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1.
J Eur Acad Dermatol Venereol ; 25(12): 1455-65, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21951235

RESUMEN

BACKGROUND: Euromelanoma is a skin cancer education and prevention campaign that started in 1999 in Belgium as 'Melanoma day'. Since 2000, it is active in a large and growing number of European countries under the name Euromelanoma. OBJECTIVE: To evaluate results of Euromelanoma in 2009 and 2010 in 20 countries, describing characteristics of screenees, rates of clinically suspicious lesions for skin cancer and detection rates of melanomas. METHODS: Euromelanoma questionnaires were used by 20 countries providing their data in a standardized database (Belgium, Croatia, Cyprus, Czech Republic, FYRO Macedonia, Germany, Greece, Hungary, Italy, Lithuania, Luxembourg, Malta, Moldavia, Portugal, Serbia, Slovenia, Spain, Sweden, Switzerland and Ukraine). RESULTS: In total, 59,858 subjects were screened in 20 countries. Most screenees were female (64%), median ages were 43 (female) and 46 (male) and 33% had phototype I or II. The suspicion rates ranged from 1.1% to 19.4% for melanoma (average 2.8%), from 0.0% to 10.7% for basal cell carcinoma (average 3.1%) and from 0.0% to 1.8% for squamous cell carcinoma (average 0.4%). The overall positive predictive value of countries where (estimation of) positive predictive value could be determined was 13.0%, melanoma detection rates varied from 0.1% to 1.9%. Dermoscopy was used in 78% of examinations with clinically suspected melanoma; full body skin examination was performed in 72% of the screenees. CONCLUSION: Although the population screened during Euromelanoma was relatively young, high rates of clinically suspected melanoma were found. The efficacy of Euromelanoma could be improved by targeting high-risk populations and by better use of dermoscopy and full body skin examination.


Asunto(s)
Melanoma/prevención & control , Neoplasias Cutáneas/prevención & control , Bélgica/epidemiología , Femenino , Humanos , Masculino , Melanoma/epidemiología , Neoplasias Cutáneas/epidemiología , Luz Solar , Encuestas y Cuestionarios
2.
Mutagenesis ; 21(2): 105-14, 2006 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16500949

RESUMEN

An adaptation of the Comet-assay was developed which enables the discrimination of viable, apoptotic and necrotic single cells by use of the common Annexin-V staining and a dye exclusion test on the cells already embedded in agarose gel on glass slides. Membrane integrity (Ethidium-Homodimer exclusion), cellular esterase activity (Calcein blue-AM) as well as translocation of phosphadidyl-serine (Annexin-V) were analysed using these stains. The advantage of the 'apo/necro-Comet-assay' is that the viability status of individual cells can be determined and correlated with the DNA fragmentation pattern (comet) formed by the same cells. Hence, DNA damage can be assessed and correlated with viable cells or cells undergoing early, mid- or late stage apoptosis or necrosis as identified by the staining pattern. The staining was verified using heat and etoposide-induced apoptosis. This technique, among others, was used to study whether apoptotic fragmentation interferes with repair kinetics measured with the comet assay following UVA exposure (doses up to 1,280 kJ/m(2)) in the cultured human keratinocytes (HaCaT). Therefore, a time course of apoptotic events (phosphatidyl translocation and TUNEL fragmentation) was established and correlated to the DNA fragmentation in the comet-assay. Apoptotic cells were detected more than 8 h later. The combined three-colour staining method with the comet assay showed that there was no significant interference of DNA repair by apoptotic fragmentation processes since DNA repair was almost completed before the onset of apoptotic fragmentation. The apo/necro-Comet-assay reduces the general problem of false-positive results in genotoxicity tests using the Comet-assay.


Asunto(s)
Ensayo Cometa/métodos , Plaguicidas , Rayos Ultravioleta , Anexina A5/farmacología , Apoptosis , Células Cultivadas , Fragmentación del ADN , Etopósido/farmacología , Humanos , Etiquetado Corte-Fin in Situ , Cinética , Necrosis , Inhibidores de la Síntesis del Ácido Nucleico/farmacología , Factores de Tiempo , Azul de Tripano/farmacología
3.
J Am Acad Dermatol ; 47(2): 258-62, 2002 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-12140473

