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1.
Rev Med Brux ; 30(5): 477-82, 2009.
Artigo em Francês | MEDLINE | ID: mdl-19998792

RESUMO

The risk to develop melanoma from small or medium size congenital naevus remain controversial. The main goal of the present study was to determine the interest of three immunohistochemical markers (Ki67, HMB45 and p53) in predicting malignant transformation of these congenital naevi and to see if a specific immunohistochemical profile of such transformed naevi can be identified. The markers (Ki67, HMB45 and p53) have been used retrospectively on sections of small or medium size congenital naevi (group NC, n = 15), of melanoma developed on small or medium size congenital naevi (group MNC, n = 15) and of melanoma developed on acquired naevi (group MNA, n = 15). The labelled cells have been counted in different cutaneous layers: junction, superficial dermal layer and deep dermal layer. No reactivity was observed for the three markers in group NC. The percentage of labelled cells was significantly different for the three markers between the group NC and the groups MNC and MNA. There was no difference between the groups MNC and MNA. In the groups MNC and MNA, a gradient in the percentage of labelled cells was observed between superficial and deep layers. These three markers do not differentiate melanoma developed from congenital naevi of small or medium size and melanoma developed from acquired naevi. Moreover, the results suggest that these three markers are useless in predicting the risk of malignant transformation of small or medium size congenital naevi.


Assuntos
Antígenos de Neoplasias/análise , Antígeno Ki-67/análise , Melanoma/patologia , Proteínas de Neoplasias/análise , Proteína Supressora de Tumor p53/análise , Biomarcadores , Humanos , Melanoma/imunologia , Antígenos Específicos de Melanoma , Nevo Pigmentado/complicações , Nevo Pigmentado/congênito , Nevo Pigmentado/patologia , Fatores de Risco , Neoplasias Cutâneas/patologia
2.
J Eur Acad Dermatol Venereol ; 22(10): 1193-9, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18489566

RESUMO

BACKGROUND: Whereas teledermatology is an emerging discipline, to date, no teledermatology service has been developed, which is specifically dedicated to black skins. OBJECTIVES: To create and develop a teledermatology service that provides a complete range of communication, information, telediagnosis and teaching services. METHODS: A multilingual clinical description of the lesion was provided for each photograph using a five-level disease classification from the 10th revised International Classification of Diseases. In parallel, a usability study to assess and improve the functionality of the platform was also conducted. RESULTS: A web prototype has been developed which integrates image acquisition, submission, clinical description, translation as well as validation, security and data protection aspects and almost 2000 images were obtained from which 600 have been integrated in the 'store and forward' telemedicine system (http://www.black-skin.org). Initial usability tests with native French medical students show good perceived usefulness, perceived usability and internal consistency (Cronbach's alpha = 0.80 and 0.84). CONCLUSION: The Black Skin project (North and South collaboration project) offers possibilities for continuous medical education (pedagogical cases), teleteaching (educational quiz) or asking for a second opinion ('Ask a specialist' item).


Assuntos
População Negra , Comportamento Cooperativo , Dermatologia , Internet , Dermatopatias/etnologia , Telemedicina , Bélgica , Humanos , Dermatopatias/diagnóstico , Dermatopatias/patologia
3.
Rev Med Brux ; 29(6): 552-8, 2008.
Artigo em Francês | MEDLINE | ID: mdl-19202711

RESUMO

The epidermal growth factor receptor (EGFR) is overexpressed in many solid tumors. Its inactivation has an inhibitory effect on the growth and spread of the tumoral cells. It therefore represents an attractive target to treat different cancers. Several molecules have already been registered while others are still under evaluation. One of the common side effects of these therapies is the development of cutaneous toxicities, more precisely a cutaneous rash, sometimes major and distressing. The physiopathology of these cutaneous side effects is poorly understood. Moreover a correlation between the severity of the rash and the tumoral response has been demonstrated in some studies. If this link is confirmed, the rash could be used as a marker for the anti-tumoral activity. This review will summarize the clinical presentations and the current recommendations for the management of cutaneous toxicities induced by EGFR inhibitors.


