PubMed Health⌕ Search

Biomedical subjects

Luc Thomas

Publications and source records attributed to Luc Thomas.

At least 19 recordsLinked to original sources
PubMed2007

Scleromyxedema: successful treatment with thalidomide in two patients.

BACKGROUND: Scleromyxedema is an unusual skin disease characterized by mucinous infiltration of the skin. There is no satisfactory treatment for this disorder. CASE REPORT: We report 2 cases of scleromyxedema, both associated with an IgG-lambda paraprotein. Treatment with thalidomide was started and great improvement of the lesion was noted as shown by a quality of life questionnaire similar to those used in rheumatoid arthritis. TNF-alpha value was elevated in both cases during this treatment. DISCUSSION: We hypothesize that the efficiency of thalidomide could be mediated by its costimulatory effect on T cytotoxic lymphocytes.

Adult↗
PubMed2006

Dependence of current and field driven depinning of domain walls on their structure and chirality in permalloy nanowires.

A magnetic domain wall (DW) injected and pinned at a notch in a permalloy nanowire is shown to exhibit four well-defined magnetic states, vortex and transverse, each with two chiralities. These states, imaged using magnetic force microscopy, are readily detected from their different resistance values arising from the anisotropic magnetoresistance effect. Whereas distinct depinning fields and critical depinning currents in the presence of magnetic fields are found, the critical depinning currents are surprisingly similar for all four DW states in low magnetic fields. We observe current-induced transformations between these DW states below the critical depinning current which may account for the similar depinning currents.

Journal Article↗
PubMed2006

Oscillatory dependence of current-driven magnetic domain wall motion on current pulse length.

Magnetic domain walls, in which the magnetization direction varies continuously from one direction to another, have long been objects of considerable interest. New concepts for devices based on such domain walls are made possible by the direct manipulation of the walls using spin-polarized electrical current through the phenomenon of spin momentum transfer. Most experiments to date have considered the current-driven motion of domain walls under quasi-static conditions, whereas for technological applications, the walls must be moved on much shorter timescales. Here we show that the motion of domain walls under nanosecond-long current pulses is surprisingly sensitive to the pulse length. In particular, we find that the probability of dislodging a domain wall, confined to a pinning site in a permalloy nanowire, oscillates with the length of the current pulse, with a period of just a few nanoseconds. Using an analytical model and micromagnetic simulations, we show that this behaviour is connected to a current-induced oscillatory motion of the domain wall. The period is determined by the wall's mass and the slope of the confining potential. When the current is turned off during phases of the domain wall motion when it has enough momentum, the domain wall is driven out of the confining potential in the opposite direction to the flow of spin angular momentum. This dynamic amplification effect could be exploited in magnetic nanodevices based on domain wall motion.

Journal Article↗
PubMed2006

Lymphomatoid papulosis localized to the face.

We report a case of lymphomatoid papulosis (LyP) localized to the face. Only ten cases of localized LyP have been reported, and those involved the extremities. Three of those cases finally evolved to classic LyP with a widespread distribution of the lesions, the other cases remain limited. The evolution into lymphoma for the localized form appears to be equivalent to that reported with the generalized LyP (20 %), underlining the need for long-term followup of these patients. This is the first reported case of LyP localized to the face.

Administration, Topical↗
PubMed2006

[Genotypic hypervariability of melanoma: a therapeutic challenge].

Cutaneous melanoma remains a management challenge. Melanoma is the leading cause of death from skin tumors worldwide. Melanoma progression is well defined in its clinical, histopathological and biological aspects, but the molecular mechanism involved and the genetic markers associated to metastatic dissemination are only beginning to be defined. The recent development of high-throughput technologies aimed at global molecular profiling of cancer is switching on the spotlight at previously unknown candidate genes involved in melanoma. Among those genes, BRAF is one of the most supposed to be of interest and targeted therapies are ongoing in clinical trials. In familial melanoma, germline mutations in two genes, CDKN2A and CDK4, that play a pivotal role in controlling cell cycle and division. It is hope that this better understanding of the biologic features of melanoma and the mechanisms underlying tumor-induced immunosuppression will lead to efficaceous targeted therapy.

