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Biomedical subjects

L Marcellin

Publications and source records attributed to L Marcellin.

At least 19 recordsLinked to original sources

Genetic alterations in primary osteosarcoma from 54 children and adolescents by targeted allelotyping.

At present, the only recognised prognostic factor for primary osteosarcoma is the histological response to preoperative chemotherapy. Our study was designed to identify new diagnostic markers that could eventually have a prognostic value. A total of 54 patients under 20 years of age with primary osteosarcomas were studied while under treatment by the French Society of Paediatric Oncology OS 94 protocol. Paired normal and biopsy samples were collected. In addition, surgical resection specimens, following preoperative chemotherapy, were obtained in 13 cases. After genomic DNA extraction, an allelotyping analysis targeting microsatellites linked to Rb and p53 genes, and 9p21, 7q31 and 5q21 regions was performed. In all, 94% of the samples at diagnosis showed allelic imbalance and the biopsies were highly rearranged except for the microsatellite targeting 7q31. The same panel was highly informative at surgical resection. Microsatellites investigating Rb, p53 and the 9p21 region were particularly altered without a significant correlation with prognosis. On the other hand, the alteration of the 7q31 locus at diagnosis was significantly correlated with a worse prognosis and a new frequently altered locus, 5q21, was described. In conclusion, this panel allowed us to characterise paediatric osteosarcomas. Correlation of prognosis with the altered 7q31 region could be a useful tool and further studies are required to confirm the importance of 5q21.

Adolescent↗

[Epiphyseal tibial osteoblastoma: report of a rare localization and review of the literature].

Osteoblastoma is an uncommon benign bone tumor diagnosed in about 1% of primary bone tumors. Predominantly observed in the axial skeleton, it can be observed in long bones (20%), generally in the diaphysis (80% of the long bone localizations). In typical cases, standard imaging is highly suggestive of the diagnosis. The typical image is a "lytic" zone surrounded by bony condensation, and a minimal osteosclerotic reaction peripherally, rarely invading the soft tissues. Diagnosis is confirmed at pathology: osteoblast-like cells disseminated in an abundant conjunctive background surrounded by immature richly vascularized bone. The tumor we report presented an unusual localization and an atypical aspect on the imaging studies. Located in the tibial epiphysis, this osteoblastoma invaded the soft tissues, as seen on the CT and MRI studies which visualized an encapsulated tumor with a calcified shell and a liquid-like tumefaction suggestive of a tumor arising from the synovial.

Adult↗

Chronic disseminated Trichosporon asahii infection in a leukemic child.

We report a case of chronic disseminated Trichosporon asahii infection in a leukemic child. Administration of amphotericin B lipid complex resulted in rapid control and improvement of the initial infection but failed to prevent the development of chronic disseminated disease. Cure was achieved after treatment was changed to a 20-month course of itraconazole. This case report demonstrates that Trichosporon species can cause chronic disseminated disease with a pattern similar to that of disease caused by Candida species.

Acute Disease↗

Expansion of marginal zone B cells is not sufficient for the development of renal disease in NZBxNZW F1 mice.

The mechanisms which govern the production of autoantibodies and of tissue damage during systemic lupus (SLE) are still unclear. In the NZBxNZW F1 (BW) model of SLE glomerulonephritis, the activation and commitment of B cells are thought to play a major role in disease progression. Previous analysis has suggested that these mice have a substantial increase of marginal zone (MZ) B cells before the occurrence of the disease. Owing to the probable role of this B cell subset in autoantibody production, it was important to define the possible link between this abnormality and the occurrence of kidney damage. Using cytofluorometry analysis, we followed the splenic MZ B cell phenotype in different series of mice with shared autoimmune genetic background and histologically defined renal status. By comparing BW females and BW males, NZB and NZW mice, we confirm that BW mice have an increase in MZ B cells but this MZ B cells expansion is not directly linked to tissue lesions. Genetically modified BW female mice with a restricted repertoire of B and T cell antigen receptors, and which do not develop nephritis, exhibit the same increase of MZ B cells, suggesting that this increase does not depend on a specific set of antigens. Moreover, our analysis brings to light a pre-disease state in BW males, with autoantibody production and mesangial deposits.

Animals↗

Iliac bone defects revealing systemic sarcoidosis.

Bone lesions are fairly uncommon in sarcoidosis (5 to 10% of cases). We report the case of a 40-year-old man in whom sarcoidosis of the lungs and bones was revealed by excruciating buttock and sacral pain. Computed tomography showed multiple punched-out defects in the left iliac bone. No similar cases have been reported in the literature.

Adult↗

[Multiple gastrointestinal tract duplication : a neonatal case report].

We report the case of newborn with multiple GI tract duplication cysts. Prenatal diagnosis was that of duodenal stenosis. A complete screening for polymalformative syndrome is required in the neonatal period and the authors insist on the importance of US and color Doppler US imaging.

Abnormalities, Multiple↗

[Activity and cost analysis in surgical pathology. Experience of a French university laboratory using the activity-based costing method].