Assuntos
Receptores ErbB/antagonistas & inibidores , Pele/patologia , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais/uso terapêutico , Anticorpos Monoclonais Humanizados , Antineoplásicos/efeitos adversos , Antineoplásicos/uso terapêutico , Cetuximab , Receptores ErbB/genética , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/patologia , Pele/efeitos dos fármacos
4.
Arch Dermatol Res ; 299(10): 483-6, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17934742

RESUMO

Dendritic cell (DC) vaccines are used for the induction of anti-tumor T cell reaction in melanoma patients. DC are generated in vitro, pulsed with antigen and matured prior to injection. They are supposed to migrate to lymph nodes and to present the processed antigen to naive T cells allowing activation of tumor-specific lymphocytes. It has been suggested that intradermal injection allows a superior migration to the lymph node. Eight HLA-A2 positive patients with stage III or IV melanomas expressing NA 17 antigen were collected. They were included in a pilot trial of vaccination in which they received IL3/INFb DC presenting the NA17 A2 antigen. In each patient, a skin biopsy was performed at the injection site, 24 h after inoculation. The striking features of the biopsies were the presence of a perivascular CD3+/CD8+ T cell infiltrate with a slight population of CD4+ cells and the presence of a massive neutrophilic infiltrate associated with the injected DC still present, realizing a suppurative granuloma. The persistence of DC 24 h after the injection suggests that migration in the lymph node is not necessary for the induction of the immune response. The skin itself could be the location of a reaction starting with a massive recruitment of neutrophils.


Assuntos
Imunoterapia Adotiva/métodos , Células de Langerhans/imunologia , Melanoma/terapia , Neutrófilos/imunologia , Neoplasias Cutâneas/terapia , Adolescente , Adulto , Idoso , Biópsia , Movimento Celular , Granuloma/imunologia , Humanos , Injeções Intradérmicas , Linfonodos/imunologia , Ativação Linfocitária , Melanoma/imunologia , Pessoa de Meia-Idade , Projetos Piloto , Neoplasias Cutâneas/imunologia , Linfócitos T/imunologia
5.
Acta Chir Belg ; 107(2): 205-7, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17515272

RESUMO

Cutaneous Fluorescence Diagnosis (FD) is a new promising dermatological procedure which is based on the combination of a local application of a photosensitizer such as 5-aminolevulinic acid (ALA) or its methyl ester (MAL) and the use of a light source (red light) adapted to the absorption spectrum of these molecules. The targeted photosensitization of skin cancers, particularily superficial and extensive lesions including superficial basal cell carcinoma and Bowen's disease, by ALA or MAL induced porphyrins leads to a selective red fluorescence which can be demonstrated by Wood's lamp. This technique may be useful either to define better the choice of margins or to detect earlier and or multifocal recurrences.


Assuntos
Carcinoma Basocelular/diagnóstico , Carcinoma Basocelular/terapia , Fluorescência , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/terapia , Adulto , Idoso , Ácido Aminolevulínico/análogos & derivados , Ácido Aminolevulínico/uso terapêutico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fotoquimioterapia , Fármacos Fotossensibilizantes/uso terapêutico , Porfirinas
6.
Bull Soc Pathol Exot ; 100(1): 22-5, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17402688

RESUMO

Melioidosis is a tropical disease caused by infection with the bacterium Burkholderia pseudomallei. Most cases present as an acute febrile illness with severe pneumonia and sepsis. Sub-acute and late onset disease can also occur Melioidosis has been diagnosed among travellers who contracted the disease while staying in endemic areas during the rainy season. We report a case of travel-associated B. pseudomallei cutaneous infection in a febrile 90-year-old woman with diabetes mellitus, with early stage manifestations of an isolated inoculation lesion. A 32 weeks' treatment with oral amoxicillin-clavulanate and doxycycline combination regimen led to resolution of the lesion and lack of relapse over fifteen months of follow-up. Melioidosis should be considered in the differential diagnosis of unusual subacute cutaneous lesions in a febrile patients returning from endemic areas, as successful management largely depends on early diagnosis and specific long-term suppressive antimicrobial therapy at an early stage of the course of the disease.


