Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
1.
J Dtsch Dermatol Ges ; 14(8): 807-16, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27509416

RESUMEN

BACKGROUND AND OBJECTIVES: (18) F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) frequently reveals incidental findings. The present study focused on incidental FDG-PET/CT findings in cutaneous melanoma patients, and verified their relevance with respect to further diagnostic measures and interventions. PATIENTS AND METHODS: Medical records of 181 consecutive melanoma patients were retrospectively evaluated to verify the management of incidental findings, with particular emphasis on histological findings. RESULTS: Thirty-three of 181 (18 %) patients showed 39 relevant incidental findings, located in the colorectal tract (n  =  15 patients), thyroid (n  =  8), prostate (n  =  2), locomotor system (n  =  2), lymph nodes (n  =  2), parotid gland (n  =  1), tonsils (n  =  1), kidneys (n  =  1), and gallbladder (n  =  1). Performed in 25 patients, additional diagnostic procedures revealed a clinical correlate in 21 cases. Sixteen of 21 patients had tumoral involvement, including five malignant lesions (four colorectal and one prostate carcinoma). The malignancies were diagnosed at an early stage, and successfully removed in the majority of cases. CONCLUSIONS: The diagnostic use of FDG-PET/CT is routinely recommended for stage IIC melanoma and higher, and is widely accepted as indication. This study effectively identified otherwise undetected cancers, especially colorectal malignancies. Early interventions were possible in most cases. Incidental findings on FDG-PET/CT should be worked up with appropriate diagnostic measures, considering the patient's condition and wishes.


Asunto(s)
Hallazgos Incidentales , Melanoma/diagnóstico por imagen , Tomografía Computarizada por Tomografía de Emisión de Positrones , Neoplasias Cutáneas/diagnóstico por imagen , Fluorodesoxiglucosa F18 , Humanos , Masculino , Estudios Retrospectivos
2.
J Dtsch Dermatol Ges ; 14(8): 807-17, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27509417

RESUMEN

HINTERGRUND UND ZIELE: Bei der (18) F-Fluordeoxyglucose-Positronenemissionstomographie/Computertomographie (FDG-PET/CT) ergeben sich häufig Zufallsbefunde. In der vorliegenden Studie konzentrierten wir uns auf mittels FDG-PET/CT erhaltene Zufallsbefunde bei Patienten mit kutanem Melanom und überprüften deren Relevanz hinsichtlich weiterer diagnostischer Maßnahmen und Interventionen. PATIENTEN UND METHODEN: Die Krankenakten von 181 konsekutiven Melanom-Patienten wurden retrospektiv ausgewertet, um das Management von Zufallsbefunden zu dokumentieren. Der Schwerpunkt lag dabei auf den histologischen Befunden. ERGEBNISSE: Bei 33 von 181 (18 %) Patienten lagen 39 relevante Zufallsbefunde vor, und zwar im Kolorektalbereich (n = 15 Patienten), in der Schilddrüse (n = 8), der Prostata (n = 2), dem Bewegungsapparat (n = 2), in Lymphknoten (n = 2), der Parotis (n = 1), den Mandeln (n = 1), den Nieren (n = 1) und der Gallenblase (n = 1). Bei 25 Patienten schlossen sich weitere diagnostische Verfahren an, wobei in 21 Fällen ein klinisches Korrelat nachgewiesen wurde. Bei 16 von 21 Patienten ergab sich eine Neoplasie, darunter fünf maligne Läsionen (vier Kolonkarzinome und ein Prostatakarzinom). Die Malignome wurden frühzeitig diagnostiziert und in der Mehrzahl der Fälle erfolgreich entfernt. SCHLUSSFOLGERUNGEN: Der Einsatz der FDG-PET/CT als Routine-Diagnostik wird in den Leitlinien empfohlen und ist indiziert bei malignem Melanom ab Stadium IIC. In dieser Studie wurden auf effektive Weise ansonsten nicht erkannte Krebserkrankungen, insbesondere Kolonkarzinome, detektiert. In den meisten Fällen war eine frühe Intervention möglich. Zufallsbefunde durch FDG-PET/CT sollten, unter Berücksichtigung des Zustands und der Wünsche des Patienten, mit den geeigneten diagnostischen Maßnahmen abgeklärt werden.