RESUMEN

BACKGROUND: Actinic keratoses (AKs) are the most common premalignant tumors. Without treatment, a significant number of patients with AK will experience squamous cell carcinoma. Photodynamic therapy (PDT) using the new highly selective photosensitizer methyl 5-aminolevulinate is a promising new treatment modality for AK. OBJECTIVE: We investigated the complete response rates, cosmetic outcome, and patient satisfaction after photodynamic therapy (PDT) using methyl 5-aminolevulinate (Metvix) versus cryotherapy in the treatment of AKs. METHODS: Patients were randomized to receive either cryotherapy with liquid nitrogen spray or PDT using methyl 5-aminolevulinate cream 160 mg/g, 3 hours application time, and red light (75 J/cm(2)). RESULTS: Efficacy results from 193 patients with 699 lesions (92% face/scalp and 93% thin/moderately thick) were analyzed. Overall complete response rates after 3 months were 69% for PDT and 75% for cryotherapy. Both treatments gave higher response rates in thin lesions (PDT 75%, cryotherapy 80%). PDT gave better cosmetic results and higher patient satisfaction than cryotherapy. CONCLUSION: PDT using methyl 5-aminolevulinate is an attractive treatment option for patients with AK, with a response rate similar to that of cryotherapy, but with superior cosmetic results and high patient satisfaction.


Asunto(s)
Ácido Aminolevulínico/uso terapéutico , Crioterapia , Queratosis/tratamiento farmacológico , Fotoquimioterapia , Fármacos Fotosensibilizantes/uso terapéutico , Administración Tópica , Adulto , Anciano , Anciano de 80 o más Años , Ácido Aminolevulínico/administración & dosificación , Ácido Aminolevulínico/análogos & derivados , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fármacos Fotosensibilizantes/administración & dosificación , Estudios Prospectivos , Resultado del Tratamiento
4.
Hautarzt ; 52(5): 423-7, 2001 May.
Artículo en Alemán | MEDLINE | ID: mdl-11405161

RESUMEN

BACKGROUND AND OBJECTIVE: UVA1 phototherapy is an new effective treatment modality for acute atopic dermatitis (AD). However there is still some controversy about the optimal UVA1 single and cumulative dose. PATIENTS/METHODS: We compared in a randomized, controlled, prospective pilot study the efficacy of a therapy with 15 treatments of a "high dose" (max. single dose of 130 J/cm2, max. cumulative dose 1840 J/cm2), "medium dose" (max. single dose of 65 J/cm2, max. cumulative dose 975 J/cm2) or "low dose" (max. single dose of 20 J/cm2, max. cumulative dose 300 J/cm2) UVA1 in patients with acutely exacerbated atopic dermatitis (SCORAD > 30). After determination of the IPD, patients randomized into one of the three treatment arms. The patients received 15 treatments (5 times per week) without any additional therapy except for topical skin care. RESULTS: After 15 treatments the "high dose" and "medium dose" groups showed a statistically significant reduction of the SCORAD. No significant reduction of the SCORAD was observed in the "low dose" group. All three treatment arms displayed no statistically significant changes in the IgE and ECP levels and in the number of eosinophils in the peripheral blood. The UVA1 therapy was well tolerated by all patients. No side effects were observed. CONCLUSIONS: This study suggests that both the "high dose" and the "medium dose" regimens are effective in the treatment of patients with acutely exacerbated atopic dermatitis.


Asunto(s)
Dermatitis Atópica/radioterapia , Terapia Ultravioleta , Enfermedad Aguda , Adolescente , Adulto , Relación Dosis-Respuesta en la Radiación , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto , Estudios Prospectivos
5.
J Photochem Photobiol B ; 56(2-3): 109-17, 2000 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11079471

RESUMEN

COMET-FISH, a single cell-based combination of COMET-assay (also known as single cell gel electrophoresis (SCGE)) with fluorescence in situ hybridization (FISH) allows region specific studies on DNA stability and damage. COMET-FISH can be used to investigate UV-A-induced DNA damage of selected whole chromosomes. In the present work, a modified COMET-FISH protocol with whole chromosome painting probes was used to study whether UV-A-induced DNA damage is distributed randomly over the whole genome or occurs at preferred sites. The study was performed with 12 different chromosome painting probes (for chromosomes 1, 2, 3, 8, 9, 11, 14, 18, 19, 21, X and Y). The results on human lymphocytes irradiated with 500 kJ/m2 at a wavelength of 365 nm indicate that the induced number of chromatin strand breaks does not correlate with the chromosome size. They therefore are distributed in a non-random manner. For example, fragments of the gene-rich chromosome chromosome 1 were found in the comet tail in only 3% of the examined cells, and thus chromosome 1 is rather stable, whereas fragmentation of the gene-poor chromosome 8 was observed in 25% of all comets. On the basis of all 12 chromosomes analyzed, an inverse correlation between the density of active genes and the sensitivity toward UV-A radiation is found.