Good self-knowledge enables us to have a well- reasoned adaptation to our environment. Starting from this precept based on simple common sense, activity and cost analysis, when applied to medical departments in a university hospital setting, represents a necessary phase in their scientific progression and in the continuation of their university vocation. This is all the more true given the present climate of economic and organizational restructuring of medical facilities. This paper relates the experience of a French surgical pathology department which was assessed for cost effectiveness using the Activity-Based Costing (ABC) method in 1999. This method, which originated in the business world and of which the general concepts are presented here, has given us a keener understanding of the diverse processes involved, their costs and how these costs are arrived at. Moreover, this method has identified the proportion of costs imputable to diagnostic work and of those linked to work specific to a university hospital, in particular teaching and research and development. The results can then be used for a clearer analysis of the figures required by prescribers and health care funding agencies, and, within the department, to enhance perception of work carried out by the entire staff in order to initiate a new type of management centered on activity (Activity-Based Management). Adaptable to any medical department, whatever its organizational structure, independent of the significance of any given code letter and regardless of the rating method used to grade activities, the ABC method also allows for comparisons between structures of a similar nature. The thoughts it inspires on economic performance must take into account the rules of good medical practice, the imperatives of quality assurance, the need for "breathing space" which are indispensable to research and a humanist conception of working relations.

Costs and Cost Analysis↗

The anatomic basis of connections between the coronary sinus musculature and the left atrium in humans.

BACKGROUND: This study determined the histological features of the atrial myocardium connecting the coronary sinus and the left atrium in humans. METHODS AND RESULTS: Ten necropsied hearts were studied by performing serial longitudinal sections parallel to the long axis of the coronary sinus that extended its full length using a large microtome. In all specimens, the venous wall of the coronary sinus was surrounded by a cuff of striated muscle extending 40+/-8 mm from the ostium. Striated myocardial connections of varying number and morphology left this coronary muscle cuff and connected to the left atrium; they ranged from 1 to 2 fascicles to a widely intermingled continuum (thickness, 2.79+/-2 mm; width, 2.91+/-3.5 mm). These connections originated 8.8+/-5.7 mm from the coronary sinus ostium and inserted 18+/-11 mm distally into the left atrium. The insulating compartment in which the connections traversed between the left atrium and the coronary sinus was mostly formed of adipose tissue. The valve of Vieussens was found in 6 hearts at a mean distance of 3.4+/-3.2 mm from the distal extremity of the coronary sinus muscle cuff. CONCLUSIONS: In the human heart, a consistent but morphologically variable left atrial coronary sinus myocardial connection was found. This emphasizes the need for surgical dissection or catheter ablation in or around the coronary sinus to eliminate these connections.

Adult↗

[Unusual cause of chronic iron-deficiency anemia and insulin resistance: cholesterol embolism].

BACKGROUND: Cholesterol embolism disease (CED) is an extremely polymorphous clinical entity. Rare reports mention digestive or endocrine manifestations. CASE REPORT: A 73 year-old female patient developed CED disclosed by iron deficiency anemia with chronic digestive bleeding associated with major insulin resistance. DISCUSSION: Solitary iron deficiency anemia as the inaugural sign of CED is exceptional. Rare reports in the literature suggest it is related to polymorphous nonspecific lesions (ulcers, pseudotumoral lesions...) leading to chronic bleeding. Careful histopathology study of the lesions of fragments of healthy mucosa provides the correct diagnosis showing biconcave and optically empty slits. Insulin resistance has not been reported although prior diabetes is often mentioned as a predisposing factor for atherosclerosis. In our case, the role of CED was not determined, but pancreatic or inflammatory involvement can be envisaged.

Aged↗

Nodular glomerulosclerosis with deposition of monoclonal immunoglobulin heavy chains lacking C(H)1.

The objective of this study was to further characterize the clinical and immunopathologic features of heavy chain deposition disease (HCDD), a recently described entity. Four patients were diagnosed as having HCDD on a kidney biopsy. All presented with nodular glomerulosclerosis with deposition of gamma1 heavy chains lacking CH1 epitopes, but without light chains. Two different patterns were observed in the serum. First, patients 1 and 2 had a circulating monoclonal IgGlambda containing a short gamma1 heavy chain lacking CH1 epitopes, with an apparent molecular weight of 40 kD consistent with a complete CH1 deletion. Biosynthetic experiments also showed that the deleted heavy chain was produced in excess compared with light chains, and was secreted in vitro together with half Ig molecules, although these abnormal components were not detected by Western blot analysis of whole serum. Second, patients 3 and 4 had a circulating monoclonal IgG1lambda with an apparently normal, nondeleted heavy chain subunit, but serum fractionation followed by immunoblotting revealed an isolated monoclonal gamma1 chain lacking CH1 epitopes. These data strongly suggest that renal deposition of a CH1-deleted heavy chain circulating in low amounts in the serum as a free unassembled subunit is a major feature of HCDD. The CH1 deletion is most likely responsible for the premature secretion in blood of the heavy chain by a clone of plasma cells.

Adult↗

[A case of a aggressive giant-cell tumor with multiple bone metastases].

PURPOSE OF THE STUDY: Giant-cell tumor are known for local recurrence. Metastases are rare (2 p. 100), and generally located in the lung. We present a case with multiple bone metastases and rapid course. MATERIAL, METHODS AND RESULTS: A 45-year-old man presented a 5 cm giant-cell tumor of his right distal tibia and two other localisation in the fifth and sixth cervical vertebral bodies. He underwent a resection of the distal tibia and reconstruction with a controlateral free vascularized fibula. The bodies of the fifth and sixth cervical vertebral were resected and replaced by an iliac crest graft. Other localisations appeared in iliac right crest, in the posterior wall of the cotyle and in the second, third and fourth cervical vertebral bodies. Chemotherapy was administered and clinical signs regressed but eight months later the patient presented a recurrence of his tumor in the distal tibia with new localisation in the left fifth rib, in the right clavicle, in the frontal bone, in right ischio-pubal branch and in the right proximal femur. A new chemotherapy was performed but had little effect and probably hasved dubic death 13 month after the first symptom. DISCUSSION: The present observation is characterised by the large number of localisations (13; the highest number found in the literature was 11 localisations) and by the rapidity of the clinical course. Low grade giant-cell tumors generally give benign metastase with a course lasting several years. The chemotherapy helpt us to slow the progression of the lesions but was unable to prevent the development of new localisation and the recurrence in the distal tibia. More over, its toxicity could have caused the death of the patient. CONCLUSION: We present the case of one patient who presented a giant-cell tumor with unusual presentation: multiple bony metastases with rapidly fatal outcome.

Antineoplastic Agents↗

Terminal deoxynucleotidyl transferase deficiency reduces the incidence of autoimmune nephritis in (New Zealand Black x New Zealand White)F1 mice.

Terminal deoxynucleotidyl transferase (TdT) enzyme activity in lymphocytes generates diversity in the Ag receptor repertoires by adding template-independent N nucleotides and disrupting homology-directed rearrangements. The importance of this diversity in vivo and the significance of the suppression of TdT during fetal life remain uncertain. Previous studies have shown that in TdT knockout mice (TdT(0)) 1) the T cell repertoire is less peptide oriented; and 2) natural autoantibody, particularly anti-DNA autoantibodies, are less polyreactive, and their mean affinities are reduced. Consequently, the suppression of TdT during early T/B cell ontogeny may participate in controlling autoimmunity. To study the impact of TdT suppression in autoimmune-prone mice, we introduced the TdT null mutation into the (NZB x NZW)F1 (B/W) mouse strain. We show that TdT deficiency significantly reduces the incidence of autoimmune nephritis and prolongs survival compared with those in control mice. Surprisingly, the long-term survivor TdT(0) mice produced amounts of anti-ADN and anti-histone autoantibodies similar to those of their TdT+ littermates. However, these TdT(0) mice showed no evidence of renal inflammation, and the immune deposits were restricted to the mesangium, whereas basal membrane deposits were clearly correlated with overt renal disease. The present study supports the idea that the absence of TdT enzyme activity in lymphocytes protects mice against autoimmunity and could offer a therapeutic approach to autoimmune diseases. Moreover, our results may help to unravel the mechanisms of lupus nephritis.

Animals↗

Loss of oral infectivity of tissue cysts of Toxoplasma gondii RH strain to outbred Swiss Webster mice.

We have developed a method for obtaining cysts of Toxoplasma gondii RH strain. Outbred Swiss Webster mice were infected subcutaneously (s.c.) or intraperitoneally (i.p) with 10(5) tachyzoites and given sulfadiazine 400 mg l-1 + NaHCO3 10 g l-1 in drinking water from day 1 to day 15 post-infection (p.i.). None of the mice infected i.p. survived, compared with 50% of the mice infected s.c. Cysts were detectable in the brain on day 45 p.i., and had ultrastructural features consistent with those of bradyzoites. However, these cysts were incapable of infecting mice via the oral route. In addition, immunofluorescence studies showed the persistence of P36 protein expression, indicating that the conversion to bradyzoites was incomplete.

Animals↗

[Muscular metastases disclosing adenocarcinoma].

The authors report the case of a 67-year old man, with no particular medical history, presenting a large swelling of the left thigh. Investigations conclude to metastases located in muscles of the left thigh and of the pelvis, secondary to an adenocarcinoma of presumed pancreatic origin. With reference to this case, features of muscular metastases are reviewed. Muscular metastases seldom occur during the course of a cancer and are exceptionally the first manifestation of a neoplastic process. They are usually described as a painful mass, but symptoms can be misleading and delay diagnosis. Images obtained by ultrasonography, tomodensitometry and magnetic resonance imaging are not specific and histological examination is necessary to confirm the diagnosis.

Adenocarcinoma↗