Asunto(s)
Terapias Complementarias , Tomografía Computarizada por Tomografía de Emisión de Positrones , Neoplasias Cutáneas/diagnóstico por imagen , Medicina Basada en la Evidencia , Alemania , Humanos , Naturopatía , Guías de Práctica Clínica como Asunto
3.
Angew Chem Int Ed Engl ; 50(4): 826-59, 2011 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-21246678

RESUMEN

Oxide nanomaterials are indispensable for nanotechnological innovations, because they combine an infinite variety of structural motifs and properties with manifold morphological features. Given that new oxide materials are almost reported on a daily basis, considerable synthetic and technological work remains to be done to fully exploit this ever increasing family of compounds for innovative nano-applications. This calls for reliable and scalable preparative approaches to oxide nanomaterials and their development remains a challenge for many complex nanostructured oxides. Oxide nanomaterials with special physicochemical features and unusual morphologies are still difficult to access by classic synthetic pathways. The limitless options for creating nano-oxide building blocks open up new technological perspectives with the potential to revolutionize areas ranging from data processing to biocatalysis. Oxide nanotechnology of the 21st century thus needs a strong interplay of preparative creativity, analytical skills, and new ideas for synergistic implementations.


Asunto(s)
Metales/química , Nanoestructuras/química , Nanotecnología , Óxidos/química , Óxidos/síntesis química , Tamaño de la Partícula , Propiedades de Superficie
4.
FASEB J ; 19(12): 1710-2, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16030176

RESUMEN

Since mammalian skin expresses the enzymatic apparatus for melatonin synthesis, it may be an extrapineal site of melatonin synthesis. However, evidence is still lacking that this is really the case in situ. Here, we demonstrate melatonin-like immunoreactivity (IR) in the outer root sheath (ORS) of mouse and human hair follicles (HFs), which corresponds to melatonin, as shown by radioimmunoassay and liquid chromatography/tandem mass spectrometry (LC/MS/MS). The melatonin concentration in organ-cultured mouse skin, mouse vibrissae follicles, and human scalp HFs far exceeds the respective melatonin serum level and is significantly increased ex vivo by stimulation with norepinephrine (NE), the key stimulus for pineal melatonin synthesis. By real-time PCR, transcripts for the melatonin membrane receptor MT2 and for the nuclear mediator of melatonin signaling, retinoid orphan receptor alpha (ROR)alpha, are detectable in murine back skin. Transcript levels for these receptors fluctuate in a hair cycle-dependent manner, and are maximal during apoptosis-driven HF regression (catagen). Melatonin may play a role in hair cycle regulation, since its receptors (MT2 and RORalpha) are expressed in murine skin in a hair cycle-dependent manner, and because it inhibits keratinocyte apoptosis and down-regulates ERalpha expression. Therefore, the HF is both, a prominent extrapineal melatonin source, and an important peripheral melatonin target tissue. Regulated intrafollicular melatonin synthesis and signaling may play a previously unrecognized role in the endogenous controls of hair growth, for example, by modulating keratinocyte apoptosis during catagen and by desensitizing the HF to estrogen signaling. As a prototypic neuroectodermal-mesodermal interaction model, the HF can be exploited for dissecting the obscure role of melatonin in such interactions in peripheral tissues.


Asunto(s)
Ectodermo/metabolismo , Folículo Piloso/embriología , Melatonina/fisiología , Mesodermo/metabolismo , Neuronas/metabolismo , Receptores de Melatonina/metabolismo , Animales , Apoptosis , Cromatografía Liquida , Regulación hacia Abajo , Receptor alfa de Estrógeno/metabolismo , Femenino , Cabello/fisiología , Folículo Piloso/metabolismo , Humanos , Inmunoensayo/métodos , Inmunohistoquímica , Queratinocitos/metabolismo , Espectrometría de Masas , Melatonina/química , Melatonina/metabolismo , Ratones , Ratones Endogámicos C57BL , Técnicas de Cultivo de Órganos/métodos , ARN Mensajero/metabolismo , Proteínas Tirosina Quinasas Receptoras , Receptores Huérfanos Similares al Receptor Tirosina Quinasa , Receptores de Superficie Celular/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal , Piel/citología , Piel/metabolismo
5.
Endocrinology ; 146(3): 1214-25, 2005 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15591132

