of a case.

A 48-year-old man with an unremarkable medical history was admitted for a painful swelling over the anteromedial aspect of his right leg. Radiographs disclosed heterogeneity of the proximal tibia, with increased uptake on the bone scan. Computed tomography findings consisted of heterogeneity of the proximal tibial metaphysis and diaphysis with subtle cortical osteolysis, periosteal appositions and soft tissue involvement. Magnetic resonance images showed low signal from the metaphysis, diaphysis and soft tissues on T1 sections that enhanced after gadolinium and converted to high signal on T2 images. Lung metastases were also found. Histologic features were consistent with leiomyosarcoma, which was considered to have originated in the tibia since no other primary localization was found. Combination chemotherapy was successful in eliminating the clinical manifestations and clearing the lung metastases. Six months later, the same chemotherapy regimen failed to improve a local and pulmonary recurrence and the patient died a few months later. Primary leiomyosarcoma of bone is a rare tumor, of which one of the most characteristic locations is the proximal third of the tibia. Magnetic resonance imaging with both T1- and T2-weighted sequences is essential to evaluate intramedullary and soft tissue tumor spread. To our knowledge, there are no characteristic signal patterns allowing to differentiate leiomyosarcoma from other primary malignancies of bone. Immunohistochemical and electron microscope studies are useful diagnostic tools.

Basement Membrane↗
PubMed1997

Peripheral neurological involvement as the first manifestation of spina bifida occulta.

A 42-year-old male was admitted for right-sided sciatica with asymptomatic septic arthritis of the fifth toe of the right foot. He had a history of active chronic hepatitis C and septic arthritis of the fifth toe of the left foot. His symptoms included low back pain, poorly systematized right-sided sciatica, impairment of all forms of sensation in both lower limbs, absent ankle jerks, episodes of urinary retention, urgency, and painless septic arthritis of the fifth toe of the right foot. Roentgenograms showed a spina bifida occulta of L5 and a bony erosin in the distal interphalangeal joint of the right fifth toe. Distal denervation in the territory of L5 was demonstrated by the electromyographic study. Magnetic resonance imaging disclosed an area of high signal on T1 and T2 images, located within the spinal canal opposite L4 and suggestive of an intraspinal lipoma, as well as tethering of the spinal cord in an abnormally distal position. Antimicrobial therapy was effective in ensuring resolution of the infectious arthritis. The low back pain and sciatica responded to nonsteroidal antiinflammatory drug therapy and did not recur subsequently. Many patients who have roentgenograms taken to evaluate low back pain and sciatica are found to have a spina bifida occulta. This complex birth defect involving the spinal canal, meninges and spinal cord or cauda equina can cause neurologic and/or urinary symptoms in adulthood. Magnetic resonance imaging is essential in this situation to evaluate the spinal cord and to look for an intraspinal lipoma.

Adult↗
PubMed1996

Comparative study of 6 types of criteria in adult Still's disease.

OBJECTIVE: To compare the sensitivity of 6 sets of criteria proposed for adult Still's disease in published papers in a well defined patient population. METHODS: For inclusion we required a diagnosis of adult Still's disease established by a senior internist or senior rheumatologist. Sensitivity was evaluated in 65 new cases of adult Still's disease from a multicenter study based on signs and symptoms (1) in the first 6 months of illness, (2) in the same period in patients followed more than one year (52 patients), and (3) at any time in patients followed more than one year. RESULTS: The Yamaguchi criteria are most sensitive (93.5%), followed by those of Calabro and Londino. Medsger et al (80.6%), Kahn (69.3%), Reginato (55.2%), and Goldman (43.7%). Sensitivity was high even from the first 6 months, except for the 2 less sensitive criteria. CONCLUSION: Awareness of these discrepancies in adult Still's disease criteria are crucial to ensure comparability of different series of this condition.

Adult↗
PubMed1993

Antibodies to Sm, RNP and SSB detected by solid-phase ELISAs using recombinant antigens: a comparison study with counter immunoelectrophoresis and immunoblotting.

Sera from 64 patients with systemic lupus erythematosus (SLE) were tested for the presence of anti-Sm, anti-RNP, and anti-SSB antibodies using commercially available solid-phase enzyme-linked immunosorbent assays (ELISAs) and recombinant nuclear proteins as substrates. The results were compared to those obtained with counterimmunoelectrophoresis (CIE) and immunoblotting (IBT) using a rabbit thymus extract (RTE) as the substrate. The ELISAs detected antibodies to Sm, RNP, and SSB in, respectively, 25%, 36%, and 15% of the SLE sera. Neither IBT-positive/ELISA-negative nor CIE-positive/ELISA-negative sera were found, regardless of the specificity considered, suggesting that ELISAs using recombinant nuclear antigens are highly sensitive. Discrepancies were observed between the results obtained with these different techniques. In addition to sera positive by both IBT and ELISA but negative by CIE, a substantial number of sera had ELISA-detectable anti-Sm, anti-RNP, and anti-SSB antibodies which failed to react with the corresponding polypeptides by IBT. The reasons for ELISA/IBT discrepancies were explored; however, no single explanation was found. Instead, a higher sensitivity of the ELISA to detect antibodies directed against certain polypeptides, the possible inability of IBT using RTE as the substrate to detect antibodies reacting with conformational antigenic determinants, and false-positive reactions in the ELISAs were suggested. Thus, it is still advisable to perform both IBT and ELISAs simultaneously in well-defined autoimmune diseases to further analyze the potential advantages of ELISAs using recombinant antigens.

Animals↗
PubMed1993

Local and systemic activation of the whole complement cascade in human leukocytoclastic cutaneous vasculitis; C3d,g and terminal complement complex as sensitive markers.

We have studied complement activation both in plasma samples and in lesional skin from patients with leukocytoclastic cutaneous vasculitis (LCV). Enzyme immunoassay (EIA) quantification of the complement activation markers, C3d,g and the terminal complement complex (TCC) in plasma, showed that their levels were significantly increased in 66% and 55% of the patients, respectively (n = 29) compared with healthy controls, whereas the standard measurements of C3, factor B, C1q, C4 and C2 were generally within normal range. Elevations of C3d,g and TCC levels in plasma were significantly correlated. Importantly, a significant correlation was found between the severity of the vasculitis and both C3d,g and TCC plasma levels. Immunofluorescence studies of skin biopsy specimens demonstrated simultaneous presence of perivascular dermal deposits of C3d,g and TCC in lesional skin from 96% and 80% respectively of the patients (n = 25). There was a significant correlation between the intensity of the deposits of both markers. Clusterin, a TCC inhibitory protein, was always found at the same sites of perivascular TCC deposits. Immunofluorescence studies at the epidermal basement membrane zone (BMZ) revealed in each case deposits of C3d,g which were accompanied by TCC deposits in 52% of the biopsy specimens. These data demonstrate that there is a local and systemic activation of the whole complement cascade in human LCV. The presence of both C3d,g and clusterin-associated TCC perivascular deposits suggests an intervention of a regulatory mechanism of local complement activation in LCV. Finally, measurement of plasma C3d,g and TCC appears to be a sensitive indicator of systemic complement activation and disease severity in LCV.

Aged↗
PubMed1993

[Erosive arthropathies in Crohn disease. Apropos of 3 cases].

Three unusual cases of destructive joint lesions in patients with Crohn's disease are reported. One patient with chronic enteropathic polyarthritis developed erosions of the wrists. The other two patients had spondyloarthropathic disease; erosions developed in the right hip in one and in the hips, knees and tibiotarsal joints in the other. The few similar cases reported in the literature are reviewed.

Adolescent↗
PubMed1993

[Aspergillus spondylodiscitis. Apropos of 3 cases].

Three cases of Aspergillus discitis are reported in immunodepressed patients. Vertebrae osteomyelitis was preceded in 2 cases by pulmonary infection. The diagnosis was established in every case by disc aspiration or closed-needle-biopsy and mycological examination of the material. Aspergillus fumigatus was identified in two cases; in one case itroconazole led to recovery within three months.

Adult↗
PubMed1993

[Intradural metastasis. Value of magnetic resonance imaging].

Imaging a 70 year old man with lymph node metastases from an adenocarcinoma developed cauda equina syndrome. The diagnosis of intradural metastatic disease was established on the basis of magnetic resonance imaging with gadolinium injection which visualized diffuse nodules in contact with the nerve roots.

Adenocarcinoma↗
PubMed1992

VAD or VMBCP in severe multiple myeloma. The Groupe d'Etudes et de Recherche sur le Myélome (GERM).

A randomized trial has been performed in which 91 patients with stage III myeloma and additional severe criteria were randomly allocated to either VAD or VMBCP. No significant difference was noted between these two groups using the following criteria: response rate (VMBCP: 54%; VAD: 39%), impact on symptoms, median survival (VMBCP: 14 months, VAD: 17 months). However, toxic effects and refusal to pursue treatment were more frequent with VAD than with VMBCP (12 v 6). Therefore, in this trial, VMBCP appears to be more useful than VAD.

Adult↗