Asunto(s)
Cromosomas Humanos/efectos de la radiación , Daño del ADN , Linfocitos/efectos de la radiación , Rayos Ultravioleta , Células Cultivadas , Cromatina/efectos de la radiación , Mapeo Cromosómico , Pintura Cromosómica/métodos , Cromosomas Humanos/genética , Cromosomas Humanos/ultraestructura , Ensayo Cometa , Femenino , Humanos , Hibridación Fluorescente in Situ , Cariotipificación , Masculino
6.
J Invest Dermatol ; 115(4): 680-6, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-10998143

RESUMEN

The combination of seawater baths and solar radiation at the Dead Sea is known as an effective treatment for patients with psoriasis and atopic dermatitis. Dead Sea water is particularly rich in magnesium ions. In this study we wished to determine the effects of magnesium ions on the capacity of human epidermal Langerhans cells to stimulate the proliferation of alloreactive T cells. Twelve subjects were exposed on four subsequent days on the volar aspects of their forearms to 5% MgCl2, 5% NaCl, ultraviolet B (1 minimal erythemal dose), MgCl2 + ultraviolet B, and NaCl + ultraviolet B. Epidermal sheets were prepared from punch biopsies and were stained for ATPase and HLA-DR. Compared with untreated skin, the number of ATPase+/HLA-DR+ Langerhans cells was significantly reduced after treatment with MgCl2 (p = 0.0063) or ultraviolet B (p = 0.0005), but not after NaCl (p = 0.7744). We next questioned whether this reduced expression of ATPase and HLA-DR on Langerhans cells bears a functional relevance. Six subjects were treated on four subsequent days with 5% MgCl2, ultraviolet B (1 minimal erythemal dose), and MgCl2 + ultraviolet B. Epidermal cell suspensions from treated and untreated skin were assessed for their antigen-presenting capacity in a mixed epidermal lymphocyte reaction with allogeneic naive resting T cells as responder cells. Treatment with MgCl2, similarly to ultraviolet B, significantly reduced the capacity of epidermal cells to activate allogeneic T cells (p = 0.0356). Magnesium ions also suppressed Langerhans cells function when added to epidermal cell suspensions in vitro. The reduced antigen-presenting capacity of Langerhans cells after treatment with MgCl2 was associated with a reduced expression by Langerhans cells of HLA-DR and costimulatory B7 molecules, and with a suppression of the constitutive tumor necrosis factor-alpha production by epidermal cells in vitro. These findings demonstrate that magnesium ions specifically inhibit the antigen-presenting capacity of Langerhans cells and may thus contribute to the efficacy of Dead Sea water in the treatment of inflammatory skin diseases.


Asunto(s)
Presentación de Antígeno/fisiología , Células de Langerhans/inmunología , Magnesio/farmacología , Adenosina Trifosfatasas/biosíntesis , Presentación de Antígeno/efectos de los fármacos , Antígeno B7-1/biosíntesis , Citocinas/biosíntesis , Antígenos HLA-DR/biosíntesis , Humanos , Células de Langerhans/efectos de los fármacos , Células de Langerhans/metabolismo , Piel/citología
7.
Immunology ; 98(2): 181-8, 1999 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-10540216