Assuntos
Melioidose/diagnóstico , Dermatopatias Bacterianas/diagnóstico , Viagem , Idoso de 80 Anos ou mais , Combinação Amoxicilina e Clavulanato de Potássio/uso terapêutico , Bangladesh/etnologia , Bélgica , Burkholderia pseudomallei/efeitos dos fármacos , Burkholderia pseudomallei/isolamento & purificação , Diabetes Mellitus Tipo 2/complicações , Suscetibilidade a Doenças , Doxiciclina/uso terapêutico , Resistência a Medicamentos , Quimioterapia Combinada , Cotovelo , Feminino , Humanos , Melioidose/tratamento farmacológico , Melioidose/microbiologia , Dermatopatias Bacterianas/tratamento farmacológico , Dermatopatias Bacterianas/microbiologia
7.
Rev Med Brux ; 28(4): 336-44, 2007 Sep.
Artigo em Francês | MEDLINE | ID: mdl-17958030

RESUMO

Psoriasis is a frequent chronic disease with a typical cutaneous expression described as erythemato-squamous lesions, and sometimes, joint involvement. This disorder rarely causes death in patients, but often alters their quality of life. A better understanding of the pathophysiology of psoriasis has led to the development of new therapeutic options among which are treatments targeted on blocking T-cell activation. Thanks to these therapies we can offer the patients long lasting remission, albeit not a curative approach. The therapeutic approach towards psoriasis will be selected in a multidisciplinary spirit, and after considering the patient himself, his disease and his lifestyle.


Assuntos
Psoríase/tratamento farmacológico , Anticorpos Monoclonais/uso terapêutico , Etanercepte , Gota/fisiopatologia , Humanos , Imunoglobulina G/uso terapêutico , Infliximab , Ativação Linfocitária/efeitos dos fármacos , Linfócitos/fisiologia , Psoríase/classificação , Psoríase/imunologia , Psoríase/fisiopatologia , Receptores do Fator de Necrose Tumoral/uso terapêutico , Inquéritos e Questionários , Linfócitos T/imunologia
8.
Rev Med Brux ; 28(5): 445-51, 2007.
Artigo em Francês | MEDLINE | ID: mdl-18069519

RESUMO

Extracorporeal photochemotherapy is an immunomodulatory treatment wich is carried out in three steps: first leukapheresis, then ex vivo PUVA treatment and finally autologous transfusion. Its current "evidence-based" indications are erythrodermic cutaneous lymphoma, graft versus host disease and cardiac graft rejection. However this treatment has already been used with success in many other diseases such as systemic sclerosis, multiple sclerosis, type 1 diabetes and various autoimmune dermatologic diseases. Randomised controlled studies are needed to confirm the efficacy of photopheresis in these diseases. We also review the different hypotheses explaining the mechanism of action of photopheresis.


Assuntos
Linfoma Cutâneo de Células T/radioterapia , Fotoferese/métodos , Doenças Autoimunes/etiologia , França , Rejeição de Enxerto/etiologia , Doença Enxerto-Hospedeiro/etiologia , Humanos , Inflamação/etiologia , Leucaférese , Fotoferese/efeitos adversos , Estados Unidos
9.
J Natl Cancer Inst ; 54(4): 825-7, 1975 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-123965

RESUMO

A double labeling method with two levels of tritiated thymidine was used to study 6 patients with seborrheic keratosis, 1 with a fibroepithelial tumor of Pinkus, and 1 with basal cell nevus syndrome manifesting three pits on the palm of the hand. The two latter types of lesions, known to be able to evolve into basal cell carcinoma, had an increased S-phase duration (18 hr for the germ cells of the palmar pits) as compared with normal epidermis (10 hr). This situation was similar to that observed in basal cell carcinoma, However, the S phase was not lengthened in seborrheic keratosis (9.2 plus or minus 1.6), a benign tumor in which malignant transformation is extremely rare. S phase was also of normal duration in the benign eosinophilic septa of the tumor of Pinkus.


Assuntos
Divisão Celular , Neoplasias Cutâneas , Carcinoma Basocelular , Dermatite Seborreica , Humanos , Cinética , Lesões Pré-Cancerosas , Síndrome , Timidina/metabolismo
10.
J Int Med Res ; 34(1): 52-7, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16604823

RESUMO

Maspin is a member of the serpin family of protease inhibitors. It is a 42 kDa cytoplasmic protein that is reported to have tumour suppressor activity. The loss of maspin gene expression is correlated with increased invasiveness and the risk of metastases in breast cancer. We studied maspin expression in primary melanoma lesions obtained from 76 patients. Immunostaining of 5 pm sections for maspin expression was obtained using the citrate antigen retrieval method. The extent of immunostaining was scored by recording the proportion of immunoreactive cells and the intensity of immunostaining. Our results demonstrated that maspin expression was down-regulated in intermediate thickness and thick melanoma lesions compared with thin lesions. These results suggest that loss of maspin expression might play a role in melanoma progression, invasion and metastatic dissemination. Further studies are needed to clarify the clinicopathological significance of maspin expression in melanoma.


Assuntos
Regulação Neoplásica da Expressão Gênica , Expressão Gênica , Melanoma/metabolismo , Melanoma/patologia , Serpinas/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Progressão da Doença , Regulação para Baixo , Feminino , Genes Supressores de Tumor , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade
11.
Ann Dermatol Venereol ; 133(3): 235-8, 2006 Mar.
Artigo em Francês | MEDLINE | ID: mdl-16800172

RESUMO

BACKGROUND: The outcome for patients with dermatitis artefacta is not well known. The primary objective of this single-centre retrospective study was to describe the initial clinical aspects and the prognosis of the disease. The secondary objective was to describe the somatic and psychological management and long-term treatment of these patients. PATIENTS AND METHODS: Records of patients with dermatitis artefacta followed in the dermatology department over the 15 last years were reviewed independently by 2 dermatologists. Diagnostic criteria consisted of evocative clinical pictures and the exclusion of other forms of dermatosis. Data collection included: file analysis, photographs, review questionnaires sent to general practitioner or completed during a phone call to patients (follow-up data). RESULTS: Thirty-one patient files were selected: 23 women and 8 men, mean age 31 years (SD = 14.8). Clinical aspects included: erythema (50%), ulceration (37%), crust (23%) and blisters (17%). The main sites were the face (67%) and arms (43%). Topical treatment was prescribed in all cases and systemic treatment was prescribed in 23% of cases. Psychological support was offered to 65% of the patients and was accepted by 50%. A follow-up study was performed for 17 patients and showed serious complications in 4 cases consisting of psychosis (n=2) and/or severe self-mutilation (n=3) occurring over several years following diagnosis (5 years for one patient and 12 years for 2 patients). DISCUSSION: The results confirm the usual and characteristics of dermatitis artefacta such as predominance in young female patients, with lesions affecting visible areas (face, upper legs). In contrastwith published studies, no cases of attempted suicide were observed in our series, although severe dermatitis artefacta was evidenced in only a minority of patients.


Assuntos
Dermatite/psicologia , Transtornos Autoinduzidos/diagnóstico , Adulto , Dermatite/terapia , Transtornos Autoinduzidos/psicologia , Transtornos Autoinduzidos/terapia , Feminino , Humanos , Masculino , Transtornos Psicóticos/diagnóstico , Transtornos Psicóticos/psicologia , Estudos Retrospectivos , Automutilação/diagnóstico , Automutilação/psicologia
12.
Rev Med Brux ; 27(1): 39-41, 2006.
Artigo em Francês | MEDLINE | ID: mdl-16608010

RESUMO

Hydroxyurea is an antitumour agent used most commonly to treat myeloproliferative disorders. We present a clinical observation illustrating different cutaneous side effects susceptible to occur during a long-term treatment by hydroxyurea : leg ulceration, oral ulcer and spinocellular carcinoma. This clinical observation is completed by a review of the literature published on the cutaneous side effects of hydroxyurea treatment.


Assuntos
Antineoplásicos/efeitos adversos , Hidroxiureia/efeitos adversos , Úlcera da Perna/induzido quimicamente , Úlceras Orais/induzido quimicamente , Idoso , Antineoplásicos/uso terapêutico , Carcinoma/induzido quimicamente , Humanos , Hidroxiureia/uso terapêutico , Masculino , Transtornos Mieloproliferativos/tratamento farmacológico , Neoplasias Cutâneas/induzido quimicamente
13.
Rev Med Brux ; 27(4): S233-8, 2006 Sep.
Artigo em Francês | MEDLINE | ID: mdl-17091884

RESUMO

Dermatology, and more specifically cutaneous oncology, has evolved from a descriptive science concept towards multifaceted medico-surgical medicine which is nowadays based not only on observation. In this view, the importance of prevention and early detection of skin cancers including cutaneous melanoma has been recognized and has created a new challenge. Thanks to this proactive approach, the improvement in the prognosis of newly diagnosed melanomas has been demonstrated, but many efforts have to be brought to reduce the incidence and the mortality of this potentially aggressive tumor.