RESUMEN

Although 17beta-estradiol (E2) is recognized as a potent hair growth modulator, our knowledge of estrogen function, signaling, and target genes in hair biology is still very limited. Between the two recognized estrogen receptors (ERs), ER alpha and ER beta, only ER alpha had been detected in murine skin. Here we show that ER alpha, ER beta, and ER beta ins are all expressed throughout the murine hair cycle, both at the protein and RNA level, but show distinct expression patterns. We confirm that topical E2 arrests murine pelage hair follicles in telogen and demonstrate that E2 is a potent inducer of premature catagen development. The ER antagonist ICI 182.780 does not induce anagen prematurely but accelerates anagen development and wave spreading in female mice. ER beta knockout mice display accelerated catagen development along with an increase in the number of apoptotic hair follicle keratinocytes. This suggests that, contrary to previous concepts, ER beta does indeed play a significant role in murine hair growth control: whereas the catagen-promoting properties of E2 are mediated via ER alpha, ER beta mainly may function as a silencer of ER alpha action in hair biology. These findings illustrate the complexity of hair growth modulation by estrogens and suggest that one key to more effective hair growth manipulation with ER ligands lies in the use of selective ER alpha or -beta antagonists/agonists. Our study also underscores that the hair cycling response to estrogens offers an ideal model for studying the controls and dynamics of wave propagation in biological systems.


Asunto(s)
Estradiol/análogos & derivados , Receptor alfa de Estrógeno/metabolismo , Receptor beta de Estrógeno/metabolismo , Estrógenos/metabolismo , Cabello/metabolismo , Animales , Apoptosis , Estradiol/metabolismo , Estradiol/farmacología , Receptor beta de Estrógeno/genética , Femenino , Fulvestrant , Cabello/fisiología , Inmunohistoquímica , Ligandos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Modelos Anatómicos , Fenotipo , ARN/metabolismo , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Piel/metabolismo , Factores de Tiempo
7.
Nanoscale ; 4(6): 2018-28, 2012 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-22327266

RESUMEN

Nanostructured Cu(x)Zn(1-x)Al(2)O(4) with a Cu:Zn ratio of »:¾ has been prepared by a microwave-assisted hydrothermal synthesis at 150 °C and used as a precursor for Cu/ZnO/Al(2)O(3)-based catalysts. The spinel nanoparticles exhibit an average size of approximately 5 nm and a high specific surface area (above 250 m(2) g(-1)). Cu nanoparticles of an average size of 3.3 nm can be formed by reduction of the spinel precursor in hydrogen and the accessible metallic Cu(0) surface area of the reduced catalyst was 8 m(2) g(-1). The catalytic performance of the material in CO(2) hydrogenation and methanol steam reforming was compared with conventionally prepared Cu/ZnO/Al(2)O(3) reference catalysts. The observed lower performance of the spinel-based samples is attributed to a lack of synergetic interaction of the Cu nanoparticles with ZnO due to the incorporation of Zn(2+) in the stable spinel lattice. Despite its lower performance, however, the nanostructured nature of the spinel catalyst was stable after thermal treatment up to 500 °C in contrast to other Cu-based catalysts. Furthermore, a large fraction of the re-oxidized copper migrates back into the spinel upon calcination of the reduced catalyst, thereby enabling a regeneration of sintered catalysts after prolonged usage at high temperatures. Similarly prepared samples with Ga instead of Al exhibit a more crystalline catalyst with a spinel particle size around 20 nm. The slightly decreased Cu(0) surface area of 3.2 m(2) g(-1) due to less copper incorporation is not a significant drawback for the methanol steam reforming.


Asunto(s)
Óxido de Aluminio/química , Cobre/química , Cristalización/métodos , Nanoestructuras/química , Nanoestructuras/ultraestructura , Agua/química , Zinc/química , Óxido de Aluminio/efectos de la radiación , Catálisis , Cobre/efectos de la radiación , Calor , Sustancias Macromoleculares/química , Sustancias Macromoleculares/efectos de la radiación , Ensayo de Materiales , Microondas , Conformación Molecular/efectos de la radiación , Nanoestructuras/efectos de la radiación , Tamaño de la Partícula , Propiedades de Superficie/efectos de la radiación , Zinc/efectos de la radiación
9.
Dalton Trans ; (23): 4423-5, 2009 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-19488435

RESUMEN

A family of novel lanthanoid-containing polytungstoarsenate(iii) polyanions with interesting structural features has been isolated: six lacunary {alpha-AsW(9)O(33)} building blocks comprising unusual pyramidal WO(5) units are templated by a caesium cation in a central cavity of the structure.