Antineoplastic Agents↗
PubMed2006

Multiple adult xanthogranuloma: case report and literature review.

BACKGROUND: Non-Langerhans cell histiocytoses form a heterogeneous group defined by the proliferation of cells with macrophage characteristics. Diagnosis is easy in typical cases but becomes more complex in unusual forms. CASE REPORT: We report the case of a 53-year-old patient who presented multiple brown-to-yellowish papules and nodules of the trunk, neck, and head evolving for 6 months. No visceral involvement was found. Histopathological examination revealed histiocytic proliferation with features of secondary xanthomization with the presence of giant foamy multinucleated Touton cells. One year later, all lesions cleared spontaneously. Based on the clinical presentation and evolution and on the immunohistologic data, we retain the diagnosis of adult xanthogranuloma (AXG) in a diffuse shape. DISCUSSION: Multiple AXG is a rare entity (15 cases reported since 1963) with a stereotypic presentation. It is important to recognize because of its good prognosis and the absence of visceral involvement therefore requiring no investigations or aggressive treatments. This case is interesting because of the complete and spontaneous healing of all the lesions within 20 months.

Antigens, CD↗
PubMed2006

Aggressive CD30 large cell lymphoma after cyclosporine given for putative atopic dermatitis.

Atopic dermatitis (AD) is not regarded as a predisposing condition for cutaneous T cell lymphoma. Cyclosporine (CsA) is an efficient therapy in AD, and its side effects, including lymphocytic proliferation, are rare at the low dose used in such cases. So far 3 cases of patients who developed cutaneous T cell lymphoma under CsA treatment for atopy have been described. An adult patient with a history of AD received CsA therapy because of an atypical flare-up of his eruption. He rapidly developed papular atypical lesions, then followed by the onset of a voluminous cutaneous tumor leading to the diagnosis of mycosis fungoides (MF) transformed in CD30+ large cell lymphoma with nodal and blood involvement. No improvement occurred after withdrawing of CsA, and he required a polychemotherapy and an allograft. This case illustrates the dramatic evolution of an MF under CsA given in the hypothesis of AD. It stresses the fact that skin biopsies should be taken in case of atypical AD to rule out MF and avoid such an aggressive evolution under immunosuppressive therapy.

Adult↗
PubMed2006

A phase II trial of miltefosine in patients with cutaneous T-cell lymphoma.

A phase II trial evaluating 6% topical miltefosine solution was performed in 12 pretreated patients with cutaneous T-cell lymphoma. Miltefosine (Miltex) was administered for 8 weeks, once per day during the first week then twice every day for seven weeks. Main side effects consisted in moderate to mild pruritus or desquamation in 57 % and 50 % of patients, respectively. No systemic nor biological toxicity was observed. This treatment was administered on an outpatient basis exclusively. The overall response rate was 58 % with a median duration of response of 12 months. Miltefosine is a safe, simple and effective treatment in certain patients with cutaneous T-cell lymphoma.

Adult↗
PubMed2005

mda-9/Syntenin: a positive regulator of melanoma metastasis.

Metastasis is a significant event in cancer progression and continues to pose the greatest challenge for a cancer cure. Defining genes that control metastasis in vivo may provide new targets for intervening in this process with profound therapeutic implications. Melanoma differentiation associated gene-9 (mda-9) was initially identified by subtraction hybridization as a novel gene displaying biphasic expression during terminal differentiation in human melanoma cells. Mda-9, also known as syntenin, is a PDZ-domain protein overexpressed in many types of human cancers, where it is believed to function in tumor progression. However, a functional role of mda-9/syntenin in tumor growth and metastasis and the signaling pathways involved in mediating these biological activities remain to be defined. Evidence is now provided, using weakly and highly metastatic isogenic melanoma variants, that mda-9/syntenin regulates metastasis. Expression of mda-9/syntenin correlates with advanced stages of melanoma progression. Regulating mda-9/syntenin expression using a replication-incompetent adenovirus expressing either sense or antisense mda-9/syntenin modifies the transformed phenotype and alters metastatic ability in immortal human melanocytes and metastatic melanoma cells in vitro and in vivo in newborn rats. A direct relationship is observed between mda-9/syntenin expression and increased phosphorylation of focal adhesion kinase, c-Jun-NH2-kinase, and p38. This study provides the first direct link between mda-9/syntenin expression and tumor cell dissemination in vivo and indicates that mda-9/syntenin expression activates specific signal transduction pathways, which may regulate melanoma tumor progression. Based on its ability to directly alter metastasis, mda-9/syntenin provides a promising new focus for melanoma cancer research with potential therapeutic applications for metastatic diseases.