Assuntos
Diagnóstico Precoce , Melanoma/diagnóstico , Melanoma/prevenção & controle , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/prevenção & controle , Humanos , Programas de Rastreamento
14.
Arch Dermatol Res ; 297(5): 185-9, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16235081

RESUMO

Three percent diclofenac in 2.5% hyaluronan gel (DHA) is approved by the Food and Drug Administration (FDA) in the treatment of actinic keratoses (AK). We conducted a meta-analysis of the few prospective studies that evaluated the effect of DHA on the target lesion number score TLNS0 (indicating complete resolution of all target lesions in the treatment area) and/or the cumulative target lesion number score CLNS0 (indicating resolution of the target and new lesions in the treatment area) with assessment 30 days after the end of treatment. A comprehensive search of the 1966-2005 MEDLINE database and review of the reference lists of relevant articles identified the published randomised trials. Three studies were included, with a total of 364 patients. The placebo was the hyaluronan vehicle gel (HAV). The intention-to-treat analyses show that DHA significantly improve the TLNS0 (OR= 3.72; 95% CI=2.05-6.74) and the CLNS0 (OR=4.09; 95% CI=2.55-6.56) compare to HAV. Overall, 42/106 (39.6% CI: 30.8- 49.1%) had a TLNS0 with mean treatment duration of 75 days +/- 21 [mean+/-standard deviation (SD)], and 70/179 (39.1% CI:32.3-46.4%) patients had a CLNS0 with a mean 78 days+/-16 treatment duration. DHA is effective compared to HAV in the treatment of AK. Further studies should establish subgroup analyses according to sites and severity of the AK lesions in order to determine if more patients could be improved in restricted indications. Biopsies, a longer follow-up evaluation, and comparisons with the other treatments of AK will also be helpful in the future to define the place of this treatment in the management of AK.


Assuntos
Anti-Inflamatórios não Esteroides/administração & dosagem , Diclofenaco/administração & dosagem , Ácido Hialurônico/administração & dosagem , Ceratose/tratamento farmacológico , Ácido Araquidônico/metabolismo , Ensaios Clínicos como Assunto , Método Duplo-Cego , Géis , Humanos
15.
J Invest Dermatol ; 95(3): 333-40, 1990 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-2384691

RESUMO

To approach the temporal relationship between alterations in keratinization and capillary leakiness in psoriasis, we studied the topography of these anomalies in spreading psoriatic lesions. Histological and immunohistochemical studies were performed on skin biopsies obtained from normal individuals and from psoriatic patients. In the latter case, biopsies were taken in uninvolved skin, in the center of lesions, and at the edge of evolving plaques (spanning uninvolved and involved skin). Alterations in epidermal differentiation were assessed by the distribution of filagrin, involucrin, and epidermal membrane-bound transglutaminase. Capillary leakiness was evaluated by the abundance of plasma proteins such as albumin, fibrinogen, and immunoglobulin G within the epidermis. Typical alterations of epidermal differentiation were already obvious at the edge of the lesions, in areas devoid of vessel abnormalities and leakiness, or significant cellular infiltration. These results strongly suggest that, during the formation of a psoriatic plaque, defects in keratinocyte differentiation precede the development of vascular anomalies.


Assuntos
Psoríase/patologia , Adulto , Biópsia , Proteínas Sanguíneas/metabolismo , Capilares/anormalidades , Diferenciação Celular , Células Epidérmicas , Feminino , Humanos , Queratinócitos/citologia , Masculino , Pessoa de Meia-Idade , Pele/patologia
16.
J Invest Dermatol ; 111(3): 349-53, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9740222