10.
Am J Pathol ; 168(3): 748-56, 2006 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16507890

RESUMEN

The prototypic pituitary hormone prolactin (PRL) exerts a wide variety of bioregulatory effects in mammals and is also found in extrapituitary sites, including murine skin. Here, we show by reverse transcriptase-polymerase chain reaction and immunohistology that, contrary to a previous report, human skin and normal human scalp hair follicles (HFs), in particular, express both PRL and PRL receptors (PRL-R) at the mRNA and protein level. PRL and PRL-R immunoreactivity can be detected in the epithelium of human anagen VI HFs, while the HF mesenchyme is negative. During the HF transformation from growth (anagen) to apoptosis-driven regression (catagen), PRL and PRL-R immunoreactivity appear up-regulated. Treatment of organ-cultured human scalp HFs with high-dose PRL (400 ng/ml) results in a significant inhibition of hair shaft elongation and premature catagen development, along with reduced proliferation and increased apoptosis of hair bulb keratinocytes (Ki-67/terminal dUTP nick-end labeling immunohistomorphometry). This shows that PRL receptors, expressed in HFs, are functional and that human skin and human scalp HFs are both direct targets and sources of PRL. Our data suggest that PRL acts as an autocrine hair growth modulator with catagen-promoting functions and that the hair growth-inhibitory effects of PRL demonstrated here may underlie the as yet ill-understood hair loss in patients with hyper-prolactinemia.


Asunto(s)
Comunicación Autocrina , Folículo Piloso/crecimiento & desarrollo , Prolactina/metabolismo , Receptores de Prolactina/metabolismo , Cuero Cabelludo/metabolismo , Apoptosis , Proliferación Celular/efectos de los fármacos , Folículo Piloso/efectos de los fármacos , Folículo Piloso/metabolismo , Humanos , Hiperprolactinemia/genética , Hiperprolactinemia/metabolismo , Queratinocitos/química , Queratinocitos/citología , Queratinocitos/metabolismo , Antígeno Ki-67/análisis , Técnicas de Cultivo de Órganos , Comunicación Paracrina , Prolactina/genética , Prolactina/farmacología , Receptores de Prolactina/efectos de los fármacos , Cuero Cabelludo/efectos de los fármacos , Transcripción Genética
11.
J Investig Dermatol Symp Proc ; 10(3): 243-6, 2005 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-16382674

RESUMEN

In this study, it was investigated how estrogens (17-beta-estradiol, E2) affect the estrogen receptor (ER) expression and gene regulation of male versus female human scalp hair follicles in vitro. Anagen VI follicles from frontotemporal scalp skin were microdissected and organ-cultured for up to 9 d in the presence of E2 (1-100 nm). Immunohistochemistry was performed for ERbeta-expression, known to be predominant in human scalp hair follicles, and for TGF-beta2-expression (as negative key hair growth modulator), and E2-responsive genes in organ-cultured human scalp hair follicles (48 h, 10 nM) were explored by cDNA microarray, using a commercial skin focus chip (Memorec, Cologne, Germany). The distribution pattern of ERbeta and TGF-beta2-immunoreactivity differed between male and female hair follicles after 48 h culture. Of 1300 genes tested, several genes were regulated sex-dependent differently. The study reveals substantial sex-dependent differences in the response of frontotemporal human scalp hair follicles to E2. Recognition and systematic dissection of the E2-dependent gene regulation will be crucial for the development of more effective, gender-tailored management strategies for female versus male pattern balding.


Asunto(s)
Estradiol/metabolismo , Receptor beta de Estrógeno/metabolismo , Folículo Piloso/metabolismo , Cuero Cabelludo/metabolismo , Alopecia/metabolismo , Alopecia/terapia , Estrógenos/metabolismo , Femenino , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Humanos , Inmunohistoquímica , Técnicas In Vitro , Masculino , Análisis de Secuencia por Matrices de Oligonucleótidos , Caracteres Sexuales , Factor de Crecimiento Transformador beta/metabolismo
12.
J Dtsch Dermatol Ges ; 2(6): 412-23, 2004 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16281598

RESUMEN

While it is undisputed that estrogens (1 beta-estradiol, E2) are mainly involved in skin physiology and operate as potent hair growth modulators, our knowledge about the estrogen target cells in skin and exact signaling pathways is still very limited. The current review provides an overview of estrogen effects on hair follicle cycling, cutaneous expression of estrogen receptors, and potential functions of estrogens in hair biology. We discuss potential target genes of estrogen receptor-mediated signaling in the skin, explore the interplay of estrogens with other hormones, growth factors and enzymes, and define major open questions in this intriguing and far too long neglected area of hair research.


Asunto(s)
Estrógenos/metabolismo , Regulación de la Expresión Génica/fisiología , Folículo Piloso/crecimiento & desarrollo , Folículo Piloso/metabolismo , Modelos Biológicos , Receptores de Estrógenos/metabolismo , Transducción de Señal/fisiología , Animales , Humanos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA