Biomedical subjects
Publications and source records attributed to G Lancien.
The authors report a case of periosteal cavernous hemangioma of the distal humeral. They describe the imaging findings of hemangiomas of long tubular bones and discuss their differential diagnosis.
The aim of this study is the histological characterisation of angiogenesis in a macroporous biomaterial with quantification techniques used in oncology. Porous tricalcium phosphate implants were seated in the tibias of 12 rabbits. This work allows (1) morphological study with photonic microscopy, transmission electron microscopic and immunohistochemistry labelling for (2) quantification of vascularisation using anti-CD31 monoclonal antibody (3) quantification of proliferation using anti-PCNA polyclonal antibody (4) study of two angiogenic growth factors: VEGF and FGF-2. Quantification of angiogenesis revealed an outbreak kinetic with early vascular growth in first several days and a second growth phase after 4 weeks. This study reveals in macropores many isolated cells without adjacent vascular lumen, with endothelial phenotype. Expression of angiogenic growth factors reveals that all endothelial cells were VEGF-negative throughout the test period. FGF-2 expression by endothelial cells began 2 weeks post-implantation. Osteoblasts strongly expressed two markers throughout the test period. Furthermore, the procedure described here can be used to compare angiogenesis in different biomaterials or in the same biomaterial with the influence of macroporosities.
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Ewing's sarcoma is found exceptionally as a primary epidural tumor of the spine. Four cases of extraosseous Ewing's sarcoma of the spinal epidural space are presented. Another 17 cases were found in the pertinent literature and are discussed. There were 15 males and 6 females with mean age of 16 years (range, 4 to 30). Symptoms included back pain and/or radicular pain, paresis of one or more limbs, sensory disturbances, and bladder and bowel dysfunction. The mean diagnostic delay was 4,7 months. Each patient underwent surgery but complete resection of the tumor was obtained in only half of the cases. Most patients received radiation therapy and chemotherapy. Twelve patients died, 1 to 54 months (mean, 18) after diagnosis. Even though the number of patients was too small in this series for statistical analysis, partially resected tumors do appear to be associated with a higher mortality.
PURPOSE OF THE STUDY: Macroporous beta tricalcium phosphate ceramic beads were elaborated to be a resorbable bone substitute and a drug delivery system carrying gentamicin or vancomycin. The aim of this study was to evaluate this implant into a rabbit experimental osteomyelitis. MATERIAL AND METHOD: Experimentation included 24 rabbits and was performed in three stages, according to Norden's description. Induction of osteomyelitis was obtained by injection of a sclerosing agent and of Staphylococcus aureus through the lateral side of the metaphysis of the proximal tibia. Three weeks after inoculation, animals were randomly dispatched to one of the three treatment groups. After surgical debridment (to collect cinetics data), the first group received no further treatment and was considered as a control; the second group received a ceramic implant; the third group received a gentamicin-loaded ceramic implant. Euthanasia occurred between 2 days and 21 days after the debridment. Bone samples were obtained to quantify the bacterial and gentamicin bone concentrations. Gentamicin level was also measured inside the ceramic implant. Antibiotic concentration was assessed by a immunoenzymatic method. RESULTS: Osteomyelitis was obtained in 21 of the 24 animals (87.5%). Antibiotic release was early and complete (before the third day) but gentamicin still remained in the bone for 10 days. Bacterial concentration suggested an antimicrobial activity of the implant, but not a full sterilisation of the osteomyelitis. CONCLUSION: Norden's experimental osteomyelitis model with rabbit was proposed to assess the therapeutic activity of systemic antibiotics, but not to evaluate biomaterials. Therefore we have shifted for experimental evaluation of biomaterials to a metaphyseal osteomyelitis in the sheep, the patterns of which are close from those of the human disease.
OBJECTIVE: To examine the respective role of the DRB1*, DQB1*, and DPB1* HLA alleles in primary Sjögren's syndrome (SS) and in the clinical and autoantibody profile of primary SS. METHODS: HLA-DRB1*, DQB1*, and DPB1* alleles were analyzed in 42 patients with primary SS and 200 controls by reverse dot blot hybridization for DRB1* and DPB1* and by polymerase chain reaction-restriction fragment length polymorphism for DQB1*. RESULTS: We found a significant increase of the HLA-DRB1*15-*03 heterozygote genotype frequency (19% primary SS vs 3.5% controls; p<0.0006, OR=6.49) and especially for the HLA-DRBI*1501-*0301 genotype (16.7% primary SS vs 3% controls; p<0.002, OR=6.47). The DQB1*0201-*0602 genotype was also significantly increased in primary SS (17.1% primary SS vs 4% controls; p<0.006, OR=4.86). However, the higher risk to primary SS development was associated with the DRB1*1501-*0301 genotype (OR=6.47 vs 4.86). There were no differences between patients and controls in DPB1* allele frequencies. The HLA-DRB1*15-*03 heterozygote genotype was also associated with systemic features such as hematologic manifestations and Raynaud's phenomenon (RP) and with autoantibody production such as antinuclear, anti-Ro(SSA) or La(SSB) autoantibodies and rheumatoid factor. CONCLUSION: Our data suggest a role of the HLA-DRB1*1501-*0301 heterozygote genotype in susceptibility to primary SS. Moreover, the HLA-DRB1*1501-*0301 genotype was also found to be associated with a particular form of the disease characterized by RP, hematologic manifestations, and autoantibody production.
Three distinct monoclonal gammopathies were identified in the serum of a 79 year-old man. In 1972 he presented with Waldenström's macroglobulinemia IgM Kappa. Twenty years later multiple myeloma was diagnoses. Serum protein electrophoresis performed at this time showed three monoclonal bands. Immunofixation identified these bands as monoclonal IgM kappa, IgG kappa and IgA kappa. Twenty-six cases of triclonal gammopathies were previously reported. Sixteen cases were associated with malignant immuno-proliferative diseases (non-hodgkin lymphoma, Waldenström's macroglobulinemia, multiple myeloma); five cases with non-hematologic diseases; three cases were of undetermined significance. The origin of three distinct monoclonal proteins may derive from three unrelated clones or alternatively from a single clone in which an isotype switch has occurred.
We have studied the action of peripheral blood lymphocytes (PBLs) and intrathyroidal lymphocytes (ITLs) on the biochemical and hormonal metabolism of autologous thyrocytes cultured in follicles in a collagen gel. The production of tumour necrosis factor alpha (TNF-alpha) in culture was also measured. Thyroid tissues and lymphocytes were obtained from ten patients with Graves' disease and from five control subjects. Lymphocyte-induced cytotoxicity was evaluated in autologous thyrocytes cultured in a collagen gel by several tests; neutral red uptake, lactate dehydrogenase activity and glutathione level. Hormonal metabolism was assessed by evaluating tri-iodothyronine (T3) and total cAMP production under TSH stimulation. TNF-alpha levels were measured in supernatants after 5 days of coculture. PBLs altered biochemical metabolism, T3 synthesis and cAMP production in autologous thyroid follicles. These inhibitions were greater than those obtained with ITLs. No difference was seen between cells obtained from patients with Graves' disease and those from normal subjects. TNF-alpha levels secreted by PBLs were higher than those secreted by ITLs. The concentrations of this cytokine decreased in coculture. Significant correlations were observed between the decrease in biochemical and hormonal parameters and TNF-alpha levels. Exogenous TNF-alpha and high doses of interferon gamma inhibited follicle metabolism, especially hormone secretion. In conclusion, thyrocytes cultured in follicles provide a more sensitive model than monolayer cultures for analysis of lymphocyte-induced interactions. Lymphocytes gradually inhibit the biochemical and hormonal metabolism of autologous thyroid follicles depending on the isolation method. These alterations may be particularly attributed to TNF-alpha secreted by lymphocytes. The cytokine-induced inhibition of thyroid hormonal function apparently involves the adenylate cyclase system.
Two large epidermoid cysts of the spleen have been accidentally discovered in two young men. These cysts are uncommon and represent about 10% of the non parasitic benign cysts of the spleen. From these cases, the authors reviewed the literature. These cysts, which are caused by an abnormal development during the seventh week of the intra-uterine life, are often asymptomatic but the occurrence of a complication may enable the diagnosis. This diagnosis relies on the surgical ablation of the cyst and the histopathologic examination. The surgery should be as conservative as possible.
We have investigated a Vancomycin and Gentamycin loaded macroporous tri-calcium phosphate-type beta-ceramic, Calciresorbr. Elution kinetics of Vancomycin and Gentamycin from spheric implants was studied by varying porosity and initial concentrations; then, the other following parameters, that can be modulated and are likely to be involved in this elution process, were analysed: Antibiotic charge: quantitative analysis (titration). qualitative analysis by scanning electron microscopy. Material's porosity: qualitative analysis: optical and scanning electron microscopy. quantitative analysis by stereology and treatment. This physicochemical characterization would favour correct manufacturing of new macroporous synthetic bioceramics in order to achieve satisfactory elution kinetics and homogenous materials.
Several different materials have been proposed as vectors to carry antibiotics to bone tissue. No material currently available satisfies all the prerequisites for the treatment of chronic osteitis with a simple procedure. The aim of this study was to assess the antibiotic releasing capacity of gentamycin-loaded beta tricalcium phosphate in vitro and in vivo in a sheep model. Experimental results showed that beta tricalcium phosphate can release a large percentage of its antibiotic load and that the kinetics of antibiotic release can be modulated by changing the volume and porosity of the blocks. This material is also well tolerated by the host and has the advantage of being porous and resorbable. Use of these properties would appear to be a major progress in the treatment of chronic bone infections.
PURPOSE OF THE STUDY: The severity of pain and functional disability contrast with the benignity and small size which characterize the osteoid osteoma. This study evaluates the clinical and histological efficiency of an intraoperative localization of the nidus by the tetracycline fluorescence test which is based on histomorphometric bone labeling techniques. MATERIAL AND METHODS: 17 out 25 osteoïd osteoma, operated between 1987 and 1995, had tetracycline fluorescence test. The patients received 1 gram orally during each of the 3 pre-operative days. Fluorescence under ultraviolet light was assessed on the removed specimen, and on the tumor site, before and after surgical resection. RESULTS: At a mean follow-up of 39 months (12-85), 15 of the 17 patients (88 per cent) were painless. The result was always acquired within the first weeks after procedure. 2 patients had a primary failure due to incomplete removal of fluorescent nidus, and one was reoperated with success after one year. One patient had a false negative test although there was histological evidence of osteoid osteoma on the removed tissues with a complete relief of pain. In summary, the test was helpful in 14 cases (82 per cent) guiding "en bloc" resection or curetage, and allowing 70 per cent of histological nidus diagnosis. DISCUSSION: This test is easy to carry out by pre-operative ingestion of tetracycline and only requires an ultra-violet light source. It demonstrated a good reliability which can be compared with that of more complex radio-labeling techniques or CT guided drill resections which impede histological confirmation in half of the cases. The fluorescence test allows a secure and precise procedure without complication, and we use it mainly for cancellous and superficial osteoid osteoma, and for revision of previous failed excisions. When the nidus is cortical and deeply located, radioguided techniques must be discussed.
PURPOSE OF THE STUDY: This survey of 48 cases of trochanteric non-union in THR showed that this complication had not only functional consequences (one patient out of three complains of some instability and mild pain) but may also lead to stem loosening (3/48) through an original mechanism. The movements of the trochanter produce wear debris, mainly from the broken metal wires fixing the trochanter (and from rubbing of the cement on the femoral side of the osteotomy). These debris create an osteolytic granuloma between the proximal lateral endocortex and the cement, which extends progressively to the distal tip of the stem. MATERIAL AND METHODS: A continuous series of 446 cemented Charnley type prostheses by the trans trochanteric approach showed 48 trochanteric non unions (11 per cent) which were examined at an average follow up of 6.5 years. Six patients were reoperated for important hip instability. Ten who suffered only from moderate instability were not reoperated on. 32 were asymptomatic and therefore where not reoperated, but 3 of them suffered from severe femoral loosening after 6 years and required revision. RESULTS: These cases of loosening due to trochanteric non union were characterized by: clinical patterns: they occurred only after 6 years, in active patients under 50; radiological aspects: osteolysis was initially limited to the lateral cortex (without any calcar resorption or radio lucency around the cup) analysis by electronic microscopy of the granuloma (harvested at revision) showed metallic debris (under 1 mu) inside macrophages, with some cement particles (secondary to the loosening). DISCUSSION: Mechanism of loosening These cases of loosening differ from those due to granuloma caused by wear debris of PE and from granulomas resulting from deterioration of the cement around the femoral stem, which both occur only much later with the Charnley prostheses. In our consecutive series of 32 cases of Charnley THR in young active patients with an average follow up of 9.5 years, the only cases of femoral loosening observed were related to trochanteric non unions. Hyposolicitation by trochanteric non union does not lead either to bone resorption or to stem loosening, as we could notice in a series of moderately active patients over 60 with loose non unions. Loosening due to trochanteric non unions was only observed in active patients with tight non unions, as the patient's activity and contact of the surfaces increase rubbing and wear of metal wires. Prevention of trochanteric non union. Despite attentive care to fixation of trochanter there is an unavoidable percentage of non union even in simple cases (3 to 4 per cent according to Charnley). Therefore we advocate this technique only when a large exposition is necessary (revisions, THR for dislocation etc..) CONCLUSIONS: Trochanteric non union may lead to stem loosening after 6 years in active patients under 50. Therefore we recommend: to restrict the use of the trochanteric approach to some difficult THR: revisions, prostheses for dislocation, etc... to reoperate patients under 50 with a trochanteric non union: if it is clinically symptomatic if a progressive granuloma of the lateral cortex, even though asymptomatic, appears.
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Monoclonal antibodies (mAb) raised against human peritoneal macrophages were selected for their non-reactivity with freshly sampled blood cells. One of these mAb, AMH152, initially non-reactive, bound to monocytes after 18 h of culture, a property which was not shared by an unrelated antibody of the same isotype (IgG1). The induction of the expression of the antigen detected by AMH152 on monocytes in culture was not influenced by the addition of serum or by the substrate used, plastic that favoured adhesion or teflon bags. Overnight incubation at 4 degrees C in adhesion conditions did not enable antigen expression. A 1-h treatment with phorbol myristate acetate or formyl-methionyl-leucyl-phenylalanine did not increase AMH152 binding. Culturing monocytes with cycloheximide tended to inhibit antigen expression. These observations suggested that antigen expression represents an active phenomenon, requiring protein synthesis. The antigen recognized by mAb AMH152 could be visualized on sections of formalin-fixed and paraffin-embedded tissues. Macrophages of healthy lymphoid organs and tissues that expressed CD68 antigen failed to bind AMH152. In contrast, chronic inflammatory lesions, like those of sarcoidosis, tuberculosis and cat scratch disease, contained epithelioid and multinucleated giant cells that reacted with AMH152. In serous exudates of cancer metastases, 10-40% of macrophages were also stained. The antigenic material was essentially present at the cell periphery. Thus, mAb AMH152 recognized a surface antigen, detectable on paraffin-embedded tissue sections, and which accompanied differentiation of monocytes into inflammatory cells. The expression of this antigen on monocytes in culture suggests that these cells underwent an activation process, even when maintained for some hours in teflon bags and in a serum-free medium.
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An intracardiac malignant lesion was found in a 28-year old male patient following orchidectomy for an advanced germinal tumour of the testicle. Although the patient is under chemotherapy, the neoplastic thrombus will be removed by surgery. Heart metastases are uncommon. When they do occur, they are usually secondary to locoregional extension and limited to the pericardium or myocardium. Endocardial or intracavitary lesions are rare, but can, in certain cases, be removed by surgery.