RESUMEN

Dendritic cells (DC) have an increasingly important role in vaccination therapy; therefore, this study sought to determine the migratory capacity and immunogenic function of murine bone-marrow (BM)-derived DC following subcutaneous (s.c.) and intravenous (i.v.) injection in vivo. DC were enriched from BM cultures using metrizamide. Following centrifugation, the low-buoyant density cells, referred to throughout as DC, were CD11c(high), Iab(high), B7-1(high) and B7-2(high) and potently activated alloreactive T cells in mixed lymphocyte reactions (MLR). In contrast, the high-density cells expressed low levels of the above markers, comprised mostly of granulocytes based on GR1 expression, and were poor stimulators in MLR. Following s.c. injection of fluorescently labelled cells into syngeneic recipient mice, DC but not granulocytes migrated to the T-dependent areas of draining lymph nodes (LN). DC numbers in LN were quantified by flow-cytometric analysis, on 1, 2, 3, 5 and 7 days following DC transfer. Peak numbers of around 90 DC per draining LN were found at 2 days. There was very little migration of DC to non-draining LN, thymus or spleen at any of the time-points studied. In contrast, following i.v. injection, DC accumulated mainly in the spleen, liver and lungs of recipient mice but were largely absent from peripheral LN and thymus. The ability of DC to induce T-cell-mediated immune responses was examined using trinitrobenzenesulphate (TNBS)-derivatized DC (TNBS-DC) to sensitize for contact hypersensitivity responses (CHS) in naive syngeneic recipients. Following s.c. injection, as few as 105 TNBS-DC, but not TNBS-granulocytes, sensitized for CHS responses. However, the same number of TNBS-DC failed to induce CHS following i.v. injection. In summary, this study provides new and quantitative data on the organ specific migration of murine BM-derived DC following s.c. and i.v. injection. The demonstration that the route of DC administration determines the potency of CHS induction, strongly suggests that the route of immunization should be considered in the design of vaccine protocols using DC.


Asunto(s)
Traslado Adoptivo , Células Dendríticas/fisiología , Dermatitis por Contacto/inmunología , Activación de Linfocitos , Linfocitos T/inmunología , Animales , Movimiento Celular , Citometría de Flujo , Inyecciones Intravenosas , Inyecciones Subcutáneas , Hígado/inmunología , Pulmón/inmunología , Ganglios Linfáticos/inmunología , Prueba de Cultivo Mixto de Linfocitos , Ratones , Bazo/inmunología , Ácido Trinitrobencenosulfónico
8.
Hautarzt ; 50(9): 649-53, 1999 Sep.
Artículo en Alemán | MEDLINE | ID: mdl-10501681

RESUMEN

In a controlled prospective study we compared the efficacy of combined salt water bath and UVA/B phototherapy to a UVA/B mono-phototherapy in patients with subacute atopic dermatitis (AD). The patients in the balneophototherapy group (n=16) were treated with baths containing 3-5% of the synthetic salt Psori-sal(trade mark), followed immediately by UVA/B irradiation, while the other treatment arm (n=12) received UVA/B phototherapy alone. After 20 treatments the balneophototherapy group showed a statistically significant (p

Asunto(s)
Balneología , Dermatitis Atópica/terapia , Sales (Química) , Terapia Ultravioleta , Adulto , Terapia Combinada , Dermatitis Atópica/diagnóstico , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Resultado del Tratamiento
9.
J Invest Dermatol ; 112(3): 322-5, 1999 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10084309

RESUMEN

Ultraviolet B (UVB, 290-320 nm) radiation is known to suppress the immune function of epidermal Langerhans cells. We have recently described that in vitro UVB irradiation perturbs the antigen-presenting cell function of Langerhans cells by inhibiting their expression of functional B7 costimulatory molecules (B7-1, B7-2). The aim of this study was to determine wavelength-specific UV effects on Langerhans cells function in vivo, specifically UVB and UVA-1. To address this issue, volunteers were irradiated on the sun protected volar aspects of their forearms with 3 x minimal erythema dose of UVB (Philips TL-12) and UVA-1 (UVASUN 5000 Mutzhaas). Langerhans cells were isolated from suction blister roofs immediately following irradiation. Langerhans cells isolated from UVB- but not from UVA-1-irradiated skin failed to activate naïve resting allogeneic T cells (mixed epidermal cell leukocyte reaction) or primed tetanus toxoid reactive autologous T cells. Langerhans cells isolated from sham-irradiated or UVA-1-irradiated skin strongly upregulated B7-2 molecules during short-term tissue culture. By contrast, Langerhans cells from UVB-irradiated skin did not upregulate B7-2 molecules. Furthermore, exogenous stimulation of the B7 pathway by anti-CD28 stimulatory monoclonal antibodies restored the capacity of UVB-irradiated Langerhans cells to activate both alloreactive and tetanus toxoid-reactive T cells, implying suppressed antigen-presenting cell activities and perturbed B7 expression of Langerhans cells isolated from UVB-irradiated skin are related. Those studies demonstrate that in vivo UVB, but not UVA-1, interferes with the activation-dependent upregulation of B7 molecules on Langerhans cells, which in turn is of functional relevance for the perturbed antigen-presenting cell function of Langerhans cells within UVB- but not UVA-1-irradiated skin.


Asunto(s)
Presentación de Antígeno/efectos de la radiación , Células Presentadoras de Antígenos/efectos de la radiación , Epidermis/efectos de la radiación , Células de Langerhans/efectos de la radiación , Rayos Ultravioleta , Células Presentadoras de Antígenos/metabolismo , Células Presentadoras de Antígenos/fisiología , Antígenos CD/metabolismo , Antígeno B7-2 , Humanos , Células de Langerhans/metabolismo , Células de Langerhans/fisiología , Glicoproteínas de Membrana/metabolismo , Piel/citología , Piel/metabolismo , Piel/efectos de la radiación
10.
Cell Adhes Commun ; 6(2-3): 157-60, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9823467

RESUMEN

Upon antigen encounter epidermal Langerhans cells (LC) and dendritic cells (DC) emigrate from peripheral organs and invade lymph nodes through the afferent lymphatic vessels and then assemble in the paracortical T cell zone and present antigen to T lymphocytes. Part of this process is mimicked by metastasizing tumor cells. Since splice variants of CD44 promote metastasis to lymph nodes we explored the expression of CD44 proteins on migrating LC and DC. We show that following antigen contact, LC and DC upregulate pan CD44 epitopes and epitopes encoded by variant exons v4, v5, v6 and v9. Antibodies against CD44 epitopes arrest LC in the epidermis, prevent the binding of activated LC and DC to the T cell zones of lymph nodes, and severely inhibit their capacity to induce a delayed type hypersensitivity reaction to a skin hapten in vivo. Our results demonstrate that CD44 splice variant expression is obligatory for the migration and function of LC and DC.


Asunto(s)
Movimiento Celular/inmunología , Células Dendríticas/química , Receptores de Hialuranos/química , Receptores de Hialuranos/inmunología , Células de Langerhans/química , Células Dendríticas/citología , Células Dendríticas/inmunología , Células Epidérmicas , Epidermis/química , Humanos , Isomerismo , Células de Langerhans/citología , Células de Langerhans/inmunología
11.
Mutat Res ; 408(2): 111-20, 1998 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-9739813

RESUMEN

During DNA repair studies, cells are occasionally kept on ice in order to suppress DNA repair. In the present studies cultivated human NC37 B-lymphoblasts were damaged by UV-A irradiation (365 nm) and DNA single strand breaks were detected at the single cell level with the alkaline comet assay in the temperature range from 4 degrees C to 44 degrees C. Single cell studies, in contrast to bulk experiments, allow to identify apoptotic or necrotic cells, which can be omitted for data analysis. Unexpectedly, similarly efficient single phase repair kinetics was found at all temperatures below 37 degrees C, i.e., particularly also in the cold. For recovery times below 20 min a linear decrease of DNA damage was detected. After 20 min, no additional repair was observed, i.e., complete repair of single strand breaks was not achieved. At 44 degrees C DNA damage increased with time, probably due to heat damage and cell death. Nucleotide excision repair inhibitors such as aphidicolin, 1-beta-D-arabinofuranosyl cytosine (araC) and hydroxyurea, but not the base excision repair inhibitor methoxyamine caused a strong increase in DNA strand breaks. The use of repair inhibitors confirmed DNA repair at 4 degrees C. In conclusion, partial repair of UV-A damage is similar at 37 degrees C and 4 degrees C and is probably governed by nucleotide excision repair. Keeping samples on ice may not result in a total suppression of DNA repair.


Asunto(s)
Reparación del ADN , ADN/efectos de la radiación , Temperatura , Rayos Ultravioleta , Linfocitos B/fisiología , Linfocitos B/efectos de la radiación , Línea Celular , Daño del ADN , Humanos
12.
Photochem Photobiol ; 67(6): 714-9, 1998 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9648536