Adenoviridae↗
PubMed2005

Telemedical wound care using a new generation of mobile telephones: a feasibility study.

BACKGROUND: Leg ulcers are an important cost factor in health care systems. It has been shown that a telemedical wound care consultation can improve quality of care and help reduce costs. In this study, we evaluated the feasibility of telemedical wound care using a new generation of mobile telephones with integrated cameras. OBSERVATIONS: Three physicians separately evaluated 61 leg ulcers for the following 9 variables: epithelialization, fibrin, necrosis, and granulation tissue at the center and normal border, erythema, cyanosis, eczema, and hyperpigmentation at the periphery. One physician performed the face-to-face consultation (gold standard), and 2 others performed the remote evaluation. The image was obtained with the mobile telephone and immediately sent via e-mail. To measure the agreement of the evaluation among the 3 physicians, we used Cohen kappa statistics. Overall, the agreement between the remote and face-to-face evaluations was very good, with kappa values of up to 0.94 The image quality was judged to be good in 36 cases (59%) and very good in 12 (20%). The participants felt comfortable making a diagnosis based on the pictures in 50 cases (82%). CONCLUSION: Although this study was performed with the first generation of these devices, we were able to demonstrate the feasibility of such a telemedical wound care consultation.

Adult↗
PubMed2005

[Pathological and clinical correlations in primary cutaneous B-cell lymphomas: a series of 44 cases].

AIMS: histological and clinical relationship study of 44 cases of primary cutaneous B cell lymphoma, classified according to WHO classification. MATERIALS AND METHODS: histological, immunological and molecular analysis was correlated with clinical data. RESULTS: 33 cases (75%) were marginal zone B-cell lymphomas (MZL), with head and trunk predominance (median age = 54 years). Relapses in other mucosa-related sites occurred in 3 patients. Histological transformation implied a more aggressive treatment in 3 cases. A favorable outcome was observed in most cases. 9 (20%) diffuse large B-cell lymphomas (DLBCL) appeared as a unique nodule, with female predominance (median age = 74 years) and 4 lymphoma-related deaths which seemed age-related (> 70 years) with only one lower limb localization. Histological aggressive features were present in 3 patients with a fatal outcome. 2 (5%) WHO grade 3 follicular lymphomas (FL) had an heterogeneous phenotype, with head localization, cutaneous relapses and good outcome. CONCLUSIONS: MZL, the predominant type, has a good prognosis, although transformation can occur, needing a more aggressive treatment. DLBCL, observed in older patients, has clinical and histological prognostic factors identical to extra-cutaneous lymphomas. FL appears rare and has an heterogeneous phenotype. Relationships with its nodal counterpart remains unclear.

Adult↗
PubMed2005

Elastosis perforans serpiginosa associated with pseudo-pseudoxanthoma elasticum during treatment of Wilson's disease with penicillamine.