RESUMO

The pathogenesis of Kaposi's sarcoma (KS), a tumor of probable vascular origin, remains an enigma. It is still unclear whether KS is a true malignancy or whether it represents a reactive polyclonal process. Using both an immunohistochemical and an immunoblot approach, we found that cells derived from KS lesions express significant levels of Bcl-2, a protein known to prolong cellular viability and to antagonize apoptosis. Bcl-2 expression was found in AIDS-related KS-derived cells, as well as in cells derived from iatrogenic and sporadic KS, indicating that Bcl-2 upregulation may be important in the pathogenesis of KS regardless of its epidemiologic form. By contrast, fibroblasts and dermal microvascular endothelial, cells which are the probable vascular progenitors of KS cells, expressed low levels of Bcl-2. The expression of Bcl-2 in KS-derived cells was associated with a long-term survival in serum-deprived conditions, a situation that has been shown to induce apoptosis in various cell types. Incubation of fibroblasts or of dermal microvascular endothelial cells with KS cell-free supernatants did not enhance Bcl-2 expression, suggesting that Bcl-2 expression is not mediated by an agent released by KS cells. Analogously, KS supernatants failed to promote the viability of fibroblasts and of dermal microvascular endothelial cells cultured in serum-free conditions. Our findings suggest that the spindle cells derived from KS have a survival advantage and may adequately represent the tumor cells of KS.


Assuntos
Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Sarcoma de Kaposi/metabolismo , Sobrevivência Celular/fisiologia , Meios de Cultura Livres de Soro , Endotélio Vascular/citologia , Endotélio Vascular/metabolismo , Fibroblastos/metabolismo , Humanos , Cinética , Sarcoma de Kaposi/patologia , Células Tumorais Cultivadas
17.
J Invest Dermatol ; 115(5): 893-900, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11069629

RESUMO

Iron is suspected to be involved in the induction and/or progression of various human tumors. More particularly, iron may be involved in the pathogenesis of Kaposi's sarcoma, a tumor of probable vascular origin. This study was designed to investigate the effect of iron deprivation on Kaposi's sarcoma. The effects of iron chelators and iron deprivation associated with serum withdrawal were investigated on Kaposi's sarcoma-derived spindle cells, on a transformed Kaposi's sarcoma cell line (Kaposi's sarcoma Y-1) and on endothelial cells, which are the probable progenitors of Kaposi's sarcoma cells. Desferrioxamine and deferiprone, two chemically unrelated iron chelators, induced a time- and concentration-dependent inhibition of endothelial and Kaposi's sarcoma cell growth. The inhibition of cell growth was associated with a decrease in Ki-67 and in both stable and total proliferating cell nuclear antigen expression. Inhibition of the progression through the G1-phase of the cell cycle was further evidenced by decreased expression of cyclin D1 and of p34 cyclin-dependent kinase 4. Terminal deoxynucleotidyl transferase-mediated desoxyuridinetriphosphate nick end labeling assay, flow cytometry with annexin-V-fluorescein and morphologic analysis indicated that iron chelation also induced a time- and concentration-dependent apoptosis. This apoptotic effect was prevented by the addition of exogenous iron. Induction of iron deprivation in the culture medium by serum withdrawal led to similar cell cycle effects, which, however, could only be partly reverted by the addition of exogenous iron. In conclusion, these results show that iron deprivation inhibits the growth and induces the apoptosis of Kaposi's sarcoma cells and of their putative endothelial precursors. This suggests that iron chelators may represent a potential therapeutic approach for the treatment of Kaposi's sarcoma.


Assuntos
Quelantes de Ferro/farmacologia , Sarcoma de Kaposi/patologia , Apoptose/efeitos dos fármacos , Técnicas de Cultura de Células , Desferroxamina/farmacologia , Endotélio Vascular/citologia , Humanos , Ferro/fisiologia , Deficiências de Ferro , Microcirculação , Ribonucleotídeo Redutases/antagonistas & inibidores
18.
J Invest Dermatol ; 116(5): 679-85, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11348455