RESUMEN

Sensitization on skin exposed to acute low-dose UVB irradiation separates normal humans into two phenotypically distinct groups: One group, following sensitization on UVB-irradiated skin, develops contact sensitivity, designated UVB resistant (UVB-R) and the second group, following sensitization on UVB-irradiated skin, fails to develop contact sensitivity, designated UVB susceptible (UVB-S). To investigate whether UVB susceptibility in humans in related to antigen-presenting activity in the skin we studied the effect of UVB irradiation on the number and function of the epidermal antigen-presenting cells in volunteers identified as UVB-R and UVB-S. Single cell suspensions of epidermal cells from control skin and skin exposed to 3 minimal erythema doses (MED) of UVB 3 days previously were stained for Langerhans cells (CD1a+HLA-DR+) and epidermal macrophages (CD1a-HLA-DR+). The UVB exposure of the skin significantly decreased the percentage of Langerhans cells (UVB-R: n = 7, P < 0.02, UVB-S: n = 6, P < 0.03) and increased the percentage of epidermal macrophages (UVB-R: n = 7, P < 0.03, UVB-S: n = 6, P < 0.03) however to the same degree in both the UVB-R and the UVB-S group. To study the effect on Langerhans cell alloreactivity, epidermal cells were harvested immediately after UVB irradiation. However, in both UVB-R and UVB-S subjects the Langerhans cell alloreactivity was blocked to the same degree immediately after UVB irradiation compared to nonirradiated epidermal cells. To determine the effect of UVB irradiation on epidermal macrophages, epidermal cells were harvested 3 days after UVB irradiation. Irradiated epidermal cells from both UVB-R and UVB-S subjects demonstrated a strong antigen-presenting capacity compared to epidermal cells from control skin leading to activation of T cells that mainly secrete interferon (IFN)-gamma and not interleukin (IL)-4. In conclusion we found that UVB susceptibility was not correlated with the number of Langerhans cells or epidermal macrophages in the skin at the same time of sensitization. Neither was it correlated with the capacity of Langerhans cells nor UVB-induced epidermal macrophages to activate T cells in vitro.


Asunto(s)
Dermatitis por Contacto/fisiopatología , Células de Langerhans/efectos de la radiación , Macrófagos/efectos de la radiación , Linfocitos T/efectos de la radiación , Rayos Ultravioleta , Adulto , Células Cultivadas , Citocinas/biosíntesis , Dermatitis por Contacto/patología , Eritema , Humanos , Células de Langerhans/citología , Células de Langerhans/inmunología , Activación de Linfocitos , Macrófagos/citología , Macrófagos/fisiología , Piel/citología , Piel/efectos de la radiación , Linfocitos T/inmunología
13.
Photochem Photobiol ; 67(5): 554-60, 1998 May.
Artículo en Inglés | MEDLINE | ID: mdl-9613238

RESUMEN

We have reported previously that low-dose UVB radiation (UVBR, 50-200 J/m2) perturbs the antigen-presenting cell (APC) function of murine Langerhans cells (LC) by interfering with yet undefined costimulatory signals. In this study, we investigated (1) the effects of UVBR on the expression of the costimulatory molecules B7-1 and B7-2 on murine LC, (2) the functional consequences of defective B7-1 and B7-2 signalling on primary and secondary T-cell responses induced by LC and (3) the mechanism by which UVBR interferes with B7-1 and B7-2 expression. Ultraviolet-B radiation dose-dependently inhibited the culture-induced upregulation of B7-1 and B7-2 on LC from both UVB-susceptible (UVBs, C57BL/6) and UVB-resistant (UVBR, Balb/c) mice and abrogated their capacity to stimulate proliferation of naive alloreactive T cells and of the KLH (keyhole limpet hemocyanin)-specific T helper (Th)1 clone HDK-1. The UVBR-induced suppression of B7-1 and B7-2 on LC and their perturbed APC function were related, because exogenous triggering of the B7/CD28 pathway with a stimulatory monoclonal antibody (mAb) for CD28 to UVB-irradiated LC partially restored T-cell proliferation. Such reconstitution was not observed when the mAb was added to killed LC, indicating that the UVBR-induced suppression of APC function was not due to lethal effects on LC. Conditioned supernatants from UVB-irradiated epidermal cells did not inhibit the functional upregulation of B7-1 and B7-2, suggesting that UVBR inhibits B7-1 and B7-2 upregulation by acting directly on LC and not by altering LC costimulatory function via release of soluble immunosuppressive factors. In conclusion, UVBR distorts the functional expression of B7-1 and B7-2 on LC from both UVBS and UVBR mice, thereby contributing to the failure of UVB-irradiated LC to stimulate resting alloreactive T cells or KLH-specific Th1 cells.


Asunto(s)
Antígenos CD/genética , Antígeno B7-1/genética , Islotes Pancreáticos/efectos de la radiación , Glicoproteínas de Membrana/genética , Rayos Ultravioleta , Animales , Antígeno B7-2 , Relación Dosis-Respuesta en la Radiación , Femenino , Ratones , Ratones Endogámicos BALB C , Linfocitos T/citología , Linfocitos T/inmunología
14.
Immunotechnology ; 3(4): 245-52, 1998 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9530558

RESUMEN

Here we report the quantification of T cell adhesion to endothelial cells using the luminescence marker BioLite. A new application for this substance was established using a microassay for the detection of TK-1 mouse T-lymphoma cell adhesion to unstimulated or TNF alpha-stimulated eEnd.2 mouse vascular endothelioma cells. Prelabelling of TK-1 with the marker resulted in luminescence values linearly related to the number of adherent T cells. The marker was not toxic for T cells or endothelial cells nor did it interfere with the expression or function of adhesion molecules on T cells (LFA-1, VLA-4) or endothelial cells (ICAM-1, VCAM-1). When compared with established techniques to quantify T cell/endothelial cell adhesion, i.e. microscopical evaluation or isotope prelabelling of T cells, this method was found to be just as reliable and sensitive.


Asunto(s)
Movimiento Celular/inmunología , Endotelio Vascular/citología , Linfocitos T/citología , Animales , Carbono , Adhesión Celular , Línea Celular , Endotelio Vascular/inmunología , Molécula 1 de Adhesión Intercelular/inmunología , Mediciones Luminiscentes , Ratones , Linfocitos T/inmunología , Molécula 1 de Adhesión Celular Vascular/inmunología
15.
J Cell Biol ; 137(5): 1137-47, 1997 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-9166413

RESUMEN

Upon antigen contact, epidermal Langerhans cells (LC) and dendritic cells (DC) leave peripheral organs and home to lymph nodes via the afferent lymphatic vessels and then assemble in the paracortical T cell zone and present antigen to T lymphocytes. Since splice variants of CD44 promote metastasis of certain tumors to lymph nodes, we explored the expression of CD44 proteins on migrating LC and DC. We show that upon antigen contact, LC and DC upregulate pan CD44 epitopes and epitopes encoded by variant exons v4, v5, v6, and v9. Antibodies against CD44 epitopes inhibit the emigration of LC from the epidermis, prevent binding of activated LC and DC to the T cell zones of lymph nodes, and severely inhibit their capacity to induce a delayed type hypersensitivity reaction to a skin hapten in vivo. Our results demonstrate that CD44 splice variant expression is obligatory for the migration and function of LC and DC.


Asunto(s)
Movimiento Celular/fisiología , Receptores de Hialuranos/fisiología , Células de Langerhans/química , Animales , Presentación de Antígeno/fisiología , Adhesión Celular/inmunología , Células Dendríticas/fisiología , Epítopos/análisis , Epítopos/inmunología , Femenino , Humanos , Receptores de Hialuranos/química , Hipersensibilidad/inmunología , Isomerismo , Células de Langerhans/citología , Células de Langerhans/ultraestructura , Ganglios Linfáticos/citología , Ratones , Ratones Endogámicos C57BL , Microscopía Electrónica , Ratas , Ratas Endogámicas , Piel/citología , Linfocitos T/citología , Linfocitos T/inmunología , Regulación hacia Arriba/inmunología
16.
Acta Psychol (Amst) ; 93(1-3): 187-206, 1996 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8826795

RESUMEN

Current theories in economics, marketing, and psychology fail to explain underlying reasons for impulse buying and, crucially, why certain goods (e.g., clothes) are bought impulsively more than others (e.g., basic kitchen equipment). We propose and examine a social psychological model, which predicts that people impulse buy to acquire material symbols of personal and social identity. We predict that consumers will differ systematically in the goods they buy on impulse, and in their reasons for doing so, depending on their attitudes towards shopping, and also along important social categories, such as gender. Specifically, our theoretical model-drawing on a social constructionist model of material possessions (e.g., Dittmar, 1992) and symbolic self-completion theory (e.g. Wicklund and Gollwitzer, 1982)-leads to three sets of hypotheses: (i) some consumer durables are more likely to be bought on impulse than others, and there may be gender differences in object choices, (ii) differences will emerge in the buying considerations (e.g., functional, emotional, symbolic) that are used for impulse and planned buying, and (iii) magnitude of self-discrepancies will predict relative impulse buying frequency and the buying considerations used, if the individual uses consumption as a self-completion strategy. These predictions were expected to hold particularly strongly for individuals high in compulsive shopping tendencies. We test our model in a questionnaire study with a sample of British consumers (n = 61). The results lend support to all three sets of hypotheses. The implications of these findings are discussed with respect to economic and consumer theory, and the treatment offered to the increasing number of 'addicted' shoppers.