BACKGROUND: Elastosis perforans serpiginosa (EPS) is a reactive perforating dermatosis characterized by the elimination of abnormal elastic fibers from the upper dermis through the epidermis. In a few cases, it occurs as a side effect of treatment by D-penicillamine (DPA). The first case of EPS induced by DPA was described in 1972 in a patient treated for Wilson's disease. Subsequently, cutaneous changes resembling pseudoxanthoma elasticum (PXE) were observed in patients treated with DPA and were reported as pseudo-PXE. CASE REPORT: We report herein the clinical, pathological and ultrastructural study of 2 new cases of DPA-induced EPS and pseudo-PXE. These patients had been treated for Wilson's disease since 14 and 16 years, respectively. Characteristic abnormal elastic fibers were found on histopathological examination of both EPS and pseudo-PXE skin and confirmed by an ultrastructural study. There was no ABCC6 mutation. DISCUSSION: Penicillamine is able to induce widespread, cutaneous and systemic, elastic fiber damage. Our patients present typical features of DPA-induced elastosis, presenting as EPS and pseudo-PXE. ABCC6 mutation is associated with PXE and, as expected, it was absent in our cases of pseudo-PXE. This elastopathy has been related to morphologic changes in elastic fibers secondary to prolonged therapy in most cases. DPA may interfere with elastin cross-linking through inhibition of the enzyme lysyl oxidase, or by formation of complexes with the cross-linked precursors, impairing a normal maturation of elastic fibers. However, no fatal complication of DPA-induced elastopathy has been reported so far. An improvement of the cutaneous lesions is expected after the drug discontinuation.

Adult↗
PubMed2005

A theoretical study of taper characteristics to optimize performance.

PURPOSE: The aim of this study was to examine the training factors that could affect taper efficiency. The analysis was done using simulations from a nonlinear model of the training effects on performance giving an individual optimal daily training (ODT). METHODS: Training responses were simulated using data from six subjects obtained in a previous training experiment (15-wk program including 3 wk without training). Assuming first a steady state with training equal to ODT, the taper was simulated with various step training reductions up to 100% of previous training. Overload period (OT) was then featured by a 20% step increase in training during 28 d before the taper. Finally, a taper with step reduction was compared with progressive reduction. RESULTS: The taper allowed performance gains if training was higher than a minimal level. The best performance without OT preceding the taper was reached with a load reduction of 30.8 +/- 11.8% and a duration of 19.3 +/- 2.3 d. The best performance with OT preceding the taper was significantly higher than without OT (P < 0.02) and was obtained with a significantly greater load reduction and duration, 39.3 +/- 9.9% and 28.0 +/- 5.1 d respectively. The best performance with a progressive load reduction was significantly higher than with a step reduction only with OT before the taper (102.2 +/- 1.7 vs 101.8 +/- 1.5% of performance with ODT, P < 0.005). CONCLUSION: Greater training volume and/or intensity before the taper would allow higher performance gains, but would demand a greater reduction of the training load over a longer period. The results also pointed out the importance of training adaptations during the taper, in addition to fatigue dissipation.

Adaptation, Physiological↗
PubMed2004

Pseudosclerodermatous panniculitis after irradiation and bronchiolitis obliterans organizing pneumonia: simultaneous onset suggesting a common origin.

Due to the technical evolution of radiation therapy of breast carcinoma, new manifestations occur as side effects. Newly described unexpected cutaneous events are morphea of the breast and pseudosclerodermatous panniculitis after irradiation (PPAI). They appear as specific consequences of megavoltage radiation. Radiotherapy-induced bronchiolitis obliterans organizing pneumonia (R-BOOP) is one of the pulmonary manifestations due to recent advances in radiotherapy of breast carcinoma. We report a case of PPAI and R-BOOP of simultaneous onset in a 60-year-old woman 6 months after megavoltage radiation therapy for breast carcinoma. We also noted an improvement of both unexpected reactions with systemic corticosteroid therapy and a common relapse when tapering the treatment. Only eight cases of PPAI have previously been reported. We believe that this entity is often underdiagnosed. The symmetrical onset and parallel evolution suggest a common origin for PPAI and BOOP in our case: the megavoltage radiation therapy. The pathogeny of R-BOOP is not direct toxicity of irradiation because untreated areas can also be affected. Pathogenesis of PPAI remains unknown, but a simultaneous onset with R-BOOP suggests a similar mechanism. While a cumulative dose of irradiation does not seem to be determinant an immune reaction to neoantigens induced by radiation could be an hypothesis.

Biopsy, Needle↗
PubMed2003

Subungual blue nevus.

Junctional or compound melanocytic nevus and melanoma may involve the nail apparatus and are usually discussed in the differential diagnosis of nail pigmentation. Blue nevus has been very rarely reported in this location. We report the second clinicopathologic study of a subungual blue nevus.

Adult↗