RESUMO

Whether Kaposi's sarcoma is a true neoplasm or a reactive endothelial cell outgrowth triggered by inflammatory cytokines remains unclear. In this study, we investigated the differential invasive properties of activated endothelial cells and Kaposi's sarcoma cells in a model of de-epidermized dermis, supplying the cells with matrix barriers similar to those found in vivo. Cells derived from early "patch-stage" and from late "nodular-stage" Kaposi's sarcoma lesions exhibited similar invasive properties, which indicates that cells with an invasive potential are present in the early stages of tumor development. Slow accumulation of the cells into the extracellular matrix, together with a low proliferation index and with expression of anti-apoptotic proteins, suggest that the progression of Kaposi's sarcoma may be related to escape from cell death rather than to increased proliferation. The Kaposi's sarcoma-Y1 cell line, which is tumorigenic in nude mice, also exhibited invasive properties. By contrast to the Kaposi's sarcoma-derived spindle cells, however, which were scattered between the collagen bundles, the Kaposi's sarcoma-Y1 cell population had a higher proliferation index and displayed a multilayer arrangement. Inflammatory cytokines and Kaposi's sarcoma cell supernatant could activate and stimulate the growth of human dermal microvascular endothelial cell, but could not induce their invasion in this model, showing that activated endothelial cells do not fit all the requirements to traverse the various barriers found in the dermal extracellular matrix. These results confer to Kaposi's sarcoma cells a tumor phenotype and suggest that the in vivo dominant endothelial cell population represents a reactive hyperplasia rather than the true tumor process.


Assuntos
Derme/patologia , Sarcoma de Kaposi/patologia , Divisão Celular , Derme/fisiopatologia , Endotélio Vascular/patologia , Endotélio Vascular/fisiopatologia , Fibroblastos/fisiologia , Genoma Viral , Técnicas Histológicas , Humanos , Músculo Liso Vascular/patologia , Músculo Liso Vascular/fisiopatologia , Invasividade Neoplásica , Estadiamento de Neoplasias , Sarcoma de Kaposi/virologia , Células-Tronco/patologia , Fatores de Tempo , Células Tumorais Cultivadas
19.
Cell Prolif ; 25(3): 233-40, 1992 May.
Artigo em Inglês | MEDLINE | ID: mdl-1596536

RESUMO

In a low concentration of calcium (0.1 mM), keratinocytes form a monolayer with about 30% of cells synthesizing involucrin. After addition of calcium to the culture medium to a concentration of 1.2 mM, the monolayer stratifies within 24 h, with a preferential migration of involucrin positive keratinocytes. In the present study, we tried to determine if keratinocytes control the decision to migrate at a distinct cell cycle point. A percentage labelled mitosis (PLM) curve was constructed for keratinocytes grown in low calcium medium and values for the length of the cell cycle (47 h), S phase duration (11 h) and G2+M period (6 h), were obtained. Monolayer cultures at 80% confluence were switched to high calcium concentration at various times (from 0 to 48 h), after pulse labelling with [3H]-thymidine. Based on the PLM data, the behaviour of cells known to be in S, G1 and G2 at the time of the migration stimulus were followed. No significant difference in the percentage of labelled suprabasal cells was found for any point of the cell cycle. For cells submitting to stratification, in S phase involucrin staining showed that about 60% of the [3H]-thymidine labelled cells were also involucrin negative. These results indicate that upward migration of keratinocytes in cultured epithelium can be triggered at all points in the cell cycle with equal probability and is not restricted to those cells that already contained involucrin.


Assuntos
Cálcio/farmacologia , Queratinócitos/citologia , Ciclo Celular/efeitos dos fármacos , Células Cultivadas , DNA/biossíntese , Humanos , Técnicas In Vitro , Precursores de Proteínas/metabolismo
20.
Cell Prolif ; 25(4): 311-9, 1992 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-1379479

RESUMO

Human keratinocytes grown at an air-liquid interface on dead de-epidermalized dermis exhibit a pattern of organization similar to that seen in vivo. Cell renewal is limited to the basal layer. The cell cycle time determined after 7 days of culture, using a percentage labelled mitoses (PLM) technique, was about 15 h. This result is comparable with published data for cultivated keratinocytes but is shorter than the parameter proposed for epidermis in vivo. Appearance of labelled cells in the granular layer was observed 4 days after pulse labelling. Despite this high cell renewal, a normal cell differentiation with expression of various keratinization markers was maintained.


Assuntos
Células Epidérmicas , Queratinócitos/citologia , Adulto , Anticorpos Monoclonais , Morte Celular , Diferenciação Celular , Divisão Celular , Células Cultivadas , Imunofluorescência , Humanos , Queratinócitos/metabolismo , Queratinas/imunologia , Queratinas/metabolismo , Cinética
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