Asunto(s)
Toma de Decisiones , Conducta Impulsiva , Autoimagen , Sexo , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad
17.
Exp Dermatol ; 4(3): 155-61, 1995 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-7551563

RESUMEN

Detailed studies on the biology of Langerhans cells (LC), which account for only 1-3% of all epidermal cells, require isolation from their cutaneous symbionts. Several techniques of LC isolation have been reported, including positive enrichment with mAb coupled to immunomagnetic beads. The disadvantage of this technique is the size of the beads (approximately 2-5 microns), which can interfere with subsequent phenotypic and functional analyses. This limitation prompted us to test whether paramagnetic microbeads (15 nm) employed by the MACS system could be used to purify LC from human skin. To isolate fresh LC (fLC), epidermal cell suspensions (EC) were stained with anti-CD1a mAb and with appropriate secondary reagents conjugated to microbeads and to FITC. They were then passed over a separation column and exposed to a strong magnetic field. Thereafter both CD1a-depleted and CD1a-enriched cells were collected. Cultured LC (cLC) were isolated by staining 72-h cultured EC with anti-HLA-DR mAb followed by the same isolation procedure. Using this technique, we could routinely isolate viable EC that were 45-88% CD1a+ or HLA-DR+ as determined by FACS. Two-color FACS analysis demonstrated the majority of MACS-purified cells to be CD1a+/HLA-DR+, indicating that they were indeed LC. By transmission electron microscopy (TEM), the MACS-purified CD1a+/HLA-DR+ cells showed typical ultrastructural characteristics of LC. Furthermore, MACS-purified fLC or cLC were functionally intact, because they stimulated the proliferation of alloreactive T cells in a primary, one-way, mixed epidermal cell leukocyte reaction (MECLR). We conclude that MACS-separation is an efficient and rapid method to isolate human fLC and cLC of high purity and unimpaired function.


Asunto(s)
Separación Inmunomagnética/métodos , Células de Langerhans/inmunología , Proteínas Bacterianas/química , Femenino , Citometría de Flujo , Fluoresceína-5-Isotiocianato/química , Antígenos HLA-DR/inmunología , Humanos , Células de Langerhans/metabolismo , Células de Langerhans/ultraestructura , Leucocitos Mononucleares/citología , Leucocitos Mononucleares/metabolismo , Prueba de Cultivo Mixto de Linfocitos , Masculino , Microscopía Electrónica , Estreptavidina
18.
Berl Munch Tierarztl Wochenschr ; 105(8): 260-3, 1992 Aug 01.
Artículo en Alemán | MEDLINE | ID: mdl-1524578

RESUMEN

In 290 Q fever positive cattle from three 2000 head dairy farms in the former district of Erfurt (Thüringen) the course of titers was examined serologically over several months by means of the complement fixation test (CFT). In 47.2% of the cows serologically observed for 2 up to 28 months complement fixing antibodies against Coxiella burnetii could be demonstrated til the end of the investigation period. Repeated tests during pregnancy showed increase of antibody titers in the first 4 months and after a short decrease again from the 5. til the 7. month. By observing the antibody titers during several pregnancies each time a new increase comparable to a booster immunisation could be found. This may explain the persistence of Q fever antibodies in cows for several years. The results of this investigation suggest that from a high antibody titer it can not be concluded an abortion in a positive cow being caused by a Coxiella burnetii infection.


Asunto(s)
Anticuerpos Antibacterianos/sangre , Enfermedades de los Bovinos/inmunología , Coxiella burnetii/inmunología , Complicaciones Infecciosas del Embarazo/veterinaria , Fiebre Q/veterinaria , Animales , Bovinos , Pruebas de Fijación del Complemento , Femenino , Embarazo , Complicaciones Infecciosas del Embarazo/inmunología , Fiebre Q/inmunología
19.
J Adolesc ; 10(1): 57-69, 1987 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-3584596

RESUMEN

Research and treatment approaches to anorexia nervosa are primarily based on behaviourist psychology. This review summarizes some attempts to understand the causes and consequent treatments of the condition from the viewpoints of psychoanalytically informed, family, existential and feminist psychology. These perspectives, which focus on the individual experience of the anorexic, leave many questions unanswered, but provide fresh frameworks from which to investigate and treat the condition.


Asunto(s)
Anorexia Nerviosa/psicología , Anorexia Nerviosa/terapia , Ego , Existencialismo , Familia , Terapia Familiar , Femenino , Humanismo , Humanos , Teoría Psicoanalítica , Autoimagen , Derechos de la Mujer
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